Objective To study a method for determining the cumulative dose of low-energy neutrons ( < 100 keV) independently based on a CR-39 detector. Methods According to the theory of track etching kinetics, the differences in the tracks formed by low-energy neutrons or fast neutrons in a BN + CR-39 detector under broad-spectrum neutron irradiation were analyzed. A method was proposed to identify the tracks produced by low-energy neutrons under specific etching conditions while avoiding interference from fast neutron tracks. Results Experimental results demonstrated that the BN + CR-39 detector using TASTRAK PADC CR-39 track-detecting plastic could independently detect the tracks of low-energy neutrons when etched in a 6.25 mol/L NaOH solution for 1 h. The track density showed a good linear relationship with the ambient dose equivalent of low-energy neutrons, and the calibration coefficient was 0.0366 μSv·tr⁻¹·cm². Conclusion The BN + CR-39 detector proposed in this study demonstrated high sensitivity to low-energy neutrons. The track identification method can be used for effective and independent determination of the cumulative dose equivalent of low-energy neutrons.

Objective To analyze the scanning parameters and radiation dose characteristics of pediatric CT examinations in Jiangxi Province, China, and to provide a basis for optimizing radiation protection in children. Methods The data of 1021 CT scans in children aged 0-15 years were collected from seven hospitals in Jiangxi Province, including one provincial hospital, four municipal hospitals, and two county-level hospitals. The data consisted of 405 head scans, 352 chest scans, and 264 abdominal scans. The scanning parameters kV, mAs, and scan length as well as the dose metrics weighted CT dose index and dose length product (DLP) were analyzed. Differences across age groups, anatomical regions, and hospitals were compared using one-way analysis of variance, and the results were compared with domestic and foreign studies. Results There were significant differences in scanning parameters and radiation doses among children of different age groups in CT examinations, and the differences between hospitals were also significant. The chest mAs and DLP in Hospital E were significantly higher than those in Hospital A, and the abdominal DLP in Hospital D was 4.3 times that of Hospital A. Compared with domestic and foreign studies, the DLP values of various anatomical regions in the < 1 year group were generally higher in the present study. The abdominal DLP in the < 1 year group (232.4 mGy·cm) was 3.3 times that in Tianjin. The head DLP in the 1-5 year group was higher than those in Germany and the United States. The chest DLP of the 11-15 year group was higher than that in Germany but lower than that in Henan Province. Conclusion There are significant differences in radiation doses received by children during CT examination in Jiangxi Province by age, anatomical region, and hospital, with some metrics exceeding domestic and international levels. Recommendations include optimizing scanning parameters (e.g., reducing mA/kV and adopting automatic exposure control technology), standardizing scan ranges, and establishing local diagnostic reference levels to mitigate radiation risks.

Objective:To investigate the impact of body mass index (BMI) on delayed extubation of patients with acute Stanford type A aortic dissection (ATAAD).Methods:A total of 400 ATAAD patients who were admitted to our hospital from October 2021 to October 2023 and underwent surgical treatment were selected as the research objects. According to BMI, they were divided into obese group (BMI≥28 kg/m 2, 119 cases) and non-obese group (BMI<28 kg/m 2, 281 cases). The differences of preoperative clinical characteristics, intraoperative and postoperative data between the two groups were compared. Starting from transferring to the ICU and ending with the first successful extubation, The risk factors of postoperative invasive mechanical ventilation time ≥ 48 h in ATAAD patients were analyzed, and the predictive efficacy of related factors for postoperative invasive mechanical ventilation time ≥ 48 h in ATAAD patients was evaluated. Results:Compared with the non-obese group, the proportion of hypertension, diabetes, admission heart rate, admission systolic blood pressure, admission diastolic blood pressure and preoperative white blood cell count in the obese group were significantly increased, and the differences were statistically significant ( P<0.05). The cardiopulmonary bypass time, aortic cross-clamp time, operation time, red blood cell transfusion volume, invasive mechanical ventilation time, secondary operation rate and total hospitalization cost in the obese group were significantly higher than those in the non-obese group, and the differences were statistically significant ( P<0.05). Univariate logistic regression analysis showed that BMI, cardiopulmonary bypass time, ascending aortic cross-clamp time, operation time, age, hypertension, and red blood cell transfusion were related factors for postoperative invasive mechanical ventilation time ≥48 h in ATAAD patients ( P<0.05). Logistic multivariate regression analysis showed that increased BMI ( OR=1.213, P<0.05) and increased age ( OR=1.020, P<0.05) were independent risk predictors of postoperative invasive mechanical ventilation time≥48 h in ATAAD patients. Receiver operating characteristic curve ( ROC) analysis showed that the area under the ROC curve ( AUC) of BMI for predicting the duration of postoperative invasive mechanical ventilation in ATAAD patients≥48 h was 0.682 ( P<0.05), and the best predictive cut-off value was 25.64 kg/m 2. Conclusion:BMI≥28kg/m 2 increases the difficulty of surgery and the duration of invasive mechanical ventilation in ATAAD patients. BMI has a high predictive value for the duration of invasive mechanical ventilation in ATAAD patients after surgery ≥48 h, and effective intervention measures can be formulated to improve the treatment effect of patients.

