Concentrations Of Aluminium Chloride Research Articles

Synthesis of high-performance polymethylsilsesquioxane xerogels by improving acid catalytic conditions in aluminum chloride aqueous solution

Organic and inorganic acids are common catalysts to promote the hydrolysis of methyltrialkoxysilanes, but they are challenging to modulate the inherent CH3SiO1.5 backbone of polymethylsilsesquioxane (PMSQ) xerogels. Here, an aluminum chloride aqueous solution is proposed for the first time as an acid catalyst to enhance the hydrolysis of methyltriethoxysilane (MTES). This approach allows the PMSQ xerogels to have a more flexible [-Al-O-]m-[SiO]n backbone structure. The optimal concentration of aluminum chloride and surfactant cetyltrimethylammonium bromide in the MTES sol was 1.069 mmol/L and 0.885 mmol/L, respectively, endowing the as-synthesized PMSQ xerogel with a high compression strength of 0.450 MPa and maximum compression strain of 76.1%. Notably, the tiny incorporation of alumina phase (0.4 mol%) in the Si-O-Si backbone made the PMSQ xerogels hydrophobic up to 400 °C for 1 h in the air. The PMSQ xerogels possessed superior thermal insulation properties (32.0–38.0 mW/(m·K)) and could be processed into desired large-sized shapes.

Genomic insights into Bacillus subtilis MBB3B9 mediated aluminium stress mitigation for enhanced rice growth

Aluminium (Al) toxicity in acid soil ecosystems is a major impediment to crop production as it drastically affects plant root growth, thereby acquisition of nutrients from the soil. Plant growth-promoting bacteria offers an interesting avenue for promoting plant growth under an Al-phytotoxic environment. Here, we report the plant growth-promoting activities of an acid-tolerant isolate of Bacillus subtilis that could ameliorate acid-induced Al-stress in rice (Oryza sativa L.). The whole genome sequence data identified the major genes and genetic pathways in B. subtilis MBB3B9, which contribute to the plant growth promotion in acidic pH. Genetic pathways for organic acid production, denitrification, urea metabolism, indole-3-acetic acid (IAA) production, and cytokinin biosynthesis were identified as major genetic machinery for plant growth promotion and mitigation of Al-stress in plants. The in-vitro analyses revealed the production of siderophores and organic acid production as primary mechanisms for mitigation of Al-toxicity. Other plant growth-promoting properties such as phosphate solubilization, zinc solubilization, and IAA production were also detected in significant levels. Pot experiments involving rice under acidic pH and elevated concentrations of aluminium chloride (AlCl3) suggested that soil treatment with bacterial isolate MBB3B9 could enhance plant growth and productivity compared to untreated plants. A significant increase in plant growth and productivity was recorded in terms of plant height, chlorophyll content, tiller number, panicle number, grain yield, root growth, and root biomass production.

Effect of Gingival Hemostatic Agents on the Surface Detail Reproduction and Dimension Stability of Three Elastomeric Impression Materials.

This study aimed to evaluate the effects of aluminum chloride based hemostatic agents on the surface detail reproduction and dimension stability. Three impression materials were investigated after contaminated with three commercial astringents with different concentration of aluminum chloride. The specimens from three impression materials were fabricated with a stainless-steel mold that followed the American Dental Association specification no.19. The mold was preliminarily contaminated with three hemostatic agents racestyptine, Dryz, and Expasyl™-and 80 specimens from each impression material-polyvinylsiloxane (PVS), polyether, and polyvinylsiloxane ether (PVSE), were fabricated and subjected to each astringent. The surface detail reproduction was examined using a stereomicroscope at 4x magnification, and the dimensional stability was analyzed at 24 hr with a measuring microscope. The surface detail data were statistically analyzed with Fisher's test at a significance level of 0.05. The dimensional stability data were analyzed using two-way ANOVA and Tukey's test at a significance level of 0.05. Aluminum chloride hemostatic agents can affect the surface detail reproduction of impression materials differently (p < 0.05). Thus, the first null hypothesis was rejected. PVS showed the highest percentage of satisfactory surface detail regardless of the hemostatic agent used in this study. PVSE showed a reduced percentage of satisfactory surface detail when the concentration of aluminum chloride was high. The three hemostatic agents affected the dimensional stability of each material differently (p < 0.05). Therefore, the second null hypothesis was also rejected.

