ASIC3 Channels Integrate Agmatine and Multiple Inflammatory Signals through the Nonproton Ligand Sensing Domain

<p>Abstract</p> <p>Background</p> <p>Acid-sensing ion channels (ASICs) have long been known to sense extracellular protons and contribute to sensory perception. Peripheral ASIC3 channels represent natural sensors of acidic and inflammatory pain. We recently reported the use of a synthetic compound, 2-guanidine-4-methylquinazoline (GMQ), to identify a novel nonproton sensing domain in the ASIC3 channel, and proposed that, based on its structural similarity with GMQ, the arginine metabolite agmatine (AGM) may be an endogenous nonproton ligand for ASIC3 channels.</p> <p>Results</p> <p>Here, we present further evidence for the physiological correlation between AGM and ASIC3. Among arginine metabolites, only AGM and its analog arcaine (ARC) activated ASIC3 channels at neutral pH in a sustained manner similar to GMQ. In addition to the homomeric ASIC3 channels, AGM also activated heteromeric ASIC3 plus ASIC1b channels, extending its potential physiological relevance. Importantly, the process of activation by AGM was highly sensitive to mild acidosis, hyperosmolarity, arachidonic acid (AA), lactic acid and reduced extracellular Ca²⁺. AGM-induced ASIC3 channel activation was not through the chelation of extracellular Ca²⁺as occurs with increased lactate, but rather through a direct interaction with the newly identified nonproton ligand sensing domain. Finally, AGM cooperated with the multiple inflammatory signals to cause pain-related behaviors in an ASIC3-dependent manner.</p> <p>Conclusions</p> <p>Nonproton ligand sensing domain might represent a novel mechanism for activation or sensitization of ASIC3 channels underlying inflammatory pain-sensing under <it>in vivo </it>conditions.</p

Bioactivity-guided fractionation identifies amygdalin as a potent neurotrophic agent from herbal medicine semen persicae extract

published_or_final_versio

Effects of vitrification and post-thawing interval on the cytoskeleton and subsequent fertilization rate of in vitro derived bovine oocytes

Vitrification may alter the cytoskeleton (microtubule, meiotic spindle, microfilament, etc.) and the subsequent fertilization rate of in vitro derived bovine oocytes. This study was conducted to evaluate the effect of vitrification and post-thawing incubation periods on the cytoskeleton and fertilization rate of in vitro matured (IVM) bovine oocytes. Following 22 h of IVM, 184 fresh matured oocytes (MO) were immediately fertilized in vitro and served as a control. The remaining MO (1009) were then vitrified by the solid surface vitrification method. Immediately after thawing, MO were incubated in maturation medium in 5% CO2 at 39 °C for 0, 30, 60, 90 and 120 min respectively. Following incubation, half of the MO from each vitrified-thawed treatment group (0, 30, 60, 90, and 120 min) was stained with fluorescein isothiocyanate conjugated (FITC) and propidium iodide (PI) to evaluate the microtubule and DNA or spindle under laser-scanning confocal microscopy. The remaining half from the vitrified-thawed MO treatment groups was washed three times in Brackett and Oliphant\'s fertilization medium and in vitro fertilized. Cleavage and blastocyst rates were recorded 48 h post-fertilization. Results demonstrated that vitrification damaged MO zona pellucida (ZP), microtubule (MT), meiotic spindle (MS), and caused chromosomal fragmentation. Both the cleavage (84%) and blastocyst rates (50%) of the control group were significantly higher compared to the vitrified-thawed treatment groups. However, extending the incubation period of vitrified MO to 120 min after thawing (prior to fertilization) improved cleavage (65%) and blastocyst (13%) rates 48 h post-fertilization. Fertilizing vitrified MO immediately (0 min group) after thawing resulted in the lowest cleavage (42%) and blastocyst (1.9%) rates. In conclusion, vitrification reduces the subsequent fertilization rate of MO, however, a prolonged post-thawing incubation period (120 min) improves survival, cleavage and blastocyst formation rates, and enhances the reorganization of MO\'s cytoskeleton (MT and MS). Keywords: Vitrification; cytoskeleton; bovine; oocytes; fertilization; in vitro matured South African Journal of Animal Science Vol. 36 (5) 2006: pp.42-4

Characterization of preconcentrated domestic wastewater toward efficient bioenergy recovery: Applying size fractionation, chemical composition and biomethane potential assay.

