Click Chemistry in Lithium-Metal Batteries.

Lithium-metal batteries (LMBs) are considered the "holy grail" of the next-generation energy storage systems, and solid-state electrolytes (SSEs) are a kind of critical component assembled in LMBs. However, as one of the most important branches of SSEs, polymer-based electrolytes (PEs) possess several native drawbacks including insufficient ionic conductivity and so on. Click chemistry is a simple, efficient, regioselective, and stereoselective synthesis method, which can be used not only for preparing PEs with outstanding physical and chemical performances, but also for optimizing the stability of solid electrolyte interphase (SEI) layer and elevate the cycling properties of LMBs effectively. Here it is primarily focused on evaluating the merits of click chemistry, summarizing its existing challenges and outlining its increasing role for the designing and fabrication of advanced PEs. The fundamental requirements for reconstructing artificial SEI layer through click chemistry are also summarized, with the aim to offer a thorough comprehension and provide a strategic guidance for exploring the potentials of click chemistry in the field of LMBs.

Fascia Lata Autografts Achieve Interface Healing With the Supraspinatus Muscle Histologically and Mechanically in a Rat Supraspinatus Tendon Reconstruction Model for Massive Irreparable Rotator Cuff Tears.

PURPOSE: To evaluate the histologic healing process and mechanical characteristics of the interface between a fascia lata autograft and supraspinatus muscle by establishing a supraspinatus tendon reconstruction model for chronic massive irreparable rotator cuff tears (MIRCTs). METHODS: A total of 40 rats were studied. Eight rats were killed to establish an intact control group, and the other rats were first established as a chronic MIRCT model and then developed as the supraspinatus tendon reconstruction model. Histology, fatty infiltration, mechanics, and open field test for the interface between the fascia lata autograft and muscle were assessed at 2, 4, 8, and 16 weeks postoperatively. RESULTS: Histologically, the interface between the fascia lata autograft and muscle gradually regenerated structural characteristics similar to the normal muscle-tendon interface by 16 weeks postoperatively. The amount of collagen I and III increased significantly during the healing time and stabilized at 8 weeks postoperatively. Fatty infiltration was obvious in the supraspinatus muscle 4 weeks after establishing the MIRCT model. However, the degree of fatty infiltration in the supraspinatus muscle gradually decreased after supraspinatus tendon reconstruction and stabilized at 8 weeks postoperatively. The ultimate failure force and ultimate stress gradually increased from 2 to 16 weeks and reached the level of the intact control tendon at 16 weeks postoperatively (P = .086). The movability of the forepaw returned to normal in the open field test (P = .907). CONCLUSIONS: In this rat supraspinatus tendon reconstruction model, fascia lata autografts showed good interface healing with the supraspinatus muscle, and fatty infiltration in the supraspinatus muscle was histologically decreased. The interface between the fascia lata autograft and muscle showed mechanical strength similar to the anatomic muscle-tendon interface. CLINICAL RELEVANCE: A supraspinatus tendon reconstruction technique using fascia lata autografts might be a good histologic and biomechanical option for treating MIRCTs.

Intelligent decision method for stability assessment of shield tunnel based on multi-objective data mining.

Due to improper operation of the shield construction process and unknown geological surveys, shield construction faces many risks in passing through complex strata, among which the excavation face instability is the most serious, potentially leading to disastrous accidents. To address these issues, this research focuses on the limit support pressure and the excavation face stability in the soil when crossing the Yangtze River. First, an analytical formula for the limit support pressure of the excavation face is established through the wedge model. The support safety coefficient is used to assess the excavation face stability quantitatively. Then the rough set algorithm is used to analyse the sensitivity of each index to establish the reduced evaluation index system for the excavation face stability. The back propagation (BP) neural network is used to train the learning data, and a neural network evaluation model with a prediction error of 5.7675 × 10-4 is established. The prediction performance of BP is verified by comparison with the TOPSIS prediction model and the cloud model. The evaluation method proposed in this paper provides an essential reference for evaluating the underwater shield tunnel excavation face stability. This article is part of the theme issue 'Artificial intelligence in failure analysis of transportation infrastructure and materials'.

