A Comparative Study and Prediction of the Ex Vivo Permeation of Six Vaginally Administered Drugs across Five Artificial Membranes and Vaginal Tissue.

The theoretical interpretation of the vaginal permeability phenomenon, the evaluation of the suitability of five artificial membranes, and the prediction of the behaviors of vaginal drugs were the main objectives of this study. Franz vertical diffusion cells and different validated HPLC methods were used to measure the permeability of six vaginally administered drugs (econazole, miconazole, metronidazole, clindamycin, lidocaine, and nonoxynol-9). This study was performed (in vitro) on different membranes of polyvinylidene fluoride (PVDF), plain cellulose or cellulose impregnated with isopropyl myristate (IPM), and cellulose combined with PVDF or IPM. The results were compared with those obtained from cow vaginal tissue (ex vivo), where cellulose was proven to be the best simulant. According to the permeability profiles (Papp), the water solubility of the drugs was considered a necessary criterion for their transport in the membranes or in the tissue, while the size was important for their penetration. Furthermore, it was found that polar compounds show clear superiority when penetrating cellulose or tissue, while non-polar ones show superiority when penetrating the lipophilic PVDF membrane. Finally, a successful attempt was made to predict the Papp values (|Papp-predPapp| < 0.005) of the six drugs under study based on a PLS (Partial Least Squares) in silico simulation model.

Enhanced Electroactive Phases of Poly(vinylidene Fluoride) Fibers for Tissue Engineering Applications.

Nanofibrous materials generated through electrospinning have gained significant attention in tissue regeneration, particularly in the domain of bone reconstruction. There is high interest in designing a material resembling bone tissue, and many scientists are trying to create materials applicable to bone tissue engineering with piezoelectricity similar to bone. One of the prospective candidates is highly piezoelectric poly(vinylidene fluoride) (PVDF), which was used for fibrous scaffold formation by electrospinning. In this study, we focused on the effect of PVDF molecular weight (180,000 g/mol and 530,000 g/mol) and process parameters, such as the rotational speed of the collector, applied voltage, and solution flow rate on the properties of the final scaffold. Fourier Transform Infrared Spectroscopy allows for determining the effect of molecular weight and processing parameters on the content of the electroactive phases. It can be concluded that the higher molecular weight of the PVDF and higher collector rotational speed increase nanofibers' diameter, electroactive phase content, and piezoelectric coefficient. Various electrospinning parameters showed changes in electroactive phase content with the maximum at the applied voltage of 22 kV and flow rate of 0.8 mL/h. Moreover, the cytocompatibility of the scaffolds was confirmed in the culture of human adipose-derived stromal cells with known potential for osteogenic differentiation. Based on the results obtained, it can be concluded that PVDF scaffolds may be taken into account as a tool in bone tissue engineering and are worth further investigation.

Enhancing proton transport in polyvinylidenedifluoride membranes and reducing biofouling for improved hydrogen production in microbial electrolysis cells.

Hydrophilic porous membranes, exemplified by polyvinylidene fluoride (PVDF) membranes, have demonstrated significant potential for replacing ion exchange membranes in microbial electrolysis cells (MECs). Membrane fouling remains a major challenge in MECs, impeding proton transport and consequently limiting hydrogen production. This study aims to investigate a synergistic antifouling strategy for PVDF membrane through the incorporation of a coating composed of polydopamine (PDA), polyethyleneimine (PEI), and silver nanoparticles (AgNPs). The PDA-PEI-Ag@PVDF membrane not only effectively mitigates fouling through steric and electrostatic repulsion forces, but also amplifies ion transport by facilitating water diffusion and electromigration. The PDA-PEI-Ag@PVDF membrane exhibited a reduced membrane resistance of 1.01 mΩ m2 and PDA-PEI-Ag modifying PVDF membrane was found to be effective in enhancing the proton transportation of PVDF membrane. Therefore, the enhanced hydrogen production rate of 2.65 ± 0.02 m3/m3/d was achieved in PDA-PEI-Ag@PVDF-MECs.

