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A photo-switchable hetero-complementary quadruple H-bonding array, which consists of an azobenzene-derived ureidopyrimidinone (UPy) module (Azo-UPy) and a nonphotoactive diamidonaphthyridine (DAN) derivative (Napy-1), is constructed based on a reversible photo-locking approach. Upon UV (390 nm)/Vis (460 nm) light irradiations, photo-switchable quadruple H-bonded dimerization between Azo-UPy and Napy-1 can be achieved with exhibiting 4.8×104 -fold differences in binding strength (ON/OFF ratios). Furthermore, smart polymeric gels with unique photo-controlled macroscopic self-assembly behavior can be fabricated by introducing such quadruple H-bonding array as photo-regulable noncovalent interfacial connections.

Purpose: To investigate the prevalence and clinical characteristics of myelinated retinal nerve fibre (MRNF) in a large teleophthalmology system.Methods: All records between January 2015 and Decemb...

For the deoxygenation of fatty acids to hydrocarbon biofuels, the catalytic mechanism is still unclear at the molecular level. Here, the deoxygenation mechanism of butyric acid catalyzed by a Ni12P6 cluster has been theoretically studied at the GGA–PBE/DNP, DSPP level in dodecane solution, in which butyric acid and the Ni12P6 cluster are preferred as the reactant model of palmitic acid and the catalyst model of Ni2P, respectively. For the deoxygenation of butyric acid, there are three main reactions i.e., (reaction (I)) through direct decarboxylation to propane, (reaction (II)) through decarbonylation and hydrodehydration/hydroreduction to propane, and (reaction (III)) through hydroreduction and/or hydrodehydration to n-butane. Propane stems from the decarbonylation (reaction (II)) rather than direct decarboxylation (reaction (I)). For reaction (II), the optimal pathway should be through butyraldehyde or direct decarbonylation and not through propyl alcohol. Furthermore, CO mainly originates from butyraldehyde at low temperature and from direct decarbonylation at high temperature. From butyraldehyde, decreasing temperature is beneficial to the n-butyl alcohol formation through hydroreduction, and increasing temperature is preferable to the propane formation through decarbonylation. For reaction (III), from n-butyl alcohol, n-butane comes from direct hydrodehydration at low temperature, and from successive dehydration and hydroreduction through n-butylene at high temperature. The present reaction mechanism network may promote the novel design of a highly selective catalyst toward the deoxygenation of fatty acids.

Al-Containing MCM-41 catalysts exhibit good catalytic activity toward glucose-to-fructose isomerization. However, the catalytic contribution of typical functional groups over Al active sites is a little unclear. Here, on the pore surface of Al-doped MCM-41, there are two different active sites, i.e., –[SiO]2[SiO(H)]Al[OH] ([Al-1]) with one hydroxyl and –[SiO][SiO(H)]Al[OH]2 ([Al-2]) with two hydroxyls. Over these two active sites, the catalytic mechanisms for the isomerization of glucose to fructose have been theoretically studied, combining molecular mechanics and hybrid quantum mechanics calculations. The glucose-to-fructose isomerization usually involves three successive reaction stages, i.e., ring-opening, tautomerization, and ring-closure. Among them, aldose–ketose tautomerization is the rate-determining step, which is related to the intramolecular C2 → C1 H-shift. The catalytic activity of the Al-containing active sites originates from three factors, i.e., the Lewis acidity of the Al site, a proton donor in the form of an Al–O(H)–Si group and a proton acceptor in the form of an Al–OH group. The [Al-2] active site with two hydroxyls displays higher catalytic activity than the [Al-1] active site with one hydroxyl, which mainly depends on the Lewis acidity of the aluminium atom in the active site.

In this paper, a unique orthogonal photoresponsive tristable [3]rotaxane molecular shuttle (R1) is constructed, which consists of two CBPQT4+ macrocycles interlocked via a dumbbell component containing three recognition sites, including photoswitchable azobenzene (AB) and naphthalene-derived azobenzene (NP-AB) units separated by a 1,5-dioxynaphthalene (DNP) unit. The two azo units that are encapsulated by the CBPQT4+ macrocycles in the pristine state can be E/Z photoisomerized separately upon irradiation using UV (365 nm) and yellow (>550 nm) light (for the AB unit) and using blue (420–430 nm) and yellow (>550 nm) light (for the NP-AB unit), thus achieving the distinctive orthogonal phototriggered shuttling of the CBPQT4+ macrocycles between the azo and DNP units. This means that charge transfer (CT) absorption (at 620 nm, generated from the NP⊂CBPQT4+ encapsulation complex) related to R1 can be fully photoregulated between three spectral states with good reversibility. Moreover, UV-light-irradiated [2]rotaxane analogues that are embedded with NP-AB or AB units are found to be insensitive to red light (620 nm) irradiation. These features, together with the peculiarity of the orthogonal photo-responsiveness, enable this novel photochromic [3]rotaxane to be potentially applied as a multistate molecular switch or as an optical information storage medium with non-destructive readout.

