RESUMEN
Nickel/photoredox catalysis has emerged as a powerful platform for exploring nontraditional and challenging cross-couplings. Herein, a metallaphotoredox catalytic protocol has been developed on the basis of a tertiary amine-ligated boryl radical-induced halogen atom transfer process under blue-light irradiation. A wide variety of aryl and heteroaryl bromides featuring different functional groups and pharmaceutical moieties were facilely coupled to rapidly install C(sp3)-enriched aromatic scaffolds. The compatibility of Lewis base-ligated borane with nickel catalysis was well exemplified to extend the chemical space for Ni-catalyzed cross-electrophile coupling.
RESUMEN
Integrating the Kondo correlation and spin-orbit interactions, each of which have individually offered unprecedented means to manipulate electron spins, in a controllable way can open up new possibilities for spintronics. We demonstrate electrical control of the Kondo correlation by coupling the bound spin to leads with tunable Rashba spin-orbit interactions, realized in semiconductor quantum point contacts. We observe a transition from single to double peak zero-bias anomalies in nonequilibrium transport-the manifestation of the Kondo effect-indicating a controlled Kondo spin reversal using only spin-orbit interactions. Universal scaling of the Kondo conductance is demonstrated, implying that the spin-orbit interactions could enhance the Kondo temperature. A theoretical model based on quantum master equations is also developed to calculate the nonequilibrium quantum transport.
RESUMEN
Compact high-power yellow laser is a critical part for sodium beacon adaptive optical systems. A narrow-linewidth quasi-continuous-wave (QCW) solid-state 589 nm laser with high-power and high beam quality simultaneously is investigated here, operating in hundreds-microsecond pulse duration with a tunable repetition rate of 400 to 1 kHz, which is flexible to allow the telescope to move in observing direction. The laser source is based on employing sum-frequency generation between 1319 and 1064 nm QCW Nd:YAG amplifiers. For a 100 µs pulse duration and 400 Hz repetition rate, the yellow laser provides a highest output power of 86.1 W with beam quality M2 = 1.37. The central wavelength can be precisely tuned to sodium-D2a line at 589.159 nm with a â¼440 MHz linewidth. This is the maximum power-reported for all-solid-state sodium guide star laser demonstrated to date. The result represents a key step toward solving the requirement of multi-conjugate adaptive optics for large adaptive optical telescopes.
RESUMEN
A 100 W level kilohertz repetition-rate microsecond (µs)-pulse all-solid-state sodium beacon laser at 589 nm is demonstrated for the first time, to the best of our knowledge, via combining two independent µs-pulsed lasers. Each beamlet is generated by the sum-frequency mixing of pulsed 1064 and 1319 nm lasers in a lithium triborate (LBO) crystal, which operate at 500 Hz pulse repetition frequency with 61 W $p$p-polarized and 53 W $s$s-polarized output, respectively. An incoherent sequence combining technology of polarized laser beams is employed to add the two beamlets. The average power of the combined beam is up to 107.5 W with a combining efficiency of 94.3%. The combined beam has a 1 kHz repetition rate with ${\sim}{120}\;\unicode{x00B5} {\rm s}$â¼120µs pulse duration and beam quality ${M^2} = {1.41}$M2=1.41. The central wavelength with a linewidth of ${\sim}{0.3}\;{\rm GHz}$â¼0.3GHz is locked to a sodium ${{\rm D}_{2a}}$D2a absorption line. To the best of our knowledge, this is a record-high power operating at kilohertz for µs-pulsed solid-state sodium beacon lasers.
