Combined Crossed Molecular Beams and Ab Initio Study of the Bimolecular Reaction of Ground State Atomic Silicon (Si; 3P) with Germane (GeH4; X1A1)

The chemical dynamics of the elementary reaction of ground state atomic silicon (Si; ³P) with germane (GeH₄; X¹A₁) were unraveled in the gas phase under single collision condition at a collision energy of 11.8±0.3 kJ mol⁻¹ exploiting the crossed molecular beams technique contemplated with electronic structure calculations. The reaction follows indirect scattering dynamics and is initiated through an initial barrierless insertion of the silicon atom into one of the four chemically equivalent germanium-hydrogen bonds forming a triplet collision complex (HSiGeH₃; ³ i1 ). This intermediate underwent facile intersystem crossing (ISC) to the singlet surface (HSiGeH₃; ¹ i1 ). The latter isomerized via at least three hydrogen atom migrations involving exotic, hydrogen bridged reaction intermediates eventually leading to the H₃SiGeH isomer i5 . This intermediate could undergo unimolecular decomposition yielding the dibridged butterfly-structured isomer ¹ p1 (Si(μ-H₂)Ge) plus molecular hydrogen through a tight exit transition state. Alternatively, up to two subsequent hydrogen shifts to i6 and i7 , followed by fragmentation of each of these intermediates, could also form ¹ p1 (Si(μ-H₂)Ge) along with molecular hydrogen. The overall non-adiabatic reaction dynamics provide evidence on the existence of exotic dinuclear hydrides of main group XIV elements, whose carbon analog structures do not exist.     

CDFI鉴别男性乳腺良恶性肿瘤价值及与CXCL1、Gab2、MVD的相关性探究

本研究选取18例男性乳腺恶性肿瘤患者作为研究组,纳入同期41例男性良性乳腺肿瘤及50例健康体检男性分别作为良性对照组和健康对照组,通过对比分析发现,研究组CDFI参数[搏动指数(PI)、阻力指数(RI)、血流速度(PSV)]高于良性对照组和健康对照组(P<0.05);PI、RI、PSV联合诊断男性乳腺恶性肿瘤的AUC高达0.854,具有较高应用价值;研究组患者PI、RI、PSV与CXC型趋化因子配体1(CXCL1)、GRB相关蛋白2(Gab2)、微血管密度(MVD)水平间存在正相关关系(P<0.05)。由此可见,CDFI在鉴别男性乳腺良恶性肿瘤方面具有较高应用价值,且与患者CXCL1、Gab2、MVD表达呈正相关。     

过渡金属-配体σ键键能在碳-氢键活化中的应用

过渡金属催化的碳-氢(C-H)键活化因其优异的原子经济性及步骤简便性在过去几十年间蓬勃发展,已成为当前构建复杂化合物最常用的策略之一.对该过程中活性中间体的热力学研究有助于加深人们对反应机理的理解,指导新催化剂、新反应的理性设计.然而,近年来该领域的发展颇为缓慢,相应的报道十分零散,缺少系统的归纳和总结.本综述简要梳理了过渡金属-配体σ键键能的研究历程,并举例阐述了这些热力学参数在分析反应可行性、判断反应选择性等方面的应用,旨在推动过渡金属络合物相关的热力学研究的快速发展.     

微纳电化学传感界面的构建及其用于单细胞实时监测

细胞是生物体形态结构和生命活动的基本单位.常规检测群体细胞的方法往往会掩盖细胞间的个体差异,因此亟需发展高效的单细胞分析策略,深入研究细胞生命活动过程,揭示疾病发生发展机制,推动个体化诊疗.超微电化学传感器具有尺寸小、灵敏度高、时空分辨率高等特点,在单细胞实时动态监测方面发挥了非常重要的作用.目前,微纳电化学传感器在电极制备、高性能传感界面构建、理论分析等方面已取得重要进展,且在单细胞实时监测及相关细胞机制研究方面取得突破.然而,单细胞内环境复杂、活性分子浓度低且随时空高度动态变化,这对微纳电化学传感器的灵敏度和选择性等综合性能提出了更高要求.我们课题组长期从事基于微纳电化学传感的单细胞与亚细胞实时动态监测研究,本文主要介绍了我们近10年来在该领域的研究进展,并对未来的挑战与机遇进行了探讨.     

