Prediction of As and Cd dissolution in various soils under flooding condition.

Although the mobility of arsenic (As) and cadmium (Cd) in soils during the flooding-drainage process has been intensively studied, predicting their dissolution among various soils still remains a challenge. After comprehensively monitoring multiple parameters related to As and Cd dissolution in 8 soils for a 60-day anaerobic incubation, the redundancy analysis (RDA) and structural equation model (SEM) were employed to identify the key factors and influencing pathways controlling the dynamic release of As and Cd. Results showed that pH alone explained 90.5 % Cd dissolution, while the dissolved-Fe(II) and 5 M-HCl extractable Fe(II) jointly only explained 50.6 % As dissolution. After data normalization, the ratio of Fe(II) to 5 M-HCl extracted total Fe (i.e. FetotII/Fetot) significantly improved the correlation to R2 = 0.824 (p < 0.001) with a fixed slope of 0.393 among the 8 soils. Our results highlight the crucial role played by the reduction degree of total iron contents in determining both the reduction and dissolution of As during flooding. In contrast, dissolved-Fe(II) was too vulnerable to soil properties to be a stable indicator of As dissolution. Therefore, we propose to replace the dissolved-Fe(II) with this novel ratio as the key index to quantitatively assess the kinetic change of As solubility potential across various soils under flooding conditions.

Alleviation of arsenic stress in pakchoi by foliar spraying of engineered nanomaterials.

Addressing heavy metal contamination in leafy vegetables is critically important due to its adverse effects on human health. In this study, we investigated the inhibitory effects of foliar spraying with four nanoparticles (CeO2, ZnO, SiO2, and S NPs) on arsenic (As) stress in pakchoi (Brassica rapa var. Chinensis). The findings reveal that foliar application of ZnO NPs at 1 ~ 2.5 mg plant-1 and CeO2 NPs at 5 mg plant-1 significantly reduces As in shoots by 40.9 ~ 47.3% and 39.4%, respectively. Moreover, 5 mg plant-1 CeO2 NPs increased plant height by 6.06% and chlorophyll a (Chla) content by 30.2% under As stress. Foliar spraying of CeO2 NPs at 0.2-5 mg plant-1 also significantly enhanced superoxide dismutase (SOD) activity in shoots by 9.4 ~ 13.9%, lowered H2O2 content by 42.4 ~ 53.25%, and increased root protein contents by 79 ~ 109.2%. CeO2 NPs regulate the As(III)/As(V) ratio, aiding in As efflux from roots and thereby reducing As toxicity to plants. In vitro digestion experiments reveal that the consumption of CeO2 NPs carries the lowest health risk of As. In addition, foliar spraying of ZnO NPs at 1 ~ 2.5 mg plant-1 can suppress plant As uptake by modulating enzyme activity, reducing leaf damage, and enhancing chlorophyll content. The study demonstrates that high CeO2 NP concentrations and suitable ZnO NP concentrations can alleviate As toxicity in pakchoi, consequently reducing human health risks.

Nanomedicine-induced cell pyroptosis to enhance antitumor immunotherapy.

Immunotherapy is a therapeutic modality designed to elicit or augment an immune response against malignancies. Despite the immune system's ability to detect and eradicate neoplastic cells, certain neoplastic cells can elude immune surveillance and elimination through diverse mechanisms. Therefore, antitumor immunotherapy has emerged as a propitious strategy. Pyroptosis, a type of programmed cell death (PCD) regulated by Gasdermin (GSDM), is associated with cytomembrane rupture due to continuous cell expansion, which results in the release of cellular contents that can trigger robust inflammatory and immune responses. The field of nanomedicine has made promising progress, enabling the application of nanotechnology to enhance the effectiveness and specificity of cancer therapy by potentiating, enabling, or augmenting pyroptosis. In this review, we comprehensively examine the paradigms underlying antitumor immunity, particularly paradigms related to nanotherapeutics combined with pyroptosis; these treatments include chemotherapy (CT), hyperthermia therapy, photodynamic therapy (PDT), chemodynamic therapy (CDT), ion-interference therapy (IIT), biomimetic therapy, and combination therapy. Furthermore, we thoroughly discuss the coordinated mechanisms that regulate these paradigms. This review is expected to enhance the understanding of the interplay between pyroptosis and antitumor immunotherapy, broaden the utilization of diverse nanomaterials in pyroptosis-based antitumor immunotherapy, and facilitate advancements in clinical tumor therapy.

Ultrasound-guided percutaneous microwave ablation of gallbladder polyps: A case report.