Domestic wastewater (DWW) can be preconcentrated to facilitate energy recovery via anaerobic digestion (AD), following the concept of "carbon capture-anaerobic conversion-bioenergy utilization." Herein, real DWW and preconcentrated domestic wastewater (PDWW) were both subject to particle size fractionation (0.45-2000 μm). DWW is a type of low-strength wastewater (average COD of 440.26 mg/L), wherein 60% of the COD is attributed to the substances with particle size greater than 0.45 μm. Proteins, polysaccharides, and lipids are the major DWW components. PDWW with a high COD concentration of 2125.89 ± 273.71 mg/L was obtained by the dynamic membrane filtration (DMF) process. PDWW shows larger proportions of settleable and suspended fractions, and accounted for 63.4% and 33.8% of the particle size distribution, and 52.4% and 32.2% of the COD, respectively. The acceptable biomethane potential of 262.52 ± 11.86 mL CH4/g COD of PDWW indicates bioenergy recovery is feasible based on DWW preconcentration and AD

Current status of urban wastewater treatment plants in China

© 2016 Elsevier Ltd. The study reported and analyzed the current state of wastewater treatment plants (WWTPs) in urban China from the perspective of treatment technologies, pollutant removals, operating load and effluent discharge standards. By the end of 2013, 3508 WWTPs have been built in 31 provinces and cities in China with a total treatment capacity of 1.48 × 108 m3/d. The uneven population distribution between China's east and west regions has resulted in notably different economic development outcomes. The technologies mostly used in WWTPs are AAO and oxidation ditch, which account for over 50% of the existing WWTPs. According to statistics, the efficiencies of COD and NH3-N removal are good in 656 WWTPs in 70 cities. The overall average COD removal is over 88% with few regional differences. The average removal efficiency of NH3-N is up to 80%. Large differences exist between the operating loads applied in different WWTPs. The average operating loading rate is approximately 83%, and 52% of WWTPs operate at loadings of <80%, treating up to 40% of the wastewater generated. The implementation of discharge standards has been low. Approximately 28% of WWTPs that achieved the Grade I-A Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002) were constructed after 2010. The sludge treatment and recycling rates are only 25%, and approximately 15% of wastewater is inefficiently treated. Approximately 60% of WWTPs have capacities of 1 × 104 m3/d-5 × 104 m3/d. Relatively high energy consumption is required for small-scale processing, and the utilization rate of recycled wastewater is low. The challenges of WWTPs are discussed with the aim of developing rational criteria and appropriate technologies for water recycling. Suggestions regarding potential technical and administrative measures are provided

Tai Chi for Chronic Pain Conditions: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Several studies reported that Tai Chi showed potential effects for chronic pain, but its role remains controversial. This review assessed the evidence regarding the effects of Tai Chi for chronic pain conditions. 18 randomized controlled trials were included in our review. The aggregated results have indicated that Tai Chi showed positive evidence on immediate relief of chronic pain from osteoarthritis (standardized mean difference [SMD],-0.54; 95% confidence intervals [CI],-0.77 to-0.30; P < 0.05). The valid duration of Tai Chi practice for osteoarthritis may be more than 5 weeks. And there were some beneficial evidences regarding the effects of Tai Chi on immediate relief of chronic pain from low back pain (SMD,-0.81; 95% CI,-1.11 to-0.52; P < 0.05) and osteoporosis (SMD,-0.83; 95% CI,-1.37 to-0.28; P = 0.003). Therefore, clinicians may consider Tai Chi as a viable complementary and alternative medicine for chronic pain conditions

