Polyvinylpyrrolidone-Aminopropyl-SBA-15 schiff Base hybrid for efficient removal of divalent heavy metal cations from wastewater.

The mesoporous silica-polymer hybrid was prepared as an adsorbent for divalent heavy metals (Pb(II), Ni(II), and Cu (II)) from rice husk and polyvinylpyrrolidone (PVP) through three successive steps. The first is the preparation of the mesoporous silica (SBA-15), the second is grafting 3-aminopropyltrimethoxysilane on SBA-15, and the following step is the formation of Schiff base (PVP-SBA-15) between amine end-capped silica and PVP moieties. The materials were characterized by different techniques, including FTIR, low and wide-angle XRD, N2-adsorption, and HR-TEM. The NH2-SBA-15 displayed a moderate affinity toward heavy element ions under study. Grafting of PVP moieties introduces a high affinity toward heavy metal ions, and the adsorption is a well-fitted Langmuir adsorption model. A series of experiment adsorption equilibrium reported with SBA-15, NH2-SBA-15, and PVP-SBA-15, which showed an adsorption capacity of 128 mg/g (Cu (II)), 175 mg/g (Pb (II)) and 72 mg/g for Ni(II). Kinetic studies have shown that the best way to describe the adsorption process of heavy metals is pseudo-first-order. The value of ΔG°, ΔH°, and ΔS° demonstrated that the adsorption of heavy metals on the PVP-SBA-15 was endothermic in nature and spontaneous. These results exhibited that PVP-SBA-15 material has considerable competence in eliminating heavy metals from wastewater.

Synthesis and applications of CaCO3/HPC core-shell composite subject to heavy metals adsorption processes.

Core-shell particles are a class of materials from nanostructures that have received increased attention recently due to their interesting properties and wide range of applications in catalysis, biology, chemistry of materials and sensors. Simple and cost-effective one-pot synthesis route to directly prepare CaCO3@highly porous carbon microsphere in a core-shell structure (denoted as CaCO3/HPC) had been developed as a high-performance heavy metals sorbent. XRD (X-Ray Diffraction), SEM (scanning electron microscopy), Raman, FTIR (Fourier Transform Infrared Spectroscopy) and BET tools were used in structure characterization of the products. The adsorption properties of the products obtained were studied. From this study the adsorption performances of CaCO3/HPCwere found to be optimal by comparing the maximum adsorption capacity of heavy metal ions (Pb (II) and Co(III)) with CaCO3/HPC.The adsorption of CaCO3/HPCtest to Pb(II) and Co(III), in particular Pb(II) had a good effect over a wide pH range (pH 2-7). The maximum adsorption capacitiesof CaCO3/HPC for Pb (II) and Co(III) were 677.6 mg/g, and 308.5 mg/g, respectively, at pH = 6 (lead ion was 5.5) and 25 °C, and the adsorption rate was fast. The lead ions can be adsorbed almost entirely in 5 minutes and only 0.2 g/L was the best effective doseof adsorbent. The prepared and carefully testednanocomposites had been found to be of excellent performances in adsorption and in analytical regeneration. The adsorption processof Pb(II) and Co(III) through core shell of the preparednanocomposite adsorbent was found to be a second-order chemical adsorption and fit for Langmuir and Freundlich isotherms, in the form of amonomolecular and multi-layer heavy metal adsorptionprocesses. The (CaCO3/HPC)-based sorbents (with and without) pelletization shows superior heavy metals adsorption performances compared to a CaCO3-based sorbent.

Synthesis of recyclable carbon/lignin biocomposite sorbent for in-situ uptake of BTX contaminants from wastewater.

