NH4Cl Treatment Research Articles

Down-regulation effects of IFN-α on p11, 5-htr1b and 5-HTR4 protein levels were affected by NH4CL or MG132 treatment in SH-sy5y cells

In previous studies, we found interferon-α (IFN-α) could reduce protein levels of p11, 5-hydroxytryptamine receptor 1b (5-HT1b) and 5-hydroxytryptamine receptor 4 (5-HT4), but does not influence their messenger RNA levels in SH-sy5y cells. Thus, we investigated the post-transcriptional modulation of these molecules by IFN-α. SH-sy5y cells were treated with IFN-α, NH4Cl or MG132 alone or in combination, and then the protein levels of p11, 5-HT1b and 5-HT4 were analyzed by western blots. The regulatory effects of p11 on 5-HT1b and 5-HT4 were also determined in p11 knock-down cells. NH4Cl but not MG132 could reverse the protein level of p11 in IFN-α-treated SH-sy5y cells. MG132 could recover the protein levels of 5-HT1b and 5-HT4 in p11 knock-down cells. The down-regulation effects of IFN-α on p11, 5-HT1b and 5-HT4 were associated with the lysosome and ubiquitin-proteasome-mediated pathways. p11 was identified as a potent regulator to modulate the ubiquitination of 5-HT1b and 5-HT4. Therefore, it could be potential target therapies in IFN-ainduced depression.

The effects of nitrogen addition on dissolved carbon in boreal forest soils of northeastern China

Understanding the effects of nitrogen (N) addition on dissolved carbon in boreal forest soils is essential for accurate evaluation of regional carbon balances. The objective of this study was to determine the effects of different levels and types of N addition on soil dissolved carbon concentration in a cold-temperate coniferous forest through an in-situ fertilization experiment. Simulated atmospheric N addition was applied in a factorial experiment with N addition level (control, 10, 20 and 40 kg of N ha−1yr−1) and N type (NH4Cl, KNO3 and NH4NO3) treatments. The experiment was conducted over the 2010 growing season (May-September) at the Kailaqi farm of Genhe Forestry Bureau, located in the northern Great Xin’an mountain range, northern China. Monthly N addition treatments were applied in three replicate plots per treatment (n = 36), and measurements of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were derived from monthly sampling of the organic and mineral soil horizons. There was a significant effect of N type, with the combined N source (NH4NO3) producing significantly higher DOC than the control (ambient addition) or the NH4Cl treatment in both the organic and mineral layers. The N addition treatment increased DIC in the organic layer at the low levels only, while N type did not have a significant effect. There was a significant interaction of the month and the N level treatment, as low level N addition tended to increase the content of soil DOC while high level N tended to inhibit soil DOC content, with these trends being most pronounced in the middle of the growing season. These results elucidate the importance of the type and timing of N additions to the dynamics of soil carbon pools.

Terapi Ammonium Khlorida-Asam Askorbat untuk Menurunkan Tingkat Keasaman Urin dan Kristalisasi Struvit pada Kucing Urolithiasis (THERAPY AMMONIUM CHLORIDE-ASCORBIC ACID FOR LOWERING URINE ACIDITY AND STRUVITE CRYSTALLIZATION IN FELINE UROLITHIASIS)

Struvite/Magnesium ammonium phosphate (MAP) is common causes of feline urolithiasis. Prevent the formation of MAP crystallization can be treated by adjusting the pH urine in acid conditions. Urine with an acid pH will decrease struvite activity product (SAP) by preventing the phosphate deprotonation process which is the main constituent of struvite components. This study aims to determine the potential of a combination of ammonium chloride (NH4Cl) and ascorbic acid to decrease SAP by retain the urine pH under normal conditions. Twelve male cats, 2-5 years old and body weight 3.0 ± 0.8 kg were diagnosed struvite urolithiasis used for this study. Cats have a9clinical history of hematuria, dysuria, polyuria, and stranguria. Diagnosis of urolithiasis performed by clinical examination, USG, x-rays, and urinalysis. Cats that found struvite urolith, treated with 200 mg/kg NH4Cl and 100 mg/kg ascorbic acid orally twice a day. The research objects were observed included urine pH and crystaluria density. The data were analyzed using analisis of varian. The result of this study showed NH4Cl and ascorbic acid treatment can decrease the urine pH at 8 cats (89%) with an average pH 6.3 ± 0.3. Microscopic examination of the urine showed the struvite crystallization more infrequently than before therapy. The study concluded that the combination of NH4Cl and asam askorbat can lower the urine pH and reduce struvite crystal density in the urine.

