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1.
Biol Trace Elem Res ; 200(1): 183-196, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33715074

RESUMO

Osteoporosis is a systemic metabolic disease defined by a decreased bone mineral density, microarchitectural deterioration, and an increased incidence of fragility fractures that may lead to morbidity and mortality. Boron may stimulate new bone formation and regeneration, when combined with nano-hydroxyapatite. We questioned whether injecting boron-containing nano-hydroxyapatite composites with hyaluronan increased the bone mineral density and new bone formation in osteoporotic rabbit femurs. The regenerative effects of injectable boron-containing nano-hydroxyapatite composites from 6 to 12 weeks, which may prevent osteoporotic femoral fractures, were assessed. Boron-containing (10 µg/ml) nano-hydroxyapatite composites were injected into the intramedullary femoral cavity with hyaluronan. These significantly increased the histomorphometric new bone surface to the total bone surface ratio at 6 and 9 weeks. The micro-tomographic bone volume to the total volume ratio and bone mineral density in osteoporotic rabbit femurs increased when compared to the hyaluronan (p = 0.004, p = 0.004, p = 0.004, p = 0.01, respectively) and the sham-control (p = 0.01, p = 0.004, p = 0.01, p = 0.037, respectively) groups. The boron-containing group had a higher bone mineralization and new bone formation compared to the nano-hydroxyapatite group, although the difference was not statistically significant. These findings reveal that intramedullary injection of boron-containing nano-hydroxyapatite with hyaluronan increases new bone formation and mineralization in ovariectomized rabbit femurs. Boron-containing nano-hydroxyapatite composites are promising tissue engineering biomaterials that may have regenerative potential in preventing primary and/or secondary femoral fractures in osteoporosis patients.


Assuntos
Durapatita , Osteoporose , Animais , Regeneração Óssea , Boro/farmacologia , Fêmur , Humanos , Osteoporose/tratamento farmacológico , Coelhos
2.
Chemosphere ; 286(Pt 2): 131680, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34365166

RESUMO

In this study, a BDD electrolytic oxidation-ceramic membrane ultrafiltration (EO-CM) system for the removals of antibiotics, organic matters and ammonia in wastewater was evaluated. Sulfamethazine (SMZ) was degraded following a pseudo first-order kinetics. The removal rate of SMZ improved with the increase of electro-oxidation time (0-60 min) and current density (5-30 mA/cm2). During the BDD electro-oxidation process, H2O2 and hydroxyl radicals (•OH) were generated which were detected by N, N-diethyl-p-phenylenediamine (DPD) method and electron paramagnetic resonance spectroscopy (EPR), respectively. Chemical oxygen demand (COD) was able to be removed by EO and CM processes, in which proteins and humic acids were regarded as the main removed components measured using excitation-emission matrix (EEM) technique. Moreover, BDD electro-oxidation pretreatment could make the CM process maintain a high water flux and significantly control the membrane fouling and relieve transmembrane pollution. In addition, the removal of ammonia was enhanced with the increase of chloride ions (Cl-) in wastewater during EO process due to the generation of active chlorine (i.e., ClO-, HClO, or Cl2) from the oxidation of Cl-. Chloramine and nitrogen were produced in the oxidation of ammonia by active chlorine. Overall, the results of this study suggest that BDD EO-CM system is a promising process for removing antibiotics, organic matters and ammonia.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Amônia , Antibacterianos , Boro , Cerâmica , Diamante , Eletrodos , Peróxido de Hidrogênio , Oxirredução , Ultrafiltração , Poluentes Químicos da Água/análise
3.
Food Chem ; 370: 131033, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509146

RESUMO

Dicofol is an organochlorine pesticide, which is widely used in fruits, tea and other crops, and is moderately toxic to humans. Therefore, the monitoring of organochlorine pesticide-dicofol is critical for food safety. In this work, a fluorometric chemosensor based on mercaptoethanol and boron dipyrromethene (BODIPY) was first constructed to detect the dicofol. The chemosensor displayed turn-off fluorescence behavior upon dicofol with a detection limit of 200 ppb. The nucleophilicity of the glutathione and other biological thiols was studied to evaluate the reactivity of thiols with dicofol. In practical applications, an obvious color difference was observed on a paper based microfluidic device modified by phenyltriethoxysilane (PTES). We designed an integrated device for pretreatment and paper-based detection, and successfully used for the detection of dicofol in tea. The applicability was demonstrated by detection of dicofol in real tea samples with good recovery ranging from 86% to 109%. The apparatus was convenient and could be used for on-site evaluation of dicofol.


