63 research outputs found
Recommended from our members
Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design.
Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)-many of which are refractory to current standard-of-care treatments-from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer
Advances in Carbon-Based Microwave Absorbing Materials
Electromagnetic (EM) pollution has been evolving as one of the most concerning environmental problems in current society, due to the extensive application of EM technology, from household electronic apparatuses to wireless base stations, as well as military radars [...
Heteroatom-Doped Carbon Nanostructures Derived from Conjugated Polymers for Energy Applications
Heteroatom-doped carbon materials have been one of the most remarkable families of materials with promising applications in fuel cells, supercapacitors, and batteries. Among them, conjugated polymer (CP)-derived heteroatom-doped carbon materials exhibit remarkable electrochemical performances because the heteroatoms can be preserved at a relatively high content and keep stable under harsh working conditions. In this review, we summarized recent advances in the rational design and various applications of CP-derived heteroatom-doped carbon materials, including polyaniline (PANI), polypyrrole (PPy), and their ramification-derived carbons, as well as transition metal-carbon nanocomposites. The key point of considering CP-derived heteroatom-doped carbon materials as important candidates of electrode materials is that CPs contain only nonmetallic elements and some key heteroatoms in their backbones which provide great chances for the synthesis of metal-free heteroatom-doped carbon nanostructures. The presented examples in this review will provide new insights in designing and optimizing heteroatom-doped carbon materials for the development of anode and cathode materials for electrochemical device applications
Cobalt-embedded carbon nanofiber derived from a coordination polymer as a highly efficient heterogeneous catalyst for activating oxone in water
Carbon fiber (CF) supported cobalt nanoparticles (NPs) are promising catalysts for activating Oxone because carbon is non-metal and earth-abundant, and CF-based catalysts exhibit a high aspect ratio, which affords more accessible and dense catalytic sites. Nevertheless, most of CF-supported catalysts are fabricated by post-synthetic methods, which involve complicated preparations. More importantly, metallic NPs are attached to the outer surface of CF rather than embedded within CF. However, there is still a great demand for developing Co-bearing carbon fibers for Oxone activation via simple and effective methods. Thus, this study proposes to develop a cobalt NP-embedded carbon nanofiber (CCNF) by a simple hydrothermal reaction of Co and nitrilotriacetic acid (NA), followed by one-step carbonization. Owing to the coordinative structure of CoNA, the derivative CCNF exhibits a fibrous carbon matrix embedded with evenly distributed and densely packed Co3O4 and magnetic Co0 nanoparticles. The fibrous structure, magnetism and embedded Co NPs enable CCNF to be a promising catalyst for Oxone activation. As degradation of Rhodamine B (RhB) is selected as a model reaction, CCNF not only rapidly activates Oxone to fully degrade RhB but also shows a much higher catalytic activity than the most common Oxone activator, Co3O4. CCNF also exhibits the lowest activation energy than any reported catalysts for Oxone activation to degrade RhB. In addition, CCNF could be re-used to activate Oxone for RhB degradation. These results indicate that CCNF is a conveniently prepared and highly effective fibrous Co/C hybrid material for activating Oxone to oxidize contaminants in water
Preparation and Thermoelectric Properties of Graphite/poly(3,4-ethyenedioxythiophene) Nanocomposites
Graphite/poly(3,4-ethyenedioxythiophene) (PEDOT) nanocomposites were prepared by an in-situ oxidative polymerization process. The electrical conductivity and Seebeck coefficient of the graphite/PEDOT nanocomposites with different content of graphite were measured in the temperature range from 300 K to 380 K. The results show that as the content of graphite increased from 0 to 37.2 wt %, the electrical conductivity of the nanocomposites increased sharply from 3.6 S/cm to 80.1 S/cm, while the Seebeck coefficient kept almost the same value (in the range between 12.0 V/K to 15.1 V/K) at 300 K, which lead to an increased power factor. The Seebeck coefficient of the nanocomposites increased from 300 K to 380 K, while the electrical conductivity did not substantially depend on the measurement temperature. As a result, a power factor of 3.2 Wm(-1) K-2 at 380 K was obtained for the nanocomposites with 37.2 wt % graphite.Funding Agencies|National Natural Science Foundation of China [61504081, 61611530550]; Shanghai Innovation action plan project [17090503600]; Program for Professor of Special Appointment (Young Eastern Scholar Program) at Shanghai Institutions of Higher Learning [QD2015039]; Swedish Foundation for Strategic Research (SSF) through the Future Research Leaders 5 program; Knut and Alice Wallenberg Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]</p
