Automatic Calculation of the Transition Temperatures for two-dimensional Heisenberg type Magnets

Theoretical prediction of the 2nd-order magnetic transition temperature (TM) used to be arduous. Here, we develop a first principle-based, fully automatic structure-to-TM method for two-dimensional (2D) magnets whose effective Hamiltonians follow the Heisenberg model. The Heisenberg exchanges, which can be calculated to an arbitrary shell, are transferred into the Monte Carlo calculation. Using Cr-based magnets as the showcases, we show that our method is a powerful tool to study the 2D magnets in two aspects. First, considering long-range exchanges enables us to identify the spin frustration in the suspended CrTe2 monolayer, whereas the heterostructure calculations reveal that the ferromagnetism can be recovered if the monolayer CrTe2 is grown onto various 2D substrates. Second, we realize a high-throughput screening of novel magnets discovered by random structure searches. Six 2D Cr chalcogenides are selected to have high TM. Our work provides a new insight for the study of 2D magnets and helps accelerate the pace of magnetic materials data-mining

Unsupervised Texture Segmentation Using Active Contour Model and Oscillating Information

Textures often occur in real-world images and may cause considerable difficulties in image segmentation. In order to segment texture images, we propose a new segmentation model that combines image decomposition model and active contour model. The former model is capable of decomposing structural and oscillating components separately from texture image, and the latter model can be used to provide smooth segmentation contour. In detail, we just replace the data term of piecewise constant/smooth approximation in CCV (convex Chan-Vese) model with that of image decomposition model-VO (Vese-Osher). Therefore, our proposed model can estimate both structural and oscillating components of texture images as well as segment textures simultaneously. In addition, we design fast Split-Bregman algorithm for our proposed model. Finally, the performance of our method is demonstrated by segmenting some synthetic and real texture images

Impact of Ultra-Low Interfacial Tension on Enhanced Oil Recovery of Ultra-Low Permeability Reservoir

Ultra-low permeability reservoirs have the characteristics of complex pore throat structure, generally higher injection pressure and lower oil recovery. By means of casting thin sections, pore structure of selected ultra-low permeability core was surveyed. The core was classified into low porosity, low permeability and without natural fractures. Vast majority of throats of the core varied in width from 2.5 μm to 15 μm. Core displacement experiments showed that surfactant flooding could have certain effect of reducing injection pressure and enhancing oil recovery. When interfacial tension was 5.93×10-2 mN/m, decompression rate reached 7.65%, and recovery was improved by 4.09%. And when interfacial tension was 4.9×10-5 mN/m, decompression rate reached 25%, and recovery was improved by 11.6%. The lower interfacial tension is, the better the effect of reducing injection pressure is, and the higher the extent of enhancing oil recovery is. In general, surfactants have a great application prospect on the oil field development of ultra-low permeability reservoir, and the interfacial tension should be reduced as far as possible.Key words: Low permeability; Surfactant; Interfacial tension; Emulsion; Enhancing oil recover

Bioactive Constituents of Verbena officinalis Alleviate Inflammation and Enhance Killing Efficiency of Natural Killer Cells

Natural killer (NK) cells play key roles in eliminating pathogen-infected cells. Verbena officinalis (V. officinalis) has been used as a medical plant in traditional and modern medicine for its anti-tumor and anti-inflammatory activities, but its effects on immune responses remain largely elusive. This study aimed to investigate the potential of V. officinalis extract (VO extract) to regulate inflammation and NK cell functions. We examined the effects of VO extract on lung injury in a mouse model of influenza virus infection. We also investigated the impact of five bioactive components of VO extract on NK killing functions using primary human NK cells. Our results showed that oral administration of VO extract reduced lung injury, promoted the maturation and activation of NK cells in the lung, and decreased the levels of inflammatory cytokines (IL-6, TNF-α and IL-1β) in the serum. Among five bioactive components of VO extract, Verbenalin significantly enhanced NK killing efficiency in vitro, as determined by real-time killing assays based on plate-reader or high-content live-cell imaging in 3D using primary human NK cells. Further investigation showed that treatment of Verbenalin accelerated the killing process by reducing the contact time of NK cells with their target cells without affecting NK cell proliferation, expression of cytotoxic proteins, or lytic granule degranulation. Together, our findings suggest that VO extract has a satisfactory anti-inflammatory effect against viral infection in vivo, and regulates the activation, maturation, and killing functions of NK cells. Verbenalin from V. officinalis enhances NK killing efficiency, suggesting its potential as a promising therapeutic to fight viral infection

Thiamine pyrophosphokinase deficiency: report of two Chinese cases and a literature review

