A pillared-layer metal-organic framework for efficient separation of C3H8/C2H6/CH4 in natural gas

Metal-organic frameworks (MOFs) have great potentials as adsorbents for natural gas purification. However, the trade-off between selectivity and adsorption capacity remains a challenge. Herein, we report a pillared-layer metal-organic framework Ni(HBTC)(bipy) for efficiently separating the C₃H₈/C₂H₆/CH₄ mixture. The experimental results show that the adsorption capacity of C₃H₈ and C₂H₆ on Ni(HBTC)(bipy) are as high as 6.18 and 5.85 mmol·g^-1, while only 0.93 mmol·g^-1 for CH₄ at 298 K and 100 kPa. Especially, the adsorption capacity of C₃H₈ at 5 kPa can reach an unprecedented 4.52 mmol·g^-1 and for C₂H₆ it is 1.48 mmol·g^-1 at 10 kPa. The ideal adsorbed solution theory predicted C₃H₈/CH₄ selectivity is as high as 1857.0, superior to most of the reported materials. Breakthrough experiment results indicated that material could completely separate the C₃H₈/C₂H₆/CH₄ mixture. Therefore, Ni(HBTC)(bipy) is a promising material for separation of natural gas.     

Influence of some organic compounds on the corrosion mechanism of carbon steel (XC 38) in 3% NaCl I. dodecyl sodium phosphonate (C10H21PO3Na2) and n-undecylimidazole (C14H26N2) surfactants

The electrochemical behaviour of carbon steel (XC38) in stirred and aerated 3% NaCl solution has been investigated using a rotating disc electrode. Steady-state and transient measurements have been carried out. The influence of surfactant additives on the corrosion process is reported.     

Genome-Wide Identification of Strawberry C2H2-ZFP C1-2i Subclass and the Potential Function of FaZAT10 in Abiotic Stress

C2H2-type zinc finger proteins (C2H2-ZFPs) play a key role in various plant biological processes and responses to environmental stresses. In Arabidopsis thaliana, C2H2-ZFP members with two zinc finger domains have been well-characterized in response to abiotic stresses. To date, the functions of these genes in strawberries are still uncharacterized. Here, 126 C2H2-ZFPs in cultivated strawberry were firstly identified using the recently sequenced Fragaria × ananassa genome. Among these C2H2-ZFPs, 46 members containing two zinc finger domains in cultivated strawberry were further identified as the C1-2i subclass. These genes were unevenly distributed on 21 chromosomes and classified into five groups according to the phylogenetic relationship, with similar physicochemical properties and motif compositions in the same group. Analyses of conserved domains and gene structures indicated the evolutionary conservation of the C1-2i subclass. A Ka/Ks analysis indicated that the C1-2i members were subjected to purifying selection during evolution. Furthermore, FaZAT10, a typical C2H2-ZFP, was isolated. FaZAT10 was expressed the highest in roots, and it was induced by drought, salt, low-temperature, ABA, and MeJA treatments. It was localized in the nucleus and showed no transactivation activity in yeast cells. Overall, these results provide useful information for enriching the analysis of the ZFPs gene family in strawberry, and they provide support for revealing the mechanism of FaZAT10 in the regulatory network of abiotic stress.     

A functional antibody mutant with an insertion in the framework region 3 loop of the VH domain: implications for antibody engineering

We have studied the effects of a four residue insertion intothe FR3 loop of the heavy chain variable region from the anti-NPantibody Bl-8. The insertion mutant is obtained as secretedantibody without major defects in biosynthesis, indicating thatantibody variable domains can accommodate length variation notonly in complementarity determining regions (CDRs), but alsoin framework region (FR) loops. The Bl-8 antigen binding siteis not affected by the change in a neighbouring loop. FR3 insertionsrepresent a new method of antibody engineering with a potentialto obtain strong antigen binding by designing additional antigencontacting residues.     

Peroxidative formation of C3-hydrocarbons from an ω-4 polyunsaturated fatty acid(16∶3ω4) in the algaBumilleriopsis

Under peroxidative conditions (i.e., illumination in the presence of Cu²⁺ or ap-nitro diphenylether herbicide), the xanthophycean microalga,Bumilleriopsis filiformis, evolves C₂ and C₅ hydrocarbons besides substantial amounts of propane and propene. Fatty acids were separated as methyl esters by argentation and reversed-phase thin layer chromatography and the fractions subsequently peroxidized by illuminated and copper-supplementedAnacystis thylakoids. These membranes do not contain polyunsaturated fatty acids and are, therefore, unable to evolve volatile hydrocarbons by itself. The C₂ and C₅ hydrocarbons formed by the fractions added match with their content of ω-3 and ω-6 fattyacid species having 2–4 double bonds. The fractions yielding C₃ hydrocarbons contain a fatty acid hitherto unknown forBumilleriopsis, which was isolated and identified as 16∶3ω4.     

