84 research outputs found

    Formation stage and controlling factors of the paleo-uplifts in the Tarim Basin: A further discussion

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    AbstractVarious types of paleo-uplifts with different characteristics are developed in the Tarim Basin. Previously, there were multiple opinions on the pale-uplifts origins and structural evolution, so the oil and gas exploration ideas and deployment in the Tarim Basin were not developed smoothly. In this paper, regional seismic interpretation and structural analysis were carried out on the deep marine carbonate rocks in this basin based on the new seismic and drilling data. Then combined with the structural denudation results, the paleo-structural frameworks were reconstructed. And finally, the formation stage and main controlling factors of paleo-uplifts were discussed. It is shown that the Middle Ordovician is the key period when regional extension was converted to compression in this basin, so stratigraphic, sedimentary and structural differences occurred. Before the deposition of Yijianfang Fm in late Middle Ordovician, three carbonate paleo-uplifts (i.e., the Northern, Central and SW Tarim paleo-uplifts) begun to appear, and they were all broad-folded paleo-uplifts of nearly E–W striking and were formed at the same stage. The distribution and development of the Phanerozoic uplifts in this basin are restricted by the Northern and Southern Tarim basement pale-uplifts of nearly E–W striking which were developed during the Precambrian. It is indicated that all the three paleo-uplifts are compressional paleo-uplifts originated from the convergence of the southern plate margin based on the basement paleo-uplifts and they are all characterized by similar structural characteristics and inherited formation and evolution. The current differences of paleo-uplifts are controlled by multi-stage intense structural reformation since the Silurian. It is concluded that the oil and gas exploration potential is immense in the carbonate reservoirs of well-preserved deep paleo-structural zones in a larger area

    Finding of widespread viral and bacterial revolution dsDNA translocation motors distinct from rotation motors by channel chirality and size

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    BACKGROUND: Double-stranded DNA translocation is ubiquitous in living systems. Cell mitosis, bacterial binary fission, DNA replication or repair, homologous recombination, Holliday junction resolution, viral genome packaging and cell entry all involve biomotor-driven dsDNA translocation. Previously, biomotors have been primarily classified into linear and rotational motors. We recently discovered a third class of dsDNA translocation motors in Phi29 utilizing revolution mechanism without rotation. Analogically, the Earth rotates around its own axis every 24 hours, but revolves around the Sun every 365 days. RESULTS: Single-channel DNA translocation conductance assay combined with structure inspections of motor channels on bacteriophages P22, SPP1, HK97, T7, T4, Phi29, and other dsDNA translocation motors such as bacterial FtsK and eukaryotic mimiviruses or vaccinia viruses showed that revolution motor is widespread. The force generation mechanism for revolution motors is elucidated. Revolution motors can be differentiated from rotation motors by their channel size and chirality. Crystal structure inspection revealed that revolution motors commonly exhibit channel diameters larger than 3 nm, while rotation motors that rotate around one of the two separated DNA strands feature a diameter smaller than 2 nm. Phi29 revolution motor translocated double- and tetra-stranded DNA that occupied 32% and 64% of the narrowest channel cross-section, respectively, evidencing that revolution motors exhibit channel diameters significantly wider than the dsDNA. Left-handed oriented channels found in revolution motors drive the right-handed dsDNA via anti-chiral interaction, while right-handed channels observed in rotation motors drive the right-handed dsDNA via parallel threads. Tethering both the motor and the dsDNA distal-end of the revolution motor does not block DNA packaging, indicating that no rotation is required for motors of dsDNA phages, while a small-angle left-handed twist of dsDNA that is aligned with the channel could occur due to the conformational change of the phage motor channels from a left-handed configuration for DNA entry to a right-handed configuration for DNA ejection for host cell infection. CONCLUSIONS: The revolution motor is widespread among biological systems, and can be distinguished from rotation motors by channel size and chirality. The revolution mechanism renders dsDNA void of coiling and torque during translocation of the lengthy helical chromosome, thus resulting in more efficient motor energy conversion

    Long-Noncoding RNA Colorectal Neoplasia Differentially Expressed Gene as a Potential Target to Upregulate the Expression of IRX5 by miR-136-5P to Promote Oncogenic Properties in Hepatocellular Carcinoma

