The shortened radio frequency wavelength in high field MRI makes it challenging to create a uniform excitation pattern over a large field of view, or to achieve satisfactory transmission efficiency at a local area. Transmit arrays are one tool that can be used to create a desired excitation pattern. To be effective, it is important to be able to control the current amplitude and phase at the array elements. The control of the current may get complicated by the coil coupling in many applications. Various methods have been proposed to achieve current control, either in the presence of coupling, or by effectively decouple the array elements. These methods are applied in different subsystems in the RF transmission chain: coil; coil-amplifier interface; amplifier, etc. In this review paper, we provide an overview of the various approaches and aspects of transmit current control and decoupling.

Purpose Develop machine learning models utilizing computed tomography (CT) and the weishaupt grading criteria to assess the degeneration severity of facet joint of osteoarthritis (FJOA). Methods The machine learning model utilizes features extracted from patient Lumbar CT at the First People's Hospital of Nantong. Use 3D Slicer software to perform semi-automatic image segmentation on CT images and extract radiological features from the segmented regions. Preliminary screening of radiomic features extracted by radiomics using t-test and rank sum test with p<0.05 as the standard. Based on the core features selected by Lasso regression, construct random forest (RF), K-nearest neighbor (KNN), and support vector machine (SVM) models. Use receiver operating characteristic (ROC) curves to evaluate the model's performance, considering metrics such as accuracy, recall, precision, F1 score, and area under curve (AUC). Results The radiomics package of 3D Slicer extracted 1037 radiomic features from ROI. The T-test combined with rank sum test preliminarily screened 589 radiomics features with statistical differences. Subsequently, Lasso regression was used to identify 28 core features. Develop machine learning models based on 28 core feature selections of RF, SVM, and KNN. The AUCs of RF model, SVM model and KNN model in the training set were 0.783, 0.803 and 0.693 respectively, and those in the validation set were 0.699, 0.719 and 0.671 respectively. Conclusion The machine learning model utilizing lumbar CT images can effectively assess lumbar facet joint degeneration. Through this model, diseases can be classified and diagnosed, and doctors can develop personalized treatment plans.

There are debates in residual end preservation technique in anterior cruciate ligament reconstruction whether it would promote the bone-tendon healing, knee proprioception recovery, vascularization of synovial membrane and transplanted ligament. This article retrieved the literatures from January 2018 to September 2022, and provided induction, summary and discussion of the influence of residual preservation in anterior cruciate ligament reconstruction on bone tunnel, proprioception recovery, vascularization of synovial membrane and transplanted ligament, and early knee function recovery. Preservation residual anterior cruciate ligament reconstruction shows advantages in promoting early tendon bone healing and vascularization of synovial membrane and transplanted ligament, and is also conducive to the recovery of proprioception, which in turn accelerate the knee joint function recovery. Clinical doctors should base on the residual type of the anterior cruciate ligament rupture in patients, for patients who meet the conditions of residual reserves, surgeons shall retaine the tissue as far as possible during anterior cruciate ligament reconstruction.

目的:比较肌腱内贫白细胞的富血小板血浆(Lp-PRP)注射治疗与肩峰下皮质类固醇注射治疗对冈上肌部分撕裂后疼痛缓解、功能改善的效果以及并发症情况.方法:选取2020年4月至2022年3月深圳大学第一附属医院收治的60例冈上肌部分撕裂的患者,随机分为观察组(接受Lp-PRP注射)和对照组(接受皮质类固醇注射),各30例.在注射治疗前和注射治疗后1、6、12个月,评价两组患者的肩关节疼痛缓解、功能改善以及并发症发生情况,并进行比较.结果:两组患者治疗后的视觉模拟评分量表(VAS)评分均较治疗前显著降低,且观察组患者治疗后的VAS评分则呈持续下降趋势,改良版加州大学肩关节评分量表(UCLA)评分均较治疗前升高,差异均具有统计学意义(P＜0.05).治疗后6个月及12个月,观察组患者的VAS评分均较对照组更低,UCLA评分均较对照组更高,差异均具有统计学意义(P＜0.05).两组患者在随访的12个月期间均未出现严重并发症.结论:对冈上肌部分撕裂的患者使用皮质类固醇或Lp-PRP注射治疗后1个月的疼痛和功能改善效果情况相似,但治疗后6个月和12个月时,Lp-PRP治疗的临床结局优于皮质类固醇.