Assuntos
Dicofol , Praguicidas , Boro , Humanos , Porfobilinogênio/análogos & derivados
4.
Biol Trace Elem Res ; 200(1): 134-146, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33634364

RESUMO

Boron has an important potential for facilitating biological activity and for use in pharmaceutical drug design. Boron glycine monoester (BGM) and boron glycine diester (BGD) compounds containing boron atoms were synthesized and investigated their cytotoxic, oxidative stress, and antimicrobial activities on the HepG2 cancer cell line. The cytotoxic activity of newly synthesized boron compounds on hepatocellular carcinoma was determined by the MTT method for 48 h. Antioxidant (CAT, GSH), lipid peroxidation (MDA), and enzyme activity (ACP, ALP) analyses were determined by spectrophotometric methods in HepG2 cells. Antimicrobial activity was determined by the disk diffusion method. After 48 h of BGM and BGD application to HepG2 cells, we found the IC50 values as 9.9 mM and 24 mM, respectively. While CAT and ACP enzyme activities decreased in all groups compared to the control, ALP enzyme activity did not change in the BGM group but increased in the BGD group. It was determined that the GSH level did not change in all groups, while the MDA level increased. It has been stated that these IC50 doses of BGM and BGD have antibacterial effects on Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922. Newly synthesized boron compounds, particularly BGM, with their cytotoxic, oxidative stress, and antimicrobial effects, could provide a new therapeutic approach for the treatment of hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Antioxidantes , Boro/farmacologia , Compostos de Boro/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Glicina , Humanos , Neoplasias Hepáticas/tratamento farmacológico
5.
Talanta ; 237: 122975, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736697

RESUMO

The contamination of water sources by anthropogenic activities is a topic of growing interest in the scientific community. Therefore, robust analytical techniques for the determination and quantification of multiple substances are needed, which often require complex and time-consuming procedures. In this context, we describe a univariate calibration method to determine emerging multi-class contaminants in different water sources. The instrumental setup is composed of a lab-made glass electrochemical cell with three electrodes: Pt counter, Ag/AgCl reference, and BDD working electrodes. With this system, we were able to simultaneously quantify tert-butylhydroquinone, acetaminophen, estrone, sulfamethoxazole, enrofloxacin, caffeine, and ibuprofen by differential pulse voltammetry. Only two calibration solutions are required for the Single-shot Dilution Differential Pulse Voltammetric Calibration (SSD-DP-VC) method described here, which can significantly improve sample throughput. Two robust univariate calibration strategies were also applied and compared with SSD-DP-VC. The new method is simple, fast, and comparable with traditional calibration methods, showing similar precision and accuracy for all determinations evaluated.


Assuntos
Boro , Diamante , Acetaminofen , Calibragem , Eletrodos
6.
Anal Chim Acta ; 1188: 339166, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34794577

RESUMO

In this paper, a vibrating boron-doped diamond (BDD) electrode electroanalytical device and respective method for the analysis of ultralow concentrations of Cd(II) in water were studied. The enhanced mass transfer on the electrode surface was studied using Ru(NH3)6Cl3. Vibration with 133 Hz frequency enhanced the Ru(III) to Ru(II) reduction by 92.6% compared to a static electrode. The peak current of the anodic stripping voltammetry (ASV) method employed was increased by a factor of 5.3 and 4.7 for 10 and 30 µg L-1 Cd(II) concentrations, respectively, when a frequency of 200 Hz was used. A calibration plot with two linear regions was resolved between 0.01 and 1 µg L-1 and 1-30 µg L-1 with the LOD and LOQ of 0.04 µg L-1 and 0.12 µg L-1, respectively. The applicability of the device and the respective method in the analysis of real environmental samples was successfully verified by analysis of river samples and comparing the results with the ICP analysis presenting high reproducibility and trueness. According to the results of this research, the vibrating BDD electrode with the ASV method has excellent analytical performance without surface modification or regular replacement or polishing of the electrode surface. Combining the exceptional electrochemical and chemical properties of BDD with enhanced mass transfer and signal strength of vibrating electrodes makes the system especially suitable for on-site and online analysis of heavy metals.


