CBe4H6: a molecular rotor with a built-in on-off switch

It is highly challenging to control (stop and resume as needed) molecular rotors because their intramolecular rotations are electronically enabled by delocalized σ bonding, and the desired control needs to be able to destroy and restore such σ bonding, which usually means difficult chemical manipulation (substitution or doping atom). In this work, we report CBe4H6, a molecular rotor that can be controlled independently of chemical manipulation. This molecule exhibited the uninterrupted free rotation of Be and H atoms around the central carbon in first-principles molecular dynamics simulations at high temperatures (600 and 1000 K), but the rotation cannot be witnessed in the simulation at room temperature (298 K). Specifically, when a C-H bond in the CBe4H6 molecule adopts the equatorial configuration at 298 K, it destroys the central delocalized σ bonding and blocks the intramolecular rotation (the rotor is turned "OFF"); when it can adopt the axial configuration at 600 and 1000 K, the central delocalized σ bonding can be restored and the intramolecular rotation can be resumed (the rotor is turned "ON"). Neutral CBe4H6 is thermodynamically favorable and electronically stable, as reflected by a wide HOMO-LUMO gap of 7.99 eV, a high vertical detachment energy of 9.79 eV, and a positive electron affinity of 0.24 eV, so it may be stable enough for the synthesis, not only in the gas phase, but also in the condensed phase.

XB2Bi2 (X = Si, Ge, Sn, Pb): Penta-Atomic Planar Tetracoordinate Si/Ge/Sn/Pb Clusters with 20 Valence Electrons

Planar tetracoordinate silicon, germanium, tin, and lead (ptSi/Ge/Sn/Pb) species are scarce and exotic. Here, we report a series of penta-atomic ptSi/Ge/Sn/Pb XB2Bi2 (X = Si, Ge, Sn, Pb) clusters with 20 valence electrons (VEs). Ternary XB2Bi2 (X = Si, Ge, Sn, Pb) clusters possess beautiful fan-shaped structures, with a Bi-B-B-Bi chain surrounding the central X core. The unbiased density functional theory (DFT) searches and high-level CCSD(T) calculations reveal that these ptSi/Ge/Sn/Pb species are the global minima on their potential energy surfaces. Born-Oppenheimer molecular dynamics (BOMD) simulations indicate that XB2Bi2 (X = Si, Ge, Sn, Pb) clusters are robust. Bonding analyses indicate that 20 VEs are perfect for the ptX XB2Bi2 (X = Si, Ge, Sn, Pb): two lone pairs of Bi atoms; one 5c-2e π, and three σ bonds (two Bi-X 2c-2e and one B-X-B 3c-2e bonds) between the ligands and X atom; three 2c-2e σ bonds and one delocalized 4c-2e π bond between the ligands. The ptSi/Ge/Sn/Pb XB2Bi2 (X = Si, Ge, Sn, Pb) clusters possess 2π/2σ double aromaticity, according to the (4n + 2) Hückel rule.

Boron-based ternary MgTa2B6 cluster: a turning nanoclock with dynamic structural fluxionality

Boron-based complex clusters are a fertile ground for the exploration of exotic chemical bonding and dynamic structural fluxionality. Here we report on the computational design of a ternary MgTa2B6 cluster via global structural searches and quantum chemical calculations. The cluster turns out to be a new member of the molecular rotor family, closely mimicking a turning clock at the subnanoscale. It is composed of a hexagonal B6 ring with a capping Ta atom at the top and bottom, whereas the Mg atom is linked to one Ta site as a radial Ta-Mg dimer. These components serve as the dial, axis, and hand of a nanoclock, respectively. Chemical bonding analyses reveal that the inverse sandwich Ta2B6 motif in the cluster features 6π/6σ double aromaticity, whose electron counting conforms to the (4n + 2) Hückel rule. The Ta-Mg dimer has a Lewis-type σ bond, and the Mg site has negligible bonding with B6 ring. The ternary cluster can be formulated as an [Mg]0[Ta2B6]0 complex. Molecular dynamics simulations suggest that the cluster is structurally fluxional analogous to a nanoclock, even at a low temperature of 100 K. The Ta-Mg hand turns almost freely around the Ta2 axis and along the B6 dial. The tiny intramolecular rotation barrier is less than 0.3 kcal mol-1, being dictated by the bonding nature of double 6π/6σ aromaticity. The present system offers a new type of molecular rotor in physical chemistry.

CB4Se5: a planar tetracoordinate carbon CB4 core stabilized by peripheral Se/Se2 bridges

Replacing one of the peripheral Se with a Se2 bridge is an effective strategy to flatten the C4v CB4Se4 cluster. The global minimum of CB4Se5 contains one fan-shaped planar tetracoordinate carbon (ptC) CB4 core, possessing double 2π + 6σ aromaticity. The peripheral Se2 bridge is dexterous and crucial for the stability of CB4Se5.

Boron-based Pd3B26 alloy cluster as a nanoscale antifriction bearing system: tubular core-shell structure, double π/σ aromaticity, and dynamic structural fluxionality

Boron-based nanoclusters show unique geometric structures, nonclassical chemical bonding, and dynamic structural fluxionality. We report here on the theoretical prediction of a binary Pd3B26 cluster, which is composed of a triangular Pd3 core and a tubular double-ring B26 unit in a coaxial fashion, as identified through global structural searches and electronic structure calculations. Molecular dynamics simulations indicate that in the core-shell alloy cluster, the B26 double-ring unit can rotate freely around its Pd3 core at room temperature and beyond. The intramolecular rotation is virtually barrier free, thus giving rise to an antifriction bearing system (or ball bearing) at the nanoscale. The dimension of the dynamic system is only 0.66 nm. Chemical bonding analysis reveals that Pd3B26 cluster possesses double 14π/14σ aromaticity, following the (4n + 2) Hückel rule. Among 54 pairs of valence electrons in the cluster, the overwhelming majority are spatially isolated from each other and situated on either the B26 tube or the Pd3 core. Only one pair of electrons are primarily responsible for chemical bonding between the tube and the core, which greatly weaken the bonding within the Pd3 core and offers structural flexibility. This is a key mechanism that effectively diminishes the intramolecular rotation barrier and facilitates dynamic structural fluxionality of the system. The current work enriches the field of nanorotors and nanomachines.

