BACKGROUND:Disc functional magnetic resonance imaging studies are mostly carried out under lying and a non-load state, and do not reflect the changes in morphology and function of the upright human body under disc load conditions. Therefore, we need to study characteristics of disc functional magnetic resonance imaging in the upright state. OBJECTIVE: To analyze the effect of axial load on apparent diffusion coefficient and T2 of intervertebral discs. METHODS:The study consisted of 17 patients with low back pain aged 34-65 years. Before and after axial load, T2 weighted MR imaging, T1 weighted MR imaging, diffusion tensor imaging, and T2-mapping imaging of the lumbar spine were performed. Load quality was 40%-50% body weight. At 10 minutes after axial load, another diffusion tensor imaging was performed. After 15-minute load, another T2-mapping sequence was scanned. Diffusion tensor imaging scan parameters: single echo-planar imaging, repetition time 2 500 ms, echo time 89 ms, six diffusion directions, b value of 400 s/mm2, sweep time 4:10 minutes. Raw data of diffusion tensor imaging were used to construct apparent diffusion coefficient map and b0 map. Apparent diffusion coefficient value of intervertebral discs was calculated before and after loading. T2 map was automaticaly constructed using T2-mapping sequence to measure apparent diffusion coefficient and T2 values in the whole intervertebral disc of nucleus pulposus, and the changes of them were analyzed under short-time axial load. RESULTS AND CONCLUSION:Pfirrmann grading results in 17 patients with 85 discs were obtained as folows: 0 in Grade I, 26 in Grade II, 19 in Grade III, 30 in Grade IV, and 10 in Grade V. Al 85 disc T2 relaxation time mapping and 84 disc apparent diffusion coefficient mapping were accepted. Under short-time axial load in 84 discs, apparent diffusion coefficient reduced in the whole disc (reduced 38×10-3 mm2/s,Z=2.567,P < 0.05) and nucleus pulposus (reduced 62×10-3mm2/s,Z=3.461,P < 0.05). Apparent diffusion coefficient changes mainly affected Grade Pfirrmann III discs (reduced 55×10-3mm2/s,Z=2.556,P < 0.05). T2 changes mainly affected normal intervertebral discs (Pfirrmann grade II). Under the load, T2 value of intervertebral discs diminished (reduced 3.17 ms,Z=2.967,P < 0.05). No significant difference in apparent diffusion coefficient and T2 value was detected under the load in other grades of the intervertebral discs (P > 0.05). These results suggest that changes in apparent diffusion coefficient and T2 values were different due to different Pfirrmann grades under short-time axial load. To evaluate magnetic resonance imaging function of intervertebral discs, we should choose different evaluation method according to different degeneration degrees.

Objective To evaluate the value of MRS in quantitative assessment of degeneration of lumbar discs.Methods Totally 82 patients with lumbago underwent lumbar MR scanning.All the discs were classified with Pfirrmann grades in the sequences of sagittal T2WI.The area under N-acetyl peak,under water peak and the ratio of N-acetyl/Water were measured by MRS.Correlation between MRS values and Pfirrmann grade,age were analyzed.Results In 82 patients,204 lumbar discs were measured by MRS.There were 89,73,39,3 discs in Pfirrmann Ⅱ,Ⅲ,Ⅳ,V respectively.The areas of N-acetyl,water peak and N-acetyl/Water ratio of nucleus region were positively correlated with Pfirrmann grading,respectively (rs =-0.460,-0.204,-0.526,all P＜0.05).There were 62,25,37,51,29 discs in patients aged ＜30,30-39,40-49,50-59,＞59 years respectively.The ares of N-acetyl peak,N-acetyl/Water ratio of nucleus region was negatively correlated with the age (rs=-0.247,-0.385,both P＜0.05).Conclusion MRS can be used for quantitative assessment of lumbar discs degeneration.

