Sulfonation of alginate grafted with polyacrylamide as a potential binder for high-capacity Si/C anodes

A systematic approach for how to find an appropriate polymer binder for high-capacity LIB anodes is presented in this study. As an example, a newly-developed SAlg-g-PAAm binder, alginate functionalized with sulfo groups and subsequently grafted with polyacrylamide, is used for the Si/C electrode. Various characteristics of the binder polymer itself, two basic characteristics of the electrode with respect to the binder, and the effect of the binder on cell performance are subsequently investigated. In all respects, the SAlg-g-PAAm polymer is a very promising binder for high-capacity anodes. The sulfo groups in the binder improve the ionic conductivities in both the binder and the electrode, leading to reduced charge transfer resistance. In addition, the sulfonation of the alginate grafted with polyacrylamide significantly enhances the mechanical and adhesion properties of the binder and consequently decreases the volume change generated during cycles. These advantages of the SAlg-g-PAAm binder ultimately lead to a considerable enhancement in the electrochemical performance of the high-capacity Si/C electrodes.

A systematic approach for how to find an appropriate polymer binder for high-capacity LIB anodes is presented in this study.     

Vinyltriethoxysilane crosslinked poly(acrylic acid sodium) as a polymeric binder for high performance silicon anodes in lithium ion batteries

In order to effectively relieve the large volume changes of silicon anodes during the cycling process in lithium ion batteries (LIBs), we developed a vinyltriethoxysilane crosslinked poly(acrylic acid sodium) polymeric binder (PVTES-NaPAA) for the Si anodes. The PVTES-NaPAA binder was synthesized by using a free radical co-polymerization method with VTES and NaPAA as precursors. In this binder, NaPAA with carboxyl groups can provide strong adhesion between Si particles and the current collector. Furthermore, VTES can be hydrolyzed and condense with each other to form a three-dimensional crosslinked network; the special network makes it possible to improve the Si electrode stability, resulting in an excellent cycling performance (78.2% capacity retention after 100 cycles) and high coulombic efficiency (99.9% after 100 cycles).

The PVTES-NaPAA binder possesses a three-dimensional crosslinked network and exhibits an excellent cycling performance.     

3D plum candy-like NiCoMnO4@graphene as anodes for high-performance lithium-ion batteries

3D plum candy-like NiCoMnO₄ microspheres have been prepared via ultrasonic spraying and subsequently wrapped by graphene through electrostatic self-assembly. The as-prepared NiCoMnO₄ powders show hollow structures and NiCoMnO₄@graphene exhibits excellent electrochemical performances in terms of rate performance and cycling stability, achieving a high reversible capacity of 844.6 mA h g⁻¹ at a current density of 2000 mA g⁻¹. After 50 cycles at 1000 mA g⁻¹, NiCoMnO₄@graphene delivers a reversible capacity of 1045.1 mA h g⁻¹ while the pristine NiCoMnO₄ only has a capacity of 143.4 mA h g⁻¹. The hierarchical porous structure helps to facilitate electron transfer and Li-ion kinetic diffusion by shortening the Li-ion diffusion length, accommodating the mechanical stress and volume change during the Li-ion insertion/extraction processes. Analysis from the electrochemical performances reveals that the enhanced performances could be also attributed to the reduced charge-transfer resistance and enhanced Li-ion diffusion kinetics because of the graphene-coating. Moreover, Schottky electric field, due to the difference in work function between graphene and NiCoMnO_4, might be favorable for the redox activity of the NiCoMnO₄. In light of the excellent electrochemical performance and simple preparation, we believe that 3D plum candy-like NiCoMnO₄@graphene composites are expected to be applied as a promising anode materials for high-performance lithium ion batteries.

3D plum candy-like NiCoMnO₄ microspheres have been prepared via ultrasonic spraying and subsequently wrapped by graphene through electrostatic self-assembly.     

