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For multiplex beams of orbital angular momentum (OAM), we propose a two-looped concentric uniform circular array (CUCA) consisting of sequentially rotated circular polarization (CP) triangle patches. Generally speaking, the rotation of the CP antenna makes feeding networks free of narrow-band phase shifters. Further investigations also reveal that CP performances of elements and the rotation parameters (including directions and centers) are critical factors. Moreover, adopting the triangle patches makes the array compact and wideband. A demonstration with 12 elements is designed and fabricated, whose radius is only 0.760. Simulations and measurements suggest that it could emit circularly polarized vortex waves of modes -1 and -2 at the X band simultaneously, and its bandwidth is about 8.7%.

This study aims to investigate the effectiveness of the transtheoretical model (TTM)–based exercise training on TTM variables, exercise adherence, and physical function in patients in the early stages after bariatric surgery (BS). We conducted a single-blinded, prospective, randomized controlled trial (RCT) to evaluate the effects of TTM-based exercise training on BS patients immediately after surgery. Participants (n = 120) were randomized into a TTM-based exercise training group (n = 60) and a control group (n = 60). Main outcomes included TTM variables (measured by exercise stages of change (ESCs), exercise self-efficacy (ESE), and decisional balance), exercise adherence, and physical function (determined by the 6-min walk distance (6MWD)). Secondary outcomes were physical activity, anthropometrics, and body composition. We performed all analyses in accordance with the intention-to-treat principle. Retention rates for the interventions were 91.7% for the intervention group and 90.0% for the control group. Compared with the control group, the 12-week TTM-based intervention significantly helped participants advance through ESCs, demonstrate higher ESE, perceive more benefits and fewer barriers to exercise, and show higher exercise adherence and better physical function afterward (all P < 0.05). However, we observed no statistically significant difference between the two groups in anthropometric parameters or body composition after intervention. The TTM-based exercise intervention had significant positive effects on the TTM variables, which could further help increase patients’ exercise adherence and physical function immediately after BS. This study was retrospectively registered at the Chinese Clinical Trial Registry (website: www.chictr.org.cn , registry number: ChiCTR2000039319).

Although several biomarkers can be used to distinguish cholangiocarcinoma (CCA) from healthy controls, differentiating the disease from benign biliary disease (BBD) or pancreatic cancer (PC) is a challenge. CCA biomarkers are associated with low specificity or have not been validated in relation to the biological effects of CCA. In this study, we quantitatively analyzed 15 biliary bile acids in CCA (n = 30), BBD (n = 57) and PC (n = 17) patients and discovered glycocholic acid (GCA) and taurochenodeoxycholic acid (TCDCA) as specific CCA biomarkers. Firstly, we showed that the average concentration of total biliary bile acids in CCA patients was quantitatively less than in other patient groups. In addition, the average composition ratio of primary bile acids and conjugated bile acids in CCA patients was the highest in all patient groups. The average composition ratio of GCA (35.6%) in CCA patients was significantly higher than in other patient groups. Conversely, the average composition ratio of TCDCA (13.8%) in CCA patients was significantly lower in all patient groups. To verify the biological effects of GCA and TCDCA, we analyzed the gene expression of bile acid receptors associated with the development of CCA in a CCA cell line. The gene expression of transmembrane G protein coupled receptor (TGR5) and sphingosine 1-phosphate receptor 2 (S1PR2) in CCA cells treated with GCA was 8.6-fold and 3.4-fold higher compared with control (untreated with bile acids), respectively. Gene expression of TGR5 and S1PR2 in TCDCA-treated cells was not significantly different from the control. Taken together, our study identified GCA and TCDCA as phenotype-specific biomarkers for CCA.

Intense spikes were experimentally and numerically studied in a feedback stimulated Brillouin scattering (SBS) system. By modulating the input pump wave with a low frequency (100 kHz) signal, the intense spikes are shown to appear rarely and randomly. Specifically, the experimental results indicate that the probability density function (PDF) is characterized by the L-shaped distribution. Theoretical simulations based on the three-wave parametric coupling model of the SBS system show a good consistency with the experimental results.

Kilowatt Ytterbium-doped fiber laser is found widespread application in medical technology, industry and military areas. At present, most of the multi-kilowatt single-mode fiber lasers are achieved by tandem-pumped master oscillator power-amplifier (MOPA) system. When the laser output power reaches kilowatt, the output will be strongly affected by nonlinear effects in the amplifier. The Stimulated Raman Scattering effects is known as the major restrictions to the increase of output signal power. Up to now, Raman effects in conventional diode-pumped amplifier have been well studied while the Raman effects in tandem-pumped has not yet been thoroughly analyzed. In this paper, a theoretical analysis of Raman effects using numerical solution of steady-state rate equations in kilowatts tandem-pumped ytterbium-doped fiber amplifiers is presented. The numerical simulation describing output power characteristics and laser distribution along the fiber is carried under the co-directional end-pumping. Furthermore, an optimization of Raman effects is discussed, which provides a solid foundation for achieving a higher fiber laser output.