The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Humans ; Finite Element Analysis ; Intervertebral Disc/physiology* ; Lumbar Vertebrae/physiology* ; Weight-Bearing/physiology* ; Biomechanical Phenomena ; Stress, Mechanical ; Computer Simulation ; Models, Biological

Nosocomial infection control personnel are crucial in ensuring the nosocomial infection management and the implementation of prevention and control measures. The level of their job competency directly determines the quality and standard of nosocomial infection management. This article reviews the research progress of competency requirements and evaluation indicators of nosocomial infection personnel domestically and internationally. It also summarizes the current gaps and primary reasons behind these gaps in China’s research， so as to offer insights for the future development and improvement of the comprehensive capabilities of these professionals.

BACKGROUND:Increasing studies have found that estrogen has a certain correlation with tendinopathy,but for a long time,there are few experiments and summaries of estrogen in tendinopathy,which makes it difficult for specialists and scholars in related fields to fully understand the research status. OBJECTIVE:To summarize the current clinical or preclinical original research,so as to summarize the role of estrogen in tendinosis,and make a certain prospect for the evaluation and management of estrogen in tendinosis in the future. METHODS:Relevant literature in PubMed,Web of Science,CNKI,WanFang,and VIP databases were searched by computer.Search time was from January 2008 to September 2023.The search terms were"oestrogen,estrogen,estrogen receptor,tendinopathy,tendonopathy,sinew,tendon,tendons,myotenositis"in English and"estrogen,estrogen receptor,tendinosis,tendon,tendinitis"in Chinese.According to the selection criteria,the search results were screened and excluded,and finally 60 documents were included for review and analysis. RESULTS AND CONCLUSION:In vivo studies have shown that estrogen can promote tendon anabolism.In vitro experiments have also proved that various estrogens can promote the proliferation of tendon cells and reduce inflammation and apoptosis,but most of the experiments are limited to animal models.Estrogen receptor β acts more in tendon injury and repair processes,but estrogen receptor α has not been found to have a major impact on tendon injury.The expression of estrogen receptor β can repair the tendon by affecting the formation of fat,the deposition of type I collagen and reducing the apoptosis of tendon cells,while its over-expression may promote inflammation and angiogenesis,thus promoting the inflammatory process and playing a role in tendon injury.Animal studies have shown that estrogen deficiency may reduce the synthesis efficiency of collagen in the tendon,decrease the elasticity of tendon,inhibit the synthesis and metabolism of the tendon,which is not conducive to the repair of tendon injury,while normal level of estrogen may stimulate the synthesis of type I collagen in tendon and promote the proliferation and metabolism of tendon cells.At present,the molecular mechanism of estrogen in tendon injury has not been fully explained.More experiments focus on tendon collagen synthesis,cell proliferation and apoptosis.Only a few documents have studied the molecular mechanisms of estrogen receptor β deficiency regulating interferon regulatory factor 5-chemokine ligand 3 axis,E2 regulating estrogen receptor α and PI-3K-Akt signaling pathways,and high levels of estradiol reducing the level of free-circulating insulin-like growth factor.Various estrogens,including endogenous estrogens and phytoestrogens,are beneficial to the repair of tendinopathy at normal levels,and estrogen receptor β mainly affects the formation of fat,the deposition of type I collagen and the reduction of apoptosis of tendon cells through,which lays a foundation for the future treatment of tendinopathy with different subtypes of estrogens in vivo and the influence of estrogen membrane receptors on tendinopathy.

BACKGROUND:Avascular necrosis of the femoral head is a refractory orthopedic disease that seriously affects the normal life of patients.Hip preservation is recommended for young patients due to the limited prosthesis longevity and revision.Accurate prediction of the mechanical properties of the necrotic area in the early stage and then intervention is the key to hip preservation. OBJECTIVE:To establish a dynamic contact mechanics finite element model of necrotic femoral head based on human hip CT data and predict effects of both necrotic volume magnitude and its position on biomechanics of the necrotic region under walking movement. METHODS:CT data of a volunteer were collected and then geometry model of the hip was rebuilt.Finite element model of the necrotic femoral head was established using the Abaqus software.Nine different necrotic femoral models were constructed by combined both three different necrotic volume magnitudes(small,medium and big volume)and three different necrotic positions(coincided with,medium deviated with and kept away from the line of the force).The Von Mises of the necrotic region for all models were predicted under both 3 000 N static load and dynamical loads of one whole ISO walking gait cycle.The collapse risk for all models was evaluated based on collapse criterion. RESULTS AND CONCLUSION:(1)More approaching of the necrotic region to the line of force and bigger collapse volume made the maximum Von Mises increasing.This also enlarged the collapse risk of the necrotic region.(2)For different load types,walking movement increased the maximum Von Mises of the necrotic region than that of the value under static load under the same necrotic volume and location.(3)In conclusion,dynamic load would result in increasing of the maximum Von Mises of the necrotic region comparing to static load during exercise.Therefore,the risk of local collapse will increase due to greater Von Mises.However,the overall collapse risk is lower than that of static load due to the dynamic change of bearing area.This factor should be carefully considered by surgeons when they evaluate the mechanical performance of the necrotic femoral head.

