Array atomic force microscopy for real-time multiparametric analysis.

Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks

Septal projections to the nucleus incertus in the rat: Bidirectional pathways for modulation of hippocampal function

Projections from the nucleus incertus (NI) to the septum have been implicated in the modulation of hippocampal theta rhythm. In this study we describe a previously uncharacterized projection from the septum to the NI, which may provide feedback modulation of the ascending circuitry. Fluorogold injections into the NI resulted in retrograde labeling in the septum that was concentrated in the horizontal diagonal band and areas of the posterior septum including the septofimbrial and triangular septal nuclei. Double-immunofluorescent staining indicated that the majority of NI-projecting septal neurons were calretinin-positive and some were parvalbumin-, calbindin-, or glutamic acid decarboxylase (GAD)−67-positive. Choline acetyltransferase-positive neurons were Fluorogold-negative. Injection of anterograde tracers into medial septum, or triangular septal and septofimbrial nuclei, revealed fibers descending to the supramammillary nucleus, median raphe, and the NI. These anterogradely labeled varicosities displayed synaptophysin immunoreactivity, indicating septal inputs form synapses on NI neurons. Anterograde tracer also colocalized with GAD-67-positive puncta in labeled fibers, which in some cases made close synaptic contact with GAD-67-labeled NI neurons. These data provide evidence for the existence of an inhibitory descending projection from medial and posterior septum to the NI that provides a "feedback loop" to modulate the comparatively more dense ascending NI projections to medial septum and hippocampus. Neural processes and associated behaviors activated or modulated by changes in hippocampal theta rhythm may depend on reciprocal connections between ascending and descending pathways rather than on unidirectional regulation via the medial septum.Grant sponsors: Fundación Alicia Koplowitz Fellowship (to A.M.S.P.), CAPES-Brasil Bex - 4494/09-1 (to F.N.S.) and 4496/09-4 (to C.W.P.) and Fapitec edital #01/08 (to F.N.S.), FIS-isciiiPI10/01399 (to J.S.), National Health and Medical Research Council of Australia - 520299 (to S.M.), 509246, 1005985, and 1005988 (to A.L.G.), the Florey Foundation (to S.M., A.L.G.), Besen Family Foundation (to A.L.G.) and a NEUREN project, FP7-PEOPLE-IRSES PIRSES-GA-2012-318997 (to A.L.G., F.E.O.-B.)

Apoptotic Potential of Artemsia sieberia Besser (Asteraceae) Fraction against Human Cancer Cell Lines

Purpose: To investigate the anti-proliferative and apoptotic activity of crude and dichloromethane fraction of A. sieberi against seven cancer cell lines (Colo20, HCT116, DLD, MCF7, Jurkat, HepG2 and L929).Methods: A. sieberi was extracted with methanol and further purification was carried out using liquidliquid extraction with hexane, dichloromethane and ethyl acetate. Each extract was assayed for cytotoxic potential against cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT) assay. The morphology of the HepG2 cell nucleus was investigated by Hoechst 33342, DNA-binding dye. A Tali™ image-based cytometer was used to assess cell viability, death and apoptosis using annexin-v /pi (propidium iodide). A chromatographic fingerprint was constructed using high performance liquid chromatography (HPLC).Results: The most effective anticancer activity of the unrefined methanol extract was against HepG2 cell lines (LC50 = 161.5 μg/mL). The hexane and ethyl acetate fractions showed no antiproliferative activity. The dichloromethane fraction displayed higher cytotoxic activity (LC50 = 61.75 μg/mL) and also repressed the migration of the cells. About 50 % of HepG2 cells were apoptotic when treated for 24 h with the dichloromethane fraction at the concentration of 120 μg/mLConclusion: A. sieberi possesses apoptotic activity and inhibited the migration of the HepG2 cell lines.Keywords: Artemsia Sieberia, Apoptosiss, Cytotoxicity, Hoescht staining, HepG2 cell line

Pyruvate Kinase Inhibits Proliferation during Postnatal Cerebellar Neurogenesis and Suppresses Medulloblastoma Formation

Aerobic glycolysis supports proliferation through unresolved mechanisms. We have previously shown that aerobic glycolysis is required for the regulated proliferation of cerebellar granule neuron progenitors (CGNP) and for the growth of CGNP-derived medulloblastoma. Blocking the initiation of glycolysis via deletion of hexokinase-2 (Hk2) disrupts CGNP proliferation and restricts medulloblastoma growth. Here, we assessed whether disrupting pyruvate kinase-M (Pkm), an enzyme that acts in the terminal steps of glycolysis, would alter CGNP metabolism, proliferation, and tumorigenesis. We observed a dichotomous pattern of PKM expression, in which postmitotic neurons throughout the brain expressed the constitutively active PKM1 isoform, while neural progenitors and medulloblastomas exclusively expressed the less active PKM2. Isoform-specific Pkm2 deletion in CGNPs blocked all Pkm expression. Pkm2-deleted CGNPs showed reduced lactate production and increased SHH-driven proliferation.13C-flux analysis showed that Pkm2 deletion reduced the flow of glucose carbons into lactate and glutamate without markedly increasing glucose-to-ribose flux. Pkm2 deletion accelerated tumor formation in medulloblastoma- prone ND2:SmoA1 mice, indicating the disrupting PKM releases CGNPs from a tumor-suppressive effect. These findings show that distal and proximal disruptions of glycolysis have opposite effects on proliferation, and that efforts to block the oncogenic effect of aerobic glycolysis must target reactions upstream of PKM

Monotonic and cyclic triaxial testing of untreated and polyurethane-treated soil and soil–rubber mixtures

