Didecyldimethylammonium Bromide Research Articles

Sustainable detergent-disinfectant agent based on whey mineralizate and silver nanoparticles for cleaner production in dairy industry

Detergents and disinfectants for dairy industry must meet a variety of characteristics, including low toxicity, high antibacterial activity, and excellent rinsing of pollutants from working surfaces. This work presents an innovative detergent-disinfectant agent based on whey mineralizate and silver nanoparticles (Ag NPs), which allows reducing production costs and ensuring high cleanliness of treated surfaces compared to analogues. For this purpose, a method for obtaining sols of Ag NPs stabilized with didecyldimethylammonium bromide (Ag NPs-DDAB) was developed and optimized using neural network algorithms. Characterization of Ag NPs-DDAB showed particles with a radius of 4.5 nm and 20 nm, stable in the pH range from 2 to 11. An acute toxicity study of Ag NPs in mice showed LD50 = 4230 μg/kg. Based on the degree of accumulation and inhalation toxicity, Ag NPs-DDAB are classified as low-hazard chemicals. The developed detergent-disinfectant had a washability of about 90%, high antimicrobial activity (0.005 mg/mL) against Penicillium roqueforti and a sanitary and hygienic effect on coliforms, general contamination and pathogenic microorganisms, a low-corrosive effect and low toxicity (315 mg/mL) to Danio rerio. It was concluded that the use of detergent-disinfectant agent will completely eliminate the consumption of water for the equipment cleaning process and can be used to clean an electrodialysis unit’s circuits, enabling the utilization of secondary waste from membrane milk processing and promoting resource efficiency and cleaner production in the dairy industry.

Insight into didecyl dimethyl ammonium bromide toxicity following acute exposure in pullets (Gallus gallusdomesticus).

Didecyl dimethyl ammonium bromide (DDAB) is a quaternary ammonium compound used for the sanitation of drinking water of poultry and water pipelines in farms. There is scarcity of information on the toxicology of DDAB in poultry. This study set out to profile the acute toxicity of DDAB in poultry. Issa brown pullets (n = 34) as experimental birds were orally administered varying doses of DDAB, using a syringe, after 12h fasting, and observed for toxicity over 14 days. Control birds (n = 10) were similarly given normal saline orally. Toxic signs in the experimental birds were depression, anorexia, adipsia, vocalization with foamy salivation, later emaciation and death. The LD50 was calculated as 458.00mg/kg. Birds given 2151mg/kg DDAB died within 24h, while those treated with 516mg/kg succumbed on Day 14. At necropsy, grossly, there were necrosis and sloughing of the oesophagus and intestines, pale and friable liver, congested and necrotic lungs, friable popped out kidneys and emaciated carcasses. Microscopically, desquamation and necrosis of the oesophagus, crop, proventriculus and intestines and disruption of the koilin membrane of the gizzard were observed. The lungs, liver and kidneys were congested with mononuclear cellular infiltration plus loss of architecture in the lungs and liver. In conclusion, at high doses, DDAB caused significant toxicity in chickens and these findings provide new information which could serve as a guide in the diagnosis of quaternary ammonium toxicity in chicken. The results could be extrapolated to other quaternary ammonium toxicities in related avian species.

An Investigation of N-Hydroxyphthalimide Catalyzed Aerobic Oxidation of Toluene without Metal Ions in Liquid Phase: Effect of Solvents and Phase Transfer Catalysts.

The selective oxidation of toluene to yield value-added oxygenates, such as benzyl alcohol, benzaldehyde, and benzoic acid, via dioxygen presents a chlorine-free approach under benign conditions. Metal-free catalytic processes are preferred to avoid metal ion contamination. In this study, we employed N-hydroxyphthalimide (NHPI) as a catalyst for the aerobic oxidation of toluene to its oxygenated derivatives. The choice of solvent exerted a significant impact on the catalytic activity and selectivity of the catalyst NHPI at reaction temperatures exceeding 70 °C. Notably, hexafluoroisopropanol substantially enhanced the selective production of benzaldehyde. Furthermore, we identified didecyl dimethyl ammonium bromide, featuring two symmetrical long hydrophobic chains, as a potent enhancer of NHPI for the solvent-free aerobic oxidation of toluene. This effect is ascribed to its unique symmetrical structure, extraction capabilities, and resistance to thermal and acid/base conditions. Based on the product distribution and control experiments, we proposed a plausible reaction mechanism. These findings may inform the industrial synthesis of oxygenated derivatives from toluene.

