Synthesis and evaluation of properties of N,N-bis(perfluorooctyl)imine acetate sodium as a gas-wetting alteration agent

The wettability of a rock’s surface is a vital factor for gas flow and fracturing fluid backflow. As a result of this, novel and effective gas wetting alteration agents are required. In this work, a gas-wetting alteration agent, N,N-bis(perfluorooctyl)imine acetate sodium, was synthesized and characterized by different methods. The wettability of a rock’s surface was evaluated by contact angle and imbibition measurements, the Owens two-liquid method and glass capillary tube rise testing. The results showed that after treatment with 0.5 wt% N,N-bis(perfluorooctyl)imine acetate sodium the contact angles of water and n-hexadecane on the surface of the rock increased from 36° and 0° to 140° and 119°, respectively. The surface free energy rapidly reduced from primeval 72 mN m⁻¹ to 3.4 mN m⁻¹ after treatment with 0.3 wt% N,N-bis(perfluorooctyl)imine acetate sodium. These values agreed with the imbibition measurements and the results of the glass capillary tube rise testing. Moreover, analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that the roughness of the rock surface significantly increased. The above results fully proved that the wettability of the rock surface is altered from its original water-wetting or oil-wetting to gas-wetting. Furthermore, thermal analysis demonstrated that the gas-wetting alteration agent has good thermal stability, which indicates its great potential to be used as a gas-wetting alteration agent for unconventional gas reservoirs under high temperature conditions.

A gas-wetting alteration agent, N,N-bis(perfluorooctyl)imine acetate sodium, was synthesized and characterized by different methods and the wettability of a rock surface was evaluated.     

Biocompatible tumor-targeting nanocomposites based on CuS for tumor imaging and photothermal therapy

Active targeting of tumor receptors is a significant approach for cancer diagnosis. Additionally, development of photothermal agents for photothermal therapy (PTT) has attracted great interest in the field of nanomedicine. In the present study, copper sulfide (CuS) nanoparticles capped with bovine serum albumin (BSA), named CuS@BSA, was synthesized by a convenient method. Then, the near-infrared (NIR) fluorescence probe MBA and the tumor-targeting ligand cyclic RGD were further conjugated on the surface of CuS@BSA, and the obtained nanocomposite was named CuS@BSA-MBA-cRGD. The morphology, optical properties, biotoxicity, tumor-targeting capability and in vitro and in vivo tumor inhibition effect were all characterized comprehensively. This nanocomplex demonstrated enhanced photothermal effects and positive tumor targeting. Thus, the nanocomposite CuS@BSA-MBA-cRGD can used as a promising tumor-targeting PTT agent for simultaneous cancer imaging and photothermal treatment.

This study provides a good platform for diagnosis and treatment, and it is expected to prompt further exploration of the active target efficiency to achieve better tumor treatment.     

Human platelet lysate supports the formation of robust human periodontal ligament cell sheets

The use of stem cell‐derived sheets has become increasingly common in a wide variety of biomedical applications. Although substantial evidence has demonstrated that human platelet lysate (PL) can be used for therapeutic cell expansion, either as a substitute for or as a supplement to xenogeneic fetal bovine serum (FBS), its impact on cell sheet production remains largely unexplored. In this study, we manufactured periodontal ligament stem cell (PDLSC) sheets in vitro by incubating PDLSCs in sheet‐induction media supplemented with various ratios of PL and FBS, i.e. 10% PL without FBS, 7.5% PL + 2.5% FBS, 5% PL + 5% FBS, 2.5% PL + 7.5% FBS or 10% FBS without PL. Cultures with the addition of all the designed supplements led to successful cell sheet production. In addition, all the resultant cellular materials exhibited similar expression profiles of matrix‐related genes and proteins, such as collagen I, fibronectin and integrin β1. Interestingly, the cell components within sheets generated by media containing both PL and FBS exhibited improved osteogenic potential. Following in vivo transplantation, all sheets supported significant new bone formation. Our data suggest that robust PDLSC sheets can be produced by applying PL as either an alternative or an adjuvant to FBS. Further examination of the relevant influences of human PL that benefit cell behaviour and matrix production will pave the way towards optimized and standardized conditions for cell sheet production.     

Cardiovascular magnetic resonance left ventricular strain in end-stage renal disease patients after kidney transplantation

Background

Cardiovascular disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and kidney transplant (KT) patients. Compared with left ventricular (LV) ejection fraction (LVEF), LV strain has emerged as an important marker of LV function as it is less load dependent. We sought to evaluate changes in LV strain using cardiovascular magnetic resonance imaging (CMR) in ESRD patients who received KT, to determine whether KT may improve LV function.

Methods

We conducted a prospective multi-centre longitudinal study of 79 ESRD patients (40 on dialysis, 39 underwent KT). CMR was performed at baseline and at 12?months after KT.

Results

Among 79 participants (mean age 55 years; 30% women), KT patients had significant improvement in global circumferential strain (GCS) (p?=?0.007) and global radial strain (GRS) (p?=?0.003), but a decline in global longitudinal strain (GLS) over 12?months (p?=?0.026), while no significant change in any LV strain was observed in the ongoing dialysis group. For KT patients, the improvement in LV strain paralleled improvement in LVEF (57.4?±?6.4% at baseline, 60.6%?±?6.9% at 12?months; p?=?0.001). For entire cohort, over 12?months, change in LVEF was significantly correlated with change in GCS (Spearman’s r?=???0.42, p?<?0.001), GRS (Spearman’s r?=?0.64, p?<?0.001), and GLS (Spearman’s r?=???0.34, p?=?0.002). Improvements in GCS and GRS over 12?months were significantly correlated with reductions in LV end-diastolic volume index and LV end-systolic volume index (all p?<?0.05), but not with change in blood pressure (all p?>?0.10).

