A QSAR prediction model for adsorption of organic contaminants on microplastics: Dubinin-Astakhov plus linear solvation energy relationships.

Numerous pharmaceuticals and personal care products (PPCPs) co-exist with various types of microplastics (MPs) in the environment, making it extremely hard to experimentally measure all their adsorption interactions. Thus, a precise prediction model is on demand. In this study, we combined the commonly used Dubinin-Astakhov (DA) model and the linear solvation energy relationships (LSERs) model to predict the adsorption capacity (Q0) and adsorption affinity (E) of MPs for PPCPs, including the key parameters of MP (specific surface area, oxygen-containing functional groups), and the Kamlet-Taft solvation parameters of organic contaminants. The model was validated with the experimental data of 8 PPCPs and 8 MPs (i.e. pristine and aged PE, PET, PS, PVC) plus some published adsorption data. This new model also indicated that the adsorption of PPCPs on those MPs was primarily governed by hydrophobic interaction and hydrogen bonding. The developed model can predict the adsorption of PPCPs onto MPs with a high accuracy and can also provide insights into the understanding of interaction forces in the adsorption process.

Layered GelMA/PEGDA Hydrogel Microneedle Patch as an Intradermal Delivery System for Hypertrophic Scar Treatment.

Hypertrophic scar (HS) is an unfavorable skin disorder that typically develops after trauma, burn injury, or surgical procedures and causes numerous physical and psychological issues in patients. Currently, intralesional multi-injection of corticosteroid, particularly compound betamethasone (CB), is one of the most prevalent treatments for HS. However, injection administration could result in severe pain and dose-related side effects. Additionally, the vacuum therapeutic efficacy of this treatment relies on the level of expertise of the healthcare professional. To overcome the limitations of conventional injections, a new method that is convenient, painless, and self-administrable is urgently required. In this study, we developed a methacrylate gelatin (GelMA)/polyethylene glycol diacrylate (PEGDA) double-network hydrogel microneedle patch loaded with CB (CB-HMNP) as an intradermal delivery system for HS treatment. The double-network structure conferred the CB-HMNP with sufficient mechanical properties to successfully penetrate scar tissue while also helping to regulate the drug's sustained release rate. Subsequently, we confirmed that the CB-HMNP had a pronounced inhibitory effect on human HS fibroblasts (hHSFs), whereas drug-free HMNPs had no effect on hHSFs, indicating its high biocompatibility. In order to assess the therapeutic efficacy of CB-HMNPs, HS models of New Zealand rabbit ears were developed. The administration of CB-HMNP three times significantly decreased the scar elevation index (SEI), collagen I/III, and transforming growth factor-ß1 (TGF-ß1) protein. Therefore, the CB-HMNP may offer an administration pathway for the treatment of HS that is less painful, more convenient, less invasive, and sustain-released.

Revealing the sorption mechanisms of carbamazepine on pristine and aged microplastics with extended DLVO theory.

The co-occurrence of microplastics (MPs) and organic contaminants in aquatic environment can complexify their environmental fate via sorption interactions, especially when the properties of MPs can even vary due to the aging effect. Thus, quantitatively clarifying the sorption mechanisms is required to understand their environmental impacts. This study selected popularly occurring carbamazepine (CBZ) and four types of MPs as model systems, including polyethylene, polyvinyl chloride, polyethylene terephthalate and polystyrene in their pristine and aged forms, to investigate the sorption isotherms, kinetics, and desorption. The variation of MPs during the aging process were analyzed with scanning electron microscopy, contact angle, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. It was found that the aging process elevated the sorption capacity and intensified the desorption hysteresis of CBZ on MPs via increasing the surface roughness, decreasing the particle size, and altering the surficial chemistry of all MPs. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory was innovatively applied hereby to calculate the interfacial free energies and revealed that the hydrophobic interaction was significantly lessened after aging for all MPs with the slightly enhanced van der Waals interaction. Then the total interfacial free energies were dropped down for all MPs, which resulted in their declined specific sorption capacity. This work reveals the sorption mechanisms of CBZ on pristine and aged MPs with XDLVO and provides a useful reference to study the sorption of other neutral organics onto MPs.

Cognitive-pragmatic functions of mitigation in therapeutic conversations emphasizing rapport management.

Based on conversations between 15 clients and 5 therapists in the context of daily treatment, this study investigated therapist-client linguistic mitigation in a natural setting. The study found that (1) the therapists and clients mainly used three major types of mitigation, among which illocutionary mitigation and propositional mitigation were employed more frequently. Furthermore, direct dissuasion and disclaimers, as subtypes of mitigators, were the most regularly employed by therapists and clients, respectively. (2) Through cognitive-pragmatic interpretation under rapport management theory, it was found that mitigation in the therapist-client conversations mainly performed cognitive-pragmatic functions in giving the means to preserve positive face, maintaining social rights and concentrating on interactive goals, which were interpenetrated with each other in therapeutic conversations. (3) This study proposed that three cognitive-pragmatic functions jointly devoted to a rapport in therapeutic relationship to reduce therapeutic risk of conflicts.

Infectious shock after liposuction.

BACKGROUND: Liposuction has become one of the most popular cosmetic surgeries in China. However, few studies have discussed infectious shock caused by C. perfringens as one of the causes of death after liposuction. CASE PRESENTATION: A 24-year-old woman was brought to the emergency department (ED) of Guangzhou Chinese Overseas Hospital for treatment. The patient had undergone liposuction in her bilateral lower limbs two days prior. At the ED, the patient was unconscious, and had bilateral equal-sized (diameter, 6 mm) round pupils, no light reflex, a blood pressure (BP) of 71/33 mmHg, a heart rate of 133 bpm, and an SpO2 of 70%. She had bilateral limb swelling, extensive ecchymoses in her lower abdomen and bilateral thighs, local crepitus, blisters, weak pulses on her femoral artery and dorsalis pedis, high skin tension, and hemoglobin of 32 g/L. The patient was diagnosed with Clostridium perfringens infection, and she underwent debridement surgery and supportive treatment. But the patient's BP could not improve. At 8:28 pm on the day of admission, the patient was declared clinically dead after the electrocardiograph showed a horizontal line and spontaneous respiration ceased. CONCLUSIONS: Failure to meet surgical disinfection and environmental standards may be the cause of infection of C. perfringens through wounds. Therefore, it is necessary to strengthen the environmental disinfection of the operating room, and standardize the sterile conditions of the operation staff and patients before and during operation. Liposuction surgery necrotizing fasciitis is a rare but fatal complications, especially if diagnosis delay, therefore it is critical for early diagnosis and treatment of gas gangrene.