Adenine-functionalized Spongy Graphene for Green and High-Performance Supercapacitors.

A simple method is demonstrated to prepare spongy adenine-functionalized graphene (SFG) as interconnected, porous 3-dimensional (3D) network crinkly sheets. Such 3D network structure provides better contact at the electrode/electrolyte interface and facilitates the charge transfer kinetics. The fabricated SFG was characterized by X-ray diffraction (XRD), FTIR, scanning electron microscopy (FESEM), Raman spectroscopy, thermogravimetric analysis (TGA), UV-vis absorption spectroscopy, and transmission electron microscopy (TEM). The synthesized materials have been evaluated as supercapacitor materials in 0.5 M H2SO4 using cyclic voltammetry (CV) at different potential scan rates, and galvanostatic charge/discharge tests at different current densities. The SFG electrodes showed a maximum specific capacitance of 333 F/g at scan rate of 1 mV/s and exhibited excellent cycling retention of 102% after 1000 cycles at 200 mV/s. The energy density was 64.42 Wh/kg with a power density of 599.8 W/kg at 1.0 A/g. Those figures of merit are much higher than those reported for graphene-based materials tested under similar conditions. The observed high performance can be related to the synergistic effects of the spongy structure and the adenine functionalization.

HAV and HEV infection in hospitalised hepatitis patients in Alexandria, Egypt.

A total of 202 serum and stool samples from acute hepatitis patients attending the Fever Hospital of Alexandria, Egypt, have been studied to reveal markers of hepatitis virus infection. Anti-HAV IgM were detected in 21 out of 202 sera (10.4%), whereas 201 sera (99.5%) had anti-HAV IgG. The first age attack was in the class-age 0-9 years with 64.7% of anti-HAV IgM positive sera. Among 202 patients, anti-hepatitis E IgG (sample/over cut off > 1.0) was identified in 90 patients (44.5%). The anti-HEV seropositivity ranged from 17.6% to 60.0% in the different age groups, with the highest level in the class-age 20 29 years. Anti-hepatitis E IgM were identified in 49 patients with the first age attack in the class-age 10-19 years (39.4%). HAV RNA was identified by nested PCR in 7 samples out of 15, whereas HEV RNA was present in 4 out of 75 stool samples. Direct DNA sequence of the latter PCR products confirmed the presence of the HEV genome; comparison of the sequences of the isolates from Egypt with those in data banks revealed the highest homology to the Burma strain. Our data confirm that HAV and HEV are common causes of acute sporadic hepatitis in Alexandria but with different peak age positivity. Occasionally, but not infrequently, dual infections (HAV-HEV and HEV-enteric viruses) were also found. The risk analysis indicates that patients living in rural areas are exposed to a higher risk of hepatitis E infection compared to the urban population, whereas the presence of anti-HEV IgG was significantly associated with consumption of common village water and use of indoor dry pit and oral therapy for schistosomiasis.

Role of calcium in the reaction between pyrroloquinoline quinone and pyridine nucleotides monomers and dimers.

Redox reactions were carried out in aerobiosis and anaerobiosis between NAD(P) dimers or NAD(P)H and pyrroloquinoline quinone (PQQ) in different buffers. The buffer system and pH significantly affected the oxidation rates of nucleotides and the ESR signal intensity of the PQQ(*) radical formed in anaerobiosis by comproportion between the quinone and quinol forms. The relative reactivity of the four nucleotides toward PQQ was affected by pH and buffer nature. PQQ, which behaves as an electron shuttle from nucleotides to oxygen, was first converted to PQQH(2) and then rapidly reoxidized by oxygen, with formation of hydrogen peroxide. Both NAD(P) dimers and NAD(P)H consumed 1 mol of oxygen per mole of reacted molecule of pyridine nucleotide, yielding 1 or 2 mol of NAD(P)(+) from NAD(P)H or from NAD(P) dimers, respectively. Chelating agents such as EDTA and phytate strongly decreased the reaction rate and the PQQ(*) radical signal intensity. Kinetics carried out in the presence of metal ions showed instead an increased reaction rate in the order Ca(2+) >> Mg(2+) > Na(+) >> K(+). Spectrofluorimetric measurements of PQQ with increasing concentrations of Ca(2+) showed a fluorescence quenching and shift of the maximum emission toward lower wavelengths, while other metal ions showed minor effects, if any. Therefore, it is demonstrated that Ca(2+) binds to PQQ, probably forming a complex which is more reactive with both one-electron (NAD(P) dimers) or two-electron donors (NAD(P)H) in nonenzymic reactions. It is important to recall that Ca(2+) was already found to play active role in PQQ-containing enzymes.

