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Shock and Vibration
The failure probability and strength of jointed and fractured rock mass under water pressure action place important constraints on the safety and stability of rock mass engineering. In this study, two strength calculation models for rock mass joint rupture failure and shear slip failure are established according to different relative sizes and working conditions, and the effects of fractal dimension, water pressure, and number of cracks on the strength and failure probability of rock mass aredoi:10.1155/2022/6372147 fatcat:wy7stv64mbgf5fs5qrl6wcgexq
more »... alyzed. The most unfavorable dip angle under shear-slip conditions is calculated. The proposed models accurately reflect the failure probability and strength of jointed rock mass, and different strength calculation methods should be selected according to the specific working conditions. The effect of water pressure on the strength of jointed rock mass is sensitive to the failure mode. Reasonable drainage should be carried out according to the different failure modes when constructing tunnels with abundant groundwater, and certain drainage or water plugging construction schemes are not necessarily applicable to all cases. The dip angle at which joint fissures are most prone to shear slip is given as π/4 + φ/2, where φ is the jointed rock mass strength parameter. An increase in the fractal dimensions, external stress, and number of fractures will enhance the rock mass failure probability regardless of failure mode. Controlled blasting and advanced grouting reinforcement measures are recommended when a tunnel traverses through a joint fissure zone to reduce the number of cracks generated in the surrounding rock and thus improve its strength and stability.
PI3K/AKT signaling is known to regulate cancer metabolism but whether metabolic pathway feedbacks and regulates the PI3K/AKT pathway is unclear. Here, we demonstrate the important reciprocal cross-talks between the PI3K/AKT signal and PPP branching metabolic pathways. PI3K/AKT activation stabilizes G6PD, the rate-limiting enzyme of PPP, by inhibiting a newly identified E3 ligase TIRM21, and promotes PPP. PPP metabolites, in turn, reinforce AKT activation and further promote cancer metabolicdoi:10.1101/750976 fatcat:47i6qq63a5cwndzdxqdvotxdhm
more »... ogramming by blocking the expression of an AKT inhibitor PHLDA3. Knockout TRIM21 or PHLDA3 promotes the cross-talks and cell proliferation. Importantly, PTEN null human cancer cells and in vivo murine models are sensitive to anti-PPP treatments, suggesting the importance of PPP in maintaining AKT activation even in the presence of a constitutively activated PI3K pathway. Our study suggests that blockade of these reciprocal cross-talks may have a therapeutic benefit for cancers with PTEN loss or PI3K/AKT activation.
PI3K/AKT signaling is known to regulate cancer metabolism, but whether metabolic feedback regulates the PI3K/AKT pathway is unclear. Here, we demonstrate the important reciprocal crosstalk between the PI3K/AKT signal and pentose phosphate pathway (PPP) branching metabolic pathways. PI3K/AKT activation stabilizes G6PD, the rate-limiting enzyme of the PPP, by inhibiting the newly identified E3 ligase TIRM21 and promotes the PPP. PPP metabolites, in turn, reinforce AKT activation and furtherdoi:10.1038/s41467-020-15819-3 pmid:32312982 fatcat:gmoixygd3bhsbfoqxvh7yfjbhu
more »... e cancer metabolic reprogramming by blocking the expression of the AKT inhibitor PHLDA3. Knockout of TRIM21 or PHLDA3 promotes crosstalk and cell proliferation. Importantly, PTEN null human cancer cells and in vivo murine models are sensitive to anti-PPP treatments, suggesting the importance of the PPP in maintaining AKT activation even in the presence of a constitutively activated PI3K pathway. Our study suggests that blockade of this reciprocal crosstalk mechanism may have a therapeutic benefit for cancers with PTEN loss or PI3K/AKT activation.
Planning utility tunnel network in the area with geological disasters poses serious concerns, especial for the utility tunnel built in the ground fissures developed cities. Many prevention and control measures have been taken when the utility tunnel crossed the ground fissures, such as finding the right intersection angle when planning the utility tunnel. In order to study the effect of intersection angle for utility tunnel when crossing ground fissures, this paper compares outcomes when thedoi:10.1155/2020/8864676 fatcat:vicwlzjxqjajphnsk2c7mipdiy
more »... lity tunnel crosses ground fissures with different intersection angle through numerical simulation method. Because actually the intersection angle of utility tunnel and ground fissures is varied, in order to make stress-strain relationship of the model more realistic, a trilinear mode of reinforcing bar stress-strain relationship was established, and the material property of utility tunnel and soil were assigned to concrete damaged plasticity and Mohr-Coulomb plasticity, respectively. The simulation result shows that the axial tension stress and vertical shear stress of utility tunnel are increased with the increasing of intersection angle, but displacement and shear stress of utility tunnel in horizontal direction are increased with the decreasing of intersection angle. The variation of intersection angle of utility tunnel and ground fissures cannot significantly reduce the damage of utility tunnel. The vertical displacement of utility tunnel does not vary with intersection angle. Finally, this paper suggests that the strengthening length of utility tunnel should not be less than 50 meters (10 times the height of utility tunnel) on both sides of the ground fissures no matter the variation of intersection angle.
