An anionic Zn-MOF composed of 1D columnar SBUs for highly C2H2/CH4 selective adsorption, dye adsorption and fluorescence sensing.

An anionic three-dimensional framework {(Me2NH2)2[Zn8(L)6(ad)4(µ4-O)]·10DMF·11H2O}(Zn-MOF, L2- = 4,4'-(3-aminopyridine-2,5-diyl)dibenzoic acid; ad- = adeninate) with a column-layered structure was synthesized. Structural studies show that the Zn-MOF has octahedral cages [Zn8(ad)4(µ4-O)], the adjacent cages are connected by O atoms to form 1D columnar SBUs, and every four SBUs are connected by L2- to form a square channel 3D framework. Gas adsorption studies show that the BET and Langmuir surface areas of Zn-MOF are 1370.31 and 1478.04 m2 g-1, respectively, and the total pore volume for single-point adsorption is 0.528 cm3 g-1. The surface of the pores of the Zn-MOF is occupied by open metal sites and uncoordinated carboxyl groups, showing good capture ability for C2H2 and good adsorption selectivity for C2H2/CH4. More importantly, the free (CH3)2NH2+ ions present in the pores of the columnar layered Zn-MOF can cation-exchange with MB, MV, and RhB ions in aqueous solution. Therefore, Zn-MOF can not only effectively adsorb the cationic dyes MB, MV, and RhB, but also exhibit particularly selective sorption towards the mixed anion and cation dyes MB/MO and MV/MO. In addition, a series of fluorescence experiments show that Zn-MOF has good fluorescence properties, exhibiting highly selective and sensitive fluorescence detection and recognition performance for Fe3+ ions in aqueous solution with a low detection limit.

4D-printed pH sensing claw.

As an example of extending the functionality of analytical devices manufactured using four-dimensional printing (4DP), in this study we employed acrylonitrile butadiene styrene (ABS) thermoplastic filaments, poly(4-vinylpyridine) (P4VP)-incorporated ABS filaments, and multi-material fused deposition modeling three-dimensional printing (3DP) to fabricate a pH measurement device that underwent pH-dependent geometric changes. Upon immersion in a solution having a pH close to the value of pKa of P4VP (ca. 5.0), electrostatic repulsion among the protonated units of P4VP resulted in swelling only of the part printed using the P4VP-incorporated ABS filaments, leading to lifting of the whole device along the z-axis (ΔH) in a pH-dependent manner. After optimizing the device's design and fabrication, this 4D-printed pH sensing claw exhibited linearity between the value of ΔH and values of pH in the range from 5.0 to 8.6. We used this 4D-printed pH sensing claw to perform pH analyses of complicated real samples, verifying its analytical reliability for non-electrochemical and non-optical pH measurement and highlighting the capability of 4DP technologies in the direct fabrication of stimuli-responsive sensing devices. We envision that 4DP technologies will prompt the manufacture of smart sensing devices through the printing of stimuli-responsive materials, thereby diversifying the development of 3DP-enabling analytical chemistry.

Solution Foaming-Treated 3D-Printed monolithic packing for enhanced solid phase extraction of trace metals.

Post-printing treatment is a promising means of enhancing the performance of devices manufactured using conventional three-dimensional printing (3DP) technologies. In this study we developed a post-printing solution foaming process-involving respective treatment with formic acid (60%, v/v) and sodium bicarbonate (5%, w/v) solutions to generate CO2 as a foaming agent-to increase the surface roughness and porosity of the polyamide 6 (PA6) monolithic packing in a multimaterial fused deposition modeling 3D-printed solid phase extraction (SPE) column, thereby enhancing the extraction of Mn, Co, Ni, Cu, Zn, Cd, and Pb ions from complicated real samples prior to their determination using inductively coupled plasma mass spectrometry. After optimizing the column fabrication process, the solution foaming treatment process, the extraction conditions, and the automatic analytical system, the 3D-printed SPE column incorporating the solution foaming-treated PA6 monolithic packing extracted these metal ions with 18.9- to 42.0-fold enhancements, relative to those of the as-printed column, with absolute extraction efficiencies all greater than 94.3% and method detection limits ranging from 0.2 to 7.7 ng L-1. We verified the reliability and applicability of this method through analyses of the tested metal ions in several reference materials (CASS-4, SLEW-3, 1643f, and 2670a) and spike analyses of seawater, river water, ground water, and urine samples. We conclude that post-printing treatment can dramatically improve the performance of 3D-printed analytical devices.

