Specific lipid magnetic sphere sorted CD146-positive bone marrow mesenchymal stem cells can better promote articular cartilage damage repair.

BACKGROUND: The characteristics and therapeutic potential of subtypes of bone marrow mesenchymal stem cells (BMSCs) are largely unknown. Also, the application of subpopulations of BMSCs in cartilage regeneration remains poorly characterized. The aim of this study was to explore the regenerative capacity of CD146-positive subpopulations of BMSCs for repairing cartilage defects. METHODS: CD146-positive BMSCs (CD146 + BMSCs) were sorted by self-developed CD146-specific lipid magnetic spheres (CD146-LMS). Cell surface markers, viability, and proliferation were evaluated in vitro. CD146 + BMSCs were subjected to in vitro chondrogenic induction and evaluated for chondrogenic properties by detecting mRNA and protein expression. The role of the CD146 subpopulation of BMSCs in cartilage damage repair was assessed by injecting CD146 + BMSCs complexed with sodium alginate gel in the joints of a mouse cartilage defect model. RESULTS: The prepared CD146-LMS had an average particle size of 193.7 ± 5.24 nm, an average potential of 41.9 ± 6.21 mv, and a saturation magnetization intensity of 27.2 Am2/kg, which showed good stability and low cytotoxicity. The sorted CD146 + BMSCs highly expressed stem cell and pericyte markers with good cellular activity and cellular value-added capacity. Cartilage markers Sox9, Collagen II, and Aggrecan were expressed at both protein and mRNA levels in CD146 + BMSCs cells after chondrogenic induction in vitro. In a mouse cartilage injury model, CD146 + BMSCs showed better function in promoting the repair of articular cartilage injury. CONCLUSION: The prepared CD146-LMS was able to sort out CD146 + BMSCs efficiently, and the sorted subpopulation of CD146 + BMSCs had good chondrogenic differentiation potential, which could efficiently promote the repair of articular cartilage injury, suggesting that the sorted CD146 + BMSCs subpopulation is a promising seed cell for cartilage tissue engineering.

Efficacy, safety, and advantages of magnetic anchor-guided endoscopic submucosal dissection vs conventional endoscopic submucosal dissection: A retrospective paired cohort study.

BACKGROUND: Endoscopic submucosal dissection (ESD) has been recommended as the first-line treatment for early gastric cancer (EGC). However, poor visualization of the operative field increases both the procedure time and the risk of complications, especially for large and difficult lesions. We introduced a novel technique, magnetic anchor-guided ESD (MAG-ESD) and compared it with conventional ESD (C-ESD) for the treatment of large EGCs in terms of efficacy, safety, and advantages. METHODS: Patients with large EGCs who underwent MAG-ESD or C-ESD at the First Affiliated Hospital of Xi'an Jiaotong University from March 2020 to March 2022 were retrospectively enrolled in this study. The patients in the MAG-ESD cohort were matched to those in the C-ESD cohort using propensity score-based matching. The operation time, submucosal dissection time, complete resection status, magnetic anchor, adverse event rate, and tumor recurrence rate were evaluated. RESULTS: Twenty-two patients who underwent MAG-ESD were ultimately matched to those who underwent C-ESD. The median operation time of MAG-ESD and C-ESD was 43 minutes (IQR, 35.2-49.5) and 50.5 minutes (IQR, 42.0-76.0), respectively, among which the submucosal dissection time was 7.6 minutes (IQR, 5.2-10.4) and 14.8 minutes (IQR, 10.8-19.6), respectively. The operation time of MAG-ESD was shorter than that of C-ESD, especially the submucosal dissection time (P < .05). There was a lower incidence of adverse events associated with MAG-ESD (P < .05) when magnetic anchors were successfully placed and retrieved. CONCLUSION: MAG-ESD is feasible, effective, safe, and simple for the treatment of large EGCs at different sites and has a high anchor success rate, which could shorten the operation time and reduce the adverse event rate.

A novel ternary magnetic nanobiocomposite based on tragacanth-silk fibroin hydrogel for hyperthermia and biological properties.