Assuntos
Boro , Metais Pesados , Cádmio , Eletrodos , Reprodutibilidade dos Testes
7.
Anal Chim Acta ; 1184: 339026, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34625266

RESUMO

In this work, boron carbon oxynitride quantum dots (BCNO QDs) were prepared by a one-step hydrothermal process of ethanolamine and boric acid. BCNO QDs exhibited blue fluorescence with the optimal excitation/emission fluorescence peak at 335 and 420 nm, respectively. As an efficient fluorescence quencher, manganese dioxide (MnO2) nanosheets can effectively quench the fluorescence of BCNO QDs via the inner filter effect (IFE). Acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylcholine (ATCh) to produce thiocholine (TCh). TCh can reductively degrade MnO2 nanosheets to generate Mn2+, thereby recovering the fluorescence of BCNO QDs. Organophosphorus pesticides (OPs) can inhibit the activity of AChE enzymes, thereby preventing the production of TCh and the decomposition of MnO2 nanosheets, resulting in the fluorescence "turn-off". Therefore, the concentration of OPs can be detected by measuring the fluorescence intensity change of AChE-ATCh-MnO2-BCNO-QDs system. Under optimal experimental conditions, the dynamic detection range of paraoxon is 0.1-250 ng mL-1, and the detection limit is 0.03 ng mL-1. Meanwhile, the reaction system also showed concentration-dependent visual color changes from colorless to brownish. Furthermore, we prepared a portable BCNO QDs test paper. By using a smartphone to identify the RGB values of the reaction solution and the corresponding test paper, we carried out the digital image chromaticity analysis, which can shorten the detection time and reduce the detection cost, and provide an effective solution for the rapid detection of OPs on site.


Assuntos
Técnicas Biossensoriais , Praguicidas , Pontos Quânticos , Acetilcolinesterase , Boro , Carbono , Colorimetria , Compostos de Manganês , Compostos Organofosforados , Óxidos , Praguicidas/análise , Smartphone
8.
Sensors (Basel) ; 21(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34640950

RESUMO

A sample of nitrogen and boron co-doped graphene (NB-Gr) was obtained by the hydrothermal method using urea and boric acid as doping sources. According to XRD analysis, the NB-Gr sample was formed by five-layer graphene. In addition, the XPS analysis confirmed the nitrogen and boron co-doping of the graphene sample. After synthesis, the investigation of the electro-catalytic properties of the bare (GC) and graphene-modified electrode (NB-Gr/GC) towards cymoxanil detection (CYM) was performed. Significant differences between the two electrodes were noticed. In the first case (GC) the peak current modulus was small (1.12 × 10-5 A) and appeared in the region of negative potentials (-0.9 V). In contrast, when NB-Gr was present on top of the GC electrode it promoted the transfer of electrons, leading to a large peak current increase (1.65 × 10-5 A) and a positive shift of the peak potential (-0.75 V). The NB-Gr/GC electrode was also tested for its ability to detect cymoxanil from a commercial fungicide (CURZATE MANOX) by the standard addition method, giving a recovery of 99%.


Assuntos
Grafite , Acetamidas , Boro , Nitrogênio
9.
Ecotoxicol Environ Saf ; 226: 112828, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34600289

RESUMO

Vanadium (V) is the fifth most abundant transition metal, elevated levels of V are hazardous to plants. Boron (B) is an essential micronutrient for plants and can mitigate heavy metal toxicity. However, the mechanism used by B to promote tolerance to vanadium is unknown. In this study, a combination of physiological and gene expression analysis was used to explain mechanism of B (75 µM) induced V (40 mg L-1) stress tolerance in watermelon. V stress severely reduced root and shoot growth and increased the accumulation of ROS. B application improved tolerance to V by enhancing the expression of B transporter genes (ClaNIP5;1-1, ClaNIP5;1-2, ClaBOR4) that facilitated B uptake and transport while restricting V transport in plant tissues. At cellular level, the higher V retention in leaves was achieved by cell wall chelation, whereas, the higher V exclusion in vacuole of root cell was driven by elevated vacuolar H+-ATPase, H+-PPase activities, and transcript level of ClaVHP1;1, ClaPDR12-1 and ClaPDR12-2 genes facilitated by B application. Moreover, B application reduced tissue ROS cascade by enhancing antioxidant enzymatic activity and expression of superoxide dismutase (ClaCSD1-1, ClaCSD1-2, ClaCSD3, ClaMSD1) and catalase (ClaCAT2-1, ClaCAT2-2) genes that enhanced the defense mechanism of the V treated plants, improved root and shoot growth and tolerance index of watermelon. In conclusion, we demonstrate that ameliorative effect of B in tolerance to V of watermelon was based on B homeostasis and improved antioxidant defense system. These findings might help to increase watermelon production in V polluted soils.


