BackgroundOsteomyelitis is a challenge for orthopaedic surgeons. There is a lack of scientific evidence to guide treatment. The purpose of this study was to report the clinical outcome of unplanned retention of antibiotic-impregnated cement spacer (ACS) in the management of osteomyelitis.MethodsEight patients (7 with tibial infections and 1 with a calcaneal infection) with osteomyelitis received radical debridement and insertion of an ACS into the bone defect as the definitive management. The mean follow-up period was 2 years (6 months to 4 years). All of these patients had a cement spacer in place.ResultsNo patient exhibited radiographic evidence of excessive bone loss. The patients reported no or occasional mild pain and exhibited complete weight-bearing abilities, with the exception of one patient who required a crutch because of a spinal cord injury. Signs of recurrence of the osteomyelitis were not noted in any of the patients, and no fractures occurred at last follow-up.ConclusionOur study suggests that a proportion of patients with unplanned retention of ACS appear to function well without necessarily requiring further surgical intervention.

With the continuous increase of electronic products, there is an urgent need to effectively recover gold from e-waste and other secondary resources other than the original mine. Here, hypercross-linking and polyamine-functionalized porous organic polymers (Pc–POSS–POP) were designed and facially synthesized based on multiple azo-coupling polymerizations between 2,9,16,23-tetraaminophthalocyanine (H2Pc­(NH2)4) and octa­(aminophenyl)-t8-silsesquioxane (OAPS) for the first time. The reaction requires no metal as a catalyst, thereby benefiting the purification of the product and the industrial scalability. Pc–POSS–POPs possess a hypercross-linking structure, highly conjugated frameworks, nitrogen-rich active sites, and extensively visible and near-infrared light absorption, which was utilized as an absorbent to retrieve Au (III). The results demonstrated that Pc–POSS–POPs have a high adsorption capacity (862.07 mg g–1) and a rapid adsorption rate toward gold recycling. The maximum adsorption capacity could reach up to 1026.87 mg g–1 as in the case of light irradiation. Due to the strong N coordination sites and the electronic interaction between the −NH4 + groups of Pc–POSS–POPs and AuCl4 –, Pc–POSS–POPs also exhibited excellent selectivity toward gold over several coordinated metals [Cr (VI), Co (II), Cd (II), Ni (II), and Hg (II)]. These properties together with the good regenerative ability and superior recyclability demonstrated that Pc–POSS–POPs possess promising potential as hypercross-linking polymers for capturing and recycling of Au (III).

The formation and metabolic balance of bone tissue is a controllable process of biomineralization, which is regulated by various cells, biomolecules, and ions. Enzyme molecules play an important role in this process, and alkaline phosphatase (ALP) is one of the most critical factors. In this study, inspired by the process of bone biomineralization, a biomimetic strategy is achieved for the preparation of mineralized ALP nanoparticles (MALPNs), by taking advantages of the unique reaction between ALP and calcium ions in Dulbecco's modified Eagle's medium. Benefiting from the mild biomineralization reaction, the MALPN system highly maintains the activity of ALP. Furthermore, the in vitro studies show that the MALPN system significantly enhances the proliferation of bone marrow mesenchymal stem cells and upregulates their osteogenic differentiation. When evaluated as synthetic graft materials for bone regeneration, the MALPN-incorporated gelatin methacryloyl graft shows excellent mechanical properties, a sustained release profile of ALP, and high biocompatibility and efficacy in guiding bone regeneration and vascularization for criticalsized rat calvarial defect. Moreover, we also demonstrate that the biomimetic mineralization strategy can be adopted for other proteins such as acid phosphatase, bovine serum albumin, fibrinogen, and gelatin, suggesting its universality for constructing mineralized protein-/enzyme-based bioactive materials for the application of tissue regeneration.

