The breakage pattern of unit particles during the production of oral solid dosage forms (OSD) is closely related to the quality of intermediate or final products. To accurately characterize the particles and study the evolution law of particle breakage, the Bonding model of the discrete element method (DEM) was used to investigate the breakage patterns of model parameters, particle shape and process conditions (loading mode and loading rate) on the dynamic breakage, force-time curve, breakage rate, maximum breakage size ratio and fracture strength of particles. The results showed that the particle breakage force was positively correlated with normal strength and bonded disk scale, negatively correlated with normal stiffness per unit area and tangential stiffness per unit area, and weakly correlated with tangential strength. The particle breakage rate was negatively correlated with the aspect ratio of the particles, and the maximum breakage size ratio was positively correlated with the aspect ratio of the particles; among the three loading modes, the breakage rate of compression breakage model was the largest, the breakage rate of shear breakage model was the second largest, and the breakage rate of wear breakage model was the smallest; the maximum breakage size ratio was positively correlated with the loading rate, the loading mode and the loading rate had no mutual influence on particle breakage rate, but had mutual influence on the maximum breakage size ratio. The research results will provide a theoretical basis for the shift of OSD from batch manufacturing to advanced manufacturing.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Objective To explore the difference in efficacy of metoprolol versus ivabradine in the treatment of postural orthostatic tachycardia syndrome(POTS)in the elderly after COVID-19 infection.Methods A total of 110 patients diagnosed with POTS at our department from Decem-ber 1,2022 to January 31,2023 were included.According to their drug regimen,they were divided into metoprolol group(62 patients)and ivabradine group(48 patients).On the 28th day of out-patient follow-up,the resting heart rate,heart rate of 10 min of standing,symptom disappearance rate,hospitalization rate,and mortality rate were compared between the two groups.Results On the 28th day of treatment,the resting heart rate and postural heart rate for 10 min were decreased in both groups when compared with the levels at initial diagnosis(P＜0.01).And there were no significant differences in the two types of heart rate between the two groups on the 28th day(71.0±7.0 vs 72.1±7.0,P=0.401;76.5±7.2 vs 77.4±7.6,P=0.573).No obvious differences were observed between the two groups in symptom disappearance rate,hospitalization rate,or mortality rate(88.7％vs 89.6％,3.2％vs2.1％,0％vs 0％,P＞0.05).Conclusion Metoprolol and ivabradine can effectively treat POTS in the elderly patients after COVID-19 infection.

BACKGROUND:Compared with traditional two-dimensional culture,three-dimensional microtissue culture can show greater advantages.However,more favorable cultivation methods in three-dimensional culture still need to be further explored. OBJECTIVE:To evaluate the cell behavior of microtissue and its ability to promote cartilage formation under two three-dimensional culture methods. METHODS:Cartilage-derived microcarriers were prepared by chemical decellularization and tissue crushing.DNA quantification and nuclear staining were used to verify the success of decellularization,and histological staining was used to observe the matrix retention before and after decellularization.The microcarriers were characterized by scanning electron microscopy and CCK-8 assay.Cartilage-derived microtissues were constructed by combining cartilage-derived microcarriers with human adipose mesenchymal stem cells through three-dimensional static culture and three-dimensional dynamic culture methods.The cell viability and chondrogenic ability of the two groups of microtissues were detected by scanning electron microscopy,live and dead staining,and RT-qPCR. RESULTS AND CONCLUSION:(1)Cartilage-derived microcarriers were successfully prepared.Compared with before decellularization,the DNA content significantly decreased after decellularization(P<0.001).Scanning electron microscope observation showed that the surface of the microcarrier was surrounded by collagen,maintaining the characteristics of the natural extracellular matrix of cartilage cells.CCK-8 assay indicated that microcarriers had no cytotoxicity and could promote cell proliferation.(2)Scanning electron microscopy and live and dead staining results showed that compared with the three-dimensional static group,the three-dimensional dynamic group had a more extended morphology of microtissue cells,and extensive connections between cells and cells,between cells and matrix,and between matrix.(3)The results of RT-qPCR showed that the expressions of SOX9,proteoglycan,and type Ⅱ collagen in microtissues of both groups were increased at 7 or 14 days.The relative expression levels of each gene in the three-dimensional dynamic group were significantly higher than those in the three-dimensional static group at 14 days(P<0.05).At 21 days,the three-dimensional static group had significantly higher gene expression compared with the three-diomensional dynamic group(P<0.001).(4)The results showed that compared with three-dimensional static culture microtissue,three-dimensional dynamic culture microtissue could achieve higher expression of chondrogen-related genes in a shorter time,showing better cell viability and chondrogenic ability.

