Analysis of Stochastic SIRC Model with Cross Immunity Based on Ornstein-Uhlenbeck Process.

In this paper, we analyze a stochastic SIRC model with Ornstein-Uhlenbeck process. Firstly, we give the existence and uniqueness of global solution of stochastic SIRC model and prove it. In addition, the existence of ergodic stationary distributions for stochastic SIRC system is proved by constructing a suitable series of Lyapunov functions. A quasi-endemic equilibrium related to endemic equilibrium of deterministic systems is defined by considering randomness. And we obtain the probability density function of the linearized system near the equilibrium point. After the proof of probability density function, the sufficient condition of disease extinction is given and proved. We prove the theoretical results in the paper by numerical simulation at the end of the paper.

Trace Doping of Pb(OH)2 Species on PdPb Alloys Boost Highly Active and Stable Ethanol Oxidation.

PdPb nanocrystals have drawn considerable attention due to their excellent catalytic properties, while their practical applications have been impeded by the severe degradation of activity, which is caused by the adsorption of intermediates (especially CO) during the operation. Herein, we first present porous PdPb alloys with the incorporation of amorphous Pb(OH)2 species as highly active and stable electrocatalysts. Alloying Pd with Pb species is initially proposed to optimize the Pd-Pd interatomic distance and adjust the d-band center of Pd. Importantly, the amorphous Pb(OH)2 species are beneficial to promoting the formation of OHad and the removal of COad. Therefore, PdPb-Pb(OH)2 catalysts show a mass activity of 3.18 A mgPd -1 and keep excellent stability for the ethanol oxidation reaction (EOR). In addition, further CO stripping and a series of CO poisoning experiments indicate that PdPb-Pb(OH)2 composites possess much better CO tolerance benefiting from the tuned electronic structure of Pd and surface incorporation of Pb(OH)2 species.

[Bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach for osteoporotic vertebral compression fracture of lumbar].

OBJECTIVE: To evaluate the feasibility and short-term effectiveness of bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach for osteoporotic vertebral compression fracture (OVCF) of lumbar. METHODS: A retrospective analysis was made on the clinical data of 93 patients with OVCF of lumbar who met the selection criteria between January 2018 and June 2019. According to the different surgical methods, they were divided into group A (44 cases, treated with bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach) and group B [49 cases, treated with percutaneous kyphoplasty (PKP) via bilateral transpedicle approach]. There was no significant difference in gender, age, body mass index, T value of bone mineral density, injury cause, fractured level, time from injury to operation, comorbidities, and preoperative Cobb angle of injured vertebra, visual analogue scale (VAS) score, and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative fluoroscopy times, bone cement injection amount, and incidence of bone cement leakage were recorded and compared between the two groups; Cobb angle of the injured vertebrae, VAS score, and ODI were measured before operation, at 2 days and 1 year after operation. The contralateral distribution ratio of bone cement was calculated according to the anteroposterior X-ray film at 2 days after operation. RESULTS: The operation time and the intraoperative fluoroscopy times in group A were significantly less than those in group B ( P<0.05). There was no bone cement adverse reactions, cardiac and cerebrovascular adverse events, and no complications such as puncture needles erroneously inserted into the spinal canal and nerve injuries occurred in the two groups. Bone cement leakage occurred in 6 cases and 8 cases in groups A and B, respectively, all of which were asymptomatic paravertebral or intervertebral leakage, and no intraspinal leakage occurred; the bone cement injection amount and incidence of bone cement leakage between the two groups showed no significant differences ( P>0.05). The contralateral distribution ratio of bone cement in group A was significantly lower than that in group B ( t=2.685, P=0.009). Patients in both groups were followed up 12-20 months, with an average of 15.3 months. The Cobb angle of the injured vertebrae, VAS score, and ODI in the two groups were significantly improved at 2 days after operation, however, the Cobb angle of the injured vertebra at 1 year after operation was significantly lost when compared with the 2 days after operation, the VAS score and ODI at 1 year after operation were significantly further improved when compared with the 2 days after operation, the differences were all significant ( P<0.05). There was no significant difference in the Cobb angle of the injured vertebrae, VAS score, and ODI between the two groups at each time point after operation ( P>0.05). CONCLUSION: Bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach is comparable to bilateral PKP in short-term effectiveness with regard to fracture reduction, reduction maintenance, pain relief, and functional improvement. It has great advantages in reducing operation time and radiation exposure, although it is inferior in bone cement distribution.

The Role of Interferon Regulatory Factor 5 in Macrophage Inflammation During Osteoarthritis.

Mounting evidence suggests that aberrant immune responses are involved in the pathogenesis of osteoarthritis (OA). Synovial macrophages are likely involved. In this study, we sought to investigate the role of interferon regulatory factor 5 (IRF5). In vitro M1-polarized macrophages presented significantly higher IRF5 expression than M2-polarized macrophages. Interestingly, IRF5 expression was observed in macrophages from the synovial fluid of OA patients, and the level of IRF expression was positively correlated with disease severity, such that stage 4 OA synovial macrophages presented significantly higher levels of IRF5 than stage 2 and stage 3 OA synovial macrophages. Circulating monocytes from OA patients, on the other hand, expressed little IRF5. However, synovial fluid from OA patients could significantly upregulate IRF5 expression in circulating monocytes. Synovial macrophages also expressed significantly higher IL-12 than circulating monocytes, and circulating monocytes conditioned in OA synovial fluid demonstrated significantly higher IL-12 expression. Direct IRF5 transfection could increase IL-12 expression in circulating monocytes. Interestingly, IRF5-transfected monocytes promoted the expression of Th1-associated genes in naive CD4 T cells via an IL-12-dependent mechanism. Overall, our study demonstrated that IRF5 expression was associated with OA severity and could contribute to the activation of the M1-Th1 axis.

