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.

Objective:To investigate the trend of radiological diagnostic examination frequency and the related influencing factors in a general hospital in recent four years.Methods:The hospital information system and the radiology information system were used to collect the information on the numbers of the outpatients, the emergency patients, and the inpatients and the radiology examination information from 2019 to 2022. The examination frequency and proportion of various imaging equipment were counted by using the perspective table of data, and the examination items and the proportion of the radiological diagnostic examinations were calculated. The positive rates of the radiological examinations were measured from 2019 to 2022. The gender and age distribution of the patients were analyzed. Spearman correlation analysis was used to analyze the relationships between the numbers of the patients undergoing radiological examinations and the numbers of the outpatients, emergency patients and the inpatients.Results:The annual frequency of radiological diagnostic examinations from 2019 to 2022 were 307 306, 245 418, 317 250 and 325 625, respectively, with a total of 1 195 599. Among them, the proportions of CT, X-rays, bedside X-rays, bone density, gastrointestinal imaging and mammography were 59.74%, 38.04%, 1.39%, 0.42%, 0.21% and 0.19%, respectively. In each year, the proportion of CT in all radiological diagnostic examinations was 49.58%, 63.40%, 60.40% and 65.20%, respectively. The frequency of emergency CT and emergency chest CT was correlated with the number of emergency patients( r =0.63, 0.61, P<0.05), and the frequency of non-emergency CT was correlated with the number of outpatients and inpatients ( r =0.61, 0.66, P<0.05). The positive rates of the CT examinations were higher than 80% except the lowest of 79.95% in 2021. Conclusions:Radiological examinations especially CT examinations have increased significantly, and played an important role in the diagnosis of diseases. However, attention should be paid to the Justification of the CT examinations. Timely statistical analysis of radiological examination information can provide data supports and references for scientific management of radiological examinations.

The increasing frequency of radiographic diagnostic imaging and the cumulative dose to the public from radiation has raised widespread concerns. However, accurate measurement of the radiation dose received by the human body is difficult to achieve. Monte Carlo simulation, as a numerical computational method guided by probability statistics theory, has been applied to various dose assessments, imaging optimizations, and radiation protection in radiographic diagnostic imaging. We provide a comprehensive review of the principles of the Monte Carlo method, the modelling process of Monte Carlo simulation and the progress of its application to diagnostic radiological dose estimation.

Objective To understand the genotyping of human immunodeficiency virus (HIV) co-infected hepatitis C virus (HCV) patients in Yunnan Province, and to analyze the differences in viral load, biochemical indicators, and blood routine indicators among different genotypes, in order to provide a laboratory basis for the diagnosis and clinical treatment of HIV/HCV co-infected patients. Methods From November 2022 to June 2023, the serum samples and basic information of patients diagnosed with HIV/HCV co-infection were collected in the antiviral outpatient clinic of Yunnan Provincial Hospital of Infectious Diseases. The HCV viral load was detected by one-step qRT-PCR amplification, the positive samples were sequenced, and genotyping was determined based on NS5 gene sequence. The differences in biochemical and blood routine indexes between HIV patients co-infected with different HCV genotypes and low/high viral loads were analyzed. Results A total of 126 HIV/HCV co-infected patients were collected, including 20 HCV genotype 1 (15.9%), 91 HCV genotype 3 (72.2%), and 15 HCV genotype 6 (11.9%). The maximum and minimum viral load of the three HCV genotypes were as follows: HCV type 1 (1.0×108, 4.8×104 IU/mL), HCV type 3 (2.2×108, 2.9×102 IU/mL), and HCV type 6 (8.1×107, 6.8×104 IU/mL). The results showed that there was no significant difference between HIV co-infection with different genotypes of HCV and three HIV treatment schemes, including nucleoside reverse transcriptase inhibitors+integrase strand transfer inhibitors (NRTIs+INSTIs), nucleoside reverse transcriptase inhibitors+non-nucleoside reverse transcriptase inhibitors (NRTIs+NNRTIs) and nucleoside reverse transcriptase inhibitors+protease inhibitor (NRTIs+PLs), and the viral load of patients (P>0.05). The analysis of biochemical indexes such as total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA), and blood routine indexes such as white blood cell (WBC), red blood cell (RBC), hemoglobin (HGB), platelet (PLT), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) among different HCV genotypes and low/high viral loads showed that there was no significant difference in biochemical indexes and blood routine indexes between low/high viral loads of HIV co-infected HCV patients (P>0.05); however, the biochemical indicators TBIL, IBIL and MCHC were significantly different statistically between patients with genotype 3 HCV infection and those with genotype 1 HCV infection (P<0.05), while other biochemical and blood routine indexes were not statistically different among different HCV genotypes (P>0.05). Conclusions There are six subtypes of HCV co-infection in HIV patients in Kunming, Yunnan Province, including three genes of genotype 1, 3, and 6. Among them, genotype 3 HCV is the main prevalent genetic virus among HIV co-infected populations. The TBIL, IBIL and MCHC values of HIV patients co-infected with HCV type 3 are different from those infected with HCV type 1.