Effects of Aluminum Chloride Impregnating Pretreatment on Physical and Mechanical Properties of Heat-Treated Poplar Wood under Mild Temperature

The acid formed by thermal degradation of wood can autocatalyze its heat treatment. In this study, exogenous acid was introduced by impregnation into poplar wood to investigate its effect on the physical and mechanical properties of wood. Equilibrium moisture content (EMC), dimensional stability, mass loss (ML), color, modulus of rupture (MOR), and modulus of elasticity (MOE) of heat-treated poplar were tested under mild temperature (130–160 °C) for different pretreatment concentrations of aluminum chloride (AlCl3). The results show that the EMC of the heat-treated wood diminishes by 2.7%–47.8%, and dimensional stability improves significantly after AlCl3 impregnation pretreatment. The samples impregnated with 0.5 mol/L AlCl3 and heat treated at 160 °C achieved the best dimensional stability, which was better than for the samples only heat-treated at 220 °C. The color changed significantly as the impregnating concentration increased, achieving a color effect similar to that of wood only heat-treated at a high temperature such as 200 or 220 °C. Heat-treatment temperature under the same ML of wood samples was reduced, which also mitigated the reduction of MOR. MOE of heat-treated wood with 0.5 mol/L impregnation pretreatment was 11.4%–30.7% more than for samples heat-treated at 160–220 °C. After exogenous acidic AlCl3 impregnation pretreatment, the cell wall structure of the heat-treated wood was found to remain relatively intact. Thus, AlCl3 impregnating pretreatment exerted a substantial and beneficial effect on the physical and mechanical properties of poplar and achieved good performance of poplar wood treated at a mild temperature.

Development and validation of analytical method by spectrophotometry UV-Vis for quantification of flavonoids in leaves of Senna occidentalis Link

Senna occidentalis Link (Fabaceae), known as “fedegoso”, is used in folk medicine due to its anti-inflammatory, antioxidant, muscle relaxant and inhibiting lipid peroxidation imputed to flavonoids contained in its composition. The species is also a constituent of processed products are commercialized in various parts of the world including Brazil, although there are few reports in the literature about the development of an analytical method for quantification of flavonoids in it. The main purpose of this research was the evaluation of an analytical methodology to determinate the content of total flavonoids in leaves of S. occidentalis, for quality control. The parameters evaluated were: drug: solvent ratio, concentration of aluminum chloride and reaction time. The quantification of total flavonoids was obtained after reaction with aluminum chloride by UV/Vis spectrophotometry. The results revealed a maximum absorption peak (λ = 392 nm) was the amount of 0.5 g of a plant raw in 100 mL of solvent and there were no significant influences between the concentrations of aluminum chloride or hydroalcoholic solutions analyzed. The evaluation of reaction time allowed to characterize the kinetics as slow, stabilizing from 60 min, choosing this as reading time. The method was specific, linear, precise, accurate and robust, according to the specifications set in RDC n. 166/2017. Finally, the results of the study showed that the measured methodology is simple and accurate and can be applied for quality assessment of the species S. occidentalis.

ФАРМАЦЕВТИЧЕСКАЯ РАЗРАБОТКА ПЕНЫ МЕДИЦИНСКОЙ КРОВООСТАНАВЛИВАЮЩЕГО ДЕЙСТВИЯ

This article is devoted to the pharmaceutical development of medical hemostatic foam. The method of parenchymal bleeding modeling in the liver of rats was used to assess hemostatic activity of various concentrations of aluminum and iron chloride. Also assessment of sedimentation rate and density of various samples of medical foam was made when polysorbates-20 and -80 were added to it in concentration range of 0-0,75%. It was found that from the point of view of its safety and efficacy concentration of aluminum chloride 10%, without iron salt is most acceptable. After evaluating density and sedimentation rate polysorbate-20 in concentrations of 0,25-0,75% was chosen as an additive.