Overexpression of Lymphocyte Activation Gene-3 Inhibits Regulatory T Cell Responses in Osteoarthritis.

Lymphocyte activation gene-3 (LAG-3) is a CD4 homologue expressed on the surface of activated conventional T cells and regulatory T (Treg) cells. In conventional T cells, LAG-3 acts as an inhibitory receptor of T cell inflammation. However, the role of LAG-3 in Treg cells remains controversial. In this study, we investigated the effect of LAG-3 on Tregs in osteoarthritis (OA). We observed that the proportion of LAG-3-expressing cells in CD4+CD25+/high T cells and Foxp3+CD4+CD25+/high T cells were significantly upregulated in OA patients. The level of LAG-3-to-Foxp3 ratio was further increased in synovial fluid. Several aspects of Treg responses in LAG-3+ and LAG-3- Treg cells were then examined. First, LAG-3+ Treg cells demonstrated significantly lower proliferation than LAG-3- Treg cells. Second, the increase in interleukin (IL)-10 and transforming growth factor (TGF)-ß expression was significantly lower in LAG-3+ Treg cells than that in LAG-3- Treg cells. Third, LAG-3+ Treg cells were less capable of inhibiting the proliferation of CD4+CD25- conventional T cells than LAG-3- Treg cells. This study suggests that Treg cells in OA may be enriched with a LAG-3-expressing population that exhibits functional impairment, which limits their capacity in suppressing inflammation.

Adaptation of muscles of the lumbar spine to sudden imbalance in patients with lower back pain caused by military training.

OBJECTIVE: This study aims to investigate the effects of sudden load changes (expected and unexpected imbalance) on the activity of muscles of the lumbar spine and their central motor control strategy in military personnel with or without chronic low back pain (LBP). DESIGN: Bilateral sudden imbalance was examined (2 × 2 factorial design). SETTING: The 117th PLA Hospital, Hangzhou, China PARTICIPANTS: Twenty-one male subjects with lower back pain and 21 male healthy control subjects were active members of the Nanjing Military Region land forces. OUTCOME MEASURES: Independent variables: LBP vs. healthy controls and imbalance anticipation (expected and unexpected imbalance). DEPENDENT VARIABLES: rapid reaction time (RRT) and intensity of rapid reaction (IRR) of bilateral lumbar (L3-L4) erector spinae (ES), lumbar (L5-S1) multifidus (MF), and abdominal external oblique muscles. Results Under expected or unexpected sudden imbalance conditions, subjects with LBP demonstrated significantly greater IRR than healthy controls in ipsilateral and contralateral ES and MF, respectively (P < 0.05 for all). IRR of contralateral ES was significantly larger than that of the ipsilateral ES. A significant group effect of RRT of both ipsilateral and contralateral ES muscles and a significant time expectation effect on RRT of contralateral MF muscles were also observed. RRT of the contralateral ES muscles was significantly lower than that of the ipsilateral ES muscles (P < 0.001). CONCLUSIONS: Sudden imbalance prolonged RRT of selected trunk muscles in patients with chronic LBP. The activation amplitude increased. The results may provide a theoretical basis for a study on the pathogenesis of chronic LBP.

Prevalence of low back pain among soldiers at an army base.

BACKGROUND: Low back pain (LBP) is a major medical and social problem among working populations and is associated with high medical expense, loss of productivity, and disability. The aim of this study is to investigate the prevalence of LBP among soldiers and evaluate the possible causative factors in military training. The results may provide an insight into changes needed in military training that will reduce the occurrence of LBP among soldiers. METHODS: A cross-sectional survey was conducted in a group of young soldiers in China to estimate the prevalence of LBP and evaluate possible causative factors in military training. RESULTS: The survey was distributed to 1659 soldiers, of whom 1624 responded. LBP was reported by 425 of the 1624 (26.2%) soldiers. The prevalence of LBP was higher in the armored force (51.3%) than in the artillery (27.5%) or infantry (11.9%). A multivariate logical regression analysis identified night training, 5 km cross-country race, and grenade-throwing training as military training risk factors for LBP. CONCLUSIONS: The relatively high incidence of LBP among soldiers was related to night training, 5 km racing, and grenade throwing. Modifications in these training methods should enhance the health of recruits and lower the incidence of LBP.

Influence of distal tibiofibular synostosis on ankle function.

OBJECTIVE: To study the influence of distal tibiofibular synostosis on ankle function. METHODS: From October 1998 to October 2004, a total of 281 consecutive patients underwent operations because of ankle fractures or distal fractures of the tibia and fibula. Distal tibiofibular synostosis occurred after operation in 8 patients. The duration of follow-up averaged 20.6 months (14-44 months). The ankle function was assessed on the basis of functional rating system described by Mazur.(1) RESULTS: According to Mazur's ankle evaluation system, 4 patients achieved an excellent result, 2 a good result and 2 a fair result. The dorsiflexion of the synostosis ankle reduced by 8.26 degrees as compared with that of the contralateral ankle, and there was little influence on the plantar flexion. All the patients had a normal gait. CONCLUSION: The distal tibiofibular synostosis after the operation of ankle fractures or distal fractures of the tibia and fibula usually gives rise to few symptoms and needs no specific treatment.