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Biodiversity change under current global warming scenario has attracted wide attentions, representing general stability and balance in ecosystems. Understanding the temporal patterns and potential driving mechanisms of biodiversity changes would provide significant knowledge for ecosystem sustainability, which requires necessary investigations on long-term records during the late Holocene. The high elevation and specific environment on the Qinghai-Tibetan Plateau (QTP) promote the development of fragile alpine ecosystems, responding sensitively to regional climate variations. Based on a high-resolution fossil pollen record retrieved from Lake Kusai on the northern QTP, late Holocene vegetation diversities were estimated based on the Hill number indices, which were subsequently evaluated at three time scales, i.e., millennial, centennial and multi-decadal time scales. The results indicate that Hill number indices could represent vegetation diversity changes on the northern QTP. Reconstructed vegetation diversity indices indicate gradual variations on millennium scale in each diversity index, along with different responses to environmental factors of regional moisture and total solar irradiance. On the centennial time scale, high consistencies were identified among the vegetation diversity indices as well as correlations with environmental factors, revealing overall positive responses between diversity variations and environmental changes. Rather complicated correspondences to environmental factors appeared on the multi-decadal scale, showing different patterns in diversity indices, which illustrates variations through time as well. Accordingly, vegetation diversity changes of the alpine communities on the northern QTP experienced serious variations during the late Holocene, and revealed complicated responses to regional environmental changes, that further investigations particularly at different time scales would be necessary in the future. [ABSTRACT FROM AUTHOR]

As an important member of the two‐component system (TCS), histidine kinases (HKs) play important roles in various plant developmental processes and signal transduction in response to a wide range of biotic and abiotic stresses. So far, the HK gene family has not been investigated in Gossypium. In this study, a total of 177 HK gene family members were identified in cotton. They were further divided into seven groups, and the protein characteristics, genetic relationship, gene structure, chromosome location, collinearity, and cis‐elements identification were comprehensively analyzed. Whole genome duplication (WGD) / segmental duplication may be the reason why the number of HK genes doubled in tetraploid Gossypium species. Expression analysis revealed that most cotton HK genes were mainly expressed in the reproductive organs and the fiber at initial stage. Gene expression analysis revealed that HK family genes are involved in cotton abiotic stress, especially drought stress and salt stress. In addition, gene interaction networks showed that HKs were involved in the regulation of cotton abiotic stress, especially drought stress. VIGS experiments have shown that GhHK8 is a negative regulatory factor in response to drought stress. Our systematic analysis provided insights into the characteristics of the HK genes in cotton and laid a foundation for further exploring their potential in drought stress resistance in cotton. [ABSTRACT FROM AUTHOR]

As an important member of the two‐component system (TCS), histidine kinases (HKs) play important roles in various plant developmental processes and signal transduction in response to a wide range of biotic and abiotic stresses. So far, the HK gene family has not been investigated in Gossypium. In this study, a total of 177 HK gene family members were identified in cotton. They were further divided into seven groups, and the protein characteristics, genetic relationship, gene structure, chromosome location, collinearity, and cis‐elements identification were comprehensively analyzed. Whole genome duplication (WGD) / segmental duplication may be the reason why the number of HK genes doubled in tetraploid Gossypium species. Expression analysis revealed that most cotton HK genes were mainly expressed in the reproductive organs and the fiber at initial stage. Gene expression analysis revealed that HK family genes are involved in cotton abiotic stress, especially drought stress and salt stress. In addition, gene interaction networks showed that HKs were involved in the regulation of cotton abiotic stress, especially drought stress. VIGS experiments have shown that GhHK8 is a negative regulatory factor in response to drought stress. Our systematic analysis provided insights into the characteristics of the HK genes in cotton and laid a foundation for further exploring their potential in drought stress resistance in cotton. [ABSTRACT FROM AUTHOR]

Antibiotic residues pose a serious threat to ecosystems and food safety. Developing convenient, visual, and on-site detection methods is therefore in high demand and has a practical purpose. In this work, a near-infrared (NIR) fluorescent probe with an analysis platform based on a smartphone has been constructed for quantitative and on-site detection of metronidazole (MNZ). CdTe quantum dots with NIR emission at 710 nm (QD710) were prepared by using a simple hydrothermal method and showed good properties. A spectral overlap between absorption of MNZ and excitation of QD710 resulted in an effective inner filter effect (IFE) between QD710 and MNZ. Because of the IFE, the fluorescence of QD710 decreased gradually with increasing concentrations of MNZ. Based on the fluorescence response, quantitative detection and visualization of MNZ was achieved. NIR fluorescence analysis and the special IFE between probe and target can improve sensitivity and selectivity for MNZ. Additionally, these were also utilized for quantitative detection of MNZ in real food samples and the results were reliable and satisfactory. Meanwhile, a portable visual analysis platform in a smartphone was constructed for on-site analysis of MNZ, which can be used as an alternative method for detection of MNZ residues in situations with limited instrumental conditions. Therefore, this work provides a convenient, visual, and real-time analysis method for detection of MNZ and the analysis platform shows great potential for commercialization. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium spp.) is the fifth largest oil crop in the world, and cottonseed provides abundant vegetable oil resources and industrial bioenergy fuels for people; therefore, it is of practical significance to increase the oil content of cotton seeds for improving the oil yield and economic benefits of planting cotton. Long-chain acyl-coenzyme A (CoA) synthetase (LACS) capable of catalyzing the formation of acyl-CoAs from free fatty acids has been proven to significantly participate in lipid metabolism, of which whole-genome identification and functional characterization of the gene family have not yet been comprehensively analyzed in cotton. In this study, a total of sixty-five LACS genes were confirmed in two diploid and two tetraploid Gossypium species, which were divided into six subgroups based on phylogenetic relationships with twenty-one other plants. An analysis of protein motif and genomic organizations displayed structural and functional conservation within the same group but diverged among the different group. Gene duplication relationship analysis illustrates the LACS gene family in large scale expansion through WGDs/segmental duplications. The overall Ka/Ks ratio indicated the intense purifying selection of LACS genes in four cotton species during evolution. The LACS genes promoter elements contain numerous light response cis-elements associated with fatty acids synthesis and catabolism. In addition, the expression of almost all GhLACS genes in high seed oil were higher compared to those in low seed oil. We proposed LACS gene models and shed light on their functional roles in lipid metabolism, demonstrating their engineering potential for modulating TAG synthesis in cotton, and the genetic engineering of cottonseed oil provides a theoretical basis. [ABSTRACT FROM AUTHOR]

A new sensitive fluorescent probe (CDs-AgNP/H2O2) for detecting sulfite and bisulfite (SO32− and HSO3−) based on the inner-filter effect (IFE) between silver nanoparticles (AgNPs) and carbon dots (CDs) was developed. Because of the spectral overlap between the absorption of AgNPs and the excitation of CDs, the fluorescence of CDs can be quenched by AgNPs owing to the IFE. H2O2 weakens the IFE and restores the fluorescence due to the oxidation of AgNPs by H2O2. However, the existence of SO32−/HSO3− can quench the fluorescence again as a result of redox reaction between SO32−/HSO3− and H2O2. The results showed a broad linear range of 20–200 μM with a low limit of detection (3.02 μM) toward SO32−/HSO3−. The combination of IFE and redox reaction led to improvement of the sensitivity and selectivity. The probe was implemented to measure SO32−/HSO3− in various agricultural products and foods with acceptable results (80.6 to 118.9% recovery). [ABSTRACT FROM AUTHOR]