Lithium sulfonate-grafted poly(vinylidenefluoride-hexafluoro propylene) ionomer as binder for lithium-ion batteries

Lithium sulfonate-grafted poly(vinylidenefluoride-hexafluoro propylene) P(VDF-HFP) ionomers are synthesized through covalent attachment of taurine and used as binder for the LiFePO₄ cathode of lithium-ion batteries(LIBs). The incorporation of the ionomer binders will add ionic conducting channels inside the electrodes, and prevent electrolyte depletion during rapid charge–discharge processes. It leads to an improved performance of LIBs using the ionomer binders including cycling stability and rate capability compared to that of LIBs using non-ionic binders (PVDF and PVDF-HFP). Therefore, the lithium sulfonate-grafted P(VDF-HFP) ionomers offer a new route to develop high-power LIBs.

Lithium sulfonate-grafted PVDF-HFP was successfully synthesized and used as binder for lithium ion batteries, improving electrochemical performance.     

Cross-linked β-CD-CMC as an effective aqueous binder for silicon-based anodes in rechargeable lithium-ion batteries

As a non-active material component, the binder can effectively maintain the integrity of battery electrodes. In this work, based on the inspired structure of fishing nets, a three-dimensional mesh adhesive using widely sourced raw materials CMC and β-CD was designed. These cross-linked cyclodextrins have the advantage of dispersing the stress at the anchor point and moderating the significant volume changes of the Si anode. The Si/β-CD-CMC electrode maintains a reversible capacity of 1702 mA h g⁻¹ even after 200 cycles at a high current of 0.5C. This work represents a significant step forward in Si anode binders and enables the cross-linked cyclodextrins to have potential applications in energy storage systems.

A three-dimensional mesh β-CD-CMC adhesive was designed based on the structure of fishing nets. This cross-linked binder has the ability to disperse the stress at the anchor point and moderate the significant volume changes of the Si anode.     

A procedure to average 3D anatomical structures

Creating a feature-preserving average of three dimensional anatomical surfaces extracted from volume image data is a complex task. Unlike individual images, averages present right-left symmetry and smooth surfaces which give insight into typical proportions. Averaging multiple biological surface images requires careful superimposition and sampling of homologous regions. Our approach to biological surface image averaging grows out of a wireframe surface tessellation approach by Cutting et al. (1993). The surface delineating wires represent high curvature crestlines. By adding tile boundaries in flatter areas the 3D image surface is parametrized into anatomically labeled (homology mapped) grids. We extend the Cutting et al. wireframe approach by encoding the entire surface as a series of B-spline space curves. The crestline averaging algorithm developed by Cutting et al. may then be used for the entire surface. Shape preserving averaging of multiple surfaces requires careful positioning of homologous surface regions such as these B-spline space curves. We test the precision of this new procedure and its ability to appropriately position groups of surfaces in order to produce a shape-preserving average. Our result provides an average that well represents the source images and may be useful clinically as a deformable model or for animation.     

G-protein sensitivity of ligand binding to human dopamine D(2) and D(3) receptors expressed in Escherichia coli: clues for a constrained D(3) receptor structure

Human dopamine D(2) and D(3) receptors were expressed in Chinese hamster ovary (CHO) and Escherichia coli cells to compare their ligand binding properties in the presence or absence of G-proteins and to analyze their ability to interact with G(i/o)-proteins. Binding affinities of agonists (dopamine, 7-OH-DPAT, PD128907, lisuride) and antagonists/inverse agonists (haloperidol, risperidone, domperidone, spiperone, raclopride, nemonapride), measured using [(125)I]iodosulpride and [(3)H]7-OH-DPAT, were similar for hD(3) receptors in E. coli and CHO cell membranes. Both agonists and antagonists showed 2- to 25-fold lower binding affinities at hD(2) receptors in E. coli versus CHO cell membranes (measured with [(3)H]spiperone), but the rank order of potencies remained similar. Purported inverse agonists did not display higher affinities for G-protein-free receptors. In CHO membranes, GppNHp decreased high affinity agonist ([(3)H]7-OH-DPAT) binding at hD(2) receptors but not at hD(3) receptors. Also, [(3)H]7-OH-DPAT (nanomolar concentration range) binding was undetectable at hD(2) but clearly measurable at hD(3) receptors in E. coli membranes. Addition of a G(i/o)-protein mix to E. coli membranes increased high affinity [(3)H]7-OH-DPAT binding in a concentration-dependent manner at hD(2) and hD(3) receptors; this effect was reversed by addition of GppNHp. The potency of the G(i/o)-protein mix to reconstitute high affinity binding was similar for hD(2) and hD(3) receptors. Thus, agonist binding to D(3) receptors is only slightly affected by G-protein uncoupling, pointing to a rigid receptor structure. Furthermore, we propose that the generally reported lower signaling capacity of D(3) receptors (versus D(2) receptors) is not due to its lower affinity for G-proteins but attributed to its lower capacity to activate these G-proteins.     

