Effect of Time Window on Endovascular Thrombectomy with or without Intravenous Thrombolysis in Acute Ischemic Stroke: Results from DIRECT-MT.

INTRODUCTION: Whether time window affects the intravenous thrombolysis (IVT) effect before endovascular thrombectomy (EVT) is uncertain. We aimed to investigate the effect of different time windows (0-3 h and >3-4.5 h from stroke onset to randomization) on clinical outcomes of EVT with or without IVT in a subgroup analysis of DIRECT-MT. METHODS: The primary outcome was the 90-day modified Rankin Scale (mRS) according to time window. Logistic regression models were used to analyze the effect of different treatments (EVT with or without IVT) on outcomes within 0-3 h or >3-4.5 h. RESULTS: Among 656 patients who were included in the analysis, 282 (43.0%) were randomized within >3-4.5 h after stroke onset (125 without IVT and 157 with IVT), and 374 (57.0%) were randomized within 0-3 h (202 without IVT and 172 with IVT). We noted no significant difference in the thrombectomy-alone effect between the time window subgroups according to 90-day ordinal mRS (adjusted common odds ratio [acOR] in patients within 0-3 h: 1.06 [95% CI: 0.73-1.52], acOR in patients within >3-4.5 h: 1.19 [95% CI: 0.78-1.82]) and 90-day functional independence. Thrombectomy alone resulted in an increased proportion of patients with 90-day mRS 0-3 treated within >3-4.5 h (62.90 vs. 48.72%) but not within 0-3 h (65.84 vs. 63.95%). However, there was no interaction effect regarding all outcomes after the Bonferroni correction. CONCLUSIONS: Our results did not support thrombectomy-alone administration within 3-4.5 h in patients with acute ischemic stroke from large-vessel occlusion in the subgroup analysis of DIRECT-MT.

An efficient method of preparing Si-Fe-Al-Ca alloy from coal gasification fine slag via plasma smelting and alternating current magnetic field.

It is of great significance to solve the environmental problems caused by the unreasonable treatment of coal gasification slag. This study successfully produced Si-Fe-Al-Ca alloy from low-carbon fine slag with petroleum coke as reducing agent in a plasma furnace with an alternating current magnetic field, which solved the problem of the high reactivity requirement of carbon reductant for plasma smelting. The optimum carbon content of the mixed low-carbon fine slag and petroleum coke is 105% of the theoretical value. As the strength of the alternating current magnetic field increased (from 0% to 100% of the maximum power), the yield of the alloy (from 25.46% to 58.19%) and the recovery ratios of each element (Si, Fe, Al, Ca, Ti) increased. In addition, as the magnetic field strength increased, the pores inside the alloy became smaller, the composition of the alloy became more homogeneous, and a better separation of the alloy from the slag was observed. The main composition of the alloy at the strongest alternating current magnetic field is Si: 51.14 wt%, Fe: 28.41 wt%, Al: 9.14 wt%, Ca: 7.15 wt%, Ti: 2.03 wt%. We attribute the enhanced smelting effect of the alternating current magnetic field to the resistive heat and Lorentz force produced by the induced current. In addition, the skin effect concentrated the induced current on the surface of the oxide particles and carbon particles, which increased the temperature of the reaction interface and promoted the carbothermal reduction reaction.

Thrombectomy alone vs thrombectomy with over 2/3-dose intravenous thrombolysis pretreatment in the DIRECT-MT trial.

