Exploring the Antimicrobial, Antioxidant, and Antiviral Potential of Eco-Friendly Synthesized Silver Nanoparticles Using Leaf Aqueous Extract of Portulaca oleracea L.

Herein, the prospective applications of green fabricated silver nanoparticles (Ag-NPs) within the biomedical field were investigated. The leaf aqueous extract of Portulaca oleracea L., a safe, cheap, and green method, was used to fabricate Ag-NPs. The maximum plasmon resonance of synthesized NPs has appeared at 420 nm. The various biomolecules present in the plant extract to assemble spherical Ag-NPs with sizes of 5-40 nm were analyzed using Fourier transform infrared and transmission electron microscopy. The Ag was the major content of the formed Ag-NPs with an atomic percent of 54.95% and weight percent of 65.86%, as indicated by EDX. The crystallographic structure of synthesized NPs was confirmed by the diffraction of the X-ray. The dynamic light scattering exhibits the homogeneity and mono-dispersity nature with a polydispersity index of 0.37 in the colloidal fluid and a zeta potential value of -36 mV. The synthesized Ag-NPs exhibited promising antimicrobial efficacy toward various prokaryotic and eukaryotic pathogenic microorganisms with low MIC values of 12.5 µg mL-1 and 6.25 µg mL-1, respectively. Additionally, the P. oleracea-formed Ag-NPs showed optimistic antioxidant activity assessed by DPPH and H2O2 assay methods with the highest scavenging percentages of 88.5 ± 2.3% and 76.5 ± 1.7%, respectively, at a concentration of 200 µg mL-1. Finally, the biosynthesized Ag-NPs showed high antiviral properties toward the hepatitis A virus and Cox-B4 with inhibition percentages of 79.16 ± 0.5% and 73.59 ± 0.8%, respectively. Overall, additional research is essential to explore the Ag-NP-based aqueous extract of P. oleracea for human health. In the current investigation the use of synthesized Ag-NPs as antimicrobial, antioxidant, and antiviral agents to protect against pathogenic microbes, degenerative diseases caused by various oxidative stresses, and deadly viruses is recommended.

Solvent-free bottom-up patterning of zeolitic imidazolate frameworks.

Patterning metal-organic frameworks (MOFs) at submicrometer scale is a crucial yet challenging task for their integration in miniaturized devices. Here we report an electron beam (e-beam) assisted, bottom-up approach for patterning of two MOFs, zeolitic imidazolate frameworks (ZIF), ZIF-8 and ZIF-67. A mild pretreatment of metal oxide precursors with linker vapor leads to the sensitization of the oxide surface to e-beam irradiation, effectively inhibiting subsequent conversion of the oxide to ZIFs in irradiated areas, while ZIF growth in non-irradiated areas is not affected. Well-resolved patterns with features down to the scale of 100 nm can be achieved. This developer-free, all-vapor phase technique will facilitate the incorporation of MOFs in micro- and nanofabrication processes.

Charged Particle-Induced Surface Reactions of Organometallic Complexes as a Guide to Precursor Design for Electron- and Ion-Induced Deposition of Nanostructures.

Focused electron beam-induced deposition (FEBID) and focused ion beam-induced deposition (FIBID) are direct-write fabrication techniques that use focused beams of charged particles (electrons or ions) to create 3D metal-containing nanostructures by decomposing organometallic precursors onto substrates in a low-pressure environment. For many applications, it is important to minimize contamination of these nanostructures by impurities from incomplete ligand dissociation and desorption. This spotlight on applications describes the use of ultra high vacuum surface science studies to obtain mechanistic information on electron- and ion-induced processes in organometallic precursor candidates. The results are used for the mechanism-based design of custom precursors for FEBID and FIBID.

The influence of palladium on the hydrogenation of acetylene on Ag(111).

We have used reflection absorption infrared spectroscopy (RAIRS) and temperature programmed reaction (TPR) to study the selective hydrogenation of acetylene on both a clean Ag(111) surface and on a Pd/Ag(111) single-atom-alloy surface. The partial hydrogenation of acetylene to ethylene is an important catalytic process that is often carried out using PdAg alloys. It is challenging to study the reaction with ultrahigh vacuum techniques because H2 does not dissociate on Ag(111), and while H2 will dissociate at Pd sites, H-atom spillover from Pd to Ag sites does not generally occur. We bypassed the H2 dissociation step by exposing the surfaces to atomic hydrogen generated by the hot filament of an ion gauge. We find that hydrogen atoms react with acetylene to produce adsorbed ethylene at 85 K, the lowest temperature studied. This is revealed by the appearance of a RAIRS peak at 950 cm-1 due to the out-of-plane wagging mode of adsorbed ethylene when acetylene is exposed to a surface on which H atoms are pre-adsorbed. The formation of both ethylene and ethane are detected with TPR, but no acetylene coupling products, such as benzene, were found. From quantitative analysis of the TPR results, the percent conversion and selectivities to ethylene and ethane were determined. Low coverages of Pd enhance the conversion but do so mainly by increasing ethane formation.

