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Hydrogels are widely used in fields such as drug delivery, tissue regeneration, soft robotics and flexible smart electronic devices, yet their application is often limited by unsatisfactory mechanical behaviors. Among the various improvement strategies, double network (DN) hydrogels from synthetic polymers demonstrated impressive mechanical properties, while those from natural polymers were usually inferior. Here, a novel DN hydrogel composed fully of natural polymers exhibiting remarkable mechanical properties and conductivity is prepared by simply soaking a virgin gellan gum/gelatin composite hydrogel in a mixed solution of Na2SO4 and (NH4)2SO4. This hydrogel exhibits a tunable Young's modulus (0.08 to 42.6 MPa), good fracture stress (0.05 to 7.5 MPa), good fracture stretch (1.4 to 7.1), high fracture toughness (up to 27.7 kJ m−2), and high ionic conductivity (up to 11.4 S m−1 at f = 1 kHz). The improvement in the mechanical properties of the DN gel is attributed to the chain-entanglement crosslinking points introduced by SO42− in the gelatin network and the electrostatic interaction crosslinking points introduced by Na+ in the gellan gum network. The high ionic conductivity of the DN gel is attributed to the infiltration of the DN gel in a salt solution of high concentration. The developed gellan gum/gelatin DN hydrogel has shown a new pathway towards strengthening natural-polymer-based DN hydrogels and towards potential applications in biomedical engineering and flexible electronic devices.

The nickel-catalyzed hydrocarboxylation of alkenes using carbon dioxide has recently become an appealing method to prepare functionalized carboxylic acids with high efficiency and regioselectivity. Herein, density functional theory (DFT) calculations were conducted on the Ni-catalyzed hydrocarboxylation of aryl-/alkyl-substituted alkenes with CO2. The α- and β-carboxylation of aromatic and aliphatic olefins originate from distinct catalytic cycles: H-transfer–carboxylation and carboxylation–H-transfer pathways. The typical hydrometallation–carboxylation mechanism is unlikely because water/carbonic acid (H-resource) are inferior hydride donors.

Nowadays, several approaches are being suggested to endow hydrogels with improved mechanical properties for practical applications as cartilage and skin replacements, soft electronics, and actuators. However, it remains a challenge to develop DN gels with both high fracture toughness and fracture stretch. Here, we introduce (bio)polyelectrolyte complexes (PECs) consisting of gelatin and κ-carrageenan as the first brittle network and covalently crosslinked polyacrylamide (PAAm) as the second stretchable network to fabricate a highly stretchable and notch-insensitive gelatin/κ-carrageenan/PAAm hydrogel. The unprecedented high stretchability (∼51.7) is ascribed to the reduction of stress concentration and defects in the network structure through the fracture of the PEC gel. In addition, a high fracture toughness (∼16053.34 J m-2) is achieved by effective energy transfer between the PECs and PAAm gel due to their covalent crosslinking, and efficient energy dissipation through destroying inter- and intramolecular interactions in the PEC gel.

Hydrogel tubes are widely used in fields such as artificial blood vessels, drug delivery, biomedical scaffolds and cell adhesion, yet their application is often limited by unsatisfactory mechanical properties and poor stability in various solutions. Herein, a novel hydrogel tube exhibiting a remarkable mechanical performance and stability in various solutions is prepared by introducing a dual physically cross-linked double network (DN) hydrogel matrix. The obtained hydrogel tube can withstand ∼60 N load without fracture and be stretched to over twice its original length before and after immersing in various solutions. The great mechanical properties and stability in various solutions of hydrogel tubes are due to the introduction of a dual physically cross-linked poly(acrylamide

This paper presents a property-directed approach to verifying recurrent neural networks (RNNs). To this end, we learn a deterministic finite automaton as a surrogate model from a given RNN using active automata learning. This model may then be analyzed using model checking as a verification technique. The term property-directed reflects the idea that our procedure is guided and controlled by the given property rather than performing the two steps separately. We show that this not only allows us to discover small counterexamples fast, but also to generalize them by pumping toward faulty flows hinting at the underlying error in the RNN. We also show that our method can be efficiently used for adversarial robustness certification of RNNs.

Background Pregnancy-associated listeriosis is a severe infectious disease and potentially leading to fetal/neonatal fatal. Limited information on pregnancy-associated listeriosis is available in China. Methods We performed a retrospective study on maternal and neonatal patients with pregnancy-associated listeriosis. The clinical characteristics of pregnancy-associated listeriosis were studied, and the outcome determinants of neonatal listeriosis were explored. Results 14 cases of pregnancy-associated listeriosis were identified. The incidence of pregnancy-associated listeriosis in our hospital was 16.69/100,000 births. All of the 14 maternal patients eventually recovered after delivery shortly with no sequelae. None of the 12 mothers who delivered in this hospital received antepartum first-line empirical treatment. Among the 14 neonatal cases, 1 was late onset listeriosis and 13 were early onset cases; 11 survived and 3 died. Fatality rates were significantly higher in outborn neonates (P=0.005). Besides, higher mortality rates were observed in neonates with lower birth weight (P=0.038), gestational ageP=0.056), and Apgar score (5th min) P=0.056), with marginally significant differences. Conclusions There is a neglected burden of pregnancy-associated listeriosis in our hospital. Timely and optimal resuscitative measures are considered to be important to reduce mortality of neonatal listeriosis. Listeriosis should be considered in the differential diagnosis of pregnancy-associated infections.