Tolerance of Douglas Fir Somatic Plantlets to Aluminum Stress: Biological, Cytological, and Mineral Studies.

Aluminum (Al) is well known as a potent inhibitor of plant growth and development. It is notably present in soils in the soluble and bioavailable form Al3+ when the soil pH drops below 5. This situation is frequent, especially in softwood forests when litter decomposition is slow. In the present work, we studied the effects of Al3+ on the growth and development of Douglas fir plantlets. Somatic plantlets, regenerated via somatic embryogenesis, were grown in vitro on media supplemented with different concentrations of aluminum chloride (AlCl3): 0 µM, 200 µM, 500 µM. and 1 mM. We show that a concentration of 500 µM AlCl3 in medium significantly reduced root elongation (−21.8%), as well as stem growth (−14.6%). Also, a 25% reduction in dry mass of the plantlets was observed in presence of a concentration of 200 µM of AlCl3. Histological analysis of root tissues revealed significant damage, especially in conducting vessels. In addition, mineral cation content of plantlets was disturbed under Al exposure. More particularly, the Mg and K contents of needles and the Ca content of stems and needles were significantly reduced in presence of a concentration of 500 µM AlCl3 in the culture medium (−35.6%, −33.5%, −24%, and −34% respectively). However, all these damages appeared at relatively high Al concentrations when compared with other herbaceous species. This study shed light on the ability of Douglas fir in vitro plantlets to cope with the acid-driven toxicity of Al.

Isolation of Aluminum-Tolerant and -Absorbing Yeast.

Aluminum ions are toxic to bacteria and are thus frequently used for preservation in the food industry. However, at higher concentrations, aluminum is toxic to animals. The extraction of aluminum from aluminum-contaminated foods would therefore be beneficial. Based on the discovery of yeast strains that can tolerate and absorb toxic metals, we aimed to identify strains that could tolerate and absorb aluminum. In this study, yeast were isolated from soil samples and cultured in medium containing the toxic concentration of aluminum chloride (5 mM) for Saccharomyces cerevisiae BY4741. Among aluminum-tolerant strains, two strains, Alt-OF2 and Alt-OF5, were identified as aluminum-absorbing. D1/D2 sequencing revealed that both strains belonged to the genus Schizoblastosporion (syn. Nadsonia).

Effect of aluminum on the growth of the in vitro culture tissues of the date palm (Phoenix dactylifera L.) cv. Um-Aldehin

Abstract This study was carried out to evaluate the effect of different concentrations of aluminum: (25, 50 and 100 mg l−1 of aluminum chloride AlCl3. 6H2O) on the enhancement of shoot multiplication, phytochemicals, as well as, antioxidant enzyme activity of in vitro cultures of the date palm cv. Um-Aldehin. The addition of aluminum in a concentration of 50 mg l−1 to the medium exhibited most effects on shoots regeneration and this substance also increased the number of shoots per a jar (73.34% and 8.2 shoots/jar, respectively), compared to the other concentrations, including the control treatment. A biochemical analysis of date palm shoots revealed that the high concentration of aluminum chloride (100 mg l−1) led to a significant accumulation of the total proline content, and to a high activity of ascorbate peroxidase, as well as a significant reduction in nitrogen, phosphorus, calcium, magnesium and chlorophyll, compared to the concentration of 50 mg l−1 for which there were recorded the highest contents of the mentioned elements, together with the highest content of chlorophyll in leaves.

Aluminium chloride-induced toxicity in zebrafish larvae.

