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Avian pathogenic Escherichia coli (APEC) causes persistent infection of poultry and multi-system diseases, which seriously endanger the development of the poultry industry. Biofilm allows bacteria to adapt to the natural environment and plays an important role in resistance to the external environment and the pathogenicity of APEC, but the mechanism of its formation and regulatory network have not been clarified. In this study, we used a Tn5 transposon random mutation library constructed with APEC and identified ydiF, a gene that has not previously been recognized in E. coli biofilm formation. To confirm that the ydiF gene really can regulate the formation of APEC biofilm, the ydiF gene deletion strain was constructed using APEC81. Protein association networks prediction results show that ydiF is mainly associated with genes related to the metabolism of sugars and fatty acids. Deletion of the ydiF gene significantly reduces the formation of APEC biofilm and scanning electron microscopy indicated that the degree of adhesion between the bacteria was also reduced. The deletion of the ydiF gene also significantly reduced the motility of APEC81 and through transmission electron microscopy APEC81 was observed to have significantly fewer flagella. However, the colony morphology of APEC81 on Congo red and Coomassie brilliant blue media was unaffected. The results of fluorescence quantification showed that the deletion of the ydiF gene caused a down-regulation in the transcription of genes related to the second messenger, sugar metabolism, and quorum sensing. These results indicate that ydiF plays an important role in biofilm formation and the movement of APEC. In addition, it may be possible to regulate the formation of APEC biofilms by different methods such as by regulating the second messenger and metabolic system.

Avian pathogenic

Avian pathogenic Escherichia coli (APEC) is the main pathogens that inflict the poultry industry. Biofilm as the pathogenic factors of APEC, which can enhance the anti-host immune system of APEC and improve its survival in the environment. In order to screen new genes related to APEC biofilm. The APEC strain APEC81 was used to construct a mutant library by Tn5 insertion mutagenesis. Moreover the 28 mutant strains with severely weakened biofilm were successfully screened from 1500 mutant strains by crystal violet staining, in which 17 genes were obtained by high-efficiency thermal asymmetric interlaced PCR (HiTAIL-PCR). The reported genes including 3 flagella genes (fliS, fliD, fliR), 4 curli fimbriae genes (csgD, csgA, csgF, csgG) and 3 type 1 fimbriae genes (fimA, fimD, fimC). The novel genes including 3 coenzyme genes (gltA, bglX, mltF) and 4 putative protein genes (yheE, 07045, 11735, 11255). To investigate whether these 17 genes co-regulate the biofilm, the 17 identified genes were deleted on APEC strain APEC81. The result shown that except for the 11735 and 11255 genes, the deletion of 15 genes significantly reduced the biofilm formation ability of APEC81 (P csgD, csgA, csgF, csgG) and other functional genes (fimC, glxK, yehE, 07045, 11255) affected the colony morphology. Particularly, the hypothetical protein YehE had the greatest influence on the biofilm. It was predicted to have the same structure as type 1 fimbria protein. When yehE was deleted, the fimE transcription was up-regulated, fimA and fimB transcription were down-regulated, resulting in a decrease in type 1 fimbriae. Hence the yehE mutant significantly reduced the biofilm and the adhesion and invasion ability to cells (P gltA, bglX, mltF, yheE, 07045) related to biofilm formation and confirmed that yehE affects biofilm formation by type 1 fimbriae, which will benefit for further study mechanism of biofilm regulation in APEC.

Aims To study the effects of environmental stress and nutrient conditions on biofilm formation of avian pathogenic Escherichia coli (APEC). Methods and Results The APEC strain DE17 was used to study biofilm formation under various conditions of environmental stress (including different temperatures, pH, metal ions, and antibiotics) and nutrient conditions (Luria-Bertani [LB] and M9 media, with the addition of different carbohydrates, if necessary). The DE17 biofilm formation ability was strongest at 25°C in LB medium. Compared to incubation at 37°C, three biofilm-related genes (csgD, dgcC, and pfs) were significantly upregulated and two genes (flhC and flhD) were downregulated at 25°C, which resulted in decreased motility. However, biofilm formation was strongest in M9 medium supplemented with glucose at 37°C, and the number of live bacteria was the highest as determined by confocal laser scanning microscopy. The bacteria in the biofilm were surrounded by a thick extracellular matrix, and honeycomb-like or rough surfaces were observed by scanning electron microscopy. Moreover, biofilm formation of the DE17 strain was remarkably inhibited under acidic conditions, whereas neutral and alkaline conditions were more suitable for biofilm formation. Biofilm formation was also inhibited at specific concentrations of cations (Na+, K+, Ca2+, and Mg2+) and antibiotics (ampicillin, chloramphenicol, kanamycin, and spectinomycin). The real-time quantitative reverse transcription PCR showed that the transcription levels of biofilm-related genes change under different environmental conditions. Conclusions Nutritional and environmental factors played an important role in DE17 biofilm development. The transcription levels of biofilm-related genes changed under different environmental and nutrient conditions. Significance and Impact of the Study The findings suggest that nutritional and environmental factors play an important role in APEC biofilm development. Depending on the different conditions involved in this study, it can serve as a guide to treating biofilm-related infections and to eliminating biofilms from the environment.