Assuntos
Antioxidantes , Citrullus , Boro/toxicidade , Citrullus/genética , Folhas de Planta , Raízes de Plantas , Vanádio/toxicidade
10.
Rom J Morphol Embryol ; 62(1): 219-226, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34609424

RESUMO

Periodontitis is a disease that affects a wide group of people, and there has been an increased interest in the research of finding useful materials that help reduce inflammation and the further loss of tissue. In this study, we have tested a boron-containing compound (BCC) Calcium Fructoborate (CaFB) and Boric Acid (BA) hydrogels on the gingival level on Wistar rats. First, we have induced the periodontal disease at the lower incisors, we have applied the hydrogels and after a week, we have euthanized the rats. Next, the oral soft tissue reaction was clinically and then histologically investigated. Our study has shown good clinical response of the oral tissue, and we have noticed lower levels of inflammation on the experimental groups treated with the BCCs hydrogels. Despite the generally good response of the biological structures to the presence of BA and CaFB on periodontal level, more scientifically proved information is needed to obtain the desired biological responses in all clinical situations.


Assuntos
Perda do Osso Alveolar , Animais , Boro , Hidrogéis , Modelos Teóricos , Ratos , Ratos Wistar
11.
Anal Chim Acta ; 1182: 338949, 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34602205

RESUMO

Novel porous boron-doped diamond (BDDporous)-based materials have attracted lots of research interest due to their enhanced detection ability and biocompatibility, favouring them for use in neuroscience. This study reports on morphological, spectral, and electrochemical characterisation of three BDDporous electrodes of different thickness given by a number of deposited layers (2, 3 and 5). These were prepared using microwave plasma-enhanced chemical vapour deposition on SiO2 nanofiber-based scaffolds. Further, the effect of number of layers and poly-l-lysine coating, commonly employed in neuron cultivation experiments, on sensing properties of the neurotransmitter dopamine in a pH 7.4 phosphate buffer media was investigated. The boron doping level of ∼2 × 1021 atoms cm-3 and increased content of non-diamond (sp2) carbon in electrodes with more layers was evaluated by Raman spectroscopy. Cyclic voltammetric experiments revealed reduced working potential windows (from 2.4 V to 2.2 V), higher double-layer capacitance values (from 405 µF cm-2 to 1060 µF cm-2), enhanced rates of electron transfer kinetics and larger effective surface areas (from 5.04 mm2 to 7.72 mm2), when the number of porous layers increases. For dopamine, a significant boost in analytical performance was recognized with increasing number of layers using square-wave voltammetry: the highest sensitivity of 574.1 µA µmol-1 L was achieved on a BDDporous electrode with five layers and dropped to 35.9 µA µmol-1 L when the number of layers decreased to two. Consequently, the lowest detection limit of 0.20 µmol L-1 was obtained on a BDDporous electrode with five layers. Moreover, on porous electrodes, enhanced selectivity for dopamine detection in the presence of ascorbic acid and uric acid was demonstrated. The application of poly-l-lysine coating on porous electrode surface resulted in a decrease in dopamine peak currents by 17% and 60% for modification times of 1 h and 15 h, respectively. Hence, both examined parameters, the number of deposited porous layers and the presence of poly-l-lysine coating, were proved to considerably affect the characteristics and performance of BDDporous electrodes.


Assuntos
Boro , Dopamina , Eletrodos , Porosidade , Dióxido de Silício
12.
In Vivo ; 35(6): 3125-3135, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34697143

