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Additional file 1: Figure S1. Doseand DERdistribution on half of the cross section in the nucleus for the irradiated cellular model as shown in Fig. 4, where the height of the partial shell was changed to 15 μm. Relationship between the dose distribution and radial distance from the center of the nucleus as well as the polar angle θ. Figure S2. Dose and DER profile along the 90-degree radial axis of the cross section of the nucleus for irradiated cellular model, as shown in Fig. 4, where the height of the partial shell was changed to 15 μm.

Bovine herpesvirus type 1 (BHV-1) is a neurotropic herpesvirus that causes infectious rhinotracheitis and vulvovaginitis in cattle. The virion host shutoff protein encoded by the BHV-1 UL41 gene is highly conserved in the Alphaherpesvirinae subfamily. This protein can degrade viral and host messenger RNA (mRNA) to interrupt host defense and facilitate the rapid proliferation of BHV-1. However, studies on the BHV-1 UL41 gene are limited, and BHV-1 defective virus construction using the CRISPR/Cas9 system is somewhat challenging. In this study, we rapidly constructed a BHV-1 UL41-deficient strain using the CRISPR/Cas9 system in BL primary bovine-derived cells. BHV-1 UL41-defective mutants were screened by Western blot analysis using specific polyclonal antibodies as the primary antibodies. During the isolation and purification of the defective strain, a mixed virus pool edited by an efficient single-guide RNA (sgRNA) showed a plaque number reduction. Viral growth property assessment showed that BHV-1 UL41 was dispensable for replication, but the UL41-defective strain exhibited early and slowed viral replication. Furthermore, the BHV-1 UL41-deficient strain exhibited enhanced sensitivity to temperature and acidic environments. The BHV-1 UL41-deficient strain regulated viral and host mRNA levels to affect viral replication.

Pain is the most significant symptom of knee osteoarthritis (OA), which seriously affects the quality of life of patients. However, the cause of pain, pain relief, and targeted treatment methods are still unclear. Based on the diversified characteristics of knee pain location, this study was aimed to explore the associations between knee pain location and the mechanical properties of soft tissues in patients with knee OA. Fifteen healthy participants and 55 patients with knee OA were recruited and divided into five groups: no pain, anterior superior pain, anterior inferior pain, medial pain, and lateral pain. The Young’s moduli of the muscles, tendons, and ligaments around the knee joint were measured by shear wave elastography (SWE), and the differences between the five groups of soft tissue material properties were compared in this study. The Young’s moduli of the quadriceps tendon (QT), patellar tendon (PT), medial collateral ligament (MCL), and lateral patellar retinaculum (LPR) were strongly associated with pain location and were significantly increased compared with the other four groups, respectively. In addition, the Young’s moduli of the remaining soft tissue were not associated with pain location, and did not change significantly compared with the other four groups. This study provides data reference for the mechanical properties of soft tissue of healthy people and patients with knee OA, and provides a theoretical basis for more targeted pain relief, treatment, and rehabilitation in knee OA.

This study aims to explore the possibility of assessing muscle stress state using shear wave elastography (SWE). Eight healthy males participated in the measurements, and the Young's modulus of 10 leg muscles of each participant were measured in six standard positions: lying, sitting, and four quasi-static walking postures. The contributions of each muscle in the four quasi-static walking postures were examined, and the relationship between the Young's modulus and simultaneously recorded plantar pressure was preliminarily explored for the most significant muscles. Results indicate that ICC3,1 ranges from 0.941 to 0.998, and 95% CI is in the range 0.909-0.999, CV ranges from 1.45% to 9.5%, and SEM ranges from 0.026 kPa to 0.824 kPa for all the tested muscles. This indicates that the Young's modulus of the muscles, measured by SWE, showed excellent retest reliability. In the lying and sitting positions, significant differences were observed in Young's modulus of 9 muscles with the only exception of biceps femoris (BF). In the heel strike and push off positions, strong linear relationships were found between the plantar pressure and Young's modulus of gastrocnemius medialis (GM) suggesting that muscle SWE measurement may be a good indicator of ground reaction forces. This study demonstrates that the SWE measures of the muscle Young's modulus can be used to reliably reflect the quantitative change in the stiffness of a muscle at different positions, and may also be employed to estimate the ground reaction forces and muscle stress state. Although this is a great progress in studying muscle force, it is still a great challenge to measure the Young's modulus of muscle and noninvasively evaluate the muscle force in vivo using SWE.

