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Although sequestering nitrate by anion exchange resins (AERs) is a proven and well-established technology, many process problems and challenges still exist, such as interference, nitrate dumping, total dissolved solids (TDS) limitations, brine waste disposal, etc. An engineered-integrated approach was devised and assessed to mitigate such limitations. The overall process optimization was based on screening, analyzing, and optimizing each respective step. A front-end sulfate removal step was suggested, evaluated, which yielded removal efficiencies >95%. Back-end options were also introduced, including reduced brine and brine wastes, recycling possibility, and usage as mixed-fertilizer with a NO3/Cl ratio of 0.65 as confirmed by mass balance calculations. Taguchi robust designs (TRD), Box-Behnken Designs (BBD), and central composite design (CCD) experimental design methods were used, enabling information mining from a minimum number of experiments. A one-factor-at-a-time strategy was applied and the regeneration process was optimized using TRD. Response analysis and regression revealed that acid concentration and volume are the most influential factors. Selectivity order was determined as SO42-->Cl−>HCO3− according to their relative coefficients of the BBD and CCD regression models. Field trials confirmed the robustness and viability of the proposed integrated approach. A process flow diagram was devised. Merits of the proposed system include: a) possible resolution of sulfate competition and nitrate dumping, b) elimination of brine waste problems, c) tolerate higher TDS levels than ever possible for AERs, d) improved economics, e) improved process robustness, f) mitigate the corrosiveness of produced water, and g) fulfilling zero liquid discharge criteria.

The contamination of water with herbicides poses a serious threat to the environment as a result of their widespread use in the agricultural field. Herein, mesoporous silica nanoparticles (MSNs) we...

The slow solvent evaporation approach was used to create a single crystal of (C

Two novel complexes, [(C

Currently, chemotherapy is an important method for the treatment of various cancers. Nevertheless, it has many limitations, such as poor tumour selectivity and multi-drug resistance. It is necessary to improve this treatment method by incorporating a targeted drug delivery system aimed to reduce side effects and drug resistance. The present work aims to develop pH-sensitive nanocarriers containing magnetic mesoporous silica nanoparticles (MMSNs) coated with pH-responsive polymers for tumour-targeted drug delivery via the folate receptor. 2-Diethyl amino ethyl methacrylate (DEAEMA) was successfully grafted on MMSNs via surface initiated ARGET atom transfer radical polymerization (ATRP), with an average particle size of 180 nm. The end groups of poly (2-(diethylamino)ethyl methacrylate) (PDEAEMA) brushes were converted to amines, followed by a covalent bond with folic acid (FA) as a targeting agent. FA conjugated to the nanoparticle surface was confirmed by X-ray photoelectron spectroscopy (XPS). pH-Responsive behavior of PDEAEMA brushes was investigated by Dynamic Light Scattering (DLS). The nanoparticles average diameters ranged from ca. 350 nm in basic media to ca. 650 in acidic solution. Multifunctional pH-sensitive magnetic mesoporous nanoparticles were loaded with an anti-cancer drug (Doxorubicin) to investigate their capacity and long-circulation time. In a cumulative release pattern, doxorubicin (DOX) release from nano-systems was ca. 20% when the particle exposed to acidic media, compared to ca. 5% in basic media. The nano-systems have excellent biocompatibility and are minimally toxic when exposed to MCF-7, and -MCF-7 ADR cells.

In present study, the molecular imprinting polymer (MIP) of p-coumaric acid was synthesized by using p-coumaric acid as a template, acetonitrile as solvent, 1,4-butanediol dimethacrylate as cross-linker, acrylic acid as monomer and 2,2-azobisisobutironitrile (AIBN) as the initiator. The synthesized polymers were characterized by FTIR and SEM. The results from SEM revealed that the polymer was in spherical shape with size in micro-range. The binding efficiency of polymers was analyzed by adsorption study. The highest rebinding efficiency for MIP was ~ 80% while for non-imprinted polymer (NIP) it was only 24%.

