Enhancing the photocatalytic efficiency by the molecular modification effect derived from pollutant adsorption on highly crystalline BiOBr.

The adsorption of pollutants can not only promote the direct surface reaction, but also modify the catalyst itself to improve its photoelectric characteristics, which is rarely studied for water treatment with inorganic photocatalyst. A highly crystalline BiOBr (c-BiOBr) was synthesized by a two-step preparation process. Owing to the calcination, the highly crystalline enhanced the interface interaction between pollutant and c-BiOBr. The complex of organic pollutant and [Bi2O2]2+ could promote the active electron transfer from the adsorbed pollutant to c-BiOBr for the direct pollutant degradation by holes (h+). Moreover, the pollutant adsorption actually modified c-BiOBr and promoted more unpaired electrons, which would coupling with the photoexcitation to promote generate more O2•-. The molecular modification effect derived from pollutant adsorption significantly improved the removal of pollutants. This work strongly deepens the understanding of the molecular modification effect from the pollutant adsorption and develops a novel and efficient approach for water treatment.

Optical, vibrational, and photoluminescence properties of holmium-doped boro-bismuth-germanate glasses.

Holmium (Ho3+)-doped boro-bismuth-germanate glasses having the chemical composition (30-x)B2O3 + 20GeO2 + 20Bi2O3 + 20Na2O + 10Y2O3 + xHo2O3, where x = 0.1, 0.5, 1.0, and 2.0 mol% were prepared by melt-quenching technique. The prepared glasses were examined for thermal, optical, vibrational, and photoluminescent properties. The prepared glasses were found to be thermally very stable. The optical bandgap and Urbach energies of 0.1 mol% Ho2O3-doped boro-bismuth-germanate glass were calculated to be 3.3 eV and 377 MeV, respectively, using the absorption spectrum. The Judd-Ofelt analysis was performed on the 0.1 mol% Ho2O3-doped glass and compared the obtained parameters with literature. The branching ratio (ß) and emission cross-section (σem) of the green band were determined to be 0.7 and 0.24 × 10-20 cm2, respectively. Under 450 nm excitation, a strong green emission around 550 nm was observed and assigned to the (5S2 + 5F4) → 5I8 (Ho3+) transition. Upon an increase of Ho2O3 content from 0.1 to 2.0 mol%, the intensities of all observed emission bands as well as decay time of the (5S2 + 5F4) → 5I8 transition have been decreased gradually. The reasons behind the decrease in emission intensity and decay time were discussed. The strong green emission suggests that these glasses may be a better option for display devices and green emission applications.

Ultrasound-responsive Bi2MoO6-MXene heterojunction as ferroptosis inducers for stimulating immunogenic cell death against ovarian cancer.

BACKGROUND: Ovarian cancer (OC) has the highest fatality rate among all gynecological malignancies, necessitating the exploration of novel, efficient, and low-toxicity therapeutic strategies. Ferroptosis is a type of programmed cell death induced by iron-dependent lipid peroxidation and can potentially activate antitumor immunity. Developing highly effective ferroptosis inducers may improve OC prognosis. RESULTS: In this study, we developed an ultrasonically controllable two-dimensional (2D) piezoelectric nanoagonist (Bi2MoO6-MXene) to induce ferroptosis. A Schottky heterojunction between Bi2MoO6 (BMO) and MXene reduced the bandgap width by 0.44 eV, increased the carrier-separation efficiency, and decreased the recombination rate of electron-hole pairs under ultrasound stimulation. Therefore, the reactive oxygen species yield was enhanced. Under spatiotemporal ultrasound excitation, BMO-MXene effectively inhibited OC proliferation by more than 90%, induced lipid peroxidation, decreased mitochondrial-membrane potential, and inactivated the glutathione peroxidase and cystathionine transporter protein system, thereby causing ferroptosis in tumor cells. Ferroptosis in OC cells further activated immunogenic cell death, facilitating dendritic cell maturation and stimulating antitumor immunity. CONCLUSION: We have succeeded in developing a highly potent ferroptosis inducer (BMO-MXene), capable of inhibiting OC progression through the sonodynamic-ferroptosis-immunogenic cell death pathway.

Multifiller-based polymer composites for shielding high energy ionising radiation.

