Self-Healing of Poly(vinyl Alcohol)/Poly(acrylic Acid)-Polytetrahydrofuran-Poly(acrylic Acid) Blend Boosted via Shape Memory.

The self-healable polymers that can repair physical damage autonomously to extend their lifetime and reduce maintenance costs are promising intelligent materials. However, utilizing shape memory to facilitate self-repair is unusual at present. In this work, a series of poly(acrylic acid)-polytetrahydrofuran-poly(acrylic acid) polymers (PAA-PTMG-PAA, diPAA-PTMG) are synthesized as a switching phase and healing accelerator to blend into poly(vinyl alcohol) (PVA). The water swelling rate of the blend is up to 400.0% at 1/1 molecular weight ratio of PTMG/PAA and 20.0 wt % blend ratio of diPAA-PTMG to PVA, and its crystallization is changed significantly under wet conditions. The blend membrane exhibits not only a good hydrothermal-response shape memory effect but also a favorable self-healing behavior. The tensile strength and elongation at break are 12.4 MPa and 320.0% after healing at 25 °C, respectively. In particular, the wound membrane can achieve a better self-healing effect with the assistance of shape memory at 37 °C, and the elongation at the break increased to 515.9% after healing. The membrane is not cytotoxic, so it will be a promising biomedical material.

The effect of Pluronic P123 on shape memory of cross-linked polyurethane/poly(l-lactide) biocomposite.

Polyurethane (PU) and poly(l-lactide) (PLLA) have attracted increasing attention in the development of shape memory polymers (SMPs) due to their good biocompatibility and degradability. Although Pluronic P123 can be used to tune polymeric surface hydrophilicity, its effect on SM performance is a mystery. In this study, a soluble cross-linked PU is synthesized as the switching phase and combined with PLLA and P123 to construct a hydrothermally responsive SM composite. The water contact angle of PU/PLLA/P123 decreases from 22.7° to 5.1° within 2 min. PU and P123 form the switching group, which enhances the SM behavior of the composite. The shape fixity (Rf) and shape recovery (Rr) of PU/PLLA/P123 are 94.4 % and 98 % in 55 °C water, respectively, and the shape recovery time is only 10 s. P123 plays the role of "turbine" in the SM process. PU/PLLA/P123 exhibits a balance between stiffness and elasticity, and good degradability. Furthermore, PU/PLLA/P123 is also biocompatible and beneficial to cell proliferation and growth. Therefore, it offers an alternative approach to developing hydrothermally responsive SM biocomposites based on P123, PU and PLLA for biomedical applications.

A shape-memory poly(ε-caprolactone) hybridized TiO2/poly(l-lactide) composite with antibacterial properties.

Organic-inorganic composites as an efficient strategy to upgrade the structural and functional properties of synthetic polymers are attracting extensive attentions. However, there are few studies on the shape memory (SM) behavior of organic-inorganic composites. In the work, poly(ε-caprolactone) hybridized TiO2 nanomaterial (PCL-TiO2) is made as the switching phase and integrated into poly (l-lactide) (PLLA) to construct an SM composite. PCL-TiO2/PLLA shows "sea-island" structure and better interfacial adhesion than PCL/PLLA, which facilitates the transmission of elastic power between the switching phase and the fixing phase. PCL-TiO2 as switching phase exhibits lower enthalpy at 57 °C than PCL, and PCL-TiO2 also acts as "heat dispersion pump station", which builds a dynamically responsive system and initiates shape change. The shape fixing and recovery ratio of PCL-TiO2/PLLA are 93.9 % and 94.4 %, respectively, and go back to the original shape within 15 s at 57 °C. At the same time, PCL-TiO2 endows SMP with good antibacterial properties. Then this work provides a well-placed way for developing SM materials with structure-function integration.

Primary hepatic mucosa-associated lymphoid tissue lymphoma: case report and literature review.

