Investigation on Upconversion Luminescence and Optical Temperature Sensing Behavior for Ba₂Gd₂Si₄O₁₃:Yb³⁺-Er³⁺/Ho³⁺/Tm³⁺ Phosphors

To explore new phosphors for temperature sensing with high detection sensitivity, the Yb³⁺-Er³⁺/Ho³⁺/Tm³⁺ doped Ba₂Gd₂Si₄O₁₃ (BGS) was designed. Different strategies were introduced based on the upconversion (UC) luminescence. For BGS:0.2Yb³⁺,0.02Er³⁺, the fluorescence intensity ratio (FIR) of two green emissions of Er³⁺ shows a gradual enhancement with increasing temperature due to the thermally coupled levels. The piecewise expression of sensitivity was proposed in the temperature range of 293–553 K based on the Boltzmann distribution. For BGS:0.2Yb³⁺,0.01Ho³⁺, the FIR of the red to green emissions of Ho³⁺ changes with temperature, showing a linear relationship from 293 to 453 K. The absolute sensitivity was gained to be 0.0452 K^–1. For BGS:0.2Yb³⁺,0.02Tm³⁺, the high absolute and relative sensitivities were both achieved by employing the thermally coupled (³F₂,³F₃) and ³H₄ levels of Tm³⁺. The above study could have special reference to the development of new luminescent materials with high sensitivity

Utilization of Li-Rich Phases in Aluminum Anodes for Improved Cycling Performance through Strategic Thermal Control

Lithium-ion batteries with aluminum anodes had appeared to resolve critical dendrite issues of lithium metal cells in the 1970s. However, the poor cycling performance attributed to aluminum anodes would lead to their obsolescence. In this work, we demonstrate how strategic thermal control in cycling aluminum anodes circumvents the problematic α/β phase transformations that yield poor cycling life. Instead, electrochemical formation of the Li3Al2 and Li2–xAl phases necessitates temperatures slightly above ambient, as the Li3Al2 and Li2–xAl phases are key enablers for high capacity and stable cycling. While delivering a competitive capacity level (ca. 1 Ah kg–1-Al), cycling among those higher-order phases is found to be significantly improved, from several cycles to 100 cycles with ca. 67% capacity retention. Importantly, because modern battery charging is likely to occur above room temperature due to ohmic heating, the thermal conditions explored here are expected to be realized in a variety of applications. Furthermore, we show that elevated temperature is not necessary for aluminum anode delithiation, thus creating additional synergies with many practical scenarios

A Combination of Guanidyl and Phenyl Groups on a Dendrimer Enables Efficient siRNA and DNA Delivery

Gene therapy has received considerable attention due to its great potential in the treatment of various diseases; however, the design of efficient and biocompatible carriers for the delivery of siRNA as well as DNA still remains a major challenge. In this study, we developed an efficient carrier for gene delivery by modification of a compound containing both guanidyl and phenyl groups on the surface of a cationic dendrimer. The guanidyl group on the dendrimer facilitates nucleic acid condensation via specific guanidinium–phosphate interactions, whereas the phenyl group on the polymer is critical for efficient endosomal escape. The combination of guanidyl and phenyl shows a synergistic effect in facilitated endocytosis. The designed material is much more efficient in siRNA and DNA delivery than control materials such as dendrimers engineered with a guanidyl or phenyl group only, as well as intact dendrimers, and shows comparable efficacy to commercial transfection reagent Lipofectamine 2000. In addition, the material and its complex with nucleic acid show minimal toxicity on the transfected cells. This study provides a new strategy to develop multifunctional polymers for efficient siRNA and DNA delivery

High-Spin Iron(II) Alkynyl Complexes with N‑Heterocyclic Carbene Ligation: Synthesis, Characterization, and Reactivity Study

