Unknown Substance Research Articles

Directly printed plasmonic substrates of gold micro-flake array for plasmonically-enhanced infrared absorption-spectroscopic biodetection

Infrared absorption-spectroscopy (IRAS) is an essential tool for identifying molecular species with specific spectral fingerprints and widely used to characterize and identify known or unknown chemical substances in scientific research and industry. Recently, plasmonic substrates that can dramatically enhance local light field have greatly boosted the performance of IRAS technology, which is generally called plasmonically-enhanced infrared absorption-spectroscopy (PEIRAS), for high-sensitivity biochemical detection. However, the fabrication of micro/nano-structures of noble metals, such as gold and silver, is still challenging and costly, which thus hinders the broad use and further development of PEIRAS technologies. Here, we present a precision photoreduction and replacement reaction combined technology to directly print plasmonic substrates of periodic gold micro-flake array for PEIRAS biodetection. Such a periodic gold micro-flake array exhibits a strong plasmonic surface-lattice resonance whose reflection spectra can be precisely tailored to desired wavelength for PEIRAS biodetection. It has been experimentally demonstrated that the directly printed plasmonic substrate of PEIRAS can be utilized to detect bovine serum albumin via IRAS at the limit of concentration level at 10 nM. The additive printing nature of its fabrication technology makes such a plasmonic substrate promising for widespread IRAS biodetection applications.

Development and validation of presumptive spot test for the identification of z-drugs used in drug-facilitated crimes.

The significance and desire for preliminary testing approaches that are straightforward, quick, selective, affordable, and practical for use in the field are highlighted by the increasing enormous amounts of potentially illegal samples being seized worldwide. The "z-drugs," which include zolpidem, zopiclone, and eszopiclone, are non-benzodiazepine medications used to treat insomnia. z-drugs are short-term solutions for sleeplessness and anxiety but have a long history of abuse and misuse. The extensive list is primarily utilized for drug-facilitated crimes and drug dependence. The presumptive color spot test for z-drugs, such as zolpidem, zopiclone, and eszopiclone, has been created and validated in this study. In the preliminary identification of zolpidem, zopiclone, and eszopiclone, no color spot test has been documented as per the literature. The color spot test is the most essential and routinely used technique for identifying any unknown sample substance. The color test method was proven to provide high-quality, dependable presumptive test findings and satisfy standards for preliminary screening usage. Validation experiments demonstrate that, at room temperature, the color change is specific to the zolpidem, zopiclone, and eszopiclone classes and unaffected by the common cutting agent's presence. It was discovered that 5, 10, and 6ppm were the operational limit of detection of the sample present against the reagents 0.1% diphenyl carbazone, aqueous potassium iodoplatinate, and modified cobalt thiocyanate reagent, respectively. The color test is immediate and validated with other substances of a similar category and 10ppm was the operational limit of detection.

Nontargeted analysis and comparison strategies for volatile and semivolatile substances in toys made of different materials

A nontargeted broad-spectrum analysis method for unknown volatile and semivolatile substances in toys was established by gas chromatography–Orbitrap high-resolution mass spectrometry. Based on the NIST spectrum library, unknown substances could be accurately identified by comprehensive scoring, retention index, chemical ionization, and fine comparison of ion fragments. For substances not included in the library, the molecular formulas of unknown substances were retrieved through online compound databases. Possible structural formulas were verified by high-resolution spectra and fragmentation mechanisms. Taking teether toys as an example, the substances differences of products made of different materials were compared through the digitization of chemical composition. Specifically, 59 substances were identified in 50 teether toys. The toys made of two different materials each had their own substance distribution, and the types and quantities of substances in thermoplastic polyurethanes samples were more than those in silicone samples. Substances with high risk included phenol, N-methylaniline, cyclohexanone, and 4-tert-amylphenol. This work can serve as a reference for the identification of unknown substances in toys and other products, as well as for the comparison the chemical composition of products made of different materials. Thus, this work has positive significance in promoting the quality and safety of toys and reducing chemical harm to children.

