Light-Assisted Semi-Hydrogenation of 1,3-Butadiene with Water.

Sustainable processes for semi-hydrogenation of alkynes/alkadienes impurities in alkenes feedstocks are in great demand in industry as the utilization of excessive hydrogen, high temperature and unsatisfactory alkenes selectivity of the current thermo-catalytic route, however, their development is still challenging. Herein, we innovate a light-assisted semi-hydrogenation process in gas-feed fixed bed reactor, with water as hydrogen atom source by in situ photocatalysis. Using Pd/TiO2 as model catalyst, this process shows an excellent catalytic performance for the semi-hydrogenation of 1,3-butadiene, with 100 % of butenes selectivity at ≈99 % of conversion over 180 h of reaction at ambient temperature driven by 66 mW cm-2 of irradiation intensity. This light-driven, H2 -free, ambient temperature semi-hydrogenation process, with superior performance to that of thermocatalytic route, shows attractive to bring an evolution in industrial hydrogenation technology to an economical and safe way.

Fatal community-acquired bloodstream infection caused by Klebsiella variicola: A case report.

BACKGROUND: Klebsiella pneumoniae (K. pneumoniae) is an infective microorganism of worldwide concern because of its varied manifestations and life-threatening potential. Genetic analyses have revealed that subspecies of K. pneumoniae exhibit higher virulence and mortality. However, infections with Klebsiella subspecies are often misdiagnosed and underestimated in the clinic because of difficulties in distinguishing K. pneumoniae from its subspecies using routine tests. This case study reports the rapid and fatal effects of K. pneumoniae subspecies. CASE SUMMARY: A 52-year-old male patient was febrile and admitted to hospital. Examinations excluded viral and fungal causes along with mycoplasma/chlamydia and parasitic infections. Bacterial cultures revealed blood-borne K. pneumoniae sensitive to carbapenem antibiotics, although corresponding treatment failed to improve the patient's symptoms. His condition worsened and death occurred within 72 h of symptom onset from sepsis shock. Application of the PMseq-DNA Pro high throughput gene detection assay was implemented with results obtained after death showing a mixed infection of K. pneumoniae and Klebsiella variicola (K. variicola). Clinical evidence suggested that K. variicola rather than K. pneumoniae contributed to the patient's poor prognosis. CONCLUSION: This is the first case report to show patient death from Klebsiella subspecies infection within a short period of time. This case provides a timely reminder of the clinical hazards posed by Klebsiella subspecies and highlights the limitations of classical laboratory methods in guiding anti-infective therapies for complex cases. Moreover, this report serves as reference for physicians diagnosing similar diseases and provides a recommendation to employ early genetic detection to aid patient diagnosis and management.

lncRNA NEAT1 aggravates sepsis-induced lung injury by regulating the miR-27a/PTEN axis.

Sepsis is an acute inflammatory reaction and a cause of acute respiratory distress syndrome (ARDS). In the present study, we explored the roles and underlying mechanism of the lncRNA Nuclear enriched abundant transcript 1 (NEAT1) in ARDS. The expression levels of genes, proteins and pro-inflammatory cytokines in patients with ARDS, LPS-stimulated cells and septic mouse models were quantified using qPCR, western blotting and ELISA assays, respectively. The molecular targeting relationship was validated by conducting a dual-luciferase reporter assay. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. The cell cycle phase was determined by flow cytometry assay. The expression levels of NEAT1 and pro-inflammatory cytokines were higher in patients with ARDS and septic models than in controls. Knockdown of NEAT1 significantly increased cell proliferation and cycle progression and prolonged mouse survival in vitro and in vivo. Mechanistically, miR-27a was identified as a downstream target of NEAT1 and directly inhibited PTEN expression. Further rescue experiments revealed that inhibition of miR-27a impeded the promoting effects of NEAT1 silence on cell proliferation and cycle progression, whereas inhibition of PTEN markedly weakened the inhibitory effects of NEAT1 overexpression on cell proliferation and cycle progression. Altogether, our study revealed that NEAT1 plays a promoting role in the progression of ARDS via the NEAT1/miR-27a/PTEN regulatory network, providing new insight into the pathologic mechanism behind ARDS.