This study involves the development of a new nanocomposite material for use in biological applications. The nanocomposite was based on tragacanth hydrogel (TG), which was formed through cross-linking of Ca2+ ions with TG polymer chains. The utilization of TG hydrogel and silk fibroin as natural compounds has enhanced the biocompatibility, biodegradability, adhesion, and cell growth properties of the nanobiocomposite. This advancement makes the nanobiocomposite suitable for various biological applications, including drug delivery, wound healing, and tissue engineering. Additionally, Fe3O4 magnetic nanoparticles were synthesized in situ within the nanocomposite to enhance its hyperthermia efficiency. The presence of hydrophilic groups in all components of the nanobiocomposite allowed for good dispersion in water, which is an important factor in increasing the effectiveness of hyperthermia cancer therapy. Hemolysis and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays were conducted to evaluate the safety and efficacy of the nanobiocomposite for in-vivo applications. Results showed that even at high concentrations, the nanobiocomposite had minimal hemolytic effects. Finally, the hyperthermia application of the hybrid scaffold was evaluated, with a maximum SAR value of 41.2 W/g measured in the first interval.

Magnetic CAR T cell purification using an anti-G4S linker antibody.

Chimeric antigen receptor (CAR) redirected T cells are successfully employed in the combat against several hematological malignancies, however, are often compromised by low transduction rates making refinement of the CAR T cell products necessary. Here, we report a broadly applicable enrichment protocol relying on marking CAR T cells with an anti-glycine4-serine (G4S) linker antibody followed by magnetic activated cell sorting (MACS). The protocol is broadly applicable since the G4S peptide is an integral part of the vast majority of CARs as it links the VH and VL recognition domains. We demonstrate the feasibility by using the canonical second generation CARs specific for CEA and Her2, respectively, obtaining highly purified CAR T cell products in a one-step procedure without impairing cell viability. The protocol is also applicable to a dual specific CAR (tandem CAR). Except for CD39, T cell activation/exhaustion markers were not upregulated after separation. Purified CAR T cells retained their functionality with respect to antigen-specific cytokine secretion, cytotoxicity, and the capacity to proliferate and eliminate cognate tumor cells upon repetitive stimulation. Collectively, the one-step protocol for purifying CAR T cells extends the toolbox for preclinical research and specifically for clinical CAR T cell manufacturing.

Nanocomposite microbeads made of recycled polylactic acid for the magnetic solid phase extraction of xenobiotics from human urine.

Nanocomposite microbeads (average diameter = 10-100 µm) were prepared by a microemulsion-solidification method and applied to the magnetic solid-phase extraction (m-SPE) of fourteen analytes, among pesticides, drugs, and hormones, from human urine samples. The microbeads, perfectly spherical in shape to maximize the surface contact with the analytes, were composed of magnetic nanoparticles dispersed in a polylactic acid (PLA) solid bulk, decorated with multi-walled carbon nanotubes (mPLA@MWCNTs). In particular, PLA was recovered from filters of smoked electronic cigarettes after an adequate cleaning protocol. A complete morphological characterization of the microbeads was performed via Fourier-transform infrared (FTIR) spectroscopy, UV-Vis spectroscopy, thermogravimetric and differential scanning calorimetry analysis (TGA and DSC), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The recovery study of the m-SPE procedure showed yields ≥ 64%, with the exception of 4-chloro-2-methylphenol (57%) at the lowest spike level (3 µg L-1). The method was validated according to the main FDA guidelines for the validation of bioanalytical methods. Using liquid chromatography-tandem mass spectrometry, precision and accuracy were below 11% and 15%, respectively, and detection limits of 0.1-1.8 µg L-1. Linearity was studied in the range of interest 1-15 µg L-1 with determination coefficients greater than 0.99. In light of the obtained results, the nanocomposite microbeads have proved to be a valid and sustainable alternative to traditional sorbents, offering good analytical standards and being synthetized from recycled plastic material. One of the main objectives of the current work is to provide an innovative and optimized procedure for the recycling of a plastic waste, to obtain a regular and reliable microstructure, whose application is here presented in the field of analytical chemistry. The simplicity and greenness of the method endows the procedure with a versatile applicability in different research and industrial fields.

[Magnetic foreign bodies of the gastrointestinal tract in pediatric practice]. / Magnitnye inorodnye tela zheludochno-kishechnogo trakta v pediatricheskoi praktike.

OBJECTIVE: To analyze the pediatric patients with multiple magnetic foreign bodies of the gastrointestinal tract undergoing surgical intervention; to present the treatment and diagnostic algorithm in pediatric practice; to compare surgical interventions for these lesions and determine the most optimal one. MATERIAL AND METHODS: A retrospective single-center study included 9 patients diagnosed with multiple magnetic foreign bodies of the gastrointestinal tract. Exclusion criteria: outpatient cases and endoscopic removal of magnetic foreign bodies. All patients underwent laparoscopy and/or laparotomy. We analyzed postoperative data and determined the preferable approach. RESULTS: All patients were discharged without complications. Length of hospital-stay was shorter after laparoscopy (7 vs. 12 days). Patients after laparoscopy didn't need for intensive care while laparotomy required ICU stay for 4.5±2.2 days. Enteral feeding started after 1 and 3 days, respectively. CONCLUSION: Laparoscopy is preferable for multiple magnetic foreign bodies of the gastrointestinal tract due to shorter hospital-stay, no need for ICU-stay, lower surgical trauma and earlier enteral feeding.

