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1.
Biosensors (Basel) ; 14(6)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38920614

ABSTRACT

Heavy metals constitute pollutants that are particularly common in air, water, and soil. They are present in both urban and rural environments, on land, and in marine ecosystems, where they cause serious environmental problems since they do not degrade easily, remain almost unchanged for long periods, and bioaccumulate. The detection and especially the quantification of metals require a systematic process. Regular monitoring is necessary because of seasonal variations in metal levels. Consequently, there is a significant need for rapid and low-cost metal determination methods. In this study, we compare and analytically validate absorption spectrometry with a sensitive voltammetric method, which uses a bismuth film-plated electrode surface and applies stripping voltammetry. Atomic absorption spectroscopy (AAS) represents a well-established analytical technique, while the applicability of anodic stripping voltammetry (ASV) in complicated sample matrices such as soil samples is currently unknown. This sample-handling challenge is investigated in the present study. The results show that the AAS and ASV methods were satisfactorily correlated and showed that the metal concentration in soils was lower than the limit values but with an increasing trend. Therefore, continuous monitoring of metal levels in the urban complex of a city is necessary and a matter of great importance. The limits of detection of cadmium (Cd) were lower when using the stripping voltammetry (SWASV) graphite furnace technique compared with those obtained with AAS when using the graphite furnace. However, when using flame atomic absorption spectroscopy (flame-AAS), the measurements tended to overestimate the concentration of Cd compared with the values found using SWASV. This highlights the differences in sensitivity and accuracy between these analytical methods for detecting Cd. The SWASV method has the advantage of being cheaper and faster, enabling the simultaneous determination of heavy elements across the range of concentrations that these elements can occur in Mediterranean soils. Additionally, a dsDNA biosensor is suggested for the discrimination of Cu(I) along with Cu(II) based on the oxidation peak of guanine, and adenine residues can be applied in the redox speciation analysis of copper in soil, which represents an issue of great importance.


Subject(s)
Bismuth , DNA , Electrodes , Metals, Heavy , Soil , Bismuth/chemistry , Bismuth/analysis , Metals, Heavy/analysis , Soil/chemistry , Biosensing Techniques , Soil Pollutants/analysis , Electrochemical Techniques , Spectrophotometry, Atomic , Cadmium/analysis
2.
Talanta ; 272: 125753, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38364560

ABSTRACT

Although peroxidase-like nano-enzymes have been widely utilized in biosensors, nano-enzyme based biosensors are seldom used for both quantitative analysis of H2O2 and differentiation of isomers of organic compounds simultaneously. In this study, a dual-functional mimetic enzyme-based fluorescent sensor was constructed using metal-organic frameworks (Bi-MOFs) with exceptional oxidase activity and fluorescence properties. This mimetic enzyme sensor facilitated quantitative analysis of H2O2 and accurate discrimination of phenylenediamine isomers. The sensor exhibited a wide linear range (0.5-400 µM) and low detection limit (0.16 µM) for the detection of H2O2. Moreover, the sensor can also be used for the discrimination of phenylenediamine isomers, in which the presence of o-phenylenediamine (OPD) leads to the appearance of a new fluorescence emission peak at 555 nm, while the presence of p-phenylenediamine (PPD) significantly quenched its fluorescence due to the internal filtration effect. The proposed strategy exhibited a commendable capability in distinguishing phenylenediamine isomers, thereby paving the way for novel applications of MOFs in the field of environmental science.


