Acetic Acid Solution Research Articles (Page 1)

Silicophosphate coatings are one of the current vectors in the field of increasing the fire resistance of extruded polystyrene foam (XPS), which is widely used in construction as a thermal insulation material. The article presents a study of the effectiveness of fire-retardant coatings based on silicic acid sols modified with orthophosphoric acid and phosphate buffer solutions. The effect of phosphorus-containing additives on the rheological properties of the compositions was determined spectrophotometrically. The highest survival rates (~2 h) were observed in sols containing phosphate buffer solutions. Using differential thermal analysis, the influence of phosphate additives on the nature of polycondensation of polysilicic acid formed during the creation of a fire-retardant composition based on aqueous solutions of liquid glass and acetic acid was established and confirmed by infrared spectroscopy. The addition of orthophosphoric acid contributes to the formation of network silicate structures that slowly decompose under the influence of temperature with a minimal increase in mass loss, which is a guarantee of preserving the integrity of the coating. However, the results of fire studies of coatings with orthophosphoric acid additives did not give a stable positive result, so in further studies, phosphate salts of alkali metals were used in the form of phosphate buffer pairs. Phosphate ions are able to be incorporated into the structure of the siloxane framework of polysilicic acid, increasing its fire resistance, which was confirmed by IR spectroscopy. The use of phosphate buffer solutions is more promising, because, firstly, it provides increased survivability of the composition and, secondly, it promotes melting of the coating under the influence of fire, therefore, during shrinkage of polystyrene foam, the coating changes its shape without the formation of cracks and reliably protects the finishing material from fire. Conducting fire tests made it possible to establish that all the studied compositions are able to eliminate the main disadvantage of polystyrene foam combustion - the formation of burning drops. It was established that the use of potassium phosphate salts provided the best fire protection for extruded polystyrene foam, which was confirmed by fire tests and microscopic examination of the material of different grades.

Laser ablation of aluminum inside acetic acid solution for superhydrophobic and delay-icing surfaces

Cervical cancer is one of the most preventable cancers, yet many women still face delayed or missed diagnoses because of something as simple as an “unsatisfactory” Pap smear result. When a sample is reported as inadequate, often due to gel, blood, or inflammation, the patient may need to return for another test, creating anxiety, extra costs, and possible delays in detecting disease. To overcome this problem, laboratories have started using a simple but promising approach known as the wash technique. In this method, inadequate samples are gently rinsed in a mild acetic acid solution and reprocessed, allowing hidden cells to be recovered and reducing background debris. We retrospectively reviewed 645 Thin Prep Pap smears that underwent the wash protocol at King Fahad Armed Forces Hospital between 2020 and 2024. After reprocessing, 69.77% of cases were satisfactory, with 83.56% reported as NILM and 16.44% showing epithelial abnormalities, including ASC-US, LSIL, HSIL, and AGC. No squamous cell carcinoma or adenocarcinoma were detected. We conclude that the wash technique substantially improves Pap smear adequacy, salvaging the majority of initially unsatisfactory cases and enabling the detection of clinically relevant abnormalities. Unsatisfactory rates increased with advancing age, highlighting the need for age-aware approaches in cytology practice. Incorporating wash protocols into routine cytology practice may reduce repeat testing, minimize diagnostic delays, and strengthen the effectiveness of cervical cancer screening programs.

This study describes the design and synthesis of novel hybrid molecular architectures based on the privileged indolin-2-one (oxindole) scaffold. The research leverages a multi-component reaction strategy, employing isatins, 2-amino-1,4-naphthoquinone, and 5-methyl-2-phenylpyrazolone as key building blocks. The solvent regulated the pathway to the aforementioned chemicals. The later compounds were produced in an acetic acid solvent under reflux conditions, whereas the former compounds were made in an ethanol solvent. Nineteen novel oxindole derivatives were synthesized in high yields, and the structures were undoubtedly identified using their NMR data as well as X-ray analysis.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21805-w.

