Shape-Selective Silver Catalysts for Ethylene Epoxidation

Epoxidation of ethylene with oxygen over promoted silver catalyst is one of the most important examples of heterogeneous catalysis to date with a multi-billion dollar annual market. Ethylene oxide (EO) can be used directly as a sterilizer, disinfectant, and fungicide, or as an intermediate chemical for producing ethylene glycol, detergents, antifreeze, polyesters, as well as a variety of other commercial chemicals. Thus, ethylene oxide is known as one of the highest volume chemicals produced in the chemical industry, accounting for approximately 40-50% of the total value of organic chemicals produced by heterogeneous oxidation. Considering the application of EO in detergents and sterilizers, the importance of EO production has been increased more than before due to the COVID19 pandemic. Preventing the total oxidation and improving the yield of selective products can be counted as one of the major challenges in selective oxidation reactions. It has been shown in the literature that the selectivity of ethylene oxide, among many other factors, depends on silver faceting of the catalyst nanoparticles. However, it is not exploited in industry, where the silver is mainly being used in nanoparticles with (111) facets due to the preparation and stability issues of the other structures. Thermodynamically, the Ag(111) facet is the most stable but the least active facet among the others ,while Ag(100) has been shown theoretically to exhibit the highest selective facet for EO formation. In this thesis, silver nanowires catalysts were synthesized via hydrothermal method and were deposited on -aluminum oxide supports using wet impregnation method. Obtaining a pure nanowires sample in not possible, however, some synthesis parameters such as time, temperature, and chemicals’ concentrations that are parameters possibly affecting the morphology, yield, length, and diameter of nanowires were varied to increase the nanowires yield. Low yield, thin nanowires resulted from a shorter synthesis time while a mixture of nanorods and nanospheres were fabricated for longer synthesis times. An optimum time (24hours) was selected for synthesis time as one of the most effective synthesis parameters. Unpromoted supported silver nanowires catalyst with an average diameter of less than 100nm and unpromoted semi-spherical silver catalyst with (111) facets that was synthesized using wet impregnation method, were tested in a single channel reactor at atmospheric pressure and for different temperatures. Structure of silver nanowires thinner than 100 nm were changed at the reaction condition while thicker nanowires remined intact

Clinical Features of Patients Newly Admitted to the Emergency Department of a Psychiatric Hospital with an Emphasis on Physical Examination

Introduction: Many medical diseases and their related signs and symptoms are not identified in routine assessments in emergency departments. Objective: We investigated the prevalence of abnormal findings in physical examination of the patients who were newly admitted to emergency department (ED) of a psychiatric hospital. Methods: We studied 200 patients (143 males, 71.5%) who were recently admitted to the ED of a psychiatric university hospital during a 4-month period in 2018. A thorough physical and neurological examination was performed on each subject. Results: Nearly all of the patients (99.3%) had at least one positive finding in physical (non-neurological) examination and 95% had at least one positive neurological finding. We also found at least one problem in gastrointestinal, respiratory or cardiac system of 22.1%, 24% and 33% of the subjects, respectively. The most frequent findings were in cranial nerve I (30%, more common in substance abuse disorder), and visual acuity (52.6%), as well as recent memory (%68.7), attention (%33.7), orientation to time (%29.5), hypokinetic movements (%28.1, more common in females and psychotic patients), akathisia (41.6%), and skin (%85.1, more common in substance abuse and personality disorders). T wave changes were seen in 31.9% and arrhythmia in 16% of the patients. Conclusions: Abnormal findings in examination of the patients admitted to EDs are very prevalent, but most of the abnormalities are not detected or reported in the routine ward examinations. More emphasis should be placed on the examination of olfactory nerve (especially in patients with substance abuse disorder), cognition (especially in older adults), extrapyramidal system, heart, abdomen and skin (especially in patients with personality disorder) during the first week of admission in a psychiatric emergency setting

How a thrombectomy service can reduce hospital deficit:a cost-effectiveness study

BACKGROUND: There is level 1 evidence for cerebral thrombectomy with thrombolysis in acute large vessel occlusion. Many hospitals are now contemplating setting up this life-saving service. For the hospital, however, the first treatment is associated with an initial high cost to cover the procedure. Whilst the health economic benefit of treating stroke is documented, this is the only study to date performing matched-pair, patient-level costing to determine treatment cost within the first hospital episode and up to 90 days post-event. METHODS: We conducted a retrospective coarsened exact matched-pair analysis of 50 acute stroke patients eligible for thrombectomy. RESULTS: Thrombectomy resulted in significantly more good outcomes (mRS 0–2) compared to matched controls (56% vs 8%, p = 0.001). More patients in the thrombectomy group could be discharged home (60% vs 28%), fewer were discharged to nursing homes (4% vs 16%), residential homes (0% vs 12%) or rehabilitation centres (8% vs 20%). Thrombectomy patients had fewer serious adverse events (n = 30 vs 86) and were, on average, discharged 36 days earlier. They required significantly fewer physiotherapy sessions (18.72 vs 46.49, p = 0.0009) resulting in a median reduction in total rehabilitation cost of £4982 (p = 0.0002) per patient. The total cost of additional investigations was £227 lower (p = 0.0369). Overall, the median cost without thrombectomy was £39,664 per case vs £22,444, resulting in median savings of £17,221 (p = 0.0489). CONCLUSIONS: Mechanical thrombectomy improved patient outcome, reduced length of hospitalisation and, even without procedural reimbursement, significantly reduced cost to the thrombectomy providing hospital