Antibacterial and Antioxidant Study of New Pharmaceutical Formulation of Didecyldimethylammonium Bromide Via Pharmaceutical Deep Eutectic Solvents (PDESs) Principle.

Combination therapies have been studied by many researchers using different techniques and methods to solve some solid drug problems and improve more effective treatments for humans and animals. One of the more significant findings to emerge from this study is that the combination of pharmaceutical agents by using pharmaceutical deep eutectic solvents (PDESs) in order toproduce dual action drugs and reduce the drug resistance. The major objective of this study was to investigate the dual functionality of drugs (antioxidant and antibacterial activity) via the principle of PDESs. The produced PDESs were characterized via different techniques, namely differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and UV-Vis spectrophotometry. We herein tested a panel of novel liquid formulations of didecyldimethylammonium bromide (DDMAB) against a selection of pathogenic bacteria, classifying their spectrum of activity against Gram-positive and Gram-negative bacteria. The current study found that the PDESs can be used to produce drugs with dual functionalities. The produced PDES from (ascorbic acid: DDMAB) exhibits stronger antibacterial activity against Gram-positive Staphyloccocus aureus and Staphyloccocus epidermidis than gram negatives. One of the most interesting PDESs studied in this research was that of DDMAB and ascorbic acid. This forms a eutectic which is far from the solid drugs issues and shows dual functionality like antibacterial and antioxidant activity. This study has found that there is a correlation between the molecular docking study and the biological activities of the combined drugs.

Bioinspired 3D-printed scaffold embedding DDAB-nano ZnO/nanofibrous microspheres for regenerative diabetic wound healing

There is a constant demand for novel materials/biomedical devices to accelerate the healing of hard-to-heal wounds. Herein, an innovative 3D-printed bioinspired construct was developed as an antibacterial/regenerative scaffold for diabetic wound healing. Hyaluronic/chitosan (HA/CS) ink was used to fabricate a bilayer scaffold comprising a dense plain hydrogel layer topping an antibacterial/regenerative nanofibrous layer obtained by incorporating the hydrogel with polylactic acid nanofibrous microspheres (MS). These were embedded with nano ZnO (ZNP) or didecyldimethylammonium bromide (DDAB)-treated ZNP (D-ZNP) to generate the antibacterial/healing nano/micro hybrid biomaterials, Z-MS@scaffold and DZ-MS@scaffold. Plain and composite scaffolds incorporating blank MS (blank MS@scaffold) or MS-free ZNP@scaffold and D-ZNP@scaffold were used for comparison. 3D printed bilayer constructs with customizable porosity were obtained as verified by SEM. The DZ-MS@scaffold exhibited the largest total pore area as well as the highest water-uptake capacity and in vitro antibacterial activity. Treatment of Staphylococcus aureus-infected full thickness diabetic wounds in rats indicated superiority of DZ-MS@scaffold as evidenced by multiple assessments. The scaffold afforded 95% wound-closure, infection suppression, effective regulation of healing-associated biomarkers as well as regeneration of skin structure in 14 d. On the other hand, healing of non-diabetic acute wounds was effectively accelerated by the simpler less porous Z-MS@scaffold. Information is provided for the first-time on the 3D printing of nanofibrous scaffolds using non-electrospun injectable bioactive nano/micro particulate constructs, an innovative ZNP-functionalized 3D-printed formulation and the distinct bioactivity of D-ZNP as a powerful antibacterial/wound healing promotor. In addition, findings underscored the crucial role of nanofibrous-MS carrier in enhancing the physicochemical, antibacterial, and wound regenerative properties of DDAB-nano ZnO. In conclusion, innovative 3D-printed DZ-MS@scaffold merging the MS-boosted multiple functionalities of ZNP and DDAB, the structural characteristics of nanofibrous MS in addition to those of the 3D-printed bilayer scaffold, provide a versatile bioactive material platform for diabetic wound healing and other biomedical applications.