Objective To analysis the effect of axial loading to ADC value, FA of lumbar intervetebral discs. Methods Forty five patients with low back pain (age range, 25 to 54 years) were evaluated with MR T2WI, MR T1WI and diffusion tensor imaging (DTI) of the lumbar spine. Following axial loading with 40% to 50% body weight for 10 minutes, a repeat DTI was performed. DTI were obtained by using an echo-planar imaging ( EPI ) sequence, TE 89 ms, TR 2500 ms, b value of 400 s/mm2,6 noncollinear diffusion directions. Scan time was approximately 4 min 10 s. An isotropic ADC map, FA map and bo map were calculated from DTI sequence. The mean ADC value, FA prior to and following axialloading were analyzed with t test and Rank Sum test. Results Forty five patients with 225 discs were evaluated and 223 discs were included in the study except for 2 calcified discs. The Pfirrmann grading results were as following: 100 Grade Ⅱ , 48 Grade Ⅲ, 59 Grade Ⅳ, and 16 Grade Ⅴ. No significant difference existed in the mean ADC value before [ ( 1666 ± 252 ) × 10-3 mm2/s ] and after [ ( 1662 ± 253 ) ×10 -3 mm2/s ] axial loading ( Z = - 1.363, P ＞ 0.05 ), but the mean FA [ ( 301 ± 104 ) × 10 -3, ( 316 ±112) × 10-3 ] value increased ( Z = - 2.794, P ＜ 0.05 ). The paired-samples t test show that the mean ADC value [ ( 1685 ± 190) × 10-3 mm2/s, ( 1624 ± 180) × 10-3mm2/s] of Grade Ⅲ discs decreased after axial loading, t=3.513, P＜0. 05, Grade Ⅲ, Ⅳdiscs mean FA value [(300±87) ×10-3, (326±87) ×10-3 for Grade Ⅲ and (348 ±67) × 10-3, (351 ± 71 ) × 10-3 for Grade Ⅳ ] increased, t = - 2. 210,- 2.006, P ＜ 0.05. No significant difference existed in Grade Ⅱ , Ⅳ and Ⅴ discs ADC value, all the P ＞0.05. No significant difference existed in Grade Ⅱ and Ⅴ discs FA value, both the P ＞ 0.05. Conclusions Short time axial loading mainly affect the mildly degenerated discs, the ADC value decreases and the disc diffusion ability decreases. No obvious change in ADC value or disc diffusion ability existed in the normal and severely degenerated discs.

Febrile seizures is one of the most common neurological diseases in childhood and the most common reason of convulsions. Although most of the convulsions have a good prognosis, prolonged febrile seizures can lead to hypoxic ischemic brain injury and influence the long-term intellectual development if the convulsions are repeated. It will lead to cognitive abilities, learning and memory decline, and even become the pathophysiological etiology of intractable epilepsy. Therefore,it has been became a great concern due to its serious impact on the quality of the child′s life. How to safely and effectively prevent the onset of febrile seizures has been an important task in pediatric clinical work. At present,there are some variously pre-ventive treatment guidelines or specifications,but it still left a debate about its effect. This article reviewed the progress of the studies on the preventive treatment of febrile seizures,so as to improve the understanding and the level of clinical preventive treatment of febrile seizures of the pediatricians.

Black phosphorus, as a novel two-dimensional nanomaterial, has received a lot of attention from researchers for its unique structure and properties. In recent years, with the increasing cross-sectional research related to black phosphorus 2D nanomaterials in various fields such as materials science, physics, chemistry, biology, and medicine, it has shown great potential for development and application in biomedicine. The excellent photoacoustic properties and good biocompatibility of black phosphorus 2D nanomaterials make them outstanding in tumor diagnosis and treatment. In this paper, the structure and properties, preparation, and functional modification of black phosphorus two-dimensional nanomaterials and their potential applications in the bio-detection and treatment of tumors, as well as the application progress of antibacterial were reviewed.