Magnetic modulation of lysosomes for cancer therapy.

Lysosomes play a central role in biochemical signal transduction and oxidative stress in cells. Inducing lysosome membrane penetration (LMP) to cause lysosomal-dependent cell death (LCD) in tumor cells is an effective strategy for cancer therapy. Chemical drugs can destroy the stability of lysosomes by neutralizing protons within the lysosomes or enhancing the fragility of the lysosomal membranes. However, there remain several unsolved problems of traditional drugs in LMP induction due to insufficient lysosomal targeting, fast metabolism, and toxicity in normal cells. With the development of nanotechnology, magnetic nanoparticles have been demonstrated to target lysosomes naturally, providing a versatile tool for lysosomal modulation. Combined with excellent tissue penetration and spatiotemporal manipulability of magnetic fields, magnetic modulation of lysosomes progresses rapidly in inducing LMP and LCD for cancer therapy. This review comprehensively discussed the strategies of magnetic modulation of lysosomes for cancer therapy. The intrinsic mechanisms of LMP-induced LCD were first introduced. Then, the modulation of lysosomes by diverse physical outputs of magnetic fields was emphatically discussed. Looking forward, this review will shed the light on the prospect of magnetic modulation of lysosomes, inspiring future research of magnetic modulation strategy in cancer therapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Selective Removal of Chlorophyll and Isolation of Lutein from Plant Extracts Using Magnetic Solid Phase Extraction with Iron Oxide Nanoparticles.

In recent years, there has been a growing interest in plant pigments as readily available nutraceuticals. Photosynthetic pigments, specifically chlorophylls and carotenoids, renowned for their non-toxic antioxidant properties, are increasingly finding applications beyond their health-promoting attributes. Consequently, there is an ongoing need for cost-effective methods of isolation. This study employs a co-precipitation method to synthesize magnetic iron oxide nanoparticles. Scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) confirms that an aqueous environment and oxidizing conditions yield nanosized iron oxide with particle sizes ranging from 80 to 140 nm. X-ray photoelectron spectroscopy (XPS) spectra indicate the presence of hydrous iron oxide FeO(OH) on the surface of the nanosized iron oxide. The Brunauer-Emmett-Teller (BET) surface area of obtained nanomaterial was 151.4 m2 g-1, with total pore volumes of pores 0.25 cm3 g-1 STP. The material, designated as iron oxide nanoparticles (IONPs), serves as an adsorbent for magnetic solid phase extraction (MSPE) and isolation of photosynthetic pigments (chlorophyll a, lutein) from extracts of higher green plants (Mentha piperita L., Urtica dioica L.). Sorption of chlorophyll a onto the nanoparticles is confirmed using UV-vis spectroscopy, Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS), and high-performance liquid chromatography (HPLC). Selective sorption of chlorophyll a requires a minimum of 3 g of IONPs per 12 mg of chlorophyll a, with acetone as the solvent, and is dependent on a storage time of 48 h. Extended contact time of IONPs with the acetone extract, i.e., 72 h, ensures the elimination of remaining components except lutein, with a spectral purity of 98%, recovered with over 90% efficiency. The mechanism of chlorophyll removal using IONPs relies on the interaction of the pigment's carbonyl (C=O) groups with the adsorbent surface hydroxyl (-OH) groups. Based on molecular dynamics (MD) simulations, it has been proven that the selective adsorption of pigments is also influenced by more favorable dispersion interactions between acetone and chlorophyll in comparison with other solutes. An aqueous environment significantly promotes the removal of pigments; however, it results in a complete loss of selectivity.

Mild magnetic hyperthermia-activated immuno-responses for primary bladder cancer therapy.