The food packaging industry is inclined toward biodegradable films, and jellyfish hold significant potential for exploitation due to their extraordinary collagen content. Thus, the primary objective of this research was to develop an antioxidant gelatine-based film from the blue cannonball jellyfish (Stomolophus sp. 2) (JG), using chitosan (CH) and the casting method, with glycerol (GLY) as a plasticiser to improve film flexibility. The JG obtained through alkaline, heat, and dialysis treatment exhibited high in vitro antioxidant activity. A commercial chitosan acetic acid solution (1%) was added to a JG water solution (1%) and a commercial gelatine (CG) solution (1%) was employed as a control. The film’s mass ratio was 4:1:2 (JG:CH:GLY). The physical, chemical, thermal, mechanical, and antioxidant properties of the JG-CH and CG-CH films were compared; JG-CH showed higher solubility and thermal stability than CG-CH. The colour and light transmittance were similar; however, their tensile strength and elongation differed. Furthermore, JG-CH films exhibited a higher ABTS radical-scavenging capacity compared to CG-CH films. FTIR and 1H NMR spectra of the JG-CH films indicated excellent compatibility between the components, primarily due to hydrogen bonding. This study demonstrates that JG-CH films possess functional properties that make this material suitable for application as a biomaterial film for food.

Punica granatum extract(PG), consistingof punicalagin, ellagic acid, and gallic acid, was loaded onto anFe3O4/Chitosan (Fe3O4@Chi)nanocomposite (Fe3O4@Chi-PG) to enhance pharmacokineticproperties. Fe3O4 was synthesized via the coprecipitationmethod and coupled with chitosan in 2% acetic acid solution via glutaraldehydecross-linking. The presence of interested polyphenols in the pomegranateextract was confirmed by HPLC analysis, and the extract was post-loadedto the nanocarrier. XRD confirmed the crystallographic orientationof the nanocarrier, and SEM analysis confirmed the successful couplingof Fe3O4 onto the chitosan surface during thefabrication of Fe3O4@Chi. BET surface area analysisrevealed the presence of micro- and mesopores in the synthesized materials.Significant reduction of the BET surface area and the pore volumeof Fe3O4@Chi-PG compared to Fe3O4@Chi suggested the loading of the porous network and surfaceby PG. The presence of vibrational bands corresponding to the functionalgroups of the relevant bioactive compounds was confirmed via FT-IRanalysis. The IC50 values of the nanocomposite for DPPHand egg albumin denaturation assays were 18.69 and 257.69 μg/mL,respectively. The PG encapsulation efficiency of Fe3O4@Chi-PG was reported to be 86.44%. The pH-responsive releaseof the polyphenols was studied by fitting the release data into fivekinetic models, including Korsemeyer–Peppas (KP) and Peppas–Sahlin(PS). The KP and PS models were selected to interpret the releasemechanism based on the R2 ≥ 0.95value. A combination of Fickian diffusion, relaxation, and swellingdominates the polyphenol release. Quasi-Fickian diffusion is responsiblefor the release in media with pH 1–6.7, whereas anomalous transportoccurs at pH 7.4 (n = 0.46) according to the KP model.Polymer relaxation is the dominant mechanism for the release of bioactivecompounds at pH 7.4, as exhibited by R/F > 1. However, the contributionof relaxation to the release of polyphenols at pH 2.5, 4, and 5.5was negligible according to the parameters (kR = 0). Characteristics of chitosan, including protonationand deprotonation of NH2 groups, surface charge of Fe3O4, ionization of COOH and OH groups of the polyphenols,and molecular weight of the active compounds, contributed to the differencesin the release behavior.

In this study, the chemical solubility (stability) of yttria-partially stabilized zirconia (2.3Y-TZP) dental ceramics, both glazed (Group 2) and non-glazed samples (Group 1), was evaluated using a modified testing protocol based on ISO 6872:2024. Chemical stability was assessed by measuring ion release with inductively coupled plasma mass spectrometry (ICP-MS) and by analyzing phase composition with X-ray diffraction (XRD). While ISO 6872 prescribes chemical stability testing in a 4 wt.% aqueous acetic acid solution at 80 °C for 16 h, the exposure duration in this study was extended to 768 h (32 days) to allow a more accurate determination of long-term solubility behavior. Additionally, the surface roughness parameters (Ra, Rmax, Rz, Sa, Sq) were analyzed and evaluated before and after solubility testing. Kinetic analysis revealed that degradation followed a near-parabolic rate law, with power-law exponents of n = 2.261 for Group 1 and n = 1.935 for Group 2. The corresponding dissolution rate constants were 3.85 × 10−5 µgn·cm−2n·h−1 for Group 1 and 132.3 µgn·cm−2n·h−1 for Group 2. XRD results indicated that the long exposure to acetic acid induced a partial phase transformation of zirconia from the tetragonal to the monoclinic phase. Under prolonged acetic exposure, the glaze layer on 2.3Y-TZP exhibited significantly higher dissolution, whereas the zirconia (polished, unglazed) showed low ion release. The temporal change in the total amount of dissolved ions was statistically analyzed for Group 1 and Group 2. The samples showed a strong correlation, but ANOVA confirmed significant differences between them.

