Novel ruthenium indenylidene catalysts : from homogeneous to heterogeneous

Nowadays a number of ruthenium metathesis catalysts have been developed owing to their accessibility, remarkable activity and selectivity, connected with good tolerance towards functional groups, air and moisture. Innovative development in the class of ruthenium metathesis catalysts coordinated with NHC has been experienced which mainly directed toward tuning their catalytic activity and selectivity through altering both steric and electronic properties. The unsymmetrical NHC ligands in particular, have been introduced to induce dissymmetry, a key for achieving higher level of selectivity in different reactions. A great number of the ruthenium complexes bearing unsymmetrical NHC ligands have been developed up to this moment. The bis-coordinated ruthenium indenylidene developed in this work showed moderate activity at higher temperature in RCM, ROMP and other kind of reactions such as isomerization of allylic alcohols and isomerization of alkenes. Failure of these catalysts to work at room temperature has been attributed to the lack of labile ligand.This call for further research which will focus on tuning of unsymmetrical NHC ligands to achieve more active and selective ruthenium complexes coordinated with non-labile NHC ligand with the labile one. The research should go in hand with design and synthesis of heterogeneous catalysts that can be recovered from the reaction mixture and be recycled. Although the support materials used in this study proved to be not suitable for metathesis, the obtained results can be considered as a challenge in the journey toward designing stable and active heterogeneous ruthenium indenylidene catalysts. Up to now a number of solid materials have been developed and successfully utilized in the immobilization of ruthenium benzylidene complexes. It is expected that the same materials can act as the suitable supports for ruthenium indenylidene and therefore, a study about development heterogeneous ruthenium indenylidene analogs would be of great interest

Ruthenium indenylidene complexes bearing N-alkyl/N-mesityl-substituted N-heterocyclic carbene ligands

We report on the synthesis and characterization of second generation ruthenium indenylidene catalysts bearing unsymmetrical N-heterocyclic carbene (NHC) ligands denoted as RuCl2(3-phenyl-1-indenylidene)(1-mesityl-3-R-4,5-dihydroimidazol-2-ylidene)(PCy3), in which R is methyl 8a, octyl 8b or cyclohexyl 8c. The characterization of 8a-c was performed by NMR spectroscopy, elemental analysis, IR, HRMS and single-crystal X-ray diffraction analysis. In addition, the catalytic activity of the obtained initiators was evaluated in various representative metathesis reactions. The results reveal that the complexes 8a-c, bearing an N-alkyl side on the NHC, show a faster catalytic initiation than the reference complex 2. Complex 8a, which performs the best among the investigated indenylidene complexes, exhibits slower initiation but better overall efficiency than its benzylidene analogue 1c, especially in a low catalyst loading

Mutation Spectrum and Birth Prevalence of Inborn Errors of Metabolism among Emiratis : A study from Tawam Hospital Metabolic Center, United Arab Emirates

Objectives: This study aimed to determine the mutation spectrum and prevalence of inborn errors of metabolism (IEM) among Emiratis. Methods: The reported mutation spectrum included all patients who were diagnosed with IEM (excluding those with lysosomal storage diseases [LSD]) at Tawam Hospital Metabolic Center in Abu Dhabi, United Arab Emirates, between January 1995 and May 2013. Disease prevalence (per 100,000 live births) was estimated from data available for 1995–2011. Results: In 189 patients, 57 distinct IEM were diagnosed, of which 20 (35%) entities were previously reported LSD (65 patients with 39 mutations), with a birth prevalence of 26.87/100,000. This study investigated the remaining 37 (65%) patients with other IEM (124 patients with 62 mutations). Mutation analysis was performed on 108 (87%) of the 124 patients. Five patients with biotinidase deficiency had compound heterozygous mutations, and two siblings with lysinuric protein intolerance had two homozygous mutations. The remaining 103 (95%) patients had homozygous mutations. As of this study, 29 (47%) of the mutations have been reported only in Emiratis. Two mutations were found in three tribes (biotinidase deficiency [BTD, c.1330G>C] and phenylketonuria [PAH, c.168+5G>C]). Two mutations were found in two tribes (isovaleric aciduria [IVD, c.1184G>A] and propionic aciduria [PCCB, c.990dupT]). The remaining 58 (94%) mutations were each found in individual tribes. The prevalence was 48.37/100,000. The most prevalent diseases (2.2–4.9/100,000) were biotinidase deficiency; tyrosinemia type 1; phenylketonuria; propionic aciduria; glutaric aciduria type 1; glycogen storage disease type Ia, and mitochondrial deoxyribonucleic acid depletion. Conclusion: The IEM birth prevalence (LSD and non-LSD) was 75.24/100,000. These results justify implementing prevention programmes that incorporate genetic counselling and screening