In this work, both palm-date pits and pulping black liquor industrial wastes were recycled as low-cost starting materials for the production of three series of granule activated carbon (gAC)/Kraft lignin (KL) (gAC/KLx, x = 33, 50 and 67%) biocomposites using a one-pot solid-state method. The gAC/KLx biocomposites with defined characteristics were examined towards batch adsorption of BTX (Benzene, Toluene, and Xylene) in multi-solute salty wastewaters. Optimization of adsorption performances under different experimental conditions were carried out using high performance liquid chromatography (HPLC). Adsorption modeling versus contact time (0-12 h) and BTX concentrations (150-2250 mg/L) were examined using non-linear forms of nine kinetic and five isotherm equations to best understand gAC/KL0.5 suitability for BTX sorption/recovery processing. Accordingly, the gAC/KLx at KL blended ratio of 50% was found to be the topmost to achieve the highest BTX capacity even at broad ranges of water salinity (0-100 g/L) and pH (3-9) values. The adsorption mechanism found to best described by physico-sorption (E ≈ 0.12-1.38 kJ/mol) via the hydrophobic interaction and diffusion mechanisms. In respect to gAC/KL0.5 affinities, the sorption capacity followed the descending sequence of X ≥ T > B. Particularly, the maximum theoretical BTX capacity using the best fitted Langmuir-Freundlich model (L-FM) for gAC/KL0.5 was found to be slightly higher than obtained by gAC (363.9 and 360.1 mg/g, respectively), along with higher initial sorption (h) rate (≈742.47 mg/g.h) than of gAC (≈559.85 mg/g.h) and KL (≈22.22 mg/g.h). Batch BTX sorption/recovery processes and estimated cost suggested the effective utilization of gAC/KL0.5 as a promising in-expensive sorbent (0.31 ±â€¯0.05 US$/kg) for commercial decontamination of petroleum hazardous (BTX) pollutants from wastewaters up to five reuse cycles.

Synthesis, spectroscopic, thermal, antimicrobial and electrochemical characterization of some novel Ru(iii), Pt(iv) and Ir(iii) complexes of pipemidic acid.

Three new solid complexes of pipemidic acid (Pip-H) with Ru3+, Pt4+ and Ir3+ were synthesized and characterized. Pipemidic acid acts as a uni-dentate chelator through the nitrogen atom of the -NH piperazyl ring. The spectroscopic data revealed that the general formulas of Pip-H complexes are [M(L) n (Cl) x ]·yH2O ((1) M = Ru3+, L: Pip-H, n = 3, x = 3, y = 6; (2) M = Pt4+, L: Pip-NH4, n = 2, x = 4, y = 0 and (3) M = Ir3+, L: Pip-H, n = 3, x = 3, y = 6). The number of water molecules with their locations inside or outside the coordination sphere were assigned via thermal analyses (TG, DTG). The DTG curves refer to 2-3 thermal decomposition steps where the first decomposition step at a lower temperature corresponds to the loss of uncoordinated water molecules followed by the decomposition of Pip-H molecules at higher temperatures. Thermodynamic parameters (E*, ΔS*, ΔH* and ΔG*) were calculated from the TG curves using Coats-Redfern and Horowitz-Metzeger non-isothermal models. X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques were carefully used to assign properly the particle sizes of the prepared Pip-H complexes. The biological enhancement of Pip-H complexes rather than free chelate were assessed in vitro against four kinds of bacteria G(+) (Staphylococcus epidermidis and Staphylococcus aureus) and G(-) (Klebsiella and Escherichia coli) as well as against the human breast cancer (MCF-7) tumor cell line.

Evening primrose oil and celecoxib inhibited pathological angiogenesis, inflammation, and oxidative stress in adjuvant-induced arthritis: novel role of angiopoietin-1.