Colon cancer is associated with high death rates worldwide and poses a serious threat to public health. GINS complex subunit 2 (GINS2) serves a carcinogenic role in many cancers, including gastric adenocarcinoma, ovarian cancer and pancreatic cancer. However, the specific function of GINS2 in the development of colon cancer has not been described in detail. The present study aimed to clarify the role of GINS2 in colon cancer. A Cell Counting Kit‑8 assay, EdU staining, TUNEL and flow cytometry analyses were performed to determine the levels of cell viability, proliferation and apoptosis and to evaluate the cell cycle. Through the analysis of BioGrid, a Protein‑Protein Interaction database, it was hypothesized that protein tyrosine phosphatase 4A1 (PTP4A1) is a protein that might interact with GINS2, which was then validated using a co‑immunoprecipitation assay. mRNA and protein levels were measured using reverse transcription‑quantitative PCR and western blotting, respectively. The results of the present study demonstrated that GINS2 expression levels were increased in colon cancer cells. Furthermore, GINS2 knockdown inhibited the proliferation of colon cancer cells, while the levels of cell cycle arrest and apoptosis were increased. By interacting with PTP4A1, GINS2 promoted the expression of PTP4A1, a novel p53 target. GINS2 knockdown was increased, while PTP4A1 overexpression decreased the protein level of p53. Notably, PTP4A1 overexpression partly reversed the effects of GINS2 downregulation on colon cancer cells. Therefore, the present study demonstrated that GINS2 regulated the proliferation and apoptosis of colon cancer cells through PTP4A1/p53 pathway, highlighting that GINS2 may serve as a novel molecular marker for colon cancer prevention and therapy.

The nickel-catalyzed hydrocarboxylation of alkenes using carbon dioxide has recently become an appealing method to prepare functionalized carboxylic acids with high efficiency and regioselectivity. Herein, density functional theory (DFT) calculations were conducted on the Ni-catalyzed hydrocarboxylation of aryl-/alkyl-substituted alkenes with CO

International audience; Web services provide a general basis of convenient access and operation for cloud applications. However, such services become very vulnerable when being attacked, especially in the situation where service continuity is one of the most important requirements. This issue highlights the necessity to apply reliable and formal methods to attack tolerance in Web services. In this paper, we propose a Coloured Petri Nets based method for attack tolerance by modelling and analysing basic behaviours of attack-network interaction, attack detectors and their tolerance solutions. Furthermore, complex attacks can be analysed and tolerance solutions deployed by identifying these basic attack-network interactions and composing their solutions. The validity of our method is demonstrated through a case study on attack tolerance in cloud-based medical information storage.

Staphylococcus epidermidis is frequently associated with biofilm-related infections. Biofilms drastically reduce the efficacy of conventional antibiotics and the host immune system. In S. epidermidis biofilm formation, a major role is played by the YycG/YycF two-component system, and previous findings have indicated that inhibitors targeting the cytoplasmic HATPase_c domain of YycG kinase in S. epidermidis exhibit bactericidal and biofilm-killing activities. Therefore, we hypothesized that monoclonal antibodies (mAbs) against YycG extracellular (YycGex) domain would block the signal transduction and influence the biofilm formation of S. epidermidis. In this study, we screened out two YycGex-specific mAbs showing the highest affinity for the target, mAbs 2F3 and 1H1. These mAbs inhibited S. epidermidis biofilm formation in a dose-dependent manner, and at a concentration of 160 μg/mL, mAbs 2F3 and 1H1 caused 78.3 and 93.1% biofilm reduction, respectively, relative to normal mouse IgG control. When co-cultivated with YycGex mAbs, S. epidermidis cells showed diminished initial-adherence capacity, and the antibody treatment further led to a marked decrease in the synthesis of polysaccharide intercellular adhesin and in the transcriptional level of genes encoding proteins involved in biofilm formation. Lastly, we determined that the epitopes recognized by the two YycGex mAbs are located within aa 59–70 of the YycGex domain. It indicates that the YycGex domain may be a potential candidate as a vaccine for the prevention of S. epidermidis biofilm infections.

The axial coordination properties of six zinc tetraarylporphyrins with seven different nitrogenous bases were examined in CH2Cl2 for derivatives containing four [Formula: see text],[Formula: see text]-fused butano or benzo groups and the equilibrium constants (log[Formula: see text] determined using spectral titration methods. The examined compounds are represented as butano(YPh)4PorZn and benzo(YPh)4PorZn, where Por is the porphyrin dianion and Y is a CH3, H or Cl substituent on the para-position of each meso-phenyl ring of the macrocycle. The initial four-coordinate butano- and benzoporphyrins will axially bind one nitrogenous base to form five-coordinate derivatives in CH2Cl2 and this leads to a 4–22 nm red-shift of the Soret and Q bands. The log[Formula: see text] values range from 1.98 to 4.69 for butano(YPh)4PorZn and from 3.42 to 5.36 for benzo(YPh)4PorZn, with the exact value depending upon the meso and [Formula: see text]-substituents of the porphyrin and the conjugate acid dissociation constants (p[Formula: see text] of the nitrogenous base.

Infections of emerging and reemerging viruses (SARS-CoVs, influenza H1N1, etc.) largely and globally affect human health. Animal models often fail to reflect a physiological status because of species tropism of virus infection. Conventional cell lines are usually genetically and phenotypically different from primary cells. Developing an in vitro physiological model to study the infection of emerging viruses will facilitate our understanding of virus-host cell interactions, thereby benefiting antiviral drug discovery. In the current work, we first established normal airway epithelial cells (upper and lower airway track) in 2D and 3D culture systems using conditional reprogramming (CR) and air-liquid interface (ALI) techniques. These long-term cultures maintained differentiation potential. More importantly, these cells express two types of influenza virus receptors, α2-6-Gal- and α2-3-Gal-linked sialic acids, and angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoVs as well. These cells were permissive to the infection of pandemic influenza H1N1 (H1N1pdm). In contrast, the lung cancer cell line A549 and immortalized airway epithelial cells (16HBE) were not susceptible to H1N1 infection. A virus-induced cytopathic effect (CPE) on 2D CRC cultures developed in a time-dependent manner. The pathological effects were also readily observed spreading from the apical layer to the basal layer of the 3D ALI culture. This integrated 2D CRC and 3D ALI cultures provide a physiological and personalized in vitro model to study the infection of emerging viruses. This novel model can be used for studying virus biology and host response to viral infection and for antiviral drug discovery.