Root extracts of Saussurea costus as prospective detoxifying food additive against sodium nitrite toxicity in male rats

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe goal of this study was to investigate the effects of three different extracts of Saussurea costus roots (ethanol, methanol, and water) as a food additive in alleviating the harmful effect of sodium nitrite in rat meals. Thirty-five adult male rats were divided into five groups as follows: control, sodium nitrite (NaNO2; 75 mg/kg BW, single oral dose), S. costus 70% ethanol, 70% methanol, and aqueous extracts (300 mg/kg BW), respectively for four weeks followed by a single dose of NaNO2 24h before decapitation. Results showed that the 70% ethanol extract of S. costus has a higher concentration of total phenolic content, total flavonoids, and antioxidant effect than the 70% methanol and water extracts. Rats pretreated with S. costus extracts reduced the harmful effects induced by NaNO2 and improved the hematological parameters, liver, and kidney function biomarkers as well as lipid profile as compared to the NaNO2 group. Furthermore, S. costus improved the histopathological alterations in the liver and kidney induced by NaNO2 and improved meat sensory evaluation. Conclusively, the 70% ethanol extract of S. costus roots is the most effective extract as an antioxidant against the toxicity of sodium nitrite in male rats and might be used safely as a natural additive in the food industry

High prevalence of cardiometabolic risk factors amongst young adults in the United Arab Emirates: the UAE Healthy Future Study

BackgroundCardiovascular disease (CVD) is the leading cause of death in the world. In the United Arab Emirates (UAE), it accounts for 40% of mortality. CVD is caused by multiple cardiometabolic risk factors (CRFs) including obesity, dysglycemia, dyslipidemia, hypertension and central obesity. However, there are limited studies focusing on the CVD risk burden among young Emirati adults. This study investigates the burden of CRFs in a sample of young Emiratis, and estimates the distribution in relation to sociodemographic and behavioral determinants.MethodsData was used from the baseline data of the UAE Healthy Future Study volunteers. The study participants were aged 18 to 40 years. The study analysis was based on self-reported questionnaires, anthropometric and blood pressure measurements, as well as blood analysis.ResultsA total of 5167 participants were included in the analysis; 62% were males and the mean age of the sample was 25.7 years. The age-adjusted prevalence was 26.5% for obesity, 11.7% for dysglycemia, 62.7% for dyslipidemia, 22.4% for hypertension and 22.5% for central obesity. The CRFs were distributed differently when compared within social and behavioral groups. For example, obesity, dyslipidemia and central obesity in men were found higher among smokers than non-smokers (p \u3c 0.05). And among women with lower education, all CRFs were reported significantly higher than those with higher education, except for hypertension. Most CRFs were significantly higher among men and women with positive family history of common non-communicable diseases.ConclusionsCRFs are highly prevalent in the young Emirati adults of the UAE Healthy Future Study. The difference in CRF distribution among social and behavioral groups can be taken into account to target group-specific prevention measures

Biogenic silver nanoparticles eradicate of Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) isolated from the sputum of COVID-19 patients

