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

The Janus kinase/signal transducers and activators of transcription (JAK-STAT) control natural killer (NK) cells development and cytotoxic functions, however, whether long non-coding RNAs (lncRNAs) are involved in this pathway remains unknown. We found that miR155HG was elevated in activated NK cells and promoted their proliferation and effector functions in both NK92 and induced-pluripotent stem cells (iPSCs)-derived NK (iPSC-NK) cells, without reliance on its derived miR-155 and micropeptide P155. Mechanistically, miR155HG bound to miR-6756 and relieved its repression of JAK3 expression, thereby promoting the JAK-STAT pathway and enhancing NK cell proliferation and function. Further investigations disclosed that upon cytokine stimulation, STAT3 directly interacts with miR155HG promoter and induces miR155HG transcription. Collectively, we identify a miR155HG-mediated positive feedback loop of the JAK-STAT signaling. Our study will also provide a power target regarding miR155HG for improving NK cell generation and effector function in the field of NK cell adoptive transfer therapy against cancer, especially iPSC-derived NK cells.

This study aims to establish a high-performance size-exclusion chromatography (HPSEC) method for determining the content of the classical swine fever virus (CSFV) E2 protein and screen the optimal stabilizer to enhance the stability of this protein. The optimal detection conditions were determined by optimizing the composition of the mobile phase, and characteristic chromatographic peaks were identified by SDS-PAGE and Western blotting. The specificity, repeatability, precision, linearity, limit of detection (LOD), and limit of quantitation (LOQ) of the method were assessed. The method established was used to determine the content of CSFV E2 protein antigen and vaccine. Differential scanning fluorimetry (DSF) was employed to screen the buffer system, pH, and salt ion concentrations, and sugar, amino acid, and alcohol stabilizers were further screened. The results showed that using a 200 mmol/L phosphate buffer provided the best column efficiency. An antigen-specific chromatographic peak appeared at the retention time of 18 min, which was identified as the CSFV E2 protein by SDS-PAGE and Western blotting. The method exhibited high specificity for detecting the CSFV E2 protein, with no absorbance peak observed in the blank control. The relative standard deviation (RSD) of the peak area for six repeated injections of the CSFV E2 protein was 0.74%, indicating good repeatability of the method. The RSD for repeated detection of two different concentrations of CSFV E2 protein samples by different operators at different time points was less than 2%, suggesting good intermediate precision of the method. The peak area of the CSFV E2 protein was linearly related to its concentration, with the regression equation showing R² of 1.000. The LOD and LOQ of the method were 14.88 μg/mL and 29.75 μg/mL, respectively. Application of the developed method in the detection of three batches of CSFV E2 protein antigen and three batches of vaccine demonstrated results consistent with those from the bicinchoninic acid (BCA) assay, which meant that the method could accurately determine the content of CSFV E2 protein antigen and vaccine. The DSF method identified 50 mmol/L Tris-HCl at pH 8.0 as the optimal buffer, and the addition of sugar and alcohol stabilizers further improved the stability of the CSFV E2 protein. The HPSEC method established in this study is simple, fast, and exhibits good accuracy and repeatability, enabling precise measurement of the CSFV E2 protein content. It is expected to play a crucial role in the quality control of the CSFV E2 vaccine. Furthermore, the strategy for improving the CSFV E2 protein stability, identified through DSF screening, has significant implications for enhancing the stability of the CSFV E2 vaccine.
Classical Swine Fever Virus/chemistry* ; Chromatography, Gel/methods* ; Animals ; Swine ; Viral Envelope Proteins/immunology*