High-spin iron­(II) alkynyl complexes [(IPr₂Me₂)₂­Fe­(CCBu^<i>t</i>)₂] (<b>1</b>) and [(IPr₂Me₂)₂Fe­(CCR)­(NHMes)] (R = Bu^<i>t</i> <b>2</b>, SiMe₃ <b>3</b>) bearing a monodentate N-heterocyclic carbene ligand IPr₂Me₂ (1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) have been prepared by salt metathesis and/or amine elimination methods and characterized by various spectroscopic methods. Complex <b>1</b> reacts with PMe₃ (4 equiv) and Bu^<i>t</i>NC (4 equiv) to form <i>trans</i>-[(PMe₃)₄­Fe­(CCBu^<i>t</i>)₂] (<b>4</b>) and [η³-{(Bu^<i>t</i>CC)­(Bu^<i>t</i>)­CC­(IPr₂Me₂)­C­(NBu^<i>t</i>)}­Fe­(NCBu^<i>t</i>)₃] (<b>5</b>), respectively. In contrast, the reactions of <b>1</b> with 4-Pr^<i>i</i>-C₆H₄NCO and Pr^<i>i</i>NCNPr^<i>i</i> lead to the formation of the zwitterionic salts 4-Pr^<i>i</i>-C₆H₄NC­(O)­(IPr₂Me₂) and (Pr^<i>i</i>N)₂C­(IPr₂Me₂), respectively. The interaction of <b>1</b> with I₂ gives Bu^<i>t</i>CCCCBu^<i>t</i> and (IPr₂Me₂)₂FeI₂. The C­(sp)–C­(sp³) cross-coupling products <i>n</i>-C₈H₁₇CCBu^<i>t</i> and <i>c</i>-C₆H₁₁CCBu^<i>t</i> are formed in high yields when <b>1</b> is treated with the corresponding alkyl halides <i>n</i>-C₈H₁₇X and <i>c</i>-C₆H₁₁X (X = Br, Cl). The formation of the ring-opening product 7,7-dimethyloct-1-en-5-yne in the reaction of <b>1</b> with cyclopropylmethyl bromide supports the radical character of the cross-coupling reaction

Upconversion Luminescence and Discussion of Sensitivity Improvement for Optical Temperature Sensing Application

Upconversion (UC) based luminescent materials have promising applications in noncontact temperature sensors. How to improve the sensitivity is one main object at present. This work presented several strategies for optical temperature sensing based on UC spectra of the Y₂WO₆:Yb³⁺-Er³⁺/Ho³⁺/Tm³⁺ phosphors. The improvement for the relative (<i>S</i>_R) and absolute (<i>S</i>_A) sensitivities were discussed by using a fluorescence intensity ratio technique. It includes thermally coupled levels (TCLs) and non-TCLs. It was proposed that a piecewise expression could be employed to achieve high <i>S</i>_A value for TCLs. However, improving the <i>S</i>_R value is limited for TCLs. With regard to the non-TCLs, <i>S</i>_R and <i>S</i>_A are not restricted, but not easy to be improved synchronously. On the other hand, the morphology and UC spectra of the samples were also studied. The above investigation could be instructive to develop new luminescent materials with high sensitivity

Anion Intercalation into Graphite Electrode from Ethylene Carbonate Solutions Dissolving both Lithium Hexafluorophosphate and Lithium Bis(trifluoromethanesulfonyl)imide

The diluted solutions of lithium bis(trifluoromethanesulfonimide) (LiTFSI) dissolving in organic solvents (ca. ethylene carbonate (EC)) are not compatible with dual-ion batteries (DIBs) mainly by virtue of the drastic decomposition of electrolyte solutions before the reversible storage of TFSI– in graphite positive electrodes. In this work, lithium hexafluorophosphate (LiPF6) is introduced into 1 M LiTFSI-EC solution to strengthen the oxidative endurance. The EC solutions with mixed salts demonstrate a synergistic effect in terms of anion storage in graphite electrode. The anion storage behavior of graphite electrode in the solutions of 1 M LiTFSI+LiPF6-EC is systematically investigated by conventional electrochemical tests of Li/graphite cells, in combination with ex situ/in situ X–ray diffraction measurements of graphite positive electrode and energy-dispersive spectroscopic analyses of the surface of graphite electrodes

The Value of Routine Biopsy during Percutaneous Kyphoplasty for Vertebral Compression Fractures

