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On the eastern Tibetan Plateau, the growth of trees is strongly affected by climate change. Previous researchers have found that climate warming changes thermal and hydraulic conditions, lengthening the growing season and promoting tree growth. Some studies have analyzed the effects of drought, precipitation, and temperature on tree growth. However, previous studies have mainly focused on natural forests, with few studies on the response of plantations to climate change. Therefore, we studied the relationship between dendrochronology (basal area increment, BAI), normalized difference vegetation index (NDVI), and climate factors to explore the response of Picea likiangensis var. rubescens plantations to climate change. The results showed that from 1990 to 2018, the temperature in the study area increased significantly; the rate of increase was 0.39∘ per decade. Among the climate factors, self-calibrated Palmer drought severity index (scPDSI) had the most significant impact on BAI. From P_May (P_ represents the month of the previous year) to December, BAI was always negatively correlated with the scPDSI, with 9 months being significantly negatively correlated. BAI was significantly positively correlated with the minimum 2 m temperature (TMN) in P_July, P_September, July, and September. BAI was significantly positively correlated with the maximum 2 m temperature (TMX) in P_October, P_December, and July. BAI was significantly positively correlated with the mean 2 m temperature (TMP) in P_July, P_December, and July. There is a significant positive correlation between BAI and annual NDVI (NDVIa), which means that NDVI can be used to study the response of plantations to climate change. Our study contributes to a better understanding of the response of plantation growth in high-altitude areas to climate change, which is needed by forest managers.

This work presents the development of a new kinetic Monte Carlo algorithm, referred to as Moving Front kinetic Monte Carlo (MFkMC), for simulating processes subject to moving interfaces. This framework is designed to capture the movement of transiently varying interfaces in a kinetic-like manner so that its movement can be described using Monte Carlo sampling. The MFkMC algorithm accomplishes this task by evaluating the behavior of the interfacial molecules and assigning kinetic Monte Carlo-style rate equations that describe the transition probability that a molecule would advance into the neighboring phase, displacing an interfacial molecule from the opposing phase and thus changing the interface. Due to its kinetic Monte Carlo structure, the MFkMC algorithm can additionally account for other important interfacial phenomena, such as interfacial surface reactions. The proposed algorithm was tested via applications to three different simple interfacial case studies. These studies validate the MFkMC algorithm and demonstrate its capabilities to accurately and efficiently simulate a variety of different moving interface systems.

The rising energy demands worldwide and difficulty in developing novel clean energy sources have greatly stimulated the exploitation of coalbed methane. Clay minerals are common fractions of coal; thus, understanding their CH4 adsorption capacities and pore structures is vital. In this study, coal, parting, roof, and floor samples were collected from the Yangquan Mining District. The mineral compositions, CH4 adsorption capacities, and pore structures of the samples were analyzed using X-ray diffraction, the CH4 isothermal adsorption method, and the low-temperature N2 adsorption method, respectively. The results indicated that organic matter had a much higher CH4 adsorption capacity (33.80 cm3/g, 35°C) than that of clay minerals. The CH4 adsorption capacities of various clay minerals are significantly different, with smectite (18.01 cm3/g), kaolinite (5.81 cm3/g), mixed-layer illite-smectite (4.47 cm3/g), and illite (2.08 cm3/g) present in decreasing order. The pore sizes of the samples consisted of sizes 4 adsorption capacities of clay minerals are mainly influenced by their pore structures, which are in turn associated with their species and formation processes. Furthermore, the conversion of kaolinite to illite, and the illitization of mixed-layer smectite-illite, exerted a negative effect on their CH4 adsorption capacities.

