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Extreme within-lake conditions have the potential to exert detrimental effects on lakes. Here we use satellite observations to investigate how the occurrence of multiple types of extremes, notably algal blooms, lake heatwaves, and low lake levels, have varied in 2724 lakes since the 1980s. Our study, which focuses on bloom-affected lakes, suggests that 75% of studied lakes have experienced a concurrent increase in at least two of the extremes considered (27% defined as having a notable increase), with 25% experiencing an increase in frequency of all three extremes (5% had a notable increase). The greatest increases in the frequency of these extremes were found in regions that have experienced increases in agricultural fertilizer use, lake warming, and a decline in water availability. As extremes in lakes become more common, understanding their impacts must be a primary focus of future studies and they must be carefully considered in future risk assessments. Satellite data reveals a rise in multivariate extreme events in lakes since the 1980s, largely linked to agricultural practices and mean climatic warming. [ABSTRACT FROM AUTHOR]

River sediments play a critical role in sustaining deltaic wetlands. Therefore, concerns are raised about wetlands' fate due to the decline of river sediment supply to many deltas. However, the dynamics and drivers of suspended sediment near deltaic coasts are not comprehensively assessed, and its response to river sediment supply changes remains unclear. Here we examine patterns of coastal suspended sediment concentration (SSC) and river sediment plume area (RPA) for 349 deltas worldwide using satellite images from 2000 to 2020. We find a global increase in SSC and RPA, averaging +0.46% and +0.48% yr−1, respectively, with over 59.0% of deltas exhibiting an increase in both SSC and RPA. SSC and RPA increases are prevalent across all continents, except for Asia. The relationship between river sediment supply and coastal SSCs varies between deltas, with as much as 45.2% of the deltas showing opposing trends between river sediments and coastal SSCs. This is likely because of the impacts of tides, waves, salinity, and delta morphology. Our observed increase in SSCs near river delta paints a rare promising picture for wetland resilience against sea-level rise, yet whether this increase will persist remains uncertain. River sediments play a critical role in sustaining coastal ecosystems. This study examines patterns of coastal suspended sediment concentration (SSC) for 349 deltas worldwide via satellite images and investigated the possible driving factors. [ABSTRACT FROM AUTHOR]

Crop production is a large source of atmospheric ammonia (NH3), which poses risks to air quality, human health and ecosystems1–5. However, estimating global NH3 emissions from croplands is subject to uncertainties because of data limitations, thereby limiting the accurate identification of mitigation options and efficacy4,5. Here we develop a machine learning model for generating crop-specific and spatially explicit NH3 emission factors globally (5-arcmin resolution) based on a compiled dataset of field observations. We show that global NH3 emissions from rice, wheat and maize fields in 2018 were 4.3 ± 1.0 Tg N yr−1, lower than previous estimates that did not fully consider fertilizer management practices6–9. Furthermore, spatially optimizing fertilizer management, as guided by the machine learning model, has the potential to reduce the NH3 emissions by about 38% (1.6 ± 0.4 Tg N yr−1) without altering total fertilizer nitrogen inputs. Specifically, we estimate potential NH3 emissions reductions of 47% (44–56%) for rice, 27% (24–28%) for maize and 26% (20–28%) for wheat cultivation, respectively. Under future climate change scenarios, we estimate that NH3 emissions could increase by 4.0 ± 2.7% under SSP1–2.6 and 5.5 ± 5.7% under SSP5–8.5 by 2030–2060. However, targeted fertilizer management has the potential to mitigate these increases.A machine learning model for generating crop-specific and spatially explicit NH3 emission factors globally shows that global NH3 emissions in 2018 were lower than previous estimates that did not fully consider fertilizer management practices. [ABSTRACT FROM AUTHOR]

Introduction: Based on the modified couple stress theory and the hyperbolic tangential mixed shear deformation theory, the free vibration and the transient responses of the functionally graded piezoelectric (FGP) sandwich microplates with considering the thermal–electric effects are investigated. Methods: By introducing the porosity volume fraction, the perfect FGP sandwich mocroplate are destroyed and porous FGP sandwich plates are constructed. Electro-elastic material properties of porous FGP microplate vary across the thickness based on the modified power-law model. The governing equations derived from Hamilton's principle are solved analytically. Results: By comparisons with the FEM simulation results and the previous results in the literature, the accuracy of the present established models is confirmed. Then the influences of thermal loadings, porosity volune fraction, material gradation, length scale to thickness ratios and facesheet thickness on the dynamic behaviors of FGP sandwich microplates are discussed. Significance: These research can provide a theoretical basis for the accurate design of smart structures made of functionally graded piezoelectric materials. [ABSTRACT FROM AUTHOR]

Phytoplankton blooms in coastal oceans can be beneficial to coastal fisheries production and ecosystem function, but can also cause major environmental problems1,2—yet detailed characterizations of bloom incidence and distribution are not available worldwide. Here we map daily marine coastal algal blooms between 2003 and 2020 using global satellite observations at 1-km spatial resolution. We found that algal blooms occurred in 126 out of the 153 coastal countries examined. Globally, the spatial extent (+13.2%) and frequency (+59.2%) of blooms increased significantly (P < 0.05) over the study period, whereas blooms weakened in tropical and subtropical areas of the Northern Hemisphere. We documented the relationship between the bloom trends and ocean circulation, and identified the stimulatory effects of recent increases in sea surface temperature. Our compilation of daily mapped coastal phytoplankton blooms provides the basis for global assessments of bloom risks and benefits, and for the formulation or evaluation of management or policy actions.Satellite observations reveal global increases in the extent and frequency of phytoplankton blooms between 2003 and 2020 and provide insights into the relationship between blooms, ocean circulation and sea surface temperature. [ABSTRACT FROM AUTHOR]

