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Langmuir : the ACS Journal of Surfaces... Jun 2024Methylammonium lead halide perovskites with highly efficient pure-color or white-light generation have gained increasing scientific interest and promote the development...
Methylammonium lead halide perovskites with highly efficient pure-color or white-light generation have gained increasing scientific interest and promote the development of a great commercial opportunity in displays, lighting, and other applications. However, the poor stabilities, lead toxicity, and unfriendly solvents and ligands in the growth process severely restrict their commercial application. Here, we proposed a green method for preparing uniform and stable polymer-encapsulated photoluminescence (PL) tunable CHNHPbBrCl NC thin films at room temperature. Utilizing the swelling effect between alcohol compounds and organic polymers and the ionization of NaCl in methanol solution, the anion exchange process can be achieved rapidly within 7 min. Moreover, the PL wavelengths of the CHNHPbBrCl NCs films were precisely tuned with steps as fine as 2 nm. Experimental results showed that NaCl dissolved in methanol solution can form Cl(CHOH), which brings ionized Cl into the polymer-encapsulated CHNHPbBr NCs film for CHNHPbBrCl NCs film growth. Based on the swelling and anion exchange dynamics, a modified NaCl-CHOH-MABr solution system was developed to trigger CHNHPbBrCl NCs film PL emission tuning from 528 to 463 nm with several-fold intensity enhancement. The realization of precisely controlled photoluminescence from the perovskite nanocrystal film would have wide applications in the optical and imaging fields.
PubMed: 38943597
DOI: 10.1021/acs.langmuir.4c01505 -
Inorganic Chemistry Jun 2024The manuscript focuses on an original method of preparation of metatitanic acid when only environmentally safe base substances are used in the synthesis process. The...
The manuscript focuses on an original method of preparation of metatitanic acid when only environmentally safe base substances are used in the synthesis process. The synthesis is based on the reaction of solid titanyl sulfate in an aqueous solution of sodium hydroxide. This method allows for (i) a full preservation of the morphology of the starting titanyl sulfate and (ii) a preparation of metatitanic acid substances with specific parameters. This can be achieved via a precise control of the alkali metal/titanyl sulfate ratio resulting in substances with varying contents of alkali metals or even sulfate anions. The prepared metatitanic acid then also contains very small weakly crystalline particles (2-3 nm) and forms pseudomorphic aggregates whose shape and dimensions correspond to those of the starting titanyl sulfate. These aggregates exhibit regular nanoporosity with a high surface area of up to 500 m·g, have no tendency to form colloids, and are mechanically highly resistant even by high-energy ultrasound. The characterization of the resulting products is done via their chemical composition and methods of structural analysis, as well as by electron microscopy and local analysis. The mechanism of product formation is discussed based on the structure of the precursor, including the so far unknown structure of metatitanic acid.
PubMed: 38943595
DOI: 10.1021/acs.inorgchem.4c00369 -
Molekuliarnaia Biologiia 2024Production of extracellular membrane vesicles plays an important role in communication in bacterial populations and in bacteria-host interactions. Vesicles as carriers...
Production of extracellular membrane vesicles plays an important role in communication in bacterial populations and in bacteria-host interactions. Vesicles as carriers of various regulatory and signaling molecules may be potentially used as disease biomarkers and promising therapeutic agents, including vaccine preparations. The composition of membrane vesicles has been deciphered for a limited number of Gram-negative and Gram-positive bacteria. In this work, for the first time, extracellular membrane vesicles of a streptomycin-resistant strain Bacillus pumilus 3-19, a producer of extracellular guanyl-preferring ribonuclease binase, are isolated, visualized, and characterized by their genome and proteome composition. It has been established that there is no genetic material in the vesicles and the spectrum of the proteins differs depending on the phosphate content in the culture medium of the strain. Vesicles from a phosphate-deficient medium carry 49 unique proteins in comparison with 101 from a medium with the high phosphate content. The two types of vesicles had 140 mutual proteins. Flagellar proteins, RNase J, which is the main enzyme of RNA degradosomes, phosphatases, peptidases, iron transporters, signal peptides, were identified in vesicles. Antibiotic resistance proteins and amyloid-like proteins whose genes are present in B. pumilus 3-19 cells are absent. Phosphate deficiency-induced binase was found only in vesicles from a phosphate-deficient medium.
Topics: Bacillus pumilus; Extracellular Vesicles; Proteome; Bacterial Proteins; Ribonucleases; Phosphates; Drug Resistance, Bacterial; Endoribonucleases
PubMed: 38943590
DOI: No ID Found -
Angewandte Chemie (International Ed. in... Jun 2024Peptide folding is a dynamic process driven by non-covalent cross-linking leading to functional nanostructures for essential biochemical activities. However, replicating...