A Prospective Study of Bevacizumab and Neoadjuvant Concurrent Chemoradiation in Locally Advanced Esophageal Squamous Cell Carcinoma: Paradoxical Increase in Circulating Vascular Endothelial Growth Factor-A and Effect on Outcome

PURPOSE/OBJECTIVE(S)

In the prior prospective biomarker study, high serum vascular endothelial growth factor-A (VEGF-A) was associated with a poor prognosis. We conducted a prospective phase II trial of adding Bevacizumab, an anti-VEGF-A monoclonal antibody, to neoadjuvant concurrent chemoradiation (neoCCRT) for patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). This prospective biomarker study aims to evaluate the expressions of angiogenesis-associated circulating biomarkers before and after neoCCRT and compare clinical outcomes for patients receiving platinum/5-fluorouracil (PF) with or without Bevacizumab.

MATERIALS/METHODS

Patients with biopsy-proven resectable non-T4 LA-ESCC were enrolled for the prospective phase II trial investigating PF-neoCCRT plus Bevacizumab (BPF group). A parallel patient cohort enrolled in a prospective biomarker study receiving PF-neoCCRT was included in the present analysis as the control group (PF group). Radiotherapy was delivered with 40 Gy in 20 fractions. All patients had restaging workups after enoCCRT and underwent radical esophagectomy if the disease remained resectable. Serums were collected before and after neoCCRT. The serum concentrations of angiogenesis-associated biomarkers were determined by the multiplex enzyme-linked immunosorbent assay. Survival analyses were performed by the Kaplan-Meier method. The t-test and log-rank test were used to compare differences in biomarker expression and survival between groups.

RESULTS

From 2016 to 2019, 43 patients (BPF/PF group: 21/22) were enrolled in the study. Twenty patients in each group had serum samples available for biomarker analysis. 15 out of 21 patients in the BPF group and 20 out of 22 patients in the PF group underwent radical esophagectomy. Six patients in the BPF group and nine patients in the PF group achieved pathological complete responses. The median overall survival for the BPF and PF group was 20.8 months and not-reached, respectively (hazard ratio = 1.33, long rank p = 0.58). In the BPF group, the serum VEGF-A level was significantly increased from an average value of 446 pg/mL to 723 pg/mL after neoCCRT (p = 0.037), while its level was decreased from 815 ng/mL to 380 pg/mL in the PF group (p = 0.104). In addition, the expression value of circulating Angiopoietin-1 was not changed in the BPF group (before neoCCRT, mean value = 828 pg/mL; after neoCCRT, mean value 762 pg/mL, p = 0.67). In contrast, serum Angiopoietin-1 level was reduced from an average value of 659 pg/mL before neoCCRT to 271 pg/mL after neoCCRT (p = 0.002) in the PF group.

CONCLUSION

The addition of Bevacizumab to PF-neoCCRT did not improve pathological or survival outcomes in patients with resectable LA-ESCC. Adding a single dose of Bevacizumab paradoxically increases circulating VEGF-A while maintaining the Angiopoietin-1 serum level after neoCCRT. Further investigation by using additional VEGF-A inhibition may be required to achieve sustained angiogenesis blocked for tumor control.

Ternary XBe4H5- (X = Si, Ge, Sn, Pb) Clusters: Planar Tetracoordinate Si/Ge/Sn/Pb Species with 18 Valence Electrons

As one of the important probes of chemical bonding, planar tetracoordinate carbon (ptC) compounds have been receiving much attention. Compared with ptC clusters, the heavier planar tetracoordinate silicon, germanium, tin, lead (ptSi/Ge/Sn/Pb) systems are scarcer and more exotic. The 18-valence-electron (ve)-counting is one important guide, though not the only rule, for the design of planar tetra-, penta-coordinate carbon and silicon clusters. The 18ve ptSi/Ge system is very scarce and needs to be expanded. Based on the isoelectronic principle and bonding similarity between the Al atom and the BeH unit, inspired by the previously reported ptSi global minimum (GM) SiAl₄^2-, a series of ternary 18 ve XBe4H5^- (X = Si, Ge, Sn, Pb) clusters were predicted with the ptSi/Ge/Sn/Pb centers. Extensive density functional theory (DFT) global minimum searches and high-level CCSD(T) calculations performed herein indicated that these ptSi/Ge/Sn/Pb XBe₄H₅^- (X = Si, Ge, Sn, Pb) clusters were all true GMs on their potential energy surfaces. These GMs of XBe₄H₅^- (X = Si, Ge, Sn, Pb) species possessed the beautiful fan-shaped structures: XBe₄ unit can be stabilized by three peripheries bridging H and two terminal H atoms. It should be noted that XBe₄H₅^- (X = Si, Ge, Sn, Pb) were the first ternary 18 ve ptSi/Ge/Sn/Pb species. The natural bond orbital (NBO), canonical molecular orbitals (CMOs) and adaptive natural densitpartitioning (AdNDP) analyses indicated that 18ve are ideal for these ptX clusters: delocalized one π and three σ bonds for the XBe₄ core, three Be-H-Be 3c-2e and two Be-H σ bonds for the periphery. Additionally, 2π plus 6σ double aromaticity was found to be crucial for the stability of the ptX XBe₄H₅^- (X = Si, Ge, Sn, Pb) clusters. The simulated photoelectron spectra of XBe₄H₅^- (X = Si, Ge, Sn, Pb) clusters will provide theoretical basis for further experimental characterization.