Two series of zinc tetraarylporphyrins containing four [Formula: see text],[Formula: see text]′-pyrrole fused butano or benzo groups were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in nonaqueous media. The examined compounds are represented as butano(Ar)4PorZn and benzo(Ar)4PorZn, where Por is the porphyrin dianion and Ar is a [Formula: see text]-CH3Ph, Ph or [Formula: see text]-ClPh substitutent on [Formula: see text]-positions of the macrocycle. Each Zn(II) butano- and benzoporphyrin undergoes two one-electron reductions to give a [Formula: see text]-anion radical and dianion in CH2Cl2. In contrast, three reductions were observed for the benzoporphyrin derivatives in pyridine, the third of which is assigned as electron addition to a benzophlorin anion generated from the doubly reduced benzoporphyrin. Two overlapped one-electron oxidations were observed for the butanoporphyrins in CH2Cl2, a result not previously observed for any other zinc porphyrin. The electrochemically measured HOMO-LUMO gap of the benzoporphyrins ranges from 1.89 to 1.90 V in CH2Cl2 and from 1.93 to 1.95 V in pyridine. Both values are smaller than the gaps of butanoporphyrins at 2.11-2.13 V in CH2Cl2 and 2.07.2.09 V in pyridine.

Cytochromes p450 (CYPs) metabolize thousands of endogenous and exogenous chemicals, including toxic compounds and drugs. The primary cells have relative short life span and are not able to sustain levels of metabolic enzymes CYPs expression and activity long enough in vitro. The immortalized cell lines are also not ideal for toxicity testing because of their low levels of CYPs expression. In this study, we established human normal bronchial epithelial cells using conditional reprogramming (CR) technique from three human donors (named as CR-HNBE1-3). These CR cells can proliferate continuously in defined culture system over 50 PDs within 2 months. The CR-HNBE cells exhibited the normal diploid karyotype, normal response to DNA damage and normal differentiation potential under the matrigel 3D culture condition. The CR-HNBE cells express the basal epithelial marker cytokeratin 14 (CK14) and epithelial secretory marker Mucin 5AC. Most importantly, CR-HNBE cells express comparable levels of CYP1B1 and CYP2E1 as those in lung tissue. These CR cells also express comparable mRNA of CYP1A1/CYP1A2, CYP2B6/CYP2C9/CYP2D6 and CYP3A4/CYP3A5 compared to the lung tissue. The basal activity of CYP1A1/CYP1B1 in these CR cells was 3–6 folds higher than that of 16HBE cells (an immortalized cell line widely used in toxicology field). Our data also demonstrated that Benzo(a)pyrene (BaP) induced up to 100 folds of mRNA expression of CYP1A1 or CYP1A2 in CR-HNBE cells. The activity of CYP1A1/CYP1B1 was induced by BaP up to 7–8 folds in CR-HNBE cells, while the activity of CYP1A1/CYP1B1 was induced maximum 2.5 folds in 16HBE cells. Taken together, CR-HNBE cells express comparable levels of CYPs and are sensitive to BaP induction, and will serve a sensitive, physiological and valuable in vitro toxicity testing model. This is the first report that normal human airway cells can be propagated for a long time and maintain comparable levels of CYPs.

Highly ordered LaTb x O y :Eu3+ nanowire arrays have been synthesised in anodic aluminium oxide template by chemical co-deposition at negative pressure suction, it is amorphous and with homogeneous morphologies. There are two peaks at 619 and 704 nm with excitation wavelength of 394 nm, which have red shift slightly relative to the 5D0–2F2 and 5D0–7F4 energy level transition of Eu3+, and Tb3+ exhibits strong fluorescence enhancement and sensitisation in LaTb x O y :Eu3+ nanowire arrays with the existence of La3+. The fluorescence intensity of LaTb x O y :Eu3+ nanowire arrays is related to the doping concentration of Eu3+ ion. When the doping concentration of Eu3+ is 8%, the fluorescence intensity reaches a maximum, and remarkably decreases at higher concentrations.

Four N-confused free-base tetraarylporphyrins containing an amino group on the inner carbon of the inverted pyrrole were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in dichloromethane and N,N-dimethylformamide containing 0.1 M tetra-[Formula: see text]-butylammonium perchlorate as supporting electrolyte. The examined compounds are represented as (NH[Formula: see text](Ar)[Formula: see text]NcpH[Formula: see text], where “Ncp” is the N-confused porphyrin macrocycle and Ar is a [Formula: see text]-CH[Formula: see text]OPh, [Formula: see text]-CH[Formula: see text]Ph, Ph or [Formula: see text]-ClPh substituent on each meso-position of the macrocycle. Each porphyrin undergoes multiple irreversible reductions and oxidations. The first one-electron addition and first one-electron abstraction are located on the porphyrin [Formula: see text]-ring system to give [Formula: see text]-anion and [Formula: see text]-cation radicals with a HOMO–LUMO gap ranging from 1.21 to 1.34 V in CH[Formula: see text]Cl[Formula: see text] and 1.06 to 1.12 V in DMF. Both electrogenerated products are unstable and undergo a rapid chemical reaction to give new electroactive species which can be further reduced at more negative potentials or further oxidized at more positive potentials. The effects of the inner amino-substituent on the UV-vis spectra and electrochemical properties of the porphyrin are discussed, and comparisons made to data in the literature for both structurally related N-confused porphyrins containing an inner carbon NO[Formula: see text] group and derivatives without the inner substituent.

