Effect of Molar Substitution on the Properties of γ-Hydroxypropyl Starch.

A new type of hydroxyalkyl starch, γ-hydroxypropyl starch (γ-HPS), was prepared by etherification of alkali-activated starch with 3-chloropropanol. The reaction efficiency, morphological change, thermodynamic and apparent viscosity properties, and other physicochemical characteristics were described. The molar substitution (MS) of modified whole starch was determined to be 0.008, 0.017, 0.053, 0.106, and 0.178, with a ratio of 5%, 15%, 25%, 35%, and 45% 3-chloropropanol to starch (v/w), respectively. Compared to native starch, the granular size and shape and the X-ray diffraction pattern of γ-HPS are not very different. For low-substituted γ-HPS, the implications may be less evident. Thermal stability measurements by means of thermogravimetric analyses and differential scanning calorimetry (TGA-DSC) proved that thermal stability was reduced and water retaining capacity was increased after hydroxypropylation. Furthermore, the findings also showed that the solubility, light transmittance, and retrogradation of γ-HPS pastes could be improved by etherification. The greater the MS of the γ-HPS, the more its freeze-thaw stability and acid resistivity increased. In this study, we provide relevant information for the application of γ-HPS in food and non-food industries.

Catalytic dehydrogenative aromatization of cyclohexanones and cyclohexenones.

Phenols and phenol derivatives serve as synthetic building blocks for the construction of compounds ranging from polymers to pharmaceuticals. Despite numerous methods for phenol synthesis, the catalytic dehydrogenation of carbocyclic compounds such as cyclohexanones and cyclohexenones to generate substituted phenol derivatives has received much attention. This review describes recent research progress concerning catalytic dehydrogenative aromatization and I2 promoted oxidative aromatization reactions in view of the types of cyclohexanone and cyclohexenone substrates and reactions, including the associated mechanisms and developments.

Vapour Phase Dehydration of Glycerol to Acrolein Over Wells-Dawson Type H6P2W18O62 Supported on Mesoporous Silica Catalysts Prepared by Supercritical Impregnation.

The H6P2W18O62/MCM-41-SUP was first synthesized using supercritical impregnation as highly efficient catalyst during glycerol conversion reaction. For comparison, the H6P2W18O62/MCM-41 prepared by conventional wet impregnation was also studied. The catalysts were studied using XRD, BET, FTIR, SEM, TEM, pyridine-FTIR, NH3-TPD, TG, ICP and elemental analysis. The characterization results showed that the preparation condition of supercritical carbon dioxide contributed to improve the dispersion of H6P2W18O62 on MCM-41, strengthen the interaction between H6P2W18O62 and MCM-41, increase the thermostability of H6P2W18O62 and enhance the amount of medium and Brønsted acid sites on the catalyst. Therefore, the formation of coke was retarded, and the lifetime of catalyst was prolonged. After 15 h reaction, the glycerol conversion rapidly reduced from 92% to 64% on H6P2W18O62/MCM-41-IMG (15.4 wt% coke), while the glycerol conversion slightly decreased from 94% to 82% on H6P2W18O62/MCM-41-SUP (9.8 wt% coke).

[Relationship between air pollution and the number of pneumonia hospitalization in a children's hospitalin Changsha].

OBJECTIVE: To explore the relationship between air pollution and the number of pneumonia hospitalization in a children's hospital in Changsha.
 Methods: Children who have been in this hospital for the treatment of pneumonia between December 2013 and December 2015 were enrolled in this study. Based on daily meteorological data and air pollution data from December 2013 to December 2015 in Changsha, we constructed a generalized additive model to analyze the relationship between air pollution and the number of pneumonia hospitalization.
 Results: During the research, the average concentration of PM2.5 and PM10 exceeded the Grade II national standards for air quality. The average concentration of SO2 exceeded the Grade I national standards. The change of all the 3 main air pollution indexes showed strong statistical relationship with the change of the number of pneumonia hospitalization (P<0.05), among which, the impact of SO2 ranked number 1, followed by PM2.5 and PM10. Effect of atmospheric pollution on the number of pneumonia boys was basically same as that in the total pneumonia children (P<0.05). The effect on girls showed no statistical relationship in both models (P>0.05).
 Conclusion: The concentrations of SO2, PM2.5 and PM10 are positively correlated with pneumonia hospitalization number of children, and their effect on boys is more obvious than that in the girls.