Radical cascade reactions are powerful tools to construct structurally complex molecules. However, the stereochemical control of acyclic radical intermediates remains a persistent challenge, due to the low differentiation between the two faces of these species. This hurdle further makes stereodivergent synthesis rather more difficult to be accomplished, in particular for intermediates resulted from complex cascades. Here we report an efficient strategy for stereoselective hydrogen atom transfer (HAT) to acyclic carbon radicals, which are generated via N-heterocyclic carbene (NHC)-boryl radicals triggered addition-translocation-cyclization cascades. A synergistic control by the NHC subunit and a thiol catalyst has proved effective for one facial HAT, while a ZnI2-chelation protocol allows for the preferential reaction to the opposite face. Such a stereoselectivity switch enables diastereodivergent construction of heterocycles tethering a boron-substituted stereocenter. Mechanistic studies suggest two complementary ways to tune HAT diastereoselectivity. The stereospecific conversions of the resulting boron-handled products to diverse functionalized molecules are demonstrated. Stereochemical control of acyclic carbon radical intermediates remains a challenge, due to the difficulty in differentiation between the two faces of the planar species. Here the authors show diastereodivergent hydrogen atom transfer to acyclic carbon radicals via control of N-heterocyclic carbene–borane reagents with either a thiol catalyst or a Lewis acid. [ABSTRACT FROM AUTHOR]

Lakes are important natural resources and carbon gas emitters and are undergoing rapid changes worldwide in response to climate change and human activities. A detailed global characterization of lakes and their long-term dynamics does not exist, which is however crucial for evaluating the associated impacts on water availability and carbon emissions. Here, we map 3.4 million lakes on a global scale, including their explicit maximum extents and probability-weighted area changes over the past four decades. From the beginning period (1984–1999) to the end (2010–2019), the lake area increased across all six continents analyzed, with a net change of +46,278 km2, and 56% of the expansion was attributed to reservoirs. Interestingly, although small lakes (<1 km2) accounted for just 15% of the global lake area, they dominated the variability in total lake size in half of the global inland lake regions. The identified lake area increase over time led to higher lacustrine carbon emissions, mostly attributed to small lakes. Our findings illustrate the emerging roles of small lakes in regulating not only local inland water variability, but also the global trends of surface water extent and carbon emissions. Lakes are essential components of the hydrological and biogeochemical cycles. Here, Pi et al develop a global lake dataset called GLAKES via high-resolution satellite images and deep learning to examine global lake changes over four decades. [ABSTRACT FROM AUTHOR]

Tin and tungsten are important metals for the industrializing society. Deciphering the origin and evolution of hydrothermal fluids responsible for their formation is critical to underpin genetic models of ore formation. Traditional approaches obtain isotopic information mainly from bulk analysis of both ore and gangue minerals, or less frequently from in situ analysis of gangue minerals, which either bear inherited complexities and uncertainties or are indirect constraints. Hence, directly obtaining isotopic information from ore minerals such as cassiterite by in situ techniques is warranted. However, this has been hampered by challenges from both analytical and applicational aspects. In this study, we first demonstrate a lack of crystallographic orientation effects during cassiterite ion microprobe oxygen isotope analysis. Along with our newly developed matrix-matched reference material, the Yongde-Cst, which has a recommended δ18O value of 1.36 ± 0.16‰ (VSMOW) as defined by gas source isotope ratio mass spectrometry, in situ oxygen isotope analysis of cassiterite now is possible. We further refine the oxygen isotope fractionation (1000 ln α) for quartz-cassiterite by first-principles calculations, which is given by the equation of 1.259 × 106/T2 + 8.15 × 103/T − 4.72 (T is temperature in Kelvin). The 1000 ln α for quartz-cassiterite has a sensitive response to temperature, and makes cassiterite-quartz an excellent mineral pair in oxygen isotope thermometry, as described by the equation of T (℃) = 2427 × (δ18Oqtz − δ18Ocst)−0.4326 − 492.4. Using the well-established 1000 ln α of quartz-water, 1000 ln α of cassiterite-water is derived as 2.941 × 106/T2 − 11.45 × 103/T + 4.72 (T in Kelvin), which shows a weak response to temperature. This makes cassiterite an ideal mineral from which to derive δ18O of fluids as robust temperature estimates are no longer a prerequisite. We have applied oxygen isotope analysis to cassiterite samples from six Sn(-W) deposits in China. The results show considerable variability in δ18O values both within a single deposit and among studied deposits. Combining the δ18O of cassiterite samples and the equilibrium oxygen isotope fractionation, we find that the δ18O values of ore-forming fluids show a strong magmatic affinity with variable but mostly no to low degree involvements (~0-10%) of meteoric water, hence our results invite a reassessment on the extent and role of meteoric water in Sn-W mineralization. This study demonstrates that in situ oxygen isotope analysis of cassiterite is a promising tool to refine sources of ore-forming fluids, and to decode hydrothermal dynamics controlling tin and tungsten mineralization. [ABSTRACT FROM AUTHOR]

Immiscible polymer blends are an important family of polymer materials. The interfacial thickness between different phases is a very important parameter that dictates, to a great extent, the morphology and properties of such a blend. This work explores and optimizes an up-to-date atomic force microscopy (AFM) of type NanoIR2™ system in order to quantitatively measure the interfacial thickness of immiscible polymer blends. This system is equipped with two nano-probes capable of detecting the response of a material to an infrared pulse called AFM-infrared spectroscopy mode (AFM-IR) or conducting resonance called AFM-Lorentz Contact Resonance mode (AFM-LCR), respectively. Its potential for quantitatively measuring the interfacial thickness of immiscible polymer blends is evaluated using blends composed of polyamide 6 (PA6) and polyolefin elastomer (POE) in the presence or absence of a POE containing maleic anhydride (POE-g-MAH) as a compatibilizer. Surface roughness affects adversely the signal intensity and consequently an accurate measurement of the interfacial thickness. Optimum sample surface preparation procedures are proposed. [ABSTRACT FROM AUTHOR]

Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel with temperature-sensitive properties can be potentially applied in smart response area. However, poor mechanical and non-conductive characteristic have greatly restricted its widespread application. In this work, PNIPAAm composite hydrogels containing graphene aerogel (GA) and graphene oxide (GO) were prepared via vacuum-assisted backfilling and in-situ polymerization. After an introduction of 0.29 wt% GA and 0.09 wt% GO, the compressive strength and modulus of PNIPAAm hydrogel increase by 100% and 582%, respectively. Moreover, the ternary composite hydrogel has a good electric conductivity, reaching up to 0.52 S/m, due to the electro-conductive network of GA. Combining the good conductivity and itself temperature-sensitive property of PNIPAAm, a smart switch was assembled and could switch off automatically under a high voltage, which has potential applications in sensor area. [ABSTRACT FROM AUTHOR]

The Angoumois grain moth, Sitotroga cerealella Olivier (Lepidoptera: Gelechiidae), is the most serious and destructive pest of stored commodities around the globe, particularly on wheat, rice and maize. Previously, we confirmed that diallyl trisulfide (DAT), an active substance from garlic essential oil, reduced oviposition of females after a fumigation at the sublethal concentration (LC20 = 0.015 µL/L); meanwhile, through transcriptome sequencing, we found that DAT significantly downregulates the expression of chitin synthase A (CHSA) gene. To gain a broader insight, we assessed effects of DAT and dsRNA of CHSA gene of S. cerealella (dsScerCHSA) on the morphology, physiology and oviposition of adult S. cerealella, and we found that ScerCHSA was expressed in the adult stage and observed higher in the cuticle. Furthermore, results indicated that DAT fumigation significantly downregulated the mRNA expression of ScerCHSA and inhibited moth oviposition at the sublethal concentration. Downregulation of ScerCHSA resulted in chitin reduction, epidermal disruption, morphological and physiological alterations. Meanwhile, silencing of ScerCHSA resulted in the oviposition reduction of the moth; moreover, the morphological and physiological alterations were similar to the group treated with DAT. Therefore, we conclude that DAT could regulate the expression of ScerCHSA at the transcriptional level, cause histological and morphological alteration and finally inhibit the moth oviposition, which proves DAT possesses the great potential for being used in pest control as a friendly biopesticide. [ABSTRACT FROM AUTHOR]

Under investigation in this paper are the nonlocal symmetries and consistent Riccati expansion integrability of the (2 + 1)-dimensional Boussinesq equation, which can be used to describe the propagation of long waves in shallow water. By constructing the Bäcklund transformation, we obtain the truncated Painlevé expansion of the system. Its Schwarzian form is also derived, whose nonlocal symmetry is localized to provide the corresponding nonlocal group. Furthermore, we verify that the system is solvable via the consistent Riccati expansion (CRE). Based on the CRE, the interaction solutions between soliton and cnoidal periodic wave are explicitly studied. [ABSTRACT FROM AUTHOR]

In this study, we consider an ensemble Kaiman inversion (EKI) for the numerical solution of time fractional diffusion inverse problems (TFDIPs). Computational challenges in the EKI arise from the need for repeated evaluations of the forward model. We address this challenge by introducing a non-intrusive reduced basis (RB) method for constructing surrogate models to reduce computational cost. In this method, a reduced basis is extracted from a set of full-order snapshots by the proper orthogonal decomposition (POD), and a doubly stochastic radial basis function (DSRBF) is used to learn the projection coefficients. The DSRBF is carried out in the offline stage with a stochastic leave-one-out cross-validation algorithm to select the shape parameter, and the outputs for new parameter values can be obtained rapidly during the online stage. Due to the complete decoupling of the offline and online stages, the proposed non-intrusive RB method — referred to as POD-DSRBF — provides a powerful tool to accelerate the EKI approach for TFDIPs. We demonstrate the practical performance of the proposed strategies through two nonlinear time-fractional diffusion inverse problems. The numerical results indicate that the new algorithm can achieve significant computational gains without sacrificing accuracy. [ABSTRACT FROM AUTHOR]

This study focuses on the evolution of flood risk in the Yangtze River Basin under climate change, which is a critical issue for socioeconomic development in future. In this study, we (1) compared the 1998 and 2020 floods and found that the destructiveness of a given discharge is now greater than before; (2) revealed three issues related to the above finding; and (3) prospected the future development of up-to-date technologies to better address the issue that floods with high water levels will frequently threaten us. The outcomes of this study would be of great significance to future flood control operation of large river basins. [ABSTRACT FROM AUTHOR]

Here, the combined approaches of a 15N tracing technique, DNA and mRNA analyses, and modeling were used to investigate the mechanisms underlying rapid nitrate (NO3−) accumulation and identify the relative contributions of autotrophic nitrification, heterotrophic nitrification, codenitrification, and denitrification to nitrous oxide (N2O) production in six vegetable soils. The soil pH had a positive effect on the NO3− retention capacity (p < 0.01) and a negative effect on the net NO3− production rate (p < 0.05), resulting in higher NO3− accumulation in acidic soils. Meanwhile, autotrophic nitrification accounted for 39-86% of N2O production in alkaline soils, whereas denitrification was responsible for 85% of N2O production in acidic soils. The results of structural equation modeling indicated that autotrophic nitrification-derived N2O production was influenced by soil C/N ratio, the gross NO3− production rate, and the ammonia-oxidizing archaea (AOA) amoA/ammonia-oxidizing bacteria (AOB) amoA mRNA ratio, while denitrification-derived N2O production was influenced by pH, the gross NO3− consumption rate, and the abundance of nirS mRNA, all of which were influenced directly and indirectly by in situ climate parameters of mean annual precipitation and mean annual temperature. Furthermore, regression analyses revealed that the soil total N content affected heterotrophic nitrification- and the pH affected codenitrification-derived N2O production, which contributed 9-76% and 0-7%, respectively, to the total N2O production in vegetable soils. The current findings improve our understanding of the mechanisms of NO3− buildup and N2O stimulation in intensively managed agricultural ecosystems. [ABSTRACT FROM AUTHOR]

