Pistacia vera L. as natural source against antimicrobial and antiviral resistance.

Increased global research is focused on the development of novel therapeutics to combat antimicrobial and antiviral resistance. Pistachio nuts represent a good source of protein, fiber, monounsaturated fatty acids, minerals, vitamins, and phytochemicals (carotenoids, phenolic acids, flavonoids and anthocyanins). The phytochemicals found in pistachios are structurally diverse compounds with antimicrobial and antiviral potential, demonstrated as individual compounds, extracts and complexed into nanoparticles. Synergistic effects have also been reported in combination with existing drugs. Here we report an overview of the antimicrobial and antiviral potential of pistachio nuts: studies show that Gram-positive bacterial strains, such as Staphylococcus aureus, are the most susceptible amongst bacteria, whereas antiviral effect has been reported against herpes simplex virus 1 (HSV-1). Amongst the known pistachio compounds, zeaxanthin has been shown to affect both HSV-1 attachment penetration of human cells and viral DNA synthesis. These data suggest that pistachio extracts and derivatives could be used for the topical treatment of S. aureus skin infections and ocular herpes infections.

Impact of National Centralized Drug Procurement policy on chemical pharmaceutical enterprises' R&D investment: a difference-in-differences analysis in China.

Objective: This study aimed to evaluate the impact of the National Centralized Drug Procurement (NCDP) policy on chemical pharmaceutical enterprises' R&D investment and provide references for improving NCDP policy design and encouraging innovation in the pharmaceutical industry. Methods: Using the panel data of 102 Shanghai and Shenzhen A-share listed enterprises from 2016 to 2022 under the chemical pharmaceutical classification of Shenwan in Wind database as the research sample, this study developed difference-in-differences (DID) models on bid-winning and bid-non-winning enterprises, respectively, to evaluate the impact of NCDP policy on their R&D investment. In addition, this study tested the heterogeneity of bid-winning enterprises based on the bid success rate, the decline of drug price, and enterprise size. Results: The NCDP policy could encourage chemical pharmaceutical companies to increase R&D investment, but the low bid success rate and excessive drug price reduction would reduce their R&D enthusiasm, especially for small- and medium-sized enterprises. Discussion: It is suggested that the NCDP policy should be further improved: first, revise the bidding rule of the NCDP policy and increase the bid success rate so that more enterprises can win bids, and second, to solve the problem of excessive drug price reduction, evaluate the rationality of bid-winning prices, and introduce a two-way selection mechanism between medical institutions and supply enterprises. Integrate pharmacoeconomic evaluation into the NCDP rules to form a benign competition among enterprises. Third, attention should be paid to supporting policies for small- and medium-sized enterprises. By increasing procurement volume, shortening payment time limits, and increasing the proportion of advance payments, enterprises' cash flow shortages can be alleviated, thus achieving fairness and inclusiveness in the implementation of the NCDP policy.

Flavor Perception and Formation Mechanism of Empty Cup Aroma in Soy Sauce Aroma Type Baijiu.

The research focused on the distinctive empty cup aroma, with the aim of identifying the key aroma compounds and the formation mechanism of empty cup aroma in soy sauce aroma type baijiu (SSB). The lasting times of SSB is significantly longer than that of other types of baijiu, with an average duration of 28 days. Key compounds such as 2,3-dimethyl-5-ethylpyrazine, phenylethyl alcohol, p-cresol, sotolon, benzeneacetic acid were identified in empty cup aroma due to their highest flavor dilution factor. Molecular dynamics (MD) simulation was performed to study the mechanism of empty cup aroma on the liquid-gas interface and solid-gas interface. The results revealed the existence of hydrogen bonding and van der Waals forces between sotolon and lactic acid, a representative nonvolatile compound, which are speculated to be an important reason for the empty cup aroma.

Engineered small extracellular vesicle-mediated ferroptosis: A new frontier in cancer immunotherapy.

Ferroptosis is a novel iron-dependent form of cell death discovered in recent years, characterized by the accumulation of ferrous iron, the production of reactive oxygen species (ROS) through the Fenton reaction, and lipid peroxidation, ultimately leading to the disruption of the antioxidant system and cell membrane damage. Extensive research has found that ferroptosis plays a significant role in regulating tumor cell immune evasion, tumor development, and remodeling the tumor microenvironment. Small Extracellular vesicles (sEVs), carrying various bioactive molecules (ncRNA, DNA, proteins), are key nanoscale mediators of intercellular communication. Increasing evidence confirms that EVs can regulate the ferroptosis pathway in tumors, promoting tumor cell immune evasion and reshaping the tumor microenvironment. This article aims to comprehensively review the key mechanisms by which sEVs mediate ferroptosis in cancer and provide new insights into targeting tumor immunotherapy.

