Unusual Electronic Structures of an Electron Transfer Series of [Cr(µ-η1 : η1 -N2 )Cr]0/1+/2.

In dinitrogen (N2 ) fixation chemistry, bimetallic end-on bridging N2 complexes M(µ-η1 : η1 -N2 )M can split N2 into terminal nitrides and hence attract great attention. To date, only 4d and 5d transition complexes, but none of 3d counterparts, could realize such a transformation. Likewise, complexes {[Cp*Cr(dmpe)]2 (µ-N2 )}0/1+/2+ (1-3) are incapable to cleave N2 , in contrast to their Mo congeners. Remarkably, cross this series the N-N bond length of the N2 ligand and the N-N stretching frequency exhibit unprecedented nonmonotonic variations, and complexes 1 and 2 in both solid and solution states display rare thermally activated ligand-mediated two-center spin transitions, distinct from discrete dinuclear spin crossovers. In-depth analyses using wave function based ab initio calculations reveal that the Cr-N2 -Cr bonding in complexes 1-3 is distinguished by strong multireference character and cannot be described by solely one electron configuration or Lewis structure, and that all intriguing spectroscopic observations originate in their sophisticate multireference electronic structures. More critical is that such multireference bonding of complexes 1-3 is at least a key factor that contributes to their kinetic inertness toward N2 splitting. The mechanistic understanding is then used to rationalize the disparate reactivity of related 3d M(µ-η1 : η1 -N2 )M complexes compared to their 4d and 5d analogs.

Snapshots of Early-Stage Quantitative N2 Electrophilic Functionalization.

Electrophilic functionalization of N2 moieties in metal dinitrogen complexes typically initiates the catalytic synthesis of N-containing molecules directly from N2. Despite intensive research in the last six decades, how to efficiently and even quantitatively convert N2 into diazenido and hydrazido species still poses a great challenge. In this regard, systematic and comprehensive investigations to elucidate the reaction intricacies are of profound significance. Herein, we report a kinetic dissection on the first and second electrophilic functionalization steps of a new Cr0-N2 system with HOTf, MeOTf, and Me3SiOTf. All reactions pass through fleeting diazenido intermediates and furnish long-lived final hydrazido products, and both steps are quantitative conversions at low temperatures. All of the second-order reaction rates of the first and second transformations were determined as well as the lifetimes of the intervening diazenido species. Based on these findings, we succeeded in large-scale and near-quantitative preparation of all hydrazido species.

[Analysis of Compatibility Laws for Acupoint Selection of Acupuncture in Treating Diabetic Gastroparasis].

OBJECTIVE: To summarize and analyze the compatibility laws for acupoint selection of acupuncture in treating diabetic gastroparasis (DGP) in modern literatures of clinical researches. METHODS: Retrieved were literatures related to treating DGP by acupuncture or acupuncture combined other therapies from PubMed, CNKI, and WF from 1982 to 2014. Analyzed were frequency of acupoint use, meridians selected acupoints belonged to, regions selected, association laws of selected compatible acupoints. RESULTS: Retrieved were 35 with compatibility frequencies more than 15 listed as follows: compatibility frequency of Zusanli (ST36) and Zhongwan (CV12) was 33 (94.29%); compatibility frequency of Zusanli (ST36) and Neiguan (PC6) was 23 (65.71%), compatibility frequency of Zhongwan (CV12) and Neiguan (PC6) was 22 (62.86%), compatibility frequency of Zusanli (ST36), Zhongwan (CV12), and Neiguan (PC6) was 22 (62.86%); compatibility frequency of Zusanli (ST36) and Sanyinjiao (SP6) was 16 (45.71%); compatibility frequency of Zhongwan (CV12) and Sanyinjiao (SP6) was 16 (45.71%); compatibility frequency of Zusanli (ST36), Zhongwan (CV12), and Sanyinjiao (SP6) was 15 (42.86%). Meridians selected acupoints belonged to were sequenced as Foot Yangming Stomach channel, Ren channel, Foot Taiyang Bladder channel, and so on. Acupoints selected were mainly in lower limbs, chest and abdomen, waist and back. The compatibility of Zusanli (ST36) and Zhongwan (CV12) was the most often used with the highest frequency. CONCLUSIONS: The compatibility laws for acupoint selection of acupuncture in treating DGP were mainly dominated as upper-lower selection, three regions selection, local selection, anterior-posterior selection. The compatibility laws for acupoint selection of acupuncture along meridians were mainly dominated as the convergence points and exterior-interior meridian points.

Proteomic analysis reveals the deregulation of inflammation-related proteins in acupuncture-treated rats with asthma onset.

Although the beneficial effects of acupuncture in asthma treatment have been well documented, little is known regarding the biological basis of this treatment. Changes in the lung proteome of acupuncture-treated rats with asthma onset were comparatively analyzed using a two-dimensional gel electrophoresis (2DE) and mass-spectrometry- (MS-) based proteomic approach. Acupuncture on specific acupuncture points appeared to improve respiratory function and reduce the total number of leukocytes and eosinophils in bronchoalveolar lavage fluid in OVA-induced asthma onset. Image analysis of 2DE gels revealed 32 differentially expressed acupuncture-specific protein spots in asthma onset; 30 of which were successfully identified as 28 unique proteins using LC-MS/MS. Bioinformatic analyses indicated that these altered proteins are most likely involved in inflammation-related biological functions, and the functional associations of these proteins result in an inflammation signaling pathway. Acupuncture regulates the pathway at different levels by regulating several key nodal proteins, including downregulating of proinflammatory proteins (e.g., S100A8, RAGE, and S100A11) and upregulating of anti-inflammatory proteins (e.g., CC10, ANXA5, and sRAGE). These deregulated inflammation-related proteins may mediate, at least in part, the antiasthmatic effect of acupuncture. Further functional investigation of these acupuncture-specific effector proteins could identify new drug candidates for the prophylaxis and treatment of asthma.