Objective To investigate the predictive value of thromboelastography(TEG)parameters in conjunction with platelet count(PLT)for guiding platelet transfusion in critically ill patients with fever associated with thrombocytopenia syndrome(SFTS).Methods Sixty-two critically ill patients with fever and thrombocytopenia syndrome were selected from the infection department of a hospital.They were divided into two groups:the bleeding group(n=30)and non-bleeding group(n=32).Changes in relevant indices,such as PLT and TEG,were com-pared between the two groups using t-test,chi-square test or non-parametric test.Binary logistic regression was employed to analyze factors predicting bleeding in critically ill patients.The efficacy of these indices in predicting bleeding was assessed by calculating the area under the receiver operating characteristic curve,determining opti-mal cut-off values,and comparing PLT levels with mortality rates using chi-square test after grouping based on MA cut-off value.Results First of all,the MA value and PLT were significantly lower in bleeding patients compared to non-bleeding patients(P<0.05),while the K value and PT were significantly higher in bleeding patients(P<0.05).Second of all,logistic regression analysis revealed that both MA value and PLT were significant influencing factors for hemorrhage in patients(P<0.05).Third of all,ROC analysis demonstrated that the area under the curve for PLT was 0.884,while for MA it was 0.890(P<0.05).Among these,PLT exhibited the highest specificity and MA value had the highest sensitivity,with a best cut-off value of 48.85 mm for MA.The combined index of K,MA,and PLT yielded an area under the curve of 0.941 and a Youden index of 0.77,which were higher than those obtained from individual indices.Finally,Rank sum test and Fisher exact test indicated that individuals with an MA value<48.85 mm had lower PLT levels and higher mortality rates(P<0.05).Conclusion The integration of TEG and PLT demonstrates significant potential in predicting bleeding events among critically ill patients with SFTS,thereby offering valuable clinical implications for guiding prophylactic platelet transfusion in this patient population.

Objective:To investigate the effects of Porphyromonas gingivalis derived outer membrane vesicles (Pg OMV) on osteoclast differentiation of macrophages and its underlying mechanisms. Methods:The morphology and the size distribution of Pg OMV were analyzed by transmission electron microscopy and nanoparticle tracing analysis, respectively. The osteoclast precursors were treated with 1, 3 and 10 mg/L Pg OMV (1, 3 and 10 mg/L OMV treatment group) or phosphate buffer solution (PBS)(control group). The formation of osteoclasts was analyzed by tartrate-resistant acid phosphase (TRAP) staining and F-actin staining and real-time quantitative PCR (RT-qPCR) were used to detect the expression of Fos and matrix metallopeptidase 9 (MMP9). Polymyxin B (PMB) was used to block lipopolysaccharide (LPS) and then Pg OMV was used to treat osteoclast precursor (PMB-OMV treatment group), and OMV treatment group was used as control. TRAP and F-actin staining were used to observe the formation of osteoclasts and actin rings. The effect of Pg OMV on the expression of Toll-like receptor (TLR) 2 and TLR4 in preosteoclasts was detected by Western blotting. The osteoclast precursors were pretreated with 10, 50, 100 and 200 μmol/L C29, an inhibitor of TLR2, and then treated with Pg OMV(OMV+10, 50, 100 and 200 μmol/L C29 treatment group) and OMV treatment group without C29 pretreatment was control. TRAP and F-actin staining were used to observe the formation of osteoclasts and actin rings. The osteoclast precursor cells were treated with OMV (OMV treatment group) and OMV incubated with PMB (PMB-OMV treatment group) and the expression of TLR2 in osteoclast precursor was detected by Western blotting.Results:Pg OMV showed classical vesicular structures, and the average particle size of Pg OMV were 179.2 nm. A large number of actin rings were observed in the 3 and 10 mg/L OMV treatment groups. The percentages of TRAP-positive osteoclast area in 3 mg/L OMV treatment group [(22.6±2.1)%] and 10 mg/L OMV treatment group [(32.0±2.3)%] were significantly increased compared with control group [(4.9±0.5)%] ( P<0.001). Compared with the control group (1.000±0.029), the mRNA relative expression of Fos in 3 mg/L OMV treatment group (1.491±0.114) and 10 mg/L OMV treatment group (1.726±0.254) was significantly increased ( P=0.013, P=0.001). Compared with the control group (1.007±0.148), the mRNA relative expression of MMP9 in the group of 10 mg/L OMV (2.232±0.097) was significantly increased ( P<0.001). Actin ring formation was less in PMB-OMV treatment groups than in OMV treatment groups. The proportion of TRAP-positive osteoclasts area [(14.8±3.8)%] in PMB-OMV treatment group was significantly lower than OMV treatment group [(31.5±6.7) %] ( P=0.004). The relative expression of TLR2 in OMV treatment group (1.359±0.134) was significantly higher than that in the control group (1.000±0.000) ( t=4.62, P=0.044). Compared with the OMV treatment group [(29.4±1.7)%], 50, 100 and 200 μmol/L C29 significantly decreased the formation of osteoclasts [(24.0±1.7)%, (18.5±2.1)%, (9.1±1.3) %] ( P=0.026, P<0.001, P<0.001). TLR2 protein expression in PMB-OMV group (0.780±0.046) was significantly lower than that in OMV group (1.000±0.000)( t=8.32, P=0.001). Conclusions:Pg OMV can promote osteoclast differentiation by carrying LPS, TLR2 plays an important role in Pg OMV mediated osteoclast differentiation.

