Enhanced electrochemical sensing of leukemia cells using drug/lipid co-immobilized on the conducting polymer layer

Electrochemical biosensors using five anticancer drug and lipid molecules attached on the conducting polymer layer to obtain the orientation of drug molecules toward cancer cells, were evaluated as sensing materials and their performances were compared. Conjugation of the drug molecules with a lipid, phosphatidylcholine (PC) has enhanced the sensitivity towards leukemia cells and differentiates cancer cells from normal cells. The composition of each layer of sensor probe was confirmed by electrochemical and surface characterization experiments. Both impedance spectroscopy and voltammetry show the enhanced interaction of leukemia cells using the drug/lipid modified sensor probe. As the number of leukemia cells increased, the charge transfer resistance (Kt) in impedance spectra increased and the amine oxidation peak current of drug molecules in voltammograms decreased at around 0.7-1.0 V. Of test drug molecules, raltitrexed (Rtx) showed the best performance for the cancer cells detection. Cancer and normal cell lines from different origins were examined to evaluate the degree of expression of folate receptors (FR) on cells surface, where cervical HeLa cell line was found to be shown the highest expression of the receptor. Impedance and chronoamperometric experiments for leukemia cell line (jurkat E6-1) showed linear dynamic ranges of 1.0 x 103(-2.5) x 10(5) cells/mL and 1.0 x 10(3)-8.0 x 10(3) cells/mL with detection limits of 68 +/- 5 cells/mL and 21 +/- 3 cells/mL, respectively. (C) 2016 Elsevier B.V. All rights reserved.1184sciescopu

A Godunov-type scheme for the drift flux model with variable cross section

\u3cp\u3eThis paper presents a modification of a classical Godunov-type scheme for the numerical simulation of a two-phase flow in a pipe with a piecewise constant cross-sectional area. This type of flow can occur in wellbores during drilling for oil and gas as well as after well completion. Contrary to classical finite-volume schemes, the numerical scheme proposed in this paper captures the steady-state solution of the system without generating non-physical discontinuities in the numerical solution close to the locations of discontinuities in the cross-section. Moreover, the proposed scheme can be extended to problems with piecewise continuous cross-sectional area. This extension is achieved by discretization of the area along the spatial domain and converting the piecewise continuous area into a piecewise constant area. The proposed scheme reduces to the classical scheme when the cross-sectional area is constant along the spatial domain. For the purpose of computational efficiency, the modification to the classical scheme is only applied at the locations of area variation and the numerical solver reduces to the classical scheme where the cross-sectional area is constant. It is also shown that the proposed scheme can be effectively used to simulate two-phase flows arising from the perturbation of the steady-state solution. The effectiveness of the proposed scheme is shown through illustrative numerical simulations. Finally, it should be noted that the proposed scheme retains the same order of accuracy as the underlying classical scheme.\u3c/p\u3

Forgotten Ureteral Stents: Who's at Risk?

The sequelae from forgotten stents carry significant morbidity and costs. In this study, we attempt to identify potential risk factors that may make patients less likely to follow up for stent removal so that more effective prevention efforts may be directed at these persons. A single-institution retrospective analysis of 187 consecutive patients who had stents placed between January 2010 and December 2010 was performed. Chart review was conducted to see if patients had undergone stent removal beyond the intended maximal stent life (MSL). Patients who were lost to follow-up were contacted to determine if stents were overdue. Logistic regression was performed to determine risk factors. Of the 187 patients who had stents placed, 147 had the stent removed before MSL and 28 had stents removed after the MSL. Twelve patients could not be contacted and were excluded from the analysis. Within our cohort of 175 patients, 48% were males, 73% were minorities (33% Latino, 30% Black, 8% Asian, and 2% Native American), 39% did not speak English, 79% were unemployed, 73% were uninsured, and 35% were married. Among the patients with forgotten stents, 68% were male, 64% were minorities (32% Latino, 29% Black, 4% Native American, and 0% Asian), 82% were unemployed, 39% did not speak English, 93% were uninsured, and 43% were married. Multivariate regression analysis demonstrated that uninsured patients (odds ratio [OR], 6.3; 95% confidence interval [CI], 1.4-28.2; P value 0.01) and males (OR, 2.8; CI, 1.2-6.8; P = 0.02) had statistically significant associations with forgotten stents. Men were 2.8 times more likely to have forgotten stents than females. Patients without health insurance were six times more likely to have forgotten stents than patients with insurance. As efforts are made to prevent forgotten stents, increased attention should be given to these higher-risk patient populations

