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The copper hydride nanocluster (NC) [Cu29Cl4H22(Ph2phen)12]Cl (2; Ph2phen = 4,7-diphenyl-1,10-phenanthroline) was isolated cleanly, and in good yields, by controlled growth from the smaller NC, [Cu25H22(PPh3)12]Cl (1), in the presence of Ph2phen and a chloride source at room temperature. Complex 2 was fully characterized by single-crystal X-ray diffraction, XANES, and XPS, and represents a rare example of an N* = 2 superatom. Its formation from 1 demonstrates that atomically precise copper clusters can be used as templates to generate larger NCs that retain the fundamental electronic and bonding properties of the original cluster. A time-resolved kinetic evaluation of the formation of 2 reveals that the mechanism of cluster growth is initiated by rapid ligand exchange. The slower extrusion of CuCl monomer, its transport, and subsequent capture by intact clusters resemble elementary steps in the reactant-assisted Ostwald ripening of metal nanoparticles. [ABSTRACT FROM AUTHOR]

Atomically precise copper nanoclusters (NCs) are of immense interest for a variety of applications, but have remained elusive. Herein, we report the isolation of a copper NC, [Cu25H22(PPh3)12]Cl (1), from the reaction of Cu(OAc) and CuCl with Ph2SiH2, in the presence of PPh3. Complex 1 has been fully characterized, including analysis by X-ray crystallography, XANES, and XPS. In the solid state, complex 1 is constructed around a Cu13 centered-icosahedron and formally features partial Cu(0) character. XANES of 1 reveals a Cu K-edge at 8979.6 eV, intermediate between the edge energies of Cu(0) and Cu(I), confirming our oxidation state assignment. This assignment is further corroborated by determination of the Auger parameter for 1, which also falls between those recorded for Cu(0) and Cu(I). [ABSTRACT FROM AUTHOR]

Two synthetic strategies for incorporating diiron analogues of [FeFe]-hydrogenases into short peptides via phosphine functional groups are described. First, utilizing the amine side chain of lysine as an anchor, phosphine carboxylic acids can be coupled via amide formation to resin-bound peptides. Second, artificial, phosphine-containing amino acids can be directly incorporated into peptides via solution phase peptide synthesis. The second approach is demonstrated using three amino acids each with a different phosphine substituent (diphenyl, diisopropyl, and diethyl phosphine). In total, five distinct monophosphine-substituted, diiron model complexes were prepared by reaction of the phosphine-peptides with diiron hexacarbonyl precursors, either (μ-pdt)Fe2(CO)6 or (μ-bdt)Fe2(CO)6 (pdt = propane-1,3-dithiolate, bdt = benzene-1,2-dithiolate). Formation of the complexes was confirmed by UV/Vis, FTIR and 31P NMR spectroscopy. Electrocatalysis by these complexes is reported in the presence of acetic acid in mixed aqueous-organic solutions. Addition of water results in enhancement of the catalytic rates. [ABSTRACT FROM AUTHOR]

The copper hydride clusters [Cu14H12(phen)6(PPh3)4][X]2 (X=Cl or OTf; OTf=trifluoromethanesulfonate, phen=1,10-phenanthroline) are obtained in good yields by the reaction of [(Ph3P)CuH]6 with phen, in the presence of a halide or pseudohalide source. The complex [Cu14H12(phen)6(PPh3)4][Cl]2 reacts with CO2 in CH2Cl2, in the presence of excess Ph3P, to form the formate complex [(Ph3P)2Cu(κ2-O2CH)], along with [(phen)(Ph3P)CuCl]. [ABSTRACT FROM AUTHOR]