Label-free electrochemical biosensor based on green-synthesized reduced graphene oxide/Fe3O4/nafion/polyaniline for ultrasensitive detection of SKBR3 cell line of HER2 breast cancer biomarker.

Cancer stands as one of the most impactful illnesses in the modern world, primarily owing to its lethal consequences. The fundamental concern in this context likely stems from delayed diagnoses in patients. Hence, detecting various forms of cancer is imperative. A formidable challenge in cancer research has been the diagnosis and treatment of this disease. Early cancer diagnosis is crucial, as it significantly influences subsequent therapeutic steps. Despite substantial scientific efforts, accurately and swiftly diagnosing cancer remains a formidable challenge. It is well known that the field of cancer diagnosis has effectively included electrochemical approaches. Combining the remarkable selectivity of biosensing components-such as aptamers, antibodies, or nucleic acids-with electrochemical sensor systems has shown positive outcomes. In this study, we adapt a novel electrochemical biosensor for cancer detection. This biosensor, based on a glassy carbon electrode, incorporates a nanocomposite of reduced graphene oxide/Fe3O4/Nafion/polyaniline. We elucidated the modification process using SEM, TEM, FTIR, RAMAN, VSM, and electrochemical methods. To optimize the experimental conditions and monitor the immobilization processes, electrochemical techniques such as CV, EIS, and SWV were employed. The calibration graph has a linear range of 102-106 cells mL-1, with a detection limit of 5 cells mL-1.

[The results of clinical application of the mesh with anti-adhesive fluoropolymer coating in laparoscopic intraperitoneal repair of primary ventral hernia]. / Rezul'taty klinicheskogo primeneniya setchatogo endoproteza s antiadgezivnym ftorpolimernym pokrytiem pri laparoskopicheskoi intraperitoneal'noi plastike pervichnykh ventral'nykh gryzh.

OBJECTIVE: The purpose of the study was to evaluate the results of using fluoropolymer-coated mesh during intraperitoneal onlay mesh hernia repair in patients with primary ventral hernias. MATERIAL AND METHODS: The multicenter, non-randomized, controlled clinical study included 88 patients of both sexes who were operated on using a laparoscopic approach using the IPOM technique for a primary ventral hernia. The duration of observation ranged from 3 to 12 months. In the main group, 48 patients received fluoropolymer-coated meshes (Ftorex). A comparison was made with a retrospective group of 40 patients who were treated with anti-adhesive collagen-coated meshes (Parietene composite, Parietex Composite, Symbotex). RESULTS: The number of early and late postoperative complications in the groups did not have significant differences, at the same time, their number was lower in the group of patients in whom fluoropolymer-coated meshes were used. Most of the complications corresponded to Clavien-Dindo class I and II and did not pose a significant threat to health. There were no recurrences of hernias observed in patients included in the study. There were slightly more adhesions in the fluoropolymer-coated mesh group (35.4% vs. 25.0% in the collagen-coated mesh group). The quality of life of patients in the study groups did not differ. CONCLUSION: In laparoscopic IPOM hernia repair fluoropolymer-coated meshes are not inferior in effectiveness and safety to traditionally used collagen-coated meshes and can be recommended for use in patients with primary ventral hernias.

Highly effective ultrafiltration membranes based on plastic waste for dye removal from water.