Development and in vivo evaluation of nanoemulsions for oral delivery of low molecular weight heparin

AimThe aim of this study was the development and in vivo evaluation of different types of nanoemulsions for oral delivery of low molecular weight heparin (LMWH). MethodsNanoemulsions (NE) were developed consisting of mainly non-digestible components and variations of polyglycerol-, PEGylated or zwitterionic surfactants. To incorporate LMWH in the oily droplets, hydrophobic ion pairs were formed with several cationic surfactants. Loaded and unloaded NE were evaluated for their size, zeta potential, stability towards pancreatin, hemolytic and toxic properties. Finally, an in vivo study on oral LMWH delivery was performed. ResultsDroplet size of all formulations was below 150 nm with a PDI <0.4. Highest logK1-butanol/water was obtained for the complex of LMWH and didecyldimethylammonium bromide (HIP). This complex was incorporated into NE containing polyglycerol- and PEGylated surfactants up to a concentration of 5% (m/v) and in zwitterionic NE up to 10% (m/m). NE containing polyglycerol-surfactants were digested to a higher extent than NE containing PEGylated surfactants. The zwitterionic NE without glycerides did not show any lipolysis but the zwitterionic NE which contained high amounts of glycerides was rapidly degradable. NE with polyglycerol-surfactants were less toxic and hemolytic than NE with PEGylated surfactants and zwitterionic NE. Toxic potential increased with HIP-loaded formulations. When performing in vivo studies, oral bioavailability of LMWH was increased up to 2.6% with non-digestible NE. ConclusionAccording to these results, non-digestible nanoemulsions improve oral bioavailability of LMWH more efficiently than biodegradable formulations.

Highly Crystalline CsPbBr3 Perovskite Nanoparticles for Liquid Crystal Displays

Synthesis of CsPbBr3 nanocrystals (NCs) in the nonpolar solvent at room temperature has made great progress in recent years. However, most of strategies require the use of toluene, which is severely against their large-scale production in future commercialization due to the toxicity concerns. Here, we propose a facile and environmentally friendly strategy to synthesize CsPbBr3 NCs by using n-hexane as the solvent for the first time. Didecyldimethylammonium bromide (DD10AB) can well passivate NCs by the strong bonding of DDA+ with the NC surface, thus improving the colloidal stability. CsPbBr3 NCs with DD10AB post-treatment not only exhibit a narrow emission (FWHM ≈ 17.0 nm) with an ultrahigh PLQY of 96% but also maintain an orthorhombic structure and bright luminescence after 120 days of storage in air. Employing a DD10AB-CsPbBr3 film, a high-performance LCD displays the color gamut of 131% NTSC and 95% Rec.2020, indicating a great potential in the application field of liquid crystal display in the future.

Passivation of Surface Defects by X-type Short-Chain Ligands for High Quantum Yield and Stable CsPbX3 Quantum Dots Synthesis and Application in WLEDs

All-inorganic CsPbX3 perovskite quantum dots have excellent optoelectronic properties and are excellent candidates for optoelectronic applications. However, the surface ligands (oleyl ammonium, oleic acid) commonly used in traditional inorganic perovskite quantum dots easily fall off from the quantum dots and their protective power is relatively weak, resulting in poor quantum yield and stability of the quantum dots, limiting their application. In this paper, we introduce an X-type short-chain ligand (DDEAB) passivation strategy to enhance the optoelectronic properties of CsPbX3 quantum dots through a facile room-temperature synthesis method and the strong affinity of X-type ligands for surface atoms. The results of TRPL and X-ray photoelectron spectroscopy showed longer lifetime and stronger surface affinity. This result confirms that didecyldimethylammonium bromide (DDEAB) has better binding to CsPbBr3 QDs and can effectively reduce surface defects and improve quantum yield. As a result, the introduction of short-chain ligands can more effectively passivate the surface halogen defects of CsPbX3 QDs, achieving high quantum yield (>90%) and long-term storage environmental stability. In addition, DDEAB-passivated CsPbBr3 QDs have been successfully applied in white light emitting diodes (WLEDs) with wider color gamut (123%), and good EL stability compared to NTSC TV color standard. Our proposed short-chain ligand DDEAB passivation strategy may provide a reference guideline for the preparation of quantum dots and photovoltaic devices with high photoluminescence and environmental stability.

