Synthesis Of Low-Coordinate Transition Metal Bis(alkoxide) Complexes And Their Reactivity Toward Small Molecules

This dissertation focused on the synthesis of new transition metal complexes in bis(alkoxide) ligand environments and the investigation of their reactivity in nitrene-group transfer catalysis and small molecule activation. Treatment of Cr(N(SiMe3)2)2(THF)2 with two equivalents of HOR (OR = OCtBu2Ph) led to the formation of the chromium(II) alkoxide dimer, Cr2(OR)4. Upon the reaction with bulky aryl and alkyl azides, Cr2(OR)4 led to the stable Cr(IV) mono(imido) complexes, Cr(OR)2(NR), featuring trigonal planar metal centers. In contrast, less bulky aryl azides led to the formation of chromium (VI) bis(imido) complexes Cr(OR)2(NR)2, independent of the amount of azide used. Chromium(IV) mono(imido) species Cr(OR)2(NR) is capable of nitrene transfer to isocyanides to form asymmetric carbodiimides (RNCNR’). When excess isocyanide is added to Cr(OR)2(NR), a new chromium(II) complex, Cr(OR)2(CNR2)4, was identified by X-ray crystallography. This tetrakis(isocyanide) chromium(II) complex is also capable of forming carbodiimide when azide is introduced. Efficient catalytic formation of carbodiimides was obtained using 2.5 mol% of Cr2(OR)4 for the mixtures of bulky organoazides and isocyanides; no catalytic reactivity was observed for the non-bulky aryl azides. DFT calculations suggest that trigonal CrIV(OR)2(NR) intermediate is the key species in the reaction mechanism as, due to it coordinative unsaturation, it allows isocyanide binding to the metal, which enables subsequent C-N bond formation. A bulkier alkoxide ligand HOR’ (R = CtBu2(3,5-Ph2Ph)) was synthesized by lithium halogen exchange reaction. The protonolysis of the metal complexes, M(N(SiMe3)2(THF)x, with HOR’ enabled an easy isolation of new bis(alkoxide) precursors M(OR’)2(THF)2 (where M = Cr, Co, Fe) featuring cis-divacant octahedral geometry. The chemistry of the iron bis(alkoxide) compound Fe(OR’)2(THF)2 with the variety of aryl azides was investigated. Catalytic formation of various azoarenes from the corresponding azides (mesityl azide, 2,6-diethylphenylazide, azidobenzene, 4-azidotoluene, 3,5-dimethylphenylazide) using 5/10 mol% loading of Fe(OR’)2(THF)2 was observed. Mechanistic investigation revealed that the reaction proceeds via formation of tetrazene complexes Fe(OR’)2 (ArNNNNAr). 57Fe Mössbauer and EPR spectroscopy demonstrate a high spin iron(III) center, antiferromagnetically coupled to the tetrazene ligand radical anion. Tetrazene complexes are capable of azoarene formation, as demonstrated by NMR spectroscopy and mass spectrometry, thus confirming their role as intermediates in nitrene coupling reaction. My next project focused on the investigation of the reactivity of Cr(OR’)2(THF)2 with organic carbonyls and CO2. Cr(OR’)2(THF)2 catalyzes the reductive coupling of a variety of aromatic aldehydes (benzaldehyde, 4-anisaldehyde, 4-(trifluoromethyl)benzaldehyde, and 2,4,6-trimethylbenzaldehyde) to form Cr(IV) diolate complexes. In contrast, the reaction of benzophenone led to the formation of the ketone adduct Cr(OR’)2(OCPh2). DFT calculations suggested that the reductive coupling of aldehydes proceeds via the Cr(III) bis-aldehyde intermediate. Partial radical character in the coordinated aldehydes in these species is sufficient for C-C bond formation. The calculation also suggested that that the more significant steric demands of ketones prevented their coupling of ketone. No reductive coupling was observed with CO2. Instead, the reaction of Cr(OR’)2(THF)2 with CO2 led to CO2 insertion into Cr-OR’ bonds to form the diamagnetic dinuclear paddlewheel complex Cr2(O2COR’)4(THF)2. Oxo- and sulfide-group transfer chemistry was also investigated. The reaction of Fe(OR)2(THF)2 with an oxo-transfer reagent, iodosobenzene (PhIO), forms the dinuclear μ-oxo complex Fe2(O)(OR)4(THF)2. Similarly, the use of triphenylantimony sulfide (Ph3SbS) allowed for the isolation of Fe2(S)(OR)4(THF)2. The complexes were isolated and characterized by X-ray crystallography, IR spectroscopy, and elemental analysis. Both Fe2(O)(OR)4(THF)2 and Fe2(S)(OR)4(THF)2 species were found to be unreactive in the group-transfer chemistry with phosphine and olefins

