Synthesizing silver nanoparticles (AgNPs) from extracts of various plant parts

and of agricultural waste is strongly affected by pH. These green synthesis

methods cconsidered simple, cost effective, ecofriendly, and biologically

effective. This brief review aimed to survey the role of pH in the green

synthesis of AgNPs using those media, with a focus on its effect on AgNPs

morphology and size. This review article revealed that the alkaline pH (9 -

10) is the optimum condition for synthesizing more stable and tiny uniform

AgNPs. In addition, according to the reviewed articles, the spherical shape is

the most dominant shape of these articles in the basic medium and the size of

these particles decreases at elevated pH values and ranged from 5-40 nm.

Heavy metals can be released from cooking stewpots into food, causing food contamination and posing a risk to human health. This research study investigated the release of heavy metals into food from stewpot cookers used in Gharyan, Libya. As well as, investigating the effect of scratches, acidic food, and storage on the concentrations of those metals. Eight new and used cooking stewpots (with scratches) made of: (Tefal, stainless steel, copper and aluminum) were collected, and then fresh tomato juice was cooked in these stewpots and left in the refrigerator for six days, the samples were digested and analyzed by atomic absorption spectrophotometer (AAS) to measure the concentration of the heavy metals: (cadmium, lead, iron, copper and zinc). Results showed that cadmium and lead concentrations were less than the detection limit of the AAS instrument, except for one sample (old Tefal stewpot with scratches), in which the lead concentration was (0.046ppm). The concentration of iron, copper and zinc in the samples was less than the maximum limit allowed by WHO/FAO; except for one sample in which the iron concentration exceeded that value (old copper pot with scratches) and its value was (2.892ppm). The results of the descriptive statistical analysis showed that the average concentration of iron (0.493 ppm) was higher than that of zinc and copper (0.054 ppm), (0.016 ppm), respectively. In addition, the rate of leakage of those elements from old (scratched) cookware was higher than that from the new ones made from the same material, and the concentration of these elements increases significantly when these stewpots contain scratches, since that increases the rate of leakage of those metals, especially in acidic food such as tomatoes.

The battle against COVID-19 does not always end when recovery is declared. Many individuals confirmed recovered from COVID-19 continue to experience a variety of symptoms. The aim of this study was to shed more light on COVID-19 and post-COVID-19 symptoms in Libya. Two hundred and twenty Libyan individuals (58% female; 42% male), who recovered from COVID‐19, were asked to answer a questionnaire that was performed to inquire about the presence of COVID-19 and post-COVID-19 symptoms. Additionally, comorbidities and demographic data were included. The most common comorbidities were hypertension (20%), diabetes (16%), and lung disease (08%). The main COVID-19 symptoms were headache (56%), anosmia and ageusia (52%), Arthralgia (48%), cough (46%) and fever (41%). While the post-COVID-19 symptoms were fatigue (64%), sleep disorders (52%), insomnia, anxiety, depression (42%), and anosmia and ageusia (32%). Persistent COVID and its related long-term complications may continue to affect patients and their families.

Abstract: This review aimed to investigate the effect of pH on morphology, and size of gold nanoparticles (AuNPs) biosynthesized using extracts of various plant parts and agricultural waste. By reviewing previous studies, it was found that the formation of AuNPs was more rapid in neutral and basic mediums than in acidic mediums. Furthermore, most of those studies indicated that the smallest sizes of biosynthesized AuNPs, produced by plant extracts, were in neutral and alkaline mediums. Regarding the morphology, it was found that multiple shapes of the AuNPs were obtained in an acidic medium of the reaction, while there was typically a dominant shape of the AuNPs in the basic medium. In conclusion, significant quantities of AuNPs with appropriate sizes and morphology could be obtained by controlling the medium of the reaction when AuNPs are biosynthesized using extracts of plant parts and agricultural waste.