Histologic and biomechanical evaluation of the thoracolumbar fascia graft for massive rotator cuff tears in a rat model.

BACKGROUND: Fascial autografts, which are easily available grafts, have provided a promising option in patients with massive rotator cuff tears. However, no fascial autografts other than the fascia lata have been reported, and the exact healing process of the fascia-to-bone interface is not well understood. The objective of this study is to histologically and biomechanically evaluate the effect of the thoracolumbar fascia (TLF) on fascia-to-bone healing. METHODS: A total of 88 rats were used in this study. Eight rats were killed at the beginning to form an intact control group, and the other rats were divided randomly into 2 groups (40 rats per group): the TLF augmentation group (TLF group) and the repair group (R group). The right supraspinatus was detached, and a 3 × 5 mm defect of the supraspinatus was created. The TLF was used to augment the torn supraspinatus in the TLF group, whereas in the R group, the torn supraspinatus was repaired in only a transosseous manner. Histology and biomechanics were assessed at 1, 2, 4, 8, and 16 weeks postoperatively. RESULTS: The modified tendon maturation score of the TLF group was higher than that of the R group at 8 weeks (23.00 ± 0.71 vs. 24.40 ± 0.89, P = .025) and 16 weeks (24.60 ± 0.55 vs. 26.40 ± 0.55, P ≤ .001). The TLF group showed a rapid vascular reaction, and the peak value appeared at 1 week. Later, the capillary density decreased, and almost no angiogenesis was observed at 8 weeks postoperatively. Immunohistochemistry results demonstrated a significantly higher percentage of collagen I in the TLF group at 4, 8, and 16 weeks (24.78% ± 2.76% vs. 20.67% ± 2.11% at 4 weeks, P = .046; 25.46% ± 1.77% vs. 21.49% ± 2.33% at 8 weeks, P = .026; 34.77% ± 2.25% vs. 30.01% ± 3.17% at 16 weeks, P = .040) postoperatively. Biomechanical tests revealed that the ultimate failure force in the TLF group was significantly higher than that in the R group at the final evaluation (29.13 ± 2.49 N vs. 23.10 ± 3.47 N, P = .022). CONCLUSIONS: The TLF autograft can promote a faster biological healing process and a better fixation strength. It could be used as an alternative reinforcement or bridging patch when the fascia lata is not appropriate or available for superior capsule reconstruction (SCR).

Effects of aging on the histology and biochemistry of rat tendon healing.

INTRODUCTION: Tendon diseases and injuries are a serious problem for the aged population, often leading to pain, disability and a significant decline in quality of life. The purpose of this study was to determine the influence of aging on biochemistry and histology during tendon healing and to provide a new strategy for improving tendon healing. METHOD: A total of 24 Sprague-Dawley rats were equally divided into a young and an aged group. A rat patellar tendon defect model was used in this study. Tendon samples were collected at weeks 2 and 4, and hematoxylin-eosin, alcian blue and immunofluorescence staining were performed for histological analysis. Meanwhile, reverse transcription-polymerase chain reaction (RT-PCR) and western blot were performed to evaluate the biochemical changes. RESULTS: The histological scores in aged rats were significantly lower than those in young rats. At the protein level, collagen synthesis-related markers Col-3, Matrix metalloproteinase-1 and Metallopeptidase Inhibitor 1(TIMP-1) were decreased at week 4 in aged rats compared with those of young rats. Though there was a decrease in the expression of the chondrogenic marker aggrecan at the protein level in aged tendon, the Micro-CT results from weeks 4 samples showed no significant difference(p>0.05) on the ectopic ossification between groups. Moreover, we found more adipocytes accumulated in the aged tendon defect with the Oil Red O staining and at the gene and protein levels the markers related to adipogenic differentiation. CONCLUSIONS: Our findings indicate that tendon healing is impaired in aged rats and is characterized by a significantly lower histological score, decreased collagen synthesis and more adipocyte accumulation in patellar tendon after repair.