Cancer metastasis accounts for nearly 90% of all cancer deaths. Metastatic cancer progression requires both cancer cell migration to the site of the metastasis and subsequent proliferation after colonization. However, it has long been recognized that cancer cell migration and proliferation can be uncoupled; but the mechanism underlying this paradox is not well understood. Here we report that TNFAIP8 (tumor necrosis factor-α-induced protein 8), a “professional” transfer protein of phosphoinositide second messengers, promotes cancer cell migration or metastasis but inhibits its proliferation or cancer growth. TNFAIP8-deficient mice developed larger tumors, but TNFAIP8-deficient tumor cells completely lost their ability to migrate toward chemoattractants and were defective in colonizing lung tissues as compared to wild-type counterparts. Mechanistically, TNFAIP8 served as a cellular “pilot” of tumor cell migration by locally amplifying PI3K–AKT and Rac signals on the cell membrane facing chemoattractant; at the same time, TNFAIP8 also acted as a global inhibitor of tumor cell growth and proliferation by regulating Hippo signaling pathway. These findings help explain the migration–proliferation paradox of cancer cells that characterizes many cancers.

A falling liquid drop, after impact on a rigid substrate, deforms and spreads, owing to the normal reaction force. Subsequently, if the substrate is non-wetting, the drop retracts and then jumps off. As we show here, not only is the impact itself associated with a distinct peak in the temporal evolution of the normal force, but also the jump-off, which was hitherto unknown. We characterize both peaks and elucidate how they relate to the different stages of the drop impact process. The time at which the second peak appears coincides with the formation of a Worthington jet, emerging through flow-focusing, and it is independent of the impact velocity. However, the magnitude of this peak is dictated by the drop's inertia and surface tension. We show that even low-velocity impacts can lead to a surprisingly high peak in the normal force, namely when a more pronounced singular Worthington jet occurs due to the collapse of an air cavity in the drop., Comment: Please find the supplemental movies here: https://youtube.com/playlist?list=PLf5C5HCrvhLGmlYTF1Gg2WviZ-Bkmy2qr

This study reports the development of a semi-empirical force balance-based moving front kinetic Monte Carlo (FB-MFkMC) model to describe droplet spreading on a smooth surface. The proposed model depicts the state-by-state evolution of a sessile droplet in a stochastic manner that captures the molecular-level events taking place in an accurate yet efficient manner. In the developed model, the movement of the droplet triple contact line is depicted using rate expressions that detail the probability that the contact line will locally advance over a set distance at each time point. These rate expressions are derived based on the force balance acting upon the droplet interface, which is captured using analytical inertial and capillary expressions from the literature. This work furthermore derives a new semi-empirical expression to depict the viscous damping force acting on the droplet. The derived viscous force term depends on a fitted parameter [Formula: see text], whose value was observed to vary solely depending on the droplet liquid as captured predominantly by the droplet Ohnesorge number. The proposed FB-MFkMC approach is subsequently validated using data obtained both from conducted experiments and from the literature to support the robustness of the framework. The predictive capabilities of the developed model are further inspected to provide insights on the sessile droplet system behavior.

The anisotropic fracture toughness G(θ) is an intrinsic feature of graphene and is fundamental for fabrication, functioning, and robustness of graphene-based devices. However, existing results show significant discrepancies on the anisotropic factor, i.e., the ratio between zigzag (ZZ) and armchair (AC) directions, G_{ZZ}/G_{AC}, both qualitatively and quantitatively. Here, we investigate the anisotropic fracture of graphene by atomic steps on cleaved graphite surfaces. Depending on the relation between the peeling direction and local lattice orientation, two categories of steps with different structures and behaviors are observed. In one category are straight steps well aligned with local ZZ directions, while in the other are steps consisting of nanoscale ZZ and AC segments. Combined with an analysis on fracture mechanics, the microscale morphology of steps and statistics of their directions provides a measurement on the anisotropic factor of G_{ZZ}/G_{AC}=0.971, suggesting that the ZZ direction has a slightly lower fracture toughness. The results provide an experimental benchmark for the widely scattered existing results, and offer constraints on future models of graphene fracture.

