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Background: Education is an important part of the work of most doctors. Clinical preceptors act as role models and supervisors. Preceptors' quality of supervision strongly influences the learning quality of clinical interns (Bartlett et al. BMC Med Educ 20:165, 2020). To ensure a consistent approach to every preceptorship experience, the competency of clinical preceptors should be assessed to ensure that the desired outcomes are achieved. This study aims to evaluate clinical preceptors' competency in learner-centered teaching, to provide constructive feedback to develop the preceptors' competency and improve supervisory skills and internship quality at Kunming Medical University (KMU) in Kunming of China. Methods: This is a cross-sectional study with a quantitative self-administered online questionnaire. The convenience sampling technique was employed. In the undergraduate internship stage of KMU, clinical preceptors (N = 340) and interns (N = 487) were invited to use the augmented Stanford Faculty Development Program questionnaire (SFDPQ) (Stalmeijer et al. Med Teach 30:e272–e277, 2008), to (self-) assess the preceptor's competency of learner-centered teaching on a five-point scale (1 = strongly disagree, 5 = strongly agree). Results: Two hundred twenty-eight preceptors and two hundred thirty-six interns completed the questionnaire correctly. Overall, the assessment was positive, but the preceptors' self-assessment significantly higher than the interns' (p < 0.00). The overall mean of each category of preceptors' self-assessment was greater than 4.5, with no difference based on educational qualification. Male preceptors scored significantly higher in two categories than female preceptors. Preceptors under 30 years of age with less than 5 years of teaching experience rated "Teacher's knowledge and attitude" lower than those over 40 years of age with more than 5 years of experience (p < 0.05). There were statistically significant differences in the four categories across disciplines (p < 0.05). Undergraduate interns rated "Teachers' knowledge" as the highest category and "Learning climate" as the lowest, and interns of different genders are evaluated without distinction in all categories of SFDPQ. Conclusions: Employing the augmented SFDPQ to evaluate learner-centered teaching competency of clinical preceptors, offers potentially useful information for delivering constructive feedback. Combining self-evaluations with learner evaluation data can contribute to exploring preceptor competency development framework to guide them in targeted learner-centered teaching skill and acquisition and improvement, finally improving the overall quality of internships. [ABSTRACT FROM AUTHOR]

Diamond based quantum sensing for on‐chip electromagnetic field imaging is an emerging field. While smaller diamond probes offer higher spatial resolution, their lower fluorescence intensity poses a challenge for the traditional Avalanche Photo Diode. In this work, we propose a tapered fiber diamond probe containing Nitrogen‐vacancy center and utilize a single photon counter module as the detector. A time domain differential pulse sequence is introduced to suppress noise caused by laser intensity fluctuation. By analyzing the relationship between the signal‐to‐noise ratio (SNR) and parameters of differential pulse sequence, we derived the formula of SNR and the basic cycle (M $M$), and obtained the optimal SNR in the same measurement time through trade‐off between two different kinds of noise. The technique was applied to a waveguide microstrip filter chip, accurately imaging the current density distribution. Our results have potential applications in on‐chip testing and failure analysis. [ABSTRACT FROM AUTHOR]

With the complexity and integration of integrated chips increasing, existing integrated circuits electromagnetic interference techniques using metallic probes cannot meet the emerging demand at single die level or wafer level, which requires micron spatial resolution and ultraweak invasiveness. In this article, we developed a non‐invasive near field probe in the fiber format using nitrogen‐vacancy center in diamond, which was attached to the tip of fiber as microwave B‐field sensing element. Subsequently, we applied the fiber diamond probe to near field scanning of a low noise amplifier chip and a power amplifier chip. Through numerical simulation, we find that the surface field strength is proportional to current density at chip surface, thus this probe can be used as a current imaging technique at microwave frequency. [ABSTRACT FROM AUTHOR]

Objective: We aimed to compare perinatal outcomes between umbilical cord occlusion techniques in monochorionic pregnancies, including umbilical cord ligation, fetoscopic laser coagulation, interstitial laser coagulation, bipolar cord occlusion, radiofrequency ablation, and microwave ablation. Methods: This study was registered with PROSPERO (CRD42020158861). PubMed, Web of Science, Cochrane Library, and Embase were searched for studies published up to May 2020. The DerSimonian‐Laird random‐effects model was used for the meta‐analysis. Subgroup analyses were performed to compare the outcomes among the six techniques. Meta‐regression was used to adjust for confounders. Results: Thirty‐four studies with 1646 participants were included. The overall survival was 76.5% after umbilical cord ligation, 78.8% after fetoscopic laser coagulation, 60.3% after interstitial laser coagulation, 79.2% after bipolar cord occlusion, 77.5% after radiofrequency ablation, and 75.0% after microwave ablation. Subgroup comparison showed the rates of overall survival and preterm premature rupture of membranes were not significant different among six techniques. However, rates of fetal loss, premature birth, live birth, and neonatal death differed significantly among the six groups. Conclusions: The choice of umbilical cord occlusion techniques will affect perinatal outcomes. We suggested that the choice of umbilical cord occlusion techniques should fully consider these differences among techniques. Key points: What's already known about this topic? Several techniques have been used for selective feticide of monochorionic pregnancies.Bipolar cord occlusion and radiofrequency ablation are two commonly used minimally invasive methods for selective feticide.However, whether the pregnancy outcomes are different among different techniques is still unknown. What does this study add? This is the first meta‐analysis comparing perinatal outcomes among six techniques of selective feticide in monochorionic pregnancies.Our findings showed that the overall survival rate after umbilical cord occlusion was 77.1% (95% CI: 73.9%–80.2%).Besides, fetal loss, premature birth, live birth, and neonatal death rates differed significantly among the six techniques.Our study suggested that the choice of umbilical cord occlusion should fully consider the difference in perinatal outcomes among procedures. [ABSTRACT FROM AUTHOR]

Pancharatnam-Berry (PB) phase, usually utilized for phase manipulation of circularly polarized (CP) waves, has inherent symmetrical response on left-handed polarized (LCP) and right-handed polarized (RCP) for orbital angular momentum (OAM), which severely hinders its application. By modulating both propagation and PB phase allows independent control of LCP and RCP of OAM, but increases the design difficulty. Here, we propose a phase compensation scheme to independent control the CP states of OAM only utilizing PB phase, where arbitrary topological charges and deflection directions of LCP and RCP beams can be realized. Two wideband metasurfaces are designed to independent control the mode, circular polarization and beam directions of OAM at the frequency range of 10-20 GHz. This work significantly motivates the development of polarization division multiplexing in wireless communication system.