Aspirin promotes tenogenic differentiation of tendon stem cells and facilitates tendinopathy healing through regulating the GDF7/Smad1/5 signaling pathway.

Tendinopathy is a common musculoskeletal system disorder in sports medicine, but regeneration ability of injury tendon is limited. Tendon stem cells (TSCs) have shown the definitive treatment evidence for tendinopathy and tendon injuries due to their tenogenesis capacity. Aspirin, as the representative of nonsteroidal anti-inflammatory drugs for its anti-inflammatory and analgestic actions, has been commonly used in treating tendinopathy in clinical, but the effect of aspirin on tenogenesis of TSCs is unclear. We hypothesized that aspirin could promote injury tendon healing through inducing TSCs tenogenesis. The aim of the present study is to make clear the effect of aspirin on TSC tenogenesis and tendon healing in tendinopathy, and thus provide new treatment evidence and strategy of aspirin for clinical practice. First, TSCs were treated with aspirin under tenogenic medium for 3, 7, and 14 days. Sirius Red staining was performed to observe the TSC differentiation. Furthermore, RNA sequencing was utilized to screen out different genes between the induction group and aspirin treatment group. Then, we identified the filtrated molecules and compared their effect on tenogenesis and related signaling pathway. At last, we constructed the tendinopathy model and compared biomechanical changes after aspirin intake. From the results, we found that aspirin promoted tenogenesis of TSCs. RNA sequencing showed that growth differentiation factor 6 (GDF6), GDF7, and GDF11 were upregulated in induction medium with the aspirin group compared with the induction medium group. GDF7 increased tenogenesis and activated Smad1/5 signaling. In addition, aspirin increased the expression of TNC, TNMD, and Scx and biomechanical properties of the injured tendon. In conclusion, aspirin promoted TSC tenogenesis and tendinopathy healing through GDF7/Smad1/5 signaling, and this provided new treatment evidence of aspirin for tendinopathy and tendon injuries.

Aspirin inhibits adipogenesis of tendon stem cells and lipids accumulation in rat injury tendon through regulating PTEN/PI3K/AKT signalling.

Tendon injury repairs are big challenges in sports medicine, and fatty infiltration after tendon injury is very common and hampers tendon injury healing process. Tendon stem cells (TSCs), as precursors of tendon cells, have shown promising effect on injury tendon repair for their tenogenesis and tendon extracellular matrix formation. Adipocytes and lipids accumulation is a landmark event in pathological process of tendon injury, and this may induce tendon rupture in clinical practice. Based on this, it is important to inhibit TSCs adipogenesis and lipids infiltration to restore structure and function of injury tendon. Aspirin, as the representative of non-steroidal anti-inflammatory drugs (NSAIDs), has been widely used in tendon injury for its anti-inflammatory and analgesic actions, but effect of aspirin on TSCs adipogenesis and fatty infiltration is still unclear. Under adipogenesis conditions, TSCs were treated with concentration gradient of aspirin. Oil red O staining was performed to observe changes of lipids accumulation. Next, we used RNA sequencing to compare profile changes of gene expression between induction group and aspirin-treated group. Then, we verified the effect of filtrated signalling on TSCs adipogenesis. At last, we established rat tendon injury model and compared changes of biomechanical properties after aspirin treatment. The results showed that aspirin decreased lipids accumulation in injury tendon and inhibited TSCs adipogenesis. RNA sequencing filtrated PTEN/PI3K/AKT signalling as our target. After adding the signalling activators of VO-Ohpic and IGF-1, inhibited adipogenesis of TSCs was reversed. Still, aspirin promoted maximum loading, ultimate stress and breaking elongation of injury tendon. In conclusion, by down-regulating PTEN/PI3K/AKT signalling, aspirin inhibited adipogenesis of TSCs and fatty infiltration in injury tendon, promoted biomechanical properties and decreased rupture risk of injury tendon. All these provided new therapeutic potential and medicine evidence of aspirin in treating tendon injury and tendinopathy.

