Flow System Research Articles

Identification of deep Czech Republic–Austria transboundary aquifer discharge and associated river chloride loading

The deep transboundary aquifer of regional scale along the Czech Republic–Austria border in Central Europe serves as a thermal-mineral water resource for balneotherapy and plays an important role in the region’s development. The aquifer is composed mostly of Jurassic carbonates at depths from 160 to − 3000 masl. Despite more than two decades of exploitation, no complex analysis of groundwater flow directions and groundwater fluxes ever took place. Now, cross-border cooperation enabled the research team to gather crucial information on the Jurassic aquifer. For a better understanding of the groundwater flow system, a numerical model was developed. To simulate the effect of variable density and viscosity occurring in such a deep aquifer, the SEAWAT numerical model was used. The simulation shows that there is an inflow of low mineralised groundwater from the crystalline outcrops in the northwest and inflow of saline groundwater from southeast. Aquifer discharge was identified along the zone partly corresponding to the course of the Dyje River. To check the model’s accuracy, the river water was sampled together with streamflow measurements. Detected sections of increasing chloride concentration indicate zones of the Jurassic aquifer discharge into the Dyje River. The discharge rate of 85 L/s derived from streamflow and chloride concentrations matches the value computed by the model. The relatively high discharge of the Jurassic aquifer contributes significantly to the high chloride loading observed in the Dyje River.

Arc Connectivity and Submodular Flows in Digraphs

AbstractLet $$D=(V,A)$$ D = ( V , A ) be a digraph. For an integer $$k\ge 1$$ k ≥ 1 , a k-arc-connected flip is an arc subset of D such that after reversing the arcs in it the digraph becomes (strongly) k-arc-connected. The first main result of this paper introduces a sufficient condition for the existence of a k-arc-connected flip that is also a submodular flow for a crossing submodular function. More specifically, given some integer $$\tau \ge 1$$ τ ≥ 1 , suppose $$d_A^+(U)+(\frac{\tau }{k}-1)d_A^-(U)\ge \tau $$ d A + ( U ) + ( τ k - 1 ) d A - ( U ) ≥ τ for all $$U\subsetneq V, U\ne \emptyset $$ U ⊊ V , U ≠ ∅ , where $$d_A^+(U)$$ d A + ( U ) and $$d_A^-(U)$$ d A - ( U ) denote the number of arcs in A leaving and entering U, respectively. Let $${\mathcal {C}}$$ C be a crossing family over ground set V, and let $$f:{\mathcal {C}}\rightarrow {\mathbb {Z}}$$ f : C → Z be a crossing submodular function such that $$f(U)\ge \frac{k}{\tau }(d_A^+(U)-d_A^-(U))$$ f ( U ) ≥ k τ ( d A + ( U ) - d A - ( U ) ) for all $$U\in {\mathcal {C}}$$ U ∈ C . Then D has a k-arc-connected flip J such that $$f(U)\ge d_J^+(U)-d_J^-(U)$$ f ( U ) ≥ d J + ( U ) - d J - ( U ) for all $$U\in {\mathcal {C}}$$ U ∈ C . The result has several applications to Graph Orientations and Combinatorial Optimization. In particular, it strengthens Nash-Williams’ so-called weak orientation theorem, and proves a weaker variant of Woodall’s conjecture on digraphs whose underlying undirected graph is $$\tau $$ τ -edge-connected. The second main result of this paper is even more general. It introduces a sufficient condition for the existence of capacitated integral solutions to the intersection of two submodular flow systems. This sufficient condition implies the classic result of Edmonds and Giles on the box-total dual integrality of a submodular flow system. It also has the consequence that in a weakly connected digraph, the intersection of two submodular flow systems is totally dual integral.

Enhancing control of dynamic flow systems through innovator controller design and parametric polynomial modeling

Enhancing control of dynamic flow systems through innovator controller design and parametric polynomial modeling

Integrated operations planning model for the automotive wiring industry

An integrated operations planning model for automotive wiring companies is studied to improve synchronization between production activities and inventory flows. These combined factors are growing in significance as they drive the need to take proactive steps in manufacturing and distributing wiring materials within the supply chain. This involves anticipating the requirements of different automotive manufacturers and thereby guaranteeing a consistent, uninterrupted, and punctual provision of raw wiring materials. This support is vital for sustaining the ongoing manufacturing operations in the automotive sector. For this push flow system, the proposed operational model is based on integer linear programming, considering capacity and bill of materials constraints to determine production quantities, inventory levels, and machine sizing. Real-life data from the automotive wiring industry validates the effectiveness of coordinated production and inventory activities, resulting in significant lead time reductions of up to 60 %. These findings provide compelling reasons for automotive wiring partners to engage in joint operations planning.