RESUMEN
BACKGROUND: Hibiscus sabdariffa is commonly used in daily life and its extract is applied widely in food and cosmetics. However, it has not been evaluated for its anti-aging effects. RESULTS: Hibiscus sabdariffa calyx aqueous extract (HSCAE) has shown potential collagenase activity suppression effects, together with tyrosinase activity inhibition, and anti-oxidation as a free radical scavenger. The current investigation demonstrated that HSCAE was not cytotoxic in skin fibroblasts, and it significantly decreased ultraviolet B (UVB)-induced reactive oxygen species (ROS) on a flow cytometry assay. Moreover, HSCAE reduced matrix metalloproteinase (MMP) expression, increased tissue inhibition of metalloproteinase (TIMP)-1 level, and enhanced collagen content by inhibiting collagenase activity. It also blocked mRNA and protein expressions of melanin production pathway key factors, including the microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and dopachrome tautomerase-2 (TRP-2). CONCLUSION: These results demonstrated, for the first time, the potential of HSCAE as a natural antioxidant with the ability to maintain collagen production and to decrease melanin syntheses under UVB radiation, for anti-aging effects. © 2019 Society of Chemical Industry.
Asunto(s)
Depuradores de Radicales Libres/farmacología , Hibiscus/química , Extractos Vegetales/farmacología , Envejecimiento de la Piel/efectos de los fármacos , Animales , Línea Celular , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/efectos de la radiación , Humanos , Oxidorreductasas Intramoleculares/genética , Oxidorreductasas Intramoleculares/metabolismo , Ratones , Monofenol Monooxigenasa/genética , Monofenol Monooxigenasa/metabolismo , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Envejecimiento de la Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversosRESUMEN
BACKGROUND: Avian influenza A (H5N6) virus poses a great threat to the human health since it is capable to cross the species barrier and infect humans. Although human infections are believed to largely originate from poultry contaminations, the transmissibility is unclear and only limited information was available on poultry environment contaminations, especially in Fujian Province. METHODS: A total of 4901 environmental samples were collected and tested for Avian Influenza Virus (AIV) from six cities in Fujian Province through the Fujian Influenza Surveillance System from 2013 to 2017. Two patient-related samples were taken from Fujian's first confirmed H5N6 human case and his backyard chicken feces in 2017. Chi-square test or Fisher's exact probability test was used to compare the AIV and the viral subtype positive rates among samples from different Surveillance cities, surveillance sites, sample types, and seasons. Phylogenetic tree analysis and molecular analysis were conducted to track the viral transmission route of the human infection and to map out the evolutions of H5N6 in Fujian. RESULTS: The overall positive rate of the H5 subtype AIVs was 4.24% (208/4903). There were distinctive differences (p < 0.05) in the positive rates in samples from different cities, sample sites, sample types and seasons. The viruses from the patient and his backyard chicken feces shared high homologies (99.9-100%) in all the eight gene segments. Phylogenetic trees also showed that these two H5N6 viruses were closely related to each other, and were classified into the same genetic clade 2.3.4.4 with another six H5N6 isolates from the environmental samples. The patient's H5N6 virus carried genes from H6N6, H5N8 and H5N6 viruses originated from different areas. The R294K or N294S substitution was not detected in the neuraminidase (NA). The S31 N substitution in the matrix2 (M2) gene was detected but only in one strain from the environmental samples. CONCLUSIONS: The H5 subtype of AIVs has started circulating in the poultry environments in Fujian Province. The patient's viral strain originated from the chicken feces in his backyard. Genetic reassortment in H5N6 viruses in Fujian Province was indicated. The H5N6 viruses currently circulating in Fujian Province were still commonly sensitive to Oseltamivir and Zanamivir, but the resistance against Amantadine has emerged.
Asunto(s)
Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Gripe Humana/epidemiología , Gripe Humana/virología , Infecciones por Orthomyxoviridae/virología , Aves de Corral/virología , Animales , Embrión de Pollo , Pollos/virología , China/epidemiología , Patos/virología , Ambiente , Microbiología Ambiental , Genes Virales , Vivienda para Animales/normas , Humanos , Virus de la Influenza A/genética , Gripe Aviar/diagnóstico , Gripe Aviar/epidemiología , Tipificación Molecular , Infecciones por Orthomyxoviridae/diagnóstico , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/transmisión , Filogenia , Enfermedades de las Aves de Corral/diagnóstico , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/virología , Factores de RiesgoRESUMEN
The incoherent dynamical properties of open quantum systems are generically attributed to an ongoing correlation between the system and its environment. Here, we propose a novel way to assess the nature of these system-environment correlations by examining the system dynamics alone. Our approach is based on the possibility or impossibility to simulate open-system dynamics with Hamiltonian ensembles. As we show, such (im)possibility to simulate is closely linked to the system-environment correlations. We thus define the nonclassicality of open-system dynamics in terms of the nonexistence of a Hamiltonian-ensemble simulation. This classifies any nonunital open-system dynamics as nonclassical. We give examples for open-system dynamics that are unital and classical, as well as unital and nonclassical.
