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Photo-cross-linkable multilayer filmscomposed of sulfonated reducedgraphene oxide (SRGO) and polystyrene-based diazonium salt (PSDAS)were fabricated by electrostatic layer-by-layer (LbL) self-assembly.Polystyrene with narrow molecular weight distribution was synthesizedby atom transfer radical polymerization (ATRP), and cationic PSDASwas prepared through nitration, reduction, and diazotization reactions.Negatively charged SRGO nanosheets were prepared through prereducedby NaBH4, modified by diazonium salt of sulfanilic acid,and then further reduced by hydrazine. The multilayer films were obtainedby alternately dipping substrates in the PSDAS solution and SRGO dispersionin acidic conditions. The cross-linking between the components occurredduring the multilayer formation process and was further achieved bythe UV light irradiation after the film preparation. The assemblingprocess and surface morphology of LbL multilayer films were monitoredby UV–vis spectroscopy, atomic force microscopy (AFM), andscanning electron microscopy (SEM). The cross-linking between SRGOand PSDAS was verified by attenuated total reflectance FTIR (ATR-FTIR)spectroscopy, X-ray photoelectron spectroscopy (XPS), and contactangle measurement. The graphene nanosheets were found to be homogeneouslydistributed in the cross-linked network of the films. The large accessiblesurface area of graphene nanosheets and the cross-linking structureafforded the LbL films with high specific capacitance and excellentcyclic stability when used as supercapacitor electrodes. At a sweepingrate of 10 mV/s, the film with nine bilayers exhibited a specificcapacitance of 150.4 F/g with ideal rectangular cyclic voltammogram.Large capacitance retention of 97% was observed after 10 000charge–discharge cycles under the scanning rate of 1000 mV/s.This new approach for preparing graphene-containing multilayer filmscan be used to develop supercapacitor electrodes and other functionaldevices. [ABSTRACT FROM AUTHOR]

The stiffness and strength of composite cylinder helical spring with hollow round wire and ±45° helical fiber plies are analyzed in this paper. Based on laminated plate theory and by using the shear modulus of fiber composite plates and the stiffness formula of isotropic springs, the expression of the stiffness of this kind of composite springs is derived. In addition, the ultimate compressive load and the maximum compressive displacement of spring are calculated respectively based on Tsai-Hill formula and bar torsion theory with the calculated results close to experimental data. This study provides certain theoretical references for the design of such composite springs. [ABSTRACT FROM AUTHOR]

Deleted in breast cancer 1 (DBC1) is a human nuclear protein that modulates the activities of various proteins involved in cell survival and cancer progression. Oxidized form of nicotinamide adenine dinucleotide (NAD+) is suggested to bind to the Nudix homology domains (NHDs) of DBC1, thereby regulating DBC1-Poly (ADP-ribose) polymerase 1 (PARP1) interactions, resulting in the restoration of DNA repair. Using Nuclear Magnetic Resonance (NMR) and Isothermal Titration Calorimetry (ITC), we confirmed NAD+ and its precursor nicotinamide mononucleotide (NMN) both bind the NHD domain of DBC1 (DBC1 354 – 396). NAD+ likely interacts with DBC1 354 – 396 through hydrogen bonding, with a binding affinity (8.99 μM) nearly twice that of NMN (17.0 μM), and the key binding sites are primarily residues E363 and D372, in the agreement with Molecular Docking experiments. Molecular Dynamics (MD) simulation further demonstrated E363 and D372's anchoring role in the binding process. Additional mutagenesis experiments of E363 and D372 confirmed their critical involvement of ligand-protein interactions. These findings lead to a better understanding of how NAD+ and NMN regulate DBC1, thereby offering insights for the development of targeted therapies and drug research focused on DBC1-associated tumors. • NAD+ and NMN bound DBC1's NHD domain (DBC1 354 – 396) at key sites E363 and D372. • NAD+ likely bonded DBC1 354 – 396 twice as strongly as NMN via hydrogen bonds. • E363 and D372 mutagenesis confirmed their vital role in ligand-protein interaction. • DBC1 354 – 396 's N-terminal loop anchored ligands via hydrogen bonds with E363, D372. [ABSTRACT FROM AUTHOR]

Two-dimensional materials with ultrahigh in-plane thermal conductivity are ideal for heat spreader applications but cause significant thermal contact resistance in complex interfaces, limiting their use as thermal interface materials. In this study, we present an interfacial phonon bridge strategy to reduce the thermal contact resistance of boron nitride nanosheets-based composites. By using a low-molecular-weight polymer, we are able to manipulate the alignment of boron nitride nanosheets through sequential stacking and cutting, ultimately achieving flexible thin films with a layer of arc-like structure superimposed on perpendicularly aligned ones. Our results suggest that arc-like structure can act as a phonon bridge to lower the contact resistance by 70% through reducing phonon back-reflection and enhancing phonon coupling efficiency at the boundary. The resulting composites exhibit ultralow thermal contact resistance of 0.059 in 2 KW -1 , demonstrating effective cooling of fast-charging batteries at a thickness 2-5 times thinner than commercial products., (© 2024. The Author(s).)

Background: To develop and validate an MRI texture-based machine learning model for the noninvasive assessment of renal function., Methods: A retrospective study of 174 diabetic patients (training cohort, n = 123; validation cohort, n = 51) who underwent renal MRI scans was included. They were assigned to normal function (n = 71), mild or moderate impairment (n = 69), and severe impairment groups (n = 34) according to renal function. Four methods of kidney segmentation on T2-weighted images (T2WI) were compared, including regions of interest covering all coronal slices (All-K), the largest coronal slices (LC-K), and subregions of the largest coronal slices (TLCO-K and PIZZA-K). The speeded-up robust features (SURF) and support vector machine (SVM) algorithms were used for texture feature extraction and model construction, respectively. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of models., Results: The models based on LC-K and All-K achieved the nonsignificantly highest accuracy in the classification of renal function (all p values > 0.05). The optimal model yielded high performance in classifying the normal function, mild or moderate impairment, and severe impairment, with an area under the curve of 0.938 (95% confidence interval [CI] 0.935-0.940), 0.919 (95%CI 0.916-0.922), and 0.959 (95%CI 0.956-0.962) in the training cohorts, respectively, as well as 0.802 (95%CI 0.800-0.807), 0.852 (95%CI 0.846-0.857), and 0.863 (95%CI 0.857-0.887) in the validation cohorts, respectively., Conclusion: We developed and internally validated an MRI-based machine-learning model that can accurately evaluate renal function. Once externally validated, this model has the potential to facilitate the monitoring of patients with impaired renal function., (© 2023. The Author(s).)

Restacking of 2D nanomaterials is often deemed to be detrimental to their applications. In contrast to this common notion, here we demonstrate that tightly packed stacked MoS2 exhibits a higher electrocatalytic activity for hydrogen evolution than the more loosely stacked ones.