Objective To explore the association between the relative expression level of SNORD55 in peripheral blood and the outcomes of all-cause mortality and stroke in patients with atrial fibrillation(AF),and to evaluate the predictive value of SNORD55 for prognosis.Methods A total of 133 patients with non-valvular AF admitted in Department of Cardiology of the First Affiliated Hospital of Army Medical University from January 2014 to December 2017 were enrolled in this study.Their baseline information was collected,and the relative expression level of plasma SNORD55 was detected.Cox proportional hazards model was used to explore the association between the relative expression level of SNORD55 in peripheral blood and all-cause mortality as well as stroke in the patients.The predictive performance of CHA2DS2-VASc score for all-cause mortality and stroke was compared with the score combined with the relative expression level of SNORD55 in the AF patients.The area under the receiver operating characteristic curve(AUC)was utilized to evaluate the discrimination,and the net reclassification index(NRI)and comprehensive discriminant improvement index(IDI)were calculated to evaluate the improvement of reclassification ability.Decision curve analysis(DCA)was applied to analyze the change in clinical net benefit.Results The results of multivariate Cox regression showed that high expression of SNORD55 in peripheral blood was an independent risk factor for all-cause mortality and stroke in the AF patients.In predicting the outcomes of all-cause mortality and stroke,the addition of relative expression SNORD55 level with the CHA2DS2-VASc score obtained higher AUC value[0.80(95％CI:0.67～0.93)vs 0.67(95％CI:0.53～0.81),P＜0.05].In predicting the outcome of all-cause death and stroke,combination of the relative expression level of SNORD55 with CHA2DS2-VASc score increased both NRI[54.3(95％CI:10.6～61.9)vs 31.9(95％CI:2.8～47.5),P＜0.05]and IDI[16.1(95％CI:2.4～27.0)vs 7.9(95％CI:0.5～14.8),P＜0.05].The results of DCA showed that our combination of CHA2DS2-VASc score relative expression level of SNORD55 had higher clinical net benefits than the foreign ABC score in the prediction of the outcomes.Conclusion Peripheral blood SNORD55 level is an independent risk factor for all-cause mortality and stroke in AF patients,and has good predictive performance for all-cause mortality and stroke in the patients.

Objectives To explore the association of peripheral blood PIWI-interacting RNA,piR-hsa-2700592,with all-cause mortality and stroke outcomes in patients with atrial fibrillation(AF),and to determine whether piR-hsa-2700592 has the potential to be an AF biomarker.Methods A total of 127 patients with non-valvular AF were enrolled,and the relative expression level of plasma piR-hsa-2700592 was detected.Cox proportional hazard regression was used to analyze the correlation between the expression of piR-hsa-2700592 and all-cause death as well as stroke outcome in the patients.Then the molecule expression level was combined with CHA2DS2-VASc score and ABC stroke(or death)score to establish 2 new prediction models,the improvement of the predictive performance was compared and analyzed.Receiver operating characteristic(ROC)curve analysis(area under the curve,AUC),net reclassification index(NRI),and comprehensive discriminant improvement index(IDI)were used to evaluate the predictive performance,and decision curve analysis(DCA)was employed to assess the clinical benefit.Results Multivariate Cox regression analysis showed that the patients with higher expression level of piR-hsa-2700592 in peripheral blood had a higher risk of stroke(HR:2.203,95%CI:1.120～4.332;P=0.022).In the stroke outcome,combination of plasma piR-hsa-2700592 expression level with CHA2DS2-VASc score and ABC stroke score obtained an AUC of 0.70(95%CI:0.55～0.85,P＜0.001)and 0.84(95%CI:0.73～0.96,P=0.02),respectively.But,no significant association was observed between high plasma piR-hsa-2700592 level and all-cause mortality in the AF patients(HR:1.997;95%CI:0.884～4.509;P=0.096).Combination of plasma piR-hsa-2700592 level improved the discriminative capability than the single CHA2DS2-VASc score and ABC stroke score models,with an NRI and IDI value of 44.20%(95%CI:3.40～59.90,P＜0.001)and 8.20%(95%CI:0.60～15.40,P＜0.001),respectively for the new CHA2DS2-VASc score model,and an NRI and IDI value of 44.20%(95%CI:9.80～58.90,P＜0.001)and 10.40%(95%CI:0.70～21.40,P＜0.001),respectively for the new ABC stroke score model.The DCA curve showed that both new prediction models obtained better net clinical benefits.Conclusion High peripheral blood expression of piR-hsa-2700592 is an independent risk factor for stroke in the AF patients,and the indicator has a good predictive value for prognosis of the patients.piR-hsa-2700592 might be used as a potential biomarker in the diagnosis and prevention of cardiovascular diseases.

