Rheological Flow Behavior of Six Gelling Agents and Their Relevance for In Vitro Culture Performance of Medicinal Plants
Doina Clapa, Monica Hârţa, Bernadette-Emőke Teleky
et al.
Gelling agents are widely used to solidify plant tissue culture media, yet differences among commercial products may influence the medium’s physical properties and in vitro development of explants. The aim of this study was to characterize the rheological behavior of six gelling agents (Daishin agar, Gelcarin, Gelrite, Microagar, Phytoagar, and Plant agar) and to examine it in parallel with in vitro performance in <i>Hypericum perforatum</i>, <i>Mentha</i> × <i>piperita</i>, and <i>Stevia rebaudiana</i>. Rheological measurements were performed under steady shear by recording apparent viscosity and shear stress across 5–300 s<sup>−1</sup>. Daishin agar showed the highest apparent viscosity (49,028.95 ± 128 mPa·s), whereas Gelrite exhibited the lowest viscosity (7826.75 ± 98 mPa·s). Plant responses were evaluated after four weeks on PGR-free Driver and Kuniyuki Walnut (DKW) medium by assessing shoot growth, rooting parameters, and shoot water content. In <i>H. perforatum</i>, the longest shoots were obtained on Gelrite (3.92 ± 0.34 cm), accompanied by the highest rooting percentage (95%). In <i>M.</i> × <i>piperita</i>, Gelcarin produced the longest shoots (8.20 ± 0.55 cm) and the highest number of roots per explant (9.75). In <i>S. rebaudiana</i>, Gelcarin promoted superior root elongation (2.86 ± 0.16 cm) and enhanced shoot growth, while Plant agar also supported favorable shoot development. Shoot water content ranged between 74% and 90%, depending on species and gelling agent. These findings highlight the practical relevance of considering low-shear rheological properties when comparing gelling agents for improving the consistency of in vitro culture media.
Observation of Molecular Complexes in Oligo-Phenylenevinylene (OPV) Organogels by Neutron Diffraction
Jean-Michel Guenet, Ayyappanpillai Ajayaghosh, Vakayil K. Praveen
In an earlier report, we conjectured that oligo-phenylenevinylene (OPV) molecules bearing terminal OH groups may form molecular complexes in organogels prepared in benzyl alcohol. This assumption was based on circumstantial evidence only. In this paper, we report on new experimental evidence by means of neutron diffraction that unambiguously demonstrates this conjecture. After ascertaining that the thermodynamic properties of OPV gels are not altered by the use of a solvent isotope (hydrogenous vs. deuterated benzyl alcohol), we show that the neutron diffraction pattern in hydrogenous benzyl alcohol differs from that in deuterated benzyl alcohol. These patterns also exhibit additional peaks with respect to those obtained by X-ray. Comparison is further achieved with an OPV molecule without hydrogen bond terminal groups. In the latter case, no molecular complex is formed. These molecular structures may have a direct bearing on the differences observed in the gel morphologies.
Preparation of Bismuth Vanadates with Rich Oxygen Vacancies Using Different Sol pH and Their Photocatalytic Behavior in Degradation of Methylene Blue
Shengli Chen, Yuanyuan Zhong, Jie Yang
et al.
Gel precursors were formed by reacting bismuth nitrate pentahydrate, acetic acid, sodium metavanadate, and NaOH. pH was adjusted using NaOH solution followed by calcination to obtain bismuth vanadate (BiVO<sub>4</sub>) photocatalysts. During synthesis, pH directly influenced the formation and structure of the gel network. Therefore, the effects of pH on the microstructure and photocatalytic activity of BiVO<sub>4</sub> were investigated. At pH 3, the sample consisted of microspheres formed by tightly packed small particles. At pH 5, the microspheres transformed into aggregated flakes. Photocatalytic performance was evaluated through methylene blue (MB) degradation, revealing the sample prepared at pH 7 (7-BVO) demonstrated the highest efficiency. The electronic band structure, bandgap, and band edge positions of 7-BVO were probed by density functional theory (DFT) and UV-vis absorption spectra. Furthermore, photoluminescence spectroscopy, electrochemical measurements, active species trapping experiments and liquid chromatography mass spectrometry technique collectively revealed the possible mechanistic pathways for MB photodegradation by 7-BVO.
