High pyroptosis activity in pancreatic adenocarcinoma: poor prognosis and oxaliplatin resistance.

BACKGROUND: Pyroptosis, as a type of inflammatory programmed cell death, has been studied in inflammatory diseases and numerous cancers but its role in pancreatic ductal adenocarcinoma (PDAC) remains further exploration. METHODS: A TCGA-PDAC cohort was enrolled for bioinformatics analysis to investigate the effect of pyroptosis on the prognosis and drug sensitivity of patients. PA-TU-8988T and CFPAC-1 cells were selected for investigating the role of GSDMC in PDAC. RESULTS: A distinct classification pattern of PDAC mediated by 21 pyroptosis-related genes (PRGs) was identified. It was suggested that higher pyroptosis activity was associated with poor prognosis of patients and higher tumor proliferation rates. We further established a prognostic model based on three PRGs (GSDMC, CASP4 and NLRP1) and the TCGA-PDAC cohort was classified into low and high-risk subgroups. It is noteworthy that the high-risk group showed significantly higher tumor proliferation rates and was proved to be highly correlated with oxaliplatin resistance. Further experiments suggested that overexpression of GSDMC promoted the proliferation and oxaliplatin resistance of PA-TU-8988T cells in vitro and vivo, while downregulation of GSDMC showed opposite effects in CFPAC-1 cells. Finally, we found that the activation of pentose phosphate pathway (PPP) was the mechanism by which GSDMC overexpression promoted the proliferation and oxaliplatin resistance of pancreatic cancer cells. CONCLUSIONS: In this study, we found that higher pyroptosis activity is associated with worse prognosis and oxaliplatin resistance of PDAC patients. In addition, as a core effector of pyroptosis, GSDMC promoted proliferation and oxaliplatin resistance of pancreatic cancer cells, which will provide new therapeutic target for PDAC patients.

FeSe2 and Its Composites for Pollutants Removal: Synthesis, Mechanisms, and Application Potential.

In recent years, the research of FeSe2 and its composites in environmental remediation has been gradually carried out. And the FeSe2 materials show great catalytic performance in photocatalysis, electrocatalysis, and Fenton-like reactions for pollutants removal. Therefore, the studies and applications of FeSe2 materials are reviewed in this work, including the common synthesis methods, the role of Fe and Se species as well as the catalyst structure, and the potential for practical environmental applications. Hereinto, it is worth noting in particular that the lower-valent Se (Se2-), unsaturated Se (Se-), and Se vacancies (VSe) can play different roles in promoting pollutants removal. In addition, the FeSe2 material also demonstrates high stability, reusability, and adaptability over a wider pH range as well as universality to different pollutants. In view of the overall great properties and performance of FeSe2 materials compared with other typical Fe-based materials, it deserves and needs further research. And finally, this paper presents some challenges and perspectives in future development, looking forward to providing helpful guidance for the subsequent research of FeSe2 and its composites for environmental application.

DFT Predirected Molecular Engineering Design of Donor-Acceptor Structured g-C3N4 for Efficient Photocatalytic Tetracycline Abatement.

The photocatalytic environmental decontamination ability of carbon nitride (g-C3N4, CN) typically suffers from their inherent structural defects, causing rapid recombination of photogenerated carriers. Conjugating CN with tailored donor-acceptor (D-A) units to counteract this problem through electronic restructuring becomes a feasible strategy, where confirmation by density functional theory (DFT) calculations becomes indispensable. Herein, DFT is employed to predirect the copolymerization modification of CN by benzene derivatives, screening benzaldehyde as the optimal electron-donating candidate for the construction of reoriented intramolecular charge transfer path. Experimental characterization and testing corroborate the formation of a narrowed bandgap as well as high photoinduced carrier separation. Consequently, the optimal BzCN-2 exhibited superior photocatalytic capacity in application for tetracycline hydrochloride degradation, with 3.73 times higher than that of CN. Besides, the BzCN-2-based photocatalytic system is determined to have a toxicity-mitigating effect on TC removal via T.E.S.T and prefers the removal of dissociable TC2- species under partial alkalinity. This work provides insight into DFT guidance for the design of D-A conjugated polymer and its application scenarios in photocatalytic decontamination.

