1. Catalytic conversion of nonequilibrium hydrogen and nitrogen species from low-pressure inductively coupled plasma to ammoniaRok Zaplotnik, Alenka Vesel, Ganji Parameswaram, Gregor Primc, Miha Čekada, Gregor Dolanc, Miran Mozetič, 2026, original scientific article Abstract: Gas conversion between hydrogen (H2), nitrogen (N2), and ammonia (NH3) is a scientific topic of interest in both methods for low-temperature synthesis of ammonia and energy-efficient production of hydrogen for powering fuel cells. The efficiency of catalysts for ammonia synthesis at room temperature was evaluated. A mixture of hydrogen and nitrogen with a ratio in a broad range between 1.5:1 and 80:1 was passed through a plasma sustained by inductively coupled radio frequency discharge in the H mode at a power of 700 W and pressures between 40 and 100 Pa. Several catalysts were placed in the flowing afterglow where the H and N densities were of the order of 1021 m−3, and the conversion efficiency (η) was evaluated. The efficiency increased almost linearly with increasing enthalpy of nitride formation. The best results were observed for copper, for which the conversion was almost twice the value in the same system without the catalyst. The efficiency of NH3 production by the conversion of N atoms into NH3 molecules versus the gas mixture exhibited a broad maximum and was as large as η ≈ 29% in the mixture of hydrogen and nitrogen between 3:1 and 10:1.
Keywords: hydrogen production
Published in DiRROS: 14.05.2026; Views: 53; Downloads: 25
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2. Utilization of waste plastic for plasma-assisted deposition of carbon nanowalls on electrodes for sustainable high-performance energy-storage devicesAlenka Vesel, Gregor Primc, Miran Mozetič, Melita Tramšek, Evelin Gruden, Haojie Fei, Petr Sáha, Marián Lehocký, Rok Zaplotnik, 2026, original scientific article Abstract: Current global policies, such as circular economy, electrification, and low carbon footprint dictate the replacement of fossil fuels for synthesizing electrodes of graphene supercapacitors with renewable sources. The traditional method for depositing graphene and similar structures is based on gaseous hydrocarbons. The possibility of replacing them with waste plastic is presented. We used propane and waste plastics (mostly polypropylene) for the deposition of a few µm-thick deposit of carbon nanowalls composed of vertically oriented multilayer graphene-like sheets on electrodes by plasma-enhanced chemical vapor deposition (PECVD). We studied their morphology and structure, as well as the performance of coin-shaped supercapacitors. The graphene-like coatings were deposited in plasma sustained at the pressure of 16 Pa by inductively coupled RF discharge in the H mode at the forward power of 500 W and power density approximately 8x106 W/m3. Such a powerful plasma caused thermal decomposition of the waste plastic. Optical emission spectroscopy showed significant differences only within the first few seconds of plasma treatment, which was enough to supply precursors for graphene growth. Both scanning and transmission electron microscopies showed similar structures for deposits prepared from propane or waste plastic, and the deposition rates of roughly 100 nm/s were observed. Waste plastic enabled the deposition of 2–3 times densely packed multilayer graphene-like sheets of a typical thickness of 5 nm at deposition times over 1 min. Raman spectroscopy indicated a somewhat lower concentration of defects for samples deposited from polypropylene, but the ID/IG versus the average distance between the neighboring multilayer graphene-like sheets followed the same line. The specific capacitance increased steeply with deposition time for deposits prepared from waste plastic and it was found to be linearly dependent on the ratio between the effective and projected areas of both precursors. The capacitance versus the ID/IG followed the same curve for both precursors. The results demonstrate the feasibility of replacing gaseous hydrocarbons with waste plastics for PECVD deposition of graphene electrodes.