Polydimethyl silicone rubber-based polymer composites filled with molybdenum and bismuth were fabricated using simple open mold cast technique. The physical and chemical structure and gamma shielding parameters like attenuation coefficient, half-value layer (HVL) thickness and relaxation length have been investigated for the said novel materials using X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR) and gamma ray spectrometer. XRD study reveals the crystalline nature of the composites. It is evident from FTIR studies that there is no chemical interaction between the polymer matrix and filler particles. The results of attenuation studies reveal that the linear attenuation coefficient increases with addition of Bi and Mo and is found to be 0.653, 1.341 and 1.017, 1.793 and 0.102, 0.152 cm-1 for 1MMB and 2MMB polymer composites at 80, 356 and 662 keV gamma rays, respectively. The HVL thickness of the materials is found to be 1.06, 0.51 and 0.68, 0.38 and 6.73, 4.532 cm for 1MMB (20Mo + 10Bi phr) and 2MMB (40Mo + 20Bi phr) at these energies, respectively. The mass attenuation coefficient of the novel composites 1MMB and 2MMB is found to be higher than the conventional materials like lead and barite for 356 keV gamma rays. In addition, the material is found to be light weight and flexible enabling to be molded in required forms, thus being a substitute for the material lead that is known to be heavy and toxic by nature.

Impact of bismuth oxide on structural, optical and gamma-ray shielding properties of calcium-sodium-borate glasses.

In the present study, we have prepared six glass samples of bismuth borate using the melt-quenching method with the composition (70-x)B2O3-10CaO-20Na2O-xBi2O3; x = 0, 3, 6, 9, 12 and 15 mol%. The density of the prepared glasses was determined using Archimedes principle. The X-ray diffraction patterns provide confirmation of the amorphous nature of the prepared samples, whereas the Fourier transform infrared measurements pointed to the existence of structural units like BO3, BO4, BiO3 and BiO6 within the glass network. An assessment of the optical absorption spectra unveiled that with the increase in the bismuth oxide content, there was a decrease observed in both the direct and indirect band gap energies. Specifically, they decreased from 3.40 to 2.79 eV and from 3.10 to 2.46 eV, respectively. The properties related to gamma ray attenuation, including the mass attenuation coefficient (µm), effective atomic number (Zeff), half-value layer (HVL) and mean free path (MFP), were examined for all the glass samples. This investigation was carried out using the Phy-X/PSD software, covering the energy range from 0.511 to 1.332 MeV. Out of all the samples, Bi-15, featuring the highest Bi2O3 content, demonstrated the highest µm, Zeff, the smallest HVL and MFP. These results suggest that the glass with 15 mol% of Bi2O3 offers the most effective gamma radiation shielding performance. Moreover, the glasses examined in this study exhibit superior radiation shielding characteristics compared with specific concrete types, namely, ordinary concrete, Hematite serpentine concrete and barite concrete, as well as commercial glasses such as RS-360 and RS-253.

Bismuth Sulfide Nanoflowers Facilitated miR339 Delivery to Overcome Stemness and Radioresistance through Ubiquitin-Specific Peptidase 8 in Esophageal Cancer.

Despite the superior efficacy of radiotherapy in esophageal squamous cell carcinoma (ESCC), radioresistance by cancer stem cells (CSCs) leads to recurrence, metastasis, and treatment failure. Therefore, it is necessary to develop CSC-based therapies to enhance radiotherapy. miR-339-5p (miR339) is involved in stem cell division and DNA damage checkpoint signaling pathways based on ESCC cohort. miR339 inhibited ESCC cell stemness and enhanced radiation-induced DNA damage by targeting USP8, suggesting that it acts as a potential CSC regulator and radiosensitizer. Considering the limited circulating periods and poor tumor-targeting ability of miRNA, a multifunctional nanoplatform based on bismuth sulfide nanoflower (Bi@PP) is developed to efficiently deliver miR339 and improve radioresistance. Intriguingly, Bi@PP encapsulates more miR339 owing to their flower-shaped structure, delivering more than 1000-fold miR339 into cells, superior to free miR339 alone. Besides being used as a carrier, Bi@PP is advantageous for dynamically monitoring the distribution of delivered miR339 in vivo while simultaneously inhibiting tumor growth. Additionally, Bi@PP/miR339 can significantly enhance radiotherapy efficacy in patient-derived xenograft models. This multifunctional platform, incorporating higher miRNA loading capacity, pH responsiveness, hypoxia relief, and CT imaging, provides another method to promote radiosensitivity and optimize ESCC treatment.