From borophosphate to fluoroborophosphate: a rational design of fluorine-induced birefringence enhancement

The introduction of oxofluoride anion into anionic group assists to tune optical properties owing to the change of coordination,electronegativity,and according anionic framework.Here,we proposed a rational design of new compounds by fluorine-driven structure and optical property evolution.A new borophosphate Ba_2BP_3O_(11)with the monoclinic space group P2_1/c has been synthesized in the sealed system.Ba_2BP_3O_(11)exhibits a rare P–O–P bridge formation,which is the first example in alkaline-earth metal borophosphates.By further substituting[BO_4]~(3-)with[BO_3F]~(4-),the first alkaline-earth metal/lead fluoroborophosphates M_2BP_2O_8F (M=Ba and Pb) with the same space group were designed.Since the scissors effect of fluorine,in M_2BP_2O_8F (M=Ba and Pb),a BO_3F tetrahedron corner-sharing with three PO_4tetrahedra forms 1D chains along the b-axial direction,which are filled by MO_n(M=Ba/Pb,n=5,6,8) distorted polyhedra.The first principles calculation shows that the borophosphate Ba_2BP_3O_(11)has a birefringence about 0.013@1,064 nm,while the fluoroborophosphates M_2BP_2O_8F (M=Ba and Pb) have the values of 0.035 and 0.043@1,064 nm,respectively.Such an apparent enhancement in birefringence is derived from synergies of the oxyfluoride and cation.The introduction of fluorine-containing heteroanionic groups provides a feasible strategy to design novel promising optical materials.     

Cationic Nonporous Macrocyclic Organic Compounds for Multimedia Iodine Capture

Over the past two decades, progress in chemistry has generated various types of porous materials for removing iodine (¹²⁹I or ¹³¹I) that can be formed during nuclear energy generation or nuclear waste storage. However, most studies for iodine capture are based on the weak host-guest interactions of the porous materials. Here, we present two cationic nonporous macrocyclic organic compounds, namely, MOC-1 and MOC-2 , in which 6I^- and 8I⁻ were as counter anions, for highly efficient iodine capture. MOC-1 and MOC-2 were formed by reacting 1,1′-diamino-4,4′-bipyridylium di-iodide with 1,2-diformylbenzene or 1,3-diformylbenzene, respectively. The presence of a large number of I⁻ anions results in high I₂ affinity with uptake capacities up to 2.15 g ⋅ g⁻¹ for MOC-1 and 2.25 g ⋅ g⁻¹ for MOC-2 .     

Large Nonlinear Optical Activity of a Near-infrared-absorbing Bithiophene-based Polymer with a Head-to-head Linkage

Although the production of near-infrared (NIR)-absorbing organic polymers with an excellent nonlinear optical (NLO) response is vital for various optoelectronic devices and photodynamic therapy, the molecular design and relevant photophysical investigation still remain challenging. In this work, large NLO activity is observed for an NIR-absorbing bithiophene-based polymer with a unique head-to-head linkage in the NIR region. The saturable absorption coefficient and modulation depth of the polymer are determined as ∼−3.5×10⁵ cm GW⁻¹ and ∼32.43%, respectively. Notably, the polymer exhibits an intrinsic nonlinear refraction index up to ∼−9.36 cm² GW⁻¹, which is six orders of magnitude larger than that of CS₂. The maximum molar-mass normalized two-photon absorption cross-section (σ₂/M) of this polymer can be up to ∼14 GM at 1200 nm. Femtosecond transient absorption measurements reveal significant spectral overlap between the 2PA and excited state absorption in the 1000–1400 nm wavelength range and an efficient triplet quantum yield of ∼36.7%. The results of this study imply that this NIR-absorbing polymer is promising for relevant applications.     