NH4Cl treatment prevents doxorubicin-induced myocardial dysfunction in vivo

AimsImprovements in cancer treatment have significantly extended the lifespan of patients. However, due to the adverse effects of cancer treatment, cancer survivors are at increased risk of cardiovascular complications. Doxorubicin is a widely used spectrum antitumor drug, but the life-threatening side-effect of cardiotoxicity limits its clinical application. Ammonium chloride (NH4Cl), as a heteropolar compound with pH value regulation, can cause intracellular alkalization and metabolic acidosis thus effecting enzymatic activity and influencing the process of biological system. The underlying effect of NH4CL in DOX-induced cardiomyocyte apoptosis and hypertrophy in mice has never been reported before. Main methodsThis study we used DOX to induce cardiac remodeling and dysfunction in mice. Myocardial histology was performed using HE staining. Myocardial cell size was measured by wheat germ agglutinin (WGA) staining. Echocardiographic evaluation of cardiac function, qPCR detection of the mRNA expression of cardiac hypertrophy and inflammation markers. Apoptosis was detected by TUNEL method. Transmission electron microscopy (TEM) was used to detect autophagy. Key findingsWe found that NH4CL effectively improved DOX-induced cardiomyocyte apoptosis and cardiac dysfunction in mice. Our results showed that NH4CL significantly improved DOX-induced contractile dysfunction, inflammation, apoptosis and autophagy in mice. SignificanceOur results indicate that NH4CL is effective in improving DOX-induced cardiac dysfunction and remodeling. It may therefore be a therapeutic entry point to limit doxorubicin-mediated adverse cardiac reactions.

Two-Dimensional Perovskite Solar Cells with 14.1% Power Conversion Efficiency and 0.68% External Radiative Efficiency

Quasi-2D perovskites are attractive because of their improved stability compared to 3D counterparts, but they suffer from reduced performance. Here we report an efficient quasi-2D perovskite (PEA)2(MA)4Pb5I16-based optoelectronic device processed with NH4SCN and NH4Cl additives, showing a stabilized photovoltaic power conversion efficiency as high as 14.1% (average value 12.9 ± 0.8%), which is among the highest-performing quasi-2D perovskite solar cells. These additives increase the perovskite crystallinity and induce a preferred orientation with the (0k0) planes perpendicular to the substrate, resulting in improved transport properties and hence increased short-circuit current density. Furthermore, the NH4Cl treatment enriches the Cl– concentration near the PEDOT:PSS/perovskite interface, which passivates the electron traps, leading to an enhanced electroluminescence external quantum efficiency (0.68% at +2.5 V bias). As a result, high open-circuit voltages of 1.21 ± 0.01 V with a record low nonradiative...

Influence of NH4Cl treatment on physical properties of CdTe thin films for absorber layer applications

The physical properties of electron beam evaporated and chlorine-passivated CdTe thin films are investigated and the influence of NH4Cl treatment on these properties is studied. X-ray diffraction, UV–Vis spectrophotometry, energy-dispersive spectroscopy, atomic force microscopy, and a source meter were used to investigate the physical properties, which were optimized by varying the temperature of the treatment after NH4Cl activation. Structural analysis reveals that the crystallinity is increased at lower annealing temperature while a partial phase transition and oxidation are observed at higher annealing temperature. The absorbance is high in the visible region, and a red shift is observed at higher wavelength, while the direct bandgap is tuned by chlorine activation. The deposition of thin films and chlorine treatment were confirmed by elemental analysis. Surface topographical study reveals that the average roughness is increased with an annealing temperature up to 320 °C, while the I-V characteristics indicated ohmic nature of the contacts. The optimized results show that the NH4Cl-treated CdTe films annealed at 320 °C may be applicable as an absorber layer in solar cells.

