The impact of digital economy on regional technological innovation capability: An analysis based on China's provincial panel data.

The development of the digital economy in China facilitates the transformation of old and new growth drivers. It can greatly promote the upgrading of technological innovation capacity, realize economies of scale and scope, and constantly promote the generation of new industries and new forms of business with the deep integration of digital economy and traditional industries, thereby promoting the high-quality development of China's economy. This paper uses inter-provincial panel data from 2013 to 2020 and a dynamic spatial Durbin model to quantify the impact of the digital economy on regional technological innovation capability (RTIC). The results show that: (1) the digital economy has positive spatial spillover effect and can boost the province's and neighboring provinces' regional technological innovation capability; (2) regional technological innovation capability has obvious spatial and temporal aggregation effects; (3) the impact of the digital economy on RTIC is mainly short-term effects, and there is regional heterogeneity, with the western region experiencing the highest effects and the eastern region experiencing less. Therefore, it is urgent to accelerate the development speed of the digital economy, grasp the law of dynamic economic development, identify the regional heterogeneity of the digital economy development, and deepen inter-regional digital technology cooperation to comprehensively drive the improvement of regional technological innovation capability.

Revealing the transmission mechanism and spatial spillover of carbon emission reduction caused by high-speed rail opening.

In the context of China's commitment to peak carbon emissions by 2030 and achieve carbon neutrality by 2060, as well as its strategy to build a strong transportation country, it is of foremost importance to study the carbon emission reduction effect of the opening of high-speed rail (HSR). This paper innovatively introduces the frequency of HSR stops as an indicator of HSR operation, and uses a time-varying difference-in-difference (DID) model, a mediating effect model and a spatial DID model to assess the direct and indirect impact, transmission mechanism, and spatial spillover effects of the opening and operation of HSR on carbon emission reduction based on a panel of 279 prefecture-level cities from 2003 to 2017. We found that the opening and operation of HSR significantly reduced urban carbon emissions. The direct transmission mechanism analysis shows that the opening of HSR can reduce carbon emissions by replacing highway passenger traffic. Indirect mechanism analysis shows that the opening of HSR can reduce carbon emissions through technological effect, structural effect and opening effect. The test of spatial spillover effect shows that the opening of HSR can promote carbon emission reduction not only in node cities, but also in neighboring cities.

[Effects of artificial disc replacement with angles on stress of adjacent intervertebral disc].

OBJECTIVE: To evaluate stress changes of intervertebral space and adjacent intervertebral space after artificial disc replacement with angles. METHODS: Artificial disc replacement with angles were designed according to existing data. Axial pressure, flexion/extension, lateral bending and torsion loading were applied on finite element models of normal cervical discs on C4,5 segments, C4,5 segments with 0 degrees artificial cervical discs and C4,5 segments with 10 degrees artificial cervical discs, then stress changes of C4,5 space was observed. The same loadings were applied on finite element models of normal cervical discs on C4-C6 segments, C4,5 segments with 0 degrees, C4,5 segments with 10 degrees, then stress changes of replaced segments space and adjacent segment space were observed. RESULTS: For C4,5 segments, 80 MPa/0 degrees artificial discs and 80 MPa/10 degrees artificial discs had the similar equivalent shear stress (Se), and were both larger than that of normal discs, when lateral bending were performed, 80 MPa/0 degrees artificial discs were closed to normal discs when axial pressure and flexion/extension were carried out, while 80 MPa/10 degrees artificial discs had a larger Se than that of normal ones,when torsion loading were applied, Szx/Szy stress of 80 MPa/0 degrees and 80 MPa/10 degrees artificial discs were closed to normal ones. For C4-C6 segments, the axial pressure, flexion/extension and lateral bending of C5,6 were all lower than normal discs after C4,5 discs were replaced by 80 MPa/10 degrees artificial discs, while Szx/Szy of torsion loading were closed to normal ones. CONCLUSION: Artificial discs with 10 degrees have less influences on stress of adjacent intervertebral space and closer to mechanical property after being implanted into intervertebral space.

[Effects of novel angled cervical disc replacement on facet joint stress].

OBJECTIVE: To analyze the biomechanical changes of the adjacent cervical facet joints when the angled cervical prosthesis is replaced. METHODS: A total of 400 northwestern people were involved, with an age of 40 years or older. The cervical vertebra lateral X-ray films were taken, and the cervical angles were measured by professional computer aided design software, then the cervical intervertebral disc prosthesis with 10 degree angle was designed. The finite element models of C4, 5 and C4-6 segments with intact cervical discs were developed; the C4, 5 disc was replaced by the cervical prosthesis with 0 degrees and 10 degrees angle respectively; and then all models were subjected to axial loading, flexion/extension, lateral bending, and torsion loading conditions; the stress effects on adjacent facet joints after replacement were observed by comparing with that of the intact model. RESULTS: The cervical angles were (9.97 +/- 3.64) degrees in C3, 4, (9.95 +/- 4.34) degrees in C4, 5, (8.59 +/- 3.75) degrees in C5, 6, and (8.49 +/- 3.39) degrees in C6, 7, showing no significant difference between C3, 4 and C4, 5, C5, 6 and C6, 7 (P > 0.05) and showing significant differences between the other cervical angles (P < 0.05). When C4, 5 model was axially loaded, no significant difference in equivalent shearing stress were observed in intact, 0 degrees, and 10 degrees groups; at flexion/extension loading, the stress was biggest in intact group, and was smallest in 10 degrees group; at lateral bending, the stress got the high rank in intact group, and was minimum in 10 degrees group; at torsion loading, the stress state of 10 degrees group approached to the intact one condition. When C4-6 model was loaded, the facet joint stress of the replaced segment (C4, 5) decreased significantly at axial loading, flexion/extension, and lateral bending; while no obvious decrease was observed at torsion loading; the stress of the adjacent inferior disc (C5, 6) decreased significantly at axial loading and lateral bending condition, while less decrease was observed at torsion loading, no significant change at flexion/extension condition, it approached to that of the intact one. CONCLUSION: The finite element analysis reveals that the biomechanical properties of 10 degrees designed prosthesis is approximate to that of the intact cervical disc, thus the 10 degrees designed prosthesis can meet the requirements of biomechanical function reconstruction of the cervical spine.