Assess the performance of the diagnosis ways of diabetic retinopathy

Considered the diagnosis of diseases using image processing is one of the most important areas of image processing techniques used in the medical field, where is the digital data in the field of ophthalmology focus of researchers for automatic detection of some important diseases such as diabetic retinopathy (DR). And is defined as damage to the retina of the eye comes as serious complications and on the human body complications resulting from diabetes in the long term and is considered one of the most important causes of blindness in the world and cause serious damage to the retina. The research aims to Assess the performance of some of the methods used in the diagnosis of diabetic retinopathy by revealing one of the most important accompanying pests him in the retina of the eye and is the exudates and through diagnosed in images digital fundus through image processing techniques where this detection process contributes in helping to early detection

Enhancing Smart Cities with IoT and Cloud Computing: A Study on Integrating Wireless Ad Hoc Networks for Efficient Communication

شهدت المدن الذكية تطورا جوهريا زاد من امكانياتها بشكل كبير .في الواقع ، لقد أتاحت التطورات الحديثة في انترنت الاشياء (IOT) فرصا جديدة من خلال حل عدد  من المشاكل الحرجة والتي ادت الى ابتكار المدن الذكية بالاضافة الى انشاء و حوسبة الخدمات و التطبيقات المتطورة للعديد من  المجاميع المطورة في المدينة . من اجل تعزيز تنمية المدن الذكية بأتجاه التواصل و المشاركة ،تركز هذه الدراسة على التطور في مجال المعلوماتية في ضوء انترنت الاشياء (IOT) و الحوسبة السحابية (CC) .جمعت بيانات انترنت الاشياء والتي تخص المدن الذكية بشكل متجانس . اصبح انترنت الاشياء الذي يسمح بتواصل الاشخاص مع بعضهم ممكنا باستخدام الذكاء الاصطناعي .بناءا على ذلك ،استخدمنا (ARF) في حسابات الذكاء الاصطناعي .للتبسيط ،ننصح باستخدام تخصيص اصول الالة الافتراضية للحوسبة السحابية التكيفية (ACC-VMRA ) .لتاكيد جدواها ،سنفحص و نضاعف كيفية تطبيق تطورات انترنت الاشياء (IOT ) و الحوسبة السحابية (CC) في المدن الذكية.تظهر نتائج التجربة ان حساب التحسين الموصى به اكثر انتاجية من الطرق الاخرى المستخدمة حاليا.Smart cities have recently undergone a fundamental evolution that has greatly increased their potentials. In reality, recent advances in the Internet of Things (IoT) have created new opportunities by solving a number of critical issues that are allowing innovations for smart cities as well as the creation and computerization of cutting-edge services and applications for the many city partners. In order to further the development of smart cities toward compelling sharing and connection, this study will explore the information innovation in smart cities in light of the Internet of Things (IoT) and cloud computing (CC). IoT data is first collected in the context of smart cities. The data that is gathered is uniform. The Internet of Things, which enables gadgets to connect with one another mostly without human involvement, is made possible by AI. In line with this, The Ad Hoc Routing Function (ARF) AI computation is used for multi-rule simplification, the use of Adaptive Cloud Computing Virtual Machine Asset Allotment Technique (ACC-VMRA) is advised. To confirm its viability, the applied developments of IoT and CC in smart cities is examined and duplicated. The experiment results show that the recommended enhancement calculation is more productive than other currently used methods

