Improved microwave-assisted saponification to reduce the variability of MOAH determination in edible oils.

BACKGROUND: Mineral oil aromatic hydrocarbon (MOAH) analysis in foods is a major analytical challenge. Quantification is associated with a high uncertainty. The sources of uncertainty are multiple, but the major one is related to data interpretation and integration, which is partially derived from insufficiently efficient sample preparation. Recently, an updated ISO method for the analysis of mineral oil in fats and oils and a standard operating procedure for infant formula analysis have been published. Both methods reported significantly different (up to 1.25) distributions of the internal standards used for quantification (i.e., tri-tert-butyl benzene (TBB) and 2-methyl naphthalene (2-MN)) over the different solvent phases used in the saponification step. RESULTS: In this work, a microwave-assisted saponification and extraction method was optimized for MOAH analysis to solve the problem related to the MOAH internal standards partition. The paper examines the impact of the solvent mixture used, the concentration of KOH on the partition of TBB and 2-MN, and the effect of the matrix and the washing step to extract the unsaponifiable fraction containing the mineral oils. SIGNIFICANCE: The optimized procedure achieved a TBB/2-MN ratio of 1.05 ± 0.01 tested in five different fats and oils, namely, sunflower, rapeseed, coconut, palm, and extra virgin olive oils. The method can significantly contribute to reducing the uncertainty of the MOAH quantification when saponification is applied.

Percutaneous microwave ablation, perfusion, and reconstruction combined with a synthetic bone substitute in symptomatic bone cysts: a minimum of 26 months follow-up.

PURPOSE: The objective was to describe the technique and clinical outcome of microwave thermal ablation (MWA) and perfusion combined with synthetic bone substitutes in treating unicameral bone cysts (UBCs) in adolescents. MATERIALS AND METHODS: A total of 14 consecutive patients were enrolled by percutaneous MWA and saline irrigation combined with synthetic bone substitutes. Clinical follow-up included the assessment of pain, swelling, and functional mobility. Radiological parameters included tumor volume, physis-cyst distance, cortical thickness of the thinnest cortical bone, and the Modified Neer classification system. RESULTS: The mean follow-up was 28.9 months (26-52 months). All UBCs were primary, and all patients underwent the MWA, saline perfusion, and reconstruction combined with a synthetic bone substitute session, except for one patient (7.1%) who required a second session. All patients had good clinical results at the final follow-up. Satisfactory cyst healing was achieved in 13 cases according to radiological parameters. Tumor volume decreased from a mean of 49.7 cm3 before surgery treatment to 13.9 cm3 at the final follow-up (p < 0.01). The physis-cyst distance increased from a mean of 3.17-4.83 cm at the final follow-up (p < 0.01). Cortical thickness improved from a mean of 1.1 mm to 2.0 mm at the final follow-up (p < 0.01). According to the proposed radiological criteria, our results were considered successful (Grading I and II) in 13 patients (92.9%) at the final follow-up. CONCLUSION: Percutaneous microwave ablation combined with a bone graft substitute is a minimally invasive, effective, safe, and cost-effective approach to treating primary bone cysts in the limbs of adolescents.

Green extraction and application of yellow natural curcumin colorant from Curcuma aromatica rhizomes for silk dyeing.

Green products such as plant tints are becoming more and more well-known worldwide due to their superior biological and ayurvedic properties. In this work, colorant from Amba Haldi (Curcuma aromatica) was isolated using microwave (MW), and bio-mordants were added to produce colorfast shades. Response surface methodology was used to develop a central composite design (CCD), which maximizes coloring variables statistically. The findings from 32 series of experiments show that excellent color depth (K/S = 12.595) was established onto MW-treated silk fabric (RS = 4 min) by employing 65 mL of radiated aqueous extract (RE = 4 min) of 5 pH cutting-edge the existence of 1.5 g/100 mL used sodium chloride at 75 °C for 45 min. It was discovered that acacia (keekar) extract (1%), pomegranate extract (2%), and pistachio extract (1.5%) were present before coloring by the use of bio-mordants. On the other hand, upon dyeing, acacia extract (1.5%), pomegranate extract (1.5%), and pistachio extract (2%) have all shown extremely strong colorfast colors. Comparatively, before dyeing, salts of Al3+ (1.5%), Fe2+ (2%), and TA (1.5%) gave good results; after dyeing, salts of Al3+ (1%) and Fe2+ (1.5%) and TA (2%) gave good results. When applied to silk fabric, MW radiation has increased the production of dyes recovered from rhizomes. Additionally, the right amount of chemical and biological mordants have been added, resulting in color fastness ratings ranging from outstanding to good. Therefore, the natural color extracted from Amba Haldi can be a sustainable option for the dyeing of silk fabric in the textile dyeing and finishing industries.