Investigation of geometric effects on confined droplets is important for the fundamental understanding of the ubiquitous wetting phenomena in nature as well as for a variety of practical applications. In this study, the effect of geometric confinement on the wetting behavior of a droplet confined between two parallel rigid planes was investigated. The closed solutions of the Young-Laplace equation were derived through an analytical method. These solutions are applicable for arbitrary values of the contact angles and the ratio of the size of the droplet to the separation of the planes. For completely nonwetting and wetting cases, an asymptotic method was employed, and the sophisticated analytical solutions of the Laplace pressure, droplet volume, surface energy, and capillary force were expressed as functions of the size and the separation of the droplet in a simple way. In order to check the applicability of the results, experiments were designed to counteract the gravity of the droplets. The asymptotic results not only quantitatively agree well with the theoretical and experimental results over a large range of the parameter space, but also provide a straightforward view for reflecting the effect of the geometric confinement on the wetting behaviors of droplets.

The decrease in friction is often observed in the initial period of sliding a fresh contact between two solid surfaces. This phenomenon is usually termed running-in. Here we report a running-in phe...

The monostable Cassie state is a favorable wetting state for superhydrophobic materials, in which water drops can automatically transfer from the Wenzel wetting state to the Cassie wetting state, such that as a consequence the water repellency can be maintained. Drop impact phenomena are ubiquitous in nature and of critical importance in industry, and previous works show that the efficiency of self-cleaning and dropwise condensation could benefit from drop impact on monostable surfaces. However, whether such a feature is sufficiently robust remains unclear when the temperature of the surface is taken into consideration. Here, we report that there exists a lower bound of the temperature of the surface, under which a transition from the Cassie wetting state to the Wenzel wetting state arises. By varying the temperature of the surface, it is found that the solid-liquid wetting region could be regulated. Based on thermodynamics, we propose a model to predict the controllable wetting region, and we show that the gradual transition of the wetting state is a result of the accumulation of droplets on the nanoscale. Connections between the dynamics occurring at the solid-liquid interfaces on the microscale and the condensation occurring in the nanotextures are constructed. These results deepen our understanding of the breakdown of superhydrophobicity under dynamic impinging in high humidity. Moreover, this study will shed new light on the applications for controllable liquid deposition and surface decoration, such as catalysts on the superhydrophobic surfaces.

Smart textiles are attracting great interest. Particularly, air-conditioning textiles are highly desired for their merits in energy conservation and personal temperature/humidity management. Currently, air-conditioning textiles can be fabricated by two strategies. One uses infrared-radiation-adaptive materials, and the other uses moisture-responsive actuators that can regulate temperature and humidity simultaneously. Here, the fabrication of a silk-yarn switch comprising electrospun highly aligned nanofibers is reported and its application in air-conditioning textiles is demonstrated. Silk yarn rotates in contact with liquid, and can be recovered by drying. The different responses and wetting behaviors of the switch to H2O and C2H6O is investigated. It is argued that alignment and surface hydrophilicity of nanofibers play important roles in this term. To elaborate, actuating trait is mainly controlled by reduction of the surface free energy of aligned silk nanofibers, during the wetting process. As proof of concept, the application of the sweat-driven silk-yarn switch in regulating the temperature/humidity of the human body is demonstrated in this work. Considering the large production, versatile processibility, and good biocompatibility, silk actuator may have practical applications in designing smart switches (or valves) for intelligent textiles, artificial muscles, and other application scenarios.

Low-temperature oxidation of anthracite coal has not been extensively investigated. In this study, variations in the structural parameters associated with aliphatic species (e.g., methyl and methylene) in anthracite coal were investigated during low-temperature oxidation (60 °C to 120 °C) using infrared spectroscopy and X-ray diffraction, and the influences on the molecular structure of coal are discussed. The results indicated that the oxidation of aliphatic species is divided into four stages. The aliphatic species were mainly oxidized at Stages 2 (80 °C to 120 °C) and 4 (>170 °C), and only slightly oxidized at Stages 1 (60 °C to 80 °C) and 3 (120 °C to 170 °C). The aliphatic species exhibited two modes of occurrence: at the edges of aromatic structure and in the interlayer spaces, which were mainly oxidized at Stages 2 and 4, respectively. The aliphatic species in the anthracite coal were dominated by those in the interlayer spaces (90.9% methylene and 88.8% methyl), followed by those at the edges (9.1% methylene and 11.2% methyl). The aliphatic species in the interlayer spaces showed a higher chemical stability than that of the species at the edges, resulting in the discontinuous low-temperature oxidation of the aliphatic species. The aliphatic chains in the interlayer spaces (A(CH3)/A(CH2)=0.77) were much longer than those at the edges (A(CH3)/A(CH2)=0.61), which was mainly attributed to coalification.