Bioelectrochemical platform with human monooxygenases: FMO1 and CYP3A4 tandem reactions with phorate

It is highly advantageous to devise an in vitro platform that can predict the complexity of an in vivo system. The first step of this process is the identification of a xenobiotic whose monooxygenation is carried out by two sequential enzymatic reactions. Pesticides are a good model for this type of tandem reactions since in specific cases they are initially metabolised by human flavin-containing monooxygenase 1 (hFMO1), followed by cytochrome P450 (CYP). To assess the feasibility of such an in vitro platform, hFMO1 is immobilised on glassy carbon electrodes modified with graphene oxide (GO) and cationic surfactant didecyldimethylammonium bromide (DDAB). UV–vis, contact angle and AFM measurements support the effective decoration of the GO sheets by DDAB which appear as 3 nm thick structures. hFMO1 activity on the bioelectrode versus three pesticides; fenthion, methiocarb and phorate, lead to the expected sulfoxide products with KM values of 29.5 ± 5.1, 38.4 ± 7.5, 29.6 ± 4.1 µM, respectively. Moreover, phorate is subsequently tested in a tandem system with hFMO1 and CYP3A4 resulting in both phorate sulfoxide as well as phoratoxon sulfoxide. The data demonstrate the feasibility of using bioelectrochemical platforms to mimic the complex metabolic reactions of xenobiotics within the human body.

Acute stress of the typical disinfectant glutaraldehyde-didecyldimethylammonium bromide (GD) on sludge microecology in livestock wastewater treatment plants: Effect and its mechanisms

Glutaraldehyde and didecyldimethylammonium bromide (GD) is a disinfectant widely used to prevent African swine fever (ASF) in livestock farms. However, the effect of residual GD on the activated sludge microbial ecology of receiving wastewater treatment plants (WWTPs) remains largely unknown. In this study, seven simulated systems were established to research the effects of GD on WWTPs and reveal the underlying mechanisms of microecological responses to GD at different concentrations. Both the nitrogen and carbon removal rates decreased with increasing GD concentrations, and nitrogen metabolism was inhibited more obviously, but the inhibition weakened with increasing stress duration. Microorganisms activated their SoxRS systems to promote ATP synthesis and electron transfer to support the hydrolysis and efflux of GD by producing a small number of ROS when exposed to GD at less than 1 mg/L. The overproduction of ROS led to a decrease of antioxidant and nitrogen removal enzyme activities, and upregulation of the porin gene increased the risk of GD entering the intracellular space upon exposure to GD at concentrations higher than 1 mg/L. Some denitrifiers survived via resistance and their basic capabilities of sugar metabolism and nitrogen assimilation. Notably, low concentrations of disinfectants could promote vertical and horizontal transfer of multiple resistance genes, especially aminoglycosides, among microorganisms, which might increase not only the adaptation capability of denitrifiers but also the risk to ecological systems. Therefore, the risks of disinfectants targeting ASF on ecology and health as well as the effects of disinfectant residuals from the COVID-19 epidemic should receive more attention.

Seed germination responses of broomrape species (Phelipanche ramosa and Phelipanche aegyptiaca) to various sanitation chemicals

AbstractBranched broomrape, an obligate root parasitic weed, has recently re-emerged in tomato fields in several California counties. California produces more tomato than any other state, and the outbreak of this noxious weed could potentially wreak havoc on the industry’s economy. Preventive measures must be taken to stop or reduce the spread of branched broomrape seeds to other areas. Branched broomrape can produce thousands of tiny seeds, which can easily spread with farm machinery over short and long distances. To prevent branched broomrape seed dispersal, sanitation and disinfection of farm equipment are necessary before entering a new farm. We tested the effectiveness of various ammonium compounds, including didecyl dimethyl ammonium chloride (DDAC), alkyl dimethyl benzyl ammonium chloride (ADBC), didecyl dimethyl ammonium bromide (DDAB), ammonium bromide (AB), and ammonium chloride (AC) on prevention of branched broomrape seed germination. Dose-response analysis showed that three chemical products, ADBC, DDAB, and DDAC, could completely inhibit branched broomrape seeds (potentially making them nonviable) at 1%, 1%, and 10% wt/vol concentrations, respectively. These three compounds were further tested in an exposure duration experiment that additionally included Egyptian broomrape. Only 10 min of exposure to these compounds was needed to prevent germination of both branched and Egyptian broomrape seeds at 1% (ADBC, DDAB) and 10% wt/vol (DDAC). Lower concentrations can provide similar inhibition effects when combined with longer exposure times. Egyptian broomrape seeds were more sensitive than branched broomrape seeds. Findings suggest that quaternary ammonium compounds could be used as potential sanitation agents to disinfect agriculture machinery from branched and Egyptian broomrape seeds.