Hemoperfusion in anesthesia and intensive care medicine: benefits, risks, and evidence for different systems

Hemoperfusion is atechnique for the extracorporeal elimination of endogenous and exogenous toxins and harmful mediators by adsorption. It can be used as astand-alone device, as part of aheart-lung machine or extracorporeal membrane oxygenation (ECMO) or, as is currently the case, integrated into akidney replacement procedure. In the meantime, various suppliers offer devices with different technologies. The aim of this work was to evaluate the benefits, risks and evidence of the different systems, how they work and for which indications they are approved in Germany. To achieve this goal, anarrative assessment of the existing literature and guidelines for different indications was performed. The focus was on in vivo studies. In principle, adistinction must be made in adsorption techniques between pure adsorption and the combination as adsorption and kidney replacement therapy. The adsorbers available in Germany include Cytosorb®, HA-330, Seraph®-100 and Toraymyxin. Combined procedures (adsorption and kidney replacement) are offered with coupled plasma filtration and adsorption (CPFA) and oXiris®. Most adsorbers have been developed for cytokine and endotoxin removal in patients with sepsis; however, to date, no randomized controlled trial (RCT) has demonstrated asurvival benefit when using hemoperfusion. Therefore, the S3 guidelines for treatment of sepsis and the surviving sepsis campaign guidelines advise against its routine use. When the corona pandemic began, hemoperfusion was considered as apromising therapeutic approach. Cytosorb®, Seraph®-100, and oXiris® received emergency approval by the FDA to be used in critically ill patients with COVID-19, so questions arose about the appropriateness and importance of its use; however, the data generated did not show positive results, so its use cannot be recommended routinely either. In addition, they are not mentioned as atreatment option in the current guidelines. The use of adsorption procedures in patients with liver failure and rhabdomyolysis has only been rudimentarily studied, so any evidence is currently lacking. The only adsorber that has CE approval in Germany for both applications is Cytosorb®. In the next few years, studies will have to follow that investigate the efficacy and thus either justify or refute the use in clinical routine. Hemoperfusion procedures are used in the heart-lung machine as part of cardiac surgery for either cytokine or anticoagulant adsorption. No congruent data are available to support the use for the elimination of cytokines. If emergency cardiac surgery is required in apatient with pre-existing anticoagulation, hemoperfusion procedures can be used to prevent bleeding complications. Cytosorb® has CE approval for this indication. All available techniques are nonselective adsorption processes, so that adsorption of known and unknown substances can occur. Unintentional adsorption of drugs, such as various anti-infective agents is arelevant risk, especially when used in patients with sepsis. Various adsorption systems can eliminate different known and unknown substances. Currently, there is alack of evidence for all indications and systems to justify their routine use except in clinical trials. Future clinical trials should evaluate the potential benefits but also dangers, so that in the meantime the routine use can be justified or arecommendation against the use can be given.

Making Every Single Puff Count-Simple and Sensitive E-Cigarette Aerosol Sampling for GCxIMS and GC-MS Analysis.

The analysis of the aerosol from tobaccoless electronic cigarettes (e-cigarettes) is an important part of understanding their impact on human health, yet sampling aerosol from e-cigarettes is still considered a challenge. It lacks a standard method for research and quality control and there are a variety of methods. However, few are simple and inexpensive, and none have been suggested for the use with gas chromatography coupled ion mobility spectrometry (GCxIMS). This work presents and evaluates such a setup made from standard lab equipment to quickly collect a quantitative sample from the aerosol of a single puff (5 s totaling 125 mL). The aerosol condensates directly in the cooled headspace (HS) vial, which is analyzed in the HS-GCxIMS or mass spectrometer (HS-GC-MS). The combined use of GC-MS and GCxIMS allows the simple and sensitive identification of unknown substances in complex mixtures and the identification of degradation products in the aerosols. A calibration of 26 flavor compounds (0.2-20 µg/g) was created using single puffs of a spiked, flavorless commercial refill solution and 2-alkanones as internal standards. This sensitive but easily reproducible setup enables a wide range of further investigations, even for labs that were previously unable to afford it.