Rotating plane flow distributing pairs have been widely used in engineering. It is very important to reduce the frictional resistance between the pairs to improve the sensitivity and prolong service life. In this paper, the traditional rotating plane flow pair is improved, and the boss is introduced to keep the rotor and the stator in incomplete contact, and then a gap is formed between the flow pairs. The relationship between the pressure distribution and the friction resistance of the flowdoi:10.1155/2020/4514936 fatcat:noul463gnvbvnmsx5schgjl5ly
more »... rs is established. The theoretical mathematical model of the fluid movement between the gaps of the structure is built. Given the complexity of model analysis, the numerical analysis method is used to analyze the fluid motion in the structure. The height of the boss is proved to be the most important parameter of the structure, the increase of the boss's height causes the pressure between the flow pairs to increase, and the pressure difference between regions gradually decreases, so the friction between the flow pairs will gradually decrease until reaching a stable value. The change of the boss's diameter has little influence on the pressure distribution of the clearance, but as the diameter increases, the friction between the flow pairs will increase linearly. Once the opening width of the waist hole on the upper rotor is smaller than the radius of the discharge hole on the lower stator, the smaller the width, the higher the pressure, but when the opening width is larger than the radius of the discharge holes, the change of the width has no obvious influence on the pressure distribution and the friction.
Despite its potential importance in the global climate system, mixing properties of the North Pacific low-latitude western boundary current system (LLWBC) remained unsampled until very recently. We report here on the first measurements of turbulence microstructure associated with these currents, made in the western boundary region of the tropical North Pacific east of the Philippines. The results suggest that thermocline mixing in the North Pacific LLWBC is generally weak with the diapycnaldoi:10.1002/2017gl075210 fatcat:mr7am6u4hfdg5avb6dlrg266mu
more »... usivity ∼ O(10 −6 ) m 2 s −1 . This is consistent with predictions from internal wave-wave interaction theory that mixing due to internal wave breaking is significantly reduced at low latitudes. Enhanced mixing is found to be associated with a permanent cyclonic eddy, the Mindanao Eddy, but mainly at its south and north flanks. There, is elevated by an order of magnitude due to eddy-induced geostrophic shear. Mixing in the eddy core is at the background level with no indication of enhancement.
(Hongyin Zhang); project administration, H.Z. (Hongyin Zhang); funding acquisition, Q.Y. and H.Z. (Hongyin Zhang). ... (Hongyin Zhang); methodology, X.Q. and Q.Y.; formal analysis, X.Q. and F.H.; investigation, X.Y. and H.Z. ...doi:10.3390/microorganisms7120672 pmid:31835573 pmcid:PMC6956011 fatcat:s5efnfutbrdc7ikgojrdsqkhzq
The pandemic of coronavirus disease 2019 (COVID-19) has become the first concern in international affairs as the novel coronavirus (SARS-CoV-2) is spreading all over the world at a terrific speed. The accuracy of early diagnosis is critical in the control of the spread of the virus. Although the real-time RT-PCR detection of the virus nucleic acid is the current golden diagnostic standard, it has high false negative rate when only apply single test. Objective Summarize the baselinedoi:10.1101/2020.04.09.20059352 fatcat:sdurl5o7y5bjllrwhhdhbdfd2a
more »... cs and laboratory examination results of hospitalized COVID-19 patients. Analyze the factors that could interfere with the early diagnosis quantitatively to support the timely confirmation of the disease. Methods All suspected patients with COVID-19 were included in our study until Feb 9th, 2020. The last day of follow-up was Mar 20th, 2020. Throat swab real-time RT-PCR test was used to confirm SARS-CoV-2 infection. The difference between the epidemiological profile and first laboratory examination results of COVID-19 patients and non-COVID-19 patients were compared and analyzed by multiple logistic regression. Receiver operating characteristic (ROC) curve and area under curve (AUC) were used to assess the potential diagnostic value in factors, which had statistical differences in regression analysis. Results In total, 315 hospitalized patients were included. Among