Microbial glycerol dialkyl glycerol tetraethers (GDGTs) in lacustrine sediments are widely used to reconstruct terrestrial paleoenvironments. However, lipids of diverse origin in lakes make it difficult to decipher environmental information, appealing for the necessity to evaluate the impact of terrigenous input on the distribution of GDGTs through long-term monitoring. In this study, we conducted two-year monitoring of GDGTs along the river, estuary, near shore, to the center of Lake Liangzi in central China. By comparing the spatiotemporal changes of GDGT distribution in suspended particulate matter (SPM) and surface sediments, we found that the archaeal isoprenoid GDGTs (isoGDGTs) were mainly produced in situ in the river-lake systems, and not affected by the soil input. In contrast, the bacterial branched GDGTs (brGDGTs) were affected, to some extent, by soil input, depending on the distance to the lakeshore. The soil input of brGDGTs was enhanced during an episode of abnormal rainfall (flood). Moreover, the large variation of isoGDGTs indicates the in situ production under the anoxic condition in lake water. The paired increase in the GDGT-0/Cren ratio and GDGT concentration might be diagnostic of flooding events in ancient times. [ABSTRACT FROM AUTHOR]

Understanding long-term vegetation diversity patterns and their potential responses to climate and/or human driven processes are important for ecosystem modeling and conservation. Late-Holocene fossil pollen assemblage and associated vegetation diversity estimates provide an opportunity to explore the interactions among vegetation, climate, and human activities. A continuous 2000-year palynological record was obtained from the Beihai Wetland, southwestern China, to represent regional vegetation history, particularly the vegetation diversity changes. The results indicate that regional vegetation was dominated by deciduous broadleaved forest components (e.g. Alnus, deciduous Quercus), which showed a gradual decrease accompanied by expansion of herbaceous taxa (mainly Poaceae) after AD 800. Such progressive decline of forest was attributed to regional deforestation driven by intensified human activities, which was further confirmed by the increasing non-pollen polymorph abundance, particularly an abrupt rise after AD 1350. Vegetation diversity based on the Hill numbers (N 0, N 1, and N 2) showed a dramatic decline between ca. AD 200–400, which was triggered by regional fire events as shown by increased charcoal abundance from a nearby lake. The vegetation diversity reduced gradually after AD 800, especially the vegetation richness reflected by N 0, revealing the transitional process from climate-driven to human-dominated vegetation changes. Minor increases of vegetation diversity occurred during Chinese dynastical transitions, probably due to reduced human activities following war-induced population crises. On the multidecadal scale, variations in vegetation diversity correlated significantly with climate fluctuations (revealed by synthesized temperature of China and stable oxygen isotope record from Dongge Cave) before AD 800, indicating a climate dominant condition. Then, the correlation between vegetation diversity and climate declined after AD 800, representing a progressive transition to human-dominant condition. In addition, the compositional turnover based on DCCA of the fossil pollen assemblage revealed a stepwise decrease, indicating reduced vegetation turnovers under anthropogenic influences. [ABSTRACT FROM AUTHOR]

The development of efficient, rapid, portable, and accurate analysis of veterinary drug residues in food matrices is in great demand for food safety assessment. Here, we have developed a smartphone-integrated platform for fluorometric quantification of metronidazole (MNZ) residues and constructed a sensor array for discrimination of different nitroimidazole antibiotics (NIIMs). Multicolor CDs (B-CDs, C-CDs, Y-CDs, and R-CD) were prepared and showed different fluorescence response to MNZ. The fluorescence of C-CDs was quenched Because of the inner filter effect (IFE) between the C-CDs and MNZ, while that of R-CDs was enhanced due to the passivation of surface defects by MNZ. Based on the response pattern, the fluorometric quantification of MNZ based on the fluorescence images of C-CD + R-CD system (R/G values) was achieved with a low detection limit of 0.45 μM. By designing a smartphone-integrated platform, the analysis can be completed within 20 min. In addition, a fluorescence sensor array based C-CDs and R-CDs was also developed. The unique fingerprint of each NIIMs was obtained by linear discriminant analysis (LDA) of the response patterns, indicating an effective discrimination of five NIIMs. Moreover, the platform was used for quantification of MNZ in food samples and the recoveries were within 84.0–106.3 % with relative standard deviations 1.2–10.2 %. Therefore, the proposed method shows great potential as a universal platform for rapid detection of veterinary drug residues. The synthesis of multicolor CDs, fluorometric quantification of MNZ based on the C-CD + R-CD system by a smartphone-integrated platform, and the discrimination of different NIIMs by fluorescence sensor array based on C-CDs and R-CDs. [Display omitted] • Multicolor carbon dots were prepared by one-step hydrothermal method. • Fluorometric quantification of metronidazole was achieved by a smartphone-integrated platform. • A fluorescence sensor array was developed for discrimination of different nitroimidazole antibiotics. • The method was used to detection metronidazole in food samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Polyimide composite films have been widely used in some advanced field of microelectronic devices, precision instruments and national defense applications. Graphene quantum dots have great application potential in polymer doping modification because of their good mechanical strength, high specific surface area and excellent tunability of physical and chemical properties. In this paper, Graphene quantum dots are prepared by pyrolysis at different temperatures. The results show that different reaction temperatures have a great influence on the size and size distribution of graphene quantum dots. When the pyrolysis temperature is 200 °C, the size of graphene quantum dots is uniform at 3–5 nm. Graphene quantum dots-polyimide nanocomposite films prepared by in-situ polymerization show excellent mechanical properties. When the doping amount of graphene quantum dots is 0.5 wt%, the tensile strength and elastic modulus of the composite films can reach 130.24 MPa and 2.93 GPa respectively, which are 41.3% and 108% higher than that of pure polyimide films, respectively. Moreover, the thermal stability of polyimide composite films increases with the increase of the doping amount of graphene quantum dots. This shows that graphene quantum dots have good dispersion in polyimide matrix and can effectively improve the interface of composites. These results provide a successful preparation method to help guide to fabricate graphene quantum dots-polyimide composite films with high performance for the advanced applications. [ABSTRACT FROM AUTHOR]

This study's major purpose was to examine the impact of two various exercise intensities on glucagon-like peptide-1 and endoplasmic reticulum stress in teenagers with type 2 diabetes. Twenty teenagers with T2DM were recruited in the trial and randomly assigned to one of two groups: HIT (n = 10) or LIT (n = 10). At a heart rate of less than 45 percent, the low-intensity intense exercise group participated in aerobic activity training. Interval training with a heart rate reserve of at least 80% was used by the high-intensity intermittent training group. Both groups had the same weekly energy expenditure (1,200 kcal/week). The nositol required enzyme 1 and X-box binding protein-1 improved in both groups, but the difference in improvement between the two groups was not statistically significant. High-intensity interval training led to a significant decrease in body fat percentage among participants. After 12 weeks, the C-peptide levels had risen and varied considerably between the two groups. According to the homeostasis model assessment, there were significant differences between the groups in fasting glucose and insulin resistance, and leptin levels reduced after 12 weeks. The 12-week rise in glucagon-like peptide-1 was different across the groups. In teenagers with type 2 diabetes mellitus, high-intensity intermittent exercise training may enhance glycemic management, physical body composition, glucagon-like peptide-1, and endoplasmic reticulum stress. [ABSTRACT FROM AUTHOR]

Ca2+ ion leaching and poor pore structure are obstacles of CaO for biodiesel production. To this end, a typical Zr–based metal organic framework, UiO–66(Zr) is adopted to support calcium acetate to prepare CaO/ZrO 2 catalyst. For comparison, catalyst precursor is activated in nitrogen (UCN) and air (UCA) atmosphere, respectively. Preparation factors including calcium acetate addition and activation temperature are evaluated. Moreover, effects of transesterification parameters on oil conversion are investigated and the optimized parameters are further used to examine catalyst reusability. Meanwhile, catalysts are characterized with TG, XRD, XPS, FTIR, Hammett indicator titration, N 2 adsorption and desorption. Results reveal UCN calcined at 650 °C (UCN650) and UCA calcined at 700 °C (UCA700) separately exhibits the best catalytic performance. The maximum conversion of 96.99% is achieved by UCN650 with catalyst amount of 6 wt% and molar ratio of methanol to oil of 9 at 65 °C for 60 min. Even after being used 3 cycles, conversion of 92.76% is still achieved by UCN650. By contrast, UCA700 shows lower conversion of 92.94% at the first cycle with catalyst amount of 8 wt% and molar ratio of methanol to oil of 9 at 65 °C for 60 min. [Display omitted] [ABSTRACT FROM AUTHOR]