Chemometrics-assisted excitation-emission matrix fluorescence spectroscopy for real-time migration monitoring of multiple polycyclic aromatic hydrocarbons from plastic products to food simulants

Polycyclic aromatic hydrocarbons (PAHs), as a class of organic pollutants that have attracted much attention, are likely to be formed with the production and processing of plastic products, and they may migrate from contaminated plastic products to food, causing the risk of poisoning or cancer. In this study, migration tests were carried out on disposable plastic products for food contact, and a novel strategy that combines excitation-emission matrix (EEM) fluorescence spectroscopy with the advanced second-order calibration method based on the three-direction resection alternating trilinear decomposition (TDR-ATLD) algorithm was used to monitor the migration of three PAHs anthracene (ANT), pyrene (PYR), and phenanthrene (PHE) from the plastic products to food simulants in real-time. With the “second-order advantage”, even if the fluorescence spectra of the target analytes overlapped seriously, and other unknown substances migrated from the plastic products to food simulants, accurate qualitative and quantitative results were still obtained by the proposed method. In the static system, the coefficient of determination (R2) of the three PAHs within the calibration range were all greater than 0.99, and the average spiked recoveries were 99.5-107.1%, with the standard deviation lower than 8.9%. The figures of merit (FOMs) and intra- or inter-day precision also showed good feasibility and reliability of the method. In the simulation study of the migration kinetic process, three PAHs can be quantified in real-time in complex matrix, then the related migration equations were established. The results indicate that the proposed method can be used for real-time migration quantitative monitoring of PAHs, providing a potential and available method for the study of the migration kinetics of hazardous substances from food contact materials to food or food simulants.

Identification of an Unknown Substance by the Methods of Multi-Energy Pulse X-ray Tomography

The inverse problem for the non-stationary radiative transfer equation is considered, which consists in finding the attenuation coefficient according to the pulsed multi-energy X-ray exposure. For a short duration of the probing pulse, the asymptotic solution of the inverse problem is found. The problem of identifying an unknown substance by attenuation coefficients approximately found on a finite set of energy values is formulated. Algorithms for solving identification problems are proposed. The results of the numerical simulation are presented for a wide range of substances of interest in medical computed tomography.

Untargeted analysis and tentative identification of unknown substances in human tears by ultra-high performance liquid chromatography-high resolution mass spectrometry: Pilot study

In this work, a new approach for the identification of unknown compounds in human tears has been developed and validated using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) linked to an intelligent data acquisition mode (AcquireX DS-dd-MS2) coupled to an automated data processing software (Compound Discoverer™ 3.2). As a pilot research study, four human tear samples from volunteers were analyzed. Data were acquired in both positive and negative ionization modes and exact mass, isotope pattern, and MS2 spectra match were used for the tentative identification. Following this approach, 58 substances were identified, 47 in positive mode and 11 in negative mode, with an estimated concentration ranging from 0.1 to 9000 ng mL−1. Most of them were amino acids, hormones, metabolites, and pharmaceuticals. In order to validate the proposed method, the system suitability was evaluated and 29 commercial analytical standards of the tentatively identified substances were analyzed, of which 28 were confirmed obtaining a high identification accuracy (96.6 %). These results confirm that the screening tool presented in this work can facilitate the discovery of new metabolites, novel potential biomarkers, and substances to which the person is exposed, such as pollutants.

AIQS-DB: Revolutionizing the Simultaneous Analysis of Organic Compounds

This paper reports a database, namely, the Automated Identification and Quantification Database System (AIQS-DB), which consists of three components, including retention times, mass data, and calibration curves, without the requirement to analyze standard substances. The AIQS-DB that are pre-registered in the database are used as the replacement for the process of measuring chemical standards. Both the target and unknown substances in the real samples were determined by the same conditions of GC-MS as those used for the initial database register in the AIQS-DB system. The article provides a comprehensive overview of the wide-ranging applications of AIQS-DB in various fields and highlights its usefulness as a tool for the simultaneous analysis of organic compounds in different matrixes such as water, soil, sediment and air, etc. It could be considered as the basis in further applications of the AIQS-DB method in determining organic compounds in other fields, specifically biology, food, agriculture, medicine, etc., allowing assessment and reflection on the quality and status of the studied products quickly and cost-effectively.