In vitro digestion of beef and vegan burgers cooked by microwave technology: Effects on protein and lipid fractions.

Commercial beef burgers and vegan analogues were purchased and, after a microwave treatment, they were submitted to an in vitro digestion (INFOGEST). Vegan cooked burgers showed similar protein content (16-17 %) but lower amounts of total peptides than beef burgers. The protein digestibility was higher in beef burgers. Peptide amounts increased during in vitro digestion, reaching similar amounts in both types of products in the micellar phase (bioaccessible fraction). The fat content in cooked vegan burgers was significantly lower than in beef burgers (16.7 and 21.2 %, respectively), with a higher amount of PUFAs and being the lipolysis activity, measure by FFA, less intense both after cooking and after the gastrointestinal process. Both types of cooked samples showed high carbonyl amounts (34.18 and 25.51 nmol/mg protein in beef and vegan samples, respectively), that decreased during in vitro digestion. On the contrary, lipid oxidation increased during gastrointestinal digestion, particularly in vegan samples. The antioxidant capacity (ABTS and DPPH) showed higher values for vegan products in cooked samples, but significantly decreased during digestion, reaching similar values for both types of products.

[Curative effect of percutaneous microwave ablation therapy on hepatocellular carcinoma survival: a 15-year real-world study].

Objective: To evaluate the long-term efficacy of percutaneous microwave ablation (MWA) therapy for hepatocellular carcinoma. Methods: 2054 cases with Barcelona Clinic Liver Cancer (BCLC) stage 0~B at the Fifth Medical Center of the Chinese People's Liberation Army General Hospital from January 2006 to September 2020 were retrospectively collected. All patients were followed up for at least 2 years. The primary endpoint of overall survival and secondary endpoints (tumor-related survival, disease-free survival, and postoperative complications) of patients treated with ultrasound-guided percutaneous MWA were analyzed. Kaplan-Meier method was used for stratified survival rate analysis. Fine-and-Gray competing risk model was used to analyze overall survival. Results: A total of 5 503 HCC nodules [mean tumor diameter (2.6±1.6) cm] underwent 3 908 MWAs between January 2006 and September 2020, with a median follow-up time of 45.6 (24.0 -79.2) months.The technical effectiveness rate of 5 375 tumor nodules was 97.5%. The overall survival rates at 5, 10, and 15-years were 61.6%, 38.8%, and 27.0%, respectively. The tumor-specific survival rates were 67.1%, 47.2%, and 37.7%, respectively. The free tumor survival rates were 25.8%, 15.7%, and 9.9%, respectively. The incidence rate of severe complications was 2.8% (108/3 908). Further analysis showed that the technical effectiveness and survival rate over the passing three time periods from January 2006-2010, 2011-2015, and 2016-September 2020 were significantly increased, with P < 0.001, especially for liver cancer 3.1~5.0 cm (P < 0.001). Conclusion: Microwave ablation therapy is a safe and effective method for BCLC stage 0-B, with significantly enhanced technical efficacy and survival rate over time.

Laparoscopic-assisted microwave ablation in treatment of small hepatocellular carcinoma: safety and efficacy in comparison with laparoscopic hepatectomy.

