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Shale gas is a green, low-carbon and clean unconventional natural gas energy. China is rich in shale gas resources. Accelerating shale gas exploration and development is of great practical significance to improve China's energy structure and achieve the goal of “2030 carbon peak neutralization and 2060 carbon neutralization”. The Ordovician Wufeng Formation to Silurian Longmaxi Formation in Sichuan Basin is the key strata for shale gas exploration and development in China. Based on the experimental analysis of shale gas in Wufeng Formation to Longmaxi Formation in Weiyuan, Changning, Zhaotong, Fuling and Weirong areas of Sichuan Basin, this paper systematically analyzes the geochemical characteristics of shale gas in Wufeng Formation to Longmaxi Formation, discusses the genesis of shale gas, the causes of hydrocarbon isotope inversion and the source of shale gas, and looks forward to the exploration prospects of shale gas resources in the basin. It has important guiding significances for shale gas exploration and development in Sichuan Basin and even in China. The results show that: (1) The shale gas of Wufeng-Longmaxi formations is a typical dry gas, and the hydrocarbon isotopes are distributed in negative sequence. The carbon isotopes of alkane gas in Changning, Zhaotong and Fuling areas are heavier and have a higher degree of thermal evolution than those in Weiyuan and Weirong areas, and the rare gas is of crustal origin. (2) Shale gas of Wufeng-Longmaxi formations is a thermogenic oil type gas at high-over mature stage, which is mainly the mixture of crude oil cracking gas and kerogen cracking gas. The hydrocarbon isotope inversion of alkane gas is mainly caused by the mixing of crude oil cracking gas and kerogen cracking gas at high-over mature stage, the exchange between formation water and methane at high evolution stage and so on. (3) The carbon isotopic values of methane in shale gas of Wufeng-Longmaxi formations match the carbon isotopic values of kerogen in mudstone of Longmaxi Formation of Lower Silurian, which conforms to the law of carbon isotopic fractionation δ13Ckerogen>δ13Coil>δ13Calkane gas. (4) The total amount of marine, marine continental transitional and continental facies shale gas resources in Sichuan Basin is about 41.5 × 1012 m3, with broad exploration prospects in resource potential.

Tight sandstone gas reservoirs of Xujiahe Formation in central Sichuan Basin have generally high water saturation. The characteristics of natural gas migration and accumulation, as well as gas reservoirs with high water saturation formation mechanism, were investigated using test data from natural gas geochemistry analysis and nuclear magnetic resonance (NMR) high pressure filling simulation experiment. The findings reveal that: (1)The Xujiahe Formation established the foundation for oil and gas near-source accumulation by interacting superimposed large areas of source rock and reservoir. As the maturity of source rocks increases, the wetness becomes smaller and the δ13C1 value becomes heavier of natural gas, indicating a near-source accumulation. (2)The gas saturation of Xujiahe Formation gas reservoirs ranges from 50% to 65%, with a pore radius of the reservoir space 0.1–10 μm. The larger the proportion of relatively large pore size, the higher the gas saturation will be. (3)As charging pressure is increased, natural gas accumulates in tight sandstone by progressively aggregating from large pore diameter to small pore diameter space, culminating “three-stage” charging characteristics of rapid increase, moderate increase and basically stable charge. The coupling between low-pressure drive and relatively large pore reservoir is the fundamental reason why the Xujiahe Formation of natural gas can form large-medium gas reservoirs but high water saturation in central Sichuan Basin. The findings will provide theoretical and technical support for the exploration of tight sandstone.

Summary Stem cell-based embryo models by cultured pluripotent and extra-embryonic lineage stem cells are novel platforms to model early postimplantation development. We showed that induced pluripotent stem cells (iPSCs) could form ITS (iPSCs and trophectoderm stem cells) and ITX (iPSCs, trophectoderm stem cells, and XEN cells) embryos, resembling the early gastrula embryo developed in vivo. To facilitate the efficient and unbiased analysis of the stem cell-based embryo model, we set up a machine learning workflow to extract multi-dimensional features and perform quantification of ITS embryos using 3D images collected from a high-content screening system. We found that different PSC lines differ in their ability to form embryo-like structures. Through high-content screening of small molecules and cytokines, we identified that BMP4 best promoted the morphogenesis of the ITS embryo. Our study established an innovative strategy to analyze stem cell-based embryo models and uncovered new roles of BMP4 in stem cell-based embryo models., Graphical abstract, Highlights • Set up machine learning-assisted image analysis to study stem cell-based embryos • Mouse iPSCs can form ITS or ITX embryos with TSCs and XEN cells • Different PSC lines differ in their abilities to form embryo-like structures • High-content screen identified BMP4 best promoted the morphogenesis of ITS embryos, In this article, Dr. J. Na and colleagues established a machine learning-assisted image analysis method to perform unbiased and automated analysis of stem cell-based embryos. With this powerful technology, the authors compared different pluripotent stem cell lines, optimized culture conditions, and conducted a small-molecule and cytokine screen to identify factors that can promote the development of stem cell-based embryos.