RESUMEN
Water-soluble wheel-like icosanuclear peroxotitanate K16[Ti20(µ-O)8(HO2)8(O2)12( R, R-tart)12]·52H2O (1) chelated by tartrate has been successfully isolated. As the largest peroxotitanate reported, {Ti20} features 20 (hydro)peroxo groups with three kinds of coordination modes in µ-η1:η2, µ-η2:η2, and η2 fashions. The cluster is stable in solution and solid states. It has been tested for the catalytic oxidations of methyl phenyl sulfide and pyridine with hydrogen peroxide, respectively, which shows reversible elimination and the addition of peroxo groups. This provides a rare example of well-characterized titanium peroxide for homogeneous catalysis and mechanism research.
RESUMEN
Chiral amino alcohol-copper(ii) catalysts Cu-L1c and Cu-ent-L1c were utilized to promote the diastereoselective nitroaldol reactions of chiral aldehydes (S)-3 or (R)-3 with nitromethane, which respectively led to the preferential formation of certain stereoisomer for nitro diol derivatives 4. Using this catalytic protocol, all the four stereoisomers of the antidepressant reboxetine were divergently prepared. The highest overall yield of this synthetic route reached up to 30.5% from aldehyde (S)-3.
Asunto(s)
Antidepresivos/química , Antidepresivos/síntesis química , Morfolinas/química , Morfolinas/síntesis química , Estructura Molecular , Reboxetina , EstereoisomerismoRESUMEN
Chiral ß-amino alcohol ligands were found effective for the copper(ii)-catalyzed asymmetric Henry reaction of benzofuran-2-carbaldehydes with nitromethane, which led to the formation of (S)-enriched benzofuryl ß-nitro alcohols with satisfactory enantioselectivities (up to 98% ee). Using this catalytic protocol, bioactive (S)-benzofuryl ß-amino alcohols could be conveniently prepared in short steps.
RESUMEN
A 65 W quasi-continuous-wave microsecond-pulse solid-state sodium beacon laser tuned to the sodium D2a line has been developed with a linewidth of 0.3 GHz, beam quality of M2=1.38, and pulse width of 120 µs at a repetition rate of 500 Hz by sum-frequency mixing 1319 and 1064 nm diode-pumped Nd:YAG master-oscillator power-amplifier systems. The laser wavelength stability is less than ±0.15 GHz through feedback controlling. The laser spiking due to relaxation oscillations is suppressed by inserting frequency doublers in both 1319 and 1064 nm oscillators. Sodium D2b re-pumping is accomplished by tuning the frequency of the electro-optic modulator with the right D2a-D2b offset. A bright sodium laser guide star with a photon return of 1820 photons/cm2/s was achieved with the laser system when a 32 W circular polarized beam was projected to the sky during our field test at the Xinglong Observatory.