Theoretical performance optimization of enzymatic electrochemical CO2 reduction to formate: Voltage, concentration, temperature, pressure, and flow rate

Formic acid (FA) is a notable fuel product due to its atom economy, low activation energy, and applications in flow cells and hydrogen storage. While metal catalysts are typically used, selectivity remains a challenge. Here, an enzymatic catalyst is employed to selectively convert CO2 to FA as formate. This study documents the development of a computational model to examine the conversion of CO2 to formate under a wide range of conditions. The model examines the electrochemical reduction of a charge carrier, ethyl viologen (EV), and its subsequent use in an enzymatic catalyst to convert CO2 and protons in solution to formate. The model was first developed for a small-scale batch reactor, then later expanded to a dual-cell flow system, where the reduction of EV and production of formate are kept in separated cells, and flow rate is introduced as an additional variable parameter. While no studies have directly used all parameters addressed in the computations presented here, many of the conditions selected align with what has previously been used in experiments, and similar production rates and efficiencies are obtained. The most challenging parameters to study were charge carrier concentration and applied voltage, which showed optimal ranges in the cases studied for the batch and flow cell. While the study gives guidance toward which conditions would be favored experimentally to increase production rate and efficiency experimental studies should nonetheless be run at suggested optimal conditions to better adapt parameters made in both models.

How to consider groundwater flow systems in the Earth's Critical Zone? – Demonstration in the Central Pannonian Basin, Hungary

Study regionCentral Pannonian Basin, Hungary. Study focusCritical Zone (CZ) Science generally focuses on the soil and weathered bedrock in a few or tens of meters depth, thus influence of deeper groundwater on the CZ is understudied. Here we aim to introduce a hydrogeological methodology that can separate normal and abnormal pressure regimes and determine the groundwater flow pattern to characterize the connection of different groundwater flow systems to the CZ. Basin-scale evaluation of about 5500 measured hydraulic data were carried out by p(z) and h(z) profiles, tomographic maps and hydraulic cross sections. New hydrological insights for the RegionThree flow domains were separated and characterized. Namely, i) the uppermost topography-driven flow systems, which penetrate only a few hundred meters, ii) a deep overpressured regime below 1600–2100 m depth, which drives fluids upward; and iii) a newly identified transition zone between the former two, which gains its energy from overpressure dissipation and contains non-renewable water resources. Topography-driven flow systems and discharge areas of the transition zone, where its upwelling saline water contributes to surface salinization, are parts of the CZ. Discharge areas of the transition zone cover about 50% of the Great Hungarian Plain. The overpressured system can only influence the CZ through the transition zone. The approach and methodology can be used in any terrestrial sedimentary basin where a deep overpressured regime exists.

Offset-Free Koopman Model Predictive Control of Thermal Comfort Regulation for a Variable Refrigerant Flow-Dedicated Outdoor Air System-Combined System

Abstract Variable refrigerant flow (VRF) system has been an appealing solution of air conditioning for residential and commercial buildings, due to its flexibility and cost effectiveness, while lack of ventilation capability is a major drawback. Incorporation of dedicated outdoor air system (DOAS) is a typical practice. However, good coordination between DOAS and VRF is critical for achieving desired thermal comfort is challenging due to the possible complexity of mixed sensible and latent heat exchanges. In this paper, to handle the nonlinear dynamic characteristics of VRF-DOAS system, we propose an offset-free Koopman model predictive control (MPC) strategy for thermal comfort regulation, in which the MPC design is computationally more efficient due to the convex problem formulation and the use of reduced-order Koopman models, and the offset-free MPC structure enhances the robustness to model uncertainties and unmeasured disturbances. A control-oriented model is obtained by hybridizing the first-principle and data-driven modeling approach. The proposed controls strategy is evaluated with a Modelica simulation model of a VRF-DOAS system. A Dymola-Python cosimulation platform is developed via the functional mockup interface (FMI), for which the MPC algorithms are implemented in Python. Simulation results show significantly better performance of the offset-free Koopman MPC in thermal comfort regulation.

