Exceptionally Strong Triply Dative Be-F Bonds in [CO]BeF and [CO]BeF Complexes: Reducing Valence Shell Electron Repulsion to Achieve High Bond Dissociation Energies.

Dative bonds are typically polar, weaker, and longer than electron-sharing covalent bonds. The intriguing diatomic BeF anion uniquely exhibits triple Be-F dative bonding with a considerable bond dissociation energy (BDE) of 88 kcal/mol. Here, we report exceptionally strong dative-bonded systems, [CO]BeF and [CO]BeF, with BDE values exceeding 155 kcal/mol by integrating [CO] and [CO] groups into the BeF framework.

Planar tetracoordinate beryllium in σ-aromatic Li4Be and Na4Be clusters: A missing member in first-octal row planar tetracoordinate family.

While planar tetracoordinate (pt) centers have been extensively explored from carbon to other octal-row elements or their heavier analogs, their counterparts involving alkali (A) and alkaline-earth metals (Ae) remain elusive due to the large atomic radius and absence of p orbitals. In this work, we found six hitherto unknown anionic ptA (A4A-) and neutral ptAe (A4Ae) centers through an extensive exploration of potential energy surfaces. The D4h-symmetry ptBe structures in Li4Be and Na4Be emerge as the lowest-energy configurations, and all the other ptA/ptAe structures are higher in energy or saddle points.

Dual structural fluxionality in the copper borozene complex Cu3B8-: A two-layered molecular rotor.

Doubly aromatic B82-, a borozene analog of benzene (C6H6) due to their similar π bonding, can be considered an ideal base for multi-layered molecular rotors. Here, we theoretically constructed the copper borozene complex Cu3B8- to investigate its stability and structural fluxionality. The lowest energy isomers consist of two-layered configurations: a B8 molecular wheel and a triangular Cu3 motif that either stands upright or lies flat above the B8 wheel.

Planar Pentacoordinate Halogens.

Planar hypercoordinate motifs represent an intriguing frontier in chemistry, challenging traditional bonding norms. As electronegativity of the central atom increases, achieving planar hypercoordination becomes more difficult due to restricted delocalization, making the design of planar hypercoordinate halogens particularly puzzling. Here, we conduct an extensive computational survey of LiX (n=4, 5, 6; X=F, Cl, Br, I) clusters, revealing a starlike D-symmetry global minimum in LiX (X=F, Cl, Br) with a planar pentacoordinate halogen (ppX), where X is located at the center of LiX crown.

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.

Exploring the Use of "Honorary Transition Metals" To Push the Boundaries of Planar Hypercoordinate Alkaline-Earth Metals.

The quest for planar hypercoordinate atoms (phA) beyond six has predominantly focused on transition metals, with dodecacoordination being the highest reported thus far. Extending this bonding scenario to main-group elements, which typically lack d orbitals despite their larger atomic radius, has posed significant challenges. Intrigued by the potentiality of covalent bonding formation using the d orbitals of the heavier alkaline-earth metals (Ae = Ca, Sr, Ba), the so-called "honorary transition metals", we aim to push the boundaries of planar hypercoordination.

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.

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.

[Characteristics of Bone Marrow Cell Morphology and Immunophenotype in Patients with NHL Leukemia and Evaluation of NHL Bone Marrow Invasion].

Objective: To observe the evaluation value of characteristics of bone marrow cell morphology and immunophenotype in patients with non-Hodgkin lymphoma (NHL) leukemia on the bone marrow invasion of NHL.

Methods: The clinical data of 104 patients with NHL treated in the hospital from March 2016 to March 2021 were retrospectively analyzed, the characteristics of bone marrow smear morphology were recorded, and the analysis of bone marrow immunophenotype was performed, the evaluation value of bone marrow cell morphology and immunophenotype on NHL bone marrow invasion was analyzed.

Results: One hundred and four patients with NHL leukemia were found to have increased lymphoma cells by examination of bone marrow cell morphology, including 57 cases of B-cell type, 39 cases of T-cell type and 8 cases of NK/T cell type.

Denitrifying bacterial communities in surface-flow constructed wetlands during different seasons: characteristics and relationships with environment factors.