In recent years, some marine microbes have been used to degrade diesel oil. However, the exact mechanisms underlying the biodegradation are still poorly understood. In this study, a hypothermophilous marine strain, which can degrade diesel oil in cold seawater was isolated from Antarctic floe-ice and identified and named as Rhodococcus sp. LH. To clarify the biodegradation mechanisms, a gas chromatography-mass spectrometry (GC-MS)-based metabolomics strategy was performed to determine the diesel biodegradation process-associated intracellular biochemical changes in Rhodococcus sp. LH cells. With the aid of partial least squares-discriminant analysis (PLS-DA), 17 differential metabolites with variable importance in the projection (VIP) value greater than 1 were identified. Results indicated that the biodegradation of diesel oil by Rhodococcus sp. LH was affected by many different factors. Rhodococcus sp. LH could degrade diesel oil through terminal or sub-terminal oxidation reactions, and might also possess the ability to degrade aromatic hydrocarbons. In addition, some surfactants, especially fatty acids, which were secreted by Rhodococcus into medium could also assist the strain in dispersing and absorbing diesel oil. Lack of nitrogen in the seawater would lead to nitrogen starvation, thereby restraining the amino acid circulation in Rhodococcus sp. LH. Moreover, nitrogen starvation could also promote the conversation of relative excess carbon source to storage materials, such as 1-monolinoleoylglycerol. These results would provide a comprehensive understanding about the complex mechanisms of diesel oil biodegradation by Rhodococcus sp. LH at the systematic level. [ABSTRACT FROM AUTHOR]

This paper reviews China's future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China's total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found. [ABSTRACT FROM AUTHOR]

Under investigation in this paper is a generalized (3 + 1)-dimensional variable-coefficient BKP equation, which can be used to describe the propagation of nonlinear waves in fluid mechanics and other fields. With the aid of binary Bell's polynomials, an effective and straightforward method is presented to explicitly construct its bilinear representation with an auxiliary variable. Based on the bilinear formalism, the soliton solutions and multi-periodic wave solutions are well constructed. Furthermore, the tanh method and the tan method are employed to construct more traveling wave solutions of the equation. Finally, the asymptotic properties of the multi-periodic wave solutions are systematically analyzed to reveal the connection between periodic wave solutions and soliton solutions. It is interesting that the periodic waves tend to solitary waves under a limiting procedure. Our results can be used to enrich the dynamical behavior of higher-dimensional nonlinear wave fields. [ABSTRACT FROM AUTHOR]

This paper presents an image denoising method based on bilateral filtering and non-local means. The non-local region texture or structure of the image has the characteristics of repetition, which can be used to effectively preserve the edge and detail of the image. And compared with classical methods, bilateral filtering method has a better performance in denosing for the reason that the weight includes the geometric closeness factor and the intensity similarity factor. We combine the geometric closeness factor with the weight of non-local means, and construct a new weight. Experimental results show that the modified algorithm can achieve better performance. And it can protect the image detail and structure information better. [ABSTRACT FROM AUTHOR]

In this paper, a lucid and systematic approach is proposed to systematically study the periodic-wave solutions and asymptotic behaviors of a (2 + 1) -dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt (gKDKK) equation, which can be used to describe certain situations from the fluid mechanics, ocean dynamics and plasma physics. Based on Bell's polynomials, the bilinear formalism and N -soliton solution of the gKDKK equation are derived, respectively. Furthermore, based on multidimensional Riemann theta functions, the periodic-wave solutions of the equation are also constructed. Finally, an asymptotic relation between the periodic-wave solutions and soliton solutions are strictly established under a limited procedure. [ABSTRACT FROM AUTHOR]

Purpose: To investigate and compare the contrast-enhanced ultrasound (CEUS) features of histologically proven HCA with those of contrast-enhanced computed tomography (CECT). Methods: Eighteen patients with proven hepatic adenoma by pathology were retrospectively selected from the CEUS database. Fourteen of them had undergone liver CECT exams. The basic features on unenhanced imaging and the enhancement level and specific features on contrast-enhanced imaging were retrospectively analyzed, and the differences between CEUS and CECT were compared. Results: All the HCAs showed hyper-enhancement in the arterial phase. During the portal and late phases, 12 HCAs (12/18, 66.7 %) on CEUS and 11 (11/14, 78.6 %) on CT showed washout. On CEUS, 10 (10/18, 55.5 %) showed centripetal filling in the arterial phase and persistent peripheral rim enhancement. Five of them (61.1 %, 11/18) showed delayed central washout in the portal or late phase. However, on CECT, 2 (14.3 %, 2/14) and 4 (28.6 %, 4/14) HCAs showed persistent enhancement of the peripheral rim and central non-enhancing hemorrhage areas, respectively. Conclusions: Compared with dynamic CT, CEUS was superior at characterizing specific dynamic features. Considering that it is radiation-free, readily availability and easy to use, CEUS is suggested as the first line imaging tool to diagnose HCA. [ABSTRACT FROM AUTHOR]

Ensemble learning is a wildly concerned issue. Traditional ensemble techniques are always adopted to seek better results with labeled data and base classifiers. They fail to address the ensemble task where only unlabeled data are available. A label propagation based ensemble (LPBE) approach is proposed to further combine base classification results with unlabeled data. First, a graph is constructed by taking unlabeled data as vertexes, and the weights in the graph are calculated by correntropy function. Average prediction results are gained from base classifiers, and then propagated under a regularization framework and adaptively enhanced over the graph. The proposed approach is further enriched when small labeled data are available. The proposed algorithms are evaluated on several UCI benchmark data sets. Results of simulations show that the proposed algorithms achieve satisfactory performance compared with existing ensemble methods. [ABSTRACT FROM AUTHOR]

