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Periprosthetic femoral fractures (PPFFs) following total hip arthroplasty (THA) present a significant clinical challenge due to their increasing incidence with an aging population and evolving surgical practices. Historically, classifications were primarily based on anatomical fracture location, the stability of the implant, and bone quality surrounding the implant. We critically analyzed 25 classification systems, highlighting the emergence and adaptations of key systems such as the Vancouver classification system (VCS) and the Unified classification system (UCS), which are lauded for their simplicity and effectiveness yet require further refinement. VCS, developed in 1995, categorizes fractures based on the site, implant stability, and bone quality, and remains widely used due to its robust applicability across different clinical settings. Introduced in 2014, UCS expands the VCS to encompass all periprosthetic fractures with additional fracture types, aiming for a universal application. Despite their widespread adoption, these systems exhibit shortcomings, including the incomplete inclusion of all PPFF types and the imprecise assessment of implant stability and surrounding bone loss. These gaps can result in misclassification and suboptimal treatment outcomes. This paper suggests the necessity for ongoing improvements in classification systems to include emerging fracture types and refined diagnostic criteria, ensuring that they remain relevant to contemporary orthopedic practices and continue to facilitate the precise tailoring of treatment to patient‐specific circumstances. This comprehensive historical review serves as a foundation for future innovations in classification systems, ultimately aiming to standardize PPFF treatment and improve patient prognosis. [ABSTRACT FROM AUTHOR]

Due to complex environmental factors, the gear transmission systems of wind turbines are continuously affected by large torque load excitation with periodic and random properties. This paper shares the load-sharing and dynamic characteristics of a herringbone planetary gear system applied in a wind turbine. The gear dynamic model is established using a typical lumped parameter method, in which the nonlinear transmission errors of the gear pairs and left and right-side coupling stiffness of the herringbone gears are included. With the help of the blade element momentum theory, the precise calculation of the hub load of the wind turbine, which is the external excitation of the gear system, is implemented, in which the wind shear, tower shadow, turbulent effect, and tip loss correction are taken into consideration. The nonlinear dynamic characteristics of the system are obtained using the Runge-Kutta method and then discussed. The results show that the turbulent effect plays a major role in the impact on the load-sharing characteristics, and a reasonable set of the support stiffness of rotational components can improve the load-sharing characteristics of the system. The purpose of this research is to provide some useful references in numerical modelling and methods for designers and researchers of wind turbine transmission systems. [ABSTRACT FROM AUTHOR]

Objective: Gastrointestinal dysfunction seriously affects the prognosis and quality of life of patients with multiple fractures. However, experimental evidence of this relationship is lacking. Here we describe a newly developed mouse model of postoperative gastrointestinal dysfunction after multiple fractures. Methods: Trauma severity was assessed using the injury severity score (ISS). Based on the ISS, a multiple fracture model was established in mice as follows: limb fractures with pelvic fractures and multiple rib fractures; limb fractures with multiple rib fractures; closed fracture of both forelegs with pelvic fracture and rib fractures; closed limb fractures; limb fracture with pelvic fracture; spinal fractures; hind leg fractures with pelvic fractures; pelvic fracture with multiple rib fractures; closed fracture of both fore legs with pelvic fracture; and closed fracture of both fore legs with multiple rib fractures. In each model group, gastrointestinal motility was assayed and the histopathology of the small intestine was examined. Western blot and immunohistochemical analyses of jejunal tissue were performed to detect c‐kit protein expression, the level of which was compared with that of a control group. The results of ANOVA are expressed as mean ± standard deviation. Results: In mice with multiple fractures, food intake was greatly reduced, consistent with histopathological evidence of an injured intestinal epithelium. The jejunal tissue of mice in groups a, c, f, and h was characterized by extensively necrotic and exfoliated intestinal mucosal epithelium and inflammatory cell infiltration in the lamina propria. In the gastrointestinal function assay, gastrointestinal motility was significantly reduced in groups a, b, c, f, and g; these group also had a higher ISS (p < 0.01). The expression of c‐kit protein in groups with gastrointestinal dysfunction was significantly up‐regulated (p < 0.001) compared with the control group. The close correlation between c‐kit expression and the ISS indicated an influence of trauma severity on gastrointestinal motility. Conclusion: Gastrointestinal dysfunction after multiple fractures was successfully reproduced in a mouse model. In these mice, c‐kit expression correlated with gastrointestinal tissue dysfunction and might serve as a therapeutic target. [ABSTRACT FROM AUTHOR]

A nonlinearity measurement of the charge-coupled device (CCD) array spectrometer using flux addition and comparison method is described. The light with various colors from the colorful light emitting diode (LED) light source is applied to measure the nonlinearity of the spectrometer at different wavelengths, respectively. An high-end CCD array spectrometer is tested. For colorful LED light sources, the nonlinearity factors of the CCD array spectrometer (absolute value) are as follows: k<0.8% for white light, k <1.1% for red light, k <2.2% for green light and k<4.7% for blue light. By using those quasi-monochromatic light sources, it is shown that the nonlinearity depends on the wavelength. It is important to be wariness about the spectral nonlinearity and related uncertainty evaluation when the narrow-band light source is tested. [ABSTRACT FROM AUTHOR]

• A dynamic model of gear-rotor-bearing with pitting faults considering friction and eccentricity is proposed. • The vibration features of the gear system with different pitting area ratios are firstly investigated. • The increase of eccentricity greatly influences the rotational frequency and cause low frequency and significant amplitude condition. • The change of friction coefficient can affect the degree of meshing impact in the pitting area. In this paper, a dynamics model of a bending-torsion coupled gear-bearing transmission system is developed, and the vibration features of a pitting fault gear system considering eccentricity and friction are analyzed. Firstly, the time-varying meshing stiffness of pitting faulty propagation is calculated by the parsing method. The vibrational differential equations for this model are obtained using an energy approach based on Lagrange equations. Then, the equations are solved using the Runge-Kutta method to obtain the vibration response of the system. Finally, the effect of the pitting area ratio on the vibration features of the pitting faulty gear is analyzed by the time, frequency, and time–frequency domains. The sideband rating factor is presented to evaluate the influences of pitting faults. The effects of the eccentricity and friction on the impact caused by the pitting is analyzed. [ABSTRACT FROM AUTHOR]