Measurement and Prediction of the Viscosity of Hydrocarbon Mixtures and Crude Oils

Crude oil is a complex mixture of hydrocarbons whose physical properties vary significantly with its composition, temperature and pressure. Viscosity is a particularly important property influencing the flow of oil in hydrocarbon reservoirs and its displacement by water and other fluids during production processes. The modelling and optimisation of such processes would be greatly aided by models which predict the viscosity of crude oils at (high) reservoir temperatures and pressures (HTHP), ideally from a knowledge of the oil composition. This research has involved making accurate HTHP viscosity measurements on a range of hydrocarbon systems and using these to evaluate the ability of an effective hard-sphere model to predict the data with minimal calibration. In the first phase, the viscosity and density of a range of pure hydrocarbons, representative of those found in crude oils, and their mixtures, were measured at temperatures and pressures covering typical reservoir conditions (up to 448.15 K and 135 MPa). The vibrating wire technique was used for viscosity in conjunction with a vibrating U-tube densimeter. The ability of the Dymond-Assael (DA) effective hard-sphere model to correlate and predict the viscosity of both the pure components and the complex mixtures was investigated. Agreement for pure components was within ± 5 % whereas for the mixtures this ranged from ± 5% to ± 25 % depending on the complexity. The same thermophysical properties were determined for two North Sea crude oil samples at temperatures ranging from (298.15 to 448.15) K and pressures up to 135 MPa. The effect of adding an alkane mixture diluent was also investigated. It was found that by treating the crude oils as effective single hydrocarbon components, the Dymond-Assael model could correlate their viscosity to within the experimental uncertainty and that of the diluted crudes to within ±10%. The overall study gives encouragement that a limited number of calibration viscosity/density measurements on a crude oil should enable prediction of its viscosity over a wide range of temperatures and pressures and enable viscosity changes to be predicted when crude oils are mixed with components whose DA parameters are known

Green synthesis of copper oxide nanoparticles using Abutilon indicum leaf extract: Antimicrobial, antioxidant and photocatalytic dye degradation activitie

Purpose: To synthesize copper oxide (CuO) nanoparticles using a ecofriendly technique and evaluate their antimicrobial, antioxidant and photo-catalytic dye degradation potentials.Methods: A superficial method (solution combustion method) was employed for the synthesis of copper oxide nanoparticles from an aqueous extract of Abutilon indicum. The CuO nanoparticles were characterized using x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy (EDX), scanning electron microscope (SEM) and ultraviolet-visible (UV-Vis) spectroscopic techniques. The antimicrobial activity of the CuO nanoparticles was determined by agar well diffusion method, while their antioxidant properties were assessed by DPPH radical scavenging, ferric reducing antioxidant power (FRAP), total antioxidant, ferric thiocyanate (FTC) and total phenolic content (TPC) assays. The photo-catalytic degradation activity of synthesized CuO nanoparticles was assessed by the degradation of Acid Black 210 (AB) dye under sunlight irradiation.Results: XRD, EDX and SEM results confirmed successful synthesis of CuO nanoparticles, with hexagonal, wurtzite and sponge crystal structure. Photo-catalytic data revealed that the nanoparticles are a good catalyst for effective degradation of Acid Black 210. The nanoparticles also exhibited remarkable antioxidant activity, with IC50 and FRAP values ranging from 40 ± 0.23 to 84 ± 0.32 μg/ml, and 0.65 ± 0.01 to 9.10 ± 0.21 Trolox equivalent/mL, respectively. Significant bactericidal activity was manifested by the CuO nanoparticles against Klebsiella and Bacillus subtilis with zone of inhibition of 14 ± 0.05 and 15 ± 0.11 mm, respectively.Conclusion: The synthesized CuO nanoparticles exhibit antibacterial and antioxidant potential, indicating that they are good candidates for future therapeutic applications.Keywords: CuO nanoparticles, Green synthesis, Photo-catalytic degradation, Antioxidant, Antimicrobia

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Measurement and prediction of the viscosity of hydrocarbon mixtures and crude oils