Role of sodium-hydrogen exchanger isoform 1 in regulating hepatocyte apoptosis induced by hyperammonaemia

BackgroundThe “secondary injury” theory of liver failure indicated that hyperammonaemia due to liver failure causes further deterioration of hepatocytes. Our previous studies have demonstrated that high blood ammonia levels may lead to hepatocyte apoptosis, as NH4Cl loading caused metabolic acidosis and an increase in sodium-hydrogen exchanger isoform 1 (NHE1). In this study, we established a hyperammonia hepatocyte model to determine the role of NHE1 in the regulation of hepatocyte apoptosis induced by NH4Cl. Materials and methodsIn current studies, intracellular pH (pHi) and NHE1 activity were analyzed using the pHi-sensitive dye BCECF-AM. The results showed that intracellular pH dropped and NHE1 activity increased in hepatocytes under NH4Cl treatment. As expected, decreased pHi induced by NH4Cl was associated with increased apoptosis, low cell proliferation and ATP depletion, which was exacerbated by exposure to the NHE1 inhibitor cariporide. We also found that NH4Cl treatment stimulated PI3K and Akt phosphorylation and this effect was considerably reduced by NHE1 inhibition. ConclusionThis study highlighted the significant role of NHE1 in the regulation of cell apoptosis induced by hyperammonaemia.

HIV-1 Nef Antagonizes SERINC5 Restriction by Downregulation of SERINC5 via the Endosome/Lysosome System.

The primate lentiviral accessory protein Nef downregulates CD4 and major histocompatibility complex class I (MHC-I) from the cell surface via independent endosomal trafficking pathways to promote viral pathogenesis. In addition, Nef antagonizes a novel restriction factor, SERINC5 (Ser5), to increase viral infectivity. To explore the molecular mechanism of Ser5 antagonism by Nef, we determined how Nef affects Ser5 expression and intracellular trafficking in comparison to CD4 and MHC-I. We confirm that Nef excludes Ser5 from human immunodeficiency virus type 1 (HIV-1) virions by downregulating its cell surface expression via similar functional motifs required for CD4 downregulation. We find that Nef decreases both Ser5 and CD4 expression at steady-state levels, which are rescued by NH4Cl or bafilomycin A1 treatment. Nef binding to Ser5 was detected in living cells using a bimolecular fluorescence complementation assay, where Nef membrane association is required for interaction. In addition, Nef triggers rapid Ser5 internalization via receptor-mediated endocytosis and relocalizes Ser5 to Rab5+ early, Rab7+ late, and Rab11+ recycling endosomes. Manipulation of AP-2, Rab5, Rab7, and Rab11 expression levels affects the Nef-dependent Ser5 and CD4 downregulation. Moreover, although Nef does not promote Ser5 polyubiquitination, Ser5 downregulation relies on the ubiquitination pathway, and both K48- and K63-specific ubiquitin linkages are required for the downregulation. Finally, Nef promotes Ser5 colocalization with LAMP1, which is enhanced by bafilomycin A1 treatment, suggesting that Ser5 is targeted to lysosomes for destruction. We conclude that Nef uses a similar mechanism to downregulate Ser5 and CD4, which sorts Ser5 into a point-of-no-return degradative pathway to counteract its restriction.IMPORTANCE Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) express an accessory protein called Nef to promote viral pathogenesis. Nef drives immune escape in vivo through downregulation of CD4 and MHC-I from the host cell surface. Recently, Nef was reported to counteract a novel host restriction factor, Ser5, to increase viral infectivity. Nef downregulates cell surface Ser5, thus preventing its incorporation into virus particles, resulting in disruption of its antiviral activity. Here, we report mechanistic studies of Nef-mediated Ser5 downregulation in comparison to CD4 and MHC-I. We demonstrate that Nef binds directly to Ser5 in living cells and that Nef-Ser5 interaction requires Nef association with the plasma membrane. Subsequently, Nef internalizes Ser5 from the plasma membrane via receptor-mediated endocytosis, and targets ubiquitinated Ser5 to endosomes and lysosomes for destruction. Collectively, these results provide new insights into our ongoing understanding of the Nef-Ser5 arms race in HIV-1 infection.

