Unusual quadruple bonds featuring collective interaction-type σ bonds between first octal-row atoms in the alkaline-earth compounds AeOLi (Ae = Be-Ba).

Quantum chemical calculations are reported for the complexes of alkaline earth metals AeOLi (Ae = Be-Ba) at the BP86-D3(BJ)/def2-QZVPP and CCSD(T)/def2-QZVPPQZVPP levels. The nature of the Ae-OLi bond has been analyzed with a variety of methods. The AeOLi molecules exhibit an unprecedented σ donor bond Ae→OLi where the ()s lone-pair electrons of the Ae atom are donated to vacant O-Li antibonding orbitals having the largest coefficient at lithium.

Predicting the efficiency of arsenic immobilization in soils by biochar using machine learning.

Arsenic (As) pollution in soils is a pervasive environmental issue. Biochar immobilization offers a promising solution for addressing soil As contamination. The efficiency of biochar in immobilizing As in soils primarily hinges on the characteristics of both the soil and the biochar.

Multiple Bonding in AeN (Ae=Ca, Sr, Ba).

Quantum chemical calculations using ab initio methods at the MRCI+Q(8,9)/def2-QZVPPD and CCSD(T)/def2-QZVPPD levels as well as using density functional theory are reported for the diatomic molecules AeN (Ae=Ca, Sr, Ba). The anions CaN and SrN have electronic triplet (Π) ground states with nearly identical bond dissociation energies D ~57 kcal/mol calculated at the MRCI+Q(8,9)/def2-QZVPPD level. In contrast, the heavier homologue BaN has a singlet (Σ) ground state, which is only 1.

MB (M=Sc, Y, La): Perfect Bowl-Like Boron Clusters.

The introduction of transition-metal doping has engendered a remarkable array of unprecedented boron motifs characterized by distinctive geometries and bonding, particularly those heretofore unobserved in pure boron clusters. In this study, we present a perfect (no defects) boron framework manifesting an inherently high-symmetry, bowl-like architecture, denoted as MB (M=Sc, Y, La). In MB , the B is coordinated to M atoms along the C-symmetry axis.

Analysis of the Unusual Chemical Bonds and Dipole Moments of AeF (Ae=Be-Ba): A Lesson in Covalent Bonding.

Quantum chemical calculations of the anions AeF (Ae=Be-Ba) have been carried out using ab initio methods at the CCSD(T)/def2-TZVPP level and density functional theory employing BP86 with various basis sets. The detailed bonding analyses using different charge- and energy partitioning methods show that the molecules possess three distinctively different dative bonds in the lighter species with Ae=Be, Mg and four dative bonds when Ae=Ca, Sr, Ba. The occupied 2p atomic orbitals (AOs) and to a lesser degree the occupied 2s AO of F donate electronic charge into the vacant sp(σ) and p(π) orbitals of Be and Mg which leads to a triple bond Ae F.

Transition Metal Behavior of Heavier Alkaline Earth Elements in Doped Monocyclic and Tubular Boron Clusters.

Quantum chemical calculations are carried out to design highly symmetric-doped boron clusters by employing the transition metal behavior of heavier alkaline earth (Ae = Ca, Sr, and Ba) metals. Following an electron counting rule, a set of monocyclic and tubular boron clusters capped by two heavier Ae metals were tested, which leads to the highly symmetric AeB, AeB, and AeB clusters as true minima on the potential energy surface having a monocyclic ring, two-ring tubular, and three-ring tubular boron motifs, respectively. Then, a thorough global minimum (GM) structural search reveals that a monocyclic B ring capped with two Ae atoms is indeed a GM for CaB and BaB, while for SrB it is a low-lying isomer.

Mimicking the C molecule: MB and MB clusters (M = Li, Na) and the reactivity of the N-heterocyclic carbene bound LiB complex.

C has attracted considerable attention from the scientific community for its debatable bonding situation. Herein, we show that the global minima of MB and MB (M = Li, Na) possess similar covalent bonding patterns to C. Because of strong charge transfer from M/M to B dimer, they can be better described as [M][B] and [M][B] salt complexes with the B core surrounded perpendicularly by two and three M atoms, respectively.