Photocurrent polarity switching photoelectrochemical aptasensor for oxytetracycline based on BiOBr/Ag2S/PDA//CuO: CuO-induced II-type to dual Z-scheme system.

BACKGROUND: As a broad-spectrum tetracycline antibiotic, Oxytetracycline (OTC) was widely used in a variety of applications. But, the overuse of OTC had led to the detection of it in food, water and soil, which could present significance risk to human health and cause damage to ecosystem. It was of great significance to develop sensitive detection methods for OTC. Herein, an environmentally friendly photoelectrochemical (PEC) aptasensor was constructed for the sensitive detection of OTC based on CuO-induced BiOBr/Ag2S/PDA (Polydopamine) photocurrent polarity reversal. RESULTS: BiOBr/Ag2S/PDA composites modified electrode not only produced stable initial anodic photocurrent but also provided attachment sites for the aptamer S1 of OTC by the strong adhesion of PDA. On the other hand, CuO loaded OTC aptamer S2 (Cu-S2) was got through Cu-S bonds. After the target OTC was identified on the electrode surface, CuO was introduced to the surface of ITO/BiOBr/Ag2S/PDA through the specific binding of OTC to S2. This identification process formed dual Z-type heterojunctions and resulted in a remarkable reversal of photocurrent polarity from anodic to cathodic. Under optimization conditions, the PEC aptasensor showed a wide linear range (50 fM âˆ¼ 100 nM), low detection limit (1.9 fM), excellent selectivity, stability and reproducibility for the detection of OTC. Moreover, it was successfully used for the analysis of OTC in real samples of tap water, milk and honey, and had the potential for practical application. SIGNIFICANCE: This work developed an environmentally friendly photocurrent-polarity-switching PEC aptasensor with excellent selectivity, reproducibility, stability, low LOD and wide linear range for OTC detection. This sensitive system, which was including BiOBr, Ag2S, PDA and CuO were low toxicity, not only reduced the risk of traditional toxic semiconductors to operators and the environment, but can also be used for the detection of real samples, broadening the wider range of applications for BiOBr, Ag2S, PDA and CuO.

Long-term effects of fecal microbiota transplantation on gut microbiota after Helicobacter pylori eradication with bismuth quadruple therapy: A randomized controlled trial.

BACKGROUND: Eradicating Helicobacter pylori infection by bismuth quadruple therapy (BQT) is effective. However, the effect of BQT and subsequent fecal microbiota transplant (FMT) on the gut microbiota is less known. MATERIALS AND METHODS: This prospective randomized controlled trial was conducted at a tertiary hospital in China from January 2019 to October 2020, with the primary endpoints the effect of BQT on the gut microbiota and the effect of FMT on the gut microbiota after bismuth quadruple therapy eradication therapy. A 14-day BQT with amoxicillin and clarithromycin was administered to H. pylori-positive subjects, and after eradication therapy, patients received a one-time FMT or placebo treatment. We then collected stool samples to assess the effects of 14-day BQT and FMT on the gut microbiota. 16 s rDNA and metagenomic sequencing were used to analyze the structure and function of intestinal flora. We also used Gastrointestinal Symptom Rating Scale (GSRS) to evaluate gastrointestinal symptom during treatment. RESULTS: A total of 30 patients were recruited and 15 were assigned to either FMT or placebo groups. After eradication therapy, alpha-diversity was decreased in both groups. At the phylum level, the abundance of Bacteroidetes and Firmicutes decreased, while Proteobacteria increased. At the genus level, the abundance of beneficial bacteria decreased, while pathogenic bacteria increased. Eradication therapy reduced some resistance genes abundance while increased the resistance genes abundance linked to Escherichia coli. While they all returned to baseline by Week 10. Besides, the difference was observed in Week 10 by the diarrhea score between two groups. Compared to Week 2, the GSRS total score and diarrhea score decreased in Week 3 only in FMT group. CONCLUSIONS: The balance of intestinal flora in patients can be considerably impacted by BQT in the short term, but it has reverted back to baseline by Week 10. FMT can alleviate gastrointestinal symptoms even if there was no evidence it promoted restoration of intestinal flora.