Avian pathogenic

The steady-state photoluminescence (PL) of CsPbBr3 films with varying thicknesses was studied under light-soaking on semiconductive and insulating contacts, showing reversible changes in PL, entirely dependent on the nature of the contact and film thicknesses. The PL at 50–100 nm CsPbBr3 on TiO2 increased, and decreased in thicker layers, with no thickness-dependent PL in CsPbBr3 on glass/Al2O3. These observations are described using a spatial charge distribution model which interprets the migration of Br– and VBr+ under light-soaking as suppressing electron injection into the TiO2 due to upward band bending, enhancing PL at the interface and nonradiative recombination further away from it.

Background: Evidence is currently accumulating for the role of inflammation in cerebral venous thrombosis (CVT). Neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/high-density lipoprotein ratio (MHR), and systematic immune-inflammation index (SII) are easily obtainable indicators of systemic inflammations. However, there were few studies on the relationship between them and CVT. Therefore, we aimed to evaluate the connection between the occurrence of CVT and the inflammatory markers described. Methods: The samples from 150 participants (including 90 CVT and 60 controls) with similar baseline characteristics were collected in this retrospective study. The NLR, PLR, MHR, SII and file records were employed to compare CVT patients with the control group.Results: The levels of NLR (3.93 [2.27, 7.87] vs. 1.65 [1.31, 2.06], P < 0.001), PLR (149.52 [98.39, 198.82] vs. 107.34 [83.31, 129.47], P < 0.001), SII (382.45 [273.51, 520.92] vs. 896.84 [559.89, 1591.87], P < 0.001) and MHR (0.51 [0.40, 0.64] vs. 0.41 [0.29, 0.53], P = 0.001) were significantly higher in the CVT group. After multivariate logistic regression analysis, the SII degree (13.136, [5.675, 30.407], P < 0.001) and MHR degree (2.620, [1.123, 6.113], P = 0.026) were found as independent predictors of CVT.Conclusions: NLR, PLR, SII, and MHR may be able to predict the onset of CVT which confirmed that inflammation played an important role in CVT.

The antibiotic residues and pathogenic resistance against the drug are very common in poultry due to usage of antibiotics in their feed. It is the need of the time to use natural feed additives as effective alternatives instead of synthetic antibiotic. The aim of this study was to investigate the immune response of Nigella sativa and Curcuma longa in broilers under biological stress against Pasteurella multocida. The total 100, one-day old chicks were divided into 5 groups. The Groups 1 and 2 were served as control negative and control positive. Both control groups were receiving simple diet without any natural feed additives but infection was given in Group 2 at day 28 with the dose of 5.14×107 CFU by IV. Groups 3A & 3B were offered 2% seed powder of Nigella sativa, Groups 4A & 4B were offered Curcuma longa 1% in powdered form and Group 5A & 5B were offered both Curcuma longa 1% & Nigella sativa 2% in feed from day 1 and groups 3B, 4B and 5B were challenged with Pasteurella multocida. The Haemagglutination inhibition titter against Newcastle Disease Virus (NDV), feed conversion ratio, mortality, gross and histopathology were studied. The results of this study revealed that haemagglutination inhibition titers against NDV were highly significant (P< 0.05) in treated groups, highest titers (3A 6.8, 3B 6.4 and 5A 7.2) were obtained from treated Group. The feed conversion ratio (FCR) of Nigella sativa + Curcuma longa treated Groups (5A 1.57 and 3A 1.76) were higher as compared to other non-treated groups. The gross and histopathological changes were much severe in control positive, but less changes were seen in treated groups. Therefore, we recommend that natural feed additives; black cumin (Nigella sativa) and turmeric (Curcuma longa) act as immune enhancer in broilers against Pasteurella multocida.