Thermal and mechanical reinforcement of a novel paraffin-based hydroxyl-terminated polybutadiene (HTPB) binder containing a three-dimension (3D) diurea–paraffin wax (DU–PW) for prevention of PW leakage

Leakage of paraffin wax (PW) is a major concern in the development of polymer bonded explosive (PBX) systems because it relates to the amount of PW that can be used as a desensitizer or a fuel, which, in turn, affects the mechanical performance and tolerance of PBX in high-temperature environments. Hydroxyl-terminated polybutadiene (HTPB) binders significantly contribute desirable polymer features to PBX. Thus, a three-dimension (3D) high-temperature non-flowing diurea–paraffin wax (DU–PW) composite was synthesized and creatively employed to a HTPB binder. DU–PW/PW/HTPB composites with different contents of the 3D DU–PW phase change material (PCM) were prepared through a cast molding process. The differential scanning calorimetry (DSC) results demonstrate that these composites can show high phase-change enthalpies and good thermal reliability. As observed from the scanning electron microscope (SEM) photographs, adding DU–PW can clearly reduce the number of holes caused by the leaked PW on the fracture surface of DU–PW/HTPB. Moreover, the addition of DU–PW can remarkably reduce the leakage of PW and improve the thermal stability as well as mechanical properties of the PW-based HTPB. These observations present the potential of utilizing form-stable PCM (FSPCM) to solve the problem of PW leakage in PBX systems.

DU is creatively used as supporting materials to shape-stablize PW. The prepared DU–PW composite can effectively improve the thermal and mechanical properties of PW/HTPB, indicating a prospect to prevent PW leakage in PBX.     

A novel square-planar Pt(ii) complex as a monomeric and dimeric G-quadruplex DNA binder

A novel phenanthroimidazole ethylenediamine Pt(ii) complex with coumarin derivative (1) was synthesized and showed higher affinity, selectivity and thermal stabilization for mixed-type dimeric G-quadruplexes (G2T1) over monomeric G-quadruplexes (G1) and duplex DNA. Complex 1 could bind to G-quadruplexes via end-stacking and external-binding modes.

A phenanthroimidazole ethylenediamine Pt(ii) complex with coumarin derivative (1) showed high binding properties and thermal stabilization for dimeric quadruplexes G2T1.

