With the potential wide uses of nanoparticles such as carbon nanotubes in biomedical applications, and the growing concerns of nanotoxicity of these engineered nanoparticles, the importance of ...nanoparticle–protein interactions cannot be stressed enough. In this study, we use both experimental and theoretical approaches, including atomic force microscope images, fluorescence spectroscopy, CD, SDS-PAGE, and molecular dynamics simulations, to investigate the interactions of single-wall carbon nanotubes (SWCNTs) with human serum proteins, and find a competitive binding of these proteins with different adsorption capacity and packing modes. The π-π stacking interactions between SWCNTs and aromatic residues (Trp, Phe, Tyr) are found to play a critical role in determining their adsorption capacity. Additional cellular cytotoxicity assays, with human acute monocytic leukemia cell line and human umbilical vein endothelial cells, reveal that the competitive bindings of blood proteins on the SWCNT surface can greatly alter their cellular interaction pathways and result in much reduced cytotoxicity for these protein-coated SWCNTs, according to their respective adsorption capacity. These findings have shed light toward the design of safe carbon nanotube nanomaterials by comprehensive preconsideration of their interactions with human serum proteins.
This paper evaluates the recoverable unconventional oil and gas resources around the world, reveals main controlling factors and potential regions for the rich accumulation of unconventional oil and ...gas, and standardizes the classification of seven types of resources (i.e., heavy oil, oil sand, tight oil, oil shale, shale gas, tight gas, and coalbed methane). By virtue of commercial databases for global petroliferous basins, together with single-well data packages in North America and basic data of exploration and development of Chinese companies in unconventional oil and gas resources blocks around the world, contour maps of abundance for global recoverable resources are formed through spatial graphic interpolation of key assessment parameters of seven types of unconventional oil and gas resources on the Geographic Information System (GIS) platform, which systematically evaluate the potential of seven types of unconventional oil and gas resources. The assessment reveals: (1) These seven types of resources around the world are distributed predominantly in 476 formations in 363 petroliferous basins. (2) Total recoverable unconventional oil and gas resources in the world are respectively 442.1 billion tons and 227 trillion cubic meters. (3) Unconventional oil and gas resources can be divided into “source-bound type” and “strata-bound type”. The “source-bound type” resources are mainly controlled by 6 groups of high-quality source rock around the world, among which, the tight oil and gas resources are featured by the “integration of reservoir and source”, presenting the best prospect for the development and application, and the “strata-bound type” oil sand and heavy oil resources, controlled by the transformation of the late structure, are mainly distributed in the slope belt of the Mesozoic-Cenozoic basins, presenting a good prospect for the resource development and application in the shallow layers. (4) Besides hot spots in North America, tight oil in the West Siberia Basin and the Neuquen Basin as well as heavy oil in the Arab Basin will become potential targets for the development of unconventional oil and gas resources in the future.
Objective
Increasing evidence from randomized controlled trials shows the anti-inflammatory and haemodynamic effects of levosimendan in advanced heart failure (AdHF), however, conflicting results ...have been reported in some studies. The aim of this study was to estimate the anti-inflammatory and haemodynamic effects of levosimendan on AdHF (registration number: INPLASY202250097).
Methods
The MEDLINE, PubMed, ClinicalTrials.com and Cochrane Library databases were systematically searched for studies published in English up to April 2019. Data were extracted from applicable articles. Meta-analyses were performed to assess interleukin (IL)-6, cardiac index, pulmonary artery pressure (PAP) and New York Heart Association (NYHA) functional class efficacy outcomes, following PRISMA 2020 guidelines.
Results
A total of 11 studies were included (211 patients who received levosimendan and 193 controls). Meta-analyses showed that the levosimendan group displayed significantly reduced IL-6 (standardized mean difference SMD −1.05; 95% confidence interval CI −1.44, −0.66; I
2
= 50.9%), improved cardiac index (SMD 0.59; 95% CI 0.29, 0.88; I2 = 0.0%); reduced PAP (SMD −1.22; 95% CI −1.91, −0.53; I2 = 89.7%) and improved NYHA functional class (SMD −1.66; 95% CI −2.27, −1.04; I2 = 74.6%) versus controls.
Conclusions
Levosimendan infusion was beneficial in patients with AdHF, displayed by anti-inflammatory and improved haemodynamic effects, and improved NYHA functional class.