Background and aims Alpine grassland on the Qinghai-Tibetan Plateau (QTP) is sensitive and fragile, and it is subject to serious degradation. It is essential to determine the effects of soil parameters on plant species to explain grassland degradation. Methods We classified plant communities into six types based on hierarchical clustering. Then we analyzed the effects of soil physico-chemical properties on plant species composition and diversity by canonical ordination and spatial regression from an elevation perspective. Results Elevation class had significant effects on soil moisture content, soil pH, and soil available nitrogen content. The primary soil parameter affecting plant species composition and diversity in alpine grassland was soil available nitrogen content. The effect of soil available nitrogen content on plant species richness varied at different elevations. For Gramineae plants (G), plant species richness declined with the increase in soil available nitrogen content at low elevation, but rose at middle elevation. Soil available nitrogen content had a more significant limiting effect on species richness at high elevation. Conclusion Analyzing the relationship between plant species and soil physico-chemical properties increases our understanding of grassland degradation, and will improve grassland restoration programs and responses to climate change.

Understanding the interactions between liquids and solids is important for many areas of science and technology. Microtextured surfaces have been extensively studied in microfluidics, DNA technologies, and micro-manufacturing. For these applications, the ability to precisely control the shape, size and location of the liquid via textured surfaces is of particular importance for the design of fluidic-based systems. However, this has been passively realized in the wetting state thanks to the pinning of the contact line, leaving the non-wetting counterpart challenging due to the low liquid affinity. In this work, confinement is imposed on droplets located on well-designed shapes and arrangements of microtextured surfaces. An active way to shape non-wetting water and liquid metal droplets into various polygons ranging from triangles, squares, rectangles, to hexagons is developed. The results suggest that energy barriers in different directions account for the movement of the contact lines and the formation of polygonal shapes. By characterizing the curvature of the liquid-vapour meniscus, the morphology of the droplet is correlated to its volume, thickness, and contact angle. The developed liquid-based patterning strategy under active regulation with low adhesion looks promising for low-cost micromanufacturing technology, DNA microarrays, and digital lab-on-a-chip.

Wnt signaling was initially recognized to be vital for tissue development and homeostasis maintenance. Further studies revealed that this pathway is also important for tumorigenesis and progression. Abnormal expression of signaling components through gene mutation or epigenetic regulation is closely associated with tumor progression and poor prognosis in several tissues. Additionally, Wnt signaling also influences the tumor microenvironment and immune response. Some strategies and drugs have been proposed to target this pathway, such as blocking receptors/ligands, targeting intracellular molecules, beta-catenin/TCF4 complex and its downstream target genes, or tumor microenvironment and immune response. Here we discuss the roles of these components in Wnt signaling pathway in tumorigenesis and cancer progression, the underlying mechanisms that is responsible for the activation of Wnt signaling, and a series of drugs targeting the Wnt pathway provide multiple therapeutic values. Although some of these drugs exhibit exciting anti-cancer effect, clinical trials and systematic evaluation should be strictly performed along with multiple-omics technology.

