248 research outputs found

    Comparative Study of Using Sea-Water for Enhanced Oil Recovery in Carbonate and Sandstone Reservoirs: Effects of Temperature and Aging Time on Oil Recovery

    Get PDF
    Oil recovery process is an essential element in the oil industry, in this study, a laboratory study to investigate the effect of temperature and aging time on oil recovery and understand some of the mechanisms of seawater in the injection process. In order to do that, the sandstone and carbonate cores were placed in the oven in brine to simulate realistic reservoir conditions. Then, they were aged in crude oil in the oven. After that, they were put in the seawater to recover, and this test is called a spontaneous imbibition test. The spontaneous imbibition test in this study was performed at room temperature to oven temperature 80 oC with different sandstone and carbonate rock with aging time of 1126 hours. The result shows that the impact of seawater on oil recovery in sandstone is higher than carbonate. At higher temperature, the oil recovery is more moderate than low temperature. Likewise, as the aging time increase for both sandstone and carbonate rocks the oil recovery increase.&nbsp

    Evaluation Of Neopterin Level And Disease Severity In Patients With Psoriasis Vulgaris Treated With Narrowband UVB

    Get PDF
    Background: Psoriasis is an immunity chronic hyperproliferative illness. An indicator of cellular immunity is neopterin, a biological substance. According to reports, psoriasis causes an increase in serum neopterin levels, which thereafter drop as a result of treatment. Objectives: To evaluate serum levels of neopterin in patients with psoriasis vulgaris. Patients and methods: This study is a case-control study that involved 30 patients with psoriasis and 30 healthy subjects as control. Patients were treated with Narrowband UVB (3session /week ) for 3 months. Serum neopetrin levels were measured pre and post treatment by performing an enzyme-linked immune sorbent assay (ELISA). All patients were clinically and photographically evaluated using Psoriasis Area and Severity Index (PASI score). Results: A Statistically significant differences in serum Neopterin level have been found in psoriatic patients comparing to healthy controls. The mean of serum Neopterin levels were 2.8 and 0.7 (nmol/L) in psoriatic patients and healthy controls, respectively (P< 0.001). We found Statistically significant improvement in disease severity, and a significant decrease in PASI scores was detected. The median of PASI score pre and post NB-UVB therapy was 31.4 and 8, respectively, with statistical significant difference (P<0.001). We noted significant difference between serum levels of Neopterin in patients before and after treatment, with a higher level of serum Neopterin among patients before treatment (P< 0.001). Conclusion: Serum neopterin was highly significant in the psoriatic patients compared to healthy controls (p < 0.05). A significant decrease was observed in serum neopterin level after the narrowband UVB therapy

    Phosphonated Lower-Molecular-Weight Polyethyleneimines as Oilfield Scale Inhibitors: An Experimental and Theoretical Study

    Get PDF
    For many years, amino methylenephosphonate (-CH2-N-PO3H2)-based scale inhibitors (SIs) have been deployed for preventing various scales in the oil and gas industry, particularly for squeeze treatment applications. However, this class of phosphonate inhibitors showed several limitations related to environmental concerns and compatibility with brine solutions. The low toxicity of low-molecular-weight polyethyleneimine (LMW-PEI) encouraged us to phosphonate a series of branched and linear PEIs via the Moedritzer–Irani reaction. The phosphonated polyethyleneimine PPEIs are branched PPEI-600, branched PPEI-1200, branched PPEI-2000, and linear PPEI-5000. The newly synthesized PPEIs (branched and linear) were screened for calcium carbonate and barium sulfate utilizing a high-pressure dynamic tube-blocking rig at 100 °C and 80 bar. Moreover, we report the compatibility activity of all PPEIs with various concentrations of calcium ions (up to 10000 ppm). The morphology of the calcium carbonate and barium sulfate scale crystals in the absence and presence of linear PPEI-5000 was also investigated under static conditions using scanning electron microscopy (SEM). The obtained results showed that all branched and linear PPEIs gave moderate calcite and barite inhibition activities. It was also found that all branched PPEIs gave moderate to poor calcium compatibility at high dosages of calcium ions (1000–10 000 ppm). Interestingly, linear PPEI-5000 displayed superior compatibility properties at high dosages of SI (up to 50 000 ppm) and high concentrations of Ca2+ ions (up to 10 000 ppm). Furthermore, field emission scanning electron microscopy analysis confirmed that the crystal shapes of CaCO3 and BaSO4 mineral scales are greatly changed in the presence of linear PPEI-5000. At high dosages of linear PPEI-5000 SI (100 ppm), the CaCO3 crystals are completely converted from cubic-shaped blocks (blank calcite) into long cluster shapes. Density functional theory (DFT) simulations reveal favorable interactions of PPEI polymers with the two mineral facets (calcite and barite) with more affinity toward the calcite surface. PPEI with more phosphonate groups exhibits affinities comparable to the commercial-scale inhibitors. The high density of the phosphonate groups on the branched PPEI and its strong affinity toward calcium ions explain its poor calcium compatibility. The polymer flocculation and sluggish barite kinetics are the potential reasons for its low performance against thepublishedVersio