A control and surveillance ITS location model to improve safety

Traffic safety in rural highways can be considered as a constant source of concern in many countries. Nowadays, transportation professionals widely use Intelligent Transportation Systems (ITS) to address safety issues. However, compared to metropolitan applications, the rural highway (non-urban) ITS applications are still not well defined. This paper provides a comprehensive review on the existing ITS safety solutions for rural highways. This research is mainly focused on the infrastructure-based control and surveillance ITS technology, such as Crash Prevention and Safety, Road Weather Management and other applications, that is directly related to the reduction of frequency and severity of accidents. The main outcome of this research is the development of a ‘ITS control and surveillance device locating model’ to achieve the maximum safety benefit for rural highways. Using cost and benefits databases of ITS, an integer linear programming method is utilized as an optimization technique to choose the most suitable set of ITS devices. Finally, computational analysis is performed on an existing highway in Iran, to validate the effectiveness of the proposed locating model

Homocysteine in Gestational Diabetes and Normal Pregnancy plus Effects of Folic Acid

"nBackground: The aim of study was to assess serum homocysteine and its relation with serum folate, vit B12 and lipid pro­files in gestational diabetes mellitus and comparison with normal pregnant women as well as effect of different doses of fo­lic acid on Homocysteine (Hcy) and pregnancy outcome."nMethods:  In a biphasic study first prospective controlled study 80 pregnant women were chosen at 24-28 weeks of gesta­tion. In case group pregnant women with gestational diabetes mellitus and control group who had normal Oral Glucose Toler­ance test (GTT) results. Levels of fasting glucose, homocysteine, vit B12, and folic acid, uric acid, total cholesterol, triglyc­eride, LDL, HDL, were measured. In phase II study a randomized clinical trial was done with diabetic women 15 with 1mg folic acid and 15 with 5 mg folic acid for six weeks and then above variables and pregnancy outcome was evalu­ated."nResults: The mean levels of homocysteine in Gestational Diabetes Mellitus (GDM) group were significantly higher but fo­lic acid and vit B12 were significantly lower. Hcy levels were decreased in both groups after six weeks folic acid but de­crease in Hcy for group 5mg was significantly more than 1mg group. "nConclusion: Homocysteine levels were higher in GDM than normal pregnancy. High dose folic acid can reduce Hcy levels more than low dose and it may be a safe, simple, inexpensive intervention that prevents major pregnancy complications. "n&nbsp

Serum homocysteine level in gestational diabetes: a prospective study

"n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Increased total plasma homocysteine (Hcy) is an accepted risk factor of cardiovascular disease (CVD), stroke, preclampsia, recurrent abortion and diabetes type I and II. The aim of the current study was to assess serum homocysteine and its relation with serum folat, vitamine B12 and lipid profile in gestational diabetes mellitus and to compare these with those of pregnant women."n"n Methods: In a prospective controlled survey 80 pregnant women (24-28 weeks) with uncomplicated pregnancies were evaluated. They were assigned to one of two groups according to the results of 100g-OGTT. In the case group there were pregnant women with gestational diabetes mellitus according to the OGTT and in the control group women who had normal OGTT results were put. Levels of fasting glucose, homocysteine, vit B12, and folic acid, uric acid, total cholesterol, triglyceride, Low Density Lipoprotein cholesterol (LDL) and High Density Lipoprotein cholesterol (HDL) were measured in both groups."n"nResults: The mean level of homocysteine in GDM group was significantly higher than control group (p=0.000). The mean level of folic acid and vit B12 was significantly lower than the level in control group (p=0.001, p=0.004 respectively). Body mass index (BMI) in GDM group was higher (p=0.000) and HDL level was lower (p=0.006) than control group. There were no significant differences among the groups with respect to levels of total cholesterol and triglyceride."n"n Conclusion: We found that patients with gestational diabetes have higher homocysteine level than normal pregnant women. This increased level seems to be related to an abnormal OGTT. Further investigations are needed to follow up these patients in the postpartum period and later on