Crude oil is a complex mixture of hydrocarbons whose physical properties vary significantly with its composition, temperature and pressure. Viscosity is a particularly important property influencing the flow of oil in hydrocarbon reservoirs and its displacement by water and other fluids during production processes. The modelling and optimisation of such processes would be greatly aided by models which predict the viscosity of crude oils at (high) reservoir temperatures and pressures (HTHP), ideally from a knowledge of the oil composition. This research has involved making accurate HTHP viscosity measurements on a range of hydrocarbon systems and using these to evaluate the ability of an effective hard-sphere model to predict the data with minimal calibration. In the first phase, the viscosity and density of a range of pure hydrocarbons, representative of those found in crude oils, and their mixtures, were measured at temperatures and pressures covering typical reservoir conditions (up to 448.15 K and 135 MPa). The vibrating wire technique was used for viscosity in conjunction with a vibrating U-tube densimeter. The ability of the Dymond-Assael (DA) effective hard-sphere model to correlate and predict the viscosity of both the pure components and the complex mixtures was investigated. Agreement for pure components was within ± 5 % whereas for the mixtures this ranged from ± 5% to ± 25 % depending on the complexity. The same thermophysical properties were determined for two North Sea crude oil samples at temperatures ranging from (298.15 to 448.15) K and pressures up to 135 MPa. The effect of adding an alkane mixture diluent was also investigated. It was found that by treating the crude oils as effective single hydrocarbon components, the Dymond-Assael model could correlate their viscosity to within the experimental uncertainty and that of the diluted crudes to within ±10%. The overall study gives encouragement that a limited number of calibration viscosity/density measurements on a crude oil should enable prediction of its viscosity over a wide range of temperatures and pressures and enable viscosity changes to be predicted when crude oils are mixed with components whose DA parameters are known.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Knowledge, attitude, and barriers toward ADRs reporting among health-care professionals at tertiary care health settings in Peshawar, Pakistan: A web based study

Background: Underreporting of adverse drug reactions (ADRs) is considered a major determinant of poor ADR signal detection in Pakistan. Considering this, the study was proposed to evaluate healthcare professionals\u27 (HCPs) knowledge attitude toward and the barriers that discourse ADRs reporting. Methods: A cross-sectional survey was distributed among HCPs in 3 major tertiary care facilities of Peshawar. A self-administered, 31 items questionnaire was circulated online to collect the required information. Relative index ranking was used to identify the top barriers to the ADR reporting process. Results: HCPs (n = 322) were requested, and over one-third (n = 122) responded. Of the total, 97 (79.5%) were males, and by designation, 59(48.4%) were resident medical officers. About 45% of the HCPs did not identify the appropriate pharmacovigilance (PV) definition. More than half of the HCPs (52.2%) distinguished the appropriate PV purpose. Nearly 80% HCPs did not know the acceptable reporting time frame, while 22.1% HCPs knew that regulatory body for ADRs does not exist in Pakistan. The majority (95.08%) of the HCPs either strongly agreed or agreed that reporting an ADRs is a professional obligation and all the HCPs were of the opinion that PV should be taught in detail to HCPs. Exploring the barriers, it was identified that the key barriers to ADRs reporting were unavailability of professional environment to discuss ADRs, Relative Importance Index (RII) = 0.813, lack of incentives for reporting (RII = 0.774), lack of knowledge regarding reporting (RII = 0.693), and insufficient knowledge of pharmacotherapy in detecting ADRs (RII = 0.662). In addition to these, complicated reporting forms (RII = 0.616), lack of motivation for reporting ADRs (RII = 0.610), and absence of professional confidence were seen as major hindrances in effective reporting of ADRs (RII = 0.598). Conclusion: Concerning PV and ADR reporting poor knowledge was noted. However, the majority of the HCPs showed an explicit attitude regarding ADRs reporting. The majority of the HCPs disclosed unavailability of professional environment to discuss about ADRs, lack of incentives, and how to report the main factors hindering the ADRs reporting. It is emphasized that health authorities carve out a niche for a well purposeful PV center and pledge educational activities and trainings for increasing understanding and approaches regarding reporting of ADR

‘Immune-inflammatory markers & clinical characteristics for outcomes in hospitalized SARS-CoV-2 infected patients of Pakistan: a retrospective analysis’

ABSTRACTObjective Accumulating evidence suggests the role of immune-inflammatory markers in early risk stratification and prognostication of COVID-19 patients. We aimed to evaluate their association with severity and the development of diagnostic scores with optimal thresholds in critical patients.Setting and participants This retrospective case study includes hospitalized COVID-19 patients from March 2019 to March, 2022, in the developing area teaching hospital in Pakistan. Polymerase chain reaction (PCR) positive patients, n = 467 were investigated for clinical outcomes, comorbidities and disease prognosis. The plasma levels of Interleukin-6 (IL-6), Lactate dehydrogenase (LDH), C-reactive protein (CRP), Procalcitonin (PCT), ferritin and Complete blood count markers were measured.Results Majority were males (58.8%) and patients with comorbidities had more severe disease. Hypertension and diabetes mellitus were the commonest comorbidities. Shortness of breath, myalgia and cough were the main symptoms. The hematological markers NLR, as well as the plasma levels of immune-inflammatory variables, IL-6, LDH, Procalcitonin, Erythrocyte sedimentation rate, Ferritin were markedly raised in severe and critical patients (p 90% of patients in terms of COVID-19 severity (AUC = 0.93, 91.7%, se; 90.3%sp). Furthermore, positive correlation with all other markers including NLR with cut-off = 2.99 (AUC = 0.87, se = 89.8%, sp = 88.4%), CRP with cut-offs at 42.9 mg/l, (AUC = 0.883, se = 89.3% and sp = 78.6%), LDH cut-off at 267μg/L, evidenced in >80% patients (AUC = 0.834 se = 84% and sp = 80%). Additionally, ESR and ferritin have the corresponding AUC 0.81 and 0.813 with cut-off at 55 mm/hr and 370, respectively.Conclusion Investigating the immune-inflammatory markers can assist physicians in providing prompt treatment and ICU admission in terms of COVID-19 severity. As a result, which may reduce the overall mortality of COVID-19 patients