A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three groups of rats were determined including control rats, rats treated with blended cigarettes (nonmenthol cigarettes) and rats treated with menthol cigarettes. The total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), total 1-hydroxypyrene (1-HOP) and 3-hydroxybenzo[a] pyrene (3-HOBaP) were determined for assessing exposure to cigarette sidestream smoke toxins. Urinary endogenous metabolites in the three groups of rats were also analyzed and the data were processed by chemometrics. Eleven endogenous metabolites were found and identified. Their relative levels were compared among the three groups. The results show that cigarette sidestream smoke has complex effect on rats. Blended cigarette group makes difference to menthol cigarette group in the rats' urinary metabolic changes. Menthol adding to cigarettes has positive and negative effects on rats, respectively. The urinary metabolic profiling of menthol cigarette group is closer to that of control group. [ABSTRACT FROM AUTHOR]

Harmful algal blooms depend on several factors linked to climate and catchment conditions. Blooms can show significant daily, monthly, seasonal, inter-annual variability as well as horizontal variation in a lake. In the present study, we use satellite data to explore the sensitivity of different sections of a large eutrophic lake (Lake Taihu) to climate and catchment-related drivers. Bloom coverage in the larger open areas of the lake, historically less eutrophic, has increased over the last 12 years even though extensive efforts were made to improve catchment conditions. Decadal trends in these lake sections were more sensitive to climate conditions and nutrient concentrations compared with the more enclosed eutrophic bays. Bloom coverage was bimodal during the year, with regional differences occurring during the second maximum. Links between climate variability, nutrients, and bloom coverage suggest that major bloom events are likely to continue to occur. [ABSTRACT FROM AUTHOR]

The transcription factor Nfic is a key regulator during tooth development. Nfic deficient mice exhibit short and abnormal molar roots and severely deformed incisors. Dental epithelial cells, known as Hertwig's epithelial root sheath (HERS), participate in root formation. However, whether Nfic is involved in HERS-mesenchyme interaction remains unclear. In this study, the detail temporal and spatial expression pattern of Nfic during rat molar development was examined using immunohistochemistry and in situ hybridization. Nfic was detected in ameloblasts, dental follicle cells (DFCs) and dental papilla cells (DPCs), especially the DPCs close to dentin, from postnatal day 5 to day 16. Nfic expression in DPCs, DFCs and HERS cells was also examined by western blot and RT-PCR. Nfic was detected in DPCs and DFCs, but not in HERS cells. Co-culture experiment further indicated that Nfic mRNA expression in DPCs was elevated by the presence of HERS cells. Our results revealed that Nfic could be a marker gene for root odontoblasts differentiation initiation and its expression might be regulated through epithelial-mesenchymal interaction. [ABSTRACT FROM AUTHOR]

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Previous studies suggest that osteopontin (OPN) levels are associated with the incidence and development of multiple types of cancer. This study analyzes the correlation between OPN gene variants and nasopharyngeal carcinoma (NPC). A total of 150 NPC patients and 150 healthy adults were enrolled and divided into NPC and control groups. In both groups, four OPN polymorphisms including rs1126772, rs4754, rs11728697 and rs9138 were quantitatively genotyped by SNaPshot SNP genotyping assay. Allele frequencies of four OPN polymorphisms were compared between two groups. No statistical significance was noted regarding genotype frequency of four OPN polymorphisms between male NPC and healthy subjects (all P > 0.05). Female subjects between two groups significantly differed in terms of genotype frequency of rs1172869 ( P = 0.002). No statistical significance was observed in allele frequencies in each of four OPN polymorphisms between two groups (all P > 0.05). For NPC patients, the polymorphisms information content (PIC) ranged from 0.2961 to 0.3584 and 0.3047 to 0.3655 for normal controls. Additionally, rs11728697 had the highest effective number of alleles (N), expected heterozygosity (H) and PIC in two groups. Female subjects in two groups significantly differed in the genotype frequency of rs1172869 while no statistical significance was noted for male counterparts. All subjects in the NPC and control groups had similar allele frequency. All the four OPN polymorphisms were moderately polymorphic. The mean N, N, Ho, He and PIC of each OPN polymorphism in the control group were higher than those in the NPC group without a significant difference. [ABSTRACT FROM AUTHOR]

The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC. The flavonoids were extracted separately by hot and cold water, and higher total flavonoid contents were detected in the former extracts than the latter ones. All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals, which indicates the health benefits of the water extracts of citrus fruits peels. For DPPH radical, the IC values of hot extract follow as Navel orange (NO)≈Mandarin orange (MO)< Lemon (LE)< Lo tangerine (LO)< Pomelo (PO), while the rank is NO< PO

The signal-to-noise ratio (SNR, or sensitivity) of an ocean color instrument is a critical parameter to determine the accuracy and precision of the data products. Yet published literature showed various formats in SNR specifications under different conditions, making a direct cross-sensor comparison difficult. Here, we compared the SNRs of GOCI spectral bands with those of SeaWiFS and MODIS/Aqua under the same radiance inputs. We also compared their ability to resolve small changes in the retrieved chlorophyll- a data products (Chl). While GOCI visible bands showed similar at-sensor SNRs to SeaWiFS, the near-infrared (NIR) bands showed significantly higher SNRs. Because the NIR bands were used for atmospheric correction, the increases in SNRs led to reduced noise in the retrieved Chl, as shown in the GOCI and SeaWiFS Chl products for Chl < 0.1 mg m. The noise in the retrieved products also depends on the retrieval algorithms in addition to the sensor SNR. When a new band-subtraction algorithm (the Ocean Color Index or OCI algorithm) was applied to the same GOCI remotesensing reflectance data derived from the GDPS software package, significant noise reduction was found in the Chl product for low concentrations (< 0.25 mg m), leading to product precision (∼3% in Chl) comparable to those from MODIS/Aqua measurements. This is certainly a significant achievement, as GOCI spatial resolution is much higher than MODIS (500 m versus 1 km). In addition, artifacts across image mosaic edges over low-concentration waters have been removed nearly completely by the OCI algorithm. Data analyses also indicated that GOCI radiometric calibration requires further improvement. [ABSTRACT FROM AUTHOR]

