Computer simulation of hypothetical hydrogen ordered structure of ice XIX.

A new ice phase, ice XIX, was discovered in 2018, and is the second hydrogen-ordered polymorph of hydrogen-disordered ice VI. The first hydrogen-ordered polymorph of ice VI is ice XV, and ices XIX, VI, and XV comprise a unique triplet group in the ice family. However, the exact crystal structure of ice XIX has not been confirmed. We constructed four possible conformations of ice XIX using neutron diffraction data obtained by Gasser et al. We then optimized these structures and simulated their Raman scattering spectra using first-principles density functional theory. By comparing these simulated spectra with the experimental Raman scattering spectra, we were able to exclude the existence of a ferroelectric structure with the space group Cc. The other three candidate structures are in good agreement with the experimental Raman scattering data; two of them are ferroelectric structures with the space group P21; and the last one is a weak ferroelectric structure with the space group Cc. We proposed that the partially hydrogen-ordered structure of ice XIX maybe a mixing of several hydrogen-ordered structures.

The pathological roles and potential mechanisms of vascular endothelial growth factor receptor-3 in gastric cancer.

OBJECTIVE: To investigate the roles and underlying mechanisms of vascular endothelial growth factor receptor-3 (VEGFR-3) in gastric cancer (GC). METHODS: VEGFR-3 gene expression profiles in human gastric adenocarcinoma (GAC) tissues were analysed using The Cancer Genome Atlas database. Human GC cell lines and were used for in vitro studies. Mouse models of GC and distant metastasis were used for in vivo studies. Silencing of VEGFR-3 gene expression was achieved using small interfering RNA. RESULTS: VEGFR-3 gene expression was significantly elevated in GAC tissues and GC cells. Higher VEGFR-3 expression was positively correlated with more advanced stages and a greater number of metastatic lymph nodes. In vitro studies in GC cells showed that knockdown of VEGFR-3 gene expression significantly suppressed cell proliferation and migration, but promoted apoptosis. In vivo investigations revealed that silencing of VEGFR-3 gene expression exhibited significant inhibition on tumour growth and metastasis. Further mechanistic studies showed that VEGFR-3 exerted its pathological roles by affecting the key molecules in the apoptotic and epithelial-mesenchymal transition pathways. CONCLUSION: The molecular pathways associated with VEGFR-3-mediated pathological effects could be targets in the development of novel approaches for the diagnosis, prognosis and treatment of GC.

Computational Analysis of Vibrational Spectra of Hydrogen Bonds in sII and sH Gas Hydrates.

The amount of energy in natural gas hydrates is thought to be equivalent to twice that of all other fossil fuels combined. However, economic and safe energy recovery has remained a challenge till now. To develop a novel method of breaking the hydrogen bonds (HBs) surrounding the trapped gas molecules, we investigated the vibrational spectra of the HBs of gas hydrates with structure types II and H. Two models of 576-atom propane-methane sII hydrate and 294-atom neohexane-methane sH hydrate were built. A first-principles density functional theory (DFT) method was employed using the CASTEP package. The simulated spectra were in good agreement with the experimental data. Compared with the partial phonon density of states of guest molecules, we confirmed that the experimental infrared absorption peak in the terahertz region mainly arose from HB vibrations. By removing the components of guest molecules, we found that the theory of two kinds of hydrogen bond vibrational modes applies. The use of a terahertz laser to enable resonance absorption of HBs (at about 6 THz, to be tested) may therefore lead to the rapid melting of clathrate ice and release of guest molecules.

Theoretical Prediction of Rhenium Separation from Ammonium Perrhenate by Phonon-Photon Resonance Absorption.

Rhenium (Re) is an extremely rare and precious element that is mainly used in the construction of aerospace components and satellite stations. However, an efficient and simple method for preparing Re has yet to be devised. To this end, we investigated the vibrational spectrum of ammonium perrhenate (NH4ReO4) using the CASTEP code based on first-principles density functional theory. We assigned the infrared (IR) absorption and Raman scattering spectra for NH4ReO4 using a dynamic process analysis of optical branch normal modes. We examined the IR-active peaks of Re-related vibrational modes in detail and found that the typical IR peak at approximately 914 cm-1 is due to the Re-O bond stretching. Thus, we posit that strong terahertz laser irradiation of NH4ReO4 at 914 cm-1 will lead to sufficient resonance absorption to cleave its Re-O bonds. This method could potentially be used to efficiently separate Re from its oxides.

CRISPR/Cas9-mediated PBP1 and PBP3 mutagenesis induced significant reduction in electrophysiological response to sex pheromones in male Chilo suppressalis.

