Design of spring-type adjustable locking mechanism

Based on the suspension of a missile using folding rotary wings and airbags, in order to improve the basic parameters and motion characteristics of the rotor during the unfolding process and analyze the aerodynamic characteristics of the entire device in the suspension state, after proposing a scheme of double-spin mechanism, the main folding and unfolding mechanism, initial driving device, rotating driving device, and locking mechanism were designed, and the simulation research is studied by the Automatic Dynamic Analysis of Mechanical System and Ansys Fluent Fluid Simulation software, respectively. The results show that the rotation rate was controlled at 41.8 mm/s, the various motion parameters are reasonable, and the operation process is relatively smooth, with high reliability. The speed and pressure value at the tip of the rotor are higher and the aerodynamic disturbance is obvious, which has a great influence on the aerodynamic performance. The speed and pressure distribution of the surrounding flow field is stable, the lift provided is 46 N, and the lift coefficient is 0.55, which can ensure the long-time suspension state of the missile. This paper puts forward a valuable design idea and has practical reference value for the research of the suspended missile.

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High-strength and fibrous capsule–resistant zwitterionic elastomers

Science Advances ◽

10.1126/sciadv.abc5442 ◽

2021 ◽

Vol 7 (1) ◽

pp. eabc5442

Author(s):

Dianyu Dong ◽

Caroline Tsao ◽

Hsiang-Chieh Hung ◽

Fanglian Yao ◽

Chenjue Tang ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Strength ◽

High Strength ◽

Design Principles ◽

Fibrous Capsule ◽

High Mechanical Strength ◽

Capsule Formation ◽

Locking Mechanism ◽

Fibrous Capsule Formation

The high mechanical strength and long-term resistance to the fibrous capsule formation are two major challenges for implantable materials. Unfortunately, these two distinct properties do not come together and instead compromise each other. Here, we report a unique class of materials by integrating two weak zwitterionic hydrogels into an elastomer-like high-strength pure zwitterionic hydrogel via a “swelling” and “locking” mechanism. These zwitterionic-elastomeric-networked (ZEN) hydrogels are further shown to efficaciously resist the fibrous capsule formation upon implantation in mice for up to 1 year. Such materials with both high mechanical properties and long-term fibrous capsule resistance have never been achieved before. This work not only demonstrates a class of durable and fibrous capsule–resistant materials but also provides design principles for zwitterionic elastomeric hydrogels.

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Comparison between selective caudal fixed screw construct and all variable screw construct in anterior cervical discectomy and fusion

Scientific Reports ◽

10.1038/s41598-021-90121-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jae Jun Yang ◽

Sehan Park ◽

Seongyun Park

Keyword(s):

Fusion Rate ◽

Anterior Cervical Discectomy ◽

Disc Space ◽

Cervical Discectomy ◽

Locking Mechanism ◽

Adjacent Disc ◽

One Year ◽

The Stability ◽

Retrospective Comparative Study ◽

Caudal Level

AbstractThis retrospective comparative study aimed to compare the efficacy of selective caudal fixed screw constructs with all variable screw constructs in anterior cervical discectomy and fusion (ACDF). Thirty-five patients who underwent surgery using selective caudal fixed screw construct (SF group) were compared with 44 patients who underwent surgery using all variable constructs (AV group). The fusion rate, subsidence, adjacent level ossification development (ALOD), adjacent segmental disease (ASD), and plate-adjacent disc space distance were assessed. The one-year fusion rates assessed by computed tomography bone bridging and interspinous motion as well as the significant subsidence rate did not differ significantly between the AV and SF groups. The ALOD and ASD rates and plate-adjacent disc space distances did not significantly differ between the two groups at both the cranial and caudal adjacent levels. The number of operated levels was significantly associated with pseudarthrosis in the logistic regression analysis. The stability provided by the locking mechanism of the fixed screw did not lead to an increased fusion rate at the caudal level. Therefore, the screw type should be selected based on individual patient’s anatomy and surgeon’s experience without concern for increased complications caused by screw type.

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