BACKGROUND: The prevalence of primary hepatic mucosa-associated lymphoid tissue (MALT) lymphomas is extremely low. Here, we describe a case of this disease misdiagnosed as hepatocellular carcinoma (HCC) and review relevant literature to prevent future misdiagnoses. CASE PRESENTATION: a 58-year-old woman complained about abdominal pain for more than four months. About two months prior, she came to our hospital with elevated levels of HBV DNA and positive HBsAg and HBcAb. After two months of entecavir treatment, HBV DNA decreased to a normal level. She returned to the hospital with worsened abdominal pain for over a month. Magnetic resonance imaging and systemic positron emission tomography-computed tomography identified two nodes in the liver, and she was diagnosed with HCC. The patient then underwent a laparoscopic hepatectomy. Microscopic examination showed a diffuse infiltrate of small-to-medium-sized lymphocytes and lymphoepithelial lesions. Immunohistochemical staining showed that most of the lymphoid cells were strongly positive for CD20, CD79a, BCL2, IgM and weakly positive for IgD, while negative for CD3, CD10, BCL6, MUM1, CD43, CD5, cyclin D1, CD23, CD30, and PD1. The Ki-67 index of lymphoid cells was 5%. Further pathologic analysis confirmed the diagnosis of primary hepatic MALT lymphoma. The patient received antiviral treatment and recovered well with no sign of relapse for 17 months. CONCLUSIONS: Primary hepatic MALT lymphoma is an uncommon disease that is difficult to diagnose and has no widely accepted treatment. Surgical resection is a good choice for both diagnosis and local therapy, and strict follow-up of the patient is essential.

Selective Cl-Decoration on Nanocrystal Facets of Hematite for High-Efficiency Catalytic Oxidation of Cyclohexane: Identification of the Newly Formed Cl-O as Active Sites.

Understanding the structure-reactivity relationship at the atomic scale is of great theoretical importance for rational design of highly active catalysts, which has long been a central concern in catalysis communities and interface science. Herein, we developed a high-efficiency catalyst for catalytic oxidation of C6H12 by poststructural decoration on well-defined single-crystal facets of hematite. Especially for Cl-decorated {012} facets, the conversion and KA oil selectivity are improved about 3.4 times and 2 times, respectively. A better catalytic performance of the newly formed active site is derived from the charge difference between Cl and the neighboring outmost O atoms, which is affected by the geometric and electronic structures of the original catalyst surface. Based on the experimental results and the theoretical analysis, we concluded that the contribution of various O terminations to Cl-decoration follows the order O(I) > O(III) > O(II). Cl-decorated {001} facets show the highest intrinsic activity, whereas Cl-decorated {012} facets show the best catalytic performance because of their more active sites for Cl-decoration.

[Analysis of trend of Oncomelania snail status in Yangtze River valley of Anhui Province, 1998-2009].

OBJECTIVE: To understand the trend of Oncomelania hupensis snail distribution in Yangtze River valley of Anhui Province so as to provide an evidence for making out schistosomiasis prevention and control strategies in the future. METHODS: The snail data from 1998 to 2009 of the Yangtze River valley in Anhui Province were collected including the snail area, newly occurred and re-occurred snail areas, densities of snails and infected snails, etc., and the trend and influence factors were analyzed. RESULTS: With several fluctuations, the snail area showed a trend of declining in general after the devastating summer flooding in 1998. From 1998 to 2009, 3 peaks of newly occurred snail areas appeared in 1998, 2004 and 2006 and 2 peaks of reoccurred snail areas appeared in 1998 and 2004. The densities of living snails and infected snails were more severe in banks of the Yangtze River than in islets of the Yangtze River. During 12 years, 1 peak of living snail density appeared in 2003, and 3 peaks of infected snail density appeared in 1999, 2003-2004 and 2006 in the islets of the Yangtze River. The densities of living snails and infected snails in banks of the Yangtze both appeared 1 peak in 1998. CONCLUSIONS: The distribution of snails in the Yangtze River valley is related to nature, society and financial circumstances, and it is hard to completely perform the snail control in a short-term. Therefore, at the same time of strengthening snail control, we should also strengthen infectious source control.