Blood-to-Retina Transport of Fluorescence-Labeled Verapamil at the Blood-Retinal Barrier.

To investigate the blood-to-retina verapamil transport at the blood-retinal barrier (BRB). EverFluor FL Verapamil (EFV) was adopted as the fluorescent probe of verapamil, and its transport across the BRB was investigated with common carotid artery infusion in rats. EFV transport at the inner and outer BRB was investigated with TR-iBRB2 cells and RPE-J cells, respectively. The signal of EFV was detected in the retinal tissue during the weak signal of cell impermeable compound. In TR-iBRB2 cells, the localization of EFV differed from that of LysoTracker® Red, a lysosomotropic agent, and was not altered by acute treatment with NH4Cl. In RPE-J cells, the punctate distribution of EFV was partially observed, and this was reduced by acute treatment with NH4Cl. EFV uptake by TR-iBRB2 cells was temperature-dependent and membrane potential- and pH-independent, and was significantly reduced by NH4Cl treatment during no significant effect obtained by different extracellular pH and V-ATPase inhibitor. The EFV uptake by TR-iBRB2 cells was inhibited by cationic drugs, and inhibited by verapamil in a concentration-dependent manner with an IC50 of 98.0μM. Our findings provide visual evidence to support the significance of carrier-mediated transport in the blood-to-retina verapamil transport at the BRB.

Toxic effects and possible mechanisms of hydrogen sulfide and/or ammonia on porcine oocyte maturation in vitro

Previous studies suggest that hydrogen sulfide (H2S) and ammonia (NH3) are two major air pollutants which can cause damage to porcine health. However, the mechanisms underlying toxic effects of these compounds on porcine oocyte maturation are not clear. To clarify the mechanism, we evaluated the oocyte quality by detecting some events during oocytes maturation. In our study, porcine oocytes were cultured with different concentrations of Na2S and/or NH4Cl in vitro and the rate of the first polar body extrusion decreased significantly. Also, actin filament was seriously disrupted to damage the cytoskeleton which resulted in reduced rate of oocyte maturation. We explored the reactive oxygen species (ROS) generation and found that the ROS level was increased significantly after Na2S treatment but not after NH4Cl treatment. Moreover, early stage apoptosis rate was significantly increased and autophagy protein LC3 B expression level was higher in oocytes treated with Na2S and/or NH4Cl, which might be caused by ROS elevation. Additionally, exposure to Na2S and/or NH4Cl also caused ROS generation and early apoptosis in cumulus cells, which might further affect oocyte maturation in vitro. In summary, our data suggested that exposure to H2S and/or NH3 decreased porcine oocyte maturation in vitro, which might be caused by actin disruption, ROS generation, early apoptosis and autophagy.

Facile preparation of core cross-linked nanomicelles based on graft copolymers with pH responsivity and reduction sensitivity for doxorubicin delivery