Zr-containing SBA-15 zeolite (Zr-SBA-15) catalysts show good catalytic performance toward xylose conversion to methyl lactate (ML). Here, we report our study on the catalytic mechanisms for the con...

Apatinib is a new oral tyrosine kinase inhibitor that targets vascular endothelial growth factor receptor-2. It has been proven effective in treating multiple solid tumors. Herein, we report the case of a 67-year-old Chinese patient who was diagnosed with recurrent and malignant transformation of intrahepatic biliary cystadenoma. After multidisciplinary team discussion, the team considered that the remaining liver volume was insufficient for surgical resection. The patient refused chemotherapy and radiotherapy and was willing to take apatinib. Initially, the patient experienced severe tongue ulcers and difficulty eating. The dose of apatinib was then adjusted to 250 mg/day. To date, he has been taking apatinib for 48 months. Regular re-examination showed that the tumor had significantly decreased in size. On January 16, 2021, a CT scan revealed a tumor diameter of 4.5 cm. In our case, the patient achieved partial response and progression-free survival(PFS) of 48.0 months. During treatment, the patient’s appetite and mental state were expected. The treatment did not induce hypertension, fatigue, hand-foot syndrome, or liver and kidney damage. Apatinib may be an option for the treatment of advanced intrahepatic biliary cystadenocarcinoma. Its toxicity is controllable and tolerable. The exact curative effect still needs to be evaluated in more cases.

It is still not clear at the molecular level how the acidic silanol and basic alkylamine bifunctional groups over SBA-15 zeolite exert catalytic functions in aldol condensation of 5-hydroxymethylfu...

Two reduced Schiff bases, namely 5-[(2-hydroxybenzyl)amino]isophthalic acid (1) and 5-[(pyridin-4-ylmethyl)amino]isophthalic acid (2), were synthesized in two-step method using 5-aminoisophthalic acid as the starting material, and were characterized by single-crystal X-ray diffraction, elemental analysis, infrared, 1H NMR, mass, absorption and fluorescence spectra. Both 1 and 2 crystallize in monoclinic system with space groups P21/c for 1 and P21/n for 2. Photophysical properties of both 1 and 2 are significantly different from those of raw material 5-aminoisophthalic acid due to stronger p → π conjugation when one amino hydrogen atom in 5-aminoisophthalic acid is substituted with electron-donor group. 1 displays a very strong narrow-band blue fluorescence with the maximum peak at 439 nm, a high quantum efficiency up to 64%, and a narrow full width at half maximum of 35 nm, while 2 has a broader and weaker fluorescence with the peak at 418 nm and FHWM of about 50 nm. Two reduced Schiff bases with blue fluorescence were synthesized from 5-aminoisophthalic acid in two-step method including formation of the corresponding Schiff bases and further reduction by NaBH4.

Heterogeneous catalysts with hierarchically porous structure are highly efficient to catalyze chemical reactions. In this work, two-dimensional (2D) nano-flakes assembled flower-like NiO is fabricated and utilized for activating peroxydisulfate (PDS) to degrade organic pollutants bisphenol A (BPA). The results demonstrate that the prepared catalyst exhibits well organized flower structure composed of uniform 2D nano-flakes. PDS combines with the catalyst to form surface-activated NiO-PDS complex, subsequently depriving electrons from BPA. For the optimized NiO-12 catalyst, large specific surface area and hierarchically porous structure benefit to exposes abundant active sites while low resistance promotes electrons transfer, bringing the high BPA degradation rate constant of 0.28 min−1 under the condition of 20 mg/L initial concentration. NiO-12 exerts a capability of catalyzing PDS to mineralize 34% of practical packaging wastewater. This study provides a new strategy to fabricate hierarchical 2D porous catalysts for persulfate activation, with application potential in practical wastewater treatment.

