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An efficient visible-light-promoted N-radical-mediated tandem radical cyclization/defluorinated alkylation of β,γ-unsaturated hydrazones, and α-trifluoromethyl alkenes is described. This protocol provides a general and effective route to synthesize various dihydropyrazole-fused gem-difluoroalkenes at moderate to excellent yields under redox-neutral, metal-free, and mild conditions.

Purpose This paper aims to focus on the variable stick force-displacement (SFD) gradience in the active side stick (ASS) servo system for the civil aircraft. Design/methodology/approach The problem of variable SFD gradience was introduced first, followed by the analysis of its impact on the ASS servo system. To solve this problem, a linear-parameter-varying (LPV) control approach was suggested to process the variable gradience of the SFD. A H∞ robust control method was proposed to deal with the external disturbance. Findings To validate the algorithm performance, a linear time-variant system was calculated to be used to worst cases and the SFD gradience was set to linear and non-linear variation to test the algorithm, and some typical examples of pitch angle and side-slip angle tracking control for a large civil aircraft were also used to verify the algorithm. The results showed that the LPV control method had less settling time and less steady tracking errors than H∞ control, even in the variable SFD case. Practical implications This paper presented an ASS servo system using the LPV control method to solve the problem caused by the variable SFD gradience. The motor torque command was calculated by pressure and position feedback without additional hardware support. It was more useful for the electronic hydraulic servo actuator. Originality/value This was the research paper that analyzed the impact of the variable SFD gradience in the ASS servo system and presented an LPV control method to solve it. It was applicable for the SFD gradience changing in the linear and non-linear cases.

An efficient visible-light-promoted N-radical-mediated tandem radical cyclization/defluorinated alkylation of β,γ-unsaturated hydrazones, and α-trifluoromethyl alkenes is described. This protocol provides a general and effective route to synthesize various dihydropyrazole-fused

Escherichia coli K1 is the most common Gram-negative bacteria causing neonatal meningitis. Polymorphonuclear leukocyte (PMN) transmigration across the blood-brain barrier (BBB) is the hallmark of bacterial meningitis. Reportedly, the deletion of virulence factor cglD (E44:ΔcglD) from E44 is responsible for a less efficient PMN transendothelial migration ability. In the present study, we found that complementation of the cglD gene into E44:ΔcglD mutant strain might restore the PMN count and myeloperoxidase level in a neonatal mouse meningitis. Using human brain microvascular endothelial cells (HBMECs), the main model of the BBB in vitro, we found that E44:ΔcglD mutant strain induced a less efficient PMN adhesion to HBMECs and down-regulated chemokines CXCL1, CXCL6 and CXCL8 and adhesion molecule E-selectin, compared with the E44 strain. Complementation of cglD restored the PMN adhesion to HBMECs and the level of these proteins. E44:ΔcglD mutant strain also induced a less efficient NF-κB pathway activation in HBMECs and reduced the soluble p65 (sp65) level in the cerebral spinal fluid of newborn mice, compared with the E44 strain. Complementation of cglD restored the NF-κB pathway activation and increased the sp65 levels. This suggests that cglD in E44 contributes to NF-κB pathway activation in the brain endothelium to promote PMN adhesion to HBMECs and transendothelial migration. Our identified novel requirement of cglD for immune activation and subsequent PMN entry into the central nervous system suggests that therapies directed at neutralising this molecule will be beneficial in preventing bacterial meningitis progression.

The Paleo-Asian Ocean (PAO) has been regarded as a long-lived ocean from Neoproterozoic to early Mesozoic, and its subduction and closure built the Central Asian Orogenic Belt (CAOB), the largest accretionary orogenic belt in Earth's history. Although the tectonic evolution of the PAO has been discussed from diverse perspectives, the spatiotemporal dynamics in the evolution of the main branch of the PAO and its relationship with the Tethys remain contentious partly because of the absence of sedimentary evidence. Specifically, as far as the Beishan Orogenic Collage (BOC) in the southernmost part of CAOB is concerned, there remain at least two key questions: how did the BOC evolve tectonically and paleogeographically through the late Paleozoic; and which ophiolitic belt represented the main branch of the PAO in the BOC? This study recognized 27 volcano-sedimentary microfacies and 14 facies associations (FAs) in nine measured Carboniferous–Permian sections from the southern BOC. FA changes in the Visean–Capitanian megasequence indicate a Visean–Moscovian regressive sequence from fore-reef slopes to tidal flats and an Artinskian–Wordian transgressive sequence from fan-deltas to abyssal plains, separated by a continental and volcanic sequence straddling the Gzhelian–Sakmarian interval. Characteristics and lateral correlation of FAs suggest an epicontinental sea during Visean–Moscovian times, followed by a marine rift basin which eventually developed into a proto-oceanic basin during the Artinskian–Wordian. Paleobiogeographic evidence further suggests that this epicontinental sea was closely linked with the Tethyan oceans. Statistical comparisons of detrital zircon ages based on data compiled from previous and the present studies supports that this sea was mainly fed from Neoproterozoic and Ordovician–Silurian rocks (ca. 983 and 425 Ma) with a sparse influx of Mesoproterozoic and Paleoproterozoic detritus (ca. 2492, 1449, and 1302 Ma). During the Artinskian–Wordian, the rift basin was connected with the PAO based on the mixed cool- and warm-temperate marine faunas of the Boreal and Tethyan realms. This rift basin is thought to have been fed by two source-to-sink provenance systems, from either Ordovician–Silurian or Early Permian rocks (ca. 450 or 277 Ma), although provenance signatures were mixed because of turbidity and other currents in deep marine environments. We thus propose a succession of Carboniferous–Permian paleogeographic reconstruction maps for the BOC based on FA correlation and paleobiogeographic features. In these reconstruction models, the PAO is inferred to have been composed of a main branch (an oceanic basin) in the northern BOC as a part of the North Tianshan–Hongshishan–Solonker–Hegenshan Ocean and an epicontinental sea that subsequently evolved into a marine rift basin in the southern BOC.