Objective To evaluate the performance and clinical application value of EasyNAT nucleic acid test kits for influenza A virus(Flu A),influenza B virus(Flu B),and Mycoplasma pneumoniae(MP)based on cross-primed amplification(CPA)technology.Methods In compliance with relevant standards,the detection limits,cross-reactivity,and anti-interference abilities of the EasyNAT Flu and MP nucleic acid test kits were validated using influenza(Flu)and MP reference materials.Additionally,a total of 811 suspected Flu or MP infection patients who visited the hospital from January 1 to July 5,2024 were enrolled in this study.Their oropharyngeal swabs were collected and tested using reverse transcription quantitative polymerase chain reac-tion(RT-qPCR)as the gold standard to evaluate the concordance and compliance of the EasyNAT Flu and MP nucleic acid test kits,thus assessing their clinical application value.Results The EasyNAT Flu and MP nucleic acid test kits yielded positive results in 8 repeated tests at the detection limit concentrations of the ref-erence materials.No pathogen-specific peaks were detected in Flu and MP negative samples that had been spiked with common cross-reacting pathogens.Furthermore,the detection results of Flu or MP positive sam-ples were unaffected by the presence of interfering substances.Among the 811 clinical samples,the sensitivity of the EasyNAT Flu A test was 97.33%,and the sensitivity for Flu B was 98.47%,both with a specificity of 98.04%.The EasyNAT MP nucleic acid test showed a sensitivity of 97.95%and specificity of 99.03%.The results demonstrated a high degree of agreement with RT-qPCR(Kappa values were over 0.900).Further-more,detection rates of the EasyNAT Flu test kits showed no difference in positive samples with different Ct values(Flu A:χ2=4.20,P=0.08;Flu B:χ2=2.22,P=0.31)and MP test kits showed significant differences in positive samples with different cycle threshold values(χ2=11.84,P<0.01).Conclusion The EasyNAT Flu and MP nucleic acid test kits exhibit excellent detection performance with high sensitivity and specificity.Moreover,the products are easy to operate,offer rapid detection,and provide accurate results.These features make them suitable for primary healthcare settings,with significant potential for clinical application.

OBJECTIVE To investigate the regulatory effect of autophagy on the resistance of human liver cancer cell Huh7 to lenvatinib. METHODS Using human liver cancer cell Huh7 as subject， the lenvatinib-resist cell model （Huh7-LR） was generated by the low-dose gradient method combined with long-term administration. The sensitivity of parental cell Huh7 and drug-resistant cell Huh7-LR to lenvatinib was detected by using CCK-8 assay and flow cytometry. Western blot assay and GFP-mCherry-LC3 plasmid transfection were performed to detect the expression levels of autophagic protein Beclin-1， autophagic adapter protein sequestosome 1 （p62）， microtubule-associated protein 1 light chain 3 （LC3） and autophagic level. Furthermore， an autophagy activation model was constructed by cell starvation， the protein expression of p62 and autophagy level were detected by using Western blot assay and GFP-mCherry-LC3 plasmid transfection， and the effect of autophagy activation on the sensitivity of Huh7-LR cells to lenvatinib was detected by flow cytometry. RESULTS Compared with parental cells， the drug resistance index of Huh7-LR cells was 6.2； protein expression of p62 was increased significantly， while apoptotic rate， protein expression of Beclin-1 and LC3Ⅱ/ LC3Ⅰ ratio were all reduced significantly （P＜0.05 or P＜0.01）； the level of autophagy was decreased to some extent. Autophagy activation could significantly increase the protein expression of p62 in Huh7-LR cells （P＜0.05） and autophagy level， and significantly increase its apoptotic rate （P＜0.05）. CONCLUSIONS Autophagy is involved in lenvatinib resistance， and activating autophagy can reverse the resistance of liver cancer cells to lenvatinib to some extent.