Inactivation efficacy and mechanism of 9.375 GHz electromagnetic wave on coronavirus.

Epidemics caused by pathogenic viruses are a severe threat to public health worldwide. Electromagnetic waves are a type of noncontact and nonionizing radiation technology that has emerged as an effective tool for inactivating bacterial pathogens. In this study, we used a 9.375 GHz electromagnetic wave to study the inactivation effect and mechanism of electromagnetic waves on MHV-A59, a substitute virus for pathogenic human coronavirus, and to evaluate the inactivation efficiency on different surface materials. We showed that 9.375 GHz electromagnetic waves inactivate MHV-A59 by destroying viral particles, envelopes, or genomes. We also found that 9.375 GHz electromagnetic waves can decrease the infectivity of viruses on the surface of inanimate materials such as plastic, glass, cloth, and wood. In conclusion, our results suggested that the 9.375 GHz electromagnetic wave is a promising disinfection technique for preventing the spread and infection of pathogenic viruses.

Molecular insights into the catalytic mechanism of a phthalate ester hydrolase.

Phthalate esters (PAEs) are emerging hazardous and toxic chemicals that are extensively used as plasticizers or additives. Diethyl phthalate (DEP) and dimethyl phthalate (DMP), two kinds of PAEs, have been listed as the priority pollutants by many countries. PAE hydrolases are the most effective enzymes in PAE degradation, among which family IV esterases are predominate. However, only a few PAE hydrolases have been characterized, and as far as we know, no crystal structure of any PAE hydrolases of the family IV esterases is available to date. HylD1 is a PAE hydrolase of the family IV esterases, which can degrade DMP and DEP. Here, the recombinant HylD1 was characterized. HylD1 maintained a dimer in solution, and functioned under a relatively wide pH range. The crystal structures of HylD1 and its complex with monoethyl phthalate were solved. Residues involved in substrate binding were identified. The catalytic mechanism of HylD1 mediated by the catalytic triad Ser140-Asp231-His261 was further proposed. The hylD1 gene is widely distributed in different environments, suggesting its important role in PAEs degradation. This study provides a better understanding of PAEs hydrolysis, and lays out favorable bases for the rational design of highly-efficient PAEs degradation enzymes for industrial applications in future.

Mechanisms mediating ethnoracial discrimination and suspiciousness in Asian, Black, and Hispanic United States college students.

BACKGROUND: Despite the robust relationship between ethnoracial discrimination and positive psychotic-like experiences (PLEs) like subclinical suspiciousness in adulthood, the underlying mechanisms remain underexamined. Investigating the mechanisms previously implicated in trauma and positive PLEs - including negative-self schemas, negative-other schemas, perceived stress, dissociative experiences, and external locus of control - may inform whether ethnoracial discrimination has similar or distinct effects from other social stressors. METHOD: We examined the indirect effects of experiences of discrimination (EOD) to suspicious PLEs and total positive PLEs through negative-self schemas, negative-other schemas, perceived stress, dissociative experiences, and external locus of control in Asian (nAsian = 268), Black (nBlack = 301), and Hispanic (nHispanic = 129) United States college students. RESULTS: Among Asian participants, results indicated a significant indirect effect of EOD to suspicious PLEs and EOD to positive PLEs via perceived stress, and EOD to positive PLEs via negative-self schemas. Among Hispanic participants, results indicated a significant indirect effect of EOD to suspicious PLEs and EOD to positive PLEs via dissociative experiences. No mechanisms appeared significant in Black participants nor were any significant direct effects observed across models, despite them reporting significantly greater experiences of ethnoracial discrimination. CONCLUSIONS: Our findings suggest some shared but potentially distinct mechanisms contribute to increased suspicious PLEs and positive PLEs in Asian, Black, and Hispanic college students, with results differing by group, compared to the mechanisms underlying trauma and positive PLEs, with implications for the treatment of PLEs in college students exposed to ethnoracial discrimination.

Compliant DNA Origami Nanoactuators as Size-Selective Nanopores.

