[en] Objective: To evaluate l-week and l-year outcomes of carotid artery stenting (CAS) using cerebral perfusion CT (PCT). Methods: The clinical database of 20 patients with unilateral carotid artery stenosis( ≥ 60%) who underwent CAS were retrospectively reviewed. Relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF) and relative mean transit time (rMTT) were measured by using cerebral PCT within one week before CAS and at one week and at one year after CAS. Cerebral MRI was performed within one week before CAS. The noncontrast CT was performed within one week before CAS and immediately after CAS. The arteriography was performed at one year after CAS. The variance analysis was performed to determine whether there were significant differences of rCBV, rCBF, rMTT in anterior cerebral artery area (ACA area), middle cerebral artery area (MCA area), posterior cerebral artery area (PCA area), basal ganglia area, front and back cortical watershed area (CWS area) and internal watershed area (IWS area) among the different time points. Results: In the three measures, there was no significant difference of' rCBV in all areas among the three time points (P>0.05), and there was no significant difference of rCBF and rMTT in PCA area (P>0.05), but there were significant differences of rCBF and rMTT in all other areas among the three time points (P<0.01). In one week before CAS, at one week and at one year after CAS, rCBF of 20 patients is 0.86±0.06, 0.95±0.04, 0.98±0.07 in ACA area, 0.81±0.04, 1.06± 0.04, 1.03±0.07 in MCA area, 0.84±0.06, 0.97±0.04, 0.96±0.04 in basal ganglia, 0.78±0.03, 0.97±0.03, 0.96±0.02 in front CWS area, 0.77±0.03, 1.00±0.02, 0.98±0.03 in back CWS area, and 0.80±0.04, 0.94±0.03, 0.93±0.04 in IWS area (F=18.95, 146.41, 63.03, 540.85, 415.97, 164.19, P<0.01). rMTT is 1.17±0.05, 1.04±0.04, 1.01±0.06 in ACA area, 1.41±0.06, 1.08± 0.04, 1.07±0.04 in MCA area, 1.20±0.06, 1.06±0.04, 1.05±0.04 in basal ganglia, 1.41±0.05, 1.10±0.05, 1.09±0.04 in front CWS area, 1.43±0.10, 1.07±0.06, 1.08±0.06 in back CWS area, 1.29±0.10, 1.09±0.05, 1.11±0.07 in IWS area (F=51.74, 248.89, 70.08, 381.689, 288.94, 41.53, P<0.01). There were significant differences of rCBF and rMTT between those measured one week before CAS and one week or one year after CAS (P<0.01), but there were no significant differences of rCBF or rMTT in any area measured between those at 1 week after CAS and those measured at 1 year after CAS (P>0.05). Conclusions: Hemodynamic outcome at one year after CAS is good in the absence of contralateral carotid artery steno-occlusive disease. In addition, the coherence of results between 1-week and 1-year indicates that the outcome of one week after CAS could predict long-term hemodynamic outcome. (authors)

[en] Objective: To investigate the value of multi-slice computed tomography angiography (MSCTA) in the detection of intracranial micro-aneurysms (aneurysm ≤3 mm in maximal diameter, IMA). Methods: The clinical history and images of 826 patients with suspected intracranial aneurysms were retrospectively analyzed. All patients underwent MSCTA on 16-slice row CT before hospitalization (from 2 h to 4 d after symtom onset). All intracranial aneurysms were confirmed by digital subtraction angiography (DSA), three-dimensional rotational angiography (3DRA) or surgery. Two independent radiologists assessed all the images. The MSCTA findings were compared with the DSA/3DRA results. The sensitivity, specificity, and accuracy of MSCTA for diagnosis of IMA was calculated. The diagnostic consistency between DSA/3DRA and MSCTA was determined by Kappa statistics. The prevalence of multiple aneurysms between the group of patients with IMA and the group of patients without IMA was evaluated by Chi-square test. Results: A total of 889 aneurysms in 788 of the 826 patients were detected. Among them, 70 patients had single aneurysm and 82 patients had multiple aneurysms. No aneurysms were detected in 38 patients. Among the 212 patients who underwent DSA/3DRA, 271 aneurysms were found and 232 were IMA. MSCTA detected 229 IMA. There was 1 false-positive finding and 4 false-negative findings by MSCTA. The sensitivity, specificity and accuracy of MSCTA for IMA was 98.3% (228/232), 97.4% (228/232), 97.4% (38/39), 98.2% (266/271). There was excellent agreement between two techniques (Kappa =0.927, P<0.05). The prevalence of multiple aneurysms was 21.2% (45/212) in the patient group with IMA and 6.4% (37/576) in the group without IMA. There was statistically significant difference between the two groups (X² =36.421, P<0.01). Conclusions: The detection value of IMA by MSCTA was high. The cutoff level of diameter of intracranial IMA should be adjusted from 4-5 mm to ≤3 mm. (authors)

