Enhanced formation of methane hydrate from active ice with high gas uptake.

Gas hydrates provide alternative solutions for gas storage & transportation and gas separation. However, slow formation rate of clathrate hydrate has hindered their commercial development. Here we report a form of porous ice containing an unfrozen solution layer of sodium dodecyl sulfate, here named active ice, which can significantly accelerate gas hydrate formation while generating little heat. It can be readily produced via forming gas hydrates with water containing very low dosage (0.06 wt% or 600 ppm) of surfactant like sodium dodecyl sulfate and dissociating it below the ice point, or by simply mixing ice powder or natural snow with the surfactant. We prove that the active ice can rapidly store gas with high storage capacity up to 185 Vg Vw-1 with heat release of ~18 kJ mol-1 CH4 and the active ice can be easily regenerated by depressurization below the ice point. The active ice undergoes cyclic ice-hydrate-ice phase changes during gas uptake/release, thus removing most critical drawbacks of hydrate-based technologies. Our work provides a green and economic approach to gas storage and gas separation and paves the way to industrial application of hydrate-based technologies.

Study on acoustic properties of hydrate-bearing sediments with reconstructed CO2 hydrate in different layers during CH4 hydrate mining.

Natural gas hydrate (NGH), a clean energy source with huge reserves in nature, and its safe and efficient exploitation fits perfectly with the UN Sustainable Development Goals (SDG-7). However, large-scale NGH decomposition frequently results in subsea landslides, reservoir subsidence, and collapse. In this work, in order to achieve safe and efficient exploitation of NGHs, the stability variation of different reservoir layers by depressurization/intermittent CO2/N2 injection (80:20 mol%, 50:50 mol%) was investigated using acoustic properties (P-wave velocity, elastic modulus), as well as reservoir subsidence under an overburden stress of 10 MPa. The P-wave velocity increased from 1282 m/s to 2778 m/s in the above-reservoir and from 1266 m/s to 2564 m/s in the below-reservoir, significantly increasing reservoir strength after CO2 hydrate formation. The P-wave velocity and elastic modulus in the top reconstructed reservoir were continually decreased by the shear damage of the overlying stress, while they remained stable in the bottom reconstructed reservoir during hydrate mining. However, due to superior pressure-bearing ability of the top CO2 hydrate reservoir, which was lacking in the bottom CO2 hydrate reservoir, the reservoir subsidence was relieved greatly. Despite the stiffness strength of reconstructed reservoir was ensured with CO2/N2 sweeping, the skeletal structure of CH4 hydrate reservoir was destroyed, and only the formation of CO2 hydrate could guarantee the stability of P-wave velocity and elastic modulus which was most beneficial to relieve reservoir subsidence. A large amount of CO2 was used in reservoir reconstruction and CH4 hydrate mining, which achieved the geological storage of CO2 (SDG-13). This work provided a new idea for safe and efficient NGHs mining in the future, and the application of acoustic properties served as a guide for the efficient construction of reconstructed reservoirs and offers credible technical assistance for safe exploitation of NGHs.

LincRNA-ROR/miR-145/ZEB2 regulates liver fibrosis by modulating HERC5-mediated p53 ISGylation.

The tumor suppressor p53 has been implicated in the pathogenesis of liver fibrosis. HERC5-mediated posttranslational ISG modification of the p53 protein is critical for controlling its activity. Here, we demonstrated that the expression of HERC5 and ISG15 is highly elevated, whereas p53 is downregulated, in fibrotic liver tissues of mice and transforming growth factor-ß1 (TGF-ß1)-induced LX2 cells. HERC5 siRNA clearly increased the protein expression of p53, but the mRNA expression of p53 was not obviously changed. The inhibition of lincRNA-ROR (ROR) downregulated HERC5 expression and elevated p53 expression in TGF-ß1-stimulated LX-2 cells. Furthermore, the expression of p53 was almost unchanged after TGF-ß1-stimulated LX-2 cells were co-transfected with a ROR-expressing plasmid and HERC5 siRNA. We further confirmed that miR-145 is a target gene of ROR. In addition, we also showed that ROR regulates the HERC5-mediated ISGylation of p53 through mir-145/ZEB2. Together, we propose that ROR/miR-145/ZEB2 might be involved in the course of liver fibrosis by regulating ISGylation of the p53 protein.

Recent Advances in the Applications of Water-soluble Resorcinarene-based Deep Cavitands.