BACKGROUND: The DIRECT-MT trial showed that endovascular thrombectomy (EVT) alone was noninferior to EVT preceded by intravenous alteplase. However, the infusion of intravenous alteplase was uncompleted before the initiation of EVT in most cases of this trial. Therefore, the additional benefit and risk of over 2/3-dose intravenous alteplase pretreatment remain to be assessed. METHODS: We assessed patients with acute anterior circulation ischemic stroke who received EVT alone or with over 2/3-dose intravenous alteplase pretreatment from the DIRECT-MT trial. Patients were assigned to the thrombectomy-alone group and the alteplase pretreatment group. The primary outcome was the distribution of modified Rankin Scale (mRS) at 90 days. The interaction of treatment allocation and collateral capacity was assessed. RESULTS: A total of 393 patients (thrombectomy alone: 315; alteplase pretreatment: 78) were identified. The thrombectomy alone was comparable with alteplase pretreatment prior to the thrombectomy on the distribution of mRS at 90 days without significant effect modification by collateral capacity (adjusted common odds ratio (acOR), 1.12; 95% CI, 0.72-1.74; adjusted P for interaction = 0.83). Successful reperfusion before thrombectomy and the number of passes in the thrombectomy alone group differed significantly from the alteplase pretreatment group (2.6% vs. 11.5%; corrected P = 0.02 and 2 vs. 1; corrected P = 0.003). There was no interaction between treatment allocation and collateral capacity on all outcomes. CONCLUSIONS: EVT alone and EVT preceded by over 2/3-dose intravenous alteplase might have equal efficacy and safety for patients with acute anterior circulation large vessel occlusion, except for successful perfusion before thrombectomy and the number of passes.

Intensive blood pressure control after endovascular thrombectomy for acute ischaemic stroke (ENCHANTED2/MT): a multicentre, open-label, blinded-endpoint, randomised controlled trial.

BACKGROUND: The optimum systolic blood pressure after endovascular thrombectomy for acute ischaemic stroke is uncertain. We aimed to compare the safety and efficacy of blood pressure lowering treatment according to more intensive versus less intensive treatment targets in patients with elevated blood pressure after reperfusion with endovascular treatment. METHODS: We conducted an open-label, blinded-endpoint, randomised controlled trial at 44 tertiary-level hospitals in China. Eligible patients (aged ≥18 years) had persistently elevated systolic blood pressure (≥140 mm Hg for >10 min) following successful reperfusion with endovascular thrombectomy for acute ischaemic stroke from any intracranial large-vessel occlusion. Patients were randomly assigned (1:1, by a central, web-based program with a minimisation algorithm) to more intensive treatment (systolic blood pressure target <120 mm Hg) or less intensive treatment (target 140-180 mm Hg) to be achieved within 1 h and sustained for 72 h. The primary efficacy outcome was functional recovery, assessed according to the distribution in scores on the modified Rankin scale (range 0 [no symptoms] to 6 [death]) at 90 days. Analyses were done according to the modified intention-to-treat principle. Efficacy analyses were performed with proportional odds logistic regression with adjustment for treatment allocation as a fixed effect, site as a random effect, and baseline prognostic factors, and included all randomly assigned patients who provided consent and had available data for the primary outcome. The safety analysis included all randomly assigned patients. The treatment effects were expressed as odds ratios (ORs). This trial is registered at ClinicalTrials.gov, NCT04140110, and the Chinese Clinical Trial Registry, 1900027785; recruitment has stopped at all participating centres. FINDINGS: Between July 20, 2020, and March 7, 2022, 821 patients were randomly assigned. The trial was stopped after review of the outcome data on June 22, 2022, due to persistent efficacy and safety concerns. 407 participants were assigned to the more intensive treatment group and 409 to the less intensive treatment group, of whom 404 patients in the more intensive treatment group and 406 patients in the less intensive treatment group had primary outcome data available. The likelihood of poor functional outcome was greater in the more intensive treatment group than the less intensive treatment group (common OR 1·37 [95% CI 1·07-1·76]). Compared with the less intensive treatment group, the more intensive treatment group had more early neurological deterioration (common OR 1·53 [95% 1·18-1·97]) and major disability at 90 days (OR 2·07 [95% CI 1·47-2·93]) but there were no significant differences in symptomatic intracerebral haemorrhage. There were no significant differences in serious adverse events or mortality between groups. INTERPRETATION: Intensive control of systolic blood pressure to lower than 120 mm Hg should be avoided to prevent compromising the functional recovery of patients who have received endovascular thrombectomy for acute ischaemic stroke due to intracranial large-vessel occlusion. FUNDING: The Shanghai Hospital Development Center; National Health and Medical Research Council of Australia; Medical Research Futures Fund of Australia; China Stroke Prevention; Shanghai Changhai Hospital, Science and Technology Commission of Shanghai Municipality; Takeda China; Hasten Biopharmaceutic; Genesis Medtech; Penumbra.

Endovascular Thrombectomy with or without Intravenous Alteplase in Acute Stroke.

