Objective To investigate the epidemiological characteristics of dengue fever in Shenzhen City in 2024, so as to provide insights into formulation of the preventive and control measures for dengue fever. Methods The epidemiological data of dengue cases reported in Shenzhen City in 2024 were extracted from the China Disease Prevention and Control Information System and field epidemiological survey data of dengue fever in Shenzhen City, and the temporal, regional and population distributions of dengue fever cases, source of acquire dengue virus infections, disease diagnosis and treatment and outbreaks were analyzed. The dengue virus nucleic acid was tested and the serotypes of dengue virus were characterized using real-time quantitative reverse transcription PCR (RT-qPCR) assay, and the dengue virus gene was sequenced using next-generation sequencing (NGS). In addition, the surveillance on the density of Aedes albopictus was performed using Breteau index (BI) and mosquito oviposition index (MOI). Results A total of 1 735 dengue fever cases were reported in Shenzhen City in 2024, including 952 local cases and 783 imported cases. Most imported dengue fever cases acquired infections from eight cities of Foshan, Guangzhou, Zhongshan, Jiangmen, Dongguan, Zhaoqing, Huizhou, and Zhuhai in the Pearl River Delta region (664 cases, 84.8% of total imported cases) into Baoan, Longgang, and Nanshan districts. The epidemic exhibited an early onset and rapid progression, peaking during the period between September and November (1 632 cases, 94.1% of total cases), and dengue fever cases were distributed across 73 subdistricts in 10 districts, with most cases reported in densely populated central and western regions. The dengue fever cases had a male-to-female ratio of 1.9∶1.0, and a median age of 37 (21) years, with a higher median age among local cases than among imported cases [40 (20) years vs. 33(15) years; Z = -10.30, P < 0.05]. Housework, unemployment, workers, and business service were predominant occupations (1 405 cases, 81.0% of total cases), and there was a significant difference in the constituent ratio of occupations between local and imported cases (χ² = 92.30, P < 0.05). Among the 1 735 dengue fever cases, the median duration from onset to definitive diagnosis was 3.3 (2.9) days, and 1 686 cases (97.2%) were identified in healthcare facilities, with a low rate of hospitalization and isolation seen in 1 701 inpatients with available epidemiological data (485 cases, 28.5% of total inpatients). A total of 29 outbreaks of dengue fever occurred in Shenzhen City across 2024, which primarily in construction sites (27 outbreaks, 93.1% of total). Dengue virus type I was the dominant serotype causing dengue fever in Shenzhen City in 2024. Sequencing showed that the genomes of dengue virus from multiple dengue fever cases in Shenzhen City shared a high sequence homology with those from cities neighboring Shenzhen City, and there might be intra-city transmission of dengue virus among multiple construction sites in Shenzhen City. The Aedes albopictus density was significantly higher in Shenzhen City in 2024 than in 2023, peaking from May to September. The annual MOI values ranged from 0.9 to 14.0, and the BI values ranged from 0.6 to 6.0. Conclusions The overall epidemic of dengue fever was severe in Shenzhen City in 2024, which was greatly affected by case importation from neighboring cities, construction sites-centered local transmission, and the effectives of routine mosquito vector control was not satisfactory. Integrated dengue fever control measures should be implemented, focusing on regional joint prevention and control mechanisms, capacity building for mosquito vector control, addressing challenges in epidemic containment at construction sites, and strengthening case detection and management systems.

Malus floribunda Siebold. (Malus) is widely cultivated all over the world, which is of high ornamental value and breeding significance. Comparative analysis of the chloroplast genome can help enrich the phylogenetic relationship and facilitate germplasm utilization of Malus. Based on the whole genome sequencing data, a complete chloroplast genome (M. floribunda) with tetrad structure was assembled. The chloroplast genome (160 037 bp) was composed of a large single-copy (LSC) region (88 142 bp), inverted repeat (IR) B (26 353 bp), a small single-copy (SSC) region (19 189 bp), and IRA (26 353 bp). A total of 111 genes were annotated: 78 protein-coding genes, 29 tRNA genes and 4 rRNA genes. In addition, a large number of repeat sequences were identified in the genome, which was slightly different from that of M. sieboldii and M. toringoides. As for the relative synonymous codon usage, 30 high-frequency codons were found, and the codons tended to end with A/T. The results of interspecific sequence alignment and boundary analysis suggested the sequence variation of the LSC region was large, and the expansion and contraction of the SC region and IR region of the eight Malus species were generally similar. According to the phylogenetic analysis of chloroplast genome sequences, M. floribunda, M. hupehensis, and M. toringoides were grouped into one clade. The findings in this study can provide data support for the development of genetic markers and utilization of germplasm resources in the future.
Genome, Chloroplast ; Malus ; Phylogeny ; Plant Breeding ; Codon