In this paper, a method based on the Dirichletto-Neumann map is developed for bandgap calculation of mixed in-plane waves propagating in 2D phononic crystals with square and triangular lattices. The method expresses the scattered fields in a unit cell as the cylindrical wave expansions and imposes the Bloch condition on the boundary of the unit cell. The Dirichlet-to-Neumann (DtN) map is applied to obtain a linear eigenvalue equation, from which the Bloch wave vectors along the irreducible Brillouin zone are calculated for a given frequency. Compared with other methods, the present method is memory-saving and time-saving. It can yield accurate results with fast convergence for various material combinations including those with large acoustic mismatch without extra computational cost. The method is also efficient for mixed fluid-solid systems because it considers the different wave modes in the fluid and solid as well as the proper fluid-solid interface condition. [ABSTRACT FROM AUTHOR]

A series of Ag, Cu and Co-doped manganese oxide octahedral molecular sieves (OMS-2) were synthesized and evaluated to remove nitrogen oxides (NO) from cigarette mainstream smoke. The three kinds of catalysts were added to cigarettes for studying the capabilities of reducing NO from cigarette mainstream smoke. The catalysis and reduction of NO in laboratory were studied. A mechanism for NO catalytic reduction from burning cigarettes with the catalysts adding to cigarettes was described. The catalysts show excellent catalytic activity for NO removal, especially the Ag-doped OMS-2 catalyst. 0.5% (mass fraction) Ag-doped OMS-2 catalyst has the best ability to remove NO from cigarette mainstream smoke. The use of Ag-doped OMS-2 as catalyst for removing carcinogenic compounds from cigarette smoke will be an effective strategy to protect the environment and public health. [ABSTRACT FROM AUTHOR]

We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m, revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake, the largest freshwater lake in China, as an example. Field surveys conducted during October 17-26, 2009 showed a wide range of TSS concentration (3-524 mg/L). Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys, which worked well at the CCD bands with relatively high reflectance. A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration. The retrieved results for the whole water area matched the in-situ data well at most stations. The retrieval errors may be related to the problem of scale matching and mixed pixel. In three selected subregions of Poyang Lake, the distribution trend of retrieved TSS was consistent with that of the field investigation. It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm. [ABSTRACT FROM AUTHOR]

In this study, the fumigant activity of garlic essential oil and its major components, diallyl disulfide, diallyl trisulfide, and diallyl sulfide, against the stored-product insect, Tribolium castaneum, were investigated. Results from the space fumigation revealed that garlic essential oil and diallyl trisulfide had strong fumigant activities against the adult insect. In glass chambers (10 cm in diameter × 125 cm in height) filled with 10, 20, 30, 40, and 50% volume of rough rice, the fumigant activity of diallyl trisulfide was more potent than that of garlic essential oil. At the concentration of 8 μl/l and 50% filling ratio, to obtain 100% mortality, exposure time of only 4 days was needed for diallyl trisulfide, but a longer exposure time (6–7 days) was required for garlic essential oil. Meanwhile, the fumigant effects on the germination rate of kernels exposure were ascertained. Results proved that there were no side effects for these substances on germination rate of kernels exposed 6 months after fumigation. In addition, the fumigant effect on F1 progeny production in rough rice was also evaluated for garlic essential oil and diallyl trisulfide. The results showed that progeny production was totally suppressed at 4 μl/l of these two substances, either at 10 or 50% filling ratio. The results may provide valuable advances for future fumigant development and possible utility as a fumigant especially as a seed protectant in warehouses filled with grain. [ABSTRACT FROM AUTHOR]

Anterior decompression and fusion is an established procedure in surgical treatment for multilevel cervical spondylotic myelopathy (MCSM). However, contiguous corpectomies and fusion (CCF) often induce postoperative complications such as nonunion, graft subsidence, and loss of lordotic alignment. As an alternative, noncontiguous corpectomies or one-level corpectomy plus adjacent-level discectomy with retention of an intervening body has been developed recently. In this study, we prospectively compared noncontiguous anterior decompression and fusion (NADF) and CCF for MCSM in terms of surgical invasiveness, clinical and radiographic outcomes, and complications. From January 2005 to June 2007, 105 patients with MCSM were randomized to NADF group ( n = 55) and CCF group ( n = 50), and followed up for average 31.5 months (range 24–48 months). Average operative time and blood loss decreased significantly in the NADF group as compared with those in the CCF group ( p < 0.05 and <0.001, respectively). For VAS, within 3 months postoperatively, there was no significant difference between the two groups. But at 6 months after surgery and final follow-up, VAS improved significantly in NADF group than that in CCF group ( p < 0.05). No significant difference of JOA score was observed between the two groups at every collection time. In NADF group, all 55 cases obtained fusion at 1 year after operation (average 5.1 months). In CCF group, 48 cases achieved fusion 1 year postoperatively, but the other 2 cases were performed posterior stabilization and achieved fusion 6 months later. The differences of cervical lordosis between two groups were insignificant at the same follow-up time. But the loss of lordosis and height of fusion segments in 6 months postoperatively and final follow-up were significantly more in CFF group than in NADF group ( p < 0.001). Complications were similar in both groups. But in CCF group three cases needed reoperation, one case with extradural hematoma was immediately re-operated after anterior decompression and two cases mentioned above were performed posterior stabilization at 1 year postoperatively. In conclusion, in the patients with MCSM, without developmental stenosis and continuous or combined ossification of posterior longitudinal ligaments, NADF and CCF showed an identical effect of decompression. In terms of surgical time, blood loss, VAS, fusion rate and cervical alignment, NADF was superior compared with CCF. [ABSTRACT FROM AUTHOR]