BACKGROUND: In acute ischemic stroke, there is uncertainty regarding the benefit and risk of administering intravenous alteplase before endovascular thrombectomy. METHODS: We conducted a trial at 41 academic tertiary care centers in China to evaluate endovascular thrombectomy with or without intravenous alteplase in patients with acute ischemic stroke. Patients with acute ischemic stroke from large-vessel occlusion in the anterior circulation were randomly assigned in a 1:1 ratio to undergo endovascular thrombectomy alone (thrombectomy-alone group) or endovascular thrombectomy preceded by intravenous alteplase, at a dose of 0.9 mg per kilogram of body weight, administered within 4.5 hours after symptom onset (combination-therapy group). The primary analysis for noninferiority assessed the between-group difference in the distribution of the modified Rankin scale scores (range, 0 [no symptoms] to 6 [death]) at 90 days on the basis of a lower boundary of the 95% confidence interval of the adjusted common odds ratio equal to or larger than 0.8. We assessed various secondary outcomes, including death and reperfusion of the ischemic area. RESULTS: Of 1586 patients screened, 656 were enrolled, with 327 patients assigned to the thrombectomy-alone group and 329 assigned to the combination-therapy group. Endovascular thrombectomy alone was noninferior to combined intravenous alteplase and endovascular thrombectomy with regard to the primary outcome (adjusted common odds ratio, 1.07; 95% confidence interval, 0.81 to 1.40; P = 0.04 for noninferiority) but was associated with lower percentages of patients with successful reperfusion before thrombectomy (2.4% vs. 7.0%) and overall successful reperfusion (79.4% vs. 84.5%). Mortality at 90 days was 17.7% in the thrombectomy-alone group and 18.8% in the combination-therapy group. CONCLUSIONS: In Chinese patients with acute ischemic stroke from large-vessel occlusion, endovascular thrombectomy alone was noninferior with regard to functional outcome, within a 20% margin of confidence, to endovascular thrombectomy preceded by intravenous alteplase administered within 4.5 hours after symptom onset. (Funded by the Stroke Prevention Project of the National Health Commission of the People's Republic of China and the Wu Jieping Medical Foundation; DIRECT-MT ClinicalTrials.gov number, NCT03469206.).

Imaging mismatch between Alberta Stroke Program Early CT Score and perfusion imaging may be a good variable for endovascular treatment.

OBJECTIVE: Some patients with acute large vessel occlusion (LVO) presented imaging mismatch, low Alberta Stroke Program Early CT Score (ASPECTS) with small ischemic core, or high ASPECTS with large ischemic core. The study was designed to explore whether patients with imaging mismatch could benefit from endovascular treatment (EVT). METHODS: We retrospectively reviewed patients with LVO treated with EVT in our center from March 2018 to Jul 2020. Patients were divided into three groups, imaging mismatch, small ischemic core, and large ischemic core groups. Pooled analyses based on stroke onset to treatment time were done. Multivariate regression analysis was performed to explore the factors for good outcomes. RESULTS: Sixty-eight of 419 patients with LVO presented with imaging mismatch, and 35 of those (51%) achieved good outcomes after EVT at 90-day. No significant differences were noted in good outcomes and symptomatic intracranial hemorrhage (sICH) between patients with imaging mismatch and small ischemic core. Compared with large ischemic core, patients with imaging mismatch presented lower risk of sICH (95% confidence interval (CI) 0.04-0.75, p = 0.011) within 6 h and higher proportion of good outcomes (95% CI 0.37-0.82, p = 0.002) at 6 to 24 h. Baseline NIHSS (odds ratio (OR) = 0.91, 95% CI 0.88-0.95)), ASPECTS (OR = 1.14, 95% CI 1.01-1.29), ischemic core (OR = 0.99, 95% CI 0.98-1.00), and sICH (OR = 61.61, 95% CI 8.09-461.32) were associated with good outcomes. CONCLUSIONS: Patients with imaging mismatch treated within 24 h could benefit from EVT and without increasing the risk of sICH. KEY POINTS: • Patients with imaging mismatch between ASPECTS and ischemic core could achieve good outcomes after endovascular treatment. • Compared with large ischemic core, patients with imaging mismatch presented lower risk of symptomatic hemorrhage within 6 h and higher proportion of good outcomes within 6-24 h. • Baseline NIHSS score, ASPECTS, ischemic core, and symptomatic intracranial hemorrhage were associated with good outcomes.