Acoustic radiation force optical coherence elastography (ARF-OCE) has been widely employed for elasticity imaging of ocular tissues, however, it has not been applied to detecting the biomechanical properties of the human cornea. In this paper, we performed the experiments on ex vivo human eyes by using ARF-OCE, where the 2D OCT structural images and elastic wave propagations from human corneas were achieved, and the resulting Young's modulus agreed well with the results measured by other methods, indicating the feasibility and reliability of ARF-OCE. With the advantages of non-invasive measurement, high resolution, high sensitivity and real-time imaging, ARF-OCE could be an effective way to rebuild the cornea elasticity and may be applied in clinical ophthalmology in the future. [ABSTRACT FROM AUTHOR]

Deep learning (DL) is bringing a big movement in the field of computed tomography (CT) imaging. In general, DL for CT imaging can be applied by processing the projection or the image data with trained deep neural networks (DNNs), unrolling the iterative reconstruction as a DNN for training, or training a well-designed DNN to directly reconstruct the image from the projection. In all of these applications, the whole or part of the DNNs work in the projection or image domain alone or in combination. In this study, instead of focusing on the projection or image, we train DNNs to reconstruct CT images from the view-by-view backprojection tensor (VVBP-Tensor). The VVBP-Tensor is the 3D data before summation in backprojection. It contains structures of the scanned object after applying a sorting operation. Unlike the image or projection that provides compressed information due to the integration/summation step in forward or back projection, the VVBP-Tensor provides lossless information for processing, allowing the trained DNNs to preserve fine details of the image. We develop a learning strategy by inputting slices of the VVBP-Tensor as feature maps and outputting the image. Such strategy can be viewed as a generalization of the summation step in conventional filtered backprojection reconstruction. Numerous experiments reveal that the proposed VVBP-Tensor domain learning framework obtains significant improvement over the image, projection, and hybrid projection–image domain learning frameworks. We hope the VVBP-Tensor domain learning framework could inspire algorithm development for DL-based CT imaging. [ABSTRACT FROM AUTHOR]

Besides natural climate variations, human activities can also cause significant changes in regional vegetation composition, especially during the late Holocene period. Southwest China has experienced a long history of human activities in terms of deforestation and agricultural development. Here we present a continuous fossil pollen record covering the past 2,100 years from Beihai Wetland in western Yunnan Province, for a better understanding of regional vegetation history and potential human activities. The pollen results indicate that the forest components show decreasing trends, including Alnus dominated deciduous broadleaved forest and evergreen broadleaved forest represented by evergreen Quercus. On the other hand, herbs such as Poaceae and Artemisia expanded along with the decline of forest, especially during the period after ad 1120. The results of ordination analysis further confirm such a pattern in which the first PCA component (PC1, capturing 42.2% of total variance) represents an increasing trend, which is subsequently interpreted as an index of human activities. Our findings show broadly identical patterns to previously published sedimentary records from Yunnan as well as historical documents. The human activities increased following the expansion in regional population, in the form of deforestation and regional agricultural development. They may also have caused the expansion of herbs, especially Poaceae, which replaced forest. Therefore, as indicated by the fossil pollen record from the Beihai Wetland, human activities in southwest China increased gradually during the past 2,100 years and more rapidly after ad 1120. Results of sediment influx and grain size analyses showed generally consistent patterns with the signs of summer monsoons captured by stable oxygen isotope records from stalagmites, indicating limited influence from human activities within the wetland system compared to the regional landscape. [ABSTRACT FROM AUTHOR]

Aims: The association between type 2 diabetes mellitus (T2DM) and risk of head and neck cancer (HNC) remains unclear. This study aims to perform a system review and meta-analysis to explore this relationship. Methods: PubMed, Web of Science, and Embase databases were searched for studies published up to July 31, 2020, regarding the association between T2DM and HNC risk. A random-effects model was utilized to calculate summary relative risks (RRs) with corresponding 95% confidence intervals (CIs). Results: Fourteen case–control studies and thirteen cohort studies were included in our analysis. We observed a weak association between T2DM and risk of HNC overall, but there was no statistical significance (RR, 1.04; 95% CI, 0.88–1.23; I2 = 83.2%). Interestingly, there was a strong association in East Asia (RR, 1.46; 95% CI, 1.21-1.77; I2 = 36.6%). For HNC subtypes, T2DM conferred a significantly elevated risk in oral cancer (RR, 1.22; 95% CI, 1.01–1.47; I2 = 89.0%). However, in subgroup analyses of smoking, alcohol use, and body mass index (BMI)/obesity adjustments, the association between T2DM and oral cancer risk became insignificant. In addition, T2DM was not associated with a statistically elevated risk of pharyngeal cancer (RR, 1.18; 95% CI, 0.94–1.49; I2 = 72.9%) and laryngeal cancer (RR, 1.03; 95% CI, 0.88–1.22; I2 = 71.2%). Conclusions: This meta-analysis indicates that T2DM is associated with an increased risk of HNC in East Asia. As for site-specific cancer types, the risk of oral cancer was significantly increased in T2DM patients, which appear to be mediated or confounded by smoking, alcohol use, or BMI/obesity. [ABSTRACT FROM AUTHOR]

Aims: Diabetes mellitus (DM) is widely recognized as a risk factor for diverse cancers in adults. However, the association between maternal diabetes and risk of childhood cancer in the offspring has so far not been well studied. We thus conducted a meta-analysis to evaluate the role of maternal diabetes on the risk of childhood cancer. Methods: We performed a comprehensive literature search to identify eligible studies published up to June 20, 2020, including the PubMed, Web of science and Embase databases. Summary odds ratios (OR) and 95% confidence intervals (CI) were computed using a random-effects model (I2 ≥ 25%) or a fixed-effect model (I2 < 25%). Results: Totally, sixteen case–control and six cohort studies on the risk of childhood cancer associated with maternal diabetes were included. Overall, children of diabetic women had a significantly increased risk in childhood malignancy (OR, 1.30; 95% CI, 1.10–1.53). Notably, a significantly elevated risk of childhood cancer in the offspring was found for women with pre-existing diabetes (OR, 1.41; 95% CI, 1.17–1.70), but not for women with gestational diabetes mellitus (GDM) (OR, 1.10; 95% CI, 0.94–1.28). For site-specific cancers, maternal diabetes was associated with a higher risk of leukemia in offspring (OR, 1.30; 95% CI, 1.15–1.48), especially for acute lymphoblastic leukemia (OR, 1.44; 95% CI, 1.27–1.64). However, no significant associations were observed between maternal diabetes and the risk of lymphomas and retinoblastoma. Conclusions: Our meta-analysis indicates that maternal diabetes is associated with an increased risk of childhood cancer in the offspring, particularly for acute lymphoblastic leukemia. Future study should investigate the underlying biological mechanisms behind the association. [ABSTRACT FROM AUTHOR]

Treating textile wastewaters were always inhibited by its higher salt concentration and temperature. In this study, a halo-thermophilic bacterial consortium YM was enriched with ability to decolorize acid brilliant scarlet GR (ABS) at 55 °C and 10% salinity. Under optimum conditions of pH (8), temperature (55 °C), and salinity (10%), YM decolorized 97% of ABS under anaerobic conditions. Alteribacillus was identified to be the dominant genus in consortium YM. Consortium YM showed significant decolorization ability under a wide range of salinity (1%–10%), pH (7–9) and temperature (45 °C–60 °C). The degradation pathway of ABS was proposed by the combination of UV–vis spectral analysis, Fourier transform infrared (FTIR), gas chromatography mass spectrometric (GC-MS), and metagenomic analysis. Azoreductase, which was an important enzyme in decolorization process, was identified with great variation in the genome of consortium YM. Meanwhile, the metabolic intermediates after decolorization was identified with low biotoxicity by phytotoxicity tests. This study first identified that Alterbacillus play an important role in azo dye decolorization and degradation process under halo-thermophlic conditions and provided significant knowledge for azo dye decolorization and degradation process. [Display omitted] • A halo-thermophilic bacterial consortium was enriched. • HT1 can decolorize azo dye at 10% salinity and 55 °C. • Possible biotransformation pathway for MYG was deduced. • Functional genes involved in degradation were identified by omics. [ABSTRACT FROM AUTHOR]