Rheumatoid arthritis is a chronic inflammatory disease characterized by overproduction of inflammatory mediators along with undermined oxidative defensive mechanisms. Pathological angiogenesis was found to play a critical role in the progression of this disease. The current study was carried out to evaluate the anti-angiogenic, anti-inflammatory, and anti-oxidant effects of evening primrose oil (EPO), rich in gamma linolenic acid (GLA), either alone or in combination with aspirin or celecoxib, on adjuvant-induced arthritis. Arthritis was induced by subcutaneous injection of complete Freund's adjuvant (CFA) in the right hind paw of male albino rats. All treatments were administered orally from day 0 (EPO, 5 g/kg b.w.) or day 4 (celecoxib, 5 mg/kg; aspirin, 150 mg/kg) till day 27 after CFA injection. In the arthritic group, the results revealed significant decrease in the body weight and increase in ankle circumference, plasma angiopoietin-1 (ANG-1) and tumor necrosis factor-alpha (TNF-α) levels. Anti-oxidant status was suppressed as manifested by significant decline in reduced glutathione content along with decreased enzymatic activity of superoxide dismutase and increased lipid peroxidation. Oral administration of EPO exerted normalization of body weight, ANG-1, and TNF-α levels with restoration of activity as shown by reduced malondialdehyde levels. Moreover, histopathological examination demonstrated that EPO significantly reduced the synovial hyperplasia and inflammatory cells invasion in joint tissues, an effect that was enhanced by combination with aspirin or celecoxib. The joint use of GLA-rich natural oils, which possess anti-angiogenic, anti-inflammatory, and anti-oxidant activities, with traditional analgesics represents a promising strategy to restrain the progression of rheumatoid arthritis.

15-PGDH inhibitors: the antiulcer effects of carbenoxolone, pioglitazone and verapamil in indomethacin induced peptic ulcer rats.

BACKGROUND AND AIM: 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is the enzyme responsible for prostaglandins (PGs) metabolism. PGs have an important role in the protection of stomach mucosa against destructive stimuli. The aim of the present study is to investigate the inhibitory effect of carbenoxolone, pioglitazone and verapamil on 15-PGDH enzyme. MATERIALS AND METHODS: The experiments were carried out in the Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt from May 2011 to August 2011. Adult male albino rats were fasted for 18 hours before administration of high dose of indomethacin (30 mg/kg, p.o.), except for the negative control group which received saline only, followed by pyloric ligation to induce acute gastric ulcers. The rats were pretreated orally with saline, pioglitazone (20 mg/kg), verapamil (25 mg/kg), carbenoxolone (30 mg/kg) or their combinations 30 minutes before indomethacin. The rats were sacrificed after four hours of pyloric ligation. The effects of the previous treatments on the ulcer index (Ui), the microscopic appearance of gastric mucosa, the gastric acid output, the gastric barrier mucus content, and 15-PGDH enzyme activity were determined. RESULTS: Indomethacin resulted in severe ulceration and increased gastric acid output (p < 0.05) compared to negative control. The rats pretreated with carbenoxolone, pioglitazone, verapamil had reduced ulcer index, gastric acid output and 15-PGDH activity (p < 0.05) compared to either indomethacin group or the negative control group. Individual treatments with carbenoxolone, pioglitazone or verapamil increased gastric barrier mucus (p < 0.05) compared to either indomethacin group or the negative control group. The combinations of verapamil with either carbenoxolone or pioglitazone caused further reduction in ulcer index, gastric acid output and 15-PGDH activity (p < 0.05), while causing further increase in gastric barrier mucus (p < 0.05) compared to their respective individual treatment group. CONCLUSIONS: The antiulcer properties of pioglitazone and verapamil are, in part, consequences of their inhibitory effect on the enzyme 15-PGDH, responsible for PGs degradation, and the resultant prolongation of PGE2 biological activity in rat stomach mucosa.

Sildenafil citrate protects against gastric mucosal damage induced by indomethacin in rats.

