ABSTRACT
Global navigation satellite systems (GNSS) are widely used for navigation and time distribution1-3, features that are indispensable for critical infrastructure such as mobile communication networks, as well as emerging technologies such as automated driving and sustainable energy grids3,4. Although GNSS can provide centimetre-level precision, GNSS receivers are prone to many-metre errors owing to multipath propagation and an obstructed view of the sky, which occur particularly in urban areas where accurate positioning is most needed1,5,6. Moreover, the vulnerabilities of GNSS, combined with the lack of a back-up system, pose a severe risk to GNSS-dependent technologies7. Here we demonstrate a terrestrial positioning system that is independent of GNSS and offers superior performance through a constellation of radio transmitters, connected and time-synchronized at the subnanosecond level through a fibre-optic Ethernet network8. Using optical and wireless transmission schemes similar to those encountered in mobile communication networks, and exploiting spectrally efficient virtual wideband signals, the detrimental effects of multipath propagation are mitigated9, thus enabling robust decimetre-level positioning and subnanosecond timing in a multipath-prone outdoor environment. This work provides a glimpse of a future in which telecommunication networks provide not only connectivity but also GNSS-independent timing and positioning services with unprecedented accuracy and reliability.
ABSTRACT
Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of end-stage liver disease, leading to a rapidly growing global public health burden. The term "gut microbiome (GM)" refers to the approximately 100 trillion microbial cells that inhabit the host's gastrointestinal tract. There is increasing evidence that GM is involved in the pathogenesis of NAFLD and may be a potential target for intervention. To explore GM-based strategies for precise diagnosis and treatment of NAFLD, great efforts have been made to develop a comprehensive and in-depth understanding of the host-microbe interaction. This review evaluates this interaction critically, mainly considering the intricate regulation of the metabolism, immunity, and inflammatory status during the evolution of the disease pathogenesis, revealing roles for the GM in NAFLD by examining advances in potential mechanisms, diagnostics, and modulation strategies. Synopsis: Considering the intricate metabolic and immune/inflammatory homeostasis regulation, we evaluate the latest understanding of the host-microbe interaction and reveal roles for the gastrointestinal microbiome in NAFLD. Strategies targeting the gastrointestinal microbiome for the diagnosis and treatment of NAFLD are proposed.
ABSTRACT
BACKGROUND: In the elderly, the cervical vertebrae will appear with different degrees of spinal stenosis caused by various factors. Notably, the incidence of cervical spinal cord injury without fracture or dislocation is high, accounting for 3%-16% of cervical spinal cord injury.OBJECTIVE: To explore the efficacy of MRI in the diagnosis and prognosis of cervical spinal cord injury without fracture or dislocation, and to analyze the influencing factors for surgical effectiveness.METHODS: Fifty-one patients with cervical spinal cord injury without fracture or dislocation in Zibo Central Hospital from August 2014 to June 2016 were analyzed retrospectively. All the patients underwent anterior, posteror, or anterior-posterior fusion, respectively, and then the intraoperative ligament injury and MRI images were compared. The age, injury type, spinal cord injury type revealed on MRI, time from injury to hospital, signal length of spinal cord injury,American Spinal injury Association grade, degree of cervical stenosis, whether hormone used or not within 8 hours after injury, time from injury to surgery, and surgical approaches were analyzed based on univariate analysis and multivariate analysis by Logistic regression analysis.RESULTS AND CONCLUSION: (1) MRI showed more comprehensive damage of the spinal cord and intervertebral disc ligament complex than the intraoperative findings (χ2=5.966,P < 0.05), and the cervical spinal cord injury was related to the injury of the corresponding intervertebral disc ligament complex (χ2=1.53, P > 0.05). (2) Univariate analysis results showed that the spinal cord injury type revealed on MRI, signal length of spinal cord injury, American Spinal injury Association grade, degrees of cervical stenosis, whether hormone used or not within 8 hours after injury, and time from injury to surgery were related to the functional recovery of spinal cord (P < 0.01). (3) Multivariate analysis results indicated that the type revealed on MRI, signal length of spinal cord injury and degrees of cervical stenosis were significantly related to the functional recovery of spinal cord (P < 0.05). (4) These results suggest that MRI has a high tissue resolution, so it plays an important role in the diagnosis of cervical spinal cord injury without fracture or dislocation.Moreover, the degrees of spinal cord injury and spinal stenosis, as well as operation time are main factors for curative efficacy.