Dye Sensitized Solar Cells (DSCs) have achieved high power conversion efficiencies at a low cost. However, high stability remains an issue that impedes their commercialization and their degradation mechanisms are still under debate. In this study, we focus on accelerated thermal stressing of industrial DSCs at 85 °C for up to 290 h. The overall reduction of the DSCs efficiency (η) under this harsh stress is relatively small (about 20%) due to nearly 10% decrease in the Short Circuit Current (Jsc) and Open Circuit Voltage (Voc) and mainly occurs in the initial stage (within the first 54 h). The ageing mechanism is studied by combining the electrical, dc (J-V) and ac (impedance) characterization of the cells with their in-situ spectroscopic analysis under bias by micro-Raman. A sharp decrease in the recombination resistance at the sensitized photoelectrode/electrolyte interface is identified for the aged cell which is ascribed to trapping of triiodide species in the photoelectrode and accounts for the Voc drop of the cells. Jsc reduction could be justified by mitigation in the electron collection efficiency.

Background Evidence is currently accumulating for the role of inflammation in cerebral venous thrombosis (CVT). Neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/high-density lipoprotein ratio (MHR), and systematic immune-inflammation index (SII) are easily obtainable indicators of systemic inflammations. However, there were few studies on the relationship between them and CVT. Therefore, we aimed to evaluate the connection between the occurrence of CVT and the inflammatory markers described. Methods The samples from 150 participants (including 90 CVT and 60 controls) with similar baseline characteristics were collected in this retrospective study. The NLR, PLR, MHR, SII and file records were employed to compare CVT patients with the control group. Results The levels of NLR (3.93 [2.27, 7.87] vs. 1.65 [1.31, 2.06], P P P P = 0.001) were significantly higher in the CVT group. After multivariate logistic regression analysis, the SII degree (13.136, [5.675, 30.407], P P = 0.026) were found as independent predictors of CVT. Conclusions NLR, PLR, SII, and MHR may be able to predict the onset of CVT which confirmed that inflammation played an important role in CVT.

In this Letter, we systematically explore the influence of TiO2 thickness with nanometric variations over a range of 20–600 nm on the photovoltaic parameters (open-circuit voltage, short circuit current, fill-factor, and power conversion efficiency) of CH3NH3PbI3-based solar cells. We fabricate several sample libraries of 13 × 13 solar cells on large substrates with spatial variations in the thickness of the TiO2 layers while maintaining similar properties for the other layers. We show that the optimal thickness is ∼50 nm for maximum performance; thinner layers typically resulted in short-circuited cells, whereas increasing the thickness led to a monotonic decrease in performance. Furthermore, by assuming a fixed bulk resistivity of TiO2, we were able to correlate the TiO2 thickness to the series and shunt resistances of the devices and model the variation in the photovoltaic parameters with thickness using the diode equation to gain quantitative insights.

High-resistance grounding (HRG) is preferred in many industrial applications where the operation continuity is critical under ground fault conditions, such as pulp, paper, oil refining, chemical, glass, and metal industries. This is due to: 1) continuity of service; 2) minimized productivity impact with the scheduled system downtime; and 3) improved safety concerns—elimination of phase to ground arc flash hazards, suppression of transient line to ground overvoltages, and minimization of the equipment damage at the point of ground fault. However, there are also some drawbacks in accurately detecting and locating a ground fault in adjustable speed drive (ASD) systems: 1) the HRG fault current (1–10 A) cannot reliably trip the overcurrent protection function in drives; 2) the existing methods are based on the line voltage/frequency (50/60 Hz), making it hard to detect and locate low-voltage/low-frequency ground faults; and 3) with the existing methods, the possible fault locations will be manually checked one by one using an Ammeter by a trained technician. This paper will present a flux linkage detection based HRG fault identification method for ASD systems. The proposed method can solve: 1) reliable HRG fault detection with wide motor speed range; 2) the HRG fault can be easily identified in multiple systems; and 3) the identification process is performed by the proposed system diagnosis method, no trained technician is required during the identification process.

