Controlling Symmetry-Breaking Charge Separation in Pyrene Bichromophores.

So far, symmetry-breaking charge separation (SB-CS) has been observed with a limited number of chromophores and is usually inhibited by the formation of an excimer. We show here that thanks to fine-tuning of the interchromophore coupling via structural control, SB-CS can be operative with pyrene, despite its high propensity to form an excimer. This is realized with a bichromophoric system consisting of two pyrenes attached to a crown ether macrocycle, which can bind cations of different sizes. By combining stationary and time-resolved spectroscopy together with molecular dynamics simulations, we demonstrate that the excited-state dynamics can be totally changed depending on the binding cation. Whereas strong coupling leads to rapid excimer formation, too weak coupling results in noninteracting chromophores. However, intermediate coupling, achieved upon binding of Mg2+, allows for SB-CS to be operative.

Multistate Aggregation-Induced Chiroptical Properties of Enantiopure Disulfide-Mediated Bispyrene Macrocycles.

A chiral bispyrene macrocycle designed for exclusive intermolecular excimer fluorescence upon aggregation was synthesized by a double hydrothiolation of a bis-enol ether macrocycle followed by intramolecular oxidation of free thiols. Unusually high stereoselectivity was achieved for the thiol-ene additions under templated conditions and Et3 B/O2 radical initiation. After enantiomer separation (chiral stationary phase HPLC), aqueous conditions provoked aggregation. Detailed structural evolution was afforded by ECD/CPL monitoring. Three regimes can be observed and characterized by strong modifications in chiroptical patterns under, at, or above a 70 % H2 O : THF threshold. In luminescence, high glum dissymmetry factors values were obtained, up to 0.022, as well as a double sign inversion of CPL signals during the aggregation, a behavior rationalized by time-dependent density functional theory (TDDFT) calculations. Langmuir layers of enantiopure disulfide macrocycles were formed at the air-water interface and transferred onto solid substrates to afford Langmuir-Blodgett films, which were then studied by AFM and UV/ECD/fluorescence/CPL.

Photo-induced thiol-ene reactions for late-stage functionalization of unsaturated polyether macrocycles: regio and diastereoselective access to macrocyclic dithiol derivatives.

Double hydrothiolation of bis enol ether macrocycles was achieved under photo-mediated conditions. The thiol-ene reactions afford a fully regioselective anti-Markovnikov post-functionalization. Thanks to the use of ethanedithiol as reagent, moderate to excellent diastereoselectivity was accomplished leading to macrocycles containing four defined stereocenters in only three steps from 1,4-dioxane, tetrahydrofuran (THF) or tetrahydropyran (THP).

Regiodivergent enantioselective C-H functionalization of Boc-1,3-oxazinanes and application to the synthesis of ß2 and ß3-amino acids.

ß2- and ß3-Amino acids are important chiral building blocks for the design of new pharmaceuticals and peptidomimetics. Here we report a straightforward regio- and enantiodivergent access to these compounds using a one-pot reaction composed of sparteine-mediated enantioselective lithiation of a Boc-1,3-oxazinane, transmetallation to zinc and direct or migratory Negishi coupling with an organic electrophile. The regioselectivity of the Negishi coupling was highly ligand-controlled and switchable to obtain the C4- or the C5-functionalized product exclusively. High enantioselectivities were achieved on a broad range of examples, and a catalytic version in chiral diamine was developed using the (+)-sparteine surrogate. Selected C4- and C5-functionalized Boc-1,3-oxazinanes were subsequently converted to highly enantio-enriched ß2- and ß3-amino acids with the (R) or (S) configuration, depending on the sparteine enantiomer employed in the lithiation step.

Identification of key genes in Ankylosing spondylitis.

Ankylosing spondylitis (AS) is a common form of seronegative spondyloarthritis. We had identified differentially expressed genes (DEGs) in AS based on our previous RNA-sequencing results. Our study aimed to identify key genes in AS by integrated microarray analysis. In this present study, we identified 1328 DEGs between AS and normal control by using integrated analysis of two datasets derived from the Gene Expression Omnibus (GEO) database. Functional annotation of DEGs were performed. Pathways in cancer, Pancreatic cancer and Natural killer cell mediated cytotoxicity were significantly enriched pathways for DEGs. Based on the shared DEGs of AS in both integrated analysis and our previous RNA-sequencing results, we constructed the protein and protein interaction (PPI) network. BIRC2, MAPILC3A and MAGED1 were hub proteins. Validation of gene expression by qRT-PCR were performed and the results were consistent with our integrated analysis generally. Our finding provided new clues for understanding the mechanism of AS.

Barbier-Negishi Coupling of Secondary Alkyl Bromides with Aryl and Alkenyl Triflates and Nonaflates.