The fundamental understanding of the cooperativity of a Bronsted acid together with its anion for cellulose conversion in an aqueous solution is limited at present, in which cellobiose has usually been regarded as a bridge that connects monosaccharides and cellulose. The mechanism of β-cellobiose conversion to 5-hydroxymethylfurfural (HMF) catalyzed by a Bronsted acid (H3O+) accompanied by counteranions in an aqueous solution has been studied using quantum chemical calculations at the M06-2X/6-311++G(d,p) level under a polarized continuum model (PCM-SMD). For the formation of the first HMF from cellobiose, there are three reaction pathways, i.e., through cellobiulose and glycosyl–HMF (C/H), through cellobiulose and fructose (C/F/H), and through glucose (C/G/H). For these three reaction pathways, the rate-determining steps are associated with the intramolecular [1,2]-H shift in the aldose–ketose tautomerization. C/H is the thermodynamically predominant pathway, while C/G/H is the kinetically dominant pathway. From cellobiose, the origin of the first HMF results kinetically from a small proportion of both C/H and C/F/H and from a large proportion of C/G/H. For the role of the counteranion in the catalytic activity of H3O+, the halide anions (Cl− and Br−) act as promoters, whereas both NO3− anions and carboxylate-containing anions behave as inhibitors. The roles of these anions in β-cellobiose conversion to HMF can be correlated with their electrostatic potential and atomic number, which may cause a decrease in the relative enthalpy energy and the value of entropy on interacting with the cation moiety. These insights may advance the novel design of sustainable conversion systems for cellulose conversion into HMF.

A novel graphene oxide (GO)-based pH sensor was designed and prepared through covalently attaching a zwitterionic betaine molecule onto a GO surface. This betaine-modified GO (BMGO) exhibited high water solubility and low toxicity. In aqueous media, BMGO displayed increased fluorescence in acidic conditions and decreased fluorescence in basic conditions. BMGO possesses a pH sensing range from 4 to 12 with excellent reversibility, quick response and high stability. With its high sensitivity and robustness, BMGO can be used to monitor the pH of intracellular contents, as demonstrated through cell imaging.

Low-molecular-weight supramolecular hydrogels are of significant attractive soft materials as particular functions can be facilely introduced by the straightforward fabrication of such self-assembled systems. In this study, an azobenzene-bridged dicationic pyridinium salt was synthesized, from which photoresponsive supramolecular hydrogel could be fabricated through the π-π stacking and hydrophobic interactions in the aqueous solution. By taking advantages of the UV–vis light induced E/Z photoisomerization behaviors of the incorporated azobenzene photochromophore, reversible gel-sol transformation of such supramolecular hydrogel could be achieved under the alternating UV–vis irradiation conditions. We believed that this photoresponsive supramolecular hydrogel will be a good supplementary in the creation of intelligent soft material.

The development of ratiometric fluorescence sensing platforms with simple synthetic routes and good anti-interference capacities are of great importance for their further application. Herein, hyperbranched polyethylenimine passivated carbon dots (HPEI-CDs) with concentration-modulated dual-excitation fluorescence property were synthesized. At a low concentration, HPEI-CDs only showed one fluorescence center, while at a relatively high concentration, its excitation peak around 355 nm would split into two peaks. Energy level splitting and broadening were demonstrated to be the origin of such dual-excitation behavior. Based on the dual-excitation signals, HPEI-CDs could serve as a ratiometric sensor for the detection of Fe3+ in aqueous solution. The assay exhibited a wide linear response concentration range (2–360 μM) with a limit of detection of 0.47 μM. Significantly, benefiting from the high concentration of HPEI-CDs, the sensor showed good selectivity and excellent anti-interference capacity. In addition, this nanosensor was successfully applied for the detection of Fe3+ in real water samples with satisfactory recoveries.

Novel visible-light responsive hydrogen-bonded supramolecular polymers have been successfully constructed by using a linear molecule, which consists of two ureido-pyrimidinone (UPy) moieties connected by a photochromic ortho-tetrafluorinated azobenzene (TFAB) linker. Benefiting from the visible-light responsive feature of the TFAB unit, reversible photoisomerization between the two isomers of the monomer can be achieved. The E-isomer prefers to form a linear supramolecular polymer through the intermolecular quadruple hydrogen bonding interactions between UPys, whereas the Z-isomer facilely forms a cyclic dimer. Therefore, the polymerization mechanisms and properties of such supramolecular polymers, e.g. reversible visible-light induced gel–sol transformation behaviour, can be regulated by the reversible visible-light triggered E/Z photo-isomerization of the TFAB chromophore.

Purpose To study the retinal oxygen saturation in normal eyes of Chinese adolescents. Methods Performing retinal oximetry with the Oxymap T1 Retinal Oximeter in healthy children and adolescents (aged 5–18 years old), we measured the arterial (SaO2) and venular (SvO2) oxygen saturation and the arteriovenous difference in oxygen saturation (Sa-vO2). Results The study included 122 individuals with a mean age of 13.0 ± 2.9 years (range: 5–18 years) and a mean refractive error of −3.25 ± 2.49 dioptres (range:−8.88 to +3.13 dioptres). Mean SaO2, SvO2 and Sa-vO2 was 85.5 ± 7.1%, 48.2 ± 5.5% and 37.3 ± 6.5%, respectively. Mean SaO2 was significantly (p 0.05) between the fundus quadrants. In multiple linear regression analysis, SaO2 increased (regression coefficient r2 = 0.28) with older age (standardized regression coefficient β: 0.23; p = 0.01) and more myopic refractive error (β: −0.39; p

