Hydrogels are attractive for applications in intelligent soft materials and flexible electronics. Herein, we report a new hydrogel with a hierarchical hydrogen bond system consisting of (1) weak hydrogen bonds between N,N-dimethylacrylamides (DMAA) and acrylic acids (AAc) and (2) strong multiple hydrogen bonds between 2-ureido-4[1H]-pyrimidinone units. By optimizing the ratios of DMAA and AAc and the balance of weak and strong hydrogen bonds, the hydrogels have unique properties. The transparent hydrogels have tunable Young’s modulus (70–1,250 kPa) and are highly stretchable (up to 4,340% strain), tough (fracture energies of 10.8 kJ/m², matching natural rubber) and insensitive to notches when it is highly stretched (λ = 19.6).

Conventional pavement materials like SMA and GA do not meet the requirement for steel bridge decks. Epoxy asphalt concrete (EAC) has good performances but also has fatigue problems stemming from their inherent chemical structures, which, in some cases, led to short service life. Herein, we report a polyurethane concrete (PUC) consisting of a one-phase tough polyurethane binder as the matrix and dolerite aggregates as filler. First, PUC samples are prepared by mixing liquid reactants like polycarbonate diol, aliphatic isocyanate and glycerine with dolerite aggregates. The optimum formula of the PUC (binder-aggregate ratio of 8.5%) is determined by the Marshall stability and compressive strength tests. Second, Hamburg wheel tracking, freeze-thaw splitting, low temperature bending and linear contraction coefficient measurements are conducted on the PUC samples. Test results show that PUC composites have strong low-temperature toughness (the flexural strength 24.3 ± 1.3 MPa and flexural strain of 7020*10⁻⁶ at −10°C) and high dynamic stability (153,000 cycles/mm, about as 5 times as epoxy asphalt concrete (EAC). The alkaline hydrolysis tests show PUC has excellent durability (remained strong after 24 days of hot alkaline water treatment). These results support PUC is a promising material for bridge deck pavement.

Injectable and biocompatible polysaccharide hydrogels are ideal scaffolds for drug delivery and tissue engineering. Here, we report a new in situ forming hydrogels by self-crosslinking chitosan and a biocompatible polymeric crosslinker, oxidized alginic acid. The dialdehyde alginic acid was synthesized by the oxidant reaction of alginic acid with sodium periodate. The gel was formed in situ by the Schiff base reactions between their amine groups of chitosan and aldehyde groups of alginic acid. It deformed under stress and kept its shape integrity at the strain of 40%. Sustained cargo release including rhodamine and bovine serum albumin from the hydrogels was obtained. The hydrogels were degraded by chitosanase within 30 d and the pH values of the solution remained neutral. H9c2 cells proliferated the hydrogels and maintained their native state. These results suggested this hydrogel can be promising cell therapy scaffolds for tissue engineering.

A series of porous S-doped carbon nitride ribbons (PSCN) were prepared by one-pot hydrothermal and sonochemical synthesis techniques. The morphologies and nanostructures of the catalysts were characterized by SEM, XRD and IR, which confirmed the pristine graphitic structures of carbon nitrides retained in the products. Due to sonication treatment, PSCN has porous structures in the thin ribbon and larger specific surface areas (PSCN 43.5 m²/g, SCN 26.6 m²/g and GCN 6.5 m²/g). XPS and elemental mappings verified that sulfur atoms were successfully introduced into the carbon nitride framework. Diffuse reflectance spectroscopy (DRS) results showed S-doping in the carbon nitride reduced the bandgap energy and enhanced their capability of the utilization of visible light, which contributed to higher photo-generated current. Photoluminescence (PL) analysis indicates the recombination of photogenerated carriers was suppressed in PSCN. Moreover, the photocatalytic performance showed that S-doping and porous and thin ribbon nanostructures may effectively boost the CO₂ reduction rate (to as much as 5.8 times of GCN) when illuminated byvisible light (>420 nm) without the need of sacrificial materials. The preliminary mechanisms of the formation of PSCN and its applications in photocatalytic CO₂ reduction are proposed. It highlights the potential of the current technique to produce effective, nonmetal-doped carbon nitride photocatalysts.

Background: For patients with locally advanced rectal cancer (LARC), it is unclear whether neoadjuvant chemoradiotherapy-induced pathologic complete response (pCR) individuals would further benefit from adjuvant chemotherapy (ACT). Methods: The pCR individuals who received different ACT cycles were paired by propensity score matching. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were calculated by Kaplan–Meier and log-rank test. Results: In total, 1041 pCR individuals were identified from 5567 LARC cases. Specifically, 303 pCR cases had no ACT treatment, and 738 pCR patients received fluoropyrimidine-based ACT (median, 4 cycles) treatment. After 1:3 propensity score matching, 297 cases without ACT treatment were matched to 712 cases who received ACT treatment. Kaplan–Meier analysis showed that pCR individuals treated with or without ACT had the similar 3-year outcome (OS, DFS, LRFS and DMFS) (all P > 0.05). Moreover, the pCR patients received different ACT cycle(s) (0 vs. 1–4 cycles, 0 vs. ≥5 cycles) had comparable 3-year OS, DFS, LRFS and DMFS (all P > 0.05). In stratified analysis, ACT treatment did not improve 3-year survival (OS, DFS, LRFS and DMFS) for the baseline high-risk (cT3–4/cN1–2) subgroup patients (all P > 0.05). Conclusion: ACT, which did not improve survival, is unnecessary to neoadjuvant treatment-induced pCR LARC patients. Trial registration: 2019ZSLYEC-136 (24-6-2019).