Pheromone-binding proteins (PBPs) are thought to bind and transport sex pheromones onto the olfactory receptors on the dendrite membrane of olfactory neurons, and thus play a vital role in sex pheromone perception. However, the function of PBPs has rarely been demonstrated in vivo. In this study, two PBPs (PBP1 and PBP3) of Chilo suppressalis, one of the most notorious pyralid pests, were in vivo functionally characterized using insects with the PBP gene knocked out by the CRISPR/Cas9 system. First, through direct injection of PBP-single guide RNA (sgRNA)/Cas9 messenger RNA into newly laid eggs, a high rate of target-gene editing (checked with polled eggs) was induced at 24 h after injection, 21.3% for PBP1-sgRNA injected eggs and 19.5% for PBP3-sgRNA injected eggs. Second, by an in-crossing strategy, insects with mutant PBP1 or PBP3 (both with a premature stop codon) were screened, and homozygous mutants were obtained in the G3 generation. Third, the mutant insects were measured for electroantennogram (EAG) response to female sex pheromones. As a result, both PBP mutant males displayed significant reduction in EAG response, and this reduction in PBP1 mutants was higher than that in PBP3 mutants, indicating a more important role of PBP1. Finally, the relative importance of two PBPs and the possible off target effect induced by sgRNA-injection are discussed. Taken together, our study provides a deeper insight into the function of and interaction between different PBP genes in sex pheromone perception of C. suppressalis, as well as a valuable reference in methodology for gene functional study in other genes and other moth species.

Functional characterization of PBP1 gene in Helicoverpa armigera (Lepidoptera: Noctuidae) by using the CRISPR/Cas9 system.

Pheromone binding proteins (PBPs) are thought to play crucial roles in perception of the sex pheromones particularly in noctuid moths, but this is rarely in vivo evidenced due to lacking an effective technique. Here, we reported an in vivo functional study of PBP1 in the important lepidopteran pest Helicoverpa armigera (HarmPBP1), by using the CRISPR/Cas9 system. Efficient and heritable mutagenesis was achieved by egg injection of mixture of Cas9-mRNA and HarmPBP1-sgRNA. The TA cloning and sequencing revealed various insertion and/or deletion (indel) mutations at the target site. Among those, one mutation resulted in a premature stop codon at the target site, which led to a highly truncated protein with only 10 amino acids. The HarmPBP1 with this mutation would completely loss its function, and thus was used to select the homozygous mutant insects for functional analysis. The electroantennogram recording showed that the mutant male adults displayed severely impaired responses to all three sex pheromone components (Z11-16:Ald, Z9-16:Ald and Z9-14:Ald). Our study provides the first in vivo evidence that HarmPBP1 plays important role in perception of female sex pheromones, and also an effective methodology for using CRISPR/Cas9 system in functional genetic study in H. armigera as well as other insects.

Transcriptome based identification and tissue expression profiles of chemosensory genes in Blattella germanica (Blattaria: Blattidae).

Blattalla germanica is one of the most notorious household insect pests, and evolutionally more primitive than those well studied moths and flies, regarding the molecular mechanisms of chemosensation. In this study, we sequenced, for the first time, the antennal transcriptome of B. germanica using the Illumina HiSeq™ 2000 platform and then conducted the bioinformatic analysis of the data. In total, we identified 73 putative chemosensory genes, with 62 genes being novel in this species. These chemosensory genes included 48 odorant binding proteins (OBPs), 9 chemosensory proteins (CSPs), 6 sensory neuron membrane proteins (SNMPs), 5 odorant receptors (ORs) and 5 ionotropic receptors (IRs). Notably, Plus-C OBPs account for an exceptionally high proportion (39.58%) of the total 48 OBPs in this primitive insect. To predict the chemosensory functions of the genes, a detailed global tissue expression profiling was investigated by reverse transcription polymerase chain reaction (RT-PCR). Most OBP genes showed a chemosensory tissue biased profile, while CSP transcripts were widely and evenly expressed in different tissues. Furthermore, we found that more than half the chemosensory genes were expressed in the cerci, implying the important chemosensory functions of the organ in B. germanica. Taken together, our study provides important bases for elucidation of the molecular mechanisms and evolution of insect chemosensation, and for development of the chemosensation based techniques to control B. germanica.

Functional characterization of SlitPBP3 in Spodoptera litura by CRISPR/Cas9 mediated genome editing.

