10 research outputs found
Additional file 1 of The survival strength of younger patients in BCLC stage 0-B of hepatocellular carcinoma: basing on competing risk model
Additional file 1: Table S1. Baseline characteristics of study patients after propensity score analysis. Figure S1. The Kaplan-Meier survival curves of Overall survival (OS) and Progression-free survival (PFS) in BCLC 0-B group. (A-B) The OS (A) and PFS (B) in tumor size. (C-D) The OS (C) and PFS (D) in esophageal and/or gastric varices. (E-F) The OS (E) and PFS (F) Child staging A and B
Modular Preparation of Discrete Polyesters through Iterative Growth
Discrete
macromolecules featuring precise chemical structures
and
uniform chain lengths are ideal model systems for resolving fundamental
principles with an exceedingly high resolution. This work develops
a robust approach to prepare orthogonally protected monomers for the
convergent synthesis of discrete sequence-defined polymers. Malic
acid derivatives bearing hydrophilic, hydrophobic, or omniphobic
substituents were designed and synthesized. All of these monomers
have the same chemical features and can be modularly connected following
the same chemistry. Discrete polyesters with diverse composition and
programmable monomer sequence, including homopolymers, diblock/triblock
copolymers, and alternating polymers, were readily prepared. The resultant
discrete species were fully characterized by nuclear magnetic resonance
(NMR) spectroscopy, size exclusion chromatography (SEC), and matrix-assisted
laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF
MS). This study expands the diversity of monomers that can be applied
in iterative growth, which is expected to serve as an efficient synthetic
platform for precise macromolecular engineering
Extraction of Phenols from Water with Functionalized Ionic Liquids
A series of hydroxyl-, benzyl-, and
dialkyl-functionalized ionic
liquids (ILs) were synthesized, and their extraction abilities for
phenol, resorcinol, <i>p</i>-nitrophenol, guaiacol, and <i>o</i>-cresol were investigated. Results showed that the extraction
efficiencies of the five phenols were significantly influenced by
the pH values, salt added, phase ratio, and chemical structure of
the IL. Phenols present in nonionized forms were preferable to transfer
into IL phases. The anion/cation hydrogen-bonding characters of ILs
were the main structural factors affecting the extraction efficiency,
which also increased with increased hydrophobicity of phenols. These
results are promising for the liquid–liquid extraction and
enrichment of phenols in separation science and related industrial
processes
Discrete Diblock Copolymers with Precise Stereoconfiguration
This work develops an iterative growth approach to synthesize
discrete
oligo lactic acids with exactly defined stereoconfiguration by connecting
enantiomeric monomers (i.e., L- and D-lactic acid) following a predesigned
sequence. A library of diblock copolymers with uniform chain length
was modularly prepared by conjugating the stereoisomeric blocks with
a chemically incompatible chain. The precise chemical structure eliminates
all molecular uncertainties associated with statistical distribution
and decouples the intertwined variables. A rich collection of ordered
structures, including unconventional Frank–Kasper A15 and σ
phases, was captured. The stereoconfiguration exerts pronounced impacts
on chain conformation, leading to appreciable variations of lattice
dimension and phase stability. This study quantitatively assessed
the critical contribution of stereoconfiguration on packing behaviors,
calling for particular attention to this essential molecular parameter
as an effective handle for rational structural engineering
Discrete Diblock Copolymers with Tailored Conformational Asymmetry: A Precise Model Platform to Explore Complex Spherical Phases
Conformational asymmetry of block copolymers is a critical
molecular
parameter dictating the self-assembly behaviors. This work develops
an efficient approach to construct block copolymers with uniform chain
length and tunable conformational mismatch. Three model discrete diblock
copolymers based on γ-alkyl-α-hydroxy glutaric acid and
lactide monomers were prepared through the iterative growth approach.
The conformational asymmetry can be adjusted via simple substitution
of the hydrocarbon side chains. The precise chemical structure rules
out all molecular uncertainties associated with statistical distribution,
providing a delicate platform for quantitatively resolving the intricate
details and underlying principles. Diverse ordered structures, including
the Frank–Kasper σ and A15 phases and quasicrystalline
phase, were captured. A phase portrait with an exceptionally high
compositional resolution was mapped, demonstrating clearly that the
spherical packing region expands and the complex phases emerge as
the conformational asymmetry increases. This study explicitly correlates
the origin of the intriguing structures with the intrinsic molecular
parameters, providing deep insights into the formation and evolution
of the complex phases in block copolymers
Modulation of the Complex Spherical Packings through Rationally Doping a Discrete Homopolymer into a Discrete Block Copolymer: A Quantitative Study
The
Frank–Kasper phase and quasicrystalline phase are an
intriguing class of complex crystalline structures, which so far are
sporadically observed only in a limited number of block copolymers.
