1,029 research outputs found
Study of Ni Metallization in Macroporous Si Using Wet Chemistry for Radio Frequency Cross-Talk Isolation in Mixed Signal Integrated Circuits.
A highly conductive moat or Faraday cage of through-the-wafer thickness in Si substrate was proposed to be effective in shielding electromagnetic interference thereby reducing radio frequency (RF) cross-talk in high performance mixed signal integrated circuits. Such a structure was realized by metallization of selected ultra-high-aspect-ratio macroporous regions that were electrochemically etched in p- Si substrates. The metallization process was conducted by means of wet chemistry in an alkaline aqueous solution containing Ni2+ without reducing agent. It is found that at elevated temperature during immersion, Ni2+ was rapidly reduced and deposited into macroporous Si and a conformal metallization of the macropore sidewalls was obtained in a way that the entire porous Si framework was converted to Ni. A conductive moat was as a result incorporated into p- Si substrate. The experimentally measured reduction of crosstalk in this structure is 5~18 dB at frequencies up to 35 GHz
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A Label-Free Platform for Identification of Exosomes from Different Sources.
Exosomes contain cell- and cell-state-specific cargos of proteins, lipids, and nucleic acids and play significant roles in cell signaling and cell-cell communication. Current research into exosome-based biomarkers has relied largely on analyzing candidate biomarkers, i.e., specific proteins or nucleic acids. However, this approach may miss important biomarkers that are yet to be identified. Alternative approaches are to analyze the entire exosome system, either by "omics" methods or by techniques that provide "fingerprints" of the system without identifying each individual biomolecule component. Here, we describe a platform of the latter type, which is based on surface-enhanced Raman spectroscopy (SERS) in combination with multivariate analysis, and demonstrate the utility of this platform for analyzing exosomes derived from different biological sources. First, we examined whether this analysis could use exosomes isolated from fetal bovine serum using a simple, commercially available isolation kit or necessitates the higher purity achieved by the "gold standard" ultracentrifugation/filtration procedure. Our data demonstrate that the latter method is required for this type of analysis. Having established this requirement, we rigorously analyzed the Raman spectral signature of individual exosomes using a unique, hybrid SERS substrate made of a graphene-covered Au surface containing a quasi-periodic array of pyramids. To examine the source of the Raman signal, we used Raman mapping of low and high spatial resolution combined with morphological identification of exosomes by scanning electron microscopy. Both approaches suggested that the spectra were collected from single exosomes. Finally, we demonstrate for the first time that our platform can distinguish among exosomes from different biological sources based on their Raman signature, a promising approach for developing exosome-based fingerprinting. Our study serves as a solid technological foundation for future exploration of the roles of exosomes in various biological processes and their use as biomarkers for disease diagnosis and treatment monitoring
Fabrication of dislocation-free tensile strained Si thin films using controllably oxidized porous Si substrates
A method to fabricate strained Si films is reported via the oxidation of a thin Si film on a porous Si substrate. The Si film can be put under tensile stress in a controllable fashion through the expansion of the porous Si upon low temperature oxidation. The thin Si layer on porous Si substrate can be fabricated using a self-limiting anodization of epitaxially grown intrinsic Si on a heavily doped p-type Si substrate. Tensile strain of up to similar to 1% is observed in 100 nm thick Si films, making it suitable for the various device applications based on strained Si. (c) 2006 American Institute of Physics
3,5-Dinitrobenzoyl chloride
The carbonyl chloride group in the title compound, C7H3ClN2O5, is disordered over two orientations with occupancies of 0.505 (5) and 0.495 (5). The molecule is approximately planar, the dihedral angle between the carbonyl chloride plane and benzene ring being 9.6 (4)° in the major disorder component and 7.1 (4)° in the minor component. The nitro group at the 5-position is twisted, forming a dihedral angle of 6.7 (4)°. The crystal packing is stabilized by C—H⋯O hydrogen bonds
Methyl 9H-carbazole-9-acetate
The title compound, C15H13NO2, was synthesized by N-alkylation of methyl bromoacetate with 9H-carbazole. The carbazole ring system is essentially planar (mean atomic deviation = 0.0346 Å) and makes a dihedral angle of 86.5 (7)° with the methyl acetate group. Weak intermolecular C—H⋯O hydrogen bonding is present in the crystal structure
Pentaaqua(1H-benzimidazole-5,6-dicarboxylato-κN 3)copper(II) pentahydrate
The title compound, [Cu(C9H4N2O4)(H2O)5]·5H2O, contains one crystallographically independent CuII atom and one 1H-benzimidazole-5,6-dicarboxylate (bdc) ligand, along with five coordinated and five uncoordinated water molecules. The CuII atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water molecules, giving an octahedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water molecules into a three-dimensional network
A turn-off fluorescent probe for the detection of Cu2+ based on a tetraphenylethylene-functionalized salicylaldehyde Schiff-base
A non-planar tetraphenylethylene-functionalized salicylaldehyde Schiff-base fluorescent probe (TPE-An-Py) with aggregation-induced enhanced emission (AIEE) characteristics was synthesized via a classical Knoevenagel condensation reaction, and exhibited a high sensitivity towards copper ions in aqueous media with a "turn-off" fluorescence mechanism; the limit of detection is 2.36 × 10-7 mol L-1. Importantly, the coordination mode of the probe towards copper was further evaluated by UV-vis and NMR spectroscopy and a 1:2 stoichiometry was identified. A single crystal X-ray diffraction study confirmed the binding mode. In addition, the AIEE fluorescent probe can be applied to the detection of Cu2+ in practical samples with satisfactory recoveries in a range of 106-111% in lake water and 97-108% in tap water
The impact of gum-chewing on postoperative ileus following gynecological cancer surgery: A systematic review and meta-analysis of randomized controlled trials
ObjectiveTo assess the effect and safety of gum-chewing on the prevention of postoperative ileus after gynecological cancer surgery.MethodsWe conducted a systematic review of randomized controlled trials (RCTs) published between 2000 and 2022 in English and Chinese, using the EBSCO, Web of Science, Scopus, Cochrane Central Register of Controlled Trials (Cochrane database), PubMed, Medline (via Ovid), Chinese National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, and Wan Fang databases. A total of 837 studies were screened using Endnote software, and those that met the inclusion criteria were selected for analysis. The main outcome of interest was the incidence of postoperative ileus, and secondary outcomes included time to first flatus, time to first bowel movement, and length of hospital stay.ResultsTwo authors extracted data and performed quality assessment independently. The review included six RCTs with a total of 669 patients. Compared with routine care, gum-chewing could significantly reduce the incidence of postoperative ileus (RR 0.46, 95% CI: 0.30, 0.72, P=0.0006), shorten the time to first flatus (WMD -9.58, 95% CI: -15.04, -4.12, P=0.0006), first bowel movement (WMD -11.31, 95% CI: -21.05, -1.56, P=0.02), and the length of hospital stay (WMD -1.53, 95% CI: -2.08, -0.98, P<0.00001).ConclusionsGum-chewing is associated with early recovery of gastrointestinal function after gynecological cancer surgery and may be an effective and harmless intervention to prevent postoperative ileus.Systemaic review registrationhttps://www.crd.york.ac.uk/prospero/#searchadvanced, identifier CRD42022384346
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