The retropharyngeal reduction plate for atlantoaxial dislocation: a finite element analysis

Objective: To investigate the biomechanical properties of the retropharyngeal reduction plate by comparing the traditional posterior pedicle screw-rod fixation by finite element analysis.Methods: Two three-dimensional finite element digital models of the retropharyngeal reduction plate and posterior pedicle screw-rod fixation were constructed and validated based on the DICOM (Digital Imaging and Communications in Medicine) data from C1 to C4. The biomechanical finite element analysis values of two internal fixations were measured and calculated under different conditions, including flexion, extension, bending, and rotation.Results: In addition to the backward extension, there was no significant difference in the maximum von Mises stress between the retropharyngeal reduction plate and posterior pedicle screw fixation under other movement conditions. The retropharyngeal reduction plate has a more uniform distribution under different conditions, such as flexion, extension, bending, and rotation. The stress tolerance of the two internal fixations was basically consistent in flexion, extension, left bending, and right bending.Conclusion: The retropharyngeal reduction plate has a relatively good biomechanical stability without obvious stress concentration under different movement conditions. It shows potential as a fixation option for the treatment of atlantoaxial dislocation

Durable superhydrophobic polyvinylidene fluoride membranes via facile spray-coating for effective membrane distillation

Membrane wetting and fouling substantially limits application and deployment of membrane distillation process. Designing high-performance superhydrophobic membranes offers an effective solution to solve the challenge. In this work, a highly durable superhydrophobic surface (water contact angle of 170.8 ± 1.3°) was constructed via a facile and rapid spray-coating of extremely hydrophobic SiO2 nanoparticles onto a porous polyvinylidene fluoride (PVDF) substrate for membrane distillation. The superhydrophobic membrane coated by fluorinated SiO2 nanoparticles exhibited a superior physicochemical stability in a wide range of extreme environments (i.e., NaOH, HCl, hot water, rust water, humic acid solution, ultrasonication, and high-speed water scouring). During 8-h continuous membrane distillation desalination experiment, the coated superhydrophobic membrane experienced a consistently stable water vapor flux (ca. 19.1 kg·m−2·h−1) and desalination efficiency (99.99 %). Additionally, such a stable superhydrophobicity endowed the spray-coated PVDF membrane to overcome membrane wetting and fouling during membrane distillation of highly saline solutions containing foulants (i.e., humic acid and rust). Results reported in this study provides a useful concept and strategy in facile construction of robust superhydrophobic membranes via spray-coating for effective membrane distillation.</p

A multifunctional photoacoustic/fluorescence dual-mode-imaging gold-based theranostic nanoformulation without external laser limitations

Theranostics is a new type of biomedical technology that organically combines the diagnosis and therapy of diseases. Among molecular imaging techniques, the integration of photoacoustic (PA) and fluorescence (FL) imaging modes with high sensitivity and imaging depth provides precise diagnostic outcomes. Gold nanorods (Au NRs) are well-known contrast agents for PA imaging and photothermal therapy. However, their high toxicity, poor biocompatibility, rapid clearance, and the need for an external laser source limit their application. Therefore, modification of Au NRs with carbon-based nanomaterials (CBNs) is done to obtain a multifunctional dual-mode gold-based nanoformulation (mdGC), which preforms dual-mode imaging of PA and FL. The results show that mdGC promotes tumor cell apoptosis and exhibits good antitumor performance through the mitochondria-mediated apoptotic pathway by increasing the production of intracellular reactive oxygen species, reducing mitochondrial membrane potential, and regulating the expression of apoptosis-related genes. The targeting rate of mdGC to tumor tissue is up to 20.71 ± 1.94% ID g-1; the tumor growth inhibition rate is as high as 80.44% without external laser sources. In general, mdGC is a potential multifunctional diagnostic and therapy integrated nanoformulation.J.Z., X.Y., and C.L. contributed equally to this study. This study was supported by the National Natural Science Foundation of China (81922037, 11575107, 21371115, and 22003038), the Shanghai UniversityUniversal Medical Imaging Diagnostic Research Foundation (19H00100), and Shanghai Biomedical Science and Technology Support Project (19441903600)

Characteristics and distribution of geohazards since the middle miocene of the Xisha sea area, South China Sea

Geological hazards can cause significant harm to the construction and maintenance of reef infrastructure projects in the Xisha Sea area. This study uses high-resolution multichannel earthquake data, single-channel seismic profiles, and multi-beam survey data to identify and analyze the geological hazards in the Xisha Sea area since the Miocene. Based on the geophysical data interpretation, the destructive geological disaster factors that are active, such as active faults, shallow gas, diapers, landslides, multistage scarps (steps), scouring troughs, and canyons, as well as the restrictive geological disaster factors without activity ability, such as buried paleochannels, pockmarks, reefs, and undersea volcanoes, are identified and analyzed. This paper discusses the causes and hazards of geological hazards and, for the first time, draws a comprehensive plane layout of the geological hazards. The above analysis demonstrates that the scarps are mainly located around the atolls or platforms, and the slope of the southeast seabed topography is significantly higher than that of the northwest. There are seven medium and large landslides, mainly located around Yongxing Plateau and Yongle Plateau, caused by gravity and faulting. Shallow gas is mainly developed in the southern part of the North Reef and is indicated by diaper structures, faults, and gas chimneys. A series of shallow faults are developed in the study area, mainly steep normal faults. The scouring troughs are primarily distributed near the Yongxing Platform, Zhongjian North Platform, and Huaguang Platform. Submarine canyons are primarily located in the northern and southern parts of the Shidao Platform. Affected by multiple factors such as hydrodynamic conditions, the stability of sedimentary layers, and sediment supply, the scour degree varies, with the general depth ranging from several meters to several hundred meters. Underwater infrastructure in the study area should not be constructed in areas with active and destructive geological hazards. The results of this study can serve as a guide for further exploration in the Xisha area and disaster prevention and mitigation during construction activity in the area