Laparoscopic-assisted microwave ablation (LAMWA), as one of the locoregional therapies, has been employed to treat hepatocellular carcinoma (HCC). This study aims to compare the efficacy and safety of LAMWA and laparoscopic hepatectomy in the treatment of small HCC.This study included 140 patients who met the inclusion criteria. Among them, 68 patients received LAMWA and 72 patients underwent laparoscopic hepatectomy. The perioperative condition, liver function recovery, the alpha fetoprotein (AFP) level, morbidities, hospitalization time, overall survival (OS), disease-free survival (DFS) and recurrence rate between the two groups were compared. The rate of complete elimination of tumor tissue was 100% and the AFP level was returned to normal within 3 months after surgery in both groups (P > 0.05). The mean alanine transaminase (ALT) and aspartate transaminase (AST) peak in the LAMWA group was lower than that in the laparoscopic hepatectomy group (259.51 ± 188.75 VS 388.9 ± 173.65, P = 0.000) and (267.34 ± 190.65 VS 393.1 ± 185.67, P = 0.000), respectively. The mean operation time in the LAMWA group was shorter than that in the laparoscopic hepatectomy group (89 ± 31 min VS 259 ± 48 min, P = 0.000). The blood loss in the LAMWA group was less than that in the laparoscopic hepatectomy group (58.4 ± 64.0 ml VS 213.0 ± 108.2 ml, P = 0.000). Compared with the laparoscopic hepatectomy group, patients in the LAMWA group had lower mean hospital stay (4.8 ± 1.2d VS 11.5 ± 2.9d, P = 0.000). The morbidities of the LAMWA group and the hepatectomy group were 14.7%(10/68) and 34.7%(25/72), respectively (P = 0.006). The one-, three-, and five-year OS rates were 88.2%, 69.9%, 45.6% for the LAMWA group and 86.1%, 72.9%, 51.4% for the laparoscopic hepatectomy group (P = 0.693). The corresponding DFS rates for the two groups were 76.3%, 48.1%, 27.9% and 73.2%, 56.7%, 32.0% (P = 0.958). Laparoscopic-assisted microwave ablation is a safe and effective therapeutic option for selected small HCC.

Ultrasound combined with microwave hydrodiffusion and gravity for enhancement of caffeine extraction from guarana powder.

The extraction of valuable compounds from dried fruits and vegetables by microwave hydrodiffusion and gravity (MHG) requires previous hydration of the plant material. In this work, ultrasound was used to speed up the hydration of guarana powder before MHG extraction and increase caffeine recovery. The humidification step was speeded up with ultrasound taking only 15 min over 60 min without ultrasound. Water and 50% (v/v) ethanol were evaluated as green solvents for humidification, with a higher concentration of caffeine obtained for the hydroalcoholic solution. Ultrasound pretreatment allowed guarana extracts from MHG with two times more caffeine for both solvents evaluated. Therefore, ultrasound can be used in the hydration step before MHG extraction to reduce time and increase caffeine recovery from guarana powder.

Elucidating the structural and conformational preferences of bioactive chromone and its monohydrate through advanced rotational spectroscopy.

Chromones are a class of naturally occurring compounds, renowned for their diverse biological activities with significant relevance in medicine and biochemistry. This study marks the first analysis of rotational spectra of both the chromone monomer and its monohydrate through Fourier transform microwave spectroscopy. The observation of nine mono-substituted 13C isotopologues facilitated a semi-experimental determination of the equilibrium structure of the chromone monomer. In the case of chromone monohydrate, two distinct isomers were identified, each characterized by a combination of O-H⋯O and C-H⋯O hydrogen bonds involving the chromone's carbonyl group. This study further delved into intermolecular non-covalent interactions, employing different theoretical approaches. The relative population ratio of the two identified isomers was estimated to be about 2:1 within the supersonic jet.

Microwave-Assisted Atom Transfer Radical Cyclization in the Synthesis of 3,3-Dichloro-γ- and δ-Lactams from N-Alkenyl-Tethered Trichloroacetamides Catalyzed by RuCl2(PPh3)3 and Their Cytotoxic Evaluation.