BACKGROUND AND OBJECTIVES:   The present study was conducted to investigate the possible gastroprotective effect of sildenafil citrate, a selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase, against indomethacin-induced gastric damage in rats. Further, the study was extended to investigate some possible mechanisms underlying this effect. MATERIALS AND METHODS: Forty rats were assigned to vehicle (saline), control (indomethacin, 30 mg/kg, p.o.), ranitidine (50 mg/kg, p.o.), sildenafil (5 mg/kg, p.o.) and sildenafil (10 mg/kg, p.o.); the drugs were administered 30 minutes prior to indomethacin. Four hours after indomethacin administration, all rats were sacrificed and the gastric juices were collected. Then, each stomach was opened and macroscopically examined for gastric lesions and longitudinal sections were used for biochemical and histopathological analysis. RESULTS: Our results indicated that indome-thacin induced marked ulceration in the gastric mucosa, in addition to an increase in gastric acidity as compared to saline group (p ≤ 0.05). Furthermore, indomethacin group showed lower concentration of mucin and reduced glutathione, whereas, lipid peroxides and tumor necrosis factor-α (TNF-α) were elevated in the stomach homogenate. Pretreatment with sildenafil (5 mg/kg) significantly reduced gastric acid secretion, ulcer score and lipid peroxides production without effect on mucin, TNF-α, or nitric oxide (NO). The higher dose of sildenafil (10 mg/kg) provided similar results with the exception of increasing tissue NO (p ≤ 0.05). CONCLUSIONS: We concluded that sildenafil can protect the gastric mucosa against the aggressive effect of indomethacin via increasing NO and inhibiting lipid peroxidation. Therefore, sildenafil might be helpful in preventing the gastric adverse effects of non-steroidal anti-inflammatory drugs in a clinical setting.

Sex hormone status in male rats after exposure to 50 Hz, 5 mTesla magnetic field.

The question of whether extremely low frequency magnetic fields can affect biological system has attracted attention. The theoretical possibility of such an interaction is often questioned and the site of interaction is unknown. The influence of extremely low frequency magnetic field of 50 Hz, 5 mTesla on sex hormone status was studied. 60 male albino rats were divided into 6 groups and were continuously exposed to 50 Hz, 5 mTesla magnetic field generated by magnetic field chamber for periods of 1, 2 and 4 weeks. For each experimental point, sham treated group was used as a control. Assay of serum testosterone LH, FSH, and prolactin were performed. Serum testosterone showed no significant changes. FSH showed significant increase than sham exposed group after 1 week magnetic field exposure. LH showed significant increase than sham exposed group only after 4 weeks magnetic field exposure, while serum prolactin hormone level showed a significant increase in all magnetic field exposed groups than sham exposed animals. Exposure to 50 Hz, 5 mTesla magnetic field for periods of 1, 2 and 4 weeks has no effect on testosterone level, some changes on FSH and LH serum levels and increase in serum prolactin level.

Diagnostic value of nitric oxide, lipoprotein(a), and malondialdehyde levels in the peripheral venous and cavernous blood of diabetics with erectile dysfunction.

Diabetes mellitus (DM) is the single most common cause of erectile dysfunction (ED) seen in clinical practice. Evaluation of penile arterial insufficiency in diabetic patients currently entails expensive and invasive testing. We assessed the diagnostic value of certain peripheral and cavernous blood markers as predictors of penile arterial insufficiency in diabetic men with ED. This study was conducted on a total of 51 subjects in three groups: 26 impotent diabetics, 15 psychogenic impotent men and 10 normal age matched control males. All subjects underwent standard ED evaluation including estimation of postprandial blood sugar and serum lipid profile. Peripheral venous levels of nitric oxide (NO), lipoprotein(a) (LP(a)), malondialdehyde (MDA) and glycosylated hemoglobin (HbA1c) were obtained in all subjects. Patients in the two impotent groups underwent additional measurement of NO, LP(a) and MDA levels in cavernous blood. They also underwent intracavernosal injection (ICI) of a trimix (papaverine, prostaglandin E1 and phentolamine mixture) and pharmaco-penile duplex ultrasonography (PPDU). Compared to patients in the psychogenic group, diabetic men had significantly lower erectile response to ICI (P<0.001), lower peak systolic velocity (PSV) (P<0.001), and smaller increase in cavernosal artery diameter (CAD) (P<0.001). Peripheral and cavernous levels of both LP(a) and MDA were higher in the diabetic group as compared to the psychogenic ED group (P<0.001), while the values of peripheral venous and cavernous NO were lower (P<0.001) in the diabetic men. Comparison of biochemical marker assays with the PPDU results showed a significant negative correlation between both venous and cavernous LP(a) and MDA levels on the one hand, and PSV, and the percentage of CAD increase on the other. At the same time, peripheral and cavernous NO levels had a significant positive correlation with the same parameters. Lipoprotein(a), MDA and NO levels were better predictors of low PSV than HbA1c, cholesterol or triglyceride levels. The finding of high levels of LP(a) and MDA with low levels of NO in the peripheral and cavernous venous blood of diabetic men with ED correlates strongly with severity of ED as measured by PPDU. This provides a rationale for further studies of biochemical markers as a surrogate for traditional invasive testing in the diagnosis of penile arterial insufficiency.