IntroductionEarly identification and treatment of diabetic peripheral neuropathy (DPN) are crucial. Presently, the mechanism of DPN is not very clear, and there are inconclusive conclusions about the influencing factors of vascular dynamic characteristics in DPN. This study aims to detect and compare the hemodynamic characteristics of plantar blood vessels in patients with mild DPN and healthy participants to explore a simple and reliable new idea and a potential method for early assessment of DPN and to investigate the influence of gender and age on hemodynamic characteristics.Research design and methodsSixty age-matched and gender-matched patients with mild DPN (30 men and 30 women) and 60 healthy participants were randomly recruited. Color Doppler ultrasound was used to measure and analyze the hemodynamic characteristics of plantar-related vessels.ResultsUltrasonic measurements had good test–retest reliability. There may be no statistically significant differences in the blood flow velocity and blood flow in the plantar-related blood vessels of participants, irrespective of their gender and age. For patients with mild DPN, color Doppler ultrasound may indicate early hemodynamic abnormalities when there are no obvious abnormalities in the large arteries of the lower limbs, which are specifically manifested as increased blood flow velocity and blood flow in the distal small vessels.ConclusionsOur study provides in vivo data support for the dynamic characteristics of the plantar blood vessel biomechanical model and provides a new idea of in vivo and non-invasive early diagnosis of DPN.

Plantar fascia plays an important role in human foot biomechanics; however, the morphology and mechanical properties of plantar fascia in patients with flexible flatfoot are unknown. In this study, 15 flexible flatfeet were studied, each plantar fascia was divided into 12 positions, and the morphologies and mechanical properties in the 12 positions were measured in vivo with B-mode ultrasound and shear wave elastography (SWE). Peak pressures under the first to fifth metatarsal heads (MH) were measured with FreeStep. Statistical analysis included 95% confidence interval, intragroup correlation coefficient (ICC1,1), one-way analysis of variance (one-way ANOVA), and least significant difference. The results showed that thickness and Young’s modulus of plantar fascia were the largest at the proximal fascia (PF) and decreased gradually from the proximal end to the distal end. Among the five distal branches (DB) of the fascia, the thickness and Young’s modulus of the second and third DB were larger. The peak pressures were also higher under the second and third MH. This study found a gradient distribution in that the thickness and Young’s modulus gradient decreased from the proximal end to the distal end of plantar fascia in the longitudinal arch of flexible flatfeet. In the transverse arch, the thickness and Young’s modulus under the second and third DB were larger than those under the other three DB in flexible flatfoot, and the peak pressures under the second and third MH were also larger than those under the other three MH in patients with flexible flatfoot. These findings deepen our understanding of the changes of biomechanical properties and may be meaningful for the study of pathological mechanisms and therapy for flexible flatfoot.

The overall distributions of the plantar fascia thickness and Young’s modulus in the ten subjects were systematically investigated in this paper using two-dimensional ultrasound and shear wave elastography (SWE). The statistical analyses showed that ICC1,1 of the plantar fascia thickness and Young’s modulus ranged from 0.950 to 0.991, with the 95% CI in the range of 0.953–0.996. This result indicated that the thickness and Young’s modulus exhibited excellent retest reliability. The conclusion that both the thickness, $d$ , and Young’s modulus, $E$ , of the plantar fascia showed a simple and specific spatial dependence on the characteristics of the gradient distribution can be drawn. As the plantar fascia extends from the calcaneus to the five toes, both the thickness, $d$ , and Young’s modulus, $E$ , of the five bundles of plantar fascia showed a downward trend of a negative exponential function, and the thickness, $d$ , and Young’s modulus, $E$ , were the largest at the tubercle of the calcaneus and closest to the lowest value at the tubercles of the five metatarsal bones. The coefficient of determination (R2) of the fitting curve of thickness, $d$ , and Young’s modulus, $E$ , was higher than 0.959 in all ten subjects. The distribution characteristics of the plantar fascia thickness, $d$ , and Young’s modulus, $E$ , showed good consistency in the healthy subjects in this paper. The conclusions of this paper may provide more accurate references and a basis for material mechanics data for plantar fascia diseases (such as fasciitis) and foot mechanical models (such as finite element models).