Search

A precise phase modulation and demodulation method was proposed to retrieve temperature distributions in axisymmetric flames by using a single-wavelength large lateral shearing interferometer. A spatial light modulator (SLM) was employed to vary the phases in each pixel continuously in the flame-phase measurement. The uniqueness of the phase extraction was mathematically proved for the first time, and a least square method was applied to recover the profile of flame phase in the interferometer. The ambiguity of the phases at different cycles of $2\pi $ was eliminated. The phase shift at each pixel was uniquely determined and verified by using simulated data. Further, precise-phase distributions were utilized to retrieve the temperature distribution in a laminar flame. In actual experiments, four axisymmetric laminar flames from diffused to premixed flames were generated by using a Bunsen burner. Profiles of temperature distribution in the flames were extracted and agreed well with the results scanned by using a thermocouple. With the increase of airflow rate, the position of high-temperature zone was observed moving down, and the thermal structure of the premixed flame became more and more obvious. The preheating zone, reaction front, and reaction zone inside the flames were clearly captured.

Plant survival in the terrestrial ecosystem is influenced by both beneficial and harmful microbes. Trichoderma spp. are a group of filamentous fungi that promote plant growth and resistance to harmful microbes. Previously, we showed that the genus Trichoderma could effectively suppress Fusarium wilt in cucumber. However, the mechanisms that underlie the effects of the genus Trichoderma on plant defense have not been fully substantiated. Two essential metabolic pathways, such as the ascorbate (AsA)-glutathione (GSH) cycle and the oxidative pentose phosphate pathway (OPPP), have been shown to participate in plant tolerance to biotic stressors; nevertheless, the involvement of these pathways in Trichoderma-induced enhanced defense remains elusive. Here, we show that Trichoderma harzianum could alleviate oxidative and nitrostative stress by minimizing reactive oxygen species (ROS; hydrogen peroxide and superoxide) and reactive nitrogen species (nitric oxide [NO]) accumulation, respectively, under Fusarium oxysporum infection in cucumber roots. The genus Trichoderma enhanced antioxidant potential to counterbalance the overproduced ROS and attenuated the transcript and activity of NO synthase and nitrate reductase. The genus Trichoderma also stimulated S-nitrosylated glutathione reductase activity and reduced S-nitrosothiol and S-nitrosylated glutathione content. Furthermore, the genus Trichoderma enhanced AsA and GSH concentrations and activated their biosynthetic enzymes, γ-GCS and l-galactono-1,4-lactone dehydrogenase. Interestingly, the genus Trichoderma alleviated Fusarium-inhibited activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, enzymes involved in the OPPP. Such positive regulation of the key enzymes indicates the adequate maintenance of the AsA-GSH pathway and the OPPP, which potentially contributed to improve redox balance, energy flow, and defense response. Our study advances the current knowledge of Trichoderma-induced enhanced defense against F. oxysporum in cucumber.

It is difficult to extract a narrow road with a width of only a few pixels from a remote sensing image. In order to solve this problem, it is proposed to process the remote sensing image with super-resolution. This paper extends the details of narrow roads by using the Deep Convolutional Neural Network (DCNN) method. Next, some noise points or roads of error extraction are processed by topological structure. To verify performance of the experimental method, experimental research on open remote sensing image data set is carried out. The experimental result is to compare the original image, super-resolution image, and topology filtering. Experimental results demonstrate that the new method has better effectiveness and superiority over the original remote sensing image.

For the problem of image matching in visual indoor positioning research, the image quality is degraded due to the interference and influence of noises during the generation or transmission of the image, which ultimately leads to the problem of image matching rate and low efficiency. Comparing existing traditional denoising algorithms and wavelet transform algorithms, we use MATLAB for simulation to compare the effects of adding different noises and denoising with different wavelet bases. The results show that the wavelet image denoising improves the shortcomings of the traditional denoising algorithm to a certain extent, but there is still room for improvement.

Introduction: The transmission pathways of coronavirus disease 2019 (COVID-19) remain not completely clear. In this case study the test for the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in pharyngeal swab and anal swab were compared. Case presentation: A 3-month-old girl was admitted to our hospital with COVID-19. Her parents had both been diagnosed with COVID-19. The results of pharyngeal swab and anal swab of the little girl were recorded and compared during the course of the disease. The oropharyngeal specimen showed negative result for SARS-CoV-2 on the 14th day after onset of the illness. However, the anal swab was still positive for SARS-CoV-2 on the 28th day after the onset of the illness. Conclusion: The possibility of fecal-oral transmission of COVID-19 should be assessed. Personal hygiene during home quarantine merits considerable attention. Key words: COVID-19; Anal swab; SARS-CoV-2; Fecal-oral transmission