RESUMO

BACKGROUND/AIM: Tumor cell destruction by boron neutron capture therapy (BNCT) is attributed to the nuclear reaction between 10B and thermal neutrons. The accumulation of 10B atoms in tumor cells without affecting adjacent healthy cells is crucial for effective BNCT. We previously reported that several types of liposomal boron delivery systems (BDS) delivered effective numbers of boron atoms to cancer tissues, and showed tumor-growth suppression after thermal neutron irradiation. In the present study, we examined the effects of BNCT after intra-arterial infusion of 10B-borono-dodecaborate (10BSH) by liposomal BDS in rabbit hepatic cancer models. MATERIALS AND METHODS: We prepared 10BSH-entrapped transferrin-conjugated polyethylene glycol liposomes constructed with distearoyl-boron lipid (TF-PEG-DSBL), and performed thermal neutron irradiation at the Kyoto University Institute for Integrated Radiation and Nuclear Science after intra-arterial infusion into rabbit VX-2 hepatic tumors. RESULTS: Concentrations of 10B in VX-2 tumors on delivery with TF-PEG-DSBL liposomes reached 25 ppm on day 3 after the injection. Tumor growth was suppressed by thermal neutron irradiation after intra-arterial injection of this 10BSH-containing liposomal BDS, without damage to normal cells. CONCLUSION: The present results demonstrate the applicability of 10B-containing TF-PEG-DSBL liposomes as a novel intra-arterial boron carrier in BNCT for cancer.


Assuntos
Terapia por Captura de Nêutron de Boro , Neoplasias Hepáticas , Animais , Boro , Lipossomos , Neoplasias Hepáticas/radioterapia , Coelhos
13.
Plant Physiol Biochem ; 167: 884-900, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34537578

RESUMO

It was aimed to examine the role of gibberellic acid (GA3) and NPK fertilizer in alleviating boron (B) toxicity in coriander (Coriandrum sativum L.) plants. Two weeks old C. sativum seedlings were subjected to different NPK fertilizers [low NPK (30 kg ha-1) and normal NPK (60 kg ha-1)], which were also supplied by GA3 (50 mg L-1), under varying levels of B i.e., 0, 200 and 400 mg kg-1 in the soil. Results revealed that B toxicity led to a substantial decreased in the plant growth and biomass, photosynthetic pigments, gas exchange characteristics, sugars and essential nutrients in the roots and shoots of C. sativum seedlings. However, B toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in C. sativum seedlings and was also manifested by hydrogen peroxide (H2O2) contents and electrolyte leakage (EL) to the membrane bounded organelles. Although, activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), non-enzymatic antioxidants like phenolic, flavonoid, ascorbic acid and anthocyanin contents and organic acids from the roots such as oxalic acid, malic acid, formic acid, citric acid, acetic acid and fumaric acid contents were increased with the increasing levels of B in the soil. The application if NPK and GA3 mitigated B toxicity by stimulated plant growth and biomass, photosynthetic efficiency, nutritional status and antioxidant machinery of the plant by decreasing MDA contents, H2O2 initiation and EL (%) in the roots and leaves of C. sativum seedlings. In addition, the application of NPK and GA3 further decreased the organic acids exudation contents in the roots C. sativum seedlings. Research findings, therefore, suggested that NPK and GA3 application can ameliorate B toxicity in C. sativum seedlings and resulted in improved plant growth and composition under B stress as depicted by balanced contents of organic acids.


Assuntos
Coriandrum , Poluentes do Solo , Antioxidantes , Boro , Giberelinas , Peróxido de Hidrogênio , Malondialdeído , Estresse Oxidativo , Plântula/química , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
14.
Chem Pharm Bull (Tokyo) ; 69(9): 819-831, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34470946

RESUMO

Novel innovative catalytic systems such as hydrogen-bond donors and thiourea hybrid catalysts have been developed for the asymmetric synthesis of biologically important pharmaceuticals and natural products. Benzothiadiazines possess a stronger hydrogen-bond donor ability compared to thioureas and exhibit remarkable catalytic performance for the activation of α,ß-unsaturated amides. Hybrid thioureas (bearing an arylboronic acid and an ammonium salt) efficiently promote the hetero-Michael addition to α,ß-unsaturated carboxylic acids and the O-alkylation of keto enols with 5-chlorofuran-2(5H)-one. These hybrid catalysts enable the first total synthesis of non-racemic avenaol, a noncanonical strigolactone, as well as the asymmetric synthesis of several pharmaceuticals. In addition, this study discovers unique chemical phenomena (i.e., the dual role of benzoic acid as a boron ligand and a proton shuttle, the chirality switch of products by solvent used, and the dynamic kinetic resolution of a racemic electrophile in an SN2-type reaction).