We review here the use of container molecules known as cavitands for performing organic reactions in water. Central to these endeavors are binding forces found in water, and among the strongest of these is the hydrophobic effect. We describe how the hydrophobic effect can be used to drive organic molecule guests into the confined space of cavitand hosts. Other forces participating in guest binding include cation-π interactions, chalcogen bonding and even hydrogen bonding to water involved in the host structure. The reactions of guests take advantage of their contortions in the limited space of the cavitands which enhance macrocyclic and site-selective processes. The cavitands are applied to the removal of organic pollutants from water and to the separation of isomeric guests. Progress is described on maneuvering the containers from stoichiometric participation to roles as catalysts.

Two-dimensional CSiO and CGeO: direct-band-gap semiconductors with normal/anomalous auxeticity for solar cells and alkali-metal-ion batteries.

Two-dimensional (2D) materials provide tremendous opportunities for next-generation energy storage technologies. We theoretically propose 2D group-IV oxides (α-, ß-, andγ-CXO, X = Si/Ge). Among them,α-CXO monolayers, composed of the C-O-X skeleton of silyl (germyl) methyl ether molecules, are the most stable phase.α-CXO possess robust dynamical, mechanical, and thermal stabilities. Remarkably,α-CGeO has an unusual negative Poisson's ratio (NPR). However,α-CSiO displays a bidirectional half-auxeticity, different from all the already known NPR behaviors. The intrinsic moderate direct-band-gap, high carrier mobility, and superior optical absorption ofα-CXO make them attractive for optoelectronics applications. A series ofα-CXO-based excitonic solar cells can achieve high power conversion efficiencies. Besides,α-CXO monolayers are promising anode materials for sodium- and potassium-ion batteries, exhibiting not only the high specific capacity (532-1433 mA h g-1) but also low diffusion barrier and open-circuit voltage. In particular, the specific capacity of K onα-CSiO exhibits one of the highest values ever recorded in 2D materials. The multifunctionality rendersα-CXO promising candidates for nanomechanics, nanoelectronics, and nano-optics.

Important Roles of Thiols in Methylmercury Uptake and Translocation by Rice Plants.

The bioaccumulation of the neurotoxin methylmercury (MeHg) in rice is a significant concern due to its potential risk to humans. Thiols have been known to affect MeHg bioavailability in microorganisms, but how thiols influence MeHg accumulation in rice plants remains unknown. Here, we investigated effects of common low-molecular-weight thiols, including cysteine (Cys), glutathione (GSH), and penicillamine (PEN), on MeHg uptake and translocation by rice plants. Results show that rice roots can rapidly take up MeHg, and this process is influenced by the types and concentrations of thiols in the system. The presence of Cys facilitated MeHg uptake by roots and translocation to shoots, while GSH could only promote MeHg uptake, but not translocation, by roots. Conversely, PEN significantly inhibited MeHg uptake and translocation to shoots. Using labeled 13Cys assays, we also found that MeHg uptake was coupled with Cys accumulation in rice roots. Moreover, analyses of comparative transcriptomics revealed that key genes associated with metallothionein and SULTR transporter families may be involved in MeHg uptake. These findings provide new insights into the uptake and translocation of MeHg in rice plants and suggest potential roles of thiol attributes in affecting MeHg bioavailability and bioaccumulation in rice.

Recognition of hydrophilic molecules in deep cavitand hosts with water-mediated hydrogen bonds.

We describe new container host molecules - deep cavitands with benzimidazole walls and ionic feet - to recognize highly hydrophilic guest molecules in water. The aromatic surfaces of the cavity recognize hydrophobic portions of the guest while bound water molecules mediate hydrogen bonding in the complex. Spectroscopic (NMR) evidence indicates slow in/out exchange on the chemical shift timescale and thermodynamic (ITC) methods show large association constants (Ka up to 6 × 104 M-1) for complexation of small, water-soluble molecules such as THF and dioxane. Quantum chemical calculations are employed to optimize the host-guest geometries and elucidate the hydrogen bonding patterns responsible for the binding.

Recognition of Hydrophilic Cyclic Compounds by a Water-Soluble Cavitand.

A water-soluble deep cavitand bearing amides on the upper rim and trimethyl ammonium groups on the feet was synthesized. The open-ended cavity is stabilized by the intramolecular hydrogen bonds formed between the adjacent amides, and the introduction of trimethylammonium imparts to the cavitand good solubility in water. The cavitand exhibits high binding affinity and selectivity to hydrophilic molecules in water. With certain guests, such as cyclohexyl alcohols, amines and acids, the recognition involves the synergistic action of hydrogen bonding with hydrophobic effects. The binding phenomena are interpreted in terms of a fixed solvent cage presented by the host to the guest.

