Search

This study aims at investigating physical–chemical properties of a water-soluble heteropolysaccharide from Plnatago asiatica L. leaves, and its immunomodulatory effects on macrophages RAW264.7 cells. Hot water-extracted crude polysaccharide from the plant leaves (PLLCP) was fractionated into four fractions by DEAE Sepharose Fast Flow eluted with 0.1–0.5 M NaCl solutions. The most abundant fraction (0.3 M NaCl elution), designated PLLP-2, was identified as a heteropolysaccharide with an average molecular weight (Mw) of 3.54 × 104 and composed mainly of Gal (34.4%), GalA (36.5%), Ara (10.1%) and Rha (8.4%). PLLP-2 was an acidic polysaccharide exhibiting inflaky curly aggregation with smooth surface. PLLCP and its main subfraction PLLP-2 displayed immunomodulatory activities by stimulating the production of pro-inflammatory cytokines, including TNF-α and IL-1β in macrophage RAW264.7 cells. These results indicate that the main polysaccharide fraction purified from P. asiatica L. leaves is probably pectin, and have potential immunomodulatory function.

Climate change, especially the rapid warming since the industrial revolution, has drawn much attention over the past decades. However, the short instrumental climate records on the Tibetan Plateau ...

In this paper, special attention is given to ternary copper germanium sulfides (Cu–Ge–S), which belong to an important class of mixed-metal chalcogenide materials called the copper-based multinary sulfides (CMSs). Like most members of the CMS family, the Cu–Ge–S compounds display enormous potential in energy-related applications especially in their nanostructured forms, but there exists very little research on the preparation of Cu–Ge–S materials in the nanometer size range. Herein, we report a simple noninjection protocol for the selective synthesis of Cu–Ge–S nanomaterials. We show that variations in the solvent environment can lead to different types of Cu–Ge–S nanostructures (i.e., from large, faceted Cu8GeS6 to smaller, irregularly-shaped Cu2GeS3). Our investigation of the growth process revealed interesting formation pathways, which could help advance our understanding of the selective formation of compositionally and structurally diverse multinary materials in solution.

Herein, we develop a facile exfoliation and in situ functionalization strategy to produce hybridized Au/MoS2 nanostructures comprised of size-controlled gold nanoparticles (Au NPs) and ultrathin MoS2 nanosheets by using bovine serum albumin (BSA)-caged Au25 clusters as both exfoliating and functionalizing agents. As revealed, BSA molecules are strongly adsorbed on MoS2via their hydrophobic interaction, and this drives the expansion of the BSA molecules that initially protect Au25 cores at pH 4, leading to the effective exfoliation of MoS2 nanosheets together with the epitaxial growth of Au25 cores into 5 nm-sized Au NPs on MoS2 nanosheets due to their reduced surface protection. Upon the addition of H2O2, the resulting Au NPs can further grow to achieve a controlled size from 5 to 30 nm with an increase of the reaction time. It is demonstrated that the hybridized Au/MoS2 nanosheets exhibit a better performance in the photocatalytic degradation of substrates compared to the individual components or their mixture. Moreover, the hybridized Ag/MoS2, Au/WO3 and Au/graphene nanosheets are further produced by the usage of BSA-caged Ag and Au clusters, respectively. Overall, this work reports the first utilization of protein-caged metal clusters for the exfoliation and hybridized functionalization of 2D materials, and this brings more opportunities to exploit unusual properties of hybridized 2D materials for novel applications.