Cross-dehydrogenative Coupling of N-Aryl Tetrahydroisoquinolines Catalyzed by an Anthraquinone-containing Polymeric Photosensitizer

This work reports the photocatalytic application of an anthraquinone-containing polymeric photosensitizer (AQ-PHEMA) in the visible light-induced cross - dehydrogenative-coupling of N-aryl tetrahydroisoquinolines with several nucleophiles, including nitromethane, 1-methyl-2-alkyl ketone and dialkyl (aryl) phosphine oxide. The results revealed that the reaction could be catalyzed by AQ-PHEMA efficiently to afford a series of 1-substituted-2-aryl-1,2,3,4-tetrahydroisoquinolines in good to excellent yields with nice substrate tolerance under aerobic conditions at room temperature. The practical application potential was also showcased by a gram-scale synthesis. More importantly, the utilization of AQ-PHEMA as a heterogeneous photosensitizer also showed nice recyclability and reusability of the catalyst, whereas AQ-PHEMA can be easily separated and reused for at least 8 times without significant loss of photocatalytic activity.     

Anti-atherosclerotic activity of Betulinic acid loaded polyvinyl alcohol/methylacrylate grafted Lignin polymer in high fat diet induced atherosclerosis model rats

Betulinic acid is one such natural pentacyclic triterpenoid compound, holding various pharmacological properties but its poor bioavailability is the only limitation. One of the biological macromolecules such as Lignin is a plant-derived aromatic, eco-friendly and low-cost polymer that certainly self-assembles into nano-sized colloids. Therefore, onto the current investigation, we increased the bioavailability of betulinic acid by coating on to a nanopolymer prepared with poly vinyl alcohol, lignins and methyl acrylate. Betulinic acid loaded polyvinyl alcohol/ethylacrylate grafted Lignin polymer (PVA/Lig-g-MA) nanoformulation was characterized using FTIR, XRD, SEM and TEM analysis and also the drug entrapment, in vitro drug releasing capacity was done to examine the efficiency of the nanoformulation of a drug. The MTT assay was evaluated the cytotoxicity of synthesized nanoformulation against normal endothelial cells HUVEC and HAPEC to confirm the side effects of the drug. The anti-atherosclerotic property of the nanoformulation was ascertained in both in vitro condition (with HUVEC and HPAEC) and in vivo studies (with Wistar rats). As a result, the characterization studies and in vitro studies clearly confirmed the Betulinic acid loaded PVA/Lig-g-MA nanoformulation is an ideal nanopolymer and it doesn’t cause any cytotoxic effect in normal endothelial cells. It also decreased the lipopolysaccharides induced inflammation through the down-regulation of NFκB and MAP/JNK signaling molecule expressions. Following in vivo results confirmed the synthesized nanoformulation effectively decreased the hyperchlostremia, inflammation and vasoconstriction, which induced over high fat diet. The results of histopathological analysis of cardiac tissues also confirmed the cardioprotective role of synthesized nanoformulation. Overall, both the in vitro and in vivo studies authentically proven the Betulinic acid loaded PVA/Lig-g-MA nanoformulation would be a potent cost effective anti-atherosclerotic nanodrug.     

SO2 Resisting Pd-doped Pr1-xCexMnO3 Perovskites for Efficient Denitration at Low Temperature

H₂-SCR is served as the promising technology for the controlling of NO_x emission, and the Pd-based derivative catalyst exhibited high NO_x reduction performance. Effectively regulating the electronic configuration of the active component is favorable to the rational optimization of noble Pd. In this work, a series of Pr_1-xCe_xMn_1-yPd_yO₃@Ni were successfully synthesized and exhibited superior NO conversion efficiency at low temperatures. 92.7 % conversion efficiency was achieved at 200 °C over Pr_0.9Ce_0.1Mn_0.9Pd_0.1O₃@Ni in the presence of 4 % O₂ with a GHSV of 32000 h⁻¹. Meanwhile, the outstanding performance was obtained in the resistance to SO₂ (200 ppm) and H₂O (8 %). Deduced from the results of XRD, Raman, XPS, and H₂-TPR, the modification of d orbit states in palladium was confirmed originating from the incorporation in the B site of Pr_0.9Ce_0.1Mn_0.9Pd_0.1O₃. The existence of higher valence (Pd³⁺ and Pd⁴⁺) than the bivalence in Pr_0.9Ce_0.1Mn_0.9Pd_0.1O₃ catalyst was evidenced by XPS analysis. Our research provides a new sight into the H₂-SCR through the higher utilization of Pd.