Modeling and numerical implementation of managed pressure drilling systems for the assessment of pressure control systems

Automated Managed Pressure Drilling (MPD) is a method to enhance downhole pressure control performance and safety during drilling operations. It is becoming more common to use model-based simulation for the evaluation of pressure control systems designed for MPD automation before using those in the field. This demands a representative hydraulics simulation model which captures the relevant aspects of a drilling system. This paper presents such a model and, additionally, an approach to numerically implement that model for simulation studies. The complexity of this simulation model should be limited to, firstly, support effective numerical implementation and, secondly and most importantly, to allow for the analysis of the behaviour and performance of the automated pressure control systems during the controller design phase. To this end, aspects of a drilling system that can considerably affect the performance of the automated MPD system are captured in the model. This hydraulics model incorporates both the distributed and multi-phase flow nature of a drilling system. Moreover, it captures nonlinear boundary conditions at the inlet of the drillstring, at the drill bit and choke manifold, and also the variations in the cross-sectional area of the flow path. Model validations against field data from real-life MPD operations and simulations of industry-relevant scenarios indicate that these aspects are effectively captured in the model and preserved during the numerical implementation

Patho-epidemiology of Cancer Cervix in Karachi South

Introduction: The present study was conducted with the objective of examining descriptive epidemiological and pathological characteristics of cancer cervix in Karachi South, an all urban district population of Karachi, Pakistan. Methodology: A total of 74 cases of cancer cervix, ICD-10 (International Classification of Diseases 10th Revision) category C53 were registered at the Karachi Cancer Registry, for Karachi South, during a 3 year period, 1st January, 1995 to 31st December 1997. Results: The age standardized incidence rate (ASR) world andcrude incidence rate (CIR) per 100,000 were 6.81 (5.2, 8.43) and 3.22 (2.49 to 3.96). Cancer cervix accounted for approximately 3.6% of all cancers in females and was the sixth malignancy in hierarchy. The mean age of the cancer cases was 53.27 years [standard deviation (SD) 11.6; 95% confidence interval (CI) 50.58, 55.96; range(R) 32-85 years)]. The distribution by religion was Muslims (90.5%), Christians (8.1%) and Hindus (1.4%). There were no cases reported in Parsees. The frequency distribution by ethnicity was Urdu speaking Mohajirs (20.3%), Punjabis (17.6%), Gujrati speaking Mohajirs (4.1%), memon Mohajirs (8.1%), Sindhis (10.8%), Baluchs (8.1%), Pathans (5.4%) and Afghan migrants (2.7%). The ethnicity was not known in approximately a fourth (23.0%) of the cases.The socio-economic distribution was 27.0% financially deprived class, 24.4% lower middle class and 48.7% upper middle and affluent classes. The majority of the women were married (86.5%); a smaller number were unmarried (2.7%) or widows (10.8%). The age-specific curves showed a gradual increase in risk from the fourth up till the seventh decade, followed by an actual apparent decrease in risk after 64 years of age. The peak incidence was observed in the 60-64 year age group. The morphological categorization was squamous cell carcinoma (86.5%), adenocarcinoma (10.9%) and adenosquamous carcinoma (2.6%). The majority of cases presented with moderately differentiated or grade 2 lesions (45.9%). There were no in-situ cases. Approximately half the cancers (58.1%) had spread regionally and 8.1% to a distant site at the time of diagnosis. Odds ratios (OR) were calculated for socioeconomic residential categories, religion, ethnicity, age groups and education. The OR for socioeconomic residential categories ranged between 0.69 and 2.9 with a marginally higher risk in the lower [OR 2.09 (95% CI .97; 4.49)] and lower middle class [OR 2.08 (95%CI 0.95; 4.58)]. Hindus [OR 1.2 (95% CI 0.18; 2.2)] had a slightly higher risk then the Muslims [OR 0.14 (95% CI 0.17; 1.2)]. A higher risk was also observed for Christians [OR 7.76 (95% CI 1.74; 34.5)]. Conclusion: The incidence of cervical cancer in Karachi South (1995-97) reflects a low risk population with a late presentation and a high stage disease at presentation. It is suggested that cervical screening if implemented should focus on once a life time methodology involving 36-45 year old women. This should be combined with HPV vaccination for the young and public health education for all. A regular cervical screening program would require mobilization of considerable financial, structural and human resources along with training for personnel. This may burden the already stretched health resources of a developing country