Histone deacetylase 4 (HDAC4) is involved in the development of multiple types of cancers. In this study, we aimed to investigate the expression and clinical significance of HDAC4 in hepatocellular carcinoma (HCC).49 patients with stage B HCC who underwent surgical resection were enrolled in this study. All patients were followed up with an observation time of 4.8 to 7 years. Immunohistochemistry was applied to investigate the expression level of HDAC4.HDAC4 protein is over-expressed in HCC tissues compared with matched adjacent non-cancer tissues. Kaplan-Meier analysis shows that the positive expression of HDAC4 is associated with poor survival in these patients.Our study shows that HDAC4 over-expression is important for the development of advanced HCC, which may serve as a useful prognostic biomarker and therapeutic target for this malignancy.

The impact abrasive wear behaviors of light-weight austenitic Fe-24Mn-7Al-lC steel with increasing impact wear conditions were studied by comparing with the modified Hadfield (Mnl3Cr2) steel. Wear tests were performed with the MLD-10 abrasive wear testing machine. Main parameters such as impact energy, impacting frequency and wear time were evaluated. To explore the abrasive wear behaviors under different impact energies, the parameters including mass loss, wear resistance and hardness were evaluated in detail. The microstructures of the steels were further analyzed using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Results showed that the light-weight austenitic Fe-24Mn-7Al-lC steel had a better wear resistance than Mnl3Cr2 steel under the impact energy tested. The wear resistance of light-weight austenitic Fe-24Mn-7Al-lC steel was about 1. 09 – 1. 17 times as high as that of Mnl3Cr2 steel under low and medium impact energy (0. 5 – 2. 0 J) conditions, and 1. 41 times under high impact energy (4. 0 J) condition. In Mnl3Cr2 steel, the evolution of dislocation substructure with increasing impact energy showed typical stacking fault, interaction of twins and dislocations, as well as mechanical twins. The high work-hardening rate in Fe-24Mn-7Al-lC steel was caused by Taylor lattice and high density of dislocation tangles.

Fusarium wilt, one of the destructive diseases of cucumber can be effectively controlled by using biocontrol agents such as Trichoderma harzianum. However, the mechanisms controlling T. harzianum-induced enhanced resistance remain largely unknown in cucumber plants. Here we screened the potent T. harzianum isolate TH58 that could effectively control F. oxysporum (FO). Glasshouse efficacy trials also showed that TH58 decreased disease incidence by 69.7 %. FO induced ROS over accumulation, while TH58 inoculation suppressed ROS over accumulation and improved root cell viability under F. oxysporum infection. TH58 inoculation could reverse the FO-induced cell division block and regulate the proportional distribution of nuclear DNA content through inducing 2C fraction. Moreover, the expression levels of cell cycle-related genes such as CDKA, CDKB, CycA, CycB, CycD3;1 and CycD3;2 in TH58 - pre-inoculated seedlings were up-regulated compared with those infected with FO alone. Taken together, these results suggest that T. harzianum improved plant resistance against Fusarium wilt disease via alterations in nuclear DNA content and cell cycle-related genes expression that might maintain a lower ROS accumulation and higher root cell viability in cucumber seedlings.

Intestinal lipomas are rare nonepithelial tumors that are typically small in size and detected incidentally. Colonic intussusception is an uncommon complication of colonic lipoma. A 56 y old woman visited our emergency room with sudden onset of intermittent abdominal cramps. A CT scan showed a 5.0 cm, nodular, homogenous, hypodense structure in the hepatic flexure of the colon as the lead point of an intussusception. The hypodense structure was suggestive of a colonic lipoma, and the tumor was suspected to be the cause of the intestinal intussusception. Laparoscopic exploration was performed, and the pathology demonstrated a mature submucosal colonic lipoma. In addition to the case report, we discuss the role of imaging modalities in diagnosing neoplasms and for assessing the clinical behavior of lipomas when symptomatic.

The CCT (continuous cooling transformation) curve of the test steel was obtained on Gleeble-1500 thermal mechanical simulator based on the thermal dilation measurement. The test steels were the deformation with 40% under the temperature of 900°C and then were cooled to room temperature at different cooling rates. The phase transformation law and hardness change rule were emphatically investigated at the cooling rate from 0.05°C/s to 30°C/s by optical microscopy (OM), scanning electron microscope (SEM) and Vickers hardness tester. The regression model of phase transformation was calculated. The results show that the transformation of ferrite and pearlite are inhibited, which cause the dynamic CCT curve shift to the right. The microstructure of the test steel consists of ferrite and pearlite after phase transformation at the cooling rate of 0.05°C/s; the granular bainite appears at the cooling rate of 0.5°C/s due to the interaction of Mo and B; as the cooling rate increases to 2°C/s, the microstructure mainly consists of lath bainite; the martensite is observed at the cooling rate of 2°C/s and there would be total martensite if the cooling rate is higher than 5°C/s and the grain growth rate is faster at the same time. The hardness of test steels increases with the increase of cooling rate, and increases obviously when the cooling rate is lower than 5 °C/s. A theoretical basis is provided to obtain the best bainite/martensite composite microstructure. The martensitic transformation start temperature is 354.6°C and the critical cooling rate is 5°C/s. The test value and the regression model can fit well and reflect the test value trend, showing a high precision of regression.

