Perioperative Dexamethasone Split Between 2 Doses Further Reduced Early Postoperative Nausea and Vomiting Than Single-Dose Dexamethasone: A Randomized Blinded Placebo-Controlled Trial.

BACKGROUND: We investigated whether 2 doses of dexamethasone are more effective than a single dose in reducing early postoperative nausea and vomiting (PONV) during total knee arthroplasty (TKA). METHODS: A total of 150 patients between June 2021 and June 2022 were randomized into 3 groups: 2 doses of normal saline (group A), a single dose of 10 mg dexamethasone before surgery and normal saline after surgery (group B), and 2 doses of 5 mg dexamethasone during the perioperative period (group C). Primary outcomes were incidences and severity of PONV within 24 hours after surgery, the number and consumption of patients requiring morphine and metoclopramine, and visual analog scale scores for nausea and vomiting at 2, 4, 6, and 24 hours after surgery. Blood glucose levels on days 1, 2, and 3 after operation and incidences of surgical site infection (SSI) as well as gastrointestinal bleeding (GIB) within 45 days after operation were compared. RESULTS: Within 24 hours after operation, the number and consumption of patients requiring morphine and metoclopramide in groups B and C were significantly lower than those in group A. Incidences and severity of PONV in groups B and C were significantly lower than those in group A. And these differences between groups B and C were significant. At 2, 4, 6, and 24 hours after operation, there were significant differences in visual analog scale scores of PONV between groups A and B, A and C, as well as B and C. On postoperative days 1, 2, and 3, there were no significant differences in blood glucose levels among the groups, and there were no incidences of SSI or GIB in any group within 45 days after operation. CONCLUSION: Dexamethasone significantly reduces PONV within 24 hours after TKA, does not result in significant changes in postoperative blood glucose levels, and does not increase the risk of SSI or GIB, particularly on group C. REGISTRATION NUMBER: ChiCTR2400088512. REGISTRATION CENTER: Chinese Clinical Trial Registry (ChiCTR). WEBSITE: www.chictr.org.cn.

The role of mitochondrial quality control mechanisms in chondrocyte senescence.

Chondrocytes are the exclusive cellular constituents of articular cartilage, and their functional status governs the health of the cartilage. The primary factor contributing to the deterioration of cartilage structure and function is chondrocyte senescence. In hypoxia and hypodextrose environment, chondrocytes heavily rely on glycolysis for energy metabolism. Mitochondria, acting as the regulatory hub for chondrocyte energy metabolism, exhibit dysfunction before chondrocyte senescence, indicating their crucial involvement in the process. Previous research has suggested that molecules associated with mitochondrial quality control mechanisms can effectively restore mitochondrial function and alleviate chondrocyte senescence. However, there remains to be clarity regarding the relationship between mitochondrial quality control mechanisms and differences in efficacy among various target molecules, which pose challenges when evaluating them in chondrocytes. By conducting a comprehensive review of the existing literature on mitochondrial quality control mechanisms and chondrocyte senescence, we gain further insights into this intricate relationship while identifying promising targets that could potentially open up novel avenues for the treatment of chondrocyte senescence.

Efficient Removal of Congo Red, Methylene Blue and Pb(II) by Hydrochar-MgAlLDH Nanocomposite: Synthesis, Performance and Mechanism.

Organic dyes and heavy metals often coexist in industrial effluents, and their simultaneous removal is a grand challenge. Herein, a hydrochar and MgAl layered double hydroxide (HC-MgAlLDH) nanocomposite was prepared via a facile one-step hydrothermal route, and applied to remove anionic Congo red (CR), cationic Methylene blue (MB) and Pb(II) from aqueous solutions. The nanocomposite was formed by interweaving amorphous HC and crystalline MgAlLDH nanoplates and possessed more functional groups, lower zeta potential and larger specific surface area than uncomposited MgAlLDH. Batch removal experiments showed that the components HC and LDH dominated the CR and MB removals, respectively, whereas Pb(II) removal was conjointly controlled by the two components. The maximum Langmuir removal capacities of the nanocomposite to sole CR, MB, or Pb(II) were 348.78, 256.54 or 33.55 mg/g. In binary and ternary systems, the removal capacities of CR and MB only slightly decreased, while the capacity of Pb(II) increased by 41.13-88.61%. The increase was related to the coordination of Pb(II) with the sulfur-containing groups in dyes and the precipitation of PbSO4. Therefore, the simultaneous removal of CR, MB and Pb(II) was involved in a synergistic effect, including electrostatic adsorption, π-π interaction, coordination and precipitation. The present work shows that the HC-MgAlLDH nanocomposite has great potential for wastewater integrative treatment.

Mn3O4@polyaniline nanocomposite with multiple active sites to capture uranium(VI) and iodide: synthesis, performance, and mechanism.

