[The preliminary study of Neuroform EZ stent in the treatment of severe intracranial atherosclerotic stenosis].

Objective: To evaluate the safety and clinical efficacy of Neuroform EZ stent in the treatment of severe intracranial atherosclerotic stenosis (ICAS). Methods: A total of 36 patients with severe ICAS receiving Neuroform EZ stent angioplasty were retrospectively analyzed at Beijing Anzhen Hospital from July 2018 to January 2020. Digital subtraction angiography (DSA) before endovascular intervention confirmed the diagnosis. Follow-up information was reviewed by neurologists at 30 days and 6 months after the procedure. The primary endpoints were transient ischemic attack (TIA), ischemic or hemorrhagic stroke and death caused by any reason within 30 days. Results: The overall technical success rate was 100%. The median stenosis rate was reduced from 93.6%±4.5% to 18.8%±11.2% (t=37.36,P<0.001).Primary endpoint event was not reported. During follow-up, one patient developed TIA and no death or ischemic stroke was observed. No in-stent restenosis at six months occurred. Conclusion: Neuroform EZ stent is safe and effective in patients with severe ICAS. However, perspective studies need to be operated for further validation via long-term follow-up.

[Comparative analysis of vertebral artery stent implantation via femoral artery and radial artery].

Objective: To study the effect and safety of vertebral artery stent implantation via femoral artery and radial artery. Methods: Twenty-four patients with vertebral artery stent implantation from December, 2017 to August, 2018 in Beijing Anzhen Hospital were randomized into 2 groups, one was research group with 12 patients, the other was control group with 12 patients. The research group underwent vertebral artery stent implantation via radial artery, the control group underwent vertebral artery stent implantation via femoral artery. The follow-up results of the two groups were analyzed. Results: The success rate of the first puncture in the research group was 100%, significantly higher than 83.33% of the control group, there was no statistical difference (χ(2)=2.528, P>0.05).The implantation time of sheath tube in the research group was (3.2±0.3) min, significantly longer than that in the control group (2.4±0.2) min, the difference was statistically significant (t=7.713, P<0.001). The time from sheath insertion to balloon dilation and bed rest time after operation in the research group were 17.3 (16.2-17.9) min, significantly less than the control group (27.1(26.1-28.3) min), the difference was statistically significant (Z=-4.157, P<0.001). The time of bed rest in the research group was 2.1 (2.0-2.2)h, significantly less than the control group (27.1(25.3- 28.9)h), the difference was statistically significant(Z=-4.167,P<0.001). No cerebrovascular events occurred during the follow-up period. One patient in the control group developed complications of vagal reflex, no patient in the research group developed complications. Conclusions: Vertebral artery stent implantation via radial artery can significantly improve the success rate and safety of the operation. Radial artery approach is a better choice for vertebral artery stent implantation.

[Clinicopathological characteristics and prognosis of diffuse midline gliomas with histone H3K27M mutation: an analysis of 30 cases].

Objective: To analyze the clinicopathological characteristics and prognosis of diffuse midline glioma (DMG) with H3K27M mutation. Methods: Thirty cases of DMG were collected in Guangdong Sanjiu Brain Hospital from October 2016 to May 2018. The patients' clinicopathological data including age, tumor site and histological grade, treatment and follow-up data were collected and analyzed. Results: There were 21 males and 9 females, with a mean age of 26 years (range 5-53 years). Fourteen tumors were located in thalamus, 12 in brainstem (one involved both thalamus and brainstem), and one each in hypothalamus, fourth ventricle, and sellar region, respectively. Two cases presented as diffuse intracranial lesions. Three cases (10.0%) were of WHO grade Ⅰ, 10 cases (33.3%) were grade Ⅱ, eight cases (26.7%) were grade Ⅲ, and nine cases (30.0%) were grade Ⅳ.All patients with gradeⅠ tumors were older than 20 years. Histologically, all were pilocytic astrocytoma-like. Immunohistochemical staining demonstrated that all tumors were IDH1 negative. Twenty-eight tumors showed diffuse expression of H3K27M, and two showed focal expression. Twenty-one tumors(100.0%, 21/21) showed absent expression of H3K27me3. Sixteen tumors (57.1%, 16/28) showed strongly positive expression of p53, and ATRX was negative in eight tumors (38.1%, 8/21). The Ki-67 proliferation index ranged from 5% to 40%. Eight cases (including two cases of H3K27M expression of individual cells) showed K27M mutation in H3F3A gene. Intracranial and spinal cord dissemination occurred in six cases (20.0%, 6/30). Median progression-free survival (PFS) was 9.5 months and median overall survival (OS) was 34 months. Mean PFS was 11.2 months and mean OS was 24.3 months. Compared with adults (>20 years old), children/adolescents (no more than 20 years old) had significantly shorter median OS (8 months vs. 34 months, P=0.013). There was no significant difference in PFS and OS between DMGs located in the brain stem/thalamus and other sites within midline (P>0.05). There was no significant difference in PFS and OS between WHO grade ⅠDMGs and WHO grade Ⅱ-Ⅳ DMGs (P>0.05). Conclusions: DMGs occur more commonly in children and adolescents with male predominance. DMGs present with WHO Ⅰ-Ⅳ tumors morphologically, and pilocytic astrocytoma-like lesions with WHO Ⅰ are more common in adults. Expression of H3K27M but not H3K27me3 is helpful for diagnosis of DMG. The prognosis of children/adolescents is significantly worse than that of adults, whereas histological grade and tumor location do not affect prognosis.