An expeditious synthesis of γ- and δ-lactams from tethered alkenyl trichloroacetamides in the presence of 5% of RuCl2(PPh3)3 is reported. In this investigation we have demonstrated that microwave activation significantly enhances reaction rates, leading to the formation of the corresponding lactams in yields ranging from good to excellent. Thus, we have been able to prepare a wide range of lactams, including indole and morphan bicyclic scaffolds, where the corresponding reactions were completely diastereoselective. This process was successfully extended to α,α-dichloroamides without affecting either their yield or their diastereoselectivity. Some of the lactams prepared in this work were evaluated for their hemolytic and cytotoxic responses. All compounds were found to be non-hemolytic at the tested concentration, indicating their safety profile in terms of blood cell integrity. Meanwhile, they exhibited interesting cytotoxicity responses that depend on both their lactam structure and cell line. Among the molecules tested, γ-lactam 2a exhibited the lowest IC50 values (100-250 µg/mL) as a function of its cell line, with promising selectivity against squamous carcinoma cells (A431) in comparison with fibroblasts (3T3 cell line).

Preoperative MRI radiomic analysis for predicting local tumor progression in colorectal liver metastases before microwave ablation.

PURPOSE: Radiomics may aid in predicting prognosis in patients with colorectal liver metastases (CLM). Consistent data is available on CT, yet limited data is available on MRI. This study assesses the capability of MRI-derived radiomic features (RFs) to predict local tumor progression-free survival (LTPFS) in patients with CLMs treated with microwave ablation (MWA). METHODS: All CLM patients with pre-operative Gadoxetic acid-MRI treated with MWA in a single institution between September 2015 and February 2022 were evaluated. Pre-procedural information was retrieved retrospectively. Two observers manually segmented CLMs on T2 and T1-Hepatobiliary phase (T1-HBP) scans. After inter-observer variability testing, 148/182 RFs showed robustness on T1-HBP, and 141/182 on T2 (ICC > 0.7).Cox multivariate analysis was run to establish clinical (CLIN-mod), radiomic (RAD-T1, RAD-T2), and combined (COMB-T1, COMB-T2) models for LTPFS prediction. RESULTS: Seventy-six CLMs (43 patients) were assessed. Median follow-up was 14 months. LTP occurred in 19 lesions (25%).CLIN-mod was composed of minimal ablation margins (MAMs), intra-segment progression and primary tumor grade and exhibited moderately high discriminatory power in predicting LTPFS (AUC = 0.89, p = 0.0001). Both RAD-T1 and RAD-T2 were able to predict LTPFS: (RAD-T1: AUC = 0.83, p = 0.0003; RAD-T2: AUC = 0.79, p = 0.001). Combined models yielded the strongest performance (COMB-T1: AUC = 0.98, p = 0.0001; COMB-T2: AUC = 0.95, p = 0.0003). Both combined models included MAMs and tumor regression grade; COMB-T1 also featured 10th percentile of signal intensity, while tumor flatness was present in COMB-T2. CONCLUSION: MRI-based radiomic evaluation of CLMs is feasible and potentially useful for LTP prediction. Combined models outperformed clinical or radiomic models alone for LTPFS prediction.

Thermal damage to the skin from 8.2 and 95 GHz microwave exposures in swine.

A study of burn thresholds from superficially penetrating radio-frequency (RF) energy at 8.2 and 95 GHz for swine skin was conducted. The study determined the thresholds for superficial, partial-thickness, and full-thickness burn severities after 5 seconds of exposure at power densities of 4-30 W/cm2and 2-15 W/cm2at 8.2 and 95 GHz, respectively. There were significant differences in he burn thresholds at the different severities between the two frequencies due to the large difference in energy penetration depths. Biopsies were collected from each burn site at 1, 24, 72, and 168 hr post exposure. Each sample was assessed by a burn pathologist against 20 histological factors to characterize the damage resulting from these RF overexposures. A one-dimensional, layered digital phantom that utilized realistic values for dielectric and thermal properties was used to explain some observed thresholds. The results of the heating and cooling response of the animal model and histology scores of each exposure are provided to enhance future efforts at simulation of RF overexposures and to establish damage thresholds.