[en] High aspect ratio features in silicon have broad applications in micro-electro-mechanical systems, microfluidic control and advanced packaging. This structure is usually fabricated by Bosch process, and the corresponding scallop should be controlled. Obtaining large scallop size seems easier than that of small scallop, however, it is a big challenge to obtain uniform large scallop. Herein, by using dry etching system, we demonstrate a novel high aspect ratio silicon trench with scallop size uniformly larger than 300 nm in both single crystal silicon and polycrystalline silicon. Additionally, the difference between single crystal silicon etching and polycrystalline silicon etching is compared. This work is beneficial to understanding the silicon etching mechanism in Bosch process and has potential applications in microelectronic and microfluidic devices.

[en] The formation of various deep silicon structures using plasma etching has wide applications in sensors, micro-electro-mechanical systems and 3D wafer level integration. However, the fabrication of silicon cavities with high accuracy at depth within a large wafer size is still a challenge due to the large amount of etching required. Herein, silicon cavity etching uniformity approaching 3% in a depth of ∼100 µm on a 12-inch wafer is achieved through tuning the focus ring height, baffle shape, double zone helium cooling system and chamber pressure. The simulation of the electromagnetic field and gas flow field separately provides the guidance for the improvement, and the way in which the wafer temperature influences the etch uniformity is demonstrated. These results have significance for both the understanding of the plasma etching mechanism and the practical application of the silicon etching process for advanced device fabrication. (paper)

[en] Micro/nanostructures with high aspect ratios in silicon wafers obtained by plasma etching are of great significance in device fabrication. In most cases, the scallop nanostructure in deep silicon etching should be suppressed. However, the scallop nanostructure could be applied in electronic device fabrication as characteristic information, which indicates the balance between deposition and etching. In this work, the applications of scallop nanostructures in etching process optimization and environmental protection are demonstrated. In addition, the minimum effect of the cycle time on the scallop size is reported for the first time. These results could bring new thoughts to the electronic devices related fields, such as micro-electro-mechanical systems (MEMS), silicon capacitors and advanced packaging. (paper)

[en] Highlights: • Several novel fullerene derivatives were synthesized as the electron transport layer for tin-lead perovskite solar cells. • Power conversion efficiency of 10% were achieved with incident photon conversion efficiency spectra onset reaching 1050 nm. • The hybrid excitonic feature of tin-lead perovskite (CH₃NH₃Sn_0.5Pb_0.5I₃) was reported for the first time. The design of organic-inorganic trihalide perovskite solar cells with higher performance, lower environmental pollution, lower cost and easier of fabrication should be a significant stride towards their practical application. Nevertheless, the contribution of exciton dissociation behavior of the perovskite to this strategy has not been recognized comparing with film morphology, device architecture and fabrication process. Here we demonstrated a series of solution-processed solid-state tin-lead organohalide perovskite photovoltaic solar cells using carefully selected fullerene derivatives as the electron transport layer. The hybrid excitonic feature of CH₃NH₃Sn_0.5Pb_0.5I₃ was revealed for the first time by comparing the exciton dissociation behaviors of CH₃NH₃Sn_0.5Pb_0.5I₃ with conventional excitonic semiconductor in both planar heterojunction solar cells and lateral architecture photosensors. By optimizing the lowest unoccupied molecular orbital level of electron transport layer materials, high open circuit voltage of 0.69 V, short circuit photocurrent density of 22.8 mA cm⁻² and power conversion efficiency of more than 10% were achieved with the incident photon conversion efficiency spectra onset reaching 1050 nm. These devices may work as high performance photodetectors with a broad spectral response expanding from UV–visible to near-infrared. Our results have suggested the exciton dissciation behavior to be an efficient perspective for the improvement of provskite solar cells.