The selective removal of oxygen from 5-hydroxymethylfurfural (HMF) is challenging for the effective utilization of biomass. The catalytic mechanisms of palladium acetate toward the conversion of HMF to furfuryl alcohol (FFA), 5-methylfurfural (5-MF) and 2,5-dihydroxymethyl furan (DHMF) have been theoretically investigated. The decarbonylation of HMF to FFA includes (i) migratory extrusion, (ii) metal-acetate-co-assisted deprotonation, (iii) decarbonylation, (iv) metal-assisted deprotonation, and (v) migratory extrusion and catalyst regeneration. Both hydrogenation and deoxidation of HMF with HCOOH as the H-source involve (i) migratory extrusion, (ii) oxidative addition, (iii) reductive elimination, (iv) metal-assisted deprotonation, and (v) migratory extrusion and catalyst regeneration. The C–H bond cleavage is the crucial reaction step, in which the metal-acetate-co-assisted deprotonation is kinetically more preferable than the oxidative addition. Both FFA and DHMF are kinetically superior to 5-MF. In terms of selectivity, increasing the temperature is beneficial to decarbonylation and decreasing the temperature is advantageous to hydrogenation. The present finding provides molecular-level insight into the functions of both the metal-center and coordinated-ligand in the Pd(OAc)2 catalyst, which may drive the novel design of catalytic systems toward both decarbonylation and hydrogenation reactions.

The variable mechanism for substitution of P-stereogenic phosphoryl chloride with alkynyl metallic reagents, which depends on temperature, stoichiometry of starting materials, and the structure of the nucleophilic reagent, is assumed as either SN2-like or Berry pseudorotation of pentacoordinated phosphorus intermediates, affording inversion and retention products, respectively. The formation of the inversion product can be controlled to occur predominantly to afford (RP)-alkynylphosphinates.

A new photo-responsive tetracationic macrocycle was designed and synthesized by connecting two bis(imidazolium)-tetrachloro-azobenzene units with o-xylene linkers. The ability of red-light triggered photoisomerization of the incorporated tetrachloroazobenzene units has featured this macrocycle with reversible photo-triggered configurational transformation, benefiting from which the distinctive red-light regulated encapsulation behavior for aromatic dicarboxylic dianions in DMSO solution could be achieved.

Pulmonary fibrosis is a prototypic chronic progressive lung disease with high morbidity and mortality worldwide. Novel effective therapeutic agents are urgently needed owing to the limited treatment options in clinic. Herein, nagilactone D (NLD), a natural dinorditerpenoid obtained from Podocarpus nagi, was found to suppress transforming growth factor-β1 (TGF-β1)-mediated fibrotic process in vitro and bleomycin (BLM)-induced pulmonary fibrosis in vivo. NLD attenuated TGF-β1-induced expression of fibrotic markers including type I and III collagen, fibronectin, α-SMA, and CTGF in human pulmonary fibroblasts (WI-38 VA-13 and HLF-1 cells). Mechanism study indicated that NLD suppressed TGF-β1-induced up-regulation of TβR I, and Smad2 phosphorylation, nuclear translocation, and transcriptional activation. Moreover, NLD ameliorated BLM-induced histopathological abnormalities in the lungs of experimental fibrotic mice, suppressed synthesis of relative fibrotic markers and fibroblast-to-myofibroblast transition, as well as BLM-induced up-regulation of TβR I expression and Smad signaling in mouse lungs. These data collectively support NLD to be a potential therapeutic agent for pulmonary fibrosis.

The development of artificial self-assembling systems with dynamic photo-regulation features in aqueous solutions has drawn great attention owing to the potential applications in fabricating elaborate biological materials. Here we demonstrate the fabrication of water-soluble cucurbit[8]uril (CB[8])-mediated supramolecular polymers by connecting the fluorinated azobenzene (FAB) containing monomers through host-enhanced heteroternary π-π stacking interactions. Benefiting from the unique visible-light-induced E→Z photoisomerization of the FAB photochromophores, the encapsulation behaviors between the CB[8] macrocycle and the monomers could be regulated upon visible light irradiation, resulting in the depolymerization of such CB[8]-mediated supramolecular polymers.