Thiamine pyrophosphokinase (TPK) deficiency, is a rare autosomal recessive disorder of congenital metabolic dysfunction caused by variants in the TPK1 gene. TPK1 variants can lead to thiamine metabolic pathway obstacles, and its clinical manifestations are highly variable. We describe two cases of TPK deficiency with completely different phenotypes and different therapeutic effects, and 26 cases of previously reported were retrospectively reviewed to improve our understanding of the clinical and genetic features of the disease. Patients with TPK deficiency present with ataxia, dysarthria, dystonia, disturbance of consciousness, seizures, and other nervous system dysfunction. Different gene variant sites may lead to different clinical features and therapeutic effects. Gene analysis is important for the diagnosis of TPK deficiency caused by TPK1 variants, and thiamine supplementation has been the mainstay of treatment for TPK deficiency to date

Exergy analysis of the multi-stage slag waste heat recovery system

Based on the black-box model, this paper analyzed the multi-stage slag waste heat recovery system. The exergy efficiency, the exergy loss coefficient and the exergy loss rate were adopted as evaluation indexes to investigate the energy consumption and the weakness of the system. Meanwhile, the performance of waste heat recovery was analyzed by comparing the comprehensive exergy efficiency between the system and other conventional waste heat recovery methods. The results showed that the comprehensive exergy efficiency of the system reached 75.75%, which was much higher than other methods, and the weakness of the system was the subsystem of waste heat boiler. In general, the system recovered the slag waste heat effectively and converted coal to clean syngas through gasification reaction, which had incredible potential in energy saving, emission reduction and consumption reduction

Risk Assessment of Water Resources Shortage in Sanjiang Plain

International audienceIn view of the problems existing in the development and utilization of water resources in Sanjiang Plain, this paper made a study on the risk assessment of water resources shortage in Sanjiang Plain. From the perspective of water resources shortage risk, analytic hierarchy process was applied to establish assessment index system and evaluation criteria, and then make a comprehensive assessment and regional difference analysis of water resources shortage risk in Sanjiang Plain. Research results showed that Shuangyashan City belonged to high degree of water resources shortage risk, while Jixi, Hegang, Jiamusi, Qitaihe, Muling and Yilan belonged to extremely high water resources shortage risk, which provided a theoretical principle for sustainable and efficient utilization of regional water resources

Effects of acupoint-stimulation for the treatment of primary dysmenorrhoea compared with NSAIDs: a systematic review and meta-analysis of 19 RCTs

Abstract Background Primary dysmenorrhoea (PD), defined as painful menses in women with normal pelvic anatomy, is one of the most common gynaecological syndromes. Acupoint-stimulation could potentially be an effective intervention for PD. Our aim was to determine the effectiveness of acupoint-stimulation compared with Non-Steroidal Anti-Inflammatory Drugs (NASIDs) in the treatment of PD. Methods Six databases were searched to December 2014. Sixteen studies involving 1679 PD patients were included. We included randomized controlled trials that compared acupoint-stimulation with NASIDs for the treatment of PD. The main outcomes assessed were clinical effectiveness rate, symptom score, visual analogue score, variation in peripheral blood prostaglandin F2α (PGF2α) and side effects. All analyses were performed using Comprehensive Meta-Analysis statistical software. Results (1) The total efficacy was better than control group: odds ratio = 5.57; 95% confidence interval (95% CI) = 3.96, 7.83; P < 0.00001; (2) The effect of intervention was positive in relieving the severity of PD symptoms: mean difference (MD) = 2.99; 95%CI = 2.49, 3.49; P < 0.00001; (3) No statistical difference existed between two groups in terms of a reduction in the VAS: MD = 1.24; 95%CI = −3.37, 5.85; P = 0.60; (4) The effect of intervention on the variation in peripheral blood PGF2α between two groups was positive: MD = 7.55; 95%CI = 4.29,10.82; P < 0.00001; (5) The side effects of control groups was more than the acupoint-stimulation group: OR = 0.03; 95%CI =0.00,0.22; P = 0.0005. Conclusions According to this article, acupoint-stimulation can relieve pain effectively in the treatment of PD and offers advantages in increasing the overall effectiveness

Investigation of Flow Through Centrifugal Pump Impellers Using Computational Fluid Dynamics

With the aid of computational fluid dynamics, the complex internal flows in water pump impellers can be well predicted, thus facilitating the design of pumps. This article describes the three-dimensional simulation of internal flow in three different types of centrifugal pumps (one pump has four straight blades and the other two have six twisted blades). A commercial three-dimensional Navier-Stokes code called CFX, with a standard k–ε two-equation turbulence model was used to simulate the problem under examination. In the calculation, the finite-volume method and an unstructured grid system were used for the solution procedure of the discretized governing equations for this problem