The Comparative Genomics of Botryosphaeriaceae Suggests Gene Families of Botryosphaeria dothidea Related to Pathogenicity on Chinese Hickory Tree.

Trunk canker poses a major threat to the production of Chinese hickory tree (Carya cathayensis Sarg.), which is primarily determined by Botryosphaeriaceae. In our previous work, we identified Botryosphaeria dothidea as the predominant pathogen of this disease. However, it is still unclear about corresponding gene families and mechanisms associated with B. dothidea's pathogenicity on Chinese hickory tree. Here, we present a comparative analysis of high-quality genome assemblies of Botryosphaeria dothidea and other isolated pathogens, showing highly syntenic relationships between B. dothidea and its closely related species and the conservative evolution of the Botryosphaeriaceae family. Higher GC contents were found in the genomes of B. dothidea and three other isolated pathogens (Botryshaeria cortices, Botryshaeria fabicerciana, and Botryshaeria qingyuanensis) compared to Macrophomina phaseolina, Neofusicoccum parvum, Diplodia corticola, and Lasiodiplodia theobromae. An investigation of genes specific to or expanded in B. dothidea revealed that one secreted glucanase, one orsellinic acid biosynthesis enzyme, and two MFS transporters positively regulated B. dothidea's pathogenicity. We also observed an overrepresentation of viral integrase like gene and heterokaryon incompatibility proteins in the B. dothidea's genome. In addition, we observed one LRR-domain-containing protein and two Sec-domain-containing proteins (Sec_1 and Sec_7) that underwent positive selection. This study will help to understand B. dothidea's pathogenicity and potential influence on the infection of Chinese hickory, which will help in the development of disease control and ensure the security of Chinese hickory production.

Gas Phase Dehydration of Glycerol to Acrolein Over Nickel Phosphate Catalysts.

We investigated the catalytic performance of glycerol conversion to acrolein on nickel phosphates samples (NiP-T (T = 300,400,500,600, and 700 °C)). The textural property, acidity of the fresh catalyst and carbon content of the used NiP-500 were also determined. The results showed that NiP was amorphous under the appropriate calcination temperature. The textural property, acid amount and strength were important in this reaction. Glycerol conversion was proportional to the acid amount of the sample. After 2 h on stream, NiP-500 with the largest pore size, largest acid amount and largest number of moderate acid sites had the maximum catalytic performance (89% glycerol conversion and 64% acrolein selectivity). NiP-700 showed the lowest performance (48% glycerol conversion and 34% acrolein selectivity), which is due to the lowest surface area, pore size and the lowest acid amount of NiP-700. Moreover, the catalyst deactivation was ascribed to carbon deposition on phosphates during the reaction.

GIPC is recruited by APPL to peripheral TrkA endosomes and regulates TrkA trafficking and signaling.

GIPC is a PDZ protein located on peripheral endosomes that binds to the juxtamembrane region of the TrkA nerve growth factor (NGF) receptor and has been implicated in NGF signaling. We establish here that endogenous GIPC binds to the C terminus of APPL, a Rab5 binding protein, which is a marker for signaling endosomes. When PC12(615) cells are treated with either NGF or antibody agonists to activate TrkA, GIPC and APPL translocate from the cytoplasm and bind to incoming, endocytic vesicles carrying TrkA concentrated at the tips of the cell processes. GIPC, but not APPL, dissociates from these peripheral endosomes prior to or during their trafficking from the cell periphery to the juxtanuclear region, where they acquire EEA1. GIPC's interaction with APPL is essential for recruitment of GIPC to peripheral endosomes and for TrkA signaling, because a GIPC PDZ domain mutant that cannot bind APPL or APPL knockdown with small interfering RNA inhibits NGF-induced GIPC recruitment, mitogen-activated protein kinase activation, and neurite outgrowth. GIPC is also required for efficient endocytosis and trafficking of TrkA because depletion of GIPC slows down endocytosis and trafficking of TrkA and APPL to the early EEA1 endosomes in the juxtanuclear region. We conclude that GIPC, following its recruitment to TrkA by APPL, plays a key role in TrkA trafficking and signaling from endosomes.

