Physicochemically modulated fluorescence-scattering ratiometric sensor for selective and visual detection of levodopa.

In this study, a facile fluorescence-scattering ratiometric sensor was designed for visual and selective detection of levodopa (LD) via a clever physicochemical modulation scheme. The alkalized products of LD can rapidly react with polyethyleneimine (PEI) to exhibit an intense blue fluorescence and decrease the second-order scattering (SOS) signal of PEI. As the concentration of LD increased, the fluorescence intensity at 420 nm increased and the SOS intensity at 675 nm decreased synchronously. Thus the fluorescence-scattering ratiometric sensor was constructed by virtue of the two simultaneously changed signals. Furthermore, red light-emitting Au nanoclusters (AuNCs) were added into the above mixture solution to enlarge the SOS signal and provide a stable red background fluorescence. The intensity ratio of fluorescence to SOS (F/(S/Sblank)) is linear dependent on CLD in the wide range of 50.0---30000.0 nM, and LD as low as 50.0 nM can be identified with the naked eye via change of fluorescence color. The developed ratiometric sensor is smart, simple and efficient, and has been applied to the convenient assay of LD in real samples. The proposed physicochemical modulation strategy provides a new and facile path for selectively and visually identifying the target from its analogues.

Application of Intraoperative Transesophageal Echocardiography in the Treatment of Renal Cell Carcinoma with Inferior Vena Cava Tumor Thrombus / 中国医学科学院学报

Objective To investigate the value of intraoperative transesophageal echocardiography (TEE) in the diagnosis and treatment of renal cell carcinoma with inferior vena cava tumor thrombus. Methods Ten patients of renal cell carcinoma with inferior vena cava tumor thrombus treated in the Second Hospital of Hebei Medical University from January 2017 to January 2021 were selected.TEE was employed to locate the position of the tumor thrombus,determine the occlusion point of the inferior vena cava,count the intraoperative tumor thrombus shedding rate,examine the tumor thrombus resection integrity,and measure blood loss and other indicators,on the basis of which the application value of TEE in the operation of renal cell carcinoma with inferior vena cava tumor thrombus was evaluated. Results All the 10 patients had completed the operations successfully,including 8 patients of open operation and 2 patients of laparoscopic operation.TEE showed tumor thrombi clearly,and all the tumor thrombi were completely removed.There was no tumor thrombus shedding during the operation.The blood loss varied within the range of 300-800 ml,with the mean of (520.0±193.2) ml.The grade III tumor thrombi in 2 patients and the grade I tumor thrombus in 1 patient diagnosed before operation were reduced to grade Ⅱ and upgraded to grade Ⅱ,respectively,by TEE.One patient had no floating tumor thrombus at the end of tumor thrombus before operation,and the blocking position was adjusted in time with the assistance of TEE to avoid the shedding of the floating tumor thrombus. Conclusion TEE can accurately determine and dynamically monitor the location and shape of inferior vena cava tumor thrombus,which provides an important reference and has a significant clinical value in the operation of renal cell carcinoma with inferior vena cava tumor thrombus.

Temperature-dependent electronic structure of γ-phase CuI: first-principles insights.

To deepen the understanding of CuI that emerges as a promising next-generation transparent display material, we investigate the temperature effect on the electronic structures of its room-temperature phase γ-CuI. Using density-functional-theory-based approaches, we investigate the bandgap renormalization, which is contributed by the electron-phonon (el-ph) interaction and lattice thermal expansion. Different from most semiconductors, the bandgap widens as temperature increases, although it only widens by 88.3 meV from 0 to 600 K. In addition, based on the temperature-dependent band structure and conventional Drude model, we investigate the influences of the effective masses and evaluate the hole mobilities limited by phonon scattering along different directions. The calculated mobilities agree well with existing experimental values. Our study not only provides a fundamental understanding of the temperature effect on the electronic structure of CuI, but also gives insights for further improvement of the electronic and thermoelectric devices based on CuI.