The global prevalence of gestational diabetes mellitus(GDM)is approximately 13.4%and is ex-pected to increase annually.However,the precise mechanism behind GDM remains to be established.Increasing evi-dence suggests that insulin resistance(IR)and β-cell impairment are key factors in the pathogenesis of GDM.Endoplas-mic reticulum stress(ERS)is characterized by the activation of the unfolded protein response through three key endoplas-mic reticulum transmembrane proteins:protein kinase RNA-like endoplasmic reticulum kinase(PERK),inositol-requiring enzyme 1α(IRE1α),and activating transcription factor 6(ATF6).ERS is implicated in IR in adipose tissue,liver,skeletal muscle,and placenta,and also plays a crucial role in β-cell impairment through processes such as apopto-sis,pyroptosis,and autophagy.Therefore,targeting ERS could be a potential therapeutic approach for the prevention and treatment of GDM.This review explores the potential role of ERS in IR and β-cell dysfunction in GDM,and provides evi-dence for the preventive and intervention effects of bioactive compounds on GDM based on the ERS pathway.This aims to enhance our understanding of the molecular pathological basis of GDM and offer new strategies for its prevention and treat-ment.

Objective:To learn about the epidemiological and clinical characteristics of children with brucellosis, in order to provide reference for clinical diagnosis and treatment of brucellosis in children.Methods:Clinical data of children with brucellosis (aged ≤14 years) who visited the Department of Infectious Diseases at Beidahuang Industry Group General Hospital from December 2020 to December 2022 were retrospectively collected, and their epidemiological characteristics, clinical characteristics, laboratory tests, treatment and outcome were summarized and analyzed.Results:A total of 34 children with brucellosis were included, including 25 males (73.53%) and 9 females (26.47%), with a gender ratio of 2.78 ∶ 1.00. The median age was 8 years and 1 month, mainly in the age group of 6 to 14 years (19 cases, 55.88%). Epidemiological investigation showed that most of the affected children were rural residents (25 cases, 73.53%), with more contact with cattle/sheep (26 cases, 76.47%). The onset time was mainly concentrated in summer (15 cases, 44.12%) and spring (13 cases, 38.24%). The clinical symptoms were mainly fever (97.06%, 33/34) and arthralgia (64.71%, 22/34). In the laboratory tests, 25 cases (73.53%) had positive blood cultures, and the white blood cell count (WBC) of 30 cases (88.24%) was (4 - 10) × 10 9/L. Among the abnormalities of liver function, aspartate aminotransferase (AST) increased in 19 cases (55.88%), alanine aminotransferase (ALT) increased in 14 cases (41.18%) and γ-glutamyl transpeptidase (GGT) increased in 6 cases (17.65%). Among the myocardial enzymatic abnormalities, α-hydroxybutyrate dehydrogenase (HBDH) increased in 29 cases (85.29%), lactate dehydrogenase (LDH) increased in 27 cases (79.41%), and creatine kinase isoenzyme (CK-MB) increased in 8 cases (23.53%). After treatment, 25 children with positive blood culture turned negative. Conclusions:Children with brucellosis are mainly male, older and rural residents. The clinical manifestations are mainly fever and arthralgia. Doctors in relevant departments should conduct detailed epidemiological investigations and laboratory tests for such children in clinical work, in order to achieve early detection, diagnosis and treatment of pediatric brucellosis.