Electron beam induced modification of ZIF-8 membrane permeation properties.

Modification of the gas permeation properties of ZIF-8 membranes using electron beam irradiation is reported. 3.8 and 3.2 fold enhancements in ideal selectivity for CO2/N2 and CO2/CH4 can be achieved with less than 1 min exposure time.

Adsorption properties of acrolein, propanal, 2-propenol, and 1-propanol on Ag(111).

Reflection absorption infrared spectroscopy and temperature programmed desorption were used to study the adsorption of acrolein, its partial hydrogenation products, propanal and 2-propenol, and its full hydrogenation product, 1-propanol on the Ag(111) surface. Each molecule adsorbs weakly to the surface and desorbs without reaction at temperatures below 220 K. For acrolein, the out-of plane bending modes are more intense than the C[double bond, length as m-dash]O stretch at all coverages, indicating that the molecular plane is mainly parallel to the surface. The two alcohols, 2-propenol and 1-propanol, have notably higher desorption temperatures than acrolein and display strong hydrogen bonding in the multilayers as revealed by a broadened and redshifted O-H stretch. For 1-propanol, annealing the surface to 180 K disrupts the hydrogen-bonding to produce unusally narrow peaks, including one at 1015 cm-1 with a full width at half maximum of 1.1 cm-1. This suggests that 1-propanol forms a highly orderded monolayer and adsorbs as a single conformer. For 2-propenol, hydrogen bonding in the multilayer correlates with observation of the C[double bond, length as m-dash]C stretch at 1646 cm-1, which is invisible for the monolayer. This suggests that for monolayer coverages, 2-propenol bonds with the C[double bond, length as m-dash]C bond parallel to the surface. Similarly, the C[double bond, length as m-dash]O stretch of propanal is very weak for low coverages but becomes the largest peak for the multilayer, indicating a change in orientation with coverage.

Reaction pathways for HCN on transition metal surfaces.

The adsorption and decomposition of HCN on the Pd(111) and Ru(001) surfaces have been studied with reflection absorption infrared spectroscopy and density functional theory calculations. The results are compared to earlier studies of HCN adsorption on the Pt(111) and Cu(100) surfaces. In all cases the initial adsorption at low temperatures gives rise to a ν(C-H) stretch peak at ∼3300 cm-1, which is very close to the gas phase value indicating that the triple CN bond is retained for the adsorbed molecule. When the Pd(111) surface is heated to room temperature, the HCN is converted to the aminocarbyne species, CNH2, which was also observed on the Pt(111) surface. DFT calculations confirm the high stability of CNH2 on Pd(111), and suggest a bi-molecular mechanism for its formation. When HCN on Cu(100) is heated, it desorbs without reaction. In contrast, no stable intermediates are detected on Ru(001) as the surface is heated, indicating that HCN decomposes completely to atomic species.

Prevalence and characteristics of tricuspid valve endocarditis among patients presented to Ain Shams Hospital echocardiography lab; one year study.

BACKGROUND: Isolated Tricuspid valve infective endocarditis is an infrequent diagnosis, the incidence of Tricuspid valve infective endocarditis accounts for 5% and up to 15% of IE cases. AIM: To assess the prevalence and the echocardiographic characteristics of tricuspid valve endocarditis among patients presented to the echo lab of Ain Shams hospital from 1-1-2016 to 1-1-2017. METHODS: This is a retrospective study which included all patients presented to the echo lab of Ain Shams university hospital from 1st January 2016 to 1st January 2017, the total number of patients were 8376, patients with infective endocarditis were 278, and patients with tricuspid valve endocarditis were 51 patients respectively. Complete transthoracic echocardiography was done for all patients and data was retrieved from a locally designed electronic database of cardiology department at Ain shams hospitals. RESULTS: The incidence of TVIE was (17.7%) of all cases of IE, and (0.67%) of all cases attending the echo lab during the study period. The mean age group in our study was (31.1 ±â€¯7.8) and about 84.3% of patient's age was between 20 and 40 years. Higher incidence of IE was in males (90.2%) than in females (9.8%) with a ratio of 9:1. The vegetations were detected in one leaflet in 33 patients (64.7%), two leaflets in 9 patients (17.6%) and in the three TV leaflets in 7 patients (13.7). The most affected leaflet was the anterior leaflet that was affected in 38 patients constituting about 74.5% of patients. The size of vegetations was large >15 mm in 40 patients (78.4%).The most encountered echocardiographic complication was severe TR, detected in 40 patients (78.4%) and abscess formation was the least present, detected in only 2 patients (3.9%). CONCLUSION: The incidence of TV IE is increasing with male gender predominance, and affects mainly young age groups. TV IE represented 0.6% of all patients, and 17.7% of IE cases. The main echocardiographic feature of TV IE is vegetations which were characterized by being large, highly mobile, and affecting mainly anterior TV leaflet. The main echocardiographic complication is severe TR, but abscess formation was infrequent.

Therapeutic efficacy of olfactory stem cells in rotenone induced Parkinsonism in adult male albino rats.

