Isolation and Screening of Spore-forming and Siderophore-producing Bacteria from the Wheat Rhizosphere

Salinity is one of the important stresses affecting the growth and yield of crops. Using rhizobacteria to reduce the harmful effects of salinity stress on plants is an effective and promising method. This research aims to isolate and screen siderophore-producing rhizobacteria that tolerate salt stress. After transferring the soil sample to the laboratory and applying heat treatment, rhizobacteria were cultured on nutrient agar. Then, the ability to produce siderophores by isolated rhizobacteria was measured using a liquid CAS assay. Consequently, the best siderophore-producing strains were selected and their ability to produce siderophores under 1.2% and 1.8% salinity stress conditions was investigated. The data obtained from the isolation of all siderophore-producing rhizobacteria were analyzed based on a completely randomized design (CRD) and the data collected from examining the ability to produce siderophore under salt stress were analyzed as a factorial based on a completely randomized design. Duncan's multiple range tests were used to compare the means. All data were analyzed using Excel and SAS software. The results showed that all isolated rhizobacteria strains could produce siderophores. K (0.933) and L (0.925) strains had the highest siderophore units, respectively. Additionally, strains F, H, L, and K produced more than 94% siderophore units under 1.2% salt stress. The findings of this study showed that there is a high diversity in terms of siderophore production in Iranian native strains. Moreover, strains F, H, L, and K can potentially be considered plant growth-promoting rhizobacteria under salinity due to their ability to produce siderophores under salt stress

N,N′-Bis(1,3-thia­zol-2-yl)methyl­ene­diamine

In the title compound, C7H8N4S2, the dihedral angle between the thia­zoline rings is 71.25 (13)°. In the crystal, inter­molecular N—H⋯N hydrogen bonds connect the mol­ecules into zigzag chains parallel to the ab plane

The versatile biomedical applications of bismuth-based nanoparticles and composites : therapeutic, diagnostic, biosensing, and regenerative properties

Studies of nanosized forms of bismuth (Bi)-containing materials have recently expanded from optical, chemical, electronic, and engineering fields towards biomedicine, as a result of their safety, cost-effective fabrication processes, large surface area, high stability, and high versatility in terms of shape, size, and porosity. Bi, as a nontoxic and inexpensive diamagnetic heavy metal, has been used for the fabrication of various nanoparticles (NPs) with unique structural, physicochemical, and compositional features to combine various properties, such as a favourably high X-ray attenuation coefficient and near-infrared (NIR) absorbance, excellent light-to-heat conversion efficiency, and a long circulation half-life. These features have rendered bismuth-containing nanoparticles (BiNPs) with desirable performance for combined cancer therapy, photothermal and radiation therapy (RT), multimodal imaging, theranostics, drug delivery, biosensing, and tissue engineering. Bismuth oxyhalides (BiOx, where X is Cl, Br or I) and bismuth chalcogenides, including bismuth oxide, bismuth sulfide, bismuth selenide, and bismuth telluride, have been heavily investigated for therapeutic purposes. The pharmacokinetics of these BiNPs can be easily improved via the facile modification of their surfaces with biocompatible polymers and proteins, resulting in enhanced colloidal stability, extended blood circulation, and reduced toxicity. Desirable antibacterial effects, bone regeneration potential, and tumor growth suppression under NIR laser radiation are the main biomedical research areas involving BiNPs that have opened up a new paradigm for their future clinical translation. This review emphasizes the synthesis and state-of-the-art progress related to the biomedical applications of BiNPs with different structures, sizes, and compositions. Furthermore, a comprehensive discussion focusing on challenges and future opportunities is presented.Peer reviewe

MXene-Integrated Silk Fibroin-Based Self-Assembly-Driven 3D-Printed Theragenerative Scaffolds for Remotely Photothermal Anti-Osteosarcoma Ablation and Bone Regeneration

Aiming to address the bone regeneration and cancer therapy functionalities in one single material, in this study, we developed a dual-functional theragenerative three-dimensional (3D) aerogel-based composite scaffold from hybridization of photo-cross-linked silk fibroin (SF) biopolymer with MXene (Ti3C2) two-dimensional (2D) nanosheets. To fabricate the scaffold, we first develop a dual-cross-linked SF-based aerogel scaffold through 3D printing and photo-cross-linking of the self-assembly-driven methacrylate-modified SF (SF-MA) gel with controlled pore size, macroscopic geometry, and mechanical stability. In the next step, to endow a remotely controlled photothermal antiosteosarcoma ablation function to fabricated aerogel scaffold, MXene 2D nanosheets with strong near-infrared (NIR) photon absorption properties were integrated into the 3D-printed scaffolds. While 3D-printed MXene-modified dual-cross-linked SF composite scaffolds can mediate the in vitro growth and proliferation of preosteoblastic cell lines, they also endow a strong photothermal effect upon remote irradiation with NIR laser but also significantly stimulate bone mineral deposition on the scaffold surface. Additionally, besides the local release of the anticancer model drug, the generated heat (45-53 ?) mediated the photothermal ablation of cancer cells. The developed aerogel-based composites and chosen therapeutic techniques are thought to render a significant breakthrough in biomaterials' future clinical applications