Prenatal features of 17q12 microdeletion and microduplication syndromes: A retrospective case series.

OBJECTIVE: To present the experience on prenatal features of 17q12 microdeletion and microduplication syndromes. MATERIALS AND METHODS: Prenatal chromosomal microarray analysis (CMA) were conducted between January 2015 and December 2018 at a single Chinese tertiary medical centre. Information of cases identified with 17q12 microdeletion or microduplication syndromes were retrospectively collected. Foetal ultrasonographic findings were reviewed, and other information about the gestation week at diagnosis, inheritance and pregnancy outcomes were also included. RESULTS: Ten pregnancies with 17q12 microdeletion and 4 with 17q12 microduplication were identified. The copy number variation (CNV) sizes were 1.39-1.94 Mb in the deleted cases and 1.42-1.48 Mb in the duplicated cases, respectively. All the duplicated and deleted regions included HNF1B and LHX1 genes. Most individuals with 17q12 deletion presented kidney anomalies (9/10), with renal hyperechogenicity being the most common finding (7/10). Fetuses with 17q12 duplication presented a wide phenotypic spectrum, including "double bubble" sign, structural anomalies of the heart and growth anomalies. CONCLUSIONS: Our experience further demonstrated the high correlation between 17q12 microdeletion and renal anomalies especially hyperechogenic kidneys. Structural anomalies of the heart were newly identified phenotypes of 17q12 duplication during prenatal period. Besides, growth anomalies and duodenal atresia might be associated with the duplication.

Dimeric capsules self-assembled through halogen and chalcogen bonding.

Supramolecular capsules are nanoscale containers useful for the study of molecular behavior in confined spaces. They offer practical applications in catalysis, molecular transport, drug delivery, and materials science. Self-assembly has proven to be an effective approach in constructing supramolecular capsules and a variety of well-known noncovalent interactions including hydrogen bonding, metal coordination and ionic interactions have been deployed. Bowl-shaped cavitand structures built up from resorcinarenes have particular advantages for the construction of supramolecular capsules, and this highlight discusses the unconventional self-assembly of molecular capsules held together by halogen and chalcogen bonds.

Relative hydrophilicities of cis and trans formamides.

Secondary formamides are widely encountered in biology and exist as mixtures of both cis and trans isomers. Here, we assess hydrophilicity differences between isomeric formamides through direct competition experiments. Formamides bearing long aliphatic chains were sequestered in a water-soluble molecular container having a hydrophobic cavity with an end open to the aqueous medium. NMR spectroscopic experiments reveal a modest preference (<1 kcal/mol) for aqueous solvation of the trans formamide terminals over the cis isomers. With diformamides, the supramolecular approach allows staging of intramolecular competition between short-lived species with subtle differences in hydrophobic properties.

Structure, bioactivity and applications of natural hyperbranched polysaccharides.

In recent years, hyperbranched polymers, especially the natural hyperbranched polysaccharides (HBPSs), are receiving much attention due to their diverse biological activities and applications. With high degree of branching (DB), HBPSs mainly exist in the form of either a comb-brush shape, dendrimer-like particulate, or globular particle. HBPSs also possess some unique properties, such as high density, large spatial cavities, and numerous terminal functional groups, which distinguish them from other polymers. As a natural biopolymer, HBPS has excellent bioavailability, biocompatibility, and biodegradability, which have versatile applications in the fields of food, medicine, cosmetic, and nanomaterials. In this review, the source and structure of HBPSs from plant, animal, microbial and fungal origins as well as their biological functions and applications are covered, with the aim of further advancing the research of their structure and bioactivity.

The application of chromosomal microarray analysis to the prenatal diagnosis of isolated mild ventriculomegaly.

OBJECTIVE: To investigate the clinical value of chromosomal microarray analysis (CMA) in the prenatal diagnosis of genetic abnormalities in fetal isolated mild ventriculomegaly. MATERIALS AND METHODS: This retrospective study reviewed 101 fetuses with isolated mild ventriculomegaly who had undergone invasive prenatal diagnosis at our hospital. CMA was performed in all cases to detect chromosomal aneuploidy as well as copy number variations (CNVs) that are too small to be detected by conventional karyotyping. Real time quantitative PCR (qPCR) or multiplex ligation dependent probe amplification (MLPA) was used to confirm all fetal CNVs <400 Kb. RESULTS: Except for three cases of chromosomal aneuploidy, CMA revealed pathogenic copy number variations (CNVs) in 3.0% (3/101) of the fetuses; these cases demonstrated involvement in the chromosomal regions 15q11.2, 1q21.1 and Xq27.3q28. Furthermore, we detected three likely pathogenic (3.0%) and two variants of uncertain significance (2.0%) among 101 fetuses diagnosed as isolated mild ventriculomegaly on ultrasound examination. CONCLUSION: Our study suggests that CNVs could aid in the risk assessment and genetic counseling in fetuses with isolated ventriculomegaly.