The knowledge concerning the relationship between vegetation restoration and soil microorganisms is limited, especially at high altitudes. In order to evaluate the restoration efficacy of the reforestation on the soil microbial community, we have examined vegetation composition, edaphic properties and structure and function of different soil microbial groups in two different aged (25- and 40-year-old) Picea likiangensis var. rubescens Rehder & E. H. Wilson (P. rubescens) plantations and the primeval coniferous forest (PCF) dominated by Abies squamata Masters by plot-level inventories and sampling in western Sichuan Province, China. Our results suggested that only the fungal samples in 25-year-old P. rubescens plantation could be distinguished from those in the PCF in both structure and function. The structure and function of the fungal community recovered relatively slowly compared with bacterial and archaeal communities. In addition to the soil chemical properties and tree species composition, the shrub composition was also a key factor influencing the soil microbial community. The P. rubescens plantations were conducive to restoring the soil microbial community in both structure and function. However, there were uncertainties in the variations of the bacterial and archaeal communities with increasing the P. rubescens plantation age.

Colorectal cancer is a malignant tumor that begins in the colorectal mucosal epithelium. NPM1 is a nucleolar phosphoprotein that has been linked to tumor progression in humans. NPM1 is significantly overexpressed in a variety of tumors, including colorectal cancer, but its role and mechanism in colorectal cancer remain unknown. Therefore, the purpose of this study was to discover the role of NPM1 in promoting colorectal cancer proliferation via PRDX6 and its molecular mechanism. NPM1 knockdown or overexpression inhibited or promoted the proliferation and cell cycle progression of HCT-116 and HT-29 colorectal cancer cells, respectively, according to our findings. Furthermore, NPM1 knockdown or overexpression increased or decreased intracellular ROS levels. Animal experiments revealed that NPM1 knockdown or overexpression inhibited or promoted the growth of colorectal cancer cells transplanted subcutaneously. NPM1 knockdown or overexpression reduced or increased PRDX6 expression and related enzyme activities, respectively, according to our findings. NPM1 formed a complex with CBX3 as evidenced by immunoprecipitation, and the double luciferase reporter gene assay confirmed that the CBX3-NPM1 complex promoted PRDX6 transcription. Our data support the role of NPM1 in promoting the proliferation of colorectal cancer, which may be accomplished by CBX3 promoting the expression of the antioxidant protein PRDX6 and thus inhibiting intracellular ROS levels. NPM1 and PRDX6 are potential colorectal cancer therapeutic targets.

When a water droplet on a micropillar-structured hydrophobic surface is submitted to gradually increased pressure, the Cassie-Baxter wetting state transforms into the Wenzel wetting state once the pressure exceeds a critical value. It has been assumed that the reverse transition (Wenzel-to-Cassie-Baxter wetting state) cannot happen spontaneously after the pressure has been removed. In this paper, we report a new wetting-state transition. When external pressure is exerted on a droplet in the Cassie-Baxter wetting state on textured surfaces with high micropillars to trigger the breakdown of this wetting state, the droplet penetrates the micropillars but does not touch the base of the surface to trigger the occurrence of the Wenzel wetting state. We have named this state the suspended penetration wetting state. Spontaneous recovery from the suspended penetration wetting state to the initial Cassie-Baxter wetting state is achieved when the pressure is removed. Based on the experimental results, we built models to establish the penetration depth that the suspended penetration wetting state could achieve and to understand the energy barrier that influences the equilibrium position of the liquid surface. These results deepen our understanding of wetting states on rough surfaces subjected to external disturbances and shed new light on the design of superhydrophobic materials with a robust wetting stability.

When a water drop is deposited on a hole drilled in a superhydrophobic plate in contact with a bath of water from underneath, the liquid in the drop will transport into the bath and a jet is then produced. It is found that the evolution of the drop diameter $D(t)$ with time $t$ obeys scaling relations $D(t)\ensuremath{\sim}{t}^{2/7}$ and $D(t)\ensuremath{\sim}{t}^{1/2}$ for small drops and large puddles, respectively, arising from the competition between the surface tension and inertia.