In this paper, a new pH-responsive nanosystem based on mesoporous silica nanoparticles (MSNs) was developed for cancer therapy. Poly(2-(diethylamino) ethyl methacrylate) (PDEAEMA) was grafted on their outer surface and acts as a gatekeeper, followed by subsequent modification of the polymer by cysteine (MSN-PDEAEMA-Cys) and poly(oligo(ethylene glycol) methyl ether methacrylate) (MSN-PDEAEMA-Cys-POEGMEMA). The physicochemical properties of these nanocarriers were characterized using scanning and transmission electron microscopies (SEM and TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS). The synthesized nanoparticles were well-dispersed with a diameter of ca. 200 nm. The obtained XPS results confirm the successful modification of MSN-PDEAEMA with Cys and POEGMEMA by increasing the peak intensity of C–O and C=O groups at 286.5 and 288.5 eV, respectively. An anti-cancer drug, doxorubicin (DOX), was encapsulated into the fabricated nanoplatform. The DOX release amount at physiological pH of 7.4 was limited (10%), while an accumulation drug release of ca. 35% was accomplished after 30 h in acidic media. The MTT cell line was used to assess the cytotoxicity of the unloaded and DOX-loaded fabricated nanoplatforms. Upon loading of DOX on these nanomaterials, they showed significant toxicity to human liver cancer cells. These results suggest that the prepared nano-structured materials showed good biocompatibility as well, and they can serve as nanocarriers for the delivery of anti-cancer drugs.

Background: Herbs usually contain a mixture of biologically active constituents, which can interact with numerous prescribed drugs and alter their safety profiles. Objective: The current investigation was aimed to evaluate the effect of commonly used herbal products, including black seed (Nigella sativa), garden cress (Lepidium sativum), and fenugreek (Trigonella foenum-graecum), on the pharmacokinetics and pharmacodynamics of clopidogrel using a Wistar rat model. Methods: A GC-MS analysis revealed the presence of several phytoconstitutents (polyphenols) in the extracts of the black seed, garden cress, and fenugreek. These polyphenols have the potential to interfere with the clopidogrel effect. Plasma concentrations of clopidogrel were measured at different time points in the absence and presence of the concurrent use of tested herbal products and the pharmacokinetic parameters were calculated. Bleeding time was measured in various groups as a measure of the antiplatelet effect of clopidogrel. Results: Area under the plasma concentration-time curves (AUC0-∞) of clopidogrel were 35.53 ±0.89 μg/ml*h (p0.05) and 32.80 ±2.51 μg/ml*h (p0.05). The pharmacodynamic evaluation of the antiplatelet effect of clopidogrel in the presence of herbal products treatment showed a significant prolongation in the bleeding time from a control baseline by ~22-26%, and by added ~8-12% about clopidogrel therapeutic effect (p Conclusion: This is probably due to changes in drug disposition and its antiplatelet action. Further confirmation can determine the clinical relevance of these observations and identify the exact constituents responsible for such activities.

Polymers have a sacred space in science. It is a well-known fact that due to some unique and specific properties polymers are used in a wide range of applications. Among them smart biopolymers have gained attention of researchers worldwide due to their unique properties such as biodegradability, biocompatibility, inexpensiveness, and renewability. Furthermore, these smart biopolymers show a characteristic property of responsiveness to stimuli such as temperature, pH, magnetic and electrical field, chemical, mechanical stress, and light. Consequently, succeeding chapter will briefly shed light about such smart biopolymers, their classification, and applications. Special attention is laid on the potential applicability of such smart biopolymers in the field of drug delivery, tissue engineering scaffolds, bioseparation, biotechnology, other medicinal fields, etc. The versatility and unique potential of these smart polymers make them one of the important parts of science, specifically medicine and drug delivery.

Polysaccharide nanocomposites have drawn attention for their peculiar property of being renewable and green alternatives. Starch is a naturally renewable polymer having great potential owing to properties such as total compostability, biocompatibility, biodegradability, and are without toxic residues, besides few limitations including low mechanical properties, high water sensitivity, and poor processability. However, insertion of nanofillers into starch nanocomposites results in substantial changes and improvements in the stability and applicability of starch-based nanocomposites. This chapter aims to provide the fundamental knowledge on the role of starch nanocomposite polysaccharides, as specific in the field of biomedical applications, especially in gene delivery, as well as recent developments in this area.

