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

Consumptive thirst such as dry mouth and polydipsia,frequent urination polyuria,fear of heat and hyperhidrosis and loss of other body fluids,yin deficiency and internal heat expression,and irritability and other abnormal emotional symptoms are common.The Synopsis of Golden Chamber need to be further explored for the treatment of miscellaneous diseases.The dialectical thought has a high clinical application value.Lily disease treatment recommendations in the Synopsis of Golden Chamber are explored.The symptoms of lily disease are varied and uncertain,which are caused by the scattering and wandering aimlessly of heat pathogen.The pathogenesis of lily disease can be examined through external symptoms such as bitter taste in mouth,red urine,and faint and rapid pulse.Diabetes is also closely related to yin deficiency and internal heat,and the pathogenesis of the two is similar.Mental symptoms are common characteristics of lily disease and diabetes.The method taken from the Synopsis of Golden Chamber and Baihe-like prescriptions for the treatment of diabetes are effective.By identifying different patterns,symptoms,and indicators,we can select lily bulb,common anemarrhena,rhizome,figwort root,unprocessed rehmannia root,and other drugs to treat diabetes,in order to improve our understanding of lily disease and provide new ideas for diabetes treatment.

Objective:To analyze clinical efficacy, failure mode and prognostic factors of nasopharyngeal carcinoma (NPC) patients undergoing intensity modulated radiation therapy (IMRT).Methods:Clinical data of 951 locally advanced NPC patients who were newly-treated with IMRT in Hunan Cancer Hospital from January 2018 to January 2019 were retrospectively analyzed. The patients' general data, overall survival (OS), local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), local recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), and progression-free survival (PFS) were analyzed. Comparison among different groups was performed by one-way ANOVA. Survival rate was calculated by Kaplan-Meier method. Survival difference was compared by log-rank test. Univariate and multivariate analyses were performed by Cox regression model.Results:The median follow-up time was 62.0 months (IQR, 58.0-65.0 months). The 5-year OS, LRFS, RRFS, LRRFS, DMFS, and PFS were 85.4%, 94.0%, 97.7%, 92.6%, 85.7% and 76.9%, respectively. According to the 8th edition staging of American Joint Committee on Cancer (AJCC), there were 10 cases (1.1%) of stage I, 76 cases (8.0%) of stage II, 445 cases (46.8%) of stage III, and 420 cases (44.2%) of stage IVA, respectively. Among them, the OS rates of stage I, II, III and IVA patients were 100%, 97.2%, 88.8% and 79.2%, respectively ( P<0.001); LRRFS rates were 100%, 90.4%, 94.7% and 90.4%, respectively( P=0.104); DMFS rates were 90.0%, 95.9%, 88.0% and 81.1%, respectively ( P<0.001); PFS rates were 90.0%, 89.1%, 80.9% and 70.1% respectively ( P<0.001). There were 183 cases of treatment failure, including 52 cases (5.5%) of local failure, 19 cases (2.0%) of regional failure, 130 cases (13.7%) of distant metastasis, 16 cases of local combined with regional failure (1.7%), 16 cases (1.7%) of local failure combined with distant metastasis, 13 cases (1.4%) of regional failure combined with distant metastasis, and 9 cases (0.9%) of local regional failure combined with distant metastasis, respectively. Multivariate regression analysis suggested that EB virus DNA copy number before treatment, T stage and N stage were the independent prognostic factors affecting OS, DMFS and PFS. Conclusions:Compared with two-dimensional radiotherapy, IMRT has improved the overall therapeutic effect for NPC, especially the local control rate. Distant metastasis is still the main failure mode. Clinical staging, prognostic risk stratification and prognostic biomarkers can be combined to deliver stratified and precise treatment, which may further improve clinical efficacy and reduce treatment-related side effects.

ObjectiveTo observe the effect of bilateral sequential repetitive transcranial magnetic stimulation on the motor function of upper limbs in stroke patients. MethodsFrom December, 2020 to December, 2022, 62 stroke inpatients in the Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine were included. They were randomly divided into control group (n = 31) and observation group (n = 31). Both groups accepted conventional medicine and rehabilitation, as well as electroacupuncture antagonistic muscle therapy. Before electroacupuncture, the observation group acceped low-frequency repetitive transcranial magnetic stimulation at primary motor cortex (M1) on the healthy side, followed by intermittent theta burst stimulation at M1 on the affected side, for four weeks. They were assessed with Fugl-Meyer Assessment-Upper Extremities (FMA-UE), modified Barthel Index (MBI) and modified Ashworth Scale (MAS), and motor evoked potential (MEP) latency was compared before and after treatment. ResultsOne patient dropped down in the observation group, and no adverse event happened. After treatment, the scores of FMA-UE and MBI significantly increased (|t| > 9.953, P < 0.001), and the score of MAS and the latency of MEP significantly decreased (|t| > 5.043, P < 0.001) in both groups; while all of them were better in the observation group than in the control group (|t| > 2.237, P < 0.05). ConclusionBilateral sequential repetitive transcranial magnetic stimulation can effectively promote the recovery of upper limb motor function in stroke patients.

By comparing the training status of clinical research methods between United States and China, this article introduces comprehensive training system in the United States in and after the university, and discusses the problems in clinical research methodology training in China. These issues include that when medical students at school do not receive the training of professional clinical research courses, and after they go to the work, they also lack professional and accurate clinical research methodology training, which make it difficult for doctors to independently conduct clinical research. Therefore, it is recommended that Chinese medical schools should systematically establish clinical research methodology courses for undergraduates and graduate students to cultivate the clinical research capabilities of medical students. Secondly, according to the clinical research levels of doctors, different training models are proposed in the study. The existing social resources should be scientifically guided. We hope our work would provide some references for the improvement of clinical research methodology in China, to promote clinicians to be independently responsible for conducting clinical research, and improve the national medical level.