ObjectiveTo investigate the antidepressant effect of Sinisan （SNS） by regulating glycogen aynthase kinase-3β （GSK-3β）/tumor necrosis factor alpha-induced protein 3（A20）/CCAAT enhancer binding protein β（C/EBPβ） to inhibit the activation of microglia. MethodA total of 72 male C57/6J mice were randomly divided into the normal group， model group， fluoxetine group （5.0 mg·kg^-1）， low-dose Sinisan group （4.9 g·kg^-1）， medium-dose Sinisan group （9.8 g·kg^-1）， and high-dose Sinisan group （19.6 g·kg^-1）， with 12 mice in each group. After one week of adaptive feeding， chronic unpredictable mild stress （CUMS） was performed to establish the depression model. In the fifth week， drug treatment was conducted for four weeks. In the ninth week， behavioral tests were performed， including sucrose preference test （SPT）， open field test （OPT）， elevated plus maze （EPM） test， and forced swimming test （FST）. Western blot was used to detect the expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， nitric oxide synthase （iNOS）， GSK-3β， A20， and C/EBPβ in the cortex. The expression of M1-polarized ionized calcium-binding adapter molecule 1 （Iba1） and cluster of differentiation 68 （CD68） in microglia was detected by immunofluorescence. ResultAfter eight weeks of CUMS， compared with the normal group， the mice in the model group had a significantly reduced sucrose preference rate （P<0.01）， and the activity in the central area of the OPT was significantly reduced （P<0.01）. The activity in the open arm area of the EPM test was significantly reduced （P<0.05）， and the immobility time of FST was increased （P<0.01）. The expression levels of inflammatory proteins IL-1β， IL-6， and iNOS were increased （P<0.01）， and the fluorescence co-localization index of Iba1 and CD68 was increased （P<0.05）. The protein expression levels of GSK-3β and C/EBPβ were significantly increased （P<0.05， P<0.01）. After four weeks of SNS intervention， compared with the model group， the mice in the SNS group had significantly increased sucrose preference rate （P<0.01）， significantly increased activities in the central area and the open arm area in the OPT and the EPM test （P<0.05）， and significantly reduced immobility time in the FST （P< 0.01）. The protein expression levels of IL-1β， IL-6， and iNOS were significantly decreased （P<0.05）， and the fluorescence co-localization index of Iba1 and CD68 was decreased in the high-dose SNS group （P<0.05）. The protein expression levels of GSK-3β and C/EBPβ in the medium-dose and high-dose SNS groups were significantly decreased （P<0.01）， and that of A20 was significantly increased （P<0.01）. ConclusionThe antidepressant effect of SNS is related to the regulation of GSK-3β/A20/C/EBPβ protein expression and the inhibition of M1-type activation of microglia.

OBJECTIVE To investigate the neuroprotective effect of curculigoside （CUR） on rats with spinal cord injury （SCI） based on phosphatase and tensin homologue deleted on chromosome ten gene-induced putative kinase 1 （PINK1）/E3 ubiquitin ligase Parkin signaling pathway. METHODS Taking male SD rats as subjects， 15 rats were randomly selected as sham operation group； the rest rats were chosen to establish SCI model by spinal cord impact method， and then were divided into model group， CUR low-dose group （36 mg/kg CUR， gavage）， CUR high-dose group （72 mg/kg CUR， gavage） and CUR high-dose+3- methyladenine （3-MA） group （72 mg/kg CUR， gavage+20 mg/kg autophagy inhibitor 3-MA， intraperitoneal injection）， with 15 rats in each group. Rats in each group were given corresponding liquid/normal saline， once a day， for 28 consecutive days. Basso- Beattie-Bresnahan （BBB） score and Rivlin inclined plate experiment were performed on the 14th and 28th day after administration； the pathological changes of spinal cord tissue in rats were observed in each group； the apoptosis of spinal cord tissue， the levels of oxidative stress factors [malondialdehyde （MDA）， superoxide dismutase （SOD）， glutathione （GSH）]， and the protein expressions of brain-derived neurotrophic factor （BDNF）， glial fibrillary acidic protein （GFAP）， PINK1， Parkin， p62 and microtubule- associated protein light chain 3 （LC3） were all determined. RESULTS Compared with the sham operation group， obvious edema and bleeding in the spinal cord tissue of rats were observed in the model group， accompanied by a large number of inflammatory cell infiltration； BBB score and inclined plate angle， SOD and GSH levels， the protein expressions of BDNF， PINK1 and Parkin， and LC3Ⅱ/Ⅰ ratio were significantly reduced； the apoptosis rate， MDA level， the protein expressions of GFAP and p62 in spinal cord tissue were significantly increased （P＜0.05）. Compared with the model group， the edema， bleeding and infiltration of inflammatory cells in the spinal cord tissue of rats were reduced in the administration groups， and the above quantitative indicators had been significantly improved （P＜0.05）； 3-MA could significantly reverse the improvement effects of the above indexes by CUR （P＜0.05）. CONCLUSIONS CUR can promote the recovery of neurological and motor functions in SCI rats， improve the pathological injury of the spinal cord and inhibit apoptosis， which may be related to mitochondrial autophagy mediated by activating the PINK1/Parkin signaling pathway.

