Design and synthesis of the superionic conductor Na10SnP2S12.

Sodium-ion batteries are emerging as candidates for large-scale energy storage due to their low cost and the wide variety of cathode materials available. As battery size and adoption in critical applications increases, safety concerns are resurfacing due to the inherent flammability of organic electrolytes currently in use in both lithium and sodium battery chemistries. Development of solid-state batteries with ionic electrolytes eliminates this concern, while also allowing novel device architectures and potentially improving cycle life. Here we report the computation-assisted discovery and synthesis of a high-performance solid-state electrolyte material: Na10SnP2S12, with room temperature ionic conductivity of 0.4 mS cm(-1) rivalling the conductivity of the best sodium sulfide solid electrolytes to date. We also computationally investigate the variants of this compound where tin is substituted by germanium or silicon and find that the latter may achieve even higher conductivity.

Clinical results of arthroscopic superior capsule reconstruction for irreparable rotator cuff tears.

PURPOSE: The objective of this study was to investigate the clinical outcome and radiographic findings after arthroscopic superior capsule reconstruction (ASCR) for symptomatic irreparable rotator cuff tears. METHODS: From 2007 to 2009, 24 shoulders in 23 consecutive patients (mean, 65.1 years) with irreparable rotator cuff tears (11 large, 13 massive) underwent ASCR using fascia lata. We used suture anchors to attach the graft medially to the glenoid superior tubercle and laterally to the greater tuberosity. We added side-to-side sutures between the graft and infraspinatus tendon and between the graft and residual anterior supraspinatus/subscapularis tendon to improve force coupling. Physical examination, radiography, and magnetic resonance imaging (MRI) were performed before surgery; at 3, 6, and 12 months after surgery; and yearly thereafter. Average follow-up was 34.1 months (24 to 51 months) after surgery. RESULTS: Mean active elevation increased significantly from 84° to 148° (P < .001) and external rotation increased from 26° to 40° (P < .01). Acromiohumeral distance (AHD) increased from 4.6 ± 2.2 mm preoperatively to 8.7 ± 2.6 mm postoperatively (P < .0001). There were no cases of progression of osteoarthritis or rotator cuff muscle atrophy. Twenty patients (83.3%) had no graft tear or tendon retear during follow-up (24 to 51 months). The American Shoulder and Elbow Surgeons (ASES) score improved from 23.5 to 92.9 points (P < .0001). CONCLUSIONS: ASCR restored superior glenohumeral stability and function of the shoulder joint with irreparable rotator cuff tears. Our results suggest that this reconstruction technique is a reliable and useful alternative treatment for irreparable rotator cuff tears. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Functional and structural outcomes of single-row versus double-row versus combined double-row and suture-bridge repair for rotator cuff tears.

BACKGROUND: Although previous biomechanical research has demonstrated the superiority of the suture-bridge rotator cuff repair over double-row repair from a mechanical point of view, no articles have described the structural and functional outcomes of this type of procedure. HYPOTHESIS: The structural and functional outcomes after arthroscopic rotator cuff repair may be different between the single-row, double-row, and combined double-row and suture-bridge (compression double-row) techniques. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: There were 206 shoulders in 201 patients with full-thickness rotator cuff tears that underwent arthroscopic rotator cuff repair. Eleven patients were lost to follow-up. Sixty-five shoulders were repaired using the single-row, 23 shoulders using the double-row, and 107 shoulders using the compression double-row techniques. Clinical outcomes were evaluated at an average of 38.5 months (range, 24-74 months) after rotator cuff repair. Postoperative cuff integrity was determined using Sugaya's classification of magnetic resonance imaging (MRI). RESULTS: The retear rates after arthroscopic rotator cuff repair were 10.8%, 26.1%, and 4.7%, respectively, for the single-row, double-row, and compression double-row techniques. In the subcategory of large and massive rotator cuff tears, the retear rate in the compression double-row group (3 of 40 shoulders, 7.5%) was significantly less than those in the single-row group (5 of 8 shoulders, 62.5%, P < .001) and the double-row group (5 of 12 shoulders, 41.7%, P < .01). Postoperative clinical outcomes in patients with a retear were significantly lower than those in patients without a retear for all 3 techniques. CONCLUSION: The additional suture bridges decreased the retear rate for large and massive tears. The combination of the double-row and suture-bridge techniques, which had the lowest rate of postoperative retear, is an effective option for arthroscopic repair of the rotator cuff tendons because the postoperative functional outcome in patients with a retear is inferior to that without retear.

Response of rabbit skeletal muscle to tibial lengthening.

BACKGROUND: Experimental and clinical studies have provided knowledge regarding osteogenesis during limb lengthening. However, response of skeletal muscle to limb lengthening is not fully understood, especially as concerns histogenesis. We studied the morphological response of rabbit skeletal muscle to limb lengthening. In this study, we investigated proliferation of satellite cells, responsible for generation of new myonuclei, during limb lengthening. METHODS: Tibialis anterior muscles of young and adult rabbits were subjected to lengthening at a rate of 0.5 mm twice per day for 20 days. After lengthening, muscle wet weight was measured to assess skeletal muscle growth, then proliferating cell nuclear antigen was measured. Immunostaining was performed to analyze proliferating cells in the proximal, middle, and distal portions of the muscle belly and the musculotendinous junction. RESULTS: Muscle wet weight increased significantly after lengthening both in adult (0.4 g) and young (0.1 g) rabbits. Satellite cells showed proliferation in response to lengthening. In adult rabbits, satellite cell proliferation increased along the entire lengthened muscle to a similar degree (from 7.1% in the middle portion to 8.6% in the musculotendinous junction). In young rabbits, proliferation was greater in the musculotendinous junction (4.8%) than that in other muscle portions (2.3% in the middle and distal portions, and 2.4% in the proximal portion). In adult rabbits, the rate of increase in satellite cell proliferation was 1780% in the middle portion to 2860% in the musculotendinous junction, whereas the rate was between 210% in the middle portion and 290% in the distal portion in young rabbit. The rate of increase in cell proliferation by lengthening was higher in adult muscle than that in young muscles as well as satellite cell proliferation. CONCLUSION: These findings indicate that limb lengthening promotes muscle growth in both young and adult rabbits.