Background: Recovery of motor dysfunction is important for patients with incomplete cervical spinal cord injury (SCI). To enhance the recovery of muscle strength, both research and treatments mainly focus on injury of upper motor neurons at the direct injury site. However, accumulating evidences have suggested that SCI has a downstream effect on the peripheral nervous system, which may contribute to the poor improvement of the muscle strength after operation. The aim of this study is to investigate the impact of early vs. delayed surgical intervention on the lower motor neurons (LMNs) distal to the injury site in patients with incomplete cervical SCI. Methods: Motor unit number index (MUNIX) was performed on the tibialis anterior (TA), extensor digitorum brevis (EDB) and abductor hallucis (AH) in 47 patients with incomplete cervical SCI (early vs. delayed surgical-treatment: 17 vs. 30) and 34 healthy subjects approximately 12 months after operation. All patients were further assessed by American spinal injury association (ASIA) motor scales and Medical Research Council (MRC) scales. Results: There are no difference of both ASIA motor scores and MRC scales between the patients who accepted early and delayed surgical treatment (P > 0.05). In contrast, the patients undergoing early surgical treatment showed lower MUSIX values in both bilateral EDB and bilateral TA, along with greater MUNIX values in both right-side EDB and right-side TA, compared to the patients who accepted delayed surgical treatment (P < 0.05). Conclusions: Cervical SCI has a negative effect on the LMNs distal to the injury site. Early surgical intervention in Cervical SCI patients may improve the dysfunction of LMNs distal to the injury site, reducing secondary motor neuron loss, and eventually improving clinical prognosis.

Background. A reemergence of interest in clavicle anatomy was prompted because of the advocacy for operative treatment of midshaft clavicle fractures. Several anatomical studies of the clavicle have been performed in western population. However, there was no anatomical study of clavicle in Chinese population. Patients and Methods. 52 patients were included in the present study. Three-dimensional reconstructions of the clavicles were generated. The length of the clavicle, the widths and thicknesses of the clavicle, curvatures of the clavicle, the areas of the intramedullary canal, and sectional areas of the clavicle were measured. All the measurements were compared between genders and two sides. Results. The mean length of the clavicles was 144.2 ± 12.0 mm. Clavicles in males were longer, wider, and thicker than in females; also males have different curvatures in both planes compared with females. The men's intramedullary canals and sectional areas of the clavicle were larger than those of women. No significant difference between the sides was found for all the measurements. Conclusion. This study provided an anatomical data of the clavicle in a Chinese population. These clavicle dimensions can be applied to the modifications of the contemporary clavicle plate or a new development for the Chinese population.

A dynamic modeling method for Multistage Planetary Gear Transmission (MPGT) is proposed based on the concept of integral planetary gearbox modeling. The integrated interaction of multiple nonlinear parameters is considered in the dynamic model. The time-varying mesh stiffness of each gear pair is calculated by the energy method. The effects of input torque, gear backlash, and meshing damping on the chaos and impact characteristics of the system are analyzed in detail. The results show that the dynamic behavior of the system is closely related to the Dynamic Meshing Force (DMF). When the system is in the states of chaos, bifurcation, and jumping, the DMF fluctuates violently, and the stability and reliability of the system are seriously affected. With the increase of input torque and meshing damping, the system exits chaos through the inverse period-doubling bifurcation path, which indicates that increasing the input torque and meshing damping can suppress the chaotic motion and enhance the stability of the system. The backlash has a significant effect on the nonlinear behavior and meshing impact characteristics of the system. When the backlash is small, the system is in bilateral impact, and the meshing impact tends to be stable as the backlash increases. In order to improve the vibration characteristics of the system, a slightly larger backlash is necessary. The results can be used to guide the dynamic characteristics design and vibration control of the MPGT.

The high performance carbon fibers could be obtained from wastes of CF/EP composites by thermal excitation of Cr 2 O 3 . Recycling experiment was designed by response surface method to investigate quantitative model, then quantitative relationship between degradation ratio of epoxy resin and process parameters was established based on the higher order response model. The effect of process parameters on degradation ratio was analyzed by graph optimization. The morphology, surface elements and functional groups, and mechanical performances of the recycled carbon fiber were analyzed and characterized under optimal process parameters. The results indicated that the error of the quantitative model was within ±5 % for wastes of leftover materials, and the error was within ±11 % for wastes of composite products; the effect degree of process parameters on degradation ratio: temperature > treatment time > O 2 concentration > O 2 flow; the optimal process parameters were temperature of 500 o C, treatment time of 25 min, O 2 concentration of 80 % and O 2 flow of 180 ml/min; the surface microlite of the recycled carbon fiber underwent oxide etching resulting in a slight graphitization; the ratio of O to C content of the recycled carbon fiber decreased by 16.67 % compared with the original carbon fiber, and monofilament tensile strength was 108 % of that of the original carbon fiber.

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