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CRISPR–Cas immune systems process and integrate short fragments of DNA from new invaders as spacers into the host CRISPR locus to establish molecular memory of prior infection, which is also known as adaptation in the field. Some CRISPR–Cas systems rely on Cas1 and Cas2 to complete the adaptation process, which has been characterized in a few systems. In contrast, many other CRISPR–Cas systems require an additional factor of Cas4 for efficient adaptation, the mechanism of which remains less understood. Here we present biochemical reconstitution of the Synechocystis sp. PCC6803 type I-D adaptation system, X-ray crystal structures of Cas1–Cas2–prespacer complexes, and negative stained electron microscopy structure of the Cas4–Cas1 complex. Cas4 and Cas2 compete with each other to interact with Cas1. In the absence of prespacer, Cas4 but not Cas2 assembles with Cas1 into a very stable complex for processing the prespacer. Strikingly, the Cas1-prespacer complex develops a higher binding affinity toward Cas2 to form the Cas1–Cas2–prespacer ternary complex for integration. Together, we show a two-step sequential assembly mechanism for the type I-D adaptation module of Synechocystis, in which Cas4–Cas1 and Cas1–Cas2 function as two exclusive complexes for prespacer processing, capture, and integration.

The malaria parasite relies on anaerobic glycolysis for energy supply when growing inside RBCs as its mitochondrion does not produce ATP. The ring stage lasts ∼ 22 hours and is traditionally thought to be metabolically quiescent. However, recent studies show that the ring stage is active for several energy-costly processes including gene transcription/translation, protein export, and movement inside the RBC. It has remained unclear if a low glycolytic flux can meet the energy demand of the ring stage. Here we show that the metabolic by-product, pyrophosphate, is a critical energy source for the development of the ring stage and its transition to the trophozoite stage. During early phases of the asexual development, the parasite utilizes Plasmodium falciparum vacuolar pyrophosphatase 1 (PfVP1), an ancient pyrophosphate-driven proton pump, to pump protons across the parasite plasma membrane to maintain the membrane potential and cytosolic pH. Conditional deletion of PfVP1 leads to delayed ring stage development and a complete blockage of the ring-to-trophozoite transition, which can be partially rescued by Arabidopsis thaliana vacuolar pyrophosphatase 1, but not by the soluble pyrophosphatase from Saccharomyces cerevisiae. Proton-pumping pyrophosphatases are absent in humans, which highlights the possibility of developing highly selective VP1 inhibitors against the malaria parasite.

Jie Deng,1 Lorne M Golub,2 Hsi-Ming Lee,2 Veena Raja,2 Francis Johnson,3 Allan Kucine,4 Wonsae Lee,5 Tian-Min Xu,1 Ying Gu6 1Department of Orthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, 100081, People’s Republic of China; 2Department of Oral Biology and Pathology, School of Dental Medicine, Stony Brook University, Stony Brook, NY, 11794, USA; 3Department of Chemistry and Pharmacological Sciences, School of Medicine, Stony Brook University, Stony Brook, NY, 11794, USA; 4Department of Oral & Maxillofacial Surgery, School of Dental Medicine, Stony Brook University, Stony Brook, NY, 11794, USA; 5Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA; 6Department of General Dentistry, School of Dental Medicine, Stony Brook University, Stony Brook, NY, 11794, USACorrespondence: Jie DengDepartment of Orthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun South Avenue, Haidian District, Beijing, 100081, People’s Republic of ChinaTel +1 631 632-3172Fax +1 631 632-9705Email jie.deng917@gmail.comTian-Min Xu Email tmxuortho@163.comPurpose: Clinically, it is challenging to manage diabetic patients with periodontitis. Biochemically, both involve a wide range of inflammatory/collagenolytic conditions which exacerbate each other in a “bi-directional manner.” However, standard treatments for this type of periodontitis rely on reducing the bacterial burden and less on controlling hyper-inflammation/excessive-collagenolysis. Thus, there is a crucial need for new therapeutic strategies to modulate this excessive host response and to promote enhanced resolution of inflammation. The aim of the current study is to evaluate the impact of a novel chemically-modified curcumin 2.24 (CMC2.24) on host inflammatory response in diabetic rats.Methods: Type I diabetes was induced by streptozotocin injection; periodontal breakdown then results as a complication of uncontrolled hyperglycemia. Non-diabetic rats served as controls. CMC2.24, or the vehicle-alone, was administered by oral gavage daily for 3 weeks to the diabetics. Micro-CT was used to analyze morphometric changes and quantify bone loss. MMPs were analyzed by gelatin zymography. Cell function was examined by cell migration assay, and cytokines and resolvins were measured by ELISA.Results: In this severe inflammatory disease model, administration of the pleiotropic CMC2.24 was found to normalize the excessive accumulation and impaired chemotactic activity of macrophages in peritoneal exudates, significantly decrease MMP-9 and pro-inflammatory cytokines to near normal levels, and markedly increase resolvin D1 (RvD1) levels in the thioglycolate-elicited peritoneal exudates (tPE). Similar effects on MMPs and RvD1 were observed in the non-elicited resident peritoneal washes (rPW). Regarding clinical relevance, CMC2.24 significantly inhibited the loss of alveolar bone height, volume and mineral density (ie, diabetes-induced periodontitis and osteoporosis).Conclusion: In conclusion, treating hyperglycemic diabetic rats with CMC2.24 (a tri-ketonic phenylaminocarbonyl curcumin) promotes the resolution of local and systemic inflammation, reduces bone loss, in addition to suppressing collagenolytic MMPs and pro-inflammatory cytokines, suggesting a novel therapeutic strategy for treating periodontitis complicated by other chronic diseases.Keywords: hyperglycemia, periodontitis, matrix metalloproteinases, inflammation, resolvins, host-modulatory therapy

Talaromyces (Penicillium) marneffei can cause fatal disseminated infection in immunocompromised hosts. However, therapeutic strategies for the mycosis are limited. Reports of the other fungi suggest that berberine, a component of traditional herb, inhibitors interact with antifungal agents to improve the treatment outcomes. In the study, we evaluated the in vitro efficacy of berberine in combination with conventional antifungal agents against the pathogenic yeast form of T. marneffei. We demonstrate the synergistic effect of combination of berberine with fluconazole (52.38%), itraconazole (66.67%), voriconazole (71.43%), amphotericin B (71.43%) or caspofungin (52.38%) of T. marneffei strains, respectively. Time-kill curves confirmed the synergistic interaction, and no antagonistic was observed in all of the combinations. In conclusion, berberine could enhance the efficacy of conventional antifungal agents against the yeast form of T. marneffei in vitro. The results indicated berberine might have a potential role in combination therapy for talaromycosis.