Subject(s)
Metal-Organic Frameworks , Hydrogen Peroxide/analysis , Bismuth/analysis , Peroxidase , Oxidoreductases , Phenylenediamines
3.
Environ Res ; 232: 116351, 2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37327844

ABSTRACT

The emerging contaminants removal from the environment has recently been raised concerns due to their presence in higher concentrations. Over usage of emerging contaminant such as sulfamethazine poses serious threat to the aquatic and human health as well. This study deals with rationally structured a novel BiOCl (110)/NrGO/BiVO4 heterojunction which is used to detoxify sulfamethazine (SMZ) antibiotic efficiently. The synthesised composite was well characterized and the morphological analysis evidenced the formation of heterojunction consisted of nanoplates BiOCl with dominant exposed (110) facets and leaf like BiVO4 on NrGO layers. Further results revealed that the addition of BiVO4 and NrGO tremendously increased the photocatalytic degradation efficiency of BiOCl with the rate of 96.9% (k = 0.01783 min-1) towards SMZ within 60 min of visible light irradiation. Furthermore, heterojunction energy-band theory was employed to determine the degradation mechanism of SMX in this study. The larger surface area of BiOCl and NrGO layers are believed to be the reason for higher activity which facilitates the excellent charge transfer and improved light absorption. In addition, SMZ degradation products identification was carried out by LC-ESI/MS/MS to determine the pathway of degradation. The toxicity assessment was studied using E. coli as a model microorganism through colony forming unit assay (CFU), and the results indicated a significant reduction in biotoxicity was observed in 60 min of degradation process. Thus, our work gives new methods in developing various materials that effectively treat emerging contaminants from the aqueous environment.


Subject(s)
Sulfamethazine , Water Pollutants, Chemical , Humans , Sulfamethazine/toxicity , Tandem Mass Spectrometry , Escherichia coli , Bismuth/analysis , Catalysis , Water Pollutants, Chemical/toxicity , Water Pollutants, Chemical/analysis
4.
J Forensic Sci ; 67(3): 1274-1279, 2022 May.
Article in English | MEDLINE | ID: mdl-35023580

ABSTRACT

Forensic assessment employs an array of methods to identify human remains. Radiologic examinations with panoramic radiographs, computed tomography scans, Waters view, and nuclear magnetic resonance imaging may offer evidentiary clues in challenging cases, such as mass disasters. In these cases, alternative forensic tools are used to narrow lists of target victims using their biological features. This study aims to I) report on the unusual radiographic aspect of chemicals used for hair dyeing, and II) discuss the potential forensic application of this finding for human identification. The case depicts an asymptomatic 14-years-old female who presented for orthodontic therapy. During radiographic examination on a lateral cephalogram, numerous thin radiopaque streaks were visible, extending to the posterior neck between the occipital region of the skull base and vertebra C6. Clinical investigations revealed that these were artifactual hair images (possibly documented for the first time in the scientific literature). Inductively coupled plasma mass spectrometry (ICP-MS) analysis of the patient's scalp hair was performed for 10 heavy metals, including zinc, copper, iron, chromium, nickel, cadmium, tin, lead, antimony, and bismuth. Eight of these metals were detected at normal levels, ranging from 160 parts per million (ppm) for zinc to less than 1 ppm for nickel, cadmium, tin, lead, and antimony. Conversely, slightly elevated levels of chromium at 0.41 ppm and bismuth at 0.025 ppm were found in the hair sample. The distinctive radiographic presentation of artifactual hair images combined with the chemical properties of hair exposed to dye products may provide useful traces for human identification, especially in mass disasters.


Subject(s)
Antimony , Cadmium , Adolescent , Antimony/analysis , Bismuth/analysis , Cadmium/analysis , Chromium/analysis , Copper/analysis , Female , Hair/chemistry , Humans , Nickel/analysis , Tin/analysis , Zinc
5.
Nutr Neurosci ; 25(1): 11-21, 2022 Jan.
Article in English | MEDLINE | ID: mdl-31900097