[Comparison the characteristics of serum adrenocortical hormone profile in patients with adrenal cortical carcinoma and adrenal coritcal adenoma]

Objective: To compare the characteristics of serum adrenocortical hormone profiles detected by liquid chromatography tandem mass spectrometry in patients with adrenal cortical carcinoma and adrenal adenoma. Methods: A total of 23 patients with adrenal cortical carcinoma and 119 patients with adrenal cortical adenoma/hyperplasia who visited the Department of Endocrinology and/or the Department of Urology of Peking University First Hospital from January 2018 to June 2022 were analyzed retrospectively. The imaging characteristics and serum adrenal cortical hormone profiles detected by liquid chromatography tandem mass spectrometry were analyzed retrospectively. The independent related factors of adrenal cortical carcinoma were screened by univariate analysis and multivariate logistic regression analysis. Results: The age of patients with adrenal cortical carcinoma was 46 (35, 57) years, and 15 (65.2%) were female; The age of adrenal cortical adenoma patients was 49 (40, 58) years old, and 80 (67.2%) were female. There was no significant difference in age and gender between the two groups (all P values>0.05). The maximum tumor diameter M (Q₁, Q₃) of patients with adrenocortical carcinoma was 7.05 (5.45, 9.78) cm, which was larger than that of patients with adrenocortical adenoma [2.1 (1.6, 3.0) cm] (P<0.001). Compared with patients with adrenal adenoma, the androstenedione (AD) of patients with adrenal cortical carcinoma [4.056 9 (1.619 5, 7.907 9) nmol/L vs 1.517 5 (0.935 1, 2.582 1) nmol/L (P<0.001)] was significantly increased; 11-ketotestosterone/11-ketoandrostenedione [0.034 3 (0.020 6, 0.079 2) vs 0.041 0 (0.028 6, 0.061 5) (P=0.089)] and 11-ketoandrostenedione/11-hydroxyandrostenedione [0.013 0 (0.006 4, 0.086 7) vs 0.063 0 (0.018 2, 0.162 5) (P=0.042)] were significantly decreased. Multivariate analysis found that AD, the largest diameter of the tumor, 11-ketotestosterone/11-ketoandrostenedione and 11-ketoandrostenedione/11-hydroxyandrostenedi-one were related factors for adrenal cortical carcinoma, with OR values (95%CI) of 1.841 (1.093-3.100), 5.130 (2.332-11.285), 0.381 (0.167-0.867) and 0.000 (0.000-0.014), respectively, all P values <0.05. Conclusions: The larger diameter of adrenal cortical tumor and the higher the level of androstenedione are independent risk factors for adrenal cortical carcinoma. The reduction conversion of 11-hydroxyandrostenedione to 11-ketoandrostenedione and 11-ketoandrostenedione to 11-ketotestosterone were independently associated with adrenal cortical carcinoma.

CAl4X4 (X = Te, Po): Double Aromatic Molecular Stars Containing Planar Tetracoordinate Carbon Atoms

Planar tetracoordinate carbon (ptC) species are scarce and exotic. Introducing four peripheral Te/Po auxiliary atoms is an effective strategy to flatten the tetrahedral structure of CAl₄ (T_d, ¹A₁). Neutral CAl₄X₄ (X = Te, Po) clusters possess quadrangular star structures containing perfect ptC centers. Unbiased density functional theory (DFT) searches and high-level CCSD(T) calculations suggest that these ptC species are the global minima on the potential energy surfaces. Bonding analyses indicate that 40 valence-electron (VE) is ideal for the ptC CAl₄X₄ (X = Te, Po): one delocalized π and three σ bonds for the CAl₄ core; four lone pairs (LPs) of four X atoms, eight localized Al-X σ bonds, and four delocalized Al-X-Al π bonds for the periphery. Thus, the ptC CAl₄X₄ (X = Te, Po) clusters possess the stable eight electron structures and 2π + 6σ double aromaticity. Born-Oppenheimer molecular dynamics (BOMD) simulations indicate that neutral ptC CAl₄X₄ (X = Te, Po) clusters are robust.

σ-Aromatic MAl6S6 (M = Ni, Pd, Pt) Stars Containing Planar Hexacoordinate Transition Metals

Hypercoordinate transition-metal species are mainly dominated by the 18-valence-electron (18ve) counting. Herein, we report ternary MAl₆S₆ (M = Ni, Pd, Pt) clusters with the planar hexacoordinate metal (phM) centers, which feature 16ve counting instead of the classic 18ve rule. These global-minimum clusters are established via unbiased global searches, followed by PBE0 and single-point CCSD(T) calculations. The phM MAl₆ units are stabilized by six peripheral bridging S atoms in these star-like species. Chemical bonding analyses reveal that there are 10 delocalized electrons around the phM center, which can render the aromaticity according to the (4n + 2) Hückel rule. It is worth noting that adding an (or two) electron(s) to its π-type lowest unoccupied molecular orbital (LUMO) will make the system unstable.

CAl11-: A molecular rotor with a quasi-planar tetracoordinate carbon

In this work, we analyzed the bonding and fluxional character of the global minimum of CAl11–. Its structure is formed by two stacked layers, one of them resembles the well-known...

B3Al4+: A Three-Dimensional Molecular Reuleaux Triangle

We systematically explore the potential energy surface of the B3Al4+ combination of atoms. The putative global minimum corresponds to a structure formed by an Al4 square facing a B3 triangle. Interestingly, the dynamical behavior can be described as a Reuleaux molecular triangle since it involves the rotation of the B3 triangle at the top of the Al4 square. The molecular dynamics simulations, corroborating with the very small rotational barriers of the B3 triangle, show its nearly free rotation on the Al4 ring, confirming the fluxional character of the cluster. Moreover, while the chemical bonding analysis suggests that the multicenter interaction between the two fragments determines its fluxionality, the magnetic response analysis reveals this cluster as a true and fully three-dimensional aromatic system.