Oxidative desulfurization (ODS) is one of the most promising methods of ultra low sulfur diesel (ULSD). Herein, metallophthalocyanine(MPc(COOH)4Cl8, M = Mn(Ⅱ), Fe(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ)) composites are synthesized by a facile in situ solid method and characterized by elemental analysis, UV–Vis, XPS and IR spectra. The simulated bionic catalytic system is composed of MPc(COOH)4Cl8 and molecular O2, which exhibited great activity for ultra-deep removal of dibenzothiophene (DBT) from the model oil containing n-octane. The catalytic activity of MPc(COOH)4Cl8 for the degradation of DBT in fuel was significantly improved at room temperature with natural light irradiation. After 90 min of catalytic reaction, the sulfur content in the model fuel decreased from (800 ppm) to 20 ppm. Catalytic activity studies revealed that the central metal ions of phthalocyanine structures presented a significant influence in the catalytic activity for the degradation of DBT. Additionally, mechanistic studies revealed that the ‘∗O2-MPcTcCl8+’ species was the key active intermediate. The metallophthalocyanine composites as active photocatalysts offer great potential for degradation of thiophene derivatives in fuel.

Background Convalescent plasma (CP) transfusion was reported to be effective in treating critically ill patients with COVID-19, and hydroxychloroquine could potently inhibit SARS-CoV-2 in vitro. Herein, we reported a case receiving combination therapy with CP transfusion and hydroxychloroquine for the first time. Case presentation Laboratory findings showed high lactic acid level (2.1 mmol/L) and C-reactive protein (CRP, 48.8 mg/L), and low white blood cell count (1.96 × 109/L) in a 65-year-old Chinese man, who was diagnosed with severe COVID-19. CP was intravenously given twice, and hydroxychloroquine was orally administrated for a week (0.2 g, three times a day). The lactic acid and C-reactive protein levels remained high (2.1 mmol/L and 73.23 mg/L, respectively), while the arterial oxyhemoglobin saturation decreased to 86% with a low oxygenation index (OI, 76 mmHg) on day 4 after CP transfusion. His temperature returned to normal and the OI ascended above 300 on day 11. Moreover, the RNA test remained positive in throat swab, and computed tomography revealed severe pulmonary lesions on day 11 after admission. Conclusion These findings suggested that the effectiveness of combination therapy with CP and hydroxychloroquine may be non-optimal, and specific therapy needs to be explored.

Oxidative desulfurization is considered to be one of the promising new methods for super-deep desulfurization of fuel oil. Herein, zinc phthalocyanine/g-C3N4 (g-C3N4/ZnTcPc) composites were synthesized by a facile in situ hydrothermal technique, utilizing g-C3N4, Zn(CH3COO)2 and 1,2,4-benzenetricarboxylic anhydride as the precursors. The crystal structure, morphology and chemical environment of the catalysts were respectively confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity of the resulting g-C3N4/ZnTcPc composites was evaluated by desulfurization of thiophene in fuel under visible light with molecular O2 as the oxidant. Compared with pure g-C3N4 and ZnTcPc, g-C3N4/ZnTcPc presented a significantly enhanced photocatalytic activity for the degradation of thiophene in fuel under visible irradiation. Sulfur content of model gasoline (800 ppm) after desulfurization for 90 min was decreased to 125 ppm. The possible preparation pathway of g-C3N4/ZnTcPc has been proposed according to the results of XRD and TEM. The formation mechanism of g-C3N4/ZnTcPc–O2 complex is proposed to be desulfurization by molecular oxygen.

Summary Wheat bran was fermented at 28 °C for 7 days under 70% humidity by Aspergillus niger, Aspergillus oryzae and Aspergillus awamori. Total phenolic content (TPC) of the unfermented sample was 1531.5 μg g−1 wheat bran. After the fermentation of Aspergillus awamori, Aspergillus oryzae and Aspergillus niger, TPC reached 5362.1, 7462.6 and 10 707.5 μg g−1, respectively. The antioxidant activity in the extractions of fermented wheat bran also increased significantly compared with the unfermented sample (P

The profile of caffeic acid in tissues of peanut sprouts and its antioxidant activity in erythrocyte-based assays were investigated. Caffeic acid was found to accumulate in the epicotyl-plumule (reached 2097.13±96μg/g DW on day 10 after peanut germination). It was purified by semipreparative high-performance liquid chromatography. The purified caffeic acid showed noticeable protective effects on human erythrocytes against 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH)-induced hemolysis. It also contributed to maintenance of normal morphological features and inhibited malondialdehyde formation and the lactate dehydrogenase release in erythrocytes under oxidative stress. Further analysis revealed that caffeic acid effectively inhibited AAPH-induced free-radical production and maintained the normal metabolism of the erythrocytic redox system, including superoxide dismutase, glutathione peroxidase, and glutathione. Our work showed that caffeic acid, which is greatly enriched in peanut sprout, can effectively protect erythrocytes from oxidative damage. These results provide valuable information for the use of peanut sprouts as a functional food.

Dendrobium officinale Kimura et Migo is a commercially and pharmacologically highly prized species widely used in Western Asian countries. In contrast to the extensive genomic and transcriptomic resources generated in this medicinal species, detailed metabolomic data are still missing. Herein, using the widely targeted metabolomics approach, we detect 649 diverse metabolites in leaf and stem samples of D. officinale. The majority of these metabolites were organic acids, amino acids and their derivatives, nucleotides and their derivatives, and flavones. Though both organs contain similar metabolites, the metabolite profiles were quantitatively different. Stems, the organs preferentially exploited for herbal medicine, contained larger concentrations of many more metabolites than leaves. However, leaves contained higher levels of polyphenols and lipids. Overall, this study reports extensive metabolic data from leaves and stems of D. officinale, providing useful information that supports ongoing genomic research and discovery of bioactive compounds.