G-quadruplex DNA, as a noncanonical secondary DNA structure, is formed by G-rich sequences widespread in biologically important regions of the human genome. Its stabilization at telomeric regions can inhibit telomerase activity and interfere with telomere biology, which makes it a potential target for the development of new anticancer therapies.^1,2 However, bioinformatic studies have shown that over 700, 000 DNA sequences within the human genome have potential to form G-quadruplex structures.³ So it is crucial to selectively bind the different sequences and conformations of G-quadruplexes. The ca. 200 bases of the single-stranded overhang of telomeric DNA can potentially fold into multimeric telomeric G-quadruplexes consisting of several consecutive G-quadruplex units linked by TTA spacers.^4,5 Moreover, multimeric G-quadruplexes could be formed by telomeric DNA and r(GGGGCC)_n RNA repeats, being relevant in amyotrophic lateral sclerosis.^6,7 Thus it is significant to design some binders for selectively binding and stabilizing multimeric G-quadruplexes.Many square-planar Pt(ii) complexes, such as square-planar platinum(ii) phenanthroline complexes, have been reported as good binders of G-quadruplexes for possessing a large electron deficient π-aromatic surface, positively charged substituents and a positively charged center.^8–12 Some Pt(ii) complexes have been modified with a pendant cyclic amine or pyridine side arm and exhibited high affinity for human telomeric G-quadruplexes.^8–10 Other structurally analogous Pt(ii) complexes, including ones with phenanthroimidazol,¹¹ dipyridophenazine,¹² and C-coordinated phenylpyridine ligands,¹² have exhibited considerably stronger interactions with G-quadruplex DNA for possessing an extended π-surface. Though a few small molecules have been studied to specifically bind multimeric G-quadruplex structures,^13–18 most square-planar Pt(ii) phenanthroline complexes have been discussed to selectively bind monomeric G-quadruplexes rather than multimeric G-quadruplexes.It has been reported that an excellent binder of monomeric G-quadruplexes, such as TMPyP4 and azatrux, could also show high binding properties toward multimeric G-quadruplexes, and even result in the significant differences of the binding properties toward multimeric G-quadruplexes and monomeric G-quadruplexes.¹⁹ With this thought in mind, together that the coumarin derivatives possess a π-surface and an amino substituent, we chose phenanthroimidazole ethylenediamine with coumarin derivative L previously reported²⁰ as a ligand, synthesized its Pt(ii) complex 1 (Scheme 1), and systematically studied its binding affinities, selectivities and thermal stabilization towards human telomeric dimeric quadruplexes G2T1 and monomeric quadruplexes G1.Open in a separate windowScheme 1Synthesis of complex 1. Reagents and conditions: (a) K₂PtCl₄, aqueous DMSO, 140 °C, 2 h; (b) ethylenediamine, EtOH, 80 °C, 12 h.Complex 1 was synthesized according to the synthetic route in Scheme 1. Phenanthroimidazole with coumarin derivative L reacted with K₂PtCl₄ in aqueous DMSO and got a red solid of Pt(ii) complex 2. Complex 2 reacted with ethylenediamine in ethanol and got the crude product, which was washed with CHCl₃ to afford complex 1 as a red solid in 39% yield. Complex 1 was fully characterized by ¹H NMR, MS (LR and HR), IR and elemental analysis (seeing ESI^†).^‡The binding effect of complex 1 on the structures of dimeric G-quadruplexes G2T1 was investigated by circular dichroism (CD) spectra. At first, addition of complex 1 led no significant changes in the ellipticity of antiparallel G2T1, and only induced minor changes in the negative ellipticity at 265 nm (Fig. S3^†). These results suggest that complex 1 brought about no structural changes and low binding affinity toward antiparallel G2T1. Subsequently, for mixed-type G2T1, addition of complex 1 led to the increasement of the band with maximum at 291 nm and the shoulder at 270 nm and the shift of the maximum band from 291 nm to 287 nm (Fig. 1a). These results show that complex 1 strongly bound with mixed-type G2T1.Open in a separate windowFig. 1(a) CD spectra of mixed-type G2T1 (3.0 μM) in the presence of complex 1: (1) 0 equiv.; (2) 2 equiv.; (3) 4 equiv. and (4) 8 equiv., respectively. (b) CD-melting profiles at 290 nm for mixed-type G2T1 (3.0 μM) with complex 1 (0, 12 and 24 μM, respectively). Values are the average ± SD of three independent measurements.Thermal stabilization of complex 1 towards mixed-type G2T1 was further assessed by CD-melting assays (Fig. 1b and S4^†). Complex 1 displayed a ΔT_m value being 9.0 °C at 4 : 1 complex-to-G2T1 ratio. And the values of ΔT_m increased with the increasing amounts of complex 1. A higher thermal stabilization (ΔT_m = 11.5 °C) was observed at 8 : 1 complex-to-G2T1 ratio, which suggests that complex 1 exhibited comparable thermal stabilization with those mixed-type G2T1 binders reported in the literature.