Applicable and low-cost ultrafiltration membranes based on waste polystyrene (WPS) blend and poly vinylidene fluoride (PVDF) were effectively cast on nonwoven support using phase inversion method. Analysis was done into how the WPS ratio affected the morphology and antifouling performance of the fabricated membranes. Cross flow filtration of pure water and various types of polluted aqueous solutions as the feed was used to assess the performance of the membranes. The morphology analysis shows that the WPS/PVDF membrane layer has completely changed from a spongy structure to a finger-like structure. In addition, the modified membrane with 50% WPS demonstrated that the trade-off between selectivity and permeability is met by a significant improvement in the rejection of the membrane with a reduction in permeate flux due to the addition of PVDF. With a water permeability of 50 LMH and 44 LMH, respectively, the optimized WPS-PVDF membrane with 50% WPS could reject 81% and 74% of Congo red dye (CR) and methylene blue dye (MB), respectively. The flux recovery ratio (FRR) reached to 88.2% by increasing PVDF concentration with 50% wt. Also, this membrane has the lowest irreversible fouling (Rir) value of 11.7% and lowest reversible fouling (Rr) value of 27.9%. The percent of cleaning efficiency reach to 71%, 90%, and 85% after eight cycles of humic acid (HA), CR, and MB filtration, respectively, for the modified PS-PVDF (50%-50%). However, higher PVDF values cause the membrane's pores to become clogged, increase the irreversible fouling, and decrease the cleaning efficiency. In addition to providing promising filtration results, the modified membrane is inexpensive because it was made from waste polystyrene, and as a result, it could be scaled up to treat colored wastewater produced by textile industries. PRACTITIONER POINTS: Recycling of plastic waste as an UF membrane for water/wastewater treatment was successfully prepared and investigated. Mechanical properties showed reasonable response with adding PVDF. The modified membrane with 50% PS demonstrated that the trade-off between selectivity and permeability is met by a significant improvement in the rejection.

A novel potentiometric screen-printed electrode based on crown ethers/nano manganese oxide/Nafion composite for trace level determination of copper ion in biological fluids.

Copper levels in biological fluids are associated with Wilson's, Alzheimer's, Menke's, and Parkinson's diseases, making them good biochemical markers for these diseases. This study introduces a miniaturized screen-printed electrode (SPE) for the potentiometric determination of copper(II) in some biological fluids. Manganese(III) oxide nanoparticles (Mn2O3-NPs), dispersed in Nafion, are drop-casted onto a graphite/PET substrate, serving as the ion-to-electron transducer material. The solid-contact material is then covered by a selective polyvinyl chloride (PVC) membrane incorporated with 18-crown-6 as a neutral ion carrier for the selective determination of copper(II) ions. The proposed electrode exhibits a Nernstian response with a slope of 30.2 ± 0.3 mV/decade (R2 = 0.999) over the linear concentration range 5.2 × 10-9 - 6.2 × 10-3 mol/l and a detection limit of 1.1 × 10-9 mol/l (69.9 ng/l). Short-term potential stability is evaluated using constant current chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). A significant improvement in the electrode capacitance (91.5 µF) is displayed due to the use of Mn2O3-NPs as a solid contact. The presence of Nafion, with its high hydrophobicity properties, eliminates the formation of the thin water layer, facilitating the ion-to-electron transduction between the sensing membrane and the conducting substrate. Additionally, it enhances the adhesion of the polymeric sensing membrane to the solid-contact material, preventing membrane delamination and increasing the electrode's lifespan. The high selectivity, sensitivity, and potential stability of the proposed miniaturized electrode suggests its use for the determination of copper(II) ions in human blood serum and milk samples. The results obtained agree fairly well with data obtained by flameless atomic absorption spectrometry.

Chloroperfluoropolyether carboxylate compounds: A review.

Several new per- and polyfluoroalkyl substances (PFASs) have been synthesized to replace traditional (legacy) PFASs frequently without clear information on their structure, use and potential toxicity. Among them, chloroperfluoropolyether carboxylates (ClPFPECAs) are an emerging group used as processing aids in the production of fluoropolymers to replace the ammonium salt of perfluorononanoic acid (PFNA). The Solvay Company has produced ClPFPECAs as a mixture of six congeners (oligomers) since the mid-1990s, but other possible manufacturers and annual quantities synthesized and used worldwide are unknown. Initial studies to monitor their presence were conducted because of public authority concerns about suspect environmental contamination near fluoropolymer plants. As of 2015, these chemicals have been found in soil, water, vegetative tissues and wildlife, as well as in biological fluids of exposed workers and people, in research carried out mainly in the United States (New Jersey) and Italy. Analysis of wildlife collected even in non-industrialized areas demonstrated widespread occurrence of ClPFPECAs. From the analytical point of view, the (presumptive) evidence of their presence was obtained through the application of non-targeted approaches performed by liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS). Available toxicological data show that ClPFPECAs have similar adverse effects than the compounds which they have replaced, whereas their carcinogenic potential and reproductive damage are currently unknown. All these observations once again cast doubt on whether many alternatives to traditional PFAS are actually safer for the environment and health.