Magnetic cobalt-embedded carbon nitride composite derived from one-dimensional coordination polymer as an efficient catalyst for activating oxone to degrade methyltheobromine in water
As methyltheobromine (MTB) has been increasingly detected in wastewater, it would be necessary to develop more intensive and effective approaches to remove MTB. As Co species immobilized on carbonaceous materials appears as a promising catalyst, doping carbon with nitrogen has been also validated to significantly enhance catalytic activities for Oxone activation. Therefore, it is desired to develop a composite of immobilizing Co species on N-doped carbonaceous supports for activating Oxone to degrade MTB. Unfortunately, very few studies have demonstrated such composites for activating Oxone to degrade MTB as this type of composites are conventionally prepared via complex procedures. Alternatively, this study aims to develop such a composite conveniently by using a cobaltic coordination polymer (CP) as a precursor. Specifically Co2+ and 4,4-bipyridine (BIPY) are selected for formulating a special one-dimensional CP, which is then carbonized to convert Co to Co nanoparticles (NPs) and transform BIPY to carbon nitride (CN) matrices. Because of 1-D coordinated structure of CoBIPY, the resulting magnetic Co NPs are well-distributed and protected within CN to form a magnetic Co-embedded carbon nitride composite (MCoCN). In comparison to pristine CN and Co3O4, MCoCN exhibits much higher catalytic activities to activate Oxone for degrading MTB completely within 7 min. MCoCN also shows a much lower activation energy of 24.6 kJ/mol than other reported catalysts for activating Oxone to degrade MTB. The findings of this study validate that the 1-D coordination polymer of CoBIPY is a useful precursor to prepare MCoCN for effectively activating Oxone to degrade MTB
Coordination polymer-derived porous Co3O4 nanosheet as an effective catalyst for activating peroxymonosulfate to degrade sulfosalicylic acid
As sulfosalicylic acid (SSA) is a widely-employed medical intermediate, the release of SSA into water causes serious damage to the aquatic environment. Because of its low bio-degradability, chemical oxidation processes are necessitated to eliminate SSA. Since sulfate-radical (SR)-based chemical oxidation processes are increasingly developed for degradation of emerging contaminants, it is important to establish effective SR-based processes for SSA degradation. As Peroxymonosulfate (PMS) is an extensively adopted source for SR and cobalt (Co) is validated as a useful metal to activate PMS, a facile technique is proposed here to develop a heterogeneous catalyst comprised of Co3O4 with a 2D sheet-like and porous configuration for enhancing catalytic activity for PMS activation to degrade SSA. Specifically, a Co-based coordination polymer consisting of Co and trismercaptotriazine (TMT) with a hexagonal nanosheet structure is adopted as a precursor. After calcination, CoTMT is transformed to porous Co3O4 nanosheet (PCNS), and this PCNS exhibits distinct surficial reactivity and textural properties from the commercial Co3O4 NP. These advantageous features enable PCNS to show much higher catalytic activities than the Co3O4 NP for activation of PMS to degrade SSA. PCNS is also reusable for multiple cycles for activating PMS to degrade SSA without loss of catalytic activity
Controlled Fabrication of Hexagonally Close-Packed Langmuir–Blodgett Silica Particulate Monolayers from Binary Surfactant and Solvent Systems
We describe a controllable method to fabricate hexagonally close-packed
Langmuir–Blodgett (LB) monolayers with stearic acid (SA) as
co-surfactant and methanol as co-solvent. The optimal SA concentrations
and volume ratios of chloroform to methanol are 0.8 mg/mL and 3:1
for particles of 140 nm, 0.50 mg/mL and 4:1 for particles of 300 nm,
and 0.05 mg/mL and 5:1 for particles of 550 nm, respectively. Additionally,
SEM detections of the monolayers transferred at different surface
pressures indicate that the monolayers deposited from the binary systems
are more compressible. The experimental results indicate that the
interparticle repulsions and particle–water interactions can
be enhanced without decreasing the particle hydrophobicity by adding
SA and methanol; thus, particulate monolayers with large hexagonally
close-packed domains composed of small silica particles can be successfully
fabricated using LB technique. We propose that the enhanced interparticle
repulsion is attributed to the Columbic repulsion resulting from the
attachment of SA molecules to the CTAB modified particles around the
three phase contact line
- …