Ultra-long YCe x O y :Eu 3+ nanowire arrays(NWAs) have been synthesized in anodic aluminum oxide (AAO) templates by chemical co-deposition at negative pressure suction, which are amorphous, and possess precise dimension and homogeneous morphologies. The SEM, TEM, XRD and EDS were employed to investigate the morphology, structure and elemental composition of YCe x O y :Eu 3+ NWAs. The fluorescence properties of the YCe x O y :Eu 3+ NWAs were measured by fluorescence spectrometer (PerkinElmer LS-55) using Xenon discharge lamp as the excitation light source. There are two emission peaks at 615 nm and 702 nm with excitation wavelength of 394 nm, which corresponds to the 5 D 0 - 2 F 2 and 5 D 0 - 7 F 4 energy level transition of Eu 3+ , respectively. The fluorescence intensity of YCe x O y :Eu 3+ NWAs is related to the doping concentration of Eu 3+ ion, which reaches a maximum with doping concentration of Eu 3+ at 8%, and remarkably decreases at higher concentrations. Ce 3+ ion dominates the fluorescence activation in YCe x O y :Eu 3+ NWAs.

In this study, we established human limbal epithelial cells (LECs) from normal limbal tissues by using Conditional Reprogramming (CR) technology (refer to CR-LEC cells in this study). We have successfully established CR-LEC cell strains from three human donors (3 out of 3), and normal rabbits (2 out of 2) and pig (1 out of 1) as well. CR-LEC cells sustained a continuous and stable proliferation status with a normal karyotype, normal response to DNA damage, well-defined structured spheres in matrigel 3D culture. Responses of CR-LEC cells to IFN α2b, Ganciclovir and 5-Fluorouracil were different, suggesting that these drugs had different toxicities to these cells as expected. More important, there was no significant difference of responses to drugs between early and late passages of CR-LEC cells (p>0.05), indicating CR-LEC cells can serve a stable normal human cell model for toxicity assessment. Toxicity tests with monolayer cultures of CR-LEC cells were measured by staining the F-actin and Dsg-1 expression. Toxicity of three drugs at LD50 concentration resulted in a gradually increased destruction of monolayer, which is, in accordance with the irritation grade of three drugs on human cornea epithelium. Therefore, CR-LEC cells provide a novel and reliable in vitro physiological cell model for corneal toxicity assessment.

This study examines the original nature, tectonic setting, and evolution of Paleoproterozoic metasedimentary rocks in the Laoling Group of northern Jiao–Liao–Ji Belt (JLJB), in the northeastern margin of the Eastern Block of the North China Craton (NCC), using new petrological, whole–rock geochemical, geochronological, and Lu–Hf isotope data. The youngest detrital zircons constrain the maximum deposition age of the metasedimentary rocks to 1.97 Ga, and two metamorphic zircon age peaks correspond to 1.91 and 1.84 Ga for their metamorphism. The protoliths of the metasedimentary rocks in the Laoling Group were medium- to fine-grained clastic sediments, dominated by shale, graywacke, and claystone, with a smaller amount of sandstone, derived from Paleoproterozoic granites and coeval acidic meta-volcanic rocks, with minor contributions from Mesoarchean–Neoarchean basement rocks and Paleoproterozoic meta-mafic rocks. The protoliths of the metasedimentary rocks in the Dalizi Formation of the Laoling Group were deposited in a convergent margin setting, and subduction along the northern JLJB likely ended before ca. 1.91 Ga when the Longgang and Nangrim blocks collided. The eHf(t) values of ca. 2.14 Ga zircons mostly lie between the depletion mantle and the chondrite evolution line, coupled with extensive coeval magmatism, are consistent with the ca. 2.14 Ga significant continental crust growth in this region. An integrated study of petrology, geochemistry, metamorphic P–T paths, and tectonic evolution suggests that the JLJB experienced two metamorphic events at ca. 1.91 and 1.84 Ga.

Combining a hydrophobic interaction crosslinked curdlan as the first network and hydrophobic interaction crosslinked polyacrylamide as the second network, we have fabricated a curdlan/HPAAm double network (DN) hydrogel using a one-pot method. The resulting DN hydrogel exhibited good mechanical properties, i.e. an elastic modulus of 103 kPa, a tensile fracture strength of 0.81 MPa, a tensile stretch of 25.3 and a compressive stress of 62.5 MPa when the compressive strain increased up to 99%. The DN gel could withstand ten compression tests under 90% compressive strain without observable damage. The DN gel demonstrated 84% stiffness recovery and 97% toughness recovery after the deformed samples were relaxed and stored at 95 °C for 4 h. The stiffness and fracture stress of the DN gel were enhanced after sterilization treatment at 120 °C. Furthermore, the gels exhibited 52% self-healing of fracture stretch after the samples were cut and brought into contact at 95 °C for 4 h. The self-recovery and self-healing properties of the DN gel both originated from the first curdlan network via the reformation of hydrophobic interactions and the second HPAAm network via reformation of the broken hydrophobic associations.

As a kind of typical soft and wet material, hydrogel has been increasingly investigated as another way to develop flexible electronics. However, the traditional hydrogel with poor strain and strength performance cannot meet the requirements for stretchable electronics; fabricating a stretchable hydrogel with balanced tensile strength, toughness, and conductivity is still a big challenge. Herein, a new type of physically cross-linked hydrogel with poly(acrylamide-co-acrylic acid)-Fe3+ and chitosan-SO42- dual ionic networks via facile free radical polymerization and soaking processes is developed to fabricate excellent high-performance flexible sensors. The abundant Fe3+ and SO42- ions in the hydrogel can not only construct tough and strong dual ionic networks but also give the hydrogel high conductivity. Consequently, the optimal hydrogel possesses high tensile strength (∼5.1 MPa), large strain capacity (∼1225%), elasticity (∼1.13 MPa), high toughness (∼32.1 MJ/m3), and high conductivity (3.04 S/m at f = 0.1M), as well as rapid self-recovery property. Furthermore, the hydrogel conductor has high stretching sensitivity with a gauge factor of 6.0 at strain of 700% and was able to detect conventional motions of the human body such as the motions of the knuckle, speaking, and swallowing, which indicates that our ionic conductive hydrogels can be used to fabricate excellent high-performance flexible sensors.