Biological nanopores crucially control the import and export of biomolecules across lipid membranes in cells. They have found widespread use in biophysics and biotechnology, where their typically narrow, fixed diameters enable selective transport of ions and small molecules, as well as DNA and peptides for sequencing applications. Yet, due to their small channel sizes, they preclude the passage of large macromolecules, e.g., therapeutics. Here, the unique combined properties of DNA origami nanotechnology, machine-inspired design, and synthetic biology are harnessed, to present a structurally reconfigurable DNA origami MechanoPore (MP) that features a lumen that is tuneable in size through molecular triggers. Controllable switching of MPs between 3 stable states is confirmed by 3D-DNA-PAINT super-resolution imaging and through dye-influx assays, after reconstitution of the large MPs in the membrane of liposomes via an inverted-emulsion cDICE technique. Confocal imaging of transmembrane transport shows size-selective behavior with adjustable thresholds. Importantly, the conformational changes are fully reversible, attesting to the robust mechanical switching that overcomes pressure from the surrounding lipid molecules. These MPs advance nanopore technology, offering functional nanostructures that can be tuned on-demand - thereby impacting fields as diverse as drug delivery, biomolecule sorting, and sensing, as well as bottom-up synthetic biology.

Histone lactylation facilitates hepatocellular carcinoma progression by upregulating endothelial cell-specific molecule 1 expression.

Hepatocellular carcinoma (HCC) is a common malignant tumor. Histone lactylation, a novel epigenetic modification, plays a crucial role in various cancers. However, the functional role and underlying mechanism of histone lactylation in HCC progression have not yet been investigated. Histone lactylation levels in HCC tissues and cells were assessed using a densitometric kit and western blot analysis. The role of histone lactylation in cell malignant phenotypes was determined through functional assays in vitro, and a xenograft tumor model was established to verify the function of histone lactylation in vivo. ChIP assay was performed to explore the interaction between histone lactylation and endothelial cell-specific molecule 1 (ESM1). Additionally, gain-and-loss-of-function assays were conducted to investigate the regulatory role of ESM1 in HCC pathogenesis. Histone lactylation levels were increased in HCC tissues and cells, and H3K9 lactylation (H3K9la) and H3K56 lactylation (H3K56la) were identified as the histone modification sites. We observed that H3K9la and H3K56la caused abnormal histone lactylation and were associated with poor prognosis. Functionally, histone lactylation was found to promote HCC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) process in vitro. However, histone lactylation inhibition with 2-deoxy-d-glucose (2-DG) reduced the malignant phenotypes of HCC cells. In vivo, 2-DG treatment reduced tumor growth and metastasis in the HCC mouse model. Mechanistically, it was revealed that histone lactylation activated ESM1 transcription in HCC cells. ESM1 was expressed at a high level in HCC and exerted a carcinogenic role. Histone lactylation facilitates cell malignant phenotypes, tumor growth, and metastasis by upregulating ESM1 expression in HCC, which reveals the downstream molecular mechanism of histone lactylation and might provide a novel therapeutic target for HCC therapy.

Preparation of catalyst for CO2 hydrogenation reaction based on the idea of element sharing and preliminary exploration of catalytic mechanism.

Under the background of the continuous rise of CO2 annual emissions, the development of CO2 capture and utilization technology is urgent. This study focuses on improving the catalytic capacity of the catalyst for CO2 hydrogenation, improving the efficiency of CO2 conversion to methanol, and converting H2 into chemical substances to avoid the danger of H2 storage. Based on the concept of element sharing, the ASMZ (Aluminum Shares Metal Zeolite catalysts) series catalyst was prepared by combining the CuO-ZnO-Al2O3 catalyst with the ZSM-5 zeolite using the amphoteric metal properties of the Al element. The basic structural properties of ASMZ catalysts were compared by XRD, FTIR, and BET characterization. Catalytic properties of samples were measured on a micro fixed-bed reactor. The catalytic mechanism of the catalyst was further analyzed by SEM, TEM, XPS, H2-TPR, and NH3-TPD. The results show that the ASMZ3 catalyst had the highest CO2 conversion rate (26.4%), the highest methanol selectivity (76.0%), and the lowest CO selectivity (15.3%) in this study. This is mainly due to the fact that the preparation method in this study promotes the exposure of effective weakly acidic sites and medium strength acidic sites (facilitating the hydrogenation of CO2 to methanol). At the same time, the close binding of Cu-ZnO-Al2O3 (CZA) and ZSM-5 zeolite also ensures the timely transfer of catalytic products and ensures the timely play of various catalytic active centers. The preparation method of the catalyst in this study also provides ideas for the preparation of other catalysts.