Unexplained elevation of erythrocyte sedimentation rate in a patient recovering from COVID-19: A case report.

BACKGROUND: A disease caused by a novel coronavirus virus, named coronavirus disease 2019 (COVID-19), broke out in Wuhan, China in December 2019, and spread around the word. As of March 4, 2020, 93090 confirmed cases and 2984 deaths have been reported in more than 80 countries and territories. It has triggered global public health security. However, the features and prognosis of COVID-19 are incompletely understood. CASE SUMMARY: We here report that the erythrocyte sedimentation rate (ESR) increased in a confirmed COVID patient. The high level of ESR sustained for a long time even after the patient recovered from COVID-19, while all results related to tumor, tuberculosis, rheumatic diseases, anemia, etc. cannot explain the abnormal elevation of ESR presented in this case. CONCLUSION: Although the increased ESR cannot be explained by all existing evidence, it possibly links the abnormal pathologic change in some COVID-19 patients and negative prognosis, and provides the clue to dissect the mechanism of illness progressing in COVID-19 and its prognosis.

Mesoscopic Detection of the Influence of a Third Component on the Self-Assembly Structure of A2B Star Copolymer in Thin Films.

The most common self-assembly structure for A2B copolymer is the micellar structure with B/A segments being the core/corona, which greatly limits its application range. Following the principle of structure deciding the properties, a reformation in the molecular structure of A2B copolymer is made by appending three segments of a third component C with the same length to the three arms, resulting (AC)2CB 3-miktoarm star terpolymer. A reverse micellar structure in self-assembly is expected by regulating the C length and the pairwise repulsive strength of C to A/B, aiming to enrich its application range. Keeping both A and B lengths unchanged, when the repulsion strength of C to A is much stronger than C to B, from the results of mesoscopic simulations we found, with a progressive increase in C length, (AC)2CB terpolymer undergoes a transition in self-assembled structures, from a cylindrical structure with B component as the core, then to a deformed lamellar structure, and finally to a cylindrical structure with A component as the core. This reverse micellar structure is formed with the assistance of appended C segments, whose length is longer than half of B length, enhancing the flexibility of three arms, and further facilitating the aggregation of A component into the core. These results prove that the addition of a third component is a rational molecular design, in conjunction with some relevant parameters, enables the manufacturing of the desired self-assembly structure while avoiding excessive changes in the involved factors.

Solvent Effect on the Self-Assembly of a Thin Film Consisting of Y-Shaped Copolymer.

The self-assembly of an amphiphilic Y-shaped copolymer consisting of two hydrophilic branches and one hydrophobic branch in a thin film is investigated under different conditions by virtue of mesoscopic computer modelling, accompanied by doping with a single solvent, doping with a binary solvent, and those solvent environments together with the introduction of confinement defined by various acting distances and influencing regions. A cylindrical micellar structure is maintained, as it is in the thin film with the doping of either 10% hydrophobic solvent or 10% hydrophilic solvent, whose structure consists of the hydrophobic core and hydrophilic shell. Attributed to the hydrophobicity/hydrophilia nature of the solvents, different solvents play an obvious role on the self-assembled structure, i.e., the hydrophobic solvent presents as a swelling effect, conversely, the hydrophilic solvent presents as a shrinking effect. Further, the synergistic effect of the binary solvents on the self-assembly produces the lowest values in both the average volumetric size and free energy density when the quantity of hydrophobic solvent and hydrophilic solvent is equivalent. Interestingly, the solvent effect becomes more pronounced under the existent of a confinement. When a lateral-oriented confinement is introduced, a periodically fluctuating change in the cylindrical size occurs in two near-wall regions, but the further addition of either hydrophobic or hydrophilic solvent can effectively eliminate such resulting hierarchical-sized cylinders and generate uniform small-sized cylinders. However, with the introduction of a horizontal-orientated confinement, the copolymers self-assemble into the spherical micellar structure. Moreover, the further addition of hydrophobic solvent leads to a decrease in the average size of micelles via coalescence mechanism, in contrast, the further addition of hydrophilic solvent causes an increase in the average size of micelles via splitting mechanism. These findings enrich our knowledge of the potential for the solvent effect on the self-assembly of amphiphilic copolymer system, and then provide theoretical supports on improving and regulating the mesoscopic structure of nanomaterials.

