Highly efficient nonlinear optical organic crystals are very attractive for various photonic applications including terahertz (THz) wave generation. Up to now, only two classes of ionic crystals based on either pyridinium or quinolinium with extremely large macroscopic optical nonlinearity have been developed. This study reports on a new class of organic nonlinear optical crystals introducing electron-accepting benzothiazolium, which exhibit higher electron-withdrawing strength than pyridinium and quinolinium in benchmark crystals. The benzothiazolium crystals consisting of new acentric core HMB (2-(4-hydroxy-3-methoxystyryl)-3-methylbenzo[d]thiazol-3-ium) exhibit extremely large macroscopic optical nonlinearity with optimal molecular ordering for maximizing the diagonal second-order nonlinearity. HMB-based single crystals prepared by simple cleaving method satisfy all required crystal characteristics for intense THz wave generation such as large crystal size with parallel surfaces, moderate thickness and high optical quality with large optical transparency range (580-1620 nm). Optical rectification of 35 fs pulses at the technologically very important wavelength of 800 nm in 0.26 mm thick HMB crystal leads to one order of magnitude higher THz wave generation efficiency with remarkably broader bandwidth compared to standard inorganic 0.5 mm thick ZnTe crystal. Therefore, newly developed HMB crystals introducing benzothiazolium with extremely large macroscopic optical nonlinearity are very promising materials for intense broadband THz wave generation and other nonlinear optical applications.

Background We evaluated the 2‐year clinical outcomes of ST‐elevation myocardial infarction (STEMI) and non‐STEMI (NSTEMI) in patients with chronic kidney disease (CKD) who received newer‐generation drug‐eluting stents (DES). Methods Overall, 18,875 acute myocardial infarction patients were divided into two groups: CKD (STEMI, n = 1707; NSTEMI, n = 1648) and non‐CKD (STEMI, n = 8660; NSTEMI, n = 6860). The occurrence of major adverse cardiac events (MACE), defined as all‐cause death, recurrent myocardial infarction (re‐MI), any repeat coronary revascularization, and definite or probable stent thrombosis (ST), was evaluated. Results After multivariable‐adjusted analysis, in the CKD group, the MACE (adjusted hazard ratio [aHR]: 1.365, p = 0.004), all‐cause death (aHR: 1.503, p = 0.004), noncardiac death (non‐CD; aHR: 1.960, p = 0.004), and all‐cause death or MI rates (aHR: 1.458, p = 0.002) were significantly higher in the NSTEMI group than in the STEMI group. In the non‐CKD group, the non‐CD rate (aHR: 1.78, p = 0.006) was also higher in the NSTEMI group. The CD, re‐MI, any repeat revascularization, and ST rates were similar between groups. In the CKD group, from 6 months to 2 years after the index procedure, all‐cause death, non‐CD, and all‐cause death or MI rates were significantly higher in the NSTEMI group than in the STEMI group. These results may be related to the higher non‐CD rate in the NSTEMI group. Conclusions In the era of contemporary newer‐generation DES, NSTEMI showed a relatively higher non‐CD rate than STEMI in both CKD and non‐CKD groups.

Level 3 autonomous vehicles require conditional autonomous driving in which autonomous and manual driving are alternately performed; whether the driver can resume manual driving within a limited time should be examined. This study investigates whether the demographics and subjective driving tendencies of drivers affect the take‐over performance. We measured and analyzed the reengagement and stabilization time after a take‐over request from the autonomous driving system to manual driving using a vehicle simulator that supports the driver's take‐over mechanism. We discovered that the driver's reengagement and stabilization time correlated with the speeding and wild driving tendency as well as driving workload questionnaires. To verify the efficiency of subjective questionnaire information, we tested whether the driver with slow or fast reengagement and stabilization time can be detected based on machine learning techniques and obtained results. We expect to apply these results to training programs for autonomous vehicles' users and personalized human–vehicle interfaces for future autonomous vehicles.

Microspheres were prepared using N-methylolurea-dodecylamine conjugate (MU-DOA), an emulsifiable and self-condensaible oil. MU was prepared by reacting urea and formaldehyde at 708 8 8 8 8C in alkali conditions and then conjugating it to DOA by a condensation reaction. The MU-DOA conjugate was emulsified in distilled water without an emulsifier, and then the oil droplets were hardened to obtain microspheres by a self-condensation reaction among methylols of the conjugate. The reactions of each step, e.g., the preparation of MU, the conjugation of MU and DOA, and the self-condensation of emulsified oil, were confirmed by Fourier transform infrared (FTIR) spectra. On scanning electron microscopy (SEM), the microspheres formed by the self-condensation of the emulsified MU-DOA were shown as spherical and less than 30 mm in diameter. The phase transition temperatures of DOA, MU-DOA, and MU-DOA microspheres were 30.38 8 8 8 8C, 21.18 8 8 8 8C, and 20.18 8 8 8 8C, respectively. The lower transition temperature of MU-DOA is probably due to the bulky MU, which could reduce the intermolecular interaction of MU-DOA. Zeta potentials of the microspheres decreased from positive to negative value as pH increased from 3.5 to 10.5. The deprotonation of the amines of MU-DOA would be responsible for that result.

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