Gravity determines the direction of nerve roots sedimentation in the lumbar spinal canal.

OBJECTIVES: To investigate the role of gravity in the sedimentation of lumbar spine nerve roots using magnetic resonance (MR) imaging of various body positions. METHODS: A total of 56 patients, who suffered from back pain and underwent conventional supine lumbar spine MR imaging, were selected from sanmen hospital database. All the patients were called back to our hospital to perform MR imaging in prone position or lateral position. Furthermore, the sedimentation sign (SedSign) was determined based on the suspension of the nerve roots in the dural sac on cross-sectional MR images, and 31 cases were rated as positive and another 25 cases were negative. RESULTS: The mean age of negative SedSign group was significantly younger than that of positive SedSign group (51.7 ± 8.7 vs 68.4 ± 10.5, P < 0.05). The constitutions of clinical diagnosis were significantly different between patients with a positive SedSign and those with a negative SedSign (P < 0.001). Overall, nerve roots of the vast majority of patients (48/56, 85.7%) subsided to the ventral side of the dural sac on the prone MR images, although that of 8 (14.3%) patients remain stay in the dorsal side of dural sac. Nerve roots of only one patient with negative SedSign did not settle to the ventral dural sac, while this phenomenon occurred in 7 patients in positive SedSign group (4% vs 22.6%, P < 0.001). In addition, the nerve roots of all the five patients subsided to the left side of dural sac on lateral position MR images. CONCLUSIONS: The nerve roots sedimentation followed the direction of gravity. Positive SedSign may be a MR sign of lumbar pathology involved the spinal canal.

Origin of the enhanced visible-light photocatalytic activity of CNT modified g-C3N4 for H2 production.

Graphitic carbon nitride (g-C3N4) hybridized with a small number of multi-walled carbon nanotubes (CNT) was synthesized using cyanamide as precursor. The optimal CNT content is found to be ∼0.2 wt% in the composite, which displays a 2.4-fold enhancement in photocatalytic water splitting over pure g-C3N4. Characterizations by a series of joint techniques including Raman spectra, UV/vis diffuse reflectance spectra, steady and time-resolved fluorescence emission spectra, and photocurrent responses were carried out, aiming to reveal the determinative factor for the improved visible-light response. Our results indicate that the increased photoactivity originates from the enhanced charge-transfer effect due to the intimate interactions between g-C3N4 and conjugated CNT. The presence of CNT in the hybrids is beneficial for improving electron-hole separation on the excited g-C3N4 by prolonging the lifetimes of charge carriers and improving the population distribution of short-lived and long-lived charge carriers.

[Strategy of acetabular anteversion in total hip arthroplasty with lumbar degenerative kyphosis].

OBJECTIVE: To investigate how to place the anteversion of acetabular prosthesis more reasonably in patients with lumbar degenerative kyphosis. METHODS: A total of 122 patients with degenerative kyphosis of lumbar spine who underwent total hip arthroplasty from December 2017 to October 2019 were included and divided into experimental group and control group, 61 cases in each group. In experimental group, there were 25 males and 36 females, with a median age of 67.0 years;the median course of disease was 46.0 months;the functional pelvic plane with acetabular anteversion was set according to different types of pelvic anterior plane bracket. In control group, there were 27 males and 34 females, with a median age of 67.0 years;the median course was 42.0 months;in control group, the anteversion was set by the traditional method. The patients were followed up for 3 months. The operation time and blood loss were recorded. The incidence of infection and dislocation within 3 months was counted. Harris score before and 3 months after operation was recorded. Functional anteversion angle of standing position was measured 3 months after operation. RESULTS: Compared with control group, there was no difference in operation time and blood loss between the two groups (P=0.918, 0.381);there was no infection between two groups within 3 months after operation;there was 1 case of hip joint dislocation in the control group and no dislocation in experimental group. There was no significant difference in Harris score before and after operation. Three months later, reexamination of pelvic standing radiographs showed that the number of patients with functional anteversion of acetabular prosthesis outside the safe area was less in experimental group thanin control group (P=0.048), and the functional anteversion angle of acetabular prosthesis was more concentrated in the range of 15 ° to 20 ° in experimental group (P<0.001). CONCLUSION: According to the preoperative evaluation and classification of patients, better functional anteversion of acetabular prosthesis can be obtained with the help of pelvic anterior plane reference bracket in hip arthroplasty with lumbar degenerative kyphosis.

A facile approach to synthesize novel oxygen-doped g-C3N4 with superior visible-light photoreactivity.

O-doped g-C(3)N(4) was synthesized for the first time by a facile H(2)O(2) hydrothermal approach. The O-doping in the g-C(3)N(4) lattice could induce intrinsic electronic and band structure modulation, resulting in its absorbance edge up to 498 nm and enhanced visible-light photoactivity, consequently.

[Effect of root canal therapy combined pulp mummification in treatment of residual pulpitis after mummification in molars of the gerontal patients].

PURPOSE: To evaluate the effect of root canal therapy combined with pulp mummification in treatment of residual pulpitis after mummification in molars of the gerontal patients. METHODS: One hundred and twenty-two molars with residual pulpitis after mummification were obtained from 108 over 70 years patients. All molars were treated with root canal therapy combined with pulp mummification, and were evaluated after 1 month, 1 year and 2 years. RESULTS: The treatment of all molars was effective within 1 month. The treatment success rate at 1- and 2-year was 86.9% and 76.2%,respectively. CONCLUSION: Root canal therapy combined with pulp mummification is one of the effective methods to treat residual pulpitis after mummification in molars of the gerontal patients over 70 years.

[Expression of NF-kappaB and COX-2 in tongue squamous cell carcinoma].

PURPOSE: To examine the expression of nuclear factor-kappaB (NF-kappaB) and cyclooxygenase-2 (COX-2) and their relationship in tongue squamous cell carcinoma (TSCC) and to evaluate their functions in the development and progression of TSCC. METHODS: The expression of NF-kappaB and COX-2 in 50 cases of TSCC was determined using SP immunohistochemical method. Data was statistically analyzed by Chi-square test with SPSS11.0 software package. RESULTS: In the poorly differentiated TSCC group, NF-kappaB an COX-2 positive expression rate was 48% and 68.0%, respectively, significantly higher than that in the moderately- and well-differentiated group (P<0.05); In the TSCC group with lymph node metastasis, NF-kappaB and COX-2 positive expression rate was 42.3% and 61.5%, respectively, significantly higher than that in the group without lymph node metastasis (P<0.05). In the cases with COX-2 negative expression, NF-kappaB positive expression rate was 3.8%(1/26), significantly lower than that in the cases with COX-2 positive expression (P<0.05). CONCLUSIONS: NF-kappaB and COX-2 expressions in the poorly differentiated and lymph node metastasis TSCC cases are higher than those in moderate- and well-differentiated and non- lymph node metastasis cases, NF-kappaB and COX-2 may be involved in the carcinogenesis and development of TSCC.