Exosomes from tendon stem cells promote injury tendon healing through balancing synthesis and degradation of the tendon extracellular matrix.

Tendon injuries are common musculoskeletal system disorders in clinical, but the regeneration ability of tendon is limited. Tendon stem cells (TSCs) have shown promising effect on tissue engineering and been used for the treatment of tendon injury. Exosomes that serve as genetic information carriers have been implicated in many diseases and physiological processes, but effect of exosomes from TSCs on tendon injury repair is unclear. The aim of this study is to make clear that the effect of exosomes from TSCs on tendon injury healing. Exosomes were harvested from conditioned culture media of TSCs by a sequential centrifugation process. Rat Achilles tendon tendinopathy model was established by collagenase-I injection. This was followed by intra-Achilles-tendon injection with TSCs or exosomes. Tendon healing and matrix degradation were evaluated by histology analysis and biomechanical test at the post-injury 5 weeks. In vitro, TSCs treated with interleukin 1 beta were added by conditioned medium including exosomes or not, or by exosomes or not. Tendon matrix related markers and tenogenesis related markers were measured by immunostaining and western blot. We found that TSCs injection and exosomes injection significantly decreased matrix metalloproteinases (MMP)-3 expression, increased expression of tissue inhibitor of metalloproteinase-3 (TIMP-3) and Col-1a1, and increased biomechanical properties of the ultimate stress and maximum loading. In vitro, conditioned medium with exosomes and exosomes also significantly decreased MMP-3, and increased expression of tenomodulin, Col-1a1 and TIMP-3. Exosomes from TSCs could be an ideal therapeutic strategy in tendon injury healing for its balancing tendon extracellular matrix and promoting the tenogenesis of TSCs.

Self-Healing Polymer Electrolytes Formed via Dual-Networks: A New Strategy for Flexible Lithium Metal Batteries.

A novel polymer electrolyte with mechanically robust and self-healing properties was fabricated through a dual-network structure, crosslinked by quadruple hydrogen bonding and chemical bonding. The dynamic ureido-pyrimidinone (UPy) dimers were the first network in the polymer matrix. This group endows the polymer electrolyte with good self-healing capacity and improves the reliability and lifetime of the polymer lithium batteries. The crosslinked polyethylene glycol-bis-carbamate dimethacrylate (PEGBCDMA) is the second network and guarantees dimensional stability and good mechanical properties of the polymer electrolyte. The dual-network self-healing polymer electrolyte (DN-SHPE) exhibits improved ionic conductivity versus the polymer electrolyte fabricated by poly(ethylene glycol) diacrylate (PEGDA). It has high thermal stability (up to 350 °C) and excellent interfacial stability with the electrodes. When the DN-SHPE-based cells were fabricated with LiFePO4 and Li metal, the resulting cells show good reversible specific capacity and considerable rate capability. Moreover, the pouch cell could maintain electrochemical function even under deformation or folding conditions.

Interleukin-15 facilitates muscle regeneration through modulation of fibro/adipogenic progenitors.

BACKGROUND: Chronic muscle injury is characteristics of fatty infiltration and fibrosis. Recently, fibro/adipogenic progenitors (FAPs) were found to be indispensable for muscular regeneration while were also responsible for fibrosis and fatty infiltration in muscle injury. Many myokines have been proven to regulate the adipose or cell proliferation. Because the fate of FAPs is largely dependent on microenvironment and the regulation of myokines on FAPs is still unclear. We screened the potential myokines and found Interleukin-15 (IL-15) may regulate the fatty infiltration in muscle injury. In this study, we investigated how IL-15 regulated FAPs in muscle injury and the effect on muscle regeneration. METHODS: Cell proliferation assay, western blots, qRT-PCR, immunohistochemistry, flow cytometric analysis were performed to investigate the effect of IL-15 on proliferation and adipogensis of FAPs. Acute muscle injury was induced by injection of glycerol or cardiotoxin to analyze how IL-15 effected on FAPs in vivo and its function on fatty infiltration or muscle regeneration. RESULTS: We identified that the expression of IL-15 in injured muscle was negatively associated with fatty infiltration. IL-15 can stimulate the proliferation of FAPs and prevent the adipogenesis of FAPs in vitro and in vivo. The growth of FAPs caused by IL-15 was mediated through JAK-STAT pathway. In addition, desert hedgehog pathway may participate in IL-15 inhibiting adipogenesis of FAPs. Our study showed IL-15 can cause the fibrosis after muscle damage and promote the myofiber regeneration. Finally, the expression of IL-15 was positively associated with severity of fibrosis and number of FAPs in patients with chronic rotator cuff tear. CONCLUSIONS: These findings supported the potential role of IL-15 as a modulator on fate of FAPs in injured muscle and as a novel therapy for chronic muscle injury.