The photovoltage of perovskite solar cells (PSCs) was studied over a wide range of light intensities, showing changes from pristine to light-soaking (LS) conditions, explained using a specific model of spatial charge distribution. Migration of ions and vacancies under photovoltage conditions results in localized charge redistribution manifested as positive charge accumulation at the TiO2 or TiO2–MgO interlayer–perovskite interface, signifying photoinduced interfacial upward band bending. Consequentially, generation of an electrostatic potential (Velec) and an increase in interfacial recombination rate are confirmed. The magnitude and effect of Velec and interfacial recombination on the photovoltage depend on the illumination intensity and on the LS duration. PSCs with mesoporous Al2O3 showed similar changes, validating the role of the compact TiO2. Faster generation and a gradual increase of Velec are apparent under LS, which expresses the constant migration of ions and vacancies toward the interface. The nonrigid TiO2–perovskite interface calls for a vital perspective change of PSCs.

// Ying Tan 1 , Ning Huang 1 , Xiang Zhang 1 , Jiangang Hu 1 , Si Cheng 2 , Li Pi 1 , Yuan Cheng 1 1 Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China 2 Department of Orthopaedics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China Correspondence to: Yuan Cheng, email: chengyuan023@aliyun.com Keywords: KIAA0247, glioma, cell proliferation, cell apoptosis, angiogenesis Received: August 19, 2016 Accepted: November 02, 2016 Published: November 23, 2016 ABSTRACT Gliomas are the most common and aggressive type of primary adult brain tumors. Although KIAA0247 previously is a speculated target of the tumor suppressor gene, little is known about the association between KIAA0247 and glioma. In this study, we clearly demonstrate that KIAA0247 expression is decreased in glioma and was negatively correlated with the histologic grade. Overexpression of KIAA0247 in glioma cells inhibits proliferation, angiogenesis and promoted apoptosis of human glioma cells in vitro . In contrast, knockdown of KIAA0247 increases the proliferation, angiogenesis and decreases apoptosis of these cells. In a tumor xenograft model, overexpression of KIAA0247 suppresses tumor growth of glioma cells in vivo , while KIAA0247 knockdown promotes the tumor growth. Mechanistically, overexpression of KIAA0247 is able to inhibit phosphorylation of AKT and Stat3 in glioma cells, resulting in inactivation of the AKT and Stat3 signaling pathways, this ultimately decreases the expression of PCNA, CyclinD1, Bcl2 and VEGF. Collectively, these data indicate that KIAA0247 may work as a tumor suppressor gene in glioma and a promising therapeutic target for gliomas.

Summary Drastic changes in open-circuit voltage decay (OCVD) response time in CH 3 NH 3 PbX 3 perovskites have been systematically investigated in order to elucidate the dynamic properties of the interface. Under pre-illumination treatment, the decay times are reduced by orders of magnitude, but if left to rest for sufficient time, the solar cell evolves to its original decay kinetics. In order to explain these observations, we developed advanced modeling of the perovskite solar cell to obtain a realistic description of the immediate vicinity of the interface, including ionic variable concentration and accumulation of holes via degenerate statistics in the space charge region. The results reveal a large amount of majority carriers at the minority carrier extraction contact, assisted by additional ionic charge. The surface band bending related to accumulation gives an electrostatic contribution to the photovoltage in a manner governed by slow dynamics of cations at the electron-selective contact. The modeling of the interface allows us to describe the dynamics of the contact region dominated by surface charging and recombination. These phenomena also play an important role in operation conditions and current-voltage scans of the solar cell.

Additional file 3. Amino acid sequence identities of APEC94 compared with E. coli MG1655 and Salmonella TL2.

Avian pathogenic Escherichia coli (APEC) causes severe respiratory and systemic diseases in poultry. The wzy gene encodes the O-antigen polymerase (Wzy), which plays an important role in the synthesis of the lipopolysaccharide (LPS) of bacteria. However, the function of the wzy gene in APEC remains unclear. Hence, in this study, a strain harboring a wzy gene mutant (DE17Δwzy) was constructed and the characteristics of this strain were analyzed. The results showed that mutant of wzy changed the phenotype of the LPS and affected serum agglutination of the O-antigen. Decreased motility and biofilm formation was also observed, but the endotoxin titer of the LPS in APEC was not affected. In addition, the wzy mutation significantly decreased the adherence and invasion to DF-1 cells, especially the survival abilities in duck serum and complement. Furthermore, an LD50 assay revealed that the virulence of mutant strain DE17Δwzy was attenuated 132-fold compared with wild-type strain DE17. Moreover, the bacterial load in the blood, liver, spleen, and kidneys of ducks infected with DE17Δwzy was decreased significantly compared with wild-type strain DE17 (p

This paper presents a standard DC bus conditioner circuit and highlights safety issues with a floating electric drive configuration in a low leakage and ground current environment. A novel circuit is developed for automatic discharge of the bus conditioner capacitor during the drive shut down. It uses DC bus voltage as an input and a control relay to discharge the capacitor across a resistor. Functional tests were conducted on a 480/690VAC system to assess the performance of the system and circuit reliability. The circuit is validated and results are presented.