The present research focuses on developing alternate sustainable base materials for a high-speed slab track. In this study, a series of monotonic triaxial, cyclic triaxial and permeability tests were conducted on four types of materials, viz. mix-A (gravel soil), mix-B (soil mixed with rubber), mix-C (polyurethane foam adhesive (PFA)-treated soil), and mix-D (PFA-treated soil–rubber mixture). The influence of cyclic loading frequency, effective confining pressure, drainage condition and relative density on the deformation, excess pore water pressure, resilient modulus and damping ratio of these different mixes is evaluated. The monotonic triaxial test results indicate that the PFA treatment of mix-A and mix-B increased their shear strength and critical state strength. In contrast, incorporating rubber into mix-A and mix-C helped enhance their ductility. The cyclic triaxial test results show that the PFA treatment of mix-A and mix-B significantly reduced the magnitude of deformation and generation of excess pore water pressure, which caused these untreated mixes to fail prematurely under lower confinement to which a typical base layer is subjected. The influence of cyclic loading frequency and effective confining pressure on the material's response differed for untreated and treated soil. The permeability test results indicate good drainage for mix-D comparable to mix-A

Sustainable Applications of Tyre-Derived Aggregates for Railway Transportation Infrastructure

Scrap tyres are used to produce tyre-derived aggregates (TDA), which can be used as fill material, backfill material, drainage layers, and vibration-damping material, among other uses. This study presents a comprehensive review of TDA applications in civil engineering with a specific focus on railway projects. A review of the existing literature reveals the lack of sufficient knowledge on the use of TDA in slab tracks. This article also analyses the adequacy of different constitutive models to properly simulate the performance of TDA while highlighting the importance of adopting the most suitable constitutive model. The variations in shear stresses and displacements with depth below ballasted and slab tracks in the presence and absence of TDA are discussed. It is shown that TDA effectively reduces the shear stresses for the subgrade layer of both track types. Moreover, the impact of TDA on stress transfer in the vertical and lateral track directions is assessed. The findings from the present analysis reveal that TDA helps in reducing the vertical and lateral stresses near its placement position in ballasted and slab tracks

A comprehensive study on the performance and emission analysis in diesel engine via optimization of novel ternary fuel blends: Diesel, manganese, and diethyl ether.

Ecosystem degradation and fossil fuel depletion are the two foremost concerns to look for alternative fuels. Rapid population growth is primarily accountable for higher consumption of fossil fuel sources, although engine technology is achieving milestones in terms of fuel efficiency and lower exhaust emissions in order to contribute towards a sustainable environment. The main root cause of global warming is carbon dioxide emissions; therefore, it is imperative to assess the impact of alternative fuels in diesel engines with an aim to minimize carbon emissions. A current study deals with the reduction of carbon emissions and improvement of efficiency through addition of manganese nano-additive to di-ethyl ether and diesel fuel blend in particulate form. Fuel blends were formed by adding various proportions of manganese to high-speed diesel fuel and stirring the mixture while heating it for 10 min. The blends were then tested in diesel engines at two distinct loads and five engine speed ranges. Emission analyzer was used to ascertain the CO2 output of engine. At higher loads for 10 % diethyl ether in diesel, the increase in brake thermal efficiency was 24.19, 28.17 and 26.86 % when the manganese amount in blend was changed as 250 mg, 375 mg and 500 mg respectively. On the other side CO2 emissions increase by 11.57, 30.52 and 20.33 % for manganese concentrations of 250 mg, 375 mg and 500 mg respectively. Analysis performed with Design Expert 13 showed that the desirability was 0.796 for a blend of 375 mg manganese at 1300 rpm and 4500 W load with 33.0611 % BTE, 334.011kg/kWh BSFC, 67.8821Nm torque, and 6.072 % CO2. Therefore, it can be deduced that manganese nanoparticle blends improved engine performance but CO2 emissions also increase which can be responsible for global warming and it should be reduced through catalytic converters

Response surface methodology application on lubricant oil degradation, performance, and emissions in SI engine: A novel optimization of alcoholic fuel blends.

For evaluating the significance of renewable alternative fuels for optimized engine performance and lower emissions, methanol has been extensively utilized as a blend with gasoline in spark-ignition engines. However, rare attempts have been rendered to examine the consequence of methanol-gasoline fuel blends (M6, M12, and M18) on lubricant oil operating for a longer period in engines. The highest and least decrease of 9.62% and 6.68% in kinematic viscosity (KV) was observed for M0 and M18, respectively. However, the flash point (FP) of degraded lubricant oil for M6, M12, and M18 was 3%, 5%, and 7% higher than that of M0, respectively. Total acid number (TAN) and ash content of degraded lubricant oil for M18 were the highest among M0, M6, and M12. An inclusive optimization of engine performance, emissions, and lubricant oil properties has been made for various methanol-gasoline fuel blends at distinct operating conditions by employing the response surface methodology (RSM) technique. RSM-based optimization portrayed the composite desirability value of 0.73 for 2137.13 watt brake power (BP), 6.08 N-m torque, 0.37 kg/kwh brake-specific fuel consumption, 22.10% brake thermal efficiency, 4.02% carbon monoxide emission, 7.15% carbon dioxide emission, 134.12 ppm hydrocarbon emission, 517.02 ppm nitrogen oxides emission, 12.44 cst KV, 203.77°C FP, 2.23 mg/g KOH TAN, and 2.65%wt ash content as responses for fuel blend M8 at 3400 rpm and higher loading condition. RSM predicted results demonstrated significant compliance with empirical findings, with absolute percentage error (APE) below 5% for each response. However, the highest APE of 4.68% was obtained for FP owing to inefficient desirability as a consequence of manual testing. The least APE of 1.57% was obtained for torque because of the highest desirability. Overall, the RSM predicted results of the designed models are effective and viable. RSM technique was found to be effective for the optimization of the broader engine characteristics spectrum