Countries across the world are in different stages of COVID-19 trajectory, among which many have implemented the lockdown measures to prevent its spread. Although the lockdown is effective in such prevention, it may put the economy into a depression. Predicting the epidemic progression with government switching the lockdown on or off is critical. We propose a transfer learning approach called ALeRT-COVID using attention-based recurrent neural network (RNN) architecture to predict the epidemic trends for different countries. A source model was trained on the pre-defined source countries and then transferred to each target country. The lockdown measure was introduced to our model as a predictor and the attention mechanism was utilized to learn the different contributions of the confirmed cases in the past days to the future trend. Results demonstrated that the transfer learning strategy is helpful especially for early-stage countries. By introducing the lockdown predictor and the attention mechanism, ALeRT-COVID showed a significant improvement on the prediction performance. We predicted the confirmed cases in one week when extending and easing lockdown separately. Results showed the lockdown measures is still necessary for a number of countries. We expect our research can help different countries to make better decisions on the lockdown measures.

Breakthroughs have been made for the natural gas exploration of the Middle Devonian and the Middle Permian formations in the Sichuan Basin in recent years. Nevertheless, its natural gas source is still not clear, which then affects the next exploration deployment decision. A comprehensive study is conducted on the geochemical characteristics of the Middle Devonian and the Middle Permian natural gas, the biomarkers of reservoir bitumen, and the source rocks. The results show that these natural gases are secondary cracking dry gas that includes more than 86% of methane content, a small amount of ethane, propane, and a non-hydrocarbon gas (e.g., nitrogen, carbon dioxide, and hydrogen sulfide). The natural gas maturity varies slightly in different regions. The carbon and hydrogen isotope values of natural gas are as follows: δ13C1 ranges from −35.7‰ to −27.3‰, δ13C2 ranges from −38.7‰ to −26.6‰, δ13C3 ranges from −37‰ to −26.5‰, δ2HCH4 ranges from −141‰ to −138‰, and δ2HC2H6 ranges from −164‰ to −112‰. The isotope values indicate that the genetic type of natural gas is the sapropelic type and the mixture type is dominated by sapropelic type. The difference between natural gas values of δ13C1, δ13C2, and δ2HCH4 in different regions is related to the contribution ratio of source rocks from different ages. The gases of the Middle Devonian and the Middle Permian of the Shuangyushi structure in Northwestern Sichuan, the Middle Permian of Southwestern Sichuan, and the Middle Permian of Paleo-uplift in Central Sichuan are mainly derived from the Cambrian Qiongzhusi Formation and the Middle-Lower Permian source rocks. The Middle-Upper Permian natural gases of the volcanic reservoir in Southwestern Sichuan is mainly from the Qiongzhusi source rock. The Middle Permian natural gases of the Hewanchang structure in Northwestern Sichuan, Eastern Sichuan, and Southern Sichuan are mainly derived from the Silurian Longmaxi source rock. The research results have important guiding significance for developing exploration and deployment solutions for natural gas of the Middle Devonian and the Middle Permian formation in the Sichuan Basin.

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease.