Resilience mechanisms of Trichopria drosophilae (Hymenoptera: Diapriinae) under global extreme cooling: insights into parasitic response and physiological adaptation.

Global climate warming and frequent extreme low-temperature events have made it essential to investigate the impact of low temperatures on parasitic wasps to protect and strengthen farmland biodiversity, which in turn enhances the biological control potential of natural enemies such as parasitic wasps. We systematically examined how low-temperature stress affects the parasitic functional response of Trichopria drosophilae to Drosophila suzukii (Diptera: Drosophilidae) pupae. Our findings indicate that the parasitic behavior of T. drosophilae towards D. suzukii pupae aligns with the Holling II functional response model following exposure to different temperatures. Within the temperature range of 8 °C to -8 °C, lower temperatures correlated decreased instantaneous attack rate of T. drosophilae and an increase in processing time. The search constant Q initially increased and then decreased with declining temperatures. Short-term low-temperature stress negatively impacted the parasitic and searching abilities of T. drosophilae but did not alter its parasitic functional response model. Notably, short-term low-temperature stress had minimal effects on the water content, protein content, and total sugar content of male and female T. drosophilae adults. However, as temperatures decreased, the activities of key enzymes, including GAPDH, SOD, T-AOC, and malondialdehyde (MDA), exhibited an initial increase followed by a decrease. Conversely, the activities of LDH and HOAD decreased, while the activities of CAT and POD increased. Further study on the effect of short-term low temperature on T. drosophilae can provide a research basis for the large-scale production and low-temperature refrigeration technology of T. drosophilae, and provide a scientific basis for its efficient use in the field.

Efficient removal of moxifloxacin through PMS activation by CuFeS2/MXene.

Due to the frequent detection and potential toxicity of moxifloxacin (MOX), its removal technology had attracted attention in recent years. In this research, CuFeS2/MXene was prepared and used to activate peroxymonosulfate (PMS) to remove MOX. The degradation efficiencies, kinetics, influences, and reaction mechanism of MOX by CuFeS2/MXene/PMS were investigated. The synergistic effect of CuFeS2 and MXene significantly enhanced PMS activation, producing SO4•-, HO•, and 1O2 as the main active species. By adding 0.12 g/L CuFeS2/MXene and 0.12 mM PMS, MOX removal efficiency reached 99.1% within 40 min, with a rate constant of 0.1073 min-1. The composite ratios of CuFeS2/MXene impacted PMS activation more significantly than catalyst dosages and PMS concentrations. Acidic conditions were favorable for the degradation of MOX, while HCO3-, HPO42-, Mn2+, and HA had the inhibitory effects. Twelve major products were detected by HPLC-MS, and DFT was used to illustrate possible degradation pathways of MOX, including the removal of nitrogen-containing heterocycle and transformations of quinolone moieties. Toxicity analysis showed that the developmental toxicity, mutagenicity, and acute toxicity of degradation products tended to decrease. CuFeS2/MXene could exhibit excellent reusability, maintaining an average MOX degradation efficiency of 90.8% in the 7-cycle experiments.

Spatially discordant alternans due to periodic pacing site alternation.

BACKGROUND: Bidirectional ventricular tachycardia (BVT) is a rare type of ventricular tachycardia that is characterized by a beat-to-beat alternation in the QRS axis. Previous studies have shown that it is caused by alternating focal activities from two locations. OBJECTIVE: This study proposes a novel mechanism for the formation of spatially discordant alternans (SDA) due to the periodic pacing site alternation that occurs in BVT. METHODS: We used mathematical models of cardiac tissue to understand the dynamical and physiological mechanisms underlying SDA formation. RESULTS: We found that SDA was formed due to periodic pacing site alternation. When tissue was paced from two locations alternately, the timing of pacing at distant locations varied, creating a long-short-long-short sequence of pacing periods and thus action potential durations. Importantly, the nodal lines were perpendicular to the wavefront, which is more arrhythmogenic than when nodal lines are parallel to the wavefront. A positive correlation was observed between the separation distance of the two sites and the alternans amplitude. SDA patterns can be predicted from the tissue geometry and pacing site locations. CONCLUSION: Periodic pacing site alternation, which occurs in BVT, leads to arrhythmogenic SDA. The nodal lines associated with this phenomenon can be predicted based on tissue geometry and focal locations.

Kinetically Controlled Self-Assembly of Ag Nanoclusters with Enhanced Luminescence.