The evolution of the Indian Summer Monsoon (ISM) has been widely investigated and traditionally interpreted as consequences of orbital forcing change and the migration of the Intertropical Convergent Zone (ITCZ). The potential influence of sea-surface temperature (SST) on ISM variation at millennial time scales has been progressively proposed in recent studies. Towards a better understanding of Holocene evolution of ISM, especially the potential response to variations in SST, a 643 cm continuous sediment sequence covering the past 11.1 ka was recovered from Beihai Wetland in western Yunnan Plateau. Fossil pollen analysis revealed that evergreen broadleaved forest dominated the regional vegetation in the early Holocene, which represented a warm and humid period associated with strong ISM. Expansions of deciduous broadleaved forest and grassland from 5.2 cal. ka BP to the present, together with the appearance of abundant plant remains, indicate the formation of the wetland system. Ordination analysis of the pollen assemblages further confirmed the abrupt vegetation turnover at ca. 5.2 cal. ka BP, which is consistent with the abrupt decline in reconstructed mean annual precipitation (Pann, from ca. 1400 to 1100 mm), and indicates an abrupt decline in the summer monsoon. We performed a climate regime shift test on various records from the ISM domain and eastern Africa and found this phenomenon as well, which could not be explained by changes in solar insolation or the migration of the ITCZ. A mid-Holocene cooling was detected from the Indian Ocean, especially a decreased SST in the tropical Indian Ocean ca. 5.5 cal. ka BP. Cooling of the tropical Indian Ocean possibly caused the abrupt retreat of the summer monsoon by restraining the duration of the monsoonal season and the convergent process, which was supported by an abrupt monsoon decline based on results from a minimal concept model. [ABSTRACT FROM AUTHOR]

The Radon transform is widely used in physical and life sciences, and one of its major applications is in medical X-ray computed tomography (CT), which is significantly important in disease screening and diagnosis. In this paper, we propose a novel reconstruction framework for Radon inversion with deep learning (DL) techniques. For simplicity, the proposed framework is denoted as iRadonMAP, i.e., inverse Radon transform approximation. Specifically, we construct an interpretable neural network that contains three dedicated components. The first component is a fully connected filtering (FCF) layer along the rotation angle direction in the sinogram domain, and the second one is a sinusoidal back-projection (SBP) layer, which back-projects the filtered sinogram data into the spatial domain. Next, a common network structure is added to further improve the overall performance. iRadonMAP is first pretrained on a large number of generic images from the ImageNet database and then fine-tuned with clinical patient data. The experimental results demonstrate the feasibility of the proposed iRadonMAP framework for Radon inversion. [ABSTRACT FROM AUTHOR]

• A new Holocene Organic Carbon Accumulation Rate (OCAR) record from southwest China. • Temporal pattern of OCAR and response to climate/environment changes are evaluated. • Synchronous late Holocene increases in OCAR are widely reported from southwest China. • Long-term variations in OCAR respond closely to intensity of Asian Summer Monsoon. The deposition of organic carbon (OC) in terrestrial water bodies serves as an important carbon sink in global carbon cycle, while the responding mechanism of organic carbon accumulation rate (OCAR) to various climate processes is still unclear. Here, we provide a continuous sediment record covering the past 11.1 kyrs retrieved from Beihai Wetland, which is predominantly influenced by the Indian Summer Monsoon (ISM) in southwest China. The temporal variation of OCAR was established and classified into five evolution stages. Subsequently, potential responses of OCAR to climatic and environmental processes were evaluated based on the Spearman's rank correlation analysis between OCAR and individual sedimentary proxies. During the early Holocene, relatively stable and low OCAR was determined owing to the predominant contributions of detrital influx and low terrestrial organic matters. Following the intensification of summer monsoon and corresponding increase in regional precipitation, extremely low OCAR were yielded in the mid-Holocene, resulted from low values of both sedimentary accumulation rate (SAR) and Loss on Ignition (LOI). The abrupt retreat of ISM led to the development of current wetland from a lake-like system, while the extremely low SAR contributed significantly to the identified low OCAR values between 5.2 and 3.0 cal. kyr BP. Afterwards, the wetland developed progressively following further retreat of ISM, that the preservation of a great amount of organic matters contributed significantly to both SAR and LOI, resulting in the highest OCAR levels during the Holocene. In addition, the rapid decline of OCAR during the last 700 years was interpreted in terms of intensified regional human activities. Such increase in OCAR during the late Holocene was broadly reported from the southwest China, proposing potential responses to the large-scale climate changes, namely the variation of ISM. [ABSTRACT FROM AUTHOR]

In this paper, we undertake a high-resolution palynological analysis of a sediment core covering the last 1500 years obtained from Lake Ayakum in the northern Tibetan Plateau, to improve the understanding of regional climate fluctuations and their driving mechanisms. The pollen spectra are dominated by herbaceous species such as Artemisia , Chenopodiaceae, Cyperaceae and Poaceae, which grew in various alpine desert settings. Four pollen assemblage zones are identified using stratigraphically constrained cluster analysis, representing climate history at different stages. The Artemisia /Chenopodiaceae (A/C) ratio and axis score of the first principal component are used to infer regional moisture conditions and reveal a temporal pattern that is consistent with various records from central Asia. The source of Cyperaceae pollen is mainly from marsh wetlands distributed around the lake, which responded sensitively to the lake level fluctuations. In contrast, arboreal pollen is mainly a long-distance transported component, reflecting changes in regional vegetation. Our findings show that the northern Tibetan Plateau experienced relatively wet conditions during the Dark Age Cold Period and the Little Ice Age, while relatively dry conditions occurred during the Medieval Warm Period and the last two centuries. Fluctuations in moisture levels are broadly consistent with moisture records elsewhere in western China, and show a good correlation with phase changes of the North Atlantic Oscillation. The climate changes in the northern Tibetan Plateau are supposed to be primarily triggered by the NAO phases through south-north migrations of the mid-latitude westerlies during the late Holocene. • Fossil pollen based 1500-year vegetation and climate changes on the northern Tibetan Plateau. • Major pollen species were analyzed and interpreted in terms of regional moisture variations. • Four vegetation and climate stages during the late Holocene were determined accordingly. • NAO phases affected northern TP climate through south-north migrations of the westerlies. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ag-CsPbBr3/CN with outstanding photocatalytic activity was first constructed. • Ag-CsPbBr3/CN sample enhanced light-harvesting and reduced charge recombination. • 7-ACA photocatalytic degradation with Ag-CsPbBr3/CN composite was first studied. • Holes and hydroxyl radicals played major roles in 7-ACA degradation process. • The Ag-CsPbBr3/CN sample exhibited stability and reusability in 7-ACA degradation. Abstract A visible-light-induced antibiotics degradation system based on a nano-Ag, CsPbBr 3 quantum dot (QDs) and bulk g-C 3 N 4 (CN) ternary assembly (Ag-CsPbBr 3 /CN) has been firstly constructed under an organic phase environment, oleylamine (OLA) and oleic acid (OA) were used as surfactants to stabilize the CsPbBr 3 , l -cysteine was used to facilitate the interaction between nano-Ag, CsPbBr 3 and CN. The new ternary assembly of Ag-CsPbBr 3 /CN composite was used to degrade 7-aminocephalosporanic acid (7-ACA) under visible light irradiation, and the 7%-Ag-CsPbBr 3 /CN composite displayed the superior photocatalytic activity, approximately 92.79% of 7-ACA has been degraded to CO 2 , H 2 O and other small molecules at 140 min, which was approximately 1.49-folds, 1.56-folds, 3.01-folds and 11.43-folds higher than 9%-CsPbBr 3 /CN, 7%-Ag/CN, pure CN and pure CsPbBr 3 , respectively. A possible mechanism for 7-ACA degradation over Ag-CsPbBr 3 /CN composite were proposed according to detailed measurements of adsorption test, Brunauer-Emmett-Teller (BET) measurement, UV–vis diffuse reflectance spectra (DRS), photoluminescence spectra (PL), transient photocurrent response and electrochemical impedance spectroscopy (EIS) measurement, and the enhanced photocatalytic activity of Ag-CsPbBr 3 /CN composite could be attributed to the excellent adsorbability, the enhanced light-harvesting and reduced charge recombination, as well as the synergistic effects of nano-Ag and CsPbBr 3 co-loaded with CN. In addition, Holes (h+) and hydroxyl radicals (OH) played major roles, electronic (e−) and superoxide radical (O 2 -) played minor roles based on the reactive-species-trapping experiments, the NBT transformation and the 7-hydroxycoumarin fluorescent experiments. Furthermore, a possible 7-ACA degradation pathway was investigated based on the Liquid Chromatography-Mass spectroscopy (LC-MS) experiment to better understand the degradation process. The present opens up a new insight for using CsPbBr 3 as photocatalyst to degrade antibiotics. [ABSTRACT FROM AUTHOR]