RATIONALE: Gallbladder polyps are a general term for localized lesions in which the gallbladder wall protrudes into the gallbladder cavity, and benign lesions are common. Although current guidelines recommend cholecystectomy for gallbladder polyps ≥ 10 mm in size, the probability of finding cancer in postoperative pathological specimens is low. We should avoid unnecessary cholecystectomy and treat polyps with gallbladder preservation. Microwave ablation is safe and effective for the treatment of solid lesions, and can inactivates polyps while preserving gallbladder. Hence, we report a case of ultrasound-guided percutaneous microwave ablation of gallbladder polyps. PATIENT CONCERNS: A 72-year-old female patient had previously diagnosed a gallbladder polyp, but it was not taken seriously. Recently, the patient had occasional right upper abdominal discomfort and a desire to preserve gallbladder. DIAGNOSES: Ultrasound showed a medium hyperechoic papillary protrusion in the gallbladder without echo behind, and the changed position did not move. Contrast-enhanced ultrasound (CEUS) showed no malignant signs. The diagnosis was a gallbladder polyp. INTERVENTIONS: The bile is drained and the drainage tube is fixed under real-time ultrasound guidance, then the gallbladder cavity is flushed and filled. Saline was injected between the serous and mucosal layers of the gallbladder to form an "edema band" to protect the gallbladder wall. Then, ultrasound-guided biopsy of gallbladder polyps was performed and sent for histological examination. Finally, the microwave needle was inserted into the target area under real-time ultrasonic guidance, and ablation was performed for 3 minutes (20 W). Postoperative CEUS: No significant enhancement was observed in the lesion. OUTCOMES: Within 6 months of follow-up, the patient's gallbladder systolic function was normal, and there was no discomfort and no recurrence. The lesion reduction rate reached 100% at 1 week after surgery. LESSONS: Ultrasound guided percutaneous microwave ablation of gallbladder polyps not only preserves the gallbladder but also inactivates the polyps without affecting the systolic function of the gallbladder, which provides a new idea for the treatment of gallbladder polyps.

Comparison of the effectiveness of lauromacrogol injection for ablation and microwave ablation in the treatment of predominantly cystic thyroid nodules: a multicentre study.

PURPOSE: To compare the therapeutic efficacy and safety of microwave ablation (MWA) and lauromacrogol injection for ablation (LIA) for benign predominantly cystic thyroid nodules. MATERIALS AND METHODS: In this retrospective study, 85 patients with predominantly cystic thyroid nodules (PCTNs) who underwent microwave ablation (MWA) or lauromacrogol injection for ablation (LIA) between June 2019 and August 2022 at three hospitals were included in our research. Forty-six patients were treated with microwave ablation, and thirty-nine patients were treated with lauromacrogol injection for ablation. The baseline characteristics, nodal volume, volume reduction rate (VRR), and incidence of postoperative complications were compared between these two groups. RESULTS: After treatment, there were significant differences in the thyroid nodule volume and the volume reduction rate (VRR) at different follow-up times between the groups (p < 0.001). There were no significant differences in the nodal volume or the volume reduction rate (VRR) between the MWA group and the LIA group at 1, 3, 6, and 12 months (p > 0.05). Of note, no serious intraoperative or postoperative complications occurred in the corresponding group. CONCLUSION: MWA and LIA are very effective and safe strategies for the treatment of predominantly cystic thyroid nodules. However, LIA is more advantageous in that it is less expensive and has a shorter length of hospital stay than MWA.

Colorimetric detection of viral RNA fragments based on an integrated logic-operated three-dimensional DNA walker.

Timely and accurate detection of virus is crucial for preventing spread of disease and early treatment of the infected cases. Herein we design an integrated logic-operated three-dimensional DNA walker for colorimetric detection of viral RNA fragments, by taking SARS-CoV-2 as an example. The DNA walker is composed of small amounts of dually-blocked walking strands and large amounts of dual-stem-loop track strands on gold nanoparticles. The walking strand contains a swing arm domain and a DNAzyme domain blocked at both sides of catalytic core, while the track strand contains a substrate domain located at the peripheral larger loop. Only the presence of both ORF1ab and N RNA fragments can fully de-block the walking strand, which then continuously hybridizes with track strands and cleaves them by DNAzyme-catalyzed hydrolysis. As the cleavage of track strands from long-stranded, double stem-loop structure to short-stranded, linear sequence, the DNA walker shows much lowered stability due to decreased negative charge density and diminished steric repulsion, which then gets aggregated at high salt concentration, accompanied by a visible color change. The colorimetric DNA walker detects RNA fragments down to 1 nM, responds dual viral genes in a "AND" logic way, and shows high specificity to target sequence. It can further detect large nucleic acids containing ORF1ab and N sequences, and reach 200 copies/mL detection limit by coupling a simple upstream amplification of sample. The method may provide a convenient way for reliable detection of viral RNA.

Vaccination games in prevention of infectious diseases with application to COVID-19.

Vaccination coverage is crucial for disease prevention and control. An appropriate combination of compulsory vaccination with voluntary vaccination is necessary to achieve the goal of herd immunity for some epidemic diseases such as measles and COVID-19. A mathematical model is proposed that incorporates both compulsory vaccination and voluntary vaccination, where a decision of voluntary vaccination is made on the basis of game evaluation by comparing the expected returns of different strategies. It is shown that the threshold of disease invasion is determined by the reproduction numbers, and an over-response in magnitude or information interval in the dynamic games could induce periodic oscillations from the Hopf bifurcation. The theoretical results are applied to COVID-19 to find out the strategies for protective immune barrier against virus variants.

