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51.
Bushra Y Ahmed Sridhara Chakravarthy Ruben Eggers Wim TJMC Hermens Jing Ying Zhang Simone P Niclou Christiaan Levelt Fred Sablitzky Patrick N Anderson AR Lieberman Joost Verhaagen 《BMC neuroscience》2004,5(1):1-11
Background
As development proceeds the human embryo attains an ever more complex three dimensional (3D) structure. Analyzing the gene expression patterns that underlie these changes and interpreting their significance depends on identifying the anatomical structures to which they map and following these patterns in developing 3D structures over time. The difficulty of this task greatly increases as more gene expression patterns are added, particularly in organs with complex 3D structures such as the brain. Optical Projection Tomography (OPT) is a new technology which has been developed for rapidly generating digital 3D models of intact specimens. We have assessed the resolution of unstained neuronal structures within a Carnegie Stage (CS)17 OPT model and tested its use as a framework onto which anatomical structures can be defined and gene expression data mapped.Results
Resolution of the OPT models was assessed by comparison of digital sections with physical sections stained, either with haematoxylin and eosin (H&E) or by immunocytochemistry for GAP43 or PAX6, to identify specific anatomical features. Despite the 3D models being of unstained tissue, peripheral nervous system structures from the trigeminal ganglion (~300 μm by ~150 μm) to the rootlets of cranial nerve XII (~20 μm in diameter) were clearly identifiable, as were structures in the developing neural tube such as the zona limitans intrathalamica (core is ~30 μm thick). Fourteen anatomical domains have been identified and visualised within the CS17 model. Two 3D gene expression domains, known to be defined by Pax6 expression in the mouse, were clearly visible when PAX6 data from 2D sections were mapped to the CS17 model. The feasibility of applying the OPT technology to all stages from CS12 to CS23, which encompasses the major period of organogenesis for the human developing central nervous system, was successfully demonstrated.Conclusion
In the CS17 model considerable detail is visible within the developing nervous system at a minimum resolution of ~20 μm and 3D anatomical and gene expression domains can be defined and visualised successfully. The OPT models and accompanying technologies for manipulating them provide a powerful approach to visualising and analysing gene expression and morphology during early human brain development. 相似文献52.
Alan R. Katritzky Bushra Agha George Z. de Ville Edward Lunt Michael L. Podmore 《Magnetic resonance in chemistry : MRC》1983,21(11):649-656
13C and 1H NMR spectra and UV spectra are recorded and assigned for a variety of substituted and hetero derivatives of benzo[8,9]quinolizino[4,5,6,7-fed]phenanthrindyliums. Large specific effects of traces of water on these spectra are traced to pseudo-base formation. 相似文献
53.
Maha Abdallah Alnuwaiser M. Faisal Javed M. Ijaz Khan M. Waqar Ahmed Ahmed M. Galal 《印度化学会志》2022,99(7):100538
The current study investigates the potential of well-known artificial neural network (ANN), Support vector regression (SVR), multilinear and multi-nonlinear regression techniques to predict total dissolve solids (TSO) and electrical conductivity (ECO), which are essential water quality indicators. To develop the anticipated models, seven effective parameters: Ca2+ Mg2+ Na+ Cl- SO42- HCO3- and pH were used as input variables. The external validation criteria were employed to address the modeling overfitting. The outcome of the study demonstrated a strong association between experimental and models predicted data. The coefficient of determination was 0.97, 0.96, 0.92, and 0.94 for SVR, ANN, MLR, and MNLR models, respectively. The lowest error value of 5.37 and 7.92 was attained by SVR model for training and testing data, respectively. Performance of the proposed techniques showed relative dominance of SVR compared to ANN, MLR and MNLR. Sensitivity analysis demonstrated that the HCO3- is the most sensitive parameter for both TSO and ECO followed by Cl- and SO42-. The models assessment on external criteria ensured generalized results. Conclusively, the outcome of the present research indicated that formulation of machine learning models for prediction of water quality parameters are cost effective and helpful in river water quality assessment, management and policy making. 相似文献
54.
55.
M. Ijaz Khan Tasawar Hayat Sumaira Qayyum Muhammad Imran Khan A. Alsaedi 《Physics letters. A》2018,382(34):2343-2353
Here a novel applications of entropy generation optimization is presented for nonlinear Sisko nanomaterial flow by rotating stretchable disk. Flow is examined in the absence of magnetohydrodynamics and Joule heating. Total irreversibility rate (entropy generation rate) is investigated for different flow parameters. Heat source/sink and viscous dissipation effects are considered. Impacts of Brownian motion and thermophoresis on irreversibility have been analyzed. Governing flow equations comprise momentum, energy and nanoparticle concentration. Von Karman's similarity variables are implemented for reduction of PDEs into ODEs. Homotopy analysis technique for series solutions is implemented. Attention is given to the irreversibility. The impacts of different flow parameters on velocity, nanoparticle concentration, temperature and irreversibility rate are graphically presented. From obtained results it is examined that irreversibility rate enhances for larger estimation of Brinkman number and diffusion. Furthermore it is also examined that temperature and nanoparticle concentration show contrast behavior through Prandtl number and Brownian motion. 相似文献
56.