Surgical intervention followed by chemotherapy is the principal treatment strategy for bladder cancer, which is hindered by significant surgical risks, toxicity from chemotherapy, and high rates of recurrence after surgery. In this context, a novel approach using mild magnetic hyperthermia therapy (MHT) for bladder cancer treatment through the intra-bladder delivery of magnetic nanoparticles is presented for the first time. This method overcomes the limitations of low magnetic thermal efficiency, inadequate tumor targeting, and reduced therapeutic effectiveness associated with the traditional intravenous administration of magnetic nanoparticles. Core-shell Zn-CoFe2O4@Zn-MnFe2O4 (MNP) nanoparticles were developed and further modified with hyaluronic acid (HA) to enhance their targeting ability toward tumor cells. The application of controlled mild MHT using MNP-HA at temperatures of 43-44 °C successfully suppressed the proliferation of bladder tumor cells and tumor growth, while also decreasing the expression levels of heat shock protein 70 (HSP70). Crucially, this therapeutic approach also activated the body's innate immune response involving macrophages, as well as the adaptive immune responses of dendritic cells (DCs) and T cells, thereby reversing the immunosuppressive environment of the bladder tumor and effectively reducing tumor recurrence. This study uncovers the potential immune-activating mechanism of mild MHT in the treatment of bladder cancer and confirms the effectiveness and safety of this strategy, indicating its promising potential for the clinical management of bladder cancer with a high tendency for relapse.

Magnetic polyimide nanocomposite for analysis of parabens in cooking wine by magnetic solid-phase extraction coupled with gas chromatography - Mass spectrometry.

A magnetic polyimide (PI) nanocomposite has been synthesized by phase inversion of PI and simultaneous encapsulation of Fe3O4 nanoparticles. The Fe3O4/PI nanocomposite was characterized by a variety of characterization techniques, including infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption isotherms, and vibrating sample magnetometry. The results showed that the prepared nanocomposite had a homogeneous structure, adequate specific surface area (76.1 m2/g) and high saturation magnetization (42.9 emu/g). Using parabens as model analytes, the performance of the Fe3O4/PI nanocomposite as an adsorbent for magnetic solid-phase extraction (MSPE) was evaluated. The extracted parabens were desorbed and determined by gas chromatography-mass spectrometry (GC-MS). The parameters affecting the extraction and desorption efficiency of parabens were optimized. Under the optimal conditions, the developed MSPE/GC-MS method was successfully applied to the determination of parabens in cooking wine. The MSPE/GC-MS method exhibited broad linearity (0.2-100 µg/L), low detection limits (0.04-0.05 µg/L), and satisfactory extraction recoveries (79.2 %-113.3 %) with relative standard deviations (RSDs) ranging from 0.7 % to 10.4 %. For real cooking wine samples, the spiked recoveries ranged from 91.7 % to 118.7 % with RSDs of 1.0 %-11.2 %. The results demonstrated that the Fe3O4/PI nanocomposite was an effective adsorbent, and this work provides a novel reference for the easy preparation of magnetic adsorbent materials.

A magnetic graphene oxide and UiO-66 based homogeneous dual recognition electrochemical aptasensor for accurate and sensitive detection of aflatoxin B1.

Aflatoxin (AFs) contamination is one of the serious food safety issues. Aflatoxin B1 (AFB1) is the most common and toxic aflatoxin, which has been classified as a class 1 carcinogen by the International Agency for Research on Cancer (IARC). It is extremely destructive to liver tissue. Developing a convenient and sensitive detection technique is essential. In this paper, we developed a homogeneous dual recognition strategy based electrochemical aptasensor for accurate and sensitive detection of aflatoxin B1 (AFB1) based on the magnetic graphene oxide (MGO) and UiO-66. The MGO was synthesized for the recognition and magnetic separation of AFB1 from complex samples. UiO-66/ferrocenecarboxylic acid (Fc)/aptamer composites were constructed as both recognition and signal probes. The probes would specifically capture AFB1 enriched by MGO, which enables dual recognition in homogeneous solution, thus further improving the accuracy of AFB1 detection. The electrochemical aptasensor for AFB1 had a linear range from 0.005 to 500 ng mL-1. Additionally, the limit of detection was 1 pg mL-1. It shows a favorable potential for both sensitive and accurate detection of AFB1 in real samples.

An alternative hybrid lipid nanosystem combining cytotoxic and magnetic properties as a tool to potentiate antitumor effect of 5-fluorouracil.