Functional gene analysis by using genome editing techniques is limited only in few model insects. Here, we reported an efficient and heritable gene mutagenesis analysis in an important lepidopteran pest, Spodoptera litura, using the CRISPR/Cas9 system. By using this system, we successfully obtained the homozygous S. litura strain by targeting the pheromone binding protein 3 gene (SlitPBP3), which allowed us to elucidate the role of this gene in the olfaction of the female sex pheromones. By co-injection of Cas9 mRNA and sgRNA into S. litura eggs, highly efficient chimera mutation in SlitPBP3 loci was detected both in injected eggs (39.1%) and in the resulting individual moths (87.5%). We used the mutant moths as parents to obtain the G1 offspring and the homozygous mutant strain in G2. The function of SlitPBP3 was explored by Electroantennogram (EAG) recordings with a homozygous mutant strain. The result showed that the EAG responses were significantly decreased in mutant males than in control males when treated with the major sex pheromone component (Z9,E11-14:Ac) and a minor component (Z9-14:Ac) at higher dosages. The results demonstrate that s SlitPBP3 gene plays a minor role in the perception of the female sex pheromones. Furthermore, our study provides a useful methodology with the CRISPR/Cas9 system for gene in vivo functional study, particular for lepidopteran species in which the RNAi approach is not efficient.

Content Determination of Polyphyllin Ⅰ and Ⅱ in Kangkeling Mixture by HPLC / 中国中医药信息杂志

Objective To establish a method for determining the contents of polyphyllin Ⅰ and polyphyllin Ⅱ in Kangkeling Mixture. Methods The contents of polyphyllin Ⅰ and Ⅱ were determined by HPLC gradient elution. Poroshell 120 Ec-C18 column (4.6 mm × 150 mm, 4 μm) was used; Acetonitrile-water (A:B) was set as the mobile phase; the flow rate was 1.0 mL/min; the detection wavelength was 210 nm; column temperature was 30 ℃. Results Polyphyllin Ⅰ showed good linear relationship in the range of 1.009–10.09 μg (r=0.999 6), and the average recovery was 97.31% (RSD=2.05%, n=6). Polyphyllin Ⅱ showed good linear relationship in the range of 0.640 5–6.405 μg (r=0.999 8), and the average recovery was 96.41% (RSD=1.67%, n=6). Conclusion The method is simple, with good repeatability and accurate results, which can be used to determine the contents of polyphyllin Ⅰ and Ⅱ in Kangkeling Mixture.

Content Determination of Polyphyllin Ⅰ and Ⅱ in Kangkeling Mixture by HPLC / 中国中医药信息杂志

Objective To establish a method for determining the contents of polyphyllin Ⅰ and polyphyllin Ⅱ in Kangkeling Mixture. Methods The contents of polyphyllin Ⅰ and Ⅱ were determined by HPLC gradient elution. Poroshell 120 Ec-C18 column (4.6 mm × 150 mm, 4 μm) was used; Acetonitrile-water (A:B) was set as the mobile phase; the flow rate was 1.0 mL/min; the detection wavelength was 210 nm; column temperature was 30 ℃. Results Polyphyllin Ⅰ showed good linear relationship in the range of 1.009–10.09 μg (r=0.999 6), and the average recovery was 97.31% (RSD=2.05%, n=6). Polyphyllin Ⅱ showed good linear relationship in the range of 0.640 5–6.405 μg (r=0.999 8), and the average recovery was 96.41% (RSD=1.67%, n=6). Conclusion The method is simple, with good repeatability and accurate results, which can be used to determine the contents of polyphyllin Ⅰ and Ⅱ in Kangkeling Mixture.

Association between ESR1 gene polymorphisms and haplotypes with schizophrenia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association between single nucleotide polymorphisms (SNPs) and haplotypes of estrogen receptor 1 (ESR1) gene with schizophrenia.</p><p><b>METHODS</b>Three SNPs (rs2234693, rs9340799 and rs3798759) were determined in 333 schizophrenic patients and 315 healthy subjects with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Allelic and genotypic frequencies and particular haplotypes were compared between the two groups using Chi-square test.</p><p><b>RESULTS</b>The allelic and genotypic frequencies of rs2234693 and rs9340799 showed no significant difference between the two groups (P U+003E 0.05). However, a significant difference was detected in the frequencies of rs3798759 G allele and GG genotype between the two groups (P U+003C 0.01). Single factor analysis stratified by sex also found that frequencies of rs3798759 GG and TG genotypes and G allele were significantly higher in female schizophrenia patients compared with healthy females (P U+003C 0.05). Haplotypes C-A-G and C-G-G were more common in schizophrenia group (P U+003C 0.05).</p><p><b>CONCLUSION</b>polymorphisms of rs3798759 may be a risk factor for female patients with schizophrenia, and haplotypes C-A-G and C-G-G may be risk factors for schizophrenia.</p>