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STUDY DESIGN: Delayed diagnosis of degenerative cervical myelopathy (DCM) is likely due to a combination of its subtle symptoms, incomplete neurological assessments by clinicians and a lack of public and professional awareness. Diagnostic criteria for DCM will likely facilitate earlier referral for definitive management. OBJECTIVES: This systematic review aims to determine (i) the diagnostic accuracy of various clinical signs and (ii) the association between clinical signs and disease severity in DCM? METHODS: A search was performed to identify studies on adult patients that evaluated the diagnostic accuracy of a clinical sign used for diagnosing DCM. Studies were also included if they assessed the association between the presence of a clinical sign and disease severity. The QUADAS-2 tool was used to evaluate the risk of bias of individual studies. RESULTS: This review identified eleven studies that used a control group to evaluate the diagnostic accuracy of various signs. An additional 61 articles reported on the frequency of clinical signs in a cohort of DCM patients. The most sensitive clinical tests for diagnosing DCM were the Tromner and hyperreflexia, whereas the most specific tests were the Babinski, Tromner, clonus and inverted supinator sign. Five studies evaluated the association between the presence of various clinical signs and disease severity. There was no definite association between Hoffmann sign, Babinski sign or hyperreflexia and disease severity. CONCLUSION: The presence of clinical signs suggesting spinal cord compression should encourage health care professionals to pursue further investigation, such as neuroimaging to either confirm or refute a diagnosis of DCM.

STUDY DESIGN: Delayed diagnosis of degenerative cervical myelopathy (DCM) is associated with reduced quality of life and greater disability. Developing diagnostic criteria for DCM has been identified as a top research priority. OBJECTIVES: This scoping review aims to address the following questions: What is the diagnostic accuracy and frequency of clinical symptoms in patients with DCM? METHODS: A scoping review was conducted using a database of all primary DCM studies published between 2005 and 2020. Studies were included if they (i) assessed the diagnostic accuracy of a symptom using an appropriate control group or (ii) reported the frequency of a symptom in a cohort of DCM patients. RESULTS: This review identified three studies that discussed the diagnostic accuracy of various symptoms and included a control group. An additional 58 reported on the frequency of symptoms in a cohort of patients with DCM. The most frequent and sensitive symptoms in DCM include unspecified paresthesias (86%), hand numbness (82%) and hand paresthesias (79%). Neck and/or shoulder pain was present in 51% of patients with DCM, whereas a minority had back (19%) or lower extremity pain (10%). Bladder dysfunction was uncommon (38%) although more frequent than bowel (23%) and sexual impairment (4%). Gait impairment is also commonly seen in patients with DCM (72%). CONCLUSION: Patients with DCM present with many different symptoms, most commonly sensorimotor impairment of the upper extremities, pain, bladder dysfunction and gait disturbance. If patients present with a combination of these symptoms, further neuroimaging is indicated to confirm the diagnosis of DCM.

Objective The health of metro communication system has a direct bearing on the efficiency and safety of metro operation. In view of the problems such as one-sided evaluation results and subjective evaluation criteria in current health evaluation method for metro communication systems, it is necessary to construct a method that can scientifically and accurately evaluate the operation status and health of the metro communication system. Method A dynamic health evaluation method based on random forests algorithm is proposed, and a communication health inspection is conducted in combination with deep learning. The evaluation index system is designed to collect the corresponding data. The mixed label method is used to determine the label and calculate the importance of each index when the label (true health degree) is not clear. The health degree of each subsystem of communication system is calculated according to the index weight and the index self scoring standards established by experts, which properly incorporates the influence of experts' knowledge. Based on the maintenance data of Chengdu Metro, the method is tested and verified. Result & Conclusion The test verification results show that with the above method, effective index importance can be obtained and the health of metro communication system can be reasonably evaluated.

Study Design: This study is a scoping review. Objective: There is a broad variability in the definition of degenerative cervical myelopathy (DCM) and no standardized set of diagnostic criteria to date. Methods: We interrogated the Myelopathy.org database, a hand-indexed database of primary clinical studies conducted exclusively on DCM in humans between 2005-2021. The DCM inclusion criteria used in these studies were inputted into 3 topic modeling algorithms: Hierarchical Dirichlet Process (HDP), Latent Dirichlet Allocation (LDA), and BERtopic. The emerging topics were subjected to manual labeling and interpretation. Results: Of 1676 reports, 120 papers (7.16%) had well-defined inclusion criteria and were subjected to topic modeling. Four topics emerged from the HDP model: disturbance from extremity weakness and motor signs; fine-motor and sensory disturbance of upper extremity; a combination of imaging and clinical findings is required for the diagnosis; and "reinforcing" (or modifying) factors that can aid in the diagnosis in borderline cases. The LDA model showed the following topics: disturbance to the patient is required for the diagnosis; reinforcing factors can aid in the diagnosis in borderline cases; clinical findings from the extremities; and a combination of imaging and clinical findings is required for the diagnosis. BERTopic identified the following topics: imaging abnormality, typical clinical features, range of objective criteria, and presence of clinical findings. Conclusions: This review provides quantifiable data that only a minority of past studies in DCM provided meaningful inclusion criteria. The items and patterns found here are very useful for the development of diagnostic criteria for DCM. [ABSTRACT FROM AUTHOR]

The demand‐side DC electricity‐using equipment and newly integrated renewables are driving the transformation of power distribution and utilization mode. The building system based on DC technology is emerging as a promising option. In the low‐voltage DC building distribution and utilization system (LVDCBDUS), global energy optimization management and operational control arrangement are key components. To obtain exemplary achievements of those, two different DC building energy management system (DC BEMS) integration schemes are investigated according to the respective features and application‐required functions of various system networking structures. Centralized and decentralized control strategies are presented and discussed for buildings with AC–DC transformation and newly built LVDCBDUSs. On this basis, the centralized DC BEMS and operational control strategy are applied to the first multi‐scenario low‐carbon city‐based future building project—Shenzhen IBR Future Complex. The operation data are recorded and analysed. Problems encountered during the implementation are summarized, and requirements of converter equipment, new technologies and marketization are further discussed to promote the high‐quality development of the LVDCBDUS. [ABSTRACT FROM AUTHOR]

In the current anti-jamming communication, the spread spectrum communication has been studied deeply with the advantages of strong anti-jamming ability and good security performance. In this paper, the code index modulation and multi-ary spread spectrum technology are analyzed and compared. Code index modulation technology is based on the development of direct sequence spread spectrum, in the transmitter information bits are mapped to the pseudo noise(PN) code index and the modulation symbol respectively. The in-phase and orthogonal parts of the modulation symbol select PN codes activated to spread spectrum, and then transmitted through an antenna. The difference between multi-ary spread spectrum technology and code index modulation technology is that the multi-ary spread spectrum technology does not have modulation symbols, and only sends out the activated spread spectrum code through the antenna. This paper will introduce the basic models, spread spectrum gain analysis and complexity analysis of the two kinds of spread spectrum technology. The simulation results show that the code index modulation system has higher spectral efficiency and anti-interference ability.