Hydrogen sulfide (H2S) is a key signaling molecule in the cytoprotection, vascular mediation and neurotransmission of living organisms. In-depth understanding of its production, trafficking, and transformation in cells is very important in the way H2S mediates cellular signal transductions and organism functions; it also motivates the development of H2S probes and imaging technologies. A fundamental challenge, however, is how to engineer probes with sensitivity and cellular penetrability that allow detection of spontaneous production of H2S in the entire cell space and live animals. Here, we report a rationally designed molecular switch capable of accessing all intracellular compartments, including the nucleus, lysosomes and mitochondria, for H2S detection. Our probe comprised three functional domains (H2S sensing, fluorescence, and biomembrane penetration), could enter almost all cell types readily, and exhibit a rapid and ultrasensitive response to H2S (≤120-fold fluorescence enhancement) for the dynamic mapping of spontaneously produced H2S as well as its distribution in the whole cell. In particular, the probe traversed blood/tissue/cell barriers to achieve mapping of endogenous H2S in metabolic organs of a live Danio rerio (zebrafish). These results open-up exciting opportunities to investigate H2S physiology and H2S-related diseases.

Biomaterials is an exciting and dynamic field, which uses a collection of diverse materials to achieve desired biological responses. While there is constant evolution and innovation in materials with time, biomaterials research has been hampered by the relatively long development period required. In recent years, driven by the need to accelerate materials development, the applications of machine learning in materials science has progressed in leaps and bounds. The combination of machine learning with high-throughput theoretical predictions and high-throughput experiments (HTE) has shifted the traditional Edisonian (trial and error) paradigm to a data-driven paradigm. In this review, each type of biomaterial and their key properties and use cases are systematically discussed, followed by how machine learning can be applied in the development and design process. The discussions are classified according to various types of materials used including polymers, metals, ceramics, and nanomaterials, and implants using additive manufacturing. Last, the current gaps and potential of machine learning to further aid biomaterials discovery and application are also discussed.

We develop an innovative approach to utilize silk, a natural polymer with discrete hydrophobic blocks interspersed with hydrophilic domains for hermetically encapsulating hydrophilic colorants to create a palette of lustrous multicolored silk while retaining its unique properties and rendering new functionalities. The success is largely dependent on the structures of colorants, the recrystallization of silk and the affinity between them. It is important to examine phase transfer capabilities and phase distribution coefficients of colorants in the presence/absence of silk, which are considered as influential factors in evaluation and selection of suitable colorants and matrices for effective encapsulation of colorants to produce safe and healthy cosmetics. As a result, this formulated silk increases color-encapsulating efficiency, prolongs color-retaining capability, enhances color physiochemical stability, reduces cytotoxicity and provides spreadability for potential use in cosmetic application. Meanwhile, it also presents flexibility to incorporate both organic and inorganic colorants together with a variety of more materials including fragrances, hydrating agents, antioxidants, UV fillers, etc.

Species-specific environmental adaptability results in different species having different suitable distribution ranges in nature. Investigating the change of relative advantages in growth performances among tree species along elevational gradients and the underlying mechanism are essential for selecting elevation-specific optimal species in forest management in mountainous regions. Xylem hydraulics has been widely reported to play a key role in tree growth and survival under water-limited environments, but whether and how it regulates tree growth performances at different elevations with contrasting water availability remain unclear. Here we combined tree-ring analyses and measurements of xylem hydraulics to investigate the patterns of tree radial growth and their linkages with water-related physiology for Prince Rupprecht's larch (Larix principis-rupprechtii Mayr) and Mongolian pine (Pinus sylvestris var. mongolica Litvinov) along a 500-m elevational gradient between 1336 and 1825 m a.s.l. in a semi-arid area of northern China where both species were widely used for afforestation. Our results showed that the radial growth rate, reflected by the slope of linear regression line for cumulative basal area increments and tree age, was higher in Prince Rupprecht's larch than in Mongolian pine at higher elevations, which coincided with the advantages in xylem hydraulic efficiency, i.e. higher sapwood area-specific hydraulic conductivity and leaf area to sapwood area ratio for the former species relative to the latter one at the middle and high elevation sites. However, the reversed pattern appeared in comparing radial growth rate for the two conifers at the low elevation sites that might be due to obviously greater loss of hydraulic conductivity caused by drought-induced xylem embolism for Prince Rupprecht's larch. This is corroborated by strong correlations between the tree-ring width indices and water-related climate variables during the growing season in Prince Rupprecht's larch but not in Mongolian pine at low elevations. Our study provides a mechanismic explanation for contrasting growth performances between the two species across elevations and implies a potential risk of growth decline under the influence of climate change in Prince Rupprecht's larch, the currently most widely used species for afforestation in this region, particularly under the drought-prone environment in the low-elevation sites.

