Functionalized Graphene Oxide with Chitosan for Dopamine Biosensing.

Detecting biological structures via a rapid and facile method has become a pronounced point of research. Dopamine (DA) detection is critical for the early diagnosis of a variety of neurological diseases/disorders. A study on the real-time optical detection of DA is described here using graphene oxide (GO) functionalized with chitosan (Cs). Hence, a computational model dependent on a high theoretical level density functional theory (DFT) using the B3LYP/LANL2DZ model is carried out to study the physical as well as electronic properties of the proposed interaction between GO functionalized with Cs and its interaction with DA. GO functionalized with a Cs biopolymer was verified as having much higher stability and reactivity. Moreover, the addition of DA to functionalized GO yields structures with the same stability and reactivity. This ensures that GO-Cs is a stable structure with a strong interaction with DA, which is energetically preferred. Molecular electrostatic potential (MESP) calculation maps indicated that the impact of an interaction between GO and Cs increases the number of electron clouds at the terminals, ensuring the great ability of this composite when interacting with DA. Hence, these calculations and experimental results support the feasibility of using GO functionalized with Cs as a DA biosensor.

Endoscopic procedure as a diagnostic tool for intestinal parasitic pathological changes.

Parasitic infections of the gastrointestinal tract (GIT) may cause severe morbidity and even death in untreated patients. In certain cases, endoscopy may be the only possible option for diagnosis and management of GIT parasitic diseases. This study aimed to elucidate the role of endoscopy in the identification of GIT pathological changes during parasitic infections. Three hundred patients suffering from GIT manifestation were enrolled in this study. Stool samples were collected from all patients and examined for the presence of parasitic stages by direct and concentrated techniques. Parasite-infected patients were further examined by CBC and narrow-band endoscopic procedure. Stool examination has demonstrated parasitic stages in stool samples of 100 (33.3%) patients. Eighty-nine patients (89%) had a single parasitic infection while 11 patients (11%) had mixed infections. Complete blood examination of infected patients was within the normal ranges in almost all types of infections except for eosinophilia in some of them. Upper endoscopic examination revealed that parasitic infections led to various pathological changes in the esophagus (6%), stomach (42%), and duodenum (50%). Colonoscopy revealed abnormal findings at the rectum (25%) and the colon (32%). In conclusion, the endoscopic examination can be considered an important diagnostic option for the detection of pathological changes in GIT during chronic parasitic diseases and can be included in the differential diagnosis of other GIT pathological changes detected by endoscopy.

Giardiasis in symptomatic children from Sharkia, Egypt: genetic assemblages and associated risk factors.

Giardia intestinalis (G. intestinalis) is a common enteric protozoan parasite worldwide and in Egypt. Identification of true prevailing Giardia assemblages helps in identification of the sources of infection. The study's aim was to determine the true prevalence of Giardia assemblages in Egyptian children from Sharkia governorate presenting with gastrointestinal symptoms and to investigate their association with molecularly detected Giardia. A total of 617 stool specimens were collected from children presenting with gastrointestinal symptoms in Alquraeen, Sharkia governorate, Egypt for 17 months. All stool specimens were microscopically examined by wet mount smear before and after stool concentration to recover parasitic stages. Giardia copro-DNA was amplified from microscopically detected stool specimens using Copro-nPCR targeting the tpi gene for Giardia, followed by sequencing products of nPCR. The molecular prevalence of Giardia among symptomatic children was 9.88%, 83% of which were assemblage B and 17% were assemblages A. Giardia affected both sexes and all ages and was most prevalent in preschool children. Abdominal pain was the most common GIT symptom followed by diarrhoea. However, none of the patients' demographic variables (sex, age, weight and height) nor clinical symptoms showed significant association with molecular detection of Giardia. Giardia was common among symptomatic children from Sharkia, Egypt, with the predominance of assemblage B, which suggests the possibility of sharing common transmission source and route. Giardia had age, sex and clinical symptom distributions without statistical significance. The results necessitate further genomic studies targeting multiple gene targets for a better understanding of the ecology, dynamics of transmission, pathogenicity and clinical impact of Giardia infection, to improve its management and strategic control.

Molecular modeling analyses for graphene functionalized with Fe3O4 and NiO.

