Coal mine safety is crucial to the healthy and sustainable development of the coal industry, and coal mine flood is a major hidden danger of coal mine accidents. Therefore, the processing of coal ...mine water source data is of great significance to prevent mine water inrush accidents. In this experiment, the water source data were obtained by laser induced fluorescence technology with the assistance of laser. The water sample data information was preprocessed by standard normal variable transformation (SNV) and multiple scattering correction (MSC), and then the principal component analysis (PCA) was used to reduce the dimension of the data and ensure the information characteristics of the original data unchanged. In order to identify the water inrush type of coal mine water source, the sparrow search algorithm (SSA) is used to optimize the BP neural network in this study. This is because the SSA algorithm has the advantages of strong optimization ability and fast convergence rate compared with particle swarm optimization (PSO) and other optimization algorithms. Experiments show that under the premise of SNV pretreatment, the R 2 of SSA-BP model is infinitely close to 1, MRE is 0.0017, RMSE is 0.0001, the R 2 of PSO-BP model is 0.9995, MRE is 0.0026, RMSE is 0.0019, the R 2 of BP model is 0.9983, MRE is 0.0140, RMSE is 0.0075. Therefore, SSA-BP model is more suitable for the classification of coal mine water sources.
Maternal effects contribute to adaptive significance for shaping various phenotypes of many traits. Potential implications of maternal effects are the cause of expression diversity, but these effects ...on mRNA expression and alternative splicing (AS) have not been fully elucidated in hybrid animals.
Two reciprocal cross hybrids following hybridization of Megalobrama amblycephala (blunt snout bream, BSB) and Culter alburnus (topmouth culter, TC) were used as a model to investigate maternal effects. By comparing the expression of BSB- and TC- homoeologous genes between the two reciprocal cross hybrids, we identified 49-348 differentially expressed BSB-homoeologous genes and 54-354 differentially expressed TC-homoeologous genes. 2402, 2959, and 3418 AS events between the two reciprocal cross hybrids were detected in Illumina data of muscle, liver, and gonad, respectively. Moreover, 21,577 (TC-homoeologs) and 30,007 (BSB-homoeologs) AS events were found in the 20,131 homoeologous gene pairs of TBF
based on PacBio data, while 30,561 (TC-homoeologs) and 30,305 (BSB-homoeologs) AS events were found in BTF
. These results further improve AS prediction at the homoeolog level. The various AS patterns in bmpr2a belonging to the bone morphogenetic protein family were selected as AS models to investigate the expression diversity and its potential effects to body shape traits.
The distribution of differentially expressed genes and AS in BSB- and TC-subgenomes exhibited various changes between the two reciprocal cross hybrids, suggesting that maternal effects were the cause of expression diversity. These findings provide a novel insight into mRNA expression changes and AS under maternal effects in lower vertebrates.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
At present, high-resolution drought indices are scarce, and this problem has restricted the development of refined drought analysis to some extent. This study explored the possibility of calculating ...the standardized precipitation index (SPI) with short-term precipitation sequences in China, based on data from 2416 precipitation observation stations covering the time period from 1961 to 2019. The result shows that it is feasible for short-sequence stations to calculate SPI index, based on the spatial interpolation of the precipitation distribution parameters of the long-sequence station. Error analysis denoted that the SPI error was small in east China and large in west China, and the SPI was more accurate when the observation stations were denser. The SPI error of short-sequence sites was mostly less than 0.2 in most areas of eastern China and the consistency rate for the drought categories was larger than 80%, which was lower than the error using the 30-year precipitation samples. Further analysis showed that the estimation error of the distribution parameters β and q was the most important cause of SPI error. Two drought monitoring examples show that the SPI of more than 50,000 short-sequence sites can correctly express the spatial distribution of dry and wet and have refined spatial structure characteristics.