Classification of Calcaneal Spurs and Their Relationship With Plantar Fasciitis.

Calcaneal spurs, as a cause of plantar fasciitis, are currently debatable. A prospective study was performed to classify calcaneal spurs according to the findings from an investigation of the relationship between calcaneal spurs and plantar fasciitis. Thirty patients with calcaneal spurs and plantar heel pain underwent calcaneal spur removal and endoscopic plantar fasciotomy. The relationship between the classification of calcaneal spurs and plantar fasciitis was evaluated by endoscopic findings, clinical symptoms, radiographic images, and biopsy findings. The visual analog scale for pain and the American Orthopedic Foot and Ankle Society ankle-hindfoot scores for functional evaluation were used preoperatively and postoperatively, respectively. The mean follow-up period was 24 months. Two separate types of calcaneal spurs were recognized. Type A calcaneal spurs were located superior to the plantar fascia insertion, and type B calcaneal spurs were located within the plantar fascia. Magnetic resonance imaging results showed a more severe plantar fasciitis grade in type B calcaneal spurs preoperatively. Histologic examination showed that the numbers of granulocytes per image in type B spurs were significantly increased compared with those in type A spurs. Statistically significant improvements were found in the mean visual analog scale and American Orthopedic Foot and Ankle Society scores and magnetic resonance imaging results in both groups. The amount of change in the visual analog scale score and American Orthopedic Foot and Ankle Society score, the number of granulocytes per image, and calcaneal spur length showed a high association with the classification of the calcaneal spurs. Calcaneal spurs were completely removed and did not recur in any of the patients on radiographic assessment during the follow-up period. Calcaneal spurs can be classified into 2 distinct types that are indicative of the severity of plantar fasciitis.

[Clinical efficacy of subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws].

OBJECTIVE: To explore the clinical efficacy of subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws for severe subtalar joint arthritis. METHODS: A total of 88 patients with 90 feet underwent subtalar joint fusion under four different incisions from April 2008 to April 2012. There were 56 males and 32 females with a mean age of 43.7 (15-74) years. All of them were evaluated by radiography or computed tomography (CT) scan and assessed by the rating scores of visual analog scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS). RESULTS: Among them, 68 cases were followed up for an average of 18.5 (6-48) months. Fusion was confirmed on radiography or CT in 67 cases with a fusion rate of 98.5%. The mean duration of fusion was 13.8 (6-28) weeks, the mean VAS score decreased from 6.00 to 1.03 points (P < 0.05) and the mean AOFAS score improved from 57.0 to 80.6 points (P < 0.05) with a good-and-excellent rate of 80.8%. CONCLUSION: Subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws is recommend for severe subtalar joint arthritis. Such a procedure has a high fusion rate, excellent clinical outcomes and fewer complications.

Clinical effectiveness of supraspinatus tendon reconstruction using autogenous fascia latas for irreparable posterosuperior massive rotator cuff tears: study protocol for a randomized, controlled clinical trial.