With Sichuan Basin as focus, this paper introduces the depositional environment, geochemical and reservoir characteristics, gas concentration and prospective resource potential of three different ...types of shale in China: marine shale, marine-terrigenous shale and terrigenous shale. Marine shale features high organic abundance (
TOC: 1.0%–5.5%), high-over maturity (
R
o: 2%–5%), rich accumulation of shale gas (gas concentration: 1.17–6.02 m
3/t) and mainly continental shelf deposition, mainly distributed in the Paleozoic in the Yangtze area, Southern China, the Paleozoic in Northern China Platform and the Cambrian-Ordovician in Tarim Basin; Marine-terrigenous coalbed carbonaceous shale has high organic abundance (
TOC: 2.6%–5.4%) and medium maturity (
R
o: 1.1%–2.5%); terrigenous shale in the Mesozoic and Cenozoic has high organic abundance (
TOC: 0.5%–22.0%) and mid-low maturity (
R
o: 0.6–1.5%). The study on shale reservoirs in the Lower Paleozoic in Sichuan Basin discoveried nanometer-sized pores for the first time, and Cambrian and Silurian marine shale developed lots of micro- and nanometer-sized pores (100–200 nm), which is quite similar to the conditions in North America. Through comprehensive evaluation, it is thought that several shale gas intervals in Sichuan Basin are the practical targets for shale gas exploration and development, and that the Weiyuan-Changning area in the Mid-South of Sichuan Basin, which is characterized by high thermal evolution degree (
R
o: 2.0%–4.0%), high porosity (3.0%–4.8%), high gas concentration (2.82–3.28 m
3/t), high brittle mineral content (40%–80%) and proper burial depth (1500–4500 m), is the core area for shale gas exploration and development, the daily gas production for Well Wei 201 is 1×10
4–2×10
4 m
3.
： 以四川盆地为重点，介绍中国海相、海陆过渡相、陆相三大类型页岩形成的沉积环境、地球化学与储集层特征、含气量与远景资源量。中国海相页岩是一套高有机质丰度（TOC为1.0%～5.5%）、高—过成熟（Ro值为2.0%～5.0%）、富含页岩气（含气量1.17～6.02 m3/t）、以陆棚相为主的沉积，主要分布在华南扬子地区古生界、华北地台古生界和塔里木盆地寒武系—奥陶系；海陆过渡相煤系炭质页岩有机质丰度高（TOC为2.6%～5.4%）、成熟度适中（Ro值为1.1%～2.5%）；中新生界陆相页岩有机质丰度高（TOC为0.5%～22.0%）、低熟—成熟（Ro值为0.6%～1.5%）。在对四川盆地下古生界页岩储集层研究中首次发现，寒武系和志留系海相页岩发育大量与北美地区相似的微米—纳米级孔隙。综合评价认为四川盆地发育的多套页岩气层系是勘探开发的现实领域，四川盆地中南部威远—长宁等地区的寒武系和志留系是页岩气勘探开发的核心区与层系，其特点是：热演化程度较高（Ro值为2.0%～4.0%）、孔隙度较高（3.0%～4.8%），含气量较高（2.82～3.28 m3/t）、脆性矿物含量较高（40%～80%）、埋深适中（1 500～4 500 m），有利于开采。图7表7参38
Based on the latest global conventional-unconventional petroleum development situation and the conclusion of petroleum geology theory and technology innovation in recent 10 years, the connotation of ...conventional and unconventional petroleum “orderly accumulation” connotation is formulated. This concept indicates that, unconventional petroleum occurs in the hydrocarbon supply direction of conventional petroleum, and conventional petroleum may appear in the outer space of unconventional petroleum. Proper evaluation methods and engineering technology are important to push the conventional-unconventional petroleum co-development, and the petroleum finding thought from outer-source into inner-source. Unconventional petroleum evaluation focuses on source rocks characteristics, lithology, physical property, brittleness, oil-gas possibility and stress anisotropy. Taking shale gas for examples, in China, these six properties are TOC>2%, laminated silicious calcareous shale or calcareous silicious shale, porosity 3%-8%, brittle minerals content 50%-80%, gas content 2.3-4.1 m3/t, pressure coefficient 1.0-2.3, natural fractures; in north America, these six properties are TOC>4%, silicious shale or calcareous shale or marl, porosity 4%-9%, brittle minerals content 40%-70%, gas content 2.8-9.9 m3/t, pressure coefficient 1.3-1.85, natural fractures. “Sweet spot area” assessment, “factory-like” operation pattern and other core evaluation methods and technologies are discussed. And 8 key elements of unconventional “sweet spot area” are proposed, 3 of them are TOC>2% (for shale oil S1>2 mg/g), higher porosity (for tight oil & gas >10%, shale oil & gas >3%), and microfractures. Multiple wells “factory-like” operation pattern is elaborated, and its implementation needs 4 elements, i.e. batch well spacing, standard design, flow process, and reutilization. Through horizontal well volume fractures in directions, “man-made reservoirs” with large-scale fracture systems can be formed underground. For “shale oil revolution” in future, non-water “gas in critical state” and etc. fracturing fluid and matching technology should be stressed to be industrially tested and encouraged to be low cost developed.
