Clinical Outcomes of Superior Capsular Reconstruction for Massive, Irreparable Rotator Cuff Tears: A Systematic Review Comparing Acellular Dermal Allograft and Autograft Fascia Lata

Purpose: To investigate clinical outcomes after superior capsular reconstruction (SCR) for the treatment of massive and/or irreparable rotator cuff tears treated with either allograft or autograft. Methods: Using the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines, in April 2020 a systematic review was performed using PubMed, MEDLINE, EMBASE, and Cochrane databases. Clinical studies were assessed for patient-reported outcomes and range of motion, comparing dermal allografts to fascia lata autografts, with a minimum follow-up of 12 months. Results: A total of 16 clinical studies involving 598 patients (606 shoulders) were included for data analysis, with a weighted mean follow-up of 36.9 months (range 12 to 60). Visual analogue scale (VAS) pain scores decreased from 4.0 to 6.9 mm preoperatively to 0 to 2.5 mm postoperatively. American Shoulder & Elbow Surgeons score increased from 20.3 to 54.5 preoperatively to 73.7 to 97.0 postoperatively. Forward flexion increased from 27.0° to 142.7° preoperatively to 134.5° to 167.0° postoperatively. External rotation increased from 13.2° to 41.0° preoperatively to 30.0° to 59.0° postoperatively. Acromiohumeral distance increased from 3.4 to 7.1 mm preoperatively to 6.0 to 9.7 mm postoperatively. The total rates of complications, graft failure, and revision surgery were 5.6%, 13.9%, and 6.9%, respectively. Conclusions: Irrespective of tissue source, SCR serves as a reasonable joint-preserving option for massive, irreparable rotator cuff tears, with favorable short- to midterm improvements in patient-reported outcomes and range of motion. Level of Evidence: IV, systematic review of level III and IV studies

Assessment of trace metal contamination in a historical freshwater canal (Buckingham Canal), Chennai, India

The present study was done to assess the sources and the major processes controlling the trace metal distribution in sediments of Buckingham Canal. Based on the observed geochemical variations, the sediments are grouped as South Buckingham Canal and North Buckingham Canal sediments (SBC and NBC, respectively). SBC sediments show enrichment in Fe, Ti, Mn, Cr, V, Mo, and As concentrations, while NBC sediments show enrichment in Sn, Cu, Pb, Zn, Ni, and Hg. The calculated Chemical Index of Alteration and Chemical Index of Weathering values for all the sediments are relatively higher than the North American Shale Composite and Upper Continental Crust but similar to Post-Archaean Average Shale, and suggest a source area with moderate weathering. Overall, SBC sediments are highly enriched in Mo, Zn, Cu, and Hg (geoaccumulation index (Igeo) class 4– 6), whereas NBC sediments are enriched in Sn, Cu,Zn, and Hg (Igeo class 4–6). Cu, Ni, and Cr show higher than Effects-Range Median values and hence the biological adverse effect of these metals is 20%; Zn, which accounts for 50%, in the NBC sediments, has a more biological adverse effect than other metalsfound in these sediments. The calculated Igeo, Enrichment Factor, and Contamination Factor values indicate that Mo, Hg, Sn, Cu, and Zn are highly enriched in the Buckingham Canal sediments, suggesting the rapid urban and industrial development of Chennai MetropolitanCity have negatively influenced on the surrounding aquatic ecosystem

Thermoreversible Gels of Poly(l‑lactide)/Poly(d‑lactide) Blends: A Facile Route to Prepare Blend α‑Form and Stereocomplex Aerogels

The demand for biodegradable polymer-based aerogels with superior comprehensive properties has escalated in various fields of application, such as packaging, tissue engineering, thermal insulation, acoustic insulation, and environmental remediation. In this work, we report a facile strategy for enhancing the thermal and mechanical properties of polylactide (PLA) aerogels through the stereocomplex (SC) formation between the opposite enantiomers. Thermoreversible gelation of poly(l-lactide) (PLLA)/poly(d-lactide) (PDLA) blend in crystal complex forming solvent and the subsequent thermal annealing of the gel resulted in crystalline pure SC gel, which, upon solvent exchange with water and freeze-drying, furnished robust SC aerogel. It was found that the SC content could be tuned by varying the annealing temperature of the blend gel and that we could prepare blend aerogels with pure α crystalline form and a mixture of α and SC. Crystalline pure blend α aerogel showed fibrillar morphology, whereas SC aerogel exhibited unique interwoven ball-like microstructures interconnected by PLLA and PDLA chains. The structural evolution during SC formation at the molecular level and the micrometer length scale instigated better properties in the PLA aerogels. When compared with the homopolymer aerogels, the crystalline pure SC aerogel showed an enhanced melting temperature of 227 ± 2 °C (50 °C higher), better thermal stability (onset of degradation was delayed by ∼40 °C), enhanced mechanical strength (compression modulus of 3.3 MPa), and better sound absorption ability. The biodegradability of PLA and the superior properties induced by stereocomplexation make these aerogels potential candidates for applications such as tissue engineering scaffolds, packaging, acoustic insulation, etc

High-Performance Flexible Piezoelectric Nanogenerator Based on Electrospun PVDF-BaTiO₃ Nanofibers for Self-Powered Vibration Sensing Applications

In the present era of intelligent electronics and Internet of Things (IoT), the demand for flexible and wearable devices is very high. Here, we have developed a high-output flexible piezoelectric nanogenerator (PENG) based on electrospun poly(vinylidene fluoride) (PVDF)-barium titanate (BaTiO3) (ES PVDF-BT) composite nanofibers with an enhanced electroactive phase. On addition of 10 wt % BaTiO3 nanoparticles, the electroactive β-phase of the PVDF is found to be escalated to ∼91% as a result of the synergistic interfacial interaction between the tetragonal BaTiO3 nanoparticles and the ferroelectric host polymer matrix on electrospinning. The fabricated PENG device delivered an open-circuit voltage of ∼50 V and short-circuit current density of ∼0.312 mA m–2. Also, the PVDF-BT nanofiber-based PENG device showed an output power density of ∼4.07 mW m–2, which is 10 times higher than that of a pristine PVDF nanofiber-based PENG device. Furthermore, the developed PENG has been newly demonstrated for self-powered real-time vibration sensing applications such as for mapping of mechanical vibrations from faulty CPU fans, hard disk drives, and electric sewing machines