BACKGROUND: Supraspinatus tendon reconstruction (STR) was recently introduced as a new treatment option for irreparable posterosuperior massive rotator cuff tears (IPMRCT). STR was thought to be more advantageous than superior capsule reconstruction (SCR) for restoring supraspinatus (SSP) dynamics. However, there has been no prospective randomized controlled study on the early clinical efficacy of STR. METHODS: A single-site, prospective, observers and patients double-blinding randomized controlled trial was designed. Fifty-eight patients aged 50-85 years with IPMRCT will be randomized 1:1 to receive either STR or SCR. The clinical outcomes were evaluated using the American Society for Shoulder and Elbow Surgery (ASES) score, range of motion (ROM), visual analogue scale (VAS) for pain, acromiohumeral distance (AHD), Goutlliar grade for fatty infiltration in the SSP, Sugaya grade for the autogenous fascia latas, isokinetic muscle strength testing and surface electromyography (EMG) testing for shoulder abduction muscle strength and complications. DISCUSSION: The results of this study will contribute to the treatment algorithm of IPMRCT and assist surgeons in making treatment decisions. This is the first randomized controlled trial to compare the effects of STR and SCR for the treatment of IPMRCT. TRIAL REGISTRATION: We registered the trial in chictr.org.cn on July 17, 2023 (register number: ChiCTR2300073716). Items from the WHO trial registry were found within the protocol.

A new method for subsea tunnel site selection based on environmental bearing capacity.

Engineering site selection is an essential and systematic work in the early engineering construction stage. At present, the subsea tunnel site selection mainly depends on manual experience. There is still a lack of subsea tunnel site selection systems based on environmental impact. This study develops a comprehensive site selection evaluation system based on the analytic hierarchy process (AHP) and fuzzy evaluation method for the subsea tunnel site selection. It is a multi-indicator mathematical model evaluation system. On this basis, the ecological site selection method of the subsea tunnel is further studied, an indicator system for evaluating the environmental carrying capacity of the island is established, and the site selection results of the subsea tunnel based on the environmental indicators are obtained. We compared the site selection results of the two methods. The results show that the conventional method and the ecological site selection method based on environmental indicators can well carry out the site selection of subsea tunnels. The two methods take into account both the overall and local optimum of the subsea tunnel route and organically combine the overall and local objectives. This way provides a reference for the design and construction of the subsea tunnel in the future and points out the direction for the site selection of other large-scale projects with significant environmental impact.

Dynamic Superior Capsular Reconstruction for Irreparable Massive Rotator Cuff Tears: Histologic Analysis in a Rat Model and Short-term Clinical Evaluation.