ObjectiveA low concentration of plasma triiodothyronine (T3) indicates euthyroid sick syndrome (ESS), which could be associated with a poor outcome in patients in intensive care units (ICUs). This study evaluated the relationship between ESS and prognostic indicators in patients admitted to an ICU and examined the free T3 (FT3) cut-off points that could be associated with 28-day mortality.MethodsThis prospective observational study included patients admitted to the ICU of The Third Hospital of Hebei Medical University between February and November 2018. Baseline variables and data on the occurrence of low FT3 were collected. The patients were divided into ESS (FT3 < 3.28 pmol/L) and non-ESS groups. The relationship between ESS and prognostic indicators in patients admitted to the ICU was evaluated, and the FT3 cut-off points that could be associated with 28-day mortality were examined.ResultsOut of a total of 305 patients, 118 (38.7%) were in the ESS group. Levels of FT3 (P < 0.001) and FT4 (P = 0.001) were lower, while the 28-day mortality rate (P < 0.001) and hospitalization expenses in the ICU (P = 0.001) were higher in the ESS group. A univariable analysis identified ESS, FT3, free thyroxine (FT4)/FT3, the APACHE II score, the sequential organ failure (SOFA) score, the duration of mechanical ventilation, creatinine (CREA) levels, the oxygenation index (HGB), white blood cells, albumin (ALB) levels, age, and brain natriuretic peptide (BNP) levels as factors associated with 28-day mortality (all P < 0.05). The cut-off value of FT3 for 28-day mortality was 2.88 pmol/L, and the 28-day mortality rate and hospitalization expenses in the ICU were higher in patients with ESS. The syndrome was confirmed to be independently associated with 28-day mortality.ConclusionThis study determined the incidence of ESS in the comprehensive ICU to be 38.7%. APACHE II, SOFA, BNP, APTT, HGB, PLT, CREA, ALB, FT4, SBP, and DBP are closely related to ESS, while BNP, PLT, and ALB are independent risk factors for the syndrome.

Due to Van der Waals or electrostatic interactions of surfactants active to all kinds of minerals, in low-rank coal (LRC) flotation, surfactants could both adsorb on the organic and mineral matter of LRC, thus increasing the hydrophobicity of them and resulting in the increase of clean coal yield as well as the ash content. In this work, density functional theory (DFT) calculations were clarified the adsorption mechanism of surfactant (C12EO, lauryl polyoxyethylene ether) on the LRC model molecules and kaolinite surfaces (the representative of organic and mineral matter in LRC). The DFT results demonstrate that the interaction strength between C12EO and LRC model molecules is stronger than that of kaolinite. Based on the calculation results, ultrasonic treatment was selected to expand the wettability difference between organic and mineral matter that adsorbed C12EO. The microcalorimetry results show that the wetting heat of organic matter that is adsorbed C12EO is unchanged basically after 30 s ultrasonic treatment. However, there is an obvious increase trend for the wetting heat of kaolinite. Flotation experiments of artificial mixed samples proved that ultrasonic treatment is useful in decreasing the extent of ash content in LRC flotation, thus improving the quality of clean coal in LRC flotation.

Purpose. Studies have shown that corneas of young children were more susceptible to Ultraviolet B (UVB) radiation damage. However, there exist limited information about the harm of UVB to eyes and preventive measures on infancy. Vitamin C as an antioxidant is widely used to prevent many diseases. Therefore, the aim of this study was to explore the protective effect of vitamin C on the cornea of infant rats with acute UVB injury. Method. Thirty-six infant rats were randomly divided into three groups: control (CON) group, UVB (UVB) group, and UVB+vitamin C (UVB+VitC) group. The UVB group was exposed to UVB irradiation (8 J/cm2, 15 min/d, 7 d) and the UVB+vitamin C group suffered the same UVB irradiation treated with vitamin C at the dose of 40 mg/kg via intraperitoneal injection. Then, corneal morphology was detected in vivo and in vitro at 7 d post-UVB exposure. Furthermore, serum inflammatory factors (IL-1, IL-6, and TNF-α) and oxidative status (4-HNE and MDA) were detected by ELISA, and the expression of vascular endothelial growth factor-α (VEGF-α) and superoxide dismutase (SOD) in the cornea was detected by western blot or immunofluorescent staining. Results. Slit lamp detection revealed that the area of corneal desquamation and corneal neovascularization in the UVB+VitC group was significantly less than those in the UVB group at 7 d post-UVB exposure (all p<0.05). OCT results showed that the thickness of the central cornea in the UVB+VitC group was decreased than that in the UVB group (p<0.05). The serum inflammatory factors (IL-1, IL-6, and TNF-α) and oxidative status (4-HNE and MDA) in the UVB group were significantly increased compared with the CON group (all p<0.05), while those factors in the UVB+VitC group were decreased compared with those in the UVB group. Furthermore, the expression of VEGF-α in the UVB+VitC group was dramatically decreased compared with that in the UVB group (p<0.05), and the expression of SOD2 in the UVB+VitC group was dramatically increased compared with that in the UVB group at 7 d post-UVB exposure (p<0.05). Conclusion. Vitamin C could protect infant rats from corneal injury induced by UVB via alleviating corneal edema, improving corneal inflammatory reaction, and decreasing VEGF-α expression.