Restriction of sulfate reduction on the bioavailability and toxicity of trace metals in Antarctic lake sediments.

In this study, Acid-Volatile Sulfur (AVS), trace metals Cu, Cd and Zn and their chemical speciation based on BCR-sequential and simultaneous extraction (SEMs) in Antarctic lake sediments (Y2-1 and YO) were analyzed to investigate the restriction of sulfate reduction on the bioavailability and toxicity of trace metals. Much higher trace metals in Y2-1 indicating a primary source from penguin guano. The main chemical speciation of Cu and Cd in Y2-1 was their oxidizable fraction in contrast to those of weak-acid extraction in YO. Lower ratio of ΣSEM/AVS in Y2-1 indicating less toxicity of the trace metals. The main chemical speciation of Cd in Y2-1 was their oxidizable fraction in contrast to that exchangeable fraction in penguin guano, indicating that although amounts of Cd was transported from marine to lake by penguins, strong sulfate reduction in ornithogenic sediments restricts the bioavailability and toxicity of Cd through the formation of insoluble sulfide.

Multianalyte determination of the kinetic rate constants of drug-cyclodextrin supermolecules by high performance affinity chromatography.

The kinetics of the dissociation is fundamental to the formation and the in vivo performance of cyclodextrin supramolecules. The individual determination of the apparent dissociation rate constant (kd,app) using high performance affinity chromatography (HPAC) is a tedious process requiring numerous separate studies and massive data fitting. In this study, the multianalyte approach was employed to simultaneously measure the kd,app values of three drugs through one injection based on the investigation of the dependence of drug-cyclodextrin interaction kinetics on the mobile phase composition. As a result, the kd,app values increased when decreasing the ion strength, increasing the ionization of drugs and adding extra organic solvents. The values of kd,app for acetaminophen, phenacetin and S-flurbiprofen estimated by the multianalyte approach were 8.54±1.81, 5.36±0.94 and 0.17±0.02s(-1), respectively, which were in good agreement with those determined separately (8.31±0.58, 5.01±0.42 and 0.15±0.01s(-1)). For both of the single and multiple flow rate peak profiling methods, the results of the multianalyte approach were statistically equivalent with that of the single compound analysis for all of the three drugs (p>0.05). The multianalyte approach can be employed for the efficient evaluation of the drug-cyclodextrin kinetics with less variance caused by cyclodextrin column bleeding.

Determination of the kinetic rate constant of cyclodextrin supramolecular systems by high performance affinity chromatography.

It is challenging and extremely difficult to measure the kinetics of supramolecular systems with extensive, weak binding (Ka<10(5)M(-1)), and fast dissociation, such as those composed of cyclodextrins and drugs. In this study, a modified peak profiling method based on high performance affinity chromatography (HPAC) was established to determine the dissociation rate constant of cyclodextrin supramolecular systems. The interactions of ß-cyclodextrin with acetaminophen and sertraline were used to exemplify the method. The retention times, variances and the plate heights of the peaks for acetaminophen or sertraline, conventional non-retained substance (H2O) on the ß-cyclodextrin bonded column and a control column were determined at four flow rates under linear elution conditions. Then, plate heights for the theoretical non-retained substance were estimated by the modified HPAC method, in consideration of the diffusion and stagnant mobile phase mass transfer. As a result, apparent dissociation rate constants of 1.82 (±0.01)s(-1) and 3.55 (±0.37)s(-1) were estimated for acetaminophen and sertraline respectively at pH 6.8 and 25°C with multiple flow rates. Following subtraction of the non-specific binding with the support, dissociation rate constants were estimated as 1.78 (±0.00) and 1.91 (±0.02)s(-1) for acetaminophen and sertraline, respectively. These results for acetaminophen and sertraline were in good agreement with the magnitude of the rate constants for other drugs determined by capillary electrophoresis reported in the literature and the peak fitting method we performed. The method described in this work is thought to be suitable for other supramolecules, with relatively weak, fast and extensive interactions.

[An oligopeptide improves solubility of paclitaxel by non-covalent interaction].

Based on the principle of non-covalent interactions between oligopeptides and paclitaxel for improving the solubility of paclitaxel, an oligopeptide, N terminal-W(L)-FFGREKD-C terminal (W8), was designed and the solubilization effect of W8 on paclitaxel was detected through experiments. The binding efficiency and the possible optimal conformation were optimized by molecular docking program. The solubilization effect of W8 on paclitaxel was determined by RP-HPLC. And the solubilization mechanism of oligopeptide to paclitaxel was proposed at molecular level. It was indicated from the docking result that there existed pi-pi interactions and several hydrogen-bond interactions between the oligopeptide and paclitaxel. After being solubilized by the oligopeptide, the aqueous solubility of paclitaxel was increased to 28 times. This study provided basis for further research of the solubilization of paclitaxel by oligopeptide and confirmed a novel approach for the design of safe oligopeptide solubilizing excipient.