p16-3MR: A Novel Model to Study Cellular Senescence in Cigarette Smoke-Induced Lung Injuries

Cellular senescence and lung aging are associated with the pathogenesis of chronic obstructive pulmonary disease (COPD). COPD progresses with aging, and chronic smoking is the key susceptibility factor in lung pathological changes concurrent with mitochondrial dysfunction and biological aging. However, these processes involving cigarette smoke (CS)-mediated lung cellular senescence are difficult to distinguish. One of the impediments to studying cellular senescence in relation to age-related lung pathologies is the lack of a suitable in vivo model. In view of this, we provide evidence that supports the suitability of p16-3MR mice to studying cellular senescence in CS-mediated and age-related lung pathologies. p16-3MR mice have a trimodal reporter fused to the promoter of the p16^INK4a gene that enables detection, isolation, and selective elimination of senescent cells, thus making them a suitable model to study cellular senescence. To determine their suitability in CS-mediated lung pathologies, we exposed young (12–14 months) and old (17–20 months) p16-3MR mice to 30 day CS exposure and studied the expression of senescent genes (p16, p21, and p53) and SASP-associated markers (MMP9, MMP12, PAI-1, and FN-1) in air- and CS-exposed mouse lungs. Our results showed that this model could detect cellular senescence using luminescence and isolate cells undergoing senescence with the help of tissue fluorescence in CS-exposed young and old mice. Our results from the expression of senescence markers and SASP-associated genes in CS-exposed young and old p16-3MR mice were comparable with increased lung cellular senescence and SASP in COPD. We further showed alteration in the; (i) tissue luminescence and fluorescence, (ii) mRNA and protein expressions of senescent markers and SASP genes, and (iii) SA-β-gal activity in CS-exposed young and old p16-3MR mice as compared to their air controls. Overall, we showed that p16-3MR is a competent model for studying the cellular senescence in CS-induced pathologies. Hence, the p16-3MR reporter mouse model may be used as a novel tool for understanding the pathobiology of cellular senescence and other underlying mechanisms involved in COPD and fibrosis.     

A reorientation of the PO3-groups and radiation damage effect in ferroelectric phase transition studied by CW-EPR of PO32- radical in glycine·H3PO3 single crystal

EPR of γ-ray generated PO₃^2- radicals indicates that the four radical centers are equivalent in the paraelectric phase and become inequivalent in the ferroelectric phase due to a ±3° rotation. The phase transition temperature is shifted by irradiation from T_c = 224 K to T_c = 180 K. The molecular mechanism of the order-disorder phase transition is discussed     

[3-13C] γ-linolenic acid: A new probe for 13C nuclear magnetic resonance studies of arachidonic acid synthesis in the suckling rat

Our objective was to develop a suitable probe to study metabolism of polyunsaturated fatty acids by ¹³C nuclear magnetic resonance (NMR) in the suckling rat pup. [3-¹³C] γ-Linolenic acid was chemically synthesized, and a 20 mg (Experiment 1) or 5 mg (Experiment 2) dose was injected into the stomachs of 6–10-day-old suckling rat pups that were then killed over a 192 h (8 d) time course. ¹³C NMR showed that ¹³C in γ-linolenate peaked in liver total lipids by 12-h post-dosing and that [5-¹³C]-arachidonic acid peaked in both brain and liver total lipids 48–96 h post-dosing. ¹³C enrichment in brain γ-linolenic acid was not detected by NMR, but gas chromatography-combustion-isotope ratio mass spectrometry showed that its mass enrichment in brain phospholipids at 48–96 h post-dosing was 1–2% of that in brain arachidonic acid. ¹³C was present in liver and brain cholesterol and in perchloric acid-extractable water-soluble metabolites in the brain, liver and carcass. We conclude that low but measurable amounts of exogenous γ-linolenic acid do access the suckling rat brain in vivo. The slow time course of [5-¹³C] arachidonic acid appearance in the brain suggests most of it was probably transported there after synthesis elsewhere, probably in the liver. Some carbon from γ-linolenic acid is also incorporated into lipid products other than n−6 long-chain polyunsaturated fatty acids.     