Quantitative derivation of a two-phase porous media system from the one-velocity Baer–Nunziato and Kapila systems

We derive a novel two-phase flow system in porous media as a relaxation limit of compressible multi-fluid systems. Considering a one-velocity Baer–Nunziato system with friction forces, we first justify its pressure-relaxation limit toward a Kapila model in a uniform manner with respect to the time-relaxation parameter associated with the friction forces. Then, we show that the diffusely rescaled solutions of the damped Kapila system converge to the solutions of the new two-phase porous media system as the time-relaxation parameter tends to zero. In addition, we also prove the convergence of the Baer–Nunziato system to the same two-phase porous media system as both relaxation parameters tend to zero. For each relaxation limit, we exhibit sharp rates of convergence in a critical regularity setting. Our proof is based on an elaborate low-frequency and high-frequency analysis via the Littlewood–Paley decomposition and includes three main ingredients: a refined spectral analysis of the linearized problem to determine the frequency threshold explicitly in terms of the time-relaxation parameter, the introduction of an effective flux in the low-frequency region to overcome the loss of parameters due to the overdamping phenomenon, and renormalized energy estimates in the high-frequency region to cancel higher-order nonlinear terms. To justify the convergence rates, we discover several auxiliary unknowns allowing us to recover crucial O(ε) bounds.

Advanced analysis of operating parameters utilizing big data to improve building cooling equipment energy efficiency standards

The rapid increase in building energy consumption has highlighted the critical contribution of building cooling/heating equipment, including room air conditioners and variable refrigerant flow (VRF) systems. However, existing energy efficiency standards for such equipment often specify testing conditions that differ from real-world usage scenarios and are unsupported by in-depth investigations, resulting in evaluations of equipment performance that do not align with actual performance. Therefore, the increasing availability of large-scale real-time monitoring datasets was leveraged in this study to develop an innovative technical approach to derive a more accurate description of VRF operation-related parameters. This approach was applied to inform suggestions for the enhancement of energy efficiency standards for VRF devices by collecting and preprocessing data, extracting operating parameters, conducting data analysis and comparisons, and discussing potential applications. The results of this study indicate that the type of building significantly influences the actual performance of a VRF and imply that large-scale monitoring data can provide a foundation for the revision of building equipment energy efficiency standards as well as future investigations of building equipment energy policies.

Propulsive study of blood flow with heat transfer enhancement connection to ferro copper magnetized nanoparticles in converging tapered stenosed arterial surface

To investigate the effects of magnetic fields and variously structured nanoparticles in narrowing, stenosed arteries, an arterial flow model is incorporated. The aim of this study here is to achieve more realistic results by modeling and simulating the arterial blood flow system with the nanoparticles and shape factor of the nanoparticles. The study of blood flow in tapered stenosed arteries with nanoparticles involves understanding the dynamics of blood circulation in vessels having application in drug delivery. Nanoparticles with specific shape factors can enhance imaging modalities like MRI, CT or ultrasound diagnosing tumor. Metallic nanoparticles in various shapes utilizing water as the base fluid have not yet been considered. Imagine a symmetrical radially but axially nonsymmetric constriction for the blood flow. Along with taking into account the regularity in the sequence of distributing the wall shear stress as well as resistance impedance, the study also takes into account a rise in these readings as the stenosis worsens. For speed, resistive impedance, wall shear and shearing forces at the stenosis throat, results have been computed in exact form. For various Cu-water-relevant parameters, the visual results of several types of converging tapering arteries have been assessed.

Solvothermally Grown Oriented WO3 Nanoflakes for the Photocatalytic Degradation of Pharmaceuticals in a Flow Reactor.

Contamination by pharmaceuticals adversely affects the quality of natural water, causing environmental and health concerns. In this study, target drugs (oxazepam, OZ, 17-α-ethinylestradiol, EE2, and drospirenone, DRO), which have been extensively detected in the effluents of WWTPs over the past decades, were selected. We report here a new photoactive system, operating under visible light, capable of degrading EE2, OZ and DRO in water. The photocatalytic system comprised glass spheres coated with nanostructured, solvothermally treated WO3 that improves the ease of handling of the photocatalyst and allows for the implementation of a continuous flow process. The photocatalytic system based on solvothermal WO3 shows much better results in terms of photocurrent generation and photocatalyst stability with respect to state-of-the-art WO3 nanoparticles. Results herein obtained demonstrate that the proposed flow system is a promising prototype for enhanced contaminant degradation exploiting advanced oxidation processes.

