[Analysis of Delayed Hemolytic Transfusion Reaction in Children with Repeated Blood Transfusion].

Objective: To summarize and analyze the characteristics of delayed hemolytic transfusion reaction in children, in order to provide a scientific basis for clinical prevention, and ensure the safety of children's blood transfusion.

Methods: The basic situation, clinical symptoms and signs, diagnosis time and disappearance time of alloantibody of delayed hemolytic transfusion reaction in children were retrospectively analyzed. The serological test, routine blood test, biochemical detection and urine analysis results were compared pre- and post-transfusion.

Effects on Mass Transfer in the Bone Lacunar-Canalicular System under Different Radial Extracorporeal Shock Waves.

Background: The bone lacunar-canalicular system (LCS) is an important microscopic infrastructure for signaling and solute transport in bone tissue, which guarantees the normal physiological processes of bone tissue, and there is a direct relationship between osteoporosis and intrabody mass transfer; however, the mass transfer pattern of the LCS has not yet been clarified under different intensities of in extracorporeal shock waves. The present study aims to assess the effect of extracorporeal shock waves on mass transfer in LCS.

Methods: Sodium fluorescein tracer was taken as the transport substance, and the fluorescence intensities of osteocytes at lacuna in bovine cortical bone were used to indicate the mass transfer effect.

Treadmill exercise promotes bone tissue recovery in rats subjected to high + Gz loads.

Introduction: High + Gz loads, the gravitational forces experienced by the body in hypergravity environments, can lead to bone loss in pilots and astronauts, posing significant health risks.

Materials And Methods: To explore the effect of treadmill exercise on bone tissue recovery, a study was conducted on 72 male Wistar rats. These rats were subjected to four weeks of varying levels of periodic high + Gz loads (1G, 8G, 20G) experiments, and were subsequently divided into the treadmill group and the control group.

[Effects of removing superficial layer of cartilage on the surface morphology and mechanical behavior of cartilage].

Superficial cartilage defect is an important factor that causes osteoarthritis. Therefore, it is very important to investigate the influence of superficial cartilage defects on its surface morphology and mechanical properties. In this study, the knee joint cartilage samples of adult pig were prepared, which were treated by enzymolysis with chymotrypsin and physical removal with electric friction pen, respectively.

Hypergravity stimulates mechanical behavior and micro-architecture of tibia in rats.

Introduction: The bone tissue is susceptible to hypergravity (+ G) environment. It is necessary to discuss the extent to which specific + G values are beneficial or detrimental to bone tissue. The objective of this study was to characterize the effects of high + G values on mechanical properties, microstructures, and cellular metabolism of bone.

First report of successful treatment of chronic pediatric tibial osteomyelitis and fracture using autologous platelet-rich plasma.

Osteomyelitis is a refractory disease caused by microbial invasion of the bone, leading to destruction of the bone tissue. It is more common in children. Osteomyelitis requires long treatment at high cost and is associated with high rates of recurrence and disability.

Parametric optimization of culture chamber for cell mechanobiology research.

Mechanical signals influence the morphology, function, differentiation, proliferation, and growth of cells. Due to the small size of cells, it is essential to analyze their mechanobiological responses with an mechanical loading device. Cells are cultured on an elastic silicone membrane substrate, and mechanical signals are transmitted to the cells by the substrate applying mechanical loads.

Irrigating degradation properties of silk fibroin-collagen type II composite cartilage scaffold in vitro and in vivo.

Silk fibroin-collagen type II scaffolds are promising in cartilage tissue engineering due to their suitable biological functionality to promote proliferation of chondrocytes in vitro. However, their degradation properties, which are of crucial importance as scaffold degradation should consistent with the new tissue formation process, are still unknown. In this study, degradability of silk fibroin-collagen type II cartilage scaffolds was probed both in vitro and in vivo.

Creep-recovery behaviors of articular cartilage under uniaxial and biaxial tensile loadings.

Creep deformation in cartilage can be observed under physiological loads in daily activities such as standing, single-leg lunge, the stance phase of gait. If not fully recovered in time, it may induce irreversible damage in cartilage and further lead to early osteoarthritis. In this study, 36 cruciform-shape samples in total from 18 bulls were employed to conduct the uniaxial and biaxial creep-recovery tests by using a biaxial cyclic testing system.

[Study on transport of small molecule rhodamine B within different layers of cartilage].

The small molecule nutrients and cell growth factors required for the normal metabolism of chondrocyte mainly transport into the cartilage through free diffusion. However, the specific mass transfer law in the cartilage remains to be studied. In this study, using small molecule rhodamine B as tracer, the mass transfer models of cartilage were built under different pathways including surface pathway, lateral pathway and composite pathway.

Study on mass transfer in the bone lacunar-canalicular system under different gravity fields.

Introduction: The bone lacunar-canalicular system (LCS) is an important microstructural basis for signaling and material transport in bone tissue, guaranteeing normal physiological processes in tissues. Spaceflight astronauts and elderly osteoporosis are related to its function, so it is necessary to reveal the mass transfer laws in bone microstructure under different gravity fields to provide insight for effective clinical treatment.

Materials And Methods: Using the natural LCS structure of bovine tibial cortical bone as the object, the mass transfer experiments on cortical bone were conducted by using sodium fluorescein tracer through different frequency pulsating pressure provided by dynamic perfusion loading device and different high G environments provided by high-speed centrifuge to analyze the mass transfer laws under different gravity fields and different pulsating pressures.

[Development of a culture chamber for mechanical loading of adherent cells with large uniform strain].

