Experimental Investigation on Magnetic Abrasive Finishing for Internal Surfaces of Waveguides Produced by Selective Laser Melting.

To enhance the surface quality of metal 3D-printed components, magnetic abrasive finishing (MAF) technology was employed for post-processing polishing. Experimental investigation employing response surface methodology was conducted to explore the impact of processing gap, rotational speed of the magnetic field, auxiliary vibration, and magnetic abrasive particle (MAP) size on the quality enhancement of internal surfaces. A regression model correlating roughness with crucial process parameters was established, followed by parameter optimization. Ultimately, the internal surface finishing of waveguides with blind cavities was achieved, and the finishing quality was comprehensively evaluated. Results indicate that under optimal process conditions, the roughness of the specimens decreased from Ra 2.5 µm to Ra 0.65 µm, reflecting a reduction rate of 74%. Following sequential rough and fine processing, the roughnesses of the cavity bottom, side wall, and convex surface inside the waveguide reduced to 0.59 µm, 0.61 µm, and 1.9 µm, respectively, from the original Ra above 12 µm. The findings of this study provide valuable technical insights into the surface finishing of metal 3D-printed components.

Natural and engineered xylosyl products from microbial source.

Glycosylation is a prevalent post-modification found in natural products and has a significant impact on the structural diversity and activity variation of natural products. Glucosylation is the most common type of glycosylation, whereas xylosylation is relatively rare. Despite their unique chemical structures and beneficial activities, xylosylated natural products from microorganisms have received little attention. This review provides, for the first time, a comprehensive summary of 126 microbial-derived xylosylated natural products, including xylosyl-cyathane diterpenes, xylosylated triterpenes, xylosyl aromatic compounds, and others. Among these compounds, xylosyl-cyathane diterpenes represent the highest number of derivatives, followed by xylosylated triterpenes. Xylosyl compounds from bacterial sources have less defined structural profiles compared to those from fungi. The characterization of xylosyltransferase EriJ from Basidiomycota extended the structural diversity of xylosyl cyathane diterpenes. This work provides a valuable reference for the research and use of xylosyltransferase for drug discovery and synthetic chemistry. Further work is needed to explore the potential applications of microbial derived xylosyl compounds and to develop novel xylosyl transferases. With the deepening of genomic sequencing of medicinal fungi, more biosynthesis of bioactive xylosyl compounds is expected to be elucidated in the future.

Secondary Metabolites of Bird's Nest Fungi: Chemical Structures and Biological Activities.

Bird's nest fungi, a general term for species in the family Nidulariaceae, are named for their fruiting bodies that resemble bird's nests. Two of their members, Cyathus stercoreus (Schw.) de Toni. and Cyathus striatus Will. ex Pers., are known as medicinal fungi in Chinese medicine. Bird's nest fungi produce a variety of secondary metabolites that provide natural materials for screening and developing medicinal compounds. This review presents a systematic summary of the literature on the secondary metabolites of bird's nest fungi up to January 2023, including 185 compounds, mainly cyathane diterpenoids, with prominently characterized antimicrobial and antineurodegenerative activities. Our work aims to advance our understanding of bird's nest fungi and support studies on their natural product chemistry, pharmacology, and biosynthesis of secondary metabolites.

Observation of the clinical efficacy of percutaneous reduction by leverage combined with intramedullary nail internal fixation in the treatment of irreducible femoral intertrochanteric fracture: a retrospective single-arm cohort study.