Enzymes play a vital role in a broad spectrum of fundamental physiological processes and therefore could be exploited as biological triggers to achieve a controlled release of cargo at the desired site. Enzyme-responsive materials are a class of stimuli-responsive materials with a variety of applications in biological systems. They have been proved to be potential biomaterials, biomedicine, and biosensing candidates. These types of smart materials undergo macroscopic changes when triggered by a selective action of enzymes. This idea has been applied successfully for the development of drug carrier systems where the tissue of interest is targeted by the release of cargo triggered by the catalytic action of an enzyme. This chapter mainly emphasizes on the few key enzyme-responsive nanomaterials such as proteases, lipases, and glucosidases and oxidoreductases for various biomedical applications.

Xanthan gum (XG) is a naturally occurring exo-polysaccharide produced by the class of bacteria Xanthomonas campestris. This hetero polysaccharide produced from Gram-negative bacteria has various unique properties such as biocompatibility, biodegradability, cytocompatibility, highly viscous and pseudo-plastic nature, nontoxicity, and solubility in both cold and hot water, which make it a promising agent in biomedical and tissue engineering applications. Traditionally, XG is an important component for various industrial and biomedical applications as a thickener, emulsion stabilizer, and additive, and is widely used in food and food packaging, cosmetics, toiletries, drug delivery, etc. Recently, it has been used in tissue engineering applications after undergoing various chemical and physical modifications through incorporation of NPs. In this chapter, we discuss the applicability of XG nanocomposites obtained through various modifications in the field of biomedicine and tissue engineering.

This work presents the synthesis of pH-responsive poly(2-(diethylamino) ethyl methacrylate) (PDEAEMA) brushes anchored on hollow mesoporous silica nanoparticles (HMSN-PDEAEMA) via a surface-initiated ARGET ATRP technique. The average size of HMSNs was ca. 340 nm, with a 90 nm mesoporous silica shell. The dry thickness of grafted PDEAEMA brushes was estimated to be ca 30 nm, as estimated by SEM and TEM. The halogen group on the surface of PDEAMA brushes was successfully derivatized with glucosamine, as confirmed by XPS. The effect of pH on the size of the hybrid nanoparticles was investigated by DLS. The size of fabricated nanoparticle decreased from ca. 950 nm in acidic media to ca. 500 nm in basic media due to the deprotonation of tertiary amine in the PDEAEMA. The PDEAEMA modified HMSNs nanocarrier was efficiently loaded with doxorubicin (DOX) with a loading capacity of ca. 64%. DOX was released in a relatively controlled pH-triggered manner from hybrid nanoparticles. The cytotoxicity studies demonstrated that DOX@HMSN-PDEAEMA-Glucosamine showed a strong ability to kill breast cancer cells (MCF-7 and MCF-7/ADR) at low drug concentrations, in comparison to free DOX.

Background: Diabetic septic foot contributes significantly to morbidity and mortality of patients with diabetes leading to substantial physical, physiological and financial burden for the patients and community at large. Objective: to determine the prevalence, patterns and risk factors of diabetic foot ulcers amongst patients with diabetes mellitus who were attending the diabetes center of Arar city in the period of the study. Methods: This was a retrospective study in the patients of the diabetes center of Arar city, Northern Saudi Arabia. The study was carried out during the period from 1 April to 31 May, 2018. All the patients attended the diabetes center in the period of the study were included in our data. The data were collected using a predesigned questionnaire. The questionnaire covered all the necessary items in the research. Data were collected through personal interviews with the participants and filling the questionnaires. Results: The prevalence of diabetic foot among the included diabetic patients was 52.8%. 77.8% had type II and 22.2% had type I, 83.3% had glucometer and 38.9% monitor their blood glucose level daily, 41.7% were obese, 77.8% had hypertension, 52.8% had hyperlipidemia. Only 11.1% examined the pulse and sensation the foot of the population. For diabetes control, 58.3% of them use oral tablets, 27.8% use insulin injection and 13.9% use both tablets and insulin but 52.8 of them have complication with treatment. Conclusion: The prevalence of diabetic foot among the included diabetic patients was high (52.8%). This emphasizes the importance of the more health education and better management of the diabetic patients in order to reduce the burden of health care costs of diabetic foot.