Tuberculosis (TB) remains a significant global health challenge, ranking second only to COVID-19 as the leading cause of death from a single infectious agent, with 1.3 million TB-related deaths reported in 2022. Treatment efficacy has been compromised by the emergence of drug-resistant strains, including rifampin-resistant TB (RR-TB), multidrug-resistant TB (MDR-TB), and extensively drug-resistant TB (XDR-TB). Although first-line drugs like isoniazid, rifampicin, pyrazinamide, and ethambutol form the cornerstone of TB therapy, the rise of resistant strains necessitates the use of second-line drugs, which often come with increased toxicity and limited accessibility. Recent advances have focused on repurposing existing compounds and developing new drugs with novel mechanisms of action. Promising agents such as second-generation bedaquiline analogs (TBAJ-587, TBAJ-876), sudapyridine (WX-081), delamanid, pretomanid, and TBI-166 (pyrifazimine) have shown efficacy against resistant Mtb strains. Innovative treatment regimens like the BPaLM protocol-combining bedaquiline, pretomanid, linezolid, and moxifloxacin-offer shorter, all-oral therapies with higher cure rates. Personalized treatment durations and dose optimizations are becoming feasible through risk stratification algorithms and pharmacokinetic/pharmacodynamic studies. Immunotherapy is emerging as a complementary strategy to enhance the host's immune response against Mtb. Agents such as vitamin D, corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs), statins, metformin, and biological agents like interleukins and granulocyte-macrophage colony-stimulating factor are under exploration. Additionally, cell therapies involving mesenchymal stem cells and immune effector cells present new therapeutic avenues. Despite these advancements, significant challenges remain in achieving the World Health Organization's "End TB Strategy" goals, particularly as the COVID-19 pandemic has diverted resources and attention. Ongoing research and global collaboration are crucial to develop novel therapeutic strategies, optimize treatment regimens, and ultimately reduce the global burden of TB.
Humans ; Antitubercular Agents/therapeutic use* ; COVID-19/epidemiology* ; Tuberculosis/epidemiology*

Objective:To explore the effect of fully automatic image segmentation of adenoid and nasopharyngeal airway by deep learning model based on U-Net network. Methods:From March 2021 to March 2022, 240 children underwent cone beam computed tomography（CBCT） in the Department of Otolaryngology, Head and Neck Surgery, General Hospital of Shenzhen University. 52 of them were selected for manual labeling of nasopharynx airway and adenoid, and then were trained and verified by the deep learning model. After applying the model to the remaining data, compare the differences between conventional two-dimensional indicators and deep learning three-dimensional indicators in 240 datasets. Results:For the 52 cases of modeling and training data sets, there was no significant difference between the prediction results of deep learning and the manual labeling results of doctors（P>0.05）. The model evaluation index of nasopharyngeal airway volume: Mean Intersection over Union（MIOU） s （86.32±0.54）%; Dice Similarity Coefficient（DSC）: （92.91±0.23）%; Accuracy: （95.92±0.25）%; Precision: （91.93±0.14）%; and the model evaluation index of Adenoid volume: MIOU: （86.28±0.61）%; DSC: （92.88±0.17）%; Accuracy: （95.90±0.29）%; Precision: （92.30±0.23）%. There was a positive correlation between the two-dimensional index A/N and the three-dimensional index AV/（AV+NAV） in 240 children of different age groups（P<0.05）, and the correlation coefficient of 9-13 years old was 0.74. Conclusion:The deep learning model based on U-Net network has a good effect on the automatic image segmentation of adenoid and nasopharynx airway, and has high application value. The model has a certain generalization ability.
Child ; Humans ; Adolescent ; Adenoids/diagnostic imaging* ; Image Processing, Computer-Assisted/methods* ; Pharynx ; Cone-Beam Computed Tomography ; Nose