A yellow-pigmented bacterial strain (JR1T) isolated from a sediment sample was subjected to a taxonomic study, based on phenotypic, genetic and physiological characterization. Here, we describe the cultivation and characteristics of strain JR1T, a novel member of the genus Carboxylicivirga in the family Marinilabiliaceae . Cells of strain JR1T were rod-shaped, Gram-stain-negative, non-motile and facultatively anaerobic. The temperature range for growth was 15–42 °C (optimum, 33 °C) and the pH range for growth was pH 6.0–8.5 (optimum, pH 7.0–7.5). Growth occurred in the presence of 0.0–10.0 % (w/v) NaCl (optimum 2.0–3.0 %). 16S rRNA gene sequence analysis produced results with 97.4 % similarity to Carboxylicivirga taeanensis MEBiC 08903T, 96.8 % similarity to Carboxylicivirga mesophila MEBiC 07026T, 94.9 % similarity to Carboxylicivirga linearis FB218T and 94.6 % similarity to Carboxylicivirga flava Q15T. The DNA G+C content was 42.3 mol% and the major fatty acids were iso-C15 : 0, C15 : 0, anteiso-C15 : 0, C17 : 1ω6c and iso-C17 : 0-3OH. The major polar lipids detected were phosphatidylethanolamine and two unidentified lipids; the major respiratory quinone detected was MK-7. The results of the phenotypical, phylogenetic and biochemical analyses between the study strain and some related type strains indicated that this strain represent a novel species of the genus Carboxylicivirga within the family Marinilabiliaceae , for which the name Carboxylicivirga sediminis sp. nov. is proposed. The type strain is JR1T (=MCCC 1K03323T=KCTC 52869T).

A library of six luminescent Ir(III) complexes were synthesized and studied for their capacity to function as probes for G-quadruplex DNA. The novel Ir(III) complex 1 was discovered to be selective for G-quadruplex structures and was subsequently used for the construction of a label-free G-quadruplex-based ochratoxin A (OTA) sensing platform in aqueous solution. The assay exhibited linearity for OTA in the range of 0 to 60 nM (R2 = 0.9933), and the limit of detection for OTA was 5 nM. Furthermore, this assay was highly selective for OTA over its structurally related analogues.

Phenyl dichlorophosphine reacted with (L)-(–)-menthol to afford two diastereomers of menthyl phenylphosphinate (RP)-1a/(SP)-1a′ in up to 89:11 dr. Compound (RP)-1a was isolated in 58 % yield (60 g) and > 99:1 dr. An HCl-promoted diastereoselective hydrolysis of the P–Cl species was found to be involved in the reaction. On the basis of this, a mixture of 1a/1a′ with 50:50 dr was converted to a mixture enriched in 1a with 88:12 dr by treatment with phosphorus trichloride.

An iridium(III) complex exhibiting higher responce towards i-motif DNA over dsDNA and ssDNA was employed for the construction of a TdT activity detection platform. The assay exhibited a linear signal enhancement for TdT in the concentration range of 0 to 8 U mL(-1), and the limit of detection for TdT was 0.25 U mL(-1).

Tumor necrosis factor α-converting enzyme (TACE) plays a critical role in diverse physiological processes such as inflammation, hematopoiesis, and development. In this study, a pharmacophore model constructed from a training set of TACE inhibitors was used to screen an in-house database of organic compounds, from which compound 1 emerged as a top candidate. In a cell-free assay, compound 1 inhibited TACE enzymatic activity in a dose-dependent manner. Moreover, compound 1 inhibited the production of soluble TNF-α in human acute monocytic leukemia THP-1 cells without impacting nitric oxide production, and exhibited anti-proliferative activity against THP-1 cells. We envisage that compound 1 may be employed as a useful scaffold for the development of more potent TACE inhibitors. This study also validates the use of pharmacophore modeling to identify enzyme inhibitors. ASTAR (Agency for Sci., Tech. and Research, S’pore)

Zinc promoted asymmetric Barbier-type homopropargylation of aldimines is demonstrated. 2-Chlorotetrafluoroethanesulfinamide was used as the chiral auxiliary and the corresponding homopropargylamines were obtained in good yields with up to 98% diastereoselectivity under mild conditions.

A series of complex oxazatricyclic systems was efficiently synthesized in satisfactory yields by three-component reaction of isoquinolinium salts, acetone, and cyclic 1,3-dicarbonyl compounds in ethanol in the presence of triethylamine as base catalyst.