Denitrification is an important part of the nitrogen cycle and the key step to removal of nitrogen in surface-flow wetlands. In this study, we explored space-time analysis with high-throughput sequencing to elucidate the relationships between denitrifying bacteria community structures and environmental factors during different seasons. Our results showed that along the flow direction of different processing units, there were dynamic changes in physical and chemical indicators.

Analysis of long noncoding RNA-associated competing endogenous RNA network in glucagon-like peptide-1 receptor agonist-mediated protection in β cells.

Background: Long noncoding RNAs (lncRNAs) and mRNAs are widely involved in various physiological and pathological processes. The use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) is a novel therapeutic strategy that could promote insulin secretion and decrease the rate of β-cell apoptosis in type 2 diabetes mellitus (T2DM) patients. However, the specific lncRNAs and mRNAs and their functions in these processes have not been fully identified and elucidated.

Is there coordination of leaf and fine root traits at local scales? A test in temperate forest swamps.

Examining the coordination of leaf and fine root traits not only aids a better understanding of plant ecological strategies from a whole-plant perspective, but also helps improve the prediction of belowground properties from aboveground traits. The relationships between leaf and fine root traits have been extensively explored at global and regional scales, but remain unclear at local scales. Here, we measured six pairs of analogous leaf and fine root traits related to resource economy and organ size for coexisting dominant and subordinate vascular plants at three successional stages of temperate forest swamps in Lingfeng National Nature Reserve in the Greater Hinggan Mountains, NE China.

lncRNA WT1-AS inhibits the aggressiveness of cervical cancer cell via regulating p53 expression via sponging miR-330-5p.

Background: Emerging evidences have demonstrated that lncRNAs play vital roles in various pathological processes, including cancer. The lncRNA WT1 antisense RNA (WT1-AS) serves as a tumor suppressor in various cancers. Nevertheless, the expression and precise function of WT1-AS in cervical carcinoma still remain not yet investigated.

Changes of the denitrifying communities in a multi-stage free water surface constructed wetland.

Microorganisms play crucial roles in the nitrogen removal processes of wetlands. However, the key functional genes and microbes related to the nitrogen removal remain largely unknown in the free water surface constructed wetland (FWS CW). Here we studied the abundances of denitrifiers by targeting the key functional genes (nirS, nirK and nosZ) and investigated the community compositions of denitrifiers and their correlations with the abiotic variables in a FWS CW.

[Distribution Characteristics of Mercury in Reed Leaves from the Jiapigou Gold Mine in the Songhua River Upstream].

At the Jiapigou gold mine of the Songhua River upstream, reed leaves (), soil, and water samples were collected from June (summer) and September (autumn) 2016 for the determination of mercury. Moreover, the mercury concentrations in the air were determined synchronously. Furthermore, the level of mercury pollution in the reed leaves was determined by a single factor pollution index method, and the relationships among mercury concentrations in the reed leaves and environmental factors were analyzed to research the distribution characteristics, influencing factors, and correlations around the gold mining area.

Hydrological Conditions Affect the Interspecific Interaction between Two Emergent Wetland Species.

Hydrological conditions determine the distribution of plant species in wetlands, where conditions such as water depth and hydrological fluctuations are expected to affect the interspecific interactions among emergent wetland species. To test such effects, we conducted a greenhouse experiment with three treatment categories, interspecific interaction (mixed culture or monoculture), water depth (10 or 30 cm depth), and hydrological fluctuation (static or fluctuating water level), and two common emergent wetland plant species, Fr. (Cyperaceae) and var.

Copper Pollution Increases the Resistance of Soil Archaeal Community to Changes in Water Regime.

Increasing efforts have been devoted to exploring the impact of environmental stresses on soil bacterial communities, but the work on the archaeal community is seldom. Here, we constructed microcosm experiments to investigate the responses of archaeal communities to the subsequent dry-rewetting (DW) disturbance in two contrasting soils (fluvo-aquic and red soil) after 6 years of copper pollution. Ten DW cycles were exerted on the two soils with different copper levels, followed by a 6-week recovery period.

[Characteristics of Bacterial Communities in Surface-flow Constructed Wetlands].

Employing high-throughput sequencing as the method, this study analyzed the relationship between the water environment and the microbial community structure in the surface-flow constructed wetland. The results showed that: the mean Shannon-Wiener index was 6.57 and there were mainly 18 categories in the microbial community, including Proteobacterice (38.