BACKGROUND: Superior capsular reconstruction (SCR) has been demonstrated to be a valuable treatment for patients with irreparable massive rotator cuff tears (IMRCTs). However, the torn medial supraspinatus (SSP) tendons, which acted as dynamic stabilizers, were left untreated in conventional SCR, and the dynamic force from the SSP tendon was not restored. PURPOSE: To evaluate the effect of dynamic SCR (dSCR) on fascia-to-bone healing in a rat model, and to compare the short-term clinical effectiveness of dSCR and SCR using autologous fascia lata (FL) in patients with IMRCTs. STUDY DESIGN: Controlled laboratory study and cohort study; Level of evidence, 3. METHODS: A total of 50 rats were divided randomly into 2 groups: the dSCR group and the SCR group (25 rats per group). First, chronic IMRCTs were created, and then the torn tendons in both groups were subjected to SCR using autologous thoracolumbar fascial (TLF) grafts. The remnant of the SSP tendon was sutured to the medial part of the TLF graft in the dSCR group but not in the SCR group. Histologic sections were assessed at 1, 2, 4, 8, and 16 weeks postoperatively. In the clinical study, 22 patients (9 SCR, 13 dSCR) were analyzed. The recovery of shoulder function, including the active range of motion (ROM), visual analog scale (VAS), American Shoulder and Elbow Surgeons score, Constant score, and University of California Los Angeles score, acromiohumeral distance (AHD), and fatty infiltration, was evaluated before surgery and at the last follow-up. RESULTS: Histologic analysis of the fascia-to-bone junction in the rat model showed that the TLF gradually migrated into tendon-like tissue over the rotator cuff defects in both groups, and the modified tendon maturation score of the fascia-to-bone interface in the dSCR group was higher than that in the SCR group at 4 weeks (12.20 ± 1.30 vs 14.60 ± 1.52; P = .004), 8 weeks (19.60 ± 1.14 vs 22.20 ± 1.10; P = .019), and 16 weeks (23.80 ± 0.84 vs 26.20 ± 0.84 P = .024). The dSCR group showed earlier fibrocartilage cell formation and angiogenesis. In the clinical study, all 22 patients completed a minimum of 12 months of follow-up after surgery, and the mean follow-up duration was 22.89 ± 7.59 months in the SCR group and 25.62 ± 7.32 months in the dSCR group. The patients in both groups showed significant improvements in terms of ROM, shoulder function scores, and AHD. At the last follow-up, abduction (56.67°± 27.39° vs 86.54°± 30.37°; P = .029), external rotation (25.00°± 9.35° vs 33.08°± 8.55°; P = .049), internal rotation cone rank (-2.78 ± 2.44 vs -4.38 ± 1.12; P = .049), VAS (-3.00 ± 0.87 vs -3.92 ± 0.95; P = .031) and Constant (47.89 ± 15.39 vs 59.15 ± 9.74; P = .048) scores, and the AHD improvement degree (3.06 ± 1.41 mm vs 4.38 ± 1.35 mm; P = .039) in the dSCR group were significantly improved compared with those in the SCR group. The results of fatty infiltration at the last follow-up showed that there was significant improvement compared with the preoperative results in both the conventional SCR (P = .036) and the dSCR (P = .001) groups. However, there were no significant differences between the 2 groups (P = .511). CONCLUSION: dSCR can promote faster fascia-to-bone healing in a rat model, and the dSCR technique could provide a preferable treatment option for patients with IMRCTs. CLINICAL RELEVANCE: dSCR might restore the dynamic of SSP in some sense and then improve the fatty infiltration in the SSP.

Integrative single-cell RNA and ATAC sequencing reveals that the FOXO1-PRDX2-TNF axis regulates tendinopathy.

Introduction: Tendinopathy, the most common form of chronic tendon disorder, leads to persistent tendon pain and loss of function. Profiling the heterogeneous cellular composition in the tendon microenvironment helps to elucidate rational molecular mechanisms of tendinopathy. Methods and results: In this study, through a multi-modal analysis, a single-cell RNA- and ATAC-seq integrated tendinopathy landscape was generated for the first time. We found that a specific cell subpopulation with low PRDX2 expression exhibited a higher level of inflammation, lower proliferation and migration ability, which not only promoted tendon injury but also led to microenvironment deterioration. Mechanistically, a motif enrichment analysis of chromatin accessibility showed that FOXO1 was an upstream regulator of PRDX2 transcription, and we confirmed that functional blockade of FOXO1 activity induced PRDX2 silencing. The TNF signaling pathway was significantly activated in the PRDX2-low group, and TNF inhibition effectively restored diseased cell degradation. Discussion: We revealed an essential role of diseased cells in tendinopathy and proposed the FOXO1-PRDX2-TNF axis is a potential regulatory mechanism for the treatment of tendinopathy.

Supraspinatus Tendon Reconstruction Using Fascia Lata Autograft for Irreparable Posterosuperior Massive Rotator Cuff Tears.

Superior capsule reconstruction has shown good long-term clinical efficacy in treating irreparable posterosuperior massive rotator cuff tears. However, conventional superior capsule reconstruction did not treat the medial supraspinatus tendons. Therefore, dynamic function of the posterosuperior rotator cuff does not restore effectively, especially the function of active abduction and external rotation. We describe a supraspinatus tendon reconstruction technique that presents a stepwise approach to accomplish the dual goals of stable anatomic reconstruction and restoring the dynamic function of the supraspinatus tendon.