Biosynthesis techniques have a number of advantages over other methods for producing silver nanoparticles (AgNPs), which provide a wide range of applications. The present work highlights the biosynthesis of AgNPs by mixing pear leaf aqueous extract with silver nitrate, and the formation of AgNPs was observed by the change of mixture color from yellow to dark brown and visible spectrophotometry. Moreover, the effect of pH, reaction time, AgNO3 concentration, extract volume and temperature on the suggested approach was also studied. The results showed that pear leaf aqueous extract is an excellent material for the biosynthesis of AgNPs, and by controlling the mentioned parameters that influence synthesis, a large number of AgNPs with small sizes may be produced. Keywords: silver nitrate, silver nanoparticles, pear leaves, biosynthesis 

Thyroid function is impaired by diabetes, resulting into thyroid disorders, accompanied by the alteration of thyroid-stimulating hormone (TSH) and thyroxine (T4) levels. The aim of this study was to investigate the role of vitamin D supplementation on TSH and total T4 levels in serum of Libyan patients suffering from type 2 diabetes mellitus (T2DM) with thyroid disorders. A total of 180 subjects were recruited and distributed into two groups: 80 participants in control group (43 females and 37 males), with an age range of 26-72 years, and 100 participants in T2DM patient group (54 females and 46 males), with an age range of 26-63 years. Each T2DM patient received a monthly intramuscular injection of 200000 ng/ml vitamin D for three months. Glucose, vitamin D, total T4 and TSH levels were determined in serum samples of healthy subjects and of T2DM patients (pre- and post-administration of vitamin D). After the T2DM group received vitamin D supplementation, the mean of vitamin D level increased in the T2DM, while the mean of glucose level decreased. Most importantly, the mean of total T4 level for patients increased significantly (p ˂ 0.05) from 1.34 to 8.23 g/dL, both of which were lower than the control group mean 10.99 g/dL. In contrast, the mean of TSH level for patients decreased significantly (p ˂ 0.05) from 11.77 to 2.71 mU/L, and both values were greater than the control group mean 2.01 mU/L. ANOVA results showed that age, gender, and body mass index had no significant individual interactions (p > 0.05) with vitamin D supplementation on total T4 and TSH levels. Vitamin D supplementation had a beneficial role on total T4 and TSH levels in serum of Libyan T2DM patients with thyroid disorders.

Biosynthesis of the metallic nanoparticle is gaining importance because it’s a single-step process, nontoxic, environmentally acceptable, and easily scaled up. The present study investigated the biosynthesis of silver nanoparticles (AgNPs) via reacting olive wastewater filtrate (OWF) with silver nitrate, and the formation of AgNPs was confirmed by a color change of the reaction mixture and visible spectrophotometry. Additionally, the influence of pH, reaction time, AgNO₃ concentration, temperature, and OWF volume on the proposed method was investigated. It was found that with increasing the previously mentioned parameters, the formation of the AgNPs was increased under the experimental conditions. The results showed that OWF represented a promising material for the biosynthesis of AgNPs.      

A convenient method of preparing ultrafine polystyrene latex nano-particles with chlorine groups on the surface is developed. Polystyrene latexes in the size range 50–400 nm were prepared via emulsion polymerization, using sodium dodecyl sulfate (SDS) as surfactant. The poly styrene with chlorine groups on the surface will be fine to use as organic filler to modify rubber. Transmission electron microscopy (TEM) was used to observe the morphology of silicon dioxide and functionalized polystyrene nanoparticles. The nature of bonding between the polymer and the reactive groups on the filler surfaces was analyzed using Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was employed to examine the filler surface.

ABSTRACT

Natural polymers with improved structure have been securing increasing value in the industry as they

are abundant, cheap, and biodegradable. Graft copolymerization is one of the effective ways to

enhance the properties of natural polymers. Starch based graft copolymers are becoming increasingly

important due to their remarkable adhesion, high water absorbency, and biodegradability. Methyl

methacrylate (MMA) grafted onto starch by using the ceric ammonium nitrate (CAN) as a redox

initiator in the presence of nitric acid in aqueous medium to form grafted copolymer (Starch-g-

PMMA) was investigated. The grafting reaction was carried out under stream of nitrogen gas. The

impact of different reaction parameters to achieve the highest percent grafting (%G) has been studied

by determining the initiator concentration, monomer concentration, time (hours), nitric acid

concentration, and polymerization temperature. The % G was found to be 97%. Evidence of grafting

was characterized and confirmed by Fourier transform infrared spectroscopy (FTIR). The peaks at

1736.70 cm-1 and 3449.78 cm-1 indicates that MMA has been successfully grafted to starch. %G was

found to be decreased at higher than 70°C, after 2 hours of reaction time, with an increase of MMA

monomer concentration, initiator concentration, and with HNO3 concentration. The highest percent

grafting was obtained at the parameters of 1 g starch, 70°C, 2 hours, 2 mmol CAN, 140 mmol MMA

and 0.4 mmol HNO3