130 research outputs found
PGMA-Based Cationic Nanoparticles with Polyhydric Iodine Units for Advanced Gene Vectors
It is crucial for
successful gene delivery to develop safe, effective,
and multifunctional polycations. Iodine-based small molecules are
widely used as contrast agents for CT imaging. Herein, a series of
star-like polyÂ(glycidyl methacrylate) (PGMA)-based cationic vectors
(II-PGEA/II) with abundant flanking polyhydric iodine units are prepared
for multifunctional gene delivery systems. The proposed II-PGEA/II
star vector is composed of one iohexol intermediate (II) core and
five ethanolamine (EA) and II-difunctionalized PGMA arms. The amphipathic
II-PGEA/II vectors readily self-assemble into well-defined cationic
nanoparticles, where massive hydroxyl groups can establish a hydration
shell to stabilize the nanoparticles. The II introduction improves
cell viabilities of polycations. Moreover, by controlling the suitable
amount of introduced II units, the resultant II-PGEA/II nanoparticles
can produce fairly good transfection performances in different cell
lines. Particularly, the II-PGEA/II nanoparticles induce much better
in vitro CT imaging abilities in tumor cells than iohexol (one commonly
used commercial CT contrast agent). The present design of amphipathic
PGMA-based nanoparticles with CT contrast agents would provide useful
information for the development of new multifunctional gene delivery
systems
Biodegradation of Phenol from Wastewater by Microorganism Immobilized in Bentonite and Carboxymethyl Cellulose Gel
<p>This study presents a microbial process for phenol degradation in coking wastewater. The optimum immobilized condition of the strain for degrading phenol was determined through orthogonal experiment. The free and immobilized microorganisms were examined for their capabilities on degrading phenol. Results indicated that the optimum immobilized conditions were 20% microorganism suspension, 5% bentonite, 3% sodium carboxymethyl cellulose content, and 1 h of crosslinking time. The biodegradation rate was optimized at 35°C and 0.23 gmL<sup>−1</sup> of immobilized microorganism bead. The degrading rate for the immobilized microorganism bead was up to 95.96% at an initial phenol concentration of 100 mgL<sup>−1</sup>; however, the immobilized microorganism considerably took more time (288 h) to reach 94.6% removal efficiency at a much higher concentration of 1000 mgL<sup>−1</sup>. The batch experiment demonstrated that 94.50% of phenol was removed using the beads with the immobilized microorganism at an initial concentration of 500 mgL<sup>−1</sup>. By contrast, only 24.60% and 33.88% of phenol were degraded using the gel beads without and with free microorganisms, respectively. The immobilized microorganism beads can used reused for up to nine cycles at the same initial phenol concentration (50 mgL<sup>−1</sup>) and can be stored up to 40 d without loss of its degradation capacity.</p
Catalytic Asymmetric Synthesis of Tröger’s Base Analogues with Nitrogen Stereocenter
Nitrogen stereocenters are common chiral units in natural
products,
pharmaceuticals, and chiral catalysts. However, their research has
lagged largely behind, compared with carbon stereocenters and other
heteroatom stereocenters. Herein, we report an efficient method for
the catalytic asymmetric synthesis of Tröger’s base
analogues with nitrogen stereocenters via palladium catalysis and
home-developed GF-Phos. It allows rapid construction
of a new rigid cleft-like structure with both a C- and a N-stereogenic
center in high efficiency and selectivity. A variety of applications
as a chiral organocatalyst and metallic catalyst precursors were demonstrated.