<div><p>Objective</p><p>Percutaneous kyphoplasty (PKP) is now widely performed to treat VCF, which is usually caused by osteoporosis. Previous researches have reported unsuspected malignancies found by biopsy. However, the safety and cost-effective profiles of routine biopsy during PKP are unclear. The purpose of this study was to evaluate the feasibility of routine biopsy during PKP in treatment of VCF.</p><p>Methods</p><p>Ninety-three patients (September 2007–November 2010) undergoing PKP without biopsy were reviewed as the control group. One hundred and three consecutive patients (November 2010–September 2013) undergoing PKP with biopsy of every operated vertebral level were prospectively enrolled as the biopsy group. The rate of unsuspected lesions was reported, and the severe adverse events, surgical duration, cement leakage rate and pain control were compared between the two groups.</p><p>Results</p><p>No statistically significant differences were found between the two groups, regarding the severe adverse events, surgical duration, cement leakage rate and pain control. Four unsuspected lesions were found in the biopsy group, three of which were malignancies with a 2.9% (3/103) unsuspected malignancy rate. The economic analysis showed that routine biopsy was cost-effective in finding new malignancies comparing with a routine cancer screening campaign.</p><p>Conclusions</p><p>Routine biopsy during PKP was safe and cost-effective in finding unsuspected malignancies. We advocate routine biopsy in every operated vertebral level during PKP for VCF patients.</p></div

Comparison of demographics, surgical duration, cement leakage rate and pain control between the biopsy and control groups.

<p>Comparison of demographics, surgical duration, cement leakage rate and pain control between the biopsy and control groups.</p

Electrostatic Assembly Preparation of High-Toughness Zirconium Diboride-Based Ceramic Composites with Enhanced Thermal Shock Resistance Performance

The central problem of using ceramic as a structural material is its brittleness, which associated with rigid covalent or ionic bonds. Whiskers or fibers of strong ceramics such as silicon carbide (SiC) or silicon nitride (Si₃N₄) are widely embedded in a ceramic matrix to improve the strength and toughness. The incorporation of these insulating fillers can impede the thermal flow in ceramic matrix, thus decrease its thermal shock resistance that is required in some practical applications. Here we demonstrate that the toughness and thermal shock resistance of zirconium diboride (ZrB₂)/SiC composites can be improved simultaneously by introducing graphene into composites via electrostatic assembly and subsequent sintering treatment. The incorporated graphene creates weak interfaces of grain boundaries (GBs) and optimal thermal conductance paths inside composites. In comparison to pristine ZrB₂–SiC composites, the toughness of (2.0%) ZrB₂–SiC/graphene composites exhibited a 61% increasing (from 4.3 to 6.93 MPa·m^1/2) after spark plasma sintering (SPS); the retained strength after thermal shock increased as high as 74.8% at 400 °C and 304.4% at 500 °C. Present work presents an important guideline for producing high-toughness ceramic-based composites with enhanced thermal shock properties

Characterization of the Translationally Controlled Tumor Protein (TCTP) Interactome Reveals Novel Binding Partners in Human Cancer Cells

Translationally controlled tumor protein (TCTP) is a highly conserved housekeeping protein present in eukaryotic organisms. It is involved in regulating many fundamental processes and plays a critical role in tumor reversion and tumorigenesis. Increasing evidence suggests that TCTP plays a role in the regulation of cell fate determination and is a promising therapeutic target for cancer. To decipher the exact mechanisms by which TCTP functions and how all these functions are integrated, we analyzed the interactome of TCTP in HeLa cells by coimmuno­precipitation (IP) and mass spectrometry (MS). A total of 98 proteins were identified. We confirmed the in vitro and in vivo association of TCTP with six of the identified binding proteins using reciprocal IP and bimolecular fluorescence complementation (BiFC) analysis, respectively. Moreover, TCTP interacted with Y-box-binding protein 1 (YBX1), and their interaction was localized to the N-terminal region of TCTP and the 1–129 amino acid (aa) residues of YBX1. The YBX1 protein plays an important role in cell proliferation, RNA splicing, DNA repair, drug resistance, and stress response to extracellular signals. These data suggest that the interaction of TCTP with YBX1 might cooperate or coordinate their functions in the control of diverse regulatory pathways in cancer cells. Taken together, our results not only reveal a large number of TCTP-associated proteins that possess pleiotropic functions, but also provide novel insights into the molecular mechanisms of TCTP in tumorigenesis