Graphene has attracted great concern in recent years as one of the potential 2D materials in various applications. This work is devoted for assessing the feasibility of functionalizing 2D graphene sheets with ferromagnetic and antiferromagnetic metal oxides namely magnetite (Fe3O4) and nickel oxide (NiO). Molecular models of the proposed candidates are exposed to energy calculations at DFT level, in addition to geometry optimization processes at PM6 method. HOMO/LUMO orbitals, MESP maps and QSAR descriptors are calculated. Results ensure that graphene doped with NiO has the highest reactivity since it possesses the largest TDM and the smallest HOMO/LUMO band gap. MESP maps illustrate that the benzene rings of graphene are most probable to undergo nucleophilic interactions. Addition of Fe3O4 creates new negatively charged active sites that are ready for nucleophilic interactions. The calculated QSAR parameters demonstrate a hydrophobic nature for pure and modified graphene suggesting that they need further modification with further groups for usage in biological applications.

THE PARASITIC PROFILE AMONG SCHOOL CHILDREN IN EI-WADI EL-GADDED GOVERNORATE, EGYPT.

Parasitic infection is still a serious public health problem in the world, especially in developing countries including Egypt. It represents a major cause of morbidity and mortality in childhood and among high-risk groups-in most parts of the world. This study detected the prevalence of parasitic infection among school children in-El-Wadi El-Gadded (the New Valley Governorate). A total of randomly chosen 1615 students aged from 6-16 years, (771 males & 844 female) from 12 primary schools and 12 preparatory schools related to four centers (El Dakhala, El Farfra, Paris and Platt) from the New Valley. Governorate. Each child was subject to: A questionnaire sheet, Urine examination through sedimentation methods, Stool examination using: Direct smear, Simple sedimentation method and Modified Ziehl-Neelsen Stain, Blood samples were collected randomly from 450 children and examined for Seropositivity of toxoplasmosis using (On-SiteToxolgG/IgM Rapid Test- Cassette) and examination of hair & clothes for ectoparasites (lice). The overall prevalence of parasites was (39.1%) among primary and preparatory school children. The helminthes were E. vermicularis (15.2% & 17.1%); A. lumbricoides (1.3% & 1.9%) and then H. nana (0.9% & 0.6%) and the protozoa were E. histolytica (14.1% & 13.2%), Giardia lamblia (3.8% & 3.9%), and then Cryptosporidium parvum (0.09%) and seropositivity of toxoplasmosis was in (3.0% & 2.7%) among primary and preparatory school children respectively. Mixed infection was in (0.4%) among primary school children. Head lice infestaiion was more prevalent among primary school children than preparatory school ones with a ratio (3.5% &0.2%) respectively, was nil among males.

Role of parasites among chronic diarrheic patients.

This work studied the role of parasitic infection among 85 chronic diarrheic patients in Delta region and cross-matched 20 normal controls. They were subjected to thorough history taking and clinical examination and stool examination by direct smear, formol-ether concentration, simple sedimentation, simple floatation and Kato-katz thick smear. Questionnaire sheet was obtained for each case included personal history, complaint, present as well as past history and family history. The results showed that 67.1% of patients suffered from parasites versus 20% in controls. They included giardiasis mixed with hymenolepiasis nana, ameobiasis, ascariaisis, S. mansoni, heterophyiasis, B. homninis, Taenia spp and enterobiasis respectively. Single infection represented 54.2 %, while mixed ones were 12.9% of total chronic diarrhea cases and non parasitic causes were responsible for 32.9%. Mixed infection was common in A. lumbricoides with E. histolytica (18.18%) and H. nana with G. lambia (27.28%). The diarrhea duration was longer in mixed infections (3 months), E. histolytica (2 months) and H. nana (1.5 months). Commonest symptom other than diarrhea was abdominal pain mainly in mixed parasitosis. Parasitic diarrhea was more common in males than females (1.28: 1). Chronic parasitic diarrhea was most prevalent among low social class (49 or 57.6%) followed by very low social class (20 or 23.5%), middle social class (10 or 11.7%) and finally high social class (6 or 7.1%) with significant increase in low social class as compared to high one, and most prevalent among positive cases in rural area than in urban area.