The Surface Confinement of FeO Assists in the Generation of Singlet Oxygen and High-Valent Metal-Oxo Species for Enhanced Fenton-Like Catalysis.

Transition metal compounds (TMCs) have long been potential candidate catalysts in persulfate-based advanced oxidation process (PS-AOPs) due to their Fenton-like catalyze ability for radical generation. However, the mechanism involved in TMCs-catalyzed nonradical PS-AOPs remains obscure. Herein, the growth of FeO on the Fe3O4/carbon precursor is regulated by restricted pyrolysis of MIL-88A template to activate peroxymonosulfate (PMS) for tetracycline (TC) removal. The higher FeO incorporation conferred a 2.6 times higher degradation performance than that catalyzed by Fe3O4 and also a higher interference resistance to anions or natural organic matter. Unexpectedly, the quenching experiment, probe method, and electron paramagnetic resonance quantitatively revealed that the FeO reassigned high nonradical species (1O2 and FeIV═O) generation to replace original radical system created by Fe3O4. Density functional theory calculation interpreted that PMS molecular on strongly-adsorbed (200) and (220) facets of FeO enjoyed unique polarized electronic reception for surface confinement effect, thus the retained peroxide bond energetically supported the production of 1O2 and FeIV═O. This work promotes the mechanism understanding of TMCs-induced surface-catalyzed persulfate activation and enables them better perform catalytic properties in wastewater treatment.

The Collision between g-C3 N4 and QDs in the Fields of Energy and Environment: Synergistic Effects for Efficient Photocatalysis.

Recently, graphitic carbon nitride (g-C3 N4 ) has attracted increasing interest due to its visible light absorption, suitable energy band structure, and excellent stability. However, low specific surface area, finite visible light response range (<460 nm), and rapid photogenerated electron-hole (e- -h+ ) pairs recombination of the pristine g-C3 N4 limit its practical applications. The small size of quantum dots (QDs) endows the properties of abundant active sites, wide absorption spectrum, and adjustable bandgap, but inevitable aggregation. Studies have confirmed that the integration of g-C3 N4 and QDs not only overcomes these limitations of individual component, but also successfully inherits each advantage. Encouraged by these advantages, the synthetic strategies and the fundamental of QDs/g-C3 N4 composites are briefly elaborated in this review. Particularly, the synergistic effects of QDs/g-C3 N4 composites are analyzed comprehensively, including the enhancement of the photocatalytic performance and the avoidance of aggregation. Then, the photocatalytic applications of QDs/g-C3 N4 composites in the fields of environment and energy are described and further combined with DFT calculation to further reveal the reaction mechanisms. Moreover, the stability and reusability of QDs/g-C3 N4 composites are analyzed. Finally, the future development of these composites and the solution of existing problems are prospected.

CaV3.2 calcium channels control NMDA receptor-mediated transmission: a new mechanism for absence epilepsy.

CaV3.2 T-type calcium channels, encoded by CACNA1H, are expressed throughout the brain, yet their general function remains unclear. We discovered that CaV3.2 channels control NMDA-sensitive glutamatergic receptor (NMDA-R)-mediated transmission and subsequent NMDA-R-dependent plasticity of AMPA-R-mediated transmission at rat central synapses. Interestingly, functional CaV3.2 channels primarily incorporate into synapses, replace existing CaV3.2 channels, and can induce local calcium influx to control NMDA transmission strength in an activity-dependent manner. Moreover, human childhood absence epilepsy (CAE)-linked hCaV3.2(C456S) mutant channels have a higher channel open probability, induce more calcium influx, and enhance glutamatergic transmission. Remarkably, cortical expression of hCaV3.2(C456S) channels in rats induces 2- to 4-Hz spike and wave discharges and absence-like epilepsy characteristic of CAE patients, which can be suppressed by AMPA-R and NMDA-R antagonists but not T-type calcium channel antagonists. These results reveal an unexpected role of CaV3.2 channels in regulating NMDA-R-mediated transmission and a novel epileptogenic mechanism for human CAE.

