The gradient field, one of the core magnetic fields in magnetic resonance imaging (MRI) systems, is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals. The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images. However, traditional point measurement methods lack accuracy in assessing the linearity of gradient fields, making it difficult to provide effective parameters for image distortion correction. This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere, followed by detailed magnetic field calculations and linearity analysis. This study, applied to assess the nonlinearity of asymmetric head gradient coils, demonstrated more comprehensive and precise results compared to point measurement methods. This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.
Magnetic Resonance Imaging/instrumentation* ; Humans ; Image Processing, Computer-Assisted/methods* ; Nonlinear Dynamics ; Magnetic Fields ; Algorithms ; Phantoms, Imaging

There exist risks of ionizing radiation in radiodiagnosis examinations. Implementing shielding protection following the optimization and as low as reasonably achievable (ALARA) principles represents a measure to reduce radiation doses to patients. The implementation of shielding protection in clinical practices should meet high requirements due to variations in the modalities and items in radiodiagnosis examinations, the characteristics and irradiation method of X-ray beams, the method of automatic selection of image quality and radiation dose-related parameters by imaging equipment, the radiation sensitivity of human tissues and organs. This review introduced the shielding products, methods and effects in various radiodiagnosis examinations, as well as the current status and challenges in their applications, aiming to provide a reference for future related research and clinical practices.

Objective:To explore age-related variations in the angle of the cochlear basal turn using temporal bone CT, providing a reference for selecting the optimal Stenvers position radiographic projection angle in children and adults.Methods:The retrospective study included children and adults who underwent temporal bone CT scans at Beijing Tongren Hospital from November 2014 to April 2023. A total of 620 participants were included, including 368 males and 252 females. Patients were divided into 20 age-ralated groups: infants under one year old (3 to 11 months) were divided into monthly subgroups (9 groups); children and adolescents aged 1 to 18 years were grouped biennially (9 groups); adults were divided into two groups: 19 to 29 years and 30 to 40 years. Using multiplanar reconstruction (MPR) techniques, the CT images of the temporal bone were reformatted into oblique transverse sections to maximize the visibility of the cochlear basal turn.The cochlear basal turn angle was defined as the angle between the vertical axis of the cochlear basal turn and the mid-sagittal plane of the skull. Statistical analysis was performed to compare age-related differences in cochlear basal turn angles. Two additional patients were included to compare Stenvers position X-ray images with corresponding temporal bone CT scans, assessing the visibility of cochlear implant electrodes post-implantation.Results:Among infants aged 3 to 11 months, the cochlear basal turn angle was 29.4°±4.5°, with no significant differences observed between subgroups ( P>0.05). However, significant differences were found between infants (<1 year old) and the 1-2-year-old group compared to each age group from 3 to 40 years ( P<0.05). Additionally, the angles differed significantly between the 3-14-year-old groups and the 19-40-year-old groups ( P<0.05), whereas no significant differences were found among the remaining groups ( P>0.05). The visibility of the cochlear implant electrodes, appearing round in shape on standard Stenvers position X-ray images, closely resembled that observed in temporal bone CT scans. Conclusion:Age-related variations in the cochlear basal turn angle provide a valuable reference for optimizing Stenvers position radiography angles after cochlear implantation, improving the accuracy and quality of post-implantation imaging.

There exist risks of ionizing radiation in radiodiagnosis examinations. Implementing shielding protection following the optimization and as low as reasonably achievable (ALARA) principles represents a measure to reduce radiation doses to patients. The implementation of shielding protection in clinical practices should meet high requirements due to variations in the modalities and items in radiodiagnosis examinations, the characteristics and irradiation method of X-ray beams, the method of automatic selection of image quality and radiation dose-related parameters by imaging equipment, the radiation sensitivity of human tissues and organs. This review introduced the shielding products, methods and effects in various radiodiagnosis examinations, as well as the current status and challenges in their applications, aiming to provide a reference for future related research and clinical practices.

