DNA translocation through short nanofluidic channels under asymmetric pulsed electric field     

C. Gupta  W.-C. Liao  D. Gallego-Perez  C. E. Castro  L. J. Lee 《Biomicrofluidics》2014,8(2)

Investigation of single molecule DNA dynamics in confined environments has led to important applications in DNA analysis, separation, and sequencing. Here, we studied the electrophoretic transport of DNA molecules through nanochannels shorter than the DNA contour length and calculated the associated translocation time curves. We found that the longer T4 DNA molecules required a longer time to traverse a fixed length nanochannel than shorter λ DNA molecules and that the translocation time decreased with increasing electric field which agreed with theoretical predictions. We applied this knowledge to design an asymmetric electric pulse and demonstrate the different responses of λ and T4 DNA to the pulses. We used Brownian dynamics simulations to corroborate our experimental results on DNA translocation behaviour. This work contributes to the fundamental understanding of polymer transport through nanochannels and may help in designing better separation techniques in the future.  相似文献   

On Static and Dynamic Intuitive Ontologies     

David Hammer  Ayush Gupta  Edward F. Redish 《学习科学杂志》2013,22(1):163-168

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The institute of Ethiopian studies library and its documentation services     

Sushma Gupta 《International Information and Library Review》2013,45(4):381-389

During the last few decades research activities have grown rapidly in Ethiopia. Introduction of higher education and foreign assistance for this purpose have led the Ethiopian Government to set up several research institutes in the country. The Institute of Ethiopian Studies is one of them, set up to enable research activities in various areas of Ethiopian culture as well as to provide a documentation centre for them. Information and documentation are considered to be the infrastructure of research work. The present state of information and documentation services of the Institute is briefly described along with its history, activities and sections. The importance of introducing some new devices, such as compiling bibliographies, cumulative indexes, book lists and starting a newsletter to keep the researchers abreast of new developments at the Institute.  相似文献   

Potential Biochemical Markers for Preterm Labor: A Pilot Study in North India     

Singh B  Goswami B  Gupta N  Bajaj AD  Mallika V 《Indian journal of clinical biochemistry : IJCB》2011,26(1):41-45

Preterm delivery is a major contributor for neonatal mortality. Intensive research is underway to establish a reliable biomarker that can ascertain the risk of preterm delivery in pregnant women. The aim of our study was to evaluate the role of various biochemical parameters as potential biomarker for risk assessment for preterm labor. Forty women presenting with preterm labor and 40 women who delivered at term were included in the study. Parameters that were evaluated include corticotrophin (ACTH), prolactin, thyroid stimulating hormone (TSH), ferritin and Alkaline Phosphatase (ALP). Serum ACTH, ferritin, ALP and Ferritin/Iron ratio were significantly higher in the subjects who delivered prematurely as compared to the controls. Comparison of sensitivity, specificity, likelihood ratio, positive and negative predictive values for different cut offs for ACTH, ferritin, ALP and ferritin/iron ratio was carried out. Ferritin emerged as the best marker with area under curve of 0.96 as compared to 0.88 for ACTH, 0.825 for ALP and 0.735 for ferritin/iron ratio. Our study establishes the superiority of ferritin as a predictive biomarker for preterm labor as compared to the rest of the parameters evaluated.  相似文献   

Regeneration of Red Cell Cholinesterase Activity Following Pralidoxime (2-PAM) Infusion in First 24 h in Organophosphate Poisoned Patients     

Parul Goel  Nidhi Gupta  Surjit Singh  Ashish Bhalla  Navneet Sharma  K. D. Gill 《Indian journal of clinical biochemistry : IJCB》2012,27(1):34-39