Let $$ \mathcal{G} $$ be the complexification of the real Lie algebra so(3) and A = ℂ[ t, t] be the Laurent polynomial algebra with commuting variables. Let L( t1, t2, 1) = $$ \mathcal{G} $$⊕C A be the twisted multi-loop Lie algebra. Recently we have studied the universal central extension, derivations and its vertex operator representations. In the present paper we study the automorphism group and bosonic representations of L( t1, t2, 1). [ABSTRACT FROM AUTHOR]

L p − L q decay estimate of solution to Cauchy problem of a linear thermoviscoelastic system is studied. By using a diagonalization argument of frequency analysis, the coupled system will be decoupled micrologically. Then with the help of the information of characteristic roots for the coefficient matrix of the system, L p − L q decay estimate of parabolic type of solution to the Cauchy problem is obtained. [ABSTRACT FROM AUTHOR]

Abstract   Background It has been reported lately that Toll-like receptors (TLRs) play an essential role in the activation of innate immunity, and TLRs are expressed in a large number of immune cells like B-lymphocytes, monocytes, plasmacytoid dendritic cells and at low levels in human respiratory cells as well as epithelial cells. In the present study, we investigated whether there is a relationship between the expression of TLR4 or TLR9 and the clinical or pathological changes in human lung cancer. Method Protein expression of TLR4 and TLR9 was assessed by using immunohistochemistry and western blotting. mRNA expressions of TLR4 and TLR9 were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results High TLR4 and TLR9 mRNA signal intensity was found in the majority of lung cancer specimens. In contrast, tumor-free lung tissue showed lower signal intensity. Consistently, the low amount of TLR4 and TLR9 protein expression was found in tumor-free lung tissue, while they were strongly expressed in lung cancer tissue. In addition, we found for the first time that the differentiation degree of tumor cells was positively correlated with the expression level of TLR4. There was no relationship between the expressions of TLR4 or TLR9 and patients’ age, gender, smoking, the histological type of tumor, lymph node metastasis, and tumor node metastases (TNM) stage. Conclusions We found that both mRNA and protein levels of TLR4 and TLR9 were strongly expressed in lung cancer tissue. In addition, we reported for the first time a positive correlation between the expression level of TLR4 and malignancy of lung cancer. These results suggested that TLR4 and TLR9 may be involved in the development of lung cancer which may have the potentials for the treatment of this malignant tumor. [ABSTRACT FROM AUTHOR]

For this study, an intercalation compounding method was used to prepare Chinese fir wood/Ca-montmorillonite (Ca-MMT) composite board to improve its properties such as surface mechanical properties, flame retardance and dimensional stability. By virtue of water-soluble phenolic resin (PF), Chinese fir wood and Ca-MMT were mixed by pressure and vacuum impregnation. The optimum impregnation technology of Chinese fir wood/Ca-MMT composite board was obtained by using an orthogonal design and a single factor design of pressure and vacuum impregnation, using weight percent gain (WPG) as the basic index. The results are as follows: 1) On the basis of the orthogonal design and an actual experiment, the optimum preparation technology of Chinese fir wood/Ca-MMT composite board is 20% PF resin dispersion concentration (wt%), 1.0 CEC amount of organic intercalation agent, 0.098 MPa vacuum degree, 5% concentration of Ca-MMT and 1.0 MPa pressure. 2) The WPG of the composite board samples of 450 mm length was much larger than that of the samples of 600, 750 and 900 mm length. Warm water extraction contributed little to WPG. [ABSTRACT FROM AUTHOR]

A new method for the determination of DNA was developed with azocarmine G(AG) in the presence of cetyltrimethylammonium bromide(CTAB) by the resonance light scattering (RLS) technique. The synthetic samples were determined with satisfactory results, and the reaction mechanism was also studied. The results show that under the optimum conditions, the weak RLS signal of AG can be enhanced by DNA, which results from the formation of a new ternary complex AG-CTAB-DNA with large size. Moreover, the enhanced RLS intensity at 552 nm is directly proportional to the concentration of DNA in the range of 0–1.0 µg/mL for fish sperm DNA (fsDNA) and 0–1.5 µg/mL for calf thymus DNA (ctDNA). Based on this, a new assay of DNA can be established. The detection limits (3 σ) are 2.1 ng/mL for fsDNA and 2.2 ng/mL for ctDNA, respectively. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of different reagents on changes of the crystalline region and amorphous region (Matrix) in wood cell walls, the creep behavior of Chinese fir ( Cunninghamia lanceolata) wood treated with dimethyl sulfoxide (DMSO) and diethyl amine, sulfur dioxide and dimethyl sulfoxide mixture (DEA-SO2-DMSO), and the untreated wood at oven-dried, air-dry and water-saturated states during adsorption and desorption processes were all examined in air or in water. The measurements were carried out at ambient temperature and atmospheric pressure. The load is constant with 62 g or 0.607 6 N. The results obtained were as follows: 1) The instantaneous compliance J 0 and the creep compliance J of specimens decrystallized with DEA-SO2-DMSO solution were bigger than those of DMSO swollen wood, and the latter was still much bigger than those of untreated wood. 2) For untreated wood, J 0 and J increased with equilibrium moisture content (EMC) of wood, but there was not apparent correlation between wood EMC and the relative compliance. 3) Specimens treated with DMSO and DEA-SO2-DMSO mixture were recrystallized after immersion in water, and the degree of recrystallization of the former was larger. 4) For oven-dried specimens, the creep compliances in water were bigger than those in air. But for fiber-saturated and water-saturated specimens they were nearly equivalent to each other. [ABSTRACT FROM AUTHOR]

