ObjectiveTo evaluate the detection specificity for clinical samples and the detection capability for standard substances of five commercially available multiplex polymerase chain reaction (PCR) nucleic acid detection kits (hereinafter referred to as the kits) for respiratory pathogens, and to provide a reference for selecting appropriate detection kits for multi-pathogen nucleic acid testing of respiratory infections. MethodsA total of 60 respiratory pathogen-positive clinical samples with known redults were selected and tested using the five kits (labeled as A, B, C, D, and E). The detection rates and Kappa coefficients were calculated to evaluate the consistency between the results from these kits and those from single-pathogen PCR kits. According to the limit of detection (LOD) provided by the kits, standard substances of respiratory pathogens (including 12 types such as influenza virus, Mycoplasma pneumoniae, and Bordetella pertussis) were diluted to four concentrations (250, 500, 1 000, and 2 000 copies·mL⁻¹). All five kits were used for detection to evaluate their respective detection capabilities. ResultsCompared with the results from single-pathogen PCR kits, the five tested kits demonstrated good consistency (all Kappa >0.80). Among them, Kit A had the highest detection rate (100.00%), followed by Kits C and E (98.33%), and then Kits B and D (95.00%). All five kits showed a relatively low false negative rate (FNR) for samples with a cycle threshold (Ct) value ≤35 (≤2.38%). However, for samples with Ct values>35, the FNR increased accordingly(average FNR=6.67%, P=0.029). Kit C exhibited the highest detection sensitivity for the tested standard substances (average LOD: 458.33 copies·mL⁻¹), followed by Kit D, then Kits A/E, and finally Kit B. ConclusionThe five multiplex PCR kits showed good consistency with single-pathogen detection results, but each had its own performance emphasis. Kit A, with the highest detection rate and high throughput, is suitable for targeted viral screening. Kit B, covering the broadest pathogen spectrum (including fungi/bacteria), is suitable for comprehensive respiratory pathogen screening. Kits C, D and E, are applicable for rapid detection. It is important to note that the detection efficacy of all kits decreases for low viral load samples with Ct values >35. In practical application, selection should be based on specific screening objectives, throughput requirements, and sample types.

Objective To establish the finite element model of upper cervical vertebrae C0-3 with Jefferson fracture, and to analyze the influence of posterior atlantoaxial fusion (PSF) and occipitocervical fusion (OCF) on biomechanical properties of the vertebral body and mechanical conduction of the screw-rod system. Methods Based on CT images, the C0-3 segment Jefferson fracture model of human upper cervical spine was established. PSF, OCF1 and OCF2 internal fixation were performed according to surgical plan in clinic, and 50 N concentrated force and 1.5 N·m torque were applied to bottom of the occipital bone. The stress distribution and range of motion (ROM) of the cervical vertebral body, the maximum stress of the screw-rod system and the stress distribution of the intervertebral disc for C0-3 segment during flexion, extension, bending and rotation of the upper cervical spine were studied. Results Compared with PSF, the ROM of OCF1 and OCF2 vertebral bodies increased, and the stress of the nail rod decreased. OCF had a better fixation effect. Conclusions PSF, OCF1 and OCF2 fixation method can reduce the upper cervical ROM and restore stability of the upper cervical spine, which make stress distributions of the vertebral body and intervertebral disc tend to be at normal level. The research result can provide a theoretical basis for clinical surgery plan.

Objective To investigate the clinical features of cerebral infarction complicated with diabetes mellitus (DCI) compared withthose without diabetes mellitus (NCI). Methods 80 DCI and 86 NCI hospitalized patients were reviewed with their serumal glucose, lipid,uric acid, hemorheology and carotid ultrasound. Results The total cholesterol, low density lipoprotein and uric acid were significantly higherin DCI group than in NCI group (P<0.05), while high density lipoprotein was significantly lower (P<0.05). There were significant differencesbetween these two groups in Hemorheological indicators except hematokrit (P<0.01). The carotid intima media thickness (IMT) wassignificantly higher in the DCI group than in the NCI group (P<0.05). Conclusion DCI patients suffered in more serious lipid, uric acid,hemorheological disorder, and IMT compared with NCI.