Exploring the impact of polyvinylidenefluoride membrane physical properties on the enrichment efficacy of microfluidic electro-membrane extraction of acidic drugs.

Membrane technology has revolutionized various fields with its energy efficiency, versatility, user-friendliness, and adaptability. This study introduces a microfluidic chip, comprised of silicone rubber and polymethylmethacrylate (PMMA) sheets to explore the impacts of polymeric support morphology on electro-membrane extraction efficiency, representing a pioneering exploration in this field. In this research, three polyvinylidenefluoride (PVDF) membranes with distinct pore sizes were fabricated and their characteristics were assessed through field-emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). This investigation centers on the extraction of three widely prescribed non-steroidal anti-inflammatory drugs: aspirin (ASA), naproxen (NAP), and ibuprofen (IBU). Quantitative parameters in the extraction process including voltage, donor phase flow rate, and acceptor phase composition were optimized, considering the type of membrane as a qualitative factor. To assess the performance of the fabricated PVDF membranes, a comparative analysis with a commercially available Polypropylene (PP) membrane was conducted. Efficient enrichment factors of 30.86, 23.15, and 21.06 were attained for ASA, NAP, and IBU, respectively, from urine samples under optimal conditions using the optimum PVDF membrane. Significantly, the choice of the ideal membrane amplified the purification levels of ASA, NAP, and IBU by factors of 1.6, 7.5, and 40, respectively.

Light-Initiated Imprinted Membrane-Based Biomimetic SERS Sensor toward Selective Detection of Trace MC-LR.

Microcystin-LR (MC-LR) is a severe threat to human and animal health; thus, monitoring it in the environment is essential, especially in water quality protections. Herein, in this work, we synthesize PVDF/CNT/Ag molecular imprinted membranes (PCA-MIMs) via an innovative combination of surface-enhanced Raman spectroscopy (SERS) detection, membrane separation, and molecular-imprinted technique toward the analysis of MC-LR in water. In particular, a light-initiated imprint is employed to protect the chemical structure of the MC-LR molecules. Furthermore, in order to ensure the detection sensitivity, the SERS substrates are combined with the membrane via the assistance of magnetism. The effect of synthesis conditions on the SERS sensitivity was investigated in detail. It is demonstrated from the characteristic results that the PCA-MIMs present high sensitivity to the MC-LR molecules with excellent selectivity against the interfere molecules. Results clearly show that the as-prepared PCA-MIMs hold great potential applications to detect trace MC-LR for the protection of water quality.

Development of a sensitive electrochemical method to determine amitraz based on perylene tetracarboxylic acid/mesoporous carbon/Nafion@SPCEs.

A cutting-edge electrochemical method is presented for precise quantification of amitraz (AMZ), a commonly used acaricide in veterinary medicine and agriculture. Leveraging a lab-made screen-printed carbon electrode modified with a synergistic blend of perylene tetracarboxylic acid (PTCA), mesoporous carbon (MC), and Nafion, the sensor's sensitivity was significantly improved. Fine-tuning of PTCA, MC, and Nafion ratios, alongside optimization of the pH of the supporting electrolyte and accumulation time, resulted in remarkable sensitivity enhancements. The sensor exhibited a linear response within the concentration range 0.01 to 0.70 µg mL-1, boasting an exceptionally low limit of detection of 0.002 µg mL-1 and a limit of quantification of 0.10 µg mL-1, surpassing maximum residue levels permitted in honey, tomato, and longan samples. Validation with real samples demonstrated high recoveries ranging from 80.8 to 104.8%, with a relative standard deviation below 10%, affirming the method's robustness and precision. The modified PTCA/MC/Nafion@SPCE-based electrochemical sensor not only offers superior sensitivity but also simplicity and cost-effectiveness, making it a pivotal tool for accurate AMZ detection in food samples. Furthermore, beyond the scope of this study, the sensor presents promising prospects for wider application across various electrochemical analytical fields, thereby significantly contributing to food safety and advancing agricultural practices.