Objective: To observe the effects of arsenic trioxide (AsO) on human renal cell carcinoma (RCC) lines in vitro and to explore its possible molecular mechanisms. Methods: The microculture tetrazolium (MTT) assay was used to determine the anti-proliterative effects of AsO on human RCC lines. Flow cytometry was performed to investigate the effects of AsO on cell cycle and cell apoptosis. The reverse transcription-polymerase chain reaction (RT-PCR) was conducted to detect mRNA expression of Bcl-2, Bax, p53 and c-myc. Results: AsO inhibited the growth of RCC lines in vitro in a concentration-dependent manner. At the concentrations of 0.5, 1.0, 2.0 and 4. 0 μmol/L, the inhibition rates of AsO on RCC-WCS cells were 27.60%, 30.09%, 41.03% and 50.77%, respectively. Compared with untreated RCC-WCS, there was significant difference at each concentration ( P<0.01). AsO induced a G phase arrest in RCC-LSL cells, but a G/M phase arrest in RCC-WCS and RCC-SHK. AsO induced cell apoptosis in these cell lines. The mRNA level of p53 and c-myc decreased, but no detectable changes of Bcl-2 and Bax were observed after AsO treatmen. Conclusion: AsO in therapeutic concentrations inhibited the in vitro growth of RCC lines via cell cycle arrest and apoptosis. One of its possible mechanisms was down-regulation of p53 and c-myc. Our results suggest that AsO is probably a new candidate agent for the treatment of human renal carcinoma. [ABSTRACT FROM AUTHOR]

The complexes of rare earth bromides with alanine, REBr3·3Ala·nH2O (RE=Ce, Pr, Sm, Eu, Gd and Tb, n=3; RE=Dy and Y, n=2.5 Ala=alanine), were prepared and characterized by means of chemical analysis, elemental analysis, molar conductivity, thermogravimetry, IR spectra and X-ray diffraction. The thermal decomposition in N2 of these complexes was studied by means of TG-DTG techniques from ambient temperature to 1000°C. During heating, the hydrated complexes of Ce, Pr and Y lose waters in one step, but the hydrated complexes of Sm, Eu, Gd, Tb and Dy lose waters in two steps. Then anhydrous complexes lose 2.5 alanine molecules except the complexes of Eu which lose three alanine molecules. Apparently, only be complex of Eu has an intermediate, EuOBr. All complexes finally decompose to oxides. [ABSTRACT FROM AUTHOR]

After removal of suspended matter in 1 liter of water by flotation with a cationic surfactant, humic acid at the μg/l level is separated from fulvic acid by coprecipitation with milligram quantities of iron(III) hydroxide at pH 7 followed by flotation with anionic surfactants. The iron(III) hydroxide is dissolved in 2 M hydrochloric acid, and the acid-insoluble humic acid is filtered off on an ultrafilter and then dissolved in 10 ml of 0.1 M potassium hydroxide solution for measurements of absorption spectra, molecular weight distribution and complexing ability. The time required for the separation is ca. 1 h. [ABSTRACT FROM AUTHOR]

Abstract Myofiber necrosis and fibrosis are hallmarks of Duchenne muscular dystrophy (DMD), leading to lethal weakness of the diaphragm. Macrophages (MPs) are required for successful muscle regeneration, but the role of inflammatory monocyte (MO)‐derived MPs in either promoting or mitigating DMD is unclear. We show that DMD (mdx) mouse diaphragms exhibit greatly increased expression of CCR2 and its chemokine ligands, along with inflammatory (Ly6Chigh) MO recruitment and accumulation of CD11bhigh MO‐derived MPs. Loss‐of‐function of CCR2 preferentially reduced this CD11bhigh MP population by impeding the release of Ly6Chigh MOs from the bone marrow but not the splenic reservoir. CCR2 deficiency also helped restore the MP polarization balance by preventing excessive skewing of MPs toward a proinflammatory phenotype. These effects were linked to amelioration of histopathological features and increased muscle strength in the diaphragm. Chronic inhibition of CCR2 signaling by mutated CCL2 secreted from implanted mesenchymal stem cells resulted in similar improvements. These data uncover a previously unrecognized role of inflammatory MOs in DMD pathogenesis and indicate that CCR2 inhibition could offer a novel strategy for DMD management.

Organoboron compounds are highly valuable in synthetic chemistry. In particular, α-borylcarbonyl compounds have shown versatile synthetic applications, owing to fruitful chemistries of both the boryl and carbonyl moieties. However, the synthesis of these molecules still remains tedious and time-consuming. Here we report a straightforward and practical route to synthesize α-borylcarbonyl molecules based on a regioselective radical α-borylation of α,β-unsaturated carbonyl compounds. The reaction features unusual α-regioselectivity and high functional-group compatibility. Further synthetic applications of new α-borylated products were also demonstrated. DFT and kinetic studies implicated that the α-regioselectivity of β-aryl-α,β-unsaturated carbonyl compounds was determined by the thermodynamically more favorable radical α-addition step, whereas the formation of α-addition products from β-alkyl-α,β-unsaturated carbonyl compounds was driven by an energetically favored hydrogen atom transfer step. Given that α,β-unsaturated carbonyl compounds can be easily obtained in abundance and variety, this method enjoys great advantages in diverse and economical synthesis of valuable α-borylcarbonyl molecules. α-Borylcarbonyl compounds are versatile synthons in organic synthesis, however their preparation is often tedious. Here, the authors report a regioselective radical α-borylation of α,β-unsaturated carbonyl compounds to afford α-borylcarbonyl molecules with high selectivity and functional group compatibility. [ABSTRACT FROM AUTHOR]