RESUMEN
The transformation of solid wastes from industrial production into effective adsorbents could significantly contribute to wastewater treatment. In this study, after acidizing and burning soft scale (SS) from coal gasification system, two magnetic adsorbents (mag-ASS and mag-BASS) were prepared via the combination of magnetite with ultrasonic, respectively. The treatment effects of mag-ASS and mag-BASS were then investigated for simulated wastewater containing macromolecular organic matter [i.e., methylene blue (MB)] and Ca2+. The results indicated that the pseudo second order kinetic, Elovich, Freundlich, Langmuir and Temkin model could well describe the adsorption behavior of MB and Ca2+ onto mag-ASS and mag-BASS. The maximum adsorption capacities of mag-ASS for MB and mag-BASS for Ca2+ were 600.53 mg/g and 102.54 mg/g, respectively. Surprisingly, the adsorption abilities of mag-ASS for MB and mag-BASS for Ca2+ show significantly higher than the others. The adsorption mechanisms of MB mainly included electrostatic interaction, π-π conjugate interaction and cation exchange, while those of Ca2+ were mainly electrostatic interaction and cation exchange. The diffusion of MB and Ca2+ onto the magnetic adsorbents might be controlled by the combined effects of intraparticle and liquid film diffusion. There was no significant reduction in adsorption capacity after 8 cycles of adsorption and desorption, indicating that SS-based magnetic adsorbents had good recyclability and stability. Moreover, the removal efficiency of mag-BASS for total hardness and total organic carbon in real coal gasification gray water (CGGW) was 82.60 and 64.10%, respectively. The treatment of CGGW and the resource of wastes would significantly promote the reasonable disposal of coal gasification scales.
Asunto(s)
Calcio , Carbón Mineral , Azul de Metileno , Azul de Metileno/química , Adsorción , Calcio/química , Aguas Residuales/química , Cinética , Contaminantes Químicos del Agua/química , Purificación del Agua/métodosRESUMEN
A metal-free photosensitized 1,2-imino-sulfamoylation of olefins by employing a tailor-made sulfamoyl carbamate as the difunctionalization reagent has been established. This protocol exhibits versatility across a broad substrate scope, including aryl and aliphatic alkenes, leading to the synthesis of diverse ß-imino sulfonamides in moderate to good yields. This method is characterized by its metal-free reaction system, mild reaction conditions, excellent regioselectivity, and high atom economy, serving as a promising platform for the preparation of ß-amino sulfonamide-containing molecules, particularly in the context of drug discovery.
RESUMEN
A novel strategy for incorporating a trifluoroacetyl functionality into a range of structurally varied unsaturated bonds was developed by using PhI(OCOMe)2 as an oxidant with a masked trifluoroacyl reagent as a trifluoroacetyl radical precursor. The oxidative decarboxylation of the masked trifluoroacyl precursor followed by a tandem radical process provides versatile access to 5-exo-trig cyclization of N-arylacrylamides, direct C(sp2)-H trifluoroacetylation of quinolines, isoquinoline, 2H-indazole, and quinoxalin-2(1H)-ones, and C(sp)-H trifluoroacetylation of alkynes. This protocol is characterized by mild reaction conditions, operational simplicity, and broad functional group compatibility.
RESUMEN
OBJECTIVE: To evaluate the in vitro activity of daptomycin against 2679 Gram-positive cocci. METHODS: A total of 2679 non-duplicate Gram-positive cocci isolates were collected from 17 teaching hospitals during January, 2010 and December, 2011. The minimal inhibitory concentrations (MICs) of daptomycin and other anti-microbial agents against 4 Gram-positive cocci were determined by micro-broth dilution method and agar dilution respectively. The data of drug susceptibility were analyzed by WHONET5.6 software. RESULTS: Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococci (MRSCoN) detection rates were 45.8% and 84.2%, respectively. The susceptibility rates of sulfamethoxazole, chloramphenicol, erythromycin, tetracycline, clindamycin and rifampicin against MRSA were 93.1%, 85.5%, 13.8%, 26.6%, 63.2% and 50.0%, respectively. The susceptibility rates of daptomycin, vancomycin and linezolid against MRSA and MRSCoN were all 100.0%. The daptomycin MIC50 and MIC90 of MRSCoN and MRSA were 0.5 mg/L. The high level gentamicin resistance rate of 513 Enterococci isolates was 56.9%. The susceptibility rates of chloramphenicol and tetracycline were 76.0% and 44.1%, respectively. The susceptibility rates of tigecycline and daptomycin reached 100.0%. The MIC50 and MIC90 of daptomycin against 17 vancomycin-resistant Enterococci (VRE) were both 2 mg/L. The susceptibility rates of daptomycin against Streptococcus pneumoniae and ß-hemolytic Streptococcus were 100.0%. The prevalence of penicillin-nonsusceptible Streptococcus pneumoniae (PNSSP) was 63.1%. The MIC50 and MIC90 of daptomycin against PNSSP were 0.125 mg/L and 0.25 mg/L, respectively according to the breakpoint of oral penicillin. The MIC50 and MIC90 daptomycin against ß-hemolytic Streptococci were 0.008 mg/L and 0.032 mg/L. CONCLUSIONS: Daptomycin have excellent in vitro activity against common Gram-positive cocci, including multi-drug resistant bacteria. It may be a good choice for clinicians to treat drug-resistant Gram-positive cocci.