The universal symbiotic associations between arbuscular mycorrhizal fungi (AMF) and plant roots remarkably stimulate plant growth, nutrient uptake, and stress responses. The present study investigated the stress ameliorative potential of the AM fungus Funneliformis mosseae against chilling in tomato seedlings. AMF-inoculated tomato seedlings exhibited significantly higher fresh weight and dry weight than non-AMF control plants under both control (25/15 °C) and low temperature (8 °C/4 °C) treatments. Under chilling stress, AMF inoculation significantly reduced the level of MDA, H2O2, and O 2 ·− along with increased calcium precipitates in the apoplast and vacuole of root cells compared with the non-AMF control. Furthermore, AMF inoculation induced activities of antioxidant enzymes and transcripts of related genes under chilling stress. Notably, AMF inoculation resulted in reduced redox state in root cells as evident by significantly increased content of reduced ascorbate, reduced glutathione, redox ratio, and the activity of l-galactono-1,4-lactone dehydrogenase in the tomato roots both under control and low temperature. Taken together, these results indicate that AMF could play an important role in optimizing chilling resistance by maintaining redox poise and calcium balance in tomato seedlings.

The flow stress, microstructure and softening mechanism of NM550 wear-resistant steel were investigated via hot compression test by using Gleeble-1500 thermal simulator in a temperature range from 800 to 1150 °C and strain rate range from 0.1 to 10s−1. With optical microscopy (OM), the effects of temperature, strain rate and true strain on the flow behavior and microstructure of the steel were discussed. The results show that the dynamic recrystallization occurs at higher temperature and lower strain rate. Hot deformation behavior of the steel specimens is sensitive to temperature and strain rate, while the strain rate affects the hot deformation behavior greatly. The apparent stress exponent and the apparent activation energy of the specimens are 7.395 and 389.611 kJ/mol, respectively. With the experimental data, the hot deformation constitutive equation and processing map of the NM550 wear-resistant steel are given. Finally, a combination of the constitutive equation and processing map provides a method for comprehensively investigating the hot deformation behavior of the steel under different conditions, and provides theoretical basis for the determination of rolling procedure in industrial production.

The E690 grade offshore platform steel was obtained by top and bottom blowing converter, curved spray continuous casting machine and thermo-mechanical control processing (TMCP). The static continuous cooling transformation curves (CCT curves) of the rolled plate were drawn by adopting thermal expansion method and metallographic analysis. The microstructures at different cooling rates were observed by optical microscope (OM) and scanning electron microscope (SEM). Results showed that the super-cooled austenite in tested steel was relatively stable and there was little high temperature microstructure transformation at the cooling rate of 0.1°C/s. The regression model of phase transformation temperature and cooling rates were obtained. According to the results of orthogonal experiment, the most optimal heat treatment process was firstly heated at 890 °C, wind cooling and then tempered at 630 °C for 60 min.

Mitochondrial uncoupling proteins (UCPs) play crucial role in the regulation of metabolic thermogenesis, photosynthesis, redox poise, and response to stress situations. However, the involvements UCPs and its regulatory mechanisms in plant mitochondrial respiration and electron transport have not yet been fully substantiated. In this article, we show that UCP is essential for effective respiratory balance and mitochondrial electron transport poise under chilling stress in tomato. Compared with pTRV (non-silenced) plants, suppression of LeUCP the expression by virus-induced gene silencing significantly decreased the total, SHAM-resistant, and CN-resistant respiratory rates, but increased cytosolic glycolysis pathway-related gene expression and enzymes’ activities under chilling stress. The transcripts’ abundances of UCRH, COX1, COX2, AOX1a, AOX2, and NDC1 genes involved in main and bypass miETC components were decreased, while those of NDUO and SDH4 were slightly increased in the leaves of LeUCP-silenced plants. In addition, silencing of LeUCP aggravated H2O2 and O2 − accumulation levels in leaves under chilling stress. Our results provide strong evidence that LeUCP is critical for respiratory homeostasis and mitochondrial electron transport signaling under chilling stress in tomato.