Objective:To investigate the effects of marathon exercise on knee cartilage volume and T2 relaxation time (T2 value) based on MRI.Methods:From December 2018 to December 2021, 25 healthy volunteers without long-distance running habits and 32 non-professional marathon runners with long-term long-distance running were recruited to undergo knee MRI 3D water-selective excitation (three dimensional water-selective excitation, 3D-WATS) and T2 mapping imaging were performed, and the cartilage volumes in 5 knee areas and T2 values in 42 subareas were extracted for analysis. To compare the cartilage volume and its ratio to body surface area of knee joint of healthy volunteers and non-professional marathon runners, the T2 value of cartilage in each subregion, and the correlation between marathon exercise intensity and the volume and T2 value of cartilage in different regions.Results:Compared with healthy volunteers, there was no significant difference in cartilage volume or the ratio of body surface area to body volume of non-professional marathon runners ( P>0.05). There were significant differences between healthy volunteers and non-professional marathon runners in cartilage T2 values of the median layer of medial condyle of femur (47.61±5.65 ms and 44.29±6.10 ms) and the deep layer of medial condyle of femur (36.82±9.05 ms and 31.67±7.59 ms), deep precondylar area of medial femur (38.37±4.68 ms and 34.09±4.19 ms), shallow area of medial condylar area of femur (52.17±11.11 ms and 45.51±7.76 ms), middle layer of medial condylar area of femur (49.09±5.08 ms and 45.63±5.04 ms), medial layer of anterior condylar region of lateral femur (45.69±4.68 ms and 42.57±5.77 ms), superficial layer of posterior condylar region of lateral femur (55.42±18.41 ms and 47.99±8.39 ms), deep layer of anterior tibial medial plateau (33.40±7.76 ms and 29.03±5.69 ms), deep layer of posterior tibial medial plateau (31.28±5.02 ms and 27.92±5.99 ms), deep layer of patellofemoral surface (35.65±6.99 ms and 32.30±5.28 ms), respectively ( P<0.05). In non-professional marathon runners, the medial tibial plateau cartilage volume was negatively correlated with step frequency ( r=-0.371, P=0.035), the lateral femoral condylar cartilage volume was negatively correlated with step frequency ( r=-0.365, P=0.043), and the lateral tibial plateau cartilage volume was negatively correlated with step frequency ( r=-0.550, P=0.001). The T2 value of the medial layer cartilage in the anterior tibial medial plateau region was negatively correlated with body weight ( r=-0.277, P=0.039) and body mass index ( r=-0.290, P=0.030). The T2 value of the superficial layer of patellofemoral surface was negatively correlated with the amount of running in 3 months ( r=-0.457, P=0.010). The superficial T2 value in the posterior lateral plateau of the tibia was negatively correlated with stride length ( r=-0.437, P=0.014), and the medial layer cartilage T2 value in the anterior condylar area of the lateral femur was negatively correlated with stride frequency ( r=-0.380, P=0.035). Conclusion:Marathon exercise had little effect on the knee cartilage volume, but had a certain effect on the cartilage T2 value, resulting in changes in cartilage structure. The higher the step frequency, the smaller the cartilage volume. The greater the body weight or body mass index, the greater the amount of running in 3 months, and the greater the stride length, the lower the cartilage T2 value.