Magnetic silica micro-spheres is a kind of novel functional materials, which is expected to be applied to targeted drug delivery, immunomagnetic beads, separation of nucleic acid and protein, immobilization of enzymes and isolation and purification of natural products in biomedicine. This review describes the methods of synthesis, surface modification and applications of magnetic silica micro-spheres, which focus on the various strategies in synthesis with core-shell and mosaic structure, sol-gel method, liquid phase deposition, self-assembly technique and micro-emulsion method. Finally, foregroud and prospect of the research are also discussed.

Objective To assess the outcome of percutaneous vertebroplasty for symptomatic vertebral hemangiomas. Methods Five cases with 7 symptomatic vertebral hemangiomas were treated with percutaneous vertebroplasty. Aggressive lesions were treated with absolute alcohol injection in addition. Patients were followed-up and clinical manifestations were observed and CT, MRI and X-ray plain film were compared between before and after vertebroplasty. Results Procedures were successful without complications. Most of the symptoms resolved within 24 hours after vertebraplasty. All patients were followed-up for 12～50 months and free of neurological deficits and symptoms. Imaging follow-up showed no vertebral collapse, nor recurrance of hemangiomas. Conclusion With effective long-term follow-up and quick elimination of symptoms, precutaneous vertebroplasty, added with absolute alcohol injection in aggressive cases, proves to be a safe and effective treatment for symptomatic vertebral hemangiomas.

Objective To evaluate the safety,effectiveness,and middle or long-term efficacy of endovascular stenting of internal carotid artery stenosis at the cavernous segment. Methods Thirty-two patients underwent endovascular stenting at the cavernous segment of internal carotid artery from January 2012 to February 2015 were enrolled retrospectively. Angioplasty and stenting were conducted using Apollo or Winspan stent system. The improvement of internal carotid artery cavernous segment stenosis and perioperative safety and the results of the medium and long-term follow-up of the 2 kinds of stents were observed. Results All the 32 patients achieved technical success. The symptoms of cerebral ischemia of the patients were relieved significantly. The length of the stenosis at cavernous segment of the internal carotid artery was 4 to 13 mm (mean,7. 2 ±2. 9 mm). The stenosis rate from 82 ± 7% before treatment decreased to the 24 ± 7% . One patient had perioperative complication (4. 7%),26 of them were followed up with DSA,and 6 were lost to follow-up. The follow-up period ranged from 7 to 29 months (mean,16 ± 7 months). During the follow-up period,1 patient had intracerebral hemorrhage,1 had cerebral infarction,and none of them died. Four patients had in-stent restenosis,three of them used Winspan stents, and 1 used Apollo stents. Conclusion The patients should be screened strictly,particularly paying attention to the length of lesions. Endovascular stent angioplasty for the treatment of internal carotid artery cavernous segment stenosis is a safe and effective method.

Micro-hardness of human teeth was measured by micro hardnessmentry at different depths i.e. enamal, enamelo-dentinal junction and dentin. A simulated dental friction test was conducted of respectively in these three areas, opposing pure titanium ball under a modified fretting machine. The results showed that micro-hardness is 320.40 +/- 22.77 HV of enamal, 232.26 +/- 32.31 HV of enamelo-dentinal junction, and 61.17 +/- 9.42 HV of dentin (P < 0.05). Wear depth is 17.33 +/- 0.58 microns of enamal, 49.44 +/- 16.47 microns of enamelo-dentinal junction and 95.20 +/- 15.07 microns of dentin(P < 0.05). Wear resistance of enamal is much better than that of dentin's. This preliminary investigation should be very useful in clinical applications.
Adult ; Hardness ; Hardness Tests ; methods ; Humans ; Tooth ; anatomy & histology ; physiology