[Use of oral anticoagulants and related factors among new-onset acute ischemic stroke patients with nonvalvular atrial fibrillation: A report from the China Atrial Fibrillation Registry Study]

Objective: This study aimed to investigate the oral anticoagulant (OAC) usage among new-onset acute ischemic stroke (AIS) patients with nonvalvular atrial fibrillation (NVAF) in China, and to explore the possible influencing factors of influent anticoagulant therapy in these patients. Methods: The NVAF patients who experienced new-onset and non-fatal AIS from August 2011 to December 2018 in the China Atrial Fibrillation Registry (China-AF), were enrolled. The follow-up ended in December 2019. Information including patients' demographic characteristics, medical history, medication usage, which were collected before and after the index stroke, were analyzed. Patients were classified into OAC group or non-OAC group according to OAC usage within 3 months post stroke. Multivariate logistic regression analysis were conducted to calculate the odds ratios (ORs) of factors which might be associated with OAC usage within 3 months post stroke. Results: A total of 957 new-onset AIS patients were enrolled, 39.4% (377/957) patients were treated with OAC within 3 months after AIS. Covering by high-reimbursement-rate insurance (OR: 1.91, 95%CI: 1.28-2.86, P=0.002), higher number of concomitant drugs (1-2 types OR: 2.10, 95%CI: 1.36-3.23, P=0.001; ≥3 types OR: 2.31, 95%CI: 1.37-3.91, P=0.002) and 3-month-peri-stroke AF recurrence (OR: 3.34, 95%CI: 2.34-4.76, P<0.001) were associated with OAC usage within 3 months post stroke, while higher HASBLED score (OR: 0.49, 95%CI: 0.40-0.60, P<0.001) and pre-stroke antiplatelet usage (OR: 0.29, 95%CI: 0.20-0.43, P<0.001) were related to no OAC usage within 3 months post stroke. Conclusions: In China, the proportion of NVAF patients who initiated OAC therapy within 3 months after new-onset AIS is as low as about 39.4%. Factors related to the OAC usage within 3 months post stroke are 3-month-peri-stroke AF recurrence, number of concomitant drugs and patients with high-reimbursement-rate insurance coverage, but higher HASBLED score and pre-stroke antiplatelet usage are related to no OAC usage within 3 months post stroke.

Ternary CE2Ba2 (E = As, Sb) Clusters: New Pentaatomic Planar Tetracoordinate Carbon Species with 18 Valence Electrons

18-valence-electron (ve) rule is one important guide for us to design planar tetracoordinate carbon (ptC) species. Using the "polarization of ligands" strategy, the new pentaatomic ptC species CE₂Ba₂ (E = As, Sb) with 18 ve are designed in this work. Computer structural searches and high-level calculations reveal that the ptC CE₂Ba₂ (E = As, Sb) species are global minima (GMs) on the potential energy surfaces, whose C center is coordinated by the interspaced E and Ba atoms. CE₂Ba₂ (E = As, Sb) are also kinetically stable. Chemical bonding analyses reveal that the ptC core is stabilized by two localized C-E σ bonds, one delocalized five-center two-electron (5c-2e) σ bond and one delocalized 5c-2e π bond. One π and three σ bonds collectively conform to the 8-electron counting, which determines the stability of ptC CE₂Ba₂ (E = As, Sb) species. Interestingly, the delocalized 2π and 2σ electrons render the ptC systems π/σ double aromaticity. Additional 10 electrons contribute to peripheral lone pairs of E and E-Ba bonding.

Boron Oxide B5O6− Cluster as a Boronyl-Based Inorganic Analog of Phenolate Anion

Boron oxide clusters have structural richness and exotic chemical bonding. We report a quantum chemical study on the binary B5O6− cluster, which is relatively oxygen-rich. A global structural search reveals planar C2v (1A1) geometry as the global minimum structure, featuring a heteroatomic hexagonal B3O3 ring as its core. The three unsaturated B sites are terminated by two boronyl (BO) groups and an O− ligand. The B5O6− cluster can be faithfully formulated as B3O3(BO)2O−. This structure is in stark contrast to that of its predecessors, Cs B5O5− and Td B5O4−, both of which have a tetrahedral B center. Thus, there exists a major structural transformation in B5On− series upon oxidation, indicating intriguing competition between tetrahedral and heterocyclic structures. The chemical bonding analyses show weak 6π aromaticity in the B5O6− cluster, rendering it a boronyl analog of phenolate anion (C6H5O−) or boronyl boroxine. The calculated vertical detachment energy of B5O6− cluster is 5.26 eV at PBE0, which greatly surpasses the electron affinities of halogens (Cl: 3.61 eV), suggesting that the cluster belongs to superhalogen anions.

Ternary 14-electron XB2Be2 (X = Si, Ge, Sn, Pb) clusters: a planar tetracoordinate silicon (ptSi) system and its ptGe/Sn/Pb congeners

A class of ternary 14-electron clusters, XB₂Be₂ (X = Si, Ge, Sn, Pb), have been computationally predicted with a planar tetracoordinate silicon (ptSi) unit, as well as its heavier ptGe/Sn/Pb congeners. These pentaatomic ptSi/Ge/Sn/Pb species are established as global-minimum structures via computer global searches, followed by electronic structure calculations at the PBE0-D3, B3LYP-D3, and single-point CCSD(T) levels. Molecular dynamics simulations indicate that they are also kinetically stable against isomerization or decomposition. Chemical bonding analyses show that the clusters have double 2π/2σ aromaticity. The latter concept underlies the stability of ptSi/Ge/Sn/Pb clusters, overriding the 14-electron count or its variants, such as the 18-electron rule. No sp³ hybridization occurs in these species, which naturally explains why they are ptSi/Ge/Sn/Pb (rather than traditional tetrahedral) systems.

Bare and ligand protected planar hexacoordinate silicon in SiSb3M3+ (M = Ca, Sr, Ba) clusters

The global minimum of SiSb3M3+ (M = Ca, Sr, Ba) is a D3h symmetric structure containing an elusive planar hexacoordinate silicon (phSi) atom. Most importantly, the phSi core remains intact in ligand protected environment as well.

Concentric Inner 2π/6σ and Outer 10π/14σ Aromaticity Underlies the Dynamic Structural Fluxionality of Planar B19- Wankel Motor Cluster

Planar C_2v B₁₉^- global-minimum (GM) cluster is known as a molecular Wankel motor, featuring unique chemical bonding and structural fluxionality. While the geometry, bonding, and molecular dynamics of the cluster are documented in the literature, it remains warranted to fully understand its bonding nature and unravel the mechanism behind the structural dynamics. We shall offer herein an updated bonding model on the bases of canonical molecular orbital (CMO) analysis and adaptive natural density partitioning (AdNDP), further aided by natural bond orbital (NBO) analysis and orbital composition calculations. The computational data indicate that the B₁₉^- cluster has inner 2π/6σ and outer 10π/14σ concentric 4-fold π/σ aromaticity. Being spatially isolated from each other, the inner B₆ disk supports 2π and 6σ subsystems, whereas the outer B₁₈ double-ring ribbon has 10π and 14σ subsystems. All 4-fold π/σ subsystems are intrinsically delocalized and conform to the (4n + 2) Hückel rule for aromaticity. The change of Wiberg bond index (WBI) from GM to transition-state (TS) for radial B-B links is minimal and uniform, which offers a semiquantitative measure of structural dynamics and underlies the low energy barrier.