Geopolymer composite spheres derived from graphene-modified fly ash/slag: Facile synthesis and removal of lead ions in wastewater.

Geopolymer composite spheres derived from potassium-activated graphene-modified slag/fly ash powder were produced in a polyethylene glycol (PEG 400) solvent. The effect of graphene type (graphene oxide (GO) and few-layered graphene (GNP)) on the pore structure and lead ions (Pb2+) removal performance of the spheres were evaluated. The results showed that the composite spheres modified with GOs (0.1-0.4 wt%) and GNPs (1-4 wt%) could be spheroidized with an improved performance to adsorb Pb2+ in solution. The graphene-containing spheres reached a maximum BET surface area of 68.85 m2/g. Pseudo-second-order and Langmuir isotherm models could express the adsorption process, which was controlled by both monolayer adsorption and chemisorption. The obtained spheres also showed high adsorption capacities for Ni2+, Cu2+, Zn2+ and Cd2+ ions. Chemical, physical, electrostatic, ion exchange and cation-π interaction were attributed to the adsorption mechanism of the spheres. The spheres showed good cycling ability compared to those without graphene, which had potential application in heavy metal wastewater treatment.

A novel process to recycle coal gasification fine slag by preparing Si-Fe-Al-Ca alloy.

Maximizing the use of valuable components in coal gasification slag is of great significance for resource recovery and the environment due to the huge annual emission of coal gasification slag. This study successfully produced Si-Fe-Al-Ca alloy with a composition of 63.83 wt% Si, 19.73 wt% Fe, 7.09 wt% Al, 6.32 wt% Ca, 1.70 wt% Ti, 0.03 wt% P, 0.66 wt% Mn, 0.05 wt% Cr, 0.53 wt% C, and 0.06 wt% others through electric arc furnace smelting from mixed coal gasification fine slag. The alloy composition is close to the standard 65% ferrosilicon, which can be used in the deoxidation of the molten steel industry. Moreover, the alloy yield was increased from 20.53% to 67.78% by using the residual carbon of the coal gasification slag as the reductant directly instead of adding petroleum coke. The transformation of coal gasification fine slag during the smelting process and the formation mechanism of the alloy were studied and the carbothermal reduction mechanism of Al2O3 and CaO can be explained by the reduction and decomposition theory of carbides. The complex liquid phase of the reactant system and product system in the smelting process made the carbothermal reaction of Al2O3 and CaO easier to occur, but it also brought the problem that the reactions were not fully completed.

Association of Intravenous Alteplase, Early Reperfusion, and Clinical Outcome in Patients With Large Vessel Occlusion Stroke: Post Hoc Analysis of the Randomized DIRECT-MT Trial.

BACKGROUND: The added value of intravenous alteplase in reperfusing ischemic brain tissue in patients undergoing endovascular treatment and directly presented to an endovascular treatment-capable hospital is uncertain. We conducted this post hoc analysis of a randomized trial (DIRECT-MT [Direct Intraarterial Thrombectomy in Order to Revascularize Acute Ischemic Stroke Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals: A Multicenter Randomized Clinical Trial]) to explore the association of intravenous alteplase, early (preendovascular treatment) reperfusion, and clinical outcome and to determine factors which may modify alteplase treatment effect on early reperfusion. METHODS: In this post hoc analysis of the DIRECT-MT randomized trial comparing intravenous alteplase before endovascular treatment versus endovascular treatment only, 623 of 656 randomized patients, with adequate angiographic evaluation for early reperfusion assessment, were included. The association of intravenous alteplase and early reperfusion (defined as expanded Thrombolysis in Cerebral Infarction score ≥2a on angiogram) was assessed using unadjusted comparisons and multivariable logistic regression. RESULTS: Among 623 patients included (317 received intravenous alteplase and 306 did not), early reperfusion occurred in 91 (15%) patients and was associated with better functional outcome (modified Rankin Scale score, 0-2 of 49/91 [54%] versus 178/531 [34%]; adjusted odds ratio, 1.92 [95% CI, 1.15-3.21]; P<0.001). Intravenous alteplase was independently associated with early reperfusion (59/317 [19%] versus 32/306 [10%]; adjusted odds ratio, 2.06 [95% CI, 1.27-3.33]; P=0.003), and the alteplase effect was modified by time from randomization to groin puncture (dichotomized by median, ≤33 minutes; adjusted odds ratio, 1.06 [95% CI, 0.53-2.10] versus >33 minutes; adjusted odds ratio, 4.07 [95% CI, 1.86-8.86]; Pinteraction=0.012). CONCLUSIONS: For patients with large vessel occlusion directly presenting to an endovascular treatment-capable hospital, intravenous alteplase increases early reperfusion when endovascular treatment gets delayed more than approximately half an hour. Thus, intravenous alteplase should be considered if endovascular treatment delays are anticipated by the treating medical team. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03469206.