In this study we systematically explored the mixed cation perovskite Csx(CH3NH3)1-xPbI3. We exchanged the A-site cation by dipping MAPbI3 films into a CsI solution, thereby incrementally replacing the MA+ in a time-resolved dipping process and analysed the resulting thin-films with UV-Vis, XRD, EDAX, SEM and optical depth-analysis in a high-throughput fashion. Additional in situ UV-Vis and time-resolved XRD measurements allowed us to look at the kinetics of the formation process. The results showed a discontinuity during the conversion. Firstly, small amounts of Cs+ are incorporated into the structure. After a few minutes, the Cs content approaches a limit and grains of δ-CsPbI3 occur, indicating a substitution limit. We compared this cation exchange to a one-step crystallisation approach and found the same effect of phase segregation, which shows that the substitution limit is an intrinsic feature rather than a kinetic effect. Optical and structural properties changed continuously for small Cs incorporations. Larger amounts of Cs result in phase segregation. We estimate the substitution limit of CsxMA1-xPbI3 to start at a Cs ratio x = 0.13, based on combined measurements of EDAX, UV-Vis and XRD. The photovoltaic performance of the mixed cation perovskite shows a large increase in device stability from days to weeks. The initial efficiency of mixed CsxMA1-xPbI3 devices decreases slightly, which is compensated by stability after a few days.

Nanoparticles have the great potential to act as drug delivery carriers, and such systems must effectively deliver the drug to the cancer cells, and provide intracellular drug release. In this research, two types of H+-triggered bubble generating nanosystems (BGNS) were developed which were obtained using hollow mesoporous silica nanoparticles loaded with doxorubicin and subsequently treated with bubble generating agents, i.e., sodium bicarbonate (SBC) and ammonium carbonate (AC). These were named BGNS-SBC and BGNS-AC. After internalization by the tumor cells, the H+ reacts with bicarbonate or carbonate to generate carbon dioxide bubbles quickly in an acidic environment of endo/lysosomes, which results in lysosomal membrane permeabilization (LMP). Then, the enhanced LMP induced cancer cell death by an apoptosis-like pathway because of the release of caspase-3 from the lysosome into the cytoplasm. In addition, BGNS-SBC and BGNS-AC possessed remarkable cytotoxicity against MCF-7 cells and efficiently overcame the multidrug resistance (MDR) of MCF-7/adriamycin cells. Therefore, these bubble generating nanosystems could be a promising nanocarrier for the treatment of tumors.

Hybrid methyl-ammonium lead trihalide perovskites are promising low-cost materials for use in solar cells and other optoelectronic applications. With a certified photovoltaic conversion efficiency record of 20.1%, scale-up for commercial purposes is already underway. However, preparation of large-area perovskite films remains a challenge, and films of perovskites on large electrodes suffer from non-uniform performance. Thus, production and characterization of the lateral uniformity of large-area films is a crucial step towards scale-up of devices. In this paper, we present a reproducible method for improving the lateral uniformity and performance of large-area perovskite solar cells (32 cm(2)). The method is based on methyl-ammonium iodide (MAI) vapor treatment as a new step in the sequential deposition of perovskite films. Following the MAI vapor treatment, we used high throughput techniques to map the photovoltaic performance throughout the large-area device. The lateral uniformity and performance of all photovoltaic parameters (V(oc), J(sc), Fill Factor, Photo-conversion efficiency) increased, with an overall improved photo-conversion efficiency of ∼100% following a vapor treatment at 140 °C. Based on XRD and photoluminescence measurements, We propose that the MAI treatment promotes a "healing effect" to the perovskite film which increases the lateral uniformity across the large-area solar cell. Thus, the straightforward MAI vapor treatment is highly beneficial for large scale commercialization of perovskite solar cells, regardless of the specific deposition method.