^16,17,19,21 In contrast, complex 1 had negligible thermal stabilization towards monomeric quadruplexes G1 (ΔT_m = 1.2 °C, Fig. S5a^†) and double-stranded (ds) DNA (ΔT_m = −2.9 °C, Fig. S5b^†). These results show that complex 1 had the preferential thermal stabilization towards mixed-type G2T1 over G1 and ds DNA.Based on higher thermal stabilization of complex 1 towards mixed-type G2T1 over G1, the binding selectivity of complex 1 was further confirmed for mixed-type G2T1 by gel electrophoresis (Fig. 2). The gel reveals that addition of complex 1 to mixed-type G1 led to no appearance of any new band (lane 2–3). However, the presence of complex 1 increased the mobility of the mixed-type G2T1 (lane 5). These results suggest that complex 1 could form a compact complex with G2T1 rather than G1,^14,16 which was further verified by incubating complex 1 with a mixture of G1 and G2T1 and then analysing their gel electrophoresis. Obviously, a mixture of G1 and G2T1 in the absence of complex 1 gave the characteristic bands corresponding to intramolecular G1 and G2T1 (lane 6). When complex 1 added to a mixture of G1 and G2T1, a new band corresponding to the complex of G2T1 with complex 1 (G2T1 + 1) appeared and became more intense with the increasing amounts of complex 1 (lanes 7 to 9). However, no new band appeared corresponding to the complex of G1 and complex 1 (lanes 7 to 9). These results indicate that complex 1 had higher binding selectivity towards G2T1 over G1.Open in a separate windowFig. 2Native gel electrophoretic analysis of G1, G2T1 and their mixture in the presence of complex 1 in Tris–HCl buffer (10 mM, 100 mM KCl and pH 7.0). Lanes 1–3: G1 (16 μM) in the presence of complex 1 (0, 16 and 32 μM); lanes 4–5: G2T1 (8 μM) in the presence of complex 1 (0 and 8 μM); lanes 6–9: mixtures of G1 (16 μM) and G2T1 (8 μM) in the presence of complex 1 (0, 8, 16 and 32 μM, respectively); lane 10: DNA ladder.The binding affinities of complex 1 towards mixed-type G2T1 and G1 were determined by UV-Vis titrations (Fig. 3 and S6a^†). The gradual addition of G2T1 and G1 to complex 1 resulted in considerable hyperchromicity, a noticeable red-shift at ca. 449 nm (15 nm for G2T1 and 11 nm for G1) and the appearance of a new and strong absorbance peak at ca. 481 nm (Fig. 3a and S6a^†), which suggests that complex 1 could interact with G2T1 and G1. Then the data of UV-Vis titrations were also used to calculate the binding constant (K) of complex 1 and the number of binding sites towards G2T1 and G1 by Scatchard eqn (1a):²²r/C_f = nk − rK1ar = C_b/C_DNA1bC_b = C_t (A − A₀)/(A_max − A₀)1chere, C_t is the total complex concentration, C_b is bound complex concentration, C_f is free complex concentration, A and A_max are the observed and maximum absorption values of complex 1 at ca. 481 nm with addition of DNA, and A₀ is the absorption value of complex 1 at ca. 481 nm without addition of DNA. In eqn (1a), r represents the number of moles of bound complex per mole of DNA, D_f represents the concentration of unbound complex, K is the binding constant, and n is the number of complex-binding sites on the G-quadruplex. The plot of r/D_fversus r gives the binding constant. The results were presented in Fig. 3b and Fig. 3b, the Scatchard plots had no single linear relationship but two regression curves, which suggests the existence of two types of binding sites in the interaction of complex 1 and DNA. The binding stoichiometries of complex 1 were 1.0 : 1 for G2T1 and 1.1 : 1 for G1, respectively, when [1]/[DNA] was lower than 1.0. And the binding stoichiometries of complex 1 were 1.5 : 1 for G2T1 and 1.7 : 1 for G1, respectively, when [1]/[DNA] was higher than 1.0 (†). These results show that complex 1 had higher binding affinity towards G2T1 over G1 and CT DNA. The K_a value of complex 1 towards mixed-type G2T1 was (9.70 ± 0.26) μM⁻¹ (13,19,21,23Open in a separate windowFig. 3(a) UV-Vis titrations of 20 μM complex 1 in the presence of mixed-type G2T1 (from 0–25 μM). (b) Scatchard plots for complex 1 with G2T1 and G1. The absorbance values at ca. 481 nm were used to construct the Scatchard plots. Values are the average ± SD of three independent measurements.Binding parameters obtained from UV-Vis titrations^a