Repository of MRI-derived models of the breast with single and multiple benign and malignant tumors for microwave imaging research.

The diagnosis of breast cancer through MicroWave Imaging (MWI) technology has been extensively researched over the past few decades. However, continuous improvements to systems are needed to achieve clinical viability. To this end, the numerical models employed in simulation studies need to be diversified, anatomically accurate, and also representative of the cases in clinical settings. Hence, we have created the first open-access repository of 3D anatomically accurate numerical models of the breast, derived from 3.0T Magnetic Resonance Images (MRI) of benign breast disease and breast cancer patients. The models include normal breast tissues (fat, fibroglandular, skin, and muscle tissues), and benign and cancerous breast tumors. The repository contains easily reconfigurable models which can be tumor-free or contain single or multiple tumors, allowing complex and realistic test scenarios needed for feasibility and performance assessment of MWI devices prior to experimental and clinical testing. It also includes an executable file which enables researchers to generate models incorporating the dielectric properties of breast tissues at a chosen frequency ranging from 3 to 10 GHz, thereby ensuring compatibility with a wide spectrum of research requirements and stages of development for any breast MWI prototype system. Currently, our dataset comprises MRI scans of 55 patients, but new exams will be continuously added.

Microwave synthesized novel biomass carbon dots applied in the fluorescent detection of crystal violet.

To establish a new method for detecting crystal violet (CV), a harmful dye, herein, a genre of novel biomass carbon dots (CDs) was synthesized via a microwave method and employed as a fluorescent probe, in which water spinach and polyethylene glycol (PEG) performed as raw materials. Based on the inner filter effect (IFE) between the luminescent CDs and CV, the blue emission of this probe at 430 nm could be quenched by CV. Hence, a new strategy was proposed to selectively determine CV in aquaculture ambient. Moreover, under the optimal experiment conditions, this method showed a good linearity between the concentration of CV (c) and fluorescence quenching rate (ΔF/F0) in the concentration range of 4-200 µmol/L with the corresponding correlation coefficient (r) and the detection limit of 0.997 and 710 nmol/L, respectively. With advantages of environmental protectivity, sensitivity, affordability, and user-friendliness, the facilely fabricated CDs could be successfully applied in detecting CV in aquaculture samples, providing a technical foundation for monitoring the pollution of CV and ensuring the quality and safety of aquatic products.

Identifying symptom clusters and temporal interconnections in patients with lung tumors after CT-guided microwave ablation: A network analysis.

PURPOSE: To explore symptom clusters and interrelationships using a network analysis approach among symptoms in patients with lung tumors who underwent computed tomography (CT)-guided microwave ablation (MWA). METHODS: A longitudinal study was conducted, and 196 lung tumor patients undergoing MWA were recruited and were measured at 24 h, 48 h, and 72 h after MWA. The Chinese version of the MD Anderson Symptom Inventory and the Revised Lung Cancer Module were used to evaluate symptoms. Network analyses were performed to explore the symptom clusters and interrelationships among symptoms. RESULTS: Four stable symptom communities were identified within the networks. Distress, weight loss, and chest tightness were the central symptoms. Distress, and weight loss were also the most key bridge symptoms, followed by cough. Three symptom networks were temporally stable in terms of symptom centrality, global connectivity, and network structure. CONCLUSION: Our findings identified the central symptoms, bridge symptoms, and the stability of symptom networks of patients with lung tumors after MWA. These network results will have important implications for future targeted symptom management intervention development. Future research should focus on developing precise interventions for targeting central symptoms and bridge symptoms to promote patients' health.

Review of the Capacity to Accurately Detect the Temperature of Human Skin Tissue Using the Microwave Radiation Method.