Global survey of dioxin- and thyroid hormone-like activities in consumer products and toys

BackgroundChildren and consumers are exposed to increasingly complex mixtures of known and as-yet-unknown toxic chemicals from toys and products. However traditional chemical analysis methods only evaluate a small number of chemicals at a time thereby restricting consumer awareness of the full range of potentially harmful chemicals in products. MethodsWe used high-throughput effect-based non-animal methods to investigate exposures to complex chemical mixtures of several kinds of brominated flame retardants (BFRs) for their dioxin- and thyroid hormone-like activities in various kinds of consumer products and toys from 26 different countries, on four continents (Africa, America, Asia and Europe) in combination with chemical analysis of various polybrominated flame retardants (BFRs) and their impurities (such as polyhalogenated PCDD/Fs and PBDD/Fs). ResultsWe found high levels of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in toys and now, for the first time, also in consumer products that are manufactured from black plastics containing certain brominated flame retardants (BFRs). The presence of PBDD/PBDFs as well as other BFRs in various black plastic materials from additional countries as well as additional kinds of consumer products as confirmed by effect-based in vitro reporter gene DR CALUX and TTR-TRβ CALUX assays as well as congener-specific chemical analysis. We compared total Toxicity Equivalent (TEQ) levels of PBDD/F-TEQs analysed by chemical analysis to by CALUX bioassay measured Biological equivalence (BEQ) concentrations (for further info see at ISO 23196, ISO, 2022). In the case of TBBPA, both chemical and TTR-TRβ CALUX analysis measure direct the amount of TBBPA. Finally, the daily ingestion of 2,3,7,8-TCDD equivalents from PBDD/Fs-contaminated plastic toys by child mouthing habits have been related to our earlier study (Budin et al., 2020). ConclusionsInteraction of children with such contaminated plastics may significantly contribute to the daily uptake of dioxin- and thyroid hormone transport disrupting-like compounds. Effect-based bioassays for dioxin- and thyroid hormone-like activities are relevant to pick-out such complex mixtures of known and yet unknown (and therefore not regulated) substances for safer and more sustainable plastics. Low POPs Content Levels and other mechanisms set under the Basel and Stockholm Conventions are set far too high to prevent a significant flow of BFRs and PBDD/Fs into consumer products.

Toxic effects of ship exhaust gas closed-loop scrubber wash water.

To meet the strict requirements of reducing sulfur emissions, an increasing number of commercial ships have installed exhaust gas cleaning systems (EGCSs). However, wash water produced during the cleaning process is discharged back to the marine environment. We investigated the effects of closed-loop scrubber (natrium-alkali method) wash water on three trophic species. Severe toxic effects were found when Dunaliella salina, Mysidopsis bahia, and Mugilogobius chulae were exposed to 0.63-6.25, 0.63-10, and 1.25-20% concentrations of wash water, respectively. The 50% effective concentration in 96h (EC50-96h) for D. salina was 2.48%, and the corresponding total polycyclic aromatic hydrocarbons (PAHs) and heavy metals were 22.81 and 23.67μg L-1. The 50% lethal concentration in 7d (LC50-7d) values for M. bahia and M. chulae were 3.57% and 20.50%, respectively. The lowest observed effect concentration (LOEC) values for M. bahia and M. chulae were 1.25% and 2.5%, respectively, and the corresponding total PAHs and heavy metals were 11.50 and 11.93 and 22.99 and 23.86μg L-1. M. bahia's body weight was negatively correlated with the amount of wash water. Low concentrations of wash water (0-5%) had no significant effect on the reproduction of M. bahia. Although concentrations of 16 PAHs and 8 heavy metals are known, different compounds might react with each other and form more unknown toxic substances, and the measured toxicity comes from synergistic effects between various pollutants. Therefore, future work is needed to clarify other more toxic contaminants in wash water. We highly recommend that wash water be treated before being discharged to the marine environment.