Anterior cruciate ligament injury is the most common sports injury in orthopaedics, which can adversely affect knee joint function and exercise of patients. Using arthroscopy to reconstruct the anterior cruciate ligament has become the first choice for treating anterior cruciate ligament rupture. However, different degrees of articular cartilage injury of the knee can be observed in patients after anterior cruciate ligament reconstruction. More importantly, the articular cartilage injury after anterior cruciate ligament reconstruction indicates that it will develop into osteoarthritis in the long term. It is of great significance to fully understand the factors that lead to the occurrence and development of cartilage injury. This article reviews the effects of surgical methods, meniscus status, different grafts, time from injury to surgical intervention, postoperative knee joint stability, postoperative rehabilitation, knee joint anatomical factors, and demographic characteristics of patients on articular cartilage degeneration after anterior cruciate ligament reconstruction. The present review provides insights into the anterior cruciate ligament reconstruction, which can be used to investigate new treatment strategies to delay and prevent the progress of osteoarthritis. At the same time, it provides a holistic understanding of the influence of multiple factors on cartilage lesions after anterior cruciate ligament reconstruction.

背景:膝关节内侧结构损伤是膝关节损伤中较为常见的损伤,常见损伤原因包括外翻暴力、旋转暴力.目前,临床上对于内侧副韧带(MCL)损伤的治疗仍存在争议.目的:发生前交叉韧带(ACL)损伤后,通过测量内侧关节间隙及膝关节外翻角大小,来评估MCL复合体对于膝关节稳定性的影响.方法:采用8例新鲜冰冻膝关节尸体进行试验.在膝关节屈曲0°、15°和30°时,使用力矩传感器机器人测试系统对标本进行生物力学测试.每具膝关节标本均经历以下3种状态:①ACL及MCL复合体完整;②ACL缺失,MCL复合体完整;③ACL及MCL复合体均缺失.将MCL复合体切断以模拟MCLⅢ级损伤.在给予外翻负荷的情况下,采用两种方法(透视、机器人检测系统)测量内侧关节间隙和外翻角.膝关节内侧间隙采用不透射线的直尺进行测量,外翻角采用Image J软件进行分析.结果:在膝关节屈曲0°、15°和30°时,ACL及MCL复合体均缺失的膝关节标本的内侧关节间隙和外翻角明显大于完整膝关节.在ACL及MCL复合体均缺失的状态下,随着屈膝角度的增大,内侧关节间隙及外翻角亦增大;在屈膝30°时,内侧间隙与外翻角最大.结论:临床随访过程中,对于ACL损伤或ACL损伤合并MCL损伤的患者应加拍屈膝30°位外翻应力位X线片以评估MCL损伤程度,为治疗方案的选择提供客观、有力的依据.

Frozen shoulder is a common shoulder disorder characterized by a gradual increase of pain and a limited range of motion. However, its pathophysiologic mechanisms remain unclear and there is no consensus as to the most effective treatment. The purpose of the study was to investigate the effect of transforming growth factor‐β (TGF‐β) on fibrosis and inflammatory response of the shoulder joint of rat models and to explore the therapeutic effect of the peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) agonist. In the study, the effect of PPAR‐γ agonist CDDO‐IM treatment on cell proliferation, migration, and extracellular matrix proteins synthesis (vimentin, α‐smooth muscle actin, collagen I, and collagen III) were tested by cell proliferation test, scratches test, real‐time quantitative polymerase chain reaction, and Western blot analysis. The frozen shoulder was also established on the rat model by injecting adenovirus‐TGF‐β1 into rats' shoulder capsule. Pathological changes of the frozen shoulder tissue of the experimental group and PPAR‐γ agonist treatment group were evaluated. The stiffness of joints of the three groups was tested. Inflammatory mediators' expression including cyclooxygenase‐1, interleukin‐1β, and tumor necrosis factor‐α of the shoulder was tested by enzyme‐linked immunosorbent assay, and the expression of extracellular matrix proteins was evaluated by hematoxylin and eosin staining and immunohistochemistry. The results showed that pathological changes of the frozen shoulder in the rat model include an abnormal proliferation of fibroblasts, infiltration of inflammatory cells, and disorder of fibrous structure, while rosiglitazone reduced the severity of the frozen shoulder in the treatment group. Clinically, PPAR‐γ agonists may be a promising target for the treatment of the frozen shoulder.