Histamine increases neuronal excitability and sensitivity of the lateral vestibular nucleus and promotes motor behaviors via HCN channel coupled to H2 receptor

published_or_final_versio

Effects of powdered activated carbon addition on filtration performance and dynamic membrane layer properties in a hybrid DMBR process

© 2017 Elsevier B.V. A powdered activated carbon-dynamic membrane bioreactor (PAC-DMBR) was developed and used to treat domestic wastewater by dosing with 3 g/L PAC. The experimental results were compared with those of a control DMBR to investigate the filtration performance and various properties of the dynamic membrane (DM) layer. One flat-sheet DM module made of nylon mesh (pore size 75 μm) was used for effluent production at a high stable flux (50–100 L/m2 h) under a 10 cm water head by gravity flow, resulting in continuous operation cycles of 60–120 h. During the operation period, the PAC-DMBR showed enhanced removal efficiency of pollutants, higher stable membrane flux (10 L/m2 h more), lower filtration resistance (6.0–8.0 × 1010 m−1), quicker formation of the DM layer (within 5 min), and better DM layer regeneration after air backwashing. The DM layer in the PAC-DMBR showed a more porous and incompressible structure, because less extracellular polymeric substance and a portion of the biological PAC were incorporated into the DM layer formed as verified by the analytical results. Using high-throughput pyrosequencing technology, it was revealed that at the genus level the diversity of bacterial communities increased from 18 to 23 genera, while several genera that were favored in the PAC-assisted environment or were responsible for degrading complex organics were enriched. Moreover, the abundance of phylum Proteobacteria, which served as pioneer surface colonizers, was reduced in the PAC-DMBR. It was concluded that PAC addition could modify various aspects of the activated sludge and the DM layer properties, which affected the filtration behavior of the DM layer in the PAC-DMBR

Feasibility study of welding dissimilar Advanced and Ultra High Strength Steels

This study concerns the weldability of dissimilar Ultra high-strength steel (UHSS) and advanced high-strength steel (AHSS), which is used in the modern machine industry. The materials offered superior strength as well as relatively low weight, which reduces microstructure contamination during a live cycle. The choice of the welding process base of the base material (BM) and welding parameters is essential to improve the weld joint quality. S700MC/S960QC was welded using a gas metal arc welding (GMAW) process and overmatched filler wire, which was performed using three heat input (7, 10, and 15 kJ/cm). The weld samples were characterized by a Vickers-hardness test, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The test reveals a decrease of softening areas in the HAZ and the formation of the stable formation of Bainite-Ferrite for S700MC and Bainite-martensite for S960QC when the heat input of 10 kJ/cm is used. It is recommended to use the GMAW process and Laser welding (Laser beam-MIG), with an optimal welding parameter, which will be achieved a high quality of manufacturing products

Transformation and utilization of slowly biodegradable organic matters in biological sewage treatment of anaerobic anoxic oxic systems

© 2016 Elsevier Ltd. This study examined the distribution of carbon sources in two anaerobic anoxic oxic (AAO) sewage treatment plants in Xi'an and investigated the transformation characteristics and utilization potential of slowly biodegradable organic matters (SBOM). Results indicated under anaerobic and aerobic conditions, SBOM could be transformed at a rate of 65% in 8 h into more readily biologically utilizable substrates such as volatile fatty acids (VFAs), polysaccharides and proteins. Additionally, non-biodegradable humus-type substances which are difficult to biodegrade and readily accumulate, were also generated. These products could be further hydrolyzed to aldehyde and ketone compounds and then transformed into substances with significant oxygen-containing functional groups and utilized subsequently. The molecular weights of proteinoid substances had a wide distribution and tended to decrease over time. Long hours of microbial reaction increased the proportion of micromolecular substances. This particular increase generated significant bioavailability, which can greatly improve the efficiency of nitrogen removal