Characterization and Hypoglycemic Activity of a Rhamnan-Type Sulfated Polysaccharide Derivative.

Polysaccharide chromium (III) derivatives are gaining increasing attention in improving type 2 diabetes. In this study, the sulfated polysaccharide from Enteromorpha prolifera (SPE) with 4.8 kDa was prepared by specific enzymatic hydrolysis. The obtained SPE was used to prepare a rhamnan-type sulfated polysaccharide derivative (SPED). Results indicated that O-H, C=O, and S=O were effectively involved in the chelation of SPED (chromium content 20.26%). Acute (half lethal dose > 2.38 g/kg) and sub-acute toxicity showed that SPED had no damaging effects on mice. Anti-diabetic experiment demonstrated that SPED improved glucose metabolism. Moreover, SPED promoted the PI3K/PKB/GSK-3ß signaling pathway by regulating mRNA expression of insulin receptors (IR), insulin receptor substrate 2 (IRS-2), phosphatidylinositol 3 kinase (PI3K), protein kinase B (PKB), and glycogen synthase kinase 3ß (GSK-3ß). In conclusion, the SPED might represent a novel marine-derived candidate against hyperglycemia, which may undergo further pharmaceutical development as a hypoglycemic agent.

Synthesis, bioactivity and mode of action of 5A 5B 6C tricyclic spirolactones as novel antiviral lead compounds.

BACKGROUND: Plant viral diseases cause tremendous decreases in yield and quality. Natural polycyclic compounds such as those containing carbocycles are often very important lead compounds for drug and pesticide development. Tricyclic spiranoid lactones with 5A 5B 6C -ring fusion topologies possess various bioactivities. In this study, 33 new 5A 5B 6C tricyclic spirolactones were rationally designed, synthesized, characterized and evaluated for antiviral activities. RESULT: These compounds showed no apparent toxicity against Italian honeybees up to 2.73 µg bee-1 . Spirolactones 14, 16, 19, 23 and 28 at a concentration of 100 µg mL-1 inactivated 90% of tobacco mosaic virus (TMV) infection, making these compounds much more potent than the positive controls. Significantly, compound 19 displayed the best inactivation activity causing inhibition of up to 98%. CONCLUSION: The results of the bioassays and QSAR studies indicated that the carbon-containing cyclic moiety was the antiviral pharmacophore, and derivative 19, which showed the best inactivation activity, could emerge as a potential antiviral agent against TMV. In vitro capsid protein (CP) assembly and TMV assembly inhibition determinations indicated that these compounds induced crosslinking in the TMV and prevented its uncoating, which was a putative new mode of action for TMV inactivation. © 2018 Society of Chemical Industry.

Synthesis of 1,2,3-Thiadiazole and Thiazole-Based Strobilurins as Potent Fungicide Candidates.

Strobilurin fungicides play a crucial role in protecting plants against different pathogens and securing food supplies. A series of 1,2,3-thiadiazole and thiazole-based strobilurins were rationally designed, synthesized, characterized, and tested against various fungi. Introduction of 1,2,3-thiadiazole greatly improved the fungicidal activity of the target molecules. Compounds 8a, 8c, 8d, and 10i exhibited a relatively broad spectrum of fungicidal activity. Compound 8a showed excellent activities against Gibberella zeae, Sclerotinia sclerotiorum, and Rhizoctonia cerealis with median effective concentrations (EC50) of 2.68, 0.44, and 0.01 µg/mL, respectively; it was much more active than positive controls enestroburin, kresoxim-methyl, and azoxystrobin with EC50 between 0.06 and 15.12 µg/mL. Comparable or better fungicidal efficacy of compound 8a compared with azoxystrobin and trifloxystrobin against Sphaerotheca fuliginea and Pseudoperonspera cubensis was validated in cucumber fields at the same application dosages. Therefore, compound 8a is a promising fungicidal candidate worthy of further development.

Modulational instability, higher-order localized wave structures, and nonlinear wave interactions for a nonautonomous Lenells-Fokas equation in inhomogeneous fibers.