ABSTRACT

Background: Head hair analysis has been used for decades to clarify mineral relationships to symptoms of ADHD, but there is little consensus among findings. We sought to explore 33 hair element concentrations and their 528 calculated ratios among two groups of boys, one with ADHD and one without.Method: 107 boys aged 7-12 years were recruited; 55 with ADHD and 52 non-ADHD Controls. Hair minerals were compared using Mann-Whitney U tests, p<0.01 was used for significance. Dietary data were obtained using a 138 item food frequency questionnaire (FFQ).Results: There were three group differences on individual elements: bismuth/Bi: 8 fold higher in ADHD, chromium/Cr: 15% lower in ADHD and germanium/Ge: 11% lower in ADHD, Cr level being the strongest predictor of ADHD symptoms. We found thirty significant group differences in element ratios, two thirds involving Bi and eight of these showing that as ADHD severity increased, the ratios with Bi as the denominator decreased (r ranging from -0.263 to -0.433, p<0.01). From the FFQ, tinned fruit was consumed more often in the ADHD group. Hair arsenic levels were somewhat elevated across both ADHD and Control groups.Discussion: While element 'imbalance' appears to be associated with ADHD, we did not replicate any previous study results of group differences on individual elements. We have raised the possibility that the ratios may be far more important than any one individual element in better elucidating the effects that minerals may have on the pathogenesis of ADHD. These are cautionary findings requiring replication.


Subject(s)
Attention Deficit Disorder with Hyperactivity/metabolism , Hair Analysis/methods , Hair/chemistry , Metals, Heavy/analysis , Trace Elements/analysis , Bismuth/analysis , Case-Control Studies , Child , Chromium/analysis , Germanium/analysis , Humans , Male
7.
Photochem Photobiol ; 97(2): 301-308, 2021 03.
Article in English | MEDLINE | ID: mdl-32898925

ABSTRACT

Three pyreno[4,5-d]imidazole derivatives are synthesized and evaluated as fluorescent sensors for bismuth (III) ion. The target compounds are prepared in 55-86% yields from a condensation reaction between pyrene-4,5-dione and aromatic aldehydes. The compound bearing a phenolic group can selectively detect bismuth (III) ion via fluorescence enhancement with a detection limit of 1.20 µm in CH3 CN-DMSO mixture and 3.40 µm in 10% pH5 aqueous in CH3 CN-DMSO mixture. The sensing mechanism involving a formation of coordination complex is investigated by UV-VIS and fluorescence titrations, 1 H-NMR and the decomplexation of the bismuth complex by sulfide ion. The application of this sensor for quantitative analysis of spiked bismuth (III) ion in real water samples from two different sources is demonstrated.


Subject(s)
Bismuth/analysis , Fluorescent Dyes/chemistry , Imidazoles/chemistry , Pyrenes/chemistry , Hydrogen-Ion Concentration , Limit of Detection , Solvents/chemistry , Spectrum Analysis/methods , Water/chemistry
8.
ACS Nano ; 14(6): 7245-7258, 2020 06 23.
Article in English | MEDLINE | ID: mdl-32432848

ABSTRACT

Ultrasound (US)-assisted oncotherapy has aroused extensive attention due to its capacities to conquer significant restrictions covering short tissue penetration depth and high phototoxicity in photoinduced therapy. We herein developed a class of pure-phase perovskite-type bimetallic oxide, namely, bismuth ferrite nanocatalysts (BFO NCs), for multimodality imaging-guided and US-enhanced chemodynamic therapy (CDT) against malignant tumors. As-prepared BFO nanoparticles with poly(ethylene glycol)-grafted phosphorylated serine (pS-PEG) modification exhibit satisfactory physiological stability and biocompatibility. The BFO NCs also present high fluorescence emission within the second near-infrared region when irradiated with an 808 nm laser. Intriguingly, the BFO NCs demonstrate highly efficient US-enhanced generation of hydroxyl free radicals, as the cavitation bubbles produced by US trigger partial grievous turbulence and promote the transfer rate of the Fenton reagents. Thus, the BFO NCs enable effective inhibition of tumor growth assisted by external US, and the treatment efficacy can be monitored by computer tomography, magnetic resonance, and fluorescence imaging. Meanwhile, H2O2 and US, as a double logic gate, activate the BFO NCs to trigger the iron-catalyzed and US-enhanced CDT with high specificity and treatment efficiency. Therefore, the BFO NCs as a theranostic agent with an enhanced chemodynamic therapeutic effect assisted by external US and a multimodality imaging capacity are put forward, which show a promising prospect for noninvasive chemodynamic oncotherapy.