Effect of Occlusion Site on the Safety and Efficacy of Intravenous Alteplase Before Endovascular Thrombectomy: A Prespecified Subgroup Analysis of DIRECT-MT.

BACKGROUND AND PURPOSE: Recent trials showed thrombectomy alone was comparable to bridging therapy in patients with anterior circulation large vessel occlusion eligible for both intravenous alteplase and endovascular thrombectomy. We performed this study to examine whether occlusion site modifies the effect of intravenous alteplase before thrombectomy. METHODS: This is a prespecified subgroup analysis of a randomized trial evaluating risk and benefit of intravenous alteplase before thrombectomy (DIRECT-MT [Direct Intra-Arterial Thrombectomy in Order to Revascularize AIS Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals]). Among 658 randomized patients, 640 with baseline occlusion site information were included. The primary outcome was the score on the modified Rankin Scale at 90 days. Multivariable ordinal logistic regression analysis with an interaction term was used to estimate treatment effect modification by occlusion location (internal carotid artery versus M1 versus M2). We report the adjusted common odds ratio for a shift toward better outcome on the modified Rankin Scale after thrombectomy alone compared with combination treatment adjusted for age, the National Institutes of Health Stroke Scale score at baseline, the time from stroke onset to randomization, the modified Rankin Scale score before stroke onset, and collateral score per the DIRECT-MT statistical analysis plan. RESULTS: The overall adjusted common odds ratio was 1.08 (95% CI, 0.82-1.43) with thrombectomy alone compared with combination treatment, and there was no significant treatment-by-occlusion site interaction (P=0.47). In subgroups based on occlusion location, we found the following adjusted common odds ratios: 0.99 (95% CI, 0.62-1.59) for internal carotid artery occlusions, 1.12 (95% CI, 0.77-1.64) for M1 occlusions, and 1.22 (95% CI, 0.53-2.79) for M2 occlusions. No treatment-by-occlusion site interactions were observed for dichotomized modified Rankin Scale distributions and successful reperfusion (extended thrombolysis in Cerebral Infarction score ≥2b) before thrombectomy. Differences in symptomatic hemorrhage rate were not significant between occlusion locations (internal carotid artery occlusion: 7.02% in bridging therapy versus 7.14% for thrombectomy alone, P=0.97; M1 occlusion: 5.06% versus 2.48%, P=0.22; M2 occlusion: 9.09% versus 4.76%; P=0.78). CONCLUSIONS: In this prespecified subgroup of a randomized trial, we found no evidence that occlusion location can inform intravenous alteplase decisions in endovascular treatment eligible patients directly presenting at endovascular treatment capable centers. Future studies are needed to confirm our findings. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03469206.

Platelet count and clinical outcomes among ischemic stroke patients with endovascular thrombectomy in DIRECT-MT.