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    Background/Aims: The long-noncoding RNA colorectal neoplasia differentially expressed (CRNDE) gene was first found to be activated in colorectal neoplasia. Now, it also has been found to be upregulated in many other solid tumors. Whether CRNDE affects tumorigenesis remains unknown. Methods: We conducted bioinformatics, real-time polymerase chain reaction (PCR), Western blot analysis, cell proliferation assay, colony formation assay, wound healing assay, cell migration and invasion assays, RNA immunoprecipitation, and reporter vector construction and luciferase assays. Results: CRNDE was upregulated in hepatocellular carcinoma (HCC). The overexpression of CRNDE promoted HCC cellular proliferation, migration, and invasion in intro and in vivo, and acted as an oncogene in HCC progression. Furthermore, CRNDE impaired miR-136-5P expression in a RISC manner, and a reciprocal repression feedback loop was possible between CRNDE and miR-136-5P. We found that the neighboring mRNA of CRNDE was IRX5, and IRX5 increased the tumorigenicity of HCC cells. IRX5 was a potential downstream target gene of miR-136-5P. MiR-136 regulated IRX5 by interacting with its 3’UTR. In addition, miR-136-5P was involved in the CRNDE-regulated expression of IRX5. Conclusion: CRNDE acted as a tumor oncogene by exhibiting oncogenic properties of human HCC and revealed a novel CRNDE-miR-136-5P-IRX5 regulatory network in HCC. CRNDE may be considered to be a potential target for HCC therapies based on its ability to upregulate IRX5, and it deserves further investigation

    An Open Invitation to Join the International Brugada Electrocardiographic Indices Registry

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    Background: The Brugada Electrocardiographic Indices Registry is a comprehensive data registry composed of patients with Brugada patterns on the electrocardiogram (ECG). The aim is to test the hypotheses that (i) ECG indices combining both depolarization and repolarization abnormalities can better predict spontaneous ventricular arrhythmias than existing ECG markers in Brugada syndrome and (ii) that serial ECG measurements will provide additional information for risk stratification, especially in asymptomatic patients. Methods: Patients with both Brugada pattern ECGs and Brugada syndrome are eligible for inclusion in this registry. Baseline characteristics and ECG variables reflecting depolarization and repolarization will be determined. The primary outcome is spontaneous ventricular tachycardia/ventricular fibrillation or sudden cardiac death. Secondary outcomes are inducible ventricular tachycardia/ventricular fibrillation and syncope. Results: As of November 15, 2019, 39 investigators from 32 cities in 18 countries had joined this registry. As of December 15, 2019, 1383 cases had been enrolled. Conclusions: The Brugada Electrocardiographic Indices Registry will evaluate the disease life course, risk factors, and prognosis in a large series of Brugada patients. It will therefore provide insights for improving risk stratification

    Visualization of Src activity at different compartments of the plasma membrane by FRET imaging

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    SummaryMembrane compartments function as segregated signaling platforms for different cellular functions. It is not clear how Src is regulated at different membrane compartments. To visualize local Src activity in live cells, a FRET-based Src biosensor was targeted in or outside of lipid rafts at the plasma membrane, via acylation or prenylation modifications on targeting tags either directly fused to the biosensor or coupled to the biosensor through an inducible heterodimerization system. In response to growth factors and pervanadate, the induction of Src activity in rafts was slower and weaker, dependent on actin and possibly its mediated transportation of Src from perinuclear regions to the plasma membrane. In contrast, the induction of Src activity in nonrafts was faster and stronger, dependent on microtubules. Hence, Src activity is differentially regulated via cytoskeleton at different membrane compartments

    An Accurate Model for Fast Calculating the Resonant Frequency of an Irregular Solenoid

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    Integrating the Eigendecomposition Approach and k-Means Clustering for Inferring Building Functions with Location-Based Social Media Data

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    Understanding the relationship between human activity patterns and urban spatial structure planning is one of the core research topics in urban planning. Since a building is the basic spatial unit of the urban spatial structure, identifying building function types, according to human activities, is essential but challenging. This study presented a novel approach that integrated the eigendecomposition method and k-means clustering for inferring building function types according to location-based social media data, Tencent User Density (TUD) data. The eigendecomposition approach was used to extract the effective principal components (PCs) to characterize the temporal patterns of human activities at building level. This was combined with k-means clustering for building function identification. The proposed method was applied to the study area of Tianhe district, Guangzhou, one of the largest cities in China. The building inference results were verified through the random sampling of AOI data and street views in Baidu Maps. The accuracy for all building clusters exceeded 83.00%. The results indicated that the eigendecomposition approach is effective for revealing the temporal structure inherent in human activities, and the proposed eigendecomposition-k-means clustering approach is reliable for building function identification based on social media data