Keywords: carbon nanomaterials, carbonnanowalls, electrode material, supercapacitators
Published in DiRROS: 28.04.2026; Views: 158; Downloads: 108
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3. Optimised anaesthesia in abdominal cancer surgery does not prevent increase in biomarkers of neuroinflammationMatej Jenko, Aleš Jerin, Alenka Spindler-Vesel, 2025, original scientific article Abstract: Neurocognitive decline during the perioperative period represents a risk of significant complications, including dementia and death. The aim of our study was to observe the change in biomarkers of neuroinflammation in optimized anesthesia without clinical signs of perioperative neurocognitive decline. Observational study included high-risk surgical patients who underwent large intestinal resections. Balanced anaesthesia was used to maximize cerebral protection. The release of NSE, protein S-100, matrix metalloproteinase-9 (MMP-9) and other biomarkers of cerebral injury were measured in serum samples using immunochemical methods during and after surgery. Profiles of proteins MMP-9 and S-100 showed perioperative increase, which was in accordance with intraoperative cerebral injury. Despite the increase, the S-100 and NSE plasma levels remained within normal range. The study highlights the perioperative expression of proteins MMP-9 and S-100, which might be useful as biomarkers of cerebral injury in the context of balanced anesthesia during major abdominal surgery.
Keywords: biomarkers, abdominal cancer surgery, anaesthesia
Published in DiRROS: 27.02.2026; Views: 311; Downloads: 154
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4. Sex dependence of postoperative pulmonary complications : a post hoc unmatched and matched analysis of LAS VEGASTom D. Vermeulen, Liselotte Hol, Pien Swart, Michael Hiesmayr, Gary H. Mills, Christian Putensen, Werner Schmid, Ary Serpa Neto, Paolo Severgnini, Marcos F. Vidal Melo, 2024, original scientific article Abstract: Study objective: Male sex has inconsistently been associated with the development of postoperative pulmonary complications (PPCs). These studies were different in size, design, population and preoperative risk. We reanalysed the database of ‘Local ASsessment of Ventilatory management during General Anaesthesia for Surgery study’ (LAS VEGAS) to evaluate differences between females and males with respect to PPCs. Design, setting and patients Post hoc unmatched and matched analysis of LAS VEGAS, an international observational study in patients undergoing intraoperative ventilation under general anaesthesia for surgery in 146 hospitals across 29 countries. The primary endpoint was a composite of PPCs in the first 5 postoperative days. Individual PPCs, hospital length of stay and mortality were secondary endpoints. Propensity score matching was used to create a similar cohort regarding type of surgery and epidemiological factors with a known association with development of PPCs. Main results: The unmatched cohort consisted of 9697 patients; 5342 (55.1%) females and 4355 (44.9%) males. The matched cohort consisted of 6154 patients; 3077 (50.0%) females and 3077 (50.0%) males. The incidence in PPCs was neither significant between females and males in the unmatched cohort (10.0 vs 10.7%; odds ratio (OR) 0.93 [0.81–1.06]; P = 0.255), nor in the matched cohort (10.5 vs 10.0%; OR 1.05 [0.89–1.25]; P = 0.556). New invasive ventilation occurred less often in females in the unmatched cohort. Hospital length of stay and mortality were similar between females and males in both cohorts. Conclusions: In this conveniently–sized worldwide cohort of patients receiving intraoperative ventilation under general anaesthesia for surgery, the PPC incidence was not significantly different between sexes.