Didecyldimethylammonium bromide: Application to control biofilms of Staphylococcus aureus and Pseudomonas aeruginosa alone and in combination with slightly acidic electrolyzed water

This project explored the antibacterial mechanism of didecyldimethylammonium bromide (DDAB) toward Staphylococcus aureus and Pseudomonas aeruginosa, and its removal effect on biofilms. Furthermore, we explored the effect of treatment by DDAB combined with slightly acidic electrolyzed water (SAEW) on biofilms of S. aureus or P. aeruginosa. First, DDAB has bacteriostatic and biofilm removal effects. Second, The effect of DDAB combined with SAEW on biofilm is more obvious than that of the two alone. DDAB at a concentration of 16 MIC combined with SAEW (ACC 30 mg/L, ORP 875 mV, pH 6.30) completely cleared the biofilm. In addition, the results of Confocal laser scanning microscopy (CLSM), Field emission scanning electron microscopy (FESEM) and Attenuated total reflection–Fourier-transform infrared spectroscopy (ATR-FTIR) showed that DDAB combined with SAEW could disrupt the structure of biofilms, reduce polysaccharides, proteins and phospholipids in biofilms. This method has the potential to be used in food production chains to control S. aureus and P. aeruginosa and their biofilms, and it can be used in other industries.

Thermal fogging with disinfectants and antifreezes enables effective industrial disinfection in subzero cold-chain environment.

During several local COVID-19 outbreaks in China in 2020, SARS-CoV-2 or its RNA was isolated or detected from frozen food or packages, revealing the lack of effective disinfection measures in the frozen food chain and risk of transmission. We explored the possibility that disinfectant plus antifreeze could be delivered as thermal fog to realize effective disinfection at subzero temperatures. We selected two disinfectant-antifreeze combinations, didecyl dimethyl ammonium bromide (DDAB) - propylene glycol (PPG) and peracetic acid (PAA) - triethylene glycol (TEG), and each combination is used with a custom-optimized thermal fogging machine. The two fogs were tested in -20°C freezer warehouses for their disinfection efficacy against a coronavirus porcine epidemic diarrhoea virus (PEDV) field strain, a swine influenza virus (SIV) field strain, and three indicator bacteria, Escherichia coli, Staphylococcus aureus and Bacillus subtilis endospores. At -20°C, the DDAB-PPG or PAA-TEG thermal fogs settle within 3.5 to 4.5h and effectively inactivated PEDV with median tissue culture infective dose of 10-3.5 0.1ml-1 and SIV-H1N1 with hemagglutination titre of 26 ml-1 within 15-60min. DDAB-PPG could inactivate S. aureus and E. coli vegetative cells (106 cfuml-1 ) within 15-60min but not effective on B. subtilis spores, while PAA-TEG could disinfect B. subtilis spores more effectively than for S. aureus and E. coli. We showed that a practical subzero temperature disinfection technology was effective in killing enveloped viruses and vegetative bacteria or bacterial spores. DDAB-PPG or PAA-TEG thermal fogging may be a practical technology for cold-chain disinfection. This subzero temperature disinfection technology could help to meet the urgent public health need of environmental disinfection in frozen food logistics against pandemic and other potential pathogens and to enhance national and international biosecurity.

2D MXene-Molecular Hybrid Additive for High-Performance Ambipolar Polymer Field-Effect Transistors and Logic Gates.

MXenes are highly conductive layered materials that are attracting a great interest for high-performance opto-electronics, photonics, and energy applications.. Their non-covalent functionalization with ad hoc molecules enables the production of stable inks of 2D flakes to be processed in thin-films. Here, the formation of stable dispersions via the intercalation of Ti3 C2 Tx with didecyldimethyl ammonium bromide (DDAB) yielding Ti3 C2 Tx -DDAB, is demonstrated. Such functionalization modulates the properties of Ti3 C2 Tx , as evidenced by a 0.47eV decrease of the work function. It is also shown that DDAB is a powerful n-dopant capable of enhancing electron mobility in conjugated polymers and 2D materials. When Ti3 C2 Tx -DDAB is blended with poly(diketopyrrolopyrrole-co-selenophene) [(PDPP-Se)], a simultaneous increase by 170% and 152% of the hole and electron field-effect mobilities, respectively, is observed, compared to the neat conjugated polymer, with values reaching 2.0 cm2 V-1 s-1 . By exploiting the balanced ambipolar transport of the Ti3 C2 Tx -DDAB/PDPP-Se hybrid, complementary metal-oxide-semiconductor (CMOS) logic gates are fabricated that display well-centered trip points and good noise margin (64.6% for inverter). The results demonstrate that intercalant engineering represents an efficient strategy to tune the electronic properties of Ti3 C2 Tx yielding functionalized MXenes for polymer transistors with unprecedented performances and functions.