The reactivity of MCl3(?1-TEMPO) (M = Fe, 1; Al, 2; TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) with a variety of alcohols, including 3,4-dimethoxybenzyl alcohol, 1-phenyl-2-phenoxyethanol, and 1,2-diphenyl-2-methoxyethanol, was investigated using NMR spectroscopy and mass spectrometry. Complex 1 was effective in cleanly converting these substrates to the corresponding aldehyde or ketone. Complex 2 was also able to oxidize these substrates; however, in a few instances the products of overoxidation were also observed. Oxidation of activated alkanes, such as xanthene, by 1 or 2 suggests that the reactions proceed via an initial 1-electron concerted proton-electron transfer (CPET) event. Finally, reaction of TEMPO with FeBr3 in Et2O results in the formation of a mixture of FeBr3(?¹-TEMPOH) (23) and [FeBr2(?¹-TEMPOH)]2(µ-O) (24), via oxidation of the solvent, Et2O. [ABSTRACT FROM AUTHOR]

Al-doped zinc oxide (AZO) thin films have been prepared by pulsed laser deposition (PLD). The structural, electrical and optical properties of these films were investigated as a function of Al-doping amount (0 to 7 wt%) in the target. Films were deposited at a low substrate temperature of 100°C under 10 Pa of oxygen pressure. It was observed that 3wt% of Al is the optimum doping amount in the target to achieve the minimum film resistivity. [ABSTRACT FROM AUTHOR]

We are interested in deriving various full Green functions through general Ward–Takahashi identities (WTIs) for quantized field theories. With the help of a postulate of gauge group parameter, the general local gauge transformation laws preserving the gauge-invariance of the generating functional itself of QED model have been established successfully. By using path-integral technique, the various WTIs with resulting anomaly terms are derived under the gauge transformations. The arising of Jacobian factor from the integration measure gives a viable possibility to express full Green function. As a consequence, the complete expressions of the full vector, the full axial-vector, the full tensor vertex functions and so on are presented respectively by solving the complete set of the WTIs in the momentum space without considering the constraint imposing any Ansatz. In addition, anomaly function also provides an effective means to judge the divergence of variant coupling currents on fields. [ABSTRACT FROM AUTHOR]

Reaction of [CuH(PPh3)]6 with 1 equiv. of Tl(OTf) results in formation of [Cu6TlH6(PPh3)6][OTf] ([1]OTf]), which can be isolated in good yields. Variable‐temperature 1H NMR spectroscopy, in combination with density functional theory (DFT) calculations, confirms the presence of a rare Tl−H orbital interaction. According to DFT, the 1H chemical shift of the Tl‐adjacent hydride ligands of [1]+ includes 7.7 ppm of deshielding due to spin‐orbit effects from the heavy Tl atom. This study provides valuable new insights into a rare class of metal hydrides, given that [1][OTf] is only the third isolable species reported to contain a Tl−H interaction. [ABSTRACT FROM AUTHOR]

A key question in condensed-matter physics is to understand how high-temperature superconductivity emerges on adding mobile charged carriers to an antiferromagnetic Mott insulator. We address this question using angle-resolved photoemission spectroscopy to probe the electronic excitations of the non-superconducting state that exists between the Mott insulator and the d-wave superconductor in Bi2Sr2CaCu2O8+δ. Despite a temperature-dependent resistivity characteristic of an insulator, the excitations in this intermediate state have a highly anisotropic energy gap that vanishes at four points in momentum space. This nodal-liquid state has the same gap structure as that of the d-wave superconductor but no sharp quasiparticle peaks. We observe a smooth evolution of the excitation spectrum, along with the appearance of coherent quasiparticles, as one goes through the insulator-to-superconductor transition as a function of doping. Our results suggest that high-temperature superconductivity emerges when quantum phase coherence is established in a non-superconducting nodal liquid. [ABSTRACT FROM AUTHOR]

