We have fabricated pentacene organic thin film transistors with spin-coated polymer gate dielectric layers, including cross-linked polyvinylphenol and a polyvinylphenol-based copolymer, and obtained devices with excellent electrical characteristics, including carrier mobility as large as 3 cm2/V s, subthreshold swing as low as 1.2 V/decade, and on/off current ratio of 105. For comparison, we have also fabricated pentacene transistors using thermally grown silicon dioxide as the gate dielectric and obtained carrier mobilities as large as 1 cm2/V s and subthreshold swing as low as 0.5 V/decade.

Organic thin film transistors (TFTs) are of interest for lowcost, large-area electronic applications, such as active-matrix displays, electronic paper, flexible microelectronics, and chemical sensors.[1±8] The performance of organic TFTs is determined primarily by the field effect mobility of the charge carriers in the organic semiconductor layer and by the efficiency of injecting and extracting carriers at the source and drain contacts. For virtually all classes of organic semiconductors, the intrinsic carrier mobility depends critically on the degree of molecular ordering and on the extent of the p±p stacking in the material.[9±11] Consequently, optimizing the chemical structure of the organic semiconductor with regard to optimum molecular ordering and maximum orbital overlap continues to be of great importance for the further advancement of organic TFT technology. Despite the extraordinary number of organic semiconductors that have been synthesized and evaluated for use in organic TFTs, [12] the relationships between molecular structure and electrical TFT performance remain sketchy at best. The fused hydrocarbon pentaceneÐby all accounts a rather unspectacular moleculeÐcontinues to deliver the highest electrical performance, regardless of the method of film deposition (thermal evaporation, vapor phase epitaxy, conversion of a solution-processed precursor) and regardless of the contact configuration (top or bottom contacts).[13±15]A useful and practical strategy for investigating the relationships between molecular structure and electrical performance is the systematic variation of the number of repeat units in a particular type of molecular semiconductor. This can be done either by varying the number of units in the conjugated backbone of the molecule, or by varying the length of alkyl substituents. One particularly useful class of model compounds for this type of investigation are the oligothiophenes, due to their relatively straightforward synthesis and because of the wide range of possible modifications in their chemical structure. Organic TFTs based on oligothiophenes were first reported by Horowitz and Garnier [16±18] and later by Dodabalapur, Katz, and others. [19±21] Carrier mobilities reported for a-sexithiophene (a-6T) TFTs have improved from 10 ±4 cm 2 / V s to greater than 0.01 cm 2 /V s.[18±21] Substituting alkyl chains at the a-and a¢-positions of the a-6T molecule led to an increase in carrier mobility to 0.13 cm 2 /V s. [22,23] Carrier mobilities near 0.2 cm 2 /V s have been reported for a-octithiophene (a-8T) TFTs with active layers deposited at 150 C and higher.[24] For many years, oligothiophenes and their alkyl-substituted derivatives have been among the most intensely investigated organic semiconductors and have even led to the demonstration of fast integrated circuits.[3]We have synthesized and evaluated a series of alkyl-substituted oligothiophenes with chromophore length ranging from four to six thiophene units (a,a¢-didecylquaterthiophene, a,a¢-didecylquinquethiophene, and a,a¢-didecy...

BackgroundFlow disruption with the WEB is an innovative endovascular approach for treatment of wide-neck bifurcation aneurysms. Initial studies have shown a low complication rate with good efficacy.PurposeTo report clinical and anatomical results of the WEB treatment in the cumulative population of three Good Clinical Practice (GCP) studies: WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm), French Observatory, and WEBCAST-2.MethodsWEBCAST, French Observatory, and WEBCAST-2 are single-arm, prospective, multicenter, GCP studies dedicated to the evaluation of WEB treatment. Clinical data were independently evaluated. Postoperative and 1-year aneurysm occlusion was independently evaluated using the 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant.ResultsThe cumulative population comprised 168 patients with 169 aneurysms, including 112 female subjects (66.7%). The patients' ages ranged between 27 and 77 years (mean 55.5±10.2 years). Aneurysm locations were middle cerebral artery in 86/169 aneurysms (50.9%), anterior communicating artery in 36/169 (21.3%), basilar artery in 30/169 (17.8%), and internal carotid artery terminus in 17/169 (10.1%). The aneurysm was ruptured in 14/169 (8.3%). There was no mortality at 1 month and procedure/device-related morbidity was 1.2% (2/168). At 1 year, complete aneurysm occlusion was observed in 81/153 aneurysms (52.9%), neck remnant in 40/153 aneurysms (26.1%), and aneurysm remnant in 32/153 aneurysms (20.9%). Re-treatment was carried out in 6.9%.ConclusionsThis series is at the moment the largest prospective, multicenter, GCP series of patients with aneurysms treated with WEB. It shows the high safety and good mid-term efficacy of this treatment.Clinical trial registrationFrench Observatory: Unique identifier (NCT18069); WEBCAST and WEBCAST-2: Unique identifier (NCT01778322).