Background Chronic intermittent hypobaric hypoxia (CIHH) can effectively alleviate type 2 diabetes mellitus (T2DM). In this process, the underlying mechanism in its association with the epigenetic regulation of DNA methylation in the promoter regions of glucose metabolism key enzyme genes remains unclear yet. Objective To investigate the effects of CIHH on expression and promoter region methylation of key enzyme genes related to glucose metabolism in diabetes mice, and to explore the underlying mechanism by which CIHH regulates glucose metabolism. Methods Forty C57BL/6J male mice were divided randomly into a normobaric normoxic control (NN/CON) group, a chronic intermittent hypobaric hypoxia intervention control (CIHH/CON) group, a normobaric normoxic diabetic model (NN/DM) group, and a chronic intermittent hypobaric hypoxia intervention diabetic model (CIHH/DM) group. The mice in the NN/DM and the CIHH/DM groups were fed for 7 weeks with high-fat and high-sugar diet. Subsequently, these mice were intraperitoneally injected consecutively with 50 mmol·L⁻¹ streptozotocin (STZ) for 5 d at a dose of 40 mg·kg⁻¹ (body weight) per day to create T2DM model mice. The mice in the CIHH/DM and the CIHH/CON groups were intervened by simulating hypobaric hypoxia at 5000 m altitude for 6 h per day, while the mice in the NN/DM and the NN/CON groups were always placed in a normobaric normoxic environment. All mice were continuously treated for 4 weeks, and blood glucose were monitored during this period. After the CIHH intervention experiment, the glucose tolerance and insulin sensitivity of mice were evaluated. A set of indicators involved in key glycolytic enzymes glucokinase (GK) and pyruvate kinase (PK), as well as key gluconeogenic enzymes phosphoenolpyruvate carboxyl kinase (PEPCK) and glucose-6-phosphatase (G6P) were measured in the liver of mice, including enzyme activity, relative mRNA expression level, and DNA methylation level in the gene promoter regions. Results Compared with the mice in the NN/DM group, the blood glucose levels of the mice in the CIHH/DM group decreased after the 25^th day of the CIHH intervention (P<0.05). Regarding the diabetic glucose tolerance curves, the area under the curve (AUC) of the mice in the CIHH/DM group was lower than that of the NN/DM group (P<0.05). Compared with the mice in the NN/DM group, the mice in the CIHH/DM group showed that the serum insulin content and HOMA of insulin resistance index (HOMA-IRI) decreased (P<0.05), the enzyme activities of GK and PK increased and the relative mRNA expression levels of their genes were up-regulated (P<0.05), while the enzyme activities of PEPCK and G6P decreased and the relative mRNA expression levels of their genes were down-regulated (P<0.05) in liver. The average DNA methylation levels in the promoter regions of GK, PK, PEPCK, and G6P genes in liver of mice in each group were not significantly different (P>0.05), and their correlations with mRNA expression levels were also not statistically significant (P>0.05). Conclusion CIHH intervention may reduce blood glucose level, improve glucose tolerance, alleviate insulin resistance, and regulate the key enzyme activities of glucose metabolism and the relative mRNA expression of their corresponding genes in T2DM mice, but the above phenomena are not related to the DNA methylation levels in the promoter regions of these key enzymes.