Asunto(s)
Antibacterianos/farmacología , Daptomicina/farmacología , Cocos Grampositivos/efectos de los fármacos , Farmacorresistencia Bacteriana , Cocos Grampositivos/aislamiento & purificación , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad MicrobianaRESUMEN
OBJECTIVE: To investigate the pathogen profile of nosocomial infection in China, and to survey the susceptibility rates of these pathogens to the clinical common antibiotics. METHODS: The non-repetitive nosocomial pathogens isolated from bloodstream infection (BSI), hospital acquired pneumonia (HAP) and intra-abdominal infection (IAI) and the case data were collected from 13 teaching hospitals in different areas of China and sent to a central laboratory for re-identification and susceptibility testing. The levels of minimal inhibitory concentration (MIC) of the common antibiotics were determined by agar dilution method. The data were analyzed by WHONET 5.6 software. RESULTS: A total of 2103 clinical isolates were collected from January to December 2011, of which gram positive cocci and gram negative organisms accounted for 23.2% and 76.8% respectively. The top three pathogens of BSI were E. coli (31.0%, 243/784), K. pneumoniae (14.8%, 116/784) and S. aureus (10.6%, 83/784). The top three pathogens of HAP were A. baumannii (24.2%, 158/652), P. aeruginosa (23.0%, 150/652) and K. pneumoniae (16.4%, 107/652). The top three pathogens of IAI were E. coli (34.3%, 229/667), E. faecium (13.3%, 89/667) and K. pneumoniae (9.6%, 64/667). Methicillin-resistant S. aureus (MRSA) and coagulase negative Staphylococcus (MRCNS) accounted for 64.4% and 78.1% respectively. The susceptibility rates of Staphylococcus species to tigecycline, vancomycin, teicoplanin and linezolid were all 100%. The prevalence of MRSA in HAP was significantly higher than that in BSI or IAI. The susceptibility rates of Enterococcus species to tigecycline, teicoplanin and linezolid were all 100%. The prevalence of extended-spectrum ß-lactamases (ESBL) was 64.3% in E. coli and 38.3% in K. pneumonia. Against Enterobacteriaceae, the most active agents were as following in order: tigecycline (92.3% - 100%) [except P.mirabilis], meropenem (87.5% - 100%), imipenem (87.5% - 100%) [except M. morganii], amikacin (87.5% - 100%), polymyxin B (75% - 100%) [except S. marcescens, P. mirabilis and M morganii], cefepime (67.8% - 100%), cefoperazone-sulbactam (66.6% - 100%), piperacillin-tazobactam (61.5% - 100%). Carbapenem-resistance Enterobacteriaceae strains emerged. The susceptibility rates of P. aeruginosa to imipenem and meropenem were 66.2% and 72.2%, respectively. The susceptibility rates of A. baumannii to imipenem and meropenem were 27.7% and 25.9%, respectively. The most active agents against A. baumannii were polymyxin B (100%), followed by tigecycline (79.8%) and minocycline (50.4%). The susceptibility rates of P.aeruginosa to antibiotics in BSI were higher than those in HAP and IAI. Susceptibility rates of S. maltophilia to trimethoprim-sulfamethoxazole, minocycline and levofloxacin were about 90% or above. Susceptibility rates of B. cepacia to trimethoprim-sulfamethoxazole, ceftazidime and meropenem were all 100%. Several P.aeruginosa and A. baumannii strains were resistant to all tested antibiotics except polymyxin B. CONCLUSIONS: The pathogen profile is different in different types of infection. The prevalence of multi-drug resistant A. baumannii is high, which is still a key problem of nosocomial infection. Tigecycline remains relatively high activity against gram-positive cocci and gram-negative bacteria (except P. aeruginosa and P. mirabilis) in vitro.