Classification of pomegranate cultivars by multivariate analysis of biochemical constituents of HPLC

Pomegranate fruits are highly diverse and may be divided into geographical groupings based on their characteristics. Genetic research has verified these categories in recent years and further categorized variants into geographic-genetic groupings. This study aimed to assess the biochemical contents of eight varieties of pomegranate fruit seed and the categorization of pomegranate using multivariate statistical analysis. Polyphenolic chemicals are key secondary metabolites in pomegranate, and their presence influences the quality and sensory qualities of the fruit they produce. Fruit extracts from the Faqyan cultivar contained the highest total phenolic content of all studied cultivars. Pomegranate cultivars such as Shaqlawa, Halabja Sour, and Faqyan were shown to have the highest antioxidant activity. Gallic acid, caffeic acid, chlorogenic acid, p-coumaric acid, cinnamic acid, rutin, apigenin, rosmaric acid, and quercetin were the most abundant phytochemical components in the study. According to the results of multivariate analysis, pomegranate cultivars were divided into four major groups. The pomegranate fruit seed is the most abundant source of antioxidants and beneficial phytochemical elements. Finally, the Sidakan Sweet and Shaqlawa cultivars included a significant content polyphenolic compounds

The Total Synthesis of Glycolipids from Streptococcus pneumoniae and a Re-evaluation of Their Immunological Activity**

Invariant natural killer (iNK) T cells, Type I iNKTs, are responsible for the production of pro-inflammatory cytokines which induce a systemic immune response. They are distinctive in possessing an semi-invariant T-cell receptor that recognizes glycolipid antigens presented by CD1d, a protein closely related to the class I major histocompatibility complex, conserved across multiple mammalian species in a class of proteins well-renowned for their high degree of polymorphism. This receptor\u27s first potent identified antigen is the α-galactosylceramide, KRN7000, a synthetic glycosphingolipid closely related to those isolated from bacteria that were found on a Japanese marine sponge. A corresponding terrestrial antigen remained unidentified until two specific diacylglycerol-containing glycolipids, reported to activate iNKT cells, were isolated from Streptococcus pneumoniae. We report the total synthesis and immunological re-evaluation of these two glycolipids. The compounds are unable to meaningfully activate iNKT cells. Computational modelling shows that these ligands, while being capable of interacting with the CD1d receptor, create a different surface for the binary complex that makes formation of the ternary complex with the iNKT T-cell receptor difficult. Together these results suggest that the reported activity might have been due to an impurity in the original isolated sample and highlights the importance of taking care when reporting biological activity from isolated natural products

Enhancing the Quality of "Produced Water" by Activated Carbon

The main objective is to contribute via this study, in solving an environmental issue and helping Qatar in finding suitable water resources; useful in agriculture. Qatar faces diverse water challenges; the number one that threats here is scarcity as water is not renewable. Due to scarcity of good quality water, reusing of low quality and contaminated water is highly increasing in Qatar. The main source of water in Qatar is desalination stations. Most of the desalinated water is for human usage. Agriculture in Qatar depends mainly on underground water; it is available but always saline and found in insufficient quantities. Due to the increasing demand for water among industries and irrigation, using other alternative water resources such as produced water during oil and gas extraction would be of importance. Generally, produced water is the water that exists in subsurface and is moved to the surface through oil and gas processes. The volume of produced water and pollutants concentration vary depending on the nature and location of the oil products. It represents the major waste stream related to oil and gas processes. Large volume of produced water generated in Qatar has the potential to enhance the water resources. The crucial goal of produced water management is to eliminate dissolved harmful components and use it for beneficial uses that can efficiently improve environmental impact and water shortage. An exclusive characteristic of produced water comparing to other wastewater resources is the large variation and complexity in water chemistry. This would play a vital role in the remediation processes.qscienc

The ITIM-Containing Receptor: Leukocyte-Associated Immunoglobulin-Like Receptor-1 (LAIR-1) Modulates Immune Response and Confers Poor Prognosis in Invasive Breast Carcinoma