The application of transition metal-modified biochar in sulfate radical based advanced oxidation processes.

Sulfate radical (SO4•-) based advanced oxidation processes (SR-AOPs) is a very important chemical oxidation technology for the degradation of recalcitrant organic pollutants in water and has been well developed. Recently, transition metals or their oxides-modified biochar has been widely used as the catalyst to catalyze peroxymonosulfate (PMS) and peroxydisulfate (PS) in SR-AOPs due to their outstanding properties (e.g., large surface area, high stability, abound catalytic sites, and diversity of material design, etc.). These composite materials not only combine the respective beneficial characteristics of biochar and transition metals (or their oxides) but also often present synergistic effects between the components. In this review, we present the synthesis of different types of transition metal (or metal oxides)/biochar-based catalysts and their application in SR-AOPs. The catalytic mechanism, including the generation process of free radicals and other reaction pathways on the surface of the catalyst were also carefully discussed. Particular attention has been paid to the synergistic effects between the components that result in enhanced catalytic performance. At the end of this review, the future development prospects of this technology are proposed.

Prognostic impact of the ratio of preoperative CA19-9 to liver enzyme levels in pancreatic cancer patients with jaundice (predictability of combined CA19-9/AST and CA19-9/γ-GGT for jaundiced PDAC patients).

BACKGROUND: Carbohydrate antigen 19-9 (CA19-9) has been reported as the most significant survival predictor of patients with pancreatic ductal adenocarcinoma (PDAC). However, the elevation of CA19-9 could interfere with obstructive jaundice and the predictive value of CA19-9 in PDAC patients with jaundice remains to be analyzed and elucidated to find possible adjustments. OBJECTIVE: To evaluate the predictability of preoperative CA19-9 and its adjustments for the overall survival (OS) of PDAC patients by analyzing the relationship between preoperative serum CA19-9 and total bilirubin (TBIL). METHODS: A total of 563 consecutive patients who underwent surgery for primary pancreatic adenocarcinoma in our center between January 2015 and September 2018 were retrospectively reviewed. Clinicopathologic information was collected and preoperative parameters such as CA19-9, CEA, TBIL, γ-GGT, AST, ALT, and ALP were recorded as well as overall survival rates, which began from the date of operation to that of death or the last follow-up. Kaplan-Meier survival curves with log-rank test and Cox regression models were applied using SPSS and the survival and survminer packages in R software. RESULTS: Using 39/390/1000 as the cut-off values for preoperative serum CA19-9, significant capability of OS stratification was found in the total cohort (p < 0.001, MST = 29.7/19.1/15.2/12.1 months) and patients with TBIL <102.6 µmol/L (p < 0.001, MST = 32.2/19.6/15.0/11.2 months). However, in the subgroup of TBIL≥102.6 µmol/L, this classification method was replaced by the combined scoring of CA19-9/AST and CA19-9/γ-GGT. CONCLUSIONS: As an independent predictor of overall survival of PDAC patients, preoperative serum CA19-9 is defective in survival stratification when TBIL≥102.6 µmol/L but a positive survival prognosis could be achieved with the application of combined preoperative CA19-9/AST and CA19-9/γ-GGT.

ClpP participates in stress tolerance, biofilm formation, antimicrobial tolerance, and virulence of Enterococcus faecalis.