As a rising star in the field of quantum dots, carbon quantum dots (CQDs) have attracted increasing advertence in recent years. In this work, sodium sulfide (Na 2 S) was used as the sulfur source for the first time to synthesize sulfur-doped carbon quantum dots (S-CQDs) with stable blue fluorescence by one-step hydrothermal. These synthesized S-CQDs have a uniform size of about 4.2 nm. Compared with CQDs, the prepared S-CQDs showed higher fluorescence intensity. And it also exhibited excitation-independent behavior, relatively high fluorescence quantum yield (QY = 21.1%) and outstanding photobleaching resistance and stability. More importantly, the S-CQDs was used as a novel fluorescent sensor to detect Hg2+ with high sensitivity and selectivity. Benefitting from above merits, this work provided a new strategy to improve the fluorescence intensity of CQDs and as-prepared S-CQDs showed the potential applications in the detection of heavy metals in the environment. Image 1 • Na 2 S was used as the sulfur source to synthesize S-CQDs for the first time. • The prepared S-CQDs possessed a relatively high fluorescence QY (21.11%). • A broader linear range (0.5μM-180μM) of S-CQDs was achieved for Hg2+ detection. • The S-CQDs realized the quantitative detection of trace Hg2+ in tap water. [ABSTRACT FROM AUTHOR]

The API Spec 6AV1 standard specifies the design requirements for valves operating in fields with sand production in order to reduce the risk of failure. In one of the validation tests, a valve is cyclically opened and closed under controlled conditions whilst a sand slurry is flowing in the loop. The carrier fluid is water with polymer viscosifiers to increase the viscosity up to about 55 cP. After completion of around 500 opening-closing cycles, high static pressure is applied upstream the valve to check for possible leakage. Objective of this study was to assess whether the occurrence of leakage might be affected by testing parameters that, being not specified by the standard, are decided by the experimenter; among them, particular attention was paid to the pressure and flow conditions during the valve operation. To this aim, numerical simulations were carried out combining different modelling approaches, and analyzing the failure of the valve from the point of view of the damage produced by impact wear. The difficulties inherent in the task of estimating erosion via numerical simulations are further enhanced in this work, since a number of complex case-specific issues had to be faced. First, the movement of the valve stem. Second, the co-existence of laminar and turbulent flow conditions due to the high viscosity of the carrier fluid. Third, the simulation of the valve as part of the entire loop. Fourth, the identification of a suitable indicator of valve leakage. Apart from the interest from a modelling point of view, the obtained results can help to improve the specification test procedures and acceptance criteria in the future. • The test procedures of the API 6A standard for safety valves are discussed. • The risk of valve leakage is related with the erosion severity. • The execution of the test in a real flow loop is numerically simulated. • Multiple computational approaches are integrated. • Significant influence is exerted by testing parameters unspecified by the standard. [ABSTRACT FROM AUTHOR]

Highlights • Intracellular Ca2+ responses to pear scab infection in two cultivars were analyzed. • Mechanisms underpinning scab-induced intracellular Ca2+ changes were elaborated. • Six Ca2+ sensor genes participate in pear scab resistance in the resistant cultivar. Abstract In this study, we investigated the role of Ca2+ signaling in pear (Pyrus. bretschneideri Rehd) in response to pear scab (Venturia nashicola Tanak et Yamamota) infection. We analyzed the responses of intracellular [Ca2+] and expression changes of Ca2+ sensor-related genes in two pear cultivars of differing resistance (the resistant 'Huangguan' and the susceptible 'Xuehua') following V. nashicola infection by using fluorescence microscopy, microplate spectrophotometry, and real-time quantitative PCR assays. Over a 60 min treatment period, V. nashicola induced elevated Ca2+ fluorescence in cell protoplasts (loaded with Fluo-3 AM) from fruit callus cultures of both pear cultivars, but the Ca2+ change patterns differed. Both LaCl 3 (a plasma membrane Ca2+ channel inhibitor) and EGTA (an extracellular Ca2+ chelator) inhibited [Ca2+] cyt in both cultivars, while BAPTA-AM (an intracellular Ca2+ chelator) showed no inhibitory effect. The relative expression levels of PbCaM1 , PbCaM5 , PbCBL1 , PbCIPK2 , PbCPK1 , and PbCPK2 in 'Huangguan' pear were significantly upregulated following infection and peaked at 72 post-infection hour. PbCPK1 and PbCPK2 underwent the most intense expression changes of these six genes tested. In 'Xuehua' pear, only PbCBL1 and PbCIPK2 were significantly upregulated following infection, while the remaining genes were downregulated to varying degrees. In conclusion, V. nashicola infection induced Ca2+ signaling in pear cells, and changes in [Ca2+] cyt were mainly due to extracellular Ca2+ influx. In 'Huangguan' pear, all tested genes related to Ca2+ sensors responded to V. nashicola infection, and might participate in resistance to the scab pathogen. [ABSTRACT FROM AUTHOR]

Abstract In the design of new fluorescent sensors, exploration of new materials with excellent properties and smart designs is of continuing interest. Herein, we designed a dual-emission ratiometric fluorescent sensor by doping ZnS quantum dots (QDs) with Cu2+ and Mn2+ ions. The codoped ZnS QDs with two separated dopant emissions were used as ratiometric fluorescent sensors for folic acid (FA). With addition of FA, the Cu dopant emission was quenched while the Mn dopant emission was enhanced. The fluorescence intensity ratios versus the FA concentrations could be fitted to a linear regression equation ranging from 0.01 to 5 μM (R2 = 0.995) and the detection limit was calculated to be 6 nM. Thus, this method generated ratiometric fluorescence signals for quantitative detection of FA. To understand the specific fluorescence response of the sensors for FA, the sensing mechanism was proposed based on electron transfer between QDs and FA. Additionally, the sensors were successfully applied to the determination of FA in spiked samples and recoveries were ranged from 95.5 to 102.2%. Therefore, the sensors show high sensitivity and selectivity for FA and the proposed method has good potential for extension to the detection of other biological molecules after further development. Graphical abstract Image 1 Highlights • The Cu-Mn codoped ZnS QDs were synthesized by two-step doping strategy. • The wavelength difference between two dopant emissions could reach about 100 nm. • The Cu-Mn codoped QDs were used as ratiometric fluorescent sensors for FA. • The method has a linearity in the range from 0.01 to 5 μM with a LOD of 6 nM. • The ratiometric sensors were applied for sensing of FA in bovine serum samples. [ABSTRACT FROM AUTHOR]

A ZnSe quantum dot (QDs)/g-C 3 N 4 composite with an excellent photocatalytic activity was synthesized to degrade Ceftriaxone sodium in an aquatic environment under visible light irradiation. The enhanced photocatalytic activity of the composite during antibiotic degradation could be attributed to the expanding light-harvesting scope and the efficient separation of photogenerated electron-hole pairs. Experiments involving reactive species trapping revealed that the reactive species OH and h + played major roles in Ceftriaxone sodium degradation. Recycling experiments showed that the ZnSe QDs/g-C 3 N 4 composite was highly stable and reusable. This work provided new insights into the construction of a novel photocatalyst that removes antibiotics in aquatic environments. [ABSTRACT FROM AUTHOR]