ЯНИС СРЕЩУ МИНОТАВЪРА: ЛЕГЕНДАТА ПРОДЪЛЖАВА (РАЗМИСЛИ ПО ПОВОД НОВАТА КНИГА НА ЯНИС ВАРУФАКИС)

A new book by Yanis Varoufakis, Technofeudalism - What Killed Capitalism, has recently been published. Do you remember Varoufakis? In early 2015, at the height of the Greek debt crisis, the little-known (at the time) university lecturer was appointed finance minister and quickly became a star. He was certainly not the first to oppose the so-called Washington Consensus and neoliberalism in economics, but he was perhaps the most eloquent and the most extreme in his criticism, backed by a deep knowledge of the workings of the modern market economy. His time in power was less than half a year, but he will certainly be remembered for a long time. After him, Greece now has its sixth finance minister, but I am sure that even there few people know their names. I allowed myself this extravagant title as I am still under the strong impression of one of his previous books, The Global Minotaur, in which Varoufakis examines economic history and crises, focusing on the role of the US in the post-World War II global economy. The author uses the myth of the Minotaur as a metaphor to explain the complex system of global financial flows that fuelled the US economy and contributed to the accumulation of global economic imbalances that ultimately led to the global financial crisis of 2007-2009.

Contact-angle hysteresis provides resistance to drainage of liquid-infused surfaces in turbulent flows

Lubricated textured surfaces immersed in liquid flows offer tremendous potential for reducing fluid drag, enhancing heat and mass transfer, and preventing fouling. According to current design rules, the lubricant must chemically match the surface to remain robustly trapped within the texture. However, achieving such chemical compatibility poses a significant challenge for large-scale flow systems, as it demands advanced surface treatments or severely limits the range of viable lubricants. In addition, chemically tuned surfaces often degrade over time in harsh environments. Here, we demonstrate that a lubricant-infused surface (LIS) can resist drainage in the presence of external shear flow without requiring chemical compatibility. Surfaces featuring longitudinal grooves can retain up to 50% of partially wetting lubricants in fully developed turbulent flows. The retention relies on contact-angle hysteresis, where triple-phase contact lines are pinned to substrate heterogeneities, creating capillary resistance that prevents lubricant depletion. We develop an analytical model to predict the maximum length of pinned lubricant droplets in microgrooves. This model, validated through a combination of experiments and numerical simulations, can be used to design chemistry-free LISs for applications where the external environment is continuously flowing. Our findings open up new possibilities for using functional surfaces to control transport processes in large systems. Published by the American Physical Society 2024

Front-end speech processing system with SVM algorithm in rail passenger flow management

In order to achieve the goal of dynamically adjusting daily passenger flow to effectively control the overall efficiency of the transportation system, this study constructs a real-time monitoring and prediction system for subway passenger flow based on front-end voice processing technology and support vector machine models. The study first conducted a railway passenger flow analysis, and then used a support vector machine model to construct a preliminary prediction system. In order to achieve global optimization, the study also introduced particle swarm optimization algorithm to construct an optimization prediction model based on PSO-SVM. The results show that the proposed PSO-SVM method has undergone 48 iterations of training, and the predicted values closely match the actual passenger flow curve. The maximum RE error is 2%, and the overall prediction error is 98%. The decision coefficient of PSO-SVM is 0.998932. Therefore, this indicates that it has high performance and feasibility in predicting and controlling passenger flow during peak hours of urban rail transit.

Edema of the upper extremity on the unaffected side in unilateral breast cancer patients.