BACKGROUND: ClpP is important for bacterial growth and plays an indispensable role in cellular protein quality control systems by refolding or degrading damaged proteins, but the physiological significance of ClpP in Enterococcus faecalis remains obscure. A clpP deletion mutant (△clpP) was constructed using the E. faecalis OG1RF strain to clarify the effect of ClpP on E. faecalis. The global abundance of proteins was determined by a mass spectrometer with tandem mass tag labeling. RESULTS: The ΔclpP mutant strain showed impaired growth at 20 °C or 45 °C at 5% NaCl or 2 mM H2O2. The number of surviving ΔclpP mutants decreased after exposure to the high concentration (50× minimal inhibitory concentration) of linezolid or minocycline for 96 h. The ΔclpP mutant strain also demonstrated decreased biofilm formation but increased virulence in a Galleria mellonella model. The mass spectrometry proteomics data indicated that the abundances of 135 proteins changed (111 increased, 24 decreased) in the ΔclpP mutant strain. Among those, the abundances of stress response or virulence relating proteins: FsrA response regulator, gelatinase GelE, regulatory protein Spx (spxA), heat-inducible transcription repressor HrcA, transcriptional regulator CtsR, ATPase/chaperone ClpC, acetyl esterase/lipase, and chaperonin GroEL increased in the ΔclpP mutant strain; however, the abundances of ribosomal protein L4/L1 family protein (rplD), ribosomal protein L7/L12 (rplL2), 50S ribosomal protein L13 (rplM), L18 (rplR), L20 (rplT), 30S ribosomal protein S14 (rpsN2) and S18 (rpsR) all decreased. The abundances of biofilm formation-related adapter protein MecA increased, while the abundances of dihydroorotase (pyrC), orotate phosphoribosyltransferase (pyrE), and orotidine-5'-phosphate decarboxylase (pyrF) all decreased in the ΔclpP mutant strain. CONCLUSION: The present study demonstrates that ClpP participates in stress tolerance, biofilm formation, antimicrobial tolerance, and virulence of E. faecalis.

Central pancreatectomy for early-stage pancreatic ductal adenocarcinoma: a single-center case-control study.

PURPOSE: Central pancreatectomy (CP) has been applied for treating benign and low-grade malignant tumors in pancreatic neck, but studies regarding CP for pancreatic ductal adenocarcinoma (PDAC) are quite limited. We aimed to investigate the role of central pancreatectomy in the treatment of PDAC in the neck of the pancreas. METHODS: Patients who underwent CP at our hospital between 2009 and 2016 were identified. Patients treated by distal pancreatectomy (DP) were matched according to the tumor size, location, and staging. The surgical and survival outcomes were compared between the CP and DP groups. RESULTS: Nine patients had CP. Five (56%) had postoperative complications and three (33%) had clinically significant (grade B + C) fistula. No significant difference was found between the CP and DP groups for the rate of overall morbidity, pancreatic fistula, reoperation, and readmission. Tumor size was smaller in the CP group compared to the DP group. The mortality of both groups was zero. The median postoperative survival was similar between the two groups (20.4 months for CP vs 19.4 months for DP, P = 0.842). CONCLUSIONS: CP is safe for patients with small PDAC at the neck of the pancreas. Considering the good preservation of pancreatic endocrine and exocrine functions, CP could be considered as an alternative procedure for single small PDAC in pancreatic neck.

Piconewton-Scale Analysis of Ras-BRaf Signal Transduction with Single-Molecule Force Spectroscopy.

Intermolecular interactions dominate the behavior of signal transduction in various physiological and pathological cell processes, yet assessing these interactions remains a challenging task. Here, this study reports a single-molecule force spectroscopic method that enables functional delineation of two interaction sites (≈35 pN and ≈90 pN) between signaling effectors Ras and BRaf in the canonical mitogen-activated protein kinase (MAPK) pathway. This analysis reveals mutations on BRaf at Q257 and A246, two sites frequently linked to cardio-faciocutaneous syndrome, result in ≈10-30 pN alterations in RasBRaf intermolecular binding force. The magnitude of changes in RasBRaf binding force correlates with the size of alterations in protein affinity and in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-sensitive glutamate receptor (-R)-mediated synaptic transmission in neurons expressing replacement BRaf mutants, and predicts the extent of learning impairments in animals expressing replacement BRaf mutants. These results establish single-molecule force spectroscopy as an effective platform for evaluating the piconewton-level interaction of signaling molecules and predicting the behavior outcome of signal transduction.

General Anesthesia Causes Epigenetic Histone Modulation of c-Fos and Brain-derived Neurotrophic Factor, Target Genes Important for Neuronal Development in the Immature Rat Hippocampus.