To achieve passive targeting and controlled drug release at tumor sites trigged by low pH value and high level of glutathione (GSH), optimized delivery system for doxorubicin (DOX) based on core cross-linked nanomicelles was developed in this research. Particularly, methoxypoly(ethylene glycol)-nitrophenyl carbonate (mPEG-NPC) and 3,4-dihydroxyphenylaceticacid were grafted onto synthesized poly(N,N′-cystamine bisacrylamide-N-Boc-1,2-diaminoethane) (poly(CBA-DAE)) to give methoxypoly(ethylene glycol)-g-poly(N,N′-cystamine bisacrylamide-N-Boc-1, 2-diaminoethane)-g-3, 4-dihydroxyphenylaceticacid (mPEG-g-SS-PCD-DA). Core cross-linked micelles (CCLMs/SS) with a decreased average particle size of 121nm were prepared by adding Fe3+ into uncross-linked micelles (UCLMs/SS) self-assembled from mPEG-g-SS-PCD-DA. DOX-loaded CCLMs/SS exhibited minimal drug leakage (17.3%) under simulated blood conditions compared to DOX-loaded UCLMs/SS (31.3%). Fast drug release (52.4%) of DOX-loaded CCLMs/SS was achieved compared to DOX-loaded CCLMs/CC (32.9%) without disulfide bonds under simulated lysosomes condition over 42h. The cytotoxicity of DOX-loaded CCLMs/SS against A549 cells pretreated with 40mM NH4Cl was decreased significantly compared to that without NH4Cl treatment, and it is higher than that of DOX-loaded CCLMs/CC, further confirmed DOX release was triggered by the low pH value and high level of reductive agents of lysosomes. Compared with free DOX, DOX-loaded CCLMs/SS showed enhanced cellular uptake ability during 24h of incubation through endocytosis. Besides, charge conversion of micelles happened when pH varied from 7.4 to 6.5, which facilitates the cellular uptake against A549 cells. In summary, all these results indicated that CCLMs/SS as a new type of intelligent nanocarriers exhibited excellent potential for drug delivery.

Nanomicelle drug with acid-triggered doxorubicin release and enhanced cellular uptake ability based on mPEG-graft-poly(N-(2-aminoethyl)-L-aspartamide)-hexahydrophthalic acid copolymers.

In order to achieve the passive tumor targeting and acid-triggered drugs release in lysosomes, optimized delivery system for doxorubicin based on pH-sensitive complex nanomicelles with suitable particle size was developed in this research. Particularly, poly(L-succinimide) was thoroughly ring-opened by ethylenediamine to give the poly(N-(2-aminoethyl)-L-aspartamide). Then, graft copolymer mPEG-graft-poly(N-(2-aminoethyl)-L-aspartamide)-hexahydrophthalic acid (mPEG-g-P(ae-Asp)-Hap) was synthesized by grafting mPEG-2000 and hexahydrophthalic anhydride onto poly(N-(2-aminoethyl)-L-aspartamide). Invitro studies revealed that mPEG-g-P(ae-Asp)-Hap copolymer was stable in neutral solutions but tend to be hydrolyzed under acidic condition, which was attributed to the acid-sensitive properties of hexahydrophthalic amides (β-carboxylic amides). MPEG-g-P(ae-Asp)-Hap copolymer with critical aggregation concentration of 0.166 mg·mL-1 could self-assemble into stable blank nanomicelles with an average particle hydrodynamic diameter of 98.1 nm, but the hydrodynamic diameter of doxorubicin-loaded nanomicelles (mPEG-g-P(ae-Asp)-Hap·Dox) was smaller and approximately 77.5 nm. MPEG-g-P(ae-Asp)-Hap·Dox nanomicelles showed sustained drug release profiles over 34 h, and the cumulative drug release showed a tendency to increase from 25% to 62% with the pH value decreasing from 7.4 to 5.0 due to the acid-triggered disassembly of nanomicelles. The cytotoxicity of mPEG-g-P(ae-Asp)-Hap·Dox nanomicelles against A549 treated with 40 mM NH4Cl (lysosomotropic weak bases) was decreased significantly than that without NH4Cl treatment, further confirmed the drug release from the nanomicelles was triggered by the low pH value of lysosome (pH 5.0). Compared with doxorubicin HCl, mPEG-g-P(ae-Asp)-Hap·Dox nanomicelle drug showed enhanced cellular uptake ability during 2 or 4 h of incubation due to the endocytosis mechanism of nanomicelle drug. In summary, the cleavage of pH-sensitive β-carboxylic amides bonds on the hydrophobic branch of mPEG-g-P(ae-Asp)-Hap copolymer triggered the disassembly of the nanomicelles and release of doxorubicin in the acidic lysosomal compartments of cancer cells. These nanomicelles exhibited excellent potential for drug delivery due to their smart properties-PEGylation, suitable size, and acid-triggered drug release.

NH4Cl affects the expression of Wnt/β-catenin pathway in hepatocytes.