The cytochrome P450 (CYP) family is the most important drug-metabolizing enzyme in human body and is responsible for the metabolism of endogenous and exogenous compounds. As the main site of the expression of the CYP family, the liver is the metabolic center of drugs, and in recent years, the role of the CYP family in the liver has attracted wide attention from the scholars in China and globally. This article reviews the distribution differences of the CYP family from the aspects of anatomy, genetics, and genomics, changes in the expression of the CYP family in the pathological processes such as non-alcoholic fatty liver disease, alcoholic liver disease, liver fibrosis, liver cirrhosis, and hepatocellular carcinoma, and the effect of CYP family-mediated enzyme activity on the treatment effect of pharmacotherapy for metabolic-associated liver diseases, in order to provide important enlightenment for identifying key drug intervention targets in diseases and enhancing clinical efficacy and safety.

Objective To assess the activity of Crohn’s disease (CD)by using the quantitative parameter of dynamic contrast-enhanced MRI (DCE-MRI).Methods 50 CD patients with ileocecal solitary lesion were recruited in this study.All of patients underwent con-ventional and DCE-MRI.The quantitative parameter of volume transfer constant (Ktrans )and the clinical data including Harvey-Brad-show index (HBI)and C-reactive protein (CRP)were recorded.(1)the reliability and repeatability of Ktrans measurement were analyzed. (2)the correlation between Ktrans value and clinical data was analyzed by using Pearson analysis.(3)according to HBI,all of the CD patients were divided into severe group,mild-moderate group,and static group.The differences of Ktrans values among the three groups were compared by using Mann-Whitney U test.Results (1)the reliability of Ktrans measurement was high (Cronbach’s Alpha=0.993).(2)there was positive correlation between HBI and Ktrans(r=0.635,P<0.001),and between CRP and Ktrans(r= 0.764,P<0.001).(3)there was significant difference of Ktrans value between the static group and the mild-moderate group (P<0.001),be-tween the static group and the severe group (P<0.001),and.between the mild-moderate group and the severe group (P<0.001). Conclusion Quantitative parameter of DCE-MRI (Ktrans )had a high reliability and can be used to assess the inflammation activity of CD.