The potential of elastomeric composites reinforced with natural fillers to replace traditional synthetic materials in applications involving exposure to acidic environments offers both economic and environmental advantages. On the one hand, these materials contribute to cost reduction and the valorization of organic waste through the development of value-added products. On the other hand, the presence of wood waste in the composite structure enhances biodegradation potential, making these materials less polluting and more consistent with the principles of the circular economy. The present study aims to evaluate the behavior of composites based on Ethylene Propylene Diene Monomer (EPDM) synthetic rubber, reinforced with silica and wood sawdust, in a weakly acidic yet strongly corrosive environment—specifically, acetic acid solutions with concentrations ranging from 10% to 30%. The study also investigates the extent to which varying the proportions of the two fillers affects the resistance of these materials under such environmental conditions. Physico-chemical, structural, and morphological analyses revealed that the materials underwent chemical modifications, such as acetylation of hydroxyl groups. This process reduced the hydrophilic character of the sawdust and, combined with the formation of stable interfaces between the elastomeric matrix and the fillers during vulcanization, limited acid penetration into the composite structure. The composites in which 20 phr or 30 phr of wood sawdust were used-replacing equivalent amounts of silica from the initial 50 phr formulation-demonstrated the highest resistance to the corrosive environments. After 14 days of exposure to a 20% acetic acid solution, the composite containing 30% wood sawdust exhibited a decrease in cross-link density of only 1.44%, accompanied by a reduction in Young’s modulus of just 0.95%. At the same time, tensile strength and specific elongation increased by 22.57% and 26.02%, respectively. FTIR and SEM analysis confirmed good rubber-filler interactions and the stability of the composite structure under acidic conditions.

Background and Purpose: Ulcerative Colitis (UC) is a long-term, inflammatory condition characterized by episodes of relapse and remission, affecting millions of people worldwide. The Nuclear Factor kappa B (NF-κB) serves as a key factor and biomarker in the inflammatory context, significantly influencing the course of mucosal inflammation in UC. This work aims to explore the relative potency and compare the efficacy of curcumin and resveratrol (natural NF-κB inhibitors) to mesalazine, a standard treatment for ulcerative colitis (synthetic inhibitor of NF-κB), in a rat model of acetic acid-induced colitis. Methods: Forty male Wistar rats were randomly divided into 5 groups, with eight animals in each group. Group I was the standard control group, and the remaining 32 rats received a rectal injection of 2 mL of 4% acetic acid solution to induce UC. They were then randomly subdivided into 4 groups: Group IIA (untreated ulcerative colitis group), Group IIB (mesalazine-treated ulcerative colitis group), Group IIC (resveratrol-treated ulcerative colitis group), and Group IID (curcumin-treated ulcerative colitis group). Oxidative stress and pro-inflammatory markers were assessed one week after UC induction or treatments. Results: This study showed that the treatment with natural NF-kB inhibitors, namely curcumin and resveratrol, was superior to the conventional mesalazine therapy in lowering malondialdehyde (MDA) and inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin 17 (IL-17), and NF-kB in the colonic tissue. Conclusion: Natural NF-kB inhibitors, namely curcumin and resveratrol, are superior to the conventional mesalazine therapy in the treatment of UC. Major Findings: Curcumin was superior to resveratrol in reducing oxidative stress and inflammatory markers associated with the disease. Histological examination of the colonic tissue demonstrated almost normal mucosa architecture with no inflammation or ulceration in the curcumin-treated group.