In this paper, the nonautonomous Lenells-Fokas (LF) model is investigated. The modulational instability analysis of the solutions with variable coefficients in the presence of a small perturbation is studied. Higher-order soliton, breather, earthwormon, and rogue wave solutions of the nonautonomous LF model are derived via the n-fold variable-coefficient Darboux transformation. The solitons and earthwormons display the elastic collisions. It is found that the nonautonomous LF model admits the higher-order periodic rogue waves, composite rogue waves (rogue wave pair), and oscillating rogue waves, whose dynamics can be controlled by the inhomogeneous nonlinear parameters. Based on the second-order rogue wave, a diamond structure consisting of four first-order rogue waves is observed. In addition, the semirational solutions (the mixed rational-exponential solutions) of the nonautonomous LF model are obtained, which can be used to describe the interactions between the rogue waves and breathers. Our results could be helpful for the design of experiments in the optical fiber communications.

Functional polymorphisms of JWA gene are associated with risk of bladder cancer.

The JWA gene is a novel cell differentiation-related gene thought to be a responsive gene in response to DNA damage and repair induced by environmental stressors. Recently, a novel single nucleotide polymorphism (SNP) was identified in the promoter of the JWA gene (-76GC) that may alter the transcription activity and thus play a role in increased risk of bladder cancer. Further, studies were conducted to screen for more novel variants in the JWA exons by using PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) followed by PCR-RFLP (PCR restriction fragment length polymorphism) methods. Finally, the functional relevance of the newly identified genetic variants in a hospital-based case-control study of 215 bladder cancer patients and 250 cancer-free controls was evaluated. In addition to the -76GC polymorphism, another novel SNP (454CA in exon2 and 723TG in exon 3) of JWA was identified. The -76GC allele and genotype frequencies were found to vary in different ethnic groups. The -76C allele and 454A allele were both associated with significantly increased risk of bladder cancer. In contrast, the 723GG genotype was associated with a decreased risk of bladder cancer. Furthermore, -76C and 454A together increased the risk of bladder caner using haplotype and stratification analysis. In conclusion, the three novel functional genetic polymorphisms of JWA gene, -76GC, 454CA, and 723TG, appear to contribute to the etiology of bladder cancer.

Identification and functional characterization of JWA polymorphisms and their association with risk of gastric cancer and esophageal squamous cell carcinoma in a Chinese population.

Recently, a novel single nucleotide polymorphism (SNP) in the promoter of the JWA gene (-76G --> C) was identified that may alter the transcription activity and thus play a role in increased risk of bladder cancer. In this study, a screen for more novel variants in the JWA exons was undertaken by using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) followed by a PCR-restriction fragment length polymorphism (PCR-RFLP) method and evaluating the functions of newl identified JWA -76G --> C using the reporter gene assay. In addition to the -76G --> C polymorphism, another novel SNP (723T --> G) in exon 3 of JWA was identified. In a case-control study of these two SNPs in 413 gastric cancer and 250 esophageal squamous-cell carcinoma (ESCC) patients and 814 cancer-free controls in a Chinese population, data showed that both SNPs were associated with enhanced risk of these cancers. The reporter gene assay showed that the -76C variant allele lost its response to benzo[a]pyrene (BaP) exposure, compared to the -76G allele. In addition, the JWA -76C allele was found to be associated with increased gastric and esophageal cancer risks in this study population. Further studies are needed to substantiate the biological significance and related mechanisms underlying the associations.

Single nucleotide polymorphism of the JWA gene is associated with risk of leukemia: a case-control study in a Chinese population.

The JWA gene was initially cloned as a novel cell differentiation-associated gene and was subsequently found to be an environmental responsive gene. The JWA gene also produced a marked effect during chemical-induced multidirectional differentiations of primary and human myeloid leukemia cells. Recently, a novel single nucleotide polymorphism (SNP) in exon2 of the JWA gene (454CA) was identified that may play a role in risk of bladder cancer. The aim of this study was to investigate the association between the 454CA (NM_006407.2) in JWA exon2 variants and risk of leukemia in a hospital-based case-control study of 202 leukemia patients and 289 cancer-free controls. Results indicated that 454A allele was found to associate with significantly increased risk of leukemia, although the 454CA is a synonymous polymorphism in coding region of the JWA gene. In conclusion, the potentially functional genetic polymorphism 454CA of the JWA gene appears to contribute to the risk of multiple kinds of leukemia in a south Chinese population.