Lymphocytes are some of the most motile cells of vertebrates, constantly navigating through various organ systems. Their specific positioning in the body is delicately controlled by site-specific directional cues such as chemokines. While it has long been suspected that an intrinsic molecular pilot, akin to a ship’s pilot, guides lymphocyte navigation, the nature of this pilot is unknown. Here we show that the TIPE (TNF-α-induced protein 8-like) family of proteins pilot lymphocytes by steering them toward chemokines. TIPE proteins are carriers of lipid second messengers. They mediate chemokine-induced local generation of phosphoinositide second messengers, but inhibit global activation of the small GTPase Rac. TIPE-deficient T lymphocytes are completely pilot-less: they are unable to migrate toward chemokines despite their normal ability to move randomly. As a consequence, TIPE-deficient mice have a marked defect in positioning their T lymphocytes to various tissues, both at the steady-state and during inflammation. Thus, TIPE proteins pilot lymphocytes during migration and may be targeted for the treatment of lymphocyte-related disorders.

The Tibetan Plateau (TP) is characterized by the world's highest timberlines, largest altitudinal range of forest distribution, and high warming rates. Whether the growth of most forests benefits from climate warming or is inhibited by warming-induced drought stress is still under debate. To understand this question, we collected tree-ring width (TRW) data from 6762 trees at 203 sites that contain 12 genera over the monsoonal TP (MTP) with an elevation range between 975 and 4478 m a.s.l. All sites were equally split into four transects along their altitudinal ranking. The mean tree growth rate (MTGR) of each transect was developed by assembling standardized TRW records. Our results suggest that MTGRs of the upper three transects (2992–4478 m) were stimulated by an increase in the summer (May-September) minimum temperature and have experienced unprecedented high values since the 1980s over the past three to four centuries. In contrast, warming-associated drought stress resulted in a sharp growth drop and minimum MTGR in the lowest transect (975–2970 m) during the 2000s, which was most pronounced in the Himalayan Mountains. We conclude that the majority of tree growth on the MTP has benefited from recent summer warming. The results are robust regardless of using alternative detrending methods, but still could be susceptible to the small replications of some species, outdated end years, oversimplification of the regional climate conditions, and varying growth response within each transect.

Stress from water scarcity as a result of rising temperatures associated with climate change has a profound impact on forest ecosystems around the world. However, few studies have assessed the influence of climate change on the dynamics of growth of alpine coniferous forests of different tree species and at different elevations on a regional scale in southeastern Tibetan Plateau (TP). The present paper examines that the impact using dendrochronological techniques with trees of the following genera: Abies, Picea, Larix, Tsuga, Pinus, Cupressus, and Juniperus. Radial growth was measured based on 46 chronologies from the cores of 2027 trees on the Hengduan Mountains (one of the Global Biodiversity Hotpots), which are part of the TP. In most cases, ring widths were strongly and significantly correlated to temperature both before and during the growing season, suggesting that climate warming plays a prominent role in the growth of alpine conifers in recent decades. Greater sensitivity to temperature and the rising temperatures have together led to faster growth of forest trees at high elevations than at low elevations. Climate warming may benefit most coniferous species by boosting their radial growth, especially in the upper treeline ecotone, but may also decrease radial growth significantly in P. yunnanensis at lower elevations because the species, unlike the other species studied, is adversely affected by high temperatures. If elevation-dependent warming in the Hengduan Mountains continues in the future, conifers at high and middle elevations (3000 m or higher) will benefit, whereas those at lower elevations (below 3000 m) will be affected adversely because of the warming-induced water deficit.

Yangquan Mining District is a major location for anthracite coal production in China. Understanding the modes of occurrences of major and trace elements in Yangquan coal is significant both geochemically and environmentally, although most elements are more depleted than those in Chinese coal. Ten coal bench and two parting samples were collected from No. 15 Coal of Yangquan Mining District. X-ray diffraction analysis was used to determine the proportions of minerals in the Yangquan coal, and X-ray fluorescence and inductively coupled plasma mass spectrometry analyses were used to determine the contents of major element oxides and trace elements, respectively. The mineral assemblages, ash yield, and (CaO + MgO + Fe2O3)/(SiO2 + Al2O3) ratio varied significantly in the vertical direction, which is attributed mainly to vertical variation in the depositional environment. The major element oxides and trace elements in the Yangquan coal were divided into four groups according to cluster analysis, which represent organic or inorganic affinity and different modes of occurrences. The coal benches underlying partings exhibited a rare-earth element and yttrium (REY) distribution pattern characterized by heavy (H)-type. This result differs from other coal benches characterized by light (L)-type REY, which is attributed to the leaching of overlying partings.