Regulating Droplet Impact and Wetting Behaviors on Hydrophobic Weed Leaves by a Double-Chain Cationic Surfactant

The addition of a surfactant is a constructive strategy to enhance the deposition of pesticides on plant leaves in agriculture. However, currently used surfactants normally require to be used at high concentrations, and most of them are anionic or nonionic. In this work, we found that didecyldimethylammonium bromide (DDAB), a double-chain cationic surfactant, can not only inhibit droplets from receding and rebounding but also promote sufficient spreading on paraffin and Chenopodium album L. leaf surfaces at an ultralow concentration (0.05%), in comparison with widely reported sodium dodecyl sulfate (SDS) and bis(2-ethylhexyl)sulfosuccinate (AOT). This phenomenon is attributed to the fast adsorption kinetics of DDAB from the bulk to the newly created interface (mere 100 ms), decreasing the surface tension significantly. Field experiments further prove that the addition of DDAB can significantly improve the control efficiency of herbicides. Our findings provide a simple and effective way for improving the droplet deposition on hydrophobic plant surfaces, which may lead to economic and environmental benefits in the future.

Gold nanoparticles produced using NaBH4 in absence and in the presence of one-tail or two-tail cationic surfactants: Characteristics and optical responses induced by aminoglycosides

Gold nanoparticles (AuNPs), produced using sodium borohydride in water (AuNPs-H), also in the presence of the surfactants cetyltrimethylammonium bromide (AuNPs-CTAB) and didecyldimethylammonium bromide (AuNPs-D10AB), were characterized and investigated in terms of their optical localized surface plasmon resonance (LSPR) response. The automation of the syntheses improved reproducibility of AuNPs. CTAB was chosen as a model one-tail surfactant capping agent for AuNPs and D10AB (two-tail surfactant) was employed for the first time, as a capping agent for AuNPs. Thus, it was possible to carry out a comparative study for the production of AuNPs, varying the surfactant concentration levels from 1.0 × 10−2 to 1 × 10-4 mol L-1. The LSPR profiles were monitored in function of the time, taking into account storage conditions (at 4 °C and at 27 °C). A more unstable behavior was observed for the AuNPs produced in the presence of D10AB at 1.0 × 10-4 mol L-1, which suggested the disassembling of AuNPs over time. The catalytic activity of the AuNPs was evaluated in the presence of 4-nitrophenol, and the most effective kinetics were observed for systems containing the one-tail surfactant CTAB, at 1.0 × 10−2 mol L-1 (8 min), and for AuNPs-H, which has no organic coating, (6 min). Finally, the evaluation of the optical response from AuNPs was conducted with four aminoglycosides (AMG), indicating that these surfactants prevent interaction between AMG and the surface of the nanoparticles since at higher concentrations of CTAB or D10AB there is no significant variation in the LSPR spectral band in presence of AMG. In contrast, strong interaction, observed as variation of LSPR band, was found for the AuNPs-H-AMG systems.

Induced plant immunity as a factor of an integrated winter wheat disease protection system

The study deals with the system of integrated protection of winter wheat against phytopathogenic organisms. This includes the use of quaternary ammonium compounds combined with nanosilver in two stages: 1) pre-sowing treatment of seeds with the tank mixture of fungicide (difenoconazole + cyproconazole) and didecyldimethylammonium bromide enriched by nanosilver (0.15 %); 2) spraying of plants with immunity inducer at the end of the tillering – the beginning of booting. The leading role both in terms of protection and yield capacity belongs to early spring spraying with didecyldimethylammonium bromide enriched by nanosilver (0.3 %). This technique allowed obtaining the biological yield of winter wheat equal to 9.52 t/ha.

Chiral 3D CdSe Nanotetrapods.