Halogens are critical elements for transporting metals in hydrothermal solution and tracing the sources of fluids and volatiles in subduction zones. This study tested the suitability of LA-ICPMS for simultaneous measurement of Cl, Br and I with selected trace elements in altered gabbros recovered from the Atlantis Bank core complex close to the SW Indian Ridge. The aim was to better understand the causes of I-enrichment in low temperature carbonate and Fe-oxyhydroxide alteration, which is intensely developed in core recovered from between ~100 and ~600 mbsf down Hole U1473A drilled during Expedition 360 of the International Ocean Discovery Program (IODP). The analysis of reference materials including scapolites, Durango apatite, USGS and NIST reference glasses and volcanic glasses demonstrate Cl, Br and I can be measured in most minerals, but accuracy is limited by matrix dependent laser backgrounds (false signals of Cl, Br and I generated during sample ablation). Silicate reference glasses define reproducible 'laser backgrounds' of ~320 μg/g Cl and ~1.7 μg/g Br that point to limits of quantification of ~200 μg/g Cl and ~1 μg/g Br in silicate glasses after correction for laser backgrounds. In contrast, laser backgrounds are much lower and possibly negligible for carbonate, suggesting limits of quantification as low as ~50 μg/g Cl and 0.1 μg/g for Br, dependent on instrument sensitivity. Laser backgrounds for I varied between minerals and analytical sessions, there was no laser background for I in apatite and under favourable conditions silicate glasses have laser backgrounds of <1 μg/g. In addition to the laser backgrounds, we report a correction for interference of doubly charged rare earth elements on Br measurement, which significantly improves data quality for some samples. The Atlantis Bank alteration minerals investigated include calcite veins and Fe-oxyhydroxide, which is intermixed with, and cut by veinlets of, calcite and smectite. The Fe-oxyhydroxide contains 100 s–1000s μg/g Cl, 10s μg/g Br and 5–30 μg/g I and it is strongly enriched in other trace elements including B and As. Most calcite veins contain <100–200 μg/g Cl, <0.4–0.9 μg/g Br and 5–26 μg/g I. Among the halogens, I is uniquely correlated with divalent cations in calcite including Mg and Sr, consistent with its incorporation into the carbonate lattice as iodate. In most cases smectite contains less I than coexisting calcite or Fe-oxyhydroxide, but three smectite grains in one sample are exceptionally enriched with 150–240 μg/g I. The in situ analyses support the attribution of exceptional iodine enrichment of Atlantis Bank lithologies to preferential adsorption of iodate over halides by Fe-oxyhydroxides and subsequent remobilisation with preferential fixing of iodate in carbonate-dominated alteration. The data demonstrate the utility of LA-ICPMS for in situ halogen studies. Iodine in carbonate veins can provide information about fluid oxidation state and fluid-rock reaction history. However, further work is required to test if Cl and Br in carbonate can provide information about fluid sources. [ABSTRACT FROM AUTHOR]

Lithium enolates derived from carboxylic acids are ubiquitous intermediates in organic synthesis. Asymmetric transformations with these intermediates, a central goal of organic synthesis, are typically carried out with covalently attached chiral auxiliaries. An alternative approach is to utilize chiral reagents that form discrete, well-defined aggregates with lithium enolates, providing a chiral environment conducive of asymmetric bond formation. These reagents effectively act as noncovalent, or traceless, chiral auxiliaries. Lithium amides are an obvious choice for such reagents as they are known to form mixed aggregates with lithium enolates. We demonstrate here that mixed aggregates can effect highly enantioselective transformations of lithium enolates in several classes of reactions, most notably in transformations forming tetrasubstituted and quaternary carbon centers. Easy recovery of the chiral reagent by aqueous extraction is another practical advantage of this one-step protocol. Crystallographic, spectroscopic, and computational studies of the central reactive aggregate, which provide insight into the origins of selectivity, are also reported. [ABSTRACT FROM AUTHOR]

The article discusses a study on the impact of trisomy 8, isolated or present concurrently with other ACAs, on the response to TKIs treatment and clinical outcome in a cohort of 2015 chronic myelogenous leukemia (CML) patients admitted to the hospital during the tyrosine kinase inhibitor (TKI) era. The study indicated that trisomy 8 occurred in 30% of CML patients who had ACAs. [ABSTRACT FROM AUTHOR]