Keywords: general anaesthesia, intraoperative ventilation, operating room, outcomes
Published in DiRROS: 26.02.2026; Views: 313; Downloads: 199
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5. Associations of intraoperative end-tidal CO2 levels with postoperative outcome : secondary analysis of a worldwide observational studyPrashant Nasa, David M.P. van Meenen, Frederique Paulus, Marcelo Gama de Abreu, Sebastiaan M. Bossers, Patrick Schober, Marcus J. Schultz, Ary Serpa Neto, Sabrine N. T. Hemmes, 2025, original scientific article Keywords: anesthesia, intraoperative ventilation, invasive ventilation, postoperative pulmonary complications
Published in DiRROS: 26.02.2026; Views: 332; Downloads: 185
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6. Surface functionalization of medical-grade polyvinyl chloride treated with ammonia plasmaRok Zaplotnik, Nina Recek, Gregor Primc, Andrej Gyergyek, Marián Lehocký, Alenka Vesel, Miran Mozetič, 2026, original scientific article Keywords: PVC polymer, ammonia plasma
Published in DiRROS: 20.02.2026; Views: 435; Downloads: 224
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7. Influence of hypnosis and acupuncture on perioperative complicationsJasmina Markovič Božič, Meta Gradišar, Mihela Petovar, Polona Mušič, Nina Pirc, Joseph Meyerson, Maks Tušak, Andrej Lapoša, Matej Tušak, Alenka Spindler-Vesel, 2025, original scientific article Abstract: Background: This randomised, single-centre study and original research manuscript aimed to evaluate whether perioperative hypnosis and acupuncture can reduce postoperative nausea and vomiting (PONV), opioid use, and other complications in spinal surgery compared to standard pharmacological management. Methods: In total, 60 patients undergoing spinal surgery were divided into three groups regarding antiemetic prevention: Hypnosis and acupuncture (HG), hypnosis, acupuncture, and antiemetic (HAG), and standard control with antiemetic (CG). Hypnosis was performed one day before surgery, or patients received premedication with midazolam on the day of surgery. Anaesthesia was induced and maintained with propofol and remifentanil. Acupuncture was performed bilaterally at points LI4 and PC6 after induction of anaesthesia. Postoperatively, the consumption of opioids and antiemetics, satisfaction and well-being, length of stay and complications were recorded. Results: In all groups, additional opioids were administered in the first hour after surgery (p = 0.4). In the ICU, only one patient in the HAG and two patients in the CG and HG required additional analgesics (p = 0.8). Overall satisfaction (9/9/0 vs. 10/6/4 vs. 9/7/3; p = 0.4) and well-being scores (10/8/0 vs. 13/5/2 vs. 13/5/1; p = 0.5) were high across all groups, with no significant differences. Two patients in CG experienced mild complications. The length of hospitalisation was similar (3 days in CG vs. 4 days in HAG and HG (p = 0.7). Only one patient in the HG required antiemetics; none were needed in CG or HAG (p = 0.4). Conclusions: Within the constraints of this exploratory single-centre trial, hypnosis appeared to provide anxiolytic benefits comparable to benzodiazepines, and intraoperative acupuncture did not increase PONV despite reduced pharmacological prophylaxis. No significant differences were detected in opioid and antiemetic consumption. Larger, adequately powered studies are needed to confirm these findings and optimise the timing and modality of non-pharmacological interventions.
Keywords: spinal surgery, anaesthesia, antiemetic, acupuncture, hypnosis
Published in DiRROS: 05.01.2026; Views: 553; Downloads: 213
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8. Green synthesis of a magnetite/graphitic carbon nitride 2D nanocomposite for efficient ▫$Hg^{2+}$▫ remediationRaghuraj S. Chouhan, Jan Gačnik, Igor Živković, Sreekanth Vijayakumaran Nair, Nigel Willy Van de Velde, Alenka Vesel, Primož Šket, Sonu Gandhi, Ivan Jerman, Milena Horvat, 2023, original scientific article Abstract: Novel nanoadsorbents demonstrate the potential to efficiently eliminate harmful substances, such as Hg2+, from the environment while preserving ecological balance. However, the search for environmentally-friendly nanomaterials as ideal adsorbents, as well as the development of suitable synthesis protocols, remains a challenge. This study presents an effective thermal-sonication technique for producing unique de novo tris-s-triazine carbon nitride nanosheets decorated with magnetite nanoparticles (M-g-CN). The structural integrity and chemical properties of the M-g-CN nanocomposite were extensively characterized using a battery of analytical instruments, including FTIR, SEM, TEM, XRD, XPS, AFM, Raman, and NMR. The obtained data, along with the analysis results, are discussed in detail. The novel synthesis method yields a high percentage (97.7%) of stable, highly selective, and reusable M-g-CN (40 mg mL−1). The resulting M-g-CN effectively binds Hg2+, with binding efficiencies of 96.0%, 97.5%, 98.2%, and 99.4% for Hg2+ concentrations of 50 pg mL−1 in marine, stream, precipitation, and ultra-pure matrices, respectively. Also, the magnetite-decorated particles can be easily retrieved using an applied magnetic field. This greener and scalable synthesis method does not require harsh chemicals, making it cost-effective, eco-friendly, and non-toxic compared to other technologies such as carbon filters, ion exchange resins, chemical precipitation, membrane filtration, electrochemical methods, and biological remediation. Overall, the synthesized M-g-CN exhibits wide-ranging potential applications, particularly as a green adsorbent in passive samplers or materials for remediation purposes.