PAMPS-graft-Ni3Si2O5(OH)4 multiwalled nanotubes as a novel nano-sorbent for the effective removal of Pb(ii) ions

The existence of Pb(ii) ions in water systems poses significant potential hazards to public health and the environment. In the present study, poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) brush-modified Ni₃Si₂O₅(OH)₄ nanotubes were prepared, and their adsorption efficiency against the Pb(ii) ions was investigated. The characterization results of FTIR spectroscopy, TGA, TEM, and XPS indicated the successful grafting of PAMPS on the surface of free Ni₃Si₂O₅(OH)₄ NTs, and the prepared PAMPS-g-Ni₃Si₂O₅(OH)₄ NTs exhibited a 6–8 nm grafting layer, which could provide abundant binding sites for metal adsorption. During the Pb(ii) removal process, a pH-dependent adsorption behavior was observed, and the adsorption processes fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm model. Compared with unmodified Ni₃Si₂O₅(OH)₄, the PAMPS-g-Ni₃Si₂O₅(OH)₄ NTs exhibited obviously faster adsorption of Pb(ii) and higher equilibrium adsorption capacity for the removal of Pb(ii). The maximum adsorption capacity calculated via the Langmuir isotherm model was 0.653 mmol g⁻¹ (135.3 mg g⁻¹) at 298 K. In a metal coexisting system, the total adsorption capacity of the NTs was increased; this indicated the potential of the proposed NTs in the removal of Pb(ii) from metal coexisting wastewater. This study showed the significant potential of PAMPS-g-Ni₃Si₂O₅(OH)₄ NTs in the effective removal of Pb(ii).

PAMPS-g-Ni₃Si₂O₅(OH)₄ NTs for the effective removal of Pb(ii).     

Surface phosphation of 3D mesoporous NiCo2O4 nanowire arrays as bifunctional anodes for lithium and sodium ion batteries

A novel surface phosphate strategy was adopted to dramatically improve the charge transport, ion diffusion, electroactive sites, and cycle stability of mesoporous NiCo₂O₄ nanowire arrays (NWAs), drastically boosting their electrochemical properties. Consequently, the as-prepared phosphated NiCo₂O₄ NWA (P-NiCo₂O₄ NWA) electrode achieved excellent energy storage performance as a bifunctional anode material for both lithium ion batteries (LIBs) and sodium ion batteries (SIBs). When evaluated as an anode for LIBs, this P-NiCo₂O₄ NWA electrode showed a high reversible capacity up to 1156 mA h g⁻¹ for 1500 cycles at 200 mA g⁻¹ without appreciable capacity attenuation, while in SIBs, the electrode could also deliver an admirable initial capacity as high as 687 mA h g⁻¹ and maintained 83.5% of this after 500 cycles at the same current density. Most important, when the current density increased from 100 to 1000 mA g⁻¹, the capacity retention was about 63% in LIBs and 54% in SIBs. This work may shed light on the engineering of efficient electrodes for multifunctional flexible energy storage device applications.

A novel surface phosphate strategy was adopted to dramatically improve the charge transport, ion diffusion, electroactive sites, and cycle stability of mesoporous NiCo₂O₄ nanowire arrays (NWAs), drastically boosting their electrochemical properties.     

Tracing in 2D to reduce the annotation effort for 3D deep delineation of linear structures

The difficulty of obtaining annotations to build training databases still slows down the adoption of recent deep learning approaches for biomedical image analysis. In this paper, we show that we can train a Deep Net to perform 3D volumetric delineation given only 2D annotations in Maximum Intensity Projections (MIP) of the training volumes. This significantly reduces the annotation time: We conducted a user study that suggests that annotating 2D projections is on average twice as fast as annotating the original 3D volumes. Our technical contribution is a loss function that evaluates a 3D prediction against annotations of 2D projections. It is inspired by space carving, a classical approach to reconstructing complex 3D shapes from arbitrarily-positioned cameras. It can be used to train any deep network with volumetric output, without the need to change the network’s architecture. Substituting the loss is all it takes to enable 2D annotations in an existing training setup. In extensive experiments on 3D light microscopy images of neurons and retinal blood vessels, and on Magnetic Resonance Angiography (MRA) brain scans, we show that, when trained on projection annotations, deep delineation networks perform as well as when they are trained using costlier 3D annotations.     