Hydrogel Performance in Boosting Plant Resilience to Water Stress—A Review
Gamareldawla H. D. Agbna, Syed Javaid Zaidi
Hydrogels have emerged as a transformative technology in agriculture, offering significant potential to enhance crop resilience, improve water use efficiency, and promote sustainable farming practices. These three-dimensional polymeric networks can absorb and retain water, making them particularly valuable in regions facing water scarcity and unpredictable rainfall patterns. This review examines the types, properties, and applications of hydrogels in agriculture, highlighting their role in improving soil moisture retention, enhancing nutrient delivery by, and increasing crop yield. The discussion extends to the economic and environmental implications of hydrogel use, including their potential to reduce irrigation costs by and minimize soil erosion. The review also explores the latest innovations in hydrogel technology, such as smart hydrogels and biodegradable alternatives, which offer new possibilities for precision agriculture and environmental sustainability. Despite promising benefits, challenges such as the higher cost of synthetic hydrogels, environmental impact, and performance variability across different soil types remain. Addressing these challenges requires a multidisciplinary approach that integrates advancements in material science, agronomy, and environmental policy. The future outlook for hydrogels in agriculture is optimistic, with ongoing research poised to refine their applications and expand their use across diverse agricultural systems. By leveraging the capabilities of hydrogels, agriculture can achieve increase in productivity, ensure food security, and move towards a more sustainable and resilient agricultural landscape.
Self-Healing and Tough Polyacrylic Acid-Based Hydrogels for Micro-Strain Sensors
Chuanjie Liu, Zhihong Liu, Bing Lu
Self-healing hydrogels hold promise for smart sensors in bioengineering and intelligent systems, yet balancing self-healing ability with mechanical strength remains challenging. In this study, a self-healing hydrogel exhibiting superior stretchability was developed by embedding a combination of hydrogen bonding and dynamic metal coordination interactions, introduced by modified fenugreek galactomannan, ferric ions, and lignin silver nanoparticles, into a covalent polyacrylic acid (PAA) matrix. Synergistic covalent and multiple non-covalent interactions enabled the hydrogel with high self-healing ability and enhanced mechanical property. In particular, due to the introduction of multiple energy dissipation mechanisms, particularly migrative dynamic metal coordination interactions, the hydrogel exhibited ultra-high stretchability of up to 2000%. Furthermore, with the incorporation of lignin silver nanoparticles and ferric ions, the hydrogel demonstrated excellent strain sensitivity (gauge factor ≈ 3.94), with stable and repeatable resistance signals. Assembled into a flexible strain sensor, it effectively detected subtle human motions and organ vibrations, and even replaced conductive rubber in gaming controllers for real-time inputs. This study provides a versatile strategy for designing multifunctional hydrogels for advanced sensing applications.
The Potential for Reusing Superabsorbent Polymer from Baby Diapers for Water Retention in Agriculture
Kamilla B. Shishkhanova, Vyacheslav S. Molchanov, Ilya V. Prokopiv
et al.