Four aryl-substituted tripyrrinone copper(II) complexes were synthesized and characterized as to their electrochemical and spectroelectrochemical properties. The examined compounds are represented as (YPh)3TPO2Cu, where TPO2 is a dianion of the tripyrrinone and Y is a CH3O, CH3, H or Cl substituent on the para-position of each phenyl ring of the compound. The neutral compounds are ESR active and show a typical d9 Cu(II) signal in frozen CH2Cl2 solution. Each Cu(II) compound undergoes three reductions between −0.61 and −1.90 V and two oxidations between 1.00 and 1.24 V in CH2Cl2 containing 0.1 mol/L tetra-n-butylammonium perchlorate. The potentials for oxidation are similar to those of copper tetraarylporphyrins but the reduction potentials are positively shifted as compared to the corresponding tetraarylporphyrins. Thus, the potential difference between the first one-electron oxidation and first one-electron reduction (the HOMO-LUMO gap) of (YPh)3TPO2Cu, which ranges from 1.68 to 1.75 V, is similar to that of copper corroles (1.73–1.85 V), but smaller than the separation of 2.30–2.37 V for the copper tetraarylporphyrins under the same solution conditions.

Three copper triarylcorroles containing a [Formula: see text]-pyrrole nitro substituent were synthesized and characterized as to their spectral and electrochemical properties in nonaqueous media. The examined compounds are represented as [Formula: see text]-NO2(YPh)3CorCu, where Cor is the trianion of a triphenylcorrole and Y is a Cl, H or CH3 substituent at the para-position of the three meso-phenyl rings of the compound. The data from absorption spectra, electrochemistry and thin-layer spectroelectrochemistry are consistent with an initial assignment of Cu[Formula: see text]-Cor[Formula: see text] in CH2Cl2, DMF and pyridine and electrogeneration of a formal Cu(II) corrole with an unreduced macrocycle, represented as Cu[Formula: see text]-Cor[Formula: see text], after the first one-electron reduction in these solvents. The doubly reduced [Formula: see text]-nitrocorrole has a sharp Soret band at 439 nm and a well-defined Q-band at 611 nm in CH2Cl2. Similar absorption spectra are seen for the three examined doubly reduced nitrocorroles in DMF and pyridine, suggesting formation of a Cu(I) species with an unreduced macrocycle which is represented as Cu[Formula: see text]-Cor[Formula: see text]. Changes in redox potentials and absorption spectra of the nitrocorroles are examined as a function of solvent and substituents on the meso-phenyl rings of the compounds and comparisons are made between spectral and electrochemical data of the newly synthesized corroles and that of structurally related tetraarylcorroles lacking a [Formula: see text]-nitro group.

Fault diagnosis is a crucial and challenging task in the automatic control of complex systems, whose efficiency depends on a system property called diagnosability. Diagnosability describes the capability of a system to determine with certainty whether a fault has effectively occurred based on a sequence of observations. The diagnosability problem of discrete event systems has received considerable attention in the literature. However, up to now little work takes into account explicit time constraints during this analysis, which are however naturally present in real-life systems and thus cannot be neglected considering their impact on this property. In this paper, we first rephrase diagnosability definition for timed automata before showing the impact of time constraints on this property. Then we propose a new SMT-based approach to verify bounded time diagnosability on timed automata. The idea is to encode the sufficient and necessary condition for diagnosability in SMT. Finally, the experimental results are presented to show the efficiency of the SMT-based paradigm.

The effects of molecular weight on the thermal degradation behavior of poly(α-methyl styrene) (PAMS) was investigated by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) and thermogravimetric analysis (TGA). The Py-GC/MS analysis results showed that the degradation of PAMS with different molecular weights in nitrogen produced only the monomer, alpha-methylstyrene. The TGA results showed a pronounced reduction in the decomposition temperature with increasing molecular weight. The degradation kinetic parameters, calculated by the Kissinger and the Coats–Redfern methods, further revealed that the activation energy and the pre-exponential factor decreased with increasing molecular weight. Most importantly, the degradation order of the PAMS in nitrogen remained around 1, independent of the molecular weight, suggesting the maintenance of the depolymerization mechanism. All the above results provided an insight into the effects of molecular weight on the thermal degradation behavior of PAMS.

У статті описано результати дослідження, присвяченого формуванню педагогічної толерантності майбутніх учителів іноземних мов початкової школи. Зокрема подано дефініцію педагогічної толерантності майбутніх учителів іноземних мов початкової школи, описано концепцію моделі її формування, визначено етапи педагогічного експерименту, підібрано методики для діагностики рівня сформованості кожного компонента педагогічної компетентності. Описано авторський тренінг, розроблений з метою підготовки викладачів англійської мови до аудиторної роботи зі студентами у межах проблеми дослідження,обґрунтовано переваги тренінгу у порівнянні з іншими методами роботи, підібрано відповідний навчальний і методичний матеріал, перевагу надано інтерактивним методам та формам взаємодії. Схарактеризовано особливості практичних занять як основної форми організації навчальної діяльності студентів, визначено їх структурні елементи. Дано опис змістового компонента моделі формування педагогічної толерантності, а саме оновлено зміст дисциплін гуманітарного циклу, основне навчальне навантаження зосереджено на авторському спецкурсі “Практика толерантної англомовної комунікації”, визначено його мету, розподілено змістове наповнення на шість модулів, які дали можливість студентам поступово ознайомитися із сутністю педагогічної толерантності та основами практичної толерантної взаємодії у межах педагогічної діяльності, створено ефективні педагогічні умови для підготовки компетентного і толерантного учителя іноземних мов, описано методичний аспект формування педагогічної толерантності у роботі зі студентами. Подано результати кількісного та якісного аналізу рівнів сформованості педагогічної толерантності на констатувальному і формувальному етапах педагогічного експерименту. Доведено ефективність авторської моделі за допомогою критерію однорідності «хі-квадрат». The results of the study on the formation of pedagogical tolerance of future teachers of foreign languages in primary school have been described in the article. In particular, the definition of pedagogical tolerance has been given, the concept of the model of its formation has been described, the stages of the pedagogical experiment have been defined, methods for diagnosing the level of formation of each component of pedagogical competence have been selected. The author's training, designed to prepare English teachers for classroom work with students in the framework of the research problem, has been described, appropriate educational and methodological materials have been selected, the interactive methods and forms of collaboration have been favored. Features of practical classes as the basic form of organization of educational activity of students have been characterized, their structural elements have been determined. The content component of the model of the formation of pedagogical tolerance has been described, namely, the content of the disciplines of the humanitarian cycle has been updated, the main educational load has been concentrated on the author's special course "Practice of tolerant English-language communication", its purpose has been determined, its content has been composed to develop students’ perception of pedagogical tolerance and basis for tolerant interaction in teaching, effective pedagogical conditions for the preparation of a competent and tolerant teacher of foreign languages have been created, methodological and content aspects of teaching tolerance have been outlined. The results of quantitative and qualitative analysis of the levels of the formation of pedagogical tolerance at different stages of the pedagogical experiment have been presented. The efficiency of the author's model has been proved.