Breast cancer-related lymphedema (BCRL) occurs usually on the affected side, and its cause and pathophysiology are well known. However, the cause of edema of the upper extremity on the unaffected side is barely known. It is often considered to be chemotherapy-induced general edema, and clinical evaluation is rarely performed in these patients. This study aimed to present the clinical characteristics of unilateral breast cancer patients with edema of upper extremity on the unaffected side, and to emphasize the importance of early diagnosis and medical interventions. This study retrospectively analyzed the medical records of unilateral breast cancer patients complaining edema of upper extremity on the unaffected side, from January 2020 to May 2021. Lymphoscintigraphy was used to assist in confirming the diagnosis of lymphedema, and Doppler ultrasonography or 3D computed tomography angiography were performed to differentiate vascular problems. Fourteen patients were enrolled in the study. Seven, 3, and 4 patients had edema of both upper extremities, edema of the upper extremity on the unaffected side only, and edema of all extremities, respectively. None of the 4 patients with edema of all extremities showed abnormal findings on examination. In patients with edema in the upper extremity on the unaffected side alone, lymphatic flow dysfunction was seen in 2 patients, and deep vein thrombosis (DVT) was diagnosed in 1. In patients with edema of both upper extremities, lymphatic flow dysfunction was seen in 2 patients, and DVT was diagnosed in 3. One patient had DVT and accompanying lymphatic flow dysfunction. Lymphedema and DVT were diagnosed in a number of patients with edema of the upper extremity on the unaffected side, and lymphedema can occur without direct injury to the lymphatic flow system. Therefore, clinicians should not overlook the fact that diseases that require early diagnosis and treatment can occur in patients with edema of the unaffected upper extremity.

Photochemical and Patternable Synthesis of 2D Covalent Organic Framework Thin Film Using Dynamic Liquid/Solid Interface.

2D covalent organic frameworks (COFs) are highly porous crystalline materials with promising applications in organic electronics. Current methods involve either on-surface synthesis (solid surface) or interfacial synthesis (liquid/liquid, liquid/gas interface) to create thin films for these applications, each with its drawbacks. On-surface synthesis can lead to contamination from COF powder or unreacted chemicals, while interfacial synthesis risks damaging the film during post-transfer processes. These challenges necessitate the development of alternative synthesis methods for high-quality 2D COF films. This study presents a novel approach for synthesizing homogeneous 2D COF thin films by combining photochemistry and a liquid-flowing system. Leveraging previous work on liquid flow systems to prevent contamination during solvothermal synthesis, this approach to the photochemical method, resulting in the synthesis of high-crystalline 2D COF films with tunable thickness is adopted. The photochemical approach offers spatially controllable energy sources, enabling patternable COF synthesis. Notably, it is successfully fabricated ultrasmooth patterned 2D COF films on hexagonal boron nitride, offering a streamlined process for optoelectronic device fabrication without additional pre, post-processing steps.

The effects of damming and dam regulation on a river–lake-aquifer system: 3D groundwater flow modeling of Poyang Lake (China)

Large numbers of dams are planned or constructed for hydroelectric power production, water supply, and flood control in many rivers around the world. While the social and environmental impacts of dams are now well-understood, there is little knowledge about the effects of dams on groundwater-surface water interactions in a complex lake–river-aquifer system. This study adopts a three-dimensional groundwater numerical model to quantify the potential impacts of dam construction, on regional groundwater flow system, exemplified by the proposed Poyang Lake Hydraulic Dam (PLHD) in China. Once implemented, the PLHD will regulate lake levels, artificially controlling the lake inundation area during the recession season (September-October) and the dry season (November-December). Modeling results indicated that the increase in lake infiltration induced by PLHD regulation would alter the regional water exchange pattern. The PLHD regulation will likely enhance the groundwater storage by 20.44 % in the general dry year (i.e., 2018), alleviating 78.1 % of the groundwater deficit in the extreme dry year (i.e., 2019). Additionally, the response of groundwater dynamics to the PLHD regulation exhibits significant spatial differences between the upstream and downstream areas of the dam, primarily depending on topographical changes. Overall, the PLHD regulation is most likely to impact groundwater levels across an area of approximately 5,700 km2, and the associated groundwater storage is anticipated to reach a stable state, under future long-term regulation. Our findings may guide policy-makers wishing to develop more suitable PLHD scheduling plans and floodplain protection strategies by providing reliable information regarding groundwater storage change and ecosystem succession.

Recent advances in catalytic asymmetric synthesis.