A mild and practical Barbier-Negishi coupling of secondary alkyl bromides with aryl and alkenyl triflates and nonaflates has been developed. This challenging reaction was enabled by the use of a very bulky imidazole-based phosphine ligand, which resulted in good yields as well as good chemo- and site selectivities for a broad range of substrates at room temperature and under non-aqueous conditions. This reaction was extended to primary alkyl bromides by using an analogous pyrazole-based ligand.

Terminal-Selective Functionalization of Alkyl Chains by Regioconvergent Cross-Coupling.

Hydrocarbons are still the most important precursors of functionalized organic molecules, which has stirred interest in the discovery of new C-H bond functionalization methods. We describe herein a new step-economical approach that enables C-C bonds to be constructed at the terminal position of linear alkanes. First, we show that secondary alkyl bromides can undergo in situ conversion into alkyl zinc bromides and regioconvergent Negishi coupling with aryl or alkenyl triflates. The use of a suitable phosphine ligand favoring Pd migration enabled the selective formation of the linear cross-coupling product. Subsequently, mixtures of secondary alkyl bromides were prepared from linear alkanes by standard bromination, and regioconvergent cross-coupling then provided access to the corresponding linear arylation product in only two steps.

Hybrid Operation for Descending Aortic Pathologies Involving Distal Aortic Arch.

Background A combined endovascular and debranching hybrid procedure was performed for descending aortic pathologies involving the distal aortic arch. We reviewed our results of this procedure to summarize clinical experiences. Methods From April 2009 to April 2013, 36 patients (21 males and 15 females) underwent the hybrid operation. Hospital stay and complications were closely monitored after operation. Follow-up CT scan was performed at postoperative 3 months and 12 months. Results The hospital stay ranged from 7 to 25 (15.1 ± 5.0) days. The mean age at operation was 67.6 ± 4.8 years (range: 60-79 years). In-hospital mortality and stroke rates were 2.8% (1/36) and 2.8% (1/36). At a mean follow-up of 22 months (4-52 months), the mortality was 0% (0/35). All remaining 35 patients returned to normal life. During the follow-up period, one patient required secondary endovascular reintervention for a type 1 distal endovascular leak. Conclusion Hybrid repair for descending aortic pathologies involving the distal arch proves to be effective and safe at midterm follow-up with acceptable surgical risks and satisfactory results.

[Chemical Constituents from Young Fruits of Citrus maxima cv. Shatian].

OBJECTIVE: To investigate the chemical constituents from the young fruits of Citrus maxima cv. Shatian. METHODS: The chemical constituents were isolated and purified by silica gel column chromatography and recrystallization, and their structures were identified on the basis of physicochemical properties and spectral analysis. RESULTS: Seven compounds were isolated and identified as naringenin (I), marmin (II), naringin (III), ß-sitosterol (IV) 5,7-dihydroxylcoumarin (V) 1, 3,5-trihydroxyhenzene (VI) and xanthotoxol (VII). CONCLUSION: Except compound III, all compounds are isolated from the young fruits of Citrus maxima cv. Shatian for the first time.

[Increasing cardiopulmonary bypass flow volume improves outcome of patient with carotid stenosis undergoing coronary artery bypass grafting].

OBJECTIVE: To evaluate the effect of increasing cardiopulmonary bypass (CPB) flow volume in improving outcome of patients with carotid artery stenosis performed coronary artery bypass grafting (CABG) procedure. METHODS: Fifty-one patients data collected from January 2006 to March 2008 and divided into two groups (A and B) based on the degree of the carotid artery stenosis diagnosed by ultrasound. Group A included 15 cases with one or both carotid artery stenosis more than 50%, 14 male and 1 female, aged (68.5 +/- 7.7) years old, 14 with hypertension, 2 with diabetes, 6 with myocardial infarction, 3 with cerebral infarction. Group B included 36 cases with stenosis less than 50%, 34 male and 2 female, aged (62.4 +/- 10.2) years old, 28 with hypertension, 7 with diabetes, 20 with myocardial infarction. Increasing CPB flow volume in A group to compare cerebral blood flow (CBF) within procedure in both groups. RESULTS: CPB flow volume in group A was much higher than it in group B (P = 0.001). Mean arterial blood pressure in group A was (67.0 +/- 9.1) mm Hg (1 mm Hg = 0.133 kPa), higher than group B (59.0 +/- 7.1) mm Hg (P = 0.009). There was no significant difference of CBF within procedure and neuropsychologic performance in both group as result. CONCLUSION: For the patients presenting with carotid artery stenosis undergoing the procedure of CABG with CPB, increasing CPB flow volume could improve significantly diseased side cerebral blood flow and might reduce neurological complications.

[Winter wheat yield gap between field blocks based on comparative performance analysis].

