An automated fast neutron computed tomography instrument with on-line focusing for non-destructive evaluation.

A fast neutron tomography imaging instrument has been designed, built, and tested at The Ohio State University 500 kW Research Reactor on a fast neutron beamline with a peak neutron flux ≈5.4 × 107 n·cm-2·s-1 at 1.6 MeV median neutron energy. The instrument and beamline are also configurable for thermal neutron imaging. The imaging apparatus is composed of a lens coupled, water-cooled Electron Multiplying Charge Coupled Device camera, a front-surface mirror, and a high light yield plastic Polyvinyl toluene scintillator. The instrument sits on a mobile cart. A total of 5 motion-control stages are built into the system for XYZ and rotational degrees of freedom for sample positioning; the fifth stage fine tunes the focal distance between the camera and the scintillator to achieve on-line focusing. A Python code with a user-friendly graphical user interface controls the fully automated image acquisition, not requiring user interaction, yet facilitating tracking of the image acquisition. A complete fast neutron computed tomography dataset with 360 projections requires less than 3 h, with 30 s per projection. On-line focusing is accomplished with a commercial, off-the-shelf, dielectrically actuated liquid lens. Finally, tomographic reconstructions are visualized using the Livermore Tomography Tools software package. The effective pixel size (width and height) is ≈0.1058 mm, yielding a minimum voxel size of 0.1058 × 0.1058 × 0.1058 mm3, and produces a spatial resolution of 231 µm when calculated from knife-edge measurements.

Influence of chitosan nanoparticle-mediated C-erbB-2 gene silencing on invasion and apoptosis of Hep-2 cells.

We aimed to measure the invasion ability of Hep-2 laryngeal cancer cells after treatment with C-erbB-2-small interfering RNA (siRNA)-chitosan nanoparticles, and assess the applied value of chitosan nanoparticle-mediated C-erbB-2 interference in inhibiting laryngeal cancer invasion and metastasis. Nanoparticles of approximately 100 nm, comprising C-erbB-2 siRNA packaged with chitosan, were prepared and used to treat Hep-2 cells. Silencing of C-erbB-2 was detected by western blot and polymerase chain reaction. Cell invasion and apoptosis were estimated by transwell assay and flow cytometry, respectively. C-erbB-2-siRNA-chitosan nanoparticles significantly down-regulated C-erbB-2 expression in Hep-2 cells (P < 0.05), and cell invasion was noticeably decreased. Moreover, they significantly induced apoptosis of the Hep-2 cells (P < 0.05). Chitosan nanoparticle-mediated C-erbB-2 gene interference can inhibit the invasion of laryngeal cancer cells and induce their apoptosis.

[Research of gestrinone-related abnormal uterine bleeding and the intervention in the treatment: a multi-center, randomized, controlled clinical trial].

OBJECTIVE: To investigate the incidence, influencing factors and intervention of gestrinone-related abnormal uterine bleeding at different dosage of gestrinone in the clinical treatment. METHODS: This was a multicenter, randomized, control study of 195 Chinese women with endometriosis or adenomyosis from June 2011 to November 2013. The subjects were randomized into three groups with oral administration of gestrinone, 2.5 mg dose at one time; twice a week group: 67 cases with oral administration twice a week last three months; double dose first month group: 67 cases with oral administration triple times a week at first month, then twice a week for two months; three times a week group: 61 cases with oral administration three times a week last three months. The improvement of the abnormal uterine bleeding, the changes in estrogen, liver function and blood coagulation were evaluated. At the same time, B-ultrasound examination evaluation were performed. RESULTS: (1) Three months later, the incidence of abnormal uterine bleeding in twice a week group was 30% (20/67), in double dose first month group and three times a week group were 7%(5/67) and 16% (10/61) respectively, there were significant difference between three groups (P<0.05). The incidence in double dose first month group was the most lower. (2) Univariate analysis showed that the dosage and ovarian size were the significant factors for abnormal uterine bleeding (OR=0.461,P= 0.003;OR=0.303,P=0.016); logistic regression analysis demonstrated that the risk of abnormal uterine bleeding in double dose first month group was the lowest when compared with twice a week group and three times a week group, the risk in twice a week group was 5-fold higher than that in double dose first month group (OR=0.211,P=0.011). The incidence of abnormal uterine bleeding in participants with abnormal ovarian volume results from ovarian cyst or ovarian surgery was significantly lower than those with normal ovarian volume (OR=0.304,P=0.018). (3) After the treatment of three months, there were no significant difference in alanine transaminase level between the groups (P>0.05). The body mass index significantly increased in three group (P<0.05), but there were no significant differences between the groups (P>0.05). As for blood coagulation, there were also no significant differences between the groups (P>0.05). CONCLUSIONS: Double dose of gestrinone in the first month could significantly decrease the incidence of gestrinone-related abnormal uterine bleeding. It is a more optimied dosage of gestrinone and without severe side effects. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry, registration number: ChiCTR-TRC-12002327.