A PHASE II STUDY OF GEMCITABINE CONCURRENT WITH RADIATION IN LOCALLY ADVANCED SQUAMOUS CELL CARCINOMA OF HEAD AND NECK: A TRIAL OF THE CANCER RESEARCH GROUP PAKISTAN

ABSTRACT Objective: To evaluate the efficacy and toxicity of weekly gemcitabine as a radiosensitizer concurrent with radical radiotherapy in locally advanced carcinoma of head and neck. Patients and Methods: From August 2001 to January 2002, thirty-nine patients with stage III or IV B inoperable carcinoma of head and neck were enrolled. Patients with histopathologically confirmed squamous cell carcinoma with at least one bidimensionally measurable lesion, no prior chemotherapy or radiotherapy, and a KPS of 60 or above were included. Patients with nasopharyngeal, glottic or sub-glottic cancer were excluded. Gemcitabine 150mg/m 2 or a total dose not exceeding 200 mg was given on day 1, 8, 15, 22, 29, and 36 during radiation treatment. Radiation was delivered with conventional fractionation to a total dose of 66-70Gy. Miller's criteria was used for response evaluation. RTOG/EORTC acute radiation (and chemotherapy) morbidity scoring system and WHO grading of acute and sub acute toxicity criteria were used for documentation of toxicity. Results: All 39 patients were evaluable for toxicity but only 35 patients were evaluable for response. An overall response rate of 94.3% ( 95% CI; 80.8-99.3) was seen with a partial response rate of 71.4% and complete response rate of 22.9 % (95 %CI; 10.4-40.1). Grade 3 mucositis was seen in 28 patients (71.8%). Grade 4 mucositis was seen in 2 patients (5.1 %). Pharyngeal toxicity was the second-most common toxicity. Grade 2 toxicity was seen in 12 patients (30.8%) and grade 3 in 6 patients (15.4%). Despite vigorous symptomatic and supportive care acute toxicities led to treatment interruption in 40% of patients. Conclusion: A high overall response rate and a high rate of acute toxicity are seen at a weekly gemcitabine dose of 150mg/m 2 concurrent with radiation. This shows that gemcitabine is a potent radiosensitizer with a marked tumor and normal tissue radio sensitization

Effects of glutathione-S-transferase polymorphisms on the risk of breast cancer: a population-based case-control study in Pakistan

Cancer is widely accepted as one of the major health issues. Diet composition and exposure to environmental genotoxic and carcinogenic agents such as polycyclic aromatic hydrocarbons (PAHs) are among the causative factors for various types of cancers, including breast cancer. Low penetrance genes including glutathione S transferases (GST) in association with environmental factors can contribute greatly in the development of breast cancer. We were interested to investigate the association of the polymorphisms of GSTM1, GSTT1, GSTP1 and GSTO2 with the risk of breast cancer in the Pakistani population. One hundred women visiting the Department of Radiology and Oncology, Nishter Hospital, Multan with pathologically confirmed breast cancer, and 100 healthy volunteers from central Pakistan were enrolled in the present study. The strength of the association of various factors with breast cancer was measured by calculating odd ratios (ORs) which were determined by logistic regression. All P values cited are two-sided; differences resulting in a P value of less or equal to 0.05 were declared statistically significant. The Hardy Weinberg equilibrium was tested for the genotype proportions in the control group, as a measure of quality control. Those aged 36-45, in menopause or with a history of cancer in the family had a significantly higher prevalence of breast cancer compared with controls. The frequency of GSTM1 and GSTT1 was similar in both control and patients suggesting no association with the risk of cancer development, however GSTM1 and GSTT1 were significantly linked with the risk of breast cancer in smokers and in women with a history of breast cancer in the family respectively. Similarly women homozygous for GSTP1 or GSTO2 and with a history of breast cancer, or in menopause, were at greater risk of breast cancer than wild type or heterozygotes. Our data suggest that genetic differences in some GST genes may be linked with an increased susceptibility to breast cancer. Furthermore it also gives an insight into the interaction between the GST polymorphisms and pre-menopausal diagnosis of breast cancer