Objective:To establish the first Mini-Formative Evaluation of Radiation Oncology (Mini-FERO) scale in China and evaluate its preliminary application value in the standardized training for radiation oncology resident physicians.Methods:Based on the educational curriculum and examination requirements for the standardized training for radiation oncology resident physicians, as well as the standardized Mini-Clinical Evaluation Exercise (Mini-CEX) scale commonly used in clinical practice, the Mini-Formative Evaluation of Radiation Oncology (Mini-FERO) scale was developed to facilitate the standardized training for resident physicians in the field of radiation oncology. In this prospective study, a randomization method using a random number table was employed to select a cohort of 26 resident physicians who completed their rotations in Department of Radiation Oncology at the Cancer Hospital, Chinese Academy of Medical Sciences from March 1, 2021 to December 31, 2021. The Mini-FERO scale was administered in the initial, middle, and final stages during the rotation period. The differences in evaluation scores before and after the assessments were analyzed by paired t-test. Furthermore, participating resident physicians and supervising teachers provided satisfaction ratings, and a comprehensive evaluation of the Mini-FERO scale was conducted. Results:The average scores of the three examinations of 26 resident physicians demonstrated a successive improvement, with individual performance in each assessed category also showing progressive enhancement. The second evaluation exhibited a more pronounced score increase compared to the first evaluation, with a mean improvement of (1.43±1.02) points ( t=7.13, P<0.001); while the third evaluation had a mean improvement of (0.41±0.50) points ( t=4.07, P<0.001) compaired to the second evaluation, with a mean difference of (1.02±1.15) points between the two ( t=4.53, P<0.001). The average time required for the assessments was (34.31±24.46) min. Overall satisfaction ratings from the evaluated resident physicians for the Mini-FERO scale were (8.42±0.85) points, and supervising teachers reported an overall satisfaction rating of (8.45±0.85) points. The satisfaction rate was 96% (25/26). Conclusions:In this study, the Mini-FERO scale was successfully developed and validated in the context of clinical teaching practice for radiation oncology resident physicians. The Mini-FERO scale is proven to be a feasible tool for assessing the gradual improvement of resident physicians throughout their learning process in the field of radiation oncology. Importantly, it offers the advantages of short assessment time, thereby avoiding additional burden on supervising teachers. The adoption of the Mini-FERO scale addresses current limitations of lacking of formative evaluation in the standardized training for radiation oncology resident physicians.

Objective:To investigate the effects of 40 Hz and 70 Hz frequency flash stimulation on the ability of learning memory and autonomous exploratory in young rats.Methods:Twenty-seven SPF grade male SD rats aged 19-21 days were divided into control group (Ctr group), 40 Hz group and 70 Hz group with 9 in each group according to the random number table.The rats in Ctr group were not given flash stimulation, while rats in the 40 Hz and 70 Hz group were received 40 Hz, 70 Hz flash stimulation (1.5 h/d for 39 days), respectively.The Morris water maze experiment was used to assess the learning and memory ability of rats, and the open field experiment was used to evaluate the ability of autonomous exploratory of rats.Nissl staining was used to assess the morphology of Nissl bodies in the hippocampus CA1 region of the rats.The local field potentials (LFPs) collected from the primary visual cortex (V1 area) region by electrophysiological experiments was used to verify the synchronization of flash evoked neural oscillations.SPSS 23.0 software was used for statistical analysis.The repeated measures ANOVA and one-way ANOVA were used to analyze normal distribution measurement data, and LSD and Tamhane tests were used for further pairwise comparison.The Kruskal-Wallis test was used for non-normal distribution measurement data.Results:(1) The flash stimulation of 40 Hz and 70 Hz both can effectively caused synchronization of neural oscillations in the primary visual cortex of healthy young rats.(2) The results of repeated measures ANOVA analysis showed that there was no interaction effect of grouping and time in the escape latency of young rats in the Morris water maze positioning navigation phase( F=1.326, P>0.05 ). The escape latency had time main effect ( F=40.025, P<0.05), but no grouping main effect ( F=2.039, P>0.05). With the increase of learning days, the escape latency of young rats in each group decreased significantly.There was no interaction effect of grouping and time in the total distance of young rats ( F=2.029, P>0.079). It had time main effect ( F=32.052, P<0.05), but not grouping main effect ( F=2.390, P>0.05) on total distance.With the increase of learning days, the total distance of young rats in each group significantly shortened.On the 6th day of the Morris water maze experiment, there was no statistically significant difference among groups in terms of time in the target quadrant and the number of crossing platforms ( F=2.511, 0.802, both P>0.05). The results of the open field experiment showed that the total distance traveled in the center of young rats in each group was statistically significant ( H=8.935, P<0.05), the total distance traveled in the center in the 70 Hz group (3.80 (2.25, 6.93) m)was significantly longer than that in the 40 Hz group (0.80 (0.72, 1.46) m), P<0.05). The percentage of time spent in the center was statistically significant in the three groups ( H=11.050, P<0.05). Young rats in the 70 Hz group spent significantly higher percentage of time in the center(3.20(2.43, 8.30)) than those in the 40 Hz group (0.95 (0.37, 1.06 ), P<0.05 ). (3) Nissl staining results showed that Nissl bodies in the hippocampal CA1 area of young rats in Ctr, 40 Hz and 70 Hz group were all arranged neatly and tightly, no edema was found in the surrounding stroma, and no obvious inflammatory cell infiltration was found. Conclusion:70 Hz frequency flash stimulation may promote the ability of learning memory and autonomous exploratory of young rats.