Low plasma triiodothyronine (T3) concentration indicates nonthyroidal illness syndrome (NTIS), which might be associated with a poor outcome in patients in the intensive care unit (ICU). This study evaluated the relationship between NTIS and prognostic indicators in patients admitted to the ICU and examined the fT3 cut-off points that could be associated with 28-day mortality. This prospective observational study included patients admitted to the ICU of The Third Hospital of Hebei Medical University from February to November 2018. The baseline variables and the occurrence of low free T3 (FT3) were collected. The patients were divided into the NTIS (FT3<3.28) and non-NTIS groups. Among 305 patients, 118 (38.7%) were in the NTIS group. FT3 (P<0.001) and FT4 (P=0.001) were lower, while the 28-day mortality rate (P<0.001) and hospitalization expenses in ICU (P=0.001) were higher in the NTIS group. The univariable analyses identified NTIS, FT3, free thyroxine/FT3, APACHEII, sequential organ failure score, duration of mechanical ventilation, creatinine, oxygenation index, white blood cells, albumin, age, and brain natriuretic peptide as being associated with 28-day mortality (all P<0.05). The cut-off value of FT3 for 28-day mortality was 2.88 pmol/L. The 28-day mortality rate and hospitalization expenses in the ICU were higher in patients with NTIS. NTIS was independently associated with 28-day mortality.

The poor flotation behavior of low-rank coal is mainly caused by the high content of functional oxygen groups present on the coal surface. Polar collectors, especially oxygenated collectors, play a significant role in the flotation enhancement of low-rank coal. In this study, to improve the low-rank coal flotation performance, octanoic acid was selected as a polar collector and the corresponding promotion mechanism was investigated at the molecular scale theoretically. The flotation results showed that an increased low-rank coal flotation response can be obtained by using an octanoic acid collector compared to a nonpolar dodecane collector. To obtain a molecular-level explanation of this phenomenon, a method of density functional theory (DFT) combined with molecular dynamics simulation was employed to explore the involved micro-mechanism. DFT calculation results suggested that the octanoic acid collector can interact with benzoic acid and phenol (representatives of oxygen-containing groups on the low-rank coal surface) through hydrogen bonding and repel water molecules present on benzoic acid and phenol. Based on theoretical calculations, in the presence or absence of water molecules, hydrogen bonding and electrostatic interactions are responsible for the strong affinity of octanoic acid to carboxyl group and hydroxyl group on the low-rank coal surface. Therefore, it was favorable for octanoic acid to form a stable adsorption layer on the low-rank coal surface, thus contributing to low-rank coal flotation significantly.

The alternative development of coal-bearing hydrocarbon source rocks and low-porosity and low-permeability tight sandstone reservoirs of the Triassic Xujiahe Formation in the Sichuan Basin is favorable for near-source hydrocarbon accumulation. The natural gas composition of the Xujiahe Formation in the Sichuan Basin is dominated by hydrocarbon gases, of which the methane content is 80.16%–98.67%. Typically, the C2+ content is larger than 5% in main wet gas. The dry gas is mainly distributed in the western and northern regions of the basin. The non-hydrocarbon gases mainly contain nitrogen, carbon dioxide, hydrogen, and helium, with a total content of δ13C4 occurs in some natural gas with a low evolution degree; such gas is mainly coal-related gas from humic-type source rocks of the Xujiahe Formation. As for the natural gas, δ2HCH4 values ranged from −195‰ to −161‰, δ2HC2H6 values ranged from −154‰ to −120‰, and δ2HC3H8 values ranged from −151‰ to −108‰. The dry coefficient, δ13C and δ2HCH4 are all positively correlated with the maturity of source rocks. The higher the maturity of source rocks is, the larger the natural gas dry coefficient is and the larger the δ13C and δ2HCH4 values are, indicative of the characteristic of near-source accumulation. The δ2HC2H6 value of natural gas is influenced by paleosalinity to a relatively large extent; the higher the paleosalinity is, the larger the δ2HC2H6 value is. The Pr/Ph value of the condensate oil ranged from 1.60 to 3.43, illustrating light oxidization–light reduction and partial-oxidization characteristics of the depositional environment of coal-bearing source rocks of the Xujiahe Formation. The natural gas light hydrocarbon (C5–C7) from the Xujiahe Formation presented two characteristics: the first was the relatively high aromatic hydrocarbon content (19%–32.1%), which reveals the characteristic of natural gas with humic substances of high-maturity; the second was the low content of aromatic hydrocarbon (0.4%–9.3%), reflecting water-washing during the accumulation of the natural gas. The reported research outcomes indicate a potential mechanism for natural gas accumulation in the Xujiahe Formation, which will further guide natural gas exploration in this region.