The lack of direct connection between traditional herbal medicines and multiple biological targets is a bottleneck in herbal research and quality evaluation. To solve this problem, a strategy for the discovery of active ingredients from function-similar herbal medicines based on multiple biological targets was proposed in this article. The technical route includes chromatographic separation, mass spectrometry analysis, enzymatic activity detection, pharmacophore analysis and molecular docking. Five citrus herbs of Citri Reticulatae Pericarpium (CRP), Citri Exocarpium Rubrum (CER), Citri Grandis Exocarpium (CGE), Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) were used as the research objects. A total of 136 chemical components were identified from above five herbs based on LC-Q-TOF-MS/MS and database matching. The extracts of the five herbs showed obvious inhibitory effects on α-glucosidase and acetylcholinesterase in a concentration-dependent manner. Interestingly, the different types of components in the herbs exhibited selectivity for different targets: flavanone glycosides are effective on α-glucosidase but ineffective on acetylcholinesterase; polymethoxyflavonoids are effective on acetylcholinesterase but ineffective on α-glucosidase. Furthermore, we found for the first time that the components in citrus herbs exhibit opposite structure-activity relationships on the above two targets. For example, the methoxy group can enhance the activity of compounds on acetylcholinesterase but weaken the activity of compounds on α-glucosidase. The selective action is a supplement to the "multi-components, multi-targets" system of herbal medicines. Pharmacophore analysis and molecular docking were applied to explore the interaction between active ingredients and biological targets from the perspective of ligands and receptors, respectively. By combining the above multiple technologies, a strong connection among herbal medicines, chemical components and multiple biological targets was established. This work not only helps to understand the similar function of citrus herbs for the treatment of diabetes and Alzheimer's disease, but also provides selective lead compounds for the development of related drugs. This strategy is also helpful to improve the quality evaluation of citrus herbs from the perspective of biological activity.

Well pattern adaptability is a key factor in determining gas recovery. Based on the characteristics of low-permeability, thin-layer and multi-layer development of carbonate reservoir in Jingbian Gas Field, the interference test, production dynamic analysis, pressure drop curve analysis and gas well radius evaluation were carried out, and the adaptability of well pattern system and residual reserves distribution were made clarified. The results showed that the average single well controlled radius of the main layer is 1.3 km, and the well pattern is basically perfect; the average single well controlled radius of the other five secondary layers is 0.2–0.6 km, and the well pattern is not perfect; the residual reserves are mainly distributed in the secondary layers, groove or channel edges and local tight areas. The research has formed the evaluation method of the well pattern of developed gas fields and has developed the corresponding development countermeasures for the quality and distribution characteristics of different types of residual reserves. It has been used in the development of Jingbian Gas Field in order to provide a basis to improve the gas recovery and also to provide reference for well pattern adaptability evaluation and infilling wells deployment of other similar gas fields.

Polyubiquitylation is canonically viewed as a posttranslational modification that governs protein stability or protein-protein interactions, in which distinct polyubiquitin linkages ultimately determine the fate of modified protein(s). We explored whether polyubiquitin chains have any nonprotein-related function. Using in vitro pull-down assays with synthetic materials, we found that polyubiquitin chains with the Lys(63) (K63) linkage bound to DNA through a motif we called the “DNA-interacting patch” (DIP), which is composed of the adjacent residues Thr(9), Lys(11), and Glu(34). Upon DNA damage, the binding of K63-linked polyubiquitin chains to DNA enhanced the recruitment of repair factors through their interaction with an Ile(44) patch in ubiquitin to facilitate DNA repair. Furthermore, experimental or cancer patient–derived mutations within the DIP impaired the DNA binding capacity of ubiquitin and subsequently attenuated K63-linked polyubiquitin chain accumulation at sites of DNA damage, thereby resulting in defective DNA repair and increased cellular sensitivity to DNA-damaging agents. Our results therefore highlight a critical physiological role for K63-linked polyubiquitin chains in binding to DNA to facilitate DNA damage repair.

As the only nutritional source for newborn piglets, porcine colostrum and milk contain critical nutritional and immunological components including carbohydrates, lipids, and proteins (immunoglobulins). However, porcine milk composition is more complex than these three components. Recently, scientists identified additional and novel components of sow colostrum and milk, including exosomes, oligosaccharides, and bacteria, which possibly act as biological signals and modulate the intestinal environment and immune status in piglets and later in life. Evaluation of these nutritional and non-nutritional components in porcine milk will help better understand the nutritional and biological function of porcine colostrum and milk. Furthermore, some important functions of the porcine mammary gland have been reported in recent published literature. These preliminary studies hypothesized how glucose, amino acids, and fatty acids are transported from maternal blood to the porcine mammary gland for milk synthesis. Therefore, we summarized recent reports on sow milk composition and porcine mammary gland function in this review, with particular emphasis on macronutrient transfer and synthesis mechanisms, which might offer a possible approach for regulation of milk synthesis in the future. Electronic supplementary material The online version of this article (10.1186/s40104-018-0291-8) contains supplementary material, which is available to authorized users.

Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) plays a vital role in immune signal transduction pathways by acting as a ubiquitin ligase (E3) for Lys63-linked polyubiquitin chain synthesis. However, the detailed mechanism by which the TRAF6 RING dimer promotes ubiquitin transfer was unknown. Through structural modeling and biochemical analysis, we here show that the TRAF6 RING dimer employs a concerted allosteric mechanism using both subunits of the TRAF6 dimer to promote ubiquitin (Ub) transfer. In particular, we reveal the importance of the C-terminal extension of the TRAF6 RING domain that mediates trans-interactions with the donor-Ub. By analyzing structures and models of E3s in complex with Ub-loaded ubiquitin-conjugating enzymes (E2s), we further highlight the roles of N-terminal and C-terminal extensions beyond the bona fide RING domains in promoting Ub transfer through engagement with a donor-Ub in cis and in trans, respectively.