Assuntos
Compostos Bicíclicos com Pontes/síntese química , Ciclopropanos/síntese química , Tioureia/química , Ácido Benzoico/química , Boro/química , Compostos Bicíclicos com Pontes/química , Catálise , Ciclopropanos/química , Ligação de Hidrogênio , Cinética , Ligantes , Estrutura Molecular
15.
Analyst ; 146(18): 5756-5766, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34515696

RESUMO

People spend up to 90% of their time indoors, and yet our understanding of indoor air quality and the chemical processes driving it are poorly understood, despite levels of key pollutants typically being higher indoors compared to outdoors. Nitrous acid (HONO) is a species that drives these indoor chemical processes, with potentially detrimental health effects. In this work, a BODIPY-based probe was synthesized with the aim of developing the first selective passive sampler for atmospheric HONO. Our probe and its products are easily detected by UV-Vis spectroscopy with molar extinct coefficients of 37 863 and 33 787 M-1 cm-1, respectively, and a detection limit of 14.8 ng mL-1. When protonated, the probe fluoresces with a quantum yield of 33%, which is turned off upon reaction. The synthesized BODIPY probe was characterized using NMR and UV-Vis spectroscopy. Products were characterized by UV-Vis and ultra high-resolution mass spectrometry. The reaction kinetics of the probe with nitrite was studied using UV-Vis spectroscopy, which had a pseudo-first-order rate of k = 7.7 × 10-4 s-1. The rapid reaction makes this probe suitable for targeted ambient sampling of HONO. This was investigated through a proof-of-concept experiment with gaseous HONO produced by a custom high-purity calibration source delivering the sample to the BODIPY probe in an acidic aqueous solution in clean air and a real indoor air matrix. The probe showed quantitative uptake of HONO in both cases to form the same products observed from reaction with nitrite, with no indication of interferences from ambient NO or NO2. The chemical and physical characteristics of the probe therefore make it ideal for use in passive samplers for selective sampling of HONO from the atmosphere.


Assuntos
Poluição do Ar em Ambientes Fechados , Ácido Nitroso , Poluição do Ar em Ambientes Fechados/análise , Boro , Humanos , Nitritos , Ácido Nitroso/análise , Porfobilinogênio/análogos & derivados
16.
Ecotoxicol Environ Saf ; 225: 112776, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34537586

RESUMO

Both cadmium (Cd) contamination and boron (B) deficiency in farmland soils pose a threat to the yield and quality of crops in Southern China. The present study investigated the mechanisms by which B reduces Cd accumulation in rice (Oryza sativa) seedlings. Boron supplementation partially restored the decline in shoot and root biomass caused by Cd treatment (26% and 33%, respectively), with no significant difference between the B+Cd and control groups. We also found that B significantly reduced shoot and root Cd concentrations (by 64% and 25%, respectively) but increased Cd concentration (by 43%) and proportion (from 38% to 55%) in root cell walls. Transcriptome analysis and biochemical tests suggested that B supplementation enhanced lignin and pectin biosynthesis, pectin demethylation, and sulfur and glutathione metabolism. Moreover, B decreased the expression of some Cd-induced transporter-related genes (i.e., HMA2, Nramp1, and several ABC genes). These results indicate that B relieved Cd toxicity and reduced Cd accumulation in rice seedlings by restraining Cd uptake and translocation from root to shoot by improving Cd tolerance and chelation ability. These novel findings would benefit further investigations into how B influences Cd uptake, translocation, detoxification, and accumulation in crops.


Assuntos
Oryza , Plântula , Boro/toxicidade , Cádmio/toxicidade , Produtos Agrícolas , Oryza/genética
17.
Environ Sci Technol ; 55(18): 12724-12730, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34473928

RESUMO

The role of boron in terrestrial plant physiology is diverse and increasingly well understood, but its role in marine aquatic eukaryotes is less clear. Our research reveals a distinctive and large offset in boron isotopes from seawater, irrespective of seaweed type or season. We show that the offset is consistent with the incorporation of borate from seawater. Boron is a known micronutrient in plants but very few studies have used boron isotopes to investigate boron's role in plant physiology. Seaweed, as the most primitive multicellular plant, has an important role in investigating wider plant adaptations that use boron to meet functional needs. Furthermore, seaweed and other plants are a key base nutrient provider in food webs, supplying boron to consumers and playing a critical role in boron environmental cycling.