Speciation and determination of inorganic antimony in tea infusion by using solid-phase extraction-based liquid chromatography-inductively coupled plasma-mass spectrometry

In this work, we developed a method to separate and detect inorganic antimony (iSb) in tea infusions based on liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). Considering that iSb was present in tea infusions in trace amounts, a commercial solid-phase extraction (SPE) column was employed to enrich iSb(III) and iSb(V). In this study, we found that iSb exists in tea infusions in a bound state with an unknown substance rather than in a free state. Therefore, the enrichment step was combined with oxidation and reduction processes. Because of the enrichment process and the high sensitivity of LC-ICP-MS, the LODs of iSb(III) and iSb(V) were both as low as 0.03 μg L−1. The RSDs (n = 6) of iSb(III) and iSb(V) were all below 8.1%, and the recoveries (n = 6) were 92–96% and 90–94%, respectively. Then, a total of six tea infusion samples were inspected. The data revealed that the total Sb in the tea infusions ranged from 0.22 to 0.97 μg L−1, and we found that 50–83% of the total Sb in the tea infusion was iSb. This method is worth promoting since it has satisfying methodological performance.

Forensic approach towards criminal use of mercury in domestic violence

The prevalence of criminal cases against women is not first-hand with statistical data from the National Crime Records Bureau in India proclaiming an even rise in cases of domestic violence. Despite numerous laws to protect women against various crimes including rape, sexual harassment, dowry death, etc., there is less respite from violence toward women in India. Indian society needs to stand up and address the existence of many socio-cultural reasons for crime against women apart from literacy to lower these crime statistics. Forensic experts play a pivotal role in the scientific examination of evidence to support the criminal justice system which in the end affects the lives of millions of female victims. A case of attempted domestic homicide is presented wherein a 21-year-old married female was poisoned with some unknown substance laced in her milk by her in-laws. This case is of interest to the scientific community as well as to persons working within the medical and judiciary fraternity.Case history: A married woman aged 21 years alleged her in-laws including her husband of attempt to murder her by giving her milk laced with some unknown substance. She had severe vomiting after drinking milk where she noticed some shining materials in the vomitus. The vomitus and the gastric lavage were analyzed subsequently.Methodology: Physical and Chemical Examinations including visual analysis and solubility, odour, etc were initially conducted on the exhibits (Gastric Lavage and Vomitus samples) and results were further confirmed by Atomic Absorption Spectrometry.Results: An abnormally high level of mercury i.e. 9.88 ppm and 332.15 ppm were detected in Gastric lavage and vomitus respectively.Conclusion: The various scientific investigations determined that the female had been poisoned by using mercury justifying the essential role of forensics in linking shreds of evidence scientifically.

Deep metric learning framework combined with Gramian angular difference field image generation for Raman spectra classification based on a handheld Raman spectrometer

Rapid identification of unknown material samples using portable or handheld Raman spectroscopy detection equipment is becoming a common analytical tool. However, the design and implementation of a set of Raman spectroscopy-based devices for substance identification must include spectral sampling of standard reference substance samples, resolution matching between different devices, and the training process of the corresponding classification models. The process of selecting a suitable classification model is frequently time-consuming, and when the number of classes of substances to be recognised increases dramatically, recognition accuracy decreases dramatically. In this paper, we propose a fast classification method for Raman spectra based on deep metric learning networks combined with the Gramian angular difference field (GADF) image generation approach. First, we uniformly convert Raman spectra acquired at different resolutions into GADF images of the same resolution, addressing spectral dimension disparities induced by resolution differences in different Raman spectroscopy detection devices. Second, a network capable of implementing nonlinear distance measurements between GADF images of different classes of substances is designed based on a deep metric learning approach. The Raman spectra of 450 different mineral classes obtained from the RRUFF database were converted into GADF images and used to train this deep metric learning network. Finally, the trained network can be installed on an embedded computing platform and used in conjunction with portable or handheld Raman spectroscopic detection sensors to perform material identification tasks at various scales. A series of experiments demonstrate that our trained deep metric learning network outperforms existing mainstream machine learning models on classification tasks of different sizes. For the two tasks of Raman spectral classification of natural minerals of 260 classes and Raman spectral classification of pathogenic bacteria of 8 classes with significant noise, our suggested model achieved 98.05% and 90.13% classification accuracy, respectively. Finally, we also deployed the model in a handheld Raman spectrometer and conducted identification experiments on 350 samples of chemical substances attributed to 32 classes, achieving a classification accuracy of 99.14%. These results demonstrate that our method can greatly improve the efficiency of developing Raman spectroscopy-based substance detection devices and can be widely used in tasks of unknown substance identification.

