Comparison of Outcomes between Stent Retriever Combined with Contact Aspiration and Contact Aspiration Alone in Patients without Hyperdense Artery Sign/Susceptibility Vessel Sign.

PURPOSE: To examine the relationship between hyperdense artery sign (HAS)/susceptibility vessel sign (SVS) and thrombus composition and evaluate the effect of HAS/SVS status on the association between first-line thrombectomy techniques and outcomes in patients with acute anterior circulation large vessel occlusion (LVO). MATERIALS AND METHODS: From January 2018 to June 2021, 103 consecutive patients with acute anterior circulation LVO (75 [63.1%] men; median age, 66 years) who underwent thrombectomy and for whom the removed clot was available for histological analyses were retrospectively reviewed. The presence of HAS and SVS was assessed on unenhanced computed tomography (CT) and susceptibility-weighted imaging, respectively. Association of first-line thrombectomy techniques (stent retriever [SR] combined with contact aspiration [CA] vs CA alone) with outcomes was assessed according to HAS/SVS status. RESULTS: Among the included patients, 55 (53.4%) were HAS/SVS-negative, and 69 (67.0%) underwent first-line SR + CA. Higher relative densities of fibrin/platelets (0.56 vs 0.51; P < .001) and lower relative densities of erythrocytes (0.32 vs 0.42; P < .001) were observed in HAS/SVS-negative patients compared with HAS/SVS-positive patients. First-line SR + CA was associated with reduced odds of distal embolization (adjusted odds ratio, 0.18; 95% CI, 0.04-0.83; P = .027) and a more favorable 90-day functional outcome (adjusted odds ratio, 5.29; 95% CI, 1.06-26.34; P = .042) in HAS/SVS-negative patients and a longer recanalization time (53 vs 25 minutes; P = .025) and higher risk of subarachnoid hemorrhage (24.2% vs 0%; P = .044) in HAS/SVS-positive patients. CONCLUSIONS: Absence of HAS/SVS may indicate a higher density of fibrin/platelets in the thrombus, and first-line SR + CA yielded superior functional outcomes than CA alone in patients with acute LVO without HAS/SVS.

Aggregation-induced emission enhancement (AIEE) of tetrarhenium(I) metallacycles and their application as luminescent sensors for nitroaromatics and antibiotics.

The self-assembly of tetrarhenium metallacycles [{Re(CO)3}2(µ-dhaq)(µ-N-N)]2 (3a, N-N = 1,3-bis(1-butylbenzimidazol-2-yl)benzene; 3b, N-N = 1,3-bis(1-octylbenzimidazol-2-yl)benzene), (H2-dhaq = 1,4-dihydroxy-9,10-anthraquinone) and [{Re(CO)3}2(µ-thaq)(µ-N-N)]2 (4, N-N = 1,3-bis(1-butylbenzimidazol-2-yl)benzene), (H2-thaq = 1,2,4-trihydroxy-9,10-anthraquinone) under solvothermal conditions is described. The metallacycles 3a,b and 4 underwent aggregation-induced emission enhancement (AIEE) in THF upon the incremental addition of water. TEM images revealed that metallacycle 3a in a 60% aqueous THF solution formed rectangular aggregates with a wide size distribution, while a 90% aqueous THF solution resulted in the formation of a mixture of nanorods and amorphous aggregates due to rapid and abrupt aggregation. UV-vis and emission spectral profiles supported the formation of nanoaggregates of metallacycles 3a,b and 4 upon the gradual addition of water to a THF solution containing metallacycles. Further studies indicated that these nanoaggregates were excellent probes for the sensitive and selective detection of nitro group containing picric acid (PA) derivatives as well as antibiotics.

Predicting mortality in acute ischaemic stroke treated with mechanical thrombectomy: analysis of a multicentre prospective registry.

OBJECTIVES: We aimed to determine predictors of mortality within 90 days and develop a simple score for patients with mechanical thrombectomy (MT). DESIGN: Analysis of a multicentre prospective registry. SETTING: In six participating centres, patients who had an acute ischaemic stroke (AIS) treated by MT between March 2017 and May 2018 were documented prospectively. PARTICIPANTS: 224 patients with AIS were treated by MT. RESULTS: Of 224 patients, 49 (21.9%) patients died, and 87 (38.8%) were independent. Variables associated with 90-day mortality were age, previous stroke, admission National Institutes of Health Stroke Scale (NIHSS), fasting blood glucose and occlusion site. Logistic regression identified four variables independently associated with 90-day mortality: age ≥80 years (OR 3.26, 95% CI 1.45 to 7.33), previous stroke (OR 2.33, 95% CI 1.04 to 5.21), admission NIHSS ≥18 (OR 2.37, 95% CI 1.13 to 4.99) and internal carotid artery or basilar artery occlusion (OR 2.92, 95% CI 1.34 to 6.40). Using these data, we developed predicting 90-day mortality of AIS with MT (PRACTICE) score ranging from 0 to 6 points. The receiver operator curve analysis found that PRACTICE score (area under the curve (AUC)=0.744, 95% CI 0.669 to 0.820) was numerically better than iScore (AUC=0.661, 95% CI 0.577 to 0.745) and Predicting Early Mortality of Ischemic Stroke score (AUC=0.638, 95% CI 0.551 to 0.725) for predicting 90-day mortality. CONCLUSIONS: We developed a simple score to estimate the 90-day mortality of patients who had an AIS treated with MT. But the score needs to be prospectively validated. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR-OOC-17013052).