The present study aimed to explore the mechanism of action of Gegen Qinlian decoction (GGQLD) in experimental non-alcoholic fatty liver disease (NAFLD). A total of 30 rats were randomly divided into five groups: The chow, model, high- and low-dose GGQLD (GGQLD-H and GGQLD-L, respectively) and resveratrol (Resl) groups, and were treated with saline, GGQLD and Resl when a model of high-fat diet (HFD)-induced NAFLD was established. Blood lipid and liver enzymes were detected following treatment for 8 weeks and liver tissue pathology was observed using Oil Red O and haematoxylin and eosin staining. Furthermore, the liver protein and mRNA expression of sirtuin (Sirt)1, peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) were measured using western blotting and reverse transcription-quantitative polymerase chain reaction. Compared with the chow group, the model group demonstrated significantly increased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels (P

The generality of ( S )-2-chlorotetrafluoroethanesulfinamide (CTFSA) induced asymmetric vinylogous Mannich (AVM) addition reaction has been investigated. The reaction of aldimines derived from ( S )-CTFSA with 2-( tert -butyldimethylsilyloxy) furan (TBSOF) took place regioselectively at the γ-site at room temperature in DMSO under air atmosphere to give the desired addition products in syn -configuration with high diastereoselectivities (up to 98:2 dr). However, anti -configuration product as major isomer was obtained in the presence of tetra-butyl ammonium fluoride (TBAF) at −78 °C. Facile removal of the auxiliary group without epimerization demonstrated their synthetic potential for piperidone derivatives.

Taking advantage of the strong electron-withdrawing effect of perfluoroalkyl groups, solution-stable perfluoroalkanesulfenic acids were synthesized for the first time by Cope-type elimination of the corresponding imines; the acids were identified by 1H NMR, 19F NMR, and IR spectroscopy and mass spectrometry. Trapping reagents were utilized to capture the in situ generated sulfenic acids, which provided further experimental evidence for the formation of these fluorinated sulfenic acids.

Aromatic methyl ketones and cyclic asymmetric ketones underwent hydrophosphorylation with P-stereogenic H-P species in the presence of potassium carbonate to produce P,C-stereogenic tertiary α-hydroxyl phosphinates in excellent yields with up to 99 : 1 dr. The diastereoselectivity was induced by a reversible conversion of less stable stereomer of product to that of a more stable one via an equilibrium, which was confirmed by aldehyde/ketone exchanging reaction. Toward the exchange, aliphatic or aldehyde carbonyl were more active than aromatic or ketone carbonyls, respectively. The stability difference between the two diastereomers was controlled by the sizes of substituents linking to phosphorus or α-carbon.

Targeting STAT5 is an appealing therapeutic strategy for the treatment of hematologic malignancies and inflammation. Here, we present the novel osmium(II) complex 1 as the first metal-based inhibitor of STAT5B dimerization. Complex 1 exhibited superior inhibitory activity against STAT5B DNA binding compared to STAT5A DNA binding. Moreover, 1 repressed STAT5B transcription and blocked STAT5B dimerization via binding to the STAT5B protein, thereby inhibiting STAT5B translocation to the nucleus. Furthermore, 1 was able to selectively inhibit STAT5B phosphorylation without affecting the expression level of STAT5B.

A luminescent iridium(III) complex has been discovered to be selective for G-quadruplex DNA, and was employed in a label-free G-quadruplex-based detection assay for 3'→5' exonuclease activity in aqueous solution. A proof-of-concept of this assay has been demonstrated by using prokaryotic exonuclease III (ExoIII) as a model enzyme. In this assay, a G-quadruplex-forming hairpin oligonucleotide (hairpin-G4 DNA, 5'-GAG3TG4AG3TG4A2GCAGA2G2ATA2CT2C4AC3TC4AC3TC-3') initially exists in a duplex conformation, resulting in a low luminescence signal due to the weak interaction between the iridium(III) complex and duplex DNA. Upon digestion by ExoIII, the guanine-rich sequence is released and folds into a G-quadruplex, which greatly enhances the luminescence emission of the iridium(III) probe. This method was highly sensitive for 3'→5' exonuclease over other DNA-modifying enzymes.

Nitric oxide (NO) and ethylene respond to biotic and abiotic stresses through either similar or independent processes. This study examines the mechanism underlying the effects of NO and ethylene on promoting root hair development in Arabidopsis under magnesium (Mg) deficiency. The interaction between NO and ethylene in the regulation of Mg deficiency-induced root hair development was investigated using NO- and ethylene-related mutants and pharmacological methods. Mg deficiency triggered a burst of NO and ethylene, accompanied by a stimulated development of root hairs. Interestingly, ethylene facilitated NO generation by activation of both nitrate reductase and nitric oxide synthase-like (NOS-L) in the roots of Mg-deficient plants. In turn, NO enhanced ethylene synthesis through stimulating the activities of 1-aminocyclopropane-1-carboxylate (ACC) oxidase and ACC synthase (ACS). These two processes constituted an NO-ethylene feedback loop. Blocking either of these two processes inhibited the stimulation of root hair development under Mg deficiency. In conclusion, we suggest that Mg deficiency increases the production of NO and ethylene in roots, each influencing the accumulation and role of the other, and thus these two signals interactively regulate Mg deficiency-induced root hair morphogenesis.