Synthesis of 3,3-Dialkyl-Substituted Isoindolinones Enabled by Nickel-Catalyzed Reductive Dicarbofunctionalization of Enamides.

Herein we report the nickel-catalyzed reductive dicarbofunctionalization of 1,1-disubstituted enamides with unactivated alkyl iodides to access the 3,3-dialkyl-substituted isoindolinone frameworks. This tandem cyclization/reductive coupling protocol exhibits broad functional group tolerance under mild conditions. The utilization of commercially accessible chiral Bn-Biox ligand allows excellent enantioselectivities to forge the tetrasubstituted stereocenters.

Cyclophilin A Plays Potential Roles in a Rat Model of Asthma and Suppression of Immune Response.

PURPOSE: Cyclophilin A (CypA) inhibits CD4+ T cell signal transduction via interleukin-2-inducible T-cell kinase (Itk), a tyrosine kinase required for T helper (Th) 2 cells function. Furthermore, mice with CypA silencing developed allergic diseases associated with increased Th2 cytokines production. CD4+ T cells with a Th2-cytokine pattern have been demonstrated to have a pivotal role in the pathogenesis of asthma. However, the effects of CypA in regulating immunity in asthma and in relieving asthmatic symptoms in vivo are entirely unknown. METHODS: Recombinant CypA protein (rCypA) was generated and purified. Ovalbumin (OVA)-challenged asthmatic rats model and acetylcholine chloride (ACh)-induced contraction of tracheal spirals were established. The pulmonary resistance (RL) value of asthmatic rats in vivo and the isometric tension of tracheal spirals ex vivo were recorded by MFLab 3.01 software. The levels of Th1 and Th2 cytokines and the quantities of immunoglobulin (IgA, IgG, IgM and IgE) in the supernatants of rat spleen lymphocytes were detected and analysed by bio-plex Suspension Array System and ELISA, respectively. CD4+ T cells were separated by MicroBeads, and the levels of interleukin (IL)-4 and interferon-γ (IFN-γ) were detected by ELISA. RESULTS: rCypA (10 ng/kg) significantly reduced RL within 2-7 min in OVA-challenged asthmatic rats in vivo, and there were no significant differences compared with terbutaline (TB) and hydrocortisone (HC). Furthermore, rCypA (10 ng/mL) significantly reduced the isometric tension in the ACh-induced contraction of the tracheal spiral ex vivo, and the effect of rCypA was better than that of TB. Additionally, rCypA suppressed the secretion of both Th1 and Th2 cytokines, and the suppressive effects of rCypA were stronger than those of HC, especially on Th2 cytokines. CONCLUSION: These findings indicate that CypA may serve as a potential novel therapeutic strategy for asthma.

[Acupoint selection: a key factor to influence the compatibility of acupoint].

In this paper, from the concept of acupoint compatibility, it is proposed that acupoint selection is a key factor to influence the compatibility of acupoint, and the nature of acupoint is closely related with the location and dominant meridian of acupoints. Acupoint selection according to the location and meridians is the basic method of acupoint compatibility, while acupoint selection based on the syndrome differentiation and the symptoms is the fundamental requirement of acupoint compatibility. Therefore, understanding the nature of acupoint, knowing the method of acupoint compatibility and selecting analogous acupoint that have identical or similar indications are the keys to improve the clinical efficacy.

Alteration of the proteome profile of the pancreas in diabetic rats induced by streptozotocin.

Type 1 diabetes mellitus (T1DM) is receiving increased attention. To obtain a better understanding of the mechanism underlying T1DM, we performed a proteomic study on a rat model induced by streptozotocin. Pancreatic proteins were separated by two-dimensional gel electrophoresis. Eighteen protein spots were differentially expressed (P<0.05) with 2-fold or more increased or decreased intensity in the diabetic rats as compared with controls, of which 11 protein spots were up-regulated and 7 protein spots were down-regulated. These protein spots were successfully identified by liquid chromatography-electrospray ionization tandem mass spectrometry. The 60 kDa heat shock protein, the carbonyl reductase 1 (Cbr1), the hydroxyacyl-CoA dehydrogenase, Δ(3,5),Δ(2,4)-dienoyl-CoA isomerase, the elongation factor 1-δ, the 26S protease regulatory subunit 7 and the transitional endoplasmic reticulum ATPase were up-regulated, while the 78 kDa glucose-regulated protein, peroxiredoxin 4 and plakoglobin were down-regulated. The expression change of Cbr1 which is closely related to diabetic complications was further validated by western blotting. Our results and those of the bioinformatics analysis suggest that oxidative stress, the Wnt pathway, fatty acid degradation and glucose transport may be closely related to T1DM.