Scaffold-Based Poly(Vinylidene Fluoride) and Its Copolymers: Materials, Fabrication Methods, Applications, and Perspectives.

Tissue engineering involves implanting grafts into damaged tissue sites to guide and stimulate the formation of new tissue, which is an important strategy in the field of tissue defect treatment. Scaffolds prepared in vitro meet this requirement and are able to provide a biochemical microenvironment for cell growth, adhesion, and tissue formation. Scaffolds made of piezoelectric materials can apply electrical stimulation to the tissue without an external power source, speeding up the tissue repair process. Among piezoelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers have the largest piezoelectric coefficients and are widely used in biomedical fields, including implanted sensors, drug delivery, and tissue repair. This paper provides a comprehensive overview of PVDF and its copolymers and fillers for manufacturing scaffolds as well as the roles in improving piezoelectric output, bioactivity, and mechanical properties. Then, common fabrication methods are outlined such as 3D printing, electrospinning, solvent casting, and phase separation. In addition, the applications and mechanisms of scaffold-based PVDF in tissue engineering are introduced, such as bone, nerve, muscle, skin, and blood vessel. Finally, challenges, perspectives, and strategies of scaffold-based PVDF and its copolymers in the future are discussed.

Room-temperature fabrication of fluorinated covalent organic polymer @ Attapulgite composite for in-syringe membrane solid-phase extraction and analysis of domoic acid in aquatic products.

A novel fluorinated covalent organic polymer @ attapulgite composite (F-COP@ATP) was prepared at room temperature for in-syringe membrane solid-phase extraction (SM-SPE) of domoic acid (DA) in aquatic products. Natural ore ATP has the advantages of low cost, good mechanical strength and abundant hydroxyl group on its surface, and in-situ modified F-COP layer can provide abundant adsorption sites. F-COP@ATP combining the advantages of F-COP and ATP, becomes an ideal adsorbent for DA extracting. Moreover, a high-throughput sample preparation strategy was carried out by using the F-COP@ATP membrane as syringe filter and assembling syringes with a ten-channel injection pump. In addition, the experimental factors were optimized, such as pH of extract, amount of adsorbent, velocity of extraction and desorption, type and volume of desorption solvent. The DA analytical method was established by SM-SPE-HPLC/tandem mass spectrometry. The method had a wide linear range with low limit of detection (0.344 ng/kg) and low limit of quantification (1.14 ng/kg). F-COP@ATP membrane can be reused more than five times. The method realized the analysis of DA in scallop and razor clam samples, which shows its application prospect in practical analysis. This study provided an efficient, low-energy and mild idea for preparing other reusable natural mineral ATP-based composite materials for separation and enrichment, which reduces the experimental cost and is closer to environmental protection and green chemistry to a certain extent.

LAMP-visualized photofuel cell self-powered dual-mode sensing platform for detection of transmissible gastroenteritis virus.

The detection of transmissible gastroenteritis virus (TGEV) is of great significance to reduce the loss of pig industry. A LAMP-visualization/PFC self-powered dual-mode output sensor platform was constructed to detect TGEV by combining a simple and intuitive photoelectrochromic material with a highly sensitive PFC self-powered sensing platform without external power supply. The PFC sensing substrate was constructed using CdS nanoparticles modified ZnO NRs (CdS/ZnO NRs) as the photoanode, which exhibited high photoactivity, and Prussian blue (PB) as the cathode. After LAMP reaction on the optical anode, visual signals caused by PB discolorimetry can be detected semi-quantitatively, or PFC power density electrical signals collected by electrochemical workstation can be used. The output power density value is logarithm of TGEV concentration. The linear relationship was good within the detection range of 0.075 fg/µL-7.5 ng/µL, with a detection limit of 0.025 fg/µL (S/N = 3). This multi-signal output sensing platform provides more choices for quantifying TGEV detection results, and the two methods can be mutually verified, which meets the needs of different scenarios and improves the reliability of detection. It has a good effect in the actual sample detection, without the use of expensive and complex instruments, and has a broad application prospect.

