Objective To evaluate the consistency of multi-slice spiral CT (MSCT), Digital Radiography (DR) and fat-suppression MRI in detecting occult knee joint injury. Method Clinical data from 150 patients with suspected occult knee injuries who presented to the Department of imaging at the General Hospital of Ordnance Industry between August 2022 and August 2023 were retrospectively reviewed. All patients underwent MSCT, DR, and fat-suppression MRI for diagnostic evaluation. Arthroscopic or surgical findings served as the gold standard. We analyzed and compared the detection rates of specific types of occult knee injuries (ligament, meniscus, occult fracture, etc.) across the three modalities, as well as their ability to assess the degree of collapse and horizontal displacement in patients with knee fractures, and their overall diagnostic performance. Result According to the gold standard, among the 150 patients with suspected occult knee injury, 103 tested positive and 47 negative. Statistically significant differences were observed among MSCT, DR, and fat-suppression MRI in detecting occult fractures(P<0.05). The detection rates ranked in descending order asfollows: fat-suppression MRI>MSCT>DR. However, no significant difference were found in the detection rates of joint effusion and patellar cartilage injuries among the three techniques (P>0.05). Statistically differences were also note among the three techniques in detecting the degree of collapse and horizontal displacement in patients with knee fractures (P<0.05). Specifically fat-suppression MRI identified a higher proportion of grade 1 and 2 lesions than both MSCT and DR. Statistically significant differences were observed among the three techniques in diagnostic sensitivity and accuracy for occult knee injuries (P<0.05). Fat-suppression MRI demonstrated superior sensitivity (99.03%) and accuracy (96.67%) compared with MSCT (75.73%, 79.33%) and DR (61.17%, 68.00%). However, no significant difference was found in diagnostic specificity among the three techniques (P>0.05). Conclusion Compared with MSCT and DR, fat-suppression MRI offers higher diagnostic sensitivity and accuracy for occult knee injuries, particularly in identifying ligament injuries, meniscus injuries, and occult fractures.

Objective To analyze the pollution characteristics of PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) during the non-heating period, heating period, and haze period in Harbin, and infer their possible sources, and to evaluate their impact on population carcinogenesis. Methods From 2020 to 2022, sampling points were set up in different districts of Harbin. PM_2.5 samples were regularly collected every month to analyze the contents of 10 types of PM_2.5-bound 4-6 rings PAHs. The pollution characteristics of PAHs were analyzed during different monitoring periods (non-heating period, heating period, and haze period). The excess carcinogenesis risks of PM_2.5-bound PAHs were assessed according to the Technical Specifications for Health Risk Assessment of Ambient Air Pollution and the U. S. Environmental Protection Agency (US EPA) risk assessment method. The characteristic ratio method and the positive matrix factorization (PMF) model were used to infer the sources of PAHs. Results The median mass concentrations of ambient PM_2.5-bound 4-6 rings PAHs (ΣPAHs) during the non-heating period, heating period, and haze period were 6.44 ng/m³, 37.85 ng/m³, and 106.79 ng/m³, respectively. During the heating season and haze period, the concentrations of benzo[a]anthracene, benzo[k]fluoranthene, pyrene and fluoranthene were relatively high. The excess carcinogenic risks for ASF_>16, ASF_2-16 and ASF_<2 caused by exposure to PM_2.5-bound 4-6rings PAHs during the heating season were 2.34×10^-6, 1.82×10^-6, and 0.88×10^-6, respectively, while the excess carcinogenic risks for the whole population during the heating season and haze period were 5.05×10^-6 and 1.75×10^-6, respectively. The results of the two source methods showed that the main characteristic elements during the heating season were fluoranthene, pyrene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene. According to the emission source standards, it was determined that the sources were mainly coal and biomass combustion, accompanied by traffic source emissions. Conclusion In Harbin, the PM_2.5-bound 4-6 rings PAHs during the haze period is significantly higher than that during the heating period. The pollution is mainly from coal combustion emissions, accompanied by continuous traffic source pollution. The exposure to PAHs during the heating period poses a potential carcinogenic risk to the population.

Objective To evaluate the consistency of multi-slice spiral CT (MSCT), Digital Radiography (DR) and fat-suppression MRI in detecting occult knee joint injury. Method Clinical data from 150 patients with suspected occult knee injuries who presented to the Department of imaging at the General Hospital of Ordnance Industry between August 2022 and August 2023 were retrospectively reviewed. All patients underwent MSCT, DR, and fat-suppression MRI for diagnostic evaluation. Arthroscopic or surgical findings served as the gold standard. We analyzed and compared the detection rates of specific types of occult knee injuries (ligament, meniscus, occult fracture, etc.) across the three modalities, as well as their ability to assess the degree of collapse and horizontal displacement in patients with knee fractures, and their overall diagnostic performance. Result According to the gold standard, among the 150 patients with suspected occult knee injury, 103 tested positive and 47 negative. Statistically significant differences were observed among MSCT, DR, and fat-suppression MRI in detecting occult fractures(P<0.05). The detection rates ranked in descending order asfollows: fat-suppression MRI>MSCT>DR. However, no significant difference were found in the detection rates of joint effusion and patellar cartilage injuries among the three techniques (P>0.05). Statistically differences were also note among the three techniques in detecting the degree of collapse and horizontal displacement in patients with knee fractures (P<0.05). Specifically fat-suppression MRI identified a higher proportion of grade 1 and 2 lesions than both MSCT and DR. Statistically significant differences were observed among the three techniques in diagnostic sensitivity and accuracy for occult knee injuries (P<0.05). Fat-suppression MRI demonstrated superior sensitivity (99.03%) and accuracy (96.67%) compared with MSCT (75.73%, 79.33%) and DR (61.17%, 68.00%). However, no significant difference was found in diagnostic specificity among the three techniques (P>0.05). Conclusion Compared with MSCT and DR, fat-suppression MRI offers higher diagnostic sensitivity and accuracy for occult knee injuries, particularly in identifying ligament injuries, meniscus injuries, and occult fractures.