Objective:To investigate the biocompatibility of coral-like barium titanate nano-piezoelectric coatings and the influence of ultrasound-excited piezoelectric effect on the early osteogenic differentiation.Methods:The barium titanate nano-piezoelectric coating (the coating group) was prepared on the surface of titanium metal by anodic oxidation, hydrothermal reaction and high-temperature annealing, and polished titanium specimens were used as control group. The surface morphology, composition, and crystal phase and hydrophilicity of the two groups of titanium specimens were characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and contact angle meter. The piezoelectric properties of the materials were characterized by piezoresponse force microscopy. Rat bone marrow mesenchymal stem cells (BMSC) were cultured and identified and seeded the surface of titanium specimens in two groups. The cells seeded on blank culture plates were used as blank group. After low intensity pulsed ultrasound intervention, cell proliferation and live/dead staining were detected to evaluate cytocompatibility of the coatings. Alkaline phosphatase (ALP) activity of each group was detected by ALP staining kit, and the expression of osteogenesis-related genes [integrin, bone morphogenetic protein 2 (BMP-2), Runt-related transcription factor 2 (RUNX2)] was detected by real-time fluorescent quantitative PCR (RT-qPCR) to evaluate the effect of the coating on promoting the early osteogenic differentiation of BMSC.Results:The surface of titanium specimens in the coating group showed a uniform coral-like morphology, and the diameter of the coral tentacles was 70-100 nm. The main component was tetragonal barium titanate. The surface hydrophilicity of the coating group (water contact angle 10.12°± 0.93°) was significantly better than that of the control group (water contact angle 78.32°±0.71°) ( F= 10 165.91, P<0.001). The coating has a stable piezoelectric property with a piezoelectric constant of about 5 pC/N. Cell experiments showed that, with or without ultrasound, the cell proliferation activity of the coating group was significantly lower than that of the blank group and the control group on the third day ( P<0.05). On the fifth day, with or without ultrasound, there was no significant difference in cell proliferation activity between the three groups ( P>0.05). After 7 days of culture, the ALP activity of the coating group was significantly higher than that of the blank group and the control group ( P<0.05). The results of RT-qPCR showed that the mRNA expression of integrin and BMP-2 in the coating group with ultrasound was significantly higher than that in the other groups with ultrasound, and was higher than that of the coating group without ultrasound ( P<0.05). The expression of integrin mRNA in the control group with ultrasound was significantly higher than that in the control group without ultrasound ( P<0.05). The expression of RUNX2 mRNA in the coating group with ultrasound was significantly higher than that in the coating group without ultrasound ( P<0.05). Conclusions:The coral-like barium titanate nano-piezoelectric coating exhibits favorable biocompatibility and stable piezoelectric property, and facilitates the early osteogenic differentiation of BMSC under the excitation of low-intensity pulsed ultrasound.

OBJECTIVE To observe the changes of static functional connectivity(sFC) and dynamic functional connectivity(dFC) of amygdala subregions in patients with bilateral idiopathic tinnitus and hearing loss(TINHL). METHODS The resting-state functional magnetic resonance imaging(fMRI) data of 30 patients with bilateral tinnitus and hearing loss and 37 normal controls(NCs) were collected to analyze the intensity changes of sFC and dFC in 8 subregions of amygdala and the whole brain in TINHL patients. RESULTS There were no significant differences in age,sex and education between the two groups. Compared with the NCs group,the sFC intensity of the right basolateral subregion and right cerebellar peduncle 1 region,the left basolateral subregion and left orbital medial frontal gyrus and left angular gyrus in TINHL group was significantly decreased. The dFC intensity of left amygdalostriatal subregion and left precuneus in TINHL group was increased,but the dFC intensity was reduced in the left basolateral subregion and right angular gyrus as well as between the right superficial subregion and right medial orbital of superior frontal gyrus. CONCLUSION Among the 8 subregions of amygdala,the bilateral basolateral subregions,the left amygdalostriatal subregion and the right superficial region shown abnormal functional connectivity with other regions of the brain,which are the important parts of emotional abnormalities in TINHL.