In recent investigations, secondary bacterial infections were found to be strongly related to mortality in COVID-19 patients. In addition, Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) bacteria played an important role in the series of bacterial infections that accompany infection in COVID-19. The objective of the present study was to investigate the ability of biosynthesized silver nanoparticles from strawberries (Fragaria ananassa L.) leaf extract without a chemical catalyst to inhibit Gram-negative P. aeruginosa and Gram-positive Staph aureus isolated from COVID-19 patient’s sputum. A wide range of measurements was performed on the synthesized AgNPs, including UV–vis, SEM, TEM, EDX, DLS, ζ -potential, XRD, and FTIR. UV-Visible spectral showed the absorbance at the wavelength 398 nm with an increase in the color intensity of the mixture after 8 h passed at the time of preparation confirming the high stability of the FA-AgNPs in the dark at room temperature. SEM and TEM measurements confirmed AgNPs with size ranges of ∼40-∼50 nm, whereas the DLS study confirmed their average hydrodynamic size as ∼53 nm. Furthermore, Ag NPs. EDX analysis showed the presence of the following elements: oxygen (40.46%), and silver (59.54%). Biosynthesized FA-AgNPs (ζ = −17.5 ± 3.1 mV) showed concentration-dependent antimicrobial activity for 48 h in both pathogenic strains. MTT tests showed concentration-dependent and line-specific effects of FA-AgNPs on cancer MCF-7 and normal liver WRL-68 cell cultures. According to the results, synthetic FA-AgNPs obtained through an environmentally friendly biological process are inexpensive and may inhibit the growth of bacteria isolated from COVID-19 patients

Melatonin downregulates the increased hepatic alpha-fetoprotein expression and restores pancreatic beta cells in a streptozotocin-induced diabetic rat model: a clinical, biochemical, immunohistochemical, and descriptive histopathological study

BackgroundDiabetes mellitus (DM) is a chronic metabolic disorder. Hepatopathy is one of the serious effects of DM Melatonin (MT) is a potent endogenous antioxidant that can control insulin output. However, little information is available about the potential association between melatonin and hepatic alpha-fetoprotein expression in diabetes.ObjectiveThis study was conducted to assess the influence of MT on diabetes-related hepatic injuries and to determine how β-cells of the pancreas in diabetic rats respond to MT administration.Materials and methodsForty rats were assigned to four groups at random (ten animals per group). Group I served as a normal control group. Group II was induced with DM, and a single dose of freshly prepared streptozotocin (45 mg/kg body weight) was intraperitoneally injected. In Group III, rats received 10 mg/kg/day of intraperitoneal melatonin (IP MT) intraperitoneally over a period of 4 weeks. In Group IV (DM + MT), following the induction of diabetes, rats received MT (the same as in Group III). Fasting blood sugar, glycosylated hemoglobin (HbA1c), and serum insulin levels were assessed at the end of the experimental period. Serum liver function tests were performed. The pancreas and liver were examined histopathologically and immunohistochemically for insulin and alpha-fetoprotein (AFP) antibodies, respectively.ResultsMT was found to significantly modulate the raised blood glucose, HbA1c, and insulin levels induced by diabetes, as well as the decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Furthermore, MT attenuated diabetic degenerative changes in the pancreas and the hepatic histological structure, increased the β-cell percentage area, and decreased AFP expression in the liver tissue. It attenuated diabetes-induced hepatic injury by restoring pancreatic β-cells; its antioxidant effect also reduced hepatocyte injury.ConclusionCollectively, the present study confirmed the potential benefits of MT in downregulating the increased hepatic alpha-fetoprotein expression and in restoring pancreatic β-cells in a streptozotocin-induced diabetic rat model, suggesting its promising role in the treatment of diabetes

Melatonin ameliorates serobiochemical alterations and restores the cardio-nephro diabetic vascular and cellular alterations in streptozotocin-induced diabetic rats

