Crewsgeisler7871

We report on the growth of high-quality stoichiometric layered Cr2Se3 single crystals with metallic and noncollinear antiferromagnetic ground state using the chemical vapor transport (CVT) method. The crystals show weak ferromagnetism in the in-plane and out-of-plane directions below the Neél temperature (T N), however, the field-cooled out-of-plane magnetization at 500 Oe and 10 K (∼0.24 μ B/f.u.) is approximately 15 times larger than that of the in-plane one, indicating strong c-axis easy uniaxial magnetic anisotropy, which is further supported by the in-plane and out-of-plane isothermal anisotropic magnetic hysteresis loops and the angular dependent magnetoresistance (MR). The latter also reveals a decrease of the coercive field of the crystal upon the tilting of the weak ferromagnetic easy axis away from the direction of the magnetic field. Further, the out-of-plane isothermal MR are negative below T N and show butterfly shapes for T less then 10 K and couple with the magnetic hysteresis M(H) loop. These results may help researchers better understand the interplay between the weak ferromagnetism and the magnetotransport properties of 2D itinerant noncollinear antiferromagnetic systems.Acoustic metamaterials are artificial materials which can manipulate and control acoustic waves in way that may not exist in nature. Pentamode metamaterials, as one kind of metamaterials, have solid structures but behaves like fluid. One application is in building acoustic cloaks. In this paper, composite pentamode metamaterials with hexagonal unit cells are proposed. The phononic band structures of the unit cell show that there are band gaps within which only compressional modes exist. With variation of structures, highly anisotropic properties can be obtained. The influences of geometric dimensions and materials on the effective properties are analyzed. The composite structures introduce more degrees-of-freedom to tailor the effective properties.Monolayer C2N has been successfully synthesized. To explore the enhancement of its stability and the expansion of its potential applications in electronics and optoelectronics, a vertical van der Waals heterostructure is constructed by C2N monolayer integrated with h-BN monolayer. The first-principles calculations based on the density functional theory show that this structure possesses a type-II band alignment with a smaller direct band gap and lager band offsets, suggesting that photo-generated electron-hole pairs can be well spatially separated, and thus an excellent photoelectric and photovoltaic material can be obtained. Also shown is that the electronic properties of such a heterostructure can be effectively regulated by a vertical strain and external electric field. For example, under compressive strain or forward electric field, its band gap can be significantly reduced to enhance light-excitation electron transition further, meanwhile the feature of direct band-gap and large band offsets is always well-preserved. Furthermore, it is found that the intrinsic heterostructure holds a wide optic adsorption range and large adsorption coefficient, and the applied compressive strain or a positive electric field can lead to a wide and high main absorption peak across the near-infrared, visible light, and ultraviolet region, implying that a tuned heterostructure has more promising applications in optoelectronics.Objective The Centers for Disease Control & Prevention (CDC) recommends that the human papillomavirus (HPV) vaccine series be initiated at ages 11-12 years, but many children never follow-through with the series. By examining differences in clinic-specific vaccine series follow-through rates across four clinics, we aimed to identify best practices related to communication around the vaccine and pathways to follow-through. Methods We used the electronic medical record (EMR) to retrospectively analyze HPV vaccine follow-through at four clinic settings. We limited the sample to children ages 11-17 who received a dose of the vaccine series at any of the clinics between January 2015 and June 2018. The primary outcome was follow-through of the HPV vaccine series within 18 months of initiation. Results A total of 3,813 patients were included in this study, 29% of which followed through with the HPV vaccine series. There was significant variability of vaccine follow-through among the clinics (p less then 0.001), with the Med/Peds clinic having the highest rate of follow-through (32%). learn more After adjusting for confounding variables, multivariable analysis found that Med/Peds and Family Medicine had higher odds of HPV vaccine series follow-through than the Pediatrics clinic. Conclusions We found that the likelihood of vaccine series follow-through was highest when the series was started in the Med/Peds and Family Medicine clinics, compared to Pediatrics and Adolescent Medicine. These results suggest that further qualitative research is needed to understand what communication strategies are most effective at facilitating HPV vaccine uptake among adolescents, and how the most effective strategies can be shared among clinics.Objectives Hearing impairment and ear diseases are among the world's leading causes of years lived with disability. Ear disorders are a major health problem in developing countries like India. The present research had been planned to screen the primary school children for ear morbidity and to study the various factors associated with ear morbidities so that corrective intervention can be initiated at the earliest. Methods A cross-sectional study was conducted among all primary school children of two schools in Aliganj, Delhi. Complete enumeration of all the school children of these two primary schools was planned for this study. Modified version of World Health Organization's (WHO's) "Ten Question Plus" screening instrument was used, followed by Otoscopy examination, in all children for confirmation of ear disease, if any. Descriptive data analysis was performed. Results Out of the total 430 study subjects, ear morbidities were found in 198 (46.0%) study participants. Presence of ear morbidity showed significant association with overcrowding, absence of a separate kitchen, passive smoking, feeding young child in lying down position, upper respiratory tract infection (URI)˃3 episodes/year and allergy (p less then 0.