Oxidation of antibiotic micropollutants in various water resources through integration of Bi2WO6 and g-C3N4.

Recently, the hazardous effects of antibiotic micropollutants on the environment and human health have become a major concern. To address this challenge, semiconductor-based photocatalysis has emerged as a promising solution for environmental remediation. Our study has developed Bi2WO6/g-C3N4 (BWCN) photocatalyst with unique characteristics such as reactive surface sites, enhanced charge transfer efficiency, and accelerated separation of photogenerated electron-hole pairs. BWCN was utilized for the oxidation of tetracycline antibiotic (TCA) in different water sources. It displayed remarkable TCA removal efficiencies in the following order: surface water (99.8%) > sewage water (88.2%) > hospital water (80.7%). Further, reusability tests demonstrated sustained performance of BWCN after three cycles with removal efficiencies of 87.3, 71.2 and 65.9% in surface water, sewage, and hospital water, respectively. A proposed photocatalytic mechanism was delineated, focusing on the interaction between reactive radicals and TCA molecules. Besides, the transformation products generated during the photodegradation of TCA were determined, along with the discussion on the potential risk assessment of antibiotic pollutants. This study introduces an approach for utilizing BWCN photocatalyst, with promising applications in the treatment of TCA from various wastewater sources.

A novel photoelectrochemical aptasensor based on 3D flower-like g-C3N4/BiOI p-n heterojunction for the sensitive detection of kanamycin.

BACKGROUND: Kanamycin (KAN) residues in animal-derived foods continuously enter the human body, which will pose serious threats to human health such as hearing loss, nephrotoxicity and other complications. Therefore, to sensitively detect KAN residues by a reliable technology is extremely urgent in food quality and safety. Compared with traditional methods being limited by cost and complexity, photoelectrochemical (PEC) biosensors benefit from some merits such as rapid response, excellent sensitivity and good stability. In this study, the construction of a highly efficient PEC platform to realize KAN residues detection is discussed. RESULTS: Herein, a novel p-n heterojunction consisting of flower-like BiOI microspheres and graphite carbon nitride (g-C3N4) nanoflakes was developed to establish a PEC aptasensor for KAN detection at 0 V. The prepared g-C3N4/BiOI heterostructure showed not only significantly enhanced PEC activity due to the larger specific surface area but also greatly increased charge separation efficiency owing to the strong internal electric field. Meanwhile, using g-C3N4/BiOI as a highly efficient photoactive material for binding amine-functionalized aptamers to capture KAN, the photocurrent signals showed a 'turn off' mode to achieve the sensitive detection of KAN. The proposed PEC aptasensor exhibited linear response for KAN from 5 × 10-9 to 3 × 10-7 mol L-1 with a low detection limit of 1.31 × 10-9 mol L-1, and satisfactory recoveries (97.44-107.38 %) were obtained in real food samples analysis. SIGNIFICANCE: This work presented a novel p-n heterojunction-based PEC aptasensor with strong selectivity and stability, rendering it allowed to detect KAN in animal-derived foods including milk, honey and pork. Additionally, the detection range satisfied the MRLs for KAN specified by the national standards, demonstrating the potential application for food analysis. The study provides a new insight into the development of efficient and practical biosensors for antibiotic residues detection.

CeO2 nanospheres incorporated with Bi2MoO6/g-C3N4 enhanced photocatalysis towards environmental pollutant Rhodamine B removal.

We have adopted a novel CeO2/Bi2MoO6/g-C3N4-based ternary nanocomposite that was synthesized via hydrothermal technique. The physiochemical characterization of as-prepared samples was examined through various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy TEM, photoluminescent spectra (PL), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and ultraviolet diffuse reflectance spectroscopy (UV-DRS) technique. In addition, the photocatalytic performance was carried out by degradation of Rhodamine B dye under visible light irradiation using this nanocatalyst. The ternary nanocomposite achieved 94% of the degradation efficiency within 100 min which is higher than the pristine and binary composites under the predetermined condition pH = 7, Rhodamine B dye = 5 mg/L, and catalyst concentration = 150 mg/L. The experimental synergetic effect of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite has been ascribed to the interfacial charge carrier migration between CeO2, Bi2MoO6, and g-C3N4. The optical absorption range of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite was enhanced, and the band gap was reduced up to 2.2 eV. In addition, scavenger trapping experiment proves that the super oxide anions (O2-.) and photogenerated holes are the major active species. The reusability and stability experiment proved the CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite keeps good durability during the photocatalytic degradation process after the five successive cycles. Furthermore, based on the results, the charge carrier transfer photocatalytic mechanism was also discussed. This CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite may offer the cheapest material and extend the great opportunity for clean and environmental remediation approach under the visible light irradiation.