Conclusions

Compared with continuation of dialysis, KT was associated with significant improvements in LV strain metrics of GCS and GRS after 12?months, which did not correlate with blood pressure change. This supports the notion that KT has favorable effects on LV function beyond volume and blood pessure control. Larger studies with longer follow-up are needed to confirm these findings.

     

Pt incorporated mesoporous carbon spheres: controllable structure with enhanced catalytic activity and stability

We report a simple synthesis process to prepare well-dispersed Pt nanoparticles incorporated in mesoporous carbon spheres. By manipulating the relative ratio of Pt precursor and resorcinol-formaldehyde resin (RF), Pt/carbon composites with different morphologies and Pt content were achieved. The as-prepared Pt/C composite materials show higher catalytic activity and reusability for the reduction of 4-nitrophenol (4-NP) than the Pt deposited commercial activated carbon (Pt/AC), which can be ascribed to the high dispersion of Pt nanoparticles in the carbon spheres.

We report a simple synthesis process to prepare well-dispersed Pt nanoparticles incorporated in mesoporous carbon spheres.     

Acetone vapour-assisted growth of 2D single-crystalline organic lead halide perovskite microplates and their temperature-enhanced photoluminescence

We adopt an acetone vapour-assisted method to grow high quality single-crystalline microplates of two-dimensional (2D) perovskite, 2-phenylethylammonium lead bromide [(C₆H₅C₂H₄NH₃)₂PbBr₄]. The microplates, converted from the spin-coated films, are well-defined rectangles. Temperature dependent photoluminescence (PL) spectroscopy shows that the band gap PL is enhanced markedly with increasing temperature up to 218 K, accompanied by the quenching of the PL related to the trap states, which perhaps results from the exciton–phonon couplings. The optical phonon energy around 50 meV and the exciton binding energy around 120 meV are derived by fitting the band gap PL linewidths and intensities at different temperatures, respectively.

We report an acetone vapour-assisted method to grow single-crystalline 2D perovskite microplates and find their temperature-enhanced photoluminescence.     

Effect of template removal using plasma treatment on the structure and catalytic performance of MCM-22

To investigate the effect of template removal methods on the structure, properties and catalytic performance of the MCM-22 zeolite, dielectric-barrier discharge (DBD) plasma treatment and thermal calcination have been comparatively studied for the removal of hexamethyleneimine (HMI) from the two-dimensional layered precursor of MCM-22 (MCM-22(P)). The materials were characterized using FT-IR, TG, XRD, N₂ adsorption at low temperature, NH₃-TPD, and ²⁷Al and ²⁹Si MAS NMR. The results revealed that the seven-membered heterocyclic compound HMI can be effectively removed from the MCM-22 zeolite, and the condensation of silanol groups on the neighboring surface of MWW nanosheets can be induced by DBD treatment. Compared with calcination, DBD treatment could preserve the structure well and decrease the formation of extra-framework aluminum. Consequently, the concentration of acidic sites over MCM-22 treated by DBD (MCM-22(DBD)) is higher than that over calcined MCM-22 (MCM-22(C)). Moreover, MCM-22(DBD) possesses a certain amount of external surface area derived from the intercrystal pores due to the inhibiting effect of the condensation of the silanol groups on the external surface of the MCM-22 crystals. The activity and product selectivity of the Fischer–Tropsch (FT) synthesis was investigated over cobalt supported on the obtained MCM-22 zeolites. Compared with Co/MCM-22(C), Co/MCM-22(DBD) shows a higher catalytic activity in the FT synthesis reaction. Moreover, Co/MCM-22(DBD) can effectively decrease CH₄ selectivity and increase C₅–C₂₀ liquid fuel selectivity.

Template removal from MCM-22 using dielectric-barrier discharge (DBD) plasma could decrease the formation of extra-framework aluminum (EFAl) and increase the concentration of the acidic sites and external surface area of MCM-22.     

132例老年期谵妄患者临床分析

目的谵妄是由多种因素引起的急性器质性脑病综合征。文中探讨老年期谵妄的临床特征、治疗及预后。方法回顾性分析南京军区南京总医院干部病区2011年1月至2013年1月诊断为谵妄的132例老年患者临床资料,按照临床结局分成有效组(痊愈与好转)和死亡组,对患者一般情况、病因、临床特征、治疗等进行总结分析。结果 132例患者中男73例,女59例;年龄65~97岁,平均(71.4±8.3)岁。所有患者均有不同程度意识障碍。组间比较发现,有效组与死亡组患者在年龄、谵妄持续时间、病程中是否昏迷、是否重症感染、是否气管插管和(或)气管切开、是否合并有多种基础疾病等方面的差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,病程中出现昏迷、气管插管和(或)切开、文化程度、体温、合并重症感染是本研究中老年期谵妄患者的独立危险因素(P<0.05)。结论老年期谵妄治疗过程中应注意患者体温和对感染的控制。针对基础疾病的有效治疗和预防有利于改善患者预后。