We intended to explore whether NH4Cl influences the viability and regulates the expression of Wnt/β-catenin pathway in hepatocytes. The Chang liver cell line was used and cultured with different concentrations of NH4Cl (2.5, 5, 10, 20, 40, and 50 mmol/L) for 12, 24, and 48 h. The viability of hepatocytes was detected by MTT assay. The mRNA and protein expression level was analyzed with qRT-PCR and Western blotting, respectively. NH4Cl concentration significantly affects the viability of hepatocytes. With the increase of NH4Cl concentration, the viability of hepatocytes was decreased, accordingly. The mRNA and protein expression of Wnt1, β-catenin, and cyclin D was significantly increased after treatment with low concentrations of NH4Cl as compared with the control group, whereas their expression levels were decreased after treatment with high concentrations of NH4Cl. The mRNA and protein expression of Wnt1, β-catenin, and cyclin D was also significantly increased after treatment with NH4Cl for a short period as compared with the control group, whereas their expression levels were decreased after treatment with NH4Cl for a long period. In addition, we found NH4Cl treatment significantly reversed the results after RNA silencing of Wnt1 in hepatocytes. NH4Cl influences the viability of hepatocytes and affects the expression of Wnt/β-catenin pathway in hepatocytes.

Impacts of long-term nitrogen fertilization on acid buffering rates and mechanisms of a slightly calcareous clay soil

Acidification of cropland soils is a serious problem in China that may cause long term pH decline, which threatens the sustainability of soil fertility and crop yields. The objective of this research was to investigate those rates and mechanisms for a slightly calcareous soil. The field data were based on selected treatments from a long-term (1991–2015) N fertilization experiment at a rice-wheat rotation on a slightly calcareous (pH7.7), young and hardly weathered clay soil (Regosol), including two plots with urea and NH4Cl fertilization and a control plot (no N fertilization). Urea and NH4Cl were applied at annual rates of 300kg (1991–1996) and 285kg (1997–2015) N ha−1. Soil pH and exchangeable Ca2+ and Mg2+ declined in the first 12years for the urea treatments, but remained constant thereafter. For the NH4Cl and control treatment, the exchangeable base cations showed an oscillating decrease over the 25years. Soil pH and exchangeable Ca2+, and Mg2+ levels were significantly (P<0.05) lower in the NH4Cl treatment plot than the control. After 25years, soil pH in the plots receiving urea and NH4Cl were 0.9 and 2.0 units lower than the control, respectively, while the total exchangeable base cations were about 10% and 16% lower, respectively. Carbonate dissolution, base cation exchange and mineral weathering were the main H+ buffer pathways of the Regosol. Long-term N fertilization favored the formation of smectite and vermiculite and accelerated the weathering of mica, potassium feldspar, and illite. This was more evident in the NH4Cl treatment than in the urea treatment. Consequently, the soil acid-buffering capacity was slightly enhanced after year 13 in the order of urea>control>NH4Cl. The increased weathering of soil primary minerals and clay minerals was the main reason that soil pH and exchangeable base cations stayed constant after about 12years.

Effects of chronic ammonia exposure on ammonia metabolism and excretion in marine medaka Oryzias melastigma

Ammonia is highly toxic to aquatic organisms, but whether ammonia excretion or ammonia metabolism to less toxic compounds is the major strategy for detoxification in marine fish against chronic ammonia exposure is unclear to date. In this study, we investigated the metabolism and excretion of ammonia in marine medaka Oryzias melastigma during chronic ammonia exposure. The fish were exposed to 0, 0.1, 0.3, 0.6, and 1.1 mmol l−1 NH4Cl spiked seawater for 8 weeks. Exposure of 0.3–1.1 mmol l−1 NH4Cl had deleterious effects on the fish, including significant reductions in growth, feed intake, and total protein content. However, the fish could take strategies to detoxify ammonia. The tissue ammonia (TAmm) in the 0.3–1.1 mmol l−1 NH4Cl treatments was significantly higher than those in the 0 and 0.1 mmol l−1 NH4Cl treatments after 2 weeks of exposure, but it recovered with prolonged exposure time, ultimately reaching the control level after 8 weeks. The amino acid catabolic rate decreased to reduce the gross ammonia production with the increasing ambient ammonia concentration. The concentrations of most metabolites remained constant in the 0–0.6 mmol l−1 NH4Cl treatments, whereas 5 amino acids and 3 energy metabolism-related metabolites decreased in the 1.1 mmol l−1 NH4Cl treatment. JAmm steadily increased in ambient ammonia from 0 to 0.6 mmol l−1 and slightly decreased when the ambient ammonia concentration increased to 1.1 mmol l−1. Overall, marine medaka cope with sublethal ammonia environment by regulating the tissue TAmm via reducing the ammonia production and increasing ammonia excretion.