Objective:To investigate the impact of China's Mental Health Law on the work of psychological counseling in colleges and universities, and to explore ways to improve the law. Methods: Totally 12 heads of college and university counseling centers in Beijing were conducted with semi-structured interviews. The average age of the interviewees was (40 ±7) years old, with master or doctor degrees in psychology or related disciplines. The method of content analysis was used to analyze the interviewees' understanding of the " Mental Health Law". Results: All of the 12 interviewees had gained some understanding of the "Mental Health Law", and accordingly amended the regulation of their counseling centers. Also, interviewees suggested the positive and negative impacts brought by the law, such as enhancing practitioners' legislative sense, clarifying their responsibilities and boundaries as college and university counseling, as well as difficulties to distinguish psychotherapy and psychological counseling, ambiguity in the legality of working with students who were diagnosed with mental disorders. Moreover, interviewees threw out suggestions on improving the law from the aspect of industry standard, supervision department and vocational qualification. Conclusion: The execution of "Mental Health Law" improves practitioners' legislative sense, clarifies their responsibility. Nevertheless, it does not clearly distinguish psychotherapy from psychological counseling, and be lack of regulation on the psychological counseling industry.

Mutations in the mitochondrial DNA have been certified to be one of the most important causes of maternally inherited sensorineural hearing loss. Among these, mitochondrial 12S rRNA1555A>G, 1494C>T and other mutations are associated with both nonsyndromic and drug induced hearing loss caused by aminoglycosides. Individuals carrying 1555A>G or 1494C>T mutation have a variety of clinical manifestations, which implies that the 1555A>G or 1494C>T mutation is a chief factor underlying the development of deafness but insufficient to produce the clinical phenotype. Therefore other modifier factors, such as aminoglycosides, mitochondrial haplotypes, secondary mutation or nuclear modifier genes, may play an important role in the phenotypic expression of the deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutation. In this review, the modifier factors for the phenotypic expression of deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutations were summarized and proposed the pathogenesis of maternally inherited deafness.

Background:Chronic inflammation is closely associated with occurrence and development of gastric cancer,and inflammatory cytokines,interleukin-18(IL-18)and IL-1β are involved via a variety of mechanisms. Aims:To determine the serum levels of IL-18 and IL-1β in patients with different gastric mucosal lesions and to explore the role of these two cytokines in gastric cancer and their clinical significance. Methods:Serum levels of IL-18 and IL-1β were detected by ELISA in patients with different gastric mucosal lesions,including 324 gastric cancer,40 chronic non-atrophic gastritis (CNAG),13 chronic atrophic gastritis with or without intestinal metaplasia(CAG/ IM)and 20 mild to moderate dysplasia. Helicobacter pylori(Hp)IgG antibody was detected in patients with gastric cancer. Correlations of serum levels of IL-18 and IL-1β with clinicopathological parameters and Hp infection were analyzed in patients with gastric cancer. RoC curve was used to assess the performance of serum IL-18 and IL-1β for diagnosis of gastric cancer. Results:Serum levels of IL-18 and IL-1β increased gradually from CNAG,CAG/ IM,dysplasia to gastric cancer;except for IL-1β between CNAG and CAG/ IM groups,significant differences were found between any two groups(P < 0. 05). In gastric cancer group,they were positively correlated with tumor size,lymph node and distant metastases,depth of invasion,TNM stage and Hp infection(P < 0. 05). Area under the RoC curve(AUC)of combined detection of serum IL-18 and IL-1β for diagnosis of gastric cancer was superior to that of IL-18 or IL-1β detection alone(0. 867 vs. 0. 837 and 0. 795). Conclusions:Serum levels of IL-18 and IL-1β increase dynamically with the tumorigenesis of gastric cancer,and are closely related to growth, invasiveness and metastasis of gastric cancer. Combined detection of serum IL-18 and IL-1β might be used as a biomarker for diagnosis and tumor progression and prognosis assessment of gastric cancer.

Objective To investigate the clinical characteristics and treatment of external auditory canal chol‐esteatoma (EACC) .Methods The clinical data of 38 cases(39 ears)with external auditory canal cholesteatoma from August 2006 to December 2014 were retrospectively analyzed .Results All the cases of EACC in this study had the external ear canal full of impacted squamous material or granulation tissue .The Holt and CT imaging examinations disclosed that 10 ears were phase I ,lesions were confined to the external auditory with no bone destruction .There were 23 ears were phase II ,the lesions were located in external auditory meatus with destruction of bone ,but with no involvement of the middle ear .There were 6 ears were phase III ,showing the lesions with disrupt external audi‐tory meatus and involvement of the middle ear ( mastoid and/or tympanic sinus) .Hearing impairment and aural fullness were the most common symptoms .The phase I cases were treated by removing cholesteatomas from the ex‐ternal auditory canal .Canaloplasty and/or tympanoplasty were performed in phase II cases .The phase III cases were successfully managed by modified radical mastoidectomy and/or tympanoplasty .There were 30 ears of tympan‐ic membrane were perfect and invaginate .There were 4 ears of ossicular chain were disrupted with one ear of facial nerve exposed .All surgeries were performed at once .No recurrence except in one patient was found during the fol‐low -up period .Conclusion The clinical stages can help identify the primary lesions and determine the choice of the best surgical approach .