A comprehensive analytical strategy based on characteristic fragments to detect synthetic cannabinoid analogs in seized products and hair samples

Synthetic cannabinoids, one of the most widely abused new psychoactive substances (NPS), are now placed under national control generally in China. Due to continuous modification of synthetic cannabinoid structure, an ongoing dilemma in the forensic laboratory is that newly emerging substances cannot be detected by established methods. Thus, the screening methods for simultaneous detection of known or unknown substances have become research hotspots. In this study, the ultra high performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-QqQ-MS) with precursor ion scan (PIS) as acquisition mode was used for prescreening purposes of all possible synthetic cannabinoids-related substances. In detail, four common characteristic fragments, m/z of 144.0, 145.0, 135.1, and 109.0 corresponding to acylium-indole, acylium-indazole, adamantyl, and fluorobenzyl cation respectively, were selected for PIS mode, and their collision energies were optimized by 97 available synthetic cannabinoids standards with relevant structures. Those suspicious signals observed in the screening experiment were confirmed by ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) via high-resolution MS and MS2 data obtained by full scan (TOF MS) and product ion scan mode. After methodological validation, the integrated strategy established above was applied to the screening and identification of the seized e-liquids, herbal blends and hair samples, confirming the presence of multiple synthetic cannabinoids in these samples. In particular, a novel synthetic cannabinoid was identified as 4 F-ABUTINACA, for which no relevant high-resolution mass spectrometry (HRMS) data has been retrieved until now, making this study the first to report the cleavage pattern of this compound in electrospray ionization (ESI) mass spectrometry. In addition, four other suspected by-products of the synthetic cannabinoids were found in the herbal blends and e-liquids, and their possible structures were also deduced via the information from high-resolution mass spectra.

Discussion on a safe approach to creating humorous ads for Premium brands: A thematic analysis

The concept of humorous ads has been extensively applied by numerous brands and the results have often been impactful and advantageous for their business. However, when it comes to premium brands, indecisiveness still remains. Many premium brands avoid the use of humor in their ads so as to maintain their elegance. Others, however, have taken a risk and have been experimenting with this unknown substance. The research aims to identify a safe approach that would help premium brands use humor in their ads while keeping their prestige and elegance intact. The study derives four themes which are brand recall, brand perception, purchase intention, and critical elements for creating humorous ads for premium brands. While humor had positive impact on brand recall and brand perception, it was indifferent to the buying behavior of respondents. The study found that appropriate messages, the use of public figures, and relevant ad messages were the key factors that would help premium brands.

Predicting the retention time of Synthetic Cannabinoids using a combinatorial QSAR approach

BackgroundAbuse of Synthetic Cannabinoids (SCs) has become a serious threat to public health. Due to the various structural and chemical group modified by criminals, their detection is a major challenge in forensic toxicological identification. Therefore, rapid and efficient identification of SCs is important for forensic toxicology and drug bans. The prediction of an analyte's retention time in liquid chromatography is an important index for the qualitative analysis of compounds and can provide informatics solutions for the interpretation of chromatographic data. MethodsIn this study, experimental data from high-resolution mass spectrometry (HRMS) are used to construct a regression model for predicting the retention time of SCs using machine learning methods. The prediction ability of the model is improved by adopting a strategy that combines different descriptors in different independent machine-learning methods. ResultsThe best model was obtained with a method that combined Substructure Fingerprint Count and Finger printer features and the support vector regression (SVR) method, as it exhibited an R2 value of 0.81 for the validation set and 0.83 for the test set. In addition, 4 new SCs were predicted by the optimized model, with a prediction error within 3%. ConclusionsOur study provides a model that can predict the retention time of compounds and it can be used as a filter to reduce false-positive candidates when used in combination with LC-HRMS, especially in the absence of reference standards. This can improve the confidence of identification in non-targeted analysis and the reliability of identifying unknown substances.