Asunto(s)
Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana , China , Hospitales de Enseñanza , HumanosRESUMEN
OBJECTIVE: To investigate the trends of resistance of S. pneumoniae and to evaluate the potential coverage of pneumococcal conjugate vaccine. METHODS: The antibiotic susceptibility and serotype distribution of 471 pneumococcal strains isolated from pneumococcal diseases in 13 hospitals across China during 2010 to 2011 were studied. In vitro susceptibility to 15 antimicrobial agents was determined by agar dilution method. Serotyping of S. pneumoniae was performed by using latex and quelling reaction. Vaccine coverage by 7-, 10-, 13- and 23- valent conjugate vaccines was estimated by calculating the percentage of isolates that belonged to the serotypes included in the vaccines. RESULTS: Among all strains tested, 50.1% (236/471) was resistant to penicillin (Oral breakpoint, MIC ≥ 2 mg/L). Overall, 27.4% (129/471), 60.3% (284/471), 58.8% (277/471) and 18.5% (87/471) of S. pneumoniae were resistant to amoxicillin/clavulanate, cefaclor, cefuroxime and ceftriaxone, respectively.1.5% (7/471) of all stains were resistant to levofloxacin and 0.6% (3/471) of all strains were resistant to moxifloxacin. The resistance rates to other antibiotic agents, such as erythromycin, clindamycin, tetracycline, trimethoprim/sulfamethoxazole, and chloramphenicol, were 93.2% (439/471), 88.7% (417/471), 89.6% (422/471), 62.8% (296/471) and 22.1% (104/471), respectively. The most prevalent serotype was 19F (112, 23.8%), followed by 19A (63, 13.4%), 3 (48, 10.2%), 14 (43, 9.1%), 23F (29, 6.2%), 15 (25, 5.3%) and 6A (23, 4.9%). The potential coverage by 7- and 13-valent pneumococcal conjugate vaccines was 45.3% (213/471) and 76% (358/471), respectively. The potential coverage of PCV7 and PCV13 in children were 59.0% (72/122) and 86.9% (106/122), and the potential coverage of PCV7 and PCV13 in adult were 42.3% (94/222) and 73.4% (163/222). CONCLUSIONS: The antibiotic resistance of S. pneumoniae was serious in China, especially to tetracycline, erythromycin and clindamycin. The majority of serotypes 19A and 19F was penicillin-resistant. The potential coverage of PCV7 and PCV13 in children was higher than those in adult. PCV13 could cover most of the isolates, especially for penicillin-resistant S. pneumoniae.
Asunto(s)
Farmacorresistencia Bacteriana Múltiple , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/efectos de los fármacos , Adolescente , Adulto , Anciano , Niño , Preescolar , China/epidemiología , Humanos , Lactante , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/microbiología , Serotipificación , Streptococcus pneumoniae/aislamiento & purificación , Adulto JovenRESUMEN
OBJECTIVE: To explore the impact of intermittent hypoxia on long-term facilitation (LTF) of hypoglossal nerve discharge. METHODS: Twelve adult SD rats were divided into the experimental group (CIH group, n = 6) and the control group (normoxia group, n = 6) by the random number table. The rats in the CIH group were fed in the intermittent hypoxia animal chambers, while the control group was placed in the normoxia animal chambers for 8 h per day (from 8:00 AM to 4:00 PM) for 4 consecutive weeks. After that, 5 min×3 stimulations of acute intermittent hypoxia (AIH) were administered and the hypoglossal never signals were recorded before and after AIH. RESULTS: The baseline frequency and average peak amplitude of hypoglossal nerve discharge in the CIH experimental group were significantly greater than those in the control group. The discharge frequency in the CIH and the control groups was (73 ± 13) Hz, and (58 ± 11) Hz, respectively(P < 0.05); and the discharge amplitude in the 2 groups was (4.6 ± 1.1) µV, and (3.3 ± 0.7) µV, respectively(P < 0.05). After intervention with AIH, the frequency and the average peak amplitude of the hypoglossal nerve discharge in the experimental and the control groups were significantly increased(all P < 0.05). The increased discharge lasted more than 1 h and this typical phenomenon was referred to as LTF. In the CIH group, the discharge frequency before and after exposure to AIH was (68 ± 16) Hz and (133 ± 20) Hz, respectively; and the discharge amplitude was (4.6 ± 1.1) µV and (8.9 ± 1.4) µV, respectively. In the control group, the discharge frequency before and after AIH was (59 ± 12) Hz and (102 ± 16) Hz, respectively; and the discharge amplitude was (3.3 ± 0.7) µV and (4.5 ± 0.7) µV, respectively(P < 0.05). After AIH stimulation, the enhanced respiratory intensity of rats in CIH group was much higher than that in the control group [(408 ± 149)% vs (242 ± 31)%, P < 0.05]. CONCLUSION: Both AIH and CIH can induce LTF of the hypoglossal nerve discharge, while the induction of LTF by AIH can be strengthened by CIH.