This clinical observation study aimed to investigate the relationship between the serum levels of vascular endothelial growth factor (VEGF) and its soluble receptors with the severity and the occurrence of late acute respiratory distress syndrome (ARDS) in early trauma.Sixty patients with multiple injuries were divided into three groups according to the Injury Severity Score (ISS) and the serum levels of VEGF, soluble VEGF receptor 1 (sVEGFR1), and sVEGFR2, were measured. Ten healthy people were recruited as controls. The incidence of late ARDS was also monitored, and its relationship to the above measures analyzed.VEGF was not associated with ISS (p0.05); sVEGFR1 was positively associated with ISS (r = 0.459, p0.0001); however, sVEGFR2 was negatively associated with ISS (r = 0.510, p0.0001). The serum VEGF levels between the ARDS group and the non-ARDS group showed no significant difference (p0.05). sVEGFR1 in the ARDS group was significantly higher than that in the non-ARDS group (p0.0001), and sVEGFR2 in the ARDS group was significantly lower than that in the non-ARDS group (p0.0001).In conclusion, the increasing of sVEGFR1 and the decreasing of sVEGFR2 in early trauma might be closely related to the occurrence of late ARDS.Prognostic study, level III.

In this letter, a stopband frequency selective surface (FSS) with great incident angle independence and polarization stability is proposed and fabricated. Each element of the FSS consists of a cross spiral patch and four same second iteration of H-shaped fractal parts in C4 rotation symmetry. This FSS exhibits great stability with the incident angle ranging from 0° to 80° for both TE and TM polarizations. In addition, patch dimension of the FSS element can tune the resonant frequency. However it has a negligible influence on incident angle independence and polarization stability. This means the proposed FSS can be applied in different frequency ranges and has potential values in practical applications. Both simulation and measurement of this FSS demonstrate stable transmission characteristics under different incident angles and polarizations and show satisfactory consistence.

Numerous oxygen-containing groups present on the low rank coal (LRC) surface makes a poor flotation performance of LRC only using common oily collector. Increasing the spreading strength of oily collector on the LRC surface is of great significance for improving its flotation behavior. In this study, molecular dynamics simulation (MDS) was employed to investigate the microscopic spreading characteristics of non-polar oil droplet on the LRC surface. For this purpose, the configurations of non-polar oil droplet, spreading area, and interaction energy were calculated. It was found that on the raw LRC surface, the non-polar oil droplet remained spherical with a small spreading area and weak interaction strength. Besides, a non-ionic surfactant, dodecyl nonaethoxyl ether (C12EO9) was used to modify the surface wettability of LRC to enhance the non-polar oil droplet spreading. After surfactant pretreatment, a pancake-like oil film was formed on the LRC surface with a larger spreading area and more negative interaction energy compared with the case of the raw LRC surface. Based on these observations, the microscopic insights were provided about the spreading of non-polar oil droplet on the surface of LRC, as well as the role of surfactant enhancing its spreading intensity. In addition, the effect of the oxygen-containing groups on the spreading behaviors of non-polar oil droplet was also explored. The results suggested that carboxyl and hydroxyl are the main groups that hinder the spreading of the non-polar oil droplet on LRC surface. The simulation results are in accordance with the available experimental data.

A novel miniaturized single-feed cross-aperture coupled circularly polarized (CP) microstrip patch antenna loaded by four identical shorting strips is proposed and discussed. Each shorting strip underneath the edges of the radiating patch is connected to the ground plane via an array of three identical and equidistant shorting pins. With the assistance of the capacitance offered by the radiating patch and the shorting strips, and the inductance induced by the shorting pins, the patch size and overall size of the proposed antenna have been significantly reduced by 75% and 69%, respectively, compared with the conventional antenna. An antenna prototype with an overall size of 50 mm× 50 mm× 7.548 mm (0.317λ0 × 0.317λ0 × 0.048λ0) and a patch size of 29.43 mm × 27.85 mm (0.186λ0 × 0.176λ0) has been fabricated and measured, which shows a measured 10-dB return loss bandwidth of 92 MHz (4.76%) from 1.886 to 1.978 GHz with a maximum right-handed CP (RHCP) gain of 4.9 dBic. The measured 3-dB axial ratio (AR) bandwidth is 28 MHz (1.46%) from 1.899 to 1.927 GHz with a 3-dB AR beamwidth of more than 140 ◦ across the operating bandwidth.