Single-chain Fv multimers of the anti-neuraminidase antibody NC10: the residue at position 15 in the VL domain of the scFv-0 (VL-VH) molecule is primarily responsible for formation of a tetramer-trimer equilibrium

Single-chain variable fragment of the murine monoclonal antibodyNC10 specific to influenza virus N9 neuraminidase, joined directlyin the V_L to V_H orientation (scFv-0), forms an equilibrium mixtureof tetramer and trimer with the tetramer as the preferred multimericspecies. In contrast, the V_H-V_L isomer was previously shownto exist exclusively as a trimer. Computer-generated trimericand tetrameric scFv models, based on the refined crystal structurefor NC10 Fv domain, were constructed and used to evaluate factorsinfluencing the transition between V_L-V_H trimer and tetramer.These model structures indicated that steric restrictions betweenloops spanning amino acid residues L55–L59 and L13–L17from the two adjacent V_L domains within the V_L-V_H trimer wereresponsible for four scFv-0 molecules assembling to form a tetramer.In particular, leucine at position L15 and glutamate at positionL57 appeared to interfere significantly with each other. Tominimize this steric interference, the site-directed mutagenesistechnique was used to construct several NC10 scFv-0 clones withmutations at these positions. Size-exclusion chromatographicanalyses revealed that several of these mutations resulted inthe production of NC10 scFv-0 proteins with significantly alteredtetramer–trimer equilibrium ratios. In particular, introductionof a polar residue, such as asparagine or threonine, at positionL15 generated a highly stable NC10 scFv-0 trimer.     

A new hybrid zinc phosphite with a pillared layered structure: Synthesis and characterization of [C6N2O2H16][Zn(HPO3)]2

By using flexible 1,2-bis(2-aminoethoxy)ethane (BAEOE) as a pillaring ligand, a new inorganic–organic hybrid open-framework zinc phosphite, [C₆N₂O₂H₁₆][Zn(HPO₃)]₂ (1), has been hydrothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. The structure of 1 consists of neutral layers of zinc phosphite which are further pillared through linear BAEOE ligands, generating a 3D framework with unusual (3, 4)-connected dmc topology. The participation of left-handed and right-handed helical chains in the construction of puckered sheet structure with 4.8²-net is also noteworthy.     

Studies on tocopherol derivatives: V. Intestinal absorption of several d,1-3,4-3H2-α-tocopheryl esters in the rat

Twelve d,1-3,4-3H2-alpha-tocopheryl esters were synthesized from d,1-3,4-3H2-alpha-tocopherol. They were acetate, propionate, butyrate, isobutyrate, caprylate, palmitate, acid succinate, benzoate, nicotinate, o-hydroxybenzoate, o-acetoxybenzoate, and pivalate. The hydrolysis of these esters with bile-pancreatic juice and with 9,000 x g supernatant of small intestine and liver homogenates of rats was examined. When these esters were incubated in small intestine or liver supernatants, hydrolysis occurred at a similar rate. In the incubation experiments, alpha-tocopheryl acetate, propionate, butyrate, isobutyrate, caprylate, palmitate, and acid succinate were classified as an easily hydrolyzable group. Alpha-tocopheryl benzoate and nicotinate were in a moderately hydrolyzable group. O-hydroxybenzoate and pivalate, which resisted hydrolysis, were in a scarcely hydrolyzable group. O-acetoxybenzoate was easily hydrolyzed to the o-hydroxybenzoate. Hydrolysis on straight chain fatty acid esters of alpha-tocopherol easily occurred in bile-pancreatic juice. In in vivo experiments, the lymphatic absorption rate of 6 esters, acetate, palmitate, acid succinate, nicotinate, o-hydroxybenzoate, and pivalate, was measured on thoracic duct fistula rats. Easily hydrolyzable esters were recovered mostly in lymph as alpha-tocopherol, whereas, an ester which strongly resisted hydrolysis, such as pivalate, appeared mainly unchanged. This fact suggested that hydrolysis of alpha-tocopheryl esters was not necessarily a prerequisite for intestinal absorption. The percentage of absorption of slowly hydrolyzed esters in lymph was relatively lower than that of moderately or easily hydrolyzable esters.     

Evaluation of Benzo[c]Chrysene Dihydrodiols in the Morphological Cell Transformation of Mouse Embryo Fibroblast C3H10T1/2CL8 Cells

The morphological cell transforming activities of three dihydrodiols of benzo[c]chrysene (B[c]C), trans?B[c]C-7,8-diol, trans?B[c]C-9,10-diol, and trans?B[c]C-1,2-diol were compared to those of B[c]C in order to study the possible routes of metabolic activation in transformable C3H10T1/2 mouse embryo fibroblasts. B[c]C-treated C3H10T1/2 cells exhibited a concentration-related increase in morphologically transformed foci over a concentration range of 0–3 μg/ml. At 3 μg/ml, B[c]C induced 1.23 Type II & III foci/dish, with 73% of the dishes exhibiting Type II or Type III foci, and a survival of 87%. trans?B[c]C-7,8-diol produced concentration-related responses over a range of 0–5 μg/ml. At 3 μg/ml, trans?B[c]C-7,8-diol produced 1.13 Type II & III foci/dish with 72% of the dishes exhibiting foci, and a survival of 76%. trans?B[c]C-9,10-diol was inactive as a morphological cell transforming agent over a concentration range of 0–3 μg/ml. trans?B[c]C-1,2-diol was also inactive as a morphological cell transforming agent over a concentration range of 0–3 μg/ml. These results suggest that a K-region dihydrodiol of B[c]C, trans?B[cC-7,8-diol, may play a role in the ability of B[c]C to morphologically transform C3H10T1/2 cells.     