Objective:To explore age-related variations in the angle of the cochlear basal turn using temporal bone CT, providing a reference for selecting the optimal Stenvers position radiographic projection angle in children and adults.Methods:The retrospective study included children and adults who underwent temporal bone CT scans at Beijing Tongren Hospital from November 2014 to April 2023. A total of 620 participants were included, including 368 males and 252 females. Patients were divided into 20 age-ralated groups: infants under one year old (3 to 11 months) were divided into monthly subgroups (9 groups); children and adolescents aged 1 to 18 years were grouped biennially (9 groups); adults were divided into two groups: 19 to 29 years and 30 to 40 years. Using multiplanar reconstruction (MPR) techniques, the CT images of the temporal bone were reformatted into oblique transverse sections to maximize the visibility of the cochlear basal turn.The cochlear basal turn angle was defined as the angle between the vertical axis of the cochlear basal turn and the mid-sagittal plane of the skull. Statistical analysis was performed to compare age-related differences in cochlear basal turn angles. Two additional patients were included to compare Stenvers position X-ray images with corresponding temporal bone CT scans, assessing the visibility of cochlear implant electrodes post-implantation.Results:Among infants aged 3 to 11 months, the cochlear basal turn angle was 29.4°±4.5°, with no significant differences observed between subgroups ( P>0.05). However, significant differences were found between infants (<1 year old) and the 1-2-year-old group compared to each age group from 3 to 40 years ( P<0.05). Additionally, the angles differed significantly between the 3-14-year-old groups and the 19-40-year-old groups ( P<0.05), whereas no significant differences were found among the remaining groups ( P>0.05). The visibility of the cochlear implant electrodes, appearing round in shape on standard Stenvers position X-ray images, closely resembled that observed in temporal bone CT scans. Conclusion:Age-related variations in the cochlear basal turn angle provide a valuable reference for optimizing Stenvers position radiography angles after cochlear implantation, improving the accuracy and quality of post-implantation imaging.

The aim of this study was to compare the immune responses of C57BL/6 mice immunized with two pathogens, foot-and-mouth disease virus (FMDV) and Senecavirus A (SVA), and to provide clues for revealing the regulatory mechanisms of acquired immunity. Inactivated and purified FMDV and SVA antigens were used to immunize C57BL/6 mice respectively, and the mice immunized with PBS were taken as the control. The percentages of Th1 and Th2 cells in the spleen lymphocytes of mice in each group were analyzed by flow cytometry at 14 and 28 days after immunization. RNA-Seq was performed for the spleen. Mouse macrophages were stimulated with the antigens in vitro to examine the expression of the differentially expressed genes (DEGs) screened out. The results showed that 14 days after immunization, there was no significant difference in the magnitude of the Th1/Th2 immune response elicited by the FMDV and SVA antigens. After 28 days, the magnitudes of the Th1 and Th2 immune responses elicited by the SVA antigen were higher than those elicited by the FMDV antigen. RNA-Seq revealed two common DEGs, Rsad2 and Tspan8, between the two immunization groups, which indicated that the two genes may be involved in the activation of the Th1/Th2 immune responses by FMDV and SVA antigens. FMDV and SVA antigens stimulated macrophages to secrete interleukin (IL)-12 and IL-33 in vitro, and the expression of Tspan8 and Rsad2 was consistent with the RNA-Seq results. The expression of Rsad2 was regulated by type I interferons (IFNα, IFNβ). In this study, we obtained the DEGs involved in the immune responses to the two antigens in mouse spleen, which provides a molecular basis for investigating the immune response mechanisms induced by FMDV and SVA.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Mice ; Spleen/cytology* ; Mice, Inbred C57BL ; Antigens, Viral/genetics* ; Transcriptome ; Th1 Cells/immunology* ; Immunization ; Viral Vaccines/immunology* ; Th2 Cells/immunology* ; Foot-and-Mouth Disease/immunology* ; Interleukin-33/genetics* ; Female ; Macrophages/immunology* ; Picornaviridae