Annually, about 2.4 million tons of superabsorbent polymers (SAPs) used in disposable diapers are thrown away, polluting our planet. This study aims to explore the potential for reusing SAPs removed from diapers to enhance soil water retention. To this end, the swelling and water retention properties of SAP gels from three different types of diapers were compared to those of an agricultural gel, Aquasorb. Sand was used as a model for soil. When mixed with sand, diaper gels have a swelling degree of ca. 100 g per gram of dried polymer, and a swelling pressure of 12–26 kPa, which are similar to those of Aquasorb gel. Using a synthesized poly(acrylamide-co-sodium acrylate) gel as an example, the correlation between the swelling pressure and the compression modulus of the swollen gel was demonstrated. Soil-hydrological constants were estimated from water retention curves obtained by equilibrium centrifugation of gel/sand mixtures. It was observed that adding 0.3 vol% of diaper gels to sand leads to a 3–4-fold increase in water range available to plants, which is close to that provided by agricultural gel Aquasorb. The water-holding properties were shown to be maintained during several swelling/deswelling cycles in the sand medium. The addition of diaper gels to soil had a significant positive impact on mustard (<i>Brassica juncea</i> L.) seed germination and seedling growth, similar to the agricultural gel Aquasorb. This suggests high potential for the reuse of SAPs from diaper waste to improve soil water retention and water accessibility to plants. This would provide both economic and environmental benefits, conserving energy and raw materials to produce new agricultural gels and limiting the amount of waste.
AI Realtor: Towards Grounded Persuasive Language Generation for Automated Copywriting
Jibang Wu, Chenghao Yang, Yi Wu
et al.
This paper develops an agentic framework that employs large language models (LLMs) for grounded persuasive language generation in automated copywriting, with real estate marketing as a focal application. Our method is designed to align the generated content with user preferences while highlighting useful factual attributes. This agent consists of three key modules: (1) Grounding Module, mimicking expert human behavior to predict marketable features; (2) Personalization Module, aligning content with user preferences; (3) Marketing Module, ensuring factual accuracy and the inclusion of localized features. We conduct systematic human-subject experiments in the domain of real estate marketing, with a focus group of potential house buyers. The results demonstrate that marketing descriptions generated by our approach are preferred over those written by human experts by a clear margin while maintaining the same level of factual accuracy. Our findings suggest a promising agentic approach to automate large-scale targeted copywriting while ensuring factuality of content generation.
Shock-induced HCNH+ abundance enhancement in the heart of the starburst galaxy NGC 253 unveiled by ALCHEMI
Y. Gong, C. Henkel, C. T. Bop
et al.
Understanding the chemistry of molecular clouds is pivotal to elucidate star formation and galaxy evolution. As one of the important molecular ions, HCNH+ plays an important role in this chemistry. Yet, its behavior and significance under extreme conditions, such as in the CMZs of external galaxies, are still largely unexplored. We aim to reveal the physical and chemical properties of the CMZ in the starburst galaxy NGC253 with multiple HCNH+ transitions to shed light on the molecule's behavior under the extreme physical conditions of a starburst. We employ molecular line data including results for four rotational transitions of HCNH+ from the ALCHEMI large program to investigate underlying physical and chemical processes. Despite weak intensities, HCNH+ emission is widespread throughout NGC253's CMZ, which suggests that this molecular ion can effectively trace large-scale structures within molecular clouds. Using the quantum mechanical coupled states approximation, we computed rate coefficients for collisions of HCNH+ with para-H2 and ortho-H2 at kinetic temperatures up to 500 K. Using these coefficients in a non-LTE modeling framework and employing a Monte Carlo Markov chain analysis, we find that HCNH+ emission originates from regions with H2 number densities of $\sim10^{2.80}-10^{3.55}$~cm$^{-3}$, establishing HCNH+ as a tracer of low-density environments. Our analysis reveals that most of the HCNH+ abundances in the CMZ of NGC253 are higher than all reported values in the Milky Way. We performed static, PDR, and shock modeling, and found that recurrent shocks could potentially account for the elevated HCNH+ abundances observed in this CMZ. We propose that the unexpectedly high HCNH+ abundances may result from chemical enhancement, primarily driven by the elevated gas temperatures and cosmic ray ionization rates of shocked, low-density gas in the nuclear starburst regions of NGC253.
Formation of Microcapsules of Pullulan by Emulsion Template Mechanism: Evaluation as Vitamin C Delivery Systems
Esther Santamaría, Naroa Lizarreta, Susana Vílchez
et al.