Asymmetric catalysis stands at the forefront of modern chemistry, serving as a cornerstone for the efficient creation of enantiopure chiral molecules characterized by their high selectivity. In this review, we delve into the realm of asymmetric catalytic reactions, which spans various methodologies, each contributing to the broader landscape of the enantioselective synthesis of chiral molecules. Transition metals play a central role as catalysts for a wide range of transformations with chiral ligands such as phosphines, N-heterocyclic carbenes (NHCs), etc., facilitating the formation of chiral C-C and C-X bonds, enabling precise control over stereochemistry. Enantioselective photocatalytic reactions leverage the power of light as a driving force for the synthesis of chiral molecules. Asymmetric electrocatalysis has emerged as a sustainable approach, being both atom-efficient and environmentally friendly, while offering a versatile toolkit for enantioselective reductions and oxidations. Biocatalysis relies on nature's most efficient catalysts, i.e., enzymes, to provide exquisite selectivity, as well as a high tolerance for diverse functional groups under mild conditions. Thus, enzymatic optical resolution, kinetic resolution and dynamic kinetic resolution have revolutionized the production of enantiopure compounds. Enantioselective organocatalysis uses metal-free organocatalysts, consisting of modular chiral phosphorus, sulfur and nitrogen components, facilitating remarkably efficient and diverse enantioselective transformations. Additionally, unlocking traditionally unreactive C-H bonds through selective functionalization has expanded the arsenal of catalytic asymmetric synthesis, enabling the efficient and atom-economical construction of enantiopure chiral molecules. Incorporating flow chemistry into asymmetric catalysis has been transformative, as continuous flow systems provide precise control over reaction conditions, enhancing the efficiency and facilitating optimization. Researchers are increasingly adopting hybrid approaches that combine multiple strategies synergistically to tackle complex synthetic challenges. This convergence holds great promise, propelling the field of asymmetric catalysis forward and facilitating the efficient construction of complex molecules in enantiopure form. As these methodologies evolve and complement one another, they push the boundaries of what can be accomplished in catalytic asymmetric synthesis, leading to the discovery of novel, highly selective transformations which may lead to groundbreaking applications across various industries.

Application of Hierarchically Porous Chitosan Monolith for Enzyme Immobilization.

Enzyme immobilization is a crucial technique for improving the stability of enzymes. Compared with free enzymes, immobilized enzymes offer several advantages in industrial applications. Efficient enzyme immobilization requires a technique that integrates the advantages of physical absorption and covalent binding while addressing the limitations of conventional support materials. This study offers a practical approach for immobilizing α-amylase on a hierarchically porous chitosan (CS) monolith. An optimized CS monolith was fabricated using chemically modified chitin by thermally induced phase separation. By combining physical adsorption and covalent bonding, this technique leverages the amino and hydroxy groups present in CS to facilitate effective enzyme binding and stability. α-Amylase immobilized on the CS monolith demonstrated excellent stability, reusability, and increased activity compared to its soluble counterpart across various pH levels and temperatures. In addition, the CS monolith exhibited a significant potential to immobilize other enzymes, namely, lipase and catalase. Immobilized lipase and catalase exhibited higher loading capacities and enhanced activities than their soluble forms. This versatility highlights the broad applicability of CS monoliths as support materials for various enzymatic processes. This study provides guidelines for fabricating hierarchical porous monolith structures that can provide efficient enzyme utilization in flow systems and potentially enhance the cost-effectiveness of enzymes in industrial applications.

Central Carbon Metabolism in Candida albicans Biofilms Is Altered by Dimethyl Sulfoxide.

The effect of dimethyl sulfoxide (DMSO) on fungal metabolism has not been well studied. This study aimed to evaluate, by metabolomics, the impact of DMSO on the central carbon metabolism of Candida albicans. Biofilms of C. albicans SC5314 were grown on paper discs, using minimum mineral (MM) medium, in a dynamic continuous flow system. The two experimental conditions were control and 0.03% DMSO (v/v). After 72 h of incubation (37 °C), the biofilms were collected and the metabolites were extracted. The extracted metabolites were subjected to gas chromatography-mass spectrometry (GC/MS). The experiment was conducted using five replicates on three independent occasions. The GC/MS analysis identified 88 compounds. Among the 88 compounds, the levels of 27 compounds were markedly different between the two groups. The DMSO group exhibited enhanced levels of putrescine and glutathione and decreased levels of methionine and lysine. Additionally, the DMSO group exhibited alterations in 13 metabolic pathways involved in primary and secondary cellular metabolism. Among the 13 altered pathways, seven were downregulated and six were upregulated in the DMSO group. These results indicated a differential intracellular metabolic profile between the untreated and DMSO-treated biofilms. Hence, DMSO was demonstrated to affect the metabolic pathways of C. albicans. These results suggest that DMSO may influence the results of laboratory tests when it is used as a solvent. Hence, the use of DMSO as a solvent must be carefully considered in drug research, as the effect of the researched drugs may not be reliably translated into clinical practice.