Visual and Quantitative Evaluation of Low-Concentration Bismuth in Dual-Contrast Imaging of Iodine and Bismuth Using Clinical Photon-Counting CT.

Simultaneous dual-contrast imaging of iodine and bismuth has shown promise in prior phantom and animal studies utilizing spectral CT. However, it is noted that in previous studies, Pepto-Bismol has frequently been employed as the source of bismuth, exceeding the recommended levels for human subjects. This investigation sought to assess the feasibility of visually differentiating and precisely quantifying low-concentration bismuth using clinical dual-source photon-counting CT (PCCT) in a scenario involving both iodinated and bismuth-based contrast materials. Four bismuth samples (0.6, 1.3, 2.5, and 5.1 mg/mL) were prepared using Pepto-Bismol, alongside three iodine rods (1, 2, and 5 mg/mL), inserted into multi-energy CT phantoms with three different sizes, and scanned on a PCCT system at three tube potentials (120, 140, and Sn140 kV). A generic image-based three-material decomposition method generated iodine and bismuth maps, with mean mass concentrations and noise levels measured. The root-mean-square errors for iodine and bismuth determined the optimal tube potential. The tube potential of 140 kV demonstrated optimal quantification performance when both iodine and bismuth were considered. Distinct differentiation of iodine rods with all three concentrations and bismuth samples with mass concentrations ≥ 1.3 mg/mL was observed across all phantom sizes at the optimal kV setting.

Glutathione and acid dual-responsive bismuth-based nanosensitizer for chemo-mediated cancer sonodynamic therapy.

Chemotherapeutic agents hold significant clinical potential in combating tumors. However, delivering these drugs to the tumor site for controlled release remains a crucial challenge. In this study, we synthesize and construct a glutathione (GSH) and acid dual-responsive bismuth-based nano-delivery platform (BOD), aiming for sonodynamic enhancement of docetaxel (DTX)-mediated tumor therapy. The bismuth nanomaterial can generate multiple reactive oxygen species under ultrasound stimulation. Furthermore, the loading of DTX to form BOD effectively reduces the toxicity of DTX in the bloodstream, ensuring its cytotoxic effect is predominantly exerted at the tumor site. DTX can be well released in high expression of GSH and acidic tumor microenvironment. Meanwhile, ultrasound can also promote the release of DTX. Results from bothin vitroandin vivoexperiments substantiate that the synergistic therapy involving chemotherapy and sonodynamic therapy significantly inhibits the growth and proliferation of tumor cells. This study provides a favorable paradigm for developing a synergistic tumor treatment platform for tumor microenvironment response and ultrasound-promoted drug release.

In situ construction of Ag/Bi2O3/Bi5O7I heterojunction with Bi-MOF for enhance the photocatalytic efficiency of bisphenol A by facet-coupling and s-scheme structure.

In this study, Ag/Bi2O3/Bi5O7I with s-scheme heterostructures were successfully synthesized in situ by nano-silver modification of CUA-17 and halogenated hydrolysis.The growth rate of Bi2O3 crystals was effectively controlled by adjusting the doping amount of Ag, resulting in the formation of a facet-coupling heterojunctions. Through the investigation of the microstructure and compositional of catalysts, it has been confirmed that an intimate facet coupling between the Bi2O3 (120) facet and the Bi5O7I (312) facet, which provides robust support for charge transfer. Under visible light irradiation, the AgBOI.3 heterojunction photocatalyst exhibited an outstanding degradation rate of 98.2% for Bisphenol A (BPA) with excellent stability. Further characterization using optical, electrochemical, impedance spectroscopy, and electron spin resonance techniques revealed significantly enhanced efficiency in photogenerated charge separation and transfer, and confirming the s-scheme structure of the photocatalyst. Density functional theory calculations was employed to elucidate the mechanism of BPA degradation and the degradation pathway of BPA was investigated by LC-MS. Finally, the toxicity of the degradation intermediates was evaluated using T.E.S.T software.