Silica-silk fibroin hybrid (bio)aerogels: two-step versus one-step hybridization

In this study, silk fibroin as a highly promising naturally occurring biopolymer extracted from silkworm cocoon is applied to mechanically reinforce silica aerogels. To this aim, two different approaches for the incorporation of silk fibroin into the silica network are compared: (1) a one-step acid catalyzed and (2) a two-step acid-base catalyzed sol-gel reaction. The total organosilane concentration, as well as the SF to silane mass fractions, regulated the hybridization process to proceed either through a one-step or two-step sol-gel reaction. In both processes, for an efficient chemical mixing the silk fibroin components with the silane phase, a silane coupling agent, 5-(trimethoxysilyl) pentanoic acid (TMSPA), comprising carboxylic acid groups and a pentyl hydrocarbon chain has been used. For a low organosilane content (3.4 mmol) along with a high SF to silane mass ratio (15-30%), the gelation of the silane and silk fibroin phases took place in a one-pot/one-step process in the presence of an acid catalyst in an entirely aqueous system. In the two-step synthesis approach, which was applied for high initial silane contents (17 mmol), and low SF to silane mass ratios (1-4%), first, the gelation of the silk fibroin phase was triggered by addition of an acid catalyst followed by a more pronounced condensation of the silane catalyzed by the addition of the base. Both synthesis approaches led to materials with promising mechanical properties-being 1) the one-step process resulting in gels with much better compressibility (up to 70% of strain), low density (0.17-0.22 g cm(-3)) and three orders of magnitude improvement in the Young's modulus (13.5 MPa) compared to that of the pristine silica aerogel but with rather high shrinkage (30-40%). The two-step process in principle could result in the hybrid aerogel with interesting bulk density (0.17-0.28 g cm(-3)) with lower shrinkage (10%), but the resultant aerogel was stiff and fragile. Also, both approaches led to a significant reduction in the time required to prepare strong hybrid aerogels compared to conventional hybrid polymer-silica aerogels with the utilization of an entirely aqueous synthesis approach for a wide range of applications

Development of Mechanically Strong Ambient Pressure Dried Silica Aerogels with Optimized Properties

Ambient pressure dried (APD) silica aerogel-like monoliths with different underlying silica structures have been developed through a simple wet chemical approach. The improvement of the mechanical properties was accomplished by cross-linking the silica surface with triacrylate cross-linker. A solvent exchange carried out by soaking the gels in a low surface tension solvent allowed to avoid the nonsafe and costly supercritical drying process. In this context, two different sets of aerogel-like monoliths have been produced, and their main properties, namely, bulk density, mechanical strength, and thermal conductivity, were studied and modeled using the statistical Central Composite Design (CCD) approach. The empirical models derived for each property of the aerogel-like monoliths lead to further evaluation of the desirability function and optimization of silica aerogel-like properties. The key properties of the optimized APD monoliths were compared with the supercritical dried aerogels with the same synthesis conditions. Finally, the suitability of optimized silica aerogel-like and aerogel monoliths for intended space applications were further investigated by conducting several standard tests. The improved properties of the obtained APD aerogel-like monoliths render them attractive for high-technology applications, and, due to the low energy consumption of the synthesis process, they are competitive with their supercritically dried (SCD) counterparts, by presenting a best value-for-money compromise

Aerogels-Inspired based Photo and Electrocatalyst for Water Splitting to Produce Hydrogen

Hydrogen fuel has been considered a sustainable, green, and alternative energy source to fossil fuels for future energy supply. Electro-and photochemical water splitting systems are reported as simple, pollutant-free, low-cost, highly efficient techniques for hydrogel production in large quantities and with high purity. As featured by high porosity, self-supportability, and large surface area, aerogels-based catalysts meet all the required criteria for efficient electro and photocatalysts design for water splitting. Besides the traditional sol-gel technique, today, aerogel synthesis and processing have advanced significantly, mainly because of the emergence of various molecular precursors and low dimensional noble, non-noble metals, and carbon-based building blocks, which require the implementation of different network formation strategies. This versatility in the synthesis and fabrication approaches combined with the unique highly 3D porous microstructural feature enhances the aerogel performance for targeted catalytic reactions with improved efficiencies. Herein, an all-embracing overview of the design and processing aspects of aerogel and aerogel-inspired-based materials with various building blocks is given to provide an insight into their electro-and photo-catalysts performance for the water-splitting process and hydrogen production. We also review the recent theoretical studies based on density functional theory (DFT) for unfolding the mechanism and physics of catalytic reactions on the studied aerogel-based materials. Considering their bright prospects, aerogel-based catalysts can pave the way for the advancement of new high-performance binder-free and free-standing electro-and photo-catalytic materials for water-splitting techniques and, ultimately, the production of green hydrogen, a fuel of the future

Hydraulic flow unit and rock types of the Asmari Formation, an application of flow zone index and fuzzy C-means clustering methods

Abstract Rock types are the reservoir's most essential properties for special facies modeling in a defined range of porosity and permeability. This study used clustering techniques to identify rock types in 280 core samples from one of the wells drilled in the Asmari reservoir in the Mansouri field, SW Iran. Four hydraulic flow units (HFUs) were determined for studied data utilizing histogram analysis, normal probability analysis, and the sum of squared errors (SSE) statistical methods. Then, two flow zone index (FZI) and fuzzy c-means (FCM) clustering methods were used to determine the rock types in the given well according to the results obtained from the HFU continuity index acts in-depth. The FCM method, with a continuity number of 3.12, compared to the FZI, with a continuity number of 2.77, shows more continuity in depth. The relationship between permeability and porosity improved considerably by utilizing HFU techniques. This improvement is achieved using the FZI method study. Generally, all samples increased from 0.55 to 0.81 in the first HFU and finally to 0.94 in the fourth HFU. Similar flow properties in an HFU characterized the samples. In comparison, the correlation coefficients obtained in the FCM method are less than those in the general case of all HFUs. This study aims to determine the flowing fluid in the porous medium of the Asmari reservoir employing the c-mean fuzzy logic. Also, by determining the facies of the rock units, especially the siliceous-clastic facies and log data in the Asmari Formation, the third and fourth flow units have the highest reservoir quality and permeability. Results can be compared to determining HFU in nearby wellbores without cores