Surface Engineering in Covalent Organic Polymers for High-Performance Li-S Batteries.

Lithium-sulfur (Li-S) batteries are a promising energy storage technology due to their tempting high theoretical capacity and energy density. Nevertheless, the wastage of active materials that originates from the shuttling effect of polysulfides still hinders advancement of Li-S batteries. The effective design of cathode materials is extremely pivotal to solve this thorny problem. Herein, surface engineering in covalent organic polymers (COPs) has been performed to investigate the influence of pore wall polarity on the performance of COP-based cathodes used for Li-S batteries. With the assistance of experimental investigation and theoretical calculations, performance improvement by increasing pore surface polarity and a synergy effect of the polarized functionalities, along with nano-confinement effect of the COPs, are disclosed, to which the improved performance of Li-S batteries including outstanding Coulombic efficiency (99.0 %) and extremely low capacity decay (0.08 % over 425 cycles at 1.0 C) is attributed. This work not only enlightens the designable synthesis and applications of covalent polymers as polar sulfur hosts with high utilization of active materials, but also provides a feasible guide for the design of effective cathode materials for future advanced Li-S batteries.

Clinical Practice of Multiple Disciplinary Team Care Model Following the Concept of Palliative Care for Advanced Head and Neck Cancer:Report of One Case / 中国医学科学院学报

We provided the palliative care of a multiple disciplinary team care mode to a patient diagnosed with advanced head and neck cancer and her caregivers.People-centered integrated health services were provided according to the specific needs and preferences of individuals.The team-based palliative care relieved the suffering and improved the quality of life of the patient and that of her family who were facing challenges associated with life-threatening illness.

Hexagonal Lu1-xInxFeO3 Room-Temperature Multiferroic Thin Films.

The hexagonal rare earth ferrites h-RFeO3(R = rare earth element) have been recognized as promising candidates for a room-temperature multiferroic system, and the primary issue for these materials is how to get a stable hexagonal structure since the centrosymmetric orthorhombic structure is generally stable for most RFeO3 at room-temperature, while the hexagonal phase is only stable under some strict conditions. In the present work, h-Lu1-xInxFeO3 (x = 0-1) thin films were prepared on a Nb-SrTiO3 (111) single-crystal substrate by a pulsed laser deposition (PLD) process, and the multiferroic characterization was performed at room temperature. With the combined effects of chemical pressure and epitaxial strain, the stable hexagonal structure was achieved in a wide composition range (x = 0.5-0.7), and the results of XRD (X-ray diffraction) and SAED (selected area electron diffraction) indicate the super-cell match relations between the h-Lu0.3In0.7FeO3 thin film and substrate. The saturated P-E hysteresis loop was obtained at room temperature with a remanent polarization of about 4.3 µC/cm2, and polarization switching was also confirmed by PFM measurement. Furthermore, a strong magnetoelectric coupling with a linear magnetoelectric coefficient of 1.9 V/cm Oe was determined, which was about three orders of magnitude larger than that of h-RFeO3 ceramics. The present results indicate that the h-Lu1-xInxFeO3 thin films are expected to have great application potential for magnetoelectric memory and detection devices.

Bimetal Substitution Enabled Energetic Polyanion Cathode for Sodium-Ion Batteries.

The practical application of Na-superionic conductor structured materials is hindered by limited energy density and structure damage upon activating the third Na+. We propose a bimetal substitution strategy with cheaper Fe and Ni elements for costive vanadium in the polyanion to improve both ionic and electronic conductivities, and a single two-phase reaction during Na+ intercalation/deintercalation and much reduced Na+ diffusion barrier are uncovered by ex-situ X-ray diffraction and density functional theory calculations. Thus, the obtained cathode, Na3Fe0.8VNi0.2(PO4)3, shows excellent electrochemical performances including high specific capacity (102.2 mAh g-1 at 0.1C), excellent rate capability (79.3 mAh g-1 at 20C), cycling stability (84.6% of capacity retention over 1400 cycles at 20C), low-temperature performance (89.7 mAh g-1 at 2C and -10 °C), and structure stability in an extended voltage window for the third Na+ utilization. A competitive energy density of ≈287 Wh kg-1 for full batteries based on cathode and anode materials is also confirmed.