Subject(s)
Bismuth , Neoplasms , Bismuth/analysis , Ferric Compounds , Humans , Hydrogen Peroxide , Precision Medicine
9.
Nano Lett ; 20(4): 2522-2529, 2020 04 08.
Article in English | MEDLINE | ID: mdl-32208714

ABSTRACT

Photothermal therapy (PTT) is an efficient approach for cancer treatment. However, accurately monitoring the spatial distribution of photothermal transducing agents (PTAs) and mapping the real-time temperature change in tumor and peritumoral normal tissue remain a huge challenge. Here, we propose an innovative strategy to integrate T1-MRI for precisely tracking PTAs with magnetic resonance temperature imaging (MRTI) for real-time monitoring temperature change in vivo during PTT. NaBiF4: Gd@PDA@PEG nanomaterials were synthesized with favorable T1-weighted performance to target tumor and localize PTAs. The extremely weak susceptibility (1.04 × 10-6 emu g-1 Oe1-) of NaBiF4: Gd@PDA@PEG interferes with the local phase marginally, which maintains the capability of MRTI to dynamically record real-time temperature change in tumor and peritumoral normal tissue. The time resolution is 19 s per frame, and the detection precision of temperature change is approximately 0.1 K. The approach achieving PTT guided by multimode MRI holds significant potential for the clinical application.


Subject(s)
Magnetic Resonance Imaging/methods , Nanostructures/analysis , Neoplasms/therapy , Photothermal Therapy/methods , Thermography/methods , Animals , Bismuth/analysis , Gadolinium/analysis , Mice , Neoplasms/diagnostic imaging , Sodium Fluoride/analysis , Temperature
10.
Chemosphere ; 234: 297-301, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31228831

ABSTRACT

In a broad environmental study in St. Joseph County, Indiana, elemental data from ∼2000 soil samples and ∼800 paint samples were collected with X-ray Fluorescence (XRF) spectroscopy. The observed lead concentrations were compared to other elemental concentrations in these data. A strong correlation between lead and bismuth concentrations was observed in a subset of the soil samples and in nearly all of the paint samples, with lead levels approximately 150 times higher than bismuth. However, some soil samples contained lead with no bismuth present. Since most lead sources likely contain bismuth as an impurity from refining of native lead ore, but leaded gasoline does not contain any bismuth impurities due to the manufacturing process of tetraethyl lead, it may be possible to distinguish environmental lead sources by XRF. To test if leaded gasoline could be the source of lead in the subset of soil samples containing no bismuth, leaded paint samples were analyzed with Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES), which confirmed the presence of bismuth in leaded paint. Aviation gasoline, which contains tetraethyl lead, was also analyzed by ICP-OES to confirm the absence of bismuth in leaded gasoline. This discovery suggests that XRF can be used to rapidly distinguish different legacy lead contamination sources from one another. For low lead concentrations, elemental measurements of bismuth by ICP-OES can be used in environmental forensics to distinguish leaded gasoline contamination from other sources of lead.


Subject(s)
Bismuth/analysis , Environmental Monitoring/methods , Lead/analysis , Soil Pollutants/analysis , Gasoline , Indiana , Paint , Spectrometry, X-Ray Emission/methods
11.
Radiat Prot Dosimetry ; 184(3-4): 453-456, 2019 Oct 01.
Article in English | MEDLINE | ID: mdl-31038699

ABSTRACT

Accurate measurement of radon progeny concentration is important for the dose assessment of radon exposure and the study of radon progeny behaviours. For measuring 218Po, 214Pb and 214Bi concentration as well as EEC with high sensitivity, an alpha-beta spectrometry method was developed and applied in a step-advanced filter radon progeny monitor. The derivation details of this method is given in this paper and the uncertainty is discussed. The comparison experiments are carried out in radon chamber and in field. Results show that the alpha-beta spectrometry method can give 218Po, 214Pb and 214Bi concentration as well as EEC with high sensitivity either for 60 min or for 30 min cycle, which leads to low uncertainty. This method can be used as a reference method for radon chamber and is suitable for portable radon progeny monitor.