PPP1R3A inhibits osteogenesis and negatively regulates intracellular calcium levels in calcific tendinopathy.

Calcific tendinopathy (CT) is defined by the progressive accumulation of calcium crystals in tendonic regions that results in severe pain in patients. The etiology of CT is not fully elucidated. In this study, we elucidate the role of PPP1R3A in CT. A significant decrease in PPP1R3A expression was observed in CT patient tissues, which was further confirmed in tissues from a CT-induced rat model. Overexpression of PPP1R3A ex vivo reduced the expression of osteo/chondrogenic markers OCN and Sox9, improved tendon tissue architecture, and reduced intracellular Ca2+ levels. Overexpression of SERCA2 and knockdown of Piezo1 decreased expression of osteo/chondrogenic markers and intracellular calcium in PPP1R3A-knockdown tendon cells. Lastly, PPP1R3A expression was regulated at the posttranscriptional level by binding of HuR. Collectively, the present study indicates that PPP1R3A plays an important role in regulating calcium homeostasis in tendon cells via Piezo1/SERCA2, rendering it a promising target for therapeutic interventions of CT.

[Percutaneous achilles tendon lengthening through double hemisection in the treatment of achilles contracture syndrome].

OBJECTIVE: To explore the surgical approach of percutaneous double hemisection and evaluate its clinical efficacies. METHODS: From May 2006 to November 2011, a total of 59 patients were recruited. There were 36 males and 21 females with a mean age of 38.2 years (range: 8 - 62). Forty-two varus and 6 valgus feet underwent percutaneous double hemisection. The 0.5 cm coracoid incision was adopted at the medial and lateral aspects of Achilles tendon. Percutaneous double hemisection was employed according to the deformity angles of varus and valgus feet. Manipulative correction was applied slowly until 30° dorsiflexion of ankle. Short leg cast was immobilized for 5 weeks at 30° dorsiflexion of ankle. The force of Achilles tendon, motion of ankle and Hannover Achilles tendon scores were followed up. RESULTS: Fifty-two patients were followed up for a mean period of 16.5 months (range: 6 - 60). Seven patients were lost. At the end of follow-up, 48 patients with varus and valgus deformities were corrected effectively. When compared with the normal side, the force of Achilles of the operated side of 50 patients had no change while that of 2 patients decreased slightly; the motion of ankle joint increased from (2.8 ± 0.3)° preoperatively to (28.5 ± 1.4)° postoperatively (P < 0.05); the Hannover Achilles Tendon Scores rose from (68.5 ± 3.5) preoperatively to (82.6 ± 4.2) points postoperatively (P < 0.05). The outcomes were excellent (n = 44), very good (n = 5), good (n = 2) and poor (n = 1). The excellent and good rate was 94.2%. CONCLUSION: As an effective therapy for Achilles tendon contracture syndrome, percutaneous double hemisection has fewer complications and a faster recovery.

[Rebalancing theory of shoulder stability mechanism for the diseases related to the shoulder instability and dysfunction of motion].

Objective: To introduce a new theory of shoulder stability mechanism, rebalancing theory, and clinical application of this new theory for the shoulder instability and dysfunction of motion. Methods: Through extensive review of the literature related to shoulder instability and dysfunction of the motion in recent years, combined with our clinical practice experience, the internal relation between passive stability mechanism and dynamic stability mechanism were summarized. Results: Rebalancing theory of shoulder stability mechanism is addressed, namely, when the shoulder stability mechanism is destructive, the stability of the shoulder can be restored by the rebalance between dynamic stability mechanism and passive stability mechanism. When dynamic stability is out of balance, dynamic stability can be restored by rebalancing the different parts of dynamic stability mechanism or to strengthen the passive stability mechanism. When passive stability mechanism is out of balance, passive stability can be restored by rebalancing the soft tissue and bone of the shoulder. Conclusion: Rebalancing theory of shoulder stability mechanism could make a understanding the occurrence, development, and prognosis of shoulder instability and dysfunction from a comprehensive and dynamic view and guide the treatment effectively.