Pullulan is a polysaccharide that has attracted the attention of scientists in recent times as a former of edible films. On the other hand, its use for the preparation of hydrogels needs more study, as well as the formation of pullulan microcapsules as active ingredient release systems for the food industry. Due to the slow gelation kinetics of pullulan with sodium trimetaphosphate (STMP), capsules cannot be formed through the conventional method of dropping into a solution of the gelling agent, as with other polysaccharides, since the pullulan chains migrate to the medium before the capsules can form by gelation. Pullulan microcapsules have been obtained by using inverse water-in-oil emulsions as templates. The emulsion that acts as a template has been characterized by monitoring its stability and by optical microscopy, and the size of the emulsion droplets has been correlated with the size of the microcapsules obtained, demonstrating that it is a good technique for their production. Although some flocs of droplets form, these remain dispersed during the gelation process and two capsule size distributions are obtained: those of the non-flocculated droplets and the flocculated droplets. The microcapsules have been evaluated as vitamin C release systems, showing zero-order release kinetics for acidic pH and Fickian mechanism for neutral pH. On the other hand, the microcapsules offer good protection of vitamin C against oxidation during an evaluation period of 14 days.
Synthesis and Characterization of Nanocomposite Hydrogels Based on Poly(Sodium 4-Styrene Sulfonate) under Very-High Concentration Regimen of Clays (Bentonite and Kaolinite)
Tulio A. Lerma, Enrique M. Combatt, Manuel Palencia
The aim of this work was to synthesize and study the functional properties of polymer-clay nanocomposite (PCNCs) based on poly(sodium 4-styrene sulfonate) (NaPSS) and two types of clay in the dispersed phase: bentonite and kaolinite, in order to advance in the development of new geomimetic materials for agricultural and environmental applications. In this study, the effect of adding high concentrations of clay (10–20 wt. %) on the structural and functional properties of a polymer–clay nanocomposite was evaluated. The characterization by infrared spectroscopy made it possible to show that the PCNCs had a hybrid nature structure through the identification of typical vibration bands of the clay matrix and NaPSS. In addition, scanning electron microscopy allowed us to verify its hybrid composition and an amorphous particle-like morphology. The thermal characterization showed degradation temperatures higher than ~300 °C with Tg values higher than 100 °C and variables depending on the clay contents. In addition, the PCNCs showed a high water-retention capacity (>2900%) and cation exchange capacity (>112 meq/100 g). Finally, the results demonstrated the ability of geomimetic conditioners to mimic the structure and functional properties of soils, suggesting their potential application in improving soil quality for plant growth.
The ALCHEMI atlas: principal component analysis reveals starburst evolution in NGC 253
Nanase Harada, David S. Meier, Sergio Martín
et al.
Molecular lines are powerful diagnostics of the physical and chemical properties of the interstellar medium (ISM). These ISM properties, which affect future star formation, are expected to differ in starburst galaxies from those of more quiescent galaxies. We investigate the ISM properties in the central molecular zone of the nearby starburst galaxy NGC 253 using the ultra-wide millimeter spectral scan survey from the ALMA Large Program ALCHEMI. We present an atlas of velocity-integrated images at a 1".6 resolution of 148 unblended transitions from 44 species, including the first extragalactic detection of HCNH$^+$ and the first interferometric images of C$_3$H$^+$, NO, HCS$^+$. We conduct a principal component analysis (PCA) on these images to extract correlated chemical species and to identify key groups of diagnostic transitions. To the best of our knowledge, our dataset is currently the largest astronomical set of molecular lines to which PCA has been applied. The PCA can categorize transitions coming from different physical components in NGC 253 such as i) young starburst tracers characterized by high-excitation transitions of HC$_3$N and complex organic molecules (COMs) versus tracers of on-going star formation (radio recombination lines) and high-excitation transitions of CCH and CN tracing PDRs, ii) tracers of cloud-collision-induced shocks (low-excitation transitions of CH$_3$OH, HNCO, HOCO$^+$, and OCS) versus shocks from star-formation-induced outflows (high-excitation transitions of SiO), as well as iii) outflows showing emission from HOC$^+$, CCH, H$_3$O$^+$, CO isotopologues, HCN, HCO$^+$, CS, and CN. Our findings show these intensities vary with galactic dynamics, star formation activities, and stellar feedback.