OBJECTIVE:To compare the effects of strontium ranelate and PTH(1-34)on bone quality of ovariectomized rats. METHODS:80 SD rats were randomly divided into sham operation group(group A,n=10)and dual ovariectomy(group B,n=70). 3 months after operation,group B were randomly divided into 7 groups,with 10 rats in each group. B0 group were given nor-mal saline [0.9 g/(kg·d)] subcutaneously;B1-B3 groups were given low-dose,medium-dose and high-dose of strontium ranelate [0.45,0.9,1.35 g/(kg·d)] intragastrically;B4-B6 groups were given low-dose,medium-dose and high-dose of PTH(1-34)[30, 60,90 μg/(kg·d),treated for 5 days,rested for 2 days] subcutaneously. Group A was same to group B0 in therapy regimen. All rats were sacrificed 8 weeks later. The contents of P1NP and CTX-1 in serum of rats were determined by ELISA assay;bone densi-ty of 4th lumbar vertebrae was detected by bone densitometer;BV/TV,Tb.Th,Tb.N and Tb.Sp were detected by CT;maximal load and elastic modulus of 5th lumbar vertebrae were measured by compression test. RESULTS:Compared with group A,the se-rum levels of P1NP and CTX-1 in B0-B6 groups increased significantly,while bone density of 4th lumbar vertebrae,maximal load and elastic modulus of 5th lumbar vertebrae decreased significantly in B0-B3 groups(P<0.05);BV/TV level of 4th lumbar verte-brae decreased significantly,while Tb.Sp level increased significantly in B0 group(P<0.05). Compared with B0 group,bone den-sity of 4th lumbar vertebrae,maximal load and elastic modulus of 5th lumbar vertebrae increased significantly in B1-B3 groups (P<0.05);P1NP content,BV/TV,Tb.N level,bone density of 4th lumbar vertebrae,maximal load and elastic modulus of 5th lumbar vertebrae increased significantly in B4-B6 groups,and were higher than in B1-B3 groups(P<0.05). Tb.Sp level of B1-B6 groups decreased significantly and were lower than those of B1-B3 groups(P<0.05). There was no statistical significance in Tb.Th level among 8 groups and CTX-1 content among B0-B6 groups (P>0.05). CONCLUSIONS:PTH(1-34) is better than strontium ranelate in inhibiting bone loss,improving vertebral bone micro-structure and biomechanical properties of ovariectomized rats.

Objective To investigate the preventive effect of Strontium ranelate on stress-absence induced osteoporo?sis in tail-suspended rat. Methods A total of 30 SD rats with average age of 6 month were randomly divided into 3 groups (n=10 in each group):Group A was normal control group while rats in group B and C were subjected to tail suspension test to establish stress absence models. Rats in group C were administered with Strontium ranelate [1 g/(kg·d)]. All rats were sacri?ficed 4 weeks later. Left femurs were harvested for bone mineral density (BMD) test and prepared for undecalcified tissue sec?tion and thereby bone histomorphometry assessment. Bone marrow from right femurs and tibias were cultured and induced to?wards osteogenic-differentiation. The expression levels of osteocalcin in the fourth-passage cultured bone marrow cells and in blood serum were detected separately. Results Rats in group B showed markedly decreased BMD comparing to those in group A and C(P<0.05). Trabecular volume (BV/TV), number (Tb.N) and thickness (Tb.Th) in group B were lower than those in group A and C;erosion percentage (Er.Pm) and osteoclast number (Oc.N) in group B and C were higher than those in group A;comparing to those in group B, bone formation rate (BFR/BV), labeled percentage (L.Pm), were higher in group C, coupled with decreased Er.Pm and Oc.N(P<0.05). mRNA expression levels of OCN in group B and C were higher than those of group A. But its level in plasma were lower in group B than those in group A and C(P<0.05). Conclusion Tail suspension could induce osteosporosis. Strontium ranelate prevent bone loss in stress-absence osteoporosis in rat induced by tail-suspension for 4 weeks, which might be partially through upregulating the expression of OCN, thereby promoting bone formation.

Objective To investigate the effects of lovastatin alone or combined with calcitonin on fracture repair in osteoporotic rats. Methods Forty 4-month-old female SD rats were randomized into 5 groups(8 rats in each group):normal fractured group (A), osteoporotic fractured group (B), lovastatin treatment group(C), calcitonin treatment group (D) and lovastatin combined with calcitonin treatment group. All rats except group A received bilateral ovariectomy. The midshaft femur fracture model was established in all rats 8 weeks after operation. The serum level of procollagen amino-terminal propeptide (PINP) was assessed by ELISA. X-ray and bone mineral density detection was used to observe the fracture healing process. The maximal loading of femoral fractures was analyzed by biomechanical method. Results (1) The serum level of PINP was significantly lower in group A than that of other groups. There was a significantly higher level of PINP in group C and group E than that of group B, and the level of PINP was significantly lower in group D than that of group C. (2) The X-ray showed more progressed fracture healing in group A and group E. The accordingly score indicated that there was a markedly higher score in groups A and group E compared to that of other three groups. (3) There was a highest bone mineral density in the full-length and in the middle of femur bone in group A, followed by group E, group D and group C. The lowest bone mineral density was found in group B. (4) The biomechanical test showed that the maximal loading in femur fracture side was significantly higher in group A than that of other four groups, in which it was higher in group E than that of group B. Conclusion The osteoporosis decreased bone mass and delayed fracture healing process in rat model. The treatment of lovastatin combined with calcitonin showed more positive effect on preventing bone loss and promoting fracture repair than lovastatin alone.