them, 108 were confirmed as COVID-19 patients and 207 were non-COVID-19 patients. Two groups of patients have significance in comparing age, contact history, leukocyte count, lymphocyte count, C-reactive protein, erythrocyte sedimentation rate (p<0.10). Multiple logistic regression analysis showed age, contact history and decreasing lymphocyte count could be used as individual factor that has diagnostic value (p<0.05). The AUC of first RT-PCR test was 0.84 (95% CI 0.73-0.89), AUC of cumulative two times of RT-PCR tests was 0.92 (95% CI 0.88-0.96) and 0.96 (95% CI 0.93-0.99) for cumulative three times of RT-PCR tests. Ninety-six patients showed typical pneumonia radiological features in first CT scan, AUC was 0.74 (95% CI 0.60-0.73). The AUC of patients age, contact history with confirmed people and the decreased lymphocytes were 0.66 (95% CI 0.60-0.73), 0.67 (95% CI 0.61-0.73), 0.62 (95% CI 0.56-0.69), respectively. Taking chest CT scan diagnosis together with patients age and decreasing lymphocytes, AUC would be 0.86 (95% CI 0.82-0.90). The age threshold to predict COVID-19 was 41.5 years, with a diagnostic sensitivity of 0.70 (95% CI 0.61-0.79) and a specificity of 0.59 (95% CI 0.52-0.66). Positive and negative likelihood ratios were 1.71 and 0.50, respectively. Threshold of lymphocyte count to diagnose COVID-19 was 1.53x109/L, with a diagnostic sensitivity of 0.82 (95% CI 0.73-0.88) and a specificity of 0.50 (95% CI 0.43-0.57). Positive and negative likelihood ratios were 1.64 and 0.37, respectively. Conclusion Single RT-PCR test has relatively high false negative rate. When first RT-PCR test show negative result in suspected patients, the chest CT scan, contact history, age and lymphocyte count should be used combinedly to assess the possibility of SARS-CoV-2 infection.
As a direct bandgap semiconductor, organic-inorganic lead halide perovskite (MAPbX 3 , MA = CH 3 NH 3 , X = Cl, Br, I) have been considered as promising materials for laser due to their excellent optoelectronic properties. The perovskite materials with 1D and 2D shapes were widely prepared and studied for Fabry-Pérot mode and whispering-gallery-mode (WGM) microcavities, but cuboid-shape is rarely reported. In this work, we successfully fabricated single crystal cuboid-shaped MAPbBr 3 perovskitedoi:10.1016/j.scib.2019.04.016 fatcat:jr6fnxou5jbfloxzfin3kmw7dm
more »... with different morphologies, named microcuboid-MAPbBr 3 (M-MAPbBr 3 ) and multi-step-MAPbBr 3 (MS-MAPbBr 3 ), via solvothermal method. Furthermore, the as-prepared crystals' excitonic recombination lifetime under different pumping energy density was studied by time-resolved photoluminescence (TRPL). Based on controllable morphology and remarkable lasing properties, these cuboid shaped single crystal perovskite could be a promising candidate for small laser, and other optoelectronic devices.
Objectives. Vitamin D deficiency plays a role in insulin resistance and the pathogenesis of type 2 diabetes mellitus. Little information is available about the association between vitamin D status and insulin resistance in the Chinese population. Currently, vitamin D status is evaluated by the concentrations of serum 25-hydroxyvitamin D [25(OH)D]. This study explores the relationship between insulin resistance and serum 25-hydroxyvitamin D concentrations in Chinese patients with type 2 diabetesdoi:10.1155/2016/1794894 pmid:27413370 pmcid:PMC4931076 fatcat:r7vggfk4kbcoblmzwzlr4hfkpa
more »... mellitus.Subjects and Methods. This study included 117 patients with type 2 diabetes. The following variables were measured: 25-hydroxyvitamin D [25(OH)D], glycosylated hemoglobin A1c (HbA1c), fasting blood glucose (FBS), fasting blood insulin (FINS), fasting blood C-peptide, serum creatinine (SCr), glomerular filtration rate (eGFR), body mass index (BMI), and homeostatic model estimates of insulin resistance (HOMA-IR).Results. The cases were divided into three groups: Group 1 (G1) with 25(OH)D ≤ 20 ng/mL [≤50 nmol/L], Group 2 (G2) with 25(OH)D values from 20 ng/mL [50 nmol/L] to 30 ng/mL [75 nmol/L], and Group 3 (G3) with 25(OH)D ≥ 30 ng/mL [≥75 nmol/L], with 52.6%, 26.3%, and 21.1% of subjects in Groups 1–3, respectively. There was a negative correlation between 25(OH)D and HOMA-IR (β= −0.314,p=0.001) adjusted by age, BMI, and eGFR.Conclusion. Better vitamin D status may be protective of glucose homeostasis since 25(OH)D was negatively associated with insulin resistance in Chinese patients with type 2 diabetes.