Persistent extreme heat events (PEHEs) exert a more negative impact on society, including agriculture, plant phenology, power production and human health, compared to general EHEs. The temporal and ...spatial characteristics of summer PEHEs in eastern China were analysed based on a daily maximum temperature dataset from 759 stations over the period of 1961–2018. The results show the following: Persistent distributions of PEHEs show that they are characterized by an exponential decay with a drop in the decay rate. In terms of spatial distribution, there is an apparent regional difference in the duration of PEHEs. North China is dominated by multi-frequency and short-duration EHEs, while South China is the opposite. PEHEs in North China and the Huanghuai region mainly occur in June-July but mostly in July and August in South China. Strongly responding to global warming, the frequency and duration of PEHEs in North China have increased since the 1990s. However, the frequency of PEHEs in North China and the Huanghuai region has shown opposite trends in June-July since the beginning of the twenty-first century. Affected by the atmospheric circulations, the regional differences in PEHE frequency are also apparent. Since the beginning of the twenty-first century, the PEHEs in North China and the Huanghuai area have shown an increasing trend in August. The short-term PEHEs in the middle and lower reaches of the Yangtze River and South China increased rapidly in the 2000s, while long-term PEHEs increased in the 2010s. This study implies that attention should be paid to not only the frequency of EH days but also to the persistence of EHE which is a key characteristic of damaging EH.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
An hourly-resolution dataset from observations at the automatic weather stations (AWSs) is developed and applied to study the characteristics of weakening surface wind in the urban areas of Beijing ...City in 2008–2017. The “Urban Stilling Island (USI)” is defined and quantified to depict the surface wind speed (WS) differences between rural and urban regions. The urban (rural) sites are represented by 45 (6) stations within (outside) the 6th Ring Road (RR). The results demonstrate remarkable smaller annual and seasonal average WS values in urban areas than in rural areas, indicating significant USI, especially in the central urban areas (within the 4th RR) in spring and winter. Further analysis reveals that the surface roughness effect dominates and enhances the USI intensity (USII) under the stronger large-scale background wind in spring and winter, whereas the Urban Heat Island (UHI) effect may dominate and decrease the USII under weaker large-scale wind in summer and autumn. The diurnal USII variations are characterized by a steady low-value phase from 1900 to 0800 Beijing Time (BT) and a high-value phase from 1100 to 1500 BT, with rapid shifts of USII in between. Long-term variation of hourly USII shows large mean USII in 2008–2012 but decreased USII in 2013–2017, possibly attributed to the change of urbanization level around the rural observation sites.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper presents a resonant pressure microsensor with the measurement range of 1 MPa suitable for the soaring demands of industrial gas pressure calibration equipment. The proposed microsensor ...consists of an SOI layer as a sensing element and a glass cap for vacuum packaging. The sensing elements include a pressure-sensitive diaphragm and two resonators embedded in the diaphragm by anchor structures. The resonators are excited by a convenient Lorentz force and detected by electromagnetic induction, which can maintain high signal outputs. In operation, the pressure under measurement bends the pressure-sensitive diaphragm of the microsensor, producing frequency shifts of the two underlining resonators. The microsensor structures were designed and optimized using finite element analyses and a 4" SOI wafer was employed in fabrications, which requires only one photolithographic step. Experimental results indicate that the Q-factors of the resonators are higher than 25,000 with a differential temperature sensitivity of 0.22 Hz/°C, pressure sensitivities of 6.6 Hz/kPa, and -6.5 Hz/kPa, which match the simulation results of differential temperature sensitivity of 0.2 Hz/°C and pressure sensitivities of ±6.5 Hz/kPa. In addition, characterizations based on a closed-loop manner indicate that the presented sensor demonstrates low fitting errors within 0.01% FS, high accuracy of 0.01% FS in the pressure range of 20 kPa to 1 MPa and temperature range of -55 to 85 °C, and the long-term stability within 0.01% FS in a 156-day period under the room temperature.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The tectonic evolution of SE China block since late Paleozoic remains debated. Here we present a new set of zircon U-Pb geochronological, Lu-Hf isotopic data and whole-rock geochemistry for two ...stages of basicintermediate dykes from the southwestern Fujian. The samples were collected from the NE-trending （mainly diabases） and NW-trending （mainly diabasic diorites） dykes and yielded zircon U-Pb ages of 315 and 141 Ma, with eHf（t） values of -8.90 to 7.49 and -23.39 to -7.15 （corresponding to TDM2 values of 850 to 1890 Ma and 737 to 2670 Ma）, respectively. Geochemically these rocks are characterized by low TiO2 （0.91-1.73 wt.%） and MgO （3.04-7.96 wt.%）, and high A1203 （12.5-16.60 wt.