Rheological Characterization of Three-Dimensional Neuronal Cultures Embedded in PEGylated Fibrin Hydrogels
Clara F. López-León, Jordi Soriano, Ramon Planet
Three-dimensional (3D) neuronal cultures are valuable models for studying brain complexity in vitro, and the choice of the bulk material in which the neurons grow is a crucial factor in establishing successful cultures. Indeed, neuronal development and network functionality are influenced by the mechanical properties of the selected material; in turn, these properties may change due to neuron–matrix interactions that alter the microstructure of the material. To advance our understanding of the interplay between neurons and their environment, here we utilized a PEGylated fibrin hydrogel as a scaffold for mouse primary neuronal cultures and carried out a rheological characterization of the scaffold over a three-week period, both with and without cells. We observed that the hydrogels exhibited an elastic response that could be described in terms of the Young’s modulus <i>E</i>. The hydrogels without neurons procured a stable <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>E</mi><mo>≃</mo><mn>420</mn></mrow></semantics></math></inline-formula> Pa, while the neuron-laden hydrogels showed a higher <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>E</mi><mo>≃</mo><mn>590</mn></mrow></semantics></math></inline-formula> Pa during the early stages of development that decreased to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>E</mi><mo>≃</mo><mn>340</mn></mrow></semantics></math></inline-formula> Pa at maturer stages. Our results suggest that neurons and their processes dynamically modify the hydrogel structure during development, potentially compromising both the stability of the material and the functional traits of the developing neuronal network.
Polymeric Hydrogels for Intervertebral Disc Replacement/Integration: Playing with the Chemical Composition for Tuning Shear Behavior and Hydrophilicity
Devid Maniglio, Elia Bissoli, Emanuela Callone
et al.
Damages to the intervertebral disc (IVD) due to improper loading or degeneration result in back pain, which is a common disease affecting an increasing number of patients. Different strategies for IVD remediation have been developed, from surgical treatment to disc replacement, by using both metallic and non-metallic materials. Hydrogels are very attractive materials due to their ability to simulate the properties of many soft tissues; moreover, their chemical composition can be varied in order to assure performances similar to the natural disc. In particular, for the replacement of the IVD outer ring, namely, the <i>anulus fibrosus</i>, the shear properties are of paramount importance. In this work, we produced hydrogels through the photo-induced crosslinking of different mixtures composed of two hydrophilic monofunctional and difunctional polymers, namely, poly(ethyleneglycol) methyl ether methacrylate (PEGMEMA) and poly(ethyleneglycol) dimethacrylate (PEGDMA), together with a hydrophobic molecule, i.e., tert-butyl acrylate (tBA). By changing the ratio among the precursors, we demonstrated the tunability of both the shear properties and hydrophilicity. The structural properties of hydrogels were studied by solid-state nuclear magnetic resonance (NMR). These experiments provided insights on both the structure and molecular dynamics of polymeric networks and, together with information obtained by differential scanning calorimetry (DSC), allowed for correlating the physical properties of the hydrogels with their chemical composition.
Poly (Vinyl Alcohol) Hydrogels Boosted with Cross-Linked Chitosan and Silver Nanoparticles for Efficient Adsorption of Congo Red and Crystal Violet Dyes
Reem T. Alfuraydi, Nouf F. Al-Harby, Fahad M. Alminderej
et al.