Fast recovery of Brønsted acid sites lost during high-temperature calcination in HZSM-5

HZSM-5 was prepared by the hydrothermal method using TPAOH as a structure directing agent without Na+ addition. The calcination process for removing the organic templates was studied and particularly the influence of calcination temperature on zeolite structure and acid property was investigated. It was found that dehydrogenation of Brønsted acid sites in zeolite framework occurred with the elevation of calcination temperature, leading to a decrease of catalytic activity for n-decane cracking. To recover the Brønsted acid sites in zeolite lost during calcination, the calcinated zeolite was treated with various reagents, including H2O, H2O2, NH3 and NH4Cl, to turn Lewis acid sites back to Brønsted acid sites. Among them, the NH4Cl treatment was found to be the most effective way, which increased conversion of n-decane from 6% to 77% and increased the B/L acid sites ratio from 0.503 to 3.95. This enhancement of catalytic cracking ability is probably related to the formation of an intermediate active component ([AlO4]0) during high temperature calcination, and these intermediate sites promoted the protonation of Lewis acid sites in the NH4Cl treatment process.

Effect of different concentrations of ammonium chloride on expression of hypoxia-inducible factor-1α in Chang liver cells

Objective: To investigate the effect of treatment with different concentrations of ammonium chloride (NH4Cl) on the mRNA and protein expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in Chang liver cells. Methods: Normal Chang liver cells were cultured and treated continuously with different concentrations of NH4Cl (1.25, 2.5, and 5 mmol/L). The Chang liver cells cultured normally were used as controls. RNA and protein were extracted at the 5th, 10th, and 15th generations. Quantitative real-time PCR, immunohistochemistry, and Western blot were used to measure the expression of HIF-1α and VEGF. Results: Quantitative real-time PCR showed that compared with the control group, the NH4Cl treatment group showed significant increases in the mRNA expression of HIF-1α and VEGF across the 5th, 10th, and 15th generations (F = 90976.659/1300.218/1896.800 and 41825.754/2381.321/2591.954, all P < 0.05). The results of immunohistochemistry showed that compared with the control group, the NH4Cl treatment group showed significant increases in the protein expression of HIF-1α and VEGF across the 5th, 10th, and 15th generations (F = 376.709/1615.358/1350.120 and 904.789/5105.186/8644.498, all P < 0.05). As was shown by the results of Western blot, compared with the control group, the NH4Cl treatment group showed significant increases in the protein expression of HIF-1α and VEGF across the 5th, 10th, and 15th generations (F = 228.499/6051.974/183.219 and 5549.429/40187.665/120982.183, all P < 0.05). Conclusion: Ammonia can increase the expression of HIF-1α and its downstream gene VEGF in Chang liver cells and cause the phenomenon of pseudohypoxemia.

1,25(OH)2D3 dependent overt hyperactivity phenotype in klotho-hypomorphic mice.