Clusters and bulky Lewis acid protected complexes with planar hexacoordinate beryllium and magnesium.

Planar hexacoordination (ph) is only rarely reported in the literature. So far, only a few neutral and cationic molecules possessing phE (E = C, Si, B, Al, Ga) in the most stable isomer are predicted theoretically. Present electronic structure calculations report hitherto unknown anionic planar hexcoordinate beryllium and magnesium, phBe/Mg, as the most stable isomer.

Global Planar Tetra-, Penta- and Hexa-coordinate Silicon Clusters Constructed by Decorating SiO with Alkali Metals.

The achievement of the rule-breaking planar hypercoordinate motifs (carbon and other elements) is mainly attributed to a practical electronic stabilization mechanism, where the bonding of the central atom p π electrons is a crucial issue. We have demonstrated that strong multiple bonds between the central atom and partial ligands can be an effective approach to explore stable planar hypercoordinate species. A set of planar tetra-, penta- and hexa-coordinate silicon clusters were herein found to be the lowest-energy structure, which can be viewed as decorating SiO by alkali metals in the MSiO , M SiO and M SiO (M=Li, Na) clusters.

B Be B : A Boron-Beryllium Sandwich Complex.

Planar boron clusters have often been regarded as "π-analogous" to aromatic arenes because of their similar delocalized π-bonding. However, unlike arenes such as C H and C H , boron clusters have not previously shown the ability to form sandwich complexes. In this study, we present the first sandwich complex involving beryllium and boron, B Be B .

Quest of Quadruple Bonding Between Two Main-Group Atoms in AeB and AeC (Ae=Ca, Sr, Ba) and the Role of d Orbitals of Heavier Alkaline-Earth Atoms in Covalent Interactions.

Quantum chemical calculations using ab initio methods at the MRCI+Q(6,8)/def2-QZVPP and CCSD(T)/def2-QZVPP levels as well as density functional theory are reported for the diatomic molecules AeB and isoelectronic AeC (Ae=Ca, Sr, Ba). The boride anions AeB have an electronic triplet ( Σ ) ground state. The quintet ( Σ ) state is 5.

Evidence basis for using dexmedetomidine to enhance the quality of paravertebral block: A systematic review and meta-analysis of randomized controlled trials.

Dexmedetomidine is considered an adjunct to local anaesthesia (LA) to prolong peripheral nerve block time. However, the results from a previous meta-analysis were not sufficient to support its use in paravertebral block (PVB). Therefore, we performed an updated meta-analysis to evaluate the efficacy of dexmedetomidine combined with LA in PVB.

Designing a Four-Ring Tubular Boron Motif through Metal Doping.

Tubular boron clusters represent a class of extremely unusual geometries that can be regarded as a key indicator for the 2D-to-3D boron structural evolution as well as the embryos for boron nanotubes. While a good number of pure boron or metal-doped boron tubular clusters have been reported so far, most of them are two-ring tubular structures, and their higher-ring analogues are very scarce. We report herein the first example of a four-ring tubular boron motif in the cagelike global minimum of BeB.

Be B : A Covalently Bonded Archimedean Beryllo-Borospherene.

A new class of beryllium-boron clusters, beryllo-borospherene, is described herein theoretically. When beryllium is gradually added to the B motif, it undergoes drastic structural modifications. The global minimum of the Be B cluster is an Archimedean beryllo-borospherene in a A electronic ground state, composed of four boron triangles linked at each corner, resulting in a truncated tetrahedron with four B rings capped with four beryllium atoms.

Uptake of oncology biosimilars: managed care strategies to improve value-based care systems.

The use of biosimilars in oncology and as supportive agents for patients with cancer has introduced an important opportunity to expand access to cost-effective care, but their utilization remains inconsistent and is influenced by a variety of factors. Promoting the uptake of biosimilars across healthcare systems relies on improving perception and education about biosimilars, which involves multiple stakeholders, including pharmacists, providers, and patients. Clinicians and managed care professionals must consider comparative analytical studies, clinical efficacy data, and reductions in costs of care associated with biosimilars when establishing protocols for their inclusion within formularies.