[Radial artery thrombosis in optical coherence tomography guided transradial coronary angiography and percutaneous coronary intervention in acute coronary syndrome patients and its risk factors analysis]

Objective: To observe the radial artery thrombosis (RAT) during transradial coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) by optical coherence tomography (OCT), and to investigate the risk factors of RAT during the CAG and/or PCI. Methods: In this retrospective study, we consecutively reviewed the radial artery OCT examination results of the patients who underwent OCT guided transradial CAG and/or PCI for acute coronary syndrome in heart center of Beijing Luhe hospital, Capital Medical University from October 2017 to July 2018. The incidence of RAT was observed. The patients were divided into the RAT group and non-RAT group, clinical data were collected and compared. Moreover, the types and distributions of thrombus in radial artery as well as the acute radial artery injuries under OCT were observed. Univariate analysis followed by multivariate analysis were performed to identify potential risk factors. The radial artery patency and ischemic symptoms of the involved limb were followed up at the 24-hour and the 1-month after procedure. Results: A total of 107 patients were included, the age was (58.1±12.5), and 78.5% were male (n=84). The incidence of RAT was 26.2% (n=28, 95%CI 17.9%-34.5%), and the main type of thrombus was white thrombus (n=15, 53.6%). The commonest position of RAT was the proximal portion of radial artery (n=17, 60.7%). The median thrombus volume was 0.05(0.03, 0.38) mm3, and the median thrombus score was 6.5 (3.3, 13.8). In univariate analysis, the frequency of acute radial artery injury and use of bivalirudin were significantly higher and the procedure time was significantly longer in RAT group than those in non-RAT group (all P<0.05). Multivariate regression analysis showed that the radial artery acute injury (OR=5.82, 95%CI: 2.09-16.20, P=0.001) and the procedure time (OR=1.04, 95%CI: 1.01-1.06, P=0.006) were independent risk factors of RAT. Rate of radial artery occlusion at 24 hours follow-up was similar between RAT and non-RAT group (7.14%(2/28), vs. 10.13%(8/79), P=1.000). None of the patients complicated severe ischemic symptom of the operative limb. Conclusions: RAT is a high frequency access complication during transradial coronary intervention. This phenomenon can be accurately observed by OCT. Acute radial artery injury and prolonged procedure time are risk factors of RAT during transradial coronary intervention.

[Clinical characteristics of primary aldosteronism with concurrent adrenal Cushing's syndrome]

Objective: To analyze and summarize the clinical characteristics of primary aldosteronism (PA) with concurrent adrenal Cushing's syndrome (ACS). Methods: The clinical, imaging and pathological data of 87 patients with PA admitted to Peking University First Hospital from January 1st, 2013 to December 31th, 2016 were reviewed. There were 45 males (51.7%) and 42 females (48.3%) with an average age of (52.7±10.5) years (range: 15-70 years). According to whether they were diagnosed with ACS, the patients were divided into PA with concurrent ACS group (n=11) and pure PA group (n=55). The clinical characteristics of PA with concurrent ACS were summarized. Results: Ten of the eleven patients in PA with concurrent ACS group were diagnosed with subclinical ACS. Compared with these in pure PA group, the patients in PA with concurrent ACS group were older [(55.6±9.1) years vs (48.4±10.2) years, P=0.033], with larger diameters of adrenal tumors [(2.3±1.6) cm vs (1.4±0.6) cm, P=0.015], higher serum cortisol levels in the circadian rhythm [158 (92, 217) nmol/L vs 71 (43, 128) nmol/L at 0∶00, P=0.004], lower plasma adrenocorticotropic hormone (ACTH) levels in the circadian rhythm [0.80 (<0.22, 1.45) pmol/L vs 4.40 (2.58, 5.93) pmol/L at 8∶00, P<0.001; 0.25 (<0.22, 0.91) pmol/L vs 2.03 (0.74, 3.69) pmol/L at 16∶00, P<0.001;<0.22 (<0.22, 0.44) pmol/L vs 1.27 (<0.22, 2.66) pmol/L at 0∶00, P<0.001], and higher serum cortisol levels after 1 mg overnight dexamethasone suppression test [95 (73, 142) nmol/L vs 30 (22, 41) nmol/L, P<0.001]. Unilateral adrenalectomy was performed in 31 patients, of whom 3 patients in PA with concurrent ACS group (3/8) and 3 patients in pure PA group (3/23) presented with adrenal insufficiency and received glucocorticoid replacement therapy after adrenalectomy. Conclusions: PA with concurrent ACS is not rare in PA patients, which are mainly complicated with subclinical ACS and easily misdiagnosed. It is recommended that elderly PA patients with large adrenal tumors should be screened for ACS by means of cortisol and ACTH circadian rhythm and 1 mg overnight dexamethasone suppression test. Postoperative adrenal insufficiency is prone to occur in those patients, who should be followed up closely after adrenalectomy, and receive glucocorticoid replacement therapy in time.

[Ergonomic risk factors of carpal tunnel syndrome in workers of an automobile factory]

Objective: To investigate the occurrence of pain symptoms and risk factors of carpal tunnel syndrome (CTS) in automobile manufacturing workers and provide theoretical basis for the prevention of CTS. Methods: From Nov.5th to Nov.19th, 2017, 446 workers in an automobile factory whose work age was above one year participate in questionnaires by cluster sampling. Chi square test and multifactor logistics regression analysis were used to analyze the factors related to the occurrence of CTS pain symptoms in workers. Results: The incidence of CTS pain among workers in this automobile factory was 20.8%. Working in the same position for a long time (OR=2.137, 95% CI:1.183-3.862) and unable to work reasonably because of uncomfortable posture (OR =2.067, 95% CI: 1.075-3.974) were identified as the risk factors of CTS pain symptoms by multifactor logistics regression analysis. Working age (OR=0.537, 95%CI:0.311-0.926) and work break (OR= 0.489, 95% CI: 0.282-0.849) were identified as the benefit factors of CTS pain symptoms. Conclusion: The incidence of CTS pain in automobile manufacturing workers is related to the posture in the process of labor . Effective ergonomic interventions should be carried out to prevent the occurrence of CTS pain in automobile manufacturing workers.