Layer‐by‐layer (LBL) spin‐coating is a widely recognized method for developing high‐efficiency organic solar cells (OSCs). However, in the LBL device with a conventional architecture, the residual solvents trapped in the underlying donor film will affect the interface between donor and acceptor materials as well as the morphology of upper acceptor materials, thus leading to poor reproducibility and efficiency. This study provides a facile strategy that spin‐coats a mixed solvent of methanol and acetic acid, facilitating the removal of residual solvents from the donor material. The introduction of the mixed anti‐solvent can also optimize the roughness, facilitate the crystallization of the donor material, and improve interfacial properties. The devices without any further treatment exhibit a power conversion efficiency (PCE) of 17.8%, while devices treated with pristine methanol achieve an efficiency up to 18.4%. Notably, devices treated with mixed methanol and acetic acid further boost efficiency to 19.3%. Furthermore, this approach is also applicable to flexible OSCs, yielding an efficiency of 18.0%.

Chicken eggshells, containing approximately 38% calcium, are a valuable source of this mineral and offer significant potential as a raw material in the pharmaceutical industry. In this study, calcium citrate was synthesized from chicken eggshells, whose main component is calcium carbonate. Calcium citrate is known for its higher solubility and bioavailability compared to the original calcium source. The synthesis was performed using a dissolution–precipitation method involving two acids through an intermediate acetate salt, resulting in a product with a purity of 98.70% and a yield of approximately 58.8%. To improve the efficiency of the synthesis, several factors were evaluated for process optimization. The optimal conditions were identified as follows: the initial reaction with an aqueous solution of acetic acid was conducted at room temperature for 5 hours, followed by a reaction with citric acid at 50 °C for 1 hour. The molar ratio of calcium acetate to citric acid was 3:2. The resulting product was a neutral salt in dihydrate form. Product characterization confirmed the identity and quality of the synthesized calcium citrate. The synthesis method is simple, environmentally friendly, and allows for solvent reuse. These results contribute to the valorization of agricultural and food industry by-products through the development of pharmaceutical ingredients.

Pain is an unpleasant sensation that can interfere with an individual's quality of life and requires effective management. Synthetic analgesics such as ketorolac, codeine, etoricoxib, and celecoxib are commonly used to relieve pain, but long-term use can cause adverse side effects, including gastrointestinal disturbances, dependence, and cardiovascular risks. Therefore, it is important to find safer, natural alternatives. One promising alternative is the extract of the dragon’s tail leaf (Rhaphidophora pinnata), a plant traditionally used in Indonesian medicine as a pain reliever. This study aims to evaluate and compare the analgesic effects of Rhaphidophora pinnata leaf extract with several synthetic drugs using the writhing test on male mice (Mus musculus). The mice were induced with pain by injecting a 0.5% acetic acid solution. The treatments included ketorolac, codeine, etoricoxib, celecoxib, and Rhaphidophora pinnata leaf extract. The results showed that all treatments, including both synthetic drugs and Rhaphidophora pinnata leaf extract, produced significant analgesic effects compared to the negative control (Na CMC 0.5%). Ketorolac showed the highest effectiveness, followed by codeine, etoricoxib, and celecoxib. Although the Rhaphidophora pinnata leaf extract showed potential as a natural analgesic, its effectiveness varied among individual test animals. Some mice showed a better response to the leaf extract, but overall, the analgesic effect was still lower than that of synthetic drugs. These findings support the use of medicinal plants as a safer alternative to synthetic analgesic drugs. Moreover, this study provides a foundation for further research aimed at isolating active compounds from Rhaphidophora pinnata leaf extract to develop more effective and safer pain-relieving medications.

While acetic acid has proven effective as a mild acidic treatment for removing adhered mortar from recycled concrete aggregate (RCA) surfaces, its potential for dissolving damage to the surface of the original natural coarse aggregate (NCA) within the RCA and its impact on the resultant concrete properties require careful consideration. This investigation systematically evaluates the effects of varying concentrations of dilute acetic acid solutions, commonly used in RCA treatment protocols, through a multi-methodological approach that includes comprehensive physical characterization, stylus and 3D optical profilometry, scanning electron microscopy (SEM), and nanoindentation analysis. The results show that even dilute acid solutions have an upper concentration limit, as excessive acid concentration, specifically 0.4 M, induces significant textural dislocations on NCA surfaces, creating millimeter-scale erosion pits that increase aggregate water absorption by 18.5%. These morphological changes significantly impair concrete workability and reduce compressive strength performance. Furthermore, microstructural analysis reveals a 45.24% expansion in interfacial transition zone (ITZ) thickness, accompanied by notable reductions in elastic modulus and microhardness characteristics. In practical RCA treatment applications, for RCA containing limestone-based NCA, it is recommended to use acetic acid concentrations between 0.1 and 0.3 M to avoid substantial physical and microstructural degradation of aggregates and concrete.