Based on the current study of the influence of mechanical factors on cell behavior which relies heavily on experiments , a culture chamber with a large uniform strain area containing a linear motor-powered, up-to-20-Hz cell stretch loading device was developed to exert mechanical effects on cells. In this paper, using the strain uniformity as the target and the substrate thickness as the variable, the substrate bottom of the conventional incubation chamber is optimized by using finite element technique, and finally a new three-dimensional model of the incubation chamber with "M" type structure in the section is constructed, and the distribution of strain and displacement fields are detected by 3D-DIC to verify the numerical simulation results. The experimental results showed that the new cell culture chamber increased the accuracy and homogeneous area of strain loading by 49.

Mechanical properties of cracked articular cartilage under uniaxial creep and cyclic tensile loading.

Cracks may change the mechanical properties of articular cartilage, and further lead to early osteoarthritis. The study aimed to probe the mechanical properties of cracked cartilage under uniaxial tensile loading. The fracture process of cracked cartilage can be divided into two stages, namely crack-tip blunting stage and crack growth stage.

External fixator combined with three different fixation methods of fibula for treatment of extra-articular open fractures of distal tibia and fibula: a retrospective study.

Background: To compare the efficacy of three different fixation methods of fibula combined with external fixation of tibia for the treatment of extra-articular open fractures of distal tibia and fibula.

Methods: From January 2017 to July 2019, 91 cases of open fractures of distal tibia and fibula were treated with external fixator, and the fibula was fixed with non-fixation (group A, n = 35), plate-screw (group B, n = 30) and Kirschner wire (group C, n = 26). The operation time, intraoperative blood loss, surgical and implants costs, fracture healing time, postoperative complications, and American Orthopaedic Foot and Ankle surgery (AOFAS) scores were compared among the groups.

Histone deacetylase 4 deletion results in abnormal chondrocyte hypertrophy and premature ossification from collagen type 2α1‑expressing cells.

Histone deacetylase 4 (HDAC4) plays a vital role in chondrocyte hypertrophy and bone formation. To investigate the function of HDAC4 in postnatal skeletal development, the present study developed lineage‑specific HDAC4‑knockout mice [collagen type 2α1 (Col2α1)‑Cre, HDAC4d/d mice] by crossing transgenic mice expressing Cre recombinase. Thus, a specific ablation of HDAC4 was performed in Col2α1‑expressing mice cells.

Ratcheting-fatigue behavior of trabecular bone under cyclic tensile-compressive loading.

This study aims to investigate the ratcheting-fatigue behaviors of trabecular bone under cyclic tension-compression, which are produced due to the accumulations of residual strain in trabecular bone. Simultaneously, the effects of different loading conditions on ratcheting behaviors of trabecular bone were probed. It is found that the gap between ratcheting strains under three stress amplitudes will gradually widen.

Conditional deletion of HDAC4 from collagen type 2α1-expressing cells increases angiogenesis in vivo.

Background: HDAC4 is a key regulator of chondrocyte hypertrophy and skeletal development, but it is not clear whether the increase in vascular invasion at growth plates is related to HDAC4 expression. To determine it, we investigated the relationship between HDAC4 and angiogenesis in both in vivo and in vitro models.

Methods: HDAC4 was deleted in Col2α1-Cre; HDAC4 mice.

Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure.

Background: Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacement. However, the mechanical behavior of titanium alloy trabecular structure at present clinical usage still is lack of in-depth study from design to manufacture as well as from structure to mechanical function.

Ratcheting Behavior of Intervertebral Discs Under Cyclic Compression: Experiment and Prediction.

Objective: To evaluate the ratcheting behavior of intervertebral discs (IVD) by experiments and theoretical study.

Method: The lumbar spines of sheep were obtained at a local slaughterhouse, and the IVD was processed with upper and lower vertebral bodies (about 5 mm) to ensure the mechanical state of the IVD in situ. The ratcheting tests of uniaxial cyclic compression loading for disc samples is carried out using the Electronic Universal Fatigue Testing System at room temperature.

Biaxial fatigue crack propagation behavior of ultrahigh molecular weight polyethylene reinforced by carbon nanofibers and hydroxyapatite.

Ultrahigh molecular weight polyethylene (UHMWPE) artificial joint has remained the preferred polymer component in total joint replacement surgery. However, more and more concerns have been raised about the failure of UHMWPE components due to the initiation and propagation of cracks at the notches with fixed functions. For this reason, biaxial fatigue crack growth (FCG) experiments of UHMWPE reinforced by carbon nanofibers (CNF) and hydroxyapatite (HA) were carried out using elastic-plastic fracture mechanics theory.

Mechanical property and biocompatibility of silk fibroin-collagen type II composite membrane.

Osteoarthritis is caused by injuries and cartilage degeneration. Cartilage tissue engineering provides new ideas for the treatment of osteoarthritis. Herein, the different ratios composite membranes of silk fibroin/collagen type II were constructed (SF50-50:50, SF70-70:30, SF90-90:10).

Depth-dependent ratcheting strains of young and adult articular cartilages by experiments and predictions.

Background: Ratcheting strain is produced due to the repeated accumulation of compressive strain in cartilage and may be a precursor to osteoarthritis. The aim of this study was to investigate the ratcheting behaviors of young and adult articular cartilages under cyclic compression by experiments and theoretical predictions.

Methods: A series of uniaxial cyclic compression tests were conducted for young and adult cartilage, and the effects of different loading conditions on their ratcheting behaviors were probed.