Planar or tetrahedral? A ternary 17-electron CBe5H4+ cluster with planar pentacoordinate carbon

A 17-electron CBe₅H₄⁺ cluster features planar pentacoordinate carbon, owing to the 2π/6σ double aromaticity. The neutral CBe₅H₄ cluster has a tetrahedral configuration despite its 18-electron counting. The latter species is governed by σ conjugation.

Boron-Based Chiral Helix Be6 B10 2- and Be6 B11 - Clusters: Structures, Chemical Bonding, and Formation Mechanism

Boron forms a rich variety of low-dimensional nanosystems, including the newly discovered helix Be₆ B₁₀ ^2- (1) and Be₆ B₁₁ ^- (2) clusters. We report herein on the elucidation of chemical bonding in clusters 1/2, using the modern quantum chemistry tools of canonical molecular orbital analyses and adaptive natural density partitioning (AdNDP). It is shown that clusters 1/2 contain a chiral helix Be₂ B₁₀ Be₂ or Be₂ B₁₁ Be₂ skeleton with a total of 11 and 12 segments, respectively, which effectively curve into "helical pseudo rings" and chemically consist of two "quasicircles" as defined by their anchoring Be centers. The helix skeleton is connected via Lewis-type B-B and Be-B-Be σ bonds, being further stabilized by island π/σ bonds and a loose π bond at the junction. The Be₆ component in 1/2 assumes a distorted prism shape only physically, and it is fragmented into four parts: two terminal Be₂ dimers and two isolated Be centers. A Be₂ dimer at the far end manages to bend over and cap a quasicircle from one side of B plane. Consequently, each quasicircle of a helical pseudo ring is capped from opposite sides by two Be₂ /Be units, facilitating intramolecular charge-transfers of 5 electrons from Be to B. Overall, the folding of B helix involves as many as 10 electrons. The enormous electrostatics offers the ultimate driving forces for B helix formation.

A designer 32-electron superatomic CBe8H12 cluster: core–shell geometry, octacoordinate carbon, and cubic aromaticity

A 32-electron CBe₈H₁₂ cluster is designed with cubic octacoordinate carbon. It features core–shell geometry, two-fold superatomic bonding, and cubic aromaticity.

Planar tetracoordinate carbon molecules with 14 valence electrons: examples of CBe4Mnn−2 (M = Li, Au; n = 1–3) clusters

Planar tetracoordinate carbon species are viable with 14 valence electrons, which violate the 18-electron rule. Chemical bonding around the C center is governed by double 2π/6σ aromaticity.

CLiAl2E and CLi2AlE (E = P, As, Sb, Bi): Planar Tetracoordinate Carbon Clusters with 16 and 14 Valence Electrons

The strategy to remove the lone pairs of ligands combined with the bonding similarity between Li and Al have been utilized to design new planar tetracoordinate carbon (ptC) species C 2v CLiAl2E and CLi2AlE based on ptC global minima CAl3E (E = P, As, Sb, Bi) clusters. The explorations of potential energy surfaces and high-level CCSD(T) calculations indicate that these planar tetracoordinate carbon (ptC) species with 16 and 14 valence electrons (ve) are the global minima except for CLiAl2P. Bonding analyses reveal that there is one π and three σ bonds between C and ligands, one delocalized σ bond between the peripheral ligands, and three/two lone pairs for CLiAl2E and CLi2AlE (E = P, As, Sb, Bi). Especially, the C=E double bonds are crucial for the stabilities of these ptC clusters. The ptC core is governed by 2π + 6σ bonding, which conforms to the 8-electron counting. Born-Oppenheimer molecular dynamics (BOMD) simulations reveal that CLiAl2E and CLi2AlE (E = P, As, Sb, Bi) clusters are robust against isomerization and decomposition. The results obtained in this work complete the series of ptC CLi n Al3-n E (E = P, As, Sb, Bi; n = 0-3) systems and 18ve, 16ve, 14ve, and 12ve counting.

Ternary 12-electron CBe3X3+ (X = H, Li, Na, Cu, Ag) clusters: planar tetracoordinate carbons and superalkali cations

Molecules with planar tetracoordinate carbons (ptCs) are exotic in chemical bonding, and they are normally designed according to the 18-electron rule. Here we report on the viability of ptC clusters with as few as 12 valence electrons, which represent the lower limit in terms of electron counting. Specifically, we have computationally designed a class of ternary 12-electron ptC clusters, CBe3X3+ (X = H, Li, Na, Cu, Ag), based on a rhombic CBe32- unit. Computer structural searches reveal that the ptC species are global minima, whose C center is coordinated in-plane by three Be atoms and a terminal X atom via robust C-Be/C-X bonding, either covalent or ionic. The other two X atoms are on the periphery and each bridge two Be atoms. Bonding analyses show that the ptC core is governed by delocalized 2π/6σ bonding, that is, double π/σ aromaticity, which collectively conforms to the 8-electron counting. Additional 4 electrons contribute to peripheral Be-X-Be and Be-Be σ bonding. The delocalized 2π/6σ frameworks appear to be universal for all ptC clusters, ranging from 18-electron down to 12-electron systems. In other words, the ptC species are dictated entirely by the 8-electron counting. Predicted vertical electron affinities of these ptC clusters range from 3.13 to 5.48 eV, indicative of superalkali or pseudoalkali cations.

99Non-ruptured plaque and platelet-rich thrombi in ST-segment elevation myocardial infarction: new insight into early spontaneous reperfusion

Objectives

To detect the potential mechanism of early spontaneous reperfusion (ESR) in STEMI.

