Virus-induced gene silencing (VIGS) is a post-transcriptional gene silencing method used for unraveling gene functions. As an attractive alternative to mutant collections or stable transgenic plants, ...it has been widely used in reverse-genetics studies owing to its ease use and quick turnaround time. Turnip yellow mosaic virus (TYMV) has the ability to induce VIGS in
Arabidopsis thaliana
. However, the conventional vector construction is difficult and the efficiencies of the infection methods are low. Here, we improved the vector construction and viral infection methods, inserted an inverted-repeat fragment of the phytoene desaturase gene into a TYMV-derived vector by homologous recombination and transformed
Brassica rapa
with plasmid DNA harboring a cDNA copy of the TYMV genome through particle bombardment. An apparent photobleaching phenotype was detected and efficient VIGS was induced. An 80-bp fragment was sufficient to produce VIGS in leaves, stems, roots, flowers, siliques, and stalks of
B. rapa
. Because TYMV has a wide host range in
Brassica
, the VIGS system described here will contribute to the improvement of high-throughput technology and efficient functional research in
B. rapa
and other
Brassicaceae
crops.
We statistically investigate the spectral scalings of magnetic fluctuations at the upstream and downstream regions near the Venusian bow shock and perform a differentiation by shock geometry. Based ...on the Venus Express data, 115 quasi-parallel (
Q
‖
) bow shock crossings and 303 quasi-perpendicular (
Q
⊥
) bow shock crossings are selected. The statistical results suggest that the bow shock tends to modify the upstream spectra flatter to 1/
f
noise in the magnetohydrodynamics (MHD) regime and steeper to turbulence in the kinetic regime after the magnetic fluctuations crossing the bow shock, and this modification for the
Q
‖
and
Q
⊥
bow shocks is basically consistent. However, the upstream spectral scalings are associated with the shock geometry. The changes of the spectral scalings of magnetic fluctuations near the
Q
‖
bow shocks are not as significant as near the
Q
⊥
bow shock crossings. That might result from the fluctuations generated by the backstreaming ions which can escape across the
Q
‖
bow shock into the foreshock. Our results suggest that the energy cascade and dissipation near Venus can be modified by the Venusian bow shock, and the
Q
‖
bow shock plays an important role on the energy injection and dissipation in the solar wind interaction with Venus. The large dispersion of spectral scalings indicates that this fluctuation environment is complicated, and the shock geometry is not the only key factor in the fluctuations across the Venusian bow shock. Other possible factors in the shock modification to the upstream fluctuations will be explored in future.
Mechanical damage to middle ear components in blast exposure directly causes hearing loss, and the rupture of the tympanic membrane (TM) is the most frequent injury of the ear. However, it is unclear ...how the severity of injury graded by different patterns of TM rupture is related to the overpressure waveforms induced by blast waves. In the present study, the relationship between the TM rupture threshold and the impulse or overpressure waveform has been investigated in chinchillas. Two groups of animals were exposed to blast overpressure simulated in our lab under two conditions: open field and shielded with a stainless steel cup covering the animal head. Auditory brainstem response (ABR) and wideband tympanometry were measured before and after exposure to check the hearing threshold and middle ear function. Results show that waveforms recorded in the shielded case were different from those in the open field and the TM rupture threshold in the shielded case was lower than that in the open field (3.4 ± 0.7 vs. 9.1 ± 1.7 psi or 181 ± 1.6 vs. 190 ± 1.9 dB SPL). The impulse pressure energy spectra analysis of waveforms demonstrates that the shielded waveforms include greater energy at high frequencies than that of the open field waves. Finally, a 3D finite element (FE) model of the chinchilla ear was used to compute the distributions of stress in the TM and the TM displacement with impulse pressure waves. The FE model-derived change of stress in response to pressure loading in the shielded case was substantially faster than that in the open case. This finding provides the biomechanical mechanisms for blast induced TM damage in relation to overpressure waveforms. The TM rupture threshold difference between the open and shielded cases suggests that an acoustic role of helmets may exist, intensifying ear injury during blast exposure.
•TM damage in blast exposure was tested in open and shielded cases in chinchillas.•Rupture threshold of the TM in shielded case was lower than that in open field.•Waveforms recorded in shielded case delivered more energy at high frequencies.•The FE model of chinchilla ear predicted the waveform-TM stress relationship.•Change of stress w.r.t. pressure wave characterized TM damage induced by blast.
AlCoCrFeNi is one of the most widely studied alloy systems in the high-entropy alloy (HEA) area due to the interesting microstructure and mechanical properties. In this study, the AlCoCrFeNi alloy ...was prepared using spark plasma sintering (SPS) with pre-alloy powders obtained through gas atomization. Then, the sintered samples were annealed at 700, 800 and 900 °C, and the effect of annealing temperature on the microstructure, mechanical and corrosion properties was studied. The results show that phase formation takes place during annealing process with the new phase (
σ
) and some nanoscale BCC precipitates formation. The size and quantity of the nanoscale precipitates increase with increasing annealing temperature. The twin is also observed after annealing at 900 °C. The annealing temperature has an obvious effect on the mechanical properties and corrosion resistance of the spark plasma sintered AlCoCrFeNi HEA. When the annealing temperature is 700 °C, the hardness, yield strength and fracture strength reach the maximum with the value of 545 HV, 1430 MPa and 2230 MPa, respectively. The compressive ratio reaches the maximum of 17.2%, with the annealing temperature increasing to 800 °C. The corrosion resistance of the samples decreases with increasing the annealing temperature.