Chitosan stability in acetic acid-permanganate solutions: Spectroscopic and viscometric approach.

Ulcerative colitis, an inflammatory disease of the colon, is prone to recurrence. Research into novel therapies for this condition is urgently required. The current investigation aims to ascertain the protective impact of microspheres loaded with mangiferin in acetic acidinduced ulcerative colitis (UC). The formulation significantly reduced inflammatory alterations, ulcer activity scores, and oxidative stress. Colitis was induced by injecting 1 mL of a 4% acetic acid solution. In addition to a macroscopical and gross evaluation, colon samples were tested for catalase and glutathione (GSH) activity. Microspheres loaded with mangiferin reduced the severity of ulcerative colitis caused by acetic acid, as indicated by improvements in weight loss, macroscopic score, ulcer area, and histological score. The anti-inflammatory effects of the microspheres may explain their ability to alleviate symptoms of acetic acid-induced ulcerative colitis. These findings suggest that enteric-coated microspheres loaded with mangiferin exhibit a protective effect against colon ulcers in rats and offer delayed-release properties compared to plain mangiferin.

Sustainable soft actuators based on chitosan and choline containing ionic liquids with high bending response.

This study aims to observe the phases of mitosis in the meristem cells of shallot roots (Allium cepa) through microscopic observation as part of the Cell Biology learning model. Mitosis is an important part of the cell cycle that plays a role in growth, tissue repair, and asexual reproduction in organisms. A deep understanding of the mitosis process is an important foundation in various branches of biology, including genetics, biotechnology, and histology. Shallot roots were chosen because they have actively dividing meristem tissue at the root tip,as well as a large and transparent cell structure that facilitates the staining and observation process. Preparation was carried out by soaking the onion roots in a solution of acetic acid and alcohol for fixation,then staining with acetocarmine acid so that the chromosomes are clearly visible. The process of crushing the root tip and pressing it on a glass object (squash method) was used to expand the observation area. A light microscope with a magnification of 400x and 1000x was used to identify the division phases. Observation results show the presence of all phases of mitosis, namely prophase (nucleolus and nuclear membrane begin to disappear,chromosomes condense), metaphase (chromosomes line up at the equator), anaphase (chromatids separate to opposite poles), and telophase (nuclear membrane and two daughter cell nuclei re-form). Visual documentation in the form of microscopic photographs and descriptive tables clarify the identification of these phases, thus facilitating student understanding.From a pedagogical perspective, this microscopic practicum-based learning has been proven to improve students' observational skills, laboratory skills, and conceptual understanding of cell division. Students not only memorize theories, but directly experience the scientific process through exploration and discussion of observation results. Evaluation of learning outcomes is carried out through post-practicum quizzes and student worksheets, showing an increase in understanding scores of more than 30%.

Porous hybrid networks were formed from methacrylated collagen (ICol-MA) fibrils and methacrylated PTMC (PTMC-tMA). Dispersing ICol-MA and dissolving PTMC-tMA in DMSO acidified with HCl (DMSO/HCl), followed by mixing, casting, freezing, photo-cross-linking, and solvent extraction, resulted in networks with high porosities and gel contents. ATR-FTIR showed that hybrid networks had compositions similar to the mixture compositions prior to photo-cross-linking. Mechanical testing of porous hybrid networks, in particular the ICol-MA:PTMC-tMA 17:83 wt % network, showed improved mechanical properties compared to non-cross-linked ICol and ICol-MA networks prepared in DMSO/HCl. Additionally, cross-linking alone already improves the properties of porous collagen structures. Interestingly, photo-cross-linking ICol-MA in acetic acid solution resulted in the best mechanical properties, suggesting that the solvent affects collagen fibril structure and thus network mechanical properties. Indeed, acetic acid does not alter the collagen banding structure, whereas DMSO/HCl does. Thus, further investigation into the effect of the solvent on the network properties is needed.