Background: The leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) plays a role in immune response homeostasis, extracellular matrix remodelling and it is overexpressed in many high-grade cancers. This study aimed to elucidate the biological and prognostic role of LAIR-1 in invasive breast cancer (BC). Methods: The biological and prognostic effect of LAIR-1 was evaluated at the mRNA and protein levels using well-characterised multiple BC cohorts. Related signalling pathways were evaluated using in silico differential gene expression and siRNA knockdown were used for functional analyses. Results: High LAIR-1 expression either in mRNA or protein levels were associated with high tumour grade, poor Nottingham Prognostic Index, hormone receptor negativity, immune cell infiltrates and extracellular matrix remodelling elements. High LAIR-1 protein expression was an independent predictor of shorter BC-specific survival and distant metastasis-free survival in the entire BC cohort and human epidermal growth factor receptor 2 (HER2)+ subtype. Pathway analysis highlights LAIR-1 association with extracellular matrix remodelling-receptor interaction, and cellular proliferation. Depletion of LAIR-1 using siRNA significantly reduced cell proliferation and invasion capability in HER2+ BC cell lines. Conclusion: High expression of LAIR-1 is associated with poor clinical outcome in BC. Association with immune cells and immune checkpoint markers warrant further studies to assess the underlying mechanistic roles

COVID-19 Vaccination Among Diverse Population Groups in the Northern Governorates of Iraq

Objectives: The present study was carried out to investigate COVID-19 vaccination coverage among populations of internally displaced persons (IDPs), refugees, and host communities in northern Iraq and the related underlying factors.Methods: Through a cross-sectional study conducted in five governorates in April–May 2022, 4,564 individuals were surveyed. Data were collected through an adapted questionnaire designed to gather data on participants.Results: 4,564 subjects were included (59.55% were 19–45 years old; 54.51% male). 50.48% of the participants (51.49% of host communities, 48.83% of IDPs, and 45.87% of refugees) had been vaccinated with at least one dose of COVID-19 vaccine. 40.84% of participants (42.28% of host communities, 35.75% of IDPs, and 36.14% of refugees) had been vaccinated by two doses, and 1.56% (1.65% of host communities, 0.93% of IDPs, and 1.46% of refugees) were vaccinated with three doses.Conclusion: Sociodemographic factors including age, gender, education, occupation, and nationality could affect vaccination coverage. Moreover, higher acceptance rate of vaccination is associated with belief in vaccine safety and effectiveness and trust in the ability of the vaccine to prevent complications

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

Left Main Coronary Artery Revascularization in Patients with Impaired Renal Function: Percutaneous Coronary Intervention versus Coronary Artery Bypass Grafting

Introduction: The evidence about the optimal revascularization strategy in patients with left main coronary artery (LMCA) disease and impaired renal function is limited. Thus, we aimed to compare the outcomes of LMCA disease revascularization (percutaneous coronary intervention [PCI] vs. coronary artery bypass grafting [CABG]) in patients with and without impaired renal function. Methods: This retrospective cohort study included 2,138 patients recruited from 14 centers between 2015 and 2,019. We compared patients with impaired renal function who had PCI (n= 316) to those who had CABG (n = 121) and compared patients with normal renal function who had PCI (n = 906) to those who had CABG (n = 795). The study outcomes were in-hospital and follow-up major adverse cardiovascular and cerebrovascular events (MACCE). Results: Multivariable logistic regression analysis showed that the risk of in-hospital MACCE was significantly higher in CABG compared to PCI in patients with impaired renal function (odds ratio [OR]: 8.13 [95% CI: 4.19–15.76], p < 0.001) and normal renal function (OR: 2.59 [95% CI: 1.79–3.73]; p < 0.001). There were no differences in follow-up MACCE between CABG and PCI in patients with impaired renal function (HR: 1.14 [95% CI: 0.71–1.81], p = 0.585) and normal renal function (HR: 1.12 [0.90–1.39], p = 0.312). Conclusions: PCI could have an advantage over CABG in revascularization of LMCA disease in patients with impaired renal function regarding in-hospital MACCE. The follow-up MACCE was comparable between PCI and CABG in patients with impaired and normal renal function