    Green Synthesis, Characterization, Antimicrobial and Anticancer Screening of New Metal Complexes Incorporating Schiff Base

    Get PDF
    A Schiff base ligand of o-vanillin and 4-aminoazobenzene and its transition metal complexes of Ni(II), Co(II), Zn(II), Cu(II), Mn(II), and Zr(IV) were prepared under microwave irradiation as a green approach compared to the conventional method. The structures of new compounds have been characterized and elucidated via elemental and spectroscopic analyses. In addition, magnetic susceptibility, electron spin resonance, and electronic spectra of the synthesized complexes explained their geometrical structures. The thermal stability of Cu(II), Zn(II), and Zr(IV) complexes was studied by thermo-gravimetric analyses (TGA). Coats–Redfern and Horowitz–Metzger equations were used to calculate the thermal and dehydration decomposition activities of proposed structures kinetically. Surface morphologies of the solid compounds were imaged by scanning electron microscopy (SEM). The particle size of prepared complexes was measured by using a particle size analyzer at a diffraction angle of 10.9°. The geometry structures of the synthesized compounds were verified utilizing electronic spectra, ESR spectrum, and magnetic moment value. The newly synthesized compounds were screened for antimicrobial activity. Also, the anticancer activity of the free Schiff base ligand and its metal complexes were studied against two cell lines: human colon (HCT-116) and human liver cancer cells (HepG-2). The obtained results showed that the Cu(II) complex displayed the highest cytotoxic activity (IC50 = 18 and 22 μg/mL for HepG-2 and HCT, respectively) compared to the free Schiff base ligand.publishedVersio

    Effect of Tadalafil on Penile Duplex parameters in Erectile Dysfunction Patients

    Get PDF
    Background: Tadalafil is a PDE-5 (phosphodiesterase inhibitor) inhibitor that supports endogenous nitric oxide's vasodilatory actions and aids in erection maintenance. The penile duplex has proven to be very useful for imaging superficial structures and for determining the reasons of erectile dysfunction (ED). Objectives: To assess the effect of daily oral tadalafil 5mg for 3 months on penile duplex parameters in erectile dysfunction patients. Patients and Methods: A case control study involved 30 Egyptian patients ED. Appropriate clinical history and penile duplex examination before and after treatment with daily oral tadalafil mg for 3 months were performed. Results: The mean age of the patients was 53.17 ± 7.8 years. We founded that there was significant (p < 0.001) improvement in the level of erection after treatment. The rate of erection E1 and E2 was decreased from 53.3% to 3.3%. Likewise, the rate of E3-E5 was increased from 46.7% to 96.7%. Moreover, the mean duration of erection was elongated from 24.7 ± 5.3 to become 37.4 ± 3.8 and this was statistically significant (p < 0.001). Also, the mean peak systolic volume (PSV) was significantly (p = 0.001) increased after treatment (38.4 ± 9.1 cm/s) compared with the pre-treatment levels (23.9 ± 6.1 cm/s). Unlikely, the mean end diastolic volume (EDV) was insignificantly (p = 0.340) lower in post-treatment (2.25 ± 0.5 mL) compared with pre-treatment levels (2.97 ± 0.4 mL). Likely, the mean resistant index (RI) showed insignificant difference (p = 0.965) after treatment (0.9 ± 0.02) compared with before treatment (0.9 ± 0.08). For penile artery diameter, there was significant (p = 0.009) increase in the diameter after treatment (0.9 ± 0.1 mm) compared with before treatment (0.8 ± 0.1 mm). Conclusion: Oral daily tadalafil 5mg for 3 months is considered an effective treatment for ED according to penile duplex parameters