Abstract In this research, we successfully fabricated a novel closed pore polyacrylonitrile (PAN)/polyvinyl pyrrolidone (PVP) composite nanofibrous membrane (PCNM) on the substrate of a commercial polypropylene window mesh. First, smooth and uniform PAN/PVP composite nanofibers (PCNs) were manufactured by blending PAN and PVP with a mass ratio of 5:5 during electrospinning. Subsequently, the prepared PCNs were hot pressed in a vacuum drying oven at a given temperature of 90°C. The morphology and filter efficiency of PCN and PCNM were investigated. It was found that hot-pressing treatment significantly affected the pore structure and orientation of PCNM, which contributed to its closed pore structure and good alignment. The filter efficiency results indicated that the hot-pressed PCNMs have excellent removal efficiency of up to 96.8% of fine particulate matter. This research demonstrates that PCNMs have potential as filters for indoor dust removal and will provide a new idea for the development of air filters.

PurposeThis work describes the construction and evaluation of a bilateral 32‐channel receive array for breast imaging at 7T.MethodsThe receive array consisted of 32 receive coils, placed on two 3D‐printed hemispherical formers. Each side of the receive array consisted of 16 receive loops, each loop having a corresponding detachable board with match/tune capacitors, active detuning circuitry, and a balun. Coil performance was evaluated on homogeneous canola oil phantoms using a Philips Achieva 7T system. Array coil performance was compared with a bilateral forced current excitation volume coil in transmit/receive mode and with a previously reported 16‐channel unilateral coil with a similar design.ResultsThe 32‐channel array had an increase in average SNR throughout both phantoms by a factor of five as compared with the volume coil, with SNR increases up to 10 times along the periphery and three times in the center. Noise measurements showed low interelement noise correlation (average: 5.4%; maximum: 16.8%). Geometry factor maps were acquired for various acceleration factors and showed mean geometry factors <1.2, for combined acceleration factors of up to six.ConclusionsThe improvements achieved demonstrate the clear potential for use in dynamic contrast‐enhanced or diffusion‐weighted MR studies, while maintaining diagnostically relevant spatial and temporal resolutions.

Ultrahigh field imaging of the body and the spine is challenging due to the large field-of-view (FOV) required. It is especially difficult for RF transmission due to its requirement on both the length and the depth of the ${\rm{B}}_{1}^{{\rm + }}$ field. One solution is to use a long dipole to provide continuous current distribution. The drawback is the natural falloff of the ${\rm{B}}_{1}$ field toward the ends of the dipole, therefore the ${\rm{B}}_{1}^{{\rm + }}$ per unit square root of maximum specific absorption rate ${\rm{(B}}_{1}^{{\rm + }}{\rm{/ \surd SAR}}_{{\rm{max}}})$ performance is particularly poor toward the end of the dipole. In this study, a segmented element design using forced-current excitation and a switching circuit is presented. The design provides long FOV when desired and allows flexible FOV switching and power distribution without additional power amplifiers. Different element types and arrangements were explored and a segmented dipole design was chosen as the best design. The segmented dipole was implemented and tested on the bench and with a phantom on a 7T whole body scanner. The switchable mode dipole enabled a large FOV in the long mode and improved ${\rm{B}}_{1}^{{\rm + }}{\rm{/ \surd SAR}}_{{\rm{max}}}$ efficiency in a smaller FOV in the short mode.

肩周炎是一种常见的肩关节疾病,患者常出现疼痛及肩关节活动受限,也被称为冻结肩、五十肩.文献报道其地区发病率为2％～5％[1],集中发病年龄在55岁上下,且女性发病率高于男性,左肩发病率高于右肩.肩周炎的主要特征为:①患肢三角肌止点周围存在慢性隐痛;②患肢夜间疼痛明显,影响睡眠;③肩关节上举活动和外旋活动均受限;④正常X线片表现.关于肩周炎的病因和发病机制,尚未明确,但目前研究已经证实肩周炎的病理改变包括盂肱关节囊增厚,伴有部分挛缩,部分患者可伴有关节囊周围韧带组织弥漫性炎症及纤维化,从而导致肩关节主被动活动明显受限[2].笔者就肩周炎不同治疗方式对缓解疼痛、改善肩关节活动度的效果进行综述,报道如下.

过氧化物酶体增殖物激活受体(PPAR)主要由PPAR α、PPARγ和PPAR β/δ 3种亚型组成.PPAR在炎症和机体代谢的调节过程中均起到重要作用,因此,与骨关节炎的发生和发展密切相关.而PPAR作为重要的核受体转录因子,在干细胞和软骨细胞的诸多功能中都起到关键性的调节作用.该文对PPAR在骨关节炎和软骨组织工程中的研究进展作一综述.