[Improvement and application for ecological networks using landscape pattern and connectivity methods.] / åŸºäºŽæ™¯è§‚æ ¼å±€å’Œè¿žæŽ¥åº¦è¯„ä»·çš„ç”Ÿæ€ç½‘ç»œæ–¹æ³•ä¼˜åŒ–ä¸Žåº”ç”¨.

In landscape ecology, the target species ecological network is often constructed by the least-cost path model (hereafter LCPM) to improve landscape connectivity among discrete habitats and to mitigate the negative impacts of habitat fragmentation. Nevertheless, the traditional ecological network method based on LCRM has insufficient understanding of landscape structure changes and ecological processes of research site. We used landscape pattern index and connectivity probability index to quantitatively evaluate the landscape structure and connectivity characteristics of the research area before and after the construction of the ecological network. The ecological network of the habitat of Presbytis leucocephalus, located in Chongzuo, Guangxi Province, was used as an example to describe the optimization and application of this method in detail. We identified the habitat and stepping stone patches of the target species, classified land use types of the study area, set up different resistant values, and obtained 20 corridors of ecological network using LCPM. The results showed that LCRM could effectively improve habitat integrity and continuity, reduce overall fragmentation level, and improve habitat quality based on the structural and functional connectivity evaluation by landscape pattern index and connectivity probability index. Meanwhile, its construction could improve the structural connectivity and functional connectivity of the habitat landscape, with significant consistency of the connection degree changes in both aspects (R2=98.3%, P<0.01). However, the relationship between landscape structure changes and functional connectivity caused by the network was not strong, and their relationship was not as significant as the inherent relationship between the structure and function.

Safety and efficacy of computed tomography-guided dye localization using patent blue V for single lung nodule for video-assisted thoracoscopic surgery: a retrospective study.

BACKGROUND: For invisible or impalpable lung nodules, video-assisted thoracoscopic surgery (VATS) has some limitations; some preoperative localization has been developed to overcome this limitation. This study aimed to assess the safety and efficacy of preoperative computed tomography (CT)-guided localization with patent blue V dye. METHODS: In this retrospective study, we examined patients with solitary pulmonary nodule undergoing preoperative CT-guided patent blue V dye localization from 2013 to 2015. We analyzed patients' demographic data, nodular features, and procedures undergone. RESULTS: We enrolled 282 patients (282 lung nodules; mean age: 56.6±11.6 years, with female preponderance) in this study. The mean size of nodules was 0.9±0.5 cm, and mean time of localization was 24 min. The leading complications after localization were asymptomatic pneumothorax (48 patients, 17%) and localized pulmonary hemorrhage (51 patients, 18%). Other rare complications included subcutaneous emphysema and hematoma. We noted two cases with intraoperative poor or fail dye localization. Most patients underwent wedge resection (221 patients, 78.4%) and segmentectomy (36 patients, 12.8%), whereas 25 patients underwent lobectomy (8.9%) after the intraoperative frozen histopathological study confirmed malignancy. Furthermore, postoperative hospital stay was 4.8±2.0 days. Few patients experienced postoperative complications such as empyema (n=1), air leakage (n=3), and chylothorax (n=1). CONCLUSIONS: This study establishes that CT-guided dye localization is a safe and efficient method with rare severe complications and high success rate.