Nonalcoholic fatty liver disease (NAFLD) is a prevalent disease, with a clinical spectrum ranging from simple fatty liver disease to nonalcoholic steatohepatitis and cirrhosis. Puerarin, baicalin and berberine are herbal products widely used in Asia, which are believed to possess therapeutic benefits for alleviating the symptoms of NAFLD. In the present study, a rat model of NAFLD, induced by a high-fat diet, was established and orthographical experimentation was used to investigate the effects of various combinations of puerarin, baicalin and berberine on the hepatic expression of proliferator-activated receptor (PPAR)-γ and insulin receptor (IR). The present study demonstrated that serum levels of total cholesterol, alanine transaminase and low-density lipoproteins were significantly decreased in the puerarin-dominated groups (P

A kind of 1,8-naphthalimide derivative grafted onto Chitosan was synthesized with Chitosan, 4-bromo-N-(2-aminoethyl)-1,8-naphthalimide and 4-bromo-1,8- naphthalic anhydride via substitution and amidation. The structures of compounds was characterized by FT-IR．Thermal stability and fluorescence spectra of the target product were investigated. Compared with 4-bromo-N-(2-aminoethyl)-1,8-naphthalimide, the maximum fluorescent intensity of the 1,8-naphthalimide derivative grafted onto Chitosan was increased 1.25 folds.

The complete sequence of transferrin has been cloned from cypermethrin-resistant strain of Culex pipiens pallens(Cr-C strain). Quantitative reverse transcription PCR analysis indicated that the transferrin transcription level was 12.6 times higher in Cr-C strain than in susceptible strain at fourth instar larvae. The transferrin expression was also found to be consistently higher throughout the life cycle of Cr-C strain. A protein of predicted size 90.8 kDa has been detected by Western blotting in transferrin-transfected mosquito C6/36 cells. These transferrin-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by methyl tritiated thymidine((3)H-TdR) incorporation. These results indicate that transferrin is expressed at higher levels in Cr-C strain and may confer some insecticide resistance in C. pipiens pallens.

Efficient synthesis of enantiopure polyfluoroalkanesulfinamides (PFSAs) has been achieved. Their application as novel chiral auxiliaries with an electron-withdrawing and (19)F NMR monitorable polyfluoroalkyl group was initially demonstrated in an asymmetric Strecker reaction under mild conditions.

A highly diastereoselective three-component inverse-electron-demand aza Diels-Alder reaction assisted by per(poly)fluoro-alkanesulfinamides is presented, providing a broad spectrum of highly functionalized piperidine derivatives with excellent endo/exo and facial diastereoselectivities. The electron-withdrawing perfluoroalkyl groups are crucial for the success of this reaction under mild conditions and facilitate monitoring the process and stereoselectivities of the reaction. The synthetic potential of these cycloadducts is also highlighted.

Background. We followed a cohort of 773 individuals who received a monovalent vaccine against 2009 pandemic influenza A (H1N1). Approximately 6 weeks after vaccination, 12 persons developed the disease. Methods. Three groups of subjects were studied (12 patients who had or had not received previous monovalent vaccine and 1 group of 49 control subjects who had previously been immunized with the same vaccine ). For all patients, clinical features were characterized and the causative viruses sequenced for possible mutations. Nasopharyngeal swabs, serum specimens, and peripheral blood monocyte cells (PBMCs) were collected at different time points up to 11 weeks after symptom onset to measure the virus load and humoral and cellular immune responses. Serum samples and PBMCs were also collected from 49 and 16 vaccinated control subjects, respectively. Results. Both patient groups had similar clinical manifestations. No substantial viral mutations were detected. Compared with unvaccinated patients, viral loads in vaccinated patients were initially higher, but the levels decreased faster to undetectable levels. However, the virus became detectable again for 6 of them. Two weeks after infection, vaccinated and unvaccinated patients had similar neutralizing antibody levels as the vaccinated control subjects. Thereafter, the neutralizing antibody levels decreased markedly in vaccinated patients. During the acute phase, memory T cell counts and tumor necrosis factor‐a levels were significantly higher in vaccinated than in unvaccinated patients. Conclusions. Although the clinical consequences of infection are comparable between vaccinated and unvaccinated patients, humoral and cellular immune responses in vaccinated patients are boosted for some weeks, indicating an additional benefit of vaccination against 2009 pandemic influenza A (H1N1) virus. Early 2009, human infections caused by a novel influenza virus, later designated as 2009 pandemic influenza A (H1N1) virus, were identified in Mexico and spread rapidly to other regions of the world [1, 2]. The first imported case was reported in China on 9 May, fol

A novel tri-functional copolymer P1 containing hole transporting units, electron transporting units and terbium complex units was synthesized via radical copolymerization. It was characterized by DSC, TGA, Fluorescence, CV and I-V data test. The results showed that the copolymer P1 was capable of pure green emission in the solid state under UV excitation and had potential application in the memory or light-emitting device.