Flotation collectors have a significant effect on the flotation performance and efficiency of fine low rank coal (LRC) particles. In this study, a mixed collector consisting of a nonpolar collector (dodecane) and a polar collector (C12EO4, tetraethylene glycol monododecyl ether) was used to improve the flotation performance of LRC. The results show that flotation behavior can be enhanced with the addition of C12EO4 in dodecane. The yield, combustible matter recovery, and flotation efficiency index increase with a larger volume ratio of C12EO4 in the mixed collector. A molecular dynamics simulation (MD) approach was applied to explore the microscopic strengthening mechanism of the mixed collector. The simulation demonstrated that the interaction strength and spreading ability of the mixed collector on the LRC surface increased due to electrostatic attraction and hydrogen bonding between the mixed collector and the LRC surface (as indicated by interaction energy and contact surface area), thereby enhancing flotation performance of the LRC. The effect of C12EO4 on the emulsification and dispersibility of dodecane is also discussed.

In this work, a combined molecular dynamics (MD) simulations and experiments were adopted to study the microscopic mechanism of the benzene ring in nonionic surfactants on low-rank coal (LRC) flotation. Two nonionic surfactants with identical headgroups, nonylphenol ethoxylate (NPEO) and dodecyl ethoxyl ethers (C12EO), were selected as the research objects. Two LRC surface models with varying metamorphism degrees were constructed. The rationality of the constructed surface models was firstly discussed from the chemical composition and structure. The morphology of the surfactants and the adsorption energy obtained by MD suggested that the arrangement of polar oxygen atoms in the surfactant depended on its interaction with the polar groups of LRC, and the presence of the benzene ring in the nonionic surfactant hardly changed its arrangement on the LRC surface. The benzene ring in the nonionic surfactant can enhance its adsorption on the higher rank coal surface via the π-bonds while it cannot promote its adsorption on the lower rank coal surface. The results obtained from the experiments are in accordance with the simulation results.

The ability of automotive millimeter-wave (MMW) radar to identify the road targets has a direct impact on the performance of Advanced Driver Assist System(ADAS). There are obvious differences in the Micro-Doppler features of the radar echo of pedestrians, automobiles and motorcycles. In this paper, a recognition method based on deep learning is proposed to realize the targets identification and classification by training and learning the Micro-Doppler features of the road targets. In this method, the time-frequency spectrogram of moving target echoes of the millimeter-wave radar is used as the training sample, convolutional neural network (CNN) is adopted to extract features and reduce dimension, and the output layer of the CNN is extended and fed into a recurrent neural networks (RNN) for sequence learning since the Micro-Doppler features of moving targets have obvious temporal correlation. The output layer of the network uses softmax regression to identify specific road targets. The Recognition results of measured data show that the proposed method has higher recognition accuracy and better recognition ability of road moving targets, compared with other machine learning methods that only use CNN.

Cancer stem cells (CSCs) drive tumor initiation and metastasis in several types of human cancer. However, the contribution of ovarian CSCs to peritoneal metastasis remains unresolved. The cell adhesion molecule CD44 has been identified as a major marker for CSCs in solid tumors, including epithelial ovarian cancer. CD44 exists as a standard form (CD44s) and also as numerous variant isoforms (CD44v) generated by alternative mRNA splicing. Here we show that disseminated ovarian tumors in the pelvic peritoneum contain highly enriched CD44v6-positive cancer cells, which drive tumor metastasis and are responsible for tumor resistance to chemotherapy. Clinically, an increased number of CD44v6-positive cancer cells in primary tumors was associated with a shortened overall survival in stage III-IV ovarian cancer patients. Furthermore, a subpopulation of CD44v6-positive cancer cells manifested the ability to initiate tumor metastasis in the pelvic peritoneum in an in vivo mouse model, suggesting that CD44v6-positive cells show the potential to serve as metastasis-initiating cells. Thus, the peritoneal disseminated metastasis of epithelial ovarian cancer is initiated by the CD44v6-positive subpopulation, and CD44v6 expression is a biomarker for the clinical outcome of advanced ovarian cancer patients. Given that a distinct subpopulation of CD44v6-positive cancer cells plays a critical role in peritoneal metastasis, definitive treatment should target this subpopulation of CD44v6-positive cells in epithelial ovarian cancer.