Automatic emissive probe apparatus for efficient plasma potential measurements.

The improved inflection point method of emissive probe is the most accurate method for plasma potential measurements, but its manual operation is quite cumbersome and time-consuming. This paper describes the design and test of an automatic emissive probe apparatus for efficient plasma potential measurements. The apparatus consists of a computer controlled data acquisition (DAQ) card, a working circuit composed of a biasing unit and a heating unit, as well as the emissive probe. The main feature of the apparatus is that both the biasing scan and the heating scan of the probe are controlled by the computer program through analog outputs of the DAQ card, which easily realizes the required timing between the biasing and heating scans of the probe. The apparatus can automatically execute the improved inflection point method of emissive probe and give the plasma potential result. The advantages of high-accuracy, high-efficiency, and durability of probe filament make the apparatus promising for extensive use in plasma potential measurements.

Self-assembled morphologies of an amphiphilic Y-shaped weak polyelectrolyte in a thin film.

Different from the self-assembly of neutral polymers, polyelectrolytes self-assemble into smaller aggregates with a more loosely assembled structure, which results from the repulsive forces acting between similar electrical compositions with the introduction of ions. The Y-shaped weak polyelectrolytes self-assemble into a core-shell type cylindrical structure with a hexagonal arrangement in a thin film, whose thickness is smaller than the gyration radius of the polymer chain. The corresponding formation mechanism consists of enrichment of the same components, adjustment of the shape of the aggregate, and the subsequent separation into individual aggregates. With the increase in the thickness of the thin film until it exceeds the gyration radius of the polymer chain, combined with the greater freedom of movement along the direction of thin film thickness, the self-assembled structure changes into a micellar structure. Under confinement, the repulsive force to the polymeric components is weakened by the repulsive forces among polyelectrolyte components with like charges, and this helps in generating aggregates with more uniform size and density distribution. In particular, when the repulsive force between the walls and the core forming components is greater than that between the walls and the shell forming components, such asymmetric confinement produces a crossed-cylindrical structure with nearly perpendicular arrangement of two cylinder arrays. Similarly, a novel three-crossed cylinder morphology is self-assembled upon removal of confinement.

One-dimensional Confinement Effect on the Self-assembly of Symmetric H-shaped Copolymers in a Thin Film.

The self-assembly of a reformed symmetric H-shaped copolymer with four hydrophilic branches and one hydrophobic stem was systematically investigated. The existence of vacancies is vital to regulate the sizes of self-assembled cylinders to be able to form a hexagonal arrangement. With the introduction of horizontal-orientated confinement, a micellar structure is formed through a coalescence mechanism. The short acting distance and large influencing area of the confinement produces numerous small-sized micelles. Additionally, the cycled "contraction-expansion" change helps achieve hexagonal arrangement. In contrast, the introduction of lateral-oriented confinement with long acting distance and small influencing area cannot change the cylindrical structure. Under the fission mechanism, in which the larger cylinder splits into smaller ones, it is quite efficient to generate hierarchical-sized cylinders from larger-sized cylinders in the middle region and smaller-sized cylinders near both walls. The results indicate the possibility of regulating the characteristics of a nanomaterial by tuning the molecular structure of the copolymer and the parameters of the introduced confinement, which are closely related to the self-assembly structure.

The expression of microRNA-324-3p as a tumor suppressor in nasopharyngeal carcinoma and its clinical significance.