Fault diagnosis is a crucial and challenging task in the automatic control of complex systems, whose efficiency depends on the diagnosability property of a system. Diagnosability describes the system property allowing one to determine with certainty whether a given fault has effectively occurred based on the available observations. However, this is a quite strong property that generally requires a high number of sensors. Consequently, it is not rare that developing a diagnosable system is too expensive. In this paper, we analyze a new discrete event system property called manifestability, that represents the weakest requirement on observations for having a chance to identify on line fault occurrences and can be verified at design stage. Intuitively, this property makes sure that a faulty system cannot always appear healthy, i.e., has at least one future behavior after fault occurrence observably distinguishable from all normal behaviors. Then, we prove that manifestability is a weaker property than diagnosability before proposing an algorithm with PSPACE complexity to automatically verify both properties. Furthermore, we prove that the problem of manifestability verification itself is PSPACE-complete. The experimental results show the feasibility of our algorithm from a practical point of view. Finally, we compare our approach with related work.

The two-component signal transduction system PhoP/PhoQ is an important regulator for stress responses and virulence in most Gram-negative bacteria, but characterization of PhoP/PhoQ in Shigella has not been thoroughly investigated. In the present study, we found that deletion of phoPQ (ΔphoPQ) from Shigella flexneri 2a 301 (Sf301) resulted in a significant decline (reduced by more than 15-fold) in invasion of HeLa cells and Caco-2 cells, and less inflammation (- or +) compared to Sf301 (+++) in the guinea pig Sereny test. In low Mg2+ (10 μM) medium or pH 5 medium, the ΔphoPQ strain exhibited a growth deficiency compared to Sf301. The ΔphoPQ strain was more sensitive than Sf301 to polymyxin B, an important antimicrobial agent for treating multi-resistant Gram-negative infections. By comparing the transcriptional profiles of ΔphoPQ and Sf301 using DNA microarrays, 117 differentially expressed genes (DEGs) were identified, which were involved in Mg2+ transport, lipopolysaccharide modification, acid resistance, bacterial virulence, respiratory, and energy metabolism. Based on the reported PhoP box motif [(T/G) GTTTA-5nt-(T/G) GTTTA], we screened 38 suspected PhoP target operons in S. flexneri, and 11 of them (phoPQ, mgtA, slyB, yoaE, yrbL, icsA, yhiWX, rstA, hdeAB, pagP, and shf-rfbU-virK-msbB2) were demonstrated to be PhoP-regulated genes based on electrophoretic mobility shift assays and β-galactosidase assays. One of these PhoP-regulated genes, icsA, is a well-known virulence factor in S. flexneri. In conclusion, our data suggest that the PhoP/PhoQ system modulates S. flexneri virulence (in an icsA-dependent manner) and stress responses of Mg2+, pH and antibacterial peptides.

Hybrid systems are complex systems that combine both discrete and continuous behaviors. Verifying behavioral or safety properties of such systems, either at design stage such as state reachability, diagnosability, and predictability or on-line such as fault detection and isolation, is a challenging task. Actually, computing the reachable set of states of a hybrid system is an undecidable matter due to the infinite state space of continuous systems. One way to verify those properties over such systems is by computing discrete abstractions and inferring them from the abstract system back to the original system. In this chapter, we are concerned with abstractions oriented towards hybrid systems diagnosability checking. Our goal is to create discrete abstractions in order to verify, at design stage, if a fault that would occur at runtime could be unambiguously detected in finite time (or within a given finite time bound for bounded diagnosability) by the diagnoser. This verification can be done on the abstraction by classical methods developed for discrete event systems, which provide a counterexample in case of non-diagnosability. The absence of such a counterexample proves the diagnosability of the original hybrid system. In the presence of a counterexample, the first step is to check if it is not a spurious effect of the abstraction and actually exists for the hybrid system, witnessing thus non-diagnosability. Otherwise, we show how to refine the abstraction, guided by the elimination of the counterexample, and continue the process of looking for another counterexample until either a final result is obtained or we reach an inconclusive verdict. We make use of qualitative modeling and reasoning to compute discrete abstractions and we define several refinement strategies. Abstractions as timed automata are particularly studied as they allow one to handle time constraints that can be captured at a qualitative level from the hybrid system.