Three-dimensional (3D) nanomaterials have been intensively investigated because of their unique properties and wide range of potential applications; however, the ligand-induced chirality in 3D semiconductor nanocrystals has been scarcely studied. In this paper, we report the synthesis of hydrophobic 3D CdSe nanotetrapods (Tps) with a high degree of uniformity in their morphology by using the hot-injection method. The core and arms of Tps are distinct in their crystal structure, thus creating an intracrystal heterojunction. The size of Tps, primarily the length of four arms, is controlled by changing the amount of didecyldimethylammonium bromide and reaction time. Next, enantiopure cysteine ligands were introduced to replace the hydrophobic native stabilizers to prepare chiral l- and d-cysteine-capped CdSe Tps. Importantly, the circular dichroism (CD) line shapes of l/d-cysteine-capped CdSe Tps are assigned to the different excitonic transitions of the core and arms, respectively. In addition, the observed CD activities are found to be sensitive to the size of the CdSe Tps, where the anisotropic g factors have increased and reached the maximum value at a moderate aspect ratio (AR) and a further increase of the AR leads to a decrease of the g factor. Because of charge transfer between the core and arms, we propose a plausible mechanism potentially responsible for the induced CD line shapes in terms of the excitonic states of Tps with two different crystal structures. We believe that chiral 3D nanomaterials with anisotropic morphologies could offer new opportunities for relevant applications.

Surface Ligand Engineering for Efficient Perovskite Nanocrystal-Based Light-Emitting Diodes.

Lead halide perovskites (LHPs) are emerging as promising materials for light-emitting device applications because of the tunability of the band gap, narrow emission, solution processability, and flexibility. Typically, LHP nanocrystals (NCs) with surface ligands show high photoluminescence quantum yields because of charge-carrier confinement with higher exciton binding energy ( Eb). However, the conventionally used oleylamine (OAm) ligands result in the low electrical conductivity and stability of perovskite NCs (PNCs) because of a long carbon chain without conjugation bonds and weak interaction with the surface of NCs. Here, we report the effect of bulkiness and chain length of ligand materials on the properties and stability of CsPbBr3 PNCs by replacing OAm with other suitable ligands. The effect of the bulkiness of quaternary ammonium bromide (QAB) ligands was systemically studied. The less bulky QAB ligands surrounded the surface of NCs effectively, and brought better surface passivation and less aggregation compared to bulky QAB ligands, and finally the optical property and stability of CsPbBr3 PNCs were enhanced. Furthermore, the electrical property of CsPbBr3 PNCs was optimized by tuning the long-chain length of QAB ligands for balanced charge-carrier transport. Finally, we achieved highly efficient green emissive CsPbBr3 PNC light-emitting diodes (LEDs) by using PNCs with optimized didecyldimethyl ammonium bromide ligands with a current efficiency of 31.7 cd A-1 and external quantum efficiency of 9.7%, which were enhanced 16-fold compared to those of CsPbBr3 LEDs using PNCs with conventional OAm ligands.

Stealth and Cationic Nanoliposomes as Drug Delivery Systems to Increase Andrographolide BBB Permeability.

(1) Background: Andrographolide (AG) is a natural compound effective for the treatment of inflammation-mediated neurodegenerative disorders. The aim of this investigation was the preparation of liposomes to enhance the penetration into the brain of AG, by modifying the surface of the liposomes by adding Tween 80 (LPs-AG) alone or in combination with Didecyldimethylammonium bromide (DDAB) (CLPs-AG). (2) Methods: LPs-AG and CLPs-AG were physically and chemically characterized. The ability of liposomes to increase the permeability of AG was evaluated by artificial membranes (PAMPA) and hCMEC/D3 cells. (3) Results: Based on obtained results in terms of size, homogeneity, ζ-potential and EE%. both liposomes are suitable for parenteral administration. The systems showed excellent stability during a month of storage as suspensions or freeze-dried products. Glucose resulted the best cryoprotectant agent. PAMPA and hCMEC/D3 transport studies revealed that LPs-AG and CLPs-AG increased the permeability of AG, about an order of magnitude, compared to free AG without alterations in cell viability. The caveolae-mediated endocytosis resulted the main mechanism of up-take for both formulations. The presence of positive charge increased the cellular internalization of nanoparticles. (4) Conclusions: This study shows that developed liposomes might be ideal candidates for brain delivery of AG.