In our previous work, three different weight ratios of chitosan/PVA (1:3, 1:1, and 3:1) were blended and then cross-linked with trimellitic anhydride isothiocyanate (TAI) at a concentration depending on their chitosan content, obtaining three hydrogels symbolized by H<sub>13</sub>, H<sub>11</sub>, and H<sub>31</sub>. Pure chitosan was cross-linked with TAI, producing a hydrogel symbolized by H<sub>10</sub>. Further, three H<sub>31</sub>-based silver nanoparticles composites (H<sub>31</sub>/AgNPs1%, H<sub>31</sub>/AgNPs3%, and H<sub>31</sub>/AgNPs5%) were also synthesized. They were investigated, for the first time in this study, as adsorbents for Congo Red (CR) and Crystal Violet (CV) dyes. The removal efficiency of CR dye increased with increasing H<sub>10</sub> content in the hydrogels, and with increasing AgNP content in the composites, reaching 99.91% for H<sub>31</sub>/AgNPs5%. For CV dye, the removal efficiency increased with the increase in the PVA content. Furthermore, the removal efficiency of CV dye increased with an increasing AgNP content, reaching 94.7% for H<sub>31</sub>/AgNPs5%. The adsorption capacity increased with the increase in both the initial dye concentration and temperature, while with an increasing pH it increased in the case of CV dye and decreased in the case of CR dye. The adsorption of CV dye demonstrated that the Freundlich isotherm model is better suited for the experimental results. Moreover, the results were best fitted with pseudo-second-order kinetic model.
Protective Effect of Alginate Microcapsules with Different Rheological Behavior on <i>Lactiplantibacillus plantarum</i> 299v
Minerva Aurora Hernández-Gallegos, Javier Solorza-Feria, Maribel Cornejo-Mazón
et al.
Alginate encapsulation is a well-known technique used to protect microorganisms from adverse conditions. However, it is also known that the viscosity of the alginate is dependent on its composition and degree of polymerization and that thermal treatments, such as pasteurization and sterilization, can affect the structure of the polymer and decrease its protection efficiency. The goal of this study was to evaluate the protective effect of encapsulation, using alginates of different viscosities treated at different temperatures, on <i>Lactiplantibacillus plantarum</i> 299v under in vitro gastrointestinal conditions and cold storage at 4 °C and −15 °C, respectively. Steady- and dynamic-shear rheological tests were used to characterize the polymers. Thermal treatments profoundly affected the rheological characteristics of alginates with high and low viscosity. However, the solutions and gels of the low-viscosity alginate were more affected at a temperature of 117 °C. The capsules elaborated with high-viscosity alginate solution and pasteurized at 63 °C for 30 min provided better protection to the cells of <i>L. plantarum</i> 299v under simulated gastrointestinal and cold storage conditions.
Gel Rheological Properties and Storage Texture Kinetics of Starches Isolated from Anchote (<i>Coccinia abyssinica</i> (<i>Lam.</i>) <i>Cogn.</i>) Cultivars
Yohannes Tolesa Wolde, Shimelis Admassu Emire, Workineh Abebe Zeleke
et al.
Anchote is a tuber crop indigenous to Ethiopia. Starch hydration properties and important gel characteristics which include: color, gel rheological properties (at 2, 4, 6, 8, and 10% starch:water <i>w</i>/<i>w</i>) and gel texture evolution (at 10% starch:water <i>w</i>/<i>w</i>), during 0 to 192 h storage (at 4 °C), of anchote starches isolated from four anchote cultivars (Desta 01, Desta 24, white and red) were evaluated and compared with potato and cassava starches (PS and CS). The lightness (L*) and whiteness scores of the anchote starch ranged up to >95, with slight differences among the cultivars, making them pure starches. Swelling power (SP) and water solubility index (WSI) of the anchote starches increased with increasing cooking temperature (40, 50, 60, 70, 80 and 90 °C), and their rate of increase varied significantly with the control starches, as follows: CS < anchote starches < PS. Anchote starch gels resisted higher stresses before breaking their structure and showed higher elasticity with lower (tan δ)<sub>1</sub> values than PS and CS gels. They also had greater viscoelastic moduli even at lower concentrations than the PS and CS gels, and their stability increased with increasing concentration. The study of the gels’ texture evolution during storage revealed that anchote starch gels had significantly higher (≥40%) initial and final (after 192 h) hardness and were less adhesive than the PS gel. Despite some significant differences in the studied starch gel quality parameters among the starches from the anchote cultivars, the results suggested their promising potential as additional new materials in the development of food products, specifically as a functional ingredient for the formulation of gel-like products.