Constructing self-assembly with definite assembly structure-property correlation is of great significance for expanding the property richness and functional diversity of metal nanoclusters (NCs). Herein, a well-designed liquid reaction strategy was developed through which a highly ordered nanofiber superstructure with enhanced green photoluminescence (PL) was obtained via self-assembly of the individual silver nanoclusters (Ag NCs). By visual monitoring of the kinetic reaction process using time-dependent and in situ spectroscopy measurements, the assembling structure growth and the structure-determined luminescence mechanisms were revealed. The as-prepared nanofibers featured a series of advantages involving a high emission efficiency, large Stokes shift, homogeneous chromophore, excellent photostability, high temperature, and pH sensibility. By virtue of these merits, they were successfully employed in various fields of luminescent inks, encryption and anticounterfeiting platforms, and optoelectronic light-emitting diode (LED) devices.

Salicylic acid improves cowpea productivity under water restriction in the field by modulating metabolism.

Introduction: Salicylic acid has shown promise in alleviating water stress in cultivated plants. However, there is a lack of studies confirming its effectiveness in cowpea plants grown in field conditions. Therefore, this research aimed to evaluate the use of salicylic acid as a water stress mitigator in cowpea cultivars under different irrigation depths in field conditions. Methods: Four cowpea cultivars (BRS Novaera, BRS Tapaihum, BRS Pujante, and BRS Pajeú) were subjected to different treatments: control (W100: 100% replacement of crop evapotranspiration - ETc), W50 (50% of ETc), W50+SA2 (50% of ETc + 276 mg L-1 of SA), and W50+SA4 (50% of ETc + 552 mg L-1 of SA). The treatments were combined in a 4×4 factorial scheme with three replications, arranged in a randomized block design. Results: Water restriction had a negative impact on the water status, growth, gas exchange, and production of the cultivars while also leading to changes in the antioxidant metabolism and osmolyte concentration. The application of SA enhanced antioxidant activity and the synthesis of osmotic adjusters under stress conditions. The most effective concentration was 276 mg L-1 in stage R2 and 552 mg L-1 in stage V7, respectively. The BRS Pujante cultivar showed increased productivity under water restriction with SA application, while the BRS Tapaihum was the most tolerant among the cultivars studied. Discussion: In summary, our findings underscore the importance of using SA to mitigate the effects of water restriction on cowpea cultivation. These discoveries are crucial for the sustainability of cowpea production in regions susceptible to drought, which can contribute to food security. We further add that the adoption of new agricultural practices can enhance the resilience and productivity of cowpea as an essential and sustainable food source for vulnerable populations in various parts of the world.

Research progress of Gastrodia elata Blume polysaccharides: a review of chemical structures and biological activities.

Gastrodia elata Blume (G. elata), listed as one of the 34 precious Chinese medicines, servers a dual purpose as both a medicinal herb and a food source. Polysaccharide is the main active ingredient in G. elata, which has pharmacological activities such as immune regulation, anti-oxidation, anti-cancer, anti-aging, neuroprotection and antibacterial activity and so on. The biological activities of G. elata polysaccharide (GPs) is closely related to its chemical structures. However, no a review has synthetically summarized the chemical structures and pharmacological activities of GPs. This study delves into the chemical structures, pharmacological action of GPs, offering insights for the future development an application of these compounds.

Lipid-lowering effect and oral transport characteristics study of curculigoside.

Introduction: The incidence of metabolic disorders during pregnancy is increasing year by year, with diseases including hypertension and hyperlipidemia. Statins are the primary drugs for treating hyperlipidemia or atherosclerosis, yet some patients remain unresponsive to them, and pregnant women are prohibited from taking statins. Curculigoside is the major biologically active natural product present in Curculigo orchioides. Methods: In this study, A high-fat mice model was developed to study the lipid-lowering effect of curculigoside. Using intestinal Caco-2 cell monolayer, the curculigoside transport properties at two temperatures and possible transporters were systemically studied. Results: Curculigoside at concentrations used during the experiments have no toxic effect to Caco-2 cells. The curculigoside transfer from the apical to the basolateral side was strongly influenced by temperature. P-glycoprotein, breast cancer resistance protein, and efflux transporters are crucial components of the human intestinal cell line Caco-2. The curculigoside can significantly affect the contents of total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol in mice. Discussion: The transport properties and potential mechanism of curculigoside offer valuable insights for the design of development of hypolipidemic drugs like anti-atherosclerotic drugs and also be helpful to the further study of the pharmacological activity of curculigoside.