Objective:To evaluate the safety and feasibility of endovascular recanalization for non-acute internal carotid artery occlusion (NA-ICAO), and to propose a new angiographic classification.Methods:From April 2015 to October 2019, 95 consecutive patients with symptomatic NA-ICAO who received endovascular recanalization were retrospectively analyzed in Beijing Tiantan Hospital, Capital Medical University. All the patients were divided into four groups according to DSA: type Ⅰ, petrous segments were distally reconstituted by collateral vessels; type Ⅱ, cavernous segments were distally reconstituted by collateral vessels; type Ⅲ, ophthalmic segments were distally reconstituted by collateral vessels; type Ⅳ, communicating segments were distally reconstituted by collateral vessels. Study data including clinical characteristics, surgical details, lesion classification, recanalization rate and perioperative complications. For the counting data, the χ 2 test was used to compare between groups. For the quantitative data, the ANOVA was used for the normal distribution data, otherwise the Kruskal-Wallis H test was used. The primary safety outcome was any stroke or death within 30 days. Results:Among the 95 patients, 67 (70.53%) had successful recanalization. The recanalization rates of type Ⅰ－Ⅳ were 92.31% (36/39), 81.82% (18/22), 47.83% (11/23) and 18.18% (2/11) respectively (χ2=29.557, P<0.001). And the complication rates of the four types were 5.13% (2/39), 13.64% (3/22), 21.74% (5/23) and 9.10% (1/11) respectively. The incidence of perioperative ischemic stroke was 2.11% (2/95). No other serious stroke and death occurred. Conclusions:Endovascular recanalization may be feasible and safe for carefully selected patients with NA-ICAO and therefore represents an alternative treatment. The patients with type Ⅰ and Ⅱ lesions had higher recanalization rates, while the patients with type Ⅳ lesions had significantly lower recalculation rate. The new angiographic classification is conducive to the selection of suitable patients and difficulty in grading.

OBJECTIVETo assess the value of stent-assistant angioplasty for intracranial vascular diseases.

METHODSThirteen patients with intracranial vascular diseases were treated consecutively by stent-assistant angioplasty for different purposes. Of these patients 7 had symptomatic intracranial artery stenosis, 3 intracranial wide-neck aneurysms, 2 intracranial pseudoaneurysms, and 1 bilateral transverse sinus stenosis. Clinical procedures and technical data of the patients were retrospectively analyzed.

RESULTSIn the 7 patients, the degree of intracranial artery stenosis reduced from 83% to 5%. Three months after the operation they exhibited good patency of stented lesions. Intracranial wide neck aneurysms (with 2 pseudoaneurysms) were successfully embolized with GDC in 5 patients. The patients with bilateral transverse sinus stenosis were implanted a self-expanded stent in the right transverse sinus. One patient failed because of the tortuous configuration of the left jugular bulb, but the patient's symptoms were improved quickly after the procedure.

CONCLUSIONStent-assistant angioplasty is a useful technique for selected intracranial vascular diseases, and it needs further investigation.

Adult ; Angioplasty, Balloon ; methods ; Cerebrovascular Disorders ; therapy ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Stents ; Treatment Outcome

OBJECTIVE: To evaluate the safety of the balloon occlusion test(BOT) and therapeutic occlusion of the internal carotid artery(ICA). METHODS: The data of 43 patients hospitalized consecutively with traumatic intractable carotid cavernous fistulas (TICCF) were analyzed. Therapeutic occlusion of ICA was performed on 39 cases and BOT was only performed on the remaining 4 cases. Our assessment consisted of: (1) angiographic evaluation of collateral circulation with or without BOT of ICA, and (2) evaluation of clinical tolerance to therapeutic occlusion of ICA with hypotensive challenge for 30 minutes. Complications of BOT and therapeutic occlusion of ICA were also analyzed retrospectively. RESULTS: Complications related to BOT occurred in 1 case (2.3%) without causing permanent deficits. Complications related to therapeutic occlusion of ICA occurred in 4 cases (10%), including 1 technical (2.5%), 2 temporary (5%) and 1 permanent (2.5%) deficit. There was no fistula recurrence or mortality. CONCLUSIONS: BOT of ICA is safe and economical. The reliability of the results is almost the same compared with that of other more complicated methods of assessing therapeutic occlusion of ICA. And it is easy to treat TICCF with therapeutic occlusion of ICA.