Objective:To observe the effect of hypoxia on the dedifferentiation process of chondrocytes in vitro and explore the role of collagen prolyl 4-hydroxylase (C-P4Hs).Methods:Chondrocytes were treated with COCl 2 for different concentrations, and selecting the optimal COCl 2 concentration for hypoxia inductionwas100 μmol/L, the mouse costal chondrocytes were divided into the normal oxygen group and the hypoxia group, and the indexes of the 3rd generation 0.5-72 h and the 1st, 3rd, 5th and 7th generation at 72 h were detected respectively. The proliferation rate was determined by CCK8 method and cell count, and the dynamic changes of HIF-1α, P4Hα1, P4Hα2 and Col II in each group were detected by RT-qPCR, IF and Western blot. Results:Costal chondrocytes were cultured under different concentration of COCl 2 for 48 h. When COCl 2>150 μmol/L, the proliferation rate ( P<0.05) was significantly decreased. Normal oxygen and hypoxia induced rib chondrocytes for 0-72 h, and RT-qPCR showed significant increases in P4Hα2 and Col II mRNA in hypoxia group ( P<0.05). IF showed that HIF-1α and P4Hα2 accumulated in the nucleus under hypoxia, and P4Hα2 gradually entered the cytoplasm from the nucleus. Westernblot analysis showed that HIF-1α and P4Hα2 protein expressions were significantly increased in hypoxia group ( P<0.05). The expression of Col II protein in hypoxia group ( P<0.05) increased at the induction stage. CCK8 and cell count results showed that the proliferation rate and cell number of each generation in the hypoxic group were significantly increased ( P<0.05), and there was still potential for proliferation when the cells were transferred to the 6-7 generation. RT-qPCR showed that hypoxia group each generation cells P4Hα2, Col II mRNΑ were significantly increased ( P<0.05). Westernblot results showed that HIF-1α, P4Hα2 and Col II protein expressions were increased in each generation of hypoxia group ( P<0.05). ConcIusion:Increased expression of P4Hα2 through hypoxia induced HIF-1α can accelerate post-translational modification of Col II in chondrocytes and increase synthesis and accumulation of Col II. P4Hα2 may be responsible for increased proliferation rate and delayed dedifferentiation of chondrocytes cultured in vitro under hypoxia condition.

OBJECTIVE: To establish a cone beam computed tomography (ECBCT) system for high-resolution imaging of the extremities. METHODS: Based on three-dimensional X-Ray CT imaging and high-resolution flat plate detector technique, we constructed a physical model and a geometric model for ECBCT imaging, optimized the geometric calibration and image reconstruction methods, and established the scanner system. In the experiments, the pencil vase phantom, image quality (IQ) phantom and a swine feet were scanned using this imaging system to evaluate its effectiveness and stability. RESULTS: On the reconstructed image of the pencil vase phantom, the edges were well preserved with geometric calibrated parameters and no aliasing artifacts were observed. The reconstructed images of the IQ phantom showed a uniform distribution of the CT number, and the noise power spectra were stable in multiple scanning under the same condition. The reconstructed images of the swine feet had clearly displayed the bones with a good resolution. CONCLUSIONS The ECBCT system can be used for highresolution imaging of the extremities to provide important imaging information to assist in the diagnosis of bone diseases.
Algorithms ; Animals ; Artifacts ; Calibration ; Cone-Beam Computed Tomography ; instrumentation ; methods ; Equipment Design ; Extremities ; diagnostic imaging ; Image Processing, Computer-Assisted ; methods ; Phantoms, Imaging ; Radiographic Image Enhancement ; instrumentation ; methods ; Swine

BACKGROUND:Proximal femoral nail anti-rotation has good biomechanical basis, and has obvious advantages for intertrochanteric fracture in aged patients, but there are some problems in the clinic, because of improper handling of material matching and operation details, which can impact therapeutic effects and functional recovery. OBJECTIVE:To analyze the efficacy and issues of proximal femoral nail anti-rotation in the treatment of intertrochanteric fracture in patients at more than 60 years old. METHODS:From July 2011 to July 2012, proximal femoral nail anti-rotation was used to treat 56 cases of intertrochanteric fractures. Clinical data bank was established to analyze intraopeative problems and postoperative complications. At 1, 3, 6, 9 and 12 months postoperatively, outpatient and telephone folow-up were carried out to evaluate therapeutic effects and functional recovery of hip joint. RESULTS AND CONCLUSION:Four patients died within 1 year. Seven patients lost within a year for other reasons. The remaining 45 patients were folowed with the time from 12 to 24 months, with an average time of 18.2 months. Harris score was (85.00±6.75) points. There were excelent in 26 cases, good in 15 cases, average in 3 cases and poor in 1 case, with an excelent and good rate of 91%. 18 cases were not satisfied with the position of fracture fragments. In 9 cases, proximal femur was not match with the proximal femoral nail anti-rotation. Seven cases were not satisfied because of the location and length of the spiral blade. Seven cases affected lateral cortex fracture. One case experienced postoperative pulmonary embolism. One case suffered from cardiovascular and cerebrovascular diseases. Nine cases suffered from local sweling. 13 cases experienced hip pain. Five cases affected the healing of fracture extended. Results showed that proximal femoral nail anti-rotation for intertrochanteric fracture in aged patients obtained good outcomes, but we should improve the separation of fracture fragments and reduce intraoperative and postoperative complications.