HaibinYu, Haojie Zhang and Yan Cheng conceived and designed the study. Fangtao Zhu, Yachao Lin and Weihua Huang ...doi:10.4314/tjpr.v19i3.9 fatcat:chwgfdhbazcqjdkxgfo5erqjau
Pandemic influenza, typically caused by reassortment of human and avian influenza viruses, can result in severe or fatal infections in humans. Timely identification of potential pandemic viruses must be a priority in influenza virus surveillance. However, the range of host species responsible for the generation of novel pandemic influenza viruses remain unclear. In this study, we conducted serological surveys for avian and human influenza virus infections in farmed mink and determined thedoi:10.1080/22221751.2021.1899058 pmid:33657971 pmcid:PMC7993395 fatcat:kzgebl6razavjjm55apfvvwc3m
more »... tibility of mink to prevailing avian and human virus subtypes. The results showed that farmed mink were commonly infected with human (H3N2 and H1N1/pdm) and avian (H7N9, H5N6, and H9N2) influenza A viruses. Correlational analysis indicated that transmission of human influenza viruses occurred from humans to mink, and that feed source was a probable route of avian influenza virus transmission to farmed mink. Animal experiments showed that mink were susceptible and permissive to circulating avian and human influenza viruses, and that human influenza viruses (H3N2 and H1N1/pdm), but not avian viruses, were capable of aerosol transmission among mink. These results indicate that farmed mink could be highly permissive "mixing vessels" for the reassortment of circulating human and avian influenza viruses. Therefore, to reduce the risk of emergence of novel pandemic viruses, feeding mink with raw poultry by-products should not be permitted, and epidemiological surveillance of influenza viruses in mink farms should be urgently implemented.
H5N6 highly pathogenic avian influenza virus (HPAIV) clade 188.8.131.52 not only exhibits unprecedented intercontinental spread in poultry, but can also cause serious infection in humans, posing a public health threat. Phylogenetic analyses show that 40% (8/20) of H5N6 viruses that infected humans carried H9N2 virus-derived internal genes. However, the precise contribution of H9N2 virus-derived internal genes to H5N6 virus infection in humans is unclear. Here, we report on the functionaldoi:10.1371/journal.ppat.1010098 pmid:34860863 pmcid:PMC8641880 fatcat:cc65zyitqjh3hmxzgqfm7r2rra
more »... of the H9N2 virus-derived matrix protein 1 (M1) to enhanced H5N6 virus replication capacity in mammalian cells. Unlike H5N1 virus-derived M1 protein, H9N2 virus-derived M1 protein showed high binding affinity for H5N6 hemagglutinin (HA) protein and increased viral progeny particle release in different mammalian cell lines. Human host factor, G protein subunit beta 1 (GNB1), exhibited strong binding to H9N2 virus-derived M1 protein to facilitate M1 transport to budding sites at the cell membrane. GNB1 knockdown inhibited the interaction between H9N2 virus-derived M1 and HA protein, and reduced influenza virus-like particles (VLPs) release. Our findings indicate that H9N2 virus-derived M1 protein promotes avian H5N6 influenza virus release from mammalian, in particular human cells, which could be a major viral factor for H5N6 virus cross-species infection.
Pigs are considered as important hosts or "mixing vessels" for the generation of pandemic influenza viruses. Systematic surveillance of influenza viruses in pigs is essential for early warning and preparedness for the next potential pandemic. Here, we report on an influenza virus surveillance of pigs from 2011 to 2018 in China, and identify a recently emerged genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus, which bears 2009 pandemic (pdm/09) and triple-reassortant (TR)-deriveddoi:10.1073/pnas.1921186117 pmid:32601207 fatcat:cfp4w74j55c3xdowe7xfu5qnr4
more »... ternal genes and has been predominant in swine populations since 2016. Similar to pdm/09 virus, G4 viruses bind to human-type receptors, produce much higher progeny virus in human airway epithelial cells, and show efficient infectivity and aerosol transmission in ferrets. Moreover, low antigenic cross-reactivity of human influenza vaccine strains with G4 reassortant EA H1N1 virus indicates that preexisting population immunity does not provide protection against G4 viruses. Further serological surveillance among occupational exposure population showed that 10.4% (35/338) of swine workers were positive for G4 EA H1N1 virus, especially for participants 18 y to 35 y old, who had 20.5% (9/44) seropositive rates, indicating that the predominant G4 EA H1N1 virus has acquired increased human infectivity. Such infectivity greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses.
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