Conjugated polyelectrolytes: A new class of semiconducting material for organic electronic devices

AbstractThis feature article presents a short review of the recent developments in the synthesis of conjugated polyelectrolytes (CPEs) along with their applications in organic optoelectronic devices with particular focus on the molecular structures of CPEs with ionic functionality, synthetic approaches, and their utilization as an interfacial layer. The orthogonal solubility of the CPEs allows the simple preparation of multilayer organic devices by solution casting on top of a nonpolar organic photoactive layer without disturbing the interfaces, showing their effectiveness in tuning the electronic structures at the interfaces for improving the charge carrier transport and resulting device properties. These achievements highlight the dynamic nature of CPEs and their applicability to a wide range of optoelectronic devices

Performance Comparison of CRUD Operations in IoT based Big Data Computing

Nowadays, due to the development of mobile devices, the kinds of data that are generated are becoming diverse, and the amount is becoming huge. The vast amount of data generated in this way is called big data. Big data must be processed in a different way than existing data processing methods. Representative methods of big data processing are RDBMS (Relational Database System) and NoSQL method. We compare NoSQL and RDBMS, which are representative database systems. In this paper, we use MySQL query and MongoDB query to compare RDBMS and NoSQL. We gradually compare the performance of CRUD operations in MySQL and MongoDB by increasing the amount of data. MongoDB sets index and compares it again.  Through result of these operations is to choose a database system that fits the situation.  This makes it possible to design and analyse big data more efficiently.

Solution-processed CdS transistors with high electron mobility

Solution-processed CdS field effect transistors (FETs) and solar cells are demonstrated via spin-coating and thermal annealing of soluble cadmium thiolate compounds. The synthesis is carried out in one simple step using cadmium oxide and tertiary alkane thiols. The cadmium thiolates are soluble in organic solvents such as chloroform and may be spin-coated, like organic semiconductors, to form thin films. The cadmium thiolate films decompose rapidly at 300 ??C to yield semiconducting cadmium sulfide films. FETs are easily fabricated using these films and exhibit electron mobilities of up to 61 cm2 V -1 s-1, which compare favourably to FETs prepared from other solution-processed materials such as organic semiconductors, inorganic nanoparticles or chalcogenide films. Initial attempts to prepare hybrid bilayer solar cells were successfully realized by spin-coating a p-type semiconducting polymer layer on top of the n-type CdS film. These devices show significant photocurrent response from both the CdS and polymer layers, indicating that the CdS films are able to participate in photo-induced electron transfer from the polymer to the CdS layer as well as photo-induced hole transfer from CdS to the polymer layer.close2

Personality traits and emotional status affecting academic achievements of medical students: testifying mediating effect of learning strategies

Purpose The purpose of this study is to identify possible causal relationships among personality traits, emotional status, learning strategies, and academic achievements of medical students and to testify mediating effect of learning strategies in these relationships. Methods The study subjects are 424 medical students in the academic year of 2020 at the Gyeongsang National University, Jinju, Korea. Using the Multi-dimensional Learning Strategy Test-II, we assessed the students’ academic achievements with personality traits, emotional status, and learning strategies. This study employed Structural Equation Modelling to explore the causal relationships among the latent variables. Results In the path model, personality traits directly affected academic achievements (β=0.285, p<0.05) and indirectly affected academic achievements via emotional status (β=0.063, p<0.01) and via learning strategies (β=0.244, p<0.05), respectively. Further, personality traits indirectly affected academic achievements via emotional status first and learning strategies next (β=0.019, p<0.05). Personality traits indirectly affected academic achievements through three multiple paths in the model (β=0.326, p<0.05). Learning strategies partially mediated the relationship between personality traits and academic achievements as well as the relationship between emotional status and academic achievements of medical students. Conclusion Study findings proved constructing the causal relationships among personality traits, emotional status, learning strategies, and academic achievements of medical students, thus supporting our hypotheses. Early habits of self-regulated learning are essential for the successful academic achievements of medical students. Therefore, medical students should know how to regulate personality traits and control emotional status, significantly affecting learning strategies

Angiographic and Clinical Result of Endovascular Treatment in Paraclinoid Aneurysms