    How the presence of a salt

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    We conducted a series of analogue experiments on shortening of a brittle cover (dry sand) above a deep, thin, frictional detachment (glass microbeads). In some experiments, the cover was homogeneous, entirely brittle. In others, there was a thin viscous silicone layer (representing salt) embedded at mid height into the cover, and initially located in the foreland of the fold-and-thrust belt. Our goal was to determine whether or not the presence of such a décollement in the cover could have an impact on the mechanics and kinematics of the underlying subsalt thrusts. Results confirm that, once the front of the foldbelt reached the hinterland salt pinch out, the kinematics of the deeper belt changed drastically: its front stopped propagating forward, and most of the subsequent shortening was accommodated by a larger-than-normal slip along the foremost and youngest deep thrust, while, above the salt décollement, the deformation front propagated very fast, creating a very low surface slope. We hypothesize that it is the gentle sub-critical surface slope associated with rocksalt’s low viscosity that prevents the build-up of an overall surface slope steep enough to allow the underlying, deep foldbelt to continue propagating forward. Finally, one experiment in which only one half of the width of the model comprised an interbedded viscous décollement has shown that the kinematics of the deep thrust was affected even in the adjacent salt-free domain

    Towards an Extensive Thumb Assist: A Comparison between Whole-Finger and Modular Types of Soft Pneumatic Actuators

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    Soft pneumatic actuators used in robotic rehabilitation gloves are classified into two types: whole-finger actuators with air chambers that cover the entire finger and modular actuators with chambers only above the finger joints. Most existing prototypes provide enough finger flexion support, but insufficient independent thumb abduction or opposition support. Even the latest modular soft actuator realized thumb abduction with a sacrifice of range of motion (RoM). Moreover, the advantages and disadvantages of using the two types of soft actuators for thumb assistance have not been made clear. Without an efficient thumb assist, patients’ options for hand function rehabilitation are very limited. Therefore, the objective of this study was to design a modular actuator (M-ACT) that could support multiple degrees of freedom, compare it with a whole-finger type of thumb actuator with three inner chambers (3C-ACT) in terms of the RoM, force output of thumb flexion, and abduction, and use an enhanced Kapandji test to measure both the kinematic aspect of the thumb (Kapandji score) and thumb-tip pinch force. Our results indicated superior single-DoF support capability of the M-ACT and superior multi-DoF support capability of the 3C-ACT. The use of the 3C-ACT as the thumb actuator and the M-ACT as the four-finger actuator may be the optimal solution for the soft robotic glove. This study will aid in the progression of soft robotic gloves for hand rehabilitation towards real rehabilitation practice

    Femtosecond laser direct inscribed 45° tilted fiber grating for a net-normal-dispersion mode-locked Er-doped fiber laser

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    The application of a femtosecond laser direct inscribed 45° tilted fiber grating (TFG) in a net-normal-dispersion mode-locked Er-doped fiber laser, as an in-fiber polarizer, has been systematically studied. The 45° TFG with a grating length of ~ 12.6 mm and a grating period of ~ 2.2 μm has a polarization dependent loss of ~ 9.8 dB and supports various types of dissipative soliton (DS) outputs. The achieved single DS mode-locked pulse centered at 1570.55 nm has a 3 dB bandwidth of 15.64 nm and a pulse duration of ~ 4.68 ps. By simply employing a section of single-mode fiber, the output pulse duration can be dechirped to ~ 250 fs. The fundamental repetition rate is 25.47 MHz and the maximum pulse output power is 24.04 mW. By appropriately adjusting the intra-cavity polarization states and increasing the pump power, the bound-state DS, as well as a harmonic mode-locked DS, can be generated. The bound-state pulse is composed of two identical DS pulses with a temporal interval of ~ 26.27 ps. The second- and third-order harmonic mode-locked DS pulses with repetition rates of 50.93 MHz and 76.40 MHz are obtained for pump powers of 298 mW and 528 mW, respectively. Our results indicate that the feasibility and versatility of the femtosecond laser inscribed 45° TFG to realize nonlinear polarization evolution mode-locking in various operation regimes. Combined with the flexibility of the femtosecond laser direct inscription technique, such a 45° TFG paves a promising route for the development of robust, compact and high-energy ultrafast all-fiber lasers
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