As an important subclass of MOFs, ZIF-8, built from 2-methylimidazole and Zn(NO3)2·6H2O, possesses excellent biocompatibility and high stability in aqueous solution. Recently, it has been found that ZIF-8 can efficiently adsorb DNA and quench the adsorbed fluorophores to a large extent. These properties make it possible to prepare DNA-based optical sensors using ZIF-8. Although practical analytical applications are being demonstrated, the basic understanding of the binding between ZIF-8 and DNA in solution has received relatively little attention. In this work, we report that the adsorption of 12-, 18-, 24-, and 36-mer single-stranded DNAs on ZIF-8 are affected by several factors. It is found from the outcomes that shorter DNAs are adsorbed more rapidly to the surface of ZIF-8. On the other hand, desorption of the probe DNA can be achieved using complementary strand DNA to restore the fluorescence value. Furthermore, the salt contributes to adsorption to some extent. These findings are important for further understanding of the interactions between DNA and ZIF-8 and for the optimization of DNA and MOF-based devices and sensors.
Introduction Although both COVID-19 and non-COVID-19 ARDS can be accompanied by significantly increased levels of circulating cytokines, the former significantly differs from the latter by its higher vasculopathy, characterized by increased oxidative stress and coagulopathy in lung capillaries. This points towards the existence of SARS-CoV2-specific factors and mechanisms that can sensitize the endothelium towards becoming dysfunctional. Although the virus is rarely detected within endothelial cells or in the circulation, the S1 subunit of its spike protein, which contains the receptor binding domain (RBD) for human ACE2 (hACE2), can be detected in plasma from COVID-19 patients and its levels correlate with disease severity. It remains obscure how the SARS-CoV2 RBD exerts its deleterious actions in lung endothelium and whether there are mechanisms to mitigate this. Methods In this study, we use a combination of in vitro studies in RBD-treated human lung microvascular endothelial cells (HL-MVEC), including electrophysiology, barrier function, oxidative stress and human ACE2 (hACE2) surface protein expression measurements with in vivo studies in transgenic mice globally expressing human ACE2 and injected with RBD. Results We show that SARS-CoV2 RBD impairs endothelial ENaC activity, reduces surface hACE2 expression and increases reactive oxygen species (ROS) and tissue factor (TF) generation in monolayers of HL-MVEC, as such promoting barrier dysfunction and coagulopathy. The TNF-derived TIP peptide (a.k.a. solnatide, AP301) -which directly activates ENaC upon binding to its a subunit- can override RBD-induced impairment of ENaC function and hACE2 expression, mitigates ROS and TF generation and restores barrier function in HL-MVEC monolayers. In correlation with the increased mortality observed in COVID-19 patients co-infected with S. pneumoniae, compared to subjects solely infected with SARS-CoV2, we observe that prior intraperitoneal RBD treatment in transgenic mice globally expressing hACE2 significantly increases fibrin deposition and capillary leak upon intratracheal instillation of S. pneumoniae and that this is mitigated by TIP peptide treatment.
In this paper, we propose a distributed resilient control method to solve an output synchronization problem for linear heterogeneous multi-agent systems (MASs) in the presence of both link and actuator attacks. A fully distributed event-trigger-based observer is proposed to estimate the state of the leader, where global information is not required and the leader's system matrices are identified in finite time. An intermittent event-triggered mechanism is also designed to avoid continuous monitor triggered conditions. For actuator attacks, a compensator, based on a distributed normal state predictor, is developed to recover paralyzed states. Theoretical analysis shows that an MAS steered by our proposed fully distributed adaptive resilient scheme achieves output synchronization, and Zeno-behaviors are excluded. Finally, a numerical example is provided to verify the effectiveness of our proposed scheme.