High-Degree Middle Cerebral Artery Stenosis : Can Advanced 3D DSA-MRI Fusion Imaging Better Illustrate Plaques and Perforators?

PURPOSE: Endovascular treatment in severe middle cerebral artery (MCA) stenosis is controversial owing to high rates of periprocedural complications, especially occlusion of the lenticulostriate arteries (LSA). The characteristics of LSAs and the spatial relationships between MCA plaques and LSAs using the fusion of three-dimensional (3D) digital subtraction angiography (DSA) and magnetic resonance imaging (3D DSA-MRI fusion) were investigated. METHODS: We retrospectively analyzed data from 32 ischemic stroke or transient ischemic attack patients with severe MCA stenosis, who underwent MRI and DSA within 2 weeks after symptom onset. The patients were divided into culprit and non-culprit MCA stenosis groups. The 3D DSA-MRI fusion was performed on dedicated workstations, which allowed automated overlays of the target vessels. The characteristics of LSAs, plaque distribution and lesion patterns, and their relationships were evaluated. RESULTS: The 3D DSA-MRI fusion image was able to illustrate the spatial relationships between MCA plaques and LSA orifices. Of 42 LSA stems in 32 patients, 10 had MCA plaque over the LSA orifice and were all found in the culprit MCA stenosis group. Over half (51.9%) of the LSA stems in patients with culprit MCA stenosis originated from the stenotic MCA segment. The MCA plaque-LSA orifice spatial relationships were classified into four types, which were significantly different between the two groups (p = 0.016). CONCLUSION: The 3D DSA-MRI fusion technique enables visualization of the LSA orifice and MCA plaque and their spatial relationships. This classification of the type of spatial relationships can provide insights into the pathogenesis of MCA stroke and useful guides for treatment strategies.

Toward quartz and cristobalite: spontaneous resolution, structures, and characterization of chiral silica-mimetic silver(I)-organic materials.

An alpha-quartz-mimetic chiral coordination network of [Ag(L1)(CF3SO3)]n (L1=5,5'-bipyrimidine), after treatment with PF6- anions, undergoes a solution-state structural transformation toward [Ag(L1)(PF6)]n with a cristobalite-mimetic chiral structures. This structural transformation is accompanied by substantial enhancement in the fluorescent intensity and in the second-harmonic-generation response. The results also demonstrate an effective design strategy based on the spontaneous resolution route for the preparation of chiral architectures.

Influence of water content on the self-assembly of metal-organic frameworks based on pyridine-3,5-dicarboxylate.

A 0D discrete molecule [Co(3,5-pdc)(H2O)5].2H2O (1) was obtained in quantitative yield from the reaction of CoCl2.6H2O and pyridine-3,5-dicarboxylate (3,5-pdc) in pure water solvent at ambient temperature. While a 1D zigzag chain species, [{Co(3,5-pdc)(H2O)4}.H2O]n (2), was produced in a water-rich environment, a 2D layer compound, [Co(3,5-pdc)(H2O)2]n (3), with a 6(3) topology was generated under a water-reduced condition and a 2D sheet structure, [{Cu(3,5-pdc)(py)2}.H2O.EtOH]n (4), was formed under a water-poor condition. Compounds 1, 2, and 4 were characterized by single-crystal X-ray diffraction analysis. The 1D zigzag chain 2 shows a recoverable collapsing property. Compound 4 adopts a 2D sheet structure with a 4.8(2) topology, observed for the first time for the 3,5-pdc-related metal-organic frameworks. Water content was found to be an important factor in determining the topologies of the products in the self-assembly of divalent metal ions (Co2+, Cu2+) and pyridine-3,5-dicarboxylate under mild conditions.

Self-assembly, reorganization, and photophysical properties of silver(I)-Schiff-base molecular rectangle and polymeric array species.

A self-assembly of AgClO(4) with a Schiff-base ligand N,N'-bis(pyridin-2-ylmethylene)benzene-1,4-diamine (1) gave a 1D zigzag polymeric array [[Ag(2)(C(18)H(14)N(4))(2)](ClO(4))(2)(CH(3)CN)](n) (3), while the self-assembly of AgClO(4) with 3,3'-dimethyl-N,N'-bis(pyridin-2-ylmethylene)biphenyl-4,4'-diamine (2) afforded the molecular rectangle [[Ag(2)(C(26)H(22)N(4))(2)](ClO(4))(2)] (4). The structures of 3 and 4 were characterized by single-crystal X-ray diffraction analysis. Structural data for 3 indicate that the Ag(I) ion is coordinated by two ligands of 1 in a distorted tetrahedral fashion thereby leading to a 1D zigzag polymeric array. The zigzag chains are interdigitated with weak pi-pi stacking interactions. The structure of 4 consists of a discrete molecular rectangle where the silver atom has a distorted square-planar coordination with the pyridyl ligands and azomethine nitrogen atoms of 2. An intramolecular pi-pi interaction between the phenyl rings of adjacent Schiff-base 2 functions to stabilize the rectangular architecture. The Ag(I)-Schiff-base coordination polymer 3 is not stable in solution. The degradation and reorganization of 3 to form a [2 x 2] grid architecture [[Ag(4)(C(26)H(22)N(4))(4)](ClO(4))(4)] (3g) was supported in a FAB-MS study. The rectangular structure of 4 remains intact in solution at ambient temperature. The complexes 3g and 4 exhibit unusual luminescence behavior in solution at room temperature with significantly red-shifted emission in the visible region.