General circulation models predict that precipitation will become more extreme, i.e. rainfall events of larger size but reduced frequency. Studies in North American grasslands have shown that such repackaging of precipitation into fewer, larger events enhanced above ground net primary productivity (ANPP), likely due to deeper soil moisture infiltration favoring plant water use over evaporation. However, ANPP responses in other regions remain poorly understood, and responses of carbon and water exchanges with the atmosphere remain unknown. Here we manipulated rainfall in a steppe ecosystem of northern China over 4 years to investigate how temporal packaging of precipitation impacts ANPP, evapotranspiration (ET), net ecosystem CO2 exchange (NEE) and the component fluxes gross primary productivity (GPP) and ecosystem respiration (RE). Experimental plots received precipitation equivalent to the 60-year growing-season average of 240 mm, variously packaged into 6, 10, 16, or 24 events representing extreme (P6) to historical average (P24) rainfall frequency. Extraordinarily extreme frequency (6 large events) reduced NEE, GPP, RE, ET and water use efficiency (WUE = |NEE|/ET). The average NEE, GPP and RE declined 35%, 45% and 48% respectively in the P6 treatment as compared to P16, which showed maximum ET and CO2 exchange. After peaking in the 16-event treatment, GPP and WUE in P24 were not distinguishable from P6. These peaks suggest that P16 was optimal for photosynthesis, with sufficiently frequent rain to maintain unregulated plants and adequately deep soil moisture infiltration to favour transpiration, with associated carbon uptake, over evaporation. Path analysis indicated the lower CO2 fluxes were influenced by reduced soil water content and leaf area index and higher soil temperature, with ET regulating the effects of these microclimatic drivers. ANPP showed a monotonic but non-significant decline with decreasing precipitation frequency, consistent with reduced CO2 fluxes. We found an increase in ANPP of xerophyte plants partially compensated for the ANPP decline in the dominant eurytopic xerophyte plants. Our results suggest that extreme temporal repackaging of precipitation into few events with correspondingly long dry intervals may reduce the capacity of steppe ecosystems to assimilate atmospheric CO2, although community diversity may moderate impacts.

To develop an improved approach in achieving an excellent combination of high strength and ductility, the solutionized Al-Cu-Li plates were subjected to rolling at cryogenic and room temperatures, respectively, to a reduction of 83%, followed by aging treatment at 160 °C. The results indicate that Al-Cu-Li alloys through cryogenic rolling followed by aging treatment possess better mechanical properties. Rolling at cryogenic temperature produces a high density of dislocations because of the suppression of dynamic recovery, which in turn promotes the precipitation of T 1 (Al 2 CuLi) precipitates during aging. Such high density of T 1 precipitates enable effective dislocation pinning, leading to an increase in strength and ductility. In contrast, room temperature rolled alloys after aging treatment exhibit lower strength and ductility due to low density of T 1 precipitates in the grain interior and high density of T 1 precipitates around subgrain boundaries.

Based on the thin viscoelastic plate assumption and the potential flow theory, the unified mathematical model was derived for the ice-water vibration problem induced by air cushion vehicle (ACV) sailing on different media (pure ice sheet, pure water, broken ice, semi-water-semi-ice, etc.). In order to solve this model, a hybrid algorithm combining Rankine source method (RSM) and finite difference method (FDM) was proposed. The displacement response and stress distribution as well as ice-breaking effect of ice sheet can be obtained by using this numerical method. Besides, a comparison with the theoretical results or experiment results is made, and a good agreement is achieved between the calculation results and the existing research results. Finally, taking the pure ice surface and semi-water-semi-ice surface as an example, some calculations are made according to the typical physical parameters of ice sheet. Our calculations shows that the mathematical model and numerical method can not only calculate the ice displacement response and its distribution characteristics of the internal stress as well as ice-breaking effect, but also can capture the critical speed of ACV.