Evidence of hepatitis E virus replication on cell cultures.

Several human and animal cell lines have been used to grow hepatitis E virus. The strain SAR-55 was adapted only on PLF/PLC/5 cell line without any visible cytopathic effect. The growth of the SAR-55 was monitored by examining the positive and the negative strands of HEV-RNA. Stool samples, obtained from hospitalised acute hepatitis patients at the Fever Hospital of Alexandria (Egypt), were used to confirm the susceptibility of PLF/PLC/5 cells. After more than one-week's cultivation, three stool samples out of 17 IgM anti-HEV positive and 1 from 52 IgG anti-HEV positive patients showed a specific RT-PCR amplification product. The nucleotide sequences of the methyltransferase region of the genome in the isolates revealed the maximum homology with Burma strain with several point mutations.

Helicobacter pylori among Egyptian patients with chronic liver diseases. A comparative study.

The prevalence of Helicobacter pylori in Egyptian patients with different stages of liver diseases was compared to those with normal liver status. Eighty patients subjected to upper gastrointestinal endoscopy were enrolled. They were divided according to their liver status into two groups; the first patients with liver cirrhosis and the second who had no liver affection. Gall bladder diseases were excluded by abdominal ultrasound examinations. Endoscopic antral mucosal biopsies were used for H. pylori screening by both culture and urease test, and for histopathological examinations. Both groups were matched as regards age, sex, and socioeconomic conditions. Culture was positive in 42.2% and 40.7% of patients in both groups respectively (P > 0.05). Urease test showed positive results in 58% and 76.6% in both groups respectively (P > 0.05). Helicobacter pylori prevalence showed no significant differences between both studied groups as regards age, sex, or type of gastric lesions. Furthermore, liver status in patients with chronic liver diseases does not play a role in distribution of infection. The study shows the high prevalence of H. pylori among Egyptians and the absence of a relation between H. pylori and chronic liver diseases.

Intravenous drug addicts: a high risk group for infection with human immunodeficiency virus, hepatitis viruses, cytomegalo virus and bacterial infections in Alexandria Egypt.

In this work the seroprevalence of HIV, HBV, HCV and CMV were studied among two groups of population; IVDA (intravenous drug addicts) (100) and control group (40). Syphilis and other bacterial infections which may be encountered among IVDA were also investigated. It was found that all serum samples (of both groups) were negative for anti-HIV. Regarding HBV markers, the prevalence of HBc antibodies was significantly higher among IVDA (62%) than the control group (27.5%). Also HBsAg was detected in 16% of IVDA while it was 75% among the control group. Prevalence of anti-HCV was significantly higher among IVDA (63%) than the control group (27.5%). The prevalence of co-infection with HBV and HCV was significantly higher in IVDA (40%) than the control group (15%). Sharing of needles and duration of drug use were positively associated with the presence of both HBV markers and anti-HCV. CMV seroprevalence was high in both groups. Antibodies to Syphilis were found in sera of 3 IVDA and one control using MHA-TP test. Although HIV infection has not yet been sufficiently introduced among IVDA in Alexandria but potentials for its spread among addicts are high as supported by observation that other infections with similar mode of transmission are common among addicts.