Apatite may be a common accessory mineral in coal seams, but interpretation of its origins can vary from syndepositional mineral detritus, early precipitation during diagenesis, and post coalification precipitation and replacement from hydrothermal or other fluids. It is hypothesised that paragenesis is reflected in the modes of occurrence in different stratigraphic units of the Late Permian in the Bowen Basin. From samples analysed in this study, apatite in the youngest unit, the Rangal Coal Measures, most commonly occurs as pore-apatites (i.e. apatites infilling preserved plant cell cavities of fusinite and semifusinite macerals and commonly associated with kaolinite) and less commonly as fracture-apatites (i.e. apatites infilling micro-fractures) and detrital-apatites intermixed with the organic coal layers (Detrital-B). In the tuffaceous Fort Cooper Coal Measures and equivalents, apatite occurs more commonly as detrital-apatites intermixed with the lithic layers (Detrital-A) (Detrital. Within the basal unit, the Moranbah Coal Measures and its equivalents, the mode is commonly encrusting-apatites (i.e. small apatite crystallites encrusting silicate minerals). Almost all apatites in the coal samples tested by electron microprobe microanalysis (EPMA), regardless of stratigraphic location and mode, are fluorapatite. Although there are some locality-driven enrichments, the minor and trace-element chemistry vary more so by mode of occurrence. For comparison, apatites from dykes intersecting the coal measures and from tuffs were also added to the study. These had lower fluorine (F) but measurable chlorine (Cl) contents and are enriched in light rare earth elements (LREE), similar to the Durango apatite that is of magmatic origins. Most of the detrital-A apatites are also enriched in LREE similar to the tuff-apatites, but with variable enrichment in the rare earth and yttrium elements. Detrital-B apatites have minimal Cl but also show the magmatic LREE trend. The pore- and fracture-apatites exhibited two trends. In the samples from tuffaceous coals (e.g., Fort Cooper Coal Measures), the pore- and fracture apatites tended to follow the magmatic LREE trend. In the Rangal Coal Measures, the pore- and fracture-apatites have elevated F contents, minimal Cl contents and depleted LREE contents (or Middle REE enrichment). Depletion of LREE could occur through leaching in an acidic environment, which is suggested by the abundance of kaolinite. Apatite precipitates under more neutral conditions although pore-apatites are commonly considered "early" and fracture-apatites "late" or post coalification. Their geochemical similarity suggests they have similar fluid origins and/or timing, with geothermal fluids moving through the porosity afforded by the structured inertinite group macerals and fractures. Verification of that geothermal source still requires further work and a technique that can analyse the isotopic composition—e.g., carbon (13C/12C), oxygen (18O/16O) and strontium (87Sr/86Sr)—of micron-sized crystals in situ. • Four primary modes of apatite occurrence were observed: pore and fracture infill, detrital (in organics and lithics), and encrusting • All apatites analysed by EPMA, regardless of mode, are fluorapatites. • The trace elements from EPMA REY patterns from LA-ICPMS differentiated by mode of occurrence • Results suggest the pore and fracture apatites precipitated or were geochemically over-printed by similar or same fluids. • Verification of source and timing requires the ability to date small (<10 μm) apatite crystals in situ. [ABSTRACT FROM AUTHOR]