Platycodonis Radix is the dry root of Platycodon grandiflorum of Campanulaceae, which has a variety of pharmacological effects and is a commonly used bulk Chinese medicine. In this study, the chloroplast genome sequences of six P. grandiflorum from different producing areas has been sequenced with Illumina HiSeq X Ten platform. The specific DNA barcodes were screened, and the germplasm resources and genetic diversity were analyzed according to the specific barcodes. The total length of the chloroplast genome of 6 P. grandiflorum samples was 172 260-172 275 bp, and all chloroplast genomes showed a typical circular tetrad structure and encoded 141 genes. The comparative genomics analysis and results of amplification efficiency demonstrated that trnG-UCC and ndhG_ndhF were the potential specific DNA barcodes for identification the germplasm resources of P. grandiflorum. A total of 305 P. grandiflorum samples were collected from 15 production areas in 9 provinces, for which the fragments of trnG-UCC and ndhG_ndhF were amplificated and the sequences were analyzed. The results showed that trnG-UCC and ndhG_ndhF have 5 and 11 mutation sites, respectively, and 5 and 7 haplotypes were identified, respectively. The combined analysis of the two sequences formed 13 haplotypes (named Hap1-Hap13), and Hap4 is the main genotype, followed by Hap1. The unique haplotypes possessed by the three producing areas can be used as DNA molecular tags in this area to distinguish from the germplasm resources of P. grandiflorum from other areas. The haplotype diversity, nucleotide diversity and genetic distance were 0.94, 4.79×10^-3 and 0.000 0-0.020 3, respectively, suggesting that the genetic diversity was abundant and intraspecific kinship was relatively close. This study laid a foundation for the identification of P. grandiflorum, the protection and utilization of germplasm resources, and molecular breeding.

Objective　To explore the mediating role of cognitive function in the association between literacy level and depressive symptoms in middle-aged and elderly people in China. Methods　 Using the fourth national follow-up data of the China Health and Elderly Care Tracking Survey 2018, 8 124 middle-aged and elderly people aged 45 years and above were included as the study subjects. The PROCESS 4.0 program was used to test the mediating effect of cognitive function between literacy level and depressive symptoms, and the Bootstrap method was used for the mediator variable validation. Results The detection rate of depressive symptoms among middle-aged and elderly people in China was 38.10%. After controlling for gender, place of residence, marital status, smoking, alcohol consumption, and exercise, literacy level was a negative predictor of depressive symptoms in middle-aged and elderly people (β =－0.480, t =－11.248, P<0.001). Cognitive function accounted for 58.75% of the amount of mediating effect between literacy level and depressive symptoms. Conclusion 　Literacy level and cognitive function are associated with depressive symptoms in middle-aged and elderly people. Literacy level can influence depressive symptoms directly or indirectly through the mediation of cognitive dysfunction.

To understand Helicobacter pylori's drug resistance,genetic diversity,and relationship with clinical diseases in the Guiyang and Qiannan minority areas of Guizhou Province,we collected samples through endoscopy,and isolated and cul-tured H.pylori.The drug resistance and genotype characteristics were determined.The differences in different regions and dis-ease types were compared,and the structural characteristics of H.pylori and mixed infections with different strains of H.py-lori in Qiannan Prefecture were analyzed.A difference in the composition ratio of EPYIA typing in the cagA variable region was observed between the two areas(P=0.012),and the composition ratio of the vacA genotype differed(P=0.000).A total of 94.6％(53/56)new sequences of H.pylori strains from two regions were obtained by MLST.The rate of infection by H.pylori mixed with different strains was 44.4％in Qiannan Pre-fecture,and no significant difference was observed in the com-position of H.pylori mixed infections among patients with dif-ferent clinical diseases(P=0.349).Differences in EPI YA typ-ing and the vacA genotype composition ratio in the cagA varia-ble region of H.pylori were observed between the Qiannan Prefecture and Guiyang City.