Aim: To investigate the effect of diallyl disulfide (DADS), a component of garlic, on apoptosis in human mammary cancer cell line (MCF-7) and its mechanisms. Methods: Cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Morphology of apoptotic cells was detected by acridine orange and ethidium bromide staining. Apoptotic cells stained with propidium iodide were examined using flow cytometry. Protein levels were detected by Western blot analysis. Results: DADS inhibited the proliferation of MCF-7 cells and induced the apoptotic ratio to increase rapidly. Cleavage of the caspase-3 and caspase-3 substrate poly(ADP-ribose) polymerase was observed in MCF-7 cells after 24 h of treatment with DADS. When the MCF-7 cells were treated with 200 μmol·DL −1 DADS, the stress-activated protein kinase extracellular signal-regulated kinase (ERK), a mitogen-activated protein kinase, was inhibited after 6 h; c-Jun N-terminal kinase (JNK), that is stress-activated protein kinase (SAPK), and p38 mitogen-activated protein kinase were activated after 6 h. Conclusion: These results suggest that DADS both inhibits the proliferation of MCF-7 cells and induces apoptosis of MCF-7 cells. The mechanisms may include the inhibition of ERK and the activation of the SAPK/JNK and p38 pathways.

We report herein the identification of an immunomodulatory natural product-like compound 1 as a direct inhibitor of TLR1–TLR2 heterodimerization. Compound 1 suppressed TNF-α and IL-6 secretion in Pam3CSK4-induced macrophages. Moreover, compound 1 inhibited the phagocytic activity of macrophages, presumably through modulation of TLR1–TLR2 signaling and inactivation of NF-κB. Molecular docking revealed that compound 1 bound to the interface region of TLR1–TLR2 by forming two hydrogen bonds with residues lining the binding site. To our knowledge, compound 1 has been only the second inhibitor overall of TLR1–TLR2 heterodimerization reported to date.

Zinc promoted asymmetric Barbier-type homopropargylation of aldimines is demonstrated. 2-Chlorotetrafluoroethanesulfinamide was used as the chiral auxiliary and the corresponding homopropargylamines were obtained in good yields with up to 98% diastereoselectivity under mild conditions.

This chapter reports the behavior of molecules confined to spaces barely large enough to accommodate them—encapsulation complexes. The molecules respond to the limited spaces with adapted shapes, prolonged contacts, and intensified interactions including accelerated reactions. Emphasis is placed on reversible encapsulation and the differences between molecules in free solution and those in hydrogen-bonded capsules.

A novel method was developed for the determination of quinolone (QN) residues such as ofloxacin, norfloxacin, ciprofloxacin and lomefloxacin by high-performance liquid chromatography (HPLC) coupled with chemiluminescence (CL) detection. The procedure was based on the chemiluminescent enhancement by QNs of the Ce(SO 4 ) 2 –Ru(bpy) 3 2+ –HNO 3 system. The separation was carried out with an isocratic elution using the mobile phase of 3:15:82 (v/v/v) acetonitrile–methanol–ammonium acetate buffer (containing 7.5 × 10 −4 M TBAB, 0.8% (v/v) TEA and 1.0 × 10 −4 M ammonium acetate, pH 3.65) at a flow rate of 1.0 ml/min. For the four QNs, the detection limits at a signal-to-noise of 3 ranged from 0.36 to 2.4 ng/ml. The relative standard deviations for the determination of QNs ranged from 1.6 to 4.5% within a day ( n = 11) and from 3.7 to 6.2% in three days ( n = 15), respectively. The method was successfully applied to the determination of QNs in prawn samples. The possible mechanism of the CL reaction was also discussed briefly.

A novel flow-injection method with chemiluminescence detection was developed for the determination of streptomycin residues in milk, based on the enhancement by streptomycin of the luminol-potassium periodate-Mn(2+) chemiluminescence system. The assay allowed analysis of streptomycin residues in whole milk samples ( approximately 3.5% fat) after sample work-up procedures. The limit of detection was 5.16 x 10(-9) mol/L for milk, and was far below the regulations of maximum residue limits (MRLs). The relative standard deviation (RSD) for 8.66 x 10(-8) mol/L streptomycin was 1.94% (n = 15) in milk. The results obtained for the assay of streptomycin residues in milk was comparable with those obtained by the official methods (ELISA) and demonstrated good accuracy and precision. The possible mechanism is briefly discussed.