Sonophotocatalytic removal of organic dyes in real water environments using reusable BiSI@PVDF-HFP nanocomposite membranes.

Focusing on the uncontrolled discharge of organic dyes, a known threat to human health and aquatic ecosystems, this work employs a dual-functional catalyst approach, by immobilizing a synthesized bismuth sulfur iodide (BiSI) into a poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymeric matrix for multifunctional water remediation. The resulting BiSI@PVDF nanocomposite membrane (NCM), with 20 wt% filler content, maintains a highly porous structure without compromising morphology or thermal properties. Demonstrating efficiency in natural pH conditions, the NCM removes nearly all Rhodamine B (RhB) within 1 h, using a combined sonophotocatalytic process. Langmuir and pseudo-second-order models describe the remediation process, achieving a maximum removal capacity (Qmax) of 72.2 mg/g. In addition, the combined sonophotocatalysis achieved a degradation rate ten and five times higher (0.026 min-1) than photocatalysis (0.002 min-1) and sonocatalysis (0.010 min-1). Furthermore, the NCM exhibits notable reusability over five cycles without efficiency losses and efficiencies always higher than 90%, highlighting its potential for real water matrices. The study underscores the suitability of BiSI@PVDF as a dual-functional catalyst for organic dye degradation, showcasing synergistic adsorption, photocatalysis, and sonocatalysis for water remediation.

Short-term outcomes of a multicentre prospective study using a "visible" polyvinylidene fluoride onlay mesh for the prevention of midline incisional hernia.

INTRODUCTION: Prophylactic meshes in high-risk patients prevent incisional hernias, although there are still some concerns about the best layer to place them in, the type of fixation, the mesh material, the significance of the level of contamination, and surgical complications. We aimed to provide answers to these questions and information about how the implanted material behaves based on its visibility under magnetic resonance imaging (MRI). METHOD: This is a prospective multicentre observational cohort study. Preliminary results from the first 3 months are presented. We included general surgical patients who had at least two risk factors for developing an incisional hernia. Multivariate logistic regression was used. A polyvinylidene fluoride (PVDF) mesh loaded with iron particles was used in an onlay position. MRIs were performed 6 weeks after treatment. RESULTS: Between July 2016 and June 2022, 185 patients were enrolled in the study. Surgery was emergent in 30.3% of cases, contaminated in 10.7% and dirty in 11.8%. A total of 5.6% of cases had postoperative wound infections, with the requirement of stoma being the only significant risk factor (OR = 7.59, p = 0.03). The formation of a seroma at 6 weeks detected by MRI, was associated with body mass index (OR = 1.13, p = 0.02). CONCLUSIONS: The prophylactic use of onlay PVDF mesh in midline laparotomies in high-risk patients was safe and effective in the short term, regardless of the type of surgery or the level of contamination. MRI allowed us to detect asymptomatic seromas during the early process of integration. STUDY REGISTRATION:  This protocol was registered at ClinicalTrials.gov (NCT03105895).

Integration of adsorption, reduction, and filtration in PANI/PVDF nanofiber composite membrane for removal of Cr(VI).

Here, polyaniline/polyvinylidene fluoride (PANI/PVDF) nanofiber composite membrane was fabricated using electrostatic spinning technology to remove hexavalent chromium Cr(VI). The employment of PANI not only extremely enhanced the hydrophilic property of the nanofiber membrane, but also facilitated the transfer of Cr2O72- from water to the membrane. The PANI/PVDF membrane had an extremely excellent performance in getting rid of Cr(VI) and a quite large flux (250 L/m2 h). The maximum adsorption quantity of the membrane could reach 334.5 mg/g in which adsorption played 52.12% part and reduction played 47.87% part. The removal rate could reach nearly 100% immediately in the permeate solution under filtration while it needed 240 min to reach 100% only by static adsorption. Therefore, the interception of the membrane and the adsorption reduction of PANI had synergistic effect on removal of Cr(VI). Furthermore, the removal rate of Cr(VI) could still reach 95.97% after reused 8 times. The membrane showed a very good reusability and application prospect.