BACKGROUND: Olfactory stem cells (OSCs) are found in the olfactory mucosa and olfactory bulb and have the capacity to proliferate and differentiate along multiple tissue lineages. Rotenone; widely used insecticide has a neurodegenerative effect on the dopaminergic cells of substantia nigra (SN) of midbrain producing Parkinsonism. The aim of this study is to isolate rat OSCs from olfactory mucosa and olfactory bulb, culture these OSCs in suitable medium to allow for their proliferation to be used in the treatment of Parkinsonism induced by rotenone. METHODS: The characteristics of OSCs, the effects of rotenone on the SN of midbrain and the curative effect of OSCs on the substantia nigra were determined morphologically, immunohistochemically, and by transmission electron microscopy. PKH 26; immunofluorescent dye was used as a cell tracer to locate the transplanted cells in host midbrain. RESULTS: OSCs were spindle shaped with irregular processes, and were positive for CD44 and Nestin and negative for CD34. Subcutaneous rotenone produced Parkinsonism through producing degeneration of the dopaminergic cells of SN of the midbrain. Transplantation of OSCs produced restoration of the normal structure of SN and dopaminergic cells and improves the clinical manifestations of Parkinsonism. CONCLUSION: These results indicate that, the isolated rat OSCs can proliferate and expand in vitro when culture in suitable medium and these cells can exert therapeutic effects in Parkinsonism by recruitment in SN and restoration of the structure and function of dopaminergic cells.

Simplifying proximal isovelocity surface area as an assessment method of mitral valve area in patients with rheumatic mitral stenosis by fixing aliasing velocity and mitral valve angle.

UNLABELLED: We aimed to test the ability of a simple equation using proximal isovelocity surface area method (PISA), created by fixing the angle to 100° and the aliasing velocity to 33 cm/s, to calculate mitral valve area (MVA) and assess severity in patients with rheumatic mitral stenosis (MS). METHODS AND RESULTS: In a series of 51 consecutive patients with rheumatic MS, MVA was assessed by four methods, conventional PISA equation (PISAconventional), simple PISA equation (PISAsimple), pressure half time (PHT), and planimetry (PLN) which was taken as the reference method. All methods correlated significantly with PLN with the highest correlation found in case of PISAconventional and PISAsimple (r = 0.97, 0.96, p < 0.001), while the correlation in case PHT was relatively weaker (r = 0.69, p < 0.001). Bland-Altman analysis revealed that the level of agreement with PLN was better in case of both PISA methods than PHT and, moreover, were close to each other. The number of cases that showed agreement of severity grade with planinetry was better in case of PISAconventional (42 cases) and PISAsimple (44 cases) than that in case of PHT (34 cases, p = 0.037). Finally, the measure of agreement with Cohen's Kappa test was better in case of PISAconventional and PISAsimple than that in case of PHT. CONCLUSION: Provided that aliasing velocity is fixed at 33 cm/s, PISA can effectively predict mitral valve area and severity of MS by a simple equation, with the advantage of easy and accurate calculation over other methods.

Clinical and biochemical predictors affect the choice and the short-term outcomes of different thrombolytic agents in acute myocardial infarction.

BACKGROUND: The presence of plasminogen activator inhibitor-1, angiotensin-converting enzyme and others may play a role in unsuccessful recanalization after thrombolytic therapy. OBJECTIVES: To find out the clinical and biochemical predictors that may affect the choice and short-term outcomes following different thrombolytic agents in acute myocardial infarction. METHODOLOGY: Angiotensin-converting enzyme and plasminogen activator inhibitor-1 plasma levels of 184 patients with acute myocardial infarction, treated with streptokinase, metalyze or reteplase, were determined. Failure of thrombolysis was assessed by noninvasive reperfusion criteria. Prolonged hospitalization, impaired left ventricular ejection fraction and reinfarction were considered as short-term outcomes. RESULTS: Patients who received streptokinase developed higher incidence of >50% resolution of ST-segment elevation (82.5 vs. 64.7%, P-value<0.05, in comparison with metalyze and 82.5 vs. 55.7%, P-value 0.001, in comparison with reteplase) than those who received other thrombolytic agents. High plasma angiotensin-converting enzyme was associated with prolonged hospitalization (55, 63 and 94%, P<0.02) following streptokinase, metalyze and reteplase, respectively. High plasma plasminogen activator inhibitor-1 is associated with impaired left ventricular ejection fraction (55.3, 76.7 and 68.5%, P<0.09), ST resolution<50% (13.2, 36.7 and 37.5%, P=0.03), ST resolution>50% (86.8, 63.3 and 62.5%, P=0.03) following streptokinase, metalyze and reteplase, respectively. CONCLUSIONS: Rapid determination of pretreatment angiotensin-converting enzyme and plasminogen activator inhibitor-1 plasma levels in patients with acute myocardial infarction may influence the choice and outcomes of the thrombolytic agents. The presence of a high plasma level of either angiotensin-converting enzyme or plasminogen activator inhibitor-1 is significantly associated with adverse short-term outcomes after treatment with reteplase or metalyze.