The high open-circuit potential (Voc) achieved by perovskite solar cells (PSCs) is one of the keys to their success. The Voc analysis is essential to understand their working mechanisms. A large number of CH3NH3PbI3-xClx PSCs were fabricated on single large-area substrates and their Voc dependencies on illumination intensity, I0, were measured showing three distinctive regions. Similar results obtained in Al2O3 based PSCs relate the effect to the compact TiO2 rather than the mesoporous oxide. We propose that two working mechanisms control the Voc in PSCs. The rise of Voc at low I0 is determined by the employed semiconductor n-type contact (TiO2 or MgO coated TiO2). In contrast, at I0 close to AM1.5G, the employed oxide does not affect the achieved voltage. Thus, a change of regime from an oxide-dominated EFn (as in the dye sensitized solar cells) to an EFn, directly determined by the CH3NH3PbI3-xClx absorber is suggested.

High Resistance Grounding is preferred in many industrial applications. However, there are some drawbacks for the traditional HRG detection methods to locate a ground fault in Adjustable Speed Drive systems. The existing methods cannot detect or identify which phase faulted once the drive has HRG fault. This paper will present a leakage flux linkage detection based HRG fault identification method to identify the faulted phase of the drive.

Pulse Width Modulation (PWM) control method has been widely studied and applied in the industrial area. For majority of the conditions, the PWM frequency is fixed to guarantee easier control implementation. However, the time constant of the IGBT thermal system is much lower than that of the inverter fundamental frequency at low speed. The lifetime of the inverter are severely reduced under low speed and high output conditions. To improve the lifetime of the inverter at lower speed without reduce the output current, a natural way is to reduce the PWM frequency under this condition. This paper evaluated the inverter performance under different PWM frequencies. After that, it studies the impact of PWM frequency to inverter losses, inverter reliability and system performance. It is concluded that operating the inverter at low switching frequencies may not sacrifice the output current waveform quality. Moreover, the inverter lifetime can be significantly increased. Analytical, simulation and experimental results will be presented to show its effectiveness.

Our previous studies have demonstrated that focused ultrasound (FUS) combined with DNA-loaded microbubbles (MBs) can induce noninvasive, reversible, local disruption of the blood brain barrier (BBB) and enable targeted exogenous gene transfer into the central nervous system. However, due to low gene loading or the absence of positive targeting, to date, there has been no therapeutic effect of MBs combined with FUS in tumor treatment. In the current study, we adopted a phospholipid complex that exhibited sufficient gene loading and peptide-mediated targeting to delay glioma growth. First, we bound MBs to shBirc5-lipo-NGR, which performed the dual function of tumor cell targeting and effective gene loading. Next, we demonstrated that FUS-aided MB-shBirc5-lipo-NGR exhibited a higher transfection efficiency compared with the control group. Finally, we evaluated the silencing effect of shBirc5 using an apoptosis assay, real time-polymerase chain reaction (PCR), western blotting (WB) in vitro and a volume measurement survival analysis in vivo. The experimental group exhibited a significant therapeutic effect, while the FUS-only, MB-shBirc5-lipo-NGR-only and FUS-aided MB-shControl-lipo-NGR groups displayed no changes in tumor growth or survival time (P .01). Consequently, our study indicated that MB-shBirc5-lipo-NGR combined with FUS is a promising new RNA interference technique for the treatment of glioma.

The LuxS/AI-2 quorum sensing mechanism can regulate the physiological functions of avian pathogenic Escherichia coli (APEC) through internalization of the small molecule autoinducer-2 (AI-2). The ptsI gene encodes enzyme I, which participates in the phosphotransferase system (PTS) that regulates the virulence and AI-2 internalization of bacteria. The aim of the present study was to determine the effect of ptsI on AI-2 internalization and other pathogenesis process in APEC using a ptsI mutant of the APEC strain DE17 (serotype O2), namely DE17ΔptsI. The results showed that deletion of the ptsI gene changed the rdar (red dry and rough) morphotype and decreased motility and biofilm formation in APEC (p 0.05). Furthermore, scanning electron microscopy showed that the biofilm structure of DE17ΔptsI became sparse and more extracellular, as compared with the wild-type strain DE17. Moreover, AI-2 assay showed that AI-2 was internalized by DE17ΔptsI, while the recombinant PtsI protein had no AI-2 binding activity. Furthermore, deletion of the ptsI gene in APEC significantly increased adherence to DF-1 cells (p 0.05). The 50% lethal dose of DE17ΔptsI was decreased by 17.8-fold and the bacterial loads of DE17ΔptsI were decreased by 13600-, 68.5-, 131-, and 3600-fold in the blood, liver, spleen, and kidney, respectively, as compared to the DE17. Moreover, histopathological analysis showed that the mutant DE17ΔptsI was associated with reduced pathological changes in the heart, liver, spleen, and kidney of ducklings, respectively, as compared to the wild-type strain DE17. The results of this study will benefit further studies on the functions of the ptsI in APEC.