In this letter, a compact four-element microstrip patch antenna array for BeiDou navigation satellite system (BDS) operation at the B3 (1268MHz) band is proposed. High permittivity dielectric substrate and slit-loaded microstrip patch are used to reduce the antenna element size down to 40mm × 40mm which implies an aperture size of only λ0/6 × λ0/6 at the B3 band. The right-handed circularly polarized (RHCP) radiation is achieved by connecting two coaxial probes to a 0◦–90◦ stripline hybrid. Four identical antenna elements are distributed with the same polarity and an inter-element separation of 80mm (λ0/3 at the B3 band). The overall size of the antenna array, including the stripline feeding network and supporting ground plane, is only 140mm × 140mm × 5.5mm. A prototype was fabricated and measured to verify the design concept. Simulated and measured results will be presented and discussed, showing that the proposed BDS antenna array is suitable for BDS applications.

Aims Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin superfamily. Although its overexpression in various cancers has been reported, little is known about its expression and clinical significance in oral squamous cell carcinoma (OSCC). This study aimed to elucidate the clinical significance of NGAL in OSCC. Methods and results We investigated NGAL expression immunohistochemically in tumour cells and stromal cells in 96 OSCC tissues. NGAL expression in tumour cells correlated significantly with histological tumour cell differentiation, as shown by its specific distribution in the horn pearl-forming keratinized tumour cells, but not with other major clinicopathological parameters. We found NGAL+ cells in the stroma that were predominantly myeloperoxidase-positive neutrophils. The number of such NGAL-expressing stromal cells was associated significantly with poor differentiation and reduced overall survival in OSCC. The prognostic value of stromal NGAL expression was significant in a univariate analysis, while only a trend was found in multivariate analyses. Conclusions This study is the first to show the clinical significance of stromal NGAL expression, which may be an indicator of poor prognosis and more aggressive histological grade in OSCC. Our data suggest that NGAL expression in tumour cells and expression in stroma are associated in different ways with OSCC differentiation.

A novel uniplanar CPW-fed tri-band stub-loaded slot antenna is proposed for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. Dual resonant modes were effectively excited in the upper band by using two identical pairs of slot stubs and parasitic slots symmetrically along the arms of a traditional CPW-fed slot dipole, achieving a much wider bandwidth. The middle band was realized by the fundamental mode of the slot dipole. To obtain the lower band, two identical inverted-L-shaped open-ended slots were symmetrically etched in the ground plane. A prototype was fabricated and measured, showing that tri-band operation with 10-dB return loss bandwidths of 150 MHz from 2.375 to 2.525 GHz, 725 MHz from 3.075 to 3.8 GHz, and 1.9 GHz from 5.0 to 6.9 GHz has been achieved. Details of the antenna design as well as the measured and simulated results are presented and discussed.

The northern margin of the Qaidam Basin is one of the main oil-gas exploration areas in western China, where source rocks are composed mostly of Middle and Lower Jurassic dark mud shale, carbargillite and coal. A large number of subsurface and outcrop samples differing in lithology with different types of organic matter were selected for resource evaluation, research and calculation. And among them, 13 samples were used for simulation experiment on hydrocarbon generating potential of various source rocks. At first, two kinds of heating modes were compared through simulation experiment, including single temperature-step heating and continual heating. Perhaps, the process of hydrocarbon generation and expulsion occurred naturally between a close system and an open system. In addition, the first heating mode was convenient, and all its reaction products were involved in the whole thermal evolution, and the final simulation experimental results were basically in consistency with the natural evolution trend. Therefore, the first heating mode was adopted and the hydrocarbon yield of every sample was worked out. According to the type and lithology of organic matter and the hydrocarbon yield of samples for simulation experiment, hydrocarbon generation and expulsion mode with three kinds of lithology and five types of source rock has been established to provide the basis for hydrocarbon generation evaluation, research and resource calculation.

In this paper broadband characteristics of sleeve antenna are analyzed using the Method of Moments. The sleeve antenna's property of three frequency bands is investigated. The first and third operating bands come from the driven dipole, while the second operating band is due to the height of the sleeve and the distance between the driven dipole and the sleeve. Some numerical results are presented and discussed.

Although in Western countries the prevalence of senile systemic amyloidosis (SSA) in the elderly (>80 years) was found to be about 25% based on examination of autopsy-derived cardiac spec...