OBJECTIVE: This study aimed to determine the expression, clinical significance, and possible biologic function of microRNA-324-3p in nasopharyngeal carcinoma (NPC) tissues. METHODS: In total, 54 NPC and 35 control tissues were collected. The correlation between miR-324-3p expression and the clinicopathologic characteristics was analyzed. A dual-luciferase reporter gene assay was employed to examine the predicted target gene of miR-324-3p. The miR-324-3p expression level in 5-8F cells was determined with quantitative reverse transcription-polymerase chain reaction following the transfection of miR-324-3p mimics and inhibitors. Cell proliferation and the percentage of apoptosis were measured with MTT and flow cytometry. Cell invasion ability was assessed by Transwell invasion assay. RESULTS: Our results showed that miR-324-3p was downregulated in the NPC tissues. The expression level of miR-324-3p in poorly differentiated NPC was significantly reduced in comparison with that in well/moderately differentiated NPC. The expression level in clinical stages III/IV was lower than that in clinical stages I/II. Moreover, the expression level of miR-324-3p was significantly lower in NPC patients with lymph node metastasis than that in NPC patients without lymph node metastasis. NPC patients with higher levels of miR-324-3p expression also demonstrated a longer survival time. Predictions from bioinformatics indicated the Hedgehog pathway transcription gene GLI3 as the target gene of miR-324-3p, and the dual- luciferase reporter assay showed that miR-324-3p is directly combined with the 3'-untranslated region of GLI3. The overexpression of miR-324-3p suppressed cell proliferation and invasion, and it enhanced apoptosis in 5-8F cells. CONCLUSION: miR-324-3p can act as a tumor suppressor in NPC cells by the negative regula- tion of GLI3 gene.

Mechanistic investigations of confinement effects on the self-assembly of symmetric amphiphilic copolymers in thin films.

The self-assembly of a copolymer thin film, whose molecular structure is composed of one hydrophobic branch and two hydrophilic branches, gives a cylindrical structure consisting of a hydrophobic core and a hydrophilic outer surface. The confinement-induced loss of entropy leads the copolymer to self-assemble into a hexagonal arrangement of cylindrical structures. This hexagonal arrangement is of two induced self-assembly structures under one-dimensional confinement in thin films, i.e., micellar structures with uniform density of an individual core, as well as lamellar structures with two separated hydrophobic layers and one hydrophilic layer. When the repulsive force of the confinement is greater for the hydrophobic polymeric component than for the hydrophilic polymeric component, the self-assembled density of the cores is broad. A proportional change in the individual volume suggests interactions between the walls and the hydrophobic core, which plays a vital role in the formation of the self-assembled structure. A basic understanding of the one-dimensional confinement investigated in this study serves to elucidate the more complex two- and three-dimensional confinements and provides further insights for the design of nanomaterials with novel morphologies.

Mesoscopic simulation of the self-assembly of the weak polyelectrolyte poly(ethylene oxide)-block-poly(methyl methacrylate) diblock copolymers.

We designed twelve types of weak polyelectrolytes (i.e., PEO-b-PMMA copolymers (BCP) in multi-arm structures, where six include EO blocks as joint points and the other six have MMA blocks as joint points). All of the BCPs with EO as the joint points form disordered phases with the exception of long-chained and four-armed BCP. The main mesophases of all of the BCPs with MMA as joint points are micelle-like and bicontinuous phases. In particular, the short-chained BCP with four-arms and EO segments outside form a new phase type (i.e., crossed lamellar phase). Using MesoDyn, we provide a comprehensive representation of the micelle and crossed lamellar phase formation mechanisms based on both thermodynamic and dynamic analyses. A shear force on a micelle-like phase could promote a hexagonal columnar phase, which is a good technique for generating an ordered arrangement of nanotube arrays. Blending homopolymers with the same constituents could promote uniformity of the micelle size and decrease the polydispersity, especially for blends with a high BCP concentration, which may provide a new approach for regulating the properties of materials.

Mesoscale simulation of the formation and dynamics of lipid-structured poly(ethylene oxide)-block-poly(methyl methacrylate) diblock copolymers.

Twelve poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA) copolymers with lipid-like structures were designed and investigated by MesoDyn simulation. Spherical and worm-like micelles as well as bicontinuous, lamellar and defected lamellar phases were obtained. A special structure, designated B2412, with two lipid structures connected by their heads, was found to undergo four stages prior to forming a spherical micelle phase. Two possible assembly mechanisms were found via thermodynamic and dynamic process analyses; namely, the fusion and fission of micelles in dynamic equilibrium during the adjustment stage. Water can be encapsulated into these micelles, which can affect their size, particularly in low concentration aqueous solutions. The assignment of weak negative charges to the hydrophilic EO blocks resulted in a clear effect on micelle size. Surprisingly, the largest effect was observed with EO blocks with -0.5 e, wherein an ordered perfect hexagonal phase was formed. The obtained results can be applied in numerous fields of study, including adsorption, catalysis, controlled release and drug delivery.

