Metal-organic framework modified carbon cloth for electric field enhanced thin film microextraction of sulfonamides in animal-derived food.

Sulfonamides (SAs) were widespread in animal-derived food at trace level, which could trigger hazards to human health. Herein, electric field enhanced thin-film microextraction (EE-TFME) was developed based on carbon cloth (CC) modified with metal-organic frameworks (MOFs) for extraction of SAs (sulfadiazine, sulfathiazole, sulfamerazine, sulfadimidine, sulfamethoxazole and sulfisoxazole), which were a series of polar analytes. MIL-101(Cr) was in situ synthesized on CC via hydrothermal reaction and then was used as positive electrode in EE-TFME for adsorption of SAs. Compared with traditional TFME, EE-TFME shortened extraction equilibrium time from 30 min to 15 min. Coupled with high-performance liquid chromatography (HPLC), the limits of detection (LODs) were 2.5-4.5 µg/L, while the repeatability and intermediate precision was lower than 9.1%. Quantitative determination of SAs in extracts of animal-derived samples, such as honey, pork, chicken and milk, was achieved with recoveries from 81.7% to 114.2%. The developed MOF/CC-based EE-TFME has a great potential in rapid extraction of similar polar or ionic analytes from complex food matrices.

Collaborative compounding of metal-organic frameworks for dispersive solid-phase extraction HPLC-MS/MS determination of tetracyclines in honey.

Metal-organic frameworks (MOFs), a sort of dispersive solid-phase extraction (d-SPE) material, has shown considerable prospects in the pretreatment of food, biological and other complex samples. Herein, we developed a method for compounding MOFs for d-SPE and trace determination of tetracyclines (TCs) in honey. When the compounding ratio of MIL-101 (Cr), MIL-100 (Fe) and MIL-53 (Al) was 7:1:2, adsorption-extraction was effective. Followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the limits of detection were 0.073-0.435 ng/g and the limits of quantitation ranged from 0.239 to 1.449 ng/g for oxytetracycline, tetracycline, chlortetracycline and doxycycline. The method was applied to four kinds of honey samples with recoveries from 88.1% to 126.2%. The compounding of MOFs provides a strategy for purification and multi-target extraction from complex food matrices by d-SPE.

Transforaminal Resection of Cervical Dumbbell Schwannomas in Patients with Additional Tumors.

BACKGROUND: It is rare for 2 primary tumors to occur simultaneously in a patient. Management of cervical dumbbell schwannomas (CDSs) with concurrent tumors (CTs) requires a specific neurosurgical strategy. The primary objective of this study is to investigate surgical strategies for CDSs with CTs while preserving as much of the mechanically relevant bone structures as possible. METHODS: Twelve patients with concurrent CTs and CDSs were identified from 3 medical centers. Surgical strategies for CDSs were based on accurate preoperative images and subsequent treatment considerations for CTs. All patients received surgical treatment for CDSs and CTs. Clinical features, surgical considerations for a transforaminal approach (TA), and ultimate outcome were studied retrospectively. RESULTS: Gross total resection of CDSs was achieved with endoscopic and microscopic assistance in 9 cases, and subtotal resection was achieved in 3 cases after the head and neck surgeons exposed and removed the extraforaminal anatomy. One patient required an additional hemilaminectomy for the resection of the intraspinal segment. After wound healing, patients were transferred to the appropriate surgical department for surgery on CTs with cervical spine stabilization after a transforaminal approach. CONCLUSIONS: In most patients, the stability of the cervical spine can be preserved with low invasive microsurgical or endoscopic transforaminal resection. CTs could be surgically treated sequentially after microscopic- and endoscopic-assisted resection of CDSs.

[Influence of healing process of extraction on related growth factors in microscrew-bone interface of implanted titanium microscrews near the extraction wounds].

OBJECTIVE: To detect the expression of growth factors relating to bone reconstructions in microscrew-bone interface of implanted titanium microscrews near the extraction wounds, and to determine the influence of healing process on the growth factors. METHODS: Eight male Beagle dogs (age 18 months) were divided into experimental and control groups. Titanium microscrews were implanted near an extraction wound in the dogs in the experimental group, while the controls had implantation without extraction wounds. The dogs were sacrificed at 1, 3, 8, 12 weeks, respectively. Immunohistochemistry and in situ hybridization sections were performed to detect the expression of TGF-beta, TNF-alpha, osteocalcin (OC) protein and Cbfal mRNA. RESULTS: The experimental group had higher levels of expression of TGF-beta, TNF-alpha protein and Cbfa1 mRNA than the controls, with significant differences appearing at week one for TNF-alpha (P<0.05), week three for TGF-beta and TNF-alpha (P<0.05), and week eight for Cbfa1 mRNA (P<0.05). The expression of OC increased over time and reached peak at week eight (P<0.05). CONCLUSION: Microscrews implanted near extraction wounds can maintain stability. Severe inflammation occurs in the early stage of healing, but does not sustain. Bone remodeling remains active over the healing process. But prolonged healing phase without force loading could weaken the remodeling.