The polarization force between an electrically charged atomic force microscope tip and a substrate has been used to follow the processes of condensation and evaporation of a monolayer of water on ...mica at room temperature. Condensation proceeds in two distinct structural phases. Up to about 25 percent humidity, the water film grows by forming two-dimensional clusters of less than a few 1000 angstroms in diameter. Above about 25 percent humidity, a second phase grows, forming large two-dimensional islands with geometrical shapes in epitaxial relation with the underlaying mica lattice. The growth of this second water phase is completed when the humidity reaches about 45 percent. The reverse process of evaporation has also been imaged.
Purpose: To evaluate the prognostic value of interleukin (IL)-6, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), leukemia inhibitory factor (LIF), and macrophage migration inhibitory ...factor (MIF) in non-metastatic nasopharyngeal carcinoma (NPC) patients undergoing radical radiotherapy. Patients and Methods: A serum panel compromising the inflammatory factors was analyzed in 372 NPC patients before and after radiotherapy. Independent prognostic factors were screened out using multivariate Cox regression analysis. A prediction model was built based on the training set data and validated using the test set data. The prognostic value of these factors was evaluated using the time-dependent receiver operating characteristic (ROC) curve and an integrated time-averaged area under the curve (AUC). Results: The baseline levels of IL-6, GM-CSF, and MIF were independent factors associated with poor OS and DMFS. A predictive model base established combining the baseline levels of these factors. The AUC values for the test set were 0.9828, 0.9968, and 0.9571 at 1, 3, and 5 years, respectively, compared to 0.9978, 0.9981, and 0.9222 for the training set, respectively. The AUC values for DMFS at 1, 3, and 5-years for the training set were 0.8744, 0.8951, and 0.9358, respectively, compared to 0.9525, 0.9663, and 0.9625 for the test set, respectively. The combination of post-treatment levels of IL-6, GM-CSF, and LIF also had good predictive value for OS with an AUC value > 0.85 during follow-up. Conclusion: IL-6, GM-CSF, and MIF baseline levels are powerful prognostic factors for non-metastatic NPC patients. The combination of these factors effectively predicts OS and DMFS in non-metastatic NPC patients. Keywords: nasopharyngeal carcinoma, inflammatory factor, radical radiotherapy, prognostic value, overall survival
Background
In many constitutive models for dynamic strain aging of aluminum alloys, the athermal component of flow stress was commonly assumed to be independent of temperature and strain rate. ...However, the assumption has not been examined experimentally due to lacking of a reliable and quantitative method to obtain statistical information of dislocation structure in the deformed aluminum alloys.
Objective
Develop a novel X-ray diffraction procedure to characterize the evolution of dislocation structure in aluminum alloys over a wide range of temperatures and strain rates, and further clarify the contributions arising from the structural and thermal components of flow stress.
Methods
The quasi-static and dynamic compression of artificial aged 2A12 aluminum alloy was carried out at the strain rates of 5×10
-3
and 1×10
3
s
-1
and within a temperature range of 173-673 K. The dislocation structure in the deformed aluminum alloy was determined by the newly developed X-ray line profile analysis procedure (CMWP). In combination with mechanical and X-ray diffraction tests, the correlation between the flow stress and microstructure for the aluminum alloy was established.
Results
X-ray diffraction measurements showed the dislocation density in the deformed 2A12 aluminum alloy is temperature and strain rate dependence. Besides the structural or athermal component of flow stress calculated from the measured microstructure parameters, a bell-shaped flow stress was revealed clearly in the total flow stress, which can be attributed primarily to the dynamic strain aging mechanism.
Conclusions
In this work, a fairly concise routine was proposed to characterize the microstructure and estimate the deformation mechanism for the 2A12 aluminum alloy, and the methodology could be easily extended to other alloys.
Tunable fluorescence emission from blue to red (see Figure) is exhibited by nanoparticles of 1,3,5‐triphenyl‐2‐pyrazoline (TPP) doped with ...4‐(dicyanomethylene)‐2‐methyl‐6‐(p‐dimethyl‐aminostyryl)‐4H‐pyran (DCM); the emission is found to be dependent on the amount of DCM dopant used. Efficient energy transfer is also shown to occur between TPP and DCM molecules.
The problem of multivariate alarm analysis and rationalization is complex and important in the area of smart alarm management due to the interrelationships between variables. The technique of ...capturing and visualizing the correlation information, especially from historical alarm data directly, is beneficial for further analysis. In this paper, the Gaussian kernel method is applied to generate pseudo continuous time series from the original binary alarm data. This can reduce the influence of missed, false, and chattering alarms. By taking into account time lags between alarm variables, a correlation color map of the transformed or pseudo data is used to show clusters of correlated variables with the alarm tags reordered to better group the correlated alarms. Thereafter correlation and redundancy information can be easily found and used to improve the alarm settings; and statistical methods such as singular value decomposition techniques can be applied within each cluster to help design multivariate alarm strategies. Industrial case studies are given to illustrate the practicality and efficacy of the proposed method. This improved method is shown to be better than the alarm similarity color map when applied in the analysis of industrial alarm data.
► A Gaussian kernel method is applied to convert binary alarm data into pseudo continuous time series. ► We use a correlation color map to visualize the time-lagged correlation between different alarms. ► Alarm tags are reordered to better group the correlated alarms to find redundancy in alarm settings. ► Multivariate analysis based on the pseudo data can reduce the influence of missed and false alarms.
Optimization of the surface structure and properties is of great concern since the failures of engineering materials such as wear, erosion and fatigue usually occur on the surface of materials. ...Plastic deformation from the sliding friction process has been utilized to realize surface nanocrystallization in commercial pure copper and tantalum plates in this work. The optical microscopy, transmission electron microscopy, X-ray photoelectron spectra, and uniaxial tensile testing results suggested that clean nanocrystalline surface layers of pure copper and tantalum were obtained, significantly strengthening the materials after the treatment.
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