Objective:To explore and compare the impacts of different scanning protocols on image quality and radiation dose in chest computed tomography (CT) scans.Methods:A retrospective analysis was conducted for the data of 65 randomly selected patients who underwent chest CT scans using a tube voltage of 120 kV, the automatic modulation technique for tube current, and z-axis radiation dose modulation at the Emergency Department of our hospital from June to July 2023. The enrolled cases were divided into two groups: the high-resolution group ( n = 34) and the conventional group ( n = 31), with the settings for scanning protocols identical to those for phantom scans. For patients in both groups, thin-layer images of the cross-sections in the lung and mediastinal windows were reconstructed using thickness/intervals of 1 mm/1 mm and 2 mm/1 mm, respectively. Meanwhile, high-resolution and conventional CT scans were conducted using a Catphan500 phantom under a tube voltage of 120 kV and a tube current of 150 mAs. Of both scanning protocols, the high-resolution CT scan utilized the lung nodule-orientated scanning mode, pitch of 1.5, and a detector combination providing a collimation of 16 × 0.75 mm. In contrast, the conventional CT scan was performed using the body-orientated scanning mode, pitch of 0.813, and a detector combination providing a collimation of 16 × 1.5 mm. Then, the high-contrast resolutions of the phantom images obtained using the two scanning protocols were objectively evaluated. Both coronal chest images in the lung window and cross-sectional images in the mediastinal window were reconstructed with a thickness/interval of 5 mm/5 mm for both groups. Then, the obtained images were imported into the Radimetrics system to compare the body size-specific dose estimation (SSDE), doses to sensitive organs on the body surface, and scanning time of both groups. For the cross-sectional images in the mediastinal window, the contrast-noise-ratio (CNR), signal-to-noise ratio (SNR), and figure-of-merit (FOM) were measured and calculated at the fixed anatomical parts. For the cross-sectional images in the lung window, their quality was subjectively evaluated by two senior diagnostic radiologists. Results:The result of phantom scans indicated that high-resolution CT scans yielded images with an approximately 5% increase in the spatial resolution in the xy-plane and a nearly 20% increase in the spatial resolution along the z-axis compared to conventional CT scans. The result of clinical data demonstrated that the conventional group exhibited significantly higher doses to the thyroid and the female breast ( t = 2.8, 2.3, P < 0.05), along with notably elevated SNR, CNR, and FOM values of the right trapezius, compared to the high-resolution group ( t = 4.1, 5.8, z=4.4, P < 0.001). However, the high-resolution group manifested significantly higher SNR, CNR, and FOM values of the thoracic aorta compared to the conventional group ( t = 3.4, 4.4, z=3.4, P < 0.001). In addition, the cross-sectional and coronal images in the lung window of the clinical cases in the high-resolution group exhibited more stable quality, with subjective scores exceeding 4 and the average scores of both groups not statistically significantly different. Conclusions:For chest CT examination, high-resolution CT scans are more suitable for observations focusing on the details of the lungs and mediastinum, while conventional CT is more suitable for those centering on soft tissues on the body surface.