A major challenge for radioactive wastewater treatment and associated environmental remediation is how to simultaneously remove cationic and anionic radionuclides. Herein, a series of Mn3O4@polyaniline (Mn3O4@PANI) nanocomposites were successfully prepared and used to remove U(VI) and I- from aqueous solution, two highly concomitant species in nuclear pollution settings. Batch adsorption experiments reveal that the component Mn3O4 is predominantly responsible for U(VI) removal, but PANI for I-. The nanocomposite with 24.2 wt% Mn3O4 possesses high removal percentages (> 85%) either for U(VI) or I- over a wide pH range, fast removal kinetics, and excellent adsorption selectivity at high concentrations of competing ions. Benefiting from the contributions of the two components and the high adsorption affinities, the nanocomposite achieves the simultaneous removal to coexisting U(VI) and I-, with a maximum adsorption capacity 102.6 mg/g for U(VI) and 126.1 mg/g for I-. X-ray photoelectron spectroscopy (XPS) results reveal that the U(VI) adsorption occurs via coordination bonding with Mn-O, -NH- , and =N- groups in the nanocomposite, whereas I- adsorption proceeds mainly through I anionic species exchange with Cl- and interactions with π-bonds in PANI, as well as the electrostatic attraction onto Mn3O4. Considering the excellent performance and multiple active sites, the Mn3O4@PANI nanocomposite is promising to remove practical radioactive U(VI) and I-.

5-methoxytryptophan induced apoptosis and PI3K/Akt/FoxO3a phosphorylation in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a highly prevalent malignancy worldwide, and new therapeutic targets urgently need to be found to prolong patient survival. 5-methoxytryptophan (5-MTP) is a tryptophan metabolite found in animals and humans. However, the effects of 5-MTP on proliferation and apoptosis of CRC cells are currently unknown. AIM: To investigate the effects of 5-MTP on the proliferation, migration, invasion, and apoptosis abilities of CRC cells. Additionally, we seek to explore whether 5-MTP has the potential to be utilized as a drug for the treatment of CRC. METHODS: In order to evaluate the effect of 5-MTP on CRC cells, a series of experiments were conducted for evaluation. Colony formation assay and Cell Counting Kit 8 assays were used to investigate the impact of 5-MTP on the proliferation of CRC cell lines. Cell cycle assays were employed to examine the effect of 5-MTP on cellular growth. In addition, we investigated the effects of 5-MTP on apoptosis and reactive oxygen species in HCT-116 cells. To obtain a deeper understanding of how 5-MTP affects CRC, we conducted a study to examine its influence on the PI3K/Akt signaling pathway in CRC cells. RESULTS: This article showed that 5-MTP promoted apoptosis and cell cycle arrest and inhibited cell proliferation in CRC cells. In many articles, it has been reported that PI3K/Akt/FoxO3a signaling pathway is one of the most important signaling pathways involved in internal regulating cell proliferation and differentiation. Nevertheless, 5-MTP combined with PI3K/Akt/FoxO3a signaling pathway inhibitors significantly promoted apoptosis and cell cycle arrest and inhibited cell proliferation in CRC cells compared with 5-MTP alone in our study. CONCLUSION: Therefore, there is strong evidence that 5-MTP can be used as an effective medicine for CRC treatment.

Fe3O4-Mg(OH)2 nanocomposite as a scavenger for silver nanoparticles: Rational design, facile synthesis, and enhanced performance.

Silver nanoparticles (AgNPs) are considered as emerging contaminants because of their high toxicity and increasing environmental impact. Removal of discharged AgNPs from water is crucial for mitigating the health and environmental risks. However, developing facile, economical, and environment-friendly approaches remains challenging. Herein, an Fe3O4-Mg(OH)2 nanocomposite, as a novel magnetic scavenger for AgNPs, was prepared by loading Fe3O4 nanoparticles on Mg(OH)2 nanoplates in a one-pot synthesis. Batch removal experiments revealed that the maximum removal capacities for the two model AgNPs (citrate- or polyvinylpyrrolidone-coated AgNPs) were 476 and 442 mg/g, respectively, corresponding to partition coefficients 8.03 and 4.89 mg/g/µM. Removal feasibilities over a wide pH range of 5-11 and in real water matrices and scavenger reusability with five cycles were also confirmed. Both Fe3O4 and Mg(OH)2 components contributed to the removal; however, their nanocomposites exhibited an enhanced performance because of the high specific surface area and pore volume. Chemical adsorption and electrostatic attraction between the coatings on the AgNPs and the two components in the nanocomposite was considered to be responsible for the removal. Overall, the facile synthesis, convenient magnetic separation, and high removal performance highlight the great potential of the Fe3O4-Mg(OH)2 nanocomposite for practical applications.

Abiotic Formation of Calcium Oxalate under UV Irradiation and Implications for Biomarker Detection on Mars.