Morphology of lipid-like structured weak polyelectrolyte poly(ethylene oxide)-block-poly(methyl methacrylate) diblock copolymers induced by confinements.

Combined with quantum calculations and mesoscale simulations, the self-assembly of twelve lipid-structured PEO-b-PMMA copolymers (BCPs) with six types of molecular topologies was investigated. The BCPs with MMA species as the connecting center of the other arms present ample mesoscale structures, such as micelles and lamellae or curved lamellar phases, and even macrophase separation occurs for the long-chained BCPs. The excluded volume effect of confinements helps form vesicle-like structures, which proved to be a possible method of confinement to regulate phase morphologies or segment distributions and, ultimately, the properties of materials. An analysis of the phase formation process of short-chained BCP with two hydrophilic EO segments and one hydrophobic MMA segment indicated that four stages were found in both neutral and non-neutral wall confinement, all of which present a hexagonal columnar phase. Surprisingly, when the repulsion effect of the wall to the EO segment is greater than that of the MMA segment, such BCP self assembles into a crossed columnar phase, and the intersection angle of the orientation of these two sets of cylinder arrays is 75 degrees, which can be used to produce heterogeneous nanotube arrays. For the short-chained BCP with four arms joined at MMA species and EO segments in the outer region, we found a novel method of exchanging the repulsive preference of the wall to the EO or MMA species that can control the adsorption or desorption of the lamellar phase with the interval of EO or MMA segments.

Bis[5-(pyridin-2-yl-κN)tetra-zolido-κN (1)]copper(II).

In the title complex, [Cu(C6H4N5)2], the Cu(II) ion lies on an inversion center and is coordinated by two chelating 5-(pyridin-2-yl)tetra-zolide ligands in a slightly distorted square-planar coordination geometry. In the crystal, π-π stacking inter-actions, with centroid-centroid distances in the range 3.4301 (14)-3.4387 (13) Å, link the complex mol-ecules along [101].

[Protective effect of ulinastatin on pulmonary function after cardiopulmonary bypass].

OBJECTIVE: To investigate the effects of Ulinastatin with different doses on pulmonary protection after cardiopulmonary bypass (CPB). METHODS: Ninety patients after CPB were brought into this study and divided into low doses Ulinastatin group (L group, n=30, 5 000 U/kg), high doses Ulinastatin group (H group, n=30, 20 000 U/kg) and control group (C group, n= 30), respectively. When the patients were transferred into ICU after CPB, Ulinastatin was given intravenously to those in L and H group, while saline was given in C group. Blood samples were harvested at the time before the treatments (T0) and 12 hours (T1), 24 hours (T2) after the treatments, for the measurements of arterial pressure of oxygen (PaO2), arterial pressure of carbon monoxide (PaCO2),difference of alveoli-arterial oxygen pressure (PO(2A), oxygenation index (Ol),and tumor necrosis factor-alpha (TNF-alpha) level. Pulmonary dynamic compliance (Cd), plat pressure (Pplat) and peak pressure (Ppeak) were determined at the time of To and wean (Tw). The durations of ventilation and intubation were recorded. RESULTS: At T0, the levels of PaO2, PaCO2, PO2A-a, OI and TNF-alpha in each group showed no significantly difference (P> 0. 05). At T1 and T2, the patients in H group had higher levels of PO2, PO2A-a. and OI, lower level of TNF-alpha, shorter duration of ventilation and intubation than the patients in other two groups(P<0. 05). The parameters in L group were better than those in C group, but the differences were not stastically significant (P>0. 05). There was no significantly difference in the levels of Cd, Pplat, and Ppeak at T0 and Tw between any two groups (P>0. 05). The intubation and ventilation time in H group were shorter than that in L and C group (P<0. 05). CONCLUSION: The application of Ulinastatin could achieve pulmonary protective effect after CPB, and it seems the effect could be better with high dose (20 000 U/kg) of Ulinastatin.

Effects of nanoparticles on the compatibility of PEO-PMMA block copolymers.