Green synthesis of Au-Pd bimetallic nanoparticles: Single-step bioreduction method with plant extract

A facile and eco-friendly method for the preparation of Au-Pd bimetallic nanoparticles (similar to 7 nm) has been developed based on simultaneous bioreduction of Au(III) and Pd(II) precursors with Cacumen Platycladi leaf extract in aqueous environment. The morphology, structure, and size were confirmed with the aid of transmission electron microscopy, selected area electron diffraction. UV-vis spectroscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. The results from Fourier transform infrared spectroscopy showed that the C=O and C-O groups in the plant extract played a critical role in capping the nanoparticles. Importantly, the process can be described as pure "green chemistry" technique since no additional synthetic reagents are used as reductants or stabilizers. (C) 2011 Elsevier B.V. All rights reserved.National Natural Science Foundation of China[21036004, 20976146]; Natural Science Foundation of Fujian Province of China[2010J05032, 2010J01052]WOS:00029506830004

The Effects of Transcranial Direct Current Stimulation (tDCS) on Working Memory Training in Healthy Young Adults

Working memory (WM) is a fundamental cognitive ability to support complex thought, but it is limited in capacity. WM training has shown the potential benefit for those in need of a higher WM ability. Many studies have shown the potential of transcranial direct current stimulation (tDCS) to transiently enhance WM performance by delivering a low current to the brain cortex of interest, via electrodes on the scalp. tDCS has also been revealed as a promising intervention to augment WM training in a few studies. However, those few tDCS-paired WM training studies, focused more on the effect of tDCS on WM enhancement and its transferability after training and paid less attention to the variation of cognitive performance during the training procedure. The current study attempted to explore the effect of tDCS on the variation of performance, during WM training, in healthy young adults. All the participants received WM training with the load-adaptive verbal N-back task, for 5 days. During the training procedure, active/sham anodal high-definition tDCS (HD-tDCS) was used to stimulate the left dorsolateral prefrontal cortex (DLPFC). To examine the training effect, pre- and post-tests were performed, respectively, 1 day before and after the training sessions. At the beginning of each training session, stable-load WM tasks were performed, to examine the performance variation during training. Compared to the sham stimulation, higher learning rates of performance metrics during the training procedure were found when WM training was combined with active anodal HD-tDCS. The performance improvements (post–pre) of the active group, were also found to be higher than those of the sham group and were transferred to a similar untrained WM task. Further analysis revealed a negative relationship between the training improvements and the baseline performance. These findings show the potential that tDCS may be leveraged as an intervention to facilitate WM training, for those in need of a higher WM ability

Biosynthesis of Gold Nanoparticles by Foliar Broths: Roles of Biocompounds and Other Attributes of the Extracts

Biosynthesis of nanoparticles has arisen as a promising alternative to conventional synthetic methodologies owing to its eco-friendly advantages, and the involved bioprotocol still needs further clarification. This research, for the first time from the standpoint of statistics, confirmed an electrostatic force or ionic bond-based interaction between the chloroauric ions and the involved bioconstituents and manifested that reducing sugars and flavonoids were both important reductants responsible for conversion of Au(III) to Au(0). The result also demonstrated that the proteins were not the reducing agents, yet they might be protection agents in biosynthesis of gold nanoparticles (GNPs). Besides, a significant linear relationship was found between the anti-oxidant ability of the foliar broths and their capability to reduce Au(III) into Au(0). Furthermore, the preliminary investigation based on the boxplot on the size/shape distribution of the biosynthesized GNPs revealed that gold nanospheres with higher degree of homogeneity in size tended to be promoted by foliar broths containing higher content of reducing sugars/flavonoids and proteins. Otherwise, i.e., for those broths with lower content of the above biocompounds, sphere GNPs of wider size distribution or even gold nanotriangles tended to be fabricated

Report of the Topical Group on Top quark physics and heavy flavor production for Snowmass 2021

This report summarizes the work of the Energy Frontier Topical Group on EW Physics: Heavy flavor and top quark physics (EF03) of the 2021 Community Summer Study (Snowmass). It aims to highlight the physics potential of top-quark studies and heavy-flavor production processes (bottom and charm) at the HL-LHC and possible future hadron and lepton colliders and running scenarios

Elucidating the Molecular Mechanism of the Proteasome-Associated Deubiquitinase UCH37/UCHL5

Deubiquitinases (DUBs) are a group of enzymes that regulate myriad biological processes by removing ubiquitin posttranslational modifications. They can either cleave ubiquitin directly from a substrate protein or disassembling a ubiquitin chain. Currently, about 100 human DUBs were identified and they were classified into seven families, and majority of them are cysteine proteases. DUBs exhibit distinct activities and preferences towards a wide variety of complex Ub chain with different linkages and architectures. Understanding how DUB achieves the selectivity towards specific substrates is important to elucidate how Ub system is regulated. This dissertation discusses our efforts to investigate the molecular mechanism of DUB, specifically the proteasome associated DUB UCH37/UCHL5. We have combined biochemical assay, biophysical characterization, mass spectrometry, and cell biology to address how DUB interacts with different ubiquitin chains to achieve substrate specificity. These lead us to uncover a novel mechanism that DUBs may use distinct surfaces for distinct activities. Finally, the discovery of the new mechanism of DUB would also provide new avenues for the DUB inhibitors development for therapeutics