The life quality of livestock population in different time and space is determined by the limitations of water and grass resources and by the fixed position of resource. Carrying capacity is a variable which is closely related to the resource that the prairie can supply. Based on the systematic analysis on the grassland resources, water resources in Damaoqi desert steppe and on the ecological principles of “determining livestock by grass and keeping a balance among the water, grass and livestock”, the threshold expansion of the carrying capacity was analyzed in the desert grassland within the environmental capacity of water and grass resources. Studies suggest that if the ecological patterns are safe in the grass and water resources, the threshold of carrying capacity would be expanded and the animal husbandry would be sustainably and scientifically developed through the construction of efficiently irrigated grassland, the adjustment of livestock varieties or herd structure and scientific grazing and so on.

During production or commercialization of fine iron powder, water content is the most important parameter for evaluating and controlling the fine iron powder properties. In order to improve the portability, operability, and speed of the water determination and to reduce testing cost, a new method to quickly detect the water content in fine iron powder using capacitance type sensor is put forward. The basic principle and characteristics of this measuring technique are examined. Structure and testing circuit for the capacity sensor are designed with parameters optimized through experimental research. A mathematical model to correlate water content to the capacitance is proposed. The present work had laid the foundation for developing an utility-type fast detecting device for water content in fine iron powder which can be adopted in real-time monitoring for processing or trading of fine iron powder.

A 3D measuring system on structure light which uses color-encoded technique and digital projection technique to realize 3D measuring is introduced. In this measuring system, a color-encoded pattern that is created by a new method is created by software on a computer and then projected to an object by a digital projection system controlled by the computer. The image of the object is captured by a CCD color digital camera position at an angle different from that of the digital projection system. The color of each pixel determined by the proportion of its primary color, red, green, and blue (RGB) has a one-to-one correspondence with the projection angle. Decoding and calculating for the color image captured, the 3D coordinates of the points on the object surface can be obtained.

A color-encoded technique for 3D measurement is presented in this paper. In this technique, a color pattern that is composed of RGB components is created by software on a computer screen and projected to an object by a digital light processing, which is controlled by the computer. The image of the object is captured by a CCD color digital camera positioned at an angle different from that of the digital projection system. The color of each pixel of the image has a one-to-one correspondence with the projection angle. The 3D depth map of the object is obtained by way of computer decoding and calculating of the color image captured. This paper mainly introduces the errors analysis and the computer simulation method. The results of the example shows that the relatively errors of the 3D measuring system are smaller than 1%. Simulations have been performed and the results validate the method.

In this paper, a NIR Spectral System based on Acoustic Optical Tunable Filter (AOTF) was developed for measuring milk constituents. Factors affecting the repeatability of measuring spectra of the system were analyzed by using the transmitted spectra of Ultra-High Temperature (UHT) sterilized milk. Orthogonal experimental design method was employed to determine the significance level of these factors and the optimal condition for measuring spectra of the system. It is concluded that the crucial factor affecting the spectra repeatability is the ambient temperature. Further temperature testing results show that, when the environmental condition is basically invariant, the temperature of the AOTF crystal is basically constant and the drifting amplitude of wave number is within 0.5cm -1 , when the ambient temperature varies, the temperature of AOTF crystal changes correspondingly. The drifting of wave number is about 1cm -1 when the temperature of AOTF crystal changes 1°C. It is found that the wave number drifting increases with decreasing temperature of AOTF crystal. These testing results are of important significance to further improve the measuring accuracy of the system.

Summary Objective: Nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) were endogenously-generated molecules gas. They owned important biological activity and participated in many pathophysiological processes. This study aimed to examine the levels of three gasotransmitters in the early phase of trauma patients. Method: Blood samples were collected from 60 trauma patients and ten healthy volunteers. Concentration of serum iNOS and HO-1 were analyzed by enzyme linked immunosorbent assay and plasma H2S was determined by colorimetric method. Meanwhile, the occurrence of multiple organ dysfunction syndrome (MODS) was also monitored. Results: The levels of iNOS, HO-1 and endogenous H2S in the patients group were significantly different from the healthy control group, and the difference was more obvious with the increase of ISS score. iNOS levels were positively correlated with ISS scores and blood lactic acid values, and HO-1 and endogenous H2S were negatively correlated with ISS scores and blood lactic acid values. Of 60 trauma patients, eight (13.33%) developed MODS. The level of iNOS in the MODS group was higher than that in non-MODS group, while HO-1 and H2S were significant lower in the MODS group. Conclusion: The three gasotransmitters participated in systemic inflammatory responses during early trauma and could be used as important indicators for trauma severity. Their measurements were meaningful for evaluating the severity and prognosis of trauma.