Here thermal dependence conductivity and nonlinear convection features in third-grade liquid flow bounded by moving surface having varying thickness are formulated. Stagnation point flow is considered. Revised FourierFick relations and double stratification phenomena are utilized for modeling energy and concentration expressions.Mathematical model of considered physical problem is achieved by implementing the idea of boundary layer theory. The acquired partial differential system is transformed into ordinary ones by employing relevant variables. The homotopic scheme yield convergent solutions of governing nonlinear expressions. Graphs are constructed for distinct values of physical constraints to elaborate the heat/mass transportation mechanisms. 相似文献
57.
Multivalent Siderophore–DOTAM Conjugates as Theranostics for Imaging and Treatment of Bacterial Infections 下载免费PDF全文
M. Sc. Kevin Ferreira Dr. Hai-Yu Hu Dr. Verena Fetz Dr. Hans Prochnow Dr. Bushra Rais Prof. Dr. Peter P. Müller Prof. Dr. Mark Brönstrup 《Angewandte Chemie (International ed. in English)》2017,56(28):8272-8276
There is a strong need to better diagnose infections at deep body sites through noninvasive molecular imaging methods. Herein, we describe the synthesis and characterization of probes based on siderophore conjugates with catechol moieties and a central DOTAM scaffold. The probes can accommodate a metal ion as well as an antibiotic moiety and are therefore suited for theranostic purposes. The translocation of the conjugates across the outer and inner cell membranes of E. coli was confirmed by growth recovery experiments with enterobactin-deficient strains, by the antibacterial activity of ampicillin conjugates, and by confocal imaging using a fluorogen-activating protein–malachite green system adapted to E. coli. The suitability of the probes for in vivo imaging was demonstrated with a Cy5.5 conjugate in mice infected with P. aeruginosa. 相似文献
58.
Muhammad Faizan Nazar Shahzad Murtaza Beenish Ijaz Muhammad Asfaq Muhammad Ali Mohsin 《Journal of Dispersion Science and Technology》2013,34(1):18-27
The present study describes the extent of interactions of an efficient food dye, Carmoisine (CAR), with conventional cationic surfactants, hexadecyltrimethylammonium bromide, and ethylhexadecyldimethylammonium bromide (EHDAB). The study was carried out by quantifying the spectral changes of CAR as a function of premicellar to postmicellar surfactant concentrations at various pH conditions. The quantification of CAR molecules entrapped by cationic micellar systems has been estimated with the help of mathematical models. Binding parameters of each surfactant were calculated using differential spectroscopic method. The enhanced solubilization of dye by switching the pH was observed. In support of the electrostatic forces, the larger and more hydrophobic head group favors the promising solubilization of CAR in the outer region of the micellar interior. These findings extend the proficiency of dye molecule as a reporter for sensing electrostatic environment in lipidic membranes and related organized assemblies. 相似文献
59.
Ijaz F. Shafqat S. S. Babar R. Rizwan M. Zafar M. N. Khan M. A. Munawar M. A. 《Russian Journal of Organic Chemistry》2020,56(3):509-513
Russian Journal of Organic Chemistry - A fine, green, and efficient method has been proposed for the synthesis of 2-aryl-4,5-diphenyl-1H-imidazoles using various sugars such as glucose, fructose,... 相似文献
60.
Bushra Rashid Dr. Kanchan Mala Mubashir Ali Dr. Umer Rafiq Mehroosa Quereshi Parvaz Ahmad Mudasir Dar Dr. Malik Wahid 《Chemphyschem》2023,24(13):e202300013
Oxide-based systems often suffer from higher overpotentials compared to transition metal sulfides and phosphides for the electrochemical hydrogen evolution reaction (HER). Interestingly, the generation of oxygen vacancy/defect has been seen as the strategy for further activating transition metal oxides (NiCo2O4 as a model system) for an electrochemical water-splitting process. Herein, we employ the temperature ramp strategy (ambient air calcination) for the generation of oxygen vacancies in NiCo2O4 (NCO) towards the tuning of electrocatalytic enhancements. The NiCo2O4 synthesized at temperature ramp rates of 2 °C/min (NCO-2), 5 °C/min (NCO-5), and 10 °C/ min (NCO-10) depicts contrasting structural features and varying Ni : Co : O surface composition. The decrease in the crystallite size and converse trend in the particle strain were observed from NCO-2 to NCO-10. Interestingly, the surface Ni : Co : O ratios of 1 : 0.78 : 3.6, 1 : 0.81 : 3.3, and 1 : 0.69 : 2.8 for NCO-2, NCO-5, and NCO-10, respectively, were observed. The reduced relative oxygen ratio in the latter implies the generation of an ample amount of oxygen vacancy defects. HER performance depicts a consistent trend with enhanced oxygen defect concentration with the overpotential requirement of 700, 647, and 597 mV for NCO-2, NCO-5, and NCO-10, respectively, for the generation of a cathodic current of 25 mA cm−2. The same trend in an electrocatalytic enhancement is observed for other cathodic currents. 相似文献