Subject(s)
Air Pollutants, Radioactive/analysis , Bismuth/analysis , Lead Radioisotopes/analysis , Polonium/analysis , Radiation Monitoring/methods , Radon Daughters/analysis , Spectrometry, Gamma/methods , Alpha Particles , Beta Particles
12.
Talanta ; 198: 249-256, 2019 Jun 01.
Article in English | MEDLINE | ID: mdl-30876558

ABSTRACT

A new simple pyrene based schiff base chemosensor 1 (nicotinic acid pyren-1-ylmethylene-hydrazide) has been constructed and is prepared from 1-pyrenecarboxaldehyde and nicotinic hydrazide. Notably, the chemosensor 1 exhibited remarkable colour changes while in the presence of trivalent metal ions like Bi3+ & Al3+ ion in DMSO-H2O, (1:1 v/v, HEPES = 50 mM, pH = 7.4). The UV-Vis spectral investigation of chemosensor 1 showed that the maximum absorption peak appeared at 378 nm. In emission studies, chemosensor 1 develops weak fluorescence, while upon the addition of Bi3+ and Al3+ ions, it exhibits an enhancement of fluorescence intensity. Nevertheless, rest of metal ions have no changes in the emission spectra. The association constant of chemosensor 1 for binding to Bi3+ & Al3+ system had a value of 1.27 × 104 M-1 and 1.53 × 104 M-1. The detection limits were 0.12 µM for Bi3+ and 0.17 µM for Al3+ respectively. The overall results reveal that chemosensor 1 can act as a dual-channel, highly selective, and sensitive probe for Bi3+ and Al3+ ions. Moreover, the fluorescence imaging of chemosensor 1 was applied in RAW 264.7 cell line and cytotoxicity assay prove that this chemosensor 1 is non-toxic as well as highly biocompatible.


Subject(s)
Aluminum/analysis , Bismuth/analysis , Fluorescent Dyes/chemistry , Optical Imaging , Pyrenes/chemistry , Animals , Ions/analysis , Mice , RAW 264.7 Cells , Spectrometry, Fluorescence
13.
J Chromatogr A ; 1573: 107-114, 2018 Oct 26.
Article in English | MEDLINE | ID: mdl-30224278

ABSTRACT

Alpha-particle-emitting radionuclides have been the subject of considerable investigation as cancer therapeutics, since they have the advantages of high potency and specificity. Among α-emitting radionuclides that are medically relevant and currently available, the lead-212/bismuth-212 radionuclide pair could constitute an in vivo generator. Considering its short half-life (T1/2 = 60.6 min), 212Bi can only be delivered using labelled carrier molecules that would rapidly accumulate in the target tumor. To expand the range of applications, an interesting method is to use its longer half-life parent 212Pb (T1/2 = 10.6 h) that decays to 212Bi. The challenge consists in keeping 212Bi bound to the vector after the 212Pb decay. Preclinical and clinical studies have shown that a variety of vectors may be used to target alpha-emitting radionuclides to cancer cells. Nanoparticles, notably liposomes, allow combined targeting options, achieving high specific activities, easier combination of imaging and therapy and development of multimodality therapeutic agents (e.g., radionuclide therapy plus chemotherapy). The aim of this work consists in assessing the in vitro stability of 212Pb/212Bi encapsulation in the liposomes. Indeed, the release of the radionuclide from the carrier molecules might causes toxicity to normal tissues. To reach this goal, Asymmetrical Flow Field-Flow Fractionation (AF4) coupled with a Multi-Angle Light Scattering detector (MALS) was used and coupling with a gamma (γ) ray detector was developed. AF4-MALS-γ was shown to be a powerful tool for monitoring the liposome size together with the incorporation of the high energy alpha emitter. This was successfully extended to assess the stability of 212Bi-radiolabelled liposomes in serum showing that more than 85% of 212Pb/212Bi is retained after 24 h of incubation at 37 °C.