Superrepellency is a favorable non-wetting situation featured by a dramatically reduced solid/liquid contact region with extremely low adhesion. However, drop impact often brings out a notable extension of the contact region associated with rather enhanced water affinity, such renders irreversible breakdowns of superhydrophobicity. Here, we report an alternative outcome, a repeated Cassie-Wenzel-Cassie (CWC) wetting state transition in the microscale occurs when a drop impacts a two-tier superhydrophobic surface, which exhibits a striking contrast to the conventional perspective. Influences of material parameters on the impact dynamics are quantified. We demonstrate that self-cleaning and dropwise condensation significantly benefit from this outcome - dirt particles or small droplets in deep textures can be taken away through the transition. The results reported in this study allows us to promote the strategy to design functional superrepellency materials., Comment: 20 pages, 5 figures

Igneous intrusions significantly affect the mineralogical composition of coal. The Jingxi Coalfield, North China was subjected to the intrusion of a Mesozoic aplite; however, the resulting coal mineralogy has not been well investigated. This paper reports on a study of the mineralogical composition of five coal bench samples collected from the No. M3 coal in the Jingxi Coalfield, which was intruded by an aplite sill along the roof. The minerals present in the highest proportions in the No. M3 coal are margarite–paragonite group mineral (21.4%) and ammonian illite (72.7%), followed by ankerite (4.2%), anatase (0.7%), and rutile (0.9%). The formation of margarite, paragonite and ammonian illite is attributed to the intrusion of the aplite sill. The margarite and paragonite were formed prior to the formation of the ammonian illite. The proportion of the margarite–paragonite group mineral decreases, and the proportion of ammonian illite increases from the sill to the roof. The Ca2+ and K+ are more easily incorporated into the aluminosilicate mineral lattices than Na+ and NH4+, respectively. Thus, the Ca2+/Na+ ratio in the margarite–paragonite group mineral decreases, and the NH4+/K+ ratio in the ammonian illite increases from the sill to the roof. The formation of ankerite is also attributed to the igneous intrusion, but this mineral was formed later than the aluminosilicate minerals. The proportion of ankerite in the coal samples increases from the sill to the roof.

Surface and interfacial energies play important roles in a number of instability phenomena in liquids and soft matters, but are rare to play a similar role in solids. Here we report a new type of mechanical instabilities that are controlled by surface and interfacial energies and are valid for a large class of materials, in particular two-dimensional layered materials. When sliding a top flake cleaved from a square microscale graphite mesa by using a probe acted on the flake through a point contact, we observed that the flake moved unrotationally for a certain distance before it suddenly transferred to a rotating-moving state. The theoretical analysis that agrees well with the experimental observation reveals that this mechanical instability is an interesting effect of the structural superlubricity (a state of nearly zero friction). Our further analysis shows that this type of instability holds generally for various sliding joints on different scales, as long as the friction is ultralow. Thus, the uncovered mechanism provides useful knowledge for manipulating and controlling all these sliding joints, and can guide design of future structural superlubricity based devices., Comment: 9 pages, 4 figures