Several environmental stimulants and hormones can affect phenolic accumulation in grape berries, but the effects of ethylene and light and their interaction have not been completely deciphered. We measured the accumulation of anthocyanins (ATs) and proanthocyanidins (PAs) in berries of a red-wine grape, Vitis vinifera cv. Cabernet Sauvignon, in four treatments: light exposure with and without ethephon, a commercial growth regulator that quickly converts to ethylene, and box-shading with and without ethephon. Ethephon did not significantly increase the weight and diameter of the berries but altered maturity parameters at 49 days after treatment. Ethephon and light increased the fresh and dry weights of the berry skins, induced the accumulation of total phenolics, total flavonoids, and PAs and up-regulated the transcription of VvLAR1, VvLAR2, VvANR, and VvMYBPA1. Light promoted the accumulation of ATs and the expression of AT biosynthetic genes more effectively than did ethephon. Ethephon and light had interactive effects on grape ripening and the contents of PAs and ATs by the way that light interfered with the effect of exogenous ethephon on endogenous ethylene biosynthesis and the downstream ethylene regulatory pathway. These findings provide new information about the physiological and molecular function of ethylene during berry development and the impact of the interaction between ethylene and light in Vitis vinifera.

Implementing parallel and multivalued logic operations at the molecular scale has the potential to improve the miniaturization and efficiency of a new generation of nanoscale computing devices. Two-dimensional photon-echo spectroscopy is capable of resolving dynamical pathways on electronic and vibrational molecular states. We experimentally demonstrate the implementation of molecular decision trees, logic operations where all possible values of inputs are processed in parallel and the outputs are read simultaneously, by probing the laser-induced dynamics of populations and coherences in a rhodamine dye mounted on a short DNA duplex. The inputs are provided by the bilinear interactions between the molecule and the laser pulses, and the output values are read from the two-dimensional molecular response at specific frequencies. Our results highlights how ultrafast dynamics between multiple molecular states induced by light−matter interactions can be used as an advantage for performing complex logic operations in parallel, operations that are faster than electrical switching.

A novel peptide was extracted from wheat germ globulin and purified using ion-exchange chromatography, gel filtration chromatography, and semi-preparative reversed-phase high-performance liquid chromatography (RP-HPLC). The sequence of the peptide was found to be Glu-Cys-Phe-Ser-Thr-Ala (ECFSTA). Its immunomodulatory effects were evaluated, and the results showed that ECFSTA could enhance phagocytosis of RAW 264.7 cells and significantly increase their secretion of nitric oxide (NO), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and reactive oxygen species (ROS). ECFSTA activated macrophages mainly through the pattern recognition receptors (PRRs) of toll-like receptor 2 (TLR2) and toll-like receptor 4 (TLR4), and the production of ROS simultaneously stimulated macrophages to produce TNF-α. Thus, ECFSTA could be used as an immunomodulator and might be a promising component of functional foods.

As a traditional medicinal plant, Juglans mandshurica has been used for the treatment of cancer. Different organs of this plant showed anti-tumor activity in clinic and laboratory. Comparative identification of constituents in different plant organs is essential for investigation of the relationship between chemical constituents and pharmacological activities. For this aim, the roots, branches, and leaves of J. mandshurica were extracted with 50% v/v methanol and then subjected to ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry analysis conducted under low and high energy. As a result, we have to date identified 111 compounds consisting of 56 tannins, 29 flavonoids, 13 organic acids, 8 naphthalene derivatives, and 5 anthracenes. Five compounds, namely, diquercetin trihydroxy-truxinoyl-glucoside, two quercetin kaempferol dihydroxy-truxinoyl-glucosides, syringoyl-tri-galloyl-O-glucose, and dihydroxy-naphthalene syringoyl-glucoside, were tentatively identified as new compounds. Of the compounds identified, 76 were found in the root extract, 67 in the branch extract, and 37 in the leaf extract. Only six compounds including four organic acids and two tannins were found in all three extracts. We developed a rapid and sensitive ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry approach to identify multiple constituents of complex extracts without separation and ion selection. The results presented provide useful information on further research of the bioactive compounds of J. mandshurica.

In our previous study, three novel polysaccharides, named MC-1, MC-2, and MC-3, were separated from the roots of maca (Lepidium meyenii), which is a food source from the Andes region. The structural information and immunomodulatory activity of MC-1 were then investigated. The structure and activity of MC-2 are still unknown. In this study, structural characterization revealed that MC-2 has an average molecular weight of 9.83 kDa and is composed of arabinose (20.9%), mannose (4.5%), glucose (71.9%), and galactose (2.7%). The main linkage types of MC-2 were proven to be (1→5)-α-l-Ara, (1→3)-α-l-Man, (1→)-α-d-Glc, (1→4)-α-d-Glc, (1→6)-α-d-Glc, and (1→6)-β-d-Gal by methylation and NMR analyses. Congo red assay showed that MC-2 possesses a triple-helix conformation. Immunostimulating assays indicated that MC-2 could induce M1 polarization of original macrophages and convert M2 macrophages into M1 phenotype. Although MC-2 could not shift M1 macrophages into M2, it could still inhibit inflammatory reactions induced by lipopolysaccharide. Furthermore, Toll-like receptor 2, tTll-like receptor 4, complement receptor 3, and mannose receptor were confirmed as the membrane receptors for MC-2 on macrophages. These results indicate that MC-2 could potentially be used toward hypoimmunity and tumor therapies.

Double haploids in lisianthus cultivars were produced using anther culture. The anther of ‘Art Peach’ was cultured on the Murashige and Skoog (MS) medium with 3% sucrose with auxin and cytokinin. The highest frequency of calli developed from anthers (100%) and green plantlets per 100 calli (60 regenerants) was observed on the medium containing 8 mg·L−1 N6-benzyladenine (BA) and 0.1 mg·L−1 naphthaleneacetic acids (NAA). When anthers were cultured on the medium supplemented with 2 mg·L−1 BA and 0.5 mg·L−1 NAA, 33.3% of calli formed plantlets. Using the anther culture, callus induction and plantlets regeneration in five cultivars were developed differently, suggesting that the genotype might predetermined anther culture response. These results indicate that a highly efficient new microprogation technique can be provided by anther culture in vitro for lisianthus. Anther culture in vitro can provide a highly efficient new microprogation technique for lisianthus.