Calcium carbonate as a phosphate binder: is there a need to adjust peritoneal dialysate calcium concentrations for patients using CaCO3?

The widespread use of calcium carbonate as a phosphate binder is limited by its tendency to develop hypercalcemia in some patients using effective dosages needed to control hyperphosphatemia. Most common continuous ambulatory peritoneal dialysis (CAPD) regimens using dialysis solutions containing 3.5 mEq/L of calcium result in net absorption of calcium from the dialysis solution and, hence limit the amount of oral calcium that can be administered. Peritoneal dialysis solutions with reduced calcium levels are needed for effective use of CaCO3 to control hyperphosphatemia in some dialysis patients.     

The role of thermal annealing on the microstructures of (Ti,Fe)-alloyed Si thin-film anodes for high-performance Li-ion batteries

Here, we studied the effect of thermal annealing on the microstructure and cyclic stability of a (Ti, Fe)-alloyed Si thin-film fabricated by a simple sputtering deposition method for Li-ion battery (LIB) anodes. The anode samples annealed at different temperatures (300–600 °C) were subjected to microstructure analysis and LIB performance test. The (Ti, Fe)-alloyed Si thin-film anode delivered a high capacity of 1563 mA h g⁻¹ for 100 cycles at 0.1 A g⁻¹ with nearly 100% capacity retention. Post-mortem analysis using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) disclosed the microstructural changes of the cycled anodes, revealing that (Ti, Fe) silicides served as a structural buffer against the large volume change of active Si during cycling for enhanced LIB performance.

We investigated the role of annealing on the microstructural changes and cyclic stability of (Ti, Fe)-alloyed Si thin-film anodes.     

PVDF-supported graphene foam as a robust current collector for lithium metal anodes

Lithium metal batteries have drawn much attention due to their ultrahigh energy density. However, the safety hazards and limited lifetime caused by severe lithium dendrite growth during cycling hinder their real application. To address this issue and improve the electrochemical performance of current lithium batteries, a current collector beyond the traditional copper foil for lithium anodes is highly needed. We proposed and prepared a PVDF-supported graphene foam (PSGF) structure as an effective current collector for lithium metal anodes. Because of its structural stability, large surface area, and lithiophilic surface chemistry, the corresponding lithium metal anode (PSGF@Li) shows an extended cycling life (∼1000 h), a decreased voltage hysteresis (∼80 mV) and an improved coulombic efficiency (∼99%). Furthermore, the practical application of the PSGF@Li anode in a full cell system was also demonstrated.

A robust lithium metal anode comprising of PSGF current collector showing long cycling life.     

Boric acid as a precatalyst for BH3-catalyzed hydroboration

We report that boric acid, BO₃H₃, is a good precatalyst for the BH₃-catalyzed hydroboration of esters using pinacolborane as a borylation agent. Using microwave irradiation as an energy source, we demonstrated that a dozen esters were converted into the corresponding boronate ethers in good yields. It was also possible to use boric acid as a precatalyst to reduce carbonates and alkynes. Considering the hazardous and pyrophoric nature of BH₃ solutions, boric acid proves to be a safe and green precatalyst for the metal-free reduction of unsaturated species.

Cheap and air-stable boric acid is shown to be a good precatalyst for BH₃ hydroboration of esters and carbonates.     

13-Cis-retinoic acid: a new form of treatment of rosacea (author's transl)

13-cis-retinoic acid was given with good results to 7 patients with exceptionally severe rosacea. Side effects were transitory and of minor consequence and subsided quickly on reduction of the dosage and topical application of mild cosmetics. The long-lasting remissions recorded to date indicate that 13-cis-retinoic acid may prove a new and successful approach to the treatment of rosacea.