Rapid Colorimetric Detection of Cartap Residues by AgNP Sensor with Magnetic Molecularly Imprinted Microspheres as Recognition Elements.

The overuse of cartap in tea tree leads to hazardous residues threatening human health. A colorimetric determination was established to detect cartap residues in tea beverages by silver nanoparticles (AgNP) sensor with magnetic molecularly imprinted polymeric microspheres (Fe3O4@mSiO2@MIPs) as recognition elements. Using Fe3O4 as supporting core, mesoporous SiO2 as intermediate shell, methylacrylic acid as functional monomer, and cartap as template, Fe3O4@mSiO2@MIPs were prepared to selectively and magnetically separate cartap from tea solution before colorimetric determination by AgNP sensors. The core-shell Fe3O4@mSiO2@MIPs were also characterized by FT-IR, TEM, VSM, and experimental adsorption. The Fe3O4@mSiO2@MIPs could be rapidly separated by an external magnet in 10 s with good reusability (maintained 95.2% through 10 cycles). The adsorption process of cartap on Fe3O4@mSiO2@MIPs conformed to Langmuir adsorption isotherm with maximum adsorption capacity at 0.257 mmol/g and short equilibrium time of 30 min at 298 K. The AgNP colorimetric method semi-quantified cartap ≥5 mg/L by naked eye and quantified cartap 0.1⁻5 mg/L with LOD 0.01 mg/L by UV-vis spectroscopy. The AgNP colorimetric detection after pretreatment with Fe3O4@mSiO2@MIPs could be successfully utilized to recognize and detect cartap residues in tea beverages.

Experimental and theoretical insights into palladium-mediated polymerization of para-N,N-disubstituted aminostyrene.

Experimental and theoretical insights into polymerization of para-N,N-disubstituted aminostyrene monomers (St-4-NR2, R = Me, Et, Ph) using cationic α-diimine palladium complexes have been initially reported. The effects of the catalyst structure and monomer substituent were studied systematically. Polymerization turnover frequency (TOF) was shown to decrease in the order of monomer substituents Me > Et > Ph, whereas the molecular weight of the produced polymers showed an opposite trend (Me < Et < Ph). Methanol-mediated polymerization of para-N,N-dimethylaminostyrene (DMAS), along with polymer chain-end analysis, and palladium intermediate isolation proved that palladium-initiated DMAS polymerization obeyed a cationic mechanism. Comprehensive theoretical calculations further revealed that the carbocation was generated from the insertion of DMAS into the palladium center rather than the polarization of the methyl palladium intermediate with a coordinated DMAS. The produced amine-functionalized amorphous polystyrenes have low stereoregularity and exhibit good hydrophilic properties. The poly(para-N,N-disphenylaminostyrene) is a luminescent polymer and shows fluorescence properties, rendering this material a promising candidate for versatile potential applications.

[Clinical application of Fastpass Scorpion suture passer for arthroscopic Bankart repair].

Objective: To explore the effectiveness and advantages of using Fastpass Scorpion suture passer to stitch the inferior capsulolabral complex in arthroscopic Bankart repair compared with traditional arthroscopic suture shuttle. Methods: The clinical data of 41 patients with Bankart lesion, who met the selection criteria and were admitted between August 2019 and October 2021, was retrospectively analyzed. Under arthroscopy, the inferior capsulolabral complex was stitched with Fastpass Scorpion suture passer in 27 patients (FS group) and with arthroscopic suture shuttle in 14 patients (ASS group). There was no significant difference between the two groups ( P>0.05) in gender, age, injured side, frequency of shoulder dislocation, time from first dislocation to operation, and preoperative Rowe score of shoulder. Taking successful suture and pull-tightening as the criteria for completion of repair, the number of patients that were repaired at 5∶00 to 6∶00 (<6:00) and 6∶00 to 7∶00 positions of the glenoid in the two groups was compared. The operation time, and the difference of Rowe shoulder score betwee pre- and post-operation, the occurrence of shoulder joint dislocation, the results of apprehension test, and the constituent ratio of recovery to the pre-injury movement level between the two groups at 1 year after operation. Results: Both groups completed the repair at 5∶00 to 6∶00 (<6∶00), and the constituent ratio of patients completed at 6∶00 to 7∶00 was significantly greater in the FS group than in the ASS group ( P<0.05). The operation time was significantly shorter in the FS group than in the ASS group ( P<0.05). All incisions in the two groups healed by first intention. All patients were followed up 12-36 months (mean, 19.1 months). No anchor displacement or neurovascular injury occurred during follow-up. Rowe score of shoulder in the two groups significantly improved at 1 year after operation than preoperative scores ( P<0.05), and there was no significant difference in the difference of Rowe shoulder score between pre- and post-operation between the two groups ( P>0.05). At 1 year after operation, no re-dislocation occurred, and there was no significant difference in the apprehension test and the constituent ratio of recovery to the pre-injury movement level between the two groups ( P>0.05). Conclusion: Compared with the arthroscopic suture shuttle, using Fastpass Scorpion suture passer to stitch the inferior capsulolabral complex in arthroscopic Bankart repair is more convenient, saves operation time, and has good effectiveness.

Tears of the Popliteomeniscal Fascicles of the Lateral Meniscus: An Arthroscopic Classification.

OBJECTIVE: To bring forward an arthroscopic classification of the popliteomeniscal fascicles of the lateral meniscus (PFLM) tears. DESIGN: Six fresh frozen knee joint samples of adult males were chosen, and the lateral meniscus at the popliteal hiatus region were measured to analyze their anatomic relationship. Patients who had received magnetic resonance imaging scan at knee joint before the surgery and diagnosed as PFLM tears by arthroscopy from April 2014 to October 2017 were selected. Data regarding the integrity of PFLM were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos. RESULTS: The average length and thickness of the popliteal hiatus of the lateral meniscus were 2.09 ± 0.21 cm and 0.43 ± 0.08 cm, respectively. The average length of anterosuperior popliteomeniscal fascicle (APF) was 0.87 ± 0.18 cm, and the posterosuperior popliteomeniscal fascicle (PPF) was 0.72 ± 0.15 cm. A total of 36 PFLM tears in 36 patients were divided as type I (APF tear; n = 5, 13.9%), type II (PPF tear; n = 20, 55.6%), and type III (both APF and PPF tears; n = 11, 30.6%). All patients were treated with arthroscopic all-inside repair using a suture hook for the PFLM tears and follow-up for 21.1 months. All patients have done well with significantly improved Lysholm and International Knee Documentation Committee scores at the last follow-up relative to preoperative scores (P < 0.01). CONCLUSION: This study suggests to possibly classify the PFLM tears for clinical practice.

The Chinese Knot Stitch Technique Using a Footprint Ultrasuture Anchor for Rotator Cuff Repair.

Management of the rotator cuff presents specific challenges to orthopaedic surgeons. Several locking suture methods have been reported but often fail for a number of reasons. We describe a different technique that is easy to perform and inspired by the Chinese knot, an arthroscopic double-locking suture using a footprint ultrasuture anchor. This technique is similar to the suture-bridge structure on the bursal side of the tendon in that it increases tissue grip and stabilizes initial tendon-to-bone fixation. This technique is especially suitable for the patients who have bursal-side partial-thickness or degenerative small- and medium-sized rotator cuff tears.