This study aimed to investigate the efficacy of different electrical waveforms in suppressing bladder overactivity during acute tibial nerve stimulation (TNS) in cats. Cystometric measurements were performed during intravesical infusion of either acetic acid (AA) or normal saline (NS) control solution. Bipolar hook electrodes were implanted on the left tibial nerve for stimulation. TNS with monophasic square waves, biphasic square waves, sine waves, and triangular waves were applied consecutively. Cystometrograms were utilized to evaluate the impacts of these different waveforms on the micturition reflex. Under physiological conditions, all four TNS waveforms significantly increased bladder capacity compared with NS control levels (10.96 ± 3.33 mL; P < 0.001). The relative increases were as follows: 151.10% ± 4.66%, 132.20% ± 3.47%, 131.30% ± 4.85%, and 128.60% ± 3.55% of control values. Under pathological conditions, the monophasic square wave demonstrated inhibitory effects compared with the other three waveforms (P < 0.001). In contrast, no significant differences in inhibitory efficacy were observed between waveforms under pathological conditions (P > 0.05). Quantitative analysis revealed significantly lower T values for both monophasic and biphasic square waves compared with sinusoidal and triangular waveforms (P < 0.001). Furthermore, the triangular wave exhibited significantly higher T values than the sine wave (P = 0.02). The efficacy of TNS waveforms showed condition-dependent variation, with no consistent performance pattern between physiological and pathological states. When considering practical clinical application factors, including stimulator longevity and minimization of tissue damage, the biphasic square wave may be more beneficial.NEW & NOTEWORTHY In this study, we determined the effects of tibial nerve stimulation (TNS) at different stimulation waveforms on bladder reflex in cats. Innovations are as follows: 1) as far as we know, the effects of TNS with different waveforms on overactive bladder has been not explored forever. 2) Our results may provide a basis for altering parameters to improve the therapeutic efficacy of TNS for overactive bladder.

Using CO2 as the primary feedstock offers the potential for high-value utilization of CO2 while forging sustainable pathways for producing valuable products. Electrochemical CO2 reduction, have received extensive attentions for their potential to utilize renewable electricity as energy sources to upgrade CO2 into valuable fuels and chemicals. However, this process is typically limited to producing simple molecules, such as formate, carbon monoxide, ethanol, acetate, and n-propanol. It remains a grand challenge to convert CO2 into more complex molecules at high production rates due to the complicated reaction pathways. Electrified cascade catalysis, which integrates electrocatalysis with other catalytic processes, offers a promising solution to this limitation. However, the disparity between the different catalytic systems, arising from variations in molecule diversity, concentration, and impurities, have limited the practical application of cascade catalysis. To address these challenges, we developed two processes that overcome the limitations posed by nexus molecules through advancements in catalyst engineering and reactor design.For ethylene glycol production, CO2 is first electroreduced to ethylene using Cu nanocubes. The ethylene is then converted to ethylene glycol on a catalyst/solid-acid composite, with electrochemically generated hydrogen peroxide serving as the oxidant. Using an integrated solid-electrolyte reactor, we achieved a high electron utilization efficiency of 60–70% at industrially relevant current densities (100–500 mA cm−2) for ethylene glycol production, with nearly 100% product selectivity.For L-tyrosine production, we developed an abiotic/biotic cascade catalysis based on blended nexus molecules. We start by constructing a solid-state reactor for the electrochemical reduction of CO2, producing a pure solution of acetic acid and ethanol as blended nexus molecules, free from impurities that could impact Escherichia coli growth. This electrochemically generated acetic acid and ethanol can be directly fed to Escherichia coli. Next, we use genetic engineering to introduce an ethanol utilization pathway and a tyrosine production pathway into Escherichia coli to facilitate L-tyrosine synthesis. The ethanol pathway works synergistically with the acetic acid pathway, significantly boosting the L-tyrosine production rate (nearly fivefold compared to the strain lacking the ethanol utilization pathway) and improving carbon efficiency. We have successfully achieved l-tyrosine synthesis at a concentration of 0.6 g L−1.In conclusion, we successfully synthesized L-tyrosine and ethylene glycol from CO2 using electrochemical-biological and electrochemical-thermal cascade catalysis, respectively. Our findings highlight the potential of process design as an effective strategy for producing complex chemical products.