Objective To assess the effect of the fusion of rabbit bone marrow stromal cells (rBMSCs) and Nano-hydroxyapatite/poly (l-lactic acid) (Nano-HA/PLLA) in repairing the rabbit knee joint with full-thickness cartilage defect. Method The rBMSCs were isolated and cultured in vitro, and the third generation of rBMSCs was co-cultured with the Nano-HA/PLLA to construct the tissue-engineered cartilage (TEC). Eighteen New Zealand white rabbits were selected and randomly divided into three groups, namely, TEC group, Nano-HA/PLLA group, and control group. A cartilage defect model with the diameter of 4.5 mm and depth of 5 mm was constructed on the articular surface of medial malleolus of rabbit femur. General observation, histological observation, and Wakitani’s histological scoring were conducted in the 12th and 24th week postoperatively. Results The results of TEC group indicated that new cartilage tissue was formed on the defect site and subchondral bone achieved physiological integration basically. Histological and immunohistochemical analyses indicated the generation of massive extracellular matrix. In contrast, limited regeneration and reconstruction of cartilage was achieved in the Nano-HA/PLLA group and control group, with a significant difference from the TEC group (p < 0.05). Moreover, the effect of cartilage repair was positively correlated with time. Conclusion The porous Nano-HA/PLLA combined with BMSCs promoted the repair of weight-bearing bone of adult rabbit’s knee joint with cartilage defect.

The present study aimed to investigate idiopathic adhesive capsulitis (frozen shoulder), to gain insights on its pathogenesis, diagnosis and therapeutic targets. Using RNA‑sequencing (seq), the present study investigated differentially expressed genes (DEGs) in five samples from five idiopathic adhesive capsulitis patients and two samples from two acromioclavicular dislocation patients, without idiopathic adhesive capsulitis. The DEGs were analyzed using the following tools: Gene Ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes pathways analysis and protein‑protein interaction analysis. A total of 188 DEGs were identified and it was observed that 150 of these were upregulated and 38 were downregulated. It was hypothesized that various nutrient associated proteins may be associated with idiopathic adhesive capsulitis. The Matrix metalloproteinase family of proteins (MMPs), may exhibit a key role in the formation of abnormal collagen cross‑links. Overall, the comprehensive and detailed information collected in the present study, regarding idiopathic adhesive capsulitis, may provide a foundation on which in‑depth follow‑up experiments may be based, aimed at identifying novel strategies for treatment of this disease.

Proximal humeral fractures are common and most challenging, due to the complexity of the glenohumeral joint, especially in the geriatric population with impacted fractures, that the development of implants continues because currently the problems with their fixation are not solved. Pre-, intra-, and postoperative assessments are crucial in management of those patients. Finite element analysis, as one of the valuable tools, has been implemented as an effective and noninvasive method to analyze proximal humeral fractures, providing solid evidence for management of troublesome patients. However, no review article about the applications and effects of finite element analysis in assessing proximal humeral fractures has been reported yet. This review article summarized the applications, contribution, and clinical significance of finite element analysis in assessing proximal humeral fractures. Furthermore, the limitations of finite element analysis, the difficulties of more realistic simulation, and the validation and also the creation of validated FE models were discussed. We concluded that although some advancements in proximal humeral fractures researches have been made by using finite element analysis, utility of this powerful tool for routine clinical management and adequate simulation requires more state-of-the-art studies to provide evidence and bases.