Embryos at shield stage and larvae at protruding mouth stage were exposed to different concentrations of aluminium chloride (AlCl3 ) for 72h with the purpose to analyse their phenotype and lethality. After 24, 48 and 72h of treatment, higher toxicity of the metal was observed on larvae with minimal lethal concentration of 0.25, 0.20 and 0.08mm, respectively, while for embryos the corresponding values were 40, 25 and 16mm. We observed pericardial oedema and alteration of heart rate in 50% of larvae after 48h of exposure to 100μm. In larvae exposed to the same concentration, there was also a neurological injury at the level of glial cells, with the number of glial fibrillary acidic protein-positive cells being significantly reduced. This study confirms the toxic nature of this metal and shows that aluminium could also interestingly represent a cardiotoxin in addition to its neurotoxic ability.

METHOD FOR RAPID ASSESSMENT OF ALUMINUM TOLERANCE OF PEA (Pisum sativum L.)

Abstract Crops vary considerably in their resistance to acidic soils, and many legumes, including pea (Pisum sativum L.), considered to be sensitive or moderately sensitive crops compared to cereals. The main factor determining the phytotoxicity of acidic soils is the increased concentration of mo-bile aluminum ions in the soil solution. Accumulation of aluminum in root tissues interferes with cell division, initiation of growth of lateral roots and uptake of minerals and water by plants. Under labo-ratory conditions the resistance of plants to aluminum is estimated by the degree of damage to the roots by aluminum using dyes (hematoxylin, eriochrome cyanine R) and the ability of roots to re-store growth after toxic effect of this metal. This work dedicated to the development of rapid assess-ment of aluminum tolerance especially for peas, which is as follows: the seeds were germinated in the growth chamber in the nutrient solution for 3 days (7000 lx illumination, temperature of 19 С at night and 21 С during the day, photoperiod 16 h), treated with a toxic concentration of aluminum chloride (3 mg Al/l) for 24 hours, incubated in fresh nutrient solution without aluminum for 2 days and stained with 0.1 % eriochrome cyanine R for 10 min. Zone of root tissue damage by aluminum painted in the color purple. Plant resistance to aluminum was determined by the length of the root re-growth area after exposure to the toxicant. Using 19 varieties of pea from the N.I. Vavilov Re-search Institute of Plant Industry collection (VIR collection) it was shown that pea has high variabil-ity in tolerance to aluminum. Varieties with a minimum (1.01.5 mm) length of the root re-growth (k-2759, k-3654 and k-3283) were characterized by intense purple color of the root, but varieties with a maximum (14.014.5 mm) length of the root re-growth (k-4376, k-9504 and k-7307) had a faint but detectable staining. The proposed method makes it possible to identify genotypes contrast-ing in aluminum tolerance, is highly reproducible and can be used for screening and study of intra-specific variability in this trait of pea plants at very early developing stage. Keywords: aluminum, hematoxylin, peas, soil acidification, acid tolerance, eriochrome cyanine R.

Efficacy and safety of aluminum chloride in controlling external hemorrhage: an animal model study.

Background:Despite all the progress in surgical science, bleeding caused by traffic accidents is still one of the challenges surgeons face in saving patients’ lives. Therefore, introducing an effective method to control external bleeding is an important research priority.Objectives:This study aimed to compare the hemostatic effect of aluminum chloride versus simple suturing in controlling external bleeding.Materials and Methods:This experimental study was conducted in Kashan, Iran. In this study, 60 male Wistar rats were randomly allocated into six groups. An incision, two centimeters (cm) long and half a cm deep, was made on each rat’s shaved back skin and the hemostatic time was measured once using aluminum chloride with different concentrations (5%, 10%, 15%, 25%, and 50%) and then using the control method (controlling hemorrhage by simple suturing). The skin tissue was assessed for pathological changes.Results:The hemostatic time of aluminum chloride 50%, 25%, 15%, 10% and 5% were 8.20 ± 0.919, 14.10 ± 1.37, 21.20 ± 1.31, 30.80 ± 1.68 and 42.00 ± 4.19 seconds, respectively. Also, the mean hemostasis time in the control group (suture) was 84.00 ± 4.05 seconds. The hemostatic times of different concentrations of aluminum chloride were significantly less than that of the control group. There was a statistically significant difference between every two hemostatic time. The pathologic examination showed the highest frequency of low-grade inflammation based on the defined pathological grading.Conclusions:The aluminum chloride method needs less time to control external hemorrhage compared to the control method (controlling external hemorrhage by simple suturing). Aluminum chloride is an effective agent in controlling external hemorrhage in an animal model.