BACKGROUND: Early postnatal exposure to general anesthesia (GA) may be detrimental to brain development, resulting in long-term cognitive impairments. Older literature suggests that in utero exposure of rodents to GA causes cognitive impairments in the first-generation as well as in the second-generation offspring never exposed to GA. Thus, the authors hypothesize that transient exposure to GA during critical stages of synaptogenesis causes epigenetic changes in chromatin with deleterious effects on transcription of target genes crucial for proper synapse formation and cognitive development. They focus on the effects of GA on histone acetyltransferase activity of cAMP-responsive element-binding protein and the histone-3 acetylation status in the promoters of the target genes brain-derived neurotrophic factor and cellular Finkel-Biskis-Jinkins murine sarcoma virus osteosarcoma oncogene (c-Fos) known to regulate the development of neuronal morphology and function. METHODS: Seven-day-old rat pups were exposed to a sedative dose of midazolam followed by combined nitrous oxide and isoflurane anesthesia for 6 h. Hippocampal neurons and organotypic hippocampal slices were cultured in vitro and exposed to GA for 24 h. RESULTS: GA caused epigenetic modulations manifested as histone-3 hypoacetylation (decrease of 25 to 30%, n = 7 to 9) and fragmentation of cAMP-responsive element-binding protein (two-fold increase, n = 6) with 25% decrease in its histone acetyltransferase activity, which resulted in down-regulated transcription of brain-derived neurotrophic factor (0.2- to 0.4-fold, n = 7 to 8) and cellular Finkel-Biskis-Jinkins murine sarcoma virus osteosarcoma oncogene (about 0.2-fold, n = 10 to 12). Reversal of histone hypoacetylation with sodium butyrate blocked GA-induced morphological and functional impairments of neuronal development and synaptic communication. CONCLUSION: Long-term impairments of neuronal development and synaptic communication could be caused by GA-induced epigenetic phenomena.

Canonical Organization of Layer 1 Neuron-Led Cortical Inhibitory and Disinhibitory Interneuronal Circuits.

Interneurons play a key role in cortical function and dysfunction, yet organization of cortical interneuronal circuitry remains poorly understood. Cortical Layer 1 (L1) contains 2 general GABAergic interneuron groups, namely single bouquet cells (SBCs) and elongated neurogliaform cells (ENGCs). SBCs predominantly make unidirectional inhibitory connections (SBC→) with L2/3 interneurons, whereas ENGCs frequently form reciprocal inhibitory and electric connections (ENGC↔) with L2/3 interneurons. Here, we describe a systematic investigation of the pyramidal neuron targets of L1 neuron-led interneuronal circuits in the rat barrel cortex with simultaneous octuple whole-cell recordings and report a simple organizational scheme of the interneuronal circuits. Both SBCs→ and ENGC ↔ L2/3 interneuronal circuits connect to L2/3 and L5, but not L6, pyramidal neurons. SBC → L2/3 interneuronal circuits primarily inhibit the entire dendritic-somato-axonal axis of a few L2/3 and L5 pyramidal neurons located within the same column. In contrast, ENGC ↔ L2/3 interneuronal circuits generally inhibit the distal apical dendrite of many L2/3 and L5 pyramidal neurons across multiple columns. Finally, L1 interneuron-led circuits target distinct subcellular compartments of L2/3 and L5 pyramidal neurons in a L2/3 interneuron type-dependent manner. These results suggest that L1 neurons form canonical interneuronal circuits to control information processes in both supra- and infragranular cortical layers.

Protocol to study microcircuits in the medial entorhinal cortex in mice using multiple patch-clamp recordings and morphological reconstruction.

Multiple patch-clamp recordings and morphological reconstruction are powerful approaches for neuronal microcircuitry dissection and cell type classification but are challenging due to the sophisticated expertise needed. Here, we present a protocol for applying these techniques to neurons in the medial entorhinal cortex (MEC) of mice. We detail steps to prepare brain slices containing MEC and perform simultaneous multiple whole-cell recordings, followed by procedures of histological staining and neuronal reconstruction. We then describe how we analyze morphological and electrophysiological features. For complete details on the use and execution of this protocol, please refer to Shi et al.1.

Simultaneous elimination of antibiotic-resistant bacteria and antibiotic resistance genes by different Fe-N co-doped biochars activating peroxymonosulfate: The key role of pyridine-N and Fe-N sites.