Microwave radiometry (MWR) is instrumental in detecting thermal variations in skin tissue before anatomical changes occur, proving particularly beneficial in the early diagnosis of cancer and inflammation. This study concisely traces the evolution of microwave radiometers within the medical sector. By analyzing a plethora of pertinent studies and contrasting their strengths, weaknesses, and performance metrics, this research identifies the primary factors limiting temperature measurement accuracy. The review establishes the critical technologies necessary to overcome these limitations, examines the current state and prospective advancements of each technology, and proposes comprehensive implementation strategies. The discussion elucidates that the precise measurement of human surface and subcutaneous tissue temperatures using an MWR system is a complex challenge, necessitating an integration of antenna directionality for temperature measurement, radiometer error correction, hardware configuration, and the calibration and precision of a multilayer tissue forward and inversion method. This study delves into the pivotal technologies for non-invasive human tissue temperature monitoring in the microwave frequency range, offering an effective approach for the precise assessment of human epidermal and subcutaneous temperatures, and develops a non-contact microwave protocol for gauging subcutaneous tissue temperature distribution. It is anticipated that mass-produced measurement systems will deliver substantial economic and societal benefits.

The Synthesis and Analysis of the Cytotoxicity of Al2O3-Supported Silver Nanoparticles Prepared by the Plasma Chemical Process Initiated by Pulsed MW Radiation in the Al2O3-Ag Powder Mixtures.

An original plasma chemical process initiated by microwave discharge in a mixture of metal and dielectric powders was applied to prepare specific materials, which consisted of microsized spherical particles of aluminum oxide covered with silver nanoparticles. The prepared materials are highly uniform in shape, size distribution, and composition. Their cytotoxicity was investigated using the human cell lines MCF7, HEK293T, A549, and VA-13 and the bacterial strains E. coli JW5503 (ΔtolC) and E. coli K12. Their cytotoxicity was found not to exceed the cytotoxicity of the starting materials. Thus, the prepared materials can be considered highly promising for catalysis and biotechnology applications.

Profiling of seized Cannabis sativa L. flowering tops by means of microwave-assisted hydro distillation and gas chromatography analyses.

This research aimed to support police forces in their battle against illicit drug trafficking by means of a multi-technique approach, based on gas chromatography. In detail, this study was focused on the profiling of volatile substances in narcotic Cannabis sativa L. flowering tops. For this purpose, the Scientific Investigation Department, RIS Carabinieri of Messina, provided 25 seized samples of Cannabis sativa L. The content of Δ9-tetrahydrocannabinol (THC), useful to classify cannabis plant as hemp (≤ 0.2 %) or as marijuana (> 0.2 %), was investigated. Essential oils of illicit drug samples were extracted using a microwave-assisted hydro-distillation (MAHD) system; GC-MS and GC-FID analytical techniques were used for the characterization of the terpenes and terpenoids fingerprint. Furthermore, the enantiomeric and carbon isotopic ratios of selected chiral compounds were investigated using a heart-cutting multidimensional GC (MDGC) approach. The latter exploited a combination of an apolar column in the first dimension, and a chiral cyclodextrin-based column in the second one, prior to parallel isotope-ratio mass spectrometry (C-IRMS) and MS detection. Finally, all the data were gathered into a statistical model, to demonstrate the existence of useful parameters to be used for the classification of seized samples.

Microwave-assisted synthesis of highly sulfated mannuronate glycans as potential inhibitors against SARS-CoV-2.

Algae-based marine carbohydrate drugs are typically decorated with negative ion groups such as carboxylate and sulfate groups. However, the precise synthesis of highly sulfated alginates is challenging, thus impeding their structure-activity relationship studies. Herein we achieve a microwave-assisted synthesis of a range of highly sulfated mannuronate glycans with up to 17 sulfation sites by overcoming the incomplete sulfation due to the electrostatic repulsion of crowded polyanionic groups. Although the partially sulfated tetrasaccharide had the highest affinity for the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant, the fully sulfated octasaccharide showed the most potent interference with the binding of the RBD to angiotensin-converting enzyme 2 (ACE2) and Vero E6 cells, indicating that the sulfated oligosaccharides might inhibit the RBD binding to ACE2 in a length-dependent manner.