Investigation of Gas Release from Recycled Plastic Shopping Bags during Melting at Low Temperatures

Recycling plastic is an excellent way to reduce the environmental impact of its production and use. In a circular economy, recycling of recycled plastic is necessary. Most plastic bags are made of thermoplastic, like high-density polyethylene (HDPE) with a melting point of 130°C, and low-density polyethylene (LDPE). In contrast, recycled plastic bags are made up of many different unknown substances. In this study, the melting of used plastic bags containing 80% unknown recycled material was investigated. FTIR analysis showed that the bags consisted mainly of HDPE. The bags were melted at 160°C, 200°C, and 250°C for 30 min. GC-FID and HP-SPME GCMS analyses showed that the bags released flammable gases (methane, ethylene, and alkane/alkene hydrocarbons) but little acetylene. Aromatic and aliphatic hydrocarbons eluded from the bags at 10% of the gas volume at 250°C. Long-chain alkanes, mostly hexadecane, were the dominant compound, amounting to 28% at 160°C and increasing to 43% at 250°C. On the other hand, alkenes decreased with a rising temperature (23% at 160°C to 3% at 250°C), as they were transformed into alkanes. Methylated compounds, for example, methylated alkanes at 10%, were present at all temperatures. Methane and methylated compounds are released from plastic and contamination of the bags with organic matter. The bags released small amounts of toxic phthalates. The results show that melting recycled plastic bags for remoulding is promising if safety precautions that ensure sufficient ventilation are utilised.

Pneumomediastinum as a Complication of Cocaine Insufflation

A 25-year-old man presents to the ED for unresponsiveness after consuming cocaine and other unknown substances. Chest imaging from the presentation was unremarkable, but after developing fever and leukocytosis, he underwent extensive work-up in search of infectious foci. A CT scan of the chest showed a small pneumomediastinum and the possibility of an esophageal tear. After recovering consciousness and the ability to recount events, the patient admitted to the concomitant use of cocaine and opiates via insufflation.

Apple polyphenol biotransformation using probiotics in vitro and dynamic simulated digestion by bionic rats.

The present study investigated the effects of fermentation by Lactobacillus rhamnosus zrx01 (LR-zrx01), Lactobacillus acidophilus zrx02 (LA-zrx02), and Lactobacillus plantarum zrx03 (LP-zrx03), as well as dynamic simulated digestion by bionic rats, on the biotransformation and antioxidant potential of apple polyphenols. Polyphenols were determined by ultra-high-performance liquid chromatography-mass spectrometry, the dynamic simulated digestion of fermented apple pulp was determined by bionic rats, and the antibacterial and antioxidant activities were analyzed. The polyphenol content of apple pulp fermented using the three strains was respectively 1.41, 1.38, and 1.36 times that of non-fermented pulp. The antibacterial activity of apple pulp improved dramatically after fermentation. Moreover, the antioxidant potential of apple pulp increased after fermentation and digestion. After dynamic simulated digestion by bionic rats, the polyphenol content in unfermented and the three fermented groups increased significantly by 1.19, 1.23, 1.20, and 1.19 times compared to that before digestion, respectively. The major polyphenols in each group with obvious changes were epicatechin, rutin, kaempferol, quercetin-3 galactoside, p-coumaric acid, and two unknown substances, 1 and 2. Fermented and digested apple polyphenols showed better biotransformation effects and mostly existed in the form of small molecules, which was conducive to the improvement of polyphenol bioavailability and beneficial to the absorption of active substances by the human body. These findings build a foundation for the development of functional food beverages. © 2023 Society of Chemical Industry.