Exceedingly fast preparation of trifluoromethyl tertiary alcohols has been accomplished from methyl ketones and trifluoromethyl ketones under solvent free conditions by cross Aldol reaction. The reaction was achieved in the presence of common inorganic base by grinding method at ambient temperature to give β -trifluoromethyl- β -hydroxyl ketones in high yields (up to 95%).

Temperature is one of the critical factors affecting the performance of proton exchange membrane fuel cell (PEMFC). The temperature control of PEMFC mainly includes cold start and thermal management. A reasonable thermal management system and fast cold start method can effectively manage the temperature of fuel cell, improve its performance and prolong life. On the contrary, it is entirely possible to reduce the PEMFC tolerance, persistence and other output performance, even give rise to experimental safety accidents in serious cases. In this paper, research on the cold start and thermal management strategies of PEMFC is reviewed, and how to control the temperature of stack quickly and effectively is discussed while analyses and summary on the temperature control strategies are made.

Optimization of operating parameters on PEMFC to obtain maximum power has a significant role to reduce the costs of this emerging technology. In this study, the operation parameters of PEMFC are optimized by the orthogonal experiment method and Central composite second order Response Surface Methodology (RSM). Three significant parameters including cathode stoichiometry, anode stoichiometry and control voltage of hydrogen tail gas valve are studied to obtain an optimal cell power. Both two tests reveal that the effect of air stoichiometric ratio on PEMFC performance is the largest under the high current in the selected range, while the effect of control voltage of hydrogen tail gas valve is the least. With the comparison of orthogonal experiment method and RSM, the optimum results show that RSM can be more accurate to predict the maximum power and the optimal values of the operating parameters.

Levosimendan is a calcium sensitizer that enhances myocardial contractility without increasing myocardial oxygen use. Limited data are available on its renal-protective effect, and no statistically significant effects have been found. A meta-analysis was conducted for randomized studies to show whether perioperative levosimendan use could reduce acute kidney injury (AKI) in patients undergoing cardiac surgery.BioMed Central, PubMed EMBASE, and the Cochrane Central Register of Controlled Trials were searched for pertinent studies.Randomized trials that compared levosimendan versus placebo or any other control in cardiac surgery with data on AKI were included. Exclusion criteria were duplicate publications, nonadult studies, oral administration of levosimendan, and studies with no data on AKI.Study endpoints, study design, population, clinical setting, levosimendan dosage, and treatment duration were extracted.Data from 529 patients in 5 randomized trials were analyzed. The analysis showed that levosimendan decreased postoperative incidence of AKI in the levosimendan group.This analysis suggests that levosimendan might reduce renal injury in adult patients undergoing cardiac surgery. More prospective randomized studies are needed to further demonstrate the benefits of levosimendan on renal protection in cardiac surgery.

This paper introduces a design of a high-speed image acquisition system based on Avalon bus which is supported with SOPC technology. Some peripherals embedded in Avalon bus were customized and utilized in this system, such as imaging unit, decoding unit and storage unit, and these improved the speed of the whole imaging system. The data is compressed to three-fourths of the original by the decoding unit. A custom DMA is designed for moving the image data to the two caches of the SDRAM. This approach discards the method that FIFO must be put up in the traditional data acquisition system. And therefore, it reduced the CPU’s task for data moving. At the same time, the image acquisition and the data transmission can complete a parallel job. Finally, the design is worked on the high-speed image acquisition system which is made up of 2K*2K CMOS image sensor. And it improved the image acquisition speed by three ways: data encoding, custom DMA controller and the parallel processing.

To investigate the related factors and pathogens of ventilator-associated pneumonia (VAP) after heart surgery.VAP was diagnosed in 105 patients out of 1688 cases (6.2%) who underwent heart surgery in our department between January 2004 and January 2011. Clinical data, pathogens and treatments were analyzed.Incidence of VAP was 6.2% (105/1688), and 53.0% (105/198) in patients who required more than 48 hours of mechanical ventilation. One hundred and ninety-eight pathogen strains were isolated by bacterial culture, in which Gram negative bacteria accounted for 69.2% (137/198), Gram positive bacteria 27.8% (55/198), and fungi for 3.0% (6/198). Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus were the main pathogens of VAP. The independent risk factors for VAP were: age70 years, emergent surgery, perioperative transfusions, reintubation and days of mechanical ventilation (all P0.01). Median length of stay in the ICU for patients who developed VAP or not was (24.7 ± 4.5) days versus (3.2 ± 1.5) days, respectively (P0.05) and in-hospital mortality was 25.7% (27/105) versus 2.9% (46/1583) respectively (P0.05).Patients undergoing heart surgery have a high frequency of developing VAP, especially in patients that require more than 48 hours of mechanical ventilation. VAP is associated with high in-hospital mortality. Age70 years, emergent surgery, perioperative transfusions, reintubation and prolonged mechanical ventilation use are independent risk factors for VAP in patients following cardiac surgery. Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus are the main pathogens of VAP.