OBJECTIVES: The prognostic role of baseline platelet count (PLT) in acute ischemic stroke patients with large vessel occlusion undergoing endovascular thrombectomy is unclear. Whether PLT modifies alteplase treatment effect on clinical outcome in those patients is also uncertain. METHODS: We derived data from a multicenter randomized clinical trial (DIRECT-MT) comparing intravenous alteplase before endovascular treatment vs. endovascular treatment only. The 654 patients with available PLT data were included. Primary outcome was the ordinal modified Rankin Scale (mRS) score evaluated at 90 days. We also assessed various secondary and safety outcomes. RESULTS: After adjusting for confounding factors, patients in the top tertile of PLT had a significantly lower risk of a worse shift in the distribution of mRS score (Odds Ratio: 0.671, 95% Confidence Interval: 0.473-0.953, p for trend=0.025), major disability and death (Odds Ratio: 0.617, 95% Confidence Interval: 0.393-0.97, p for trend=0.037) as well as death (Odds Ratio: 0.544, 95% Confidence Interval: 0.313-0.947, p for trend=0.031), respectively, compared with the bottom one. Among patients in the bottom tertile of PLT, combination therapy was associated with a better imaging outcome of eTICI score of 2b, 2c or 3 on final angiogram (Odds Ratio: 3.23, 95% Confidence Interval: 1.49-7.002) with a marginally significant interaction effect. CONCLUSIONS: Participants with higher baseline PLT had a decreased risk of poor functional outcomes. Low baseline PLT modified alteplase treatment effect on the eTICI score on final angiogram. Combination therapy was beneficial for patients with low baseline PLT to have a better reperfusion status.

3D nitrogen-doped graphene created by the secondary intercalation of ethanol with enhanced specific capacity.

Here, we report an improved synthesis strategy for 3D nitrogen-doped graphene to increase the specific capacity of supercapacitors. Ethanol replaces the strong oxidant hydrogen peroxide in the improved Hummers method, and the loose porous structure is conducive to charge transfer. N-doped porous 3D graphene was synthesized from RGO-C prepared by ethanol secondary intercalation modification of functional groups. Ammonia was selected as the dopant; the microstructure and electrochemical performance of samples synthesized at different temperatures were examined. The results demonstrate that the 3D nitrogen-doped graphene (N-RGO-5) had a layered tuple shape with a sheet thickness of 0.612 nm.The specific surface area of the 3D N-RGO-5, which was prepared at 190°C, was 258.371 m2g-1, which was higher than that (5.877 m2g-1) of the original graphite. The 3D N-RGO-5 exhibited a specific capacitance of 236 F g-1and an energy density of 32.78 Wh kg-1at a current density of 1 A g-1, which is 27% higher than the specific capacitance of RGO. The 3D N-RGO-5 demonstrated an excellent capacity retention rate of 93.6% after 5000 cycles at a current density of 1 A g-1. This study demonstrates that the unique 3D structure and N-doping of N-RGO considerably improved the overall energy storage performance of graphene-based nanomaterials.

Preparation of Al-Si alloys with silicon cutting waste from diamond wire sawing process.

Large amounts of silicon cutting waste (SCW) are generated during Si wafers producing process. In this paper, SCW was mixed with Al powder to prepare Al-Si alloys by a one-step smelting process in corundum crucibles. The influences of smelting temperature (1000 °C, 1200 °C and 1500 °C) on the products of each zone (surface layer zone, loose granular zone and blocky products zone) were investigated. Al-Si alloys in the form of granular and blocky were prepared and the blocky Al-Si alloys mainly concentrated in the blocky products zone. The increase of smelting temperature can promote the aggregation of Al-Si alloy particles. The yields of Al-Si alloy blocks obtained at 1000 °C, 1200 °C and 1500 °C were 0%, 58% and 69%, respectively. The Si contents of Al-Si alloy blocks at 1200 °C and 1500 °C were 15.8 wt% and 17.1 wt% respectively. After compacting the raw materials, the yields of the blocky Al-Si alloys obtained at 1000 °C, 1200 °C and 1500 °C were increased to 65%, 72% and 79% and the corresponding Si contents of the blocky Al-Si alloys were increased to 16.0 wt%, 16.5 wt% and 17.3 wt% respectively. The reaction mechanism of the alloying process was also investigated.

Bifunctional nanoporous Ni-Zn electrocatalysts with super-aerophobic surface for high-performance hydrazine-assisted hydrogen production.

