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Tychsen Trolle posted an update 4 months, 1 week ago
Because of the excellent electrical properties, III-V semiconductor nanowires are promising building blocks for next-generation electronics; however, their rich surface states inevitably contribute large amounts of charge traps, leading to gate bias stress instability and hysteresis characteristics in nanowire field-effect transistors (FETs). Here, we investigated thoroughly the gate bias stress and hysteresis effects in InAs nanowire FETs. It is observed that the output current decreases together with the threshold voltage shifting to the positive direction when a positive gate bias stress is applied, and vice versa for the negative gate bias stress. For double-sweep transfer characteristics, the significant hysteresis behavior is observed, depending heavily on the sweeping rate and range. On the basis of complementary investigations of these devices, charge traps are confirmed to be the dominant factor for these instability effects. Importantly, the hysteresis can be simulated well by utilizing a combination of the rate equation for electron density and the empirical model for electron mobility. This provides an accurate evaluation of carrier mobility, which is in distinct contrast to the overestimation of mobility when using the transconductance for calculation. All these findings are important for understanding the charge trap dynamics to further enhance the device performance of nanowire FETs.The orange carotenoid protein (OCP) is involved in the photoprotective processes in cyanobacteria via nonphotochemical quenching. Triggered by blue-green light absorption, the carotenoid chromophore undergoes translocation, displacing around 12 Å from the C-terminal domain (CTD) to the N-terminal domain (NTD). The detailed molecular rearrangements that occur within the carotenoid and the protein during this process remain largely elusive. By using a combination of molecular dynamics, well-tempered metadynamics, and hybrid quantum mechanical/molecular mechanical (QM/MM) calculations, we were able to mimic the translocation of the carotenoid from the inactive OCPO and obtain metastable red-shifted states in the photoactivation mechanism, replicating the λmax values of reference experimental spectra. In addition, our simulations give insight into the structure of the red-shifted form of the inactive state of OCP.A highly stereoselective umpolung 1,4-addition of vinyl bromides to enals is enabled by NHC/palladium cooperative catalysis, generating various valuable γ,δ-unsaturated carbonyl derivatives in excellent yields (up to 90%). A detailed mechanism investigation indicates the NHC act as both organocatalyst and ligand for palladium during this system.As nanoelectronic synapses, memristive ferroelectric tunnel junctions (FTJs) have triggered great interest due to the potential applications in neuromorphic computing for emulating biological brains. Here, we demonstrate multiferroic FTJ synapses based on the ferroelectric modulation of spin-filtering BaTiO3/CoFe2O4 composite barriers. Continuous conductance change with an ON/OFF current ratio of ∼54 400% and long-term memory with the spike-timing-dependent plasticity (STDP) of synaptic weight for Hebbian learning are achieved by controlling the polarization switching of BaTiO3. LY3522348 Supervised learning simulations adopting the STDP results as database for weight training are performed on a crossbar neural network and exhibit a high accuracy rate above 97% for recognition. The polarization switching also alters the band alignment of CoFe2O4 barrier relative to the electrodes, giving rise to the change of tunneling magnetoresistance ratio by about 10 times and even the reversal of its sign depending upon the resistance states. These results, especially the electrically switchable spin polarization, provide a new approach toward multiferroic neuromorphic devices with energy-efficient electrical manipulations through potential barrier design. In addition, the availability of spinel ferrite barriers epitaxially grown with ferroelectric oxides also expends the playground of FTJ devices for a broad scope of applications.The aim of this study was to monitor the degradation of three insecticides licensed for the control of cabbage moths during the 14-day fermentation period of sauerkraut samples. The hypothesis of this study is that the different sauerkraut fermentation processes could affect the degradation of applied insecticides. For this purpose, the fresh cabbage leaves contaminated with (λ-cyhalothrin, malathion, and chlorpyrifos-methyl) were left for fermentation with and without (natural) starter addition (Lactobacillus plantarum 112), and vacuum-packed as a control under laboratory conditions. The pH values and microbial growth were periodically monitored in sauerkraut samples during the fermentation period. During this time, the insecticide residues were determined in control and treatment samples using LC-MS-MS. In control samples, the degradation of chlorpyrifos-methyl and malathion was higher with rates of 69 and 98%, respectively, compared with the sauerkraut samples (12 and 59%; 31 and 34%, respectively) 14 days after the insecticide application. At the end of fermentation (14 d), no significant reduction in λ-cyhalothrin was detected in both treatments and control (13-19% reduction). The current study demonstrated that the presence of the lactic acid bacteria in the sauerkraut fermentation accelerated pH decline (below 4.0), and these fermentation conditions probably decelerated the degradation of malathion and chlorpyrifos-methyl. The results showed that the stability of different insecticides varied during the same fermentation process.Objective To evaluate the pathologic findings from biopsy samples to predict the status of nodal metastasis for patients with usual cervical adenocarcinoma. Methods The 32-pair samples of cervical adenocarcinoma specimens (32 cervical biopsies and 32 hysterectomies with staging) from 2013 to 2019 were selected for retrospective study in Shanghai first Maternal and infant Health Care Hospital Affiliated to Tongji University. The correlation between histopathologic features including necrotic tumor debris (NTD), nuclear grade, mitotic count and pattern-based classification system and the status of lymph node metastasis was evaluated. Results Tumor invasive patterns of cervical adenocarcinoma, as described previously, could be discerned in hysterectomy/staging specimens, but not in cervical biopsies. Because the biopsy tissues were small, only 14(14/32, 43.8%) cases could be classified according to pattern of invasion, and the concordance rate with resected specimens was 37.5%. NTD (9/19) and grade 3 nuclei (11/19) were positively correlated with invasive pattern C and nodal metastases (P less then 0.