The compatibility of six kinds of designed poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA) copolymers was studied at 270, 298 and 400 K via mesoscopic modeling. The values of the order parameters depended on both the structures of the block copolymers and the simulation temperature, while the values of the order parameters of the long chains were higher than those of the short ones; temperature had a more obvious effect on long chains than on the short ones. Plain copolymers doped with poly(ethylene oxide) (PEO) or poly(methyl methacrylate) (PMMA) homopolymer showed different order parameter values. When a triblock copolymer had the same component at both ends and was doped with one of its component polymers as a homopolymer (such as A5B6A5 doped with B6 or A5 homopolymer), the value of its order parameter depended on the simulation temperature. The highest order parameter values were observed for A5B6A5 doped with B6 at 400 K and for A5B6A5 doped with A5 at 270 K. A study of copolymers doped with nanoparticles showed that the mesoscopic phase was influenced by not only the properties of the nanoparticles, such as the size and density, but also the compositions of the copolymers. Increasing the size of the nanoparticles used as a dopant had the most significant effect on the phase morphologies of the copolymers.

Modeling and analysis of the compatibility of polystyrene/poly(methyl methacrylate) blends with four inducing effects.

The compatibility of polystyrene (PS) and poly(methyl methacrylate) (PMMA) blends was studied over a wide range of compositions at 383, 413 and 443 K, respectively, by atomistic and mesoscopic modeling. All the calculated Flory-Huggins interaction parameters showed positive values; furthermore, they were all above the critical Flory-Huggins interaction parameter value, which means that the PS/PMMA blends were immiscible. Both the addition of a block copolymer and the introduction of a shear field influenced the phase morphologies of the blends, while the degree of influence depended on the compositions of the blends. The study of PS/PMMA blends doped with nanoparticles showed that the mesoscopic phase was influenced by not only the properties of the nanoparticles, such as their size, number and number density, but also the compositions of the blends. The effect of the surface roughness of the planes on the phase separation of the blends was also studied.

[Detection of metal residue in aqueous solutions by electrolyte cathode atmospheric glow discharge emission spectroscopy].

Toxic metal elements in waters and wastewaters contaminate the environment and greatly threaten the health of human beings, therefore developing a rapid monitor for metal residues in aqueous solutions is urgently required. In the present work, a new homemade apparatus of electrolyte cathode atmospheric glow discharge emission spectroscopy was developed and described. It can detect and discriminate many kinds of trace mental elements by atomic emission spectrum from atmospheric pressure liquid cathode glow discharge. In order to estimate the analytical performance of the present atmospheric pressure electrolyte cathode glow discharge emission spectroscopy system, the detection limit values for Na, Li, Cu, Pb and Mn were obtained based on 3sigma of the background signal, and the current limits of detection were 0.008, 0.005, 1.1, 2.06 and 1.95 mg L(-1), respectively. It demonstrates that the atmospheric pressure electrolyte cathode glow discharge emission spectroscopy has a promising application in real time measurements of metal residues in aqueous solutions.

[Characterization of an atmospheric pressure DC microplasma jet].

In the present work, a simply designed and easy made micrometer plasma jet device operating under atmospheric pressure was characterized. The microplasma jet operates in many kinds of working gas at atmospheric pressure, such as Ar, He, N2 etc, and is powered by a direct current power source. It can generate high current density glow discharge. In order to identify various excited species generated by the direct current microplasma jet device, the optical emission spectra of the jet with argon or nitrogen as working gas were studied. Based on the optical emission spectroscopy analysis of argon microplasma jet, the electron excitation temperature was determined to be about 3 000 K by the intensity ratio of two spectral lines. It is much lower than the electron excitation temperature of atmospheric pressure plasma torch, and hints that the atmospheric pressure direct current microplasma jet is cold compared with the atmospheric pressure plasma torch. The emission spectra of the N2 second positive band system were used to determine the vibrational temperature of the atmospheric pressure direct current microplasma jet. The experimental result shows that the molecular vibrational temperature of N2 is about 2 500 K. The electron density of the microplasma jet is about 10(13) cm(-3), which can be estimated from the electrical parameters of the discharge in the microplasma jet. A simple example of application of the microplasma jet is given. General print paper surface was modified with the microplasma jet and afterwards a droplet test was carried out. It was shown that the microplasma jet is more efficient in changing the hydrophilicity of general print paper.