Background: There are few reports on the efficacy and safety of percutaneous lever reduction combined with intramedullary nailing in the treatment of irreducible functional intertrochanteric fracture. This study was designed to investigate the clinical effect of percutaneous reduction by leverage combined with intramedullary nail internal fixation in the treatment of irreducible femoral intertrochanteric fracture. Methods: A total of 26 patients with irreducible femoral intertrochanteric fracture admitted to Qilu Hospital were included in this study, including 10 males and 16 females. All fractures were reduced through an incision made at the insertion point of the intramedullary nail head or the main nail with the aid of auxiliary equipment such as a periosteal dissector or a bone-holding forcep. Indicators such as operative time, blood loss, and complications were recorded, and the quality of fracture reduction was evaluated by the Baumgaetner modified method. All the patients were followed up regularly for 3 months, 1 year, and 2 years postoperatively, and the Zuckerman Functional Recovery Scale (FRS) for Hip Fracture was utilized to evaluate the hip function of the patients. The Euro-Quality of Life-5 Dimension (EQ-5D) was used to evaluate the quality of life of patients. Hip pain was assessed by the visual analog scale (VAS) at the last follow-up. Results: According to the Evans-Jensen classification of fractures, 12 cases were classified as type III, 10 as type IV, and 4 as type V. The mean operation time was 67.9±16.4 min and the intraoperative blood loss was 165.8±58.3 mL. All fractures healed completely. In terms of fracture reduction quality, 14 cases were excellent and 11 cases were good. At the last follow-up, the FRS scores decreased from 93.3±5.7 preoperatively to 81.5±18.5 postoperatively, and the EQ-5D index decreased from 0.95±0.05 preoperatively to 0.86±0.14 postoperatively. Conclusions: With mini-incision assisted reduction combined with intramedullary nail internal fixation to treat of irreducible femoral intertrochanteric fracture, favorable clinical results can be obtained, and the walking ability and quality of life of the patients can be improved postoperatively.

Percutaneous Cerclage Wiring Combined with Cephalomedullary Nailing for Irreducible Subtrochanteric Fractures.

OBJECTIVE: To explore the surgical method, operation essentials and the clinical effect of the treatment of irreducible subtrochanteric femoral fractures by percutaneous cerclage wiring and Cephalomedullary nail. METHOD: From February 2016 to October 2019, 17 cases of irreducible subtrochanteric femoral fractures (SFFs) treated via a minimally invasive wire system and intramedullary nail fixation were reviewed retrospectively. Ten male and seven female patients were involved. The average age was 59.88 ± 16.13 years, ranging from 41 to 94 years. Among the patients, seven were injured in traffic accidents, five fell from a standing height, and five injured themselves from falling. The cases were classified based on the Seinsheimer classification. Specifically, five cases were type IIIA, five cases were type IIIB, one case was type IV, and six cases were type V. According to the AO/OTA classification, 10 cases were 32B3, and seven cases were 32C3. During surgery, the patients were placed on a traction bed andattempted closed reduction. For those patients whose closed reduction failed confirmed by fluoroscopy, we performed a small anterolateral incision through which a self-made minimally invasive percutaneous wire introducer (passer; patent Z: 2016 2 1002800.8) was employed for temporary fixation with a wire. A double-stranded steel wire was introduced into a self-made wire traction and lifting device (patent ZL 2020 2 0205658.7), the wire was pulled vertically and firmly fixed. Then an long InterTan nail was used for the fixation. The following information was recorded: (i) length of the invasive incision, (ii) blood loss on the third day after surgery, (iii) operation time; and (iv) maximum displacement and angulation of the fracture ends of the x-rayed front and side fractures before and after surgery and the maximum displacement and formation of the three-dimensional CT-scanned fracture ends in the coronal plane, sagittal plane, and cross section before and after surgery. RESULT: A total of 15 of the 17 patients were followed for 12 to 24 months. The 15 patients recovered, but one died from pulmonary infection 1 year after surgery. In the postoperative X-ray and three-dimensional CT observation reduction treatment, fracture displacement was less than 5 mm, each plane angle was less than 10 degrees, and postoperative fracture healing time was 3 to 14 months, with an average of 4.19 ± 4.04 months. The postoperative Harris hip function score ranged from 66 to 95 points, with an average of 80.81 ± 9.67 points. In terms of clinical outcomes, 11 cases were excellent, four cases were satisfactory, and one case was fair. CONCLUSION: For refractory subtrochanteric fractures, percutaneous wiring combined with Cephalomedullary nail fixation is a minimally invasive, rapid, and effective method, which can achieve satisfactory results in clinical practice and is worth promoting.