Two series of copper tetraarylporphyrins containing β,β′-fused tetrabutano or tetrabenzo groups were synthesized and characterized as to their electrochemistry and spectroelectrochemistry in nonaqueous media. The examined compounds are represented as butano-(TpYPP)CuII and benzo-(TpYPP)CuII, where TpYPP is the porphyrin dianion and Y is a CH3, H or Cl substituent on the para-position of the four meso-phenyl rings of the compound. Each neutral porphyrin in the two series is ESR active and shows a typical d9 Cu(II) signal in frozen CH2Cl2 solution. Each Cu(II) porphyrin also undergoes two reversible one-electron reductions and two reversible one-electron oxidations in DMF or CH2Cl2 containing 0.1 M tetra-n-butylammonium perchlorate to give a π-anion radical and dianion upon reduction and a π-cation radical and dication upon oxidation. A third one-electron oxidation is also observed for butano-(TpYPP)Cu (Y = CH3 and H) and benzo-(TPP)Cu in PhCN and this process is assigned to the CuII/CuIII transition. The reversible half-wave potential for the first oxidation of each compound in both series is shifted negatively by about 500 mV as compared to E1/2 values for oxidation of the related copper tetraarylporphyrin without the four fused benzo or butano rings while smaller positive shifts of 60 and 300 mV are seen for reduction of the tetrabenzotetraarylporphyrins and tetrabutaotetraarylporphyrins, respectively, as compared to the same redox reactions of the related tetraarylporphyrins. The electrochemically measured HOMO–LUMO gap averages 1.76 ± 0.05 V for benzo-(TpYPP)CuII, 2.04 ± 0.06 V for butano-(TpYPP)CuII and 2.33 ± 0.03 for (TpYPP)Cu in CH2Cl2.

In this work, we have successfully synthesized ultrasmall Cu2O nanocrystals with uniform sizes through a solution-based method. By virtue of the ideal Cu2O building blocks, 2D or 3D Cu2O superstructures can be easily achieved by tailoring the assembly process. The results indicate that diethyl carbonate (DEC) plays a crucial role for controlled self-assembly of Cu2O nanoparticles into a range of superstructures. Interestingly, the aggregative growths of Cu2O nanocrystals in the self-assembly process are accompanied by oriented attachment and Ostwald ripening. Furthermore, Cu2O and Cu2O–Au 3D colloidal spheres can be also obtained by an emulsion-based bottom-up self-assembly strategy. The results show that, compared with pure Cu2O nanospheres, the as-obtained Cu2O–Au nanospheres exhibit remarkable photocatalytic activities in the photodegradation of methyl orange (MO).

Three series of cobalt tetraarylporphyrins were synthesized and characterized by electrochemistry and spectroelectrochemistry. The investigated compounds have the general formula (TpYPP)Co, butano(TpYPP)CoII, and benzo(TpYPP)CoII, where TpYPP represents the dianion of the meso-substituted porphyrin, Y is a CH3, H, or Cl substituent on the para position of the four phenyl rings, and butano and benzo are respectively the β- and β′-substituted groups on the four pyrrole rings of the compound. Each porphyrin undergoes one or two reductions depending upon the meso substituent and solvent utilized. Two irreversible reductions are observed for (TpYPP)CoII and butano(TpYPP)CoII in CH2Cl2 containing 0.1 M tetra-n-butylammonium perchlorate; the first leads to the formation of a highly reactive cobalt(I) porphyrin, which can then rapidly react with a solvent to give a CoIIICH2Cl as the product. Only one reversible reduction is seen for benzo(TpYPP)CoII under the same solution conditions, and the one-electron-reducti...

The two-component signal transduction system PhoP/PhoQ is an important regulator for stress responses and virulence in most Gram-negative bacteria, but characterization of PhoP/PhoQ in Shigella has not been thoroughly investigated. In the present study, we found that deletion of phoPQ (ΔphoPQ) from Shigella flexneri 2a 301 (Sf301) resulted in a significant decline (reduced by more than 15-fold) in invasion of HeLa cells and Caco-2 cells, and less inflammation (− or +) compared to Sf301 (+++) in the guinea pig Sereny test. In low Mg2+ (10 μM) medium or pH 5 medium, the ΔphoPQ strain exhibited a growth deficiency compared to Sf301. The ΔphoPQ strain was more sensitive than Sf301 to polymyxin B, an important antimicrobial agent for treating multi-resistant Gram-negative infections. By comparing the transcriptional profiles of ΔphoPQ and Sf301 using DNA microarrays, 117 differentially expressed genes (DEGs) were identified, which were involved in Mg2+ transport, lipopolysaccharide modification, acid resistance, bacterial virulence, respiratory, and energy metabolism. Based on the reported PhoP box motif [(T/G) GTTTA-5nt-(T/G) GTTTA], we screened 38 suspected PhoP target operons in S. flexneri, and 11 of them (phoPQ, mgtA, slyB, yoaE, yrbL, icsA, yhiWX, rstA, hdeAB, pagP, and shf–rfbU-virK-msbB2) were demonstrated to be PhoP-regulated genes based on electrophoretic mobility shift assays and β-galactosidase assays. One of these PhoP-regulated genes, icsA, is a well-known virulence factor in S. flexneri. In conclusion, our data suggest that the PhoP/PhoQ system modulates S. flexneri virulence (in an icsA-dependent manner) and stress responses of Mg2+, pH and antibacterial peptides.

Verifying behavioral or safety properties of hybrid systems, either at design stage such as state reachability and diagnosability, or on-line such as fault detection and isolation is a challenging task. We are concerned here with abstractions oriented towards hybrid systems diagnosability checking. The verification can be done on the abstraction by classical methods developed for discrete event systems extended with time constraints, which provide a counterexample in case of non-diagnosability. The absence of such a counterexample proves the diagnosability of the original hybrid system. In the presence of a counterexample, the first step is to check if it is not a spurious effect of the abstraction and actually exists for the hybrid system, witnessing thus non-diagnosability. Otherwise, we show how to refine the abstraction, guided by the elimination of the counterexample, and continue the process of looking for another counterexample until either a final result is obtained or we reach an inconclusive verdict. We make use of qualitative modeling and reasoning to compute discrete abstractions. Abstractions as timed automata are particularly studied as they allow one to handle time constraints that can be captured at a qualitative level from the hybrid system.