AIMS: Colorectal cancer is the third most frequent type of cancer and the second leading cause of cancer-related deaths worldwide. The majority of cases are diagnosed at a later stage, leading to the need for more aggressive treatments such as chemotherapy. 5-Fluorouracil (5-FU), known for its high cytotoxic properties has emerged as a chemotherapeutic agent. However, it presents several drawbacks such as lack of specificity and short half-life. To reduce these drawbacks, several strategies have been designed namely chemical modification or association to drug delivery systems. MATERIALS AND METHODS: Current research was focused on the design, physicochemical characterization and in vitro evaluation of a lipid-based system loaded with 5-FU. Furthermore, aiming to maximize preferential targeting and release at tumour sites, a hybrid lipid-based system, combining both therapeutic and magnetic properties was developed and validated. For this purpose, liposomes co-loaded with 5-FU and iron oxide (II, III) nanoparticles were accomplished. KEY FINDINGS: The characterization of the developed nanoformulation was performed in terms of incorporation parameters, mean size and surface charge. In vitro studies assessed in a murine colon cancer cell line confirmed that 5-FU antiproliferative activity was preserved after incorporation in liposomes. In same model, iron oxide (II, III) nanoparticles did not exhibit cytotoxic properties. Additionally, the presence of these nanoparticles was shown to confer magnetic properties to the liposomes, allowing them to respond to external magnetic fields. SIGNIFICANCE: Overall, a lipid nanosystem loading a chemotherapeutic agent displaying magnetic characteristics was successfully designed and physicochemically characterized, for further in vivo applications.

Comprehensive life cycle assessment of NH2-functionalized magnetic graphene oxide for mercury removal: Carbon emissions and economic evaluation.

Heavy metals contamination critically affects human health and ecosystems, necessitating pioneering approaches to diminish their adverse impacts. Hence, this study synthesized aminated magnetic graphene oxide (mGO-NH2) for the removal of mercury (Hg) from aqueous solutions. Although functionalized GO is an emerging technology at the early stages of development, its synthesis and application require special attention to the eco-environmental assessment. Therefore, the life cycle assessment and life cycle cost of mGO-NH2 were investigated from the cradle-to-gate approach for the removal of 1 kg Hg. The adsorption process was optimized based on pH, Hg concentration, adsorbent dose, and contact time at 6.48, 40 mg/l, 150 mg/l, and 35 min, respectively, resulting in an adsorption capacity of 184.17 mg/g. Human carcinogenic toxicity with a 40.42% contribution was the main environmental impact, relating to electricity (35.76%) and ethylenediamine (31.07%) usage. The endpoint method also revealed the pivotal effect of the mGO-NH2 synthesis on human health (90.52%). The most energy demand was supplied by natural gas and crude oil accounting for 70.8% and 22.1%, respectively. A 99.02% CO2 emission originated from fossil fuels consumption based on the greenhouse gas protocol (GGP). The cost of mGO-NH2 was about $143.7/kg with a net present value of $21064.8 per kg Hg removal for a 20-year lifetime. Considering the significant role of material cost (>70%), the utilization of industrial-grade raw materials is recommended to achieve a low-cost adsorbent. This study demonstrated that besides the appropriate performance of mGO-NH2 for Hg removal, it is essential that further studies evaluate eco-friendly approaches to decrease the adverse impacts of this emerging product.

Magnetic Lipid-Based hybrid nanosystems: A combined stimuli- responsive nanocarriers for enriched chemotherapeutic potential of L-carnosine in induced breast Ehrlich ascites tumor model.

Magnetic Lipid-Based Hybrid Nanosystems (M-LCNPs) is a novel nanoplatform that can respond to magnetic stimulus and are designed for delivering L-carnosine (CN), a challenging dipeptide employed in the treatment of breast cancer. CN exhibits considerable water solubility and undergoes in-vivo degradation, hence restricting its application. Consequently, it is anticipated that the developed M-LCNPs will enhance the effectiveness of CN. To ensure the physical stability of MNPs, they were initially coated with a mixture of oleic acid and oleylamine before being included in pegylated liquid crystalline nanoparticles (PLCNPs). The proposed M-LCNPs exhibited promising in-vitro characteristics, notably a small particle size (143.5 nm ± 1.25) and a high zeta potential (-39.5 mV ± 1.54), together with superparamagnetic behavior. The in-vitro release profile exhibited a prolonged release pattern. The IC50 values of M-LCNPs were 1.57 and 1.59 times lower than these of the CN solution after 24 and 48 hours, respectively. Female BALB/C female mice with an induced breast cancer (Ehrlich Ascites tumor [EAT] model) were used to study the influence of an external magnetic field on the chemotherapeutic activity and toxicity of CN loaded in the developed M-LCNPs. Stimuli-responsive M-LCNPs exhibited no apparent systemic toxicity in addition to enhanced chemotherapeutic efficacy compared to nontargeted M-LCNPs and CN solution, as evidenced by a reduction of % tumor growth (11.7%), VEGF levels (22.95 pg/g tissue), and cyclin D1 levels (27.61 ng/g tissue), and an increase in caspase-3 level (28.9 ng/g tissue). Ultimately, the developed stimuli-responsive CN loaded M-LCNPs presented a promising nanoplatform for breast cancer therapy.