Background

Early spontaneous reperfusion occurs in around 20% of STEMI and is associated with favorable outcomes. Optical coherence tomography (OCT) is more accurate in detecting subtle morphological details of the culprit lesion.

Methods

In this prospective study, a total of 107 consecutive patients with STEMI were enrolled from July 2016 to May 2017. Of that total, 21 (19.6%) met the criteria of angiographic ESR (TIMI-3 flow in the initial angiogram). Among those without ESR (TIMI-0 flow in the initial angiogram), 21 patients were assigned into the control group according to propensity score matching with the ESR group. The OCT findings and one-year clinical outcomes were compared between the two groups.

Results

Although baseline characteristics were comparable, plaque features significantly differed between the ESR and control group (P<0.001), including plaque rupture (23.8% vs. 66.7%), plaque erosion (47.6% vs. 33.3%), calcified nodule (9.5% vs. 0%) and vasospasm (19.1% vs. 0%). Red thrombus (19.1% vs. 85.7%) was far less found whereas white thrombus (61.9% vs. 14.3%) was more common in the ESR group. In addition, despite of less stent placement (0.6±0.5 vs. 1.3±0.9, P<0.001), patients in the ESR group had a non-statistically lower rate of cardiac adverse events (4.8% vs. 14.3%, P=0.269) during one-year follow up.

The OCT finding Variables ESR group (n=21) Control group (n=21) P value The OCT imaging <0.001   Plaque erosion 10 (47.6) 7 (33.3)   Plaque rupture 5 (23.8) 14 (66.7)   Calcified nodule 2 (9.5) 0 (0)   Vasospasm 4 (19.1) 0 (0) The Type of Thrombus <0.001   Red thrombus 4 (19.1) 18 (85.7)   White thrombus 13 (61.9) 3 (14.3)   No thrombus (vasospasm) 4 (19.1) 0 (0)   MLA (mm2) 2.7±2.2 2.3±2.4 0.534 Values are n (%), mean ± SD. ESR = early spontaneous reperfusion; MLA = Minimum lumen area; OCT = optical coherence tomography.

ESR and control group

Conclusions

Relief of coronary occlusion induced by non-ruptured plaque and platelet-rich thrombi may be one of the main mechanism underlying early spontaneous reperfusion in STEMI.

Acknowledgement/Funding

No.81470491 from the National Natural Science Foundation of China and No.7192078 from Beijing Municipal Natural Science Foundation to Dr. Li.

Planar Pentacoordinate versus Tetracoordinate Carbons in Ternary CBe4Li4 and CBe4Li42- Clusters

Planar hypercoordinate carbon molecules are exotic species, for which the 18-electron counting has been considered a rule. We report herein computational evidence of perfectly planar C_{2 v} CBe₄Li₄ (1) and D_{4 h} CBe₄Li₄^2- (3) clusters. These ternary species contain 16 and 18 electrons, respectively. The dianion is highly symmetric with a planar tetracoordinate carbon (ptC), whereas the neutral features a planar pentacoordinate carbon (ppC). Thus, charge-state alters the coordination environments of a cluster. Chemical bonding analysis shows that both clusters have 2π and 6σ delocalization around the C center, suggesting that ppC or ptC clusters are governed by double π/σ aromaticity, rather than the 18-electron rule. The outer Be₄Li₄ ring in 1 and 3 also supports 2σ aromaticity, collectively leading to 3-fold π/σ aromaticity for these ppC/ptC clusters. Structural transformation from ptC (3) to ppC (1) is discussed, in which the 16-electron quasi-ptC CBe₄Li₄ (2) cluster serves as an intermediate. Cluster 2 as a local minimum has severe out-of-plane distortion. Flattening of 2 leads to reorganization of Be₄ ring around the C center, which offers space for the fifth atom to coordinate and facilitates ppC formation. The latter arrangement optimizes π aromaticity and better manages intramolecular Coulomb repulsion. This work highlights the geometric factor (and unconventional electron counting) in the design of planar hypercoordinate carbons.

Boron-based binary Be6B102- cluster: three-layered aromatic sandwich, electronic transmutation, and dynamic structural fluxionality

Boron-based nanoclusters have unique structures, bonding, and dynamic properties, which originate from boron's electron-deficiency. We demonstrate here that pouring in extra electrons can alter such systems fundamentally. A coaxial triple-layered Be6B102- sandwich cluster is designed via global structural searches and quantum chemical calculations. It is well defined as the global minimum, which consists of a slightly elongated B10 monocyclic ring and two Be3 rings, the latter forming a Be6 trigonal-prism albeit without interlayer Be-Be bonding. The B10 ring shows structural and chemical integrity with respect to the Be3 rings, and yet it differs markedly from the free B10 cluster and closely resembles the C10 cluster. The present data testify to the idea of electronic transmutation, in which a B- is equivalent to C and a B10 cluster, upon charge-transfer, is converted to and stabilized as a monocyclic ring analogous to C10. Chemical bonding analyses reveal that the B10 ring in the Be6B102- cluster has 10π and 10σ delocalization and each Be3 ring is held together by 2σ electrons, collectively rendering four-fold π/σ aromaticity. The bonding pattern is in line with the formula of [Be3]4+[B10]10-[Be3]4+, suggesting a highly charged electron-transfer complex. Furthermore, the Be6B102- cluster is dynamically fluxional with dual modes of revolution (orbiting) and rotation (twisting), being structurally robust at least up to a temperature of 1500 K.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

Viable aromatic BenHn stars enclosing a planar hypercoordinate boron or late transition metal

Similar to B_n rings, star-like Be_nH_n rings can serve as the n-electron σ-donors for designing species with planar hypercoordinate atom.

Ternary CBe4Au4 cluster: a 16-electron system with quasi-planar tetracoordinate carbon

A ternary CBe₄Au₄ cluster contains quasi-planar tetracoordinate carbon (quasi-ptC). It adds the new 16-electron counting to ptC complexes, featuring 2π and 6σ double aromaticity.