Oximes such as pralidoxime chloride reactivate acetylcholinesterase. However their role in management of organophosphate poisoning is controversial. The study was carried out to find effectiveness of pralidoxime chloride (2-PAM) in regenerating red cell acetyl cholinesterase in first 24 h following administration of it in dose recommended by WHO. Eight patients with OPP [chlorpyriphos (3), phorate (3), dichlorvos (1) and monocrotophos (1) who fulfilled the criteria for inclusion were investigated. In addition to decontamination and atropine, all these patients were administered 30 mg/kg body wt of 2-PAM as bolus dose followed by 7.5 mg/kg body wt/h with maximum dose being 500 mg/h as continuous infusion till first 24 h. Red cell AChE activity was estimated every 15 min for first 4 h, one hourly for next 4 h and then 2 hourly till 24 h and subsequently without 2-PAM every 12 h till 7 days or discharge or death which ever earlier. In all the patients maximum increase in activity was observed in first 4 h following which rise was very slow despite continued 2-PAM infusion and reaching a steady state in 20 h in all the cases. The increase in red cell AChE activity observed in diethyl group at 24 h of 2-PAM infusion was 154% vs. 81% in dimethyl group. At 7 days the increase in activity was 215% vs. 118% respectively. However on multiple repeated ANOVA, no statistically significant difference was observed between diethyl and dimethyl groups at admission and discharge (P > 0.05). Similarly no significant difference was observed in three groups when patients were categorized according to WHO classification of organophosphates (P > 0.05). The maximum increase in red cell AChE activity occurs in first 4 h of 2-PAM administration followed by a slow increase despite 2-PAM infusion till 24 h.  相似文献   

Does LDL-C Estimation Using Anandaraja’s Formula Give a Better Agreement with Direct LDL-C Estimation than the Friedewald’s Formula?     

Shalini Gupta  Minni Verma  Kamaljit Singh 《Indian journal of clinical biochemistry : IJCB》2012,27(2):127-133

Estimation of low density lipoprotein cholesterol (LDL-C) is crucial in management of coronary artery disease patients. Though a number of homogenous assays are available for estimation of LDL-C, use of calculated LDL-C by Friedewald’s formula (FF) is common in Indian laboratories for logistic reasons. Recently Anandaraja and colleagues have derived a new formula for calculating LDL-C. This formula needs to be evaluated before it is extensively applied in diagnosis. We measured LDL-C by homogenous method (D-LDL-C) in 515 fasting samples. Friedewald’s and Anandaraja’s formulas were used for calculation of LDL-C (F-LDL-C and A-LDL-C, respectively). The mean LDL-C levels were 123.3 ± 53.2, 112.4 ± 50.2 and 109.2 ± 49.8 mg/dl for D-LDL-C, F-LDL-C and A-LDL-C, respectively. There was a statistically significant difference between the results (P > 0.001) obtained by calculation formulas compared to the measured LDL-C. There was underestimation of LDL-C by 10.8 and 14 mg/dl by Friedewald’s and Anandaraja’s formulas respectively. The Pearson’s correlation between F-LDL-C and D-LDL-C was 0.931 and that between A-LDL-C and D-LDL-C was 0.930. Bland–Altman graphs showed a definite agreement between mean and differences of the calculation formulas and direct LDL-C with 95% of values lying with in ±2 SD limits. The mean percentage difference (calculated as {(Calculated LDL-C)-(D-LDL-C)}/D-LDL-C × 100) for F-LDL-C was maximum (−11.6%) at HDL-C ≥ 60 mg/dl and TG levels of 200–300 mg/dl (−10.4%) compared to D-LDL-C. A-LDL-C results gave highest mean percentage difference at total cholesterol concentrations <100 mg/dl (−37.3%) and HDL-C < 40 mg/dl (−17.1%), respectively. The results of our study showed that FF is better in agreement with D-LDL-C than Anandaraja’s formula for estimation of LDL-C by calculation though both lead to its underestimation.  相似文献   

