Real-time polymerase chain reaction detection and surgical treatment of thoracic and lumbar spondylitis due to Brucella infection: two typical case reports.

Background: Spondylitis caused by Brucella infection is a rare but challenging condition, and its successful management depends on timely diagnosis and appropriate treatment. This study reports two typical cases of thoracic and lumbar brucellosis spondylitis, highlighting the pivotal roles of real-time polymerase chain reaction (real-time PCR) detection and surgical intervention. Case presentation: Case 1 involved a 49-year-old male shepherd who presented with a 6-month history of fever (40°C), severe chest and back pain, and 2-week limited lower limb movement with night-time exacerbation. Physical examination revealed tenderness and percussion pain over the T9 and T10 spinous processes, with grade 2 muscle strength in the lower limbs. CT showed bone destruction of the T9 and T10 vertebrae with narrowing of the intervertebral space, whereas MRI demonstrated abnormal signals in the T9-T10 vertebrae, a spinal canal abscess, and spinal cord compression. The Rose Bengal plate agglutination test was positive. Case 2 was a 59-year-old man who complained of severe thoracolumbar back pain with fever (39.0°C) and limited walking for 2 months. He had a 2.5 kg weight loss and a history of close contact with sheep. The Rose Bengal test was positive, and the MRI showed inflammatory changes in the L1 and L2 vertebrae. Diagnosis and treatment: real-time PCR confirmed Brucella infection in both cases. Preoperative antimicrobial therapy with doxycycline, rifampicin, and ceftazidime-sulbactam was administered for at least 2 weeks. Surgical management involved intervertebral foraminotomy-assisted debridement, decompression, internal fixation, and bone grafting under general anesthesia. Postoperative histopathological examination with HE and Gram staining further substantiated the diagnosis. Outcomes: both patients experienced significant pain relief and restored normal lower limb movement at the last follow-up (4-12 weeks) after the intervention. Conclusion: Real-time PCR detection offers valuable diagnostic insights for suspected cases of brucellosis spondylitis. Surgical treatment helps in infection control, decompression of the spinal cord, and restoration of stability, constituting a necessary and effective therapeutic approach. Prompt diagnosis and comprehensive management are crucial for favorable outcomes in such cases.

The Nonlinear Dynamics of a MEMS Resonator with a Triangular Tuning Comb.

The nonlinear dynamic response of a MEMS resonator with a triangular tuning comb is studied. The motion equation with dis-smooth tuning electrostatic force is derived according to Newton's second law. The analytical solution of the periodic response is obtained using the harmonic balance method and section integral method. The singularity theory is then applied to investigate the bifurcation of the periodic response of the untuned system. The transition sets on the DC-AC voltage plane dividing the planes into several persistent regions are obtained. The bifurcation diagrams' topological structures and jump phenomena corresponding to different parameter regions are analyzed. We explore the effects of tuning voltage on the response. This demonstrates that the amplitude-frequency curves present more hardening characteristics with increased tuning voltage. Many twists, bifurcation points, and unstable solutions appear, leading to complicated jump phenomena. Two bifurcation points exist on the response curves: the smooth and dis-smooth bifurcation points, with the latter occurring on the switching plane of non-uniform fingers.

Inclination Effect on the Periodic Response of a Symmetrical MEMS Gyroscope.

The inclination effect caused by fabrication errors on the periodic response of a symmetric MEMS gyroscope is investigated. The dynamic equation is established considering the inclination effect on support stiffness and electrostatic forces. The periodic response is obtained by the averaging method. The two-variable singularity theory is employed to study the bifurcation characteristics and give transition sets on the DC-AC voltage plane, which divide the plane into four persistent regions. The amplitude-frequency curves demonstrate that only the two persistent regions with low voltages are feasible for the gyroscope. Both over-etching and under-etching reduce the feasible region. The effect of parameters on the performance is present. The mechanical sensitivity and nonlinearity increase with the voltages. With the increase in the inclination angle, the mechanical sensitivity and nonlinearity decrease first and then increase. The full temperature stability of the mechanical sensitivity is also considered. The variation in mechanical sensitivity with temperature is small at a large voltage and negative inclination angle. Under-etching, which leads to small nonlinearity and good temperature stability, is more beneficial to the performance of the gyroscope than over-etching.

Comfort evaluation of a subject-specific seating interface formed by vibrating grains.

Sitting is the most common posture for work in offices, and spinal cord injury (SCI) patients who are wheelchair dependent spend 10.6 h per day seated in wheelchairs. Thus, the comfort of subject-specific interfaces is increasingly important for the well-being of patients and office workers. This paper introduces a new method of forming a subject-specific interface, based on vibrating grains. Twenty subjects (10 females and 10 males) participated in the sitting test. Interface comfort was evaluated using the pressure distribution and subjective rating methods. Five seating interface types were compared. The results showed that compared with a flat interface, the interfaces formed by vibrating grains had a significantly reduced peak contact pressure (PeakCP) (by more than 58.03%), and that PeakCP was highly correlated with the comfort rating (R = -0.533) and discomfort rating(R = -0.603). This new method shows promise for guiding the future development of customized seating interfaces.