A Covalent Organic Framework with Extended π-Conjugated Building Units as a Highly Efficient Recipient for Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries have recently become a research hotspot because of their tempting theoretical capacity and energy density. Nevertheless, the notorious shuttle of polysulfides hinders the advancement of Li-S batteries. Herein, a two-dimensional covalent organic framework (COF) with extended π-conjugated units has been designed, synthesized, and used as sulfur recipients with 88.4 wt % in loading. The COF offers an elaborate platform for sufficient Li-S redox reactions with almost theoretical capacity release (1617 mA h g-1 at 0.1 C), satisfactory rate capability, and intensively traps polysulfides for a decent Coulombic efficiency (ca. 98.0%) and extremely low capacity decay (0.077% per cycle after 528 cycles at 0.5 C). The structural factors of the COF on the high-performance batteries are revealed by density functional theory calculations to be the high degrees of conjugation and proper interlayer space. This work not only demonstrates the great potential of COFs as highly efficient sulfur recipients but also provides a viable guidance for further design of COF materials to tackle shuttling issues toward active materials in electrochemical energy storage.

Giant Resistivity Change of Transparent ZnO/Muscovite Heteroepitaxy.

The piezoresistive effect has shown a remarkable potential for mechanical sensor applications and been sought for its excellent performance. A great attention was paid to the giant piezoresistive effect and sensitivity delivered by silicon-based nanostructures. However, low thermal stability and complicated fabrication process hinder their practical applications. To overcome these issues and enhance the functionalities, we envision the substantial piezopotential in a zinc oxide (ZnO)/muscovite (mica) heteroepitaxy system based on theoretical consideration and realize it in practice. High piezoresistive effect with giant change of resistivity (-80 to 240%) and large gauge factor (>1000) are demonstrated through mechanical bending. The detailed features of heteroepitaxy, electrical transport, and strain are probed to understand the mechanism of such a giant resistivity change. In addition, a bending model is established to reveal the distribution of strain. Finally, we demonstrate a flex sensor featuring high sensitivity, optical transparency, and two-segment sensing with a great potential toward practical applications. Such an oxide heteroepitaxy exhibits excellent piezoresistive properties and mechanical flexibility. In the near future, the importance of flex sensors will emerge because of the precise control in the automation industries, and our results lead to a new design in the field of flex sensors.

Multifield Control of Domains in a Room-Temperature Multiferroic 0.85BiTi0.1Fe0.8Mg0.1O3-0.15CaTiO3 Thin Film.

Single-phase materials that combine electric polarization and magnetization are promising for applications in multifunctional sensors, information storage, spintronic devices, etc. Following the idea of a percolating network of magnetic ions (e.g., Fe) with strong superexchange interactions within a structural scaffold with a polar lattice, a solid solution thin film with perovskite structure at a morphotropic phase boundary with a high level of Fe atoms on the B site of perovskite structure is deposited to combine both ferroelectric and ferromagnetic ordering at room temperature with magnetoelectric coupling. In this work, a 0.85BiTi0.1Fe0.8Mg0.1O3-0.15CaTiO3 thin film has been deposited by pulsed laser deposition (PLD). Both the ferroelectricity and the magnetism were characterized at room temperature. Large polarization and a large piezoelectric effective coefficient d33 were obtained. Multifield coupling of the thin film has been characterized by scanning force microscopy. Ferroelectric domains and magnetic domains could be switched by magnetic field ( H), electric field ( E), mechanical force ( F), and, indicating that complex cross-coupling exists among the electric polarization, magnetic ordering and elastic deformation in 0.85BiTi0.1Fe0.8Mg0.1O3-0.15CaTiO3 thin film at room temperature. This work also shows the possibility of writing information with electric field, magnetic field, and mechanical force and then reading data by magnetic field. We expect that this work will benefit information applications.

