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The proper microenvironment is critical for the storage and transportation of embryonic stem cells (ESCs). To mimic a dynamic 3D microenvironment as it exists in vivo and consider “off-the-shelf” availability reaching the destination, we proposed an alternative approach that allows for facile storage and transportation of stem cells in the form of ESCs-dynamic hydrogel construct (CDHC) under ambient conditions. To form CDHC, mouse embryonic stem cells (mESCs) were in-situ encapsulated within a polysaccharide-based dynamic and self-biodegradable hydrogel. After storing CDHC in a sterile and hermetic environment for 3 days and then transferring to a sealed vessel with fresh medium for another 3 days, the large and compact colonies retained a 90% survival rate and pluripotency. Furthermore, after transporting and arriving at the destination, the encapsulated stem cell could be automatically released from the self-biodegradable hydrogel. After continuous cultivation of 15 generations of retrieved cells, automatically released from the CDHC, the mESCs underwent 3D encapsulation, storage, transportation, release, and continuous long-term subculture; resumed colony forming capacity and pluripotency were revealed by stem cell markers both in protein and mRNA levels. We believe that the dynamic and self-biodegradable hydrogel provides a simple, cost-effective, and valuable tool for storing and transporting “ready-to-use” CDHC under ambient conditions, facilitating “off-the-shelf” availability and widespread applications.

Magnetorheological fluids, especially those in high-power magnetorheological devices, inevitably work at high temperatures because of the wall slip, energized coils and frictions between particles. In order to prepare a magnetorheological fluid for high temperatures, this work investigates the properties of three main components (soft magnetic particles, surfactants and base carrier fluids) for a magnetorheological fluid at high temperatures. On this basis, a novel magnetorheological fluid for high temperatures is prepared. Its sedimentation stability, viscosity and shear yield stress are investigated at high temperatures. The results show that the novel magnetorheological fluid has acceptable sedimentation, suitable viscosity and stable shear yield stress at high temperatures. The novel magnetorheological fluid for high temperatures can be applied to most magnetorheological devices, especially high-power magnetorheological devices.

In order to prepare magnetorheological fluid with excellent sedimentation stability, various surfactants are applied to coat carbonyl iron powder. The prepared magnetorheological fluid shows excell...

Additional file 2. The non-pharmaceutical interventions of different level.

Additional file 1. The classification of 21 infectious diseases.

In order to use shear yield stress model of magnetorheological fluid more accurately, the influence of particle size, particle spacing and magnetic field intensity on the model error of single-chain dipole is compared and analyzed based on the finite element model. The results show that particle size and particle spacing have few effects on the single-chain dipole model, but the magnetic field intensity is the most important factor affecting the error of single-chain dipole model. As the magnetic field strengthens, the error of the single-chain dipole model decreases gradually. Based on the research, the single-chain dipole model is optimized by finite element method. Experimental results show that the error of optimized single-chain dipole model is reduced by 80% compared with that of the model before optimization, which is more accurate.

In order to study the internal damage and static compressive strength of concrete under different water pressures, the wave velocity test and compressive test were carried out by NN-4B non-metallic ultrasonic testing analyzer and electro-hydraulic servo testing machine. The test results show that the high water pressure of concrete has an adverse impact on the development of its internal structure, and with the increase of high water pressure level, the slower the longitudinal wave passes through the specimen, the more serious the damage and deterioration of concrete, and the compressive strength decreases gradually with the increase of water pressure.

In order to investigate the shear yield stress of magnetorheological (MR) fluid at different temperatures, shear gaps, and shear rates, a ring measurement system is designed based on the MR characteristics. The magnetic field and temperature field of the system are simulated and analyzed, which proves that the design of the measurement system is reasonable. On this basis, the measurement system is manufactured and experiments are carried out to verify its performance. The results show that the system can provide a uniform and strong enough magnetic field to make MR effects occur. Meanwhile, the temperature of the shear gap can reach 100 °C in 610 s, and it can increase up to 240 °C when heating continues, which can provide stable measurement conditions at different temperatures, especially at high temperatures. All the results of the experiments show that the measurement system meets the requirements of measuring the shear yield stress of MR fluid. To test the accuracy of the measurement system, repeated experiments are carried out as well. The shear yield stress by the system is almost the same as that provided by the manufacturer, showing excellent measuring precision. The repeatability error of the measurement system is less than 4.02%, indicating that the measurement system is of high accuracy.