The activated methyl cycle (AMC) regulates the cellular levels of S-adenosyl-l-homocysteine (SAH) in bacteria, which plays a crucial role in bacterial pathogenicity. There are two AMC pathways in bacteria: one is a two-step reaction pathway (named the LuxS/Pfs pathway) in which LuxS and Pfs catalyze the conversion of SAH to l-homocysteine and autoinducer-2 (AI-2), and the other is a one-step reaction (named the SahH pathway) mediated by S-adenosyl-l-homocysteine hydrolase (SahH), which completes this cycle without producing AI-2. In this study, we evaluated the effects of different AMC pathways on the pathogenicity of avian pathogenic Escherichia coli (APEC). The plasmid pSTV-sahH (containing the sahH gene of Pseudomonas aeruginosa) was transformed into the wild-type APEC strain DE17 (containing the LuxS/Pfs pathway) and the pfs mutant strain DE17Δpfs, which lacks the LuxS/Pfs pathway, to create the strains SahH-DE17Δpfs (containing the SahH pathway) and SahH-DE17 (containing the LuxS/Pfs and SahH pathways). The results showed that the different AMC pathways had different effects on the growth rate, AI-2 activity, and motility in APEC. Furthermore, we showed that the 50% lethal doses of the DE17Δpfs and SahH-DE17Δpfs strains were reduced by 650-fold and 52-fold, respectively, in ducklings, compared with that of the DE17 strain. The DE17Δpfs strain exhibited significantly reduced adherence and invasion (p

A method for luteoskyrin in Chinese rice wine was developed using high-performance liquid chromatography–ion trap tandem mass spectrometry. The detection limit of luteoskyrin was 0.10 µg/kg. The recovery values of luteoskyrin in fortified Chinese rice wine were between 85.7% and 88.9% at levels between 0.5 µg/kg and 100 µg/kg (R > 0.999). The relative standard deviations were in the range of 1.10% to 3.20%. The method achieved rapid and accurate determination of luteoskyrin in Chinese rice wine while meeting minimum residue measurement requirements.

// Xiang Zhang 1, 2 , Jiangang Hu 1, 2 , Guanjian Zhao 1, 2 , Ning Huang 1 , Ying Tan 1 , Li Pi 1 , Qing Huang 1 , Feng Wang 1 , Zhigang Wang 2 , Zhibiao Wang 3 , Yuan Cheng 1 1 Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China 2 Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging of Chongqing Medical University, Chongqing, 400016, China 3 Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering of Chongqing Medical University, Chongqing, 400016, China Correspondence to: Yuan Cheng, email: chengyuan023@aliyun.com Keywords: blood brain barrier, focused ultrasound, acoustic droplet vaporization, perfluoropentane, PLGA Received: January 17, 2017 Accepted: April 05, 2017 Published: April 17, 2017 ABSTRACT Previous studies have shown that focused ultrasound (FUS) combined with systematic administration of microbubbles (MBs) can open the blood brain barrier (BBB) locally, transiently and reversibly. However, because of the micro size diameters, MBs are restricted in the intravascular space and cannot extravasate into diseased sites through the opened BBB. In this study, we fabricated one kind of nanoscale droplets which consisted of encapsulated liquid perfluoropentane cores and poly (ethyleneglycol) - poly (lactide-co-glycolic acid) shells. The nanodroplets had the capacity to realize liquid to gas phase shift under FUS. Significant extravasation of Evan’s blue appeared when acoustic pressure reached 1.0 MPa. Intracerebral hemorrhages and erythrocyte extravasations were observed when the pressure was increased to 1.5 MPa. Prolonged sonication duration could enhance the level of BBB opening and broaden the time window simultaneously. Furthermore, compared with MBs, the distribution of EB extravasation was firmly confined within narrow region in the center of focal zone, suggesting the site of FUS induced BBB opening could be controlled with high precision by this procedure. Our results show the feasibility of serving PEGylated PLGA-based phase shift nanodroplet as an effective alternative mediating agent for FUS induced BBB opening.