Pathogenic relationship between phenotypes of ARPKD and novel compound heterozygous mutations of PKHD1.

Background: To investigate whether the novel mutation of PKHD1 could cause polycystic kidney disease by affecting splicing with a recessive inheritance pattern. Methods: A nonconsanguineous Chinese couple with two recurrent pregnancies showed fetal enlarged echogenic polycystic kidney and oligoamnios were recruited. Pedigree WES, minigene splicing assay experiment and following bioinformatics analysis were performed to verify the effects, and inheritance pattern of diseasing-causing mutations. Results: WES revealed that both fetuses were identified as carrying the same novel mutation c.3592_3628 + 45del, p.? and c.11207 T>C, p.(Ile3736Thr) in the PKHD1 gene (NM_138694.4), which inherited from the father and mother respectively. Both bioinformatic method prediction and minigene splicing assay experience results supported the mutation c.3592_3628 + 45del, p.? affects the splicing of the PKHD1 transcript, resulting in exon 31 skipping. Another missense mutation c.11207 T>C, p.(Ile3736Thr) has a low frequency in populations and is predicted to be deleterious by bioinformatic methods. Conclusion: These findings provide a direct clinical and functional evidence that the truncating mutations of the PKHD1 gene could lead to more severe phenotypes, and cause ARPKD as a homozygous or compound heterozygous pattern. Our study broadens the variant spectrum of the PKHD1 gene and provides a basis for genetic counseling and diagnosis of ARPKD.

Photocatalytic Formamide Synthesis via Coupling of Electrophilic and Nucleophilic Radicals over Atomically Dispersed Bi Sites.

Formamide (HCONH2) plays a pivotal role in the manufacture of a diverse array of chemicals, fertilizers, and pharmaceuticals. Photocatalysis holds great promise for green fabrication of carbon-nitrogen (C-N) compounds owing to its environmental friendliness and mild redox capability. However, the selective formation of the C-N bond presents a significant challenge in the photocatalytic synthesis of C-N compounds. This work developed a photocatalytic radical coupling method for the formamide synthesis from co-oxidation of ammonia (NH3) and methanol (CH3OH). An exceptional formamide yield rate of 5.47 ± 0.03 mmol·gcat-1·h-1 (911.87 ± 0.05 mmol·gBi-1·h-1) was achieved over atomically dispersed Bi sites (BiSAs) on TiO2. An accumulation of 45.0 mmol·gcat-1 (0.2 g·gcat-1) of formamide was achieved after long-term illumination, representing the highest level of photocatalytic C-N compounds synthesis. The critical C-N coupling for formamide formation originated from the "σ-σ" interaction between electrophilic ●CH2OH with nucleophilic ●NH2 radical. The  BiSAs sites facilitated the electron transfer between reactants and photocatalysts and enhanced the nucleophilic attack of â—NH2 radical at the â—CH2OH radical, thereby advancing the selective C-N bond formation. This work deepens the understanding of the C-N coupling mechanism and offers an alternative and intriguing photocatalytic approach for the efficient and sustainable production of C-N compounds.

Polydopamine coating for enhanced electrostatic adsorption of methylene blue by multiwalled carbon nanotubes in alkaline environments.

The removal of dye molecules in alkaline environments is an issue that should receive increased attention. In this study, the interaction mechanism between polydopamine-modified multiwalled carbon nanotubes (P-MWCNTs) and multiwalled carbon nanotubes (MWCNTs) with the cationic dye methylene blue (MB) in alkaline environments was explained in depth by adsorption, spectroscopy, and density functional theory (DFT). The mechanism of action and dominant forces between the adsorbent and adsorbate were analyzed graphically by introducing energy decomposition analysis (EDA) and an independent gradient model (IGM) into the DFT calculations. In addition, the force distribution was investigated through an isosurface. Moreover, batch adsorption studies were conducted to evaluate the performance of MWCNTs and P-MWCNTs for MB removal in alkaline environments. The maximum MB adsorption capacities of the MWCNTs and P-MWCNTs in solution were 113.3 mg‧g-1 and 230.4 mg‧g-1, respectively, at pH 9. The IGM and EDA showed that the better adsorption capacity of the P-MWCNTs originated from the enhancement of the electrostatic effect by the proton dissociation of polydopamine. Moreover, the adsorption of MB by MWCNTs and P-MWCNTs in alkaline environments was governed by dispersion and electrostatic effects, respectively. Through this study, it is hoped that progress will be made in the use of DFT to explore the mechanism of adsorbent-adsorbate interactions.