Fabrication of Bi2Te3 and Sb2Te3 Thermoelectric Thin Films using Radio Frequency Magnetron Sputtering Technique.

Through various studies on thermoelectric (TE) materials, thin film configuration gives superior advantages over conventional bulk TEs, including adaptability to curved and flexible substrates. Several different thin film deposition methods have been explored, yet magnetron sputtering is still favorable due to its high deposition efficiency and scalability. Therefore, this study aims to fabricate a bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) thin film via the radio frequency (RF) magnetron sputtering method. The thin films were deposited on soda lime glass substrates at ambient temperature. The substrates were first washed using water and soap, ultrasonically cleaned with methanol, acetone, ethanol, and deionized water for 10 min, dried with nitrogen gas and hot plate, and finally treated under UV ozone for 10 min to remove residues before the coating process. A sputter target of Bi2Te3 and Sb2Te3 with Argon gas was used, and pre-sputtering was done to clean the target's surface. Then, a few clean substrates were loaded into the sputtering chamber, and the chamber was vacuumed until the pressure reached 2 x 10-5 Torr. The thin films were deposited for 60 min with Argon flow of 4 sccm and RF power at 75 W and 30 W for Bi2Te3 and Sb2Te3, respectively. This method resulted in highly uniform n-type Bi2Te3 and p-type Sb2Te3 thin films.

CdS/Bi2S3/NiS ternary heterostructure-based photoelectrochemical immunosensor for the sensitive detection of carbohydrate antigen 125.

The sensitive, accurate and rapid detection of carbohydrate antigen 125 (CA125) is essential for the early diagnosis and clinical management of ovarian cancer, but there is still challenge. Herein, a photoelectrochemical (PEC) immunosensor based on CdS/Bi2S3/NiS ternary sulfide heterostructured photocatalyst was presented for the detection of CA125. The CdS/Bi2S3/NiS was synthesized by a one-step hydrothermal approach. The heterojunction comprising of CdS and Bi2S3 could separate photogenerated carriers, the introduced narrow bandgap NiS could act as electron-conducting bridge to facilitate the transfer of interfacial photogenerated electrons, thereby improving the photoelectric conversion efficiency. Due to their synergistic effect, the photocurrent response produced by the composite was up to 14.6 times of pure CdS. On the basis, a PEC immunosensor was constructed by introducing the CA125 antibody through thioglycolic acid linkage. It was found that the resulting immunosensor showed good performance. Under the optimized conditions, its linear detection range was as wide as 1 pg mL-1-50 ng mL-1, and the detection limit was low to 0.85 pg mL-1. Furthermore, we experimentally tested its anti-interference, stability and reproducibility, and satisfactory results were achieved. The practicable feasibility of the sensor was confirmed by testing serum sample. Thus this work provided a simple, fast and enough sensitive approach for CA125 monitoring.

Bismuth Film along with dsDNA-Modified Electrode Surfaces as Promising (bio)Sensors in the Analysis of Heavy Metals in Soils.

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.

Electrochemical biosensor for sensitive detection of SARS-CoV-2 gene fragments using Bi2Se3 topological insulator.

In this study, we have designed an electrochemical biosensor based on topological material Bi2Se3 for the sensitive detection of SARS-CoV-2 in the COVID-19 pandemic. Flake-shaped Bi2Se3 was obtained directly from high-quality single crystals using mechanical exfoliation, and the single-stranded DNA was immobilized onto it. Under optimal conditions, the peak current of the differential pulse voltammetry method exhibited a linear relationship with the logarithm of the concentration of target-complementary-stranded DNA, ranging from 1.0 × 10-15 to 1.0 × 10-11 M, with a detection limit of 3.46 × 10-16 M. The topological material Bi2Se3, with Dirac surface states, enhanced the signal-to-interference plus noise ratio of the electrochemical measurements, thereby improving the sensitivity of the sensor. Furthermore, the electrochemical sensor demonstrated excellent specificity in recognizing RNA. It can detect complementary RNA by amplifying and transcribing the initial DNA template, with an initial DNA template concentration ranging from 1.0 × 10-18 to 1.0 × 10-15 M. Furthermore, the sensor also effectively distinguished negative and positive results by detecting splitting-synthetic SARS-CoV-2 pseudovirus with a concentration of 1 copy/µL input. Our work underscores the immense potential of the electrochemical sensing platform based on the topological material Bi2Se3 in the detection of pathogens during the rapid spread of acute infectious diseases.