Peptide folding is a dynamic process driven by non-covalent cross-linking leading to functional nanostructures for essential biochemical activities. However, replicating this process in synthetic systems is challenging due to the difficulty in mimicking nature's real-time regulation of non-covalent crosslinking for single-chain polymer folding. Here, we address this by employing anionic dithiol building blocks to create macrocyclic disulfides as non-covalent crosslinkers that adapted to the folding process. Initially, small macrocycles facilitated a low degree folding of a polycation. Then, this preorganized structure catalysed the production of larger macrocycles that enhanced the folding conversely. The self-adaptive synthesis was verified through the encapsulation of an anticancer drug, showing an updated production distribution of non-covalent crosslinkers and maximizing drug-loading efficiency against drug-resistant cancer in vitro. Our research advances the understanding of molecular systems by exploring species evolution via the structural dynamics of polymer folding. Additionally, adaptive synthesis enables controlled, sequential folding of synthetic polymers, with the potential to mimic protein functions.
PubMed: 38943429
DOI: 10.1002/anie.202408670 -
Journal of Nanobiotechnology Jun 2024The whole-cell inorganic-biohybrid systems show special functions and wide potential in biomedical application owing to the exceptional interactions between microbes and...
The whole-cell inorganic-biohybrid systems show special functions and wide potential in biomedical application owing to the exceptional interactions between microbes and inorganic materials. However, the hybrid systems are still in stage of proof of concept. Here, we report a whole-cell inorganic-biohybrid system composed of Spirulina platensis and gold nanoclusters (SP-Au), which can enhance the cancer radiotherapy through multiple pathways, including cascade photocatalysis. Such systems can first produce oxygen under light irradiation, then convert some of the oxygen to superoxide anion (•O), and further oxidize the glutathione (GSH) in tumor cells. With the combination of hypoxic regulation, •O production, GSH oxidation, and the radiotherapy sensitization of gold nanoclusters, the final radiation is effectively enhanced, which show the best antitumor efficacy than other groups in both 4T1 and A549 tumor models. Moreover, in vivo distribution experiments show that the SP-Au can accumulate in the tumor and be rapidly metabolized through biodegradation, further indicating its application potential as a new multiway enhanced radiotherapy sensitizer.
Topics: Animals; Humans; Gold; Mice; Mice, Inbred BALB C; Glutathione; Metal Nanoparticles; Spirulina; A549 Cells; Cell Line, Tumor; Neoplasms; Female; Photosynthesis; Superoxides; Radiation-Sensitizing Agents
PubMed: 38943158
DOI: 10.1186/s12951-024-02654-7 -
BMC Oral Health Jun 2024Fluoride is the main factor in reducing the prevalence of caries worldwide. However, there is insufficient knowledge about whether people in different age groups are...
INTRODUCTION
Fluoride is the main factor in reducing the prevalence of caries worldwide. However, there is insufficient knowledge about whether people in different age groups are aware of the benefits of fluoride toothpaste, as well as about people's daily oral care habits and whether they use fluoride. The purpose of this research is to investigate the knowledge and performance of Iranian students regarding the use of toothpaste containing fluoride.
METHOD
This study was conducted on the first- and second-year high school students of Kerman city. Questionnaires containing personal questions, general questions, and questions related to students' knowledge and performance regarding the use of fluoride toothpaste were provided to them and then they were asked to complete and submit it. The results obtained from the survey were analyzed by T-test, Mann-Whitney test, and Chi-Square test in SPSS Version 24. The significance level in data analysis was P < 0.05.
RESULTS
In this research, 681 forms including 252 boys and 429 girls were examined. The average age of the participants was 14.1 ± 0.4. 91.2% declared that they use toothpaste and 77.8% of them used toothpaste containing fluoride. 521 people stated that the price of toothpaste is important in using the type of toothpaste. 621 people used regular toothbrush and 609 people evaluated their oral health as good. 621 of the participants stated that toothpaste makes the mouth healthy. The average knowledge score was 16.7 ± 2.1 out of 24, which indicates the average knowledge of students in this field.
CONCLUSION
This study showed that students' knowledge and performance about using fluoride-containing toothpaste is average. There was no significant relationship between performance and knowledge with age and gender. There was also a positive correlation between knowledge and performance indicating that increasing knowledge leads to an increase in behavioral changes. Also, there was a positive correlation between knowledge and performance, and a correlation coefficient of 0.731 was obtained between knowledge and performance. It shows that increasing knowledge leads to increasing behavioral changes.
Topics: Humans; Toothpastes; Iran; Female; Male; Adolescent; Health Knowledge, Attitudes, Practice; Fluorides; Cariostatic Agents; Surveys and Questionnaires; Students; Toothbrushing
PubMed: 38943104
DOI: 10.1186/s12903-024-04513-1 -
Environmental Monitoring and Assessment Jun 2024Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the...
Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the performance of simultaneous degradation of the mixed pollutants (amoxicillin, acetaminophen, and ciprofloxacin) for an aqueous solution using the solar Fenton process. Operating parameters such as pH, iron doses, HO doses, pollutant concentrations, and time were studied. From the experimental results, the ideal conditions were obtained for the removal of mixed pollutants such as pH 3, Fe 0.04 mM, HO 4 mM, the concentration of the mixed pollutants 5 mg/L, solar radiation 400 W/m, and time 10 min, respectively. The pseudo-first-order kinetics were utilized to investigate the degradation efficacy of the mixed pollutants. The result of the study indicates that the degradation efficiency was > 99% for the mixed pollutants. A maximum of 63% mineralization was observed, and hydroxyl radical scavenger effects were studied. The best optimal conditions were applied to assess the spiked wastewater (municipal wastewater (MWW) and hospital wastewater (HWW)). The highest elimination rates for AMX, ACET, and CIP were observed as 65%, 89%, and 85% for MWW and 76%, 92%, and 80% for HWW, respectively. The degraded by-products were detected by LC-ESI-MS in the water matrix (aqueous solution and spiked wastewater), and ECOSAR analysis was performed for the transformed products. The study concluded that the solar Fenton technique is promising and effective for the removal of mixed pollutants from the water matrix.
Topics: Water Pollutants, Chemical; Hydrogen Peroxide; Kinetics; Iron; Waste Disposal, Fluid; Sunlight; Wastewater; Oxidation-Reduction; Ciprofloxacin; Acetaminophen; Amoxicillin
PubMed: 38942963
DOI: 10.1007/s10661-024-12837-2 -
Mikrochimica Acta Jun 2024The engineering of a home-made portable double-layer filtration and concentration device with the common syringe for rapid analysis of water samples is reported. The...
The engineering of a home-made portable double-layer filtration and concentration device with the common syringe for rapid analysis of water samples is reported. The core elements of the device were two installed filtration membranes with different pore sizes for respective functions. The upper filtration membrane was used for preliminary intercepting large interfering impurities (interception membrane), while the lower filtration membrane was used for collecting multiple target pathogens (enrichment membrane) for determination. This combination can make the contaminated environmental water, exemplified by surface water, filtrated quickly through the device and just retained the target bacteria of Escherichia coli O157:H7, Staphylococcus aureus, and Listeria monocytogenes on the lower enrichment membrane. Integrating with surface-enhanced Raman spectra (SERS) platform to decode the SERS-Tags (SERS-Tag, SERS-Tag, and SERS-Tag) already labeled on each of the enriched bacteria based the antibody-mediated immuno-recognition effect, fast separation, concentration, and detection of multiple pathogenic bacteria from the bulk of contaminated environmental water were realized. Results show that within 30 min, all target bacteria in the lake water can be simultaneously and accurately measured in the range from 10 to 10 CFU mL with detection limit of 10.0 CFU mL without any pre-culture procedures. This work highlights the simplicity, rapidness, cheapness, selectivity, and the robustness of the constructed method for simultaneous detecting multiple pathogens in aqueous samples. This protocol opens a new avenue for facilitating the development of versatile analytical tools for drinking water and food safety monitoring in underdeveloped or developing countries.
Topics: Spectrum Analysis, Raman; Drinking Water; Filtration; Staphylococcus aureus; Listeria monocytogenes; Limit of Detection; Escherichia coli O157; Metal Nanoparticles; Water Microbiology
PubMed: 38942915
DOI: 10.1007/s00604-024-06492-0 -
Scientific Reports Jun 2024Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve...
Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve barley's adaptation to salinity stress by deeply studying the effects of salt stress and the responses of barley to this stress. In this context, our study aims to explore the variation in physiological and biochemical responses of five Tunisian spring barley genotypes to salt stress during the heading phase. Two salinity treatments were induced by using 100 mM NaCl (T1) and 250 mM NaCl (T2) in the irrigation water. Significant phenotypic variations were detected among the genotypes in response to salt stress. Plants exposed to 250 mM of NaCl showed an important decline in all studied physiological parameters namely, gas exchange, ions concentration and relative water content RWC. The observed decreases in concentrations ranged from, approximately, 6.64% to 40.76% for K, 5.91% to 43.67% for Na, 14.12% to 52.38% for Ca, and 15.22% to 38.48% for Mg across the different genotypes and salt stress levels. However, under salinity conditions, proline and soluble sugars increased for all genotypes with an average increase of 1.6 times in proline concentrations and 1.4 times in soluble sugars concentration. Furthermore, MDA levels rose also for all genotypes, with the biggest rise in Lemsi genotype (114.27% of increase compared to control). Ardhaoui and Rihane showed higher photosynthetic activity compared to the other genotypes across all treatments. The stepwise regression approach identified potassium content, K/Na ratio, relative water content, stomatal conductance and SPAD measurement as predominant traits for thousand kernel weight (R2 = 84.06), suggesting their significant role in alleviating salt stress in barley. Overall, at heading stage, salt accumulation in irrigated soils with saline water significantly influences the growth of barley by influencing gas exchange parameters, mineral composition and water content, in a genotype-dependent manner. These results will serve on elucidating the genetic mechanisms underlying these variations to facilitate targeted improvements in barley's tolerance to salt stress.
Topics: Hordeum; Salt Stress; Water; Minerals; Genotype; Salinity; Sodium Chloride
PubMed: 38942909
DOI: 10.1038/s41598-024-65967-5 -
British Dental Journal Jun 2024
Topics: Humans; Fluorides; Dental Caries; Cariostatic Agents; United Kingdom; Fluoridation
PubMed: 38942836
DOI: 10.1038/s41415-024-7577-3