Colorimetric aptasensors based on gold nanoparticles (AuNPs) commonly feature ssDNA probes nonspecifically adsorbed to surface gold particles. A major limitation of this versatile method is the incomplete dissociation of the adsorbed nontarget binding segments of the aptamer sequence upon target binding. This results in weak or nonexistent sensor performance by preventing the particles from aggregating when the optimized salt concentration is added. Rather than removing the nonbinding nucleotides flanking the binding region of the aptamer, proposed herein is an alternative strategy, simply introducing a centrifugation and resuspension step after target recognition that eliminates residual binding between the aptamer and the surface of the particles. The performance of two different vitamin D3 (VTD3) aptamers were tested. The method enhanced the performance of the sensor that used the higher detection limit (1 µM) aptamer by fourfold. The superiority of the proposed method became apparent in a nonworking colorimetric sensor became a highly sensitive sensor with a one nanomolar detection level and excellent discrimination against potential interfering molecules including VTD2 when the centrifugation and resuspension process was implemented. The level of VTD3 in human blood was determined colorimetrically after extraction with n-hexane. The results were in agreement with those obtained by HPLC. The proposed method could be applied to aptamers targeting small molecules with no need to reprocess the SELEX-isolated sequence by knowing the binding region and removing the flanking primers.

BACKGROUND: Exposure to stressful working conditions without adequate stress-coping strategies may lead to stress and even psychiatric morbidity. There are a dearth of studies on stress-coping strategies among consultant physicians in the Arabian Gulf. OBJECTIVES: Determine stress-coping strategies among consultants in Saudi Arabia and the relationship of strategies to level of stress. DESIGN: Analytical cross-sectional study. SETTINGS: Conducted between November 2014 and March 2015 among physician consultants registered at the Saudi Commission for Health Specialties. SUBJECTS AND METHODS: Text messages were used to directly ask consultants to complete an online questionnaire. MAIN OUTCOME MEASURES: The 28-item Brief COPE inventory and the Perceived Stress Scale. SAMPLE SIZE: 582. RESULTS: The consultants were largely males (71%) and Saudi (56%), and their mean age was 46.9 (7.9) years. Adaptive stress-coping strategies were more frequently used than maladaptive stress-coping strategies (68% versus 49%). Stress levels were positively correlated with maladaptive stress-coping strategies (r=0.41, P

The aim of this cross-sectional study was to determine the prevalence, risk factors, other associated sleep disorders and commodities of Restless Legs Syndrome (RLS) among a sample of Saudis population. The diagnosis of RLS was based on the four criteria designated by the International Restless Legs Syndrome Study Group (IRLSSG). Of 2095 participants, the average age of the sample was 42.3 (±15.5), and 848 (40.7%) were females. The prevalence of RLS was 14.7% with 95% confidence intervals (CI) of 13.3–16.3%. The presence of RLS was higher in males than females (16.3% in males vs. 12.5% in females, P = 0.016). Risk factor for RLS was smoking (P = 0.002), depression (P = 0.001), short sleep duration (P = 0.005), hyperlipidemia (P = 0.013), poor sleep quality (P = 0.001), and high risk for sleep apnea (P = 0.001). The prevalence of RLS was not affected by various age groups (14.1% in the young age group (18–29 years), 15.9% in the middle-age group (30–60), and 11.7% in the elderly (over 60), P = 0.139). Among participants with RLS, 20.8% reported severe RLS, 30.7% reported moderate RLS, and 48.5% reported mild RLS. Using the multivariate logistic regression model we found that smoking (aOR = 1.686; 95% CI 1.199–2.372; P = 0.003), short sleep duration (aOR = 1.568; 95% CI 1.024–2.400; P = 0.039), poor sleep quality (aOR = 1.969; 95% CI 1.236–3.139; P = 0.004), and high risk of sleep apnea (aOR = 1.598; 95% CI 1.113–2.295; P = 0.011) were all significantly associated with the presence of RLS.