This study prepared the in situ formed iron hydroxide (in situ FeOxHy) by the interactions between Fe3+ and OH- at different molar ratios of 1:0, 1:1, 1:2 and 1:3. The influences of molar ratios and pH on the removal of phosphate were investigated and the surface of in situ FeOxHy before and after adsorption was analyzed. The phosphate removal rate with mass unit iron hydroxide is greater at the molar ratios of 1:3 between Fe3+ and OH-. The phosphate removal rate is maximum at the pH 6~7. The compatibility of iron hydroxide towards raw water pH value is better when the proportion of hydroxyl ion is greater. The disposal effect is good at the pH 4~9. The iron hydroxide formed at different molar ratios is not definitive shape and it can remove phosphate by the chemical action of adsorption and sedimentation.

Worldwide, cervical cancer (CC) is the third most common malignancy in women, and it remains a leading cause of cancer-related death of women. Genomic studies indicate that phosphoinositide 3-kinase (PI3K)/AKT signaling is one of the most frequently deregulated pathways in several human cancers, including CC. This signaling pathway has an important role in cancer cell proliferation, survival, motility, and metabolism, and therefore could be an attractive therapeutic target. In a previous study, we used a sensitive and high-speed homogeneous assay for the detection of kinase activity and for screening of PI3K/AKT signaling inhibitors in a high-throughput screening (HTS) format and then obtain formononetin, as an O-methylated isoflavone existed in a number of plants and herbs like Astragalus membranaceus. We showed that formononetin inhibited the phosphorylation of AKT and induced the apoptosis of CC cell line HeLa in a dose-dependent manner. Furthermore, formononetin suppressed xenograft tumor growth in nude mice. Our results indicated that formononetin may be used as an anti-cancer drug for cervical cancer in the future.

One alkyl glycoside, saussurostelloside A (1), two phenolic glycosides, saussurostellosides B1 (2) and B2 (3), and 27 known compounds, including eleven flavonoids, seven phenolics, six lignans, one neolignan, one phenethyl glucoside and one fatty acid, were isolated from an ethanol extract of Saussurea stella (Asteraceae). Their structures were elucidated by NMR, MS, UV, and IR spectroscopic analysis. Of the known compounds, (+)-medioresinol-di-O-β-D-glucoside (7), picraquassioside C (10), and diosmetin-3'-O-β-D-glucoside (27) were isolated from the Asteraceae family for the first time, while (+)-pinoresinol-di-O-β-D-glucoside (6), di-O-methylcrenatin (11), protocatechuic acid (14), 1,5-di-O-caffeoylquinic acid (17), formononetin (28), and phenethyl glucoside (29) were isolated from the Saussurea genus for the first time. The anti-inflammatory activities of three new compounds (1-3), five lignans ((-)-arctiin (4), (+)-pinoresinol-4-O-β-D-glucoside (5), (+)-pinoresinol-di-O-β-D-glucoside (6), (+)-medioresinol-di-O-β-D-glucoside (7) and (+)-syringaresinol-4-O-β-D-glucoside (8)), one neolignan (picraquassioside C (10)), and one phenolic glycoside (di-O-methylcrenatin (11)) were evaluated by testing their inhibition of the release of β-glucuronidase from PAF-stimulated neutrophils. Only compound 5 showed moderate inhibition of the release of β-glucuronidase, with an inhibition ratio of 39.1%.

The atomic-scale friction in fluorographene and graphane is investigated employing the density functional theory calculation including the dispersion correction (DFT-D). Fluorographene and graphane exhibit low friction because of the low interlayer interaction induced by the repulsive electrostatic forces between F or H atoms at the interfaces. Moreover, owing to the less electronegativity of H atoms than F atoms, the variation of interlayer spacing and system energy corrugation, which is predominantly determined by the variation of dispersion energy during both loading and sliding processes, as elucidated in this paper, is found to be much larger in graphane, which well explains the larger friction in graphane than in fluorographene. The more charged F atom in fluorographene diminishes the variation of the interlayer spacing, which finally decreases the variation of the dispersion energy in the fluorographene. The study theoretically reveals the general mechanism of atomic-scale friction in various graph...

Large area epitaxial graphene (EG) layers are synthesized on 6H-SiC (0001) by annealing at 1500 °C for 5 min in a closed graphite chamber at low vacuum of 10-3 mbar and its 2D band in Raman spectra can be satisfactorily fitted by a single Lorentzian. From Raman spectroscopy, measurements indicate that too high growth temperature is to the disadvantage of the formation of graphene. The results of atomic force microscope (AFM) and field-emission scanning electronic microscope (FE-SEM) reveal the surface morphology of graphene is related with its growth temperature.

Therapeutic small interfering RNAs (siRNAs) are composed of chemically modified nucleotides, which enhance RNA stability and increase affinity in Watson-Crick base pairing. However, the precise fate of such modified nucleotides once the siRNA is degraded within the cell is unknown. Previously, we demonstrated that deoxythymidine release from degraded siRNAs reversed the cytotoxicity of thymidylate synthase (TS)-targeted siRNAs and other TS inhibitor compounds. We hypothesized that siRNAs could be designed with specific nucleoside analogues that, once released, would enhance siRNA cytotoxicity. TS-targeted siRNAs were designed that contained 5-fluoro-2'-deoxyuridine (FdU) moieties at various locations within the siRNA. After transfection, these siRNAs suppressed TS protein and messenger RNA expression with different efficiencies depending on the location of the FdU modification. FdU was rapidly released from the siRNA as evidenced by formation of the covalent inhibitory ternary complex formed between TS protein and the FdU metabolite, FdUMP. These modified siRNAs exhibited 10-100-fold greater cytotoxicity and induced multiple DNA damage repair and apoptotic pathways when compared with control siRNAs. The strategy of designing siRNA molecules that incorporate cytotoxic nucleosides represents a potentially novel drug development approach for the treatment of cancer and other human diseases.