In the face of changing global climate the future of corals reefs is uncertain. High latitude reefs may offer potential refugia for corals under projected increasing sea surface temperatures (SSTs). To understand the reef growth potential of modern high latitude reefs it is first necessary to understand past reef growth and response to climatic and environmental changes. The history of the Great Barrier Reef (GBR) has been shown to be punctuated by a multi-millennial Mid-Holocene reef "turn-off" or initiation hiatus in the Northern and Southern GBR (∼5500–2500 years before present [yr. BP]). Here we present the results of chronologically constrained reef matrix cores from five continental island fringing reefs and coral communities in the Keppel Islands to revaluate the timing, extent and possible drivers of the Mid-Holocene hiatus in the Southern GBR. Earliest initiation occurred at Wedge and Halfway Islands at 7773 ± 19 yr. BP and 7455 ± 20 yr. BP, respectively. Following initiation, vertical reef accretion at Halfway was comparable to previously reported rates for the GBR of ∼3.4 mm yr−1, increasing to ∼8.0 mm yr−1 between 6100 and 5500 yr. BP. Conversely, the coral community at Wedge Island, located closer to mainland terrestrial influence, accreted <1.0 mm yr−1 to 5500 yr. BP after which a 3000-year stratigraphic hiatus is observed. A negative relative sea level oscillation at 5500 yr. BP coincides with the transition of Halfway reef from vertical accretion to lateral progradation and the "turn-off" of the Wedge Island coral community. The reef at Middle Island appears to have initiated in the midst of the Mid-Holocene hiatus period at ∼3500 yr. BP, with vertical accretion at both Middle and Halfway Islands being the highest for the region's history at 12.5 ± 3.3 mm yr−1 and 15.0 ± 6.0 mm yr−1, respectively, between 3500 and 3000 yr. BP. A proposed late-Holocene relative sea level highstand of ∼1 m at ∼2000 yr. BP coincides with the first dates identified at near-shore Divided Island, and the re-initiation of coral growth at Wedge Island, although both showed limited net vertical accretion. These near-shore sites "turned-off" again between 1300 and 900 yr. BP, likely associated with a rapid relative sea level fall. Reef progradation also slowed at Halfway Island and Middle Island after 1200 yr. BP until a recent increase in reef growth at Middle Island since the late 1970's associated with modern increases in average SSTs. Our data suggests that although reef-scale "turn-off" events occurred, there is no evidence for a regional scale hiatus in coral growth or initiation comparable to that found further north on the GBR. A comparison with other Southern and south-Central GBR reef cores suggests that relative sea level oscillations in conjunction with changes to climate, appear to have driven varying, but synchronous, modifications to reefs at 5500, 4600, 2800 and 1200 yr. BP. • Limited evidence of a regional scale Holocene reef hiatus in the Keppel Islands. • Reefs display both broadly synchronous and completely disparate growth histories. • Sea level variability appears to be the primary driver of synchronous changes. • Palaeoclimate variability is associated with changes in net accretion rates. • The Keppel Islands offer potential refugia for corals under future climate challenges. [ABSTRACT FROM AUTHOR]

Background No standard treatment strategy for patients with recurrent/metastatic esophageal squamous cell carcinoma (ESCC) experiencing progression after one or more lines of chemotherapy. The aim of this study was to assess the efficacy and safety of apatinib, an oral vascular endothelial growth factor receptor 2 (VEGFR-2) tyrosine kinase inhibitor, in patients with recurrent/metastatic ESCC for whom at least one line of prior chemotherapy had failed. Methods This was a phase II trial that enrolled patients with recurrent/metastatic ESCC who had evidence of disease progression after first-line or more lines chemotherapy. All patients received continuous apatinib 500mg once daily until disease progression, death, or intolerable toxicity, dose escalation was allowed. The primary end point was progression free survival (PFS). Results Between July 2017 and August 2018, 40 patients were recruited. Data was cutoff at June 26, 2019. Among the 40 patients, 5 patients achieved partial response while 21 had stable disease. Primary end point median PFS (mPFS) was 113 days (95% 45-180). Median OS (mOS) was 158 days (95% 101-215), Objective response rate (ORR) was 12.5%. The incidence of drug-related adverse events (AEs) was 87.5%. 40.0% patients developed severe AEs. Main AEs were Fatigue (37.5%), Hand-foot syndrome (27.5%) and Hypertension (25%). Two patients with massive hemoptysis, and two patients with tracheal esophageal fistula had the uncontrolled primary tumor or trachea/bronchi eroded. Conclusions The study confirmed that apatinib was effective as second-line or more lines treatment for recurrent/metastatic ESCC patients, and most adverse effect were acceptable. However, patients with uncontrolled primary tumor or trachea/bronchi eroded should been cautiously considered to use. Clinical trial identification NCT03274011. Legal entity responsible for the study Fudan University Shanghai Cancer Center. Funding Jiangsu Hengrui Medicine. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]