BACKGROUND: Alternative medicine is defined as medical therapies that are not regarded as orthodox by the medical profession. The teaching of complementary and alternative medicine (CAM) in medical schools is becoming prevalent worldwide. Only a few studies have been done to assess medical students' attitude toward CAM and the need for CAM courses. MATERIALS AND METHODS: An observational, descriptive, cross-sectional study was conducted on medical students in two universities, King Saud (KSU) and Majmaah (MU) medical colleges, between February and April 2015. A survey was developed and validated by a pilot study. Data were gathered from both colleges by means of hard and soft copy surveys. Medical students of both genders from the 1st year to the 5th year from both universities were targeted in this study. Fifth-year students from Majmaah and students from the preparatory year were excluded from the study. KSU students comprised 1433, while MU students comprised only 180. The sample size was 384. Data were analyzed using SPSS software. RESULTS: The study included 399 medical students. Bloodletting is the most known modality (80.7%), while homeopathy is the least known with a percentage of 7.47%. The overall assessment of the attitude toward CAM was neutral, with a mean of 3.1. Students who had taken a CAM course previously were more satisfied with their knowledge than those who had not, showing a statistical significance of P = 0.0001. CONCLUSION: This study showed a lack of knowledge of CAM among medical students. There was an association between taking a CAM course and students' satisfaction with their knowledge. Most of the students agreed with the inclusion of CAM courses in the medical curriculum.

Fahad D Alosaimi,1 Hossam S Alawad,2 Ayedh K Alamri,2 Abdullah I Saeed,2 Khalid A Aljuaydi,2 Alwaleed S Alotaibi,2 Khalid M Alotaibi,2 Eiad A Alfaris3 1Department of Psychiatry, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Department of Psychiatry, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 3King Saud University Chair for the Development of Medical Education, Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia Background: Physicians experience several work-related stressors that have been mounting up in recent decades. This study aimed to examine perceived stress and its risk factors and consequences among consultant physicians in Saudi Arabia. Methods: A cross-sectional study was conducted from November 2014 to March 2015 among physicians who were assigned rank of consultant. The stress level was assessed using perceived stress scale (PSS).Results: A total of 582 consultants participated. The average age was 46.9±7.9 years, 71% were males, 56% were Saudi, 15% were smokers, and 68% slept ≤6 hours per night. The median PSS score was 17 (interquartile range of 14–21), which represented 44% of maximum possible PSS score. The upper tertile of PSS score (represents a high stress level) was significantly associated with being younger, female, and Saudi. The majority (85%) considered job environment to be stressful and ~50% attributed that to a high workload and a noncooperative administration. In the year preceding this study, half of consultants frequently contemplated or even worked toward changing their medical institutes or even moving to work outside Saudi Arabia because of perception of a stressful working environment. Over the previous year, encountering life stressors, considering job environment as stressful and experiencing passive suicidal ideation, were significantly associated with higher levels of stress. In multivariate analysis, the following factors were independently associated with stress: female gender (odds ratio [OR]=2.41, 95% CI 1.58–3.70) and perceived stressful working environment (OR=3.66, 95% CI 1.87–7.17).Conclusion: Consultant physicians in Saudi Arabia experience moderate to high levels of perceived stress that are relatively comparable to physicians worldwide. A significant association was found between stress levels and both female gender and perception of a stressful working environment. Further studies are required to assess physician-based interventions and organization-directed approaches to management of stress among physicians. Keywords: stress, Saudi Arabia, consultants, patterns, risk factors

The aim of this study was to determine the risk and symptoms for obstructive sleep apnea (OSA) among Saudi Arabian adults. This cross-sectional survey among healthy participants was conducted at King Abdulaziz Medical City-Riyadh (KAMC-R). The Berlin Questionnaire (BQ) was used to assess the risk of OSA, and Epworth Sleepiness Scale (ESS) was used to measure excessive daytime sleepiness (EDS) as a manifestation of OSA in participants. The total number of participants was 2095, mean age of the sample was 42.3 (±15.5) years and 848 (40.7%) were females. Using BQ, 31.9% of the participants were classified as high risk for OSA (33.4% among females and 31.1% among males). The risk for OSA increased with age: 19.4% among the young group (≤29 years), 35.2% among the middle-aged (30–59 years), and 41% among the elderly (≥60 years). The risk of symptomatic OSA by combining both BQ and ESS was 7.8% and increased with age (5.5% among the young group, 8.5% among the middle-aged, and 9.7% among the elderly), but there was no difference between gender (8% among females vs. 7.7% among males). This study showed that the risk for OSA is very high, is equal in both genders and it increases with age and obesity.