Efficacy of Tetracycline Three Times Daily was Comparable to That of Four Times Daily for Helicobacter pylori Rescue Treatment: A Multicenter, Noninferiority, Randomized Controlled Trial.

BACKGROUND: The optimal dosage of tetracycline remains unclear for Helicobacter pylori eradication. Frequent dosing requirements may decrease patient adherence and increase the incidence of adverse events, potentially reducing treatment efficacy. This study aimed to compare the efficacy of different tetracycline dosages in rescue treatment for H. pylori infection. METHODS: A total of 406 patients needing H. pylori rescue treatment were enrolled. Patients were randomized into two groups and received bismuth-containing quadruple therapies as follows: esomeprazole 40 mg twice daily, bismuth 220 mg twice daily, amoxicillin 1000 mg twice daily, and tetracycline 500 mg either three (TET-T group) or four (TET-F group) times daily. At least 6 weeks after treatment completion, a 13C-urea breath test was performed to evaluate H. pylori eradication. RESULTS: The intention-to-treat (ITT) eradication rates were 91.13% (185/203) and 90.15% (183/203) (p = 0.733), the modified ITT (MITT) eradication rates were 94.87% (185/195) and 95.31% (183/192) (p = 0.841), and the per-protocol (PP) eradication rates were 94.79% (182/192) and 95.21% (179/188) (p = 0.851) in the TET-T group and TET-F group, respectively. The eradication rates for the TET-T group were not inferior to those of the TET-F group in ITT, MITT, and PP analyses. The incidence of adverse effects was significantly lower in the TET-T group than in the TET-F group (23.65% vs. 33.50%, p = 0.028). No significant differences were observed in treatment compliance between the groups. CONCLUSIONS: The dose of tetracycline administered three times daily showed comparable efficacy to that administered four times daily, while significantly reducing the incidence of adverse events. The combination of tetracycline and amoxicillin in bismuth-containing quadruple therapy achieved a high eradication rate in H. pylori rescue treatment.

The second Irish Helicobacter pylori Working Group consensus for the diagnosis and treatment of Helicobacter pylori infection in adult patients in Ireland.

BACKGROUND: There has been an increase in resistance to many of the antimicrobials used to treat Helicobacter pylori ( H. pylori ) nationally and internationally. Primary clarithromycin resistance and dual clarithromycin and metronidazole resistance are high in Ireland. These trends call for an evaluation of best-practice management strategies. OBJECTIVE: The objective of this study was to revise the recommendations for the management of H. pylori infection in adult patients in the Irish healthcare setting. METHODS: The Irish H. pylori working group (IHPWG) was established in 2016 and reconvened in 2023 to evaluate the most up-to-date literature on H. pylori diagnosis, eradication rates and antimicrobial resistance. The 'GRADE' approach was then used to rate the quality of available evidence and grade the resulting recommendations. RESULTS: The Irish H. pylori working group agreed on 14 consensus statements. Key recommendations include (1) routine antimicrobial susceptibility testing to guide therapy is no longer recommended other than for clarithromycin susceptibility testing for first-line treatment (statements 6 and 9), (2) clarithromycin triple therapy should only be prescribed as first-line therapy in cases where clarithromycin susceptibility has been confirmed (statement 9), (3) bismuth quadruple therapy (proton pump inhibitor, bismuth, metronidazole, tetracycline) is the recommended first-line therapy if clarithromycin resistance is unknown or confirmed (statement 10), (4) bismuth quadruple therapy with a proton pump inhibitor, levofloxacin and amoxicillin is the recommended second-line treatment (statement 11) and (5) rifabutin amoxicillin triple therapy is the recommend rescue therapy (statement 12). CONCLUSION: These recommendations are intended to provide the most relevant current best-practice guidelines for the management of H. pylori infection in adults in Ireland.