To observe the impacts of electro-acupuncture (EA) and psychological intervention (PI) on impulsive behavior among internet addiction (IA) adolescents.Thirty-two IA adolescents were allocated to either EA (16 cases) or PI (16 cases) group by a randomized digital table. Subjects in the EA group received EA treatment and subjects in the PI group received cognition and behavior therapy. All adolescents underwent 45-d intervention. Sixteen healthy volunteers were recruited into a control group. Barratt Impulsiveness Scale (BIS-11) scores, Young's Internet Addiction Test (IAT) as well as the ratio of brain N-acetyl aspartate (NAA) to creatine (NAA/Cr) and choline (Cho) to creatine (Cho/Cr) were recorded by magnetic resonance spectroscopy before and after intervention respectively.The IAT scores and BIS-11 total scores in both EA and PI group were remarkably decreased after treatment (P0.05), while EA group showed more significant decrease in certain BIS-11 sub-factors (P0.05). Both NAA/Cr and Cho/Cr were significantly improved in EA group after treatment (P0.05); however, there were no significant changes of NAA/Cr or Cho/Cr in PI group after treatment (P0.05).Both EA and PI had significantly positive effect on IA adolescents, especially in the aspects of psychological experiences and behavioral expressions, EA might have an advantage over PI in terms of impulsivity control and brain neuron protection. The mechanism underlying this advantage might be related to the increased NAA and Cho levels in prefrontal and anterior cingulate cortices.

Betaine (BET) is a native compound widely studied as an antioxidant in agriculture and human health. However, the antioxidant mechanism of BET remains unclear. In this research, radical scavenging assays showed that BET had little free radical scavenging activity. However, the antioxidant activity of BET was confirmed by cellular antioxidant activity (CAA) and erythrocyte hemolysis assays. The results of quantitative PCR (qPCR) and enzyme activity determination kits showed that the antioxidant activity of BET was not due to the gene expression and activity of antioxidases. High-pressure liquid chromatography (HPLC) assessment of the effect of BET on sulfur-containing amino acid metabolism showed that BET increased the levels of nonenzymatic antioxidants,S-adenosylmethionine (SAM) and methionine (p0.05), via the regulation of the methionine-omocysteine cycle. Additionally, the three methyl groups of BET were found to play a key role in its antioxidant activity. The possible reason was that because of the hydrophobicity of the three methyl groups and hydrophilicity of the carboxyl of BET, a tight protective membrane was formed around cells to prevent oxidative stress inducer from inducing ROS generation and cell damage. In conclusion, the antioxidant mechanism of BET was found to enhance nonenzymatic antioxidant defenses via the methionine-homocysteine cycle and form a protective membrane around cells.

Cobalamin-independent methionine synthase (MetE) catalyzes the direct transfer of a methyl group from methyltetrahydrofolate to l- homocysteine to form methionine. Previous studies have shown that the MetE active site coordinates a zinc atom, which is thought to act as a Lewis acid and plays a role in the activation of thiol. Extended X-ray absorption fine structure studies and mutagenesis experiments identified the zinc-binding site in MetE from Escherichia coli. Further structural investigations of MetE from Thermotoga maritima lead to the proposition of two models: “induced fit” and “dynamic equilibrium”, to account for the catalytic mechanisms of MetE. Here, we present crystal structures of oxidized and zinc-replete MetE from Streptococcus mutans at the physiological pH. The structures reveal that zinc is mobile in the active center and has the possibility to invert even in the absence of homocysteine. These structures provide evidence for the dynamic equilibrium model.

Self-assembly among the Schiff base 2-[(2-dimethylaminoethylimino)methyl]-6-ethoxyphenol (HL) with ammonium thiocyanate and cadmium(II) acetate affords a dinuclear cadmium(II) complex [Cd2L2(NCS)2]. The complex was structurally characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal structure of the complex was investigated. Both Cd atoms are best described as distorted pentagonal bipyramids. The crystal of the complex is triclinic: space group P\( \bar 1 \), a = 11.3719(2), b = 11.7972(3), c = 15.0847(3)A, α = 70.1520(10)°, β = 83.4690(10)°, γ = 62.2470(10)°, V = 1682.13(6) A3, Z = 2.

Self-assembly between silver carboxylates with 2-aminopyridine derivatives give two silver(I) complexes, [[Ag(5MP)2(CNB)] · NH3 (I) and [Ag(3MP)2(HMB)] (II), where 5MP, CNB, 3MP, and HMB represent 2-amin-5-methylpyridine, 5-chloro-2-nitrobenzoate, 2-amino-3-methylpyridine, and 2-hydroxy-3-methoxybenzoate, respectively. The crystal structures of the complexes were investigated. The Ag atom in each complex is coordinated by two pyridine N atoms and weakly coordinated by a carboxylic O atom. The crystal of I is triclinic: space group P\( \bar 1 \), a = 7.562(2), b = 11.708(3), c = 12.933(3) A, α = 103.378(4)°, β = 93.910(4)°, γ = 99.001(4)°, V = 1093.7(5) A3, Z = 2. The crystal of II is monoclinic: space group C2/c, a = 25.727(5), b = 10.274(2), c = 19.872(4) A, β = 126.62(3)°, V = 4215.7(15) A3, Z = 4.

Wheat (Triticum aestivum L.) line Lankao 90 (6) carries a recessive powdery mildew resistance gene temporarily named PmLK906 on chromosome 2AL. Near PmLK906 there is another known powdery mildew resistance gene locus Pm4. To track the two powdery mildew resistance genes in wheat breeding program by marker assisted selection (MAS), a linked molecular marker was developed in this study. Wheat gene chip hybridization combined with bulked segregant analysis (BSA) was used to develop an sequence-tagged sites (STS) marker for PmLK906 and Pm4. A new 2125 bp full-length cDNA clone (GenBank accession no. EU082094) similar to csAtPR5 of Aegilops tauschii was isolated from Lankao 90 (6) 21-12, and temporarily named TaAetPR5. Specific products could be amplified from cultivars or lines possessing Pm4a, Pm4b and PmLK906 with primers p9-7p1 and p9-7p2 derived from TaAetPR5. TaAetPR5 was linked to PmLK906 at a genetic distance of 7.62 cM, and cosegregated with Pm4a. The p9-7p1 and p9-7p2 could be used as an STS marker for these resistance genes in wheat breeding. Because this marker was cosegregated with Pm4a, it can be used in map-based cloning of the alleles atPm4 locus also.