Keywords: mercury, elimination, nanoadsorbents, nanocomposites
Published in DiRROS: 05.01.2026; Views: 447; Downloads: 215
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9. Association of preoperative smoking with the occurrence of postoperative pulmonary complications : a post hoc analysis of an observational study in 29 countriesGalina Dorland, W. Saadat, David M.P. van Meenen, Ary Serpa Neto, Michael Hiesmayr, 2025, original scientific article Abstract: Introduction: While smoking has been consistently identified as a significant contributor to postoperative complications, the existing literature on its association with postoperative pulmonary complications remains conflicting. Aim: We examined the association of preoperative smoking with the occurrence of postoperative pulmonary complications (PPCs). Methods: Post hoc analysis of an observational study in 146 hospitals across 29 countries. We included patients at increased risk of PPCs, according to the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score (≥ 26 points). The primary endpoint was the occurrence of one or more predefined PPCs in the first five postoperative days, including unplanned postoperative need for supplementary oxygen, respiratory failure, unplanned need for invasive ventilation, ARDS, pneumonia and pneumothorax. Secondary endpoints included length of hospital stay and in–hospital mortality. We performed propensity score matching to correct for factors with a known association with postoperative outcomes. Results: Out of 2632 patients, 531 (20.2 %) patients were smokers and 2102 (79.8 %) non-smokers. At five days after surgery, 101 (19.0 %) smokers versus 404 (19.2) non–smokers had developed one or more PPCs (P = 0.95). Respiratory failure was more common in smokers (5.1 %) than non–smokers (3.0 %) (P = 0.02), while rates of other PPCs like need for supplementary oxygen, invasive ventilation, ARDS, pneumonia, or pneumothorax did not differ between the groups. Length of hospital stay and mortality was not different between groups. Propensity score matching did not change the findings. Conclusion: The occurrence of PPCs in smokers is not different from non–smokers.
Keywords: anaesthesia, intraoperative ventilation, smoking, postoperative outcome, postoperative pulmonary complications, PPCs, respiratory complications
Published in DiRROS: 23.12.2025; Views: 613; Downloads: 228
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10. Hydrophilization of rice seeds by plasma treatments – super-hydrophilic surface finish and hydrophobic recoveryAlenka Vesel, Anca Macovei, Alma Balestrazzi, Dane Lojen, Gregor Primc, Rok Zaplotnik, Nives Ogrinc, Marián Lehocký, Miran Mozetič, 2025, original scientific article Abstract: The hydrophobic character of rice seeds protects them from quick water adsorption and, thus, premature germination. This property is, however, a drawback in modern agriculture, where rapid and uniform germination represents a high-quality trait. A method for rapid hydrophilization of the Lomello variety of rice is presented. The rice seeds were treated with low-pressure gaseous plasma to tailor the wettability. The treatment of seeds with hulls with oxygen plasma afterglow enabled the super-hydrophilic surface finish within 10 ms. Such extremely fast hydrophilization was attributed to irreversible surface oxidation by neutral oxygen atoms whose flux onto the seeds was approximately 3 × 1023 m−2s−1. Dehulled seeds were made super-hydrophilic by subsequent treatments with hydrogen and oxygen plasma, and the required dose of O atoms was between 2 × 1023 and 6 × 1024 m−2. Larger doses caused a loss of the super-hydrophilicity. Hydrophilization kinetics is proposed and supported by measuring surface wettability, morphology, and composition using various techniques. The hydrophobic recovery of seeds with hulls is marginal within the first few days after plasma treatments, but dehulled seeds lose the super-hydrophilic surface finish within a few minutes after the plasma treatment when stored at ambient conditions.
Keywords: rice seed, water adsorption, surface treatment, wettability, super-hydrophilicity
Published in DiRROS: 10.11.2025; Views: 461; Downloads: 300
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