Asunto(s)
Nervio Hipogloso/fisiopatología , Hipoxia/fisiopatología , Potenciación a Largo Plazo/fisiología , Animales , Nervio Hipogloso/fisiología , Hipoxia/complicaciones , Masculino , Nervio Frénico/fisiología , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Mecánica Respiratoria/fisiología , Factores de TiempoRESUMEN
Treadmill exercise and mesenchymal stem cell transplantation are both practical and effective methods for the treatment of cerebral ischemia. However, whether there is a synergistic effect between the two remains unclear. In this study, we established rat models of ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours. Rat models were perfused with bone marrow mesenchymal stem cell-derived exosomes (MSC-exos) via the tail vein and underwent 14 successive days of treadmill exercise. Neurological assessment, histopathology, and immunohistochemistry results revealed decreased neuronal apoptosis and cerebral infarct volume, evident synaptic formation and axonal regeneration, and remarkably recovered neurological function in rats subjected to treadmill exercise and MSC-exos treatment. These effects were superior to those in rats subjected to treadmill exercise or MSC-exos treatment alone. Mechanistically, further investigation revealed that the activation of JNK1/c-Jun signaling pathways regulated neuronal apoptosis and synaptic-axonal remodeling. These findings suggest that treadmill exercise may exhibit a synergistic effect with MSC-exos treatment, which may be related to activation of the JNK1/c-Jun signaling pathway. This study provides novel theoretical evidence for the clinical application of treadmill exercise combined with MSC-exos treatment for ischemic cerebrovascular disease.
RESUMEN
To prevent the scale formation in the equipments and pipelines after pre-treated coal gasification gray water (CGGW) entering the reuse system and reduce the influence of various pollutants in the effluent on subsequent biochemical treatment, this study presented a coupled use of pulse electrocoagulation (PEC) and chemical precipitation (CP) coupling method for the pretreatment of coal gasification gray water (CGGW). In addition, the operation parameters of PEC and the reaction conditions of PEC-CP were optimized based on iron plate as electrode and total hardness, turbidity and sludge yield as assessment indicators. Due to the formation of multi-hydroxyl iron by several minutes of pulse current, and the addition of pH regulator and coagulant aid, the efficient removal of various ions, hardness and turbidity was significantly reduced via various mechanism such as redox, precipitation, adsorption and coagulation reaction. The result indicated that under the optimal operation conditions, the total hardness, turbidity, and Fen+ of PEC-CP effluents were 275.0 mg/L, 3.0 NTU and 5.6 mg/L, respectively and sludge amount was 0.88 kg/m3. The removal rates of Si, B, Mn, Ba, COD, NPOC and NH4+-N by PEC-CP reached 80.0%, 75.4%, 97.0%, 99.8%, 35.0%, 33.6% and 23.8%, respectively. The present results suggested that the CGGW pretreatment effluents could be not only reused directly, but also greatly alleviate the scaling problem of water pipeline and coal gasification production facilities.