Photoinduced charge generation of nanostructured carbon derived from human hair biowaste for performance enhancement in polyvinylidene fluoride based triboelectric nanogenerator.

Carbon nanostructures derived from human hair biowaste are incorporated into polyvinylidene fluoride (PVDF) polymer to enhance the energy conversion performance of a triboelectric nanogenerator (TENG). The PVDF filled with activated carbon nanomaterial from human hair (AC-HH) exhibits improved surface charge density and photoinduced charge generation. These remarkable properties are attributed to the presence of graphene-like nanostructures in AC-HH, contributing to the augmented performance of PVDF@AC-HH TENG. The correlation of surface morphologies, surface charge potential, charge capacitance properties, and TENG electrical output of the PVDF composites at various AC-HH loading is studied and discussed. Applications of the PVDF@AC-HH TENG as a power source for micro/nanoelectronics and a movement sensor for detecting finger gestures are also demonstrated. The photoresponse property of the fabricated TENG is demonstrated and analyzed in-depth. The analysis indicates that the photoinduced charge carriers originate from the conductive reduced graphene oxide (rGO), contributing to the enhanced surface charge density of the PVDF composite film. This research introduces a novel approach to enhancing TENG performance through the utilization of carbon nanostructures derived from human biowaste. The findings of this work are crucial for the development of innovative energy-harvesting technology with multifunctionality, including power generation, motion detection, and photoresponse capabilities.

Oxidative Transformation of Nafion-Related Fluorinated Ether Sulfonates: Comparison with Legacy PFAS Structures and Opportunities of Acidic Persulfate Digestion for PFAS Precursor Analysis.

The total oxidizable precursor (TOP) assay has been extensively used for detecting PFAS pollutants that do not have analytical standards. It uses hydroxyl radicals (HO•) from the heat activation of persulfate under alkaline pH to convert H-containing precursors to perfluoroalkyl carboxylates (PFCAs) for target analysis. However, the current TOP assay oxidation method does not apply to emerging PFAS because (i) many structures do not contain C-H bonds for HO• attack and (ii) the transformation products are not necessarily PFCAs. In this study, we explored the use of classic acidic persulfate digestion, which generates sulfate radicals (SO4-•), to extend the capability of the TOP assay. We examined the oxidation of Nafion-related ether sulfonates that contain C-H or -COO-, characterized the oxidation products, and quantified the F atom balance. The SO4-• oxidation greatly expanded the scope of oxidizable precursors. The transformation was initiated by decarboxylation, followed by various spontaneous steps, such as HF elimination and ester hydrolysis. We further compared the oxidation of legacy fluorotelomers using SO4-• versus HO•. The results suggest novel product distribution patterns, depending on the functional group and oxidant dose. The general trends and strategies were also validated by analyzing a mixture of 100000- or 10000-fold diluted aqueous film-forming foam (containing various fluorotelomer surfactants and organics) and a spiked Nafion precursor. Therefore, (1) the combined use of SO4-• and HO• oxidation, (2) the expanded list of standard chemicals, and (3) further elucidation of SO4-• oxidation mechanisms will provide more critical information to probe emerging PFAS pollutants.

Large-scale cranial window for in vivo mouse brain imaging utilizing fluoropolymer nanosheet and light-curable resin.

Two-photon microscopy enables in vivo imaging of neuronal activity in mammalian brains at high resolution. However, two-photon imaging tools for stable, long-term, and simultaneous study of multiple brain regions in same mice are lacking. Here, we propose a method to create large cranial windows covering such as the whole parietal cortex and cerebellum in mice using fluoropolymer nanosheets covered with light-curable resin (termed the 'Nanosheet Incorporated into light-curable REsin' or NIRE method). NIRE method can produce cranial windows conforming the curved cortical and cerebellar surfaces, without motion artifacts in awake mice, and maintain transparency for >5 months. In addition, we demonstrate that NIRE method can be used for in vivo two-photon imaging of neuronal ensembles, individual neurons and subcellular structures such as dendritic spines. The NIRE method can facilitate in vivo large-scale analysis of heretofore inaccessible neural processes, such as the neuroplastic changes associated with maturation, learning and neural pathogenesis.