In our study, the synthesis conditions of ternary alloyed ZnCdS quantum dots (QDs) with different Zn/Cd molar ratios were investigated. Our results indicated that the optimal reaction conditions of ZnCdS QDs with various molar ratios were different. The ternary ZnCdS QDs were synthesized by a rather simple, facile, low-cost and effective aqueous synthesis method using air-stable compounds. UV–visible (UV–Vis) absorbance and photoluminescence (PL) emission spectra of the ZnCdS QDs showed a blue shift with the decrease of Cd, indicating the formation of alloyed QDs. The optimal reaction conditions, such as refluxing time and S/(Zn+Cd) molar ratios were different for ZnCdS QDs with different Zn/Cd ratios. The cause of the difference was attributed to the different properties of metal ions. In addition, the investigation on the photostability showed that the as-prepared ternary alloyed QDs had strong light resistance. Therefore, the ternary alloyed QDs with outstanding optical properties and high photostability showed potential biological applications and the results also offered new insights for the synthesis of ZnCdS QDs. [ABSTRACT FROM AUTHOR]

The morphology-controlled synthesis of nano-structure photocatalyst have leaded a new possibility to improve their physical and chemical properties. Herein, Bi 2 WO 6 nanocrystals (BWO) with nano-flower, nano plates, knot shape, rod like and irregular morphologies have been successfully synthesized through a highly facile hydrothermal process by simply adjusting pH values, reactive solvents and temperature. Photocatalytic activity of the as-prepared samples were evaluated by degradation of Ceftriaxone sodium under visible light irradiation (λ > 420 nm), the results indicated that all the BWO samples exhibit morphology-associated photocatalytic activity, and the 3D flowerlike-structure of BWO composed of well-ordered nano plates (BWO-D-5) displayed the outstanding photocatalytic activity. Through getting insight into the mechanism, h + and O 2 − play major roles compared with OH in photocatalytic degradation process. The possible pathway of Ceftriaxone sodium and the intermediates were proposed to better understand the reaction process. Moreover, this work not only provides an example of morphology-dependent photocatalytic activity of BWO but also provides an illustrative example for removing organic pollutant molecules according to practical requirements. [ABSTRACT FROM AUTHOR]

A novel form of carbon dots (PEG-CDs) was prepared by using one-step hydrothermal synthesis with glycine as the precursor and polyethylene glycol (PEG)-2000 as the surface modifier. The prepared PEG-CDs were characterized with HRTEM, XRD, PL, FTIR and UV. The results showed that they were quasi spherical particles with a diameter of approximately 12 nm and had a fine fluorescence property, good water solubility, favorable stability and high quantum yield with 28.58%. Doxorubicin hydrochloride (DOX) as a potential anti-cancer drug was loaded on the PEG-CDs. The drug loading capacity was 24.25 mg/g and the encapsulation efficiency was 77.23% at pH 9.0 with 36 h of dialysis; DOX release in PBS system with a pH of 5.5 could reach up to 76.67% in 23 h. [ABSTRACT FROM AUTHOR]

For ITER or the future DEMO remote maintenance system (WPRM), several types of special tailored automatic manipulators are needed for vacuum vessel (VV) component transportation, inspection, and removal from and replacement to the VV wall. Due to the extreme work conditions such as big size, big payload and high environment temperature, both the static and dynamic error sources should be considered when design a controller. In this paper, the accuracy improvement issues regarding the static and dynamic error sources are taken into account. The paper proposed a plane constraint calibration method for static error calibration, whilst the dynamic errors are calibrated using a linear inverse dynamic error model. Differential Evolution global optimization method was used to generate optimal excitation trajectories, and to identify the static and dynamic parameter errors. A 6-DOF (degrees of freedom) commercial industrial serial robot was employed to carry out the corresponding simulation and experimental studies. This paper mainly focuses on the general case studies, the results found in this research would be extrapolated to support the ITER or the future DEMO remote handling systems. [ABSTRACT FROM AUTHOR]

In this paper, a novel detection method based on luminescence resonance energy transfer (LRET) system for sensitive detection of Mn 2+ ions has been proposed. The positively charged upconversion nanoparticles capped with polyethyleneimin (PEI-UCNPs) and negatively charged Ag NPs capped with tripolyphosphate (P 3 O 10 5− -Ag NPs) were bound through electrostatic interaction. They were used as energy donors and acceptors, respectively. The green upconversion luminescence could be quenched because of a good overlap between the UCNPs emission and the Ag NPs absorption spectra. Nevertheless, the LRET was disrupted and the green upconversion luminescence was restored in the presence of Mn 2+ because of the coagulation of P 3 O 10 5− -Ag NPs. Thus, the relative luminescence intensity increased as the concentrations of Mn 2+ increased. The response is linear to the concentrations of Mn 2+ in the range from 0.2 to 5 μM, and the detection limit is evaluated to be 150 nM (S/N = 3). This probe was easy to operate with satisfactory selectivity and excellent sensitivity, which would be able to satisfy the requirements of Mn 2+ -related detection. [ABSTRACT FROM AUTHOR]

The concept of a Global Monsoon (GM) has been proposed based on modern precipitation observations, but its application over a wide range of temporal scales is still under debate. Here, we present a synthesis of 268 continental paleo-moisture records collected from monsoonal systems in the Eastern Hemisphere, including the East Asian Monsoon (EAsM), the Indian Monsoon (IM), the East African Monsoon (EAfM), and the Australian Monsoon (AuM) covering the last 18,000 years. The overall pattern of late Glacial to Holocene moisture change is consistent with those inferred from ice cores and marine records. With respect to the last 10,000 years (10 ka), i.e. a period that has high spatial coverage, a Fuzzy c -Means clustering analysis of the moisture index records together with “Xie-Beni” index reveals four clusters of our data set. The paleoclimatic meaning of each cluster is interpreted considering the temporal evolution and spatial distribution patterns. The major trend in the tropical AuM, EAfM, and IM regions is a gradual decrease in moisture conditions since the early Holocene. Moisture changes in the EAsM regions show maximum index values between 8 and 6 ka. However, records located in nearby subtropical areas, i.e. in regions not influenced by the intertropical convergence zone, show an opposite trend compared to the tropical monsoon regions (AuM, EAfM and IM), i.e. a gradual increase. Analyses of modern meteorological data reveal the same spatial patterns as in the paleoclimate records such that, in times of overall monsoon strengthening, lower precipitation rates are observed in the nearby subtropical areas. We explain this pattern as the effect of a strong monsoon circulation suppressing air uplift in nearby subtropical areas, and hence hindering precipitation. By analogy to the modern system, this would mean that during the early Holocene strong monsoon period, the intensified ascending airflows within the monsoon domains led to relatively weaker ascending or even descending airflows in the adjacent subtropical regions, resulting in a precipitation deficit compared to the late Holocene. Our conceptual model therefore integrates regionally contrasting moisture changes into the Global Monsoon hypothesis. [ABSTRACT FROM AUTHOR]

The water-soluble CuInS 2 quantum dots (CIS QDs) have been successfully synthesized by a one-pot aqueous-phase synthesis method using indium chloride and copper chloride as reactants. The type-I structure CIS/ZnS core/shell QDs were synthesized in situ for surface passivation, which led to a dramatic enhancement of fluorescence intensity. The CIS/ZnS QDs exhibited a tunable emission in the range of 500–680 nm by changing the ratio of Cu:In without the variation of size. And the corresponding fluorescent color changed from green to red. The QDs with uniform diameter could be assigned to a typical chalcopyrite structure according to XRD analysis. The as-prepared CIS/ZnS QDs have a good potential to be applied in biomedical fluorescence label and probes due to their low toxicity and excellent optical features. [ABSTRACT FROM AUTHOR]