The coexistence of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in the environment poses a potential threat to public health. In our study, we have developed a novel advanced oxidation process for simultaneously removing ARGs and ARB by two types of iron and nitrogen-doped biochar derived from rice straw (FeN-RBC) and sludge (FeN-SBC). All viable ARB (approximately 108 CFU mL-1) was inactivated in the FeN-RBC/ peroxymonosulfate (PMS) system within 40 min and did not regrow after 48 h even in real water samples. Flow cytometry identified 96.7 % of dead cells in the FeN-RBC/PMS system, which verified the complete inactivation of ARB. Thorough disinfection of ARB was associated with the disruption of cell membranes and intracellular enzymes related to the antioxidant system. Whereas live bacteria (approximately 200 CFU mL-1) remained after FeN-SBC/PMS treatment. Intracellular and extracellular ARGs (tetA and tetB) were efficiently degraded in the FeN-RBC/PMS system. The production of active species, primarily •OH, SO4•- and Fe (IV), as well as electron transfer, were essential to the effective disinfection of FeN-RBC/PMS. In comparison with FeN-SBC, the better catalytic performance of FeN-RBC was mainly ascribed to its higher amount of pyridine-N and Fe0, and more reactive active sites (such as CO group and Fe-N sites). Density functional theory calculations indicated the greater adsorption energy and Bader charge, more stable Fe-O bond, more easily broken OO bond in FeN-RBC/PMS, which demonstrated the stronger electron transfer capacity between FeN-RBC and PMS. To encapsulate, our study provided an efficient and dependable method for the simultaneous elimination of ARGs and ARB in water.

Self-generating electricity system driven by aqueous humor flow and trabecular meshwork contraction motion activated BCKa for glaucoma intraocular pressure treatment.

Primary open-angle glaucoma (POAG) is the most common form of glaucoma and the leading cause of irreversible vision loss and blindness worldwide. Intraocular pressure (IOP) is the only modifiable risk factor, and prompt treatment to lower IOP can effectively slow the rate of vision loss due to glaucoma. Trabecular meshwork (TM) cells can maintain IOP homeostasis by correcting and adjusting the resistance to aqueous humor outflow in response to sustained pressure changes. TM cells' function is reduced, and membrane ion channels are impaired in POAG. The dysfunction of Large conductance Ca2+-activated K+ (BKCa) plays a central role in the pathogenesis of POAG. In this work, we targeted MXene nanoparticles (MXene-RGD) with piezoelectric response to TM cells in a 3D model of glaucoma in vitro as well as in the rabbit Transient Ocular Hypertension (OHT) Model in vivo. MXene-RGD gives the TM electromechanical transfer properties, while the self-enhancing and self-generated electricity properties of the TM are determined by the aqueous humor flow rate and the size of the deformation of the TM. MXene-RGD is nontoxic, as illustrated by a cell toxicity study and histological examination. In a 3D in vitro model of high-pressure glaucoma, whole-cell patch-clamp confirmed that piezoelectric stimulation turns on BKCa, which reduces the volume of the cell. MXene-RGD was injected into the anterior chamber with minimal trauma, i.e., anterior chamber injection, and specifically targeted to TM cells. The OHT model in vivo confirmed the potential IOP-lowering ability of MXene-RGD. We evaluated the ion channels involved in the reduction of IOP by MXene-RGD by pre-treatment with a BKCa channel blocker (iberiotoxin, IbTX) and a voltage-gated Ca2+channel blocker (nifedipine). Quantitative qPCR analysis showed that MXene-RGD inhibited the upregulation of mRNA expression levels of the myofibroblast marker α-smooth muscle actin (α-SMA) and the inflammatory response marker interleukin-6 (IL-6) induced by IOP. Histology confirmed that MXene-RGD attenuated IOP-induced proliferation and collagen production in the TM. Taken together, we present for the first time a minimally invasive surgical approach for targeting TM cells for POAG by utilizing piezoresponse nanomaterials to target BKCa to repair or awaken the ability of TM cells to regulate IOP homeostasis on their own.

In-Depth Investigation of Role of -BCO2 in the Degradation of Sulfamethazine by Metal-Free Biochar/Persulfate: The Mechanism of Occurrence of Nonradical Process.