Objective:To investigate the effect of 980 nm semiconductor laser preablation of urethra mucosa at the prostatic tip in small volume benign prostatic hyperplasia (BPH).Methods:The case data of 120 patients diagnosed with small volume BPH in the Yan′an University Affiliated Hospital from June 2020 to June 2022 were retrospectively analyzed, and they were divided into improved group and conventional group according to different treatment methods, with 60 cases in each group. Patients in the improved group were treated with 980 nm semiconductor laser preablation of urethra mucosa at the prostatic tip, and patients in the conventional group were treated with 980 nm semiconductor laser vaporization of prostate. The sexual function of the patients was evaluated by the international erectile function index-5(IIEF-5) score, erectile hardness score (EHS) and retrograde ejaculation before surgery and 1, 3, 6, and 12 months after surgery. International prostate symptom scale (IPSS), quality of life (QOL) score, the maximum urine flow rate (Qmax) and postvoid residual urine (PVR) were used to evaluate urinary control function. The incidence of urinary incontinence, bladder neck contracture and other complications were compared between the two groups. Measurement data were expressed as mean±standard deviation ( ± s), and t-test was used for comparison between groups. The count data were expressed as cases and percentage, and Chi-square test was used for comparison between groups. Results:There was no significant difference in PVR, Qmax, IPSS score, QOL score, IIEF-5 score and EHS score between two groups ( P>0.05). In terms of PVR, Qmax, IPSS score, QOL score, IIEF-5 score and EHS score at 1, 3, 6 and 12 months after surgery, all these parameters were significantly improved compared with the preoperative, the differences were statistically significant ( P< 0.05). However, there was no significant difference between the two groups ( P> 0.05). There was no significant difference in IIEF-5 score and EHS score between the two groups during postoperative follow-up and before and after operation ( P> 0.05). The incidence of retrograde ejaculation rate in the improved group was lower than that in the conventional group during the follow-up 1, 3, 6 months after surgery, and the difference was statistically significant ( P<0.05). In the follow-up 1, 3 months after surgery, the incidence of stress urinary incontinence in the improved group was lower than that in the conventional group, the differences were statistically significant ( P< 0.05). At follow-up 6, 12 months after surgery, the rates of stress urinary incontinence were similar between the two groups, and the difference was not statistically significant ( P> 0.05). In the follow-up 12 months after surgery, there were 2 cases (3.33%) of bladder and neck contracture in the improved group, and 8 cases (13.33%) in the conventional group, the difference was statistically significant ( P<0.05). Conclusions:The effect of 980 nm semiconductor laser preablation of urethra mucosa at the prostatic tip in small volume BPH patients is similar to that of conventional vaporization, and the operation time is short. At the same time, the proximal 1 cm tissue of the verticulae and the integrity of the bladder neck are preserved, and the internal and external sphincter of the urethra are protected, thus improving the immediate postoperative urinary control rate and the incidence of retrograde ejaculation in small volume BPH patients.

Objective:To explore the cutoff value for assessing small airway dysfunction in children with asthma.Methods:A total of 364 asthmatic children aged 5 to 14 years, with normal ventilatory function, followed up at the Asthma Clinic of the Children′s Hospital of Capital Institute of Pediatrics from January 2017 to January 2018, were selected as the case group. Concurrently, 403 healthy children of the same age range and without any symptoms in the community were chosen as the control group, and pulmonary function tests were conducted. The values of forced expiratory volume in 1 second (FEV 1), forced vital capacity (FVC), forced expiratory flow at 50% of FVC (FEF 50), forced expiratory flow at 75% of FVC (FEF 75) and maximum mid-expiratory flow (MMEF) were compared between case group and control group. Statistical tests such as t-test, χ2 test, or Mann-Whitney U test were used to analyze the differences between the groups. Receiver operating characteristic (ROC) curves were constructed, and the maximum Youden Index was utilized to determine the optimal cutoff values and thresholds for identifying small airway dysfunction in asthmatic children. Results:This study comprised 364 children in the case group (220 boys and 144 girls) and 403 children in the control group (198 boys and 205 girls). The small airway parameters (FEF 50%pred, FEF 75%pred, MMEF%pred) in the asthmatic group were significantly lower than in the control group (77% (69%, 91%) vs. 95% (83%, 109%), 67% (54%, 82%) vs. 84% (70%, 102%), 76% (66%, 90%) vs. 97% (86%, 113%), Z=12.03, 11.35, 13.66, all P<0.001). The ROC curve area under the curve for FEF 50%pred, FEF 75%pred, MMEF%pred was 0.75, 0.74, and 0.79, respectively. Using a cutoff value of 80% for FEF 50%pred achieved a sensitivity of 56.9% and specificity of 81.4%. A cutoff value of 74% for FEF 75%pred resulted in a sensitivity of 67.3% and specificity of 69.2%. Finally, using a cutoff value of 84% for MMEF%pred achieved a sensitivity of 67.9% and specificity of 77.2%. Conclusion:In the presence of normal ventilatory function, utilizing FEF 50<80% predicted or MMEF<84% predicted can accurately serve as criteria for identifying small airway dysfunction in children with controlled asthma.