Molecular identification of hemoplasma and piroplasma species from Rattus edwardsi based on sequences analysis of ribosomal DNA, China

The present study provides the first report on the molecular epidemiological data regarding infection by hemoplasma and piroplasma species in wild Rattus edwardsi, from China. In the current study, blood samples were investigated from 32 wild Rattus edwardsi from Hunan (23) and Guangxi (9) provinces, China. The prevalence of hemoplasma and piroplasma was 65.63% (21/32) and 6.25% (2/32), respectively. Phylogenetic analyses indicated that hemoplasmas (HQ183731, HQ183732) derived from wild Rattus edwardsi in China, can be grouped into a solitary clade closely related to H. muris (HMU82963) and M. haemomuris (AB758435). In addition, it was shown that piroplasmas from this study have very close genetic distance to other unidentified piroplasma species isolated from China (AB242140) and Japan (AB188086). The results suggested that hemoplasmas isolated in this study should be represented as a new genotype. Piroplasmas on the other hand needs more sequenced samples in its life-cycle and evidence to check its taxonomic status. These data may have important implications for researching on the epidemiology and population biology as well as for studying the taxonomy status of hemoplasmas and piroplasmids of wild rodents.

[Bit1 mediates the malignant behaviors in pancreatic cancer and its potential clinical significance]

Objective: To investigate the potential role of Bit1 in the pathogenesis of pancreatic ductal cancer cells(PDAC) and its potential clinical application value. Methods: Real-time PCR and Western blot were employed to detect the expression of Bit1 in six pancreatic cancer cells, then the tool cells were selected to further study the function of Bit1.PolyHEMA was used to monitor the suspended cell culture condition in vitro.The invasion and migration abilities of pancreatic cancer cells were detected through Transwell assay. Western blot and confocal assay were used to explore the potential mechanism of Bit1 in the process of metastasis.The expression of Bit1 was detected through tissue microarray, the potential relationship between Bit1 and other clinical factors were analyzed. Results: The results of real-time PCR and Western blot indicated that the expression of Bit1 was highest in the PANC1 cells and lowest in the Mia paca2 cells (gene: 3.13±0.40 vs. 1.00±0.35, protein: 1.77±1.00 vs. 0.23±0.45). The shBit1 PANC1 and Bit1-OE(over expression) Mia paca2 cells were successfully constructed.Bit1 over expression could promote the anoikis rate of Mia paca2 cells, and Bit knockdown could inhibit the anoikis incidence.Bit1 over expression suppressed the motility and invasion of Mia paca2 cells, but Bit1 knockdown could accelerate the migration and invasion ability of PANC1 cells.Bit1 could potentially affect pancreatic cancer cells' malignant behaviors through epithelial-mesenchymal transition process.Bit1 expression was significantly associated with pancreatic cancer's neural invasion (P<0.05). Conclusions: Bit1 could affect the anoikis incidence of pancreatic cancer, Bit1 negatively affect the migration and invasion abilities of PDAC, the EMT process was potentially involved in the whole modulation process.Bit1 expression is associated with neural invasion in pancreatic cancer patients.

Coaxial Triple-Layered versus Helical Be6 B11- Clusters: Dual Structural Fluxionality and Multifold Aromaticity

Two low-lying structures are unveiled for the Be₆ B₁₁^- nanocluster system that are virtually isoenergetic. The first, triple-layered cluster has a peripheral B₁₁ ring as central layer, being sandwiched by two Be₃ rings in a coaxial fashion, albeit with no discernible interlayer Be-Be bonding. The B₁₁ ring revolves like a flexible chain even at room temperature, gliding freely around the Be₆ prism. At elevated temperatures (1000 K), the Be₆ core itself also rotates; that is, two Be₃ rings undergo relative rotation or twisting with respect to each other. Bonding analyses suggest four-fold (π and σ) aromaticity, offering a dilute and fluxional electron cloud that lubricates the dynamics. The second, helix-type cluster contains a B₁₁ helical skeleton encompassing a distorted Be₆ prism. It is chiral and is the first nanosystem with a boron helix. Molecular dynamics also shows that at high temperature the helix cluster readily converts into the triple-layered one.

Why nanoscale tank treads move? Structures, chemical bonding, and molecular dynamics of a doped boron cluster B10C

Planar boron clusters form dynamic rotors, either as molecular Wankel motors or subnanoscale tank treads, the latter being exemplified by an elongated B₁₁^- cluster. For an in-depth mechanistic understanding of the rotors, we investigate herein a doped boron cluster, B₁₀C, in which a C atom isovalently substitutes B^- in the B₁₁^- tank tread. Two critical structures are achieved: the C_s (¹A') global minimum (GM) with C positioned in the peripheral ring and the C_2v (¹A₁) local minimum (LM) with C in the diatomic core. In the GM the C atom completely halts the rotation of B₁₀C, whereas in the LM the dynamic fluxionality remains. The energy barriers for in-plane rotation differ markedly: 12.93/18.31 kcal mol^-1 for GM versus 1.84 kcal mol^-1 for LM at the single-point CCSD(T) level. The GM rotates via two transition states (TS), compared to one for the LM. Chemical bonding in the structures is elucidated via canonical molecular orbital (CMO) analysis, adaptive natural density partitioning (AdNDP), electron localization functions (ELFs), and Wiberg bond indices (WBI). Electron delocalization is shown to be essential for structural fluxionality. In particular, the variation of WBI from the GM or LM geometries to their TS structures correlates positively with the energy barrier, which offers a quasi-quantitative measure of the barrier height and hence controls the dynamics. This finding may be extended to all molecular rotors. It also helps rationalize why a strongly covalently bound system can behave dynamically in a manner similar to a weakly bound one; it is the latter that is generally anticipated to be structurally fluxional.

[Current situation and thoughts on precision medicine about the treatment of tumor in China]

With United States starting"precision medical plan", it is widespread all over the world and opens a new direction to the development of medicine. Our country also starts the plan, trying to take the opportunity. At present, tumor threats human health with high incidence and mortality. In China, the incidence and mortality of tumor has been on the rise.So the tumor has become one of the most important fields of precision medicine.Precision medicine, hoping to reveal the Chinese characteristics of precision medicine, and getting the personal and social maximize health benefits are discussed in the paper.