The ZmCLA4 gene in the qLA4-1 QTL controls leaf angle in maize (Zea mays L.).

Maize architecture is a major contributing factor to their high level of productivity. Maize varieties with an erect-leaf-angle (LA) phenotype, which increases light harvesting for photosynthesis and grain-filling, have elevated grain yields. Although a large body of information is available on the map positions of quantitative trait loci (QTL) for LA, little is known about the molecular mechanism of these QTL. In this study, the ZmCLA4 gene, which is responsible for the qLA4-1 QTL associated with LA, was identified and isolated by fine mapping and positional cloning. The ZmCLA4 gene is an orthologue of LAZY1 in rice and Arabidopsis. Sequence analysis revealed two SNPs and two indel sites in ZmCLA4 between the D132 and D132-NIL inbred maize lines. Association analysis showed that C/T/mutation667 and CA/indel965 were strongly associated with LA. Subcellular localization verified the functions of a predicted transmembrane domain and a nuclear localization signal in ZmCLA4. Transgenic maize plants with a down-regulated ZmCLA4 RNAi construct and transgenic rice plants over-expressing ZmCLA4 confirmed that the ZmCLA4 gene located in the qLA4 QTL regulated LA. The allelic variants of ZmCLA4 in the D132 and D132-NIL lines exhibited significant differences in leaf angle. ZmCLA4 transcript accumulation was higher in D132-NIL than in D132 during all the developmental stages and was negatively correlated with LA. The gravitropic response was increased and cell shape and number at the leaf and stem junctions were altered in D132-NIL relative to D132. These findings suggest that ZmCLA4 plays a negative role in the control of maize LA through the alteration of mRNA accumulation, leading to altered shoot gravitropism and cell development. The cloning of the gene responsible for the qLA4-1 QTL provides information on the molecular mechanisms of LA in maize and an opportunity for the improvement of plant architecture with regard to LA through maize breeding.

A multi-detector, digitizer based neutron depth profiling device for characterizing thin film materials.

Neutron depth profiling (NDP) is a mature, nondestructive technique used to characterize the concentration of certain light isotopes in a material as a function of depth by measuring the residual energy of charged particles in neutron induced reactions. Historically, NDP has been performed using a single detector, resulting in low intrinsic detection efficiency, and limiting the technique largely to high flux research reactors. In this work, we describe a new NDP instrument design with higher detection efficiency by way of spectrum summing across multiple detectors. Such a design is capable of acquiring a statistically significant charged particle spectrum at facilities limited in neutron flux and operation time.

[A preliminary investigation of human chromosomal fragile site 3p14 using scanning electron microscopy (SEM)].

A preliminary scanning electron microscopical observation on the most common human chromosomal fragile site 3p14 of the peripheral lymphocytes was reported. It was shown that chromatid break or gap at 3p14 observed under SEM may be a sign of under-packing of DNA filaments and the possibility of various packing-patterns might be in existence. The result of the present work might be of significance in the understanding of natures of breaking or gap of chromatid and may be of help to the study of the mechanisms of chromosomal fragile site formation.