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991.
It is undeniable that HIV infection has been a censorious public health concern over the past four decades. It is reported that HIV is the main reason for AIDs which has decimated the global population of humans and imposed a significant economic burden on affected areas. Hence, it is significant to study the transmission of HIV viruses in the body of a human host. In this study, we use a fractional framework to organise the intricate interactions of CD4+ T-cells and HIV viruses in order to investigate HIV infection with control interventions. We apply the operators of Caputo and Atangana–Baleanu to interrogate the transmission phenomena of HIV viruses. For the analysis of our system, we present the basic concepts of the fractional operators. Numerical schemes are provided to show the solution pathways of the system with the variation of input parameters. Furthermore, the findings emphasise the chaotic and dynamical behaviour of HIV. We run several simulations to visualise the influence of input factors and quantitatively illustrated the dynamics of HIV. Chaos and oscillatory behaviour are intimately linked, and this is owing to the system's nonlinearity. Furthermore, our findings indicate the most important factors for infection control and prevention. 相似文献
992.
JPC – Journal of Planar Chromatography – Modern TLC - A reliable and sensitive thin-layer chromatographic (TLC)-densitometric method is developed for the analysis of danazol in its... 相似文献
993.
This paper described a new approach for the preconcentration of lead (Pb2+) by temperature controlled ionic liquid-dispersive liquid phase microextraction (TIL-DLME) prior to analyzing by flame atomic absorption spectrometry (FAAS). An ionic liquid (IL) 1-Butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] was used as an extractant solvent. The Pb2+ was complexed with ammonium pyrrolidinedithiocarbamate (APDC) and then entered into the infinite IL drops at high temperature (> 70 °C). Important variables affecting the microextraction efficiency such as pH, ligand concentration, amount of IL, temperature and incubation time were investigated. The results showed that the coexistent ions had no obvious negative effect on the determination of Pb2+. In the optimum experimental conditions, the limit of detection (LOD) and the enhancement factor (EF) were 0.13 μg L? 1 and 93, respectively. The relative standard deviation (RSD) of 10 μg L? 1 Pb2+ was 4.3%. The developed method was validated by determining Pb2+ in certified reference material (CRM) and the results showed that the determined values of Pb2+ were in good agreement with the certified value. The proposed method was applied satisfactorily for the preconcentration of Pb2+ in acid digested blood samples of children with different respiratory disorders. 相似文献
994.
Banerjee S Prasad P Hussain A Khan I Kondaiah P Chakravarty AR 《Chemical communications (Cambridge, England)》2012,48(62):7702-7704
Curcumin (Hcur) as a cellular imaging and PDT agent shows remarkable photocytotoxicity in HeLa cells in visible light of 400-700 nm giving IC(50) = 8.2 ± 0.2 μM and its degradation is arrested on formation of photocytotoxic dipyridophenazine (dppz) complex [VO(cur)(dppz)Cl] (IC(50) = 3.3 ± 0.4 μM), while both are less toxic in the dark. 相似文献
995.
Saeed MA Pramanik A Wong BM Haque SA Powell DR Chand DK Hossain MA 《Chemical communications (Cambridge, England)》2012,48(69):8631-8633
An unanticipated anion-water cluster is assembled by one bromide and three highly-ordered "water tetramers" within the cavity of a receptor, providing a perfect C(3) symmetric propeller-shaped bromide-water cluster of [Br(H(2)O)(12)](-). 相似文献
996.
Cerasoli E Ravi J Gregor C Hussain R Siligardi G Martyna G Crain J Ryadnov MG 《Physical chemistry chemical physics : PCCP》2012,14(3):1277-1285
Membrane-mediated structural modulation in two short fragments of the human HIV-1 envelope protein gp41 is demonstrated. Derived from the C-terminal membrane proximal external (MPE) and N-terminal fusion peptide proximal (FPP) regions, these peptides are widely separated in the primary sequence but form tertiary contacts during the intermediate (hemifusion) phase of HIV infection. The structural perturbations observed at the membrane interface offer evidence of rudimentary regulatory mechanisms operating in the free peptides which may be relevant in the biological system. No such regulatory phenomena were observed for the individual peptides in a membrane environment or between the peptides in aqueous solutions. Structure determination is made using a combination of circular and linear dichroism spectroscopy (supported by calorimetric measurements) and molecular dynamics simulations. Specifically, we show that these peptides interact locally without the conformational support of helical heptad repeat regions in native gp41 and that the modulation is not mutual with the FPP peptide operating as a primary regulator of the MPE-FPP interactions in the hemifusion phase. 相似文献
997.