Ultrasound imaging guided targeted sonodynamic therapy enhanced by magnetophoretically controlled magnetic microbubbles.

Sonodynamic therapy (SDT) utilizes ultrasonic excitation of a sensitizer to generate reactive oxygen species (ROS) to destroy tumor. Two dimensional (2D) black phosphorus (BP) is an emerging sonosensitizer that can promote ROS production to be used in SDT but it alone lacks active targeting effect and showed low therapy efficiency. In this study, a stable dispersion of integrated micro-nanoplatform consisting of BP nanosheets loaded and Fe3O4 nanoparticles (NPs) connected microbubbles was introduced for ultrasound imaging guided and magnetic field directed precision SDT of breast cancer. The targeted ultrasound imaging at 18 MHz and efficient SDT effects at 1 MHz were demonstrated both in-vitro and in-vivo on the breast cancer. The magnetic microbubbles targeted deliver BP nanosheets to the tumor site under magnetic navigation and increased the uptake of BP nanosheets by inducing cavitation effect for increased cell membrane permeability via ultrasound targeted microbubble destruction (UTMD). The mechanism of SDT by magnetic black phosphorus microbubbles was proposed to be originated from the ROS triggered mitochondria mediated apoptosis by up-regulating the pro-apoptotic proteins while down-regulating the anti-apoptotic proteins. In conclusion, the ultrasound theranostic was realized via the magnetic black phosphorus microbubbles, which could realize targeting and catalytic sonodynamic therapy.

Facile extraction and determination of organophosphorus pesticides using poly (8-hydroxyquinoline) functionalized magnetic multi-walled carbon nanotubes nanocomposite in water, fruits, and vegetables samples.

This study presents a dispersive micro-solid phase extraction (D-µ-SPE) approach for extracting and determining of two organophosphorus pesticides (OPPs), including diazinon and chlorpyrifos as model analytes in various samples. For this purpose, we synthesized, characterized, and utilized magnetic multi-walled carbon nanotubes coated with poly 8-hydroxyquinoline (MWCNTs/Fe3O4@PHQ) as a novel sorbent. The impact of various parameters, including sorbent type, sample pH, sample volume, sorbent amount, desorption solvent (type and volume), extraction time, and ionic strength on the extraction efficiency was investigated and optimized. Following the extraction, the desorbed pesticides in acetone were analyzed using gas chromatography with an FID detector. Under the optimized experimental conditions, the proposed method showed excellent linearity in the range of 3-1000 µg/L, low detection limit (0.9-1.5 µg/L), good relative recoveries (86-101.5 %), and high precision (RSD < 6.5 %). Finally, the applicability of this method was evaluated by analyzing the target OPPs in a variety of real samples, and obtained satisfactory results.

Y-Z deformable magnetic ring for the treatment of rectal stricture: A case report and review of literature.

BACKGROUND: Treatment of postoperative anastomotic stenosis for colorectal cancer is often challenging, especially for patients who do not respond well to endoscopy. In cases where patients have undergone an enterostomy, the stenosis can be easily resolved through magnetic compression. However, common magnetic compression techniques cannot be performed on those without enterostomy. We designed a novel Y-Z deformable magnetic ring (Y-Z DMR) and successfully applied it to a patient with a stenosis rectal anastomosis and without enterostomy after rectal cancer surgery. CASE SUMMARY: We here report the case of a 57-year-old woman who had undergone a laparoscopic radical rectum resection (Dixon) for rectal cancer. However, she started facing difficulty in defecation 6 months after surgery. Her colonoscopy indicated stenosis of the rectal anastomosis. Endoscopic balloon dilation was performed six times on her. However, the stenosis still showed a trend of gradual aggravation. Because the patient did not undergo an enterostomy, the conventional endoscopic magnetic compression technique could not be performed. Hence, we implemented a Y-Z DMR implemented through the anus under single channel. The magnetic ring fell off nine days after the operation and the rectal stenosis was relieved. The patient was followed up for six months and reported good defecation. CONCLUSION: The Y-Z DMR deformable magnetic ring is an excellent treatment strategy for patients with rectal stenosis and without enterostomy.