A Novel Strategy to Fabricate Cation-Cross-linked Graphene Oxide Membrane with High Aqueous Stability and High Separation Performance.

Graphene oxide (GO) membranes have shown enormous promise in desalination and molecular/ionic sieving. However, the instability of GO membranes in aqueous solutions seriously hinders their practical applications. Herein, we report a novel and simple strategy to fabricate stable GO membranes in water-based environments through the insertion of various metal cations from metal foils (e.g., copper (Cu), iron (Fe), nickel (Ni), and zinc (Zn) foils) and natural deposition. Based on the cation-π, coordination, and electrostatic interaction between metal cations and GO nanosheets, the aqueous stability and mechanical strength of the membranes are significantly improved. The permeation rates for acetone, toluene, and p-xylene molecules across the GO membrane cross-linked by copper ions with a deposition time of 24 h are 0.966, 0.074, and 0.100 mol m-2 h-1, respectively. Moreover, this membrane displays excellent separation performance, and the separation factor of K+/Mg2+ is up to 68.8 in mono-/multivalent metal cation sieving, which indicate the effective molecular/ionic sieving performance. Meanwhile, the ionic sieving of the GO membrane cross-linked by copper ions has excellent repeatability and long-term stability. The versatility of this natural deposition strategy to fabricate GO membranes cross-linked by metal cations is investigated by using Fe foil, Zn foil, and Ni foil as well as other porous substrates such as polyvinylidene fluoride (PVDF), polyethersulfone (PES), and nylon membranes and filter paper. This fabrication strategy also enables low-cost preparation of large-area GO membranes. Therefore, GO membranes cross-linked by metal cations and prepared by this simple metal cation incorporation strategy have large potential application for molecular/ionic sieving in various solution systems.

Nanostructured Thermoresponsive Surfaces Engineered via Stable Immobilization of Smart Nanogels with Assistance of Polydopamine.

Thermoresponsive surfaces featured with nanostructures have found wide potential applications in biological and chemical fields. Herein, we report nanostructured thermoresponsive surfaces engineered via stable immobilization of thermoresponsive nanogels with the assistance of polydopamine. The results show that the thin layer of polydopamine on the poly( N-isopropylacrylamide) (PNIPAM) nanogels nearly does not affect the thermoresponsive property of the nanogels. The stability of the thermoresponsive nanogels on the substrate surfaces immobilized under different pH conditions of dopamine solutions are quatitively studied by fluid shearing experiments inside capillaries, and the characterization results show that the strong interaction forces between the polydopamine layer on the substrate surfaces and the thermoresponsive nanogels are heavily dependent on the oxidation state of the dopamine molecules. With the proposed strategy, thermoresponsive nanostructured surfaces immobilized with PNIPAM nanogels on two-dimensional and three-dimensional substrate surfaces are generated to achieve smart cell culture plates and smart gating membranes, respectively, which demonstrate versatile applications of the nanostructured thermoresponsive surfaces.

Novel Smart Microreactors Equipped with Responsive Catalytic Nanoparticles on Microchannels.

Nowadays efficient and reliable control of highly exothermic reactions to effectively prevent overheating or even explosions still remains a challenging task, although newly developed microreactor technology has shown promise. Here, we report a novel smart microreactor system equipped with responsive catalytic nanoparticles on microchannels for self-regulated control over highly exothermic reactions by responding to the reaction-generated heat. On the basis of shrinking/swelling behaviors of polymeric networks in the responsive catalytic nanoparticles, the smart microreactor could respond to the change of reaction temperature to tune the catalysis activity of catalytic particles in a thermo-feedback process. As a breakthrough result, highly exothermic reactions carried out in such a microreactor can be well-controlled in a self-regulation process without any manual assistance, efficiently ensuring the safety of the reaction. Such smart responsive catalytic systems have high potential and are attractive as a new generation of efficient tools that feature a self-regulation property for highly exothermic catalytic reactions.

[Analysis of prognostic factors in patients with huge primary liver cancer after surgical resection].

OBJECTIVE: To analyze the prognostic factors in patients after surgical resection of a huge primary liver cancer (HPLC). METHODS: Clinical and follow-up data of 69 cases of huge HPLC treated in our hospital from July 2001 to July 2008 were retrospectively analyzed. Sixteen clinicopathologic factors possibly influencing the survival were selected, and multivariate analysis of these parameters was performed using the Cox proportional hazards model. RESULTS: The cumulative 1-, 3-, 5-year survival rates of 58 patients were 58.2%, 31.4% and 12.3%, respectively. Univariate analysis showed that radical resection, intrahepatic metastasis, vascular invasion and degree of hepatic cirrhosis significantly affect the postoperative survival. The Cox multivariate analysis indicated that radical resection, intrahepatic metastasis and degree of hepatic cirrhosis are independent prognostic factors. CONCLUSIONS: Surgical resection is a major and active treatment for huge HPLC. The therapeutic efficacy depends on intrahepatic metastasis, degree of hepatic cirrhosis and radical resection. Aggressive treatment and prevention on postoperative intrahepatic recurrence and metastasis is an important strategy to improve the survival of patients with huge HPLC.

[Diagnosis and treatment for solitary necrotic nodule of the liver: report of 15 patients].

OBJECTIVE: To investigate the diagnostic and therapeutic approach of solitary necrotic nodule of the liver (SNNL). METHODS: Fifteen cases were diagnosed as SNNL from June 1999 to December 2005. The clinical characteristics, imaging findings, diagnosis and treatment were analyzed with related literature retrospectively. RESULTS: The patients manifested abdominal pain and discomfort in 7 cases (46.7%), fever in 1 case (6.7%), debilitation in 1 case (6.7%). Lesions were screened as hypoechogenic patterns in B ultrasound, and CT scan confirmed that the lesion appeared slightly hypodense compared with the normal liver parenchyma without detectable enhanced graphic phases. No significant enhancement was on dynamic magnetic resonance imaging study. All of the nodules demonstrated hypointense and isointense signal relative to parenchyma of liver on both T1 and T2-weighted images. Histologically, the lesion composed mainly of coagulative necrosis with a homogeneous periphery, and the central zone had a rough patchy appearance with cellular debris. The coagulative necrosis was surrounded by a thin boundary of collagen fibers with scanty mononuclear, lymphocyte, plasmocyte inflammatory cells and elastic fibers. Preoperative laboratory examinations showed hepatic function slightly abnormal in 3 patients, and AFP level was normal in all patients. Diagnosis of SNNL was established in 4 cases (26.7%) preoperatively. All patients underwent liver resection with no recurrence within 3 months to 6 years follow-up. CONCLUSIONS: Preoperative diagnosis of SNNL can be established via comprehensive analysis of clinical characteristics and imaging findings. Liver resection is the optimal therapeutic approach.