Stedtfeld RD Tourlousse DM Seyrig G Stedtfeld TM Kronlein M Price S Ahmad F Gulari E Tiedje JM Hashsham SA 《Lab on a chip》2012,12(8):1454-1462
By 2012, point of care (POC) testing will constitute roughly one third of the $59 billion in vitro diagnostics market. The ability to carry out multiplexed genetic testing and wireless connectivity are emerging as key attributes of future POC devices. In this study, an inexpensive, user-friendly and compact device (termed Gene-Z) is presented for rapid quantitative detection of multiple genetic markers with high sensitivity and specificity. Using a disposable valve-less polymer microfluidic chip containing four arrays of 15 reaction wells each with dehydrated primers for isothermal amplification, the Gene-Z enables simultaneous analysis of four samples, each for multiple genetic markers in parallel, requiring only a single pipetting step per sample for dispensing. To drastically reduce the cost and size of the real-time detector necessary for quantification, loop-mediated isothermal amplification (LAMP) was performed with a high concentration of SYTO-81, a non-inhibiting fluorescent DNA binding dye. The Gene-Z is operated using an iPod Touch, which also receives data and carries out automated analysis and reporting via a WiFi interface. This study presents data pertaining to performance of the device including sensitivity and reproducibility using genomic DNA from Escherichia coli and Staphylococcus aureus. Overall, the Gene-Z represents a significant step toward truly inexpensive and compact tools for POC genetic testing. 相似文献
998.
Zhenyu Luo Chunxiao Zou Saad Syed Luthfia A. Syarbaini Guofang Chen 《Colloid and polymer science》2012,290(2):141-150
Chemically reactive particles with controllable sizes from 383 to 756 nm in very narrow size distributions (well below 5%)
have been synthesized by the modified surfactant-free emulsion homopolymerization of inhibitor-free glycidyl methacrylate
with the dropwise addition of ionic initiators during the initial reaction of 10 min. The effects of monomer concentration
and the amount of initiator were systematically studied on the particle diameter. In addition, changes of the particle diameter
and its size distribution during the whole synthesis process were also investigated. The mechanism for the formation of coalesced
and highly monodisperse chemically reactive colloidal particles was discussed based on the colloidal stability governed by
chemical reaction and physical interactions between the precursor or primary particles. Colloidal photonic crystals with different
brilliant visible colors in a large scale were prepared by shearing assembly of such chemically reactive monodisperse particles
with spin coating technique. The reflection wavelengths in the visible spectrum range are from the high-order including the
second-order light diffraction of the as-prepared PGMA photonic crystals. Such monodisperse chemically reactive particles
will be very useful in optical and sensing technologies, and in biochemical analysis. 相似文献
999.
Bakhat Ali Rashad Mehmood Uzma Rasheed Mughal Abdul Malik Muhammad Safder Riaz Hussain Muhammad Imran Rasool Bakhsh Tareen 《Helvetica chimica acta》2012,95(4):586-593
Eremosides A–C ( 1 – 3 ), three new iridoid glucosides, were isolated from the AcOEt‐soluble fraction of the EtOH extract of the whole plant of Eremostachys loasifolia, along with buddlejoside B ( 4 ), 10‐O‐benzoylcatalpol ( 5 ), and pakiside A ( 6 ) reported for the first time from this species. The structures of these compounds were elucidated by spectroscopic data including 2D‐NMR, FAB‐MS, ESI‐MS, as well as by acid and basic hydrolyses. 相似文献
1000.
Parvin Kumar Meenakshi Sunil Kumar Ashwani Kumar Khalid Hussain Suresh Kumar 《Journal of heterocyclic chemistry》2012,49(5):1243-1249
In this article, an efficient, environmentally benign, one‐pot and simple synthesis of 2‐aryl/heteroarylbenzothiazoles by the reaction of 2‐aminothiophenol and aryl/heteroaryl aldehydes mediated by hypervalent iodine (III) reagents under solvent‐free condition at room temperature is demonstrated. All the reactions were carried out by grinding the reactants (2‐aminothiophenol and aryl/heteroaryl aldehydes) with hypervalent iodine (III) reagents in a mortar with pestle. Phenyliodine bistrifluoroacetate act as an efficient oxidizing reagent in comparison to iodobenzene diacetate in term of reaction time but yields are comparative. The advantages of this protocol are the one‐step procedure, mild reaction conditions, high yields of the products, and no side reactions. 相似文献