Objective To review the experience of multiple modality endovascular treatment for intracranial venous thrombosis, and to evaluate the efficacy and risk of endovascular thrombolysis for intracranial venous thrombosis.Methods From October, 2000 to October, 2001, 12 patients with intracranial venous thrombosis confirmed by CT, MRI, MRV, and/or DSA were treated with multiple modality endovascular thrombolysis including intravenous thrombolysis, mechanical thrombus maceration, intraarterial thrombolysis, and stenting.After thrombolysis, treatment aimed at the primary diseases was continued and warfarin was used for 6 months.The patients were followed-up for 17-29 months, averaged 23 months.Results Of the twelve patients, all underwent transvenous thrombolysis, ten underwent combined transvenous thrombolysis and clot maceration, seven underwent transvenous infusion of urokinase combined with transarterial infusion of urokinase.Two underwent transvenous infusion of urokinase combined with transarterial infusion of urokinase.The thrombolysis duration was from one to three days.The infusion dose of urokinase was 800 000 to 2 900 000 IU, the averaging dosage of urokinase was less than 1 000 000 IU per day.All patients achieved from recanalization of sinuses as confirmed on postprocedural angiography, MRI, and MRV studies prior to hospital discharge.At discharge, all the patients improved neurologically, and GCS improved from averaged 12 of pre-operation to 14 of post-operation.During the averaging 23 months follow-up, no patient recurred. Conclusion Combined multiple modality endovascular treatment is an effective and safe procedure for potentially catastrophic intracranial venous thrombosis.

Objective:To compare the safety and therapeutic effect of bridging therapy versus direct endovascular treatment in patients with acute ischemic stroke(AIS)aged 80 years and over, who received the therapy within 4.5 h of onset.Methods:A total of 89 AIS patients aged 80 years and over receiving the endovascular therapy at our hospital from January 2016 to June 2019 were studied with versus without intravenous thrombolysis before endovascular therapy(the former as bridging therapy group, n=49; the latter as the direct endovascular treatment group, n=40). Baseline information including gender, the modified Rankin scale(mRS)score, medical history, smoking history, preoperative national institute of health stroke scale(NIHSS)score were collected.Clinical data related to the operation including the times from onset to hospital, door-to-puncture and door-to-recanalization, complications(symptomatic cerebral hemorrhage, mortality)and mRS at 90 d after treatment were compared between the two groups.Multiple logistic regression analysis was used to determine whether or not bridging therapy with intravenous thrombolysis was a prognostic factor.Results:There was no significant difference in baseline information between the two groups( P>0.05). The times from onset to hospital, door-to-puncture, door-to-recanalization had no significant difference between the two groups( P>0.05). There was no significant difference in the incidence of symptomatic cerebral hemorrhage and mortality within 90 d between the two groups(26.5% or 13 cases vs. 17.5% or 7 cases, 14.3% or 7 cases vs.7.5% or 3 cases, χ2=1.031 and 1.017, P=0.310 and 0.313). With different clinical outcomes as dependent variables, after adjusting factors such as gender, admission NIHSS and medical history, Logistic regression analysis showed that the bridging therapy with intravenous thrombolysis was not a prognostic factor( OR=0.795, 95% CI: 0.280~2.258, P=0.666). Conclusions:The bridging therapy is as safe and effective as the direct intravascular therapy for AIS patients aged 80 and over within 4.5 hours of onset.The intravenous thrombolysis should be given as soon as possible within time window.

Objective To evaluate the safety and therapeutic effects of stent retriever-based thrombectomy (SRT) on acute ischemic stroke (AIS) in patients aged 80 years and older.Methods A cohort of 157 AIS patients hospitalized in Capital Medical University Affiliated Beijing Tiantan Hospital were selected for SRT from January 2016 to May 2017.Based on the age,all patients were divided into two groups:groups aged ＜ 80 years and ≥ 80 years.Baseline information including gender,the Modified Rankin Scale (mRS) score,past medical history,smoking history,preoperative National Institutes of Health Stroke Scale (NIHSS),the Alberta Stroke Program Early CT Scores (ASPECTS),intravenous thrombolysis and clinical outcomes were compared between two groups.The informations related to the operation,including time from onset to hospital,door-to-needle puncture time,door-to-recanalization time,SRT complications (symptomatic cerebral hemorrhage,mortality) and good outcome,were compared between two groups.Logistic regression analysis was used to determine whether the age of 80 years and over was a risk factor for adverse prognosis after SRT.Results There were 130 patients in the group ＜ 80 years of age,and 27 patients in the group ≥80 years.No significant differences were found in baseline information between the two groups (all P＞ 0.05).In addition,there were no significant differences in the proportions of the operative information,complications of SRT and the good outcome (all P＞0.05).Furthermore,advanced age (≥80 years) was not a risk factor for adverse outcome after SRT (OR =0.738,95％ CI:0.300-1.813).Conclusions Stent retriever-based thrombectomy is safe and beneficial for patients with acute ischemic stroke,even in patients aged 80 years and over.