BACKGROUND: The addition of growth factiors is commonly applied to improve the osteogenic differentiation of stem cells. However, for human pluripotent stem cells (hPSCs), their complex differentiation processes result in the unknown effect at different stages. In this study, we focused on the widely used bone forming peptide-1 (BFP-1) and investigated the effect and mechanisms of its addition on the osteogenic induction of hPSCs as a function of the supplementation period. METHODS: Monolayer-cultured hPSCs were cultured in osteogenic induction medium for 28 days, and the effect of BFP-1 peptide addition at varying weeks was examined. After differentiation for varying days (0, 7, 14, 21 and 28), the differentiation efficiency was determined by RT–PCR, flow cytometry, immunofluorescence, and alizarin red staining assays. Moreover, the expression of marker genes related to germ layers and epithelial-mesenchymal transition (EMT) was investigated at day 7. RESULTS: Peptide treatment during the first week promoted the generation of mesoderm cells and mesenchymal-like cells from hiPSCs. Then, the upregulated expression of osteogenesis marker genes/proteins was detected in both hESCs and hiPSCs during subsequent inductions with BFP-1 peptide treatment. Fortunately, further experimental design confirmed that treating the BFP-1 peptide during 7–21 days showed even better performance for hESCs but was ineffective for hiPSCs. CONCLUSION The differentiation efficiency of cells could be improved by determining the optimal treatment period.Our study has great value in maximizing the differentiation of hPSCs by adding osteogenesis peptides based on the revealed mechanisms and promoting the application of hPSCs in bone tissue regeneration.

【Objective】 To summarize the clinicopathological features and prognosis of young patients (18-40 years old) with non-clear cell renal cell carcinoma (nccRCC) treated in a single center to provide reference for the diagnosis and treatment of similar patients. 【Methods】 Clinical data of 113 nccRCC patients treated during Jan. 2012 and Aug. 2022 were retrospectively analyzed, including 57 males (50.4%) and 56 females (49.6%). The average age of onset was (31.6±5.8) years. Among all patients, 57 had lesions (50.4%) on the left side, and 56 (49.6%) on the right side. Young patients undergoing renal cancer surgery accounted for approximately 12.4% of the total number of renal cancer patients undergoing surgery, and nccRCC accounted for 34.8% of the total number of cases. 【Results】 Minimally invasive surgery (laparoscopic or robot-assisted) was performed in 102 cases (90.3%), and open surgery in 11 cases (9.7%). Fifty-five cases (48.7%) underwent partial nephrectomy and 58 (51.3%) radical nephrectomy. Among them, 11 patients (9.7%) developed tumor thrombi. All surgeries were successful with no serious complications. The pathological types included 32 cases (28.3%) of chromophobe renal cell carcinoma, 25 cases (22.1%) of MiT family translocation renal cell carcinoma, and 20 cases (17.7%) of papillary renal cell carcinoma. The total proportion of the three pathological subtypes reached 68.1%. After 46 (2-115) months of follow-up, 8 cases (7.8%, 8/102) developed tumor metastasis and 2 died. 【Conclusion】 The nccRCC is rare in young patients. The major pathological type is chromophobe, and the major treatment method is minimally invasive surgery. Most pathological types have good long-term prognosis, while patients with tumor thrombi have a high risk of metastasis and poor prognosis.