Volume density structure of the NGC253 CMZ through ALCHEMI excitation analysis
Kunihiko Tanaka, Jeffrey G. Mangum, Serena Viti
et al.
We present a spatially-resolved excitation analysis for the central molecular zone (CMZ) of the starburst galaxy NGC 253 using the data from the ALMA Large program ALCHEMI, whereby we explore parameters distinguishing NGC 253 from the quiescent Milky Way's Galactic Center (GC). Non-LTE analyses employing a hierarchical Bayesian framework are applied to Band 3-7 transitions from nine molecular species to delineate the position-position-velocity distributions of column density ($N_\mathrm{H_2}$), volume density ($n_\mathrm{H_2}$), and temperature ($T_\mathrm{kin}$) at 27 pc resolution. Two distinct components are detected: a low-density component with $(n_\mathrm{H_2},\ T_\mathrm{kin})\sim(10^{3.3}\ \mathrm{cm}^{-3}, 85 K)$ and a high-density component with $(n_\mathrm{H_2},\ T_\mathrm{kin})\sim (10^{4.4}\ \mathrm{cm}^{-3}, 110\ \mathrm{K})$, separated at $n_\mathrm{H_2}\sim10^{3.8}\ \mathrm{cm}^{-3}$. NGC 253 has $\sim10$ times the high-density gas mass and $\sim3$ times the dense-gas mass fraction of the GC. These properties are consistent with their HCN/CO ratio but cannot alone explain the factor of $\sim30$ difference in their star formation efficiencies (SFEs), contradicting the dense-gas mass to star formation rate scaling law. The $n_\mathrm{H_2}$ histogram toward NGC 253 exhibits a shallow declining slope up to $n_\mathrm{H_2}\sim10^6\ \mathrm{cm}^{-3}$, while that of the GC steeply drops in $n_\mathrm{H_2}\gtrsim10^{4.5}\ \mathrm{cm}^{-3}$ and vanishes at $10^5\ \mathrm{cm}^{-3}$. Their dense-gas mass fraction ratio becomes consistent with their SFEs when the threshold $n_\mathrm{H_2}$ for the dense gas is taken at $\sim 10^{4.2\mbox{-}4.6}\ \mathrm{cm}^{-3}$. The rich abundance of gas above this density range in the NGC 253 CMZ, or its scarcity in the GC, is likely to be the critical difference characterizing the contrasting star formation in the centers of the two galaxies.
Tamoxifen Citrate Containing Topical Nanoemulgel Prepared by Ultrasonication Technique: Formulation Design and In Vitro Evaluation
Mohammad H. Alyami, Hamad S. Alyami, Abdullah A. Alshehri
et al.