Responses of the earthworm Eisenia andrei exposed to sublethal aluminium levels in an artificial soil substrate

Industrial discharges of Al are increasingly common. In this study, the activities of three antioxidases, malondialdehyde (MDA) content and changes in coelomocytes were investigated in earthworms (Eisenia andrei) exposed to different concentrations of aluminium chloride (range 0–200 mg Al kg−1 dry soil) in artificial soils for 32 days. Within the first 16 days of Al exposure, catalase activity was elevated in most treatments, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were inhibited in all treatments. After 16 days exposure, SOD and GSH-Px activities returned to normal at lower Al concentrations, but were still inhibited at higher concentrations, hence the inhibition of SOD and GSH-Px showed some exposure-level dependence during the late exposure phase. MDA content was significantly elevated from 16 days after initial exposure. Neutral Red retention time of coelomocytes decreased at the highest exposure concentrations after 32 days, and an increased proportion of cells showing membrane damage was also observed at this time using flow cytometry. We conclude that excessive Al in soils can cause oxidative stress and cell damage in earthworms. Hence, Al accumulation in the environment may present an ecological hazard through suppression of the important functions of earthworms in soil ecosystems.

Potential use of a megamolecular polysaccharide sacran as a hydrogel-based sustained release system.

A megamolecular polysaccharide sacran was newly extracted from cyanobacterium Aphanothece sacrum. Sacran has many preferable properties for transdermal application, e.g. a safe biomaterial, a high moisturizing effect, a formation of film and hydrogel. Additionally, it was recently discovered that sacran has an anti-inflammatory effect for atopic dermatitis model mice. In this study, in order to evaluate the feasibility of sacran-hydrogel as a novel sustained release system, we prepared a sacran-hydrogel containing 4-biphenyl acetic acid (BPAA, an acidic drug), prednisolone (PD, a neutral drug) or chlorpheniramine maleate (CPM, a basic drug), and performed the in vitro release studies. The sacran-hydrogel containing BPAA, PD or CPM provided a sustained release profile in accordance with a quasi-Fickian diffusion model. Furthermore, the release rate of drugs from sacran-hydrogels can be controlled by adjusting the concentration of aluminum chloride as a cross linker. These results suggest the potential use of sacran-hydrogel as a sustained release system for drugs.

The Study of an Inorganic Gel for Profile Modification in High-Temperature and Low-Permeability Sandstone Reservoirs

Chemical water control technique has been successfully used to improve oil recovery of mature waterflooding reservoirs. However, for high-temperature and low-permeability sandstone reservoirs, not many options are available. An inorganic gel composed of aluminum chloride hexahydrate as gelling agent and urea as an activator was developed. Based on the proper gelation time and degree of syneresis, the optimum mass ratio of aluminum chloride and urea was 1:0.625. According to the gel strength and economical cost, the reasonable concentration of aluminum chloride should range from 3.0% to 6.0%. Gel compatibility with various formation brines showed that the gel could tolerate sodium chloride concentrations up to 80 g·L −1 and calcium chloride concentrations up to 40 g·L −1. Long-term thermal stability and sandpack flow results showed that after aging for 60 days at 110°C, the gel showed approximately 82% permeability reduction when about 16% syneresis was observed in bulk samples.