A comparative study of the D.C. conductivities for certain Eu3 : Fluoroborate glasses

This short note brings out the study of D.C. conductivity of certain newly prepared Eu³⁺ -doped fluoroborate glasses.     

Nowotny phase Mo3+2xSi3C0.6 dispersed in a porous SiC/C matrix: A novel catalyst for hydrogen evolution reaction

The ternary Nowotny phase (NP), with a composition Mo_3+2xSi₃C_0.6 (x = 0.9-0.764), is found to be catalytically active in the field of electrochemical water splitting. The NP embedded in a porous SiC/C nanocomposite matrix is synthesized via a single-source-precursor approach which involves the reaction of allylhydridopolycarbosilane with MoO₂(acac)₂. Thermal treatment of the single-source-precursor up to 1400°C in a protective atmosphere results in the in situ formation of nanocrystalline Mo_3+2xSi₃C_0.6 immobilized in a thermally and corrosion-stable SiC/C matrix. The weight fractions of the observed crystalline phases Mo_3+2xSi₃C_0.6 and SiC amount to ca. 28 (26) and 72 (74) wt%, respectively, when prepared at 1400°C (1350°C). The porosity of the formed nanocomposite is adjusted by the addition of polystyrene (PS) as a pore former to the single-source-precursor resulting in a specific surface area up to 206 m²/g. The electrocatalytic activity of the Mo_3+2xSi₃C_0.6/C/SiC nanocomposite with respect to the hydrogen evolution reaction (HER) is characterized by low over potentials of 22 and 138 mV vs reversible hydrogen electrode (RHE) for applying 1 and 10 mA cm⁻² of current density, respectively. The analyzed electrocatalytic performance exceeds that of most Mo-based electrocatalysts and shows high stability (over 90%) during 35 hours.     

Identification of Stereochemical Configurations of Cyclopenta[ cd ]pyrene DNA Adducts in Strain A/J Mouse Lung and C3H10T1/2CL8 Cells

Four major and several minor DNA adducts were resolved by 32 P-postlabeling analysis of DNA from strain A/J mouse lung and C3H10T1/2CL8 (C3H10T1/2) mouse embryo fibroblasts treated with cyclopenta[ cd ]pyrene (CPP). The identical pattern of adducts was seen in vivo and in vitro. Cochromatography of synthetic resolved diastereomers of cis - and trans - N 2 -CPP-deoxyguanosine-3'-phosphates with the in vivo adducts obtained from strain A/J mouse lung and in vitro adducts obtained from C3H10T1/2 cells allowed identification of the predominant DNA adduct as cis -(3 R ,4 S )- N 2 -CPP-deoxyguanosine. The second most abundant adduct formed in vivo and in vitro was identified as trans -(3 S ,4 S )- N 2 -CPP-deoxyguanosine.     

Influence of some organic compounds on the corrosion mechanism of carbon steel (XC38) in 3% NaCl II. Orthoaminothiophenol (C6H7NS) and surfactant dodecyl sodium phosphate (C10H21PO4Na2)

This paper presents an investigation of the influence of added organic compounds on the electrochemical behaviour of the carbon steel (XC38) in stirred and aerated 3% NaCl. Steady-state and transient measurements have been made using a rotating disc electrode. The influence of dodecyl sodium phosphate (C₁₀H₂₁PO₄Na₂) and orthoaminothiophenol (C₆H₇NS) have been studied. Results obtained allowed corrosion inhibition mechanism to be established. The nature of the electrode process has been elucidated.     

A222型阴离子交换树脂脱除HPPH+体系中的SO42-、NO3-

优化选取凝胶型强碱性苯乙烯系A222型阴离子交换树脂,对HPPH⁺溶液中SO₄^2-、NO₃^-的交换性能进行了研究。通过静态法分别考察了A222型阴离子交换树脂在水溶液及0.05mol/L HPPH⁺溶液中对SO₄^2-和NO^3-脱除过程。结果表明,A222型阴离子交换树脂对HPPH⁺无化学吸附作用,在水体系中对SO₄^2-和NO₃^-的平衡交换量分别为0.8382mmol/g和1.2980mmol/g,符合Langmuir和Freundlich吸附经验方程。树脂用量和温度是离子交换过程的主要影响因素,温度升高有利于离子交换的进行,树脂的优化用量为4g/L。A222型阴离子交换树脂可高效联合脱除HPPH⁺体系中的SO₄^2-和NO₃^-。FTIR谱图表征显示,SO₄^2-和NO₃^-可与树脂交换基团进行交换。