E ndovascular treatment is now the first-line treatment for both ruptured and unruptured aneurysms. 1,7,17 However, aneurysms with a complex anatomy (singularly wide-neck aneurysms) are in some cases untreatable or difficult to treat with standard coiling. For this reason, more complex endovascular techniques have been developed, such as balloon-assisted coiling, stent-assisted coiling, and flow diversion. 18Flow disruption is a new endovascular approach, which involves placement of an endosaccular device (WEB), abbreviatioNs ACoA = anterior communicating artery; BA = basilar artery; CCT = Cerecyte Coil Trial; DSA = digital subtraction angiography; ICA = internal carotid artery; ITT = intention to treat; MCA = middle cerebral artery; mRS = modified Rankin Scale; WEBCAST = WEB Clinical Assessment of Intrasaccular Aneurysm Therapy. obJective WEB is an innovative intrasaccular treatment for intracranial aneurysms. Preliminary series have shown good safety and efficacy. The WEB Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) trial is a prospective European trial evaluating the safety and efficacy of WEB in wide-neck bifurcation aneurysms. methods Patients with wide-neck bifurcation aneurysms for which WEB treatment was indicated were included in this multicenter good clinical practices study. Clinical data including adverse events and clinical status at 1 and 6 months were collected and independently analyzed by a medical monitor. Six-month follow-up digital subtraction angiography was also performed and independently analyzed by a core laboratory. Success was defined at 6 months as complete occlusion or stable neck remnant, no worsening in angiographic appearance from postprocedure, and no retreatment performed or planned. results Ten European neurointerventional centers enrolled 51 patients with 51 aneurysms. Treatment with WEB was achieved in 48 of 51 aneurysms (94.1%). Adjunctive implants (coils/stents) were used in 4 of 48 aneurysms (8.3%). Thromboembolic events were observed in 9 of 51 patients (17.6%), resulting in a permanent deficit (modified Rankin Scale [mRS] Score 1) in 1 patient (2.0%). Intraoperative rupture was not observed. Morbidity (mRS score > 2) and mortality were 2.0% (1 of 51 patients, related to rupture status on entry to study) and 0.0% at 1 month, respectively. Success was achieved at 6 months in 85.4% of patients treated with WEB: 23 of 41 patients (56.1%) had complete occlusion, 12 of 41 (29.3%) had a neck remnant, and 6 of 41 (14.6%) had an aneurysm remnant. coNclusioNs The WEBCAST study showed good procedural and short-term safety of aneurysm treatment with WEB and good 6-month anatomical results.Clinical trial registration no.: NCT01778322 (clinicaltrials.gov) http://thejns.org/doi/abs/10.3171/2015.2.JNS142634

Background and Purpose-To assess the association of lesion location and risk of aspiration and to establish predictors of transient versus extended risk of aspiration after supratentorial ischemic stroke. Methods-Atlas-based localization analysis was performed in consecutive patients with MRI-proven first-time acute supratentorial ischemic stroke.

Organic thin‐film transistors and circuits have been fabricated on glass and on flexible substrates, achieving carrier mobilities of 0.3 cm2 V–1 s–1 on glass. In particular, the authors investigate how the substitution of inorganic gate dielectrics and metals with solution‐processed polymers affects the performance of the transistors. Two pentacene inverters on glass are shown in the Figure (see also cover).

Background: Several case series and a recent meta-analysis indicate that intra-arterial thrombolysis (IAT) is effective for the treatment of acute central retinal artery occlusion (CRAO). Methods: A total of 37 patients with acute monocular blindness because of unilateral thromboembolic CRAO were treated with IAT using urokinase within six hours of the onset of symptoms. Visual outcome was compared with a control group of 19 patients, also seen within six hours, who did not undergo thrombolytic treatment. In both groups some patients were treated by paracentesis and/or acetazolamide. Predictors of visual outcome were evaluated. Results: Visual improvement was more likely with IAT (p = 0.01) as were the chances to regain visual acuity of .0.6 significantly better (p = 0.04): 8/37 patients (22%) regained visual acuity of .0.6 in the IAT group and none (0/19) in the control group. Younger patients were more likely to regain some vision with (p = 0.012) or without IAT (p = 0.026). Three patients had minor treatment related cerebral ischaemic events, two had transient ischaemic attacks and one a minor stroke. There were no haemorrhagic complications. Conclusions: This series of patients with CRAO demonstrated that IAT enhanced the chances of visual improvement compared with conventional treatment only. Furthermore, younger patients have a better chance to achieve some visual recovery.

Knowledge about the recovery of oral intake after hemispheric stroke is important to guide therapeutic decisions, including the administration of enteral tube feeding and the choice of the appropriate feeding route. They aimed to determine the localization and connectivity of lesions in impaired recovery versus recovered swallowing after initially dysphagic stroke. Sixty-two acute ischemic hemispheric stroke patients with impaired oral intake were included in a prospective observational cohort study. Voxel-based lesion-symptom mapping and probabilistic tractography were used to determine the association of lesion location and connectivity with impaired recovery of oral intake ≥7 days (indication for early tube feeding) and ≥4 weeks (indication for percutaneous endoscopic gastrostomy feeding) after stroke. Two distinct patterns influencing recovery of swallowing were recognized. Firstly, impaired recovery of oral intake after ≥7 days was significantly associated with lesions of the superior corona radiata (65% of statistical map, P < 0.05). The affected fibers were connected with the thalamus, primary motor, and supplemental motor areas and the basal ganglia. Secondly, impaired recovery of oral intake after ≥4 weeks significantly correlated with lesions of the anterior insula (54% of statistical map, P < 0.05), which was connected to adjacent operculo-insular areas of deglutition. These findings indicate that early swallowing recovery is influenced by white matter lesions disrupting thalamic and corticobulbar projection fibers. Late recovery is determined by specific cortical lesions affecting association fibers. This knowledge may help clinicians to identify patients at risk of prolonged swallowing problems that would benefit from enteral tube feeding. Hum Brain Mapp 38:2165-2176, 2017. © 2017 Wiley Periodicals, Inc.