Nanotechnology: A Revolution in Cancer Diagnosis     

V. Jaishree  P. D. Gupta 《Indian journal of clinical biochemistry : IJCB》2012,27(3):214-220

Nanotechnology has brought revolution in cancer detection and treatment. It has capability to detect even a single cancerous cell in vivo and deliver the highly toxic drugs to the cancerous cells. Nanoshells, carbon nanotubes, quantum dots, supermagnetic nanoparticles, nano wires, nanodiamonds, dandrimers, and recently synthesized nanosponges are some of the materials used for cancer detection. Using specific cross linkers, such as specific antibodies against cancer cells individual cancer cells can be located. With the aid of a novel set of lipid-coated, targeted quantum dots a method for quantifying multiple specific biomarkers on the surfaces of individual cancer cells was also developed. This approach to quantitative biomarker detection stands to improve the histopathology methods used to diagnosis pancreatic and other cancers and enable the development of methods to spot cancer cells circulating in the blood stream. Certain nano materials can also deliver cancer drugs at the site so the drug toxicity can also be reduced.  相似文献   

Silver Nano Particles Prevent Platelet Adhesion on Immobilized Fibrinogen     

Debapriya Bandyopadhyay  Haren Baruah  Bharat Gupta  Shailja Sharma 《Indian journal of clinical biochemistry : IJCB》2012,27(2):164-170

Vascular thrombotic disorders have emerged as a serious threat to our society. Platelet adhesion to fibrinogen, collagen and other platelet activators exposed over the atherosclerotic plaques can trigger platelet signaling events, activate platelets and lead to thrombotic events. Since anticoagulant and thrombolytic treatment strategies are usually associated with serious bleeding complications, preventing platelets adhesion may help to maintain platelets in an inactive state. In this study we tried to find out the effect of Silver nanoparticles, through their interaction with various platelet surface integrins on platelet adhesion on immobilized fibrinogen. Platelets, isolated from anti-coagulated human whole blood sample from healthy donors, were suspended in physiological buffer and each sample was divided into four tubes. In three of them 0.05, 0.5, and 5 μM concentrations of Silver nanoparticles were added, fourth tube served as control. Platelet adhesion on immobilized fibrinogen matrices and integrin mediated cell signaling events were studied in all the four samples. In the present study we show that nanosilver prevent platelet adhesion without conferring any lytic effect on them and effectively prevents integrin-mediated platelet responses in a concentration-dependent manner.  相似文献   

Erratum to: Linear Analysis of Autonomic Activity and Its Correlation with Creatine Kinase-MB in Overt Thyroid Dysfunctions     

Manisha Mavai  Yogendra Raj Singh  R. C. Gupta  Sandeep K. Mathur  Bharti Bhandari 《Indian journal of clinical biochemistry : IJCB》2018,33(2):229-230

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Oxygen derived free radicals in clinical context     

V. K. Gupta  V. Mallika  Yashika Gupta  D. K. Srivastava 《Indian journal of clinical biochemistry : IJCB》1992,7(1):3-10

Oxygen derived free radicals have been implicated in a number of clinical disorders including atherosclerosis (1), ischemic heart disease (IHD) (2), post ischemic reperfusion injury (3) and respiratory distress syndrome (4). These radical are generated by sequential reduction of molecular oxygen; the primary product being superoxide anion (O₂ ^.−) which is subsequently reduced to hydrogen peroxide (H₂O₂), hydroxy1 radical (OH^.) and singlet oxygen (¹O₂). However the evidence for ODFR induced cell damage in various clinical disorders is still debated and rests largely on free radical scavenging studies, through electron paramagnetic resonance spectroscopic (EPRS) studies have provided direct evidence for ODFR generation following coronary artery ligation (5). By definition, a free radical is an atom, ion or molecule with one or more unpaired electrons (the presence of unpaired electron in a free radical being represented by a superscribed bold dot-R^.) and may be formed as a result of homolytic fission of a covalent bond or by electron transfer reactions, and may have cationic (NH₃ ⁺), anionic (O₂ ^.−) or neutral (NO) characteristics. The most important in vivo source for these radical species have been found to be univalent biochemical redox reactions involving oxygen. (a) A:B→A^.+B^. (b) A:+B→A^.+B^.  相似文献