The remediation of organic wastewater through advanced oxidation processes (AOPs) based on metal-free biochar/persulfate systems has been extensively researched. In this work, boron-doped alkali lignin biochar (BKC1:3) was utilized to activate peroxymonosulfate (PMS) for the removal of sulfamethazine (SMZ). The porous structure and substantial specific surface area of BKC1:3 facilitated the adsorption and thus degradation of SMZ. The XPS characterization and density functional theory (DFT) calculations demonstrated that -BCO2 was the main active site of BKC1:3, which dominated the occurrence of nonradical pathways. Neither quenching experiments nor EPR characterization revealed the generation of free radical signals. Compared with KC, BKC1:3 possessed more electron-rich regions. The narrow energy gap (ΔEgap = 1.87 eV) of BKC (-BCO2) promoted the electron transfer to the substable complex (BKC@PMS*) on SMZ, driving the electron transfer mechanism. In addition, the adsorption energy of BKC(-BCO2)@PMS was lower (-0.75 eV → -5.12 eV), implying a more spontaneous adsorption process. The O-O (PMS) bond length in BKC(-BCO2)@PMS increased significantly (1.412 Š→ 1.481 Å), which led to the easier decomposition of PMS during adsorption and facilitated the generation of 1O2. More importantly, a combination of Gaussian and LC-MS techniques was hypothesized regarding the attack sites and degradation intermediates of the active species in this system. The synergistic T.E.S.T software and toxicity tests predicted low or even no toxicity of the intermediates. Overall, this study proposed a strategy for the preparation of metal-free biochar, aiming to inspire ideas for the treatment of organic-polluted wastewater through advanced oxidation processes (AOPs).

Microplastic dilemma: Assessing the unexpected trade-offs between biodegradable and non-biodegradable forms on plant health, cadmium uptake, and sediment microbial ecology.

Despite extensive substitution of biodegradable plastics (BPs) for conventional plastics (CPs), research on their environmental ecological consequences as microplastics (MPs) is scarce. This study aimed to fill this gap by investigating the impacts of six prototypical MPs (categorized into BMPs and CMPs) on plant growth, cadmium (Cd) translocation, and bacterial communities in contaminated sediments. Results showed both BMPs and CMPs hindered plant development; yet interestingly, BMPs provoked more pronounced physiological and biochemical changes alongside increased oxidative stress due to reactive oxygen species accumulation. Notably, most MP types promoted the absorption of Cd by plant roots potentially via a "dilution effect". BMPs also induced larger shifts in soil microbial metabolic functions compared to CMPs. Ramlibacter was identified as a key biomarker distinguishing BMPs from CMPs, with link to multiple N metabolic pathways and N assimilation. This study offers novel insights into intricate biochemical mechanisms and environmental chemistry behaviors underpinning MP-Cd interactions within the plant-microbe-sediment system, emphasizing BMPs' higher potential ecological risks based on their significant effects on plant health and microbial ecology. This work contributes to enhancing the comprehensive understanding of their ecological implications and potential threats to environmental security.

In sight the behavior of natural Bletilla striata polysaccharide hydrocolloids by molecular dynamics method.

Plant polysaccharides, distinguished by diverse glycosidic bonds and various cyclic sugar units, constitute a subclass of primary metabolites ubiquitously found in nature. Contrary to common understanding, plant polysaccharides typically form hydrocolloids upon dissolution in water, even though both excessively high and low temperatures impede this process. Bletilla striata polysaccharides (BSP), chosen for this kinetic study due to their regular repeating units, help elucidate the relationship between polysaccharide gelation and temperature. It is suggested that elevated temperatures enhance the mobility of BSP molecular chains, resulting in a notable acceleration of hydrogen bond breakage between BSP and water molecules and consequently, compromising the conformational stability of BSPs to some extent. This study unveils the unique relationship between polysaccharide dissolution processes and temperature from a kinetics perspective. Consequently, the conclusion provides a dynamical basis for comprehending the extraction and preparation of natural plant polysaccharide hydrocolloids, pharmaceuticals and related fields.