Subject(s)
Drug Delivery Systems/instrumentation , Fractionation, Field Flow , Bismuth/analysis , Half-Life , Humans , Lead Radioisotopes/analysis , Liposomes/chemistry , Nanoparticles/chemistry , Radioisotopes/analysis
14.
J Environ Radioact ; 189: 202-206, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29694943

ABSTRACT

The Brazilian Nuclear Energy Agency (CNEN) is responsible for any radioactive waste storage and disposal in the country. The storage of radioactive waste is carried out in the facilities under CNEN regulation and its disposal is operated, managed and controlled by the CNEN. Oil NORM (Naturally Occurring Radioactive Materials) in this article refers to waste coming from oil exploitation. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of a regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is the modeling of radioisotopes normally present in oil pipe contamination such as 228Ac, 214Bi and 214Pb analyzed by gamma spectrometry. The specific activities of elements from different decay series are plotted in a scatter diagram. This method was successfully tested with gamma spectrometry analyses of oil sludge NORM samples from four different sources obtained from Petrobras reports for the Campos Basin/Brazil.


Subject(s)
Industrial Waste/analysis , Oil and Gas Industry , Radioactive Waste/analysis , Waste Management/methods , Bismuth/analysis , Brazil , Lead Radioisotopes/analysis , Radioisotopes/analysis
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 192: 188-193, 2018 Mar 05.
Article in English | MEDLINE | ID: mdl-29136584

ABSTRACT

In this work, synthesis of novel symmetrical 4-(2-bromo-4-(5-bromo-1H-benzo[d] imidazol-2-yl) phenoxy) tetra substituted zinc phthalocyanine has been reported. The novel benzimidazole zinc phthlocynine compound (3) has been characterized by MALDI-TOF MS, FT-IR, UV-vis, and 1H NMR spectroscopy. This new compound 3 displayed excellent selectivity towards Bi3+ ion in the presence of other competitive ions including Ca2+, Cd2+, Co2+ Cu2+, Fe3+, Hg2+, Sn2+, Mg2+, Na+, Ni2+ and Pb2+ respectively. Upon addition of Bi3+ into the solution of compound 3 in DMSO, dramatic change was observed in the Q- and the B-bands in UV-visible spectra as a result of donor acceptor interactions. Reactive oxygen species (ROS) were also studied using 2,7-dichlorofluorescin diacetate (DCFH-DA) a fluorescent probe which is converted to highly fluorescent dichlorofluorescein (DCF) in the presence of ROS. This property of non-aggregating zinc phthalocyanine is promising as a photosensitizer in photodynamic therapy of cancer.


Subject(s)
Benzimidazoles/chemistry , Benzimidazoles/chemical synthesis , Bismuth/analysis , Indoles/chemistry , Indoles/chemical synthesis , Organometallic Compounds/chemistry , Organometallic Compounds/chemical synthesis , Reactive Oxygen Species/chemistry , Electrons , Ions , Isoindoles , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Spectrophotometry, Ultraviolet , Zinc Compounds
16.
Environ Sci Pollut Res Int ; 24(31): 24400-24408, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28891025