Coupling of DNA synthesis and histone synthesis in S phase independent of cyclin/cdk2 activity.

DNA and histone synthesis are both triggered at the beginning of S phase by cyclin/cdk2 activity. Previous studies showed that inhibition of DNA synthesis with hydroxyurea or cytosine arabinoside (AraC) triggers a concerted repression of histone synthesis, indicating that sustained histone synthesis depends on continued DNA synthesis. Here we show that ectopic expression of HIRA, the likely human ortholog of two cell cycle-regulated repressors of histone gene transcription in yeast (Hir1p and Hir2p), represses transcription of histones and that this, in turn, triggers a concerted block of DNA synthesis. Thus, in mammalian cells sustained DNA synthesis and histone synthesis are mutually dependent on each other during S phase. Although cyclin/cdk2 activity drives activation of both DNA and histone synthesis at the G1/S transition of cycling cells, concerted repression of DNA or histone synthesis in response to inhibition of either one of these is not accompanied by prolonged inhibition of cyclin A/cdk2 or E/cdk2 activity. Therefore, during S phase coupling of DNA and histone synthesis occurs, at least in part, through a mechanism that is independent of cyclin/cdk2 activity. Coupling of DNA and histone synthesis in S phase presumably contributes to the prompt and orderly assembly of newly replicated DNA into chromatin.

Identification and characterization of a novel cytoplasm protein ICF45 that is involved in cell cycle regulation.

A novel cytoplasm protein, interphase cytoplasm foci protein 45 kDa (ICF45), was identified by screening the cDNA expression library for HeLa cells with serum from an autoimmune patient. The complete cDNA sequence of ICF45 was determined to be 1.32 kb and to encode 298 amino acids with an apparent molecular mass of 45 kDa. The ICF45 transcripts were detected in different tissues and were relatively rich in human liver and lung tissues but scarce in brain tissue. Immunofluorescence with anti-ICF45-specific antibodies demonstrated that ICF45 is strongly expressed in interphase and cannot be seen in mitosis. The subcellular localization of ICF45 and fusion proteins GFP-ICF45, ICF45-GFP, and HA-ICF45 showed ICF45 centralized into 1-2 dots in the cytoplasm and always near the nuclear membrane. The staining foci of ICF45 appeared to be slightly larger than centrosomes and in some cases were found to colocalize with centrosomes. After effectively silencing the ICF45 by RNAi, the growth and proliferation of the cells were significantly inhibited, and p53 was detected to be up-regulated. The silencing of ICF45 also resulted in an appearance of polycentrosome and multinuclear cells, which finally went to apoptosis. Our results suggest that ICF45 is a highly conserved novel protein, which is expressed in a cell cycle-dependent manner and seemed to be involved in cell cycle progression and cell proliferation.

Cyclin/CDK regulates the nucleocytoplasmic localization of the human papillomavirus E1 DNA helicase.

Cyclin-dependent kinases (CDKs) play key roles in eukaryotic DNA replication and cell cycle progression. Phosphorylation of components of the preinitiation complex activates replication and prevents reinitiation. One mechanism is mediated by nuclear export of critical proteins. Human papillomavirus (HPV) DNA replication requires cellular machinery in addition to the viral replicative DNA helicase E1 and origin recognition protein E2. E1 phosphorylation by cyclin/CDK is critical for efficient viral DNA replication. We now show that E1 is phosphorylated by CDKs in vivo and that phosphorylation regulates its nucleocytoplasmic localization. We identified a conserved regulatory region for localization which contains a dominant leucine-rich nuclear export sequence (NES), the previously defined cyclin binding motif, three serine residues that are CDK substrates, and a putative bipartite nuclear localization sequence. We show that E1 is exported from the nucleus by a CRM1-dependent mechanism unless the NES is inactivated by CDK phosphorylation. Replication activities of E1 phosphorylation site mutations are reduced and correlate inversely with their increased cytoplasmic localization. Nuclear localization and replication activities of most of these mutations are enhanced or restored by mutations in the NES. Collectively, our data demonstrate that CDK phosphorylation controls E1 nuclear localization to support viral DNA amplification. Thus, HPV adopts and adapts the cellular regulatory mechanism to complete its reproductive program.