Objective:To investigate the therapeutic effect of Baduanjin combined with resistance exercise and Baduanjin alone on elderly patients with type 2 diabetes mellitus(T2DM).Methods:The databases of CNKI,Wanfang,VIP,PubMed,and Web of Science were searched for randomized controlled trials(RCTs)on the effects of Baduanjin alone or combined with resistance exercise in elderly patients with T2DM.The search date was from the establishment of the database to Sep 21,2023.Review Manager 5.4 and Stata 16.0 softwares were used to conduct meta-analysis.Results were expressed as Random effect model standardized mean difference(SMD)and 95%confidence interval(CI).Results:A total of 14 RCTs involving 1 224 elderly patients with T2DM were included.The results of meta-analysis showed that Baduanjin alone or combined with resistance exercise in the treatment of elderly T2DM patients were better than the conventional treatment group in FPG,HbAlc,TC,TG,2hPG,HDL and LDL,and Baduanjin combined with resistance exercise were better than the Baduanjin alone group in FPG,HbAlc,TC,TG and LDL.Conclusion:Baduanjin alone or combined with resistance exercise has a significant therapeutic effect on elderly patients with T2DM,and the therapeutic effect of Baduanjin combined with resistance exercise is better.

Objective To compare the clinical efficacy of 25G+and 27G+pars plana vitrectomy(PPV)in the treat-ment of idiopathic epiretinal membrane(iERM).Methods A total of 50 iERM patients(50 eyes)who were admitted to the Third Affiliated Hospital of Xinxiang Medical University from December 2019 to August 2022 were selected as the research subjects.These patients were divided into the control group and observation group based on different surgical methods,with 25 patients(25 eyes)in each group.Patients in the control group received 25G+PPV treatment,while patients in the observation group received 27G+PPV treatment.The surgical duration and postoperative 1-day incision subconjunctival hemorrhage and e-dema of patients in two groups were compared;central macular thickness(CMT)was measured by optical coherence tomo-graphy before surgery,1 day,1 week,1 month,and 3 months postoperatively in the two groups.Visual acuity of patients in both groups was assessed according to the early treatment diabetic retinopathy study(ETDRS)visual acuity chart.Intraocular pressure was measured by using a non-contact Callon tonometer.Complications,such as intraoperative macular injury,retinal hole,postoperative choroidal detachment,retinal hemorrhage,retinal detachment,and intraocular infection,were observed in both groups.Results The surgical duration of patients in the observation group was significantly shorter than that in the control group(t=2.314,P＜0.05).The extent of subconjunctival hemorrhage and edema of patients in the observation group was significantly smaller than that in the control group(t=13.706,P＜0.01).The ETDRS visual acuity of patients at 1 day,1 week,1 month,and 3 months after surgery in both groups was significantly higher than that before surgery(P＜0.05).There was no signifi-cant difference in ETDRS visual acuity of patients between the two groups at 1 day,1 week,1 month,and 3 months postoperatively(P＞0.05).At 1 day after surgery,the intraocular pressure of patients in the observation group was significantly higher than that in the control group(P＜0.05).At 1 week,1 month,and 3 months after surgery,there was no significant difference in intraocular pressure of patients between the two groups(P＞0.05).Two patients in the control group experienced transient ocular hypotension 1 day after surgery,while no such complication was observed in the observation group.Patients in both groups presented with varying degrees of retinal nerve epithelial layer traction,retinal edema,thickening,and vascular distortion before surgery.At 1 day after surgery,epiretinal membrane traction was relieved in both groups,and there was a significant improvement in the anatomical structure of the macular area compared to preoperative conditions.At 1 day,1 week,1 month,and 3 months after surgery,the CMT of patients in both groups was reduced compared to preoperative values(P＜0.05);there was no significant difference in CMT of patients between the two groups at 1 day,1 week,1 month,and 3 months after surgery(P＞0.05).In the control group,18 eyes(72.0％)were sutured at the scleral puncture sites due to leakage,while no suturing was performed in the observation group.Patients in both groups completed the surgery successfully,without any intraoperative complications such as macular injury or retinal hole.During the 3-month follow-up,no postoperative complications such as choroidal detachment,retinal hemorrhage,retinal detachment,or intraocular infection were observed in both groups.Conclusion Both 27G+PPV and 25G+PPV have good clinical effects and high surgical safety in the treatment of iERM.Compared with 25G+PPV,27G+PPV can shorten the surgical duration,better maintain postoperative intraocular pressure stability,and reduce the range of subconjunctival bleeding and edema.