The present study aims to design and develop a nanoemulgel formulation of Tamoxifen citrate (TAM), a water-insoluble, potent anticancer drug, using the spontaneous emulsification method to improve topical delivery, achieve high accumulation at the tumour site, and spare the healthy tissues. The oil-based selection was related to the TAM solubility, while the surfactant and co-surfactant were chosen based on the droplets’ thermodynamic stability and size. Afterwards, a pseudo-ternary phase diagram was built for the most promising formulation using two oils, olive and sesame, with a varied mix of Tween 40 as the surfactant and Trascutol HP as the co-surfactant (S<sub>mix</sub>), by the optimisation of experiments. The nanoemulsion (NE) formulations that were prepared were found to have an average droplet size of 41.77 ± 1.23 nm and 188.37 ± 3.53 nm, with suitable thermodynamic stability and physicochemical properties. Both olive and sesame oils are natural food additives due to their associated antioxidant effects; therefore, they showed no toxicity profile on breast cell lines (MCF-7, ATCC number HTB-22). The TAM-NE preparations revealed a prolonged and doublings superior cumulative percentage of in vitro release of TAM compared to TAM plain gel suspension over 24 h. The release data suggested that the Higuchi model was the best fitting kinetical model for the developed formulations of NE1, NE9, and NE18. The extended release of the drug as well as an acceptable amount of the drug permeated TAM via nanogel preparations suggested that nanoemulgel (NEG) is suitable for the topical delivery of TAM in breast cancer management. Thus, this work suggests that a nanogel of TAM can improve anticancer properties and reduce systemic adverse effects compared to a suspension preparation of TAM when applied in the treatment of breast cancer.
Investigation on In Situ Carbon-Coated ZnFe<sub>2</sub>O<sub>4</sub> as Advanced Anode Material for Li-Ion Batteries
Mir Waqas Alam, Amal BaQais, Mohammed M. Rahman
et al.
ZnFe<sub>2</sub>O<sub>4</sub> as an anode that is believed to attractive. Due to its large theoretical capacity, this electrode is ideal for Lithium-ion batteries. However, the performance of ZnFe<sub>2</sub>O<sub>4</sub> while charging and discharging is limited by its volume growth. In the present study, carbon-coated ZnFe<sub>2</sub>O<sub>4</sub> is synthesized by the sol–gel method. Carbon is coated on the spherical surface of ZnFe<sub>2</sub>O<sub>4</sub> by in situ coating. In situ carbon coating alleviates volume expansion during electrochemical performance and Lithium-ion mobility is accelerated, and electron transit is accelerated; thus, carbon-coated ZnFe<sub>2</sub>O<sub>4</sub> show good electrochemical performance. After 50 cycles at a current density of 0.1 A·g<sup>−1</sup>, the battery had a discharge capacity of 1312 mAh·g<sup>−1</sup> and a capacity of roughly 1220 mAh·g<sup>−1</sup>. The performance of carbon-coated ZnFe<sub>2</sub>O<sub>4</sub> as an improved anode is electrochemically used for Li-ion energy storage applications.
Nanotechnology in Cosmetics and Cosmeceuticals—A Review of Latest Advancements
Vaibhav Gupta, Sradhanjali Mohapatra, Harshita Mishra
et al.
Nanotechnology has the potential to generate advancements and innovations in formulations and delivery systems. This fast-developing technology has been widely exploited for diagnostic and therapeutic purposes. Today, cosmetic formulations incorporating nanotechnology are a relatively new yet very promising and highly researched area. The application of nanotechnology in cosmetics has been shown to overcome the drawbacks associated with traditional cosmetics and also to add more useful features to a formulation. Nanocosmetics and nanocosmeceuticals have been extensively explored for skin, hair, nails, lips, and teeth, and the inclusion of nanomaterials has been found to improve product efficacy and consumer satisfaction. This is leading to the replacement of many traditional cosmeceuticals with nanocosmeceuticals. However, nanotoxicological studies on nanocosmeceuticals have raised concerns in terms of health hazards due to their potential skin penetration, resulting in toxic effects. This review summarizes various nanotechnology-based approaches being utilized in the delivery of cosmetics as well as cosmeceutical products, along with relevant patents. It outlines their benefits, as well as potential health and environmental risks. Further, it highlights the regulatory status of cosmeceuticals and analyzes the different regulatory guidelines in India, Europe, and the USA and discusses the different guidelines and recommendations issued by various regulatory authorities. Finally, this article seeks to provide an overview of nanocosmetics and nanocosmeceuticals and their applications in cosmetic industries, which may help consumers and regulators to gain awareness about the benefits as well as the toxicity related to the continuous and long-term uses of these products, thus encouraging their judicious use.