• Using EIV model in point cloud registration, random errors contained in the two neighboring LiDAR stations can both be considered, which is more in line with the reality. • Unit quaternions are introduced to represent spatial rotation, which makes the expression of the spatial similarity transformation model become more concise. More importantly, no matter what the initial estimates are given for the experimental scheme designed in this paper, the correct results can always be obtained. • The introduction of unit quaternions makes the solution be applicable to the case where the rotation angle between the two neighboring systems are big. • The constraint that the modulo of the unit quaternions which represent 3D spatial rotation must be 1 is explicitly added into our algorithm. As a result, the scaling factor is no longer integrated with the rotation matrix, which makes it possible to estimate the scaling factor directly. The essence of point cloud registration is to estimate the seven similarity transformation parameters of the Bursa-Wolf model which describes the relative position of the two neighboring LiDAR stations. So far, Gauss–Markov (GM) model has been widely used in point cloud registration, however, only the random errors contained in one LiDAR station are considered, which is seriously inconsistent with the reality. To simultaneously take the random errors contained in both of the two neighboring LiDAR stations into account in registration, the EIV model is constructed based on the introduction of unit quaternions to describe the spatial rotation in 3D similarity transformation, and an iterative solution to the estimation of the transformation parameters is systematically discussed. Detailed derivation of the formulas for the estimation of the seven transformation parameters are displayed step by step. Finally, three experiments are designed to verify the correctness and effectiveness of the solution. [ABSTRACT FROM AUTHOR]

Most of the traditional II–VI quantum dots (QDs) are only excited under short-wavelength light below 600 nm, which limits their applications. We herein report the near-infrared (NIR) excitation of CdTe QDs based on fluorescence resonance energy transfer (FRET). In the FRET systems (UCQDs), UCNPs and QDs were used as energy donors and acceptors, respectively. For UCQDs with different CdTe QDs as acceptors, the new broad QD emission bands were observe under 980 nm excitation, which was due to the FRET from UCNPs to QDs. In addition, the UCQDs were used as fluorescent sensors for dopamine (DA) detection. Experimental results showed that the FRET-sensitized QD emission intensity (at 630 nm, F 630 ) was quenched gradually with the introduction of DA, which was the result of the inhibition of FRET between UCNPs and QDs. Importantly, the F 630 was linearly proportional to the DA concentrations in the range from 10 to 300 nM, with a detection limit of 8 nM (S/N = 3), which showed better performance than traditional QDs with UV excitation. Therefore, the results presented in this study not only offer an approach to realizing NIR excitation of QDs but also show good potential for biosensor applications. [ABSTRACT FROM AUTHOR]

As an essential nutrient, Selenium (Se) is involved in many metabolic activities including mimicking insulin function. Data on Se in various biological samples and insulin resistance are contradictory, moreover there is no large study available regarding the relationship of dietary Se intake with insulin resistance in the general population. To investigate the association between dietary Se intake and variation of insulin resistance in a large population based study, a total of 2420 subjects without diabetes from the CODING (Complex Diseases in the Newfoundland Population: Environment and Genetics) study were assessed. Dietary Se intake was evaluated from the Willett Food Frequency questionnaire. Fasting blood samples were used for the measurement of glucose and insulin. Insulin resistance was determined with the homeostasis model assessment (HOMA-IR). Body composition was measured using dual energy X-ray absorptiometry. Analysis of covariance showed that high HOMA-IR groups in both males and females had the lowest dietary Se intake (μg/kg/day) (p < 0.01), being 18% and 11% lower than low HOMA-IR groups respectively. Insulin resistance decreased with the increase of dietary Se intake in females but not in males after controlling for age, total calorie intake, physical activity level, serum calcium, serum magnesium, and body fat percentage (p < 0.01). Partial correlation analysis showed that dietary Se intake was negatively correlated with HOMA-IR after adjusting for the Se confounding factors in subjects whose dietary Se intake was below 1.6 μg/kg/day (r = -0.121 for males and -0.153 for females, p < 0.05). However, the negative correlation was no longer significant when dietary Se intake was above 1.6 μg/kg/day. Our findings suggest that higher dietary Se intake is beneficially correlated with lower insulin resistance when total dietary Se intake was below 1.6 μg/kg/day. Above this cutoff, this beneficial effect disappears. [ABSTRACT FROM AUTHOR]

Reconstruction of past vegetation change is critical for better understanding the potential impact of future global change on the fragile alpine ecosystems of the Qinghai-Tibetan Plateau (QTP). In this paper, pollen assemblages comprising 58 records from the QTP, spanning the past 15 kyrs, were collected to reconstruct biome compositions using a standard approach. Six forest biomes were identified mainly on the southeastern plateau, exhibiting a pattern of gradual expansion along the eastern margin during early to mid-Holocene times. The alpine meadow biome was separately identified based on an updated scheme, and showed notable westward expansions towards lower latitudes and higher altitudes during early Holocene times. Consistent patterns of migration could also be identified for the alpine steppe biome, which moved eastward during the late Holocene after 4 ka. As the dominant biome type, temperate steppe was distributed widely over the QTP with minor migration patterns, except for a progressive expansion to lower altitudes in the late Holocene times. The desert biome was inferred mainly as covering the northwestern plateau and the Qaidam Basin, in relatively restricted areas. The spatial distribution of the reconstructed biomes represent the large-scale vegetation gradient on the QTP. Monsoonal precipitation expressed predominant controls on the development of alpine ecosystems, while the variations in desert vegetation responded to regional moisture brought by the mid-latitude Westerlies. Temperature changes played relatively minor roles in the variations of alpine vegetation, but exerted more significant impacts on the forest biomes. • Fossil pollen based biome reconstruction on the Qinghai-Tibetan Plateau since 15 ka. • Spatial/temporal patterns of biome changes on the QTP were illustrated and examined. • Forest and alpine meadow biomes experienced migrations during the mid-Holocene. • Vegetation changes responded closely to moisture changes with spatial divergence. [ABSTRACT FROM AUTHOR]

• A continuous Holocene sediment record was recovered from southwestern China. • Grain size and elements represented catchment erosions and regional moisture changes. • Mid-Holocene intensification of ISM was modulated by tropical Indian Ocean SST modes. • Synchronous positive phases of IOB and IOD modes triggered the strengthening of ISM. The evolution of the Indian Summer Monsoon (ISM) has been widely investigated owing to its significant climatic and socioeconomic influences. However, debates remain concerning the temporal variation during the Holocene and its driving mechanisms, particularly the potential contribution of sea-surface temperature (SST) in the tropical Indian Ocean (TIO). Here, we present a continuous sediment record covering the past 11.1 kyrs from the Beihai Wetland, southwestern China. The grain size, geochemical element composition and total organic carbon content (TOC) were analyzed and interpreted in terms of the sedimentary conditions, catchment erosion and regional climate variations. Higher detrital inputs and possibly high water levels were determined during the early to mid-Holocene period, suggesting strong catchment erosion under an intensified ISM. The maximum monsoon intensity appeared between 7.5 and 5.2 cal. kyr BP, which is broadly consistent with various ISM records. We propose that such mid-Holocene monsoon strengthening was primarily triggered by the TIO SST anomaly modes, i.e., the Indian Ocean Basin (IOB) mode and the Indian Ocean dipole (IOD) mode. Based on Holocene SST records from the TIO, a positive SST anomaly (positive IOB mode) and positive zonal SST anomaly gradient (positive IOD mode) may have occurred during the mid-Holocene, which jointly triggered intensification of the ISM. Our findings emphasize the significant contribution of the TIO in modulating the summer monsoon system. The abrupt increases in TOC content and median grain size indicate the formation of the current wetland system at approximately 5.2 cal. kyr BP following the decline in regional moisture as well as the retreat of the ISM. In addition, notable human impacts were determined during the last 800 years, as indicated by intensified catchment erosion in response to human-induced deforestation. [ABSTRACT FROM AUTHOR]

Background: Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans. Objective: To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study. Design: A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics) study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses. Result: Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF), percent trunk fat (%TF), percent android fat (%AF), percent gynoid fat (%GF) and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine, p<0.001 for all). Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine (p<0.001). Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes. Conclusion: Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body composition in humans. [ABSTRACT FROM AUTHOR]