Liquid chromatography coupled with diode array detector and electrospray ionization mass spectrometry was developed for the qualitative and quantitative comparison of the main constituents in Saussurea laniceps (SL) and S. medusa (SM), two species of plants used under the name “Xuelianhua” in traditional Tibetan medicine. A method validation including linearity, limit of detection, precision and recovery was performed. The results showed that a good linearity with R 2 > 0.99 was achieved, and the limit of detection of the quantified constituents was reported to be between 0.8 and 3.3 ng. The relative standard deviation value was below 3.82% for repeatability, and recovery studies for the quantified compounds were found to be within the range 90.92–103.12%. The unique properties of the present method were evaluated by analyzing twelve related herbal samples including five S. laniceps samples and seven S. medusa samples. Twenty-two compounds including phenolic acids, cumarins, lignanoids and flavonoids were identified by online ESI–MS and by comparison with literature data and standard compounds, and seven of them were quantified by LC–DAD simultaneously. The results demonstrated that the common constituents in the two herbs were protocatechuic acid, syringoside, chlorogenic acid, isoquercitroside, 1,5-dicaffeoylquinic acid, apigenin 7-O-β-d-glucoside, chrysoeriol 7-O-β-d-glucoside, acacetin 7-O-β-d-glucoside, apigenin and chrysoeriol. In the present study, it was found that the characteristic constituents were umbelliferone, scopoletin and their glucosides in S. laniceps, as well as arctiin and arctigenin in S. medusa. It was feasible to choose these characteristic compounds for the quality evaluation as well as chemical authentication of the two related herbs. The results also support discrimination between the two species when using them in folk medicine.

The wax precipitation behavior in three Chinese reservoir oil samplesXinli, MuH, and Xinmin reservoir oilshave been studied under CO2-injection conditions. The effects of the injected CO2 concentration on the amount of wax precipitation from the three oils have been studied at the reservoir temperatures and pressures. Considerable wax precipitations have been detected as the injected CO2 concentration exceeds 50 mol %, and the amount of wax precipitation increases with the injected CO2 concentration. The hydrocarbons extracted into the vapor phase during the multiple-contact extraction process using CO2 have been observed to be mainly limited to C1−C5. The onset temperatures of wax precipitations from the CO2-saturated Xinli reservoir oil and the Xinli reservoir oil have been detected using a solid detection system (SDS) logging system at the reservoir pressure. The results show that the onset temperature of the Xinli reservoir oil is decreased as the saturation of CO2 at the reservoir pressure increases....

Preferred growth of nanocrystalline silicon (nc-Si) was first found in boron-doped hydrogenated nanocrystalline (nc-Si:H) films prepared using plasma-enhanced chemical vapor deposition system. The films were characterized by high-resolution transmission electron microscope, X-ray diffraction (XRD) spectrum and Raman Scattering spectrum. The results showed that the diffraction peaks in XRD spectrum were at 2theta approximate to 47degrees and the exponent of crystalline plane of nc-Si in the film was (220). A considerable reason was electric field derived from dc bias made the bonds of Si-Si array according to a certain orient. The size and crystalline volume fraction of nc-Si in boron-doped films were intensively depended on the deposited parameters: diborane (B2H6) doping ratio in silane (SiH4), silane dilution ratio in hydrogen (H-2), rf power density, substrate's temperature and reactive pressure, respectively. But preferred growth of nc-Si in the boron-doped nc-Si:H films cannot be obtained by changing these parameters. (C) 2004 Elsevier Ltd. All rights reserved.

The asphaltene precipitation of two reservoir oil samples collected from Jinlin oil field has been studied under pressure and with/without CO2-injection conditions. No asphaltene precipitation was detected during the pressure depletion processes without CO2 injection. For the CO2-injected oil systems, the effects of operating pressure, injected CO2 concentration, and multiple-contact on the onset and amount of asphaltene precipitation were studied under the reservoir temperature. No asphaltene precipitation was observed when the operating pressure is remote from the minimum miscibility pressure (MMP). However, appreciable asphaltene precipitation was detected when the operating pressure approached or exceeded the MMP. The amount of asphaltene precipitation increased with the concentration of injected CO2. A generalized corresponding states principle (CSP) for prediction of asphaltene precipitation data is produced and reported here. The proposed CSP theory complements the scaling equation for asphaltene precipitation under the influence of n-alkane precipitants. Based on literature data and the data measured in this work, the parameters and exponents of a corresponding states equation capable of describing the asphaltene precipitation behavior in the studied high-pressure CO2-injected crude oil systems are reported. D 2003 Published by Elsevier B.V.

In this paper, the two-step hydrate formation mechanism proposed by the authors (Chen and Guo, 1998) has been extended to structure-H hydrates (sH). It was assumed that the basic sH hydrate can be formed by large molecules only, termed as sH hydrate formers. A hydrate model based on this formation mechanism has been developed, in which the evaluation of both the thermodynamic parameters of an unstable empty hydrate lattice and the potential parameters of a sH hydrate former are not involved. The characterization parameters of 20 basic sH hydrates were determined from experimental data. The proposed model has been tested on the calculation of the hydrate formation pressures of 20 sH hydrates constituted by a single sH hydrate former and methane (help gas). Parallel comparison with the results reported by Mehta and Sloan [4] using the traditional Van der Waals–Platteeuw type model has been made. In addition, the proposed model was adopted to predict the hydrate formation pressures of systems containing methylcyclopentane/(methylcyclohexane+nitrogen)/(nitrogen+methane). Encouraging results were obtained.

Hydrate formation conditions of (CH 4 +C 2 H 4 ) and (CH 4 +C 3 H 6 ) binary gas mixtures in the presence of pure water were measured in a sapphire cell using the “pressure search” method. The experimental temperature-range was 273.7–287.2 K, and pressure-range was 0.53–6.6 MPa. Ethylene content in the gas mixtures varied from 7.13 to 100 mol%, and the propylene content varied from 0.66 to 71.96 mol%. The Chen–Guo hydrate model has been successfully applied to represent the measured data.