Petroleum geology is evolving into two branches, conventional petroleum geology and unconventional petroleum geology, with the latter becoming a new theoretical frontier in the petroleum industry. ...The core of conventional hydrocarbon geological study is based on identifying the match between source rock, reservoir, caprock, migration, trap, preservation and timing; the core of unconventional hydrocarbon geological study evaluates if the oil and gas is part of a continuous accumulation, where stress is placed on the evaluation of “lithology, physical properties, brittleness, oiliness, source rock features, stress anisotropy” and their configuration. The oil and gas accumulation mode and theoretical formula at various low limits of pore throat diameter have been established, as well as the “L” type production curve. Theoretical production prediction models for unconventional oil and gas, and formation mechanism and development patterns for unconventional oil and gas are being revealed. The connotation, characteristics, potential and technology for unconventional oil and gas have been observed, and two key marks to identify unconventional hydrocarbon have been put forward: (1) continuous distribution of hydrocarbon-bearing reservoirs over a large area, with no obvious trap boundary; and (2) no natural stable industrial production, and no obvious Darcy flow. Systematic research shows that the proportion of global unconventional to conventional hydrocarbon resources is 8:2, in which the unconventional oil is almost equal to conventional oil, and the unconventional gas is about 8 times that of conventional gas. In China, unconventional oil resources are about 240×108 t and unconventional gas resources are about 100×1012 m3. In recent years the development of tight gas and tight oil should be strengthened to realize industrial reserves and increase production. Construction of shale gas pilot plants and shale oil research should be strengthened. Unconventional oil and gas industrial systems and research should be set up, including unconventional hydrocarbon geology, fine particle sedimentology, unconventional reservoir geology, seismic reservoir prediction, massive fracturing of horizontal wells, “factory-like” operation, low cost management and subsidy policy and personnel training.
The measured data of dams in complex environments are influenced by factors such as external forcing and instrumentation errors and inevitably contain noise, which makes accurately predicting dam ...deformation challenging. Traditional denoising methods suffer from both excessive denoising and incomplete denoising, resulting in limited improvement in prediction accuracy. To better address these problems, this paper proposes a denoising method that combines adaptive variational modal decomposition (VMD) with improved multichannel singular spectrum analysis (MSSA). The algorithm denoises the decomposed subsequence while accounting for the covariance between the subsequence and extracts valid information from the residual sequences. A concrete panel rockfill dam is used as an example for validation. The results show that the proposed algorithm effectively preserves the intrinsic components and coupling relationships between the decomposed subsequence. Based on machine learning models with different sensitivities to noise, the prediction accuracy of the proposed denoising algorithm model is better than that of the traditional denoising algorithm model. It is more suitable for deformation prediction modelling in complex situations involving actual dams, which further enhances the generalization ability of the prediction model.
The construction of a reasonable and reliable deformation prediction model is of great practical significance for dam safety assessment and risk decision-making. Traditional dam deformation ...prediction models are susceptible to interference from redundant features, weak generalization ability, and a lack of model interpretation. Based on this, a deformation prediction model that considers the lag effect of environmental quantities is proposed. The model first constructs a new deformation lag influence factor based on the plain HST model through the lag quantization algorithm. Secondly, the attention and memory capacity of the model is improved by introducing a multi-head attention mechanism to the features of the long-time domain deformation influence factor, and finally, the extracted dynamic features are transferred to the ConvLSTM model for learning, training, and prediction. The results of the simulation tests based on the measured deformation data of an active dam show that the introduction of the deformation lag factor not only improves the interpretation of the prediction model for deformation but also makes the prediction of deformation more accurate, and it can improve the evaluation indexes such as RMSE by 50%, the nMAPE by 40%, and R2 by 10% compared with the traditional prediction model. The combined prediction model is more capable of mining the hidden features of the data and has a deeper picture of the overall peak and local extremes of the deformation data, which provides a new way of thinking for the dam deformation prediction model.
Real-time noninvasive monitoring of crop water information is an important basis for water-saving irrigation and precise management. Nano-electronic technology has the potential to enable smart plant ...sensors to communicate with electronic devices and promote the automatic and accurate distribution of water, fertilizer, and medicine to improve crop productivity. In this work, we present a new flexible graphene oxide (GO)-based noninvasive crop water sensor with high sensitivity, fast responsibility and good bio-interface compatibility. The humidity monitoring sensitivity of the sensor reached 7945 Ω/% RH, and the response time was 20.3 s. We first present the correlation monitoring of crop physiological characteristics by using flexible wearable sensors and photosynthesis systems, and have studied the response and synergistic effect of net photosynthetic rate and transpiration rate of maize plants under different light environments. Results show that in situ real-time sensing of plant transpiration was realized, and the internal water transportation within plants could be monitored dynamically. The synergistic effect of net photosynthetic rate and transpiration of maize plants can be jointly tested. This study provides a new technical method to carry out quantitative monitoring of crop water in the entire life cycle and build smart irrigation systems. Moreover, it holds great potential in studying individual plant biology and could provide basic support to carry out precise monitoring of crop physiological information.
Because of the importance of durability against electromagnetic interference in modern life, the shielding effectiveness of a rectangular cavity with apertures on different sides irradiated by the ...plane electromagnetic wave is modeled in this paper. In the modeling process, the incident angle and the polarization angle of the plane electromagnetic wave are introduced, and the scattering voltage produced on the outer aperture is taken as the radiation source. The aperture is taken as the asymmetrical coplanar stripline and the rectangular cavity is taken as a rectangular waveguide with one end completely open and another end completely closed. The shielding effectiveness of any point in the cavity is calculated using transmission line theory. Compared to other authors before, this method improves the completeness of the model and computation speed which supplies good reference for engineering practice.
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