ABSTRACT

Stable catalysts require high catalytic efficiency and repeated consecutive use, low mass loss, and metal leaching. This study investigated BiFeO3 (BFO) composite with high stability and reusability using a one step microwave-assisted hydrothermal method (MAHS) to decompose bisphenol A (BPA) used as the target contaminant. After six consecutive reaction cycles in microwave-enhanced Fenton-like process (MW-Fenton-like), the removal rate of BPA decreased from 94 to 87.4% with low metal leaching ratio and mass loss. The morphology, crystal, reaction kinetics, and hydroxyl radical (·OH) were used to demonstrate the high stability of BFO-MAHS. The results indicated that the benign stability and reusability of BFO-MAHS probably occurred because (1) the thermal-effect of MW improved heating rate, which led to the rapid formation stable cube structure and (2) MW mechanical vibrations existed in the preparation process, which further enhanced the cube structure. Therefore, MAHS could be used as a green and environmental friendly method to apply in catalysts synthesis, which could immensely shorten preparation time and enhance the catalytic performance with no waste production.


Subject(s)
Benzhydryl Compounds/chemistry , Bismuth/analysis , Ferric Compounds/analysis , Metal Nanoparticles/analysis , Microwaves , Phenols/chemistry , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/chemistry , Heating , Hydroxyl Radical/chemistry , Kinetics , Waste Disposal, Fluid/instrumentation
17.
J Environ Radioact ; 178-179: 77-83, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28797795

ABSTRACT

It is necessary to establish a reference atmosphere in a thoron chamber containing various ratios of 212Bi to 212Pb activity concentrations (C(212Bi)/C(212Pb)) to simulate typical environmental conditions (e.g., indoor or underground atmospheres). In this study, a novel method was developed for establishing and controlling C(212Bi)/C(212Pb) in a thoron chamber system based on an aging chamber and air recirculation loops which alter the ventilation rate. The effects of main factors on the C(212Bi)/C(212Pb) were explored, and a steady-state theoretical model was derived to calculate the ratio. The results show that the C(212Bi)/C(212Pb) inside the chamber is mainly dependent on ventilation rate. Ratios ranging from 0.33 to 0.83 are available under various ventilation. The stability coefficient of the ratios is better than 7%. The experimental results are close to the theoretical calculated results, which indicates that the model can serve as a guideline for the quantitative control of C(212Bi)/C(212Pb).


Subject(s)
Air Pollutants, Radioactive/analysis , Bismuth/analysis , Lead Radioisotopes/analysis , Radiation Monitoring , Models, Theoretical , Radon/analysis , Radon Daughters/analysis
18.
Biomaterials ; 141: 284-295, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28709019

ABSTRACT

Biocompatible single-component theranostic agents integrating multimodal imaging and therapeutic functions (namely, "all-in one" agents) are highly desired for clinical cancer treatments. Herein, PEGylated pure metallic bismuth nanocrystals (Bi-PEG NCs) have been developed to be a competent theranostic agent for in vivo high-performance multimodal bio-imaging and photothermal ablation of tumors. The resultant Bi-PEG NCs show excellent physiological stability, biocompatibility, prolonged blood circulation half-life and preferential tumor accumulation. Thanking to the strong near-infrared (NIR) absorbance as well as the high photothermal conversion efficiency and conversion stability, highly effective in vivo photothermal ablation on tumors has been realized upon NIR irradiation, without noticeable toxicity. Impressively, the Bi-PEG NCs show ultrahigh X-ray computed topography (CT) enhancement efficiency (∼60.3 HU mL mg-1), overwhelming all CT contrast agents reported so far. Combining the strong CT contrast ability and photoacoustic/photothermal effect, high-contrast CT, photoacoustic (PA) and infrared thermal (IRT) triple-modal imaging have been demonstrated both in vitro and in vivo. This work highlights the potentials of such NCs as a powerful "all-in-one" theranostic nanoplatform for bioimaging and antitumor therapy, and may have provided a rather promising candidate for clinically-applied antitumor treatments based on single-component agents.