Atrophic gastritis is considered to be an antecedent to intestinal metaplasia and gastric cancer. A previous study identified that Helicobacter pylori was absent at the severe atrophic gastritis stage, and alterations in the gastric microbial composition resembled those in gastric cancer. To explore the role of the bacteria absence of H. pylori in gastric carcinogenesis, in the current study, we compared the microbiota of clinically collected H. pylori-free gastric fluids from 30 patients with non-atrophic gastritis (N) and 22 patients with severe atrophic gastritis (S). We estimated the bacterial loads in the N and S groups by colony counting in culture agar as well as by measuring the concentration of the extracted DNA. The results showed a significant increase in bacterial load in patients with atrophic gastritis in comparison to non-atrophic gastritis. Then, we analyzed the microbial communities of the gastric fluids from all 52 patients using high-throughput sequencing of 16S rRNA amplicons. The Chao 1, Shannon and Simpson diversity indexes demonstrated that the bacterial richness and diversity were not significantly different between the N and S groups. Moreover, principal component analysis illustrated that the microbiomes from the S group were more scattered. Microbiota composition analysis showed that the entire dataset was clustered into 27 phyla, 61 classes, 106 orders, 177 families, 292 genera and 121 species. At the genus level, only the abundance of Prevotella was significantly different between the N and S groups. Further analysis showed that all the higher taxonomic categories were significantly different between the N and S groups. To assess the effects of the metabolic products of Prevotella spp. on gastric cell physiology, we treated the human gastric epithelial cell line AGS with acetic acid and monitored nitric oxide (NO) production. The results showed that acetic acid at low concentrations (0.5 and 5 µM) significantly inhibited AGS cells to secrete NO compared to phosphate buffer saline-treated control cells. These results suggest that the microbiota in non-atrophic gastritis may influence gastric epithelial cell physiology.

// Tianyi Dong 1, 2, * , Yanping Peng 1, * , Ning Zhong 3 , Fengyan Liu 3 , Hanyu Zhang 1 , Mengchen Xu 4 , Rutao Liu 4 , Mingyong Han 5 , Xingsong Tian 2 , Jihui Jia 1 , Lap Kam Chang 1 , Liang-Hong Guo 6 and Shili Liu 1 1 School of Medicine, Shandong University, Jinan, Shandong, 250012, China 2 Department of Breast Thyroid Surgery, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, 250021, China 3 Department of Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong, 250012, China 4 School of Environmental Science and Engineering, Shandong University, Jinan, Shandong, 250100, China 5 Cancer Therapy and Research Center, Shandong Provincial Hospital, Shandong university, Jinan, Shandong 250021, China 6 State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China * These authors contributed equally to this work Correspondence to: Liang-Hong Guo, email: lhguo@rcees.ac.cn Shili Liu, email: liushili@sdu.edu.cn Keywords: PFDA, proliferation, sPLA2-IIA, TCF4 Received: September 06, 2016 Accepted: April 05, 2017 Published: April 20, 2017 ABSTRACT The association of perfluorodecanoicacid (PFDA) with tumor promotion and associated effects is not clear. Given that PDFA is mostly consumed with food and drinking water, we evaluated the effects of PFDA on a gastric cell line. When added to cell cultures, PFDA significantly increased growth rate and colony forming ability compared with control treatment. We found that suppression of cell senescence, but not apoptosis or autophagy was associated with PFDA-induced promotion of cell amount. To determine the molecular mechanism that was involved, DNA microarray assays was used to analyze changes in gene expression in response to PFDA treatment. Data analysis demonstrated that the vascular endothelial growth factor signaling pathway had the lowest p -value, with sPLA2-IIA ( pla2g2a ) exhibits the most altered expression pattern within the pathway. Moreover, sPLA2-IIA and its transcription factor TCF4, known as a direct target and a binding partner of Wnt/β-catenin signaling in gastric cells respectively, were the third and second most varied genes globally. Cells transfected with expression plasmids pENTER- tcf4 and pENTER- pla2g2a show reduced cell proliferation by more than 60% and 30% respectively. Knockdown with sPLA2-IIA siRNA provided additional evidence that sPLA2-IIA was a mediator of PFDA-induced cell senescence suppression. The results suggest for the first time that PFDA induced suppression of cell senescence through inhibition of sPLA2-IIA protein expression and might increased the proliferative capacity of an existing tumor.

SUMMARYThis paper focuses on the problem of robust time-optimal trajectory planning of robotic manipulators to track a given path under a probabilistic limited actuation, that is, the probability for the actuation to be limited is no less than a given bound κ. We give a general and practical method to reduce the probabilistic constraints to a set of deterministic constraints and show that the deterministic constraints are equivalent to a set of linear constraints under certain conditions. As a result, the original problem is reduced to a linear optimal control problem which can be solved with linear programming in polynomial time. In the case of κ = 1, the original problem is proved to be equivalent to the linear optimal control problem. Overall, a very general, practical, and efficient algorithm is given to solve the above problem and numerical simulation results are used to show the effectiveness of the method.

As a light-activated noninvasive cancer treatment paradigm, photodynamic therapy (PDT) has attracted extensive attention because of its high treatment efficacy and low side effects. Especially, spatiotemporal control of singlet oxygen (1O2) release is highly desirable for realizing on-demand PDT, which, however, still remains a huge challenge. To address this issue, a novel switchable near-infrared (NIR)-responsive upconversion nanoprobe has been designed and successfully applied for controlled PDT that can be optically activated by tumor-associated disruption of labile Zn2+ (denoted as Zn2+ hereafter) homeostasis stimuli. Upon NIR irradiation, this theranostic probe can not only quantitatively detect the intracellular endogenous Zn2+ in situ but also selectively generate a great deal of cytotoxic reactive oxygen species (ROS) for efficiently killing breast cancer cells under the activation of excessive endogenous Zn2+, so as to maximally avoid adverse damage to normal cells. This study aims to propose a ...

Objective: To study the effect of Xianling Gubao-assisted surgical treatment on postoperative healing, calcium and phosphorus contents as well as bone metabolism in elderly women with Colles fracture. Methods: A total of 96 elderly female patients with Colles fracture treated in our hospital between June 2013 and December 2015 were selected and randomly divided into two groups, the observation group of patients received Xianling Gubao capsule combined with manual reduction and plaster external fixation therapy, and control group of patients only received reduction and external fixation therapy. The fracture healing time was followed up after treatment, and 3 months after treatment, serum was collected to determine the content of calcium-phosphorus metabolism indexes and bone metabolism indexes. Results: The fracture healing time of observation group was significantly shorter than that of control group; 1 month and 3 months after treatment, serum Ca, P, ALP, IGF-1, PDGF, BGP and PICP levels of both groups were significantly higher than those before treatment while CTX-1, tPINP and TRACP- 5b levels were significantly lower than those before treatment; serum Ca, P, ALP, IGF-1, PDGF, BGP and PICP levels of observation group after treatment were significantly higher than those of control group while CTX-1, tPINP and TRACP-5b levels were significantly lower than those of control group. Conclusion: Adjuvant Xianling Gubao capsule therapy can promote the Colles fracture healing in elderly women, also improve calcium-phosphorus metabolism, promote bone formation and inhibit bone resorption.