Klotho, a protein mainly expressed in kidney and cerebral choroid plexus, is a powerful regulator of 1,25(OH)2D3 formation. Klotho-deficient mice (kl/kl) suffer from excessive plasma 1,25(OH)2D3-, Ca2+- and phosphate-concentrations, leading to severe soft tissue calcification and accelerated aging. NH4Cl treatment prevents tissue calcification and premature ageing without affecting 1,25(OH)2D3-formation. The present study explored the impact of excessive 1,25(OH)2D3 formation in NH4Cl-treated kl/kl-mice on behavior. To this end kl/kl-mice and wild-type mice were treated with NH4Cl and either control diet or vitamin D deficient diet (LVD). As a result, plasma 1,25(OH)2D3-, Ca2+- and phosphate-concentrations were significantly higher in untreated and in NH4Cl-treated kl/kl-mice than in wild-type mice, a difference abrogated by LVD. In each, open field, dark-light box, and O-maze NH4Cl-treated kl/kl-mice showed significantly higher exploratory behavior than untreated wild-type mice, a difference abrogated by LVD. The time of floating in the forced swimming test was significantly shorter in NH4Cl treated kl/kl-mice compared to untreated wild-type mice and to kl/kl-mice on LVD. In wild-type animals, NH4Cl treatment did not significantly alter 1,25(OH)2D3, calcium and phosphate concentrations or exploratory behavior. In conclusion, the excessive 1,25(OH)2D3 formation in klotho-hypomorphic mice has a profound effect on murine behavior.

Mechanism of inhibition and decoupling of oxygen evolution from electron transfer in photosystem II by fluoride, ammonia and acetate

Ca2+ extraction from oxygen-evolving complex (OEC) of photosystem II (PSII) is accompanied by decoupling of oxygen evolution/electron transfer processes [Semin et al. Photosynth. Res. 98 (2008) 235] and appearance of a broad EPR signal at g=2 (split “S3” signal) what can imply the relationship between these effects. Split signal have been observed not only in Ca-depleted PSII but also in PSII membranes treated by fluoride anions, sodium acetate, and NH4Cl. Here we investigated the question: can such compounds induce the decoupling effect during treatment of PSII like Ca2+ extraction does? We found that F−, sodium acetate, and NH4Cl inhibit O2 evolution in PSII membranes more effectively than the reduction of artificial electron acceptor 2,6-dichlorophenolindophenol, i.e. the action of these compounds is accompanied by decoupling of these processes in OEC. Similarity of effects observed after Ca2+ extraction and F−, CH3COO− or NH4Cl treatments suggests that these compounds can inactivate function of Ca2+. Such inactivation could originate from disturbance of the network of functionally active hydrogen bonds around OEC formed with participation of Ca2+. This inhibition effect is observed in the region of low concentration of inhibitors. Increasing of inhibitor concentration is accompanied by appearance of other sites of inhibition.

Endogenous grouper and barramundi Mx proteins facilitated the clearance of betanodavirus RNA-dependent RNA polymerase

This study confirmed that the infection of nervous necrosis virus (NNV), belonging to the betanodavirus, can induce the expression of endogenous Mx in grouper fin-3 (GF-3), grouper brain (cGB), and barramundi brain (cBB) cells, but not in grouper fin-1 (GF-1) cells. In a co-sedimentation assay, RdRp appeared in the mitochondrial pellet of GF-1 cells without endogenous Mx expression. However, in GF-3, cGB, and cBB cells, RdRp was detected in the nuclear pellet accompanied by endogenous Mx. By immunostaining, RdRp was found to colocalize with not only endogenous Mx but also lysosomes and monodansylcadaverine (MDC)-labeled autophagic vacuoles. In GF-1 cells, the RdRp level continuously increased during 24–72 h post infection (hpi). When endogenous Mx expressed during 24–72 hpi in virus-infected GF-3, cGB, and cBB cells, the RdRp level peaked at 24 hpi but decreased at 48–72 hpi. The degradation of RdRp could be suppressed by treatment with 3-methyladenine (3MA), NH4Cl, and Mx-specific siRNA respectively. After poly I:C transfection, the endogenous Mx level peaked at 3 days post transfection (dpt) and then spontaneously decreased at 5–7 dpt. The poly I:C-indued Mx also colocalized with MDC-labeled autophagic vacuoles at 3 dpt, and its degradation could be inhibited by 3MA or NH4Cl treatments. Therefore, the anti-NNV mechanism of endogenous grouper and barramundi Mx is suggested to sequester RdRp for degradation through autophagy and lysosomes.