Subject(s)
Bismuth/therapeutic use , Contrast Media/therapeutic use , Nanoparticles/therapeutic use , Neoplasms/diagnostic imaging , Neoplasms/therapy , Theranostic Nanomedicine/methods , Animals , Bismuth/analysis , Contrast Media/analysis , Female , HeLa Cells , Humans , Hyperthermia, Induced/methods , Mice, Inbred BALB C , Multimodal Imaging/methods , Nanoparticles/analysis , Photoacoustic Techniques/methods , Phototherapy/methods , Polyethylene Glycols/analysis , Polyethylene Glycols/therapeutic use , Thermography/methods , Tomography, X-Ray Computed/methods
19.
ACS Nano ; 11(7): 6672-6681, 2017 07 25.
Article in English | MEDLINE | ID: mdl-28644009

ABSTRACT

In order to assess the therapeutic potential of cell-based strategies, it is of paramount importance to elaborate and validate tools for monitoring the behavior of injected cells in terms of tissue dissemination and engraftment properties. Here, we apply bismuth ferrite harmonic nanoparticles (BFO HNPs) to in vitro expanded human skeletal muscle-derived stem cells (hMuStem cells), an attractive therapeutic avenue for patients suffering from Duchenne muscular dystrophy (DMD). We demonstrate the possibility of stem cell labeling with HNPs. We also show that the simultaneous acquisition of second- and third-harmonic generation (SHG and THG) from BFO HNPs helps separate their response from tissue background, with a net increase in imaging selectivity, which could be particularly important in pathologic context that is defined by a highly remodelling tissue. We demonstrate the possibility of identifying <100 nm HNPs in depth of muscle tissue at more than 1 mm from the surface, taking full advantage of the extended imaging penetration depth allowed by multiphoton microscopy in the second near-infrared window (NIR-II). Based on this successful assessment, we monitor over 14 days any modification on proliferation and morphology features of hMuStem cells upon exposure to PEG-coated BFO HNPs at different concentrations, revealing their high biocompatibility. Successively, we succeed in detecting individual HNP-labeled hMuStem cells in skeletal muscle tissue after their intramuscular injection.


Subject(s)
Bismuth/analysis , Cell Tracking/methods , Ferric Compounds/analysis , Muscle, Skeletal/cytology , Nanoparticles/analysis , Optical Imaging/methods , Stem Cells/cytology , Adolescent , Animals , Cells, Cultured , Child , Humans , Infrared Rays , Mice , Muscle, Skeletal/diagnostic imaging , Muscular Dystrophy, Duchenne/diagnostic imaging , Muscular Dystrophy, Duchenne/therapy , Stem Cell Transplantation
20.
J Agric Food Chem ; 65(23): 4839-4842, 2017 Jun 14.
Article in English | MEDLINE | ID: mdl-28545295

ABSTRACT

A microwave-induced plasma optical emission spectrometer with N2-based plasma was combined with a multimode sample introduction system (MSIS) for hydride generation (HG) and multielemental determination of As, Bi, Ge, Sb, and Sn in samples of forage, bovine liver, powdered milk, agricultural gypsum, rice, and mineral fertilizer, using a single condition of prereduction and reduction. The accuracy of the developed analytical method was evaluated using certified reference materials of water and mineral fertilizer, and recoveries ranged from 95 to 106%. Addition and recovery experiments were carried out, and the recoveries varied from 85 to 117% for all samples evaluated. The limits of detection for As, Bi, Ge, Sb, and Sn were 0.46, 0.09, 0.19, 0.46, and 5.2 µg/L, respectively, for liquid samples, and 0.18, 0.04, 0.08, 0.19, and 2.1 mg/kg, respectively, for solid samples. The method proposed offers a simple, fast, multielemental, and robust alternative for successful determination of all five analytes in agricultural samples with low operational cost without compromising analytical performance.


Subject(s)
Antimony/analysis , Arsenic/analysis , Bismuth/analysis , Crops, Agricultural/chemistry , Germanium/analysis , Milk/chemistry , Spectrum Analysis/methods , Tin/analysis , Animals , Cattle , Liver/chemistry , Microwaves
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