Bonding situations in tricoordinated beryllium phenyl complexes.

The bonding situation in the tricoordinated beryllium phenyl complexes [BePh ] , [(pyridine)BePh ] and [(trimethylsilyl-N-heterocyclic imine)BePh ] is investigated experimentally and computationally. Comparison of the NMR spectroscopic properties of these complexes and of their structural parameters, which were determined by single crystal X-ray diffraction experiments, indicates the presence of π-interactions. Topology analysis of the electron density reveals elliptical electron density distributions at the bond critical points and the double bond character of the beryllium-element bonds is verified by energy decomposition analysis with the combination of natural orbital for chemical valence.

A biomass-derived Schiff base material composited with polylactic acid nanofiber membrane as selective fluorescent 'turn off/on' platform for Pb quantitative detection and characterization.

Herein, a biomass-derived compound Z1 is synthesized via 'one pot' method for detection Pb using fluorescence and visual dual-mode in aqueous solution. Z1 shows good response to Pb with a limit of detection (LOD) of 13.4 nM.

Two-layer molecular rotors: A zinc dimer rotating over planar hypercoordinate motifs.

Multi-layer molecular rotors represent a class of unique combination of topology and bonding, featuring a barrier-free rotation of one layer with respect to other layers. This emerging fluxional behavior has been found in a few doped boron clusters. Herein, we strongly enrich this intriguing family followed by an effective design strategy, summarized as essential factors: i) considerable electrostatic interactions originated from a strong charge transfer between layers; ii) the absence of strong covalent bonds between layers; and iii) fully delocalized σ/π electrons from at least one layer.

Managed care opportunities and approaches to select treatment for sight preservation.

Anti-vascular endothelial growth factor therapies have become the mainstay of treatment for both diabetic macular edema and neovascular age-related macular degeneration. This treatment is imperative for vision preservation including visual acuity. However, treatment burdens include high costs, frequent injections, continued visual loss, and loss of ability to perform day-to-day functions.

σ-Aromaticity Planar Pentacoordinate Beryllium Atoms.

Six-valence-electron planar pentacoordinate beryllium (ppBe) is explored herein as a global minimum, which is only constructed by s-block metals in BeM (M = Cu, Ag, Au). The bonding in ppBe can be regarded as the excited-stated Be with a 2p2p electronic configuration, forming electron sharing with doublet M motifs followed by two sets of Be(p) → [M] σ donations and one Be(s) ← [M] σ back-donation. Thus, the σ aromaticity originating from three delocalized σ orbitals gives rise to the whole stability of the high -symmetry ppBe and strongly enriches s-block planar hypercoordinate bonding.

Utilizing oncology biosimilars to minimize the economic burden associated with cancer treatment: managed care considerations.

The high cost of therapies for treatment of cancer places a substantial burden on the United States healthcare system. In recent years, there has been increased attention to the cost-savings benefits associated with clinical uptake of biosimilars and their market availability, with several biosimilars with oncology-related indications currently available. Though the biosimilar development process has contributed to price reductions and increased patient access to care, misconceptions about biosimilar safety and efficacy as well as inconsistent prescribing patterns have emerged as main barriers to their use in clinical practice.

Linear Group 13 E≡E Triple Bonds in E Li .

The triply bonded heavier main-group compounds have a textbook trans-bent geometry, in contrast to a familiar linear form found for the lightest analogues. Strikingly, the unexpected linear group 13 E≡E triple bonds were herein found in the D -symmetry E Li clusters, and they possess a large barrier (>18.0 kcal/mol) towards the dissociation of Li .

Overcoming barriers to biosimilar adoption: real-world perspectives from a national payer and provider initiative.

In response to a published national payer survey indicating striking needs for multistakeholder initiatives to increase biosimilar adoption, a focus workgroup meeting joining payers and providers was conducted in December 2019 in Boston, MA. Before the focus group meeting, a survey was sent to health care providers to collect perceptions about barriers to biosimilar adoption and gather input on best potential strategies for addressing these barriers. The focus group panel consisted of 5 managed care pharmacists and 3 physician experts in rheumatology, dermatology, and gastroenterology, representing large managed care organizations and health care systems in the Boston area.