Assuntos
Boratos , Alga Marinha , Boro , Isótopos , Plantas
18.
Chemistry ; 27(62): 15277-15326, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34499378

RESUMO

This review discusses recent advances in the chemistry of saturated boronic acids, boronates, and trifluoroborates. Applications of the title compounds in the design of boron-containing drugs are surveyed, with special emphasis on α-amino boronic derivatives. A general overview of saturated boronic compounds as modern tools to construct C(sp3 )-C and C(sp3 )-heteroatom bonds is given, including recent developments in the Suzuki-Miyaura and Chan-Lam cross-couplings, single-electron-transfer processes including metallo- and organocatalytic photoredox reactions, and transformations of boron "ate" complexes. Finally, an attempt to summarize the current state of the art in the synthesis of saturated boronic acids, boronates, and trifluoroborates is made, with a brief mention of the "classical" methods (transmetallation of organolithium/magnesium reagents with boron species, anti-Markovnikov hydroboration of alkenes, and the modification of alkenyl boron compounds) and a special focus on recent methodologies (boronation of alkyl (pseudo)halides, derivatives of carboxylic acids, alcohols, and primary amines, boronative C-H activation, novel approaches to alkene hydroboration, and 1,2-metallate-type rearrangements).


Assuntos
Alcenos , Ácidos Borônicos , Boro , Compostos de Boro , Química Farmacêutica
19.
Plant Physiol Biochem ; 167: 529-540, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34425397

RESUMO

Proline biosynthesis and accumulation is a common response to unfavorable environment in many plants. This work aimed to elucidate the effects of boron (B)-deficiency and toxicity on proline metabolism and biosynthesis in Brassica napus in a hydroponic experiment. The results showed that B-deficiency and toxicity exert injurious impact on plant growth, accumulated high malondialdehyde (MDA) content, and caused the destruction of subcellular structure. Proline accumulated in both B deprivation and B toxicity plants, except B toxicity-treated root. In roots, B-deficiency increased ornithine content and pyrroline-5-carboxylate reductase (P5CR) activity, with the higher expression of BnaC03.P5CR, whilst decreased glutamate, glutamate-1-semialdehyde (GSA), pyrroline-5-carboxylate (P5C) contents and ornithine-δ-aminotransferase (δ-OAT), pyrroline-5-carboxylate synthetase (P5CS), proline dehydrogenase (ProDH) activities in terms of down-regulated the BnaC04.P5CS2, BnaA04.P5CS2, and BnaAnn.ProDH expression. The glutamate and GSA contents were decreased while P5C, arginine, and ornithine contents were enhanced in leaves under B-deficient and toxicity conditions. Lower glutamate pathway-related substance contents, P5CR, and δ-OAT activities while higher ProDH activity along with the same trend of related-gene expression were observed in B-toxicity-treated roots. Importantly, principal component analysis (PCA) in conjunction with correlation analysis indicated that ornithine pathway-related substances and enzymes contributed more to proline accumulation in B-deficient plant and B toxicity-treated leaves. Collectively, proline accumulation is caused by increased synthesis and decreased decomposition, and positively contributed, at least partly, by regulated ornithine pathway.


Assuntos
Brassica napus , Boro/toxicidade , Ácido Glutâmico , Prolina , Prolina Oxidase
20.
Phys Med ; 89: 226-231, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34425513

RESUMO

The aim of the NEPTUNE (Nuclear process-driven Enhancement of Proton Therapy UNravEled) project is to investigate in detail both the physical and radiobiological phenomena that could justify an increase of the proton-induced cytogenetic effects in cells irradiated in presence of an agent containing natural boron. In this work, a double-stage silicon telescope coupled to different boron converters was irradiated at the CATANA proton therapy facility (INFN-LNS) for studying the proton boron fusion and the neutron boron capture reactions by discriminating secondary particles from primary protons. Different boron targets were developed by depositing boric acid, enriched with a higher than 99% content of 10B or 11B, on a 50 µm thick PolyMethilMetacrylate (PMMA) substrate. The 10B target allows to evaluate the contribution of lithium and alpha particles produced by the boron neutron capture reaction triggered by secondary thermal neutrons, while the 11B target is exploited for studying the effect of the p + 11B → 3α nuclear reaction directly triggered by primary protons. Experimental results clearly show the presence of alpha particles from both the reactions. The silicon telescope is capable of discriminating, by means of the so-called "scatter plots", the contribution of alpha particles originated by thermal neutrons on 10B with respect to the ones produced by protons impinging on 11B. Although a reliable quantitative study of the alpha production rate has not been achieved yet, this work demonstrates that low energy and, therefore, high-LET particles from both the reactions can be measured.


Assuntos
Terapia por Captura de Nêutron de Boro , Terapia com Prótons , Boro , Nêutrons , Prótons
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