    Assessment of knowledge, attitude and practice of diabetic people in Najran, Kingdom of Saudi Arabia

    Get PDF
    Background: This cross-sectional hospital based study aimed at determining the level of knowledge, attitude and practice of diabetes among local people of Najran, Saudi Arabia.Methods: We aimed to investigate the levels of knowledge, attitude and practice among diabetic people in Najran area.Results: 10% of the participants scored >7, 28% scored >5 and 62% scored 5 and less in Knowledge questionnaire. None [0.00%] of the participants scored 7 or more out of the attitude questionnaire. 100% of the participants scored 5 and less out of 12. 100% of the participants scored >6 and 0% scored 12 or more in the practice questionnaire.Conclusions: Our study revealed that the level of knowledge, attitude and practice of diabetes in the area of Najran is very poor. We suggest that a structured educational program to be adopted by the health authorities in Saudi Arabia

    Paternal postnatal depression among fathers of newborn in Saudi Arabia

    Get PDF
    Paternal postnatal depression (PPND) is not a commonly recognized phenomenon. The aim of the study was to identify the Edinburgh Postnatal Depression Scale (EPDS) cutoff for Saudi fathers, to estimate PPND prevalence and to determine the risk factors of PPND among fathers of newborn in Saudi Arabia. A cross-sectional study of fathers with babies born up to 6 months prior to the survey was conducted. Fathers were screened using EPDS and demographic questionnaire. The fathers were selected using systematic random sampling from visitors to the birth registration office. A subsample of participants from the postnatal wards in a tertiary care was invited for additional evaluation by a psychologist using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for major depressive disorders. Receiver operating characteristic curve was utilized to identify fathers with depression; a cutoff of 8/9 was optimal to achieve sensitivity 77.8% and specificity 81.3%. Adjusted prevalence of PPND was reported with corresponding Wilson 95% confidence interval. Two hundred and ninety fathers completed the EPDS and demographic questionnaire. Of 72 invited participants, 57 (79.16%) attended the diagnostic interview. The average age of fathers was 34.97 ± 8.56 years, the average maternal age was 29.18 ± 7.41 years, average age of the newborn was 43.13 ± 35.88 days. PPND adjusted prevalence was 16.6% (95% CI [8.5, 25.6]). Paternal mental health needs equal attention during and postdelivery of newborn. Fathers should receive perinatal and postnatal mental health assessment to prevent behavioral problems in their children and disruption of relationship with their spouse

    Exploring the molecular mechanisms of MSC-derived exosomes in Alzheimer's disease : Autophagy, insulin and the PI3K/Akt/mTOR signaling pathway

    Get PDF
    The authors thank you for acknowledging technical and financial support from the Ministry of Education and the University of Hafr Al Batin, Saudi Arabia. The authors gratefully acknowledge all mothers’ volunteers in the community around the Faculty of Agriculture, Benha University, for their cooperationPeer reviewe

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Perspective Chapter: The Toxic Silver (Hg)

    Get PDF
    In the late 1950s, residents of a Japanese fishing village known as “Minamata” began falling ill and dying at an alarming rate. The Japanese authorities stated that methyl-mercury-rich seafood and shellfish caused the sickness. Burning fossil fuels represent ≈52.7% of Hg emissions. The majorities of mercury’s compounds are volatile and thus travel hundreds of miles with wind before being deposited on the earth’s surface. High acidity and dissolved organic carbon increase Hg-mobility in soil to enter the food chain. Additionally, Hg is taken up by areal plant parts via gas exchange. Mercury has no identified role in plants while exhibiting high affinity to form complexes with soft ligands such as sulfur and this consequently inactivates amino acids and sulfur-containing antioxidants. Long-term human exposure to Hg leads to neurotoxicity in children and adults, immunological, cardiac, and motor reproductive and genetic disorders. Accordingly, remediating contaminated soils has become an obligation. Mercury, like other potentially toxic elements, is not biodegradable, and therefore, its remediation should encompass either removal of Hg from soils or even its immobilization. This chapter discusses Hg’s chemical behavior, sources, health dangers, and soil remediation methods to lower Hg levels
    corecore