Furthermore, DFT calculations suggest that the NH···O
hydrogen bonding and weak interaction between the substrate and ligand
are crucial for the excellent enantioselectivity control
Additional file 2 of Establishment and validation of an immune infiltration predictive model for ovarian cancer
Additional file 2: Figure S2. Calibration plot at 1-, 3-, and 5-year of nomogram without IPM
Additional file 5 of Establishment and validation of an immune infiltration predictive model for ovarian cancer
Additional file 5: Table S1. Clinical information of TCGA-OV patients. Table S2. Immune-related genesets enriched in TP53 MUT OVs. Table S3. Differentially expressed immune-related genes between TP53 WT and TP53 MUT OVs.Table S4. Univariate Cox regression analysis of differentially expressed immune-related genes. Table S5. Analysis of correlations between risk score and immune checkpoints. Table S6. Top 20 clusters with their representative enriched terms by Metascape
Carbon Dot Nanomaterials with High Interfacial Activity for Unconventional Reservoir Development
Carbon
dot nanomaterials (<10 nm) exhibit superior application
prospects as oil displacement materials for unconventional reservoir
development. However, the limited oil–water and oil–solid
interfacial activity of carbon dot nanomaterials restricts their broader
application. In this study, carbon dot nanomaterials (CDs) are expeditiously
prepared via a microwave-assisted synthesis method utilizing urea
and citric acid as precursor compounds. OAB-modified active carbon
dot nanomaterials (OCDs) are prepared by grafting oleic acid amidopropyl
betaine (OAB) through hydrothermal reaction at 90 °C for 5 h
using CDs as a carbon dot carrier. Stability experiments show that
the plentiful hydrophilic groups present on the surface of the OCD
augment electrostatic repulsion among them, thereby imparting dispersibility,
temperature tolerance (90 °C), and salt resistance (2.6 ×
104 mg/L). Additionally, OCDs demonstrate optimal effectiveness
at a concentration of 0.5 wt %. At this concentration, OCDs can reduce
the interfacial tension to 0.66 mN/m and achieve the underwater oil
contact angle to 126°. Within 24 h, OCDs can strip 60.6% of the
oil film. OCDs show the excellent ability to enhance oil–water
and oil–solid interfacial activity. Meanwhile, OCD nanofluids
can effectively form emulsions with crude oil and spontaneously demulsify
within 2 h in a state. Core flooding tests demonstrate that OCD nanofluids,
when compared with simulated formation water, reduce injection pressure
by 46.3% and enhance oil recovery by 31.1%. This study offers a promising
solution for the efficient development of unconventional reservoirs
with carbon dot nanomaterials
Catalytic Asymmetric Synthesis of Tröger’s Base Analogues with Nitrogen Stereocenter
Nitrogen stereocenters are common chiral units in natural
products,
pharmaceuticals, and chiral catalysts. However, their research has
lagged largely behind, compared with carbon stereocenters and other
heteroatom stereocenters. Herein, we report an efficient method for
the catalytic asymmetric synthesis of Tröger’s base
analogues with nitrogen stereocenters via palladium catalysis and
home-developed GF-Phos. It allows rapid construction
of a new rigid cleft-like structure with both a C- and a N-stereogenic
center in high efficiency and selectivity. A variety of applications
as a chiral organocatalyst and metallic catalyst precursors were demonstrated.
Furthermore, DFT calculations suggest that the NH···O
hydrogen bonding and weak interaction between the substrate and ligand
are crucial for the excellent enantioselectivity control
Additional file 1 of Establishment and validation of an immune infiltration predictive model for ovarian cancer
Additional file 1: Figure S1. Correlatio between IPM and patient survival. (A) Status distribution in high- and low group. (B) Correlation between risk score and survival
Additional file 3 of Establishment and validation of an immune infiltration predictive model for ovarian cancer
Additional file 3: Figure S3. Distuibution of risk score in TP53 status
An Organocatalytic System for <i>Z</i>‑Alkene Synthesis via a Hydrogen-Bonding-Assisted Photoinduced Electron Donor–Acceptor Complex
A general
catalytic donor for the combination of a photoinduced
electron donor–acceptor (EDA) complex and energy transfer was
developed. This mild and metal-free protocol allows facile access
to various Z-alkenes. Mechanism studies revealed
that the organophotocatalyst, 4-CzIPN, formed a distinct three-component
EDA complex with redox-active esters and (C6H5O)2P(O)OH to trigger the photoredox catalysis. The E → Z isomerization was achieved
via electron exchange energy transfer from 4-CzIPN
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