Aim of the work: diabetic foot disease(DFD) is diabetic patient's foot affection by ulcers which are accompanied by peripheral vascular disease and/or diabetic neuropathy of the lower limb. Prevalence of diabetic ulcer is ranging from 2%-10%. High rate of lower limb amputation in DFD (More than 15%) and survival rate for undertaken amputation patient are short. Ninety diabetic amputations are performed monthly in Saudi Arabia capital of Riyadh. Identification of DFD and diabetic patient's awareness of DFD and how to take care of it will reduce the incidence of more complications like amputation. This study aimed to evaluate knowledge, education, attitude and practice with diabetic foot among diabetic patients all over Saudi Arabia. Patients and Method: cross-sectional study directed among the diabetic clinic visitors in Primary Health Care Centers (PHCs s). Selection of 55 PHCs was done by random sampling. Ten diabetic patients were randomly selected from each PHCs and collecting of data was done by interviews. Research questionnaire contains three parts; first part is asking about demographic data; second part is about data that are focusing on diabetes and its related questions and last part is the main part which asking about diabetic foot. Results: 519 diabetic patients were participated in this study. Only 180 participants were complaining of diabetic complications (34.7%). Most of participants (55.1%) get high score 7-8 out of 8 questions in Knowledge. Although, there were 166 persons (32%) who couldn’t reach full score in attitude evaluation. There was a large percentage of our participants (69%) had very low score 0-2 out of 6 in assessment of previous education of diabetic foot. More than half of participants (56.5%) had score 6-10 out of 15 in evaluation of practice with diabetic foot. Conclusion: diabetic foot in Saudi Arabia is existing, even amputations and other diabetic foot complications were also present. Diabetic patients have good knowledge and attitude toward diabetic foot. Education about diabetic foot and practice is still weak.

The aim of this study is to compare the creep/recovery behavior of bulk-fill dental composites after storage in various food simulating organic solvents. For this purpose, five different resin-composites (four bulk-fills and one conventional) were used. A total of 20 rectangular specimens (14 mm &times, 3 mm &times, 0.7 mm) were prepared by filling the resin-composites in Teflon mold. All of the specimens for each material (n = 5) were divided into four groups namely dry (control), distilled water (DW), artificial saliva, and absolute ethanol. The specimens were subjected to three-point bending creep test during immersion directly. A constant load of 2 N was used for each specimen with loading and unloading time 2 h each. Results: SF2 and XF showed a lower creep strain % after immersion, ranging from 0.44 (dry) to 0.75 (saliva) and 0.43 (dry) to 0.80 (ethanol), respectively. TNC BF depicts the maximum creep strain % ranging from 1.24% (dry) to 2.87% (ethanol) followed by FBF ranging from 1.17 (dry) to 2.59 (ethanol). However, the conventional material (GR) showed lower creep strain after immersion ranging from 0.28 to 0.54. Moreover, SF2 resulted in the highest creep recovery in all of the composites groups, as well as conventional material. The other composite groups showed lower creep recovery as compared to the conventional material (GR). The creep strain % for all the bulk-fill composites materials were increased during immersion in the liquids. However, for the conventional material, the creep deformation is decreased after immersion. SF2 showed the highest percentage of creep recovery among the bulk-fill composites, followed by XF.

With more competition and ever changing consumer demands, manufacturers are frequently realizing to reengineer their facility to satisfy the needs of many product groups. In such cases simulation can be a useful tool when analyzing complex production systems to help sort through cause-and effect relationships and gain a better understanding of what is actually causing a particular problem in the system. Once problems are identified, changes for improvement can be made more intelligently and then verified using simulation. The paper presents modeling of juice production line using simulation as tool. Objective is to estimate the present production line utilization and the bottleneck. The subsequent objective is then to suggest and verify a solution to enhance production capacity and reduce the bottleneck which results in the fulfillment of current and future market long term demand. Arena simulation package is used to develop the model.