A major objective in the exploration of Mars is to test the hypothesis that the planet has ever hosted life. Biogenic compounds, especially biominerals, are believed to serve as biomarkers in Raman-assisted remote sensing missions. However, the prerequisite for the development of these minerals as biomarkers is the uniqueness of their biogenesis. Herein, tetragonal bipyramidal weddellite, a type of calcium oxalate, is successfully achieved by UV-photolyzing pyruvic acid (PA). The as-prepared products are identified and characterized by micro-Raman spectroscopy and field emission scanning electron microscopy. Persistent mineralization of weddellite is observed with altering key experimental parameters, including pH, Ca2+ and PA concentrations. In particular, the initial concentration of PA can significantly influence the morphology of weddellite crystal. Oxalate acid is commonly of biological origin; thus calcium oxalate is considered to be a biomarker. However, our results reveal that calcium oxalate can be harvested by a UV photolysis pathway. Moreover, prebiotic sources of organics (e.g., PA, glycine, alanine, and aspartic acid) have been proven to be available through abiotic pathways. Therefore, our results may provide a new abiotic pathway of calcium oxalate formation. Considering that calcium oxalate minerals have been taken as biosignatures for the origin and early evolution of life on Earth and astrobiological investigations, its formation and accumulation by the photolysis of abiological organic compounds should be taken into account.

Morphogenesis and evolution mechanisms of bacterially-induced struvite.

Bacteria are able to induce struvite precipitation, and modify struvite morphology, leading to the mineral with various growth habits. However, the relevant work involving the morphogenesis is limited, thereby obstructing our understanding of bacterially mediated struvite mineralization. Here, an actinomycete Microbacterium marinum sp. nov. H207 was chosen to study its effect on struvite morphology. A combination of bacterial mineralization and biomimetic mineralization techniques was adopted. The bacterial mineralization results showed that strain H207 could induce the formation of struvite with grouping structure (i.e., a small coffin-like crystal grown on a large trapezoid-like substrate crystal), and the overgrowth structure gradually disappeared, while the substrate crystal further evolved into coffin-like, and quadrangular tabular morphology with time. The biomimetic experiments with different organic components confirmed that the soluble macromolecules rich in electronegative carboxyl groups secreted by strain H207 dominate the formation of the struvite grouping. The time-course biomimetic experiments with supernatant testified that the increase in pH and NH4+ content promoted the evolution of crystal habits. Moreover, the evolution process of substrate crystal can be divided into two stages. At the first stage, the crystal grew along the crystallographic b axis. At the later stage, coupled dissolution-precipitation process occurred, and the crystals grew along the corners (i.e., [110] and [1-10] directions). In the case of dissolution, it was also found that the (00-1) face of substrate crystal preferentially dissolved, which results from the low initial phosphate content and high PO43- density on this face. As a result, present work can provide a deeper insight into bio-struvite mineralization.

Removal and recovery of silver nanoparticles by hierarchical mesoporous calcite: Performance, mechanism, and sustainable application.

The widespread use of silver nanoparticles (AgNPs) inevitably leads to the environmental release of AgNPs. The released AgNPs can pose ecological risks because of their specific toxicity. However, they can also be used as secondary sources of silver metal. Herein, hierarchical mesoporous calcite (HMC) was prepared and used to remove and recover AgNPs from an aqueous solution. The batch experiments show that the HMC has high removal percentages for polyvinylpyrrolidone- and poly (vinyl alcohol)-coated AgNPs (PVP- and PVA-AgNPs) over a wide pH range of 6-10. The adsorption isotherms indicate that the maximum removal capacities are 55 and 19 mg g-1 for PVP-AgNPs and PVA-AgNPs, respectively, corresponding to partition coefficients (PCs) of 0.55 and 0.77 mg g-1 µM-1. Furthermore, the removal performance is also not impaired by coexisting anions, such as Cl-, NO3-, SO42-, and CO32-. Their removal mechanisms can be ascribed to the electrostatic attraction and chemical adsorption between the HMC and polymer-coated AgNPs. Calcium ions on the HMC surface serve as active sites for coordination with the oxygen-bearing functional groups of AgNP coatings. Moreover, the AgNPs adsorbed onto HMC show high catalytic activity and good reusability for the reduction of the organic pollutant 4-nitrophenol. This work may pave the way not only to remove metal nanopollutants from waters but also to convert them into functional materials.

Fluorescent CDs@PCL hybrids via tartaric acid, CDs-cocatalyzed polymerization.

In this paper, the environment-friendly, water-soluble carbon dots (CDs) with stable photoluminescence (PL) have been prepared via the one-step pyrolysis of lotus leaf. Then the as-prepared CDs containing abundant hydroxylic and carboxylic groups were employed as cocatalyst with tartaric acid (TA) in ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The low-toxic organic acid TA, as main catalyst, was used to catalyze the ROP of ε-CL efficiently. The fluorescent CDs@PCL hybrids were obviously hydrophobic and they exhibited an excellent biocompatibility, and biodegradability due to the existence of PCL. Therefore the hydrophobic, biodegradable and multi-color fluorescent CDs@PCL hybrids may have potential applications in biomedicine, photocatalyst, bioimaging, and environmental analysis. Furthermore the application of CDs in catalyzing and initiating polymerization reaction will exemplify the versatility of CDs in the most unexpected fields.