У статті розглянуто динаміку розвитку гендерних студій у сучасній вітчизняній та зарубіжній лінгвістиці. Усі сучасні студії умовно поділені на есенціалістський та антиесенціалістський напрями. З позицій першого напряму, мовлення є частиною соціальної ролі, у межах якої гендерна ідентичність як соціальна категорія передує її мовному вираженню. У контексті другого – гендер є продуктом дискурсу, відповідно, мовлення не визначається гендерною ідентичністю, а конструює її. Обидва напрями представлені лінгвістичними дослідженнями гендеру з позицій парадигм гомогенності, аналогії й гетерогенності. Кожна парадигма розглянута крізь призму певних теорій та підходів: фольклорлінгвістичного підходу, теорії дефіцитності, теорією домінування, теорією розбіжностей, теорією субкультур, теорія перформативності, теорія інтерактивності. Основну цікавість викликають конструювання гендерної ідентичності, тобто сконструйовані версії фемінності та маскулінності. The article focuses on the dynamics of the development of gender studies in modern native and foreign linguistics. All modern studies are conventionally divided into essentialistic and antiessentialistic concepts. According to the first concept speech is a part of the social role, within which gender identity as a social category takes priority over its language expression. As far as the second concept is concerned, gender is a discourse product, consequently speech is not defined by gender identity, but constructing it. Both concepts are represented by linguistic gender studies from the perspective of analogy paradigm, homogeneity paradigm and heterogeneity paradigm. Each paradigm is analyzed in the light of certain theories and approaches: folklinguistics, deficit approach, domination approach, subcultures approach, performative and interactive approaches. The point of real interest is gender identity constructing that is constructed versions of feminity and masculinity

A series of N-confused free-base meso-substituted tetraarylporphyrins was investigated by electrochemistry and spectroelectrochemistry in nonaqueous media containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) and added acid or base. The investigated compounds are represented as (XPh)4 NcpH2 , in which "Ncp" is the N-confused porphyrin macrocycle and X is a OCH3 , CH3 , H, or Cl substituent on the para position of each meso-phenyl ring of the macrocycle. Two distinct types of UV/Vis spectra are initially observed depending upon solvent, one corresponding to an inner-2H form and the other to an inner-3H form of the porphyrin. Both forms have an inverted pyrrole with a carbon inside the cavity and a nitrogen on the periphery of the π-system. Each porphyrin undergoes multiple irreversible reductions and oxidations. The first one-electron addition and first one-electron abstraction are located on the porphyrin π-ring system to give π-anion and π-cation radicals with a potential separation of 1.52 to 1.65 V between the two processes, but both electrogenerated products are unstable and undergo a rapid chemical reaction to give new electroactive species, which were characterized in the present study. The effect of the solvent and protonation/deprotonation reactions on the UV/Vis spectra, redox potentials and reduction/oxidation mechanisms is discussed with comparisons made to data and mechanisms for the structurally related free-base corroles and porphyrins.

A cobalt(III) corrole, represented as ( Cl2Ph )3CorCo ( PPh3), where ( Cl2Ph )3Cor is the trianion of 5,10,15-tri(2,4-dichlorophenyl)corrole, was synthesized and characterized as to its electrochemical and spectroelectrochemical properties. Single-crystal structure analysis showed the corrole to be monoclinic and have a space group P21/c with α = 13.441(3), b = 28.058(6), c = 27.584(6) Å, α = 90, β = 92.75(3), γ = 90°, Mr= 1144.38, V = 1039.1(4) Å3, Z = 8, Dc= 1.463 mg/cm3, μ = 0.816, F(000) = 4644, Rint= 0.0447, R(I > 4σ(I)) = 0.0769, wR(I > 4σ(I)) = 0.2104, R( all data ) = 0.1214 and wR( all data ) = 0.2705. The compound was also examined as a catalyst for the electroreduction of dioxygen when coated on an edge-plane pyrolytic graphite electrode in 1.0 M HClO4. Cyclic voltammetry and linear sweep voltammetry with a rotating disk electrode (RDE) or a rotating ring disk electrode (RRDE) were utilized to evaluate the catalytic activity of the corrole and elucidate the products of reduction, H2O or H2O2. Analysis of the data shows exclusively a two-electron transfer process to give 100% H2O2as the product and no H2O was detectable.

Two novel soluble chemosensors (L1, L2) modified by aza-crown ether groups have been synthesized by one-step facile reaction. The chemosensors were fully characterized by IR, 1H NMR, 13C NMR and MS spectra. The recognition abilities of two sensors with a range of metal ions were evaluated. The results showed that L1 was a specialized sensor for Cu2+ and L2 was a multi-functional sensor being able to recognize Al3+ and Cr3+ via two different optical behaviors, which demonstrated the subtle structural changes of sensors can have a remarkable effect on recognizing metal ions.

By self-assembly of (E)-2-(3-(4-(1H-imidazol-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L(1)) and (E)-2-(3-(4-(1H-1,2,4-triazol-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L(2)) with silver(I) salts, eight new complexes, namely AgL(1)2ClO4 (1), AgL(1)2NO3 (2), [AgL(1)2NO3]·C6H6 (3), [AgL(1)2OOCCF3]·C6H6 (4), [AgL(1)2PF6]·C6H6 (5), AgL(2)2NO3 (6), [AgL(2)OOCCF3]2 (7) and AgL(2)2PF6 (8), are presented along with an analysis of their structural features. The structures are built up through the combination of coordination bonds, Ag···π, Ag···F (or O), hydrogen bonding, and π···π stacking interactions to generate new supramolecular architectures. We observed the formation of two-dimensional coordination polymers for complex 7. Solvent benzene molecules and anions are dispersed in the supramolecular structure and play a vital role in building the supramolecular structures of the complexes. The nonlinear optical (NLO) properties of the complexes were investigated using the Z-scan technique and complexes 1, 2, 3, 4 and 7 show obviously nonlinear absorption compared with ligands (L(1) and L(2)).