Objective To evaluate the consistency of multi-slice spiral CT (MSCT), Digital Radiography (DR) and fat-suppression MRI in detecting occult knee joint injury. Method Clinical data from 150 patients with suspected occult knee injuries who presented to the Department of imaging at the General Hospital of Ordnance Industry between August 2022 and August 2023 were retrospectively reviewed. All patients underwent MSCT, DR, and fat-suppression MRI for diagnostic evaluation. Arthroscopic or surgical findings served as the gold standard. We analyzed and compared the detection rates of specific types of occult knee injuries (ligament, meniscus, occult fracture, etc.) across the three modalities, as well as their ability to assess the degree of collapse and horizontal displacement in patients with knee fractures, and their overall diagnostic performance. Result According to the gold standard, among the 150 patients with suspected occult knee injury, 103 tested positive and 47 negative. Statistically significant differences were observed among MSCT, DR, and fat-suppression MRI in detecting occult fractures(P<0.05). The detection rates ranked in descending order asfollows: fat-suppression MRI>MSCT>DR. However, no significant difference were found in the detection rates of joint effusion and patellar cartilage injuries among the three techniques (P>0.05). Statistically differences were also note among the three techniques in detecting the degree of collapse and horizontal displacement in patients with knee fractures (P<0.05). Specifically fat-suppression MRI identified a higher proportion of grade 1 and 2 lesions than both MSCT and DR. Statistically significant differences were observed among the three techniques in diagnostic sensitivity and accuracy for occult knee injuries (P<0.05). Fat-suppression MRI demonstrated superior sensitivity (99.03%) and accuracy (96.67%) compared with MSCT (75.73%, 79.33%) and DR (61.17%, 68.00%). However, no significant difference was found in diagnostic specificity among the three techniques (P>0.05). Conclusion Compared with MSCT and DR, fat-suppression MRI offers higher diagnostic sensitivity and accuracy for occult knee injuries, particularly in identifying ligament injuries, meniscus injuries, and occult fractures.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

Objective: To investigate the prevalence of human T-lymphotropic virus (HTLV) infection among blood donors in Hunan Province from 2022 to 2024. Methods: A total of 1 830 342 blood donors from 14 prefecture-level blood centers in Hunan Province over the past three years were screened for anti-HTLV-Ⅰ/Ⅱ using enzyme-linked immunosorbent assay (ELISA). Initially reactive samples were further tested with Line Immunoassay (LIA )/MP-Western blot and RT-PCR nucleic acid test for confirmation. Blood donors confirmed positive for HTLV were tracked and followed up. Results: From 2022 to 2024, the initial ELISA reactive rate for anti-HTLV-I/II among blood donors in Hunan Province was 1.36 per 10 000 (249/1 830 342). The confirmed positive rate was 0.20 per 10 000 (37/1 830 342), accounting for 14.86% of the initially reactive donors. The follow-up success rate for confirmed HTLV-positive blood donors was only 18.92%, while that for HTLV-indeterminate donors was 54.17%. Conclusion: The confirmed HTLV infection rates in Yueyang, Loudi, Shaoyang, Yiyang, and Zhuzhou cities were higher than the provincial (0.20 per 10 000). Chenzhou, Yongzhou, Zhangjiajie, and Xiangxi were identified as low prevalence areas, with an infection rate of 0. The overall follow-up success rate was low, indicating significant difficulties and bottlenecks in follow-up work. The comprehensive screening for HTLV and follow-up studies in Hunan provide valuable data to further improve blood safety testing strategies and risk warning mechanisms.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

Objective To develop nanobodies with broad-spectrum reactivity,specificity,and high sensitivity that can be used for detecting multiple subtypes of influenza A virus,and to establish a nanobody-based enzyme-linked immunosorbent assay(ELISA)method.Methods Gene sequences of twelve nanobodies against influenza A virus were retrieved from the National Center for Biotechnology Information(NCBI)and nanobody databases.The nanoantibodies were prepared using molecular biological techniques including gene synthesis and recombinant expression.The binding activity,specificity,sensitivity,and affinity of these nanobodies were determined by ELISA screening and Gator affinity analysis.A double-antibody sandwich ELISA assay was established by combining the selected nanobody with a traditional mouse monoclonal antibody.Results Twelve nanobodies were expressed and purified.Two nanobodies capable of binding to multiple subtypes of influenza virus including H1,H3,H5,H7,and H9 were obtained and designated as VHH54 and KV108.Both nanobodies showed no cross-reactivity with other respiratory virus antigens.Furthermore,the KV108 nanobody exhibited the highest binding affinity,with a dissociation constant of 5.94×10-9mol/L for the influenza virus nucleoprotein(NP),and the lowest detection concentration for the NP antigen reached 0.00064 μg/mL.The double-antibody sandwich ELISA,using a combination of KV108 and a mouse monoclonal antibody,could sensitively detect the five common subtypes of influenza A virus(H1N1,H3N2,H5N1,H7N9,and H9N2).The lowest detection limit reached 110-403 PFU/mL,which was higher than that of the commercial colloidal gold kitfor influenza virus detection.Conclusion This study has identified a nanobody KV108,which is capable of binding to multiple subtypes of influenza virus,and established a nanobody-based ELISA method that can detect multiple subtypes of influenza A virus.This study can facilitate the development of nanobody-based influenza detection technologies.