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Fabrication of hydrogels with unique microstructures and better mechanical properties through the self-assembly of commercially available synthetic polymers and small molecules is of great scientific and practical importance. A type of physical hydrogels is prepared by the self-assembly of polyvinyl alcohol (PVA) and tannic acid (TA) in aqueous solution with a low PVA–TA concentration (0.5–6.0 wt %) at room temperature. With the increase of the PVA–TA concentration, the water content of the hydrogels increases, and the content of TA in the hydrogels decreases from 23.1 to 6.4%. The driving force for the self-assembly is proven to be the hydrogen bonding between PVA and TA, which also induces the crystallization of PVA chains. The self-assembled PVA–TA hydrogels have diverse morphologies that change from microspheres to oriented porous structures with the increase of the PVA–TA concentration, and these structures are all composed of nanosized particles, fibers, and/or sheets. Most of the self-assembled PVA–TA hydrogels show good mechanical properties. The highest tensile strength and elastic modulus of the PVA–TA hydrogel prepared with 1.0 wt % PVA–TA concentration are about 84 and 30 kPa, respectively. This self-assembly method would lead to the fabrication of more hydrogels with unique microstructures and properties for practical applications.

Shape memory hydrogels (SMHs) have a wide range of potential practical applications. However, the mechanically weak and soft nature of most SMHs strongly impedes their applications. Here, we report a novel kind of thermal-responsive SMH with high tensile strength and high elastic moduli. Organogels are first prepared by the copolymerization of a hydrophilic monomer N-vinylpyrrolidone (NVP) and a hydrophobic monomer acryloxy acetophenone (AAP) in N, N'-dimethylformamide (DMF) solutions, and then, poly(vinylpyrrolidone- co-acryloxy acetophenone) [poly(NVP- co-AAP)] hydrogels are obtained by solvent exchange with water. Because of the strong and reversible hydrophobic association and π-π stacking of acetophenone groups, the poly(NVP- co-AAP) hydrogels exhibit tensile strengths up to 8.41 ± 0.83 MPa and Young's moduli up to 94.2 ± 1.3 MPa, which are more than 1 or 3 orders of magnitude higher than those of the organogels, respectively. The poly(NVP- co-AAP) hydrogels exhibit good shape memory behaviors, with a complete fixation ratio and a recovery ratio of 74-89%, as well as very fast shape-fixing and recovering rates (in seconds). These rigid and strong hydrogels are demonstrated to be an ideal shape memory material for surgical fixation devices to wrap around and support various shapes of limbs.

The frequency of antimicrobial resistance has increased globally due to misuse and overuse of antibiotics, and multi-drug resistant (MDR) bacteria are now recognized as a major cause of hospital-acquired infections (HAI). Our aim was to investigate the prevalence, distribution, and antimicrobial susceptibility rates of MDR bacteria in patients with HAI from a tertiary hospital in China. We retrospectively evaluated all patients with a confirmed diagnosis of bacterial infection at a tertiary general hospital in Jining, for the period between January 2012 and December 2014. The following clinical and demographic data were collected: age, sex, specimens, treatment, microbiology results, and antibiotic resistance patterns of isolates. Bacterial identification and susceptibility testing were performed using VITEK 2 COMPACT system. We screened a total of 15,588 patients, out of which 7579 (48.6%) had an HAI. MDR showed 3223 out of 7579 isolates (42.5%). The most frequently isolated MDR bacteria in patients with HAI were extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n = 1216/3223, 37.7%), MDR Pseudomonas aeruginosa (n = 627/3223, 19.5%) and MDR Acinetobacter baumannii (n = 588/3223, 18.2%). MDR-HAI were more common in males (2074/3223, 64.4%) and in elderly patients (≥60 years; 1196/3223, 37.1%). Sputum was the main source of MDR isolates (2056/3223, 63.8%). Patients with MDR-HAI were predominantly distributed in different types of intensive care units. MDR strains in our study showed resistance to most current antibiotics. Overall, patients with HAI infections attributed to MDR bacteria were widely distributed in our hospital. Enhanced surveillance of MDR bacteria is critical for guiding the rational use of antibiotics and reducing the incidence of HAI.

Nonconventional luminescent copolymers poly(itaconic anhydride-co-vinyl caprolactam) (PIVC) and poly(itaconic anhydride-co-vinyl pyrrolidone) (PIVP) emit strong orange-red and bright white emissions, respectively.

If complete surgical resection is not possible, partial resection followed by hormone therapy using gonadotropin-releasing hormone agonists is recommended, which in this study achieved the same favorable prognosis with regard to remission.

Many nonconventional luminescent polymers are found to exhibit intrinsic photoluminescence and “aggregation‐induced emission” (AIE) behavior. Strong physical interactions among polymer chains and/or a rigid molecular conformation of polymer chains are thought to be beneficial to boost stronger emissions. The purpose of this work is to prove that increasing chain flexibility is, at least in some cases, beneficial to enhance the photoluminescence of nonconventional luminescent polymers. Poly(itaconic anhydride) (PITA) and poly[(1‐octene)‐co‐(itaconic anhydride)] (POITA) synthesized in this work are highly emissive in concentrated solutions and in solid state, exhibiting typical AIE characteristics, and very interestingly, the copolymer POITA exhibits stronger and red‐shifted emissions than the homopolymer PITA in both solutions and in the solid state. These results are explained by the increase of chain flexibility, which makes the nonconventional chromophores adopt proper conformations for strong intra‐ and/or interchain n‐π* and/or π–π* interactions. This study sheds some light on designing nonconventional luminescent materials with high emission efficiency and long wavelength emission.

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