Incorporation of a homopolymer into a block copolymer has recently
been demonstrated as an effective and robust approach to regulate
the formation and evolution of these complex spherical phases. The
experimental explorations, however, suffer from inherent chain length
distribution of the blending stocks. In this study, we quantitatively
assessed the phase behaviors of the block copolymer/homopolymer binary
blends using discrete species with a precise chemical structure and
uniform chain length, ruling out all interferences associated with
chemical heterogeneities. Diverse spherical packings, including σ,
A15, C15, and C14 phases, were captured by rationally tuning the chain
length and loading content of the homopolymer. The short chains swell
the spherical core and drive a transition toward the lattices with
a lower interfacial curvature (i.e., σ →
A15 → HEX), whereas the long chains localize in the center
of the core and prompt the formation of the Frank–Kasper phases
with the increasing particle volume asymmetry (C15 and C14). The experimental
observation validates the recent theoretical advances, demonstrating
that the blending strategy is a robust approach for structural engineering
Local Chain Feature Mandated Self-Assembly of Block Copolymers
This work demonstrates an effective and robust approach
to regulate
phase behaviors of a block copolymer by programming local features
into otherwise homogeneous linear chains. A library of sequence-defined,
isomeric block copolymers with globally the same composition but locally
different side chain patterns were elaborately designed and prepared
through an iterative convergent growth method. The precise chemical
structure and uniform chain length rule out all inherent molecular
defects associated with statistical distribution. The local features
are found to exert surprisingly pronounced impacts on the self-assembly
process, which have yet to be well recognized. While other molecular
parameters remain essentially the same, simply rearranging a few methylene
units among the alkyl side chains leads to strikingly different phase
behaviors, bringing about (i) a rich diversity of nanostructures across
hexagonally packed cylinders, Frank–Kasper A15 phase, Frank–Kasper
σ phase, dodecagonal quasicrystals, and disordered state; (ii)
a significant change of lattice dimension; and (iii) a substantial
shift of order-to-disorder transition temperature (up to 40 °C).
Different from the commonly observed enthalpy-dominated cases, the
frustration due to the divergence between the native molecular geometry
originating from side chain distribution and the local packing environment
mandated by lattice symmetry is believed to play a pivotal role. Engineering
the local chain feature introduces another level of structural complexity,
opening up a new and effective pathway for modulating phase transition
without changing the chemistry or composition
Precisely Encoding Geometric Features into Discrete Linear Polymer Chains for Robust Structural Engineering
Molecular shape is an essential parameter
that regulates the self-organization
and recognition process, which has not yet been well appreciated and
exploited in block polymers due to the lack of precise and efficient
modulation methods. This work (i) develops a robust approach to break
the intrinsic symmetry of linear polymers by introducing geometric
features into otherwise homogeneous chains and (ii) quantitatively
highlights the critical contribution of molecular geometry/architecture
to the self-assembly behaviors. Iteratively connecting homologous
monomers of different side chains according to pre-designed sequences
generates discrete polymers with exact chemical structure, uniform
chain length, and programmable side-chain gradient along the backbone,
which transcribes into diverse shapes. The precise chemistry eliminates
all the defects and heterogeneities, providing a delicate platform
for fundamental inquiries into the role of molecular geometry. A rich
collection of unconventional complex phases, including Frank–Kasper
A15 and σ phases, as well as a dodecagonal quasicrystal phase,
were captured in these rigorous single-component systems. The self-assembly
behaviors are strikingly sensitive to subtle variations of geometry,
such that simply migrating a few methylene units among the side chains
would generate substantial differences in lattice size or phase stability,
or even trigger a phase transition toward distinct structures. The
phenomena can be rationalized with a geometric argument that nonuniform
side chain distribution leads to conformational mismatch between two
immiscible blocks, resulting in varied interfacial curvatures and
distinct lattice symmetries. The profound contribution demonstrates
that molecular geometry is an effective and robust parameter for structural
engineering
Additional file 1 of Primary non-response to antiviral therapy affects the prognosis of hepatitis B virus-related hepatocellular carcinoma
Additional file 1: Supplementary Table 1. Demographic data and clinical characteristics of the patients after the 1:3 PSM. Supplementary Figure 1. Kaplan-Meier curve showing 1-year overall survival (OS) in the two groups. Supplementary Figure 2. Subgroup analysis according to tumor stage and treatment modality
Discrete Linear–Branched Block Copolymer with Broken Architectural Symmetry
Rationally
introducing chain length heterogeneity, such as binary
blending, is a robust approach to regulate phase behavior of block
copolymers. This work designed a library of discrete linear–branched
block copolymers bearing two unequal branches. Diverse ordered nanostructures,
including complex Frank–Kasper phases and quasicrystalline
phase, were captured by tuning the compositional and architectural
asymmetry. The precise chemistry rules out the interferences associated
with statistical distribution, while the discrete feature decouples
the intertwined variables. Compared with the symmetric counterparts,
the synergies between the long and short chains effectively release
the packing frustration during the formation of ordered structures,
leading to a significant increase of lattice dimension and phase stability.
The “built-in” chain length heterogeneity circumvents
the shortcomings encountered by the conventional blending strategy,
providing an excellent alternative for quantitatively assessing the
effect of molecular symmetry on the self-assembly behaviors of block
copolymers