Kinetics of leaching fluoride from mixed rare earth concentrate with hydrochloric acid and aluminum chloride

A mixed rare earth concentrate from Baotou was adopted to investigate the complex leaching kinetics of fluoride with a HCl–AlCl3 solution. In addition, we explored the effects of HCl concentration, AlCl3 concentration, temperature, reaction time, liquid–solid ratio and stirring speed on leaching kinetics of fluoride. The results showed that an extraction of about 99% was achieved under the leaching conditions: 4M HCl, 1.5M AlCl3, 85°C, 20ml/g liquid–solid ratio, 300rpm stirring speed and 90min. SEM and XRD analysis indicated that no new reaction solid product was formed on the surface of leaching residue particle. The apparent activation energy was 40.4kJ/mol and the reaction orders with respect to hydrochloric acid concentrations, aluminum chloride concentrations and liquid–solid ratio were determined to be 1.66, 1.54 and 1.48, respectively. A semi-empirical rate equation was obtained to describe the process. The kinetic data fitted a new variant of the shrinking core model, in which both the interfacial transfer and diffusion through the product layer affected the reaction rate.

Emergência de plântulas e crescimento inicial do pinhão manso exposto a alumínio

Jatropha curcas L. is a potential oilseed crop for biodiesel production with scarce information about the aluminum effect on the emergence and early growth. This work aimed to evaluate the seed germination and early plant growth of Jatropha plants subjected to aluminum in the irrigation water. Seedlings emergence was evaluated in the presence of five concentrations of aluminum chloride hexahydrated (AlCl3.6H2O) in irrigation water: 0, 5, 10, 15 and 20 mmol L-1. Data was taken on percentage of seedling emergence, speed index, average time for emergence, height, root lengths and shoot and root dry weights. In another experiment, the plants were raised in absence of aluminum up to 25 days after sowing (DAS) and then subjected to the same aluminum concentration in the first experiment. Data was taken on survival rate, chlorophyll content, leaf area, height, root length and shoot and root dry weights. The emergence and speed index of Jatropha seedlings was reduced by the increased aluminum concentrations in irrigation water, with a decrease in seedling emergence of 98% at concentration of 20 mmol L-1. The plants exposed to aluminum at 25 DAS had leaf edge rolling, leaf chlorosis and necrosis, and reduced survival rate, leaf area, chlorophyll content, and shoot and root lengths and dry weights. Therefore, the aluminum in solution affect the seedlings emergence and early growtht of Jatropha plants, observing its toxic effect from the concentration of 5 mmol L-1.

Effects of Aluminum Chloride Concentrations on Structural and Optical Properties of Al-doped ZnO Thin Films Prepared by the Sol-Gel Method

Al-doped ZnO (AZO) thin films were grown on quartz substrates by the sol-gel method. The effects of the Al mole fraction on the structural and optical properties of the AZO thin films were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-VIS spectroscopy. The particle size of the AZO thin films decreased with an increase in Al concentrations. The optical parameters, the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity, were studied in order to investigate the effects of Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at an infinite wavelength of the AZO thin films were affected by the Al incorporation. The optical conductivity of the AZO thin films also increased with increasing photon energy.

Metals and Disease

Metals and Disease

Hyperhidrosis plantaris - a randomized, half-side trial for efficacy and safety of an antiperspirant containing different concentrations of aluminium chloride

Primary focal hyperhidrosis plantaris can cause impairment in social, physical, leisure and occupational activities. Topical treatment with aluminium chloride is the first-line treatment. The aim of this trial was to evaluate efficacy and safety of two different concentrations of aluminium chloride hexa-hydrate (12.5%, 30%) for 6 weeks. 20 volunteers with hyperhidrosis plantaris were included. Efficacy was evaluated using a clinical rating scale of the hyperhidrosis level and qualitative assessments including Minor's (iodine-starch) test and a standardized sniff test. Furthermore a patient questionnaire and measurements of skin surface pH were done to evaluate the subjective assessments and side effects. The hyperhidrosis level significantly decreased in both concentrations. There were no differences in tolerability regarding the skin surface pH and the patient questionnaires. In addition the hidrotic areas decreased after application of both products and the sniff test improved. Topical application of an antiperspirant containing aluminium chloride reduced sweat production in plantar hyperhidrosis significantly. As both 12.5% and 30% were efficacious and safe, we would recommend 12.5% for outpatient treatment.