Dielectrophoresis of an inhomogeneous colloidal particle under an inhomogeneous field: a first-principles approach.

In reality, colloidal particles often possess an arbitrary inhomogeneity profile. We present a first-principles approach to dielectrophoresis of such an inhomogeneous colloidal particle under an inhomogeneous field of an oscillating electric dipole moment. For numerical simulations, we treat the inhomogeneous particle as a specific graded one with a physically motivated dielectric model and conductivity profile. We find that both multipolar interactions and spatial fluctuations inside the particle can affect the dielectrophoretic spectrum of the particle significantly.

[Study of sintering temperature of HN-97 porcelain stain].

OBJECTIVE: To determine the sintering temperature range and the best temperature of coloration of HN-97 porcelain stain,and matched porcelain powders. METHODS: (1) The authors used prepared experiments of sintering temperatures and different sintering temperatures with different porcelain powders. RESULTS: The results showed sintering temperature range of the stain was 820-955 degrees centigrade; (2)The stain can be matched with many porcelain powders (e.g.Vita,Densply. Shofu and Shanghai); (3)Surface of stain was smooth, colour was stable,integrate was good. CONCLUSION: The stain can be used once coloration and glaze for restoration of porcelain, autoglazing temperature of which is between 820-955 degrees centigrade and the operation is easy.

[Two components in bereitschaftspotential].

In this work the BP onsettimes of voluntary movement and instructed movement were compared. Our results show that there is no significant difference (P > 0.05) between BP onsettimes of the two kinds of movement and that BP occurs before the instruction of movement. The early component of BP, i.e. the negative wave before the presentation of instruction, had no relationship with movement preparation. For the analysis of the source of the BP early component, the BP onsettimes of unconscious eyeblink and instructed eyeblink or self-initiated voluntary eyeblink were compared. It was found that the BP onsettime of unconscious eyeblink was much shorter than that of the two kinds of conscious (P < 0.05) eyeblink. These results suggest that the BP early component is elicited by psychological factors, rather than the result of the preparatory processes of movements in the brain.

Altered pyruvate dehydrogenase control and mitochondrial free Ca2+ in hearts of cardiomyopathic hamsters.

The fraction of total pyruvate dehydrogenase in the active, dephosphorylated form is much lower in the glucose-perfused isolated hearts of two myopathic strains of Syrian hamster (BIO 14.6 and TO-2) than in the hearts of healthy control animals (F1B). The myopathic hearts also develop significantly less pressure under these conditions. Experiments with isolated myocytes from the BIO 14.6 heart reveal that intramitochondrial free Ca2+ ([Ca2+]m), a positive effector of pyruvate dehydrogenase interconversion, rises much less in response to a protocol of increased frequency of electrical stimulation and adrenergic stimulation than does [Ca2+]m in cells from the healthy control animals (viz from 248 +/- 15 to 348 +/- 44 nM in BIO 14.6 vs. from 241 +/- 35 to 830 +/- 124 nM in F1B, at 4 Hz). As the concentration of Ca2+ that produces half-maximal activation of pyruvate dehydrogenase within mitochondria is 650 nM, this difference between strains is likely the mechanism of the altered enzyme interconversion. The lesser response of [Ca2+]m to electrical stimulation in the BIO 14.6 cells probably results mainly from smaller systolic transients in cytosolic free Ca2+ in response to excitation of single myocytes from the BIO 14.6 animal. Lowered values of [Ca2+]m within the range described would compromise not only pyruvate dehydrogenase activity, but also flux through the tricarboxylate cycle in the myopathic heart, owing to the sensitivity of 2-oxoglutarate dehydrogenase to Ca2+. This may explain the decreased activity of oxidative phosphorylation and performance of work in the myopathic heart.