%） and K20 （0.60-3.63 wt.%）. Further they are enriched in LREEs and LILEs （Rb, Ba, Th and K）, but depleted in HFSEs （Nb, Ta and Zr）. The tectonic discrimination analysis revealed that the dykes were formed in an intraplate extensional envi- ronment. However, the NW trending dykes show crust-mantle mixed composition, which indicate an extensional tectonic setting with evidence for crustal contamination. The SE China block experienced two main stages of extensional tectonics from late Carboniferous to early Cretaceous. The tectonic evolution of the SE China block from late Devonian to Cretaceous is also evaluated.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Successful treatment of neurodegenerative diseases (NDDs), including Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD), remains a significant challenge for ...neurologists due to the undesirable curative outcomes. Apart from surgeries, most drugs are only used to relieve the patients’ symptoms without a permanent cure of the disease. The development of novel biomaterials targeting NDDs is greatly hindered by the limited understanding of underlying molecular mechanisms. Considering the difficulties in NDD drug development and clinical trials, a comprehensive and up-to-date review of disease pathogenesis and related novel therapies are needed. In the current article, the basic concepts and pathogenic characteristics of NDDs are firstly illustrated. Following the detailed description of molecular mechanisms underlying three common NDDs, recent advances of drug development based on targeting different pathogenic mechanisms are clarified. Hopefully, this review will be beneficial to address the gap between materials and targeted mechanisms while simultaneously provide suggestions for the future design of precise NDD medicine.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
T
here are few reports on the relationship between the biological activity and structure of secondary metabolites from
Dictyota dichotoma
. In this work, the geometric and electronic structures, ...infrared spectra, ultraviolet spectra,
13
C and
1
H NMR spectra of 16 xenicane-type diterpenoids extracted from
Dictyota dichotoma
were studied by the density functional theory
ω
B97XD/6-311+G(2
d,p
) method. The analysis of the reactivity indices was carried out
via
the conceptual density functional theory. Furthermore, a pharmacodynamic evaluation was performed using ADME/Tox. The geometric structure analysis found that all 16 diterpenoids had the same unsaturated, branched chains and could be divided into two categories according to the ring size, including nine-membered and eight-membered rings. A hydroxyl group on the lactone ring reduced the stability of the compound. In contrast, a hydroxyl group on the parent ring had little effect on the compound’s stability. The electrostatic potential results preliminarily predicted active sites for nucleophilic/electrophilic reactions. The fitting results of infrared and nuclear magnetic resonance(NMR) data showed that the theoretical values obtained by this method were consistent with the experimental values. The UV-visible absorption spectra showed that the solvent effects caused different redshifts of the absorption peaks. The absorption strength was enhanced. The sixteen diterpenoids displayed a strong absorption peak in the range of 180–200 nm, but the compound containing a carbonyl group presents a weaker absorption peak in the field of 200–240 nm. Compounds
9
―
11
,
14
, and
15
have better stability and reactivity with lower chemical potentials and higher electronegativity, electrophilic index, and hardness values. The local reactivity descriptors further identified nucleophilic/electrophilic reaction sites for the sixteen compounds. Finally, the pharmacodynamic evaluation results predicted that compounds
2
,
4
,
8
,
11
, and
14
―
16
have optimal drugability. The theoretical results of this work may provide a rich data information for the other experimental study on the cembrane diterpenoids in medicine.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A self-powered photoelectrochemical (PEC) aptamer probe is presented for the determination of oxytetracycline (OTC). The assay is based on the use of g-C
3
N
4
and NiO nanocrystals (NCs) which form a ...heterojunction. The latter was prepared by two-step hydrothermal pyrolysis by using the ionic liquid 1-hydroxyethyl-3-methylimidazole chloride which functions as a morphological template to form NiO NCs. The heterojunction exhibits much better electronic conductivity, wider absorption range, higher electron-hole-separation productivity, and stronger photocurrent compared to plain g-C
3
N
4
. The heterojunction was adopted to construct a self-powered PEC aptamer probe for OTC detection. An OTC-binding aptamer was immobilized on the heterojunction and the probe was constructed. The aptamer on the probe binding with OTC can form steric hindrance for transmitting of electrons and cause the PEC signal change depending on the OTC concentration. The photocurrent decreases with increasing OTC concentration in the 0.01 to 100 nM concentration range and its detection limit is 4 pM (at S/
N
= 3).
Graphical abstract
Schematic representation of a self-powered photochemical aptamer probe. The probe performs enhanced ability for oxytetracycline (OTC) determination due to the formation of NiO nanocrystals/g-C
3
N
4
(NiO NCs/g-C
3
N
4
) heterojunction and the specification recognition of the aptamer.
PDF