The internal structure of off-axis three-mirror system is commonly complex. The mirror installation error in assembly always affects the imaging line-of-sight and further degrades the image quality. Due to the complexity of the optical path in off-axis three-mirror optical system, the straightforward theoretical analysis on the variations of imaging line-of-sight is extremely difficult. In order to simplify the theoretical analysis, an equivalent single-mirror system is proposed and presented in this paper. In addition, the mathematical model of single-mirror system is established and the accurate expressions of imaging coordinate are derived. Utilizing the simulation software ZEMAX, off-axis three-mirror model and single-mirror model are both established. By adjusting the position of mirror and simulating the line-of-sight rotation of optical system, the variations of imaging coordinates are clearly observed. The final simulation results include: in off-axis three-mirror system, the varying sensitivity of the imaging coordinate to the rotation of line-of-sight is approximately 30 um/″; in single-mirror system, the varying sensitivity of the imaging coordinate to the rotation of line-of-sight is 31.5 um/″. Compared to the simulation results of the off-axis three-mirror model, the 5p relative error of single-mirror model analysis highly satisfies the requirement of equivalent analysis and also verifies its validity. This paper presents a new method to analyze the installation error of the mirror in the off-axis three-mirror system influencing on the imaging line-of-sight. Moreover, the off-axis three-mirror model is totally equivalent to the single-mirror model in theoretical analysis.

To obtain a method for measuring thread functional diameter, a new probe based on the synthetic measurement principle is designed to quantify the practical effect of each parameter in all axial sections. The probing element is an axial slice of a standard thread with a certain thickness; hence, the slice has a determined lead angle and curvature radius. When threads with different diameters are measured by slices, the maximum error caused by the lead angle and curvature radius can approach 99 μm according to the simulation results. To solve this problem, a measurement error model is established by analyzing the relationship between the contact points of the measuring tip and thread. By simulations and experiments, our results show that most of the effect of lead angle and curvature radius can be compensated. Using six slices with different pitches, a precise detection of 192 kinds of threads is achieved after error compensation within the range of M65–M300.

Background The aim of our study was to evaluate the clinical efficacy of posterior vs. anterior instrumentation for the treatment of spinal tuberculosis in adults. Methods The electronic databases such as PubMed, MEDLINE, Springer, EMBASE, Google scholar, and Cochrane library were searched to select the potentially relevant reports that compared the efficacy of posterior instrumentation group (group A) with anterior instrumentation group (group B) in the treatment of spinal tuberculosis. Outcome assessments were correction of angle, loss of correction, fusion rate of the grafting bone, and complications after surgery. Results This meta-analysis included four trials published between 2006 and 2012, involving 291 adult patients (group A, 154; group B, 137) with spinal tuberculosis. The overall meta-analysis showed that there were no significant differences (P > 0.01) between group A and group B in correction of angle and loss of correction at final follow-up after operation The pooled WMD (weighted mean difference) of group A and group B was 2.85 (95% CI (confidence interval) = -1.25 ~ 6.94) and 1.14 (95% CI = -3.07 ~ 5.34), respectively. Besides, no significant differences (P > 0.01) were observed in fusion rate of the grafting bone and complications after operation between group A and group B, and the pooled ORs (odds ratio) were 0.65 (95% CI = -0.23 ~ 1.85) and (95% CI = -0.19 ~ 1.50), respectively. Conclusions Our results suggested that the posterior instrumentation appeared to have the same clinical outcome with the anterior instrumentation in the treatment of the adult patients with spinal tuberculosis.

Publication in the conference proceedings of EUSIPCO, Aalborg, Denmark, 2010

Purpose: To evaluate the effect of free vascularized fibula grafts on developing donor leg function, the authors reviewed their experience of procedures performed in children. Methods: Over a 10-year period, 30 children (average age 7.2 years, without gender concern) underwent fibula harvest via an anterolateral approach. Graft length averaged 6.0 cm. Follow-up averaged 8 years. Results: No vascular injury or shank dysplasia ensued. Neural injury occurred in 8 patients: to the profound peroneal nerve in 1 and to the superficial peroneal nerve in 7. Symptoms resolved spontaneously at 3 to 5 months in 6, but persisted in 2 patients in the latter group at 8 years' follow-up. Of 24 children who underwent rapid walking (200 m) followed by immediate stair climbing (50 steps), 2 (whose grafts were longer than average) had slight and 1 had obvious ankle pain. However, muscle strength and range of motion in the donor ankle were no different from values in the recipient leg in the 24 cases. X-ray findings showed that, with growth, the remaining 2 fibular segments in the donor leg became longer, but the length of the gap between did not change. Thus, the gap left by harvest became relatively shorter long after operation, benefiting the stability of the ankle joint in adulthood. Conclusion: Unlike free vascularized fibula grafts performed in adulthood, from which serious complications to the donor leg have been reported, the procedure performed in childhood appears not to have an adverse effect on functional development. J Pediatr Surg 35:1226-1229. Copyright © 2000 by W.B. Saunders Company.