Ying Wang,Zaiwen Lin,Qi Liu,Jiahui Zhu,Jingyuan Liu,Jing Yu,Rongrong Chen,Peili Liu,Jun Wang
The uranium(VI) (U(VI)) extraction from seawater was crucial for future energy problems such as increasingly depleted fossil fuels and serious environmental pollution , and it could improve the current situation of limited U(VI) reserves on land. In this study, the natural material bamboo strips (BS) were utilized due to the flexibility and richness of various functional groups, and the amidoximized bamboo strips (AOBS) could be directly prepared by a simple one-step method. The amidoximation of materials not only adjusted the optimal adsorption pH from 4 to 6, but also advanced the hydrophilicity, speeded up the reaction rate (adsorption equilibrium within 1 h, about 0.17 times of BS), and increased the adsorption capacity (q e = 268.41 mg g −1 at pH = 6, about 1.7 times of BS). Importantly, the AOBS maintained its initial stitchability through flexibility adjustment, and was woven into a macro-shaped adsorbent (AOBS-M). After being placed in the Yellow Sea basin for 30 days, approximately 44.75 g of crude U(VI) (U(VI) content = 40.45 mg) was obtained (q e = 0.97 mg g −1 ), and it showed the excellent selectivity for U(VI). The AOBS-M not only overcame the problem that the existing adsorption materials were difficult to achieve macroscopic large-area molding, but also realized the flexibility adjustment during the modification process by controlling the reaction conditions, and promoted the industrial development of U(VI) extraction from seawater.
Shaowei Bo,Dong Zhang,Mengjie Ma,Xukai Mo,Julia Stabinska,Michael T. McMahon,Changzheng Shi,Liangping Luo
Chemical exchange saturation transfer (CEST) MRI is a versatile molecular imaging approach that holds great promise for clinical translation. A number of compounds have been identified as suitable for performing CEST MRI, including paramagnetic CEST (paraCEST) agents and diamagnetic CEST (diaCEST) agents. DiaCEST agents are very attractive because of their excellent biocompatibility and potential for biodegradation, such as glucose, glycogen, glutamate, creatine, nucleic acids, et al. However, the sensitivity of most diaCEST agents is limited because of small chemical shifts (1.0–4.0 ppm) from water. To expand the catalog of diaCEST agents with larger chemical shifts, herein, we have systematically investigated the CEST properties of acyl hydrazides with different substitutions, including aromatic and aliphatic substituents. We have tuned the labile proton chemical shifts from 2.8–5.0 ppm from water while exchange rates varied from ~680 to 2340 s−1at pH 7.2, which allows strong CEST contrast on scanners down to B0= 3 T. One acyl hydrazide, adipic acid dihydrazide (ADH), was tested on a mouse model of breast cancer and showed nice contrast in the tumor region. We also prepared a derivative, acyl hydrazone, which showed the furthest shifted labile proton (6.4 ppm from water) and excellent contrast properties. Overall, our study expands the catalog of diaCEST agents and their application in cancer diagnosis.Keywords:chemical exchange saturation transfer (CEST);acyl hydrazides;acyl hydrazones;cancer diagnosis