BackgroundAutomatic quantification of neuronal morphology from images of fluorescence microscopy plays an increasingly important role in high-content screenings. However, there exist very few freeware tools and methods which provide automatic neuronal morphology quantification for pharmacological discovery.ResultsThis study proposes an effective quantification method, called NeurphologyJ, capable of automatically quantifying neuronal morphologies such as soma number and size, neurite length, and neurite branching complexity (which is highly related to the numbers of attachment points and ending points). NeurphologyJ is implemented as a plugin to ImageJ, an open-source Java-based image processing and analysis platform. The high performance of NeurphologyJ arises mainly from an elegant image enhancement method. Consequently, some morphology operations of image processing can be efficiently applied. We evaluated NeurphologyJ by comparing it with both the computer-aided manual tracing method NeuronJ and an existing ImageJ-based plugin method NeuriteTracer. Our results reveal that NeurphologyJ is comparable to NeuronJ, that the coefficient correlation between the estimated neurite lengths is as high as 0.992. NeurphologyJ can accurately measure neurite length, soma number, neurite attachment points, and neurite ending points from a single image. Furthermore, the quantification result of nocodazole perturbation is consistent with its known inhibitory effect on neurite outgrowth. We were also able to calculate the IC50 of nocodazole using NeurphologyJ. This reveals that NeurphologyJ is effective enough to be utilized in applications of pharmacological discoveries.ConclusionsThis study proposes an automatic and fast neuronal quantification method NeurphologyJ. The ImageJ plugin with supports of batch processing is easily customized for dealing with high-content screening applications. The source codes of NeurphologyJ (interactive and high-throughput versions) and the images used for testing are freely available (see Availability).

The microtubule (MT) cytoskeleton is essential for the formation of morphologically appropriate neurons. The existence of the acentrosomal MT organizing center in neurons has been proposed but its identity remained elusive. Here we provide evidence showing that TPX2 is an important component of this acentrosomal MT organizing center. First, neurite elongation is compromised in TPX2-depleted neurons. In addition, TPX2 localizes to the centrosome and along the neurite shaft bound to MTs. Depleting TPX2 decreases MT formation frequency specifically at the tip and the base of the neurite, and these correlate precisely with the regions where active GTP-bound Ran proteins are enriched. Furthermore, overexpressing the downstream effector of Ran, importin, compromises MT formation and neuronal morphogenesis. Finally, applying a Ran-importin signaling interfering compound phenocopies the effect of TPX2 depletion on MT dynamics. Together, these data suggest a model in which Ran-dependent TPX2 activation promotes acentrosomal MT nucleation in neurons.

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The microstructures and mechanical properties of the Fe-10 mass%Al-(5-40)mass%Mn-1.0 mass%C alloys sheet castings have been investigated by using optical microscope (OM), transmission electron microscope (TEM), scanning electron microscope (SEM), experimental model analysis, tensile test and hardness test. Based on the present studies, the macroscopic microstructure of the present alloys are a mixture of austenite (γ ) and ferrite (α) duplex phases, and the α phase would decrease with the Mn content increased. In the meantime, according to the examination of TEM, the macroscopic γ phase is a mixture of the γ + fine(Fe, Mn) 3 AlC x (κ) + (Fe, Mn) 3 AlC x (κ ) phases and the macroscopic α phase is a mixture of the D0 3 + coarse(Fe, Mn) 3 AlC x (κ ) phases. The mechanical properties such as the ultimate tensile strength (UTS), yield strength (Y.S.), elongation of these alloys were in the range of 646-887 MPa, 575-824 MPa, and 16.3-29.2%, respectively. The hardness of these alloys were in the range of HR C 31-44. Moreover, the relationship between hardness and ultimate strength is UTS 20.93HR C . In addition, the damping ratios and Young's modulus of the present alloys were in the range of 0.0603-0.0417, and 139-165 GPa, respectively. It is noted here that the results have never observed by other research workers in the Fe-Al-Mn-C alloy system.

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