Effects of acute exposure to the radiofrequency fields of cellular phones on plasma lipid peroxide and antioxidase activities in human erythrocytes.

Radiofrequency fields of cellular phones may affect biological systems by increasing free radicals, which appear mainly to enhance lipid peroxidation, and by changing the antioxidase activities of human blood thus leading to oxidative stress. To test this, we have investigated the effect of acute exposure to radiofrequency fields of commercially available cellular phones on some parameters indicative of oxidative stress in 12 healthy adult male volunteers. Each volunteer put the phone in his pocket in standby position with the keypad facing the body. The parameters measured were lipid peroxide and the activities of superoxide dismutase (SOD), total glutathione peroxidase (GSH-Px) and catalase. The results obtained showed that the plasma level of lipid peroxide was significantly increased after 1, 2 and 4 h of exposure to radiofrequency fields of the cellular phone in standby position. Moreover, the activities of SOD and GSH-Px in human erythrocytes showed significant reduction while the activity of catalase in human erythrocytes did not decrease significantly. These results indicate that acute exposure to radiofrequency fields of commercially available cellular phones may modulate the oxidative stress of free radicals by enhancing lipid peroxidation and reducing the activation of SOD and GSH-Px, which are free radical scavengers. Therefore, these results support the interaction of radiofrequency fields of cellular phones with biological systems.

Evaluation of in vitro antibacterial activity of some disinfectants on Escherichia coli serotypes.

Three disinfectants commonly used in poultry farms (formalin, TH4+, and Virkon-S) were chosen for the present study. The effect of disinfectant concentration and the duration of exposure to these disinfectants on the survival of Escherichia coli serotypes (O114:K-, O86, O55:K39, and O86:K60) were investigated. Formalin (0.6%), TH4+ (0.06%), and Virkon (0.5%) all killed the four serotypes within 5 min of exposure. As the disinfectant concentration decreases, the length of exposure time to kill serotype increases. At 0.03%, 0.007%, and 0.03% of formalin, TH4+ and Virkon-S concentrations failed to kill the four E. coli serotypes within 360 min, respectively. An improvement of the inhibitory effect of these disinfectants occurred when added together with the inoculum instead of an established population. The influence of formalin, TH4+, and Virkon-S on the cell morphology of E. coli O55:K39 was investigated by using transmission electron microscopy. Formalin-treated cells exhibited normal cell morphology, with the exception that the treated cell was less fimbriated, and more destruction of pili increased when formalin concentrations were doubled. Cells treated with TH4+ (0.03%) showed destruction of the cell wall and cell surface membrane after 5 min. Cell filamentation occurred at 0.015% and increased with the increase of exposure time to this drug. Spheroplasts were observed only when cells were treated with 0.125% Virkon-S for 60 min, and cell lysis started to occur when 0.25% Virkon-S was applied for 15 min. Scanning electron microscope study revealed that Virkon-S at 0.03% and TH4+ at 0.007% completely prevented the adherence of E. coli O55:K39 serotype to chicken tracheal organ, whereas formalin (0.03%) disinfection minimized the adherence of E. coli cells to tracheal explants after 360 min of incubation.