Melatonin possesses a wide range of pharmacological activities, including antidiabetic properties. Diabetes mellitus (DM) induces several physiopathological changes in body organs, which could be observed lately after systemic failure. In the current study, we aimed to investigate the serobiochemical changes and the histopathological picture in the diabetic heart and the kidney early before chronic complications and highlight the association between hyperglycemia, glomerular alterations, and cardiovascular changes. In addition, the role of melatonin in the treatment of cardio-nephro diabetic vascular and cellular adverse changes in streptozotocin-induced diabetic rats was also studied. A total of 40 mature Wistar albino rats were distributed into five groups; (1) control untreated rats, (2) diabetic mellitus untreated (DM) rats, in which DM was induced by the injection of streptozotocin (STZ), (3) control melatonin-treated (MLT), (4) melatonin-treated diabetic (DM + MLT) rats, in which melatonin was injected (10 mg/kg/day, i.p.) for 4 weeks, and (5) insulin-treated diabetic (DM + INS) rats. The serum biochemical analysis of diabetic STZ rats showed a significant (P < 0.05) increase in the concentrations of blood glucose, total oxidative capacity (TOC), CK-MB, endothelin-1, myoglobin, H-FABP, ALT, AST, urea, and creatinine as compared to control rats. In contrast, there was a significant (P < 0.05) decrease in serum concentration of insulin, total antioxidative capacity (TAC), total nitric oxide (TNO), and total protein level in DM rats vs. the control rats. Significant improvement in the serobiochemical parameters was noticed in both (DM + MLT) and (DM + INS) groups as compared with (DM) rats. The histological examination of the DM group revealed a disorder of myofibers, cardiomyocyte nuclei, and an increase in connective tissue deposits in between cardiac tissues. Severe congestion and dilation of blood capillaries between cardiac muscle fibers were also observed. The nephropathic changes in DM rats revealed various deteriorations in glomeruli and renal tubular cells of the same group. In addition, vascular alterations in the arcuate artery at the corticomedullary junction and interstitial congestion take place. Melatonin administration repaired all these histopathological alterations to near-control levels. The study concluded that melatonin could be an effective therapeutic molecule for restoring serobiochemical and tissue histopathological alterations during diabetes mellitus

The interrelationship and accumulation of cardiometabolic risk factors amongst young adults in the United Arab Emirates: The UAE Healthy Future Study.

INTRODUCTION: Similar to other non-communicable diseases (NCDs), people who develop cardiovascular disease (CVD) typically have more than one risk factor. The clustering of cardiovascular risk factors begins in youth, early adulthood, and middle age. The presence of multiple risk factors simultaneously has been shown to increase the risk for atherosclerosis development in young and middle-aged adults and risk of CVD in middle age. OBJECTIVE: This study aimed to address the interrelationship of CVD risk factors and their accumulation in a large sample of young adults in the United Arab Emirates (UAE). METHODS: Baseline data was drawn from the UAE Healthy Future Study (UAEHFS), a volunteer-based multicenter study that recruits Emirati nationals. Data of participants aged 18 to 40 years was used for cross-sectional analysis. Demographic and health information was collected through self-reported questionnaires. Anthropometric data and blood pressure were measured, and blood samples were collected. RESULTS: A total of 5126 participants were included in the analysis. Comorbidity analyses showed that dyslipidemia and obesity co-existed with other cardiometabolic risk factors (CRFs) more than 70% and 50% of the time, respectively. Multivariate logistic regression analysis of the risk factors with age and gender showed that all risk factors were highly associated with each other. The strongest relationship was found with obesity; it was associated with four-fold increase in the odds of having central obesity [adjusted OR 4.70 (95% CI (4.04-5.46)], and almost three-fold increase odds of having abnormal glycemic status [AOR 2.98 (95% (CI 2.49-3.55))], hypertension (AOR 3.03 (95% CI (2.61-3.52))] and dyslipidemia [AOR 2.71 (95% CI (2.32-3.15)]. Forty percent of the population accumulated more than 2 risk factors, and the burden increased with age. CONCLUSION: In this young population, cardiometabolic risk factors are highly prevalent and are associated with each other, therefore creating a heavy burden of risk factors. This forecasts an increase in the burden of CVD in the UAE. The robust longitudinal design of the UAEHFS will enable researchers to understand how risk factors cluster before disease develops. This knowledge will offer a novel approach to design group-specific preventive measures for CVD development

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely