350 research outputs found
Antimicrobial Effect of Methanolic and Acetonic of Zataria Multiflora, Capsicum Annum L. and Piper Nigrum L. Extracts on Pseudomonas aeruginosa Strains Isolated from Patients Hospitalized in the Burn Ward of Shahid Motahari Hospital in Tehran
Background: Pseudomonas aeruginosa (P. aeruginosa) is one of the main causes of nosocomial infection. Burn patients are at high risk of acquiring this bacterium due to skin damage and their immune deficiency, and mortality rate in these infected patients is high (40-50%). Therefore, due to antibiotic resistance of MBL containing strains in this bacterium, the aim of this study is to investigate the effect of methanol and acetone of Zataria multiflora, Capsicum annum L. and Piper nigrum L. on strains containing MBL in this bacterium.Materials and Methods: This lab study was conducted on samples from burn patients, which were gathered between 2015 and 2016. In this study first, disc diffusion and MIC were done based on the CLSI protocol; and using a combined disk, we detected metallo-beta-lactamase. Next, the bla (IMP) and bla (VIM) genes were identified by the PCR method. In order to investigate the effect of three plants extract on bacteria, the bacteria was affected by triple extracts using MIC and disk diffusion.Results: According to the results, all three plants had an acceptable effect on Pseudomonas aeruginosa strains containing metallo-beta-lactamase, and to be more precise, the acetone type of extract of Capsicum Annum L at a concentration of 1.5 mg / ml had the best effect in treating of these bacteria.Conclusion: The results of this study indicate the presence of several mechanisms of resistance to beta-lactam antibiotics among Pseudomonas aeruginosa strains collected from burn patients. The emergence of these types of XDRs has led to health problems, especially in burn patients. According to the results, the methanolic and acetonic extract of all three plants have been shown to be effective in inhibiting the growth of MBL-containing Pseudomonas aeruginosa
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Modeling conformance control and chemical EOR processes using different reservoir simulators
textSuccessful field waterflood is a crucial prerequisite for improving the performance before EOR methods, such as ASP, SP, and P flooding, are applied in the field. Excess water production is a major problem in mature waterflooded oil fields that leads to early well abandonment and unrecoverable hydrocarbon. Gel treatments at the injection and production wells to preferentially plug the thief zones are cost-effective methods to improve sweep efficiency in reservoirs and reduce excess water production during hydrocarbon recovery. There are extensive experimental studies performed by some researchers in the past to investigate the performance of gels in conformance control and decreasing water production in mature waterflooded reservoirs, but no substantial modeling work has been done to simulate these experiments and predict the results for large field cases.
We developed a novel, 3-dimensional chemical compositional and robust general reservoir simulator (UTGEL) to model gel treatment processes. The simulator has the capability to model different types of microgels, such as preformed particle gels (PPG), thermally active polymers (TAP), pH-sensitive microgels, and colloidal dispersion gels (CDG). The simulator has been validated for gel flooding using laboratory and field scale data. The simulator helps to design and optimize the flowing gel injection for conformance control processes in larger field cases.
The gel rheology, adsorption, resistance factor and residual resistance factor with salinity effect, gel viscosity, gel kinetics, and swelling ratio were implemented in UTGEL. Several simulation case studies in fractured and heterogeneous reservoirs were performed to illustrate the effect of gel on production behavior and water control. Laboratory results of homogeneous and heterogeneous sandpacks, and Berea sandstone corefloods were used to validate the PPG transport models. Simulations of different heterogeneous field cases were performed and the results showed that PPG can improve the oil recovery by 5-10% OOIP compared to waterflood.
For recovery from fractured reservoirs by waterflooding, injected water will flow easily through fractures and most part of reservoir oil will remain in matrix blocks unrecovered. Recovery from these reservoirs depends on matrix permeability, wettability, fracture intensity, temperature, pressure, and fluid properties. Chemical processes such as polymer flooding (P), surfactant/polymer (SP) flooding and alkali/surfactant/polymer (ASP) flooding are being used to enhance reservoir energy and increase the recovery. Chemical flooding has much broader range of applicability than in the past. These include high temperature reservoirs, formations with extreme salinity and hardness, naturally fractured carbonates, and sandstone reservoirs with heavy and viscous crude oils.
The recovery from fractured carbonate reservoirs is frequently considered to be dominated by spontaneous imbibition. Therefore, any chemical process which can enhance the rate of imbibition has to be studied carefully. Wettability alteration using chemicals such as surfactant and alkali has been studied by many researchers in the past years and is recognized as one of the most effective recovery methods in fractured carbonate reservoirs. Injected surfactant will alter the wettability of matrix blocks from oil-wet to water-wet and also reduce the interfacial tension to ultra-low values and consequently more oil will be recovered by spontaneous co-current or counter-current imbibition depending on the dominant recovery mechanism.
Accurate and reliable up-scaling of chemical enhanced oil recovery processes (CEOR) are among the most important issues in reservoir simulation. The important challenges in up-scaling CEOR processes are predictability of developed dimensionless numbers and also considering all the required mechanisms including wettability alteration and interfacial tension reduction. Thus, developing new dimensionless numbers with improved predictability at larger scales is of utmost importance in CEOR processes. There are some scaling groups developed in the past for either imbibition or coreflood experiments but none of them were predictive because all the physics related to chemical EOR processes (interfacial tension reduction and wettability alteration) were not included.
Furthermore, most of commercial reservoir simulators do not have the capability to model imbibition tests due to lack of some physics, such as surfactant molecular diffusion. The modeling of imbibition cell tests can aid to understand the mechanisms behind wettability alteration and consequently aid in up-scaling the process. Also, modeling coreflood experiments for fractured vuggy carbonates is challenging. Different approaches of random permeability distribution and explicit fractures were used to model the experiments which demonstrate the validity and ranges of applicability of upscaled procedures, and also indicate the importance of viscous and capillary forces in larger scales. The simulation models were then used to predict the recovery response times for larger cores.Chemical Engineerin
Effect of progressive muscle relaxation and aerobic exercise on anxiety, sleep quality, and fatigue in patients with chronic renal failure undergoing hemodialysis
Insomnia, anxiety, and fatigue are more common in hemodialysis patients than in healthy people and affect patients' quality of life. In the present study, the effects of progressive muscle relaxation (PMR) and aerobic exercise on anxiety, sleep quality, and fatigue in patients with chronic renal failure undergoing hemodialysis were evaluated. In this double-blind clinical trial, 100 hemodialysis patients were randomly assigned to three groups: PMR, aerobic exercise, and control. Patients performed relaxation and aerobic exercise daily for 60 days. Questionnaires of anxiety, sleep quality, and fatigue were completed by participants before and after the interventions. Data were analyzed by Stata software. PMR program significantly decreased general anxiety, trait anxiety, state anxiety, and Beck anxiety and aerobic exercise significantly reduced beck anxiety. PMR program and aerobic exercise both significantly improved sleep quality in hemodialysis patients. PMR program significantly reduced Rhoten fatigue but did not affect Piper fatigue. Aerobic exercise had no effect on Rhoten and Piper fatigue. Results showed better function of PMR compared to aerobic exercise in improving the symptoms of anxiety, sleep disorders, and fatigue in hemodialysis patients. Given that fatigue and sleep quality cause severe anxiety and somehow undermine quality of life in hemodialysis patients, taking into account non-pharmacological treatments such as aerobic exercise particularly PMR is a highly economical but efficient and efficacious strategy to manage several problems of these patients. Healthcare teams can incorporate these safe programs in care designs
GeoStrain : an open source software for calculating crustal strain rates
We developed an open source software for crustal strain analysis using the least-squares collocation method based on the spherical model of the earth. The software is able to simultaneously determine the signal and noise of the velocities at the observation points with the best possible removal of the observational errors, or at any other position with no velocity observation. Furthermore, the software can calculate strain and rotation rate tensors at any points of interest, including observation points, grid points or points along a fault line. The advantage of the software is that the sphericity of the earth is considered in all the calculations. Moreover, it can optionally consider the effect of the vertical velocities on the strain rates that is principally important for regions where vertical deformation is the major geophysical signal compared to the horizontal deformation
The antibacterial activity of Iranian plants extracts against metallo beta-lactamase producing Pseudomonas aeruginosa strains
Metallo β-lactamases (MBLs) producing Pseudomonas aeruginosa (P. aeruginosa) isolates are becoming an escalating global threat. Among the antibiotics used to treat infections associated with P. aeruginosa, resistance to carbapenem is a serious therapeutic challenge. The aim of the present study was to detect MBL-producing P. aeruginosa and to evaluate the extracts of Urtica. dioica, Carum. copticum, and Zataria multiflora on these clinical pathogens. The study was performed on hospitalized burn patients during 2014. Antibiotic susceptibility testing was tested by broth micro dilution and disc diffusion methods. The MBLs were detected using combination disk diffusion test (CDDT) phenotypically. Then, PCR and sequencing methods were carried out to detect the MBL encoding genes. Among 83 imipenem resistant P. aeruginosa strains, 48 (57.9%) isolates were MBL-producing P. aeruginosa. PCR and sequencing methods confirmed that these strains were blaIMP-1positive genes, whereas none were positive for blaVIM genes. Hospitalized burn patients with MBL-producing P.aeruginosa infection had 4/48 (8.3%) mortality rate. It was demonstrated that C. copticum, U. dioica, and Z. multiflora extracts had significant antibacterial effects on regular and IMP-producing P. aeruginosa strains. The prevalence of MBL-producing P .aeruginosa isolates in burn patients is very high. In this study, all MBL-producing strains encode the blaIMP-1gene. Therefore, detection of MBL-producing strains has major importance in identifying drug resistance patterns in P. aeruginosa and in controlling of infections. In the current study, the extracts from C. copticum, U. dioica, and Z. multiflora had high antibacterial effects against β-lactamase producing P. aeruginosa isolates.
Noise behavior in CGPS position time series : the eastern North America case study
We analyzed the noise characteristics of 112 continuously operating GPS stations in eastern North America using the Spectral Analysis and the Maximum Likelihood Estimation (MLE) methods. Results of both methods show that the combination ofwhite plus flicker noise is the best model for describing the stochastic part of the position time series. We explored this further using the MLE in the time domain by testing noise models of (a) powerlaw, (b)white, (c)white plus flicker, (d)white plus randomwalk, and (e) white plus flicker plus random-walk. The results show that amplitudes of all noise models are smallest in the north direction and largest in the vertical direction. While amplitudes of white noise model in (c–e) are almost equal across the study area, they are prevailed by the flicker and Random-walk noise for all directions. Assuming flicker noise model increases uncertainties of the estimated velocities by a factor of 5–38 compared to the white noise model
Detection of acrA, acrB, aac(6′)-Ib-cr, and qepA genes among clinical isolates of Escherichia coli and Klebsiella pneumoniae
Background: The distribution of drug resistance among clinical isolates of Escherichia coli and Klebsiella pneumoniae has limited the therapeutic options. The aim of this study was to report the prevalence of quinolone resistance genes among E. coli and K. pneumoniae clinical strains isolated from three educational hospitals of Tehran, Iran. Materials and methods: A total of 100 strains of E. coli from Labbafinejad and Taleghani Hospitals and 100 strains of K. pneumoniae from Mofid Children and Taleghani Hospitals were collected between January 2013 and May 2014. Antimicrobial susceptibility tests were done by disk diffusion method based on Clinical and Laboratory Standards Institute guidelines. Detection of qepA, aac(6′)-Ib-cr, acrA, and acrB genes was done by polymerase chain reaction (PCR). Results: In this study, fosfomycin and imipenem against E. coli and fosfomycin and tigecycline against K. pneumoniae had the best effect in antimicrobial susceptibility tests. PCR assay using specific primers demonstrated that the prevalence of qepA, aac(6′)-Ib-cr, acrA, and acrB genes among the 100 E. coli isolates was 0 (0%), 87 (87%), 92 (92%), and 84 (84%), respectively. The prevalence of qepA, aac(6′)-Ib-cr, acrA, and acrB genes among the 100 K. pneumoniae isolates was 4 (4%), 85 (85%), 94 (94%), and 87 (87%), respectively. Conclusion: The distribution of qepA, aac(6′)-Ib-cr, acrA, and acrB resistance determinants in E. coli and K. pneumoniae is a great concern. Therefore, infection control and prevention of spread of drug-resistant bacteria need careful management of medication and identification of resistant isolates
Caring experiences and challenges of families with patients in vegetative state
زمینه و هدف: داشتن یک بیمار نباتی در خانواده تجربه پیچیده و استرس زایی است و مراقبت از چنین بیمارانی با ناتوانی کامل در منزل بسیار چالش زا می باشد. مطالعه حاضر با هدف تبیین تجارب و چالش های مراقبتی خانواده های دارای بیمار در وضعیت نباتی صورت گرفته است. روش بررسی: در مطالعه کیفی حاضر که به صورت مقطعی از مرداد ماه سال 1392 تا شهریور ماه سال 1393 در برخی استان های ایران (خوزستان، تهران و لرستان) صورت گرفت، 17 مشارکت کننده شامل 14 مراقب خانگی و 3 مراقب حرفه ای به مطالعه وارد شدند. جهت جمع آوری داده ها از مصاحبه های بدون ساختار و مشاهده استفاده شد. جمع آوری داده ها تا رسیدن به اشباع داده ها و پدیدار شدن الگوهای اصلی ادامه یافت. تحلیل داده ها با استفاده از روش تحلیل محتوایی صورت گرفت. یافته ها: چالش های مراقبتی که خانواده های دارای بیمار نباتی با آن مواجه بودند در قالب پنج الگوی اصلی شامل ولع آموزش، عهده داری مراقبتی دشوار، هزینه های فرساینده، برزخ حرف و حدیث ها و پسرفت روحی پدیدار گردید. نتیجه گیری: یافته های مطالعه حاضر نشان داد که خانواده های دارای بیماران نباتی طی دوره مراقبت از بیمار خود با چالش های متعددی روبرو هستند که بخش عمده ی این چالش ها مرتبط با سیاست های سیستم سلامت و برخی نیز مرتبط با سطح آگاهی عموم جامعه می باشد، لذا توجه بیشتر به این چالش ها از سوی مسئولان مرتبط پیشنهاد می گردد
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