In the present study, an effective approach is proposed to replace the oxygen evolution reaction with the substituted anodic hydrazine oxidation reaction (HzOR) to assist in hydrogen generation based on a bifunctional porous Ni-Zn electrocatalyst with nanosheet arrays. The Ni-Zn catalyst exhibits an extraordinary HzOR performance with a high current density of 970 mA cm-2 at 0.7 V, and 93.8% of its initial activity after 5000 s, simultaneously delivering an overpotential of 68 mV at 10 mA cm-2 for the hydrogen evolution reaction. Moreover, the electrolytic cell is constructed employing Ni-Zn catalysts as both the anode and cathode, achieving 100 mA cm-2 at an ultralow cell voltage of 0.497 V with an outstanding stability over 10 h. The superior electrocatalytic performance can be ascribed to its porous structure with large active surface area, high electrical conductivity, and most importantly the super-aerophobic nature of the Ni-Zn surface. This work also provides a novel approach to designing and constructing porous structured non-noble metal bifunctional electrocatalysts with super-aerophobic surface to be used for energy-saving hydrogen production.

One-step electrodeposited 3D porous NiCoSe2 nanosheet array for high-performance asymmetric supercapacitors.

3D porous nanosheet arrays are desirable structures for supercapacitors due to their large surface and fast transportation for ions and electrons. However, their synthesis usually involves two or more steps, which is not only time-consuming but also makes the in situ growth more difficult to achieve. In this work, 3D porous NiCoSe2 nanosheet array were in situ synthesized on Ni foam by one-step electrodeposition, and then employed as a supercapacitor electrode for the first time. The electrodeposited NiCoSe2 electrode displays a high specific capacity of 520 C g-1 at 1 A g-1 and good rate capability of 53.7% with a 30-fold increase to 30 A g-1. In addition, an asymmetric supercapacitor (ASC) device was assembled with NiCoSe2 and activated carbon as the binder-free positive and negative electrode, respectively. The ASC exhibits a high specific energy of 44.4 Wh kg-1 at a specific power of 776.7 W kg-1, and outstanding cycling stability of 133% after 10000 cycles. Most importantly, the energy storage mechanism of NiCoSe2 was proposed. This is mainly due to the significantly increased electroactive surface area and superior electron transfer properties of NiCoSe2, which can compensate for the capacity decay of NiCoSe2 induced by Se and Co loss after cycling.

The "distal-to-proximal" strategy for the treatment of posterior circulation tandem occlusions: a single-centre experience.

PURPOSE: Data on posterior circulation tandem occlusions in acute ischemic stroke are scarce: recognition may be challenging and little is known about optimal treatment strategy. We report our endovascular treatment strategy for posterior circulation tandem occlusion. METHODS: Consecutive patients with posterior circulation tandem occlusions in our centre were enrolled retrospectively. The preferred strategy was "distal-to-proximal" strategy, which means opening the distal occlusion first followed by treatment of the proximal pathology. The imaging characteristics, treatment strategy, clinical outcomes, and complications of patients with posterior circulation tandem occlusions were analyzed. RESULTS: In total, 21 patients with posterior circulation tandem occlusions were enrolled in the study, which accounted for 23.6% of patients with posterior circulation stroke in our centre. The mean age was 60 years (range 32 to 80), and median pre-procedure NIHSS score was 28 (interquartile range: 13-31). Eighteen patients (85.7%) had vertebrobasilar artery tandem occlusions and 3 (14.3%) had basilar artery to basilar artery tandem occlusions. All distal occlusions were successfully recanalized (modified TICI 2b/3). Two (9.5%) of the proximal lesions were not treated. A total of 57.1% of the patients had stents implanted on the proximal occlusions. The rate of mRS 0-3 at 3 months was 57.1% and the mortality rate was 19.0%. CONCLUSION: In patients with acute ischaemic stroke caused by posterior circulation tandem occlusions, we favor "distal-to-proximal" strategy based on the positive results in this small series. Nevertheless, a more extensive study is required to explore the optimal treatment strategy further.

Hydrometallurgical recovery of spent cobalt-based lithium-ion battery cathodes using ethanol as the reducing agent.