Abstract Novel biodegradable dendritic contrast agents (DCAs) based on polyester dendrimers were synthesized and characterized. The DCAs were stable at acidic pH, but hydrolyzed rapidly at physiological pH, which rendered the DCA's long‐term Gd 3+ retention as low as that of small molecule CAs. Their longitudinal relaxivities of 10.2 to 17.5 L·mmol −1 ·s −1 were about 2.4 to 4.1 times higher than that of DTPA‐Gd, indicating their superior contrast‐enhancing capability to the clinically used contrast agent. The in vivo MRI study suggested that the DCA at lower generation (G2‐DTPA‐Gd) could effectively enhance the MRI of tumor, while the one at higher generation (G5‐DTPA‐Gd) showed more potential in liver imaging.
Objective:From the viewpoint of the physiology and biochemistry,to research the relativity of the different phenotype and the traditional Chinese medicine constitution classification of the essential hypertensive patients.Methods:to classify constitution according to the traditional Chinese medicine sorting standard and to assay blood pressure、boody mass index、electrocardiogram and biochemistry indexes.Results:yangkang、tanshi and pinghe are in the proportion of 37 4%、47 6%、1 5%among essential hypertensive patients,respectively.Tanshi belongs to obesity type and the level of its serum glucose、cholesterol、triglyceride is the highest,the level of its high density lipoprotein is the lowest and the percentage of the abnormal electrocardiogram is obviously higher than yangkang group.Conclusions:yangkang and tanshi are two essential types in the patients of the essential hypertension.Tanshi hypertensive patients mostly belong to obese type and the prognosis of them may be worse than that of the patients of other constitutive types.
The operation control of smart distribution network is facing enormous challenge. Focusing on improving the dynamic characteristics of smart distribution network, a novel supplementary controller for optimizing dynamic characteristics of smart distribution network is proposed in this paper. The proposed method is based on the hierarchical distribution control network and PMU data. In this paper, the principle and the operating mechanism of the proposed method are introduced. The software tool PSCAD is used to simulate a case system under different disturbance scenarios. The simulation results reveal the effectiveness of the proposed method on improving dynamic characteristics of smart distribution network.
A serine-threonine protein kinase, WNK4, reduces Na⁺ reabsorption and K⁺ secretion in the distal convoluted tubule by reducing trafficking of the thiazide-sensitive Na-Cl cotransporter to and enhancing renal outer medullary potassium channel retrieval from the apical membrane. Epithelial sodium channels (ENaC) in the distal nephron also play a role in regulating Na⁺ reabsorption and are also regulated by WNK4, but the mechanism is unclear. In A6 distal nephron cells, transepithelial current measurement and single channel recording show that WNK4 inhibits ENaC activity. Analysis of the number of channel per patch shows that WNK4 reduces channel number but has no effect on channel open probability. Western blots of apical and total ENaC provide additional evidence that WNK4 reduces apical as well as total ENaC expression. WNK4 enhances ENaC internalization independent of Nedd4-2-mediated ENaC ubiquitination. WNK4 also reduced the amount of ENaC available for recycling but has no effect on the rate of transepithelial current increase to forskolin. In contrast, Nedd4-2 not only reduced ENaC in the recycling pool but also decreased the rate of increase of current after forskolin. WNK4 associates with wild-type as well as Liddle's mutated ENaC, and WNK4 reduces both wild-type and mutated ENaC expressed in HEK293 cells.
A 46-year-old male patient developed scatterred reddish-brown plaques and nodules on the back 6 years prior to the presentation. Then, the lesions gradually spread to the axillary fossa and protothorax, and became indurated with slight itching in winter. Laboratory examination revealed hypergammaglobulinemia. Computed tomography (CT) scan showed multiple nodular or patchy shadows in both lungs, lymphadenectasis in axillary, mediastinal and inguinal regions, and spleen enlargement. Histopathological examination of skin lesions showed granulomatous infiltrates with plenty of lymphocytes, histiocytes and mature plasma cells in the middle and lower dermis with the presence of lymphoid follicle-like structures, but no cell atypia was observed. Immunohistochemical study showed positive staining for CD38, CD138, CD79a, κ and λ light chains. According to clinical manifestations and laboratory examination results, the patient was diagnosed with cutaneous and systemic plasmacytosis.
Key words:
Neoplasms, plasma cell; Skin manifestations; Hypergammaglobulinemia; Plasmacytosis
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