Integrin β6 (ITGB6), an epithelial-specific integrin, is upregulated in oral squamous cell carcinomas (OSCC) and is associated with progression and metastasis of OSCC. Lysophosphatidic acid (LPA), an important bioactive phospholipid present in saliva, has also been related to OSCC cell migration and invasiveness. LPA exerts its biological effects through signal transduction pathways that ultimately regulate gene expression. However, it is unclear whether LPA signaling is involved in ITGB6 upregulation in OSCC. Therefore, the aim of the current study was to investigate the role of LPA in the regulation of ITGB6 expression in OSCC cells, and to delineate the molecular signaling pathways involved. Using SAS and HSC-3 OSCC cell lines, we found that LPA increases ITGB6 mRNA expression without affecting mRNA stability, suggesting that LPA acts by regulating ITGB6 gene transcription. In addition, we show that LPA stimulation increases phosphorylation and binding of the transcription factors SMAD3 and ETS-1 to the ITGB6 promoter resulting in ITGB6 active transcription. Finally, we demonstrate that LPA-induced ITGB6 expression is mediated via the LPA receptors 1 (LPAR1) coupling to Gα

Although recent studies have demonstrated that annual growth rings are present among perennial forbs species at high northern latitudes, little is known about whether there are demarcated growth rings of perennial forbs in the Loess Plateau of China where plant growth is strongly limited by dry climate conditions and severe soil erosion. In this study, we collected the main roots of 11 perennial forbs species along the precipitation gradient in the Loess Plateau, and analyzed the growth rings in the secondary root xylem. We found that ten species showed distinct annual growth rings, and the anatomical patterns, including vessel size and density, varied considerably among different families. Our results suggest, for forbs species in the Loess Plateau, that vessel diameter in the root xylem was strongly correlated with growth rate of the forb’s roots. Ring widths of the forbs showed a significant declining trend, reflecting the deteriorating signal of growth condition with age. In comparison to other families, forb species of Fabaceae usually have the evidently larger vessels that link directly to higher hydraulic capacity and growth rate. In terms of annual ring width patterns, this study provides an applicable approach to detecting effects of limited climatic conditions and life history strategies on herbaceous vegetation in the Loess Plateau.

Purpose The pattern of eukaryotic macroorganisms varies with altitude is well-documented; by contrast, very little is known of how a bacterial pattern in soils varies with the elevation in a montane ecosystem. Mostly, previous studies on soil bacteria have either found a diversity decline, no trend, or a hump-back trend with increasing elevation. The aim of this study was to investigate the bacterial community composition and diversity patterns of Mount Nadu in Wolong Nature Reserve, Western Sichuan Plateau (3000–3945 masl).

Ammonian illite is observed to be presented in the intra-seam coal partings of the Permo-Carboniferous coal seams from the Qinshui Coalfield, North China. This paper provides new insights into its geochemical and mineralogical characteristics, as well as the factors influencing its formation and its nitrogen isotope ratios. The interlayer cations of ammonian illite in the samples presented in this study were dominated by NH 4 + with a certain amount of K + and distributed homogeneously in each illite layer. Ammonian illite has an NH 4 + /(NH 4 + + K + ) ratio of 0.87 on average, with a basal spacing (d 001 , 10.267 A on average) greater than those of potassian illite and muscovite, but lower than that of tobelite. The average stoichiometric formula of the ammonian illite was inferred as (NH 40.67 ,K 0.11 )(Al 1.90 ,Fe 0.06 ,Mg 0.04 )(Al 0.68 ,Si 3.32 )O 10 (OH) 2 , and the average Si/Al IV ratio (4.88) was found to be higher than that of tobelite. This indicates that the conversion of ammonian illite to tobelite includes the expulsion of Si from the tetrahedral sheets and the incorporation of Al into the octahedral and tetrahedral sheets. The d 005 is influenced not only by the NH 4 + /(NH 4 + + K + ) ratio but also, to some extent, by the entrance of Al IV into tetrahedral sites. It is inferred that the ammonian illite was formed by the incorporation of Si into pre-existing kaolinite during diagenesis, and that its formation was influenced not only by the diagenetic temperature but also by the depositional environment. Brackish water favors the formation of ammonian illite during deposition. The NH 4 + of the ammonian illite was mainly derived from pyrrolic (N-5) and pyridinic (N-6