Advances in Mechanisms for Prevention and Treatment of Pathological Scars with Mesenchymal Stem Cells / 中国医学科学院学报

Pathological scars,including keloids and hypertrophic scars,result from aberrations in the process of physiologic wound healing.An exaggerated inflammatory process is one of the main pathophysiological contributors.Pathological scars may cause pain and pruritis,limit joint mobility,and cause a range of cosmetic deformities that affect the patient's quality of life.However,the effectiveness of currently available prevention and treatment measures remains unsatisfactory.Mesenchymal stem cells,among their multifunctional roles,have the functions of immunomodulation and promotion of angiogenesis.Thus,they have been proposed to be a major candidate for cell therapy to treat or prevent pathologicalscars.This article reviews the mechanism and potentials of stem cell therapy in the prevention and treatment of pathological scars.

Tuning the functionalities of a mesocrystal via structural coupling.

In the past decades, mesocrystal, a kind of nanocrystals with specific crystallographic orientation, has drawn a lot of attention due to its intriguing functionalities. While the research community keeps searching for new mesocrystal systems, it is equally crucial to develop new approaches to tune the properties of mesocrystals. In this work, a self-organized two-dimensional mesocrystal composed of highly oriented CoFe2O4 (CFO) nano-crystals with assistance of different perovskite matrices is studied as a model system. We have demonstrated that the strain state and corresponding magnetic properties of the CFO mesocrystal can be modulated by changing the surrounding perovskite matrix through their intimate structural coupling. Interestingly, this controllability is more strongly correlated to the competition of bonding strength between the matrices and the CFO mesocrystals rather than the lattice mismatch. When embedded in a matrix with a higher melting point or stiffness, the CFO mesocrystal experiences higher out-of-plane compressive strain and shows a stronger magnetic anisotropy as well as cation site-exchange. Our study suggests a new pathway to tailor the functionalities of mesocrystals.

The application of free tissue flap in simultaneous reconstruction of defects after tongue cancer / 中华整形外科杂志

<p><b>OBJECTIVE</b>To discuss the feasibility of using free tissue flap for simultaneous tongue reconstruction after tongue cancer resection.</p><p><b>METHOD</b>Radial forearm flaps and anterolateral thigh flaps were used for simultaneous reconstruction of different defects after tongue cancer resection in 47 cases. The functional evaluation was assessed during the follow-up period of 3 months to 9 years.</p><p><b>RESULTS</b>Only one flap failed,giving a success rate of 97.7%. The 36 patient available for postoperative follow-up were all able to communicate in basic languages and eat normally. Among them, normal speech was found in 34, while slurred speech was found in two. 31 patients could eat normal diet ,while eight could eat soft diet and two could eat liquid diet.</p><p><b>CONCLUSIONS</b>Simultaneous tongue reconstruction with free tissue flap is a reliable method with high successful rate. Flaps selection based on different tongue defects is the key point to achieve good functional and cosmetic results for the reconstruction tongue.</p>

Reconstruction of large through-and-through palate defects with folded free forearm flap / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the reconstruction method of large through-and-through palate defects.</p><p><b>METHODS</b>From 2003 to 2006, 7 cases of large through-and-through palate defects were reconstructed with vascularized folded free forearm flap. 8 flaps were used, including 7 free forearm flaps and 1 pectoralis major myocutaneous flap.</p><p><b>RESULTS</b>All the tissue flaps survived well except one flap necrosis because of arterial thrombosis. The appearance of reconstructed palate was acceptable, and the functions of swallowing and speech were normal or almost normal.</p><p><b>CONCLUSIONS</b>It is feasible and effective to repair large through-and-through palate defects with folded free forearm flap.</p>