Interfacial tension data of (CH4 + N2) + H2O and (CO2 + N2) + H2O systems were measured using a pendant-drop method. The temperature and pressure ranges were 298−373 K and 1−30 MPa, respectively. The effects of gas composition, temperature, and pressure on the interfacial tension of the systems studied have been investigated. The linear gradient theory (LGT) was used to calculate the interfacial tensions of these two systems. The results show good agreement between the calculated and experimental interfacial tension data for the (CH4 + N2) + H2O system. However, it was found that the LGT model with one adjustable parameter is inadequate to give accurate predictions for the CO2 + H2O system and thus is not suitable for the description of the (CO2 + N2) + H2O system.

Hydrate formation conditions of hydrogen + hydrocarbon gas mixtures (H2 + CH4, H2 + C3H8, H2 + CH4 + C3H8, and H2 + CH4 + C2H6 + C3H8) in pure water have been measured in a sapphire cell using the “pressure search” method. The experimental temperature range was (274−280) K, and the pressure-range was (0.65−7.0) MPa. The hydrogen content in the gas mixtures varies from 22 mol % to 92 mol %.

The hydrate formation conditions of CO 2 and CO 2 -rich gas mixtures (CO 2 >90 mol%) containing N 2 /CH 4 /C 2 H 6 and (N 2 +CH 4 +C 2 H 6 ) in the presence of aqueous solutions of ethylene glycol were measured in a sapphire cell equipped with magnetic stirrer and data acquisition system. Isothermal pressure-search method was adapted in the pressure range of 0.8–3.5 MPa and a temperature range of 267.2–279.7 K. Eight systems have been studied and a total of 36 data points were measured. In the modeling part, the hydrate models recently developed by this group (Chen–Guo and Zuo–Guo model) and a typical literature reported van der Waals–Platteeuw type model were tested against the hydrate formation data of CO 2 -rich gas mixtures in water and aqueous solutions of ethylene/sodium chloride. The performance of various models is evaluated.

The prediction of gas hydrate formation conditions in solutions containing single electrolyte and mixed electrolytes and solutions containing both electrolytes and methanol has been performed using the modified Zuo-Gommesen-Guo hydrate model proposed by the authors. The results show that agreement between experimental and calculated values is satisfactory.

An experimental apparatus was built for measuring the gas solubility at high temperature and pressure. An auxiliary system was developed to keep the system pressure constant while the liquid samples are withdrawn. Solubility of methane, carbon dioxide and nitrogen in ethylene glycol (EG) was determined experimentally at temperatures of 323.15, 373.15 and 398.15 K and pressures up to 40 MPa. SRK equation of state was used to calculate the phase equilibria for those polar asymmetric systems.

A new composite system is fabricated by depositing the TiO2 film on a silicon nanoporous pillar array (Si-NPA) and annealing at 500°C using the spin coating method. Such a composite system exhibits a uniform morphology with the micron-dimension pillar array. Photocatalytic properties are investigated based on the degradation of methyl orange dye solution, and the results show that the photocatalytic efficiency of such a nano-composite system is 1.7 times that of the TiO2/glass system. The enhancement of photocatalytic efficiency is attributed to the large surface area of the TiO2/Si-NPA system.

The relative ozonation rate constants for p-phenylenediamines have been estimated from the linear correlation of the ozonation rate constants with the ionization potentials (Figure 1). The efficient antiozonants were found to have relatively lower ionization potentials, but not too low to react with the atmospheric molecular oxygen. The bond dissociation enthalpies (BDEs) of the N—H bonds of p-aminodiphenylamine and related derivatives were found to be about 80 kcal/mol, suggesting that the p-aminodiphenylamines are not only efficient antiozonants, but are also efficient antioxidants. Efficient antiozonants should also be efficient antioxidants to quench the reactive radical intermediates formed during the degradation.

Commercial pure iron was treated by Al + N + and Ti + N + ion beam assisted deposition (IBAD). The authors investigated the friction and wear properties of samples before and after the treatment. The microstructures, composition and morphology of the wear surfaces were analyzed and the properties of the modified layers were studied. The mechanisms of the improvement of the friction and wear properties were also discussed. The experimental results indicate that the IBAD with Al + N + or Ti + N + can effectively decrease the friction coefficients and strikingly improve the wear resistance. The compounds of Fe 4 N and Fe 3 Al formed in the surface layers of pure iron when treated by Al + N + , while Fe 2 N and Fe 2 Ti formed when treated by Ti + N + . These compounds much strengthen the surfaces. The IBAD treatment also promotes the formation and reform of the oxide films during the wearing process. These may transform the wear mechanism of pure iron from adhesive wear to adhesive/oxidative wear.

Hydrate formation has been studied for a synthetic natural gas mixture in pure water and in aqueous solutions containing electrolyte(s), methanol, and a combination of (electrolyte + methanol). Special attention has been given to (electrolyte + methanol) systems, as such data are extremely scarce in the open literature yet are of industrial significance. Sixteen experiments (a total of 107 data points) have been performed in the temperature range of (260.8−281.9) K and pressure range of (0.54−11.18) MPa using the isothermal pressure search method. The generalized hydrate model proposed by Zuo et al. (1996) has been applied successfully to predict the measured data for aqueous systems containing pure water, electrolyte(s), or methanol. A simple exponential expression is proposed to correlate the measured data for aqueous systems containing both electrolyte and methanol. It was found that the addition of methanol would affect the sequence of inhibiting strength of electrolytes.

Based on the similarity between P-v-T and T-μ-P relationships, viscosity (μ) models for pure hydrocarbons (mainly for n -alkanes) have been developed from the three-parameter Patel-Teja (PT) and two-parameter Peng-Robinson (PR) cubic equations of state. The EOS-based viscosity models are applicable to both liquid and gas phases, and have been successfully extended to hydrocarbon mixtures containing defined components as well as undefined C 7 + -fraction. Compared to the typical viscosity correlations widely used in the petroleum industry, significant improvement in prediction accuracy was achieved. Since the P-v-T , V-L-E and viscosity calculations can be performed by using a single equation of state, the thermodynamic consistency of reservoir simulation and process simulation calculations is improved.