Objective: Total hip arthroplasty (THA) is associated with substantial blood loss. The objective of present systematic review and meta-analysis is to provide evidence from randomized controlled trials (RCTs) on the efficiency and safety of administration of fibrin sealant (FS) for reducing blood loss in patients undergoing primary THA.Methods: Potential relevant studies were identified from electronic databases including Medline, PubMed, Embase, ScienceDirect, web of science and Cochrane Library. Gray academic studies were also identified from the reference list of included studies. There was no language restriction. Pooling of data was carried out by using RevMan 5.1.Results: Six randomized controlled trials (RCTs) met the inclusion criteria. Current meta-analysis indicated that there were significant differences in terms of total blood loss (MD = -153.77, 95% CI: -287.21 to -20.34, P = 0.02), postoperative hemoglobin level (MD = -0.25, 95% CI: -0.46 to -0.05, P = 0.02) and transfusion rate (RD = -0.12, 95% CI: -0.22 to -0.03, P = 0.01) between groups. No significant differences were found regarding the incidence of deep venous thrombosis (DVT) (RD -0.00, 95% CI: -0.01 to 0.01, P = 0.51) or other side effects.Conclusion: Administration of fibrin sealant in total hip arthroplasty may reduce total blood loss, postoperative hemoglobin decline and transfusion requirements. Moreover, no adverse effect was related to FS. Due to the limited quality of the evidence currently available, higher quality RCTs are required. (C) 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Frozen shoulder is a chronic condition characterized by pain in the shoulder and restriction of movements in all directions. Some patients are left with long-term limitation of shoulder joint activity with various severities, which results in reduced quality of life. Currently, there is a paucity of literature on the molecular biology of frozen shoulder, and the molecular biological mechanism for periarthritis-induced limitation of shoulder joint movements remains unclear. Research in this field is focused on inflammation and cytokines associated with fibrosis. Repeated investigations confirmed alterations of specified inflammatory mediators and fibrosis-associated cytokines, which might be involved in the pathogenesis of frozen shoulder by causing structural changes of the shoulder joint and eventually the limitation of shoulder movements. The aim of this article is to review studies on molecular biology of frozen shoulder and provide a reference for subsequent research, treatment, and development of new drugs.

The transforming growth factor β1 (TGFβ1) plays an important role in cartilage development. However, whether TGFβ1 stimulates chondrocyte proliferation and cartilage regeneration in osteoarthritis (OA) remains elusive, especially in the context of different treatment and tissue environments. In the present study, we investigated the role of TGFβ1 in human chondrocyte culture in vitro, focusing on the morphological change of chondrocytes and the expression of angiogenic factors upon TGFβ1 stimulation. We found increased expression of biomarkers indicating chondrocyte hypertrophy and the chondrocytes aggregated to form networks when they were treated with TGFβ1. DNA microarray analysis revealed significantly increased expression of genes related to blood vessel formation in TGFβ1 treatment group compared to control group. Matrigel assay further demonstrated that chondrocytes had the potential to form network-like structure. These results suggested that TGFβ1 induces the hypertrophic change of chondrocytes culture in vitro and induce expression of angiogenic biomarkers. Therefore, application of TGFβ1 for chondrocyte culture in practice should be considered prudentially and targeting TGFβ1 or relevant receptors to block the signaling pathway might be a strategy to prevent or alleviate progression of osteoarthritis.

BACKGROUND:By mixing technology, various materials are mixed and complemented each other to enhance heat sensitivity, mechanical properties, viscoelasticity of the materials and improve their biocompatibility, biodegradability and other biomedical properties.OBJECTIVE:To prepare polyvinyl alcohol (PVA)/chitosan (CS) porous hydrogel and to observe its effects on the repair of articular cartilage defects.METHODS: PVA, CS and polysorbate-80 were used as raw materials to prepare the hydrogels at the PVA/CS ratio of 5:5, 6:4, 7:3, 8:2 and 9:1 by freezing-thawing cycle and emulsification-frostice phase separation, and the physical and chemical properties, mechanical properties, and biocompatibility of the hydrogels were detected to find out the best PVA/CS ratio. Eighteen New Zealand rabbits were enroled to make models of bilateral articular cartilage defects, and then randomized into three groups: blank control group; control group; experimental group. The prepared hydrogel was compounded with rabbit bone marrow mesenchymal stem cells (BMSCs) and then implanted into the rabbit articular cartilage defect in the experimental group, the PVA/CS hydrogel was implanted in the control group, and nothing was implanted in the blank control group. After 12 weeks, the animals were killed and the repairing effect was observed by gross observation and histological examination.RESULTS AND CONCLUSION:The PVA/CS porous composite hydrogel was successfully prepared, and PVA:CS=6:4 was the best in the presence of good mechanical properties, stable physical and chemical properties, and water content≥ 90%. In additional, scanning electron microscopy showed a porous network structure, with the porosity≥ 90%. The results of cell counting kit-8 assay and the results of cell death and survival showed that the hydrogel was non-cytotoxic and beneficial to the cell proliferation. In the blank control group, knee articular cartilage defects were not repaired within 12 weeks after surgery, showing significant granulation tissue filling. In the control group, knee articular cartilage defects were full of cartilage-like tissues with no smooth surface, but there were a great amount of chondrocyte-like cells. In the experimental group, knee articular cartilage defects were well repaired and full of a great amount of chondrocytes with the smooth surface. To conclude, the PVA/CS porous composite hydrogel could repair articular cartilage defects as an ideal tissue-engineered cartilage material.