Advanced "turn-on" colorimetric uranium platform based on the enhanced nanozyme activity of a donor-acceptor structured covalent organic framework

BACKGROUND

The increasing uranium containing wastes generated during uranium mining and finishing pose a huge threat to the environment and human health, and thus robust strategies for on-site monitoring of uranium pollutant are of great significance for environmental protection around uranium tailings.

RESULTS

Herein, a facile "turn-on" colorimetric platform that can achieve uranium detection by spectrometry and naked eyes was developed based on the uranium-enhanced nanozyme activity of covalent organic framework (JUC-505). Thanks to the extended π-conjugated skeleton and donor-acceptor (D-A) structure, JUC-505 exhibited superior photo-activated nanozyme activity, which would be prohibited when the cyano group in JUC-505 skeleton was transformed to the amidoxime group. Further results elucidated that the coordination of uranium with amidoxime groups led to the electron transfer between uranium and the JUC-505-AO skeleton, and thus significantly restored the nanozymatic activity of JUC-505-AO with the subsequent remarkable color changes. Moreover, the uranium concentrations in uranium tailing wastewater detected by the present "turn-on" colorimetric method were well agreed with those by ICP-MS, demonstrating a high accuracy of the present method in real samples.

SIGNIFICANCE

The D-A structured JUC-505 with superior photocatalytic property and nanozymatic activity was applied to facilitate colorimetric detection of uranium, which displays the advantages of low detection limit, excellent selectivity, fast response and simple operation for uranium detection in real samples, and shows a great potential in on-site monitoring of uranium pollutant around uranium tailings as well as nuclear power plant.

A modified Casson equation to characterize blood rheology for hypertension

A modified Casson equation was established, verified satisficatorily for real conditions and suggested for use in clinical hemorheology. It provides 5 Casson parameters, i.e., Casson yield stress, Casson viscosity, the first critical point of shear rate to cause rouleaux to be broken down into smaller units, the second critical point of shear rate to completely disaggregate into individual erythrocytes, the difference between the two critical points, and also gives two series of the 5 above-mentioned Casson parameters, respectively, under original hematocrit and the standardized hematocrit of 45%. This equation not only reveals the apparent abnormalities of hypertensive patients and normalities of the healthy persons, but also reveals hidden abnormalities for patients with either low or high hematocrit. For 20 cases of hypertensive patients with low hematocrit, the 5 Casson parameters have lower values than control, but the modified equation reveals their hidden higher values than control when their hematocrit is standardized to 45%. For 7 cases of polycythemia complicated with hypertension, the 5 Casson parameters are higher at their original hematocrit, and the modified equation reveals the higher parameters than control also when the hematocrit is standardized to 45%. For 8 cases of polycythemia without complications, the 5 Casson parameters are higher at their original hematocrit than control, while the modified equation still reveals their normalities when standardizing their hematocrit to 45%.

Hemorheology and walking of peripheral arterial occlusive diseases patients during treatment with Ginkgo biloba extract

AIM

To study the effects of Ginkgo biloba extract 761 (GbE) from the points of view of hemorheology for patients of peripheral arterial occlusive diseases (PAOD).

METHODS

The treatment with GbE (240 mg.d-1, po) and the pain-free walking distance (PFWD) were carried out for 24 PAOD patients (12 nondiabetic, ND and 12 diabetic, D) over 48 wk. The parameters erythrocyte stiffness (ES) and relaxation time (RT), the blood plasma viscosity (eta), the plasma fibrinogen concentration (Cf) and the blood sedimentation rate (BSR), the PFWD, and maximal walking distance (MWD) were determined at 6 wk before treatment (-6), at the beginning of the treatment (0), and after 6, 11, 16, and 48 wk of treatment.

RESULTS

At wk -6, ES and RT of both the ND- and D-group were not significantly different from a healthy control group. At wk 0, stiffness and RT were significantly higher than healthy control, and the mean PFWD was only 111 m. The eta value was significantly elevated and Cf and BSR were enhanced. Throughout 11 wk of treatment ES, RT, eta, and Cf decreased gradually and PFWD improved. Between 16 and 48 wk, ES, and RT were no longer significantly different from the controls, whereas eta and Cf decreased gradually but remained higher than normal, BSR decreased, and the PFWD improved by a factor of 3.8 times (D) and 3.3 times (ND).

CONCLUSION

GbE gives therapeutic effects in PAOD patients.

Detection of Fcgamma receptors on human endothelial cells stimulated with cytokines tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma)

This investigation was conducted to detect Fcgamma receptors (FcgammaR) on cytokine-stimulated human endothelial cells (EC) by measuring anti-FcgammaR MoAb binding with an ELISA. TNF-alpha and IFN-gamma significantly increased the expression of FcgammaR type II (FcgammaRII) and type III (FcgammaRIII) on aortic EC. Simultaneous treatment with both cytokines had a synergistic effect and pretreatment of EC with IFN-gamma augmented the effect of TNF-alpha. The greatest effect was the increase (up to four-to-six-fold) in expression of FcgammaRII found by the simultaneous treatment of aortic EC with both cytokines. The receptors were expressed on the cell surface and showed receptor capping after incubation at 37 degrees C. This study showed that the inflammatory cytokines TNF-alpha and IFN-gamma enhanced low-affinity FcgammaR expression on human EC in vitro. The expression of FcgammaR may contribute to the specific localization of circulating immune complexes on blood vessels in areas of vasculitis.

[Relationship among blood pressure, viscosity of blood and cerebro-vascular disease]

In this article, 163 cases of hypertension patients and 117 cases of stroke patients with acute period including 43 cases of hemorrhagic strokes and 74 cases of ischemic strokes were analyzed between average arterial blood pressure and blood viscosity. The curves of relation of blood pressure versus blood viscosity in the hypertension patients' group showed "M" shape. The hemorrhagic stroke patients were located by up-side of the "M" shape curve and the ischemic stroke patients were situated by the down-side of the "M" shape curve.

[Fluidity of erythrocyte membranes in patients with ischemic cerebral vascular disease]

Measurement of fluidity of erythrocyte membrane (FEM) in thirty-six patients with ischemic cerebral vascular disease (ICVD) by fluorescence polarization of DPH (1,6,-Diphenyl-1,3,5-hexatriene) labelled on lipo-region in intact erythrocyte membrane. Twenty one healthy subjects without any stagnation of blood as control. Also research on coefficient of multiple correlation among the FEM and other factors in whole blood or plasma by using stepwise multi-regression analysis. The results revealed that: (1) FEM of patients with ICVD was 3.55 +/- 0.21 (eta), which was significantly higher than that of healthy subjects (2.77 +/- 0.12 eta), P less than 0.001. (2) The FEM of patients with ICVD were positive correlation with RBC electrophoresis rate, whole blood viscosity and low density lipo-proteins and were negative correlation with high density lipo-proteins. These findings suggested that it would be available for preventing ICVD by increasing of the surface charge on erythrocyte and of the high density lipo-proteins.