PurposeThe purpose of this study was to analyze the results of an immediate and mid-term angiographic and clinical follow-up of endovascular treatment for paraclinoid aneurysms.Materials and MethodsFrom January 2002 to December 2012, a total of 113 consecutive patients (mean age: 56.2 years) with 116 paraclinoid saccular aneurysms (ruptured or unruptured) were treated with endovascular coiling procedures. Clinical and angiographic outcomes were retrospectively evaluated.ResultsNinety-three patients (82.3%) were female. The mean size of the aneurysm was 5.5 mm, and 101 aneurysms (87.1%) had a wide neck. Immediate catheter angiography showed complete occlusion in 40 aneurysms (34.5%), remnant sac in 51 (43.9%), and remnant neck in 25 (21.6%). Follow-up angiographic studies were performed on 80 aneurysms (69%) at a mean period of 20.4 months. Compared with immediate angiographic results, follow-up angiograms showed no change in 38 aneurysms, improvement in 37 (Fig. 2), and recanalization in 5. There were 6 procedure-related complications (5.2%), with permanent morbidity in one patient.ConclusionOut study suggests that properly selected patients with paraclinoid aneurysms can be successfully treated by endovascular means

Pendant group effects on the optical and electrical properties of carbazole-diketopyrrolopyrrole copolymers

Two kinds of novel carbazole and diketopyrrolopyrrole based conjugated copolymers, poly[N-9&apos;-heptadecanyl-2,7-carbazole-alt-5,5-(3,6-dithien-2-yl-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4-dione)] (P1) and poly[N-9&apos;-(3,5-bis(octyloxy) phenyl)-2,7-carbazole-alt-5,5-(3,6-dithien-2-yl-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c] pyrrole-1,4-dione)] (P2), were synthesized via a Suzuki cross coupling reaction. The optical and electrical properties of these polymers, in which the pendent groups on the carbazole moiety were modified, were investigated. Aryl substituted P2 shows a narrower band gap (1.61 eV), higher hole mobility (4.4 x 10(-3) cm(2) V-1 s(-1)) and more planar backbone structure than alkyl substituted P1. The modification of side groups significantly affected their surface morphologies. The device performance of solar cells based on these polymers and a fullerene acceptor was characterized.close3

Gamma oscillation in functional brain networks is involved in the spontaneous remission of depressive behavior induced by chronic restraint stress in mice

Additional file 1: Table S1. Statistical results of the cross-correlation in Fig. 2c

Swapping field-effect transistor characteristics in polymeric diketopyrrolopyrrole semiconductors: Debut of an electron dominant transporting polymer

A fact-finding study on thiophenyl diketopyrrolopyrrole (TDPP)-containing polymers for electronically convertible transport characteristics in organic field effect transistors (OFETs) is presented. In the subject of this consideration, a TDPP-based polymer with bis-benzothiadiazole (BisBT) units that serve as powerful electron-deficient building blocks, namely PDTDPP-BisBT, is prepared in order to achieve an n-channel transistor. The resulting polymer shows n-channel dominant ambipolar OFET characteristics and its electron mobility (1.3 x 10(-3) cm(2) V(-1) s(-1)) is found to be one order of magnitude higher than the hole mobility. Besides, the PDTDPP-BisBT OFET performance is independent of film-deposition conditions due to its completely amorphous microstructure, supported by the atomic force microscopy (AFM) and X-ray diffraction (XRD) analyses. Herein, we report an intriguing discovery in sync with our previous studies that TDPP-based polymers can function as a p-type, n-type, or ambipolar organic semiconductor in accordance with the degree of electron affinity of the comonomers.close211

High mobility solution-processed hybrid light emitting transistors

We report the design, fabrication, and characterization of high-performance, solution-processed hybrid (inorganic-organic) light emitting transistors (HLETs). The devices employ a high-mobility, solution-processed cadmium sulfide layer as the switching and transport layer, with a conjugated polymer Super Yellow as an emissive material in non-planar source/drain transistor geometry. We demonstrate HLETs with electron mobilities of up to 19.5 cm2/V s, current on/off ratios of &gt;107, and external quantum efficiency of 10-2% at 2100 cd/m2. These combined optical and electrical performance exceed those reported to date for HLETs. Furthermore, we provide full analysis of charge injection, charge transport, and recombination mechanism of the HLETs. The high brightness coupled with a high on/off ratio and low-cost solution processing makes this type of hybrid device attractive from a manufacturing perspective.open0