Recent high-throughput techniques have generated a flood of biological data in all aspects. The transformation and visualization of multi-dimensional and numerical gene or protein expression data in a single heatmap can provide a concise but comprehensive presentation of molecular dynamics under different conditions. In this work, we developed an easy-to-use tool named HemI (Heat map Illustrator), which can visualize either gene or protein expression data in heatmaps. Additionally, the heatmaps can be recolored, rescaled or rotated in a customized manner. In addition, HemI provides multiple clustering strategies for analyzing the data. Publication-quality figures can be exported directly. We propose that HemI can be a useful toolkit for conveniently visualizing and manipulating heatmaps. The stand-alone packages of HemI were implemented in Java and can be accessed at . [ABSTRACT FROM AUTHOR]

In this paper, we reported a simple synthetic method of highly photoluminescent (PL) and stable Mn 2+ -doped ZnS quantum dots (QDs) with glutathione (GSH) as the capping molecule and focused on mechanism of the surface passivation of QDs. The Mn 2+ -doped ZnS QDs that was synthesized in basic solution (pH 10) at 120 °C for 5 h exhibited blue trap-state emission around 418 nm and a strong orange-red emission at about 580 nm with an excitation wavelength of 330 nm. The optimum doping concentration is determined to be 1.5 at.%, and the present Mn 2+ -doped ZnS QDs synthesized under the optimal reaction condition exhibited a quantum yield of 48%. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) indicated that the Mn 2+ -doped ZnS QDs were 3–5 nm in size with a zinc blend structure. More importantly, the PL intensity and chemical stability can be improved using organic ligand modification strategies, it was found that GSH could passivate surface defects very efficiently by comparing and analyzing the results of the different organic ligands modification. The cadmium-free Mn 2+ -doped ZnS QDs well-passivated with GSH as capping molecule acquired the advantages of strong PL and excellent chemical stability, which are important to QD applications. [ABSTRACT FROM AUTHOR]

In the process of assembly and maintenance of ITER vacuum vessel (ITER VV), various machining tasks including threading, milling, welding-defects cutting and flexible hose boring are required to be performed from inside of ITER VV by on-site machining tools. Robot machine is a promising option for these tasks, but great chatter (machine vibration) would happen in the machining process. The chatter vibration will deteriorate the robot accuracy and surface quality, and even cause some damages on the end-effector tools and the robot structure itself. This paper introduces two vibration control methods, one is passive and another is active vibration control. For the passive vibration control, a parallel mechanism is presented to increase the stiffness of robot machine; for the active vibration control, a hybrid control method combining feedforward controller and nonlinear feedback controller is introduced for chatter suppression. A dynamic model and its chatter vibration phenomena of a hybrid robot is demonstrated. Simulation results are given based on the proposed hybrid robot machine which is developed for the ITER VV assembly and maintenance. [ABSTRACT FROM AUTHOR]

Abstract: The representation of similarity transformation in three-dimensional (3D) space, especially of orientation, is a crucial issue in navigation, geodesy, photogrammetry, robot arm manipulation, etc. Considering the large amount of computer resources required by iterative algorithms designed for spatial similarity transformation, the high dependence on initial values of unknown parameters, and the instability of solving transformation parameters for large-angle registration, a closed-form solution for pairwise light detection and ranging (LiDAR) point cloud registration is proposed. In this solution, dual-number quaternions are used to represent the 3D rotation. The relationship between the rotation matrix-based representation of similarity transformation and the dual quaternion-based representation is described first. Considering that the same features from two neighboring stations coincide after pairwise registration, a dual quaternion-based error norm, which is associated with the sum of the position errors, is constructed. Based on theory of least squares and by extreme value analysis of the error norm, detailed derivations of the model and the main formulas are obtained. Once the similarities between the same features from the two neighboring LiDAR stations are constructed, the rotation matrix, the scale parameter, and the translation vector are simultaneously derived. Two experiments are conducted to verify the feasibility and effectiveness of the proposed algorithm. The proposed algorithm has the advantages of simplicity and ease of implementation, making it better than the traditional methods that use matrices to describe spatial rotation. Moreover, it solves the transformation parameters without the initial estimates of unknown parameters, making it better than iterative algorithms. Most importantly, in contrast to unit quaternion-based algorithms, the proposed algorithm solves seven unknown parameters simultaneously. Therefore, it effectively avoids the accumulation of introduced error in calculation and the negative impact from the inappropriate choice of initial values. [Copyright &y& Elsevier]

Abstract: Zinc is one of the most essential metals utilized by organisms, and zinc-binding proteins play an important role in a variety of biological processes such as transcription regulation, cell metabolism and apoptosis. Thus, characterizing the precise zinc-binding sites is fundamental to an elucidation of the biological functions and molecular mechanisms of zinc-binding proteins. Using systematic analyses of structural characteristics, we observed that 4-residue and 3-residue zinc-binding sites have distinctly specific geometric features. Based on the results, we developed the novel computational program Geometric REstriction for Zinc-binding (GRE4Zn) to characterize the zinc-binding sites in protein structures, by restricting the distances between zinc and its coordinating atoms. The comparison between GRE4Zn and analogous tools revealed that it achieved a superior performance. A large-scale prediction for structurally characterized proteins was performed with this powerful predictor, and statistical analyses for the results indicated zinc-binding proteins have come to be significantly involved in more complicated biological processes in higher species than simpler species during the course of evolution. Further analyses suggested that zinc-binding proteins are preferentially implicated in a variety of diseases and highly enriched in known drug targets, and the prediction of zinc-binding sites can be helpful for the investigation of molecular mechanisms. In this regard, these prediction and analysis results should prove to be highly useful be helpful for further biomedical study and drug design. The online service of GRE4Zn is freely available at: http://biocomp.ustc.edu.cn/gre4zn/. This article is part of a Special Issue entitled: Computational Proteomics, Systems Biology & Clinical Implications. Guest Editor: Yudong Cai. [Copyright &y& Elsevier]

One of the major tasks of phosphoproteomics is providing potential biomarkers for either diagnosis or drug targets in medical applications. Because most complex diseases are due to the actions of multiple genes/proteins, the identification of complex phospho-signatures containing multiple phosphorylation events within phosphoproteomics-based networks generates more efficient and robust biomarkers than a single, differentially phosphorylated substrate or site. Here, we briefly summarize the current efforts and progress in this newly emerging field of phosphoproteomics-based network medicine by reviewing the computational (re)construction of phosphorylation-mediated signaling networks from unannotated phosphoproteomic data, the discovery of robust network phospho-signatures and the application of these signatures for classifying cancers and predicting drug responses. The challenges as well as the potential advantages are evaluated and discussed. Although the current techniques are at present far from mature, we believe that such a systematic approach as we describe can generate more useful and robust biomarkers for biomedical usage, even at the current stage of development. [ABSTRACT FROM AUTHOR]

Abstract: This paper focuses on the kinematic calibration of a 10 degree-of-freedom (DOF) redundant serial–parallel hybrid robot to improve its accuracy. The robot was designed to perform the assembling and repairing tasks of the vacuum vessel (VV) of the international thermonuclear experimental reactor (ITER). By employing the product of exponentials (POEs) formula, we extended the POE-based calibration method from serial robot to redundant serial–parallel hybrid robot. The proposed method combines the forward and inverse kinematics together to formulate a hybrid calibration method for serial–parallel hybrid robot. Because of the high nonlinear characteristics of the error model and too many error parameters need to be identified, the traditional iterative linear least-square algorithms cannot be used to identify the parameter errors. This paper employs a global optimization algorithm, Differential Evolution (DE), to identify parameter errors by solving the inverse kinematics of the hybrid robot. Furthermore, after the parameter errors were identified, the DE algorithm was adopted to numerically solve the forward kinematics of the hybrid robot to demonstrate the accuracy improvement of the end-effector. Numerical simulations were carried out by generating random parameter errors at the allowed tolerance limit and generating a number of configuration poses in the robot workspace. Simulation of the real experimental conditions shows that the accuracy of the end-effector can be improved to the same precision level of the given external measurement device. [Copyright &y& Elsevier]