Based on a two-year household survey data, the yield gap of winter wheat in Quzhou County of Hebei Province, China in 2003-2004 was studied through comparative performance analysis (CPA). The results showed that there was a greater yield gap (from 4.2 to 7.9 t x hm(-2)) between field blocks, with a variation coefficient of 0.14. Through stepwise forward linear multiple regression, it was found that the yield model with 8 selected variables could explain 63% variability of winter wheat yield. Among the variables selected, soil salinity, soil fertility, and irrigation water quality were the most important limiting factors, accounting for 52% of the total yield gap. Crop variety was another important limiting factor, accounting for 14%; while planting date, fertilizer type, disease and pest, and water press accounted for 7%, 14%, 10%, and 3%, respectively. Therefore, besides soil and climate conditions, management practices occupied the majority of yield variability in Quzhou County, suggesting that the yield gap could be reduced significantly through optimum field management.

Molecular cloning and responsive expression of macrophage expressed gene from small abalone Haliotis diversicolor supertexta.

The complete cDNA sequence of macrophage expressed gene (saMpeg1), a perforin-like molecule, was isolated from small abalone (Haliotis diversicolor supertexta) by homology cloning and rapid amplification of cDNA ends (RACE). The full-length cDNA of saMpeg1 was 2781 bp, consisting of a 5'-terminal untranslated region (UTR) of 252 bp, a 3'-terminal UTR of 342 bp with a signal sequence TAA and a poly (A) tail, and an open reading frame of 2184 bp. The deduced protein (saMpeg1) was composed of 728 amino acids, and contains the cytolytic "helix-turn-helix" domain of perforin (residues 171-218), of which the alpha-helices are amphipathic as are those of perforin. A putative single transmembrane domain is located at residues 667-689, and a modified furin cleavage site (KRRRK; residues 689-693) immediately follows. The result of real time quantitative PCR showed that saMpeg1 was highly expressed at 8h and 96 h post-injection of the Gram-negative bacterium Vibrio parahaemolyticus, but there was no change after TBT exposure. The structural similarity to mammalian perforin and the different gene expression level to bacterial infection and TBT exposure suggest that saMpeg1 may play a role in the immune response against microorganisms in small abalone.

[Spatial-temporal dynamic change of land resource degradation in China].

Large scale spatial and temporal land use survey data were used to study the dynamics of land use change in China recently. With the aid of GIS, the spatial-temporal dynamic change of land resource degradation at the national level was investigated using authoritative datasets from detailed land use surveys (early 1990s approximately 2003). As a result, seven major types of land degradation processes were identified, including sandy desertification, rocky desertification, secondary salinification, non-agricultural land occupation, deforestation, natural grassland degradation and wetlands shrinking. This paper comprehensively explored the characteristics of these land degradation processes and revealed the status and trend of the holistic land resource degradation in China. Results shows that: (1) Although land degradation has been controlled in local area, but it is still continuing to spread in the whole country. The total degradation index of the holistic land resource presented fluctuating trend. Indexes of non-agricultural construction occupation and wetland shrinking process are far more than that of other process, which are two primary causes contribution to heading straight towards full-scale land resource deterioration in China. (2) Land resource degradation process of China focused on natural grass land, and non-agricultural construction land, which attained 66.27%; Land resource degradation rehabilitation mainly focused on desertification and forest restoration, which accounts for 57.5%. (3) Sandy desertification and rocky desertification process have been reversing greatly. The total net change of their quantities was decreased by 15,578km2. But most of the rehabilitation of land desertification was concentrated on the originally ecological vulnerable northwestern zone, whereas newly added desertified land has been expanding and aggravating in eastern zone, especially around river watersheds. (4) Over two-thirds of non-agriculture land expansion came from cultivated land. In addition, almost 60 percent of the loss cultivated land occupied by non-agricultural land was appeared in the Northeast, the Eastern coast and Central China where have many high productive agricultural lands of China. This kind of land degradation has threatened food security of China seriously. (5) However, large scale reclamation of ecological land transferred into cultivated land was the most dominant factor of degradation. For example, the conversion of wetland resource to croplands by reclamation accounts for over 50 percent of wetland shrinking.

[Studies of TGF-beta/Smads expression in lung cancer].

Smad proteins transduce signals from transforming growth factor beta superfamily ligands that regulate cell proliferation, differentiation and death through activation of receptor serine/threonine kinases. TGF-beta/Smads signal pathway not only has transforming potential but can also drive tumourigenesis, malignant progression, invasion and metastasis of human cancers. Using the immuno-histochemistry, we investigate the expression and location of TGF-beta R II, Smad2, Smad4 and Smad7 in 20 lung cancer specimens and 8 lung cancer cell lines. The results suggest that aberrant smads protein expression is significantly related to lung cancer tumoruigenesis and progression. Interestingly, TGF-beta R II and Smad7 strongly express in high metastasis cell lines. High expression of TGF-beta R II and smad7 in the cell lines with high-metastatic potential showed a conceivable TGF-beta signal pathway independent Smads in the lung cancer, and that might mediate invasion and metastasis of lung cancer.