A reducing agent can reduce Co3+ to Co2+ in LiCoO2, thus increasing the leaching efficiency and extraction rate of Co-based cathode materials from spent lithium-ion batteries (LIBs). Herein, ethanol was employed as the reducing agent to leach LiCoO2 obtained from LIBs in a sulfuric acid solution. The effects of operating temperatures (50-90 °C), dosage of ethanol (0-20 vol%), concentration of sulfuric acid (2-6 mol/L), and solid/liquid ratio (10-40  g/L) on the leaching efficiency of LiCoO2 were investigated. By adding 5 vol% ethanol in a 6 mol/L sulfuric acid solution at 90 °C, the extraction efficiency of Co and Li are both over 99%, meaning that ethanol can reduce Co3+ to Co2+ while the ethanol was oxidized to acetic acid. The dissolution of LiCoO2 obeys the residue layer diffusion control model. Although ethanol is a promising reducing agent, future efforts should pay to the management of the secondary wastewater. Overall, the ethanol can be used as a reducing agent to assist the leaching of cathode materials from spent LIBs.

Individualized intravenous thrombolytic strategy for acute ischemic stroke with large vessel occlusion on the era of mechanical thrombectomy: cases report.

Intravenous thrombolysis for acute ischemic stroke within 4.5 h after the onset of symptoms has become a standard therapy that is recommended by many trials and clinical guidelines. As on the era of mechanical thrombectomy for acute ischemic stroke with large vessel occlusions, whether intravenous thrombolysis (IVT) is still necessary, and how to choose the optimal dose are still controversy. Here, we reported two cases of acute ischemic stroke with large vessel occlusions that both achieved complete recanalization after IVT. Then, IVT was terminated in advance, and dynamic surveillance by DSA was performed to achieve individual treatment. However, both of the cases presented with hemorrhagic transformation. We analyzed the probable reasons and put forward thoughts from ourselves.

Nucleation and growth mechanism of a nanosheet-structured NiCoSe2 layer prepared by electrodeposition.

Ni-Co-Se layers have attracted a great deal of attention in the field of solar cells, electrocatalyst water splitting and supercapacitors. Electrodeposition is a simple, convenient and low-cost way to obtain Ni-Co-Se layers. However, until now, the electrochemical kinetics of the Ni-Co-Se system, including its growth and nucleation mechanisms, are still unclear. In present work a NiCoSe2 layer with a nanosheet structure was electrodeposited in a chloride bath. The electrochemical mechanisms of the Ni-Co-Se system were also studied. It is noted that the electrochemical kinetics of Ni-Co-Se electrodeposition can be influenced by both temperature and electrode material; however, temperature does not change the progressive nucleation process and mixed controlled growth mechanism of Ni-Co-Se. The diffusion coefficient D and charge-transfer coefficient α of the Ni-Co-Se system were calculated. The values of D obtained by cyclic voltammogram and chromoamperometry are close to each other at both 20 and 50 °C, respectively, and increase with the increase of temperature. Moreover, the activation energy E a was also calculated. Specially, a uniform 3D network-structure NiCoSe2 layer was electrodeposited on ITO glass at -0.9 V and 40 âˆ¼ 60 °C. The increased overpotential during deposition makes the NiCoSe2 layer more easily gather together; however, there is no significant effect on the surface morphology of the NiCoSe2 layer when the temperature is between 40 and 60 °C.

Recovery and reutilization of high-quality boron carbide from sapphire wafer grinding-waste.

Considerable amounts of high-quality boron carbide (B4C) are discarded as J240 sapphire-wafer grinding waste (J240-W), which can be mostly recovered and reutilized after purification for environmental protection. This paper has developed a feasibility method that simultaneously removes the alumina (Al2O3) and iron (Fe) impurities from J240-W with microwave-assisted acid leaching strategy. The influence factors on the Al2O3 leaching ratio, such as leaching temperature, sulfuric acid concentration, liquid-solid ratio and time, have been investigated and optimized. For comparison, the leaching of Al2O3 with conventional and ultrasound-assisted methods has also been performed. The result indicates that the Al2O3 leaching ratio at 80 °C with microwave assistance is 68.95%, much higher than that of conventional (23.66%) and ultrasound (53.13%) methods. Attributed to the unique heating mode of microwave, the Al2O3 leaching ratio can rise to 95.28% at optimum condition, while the content of purified B4C can reach to 98.22% with the residual Al2O3 and Fe fall to 0.26% and 0.12%, respectively. The recovered B4C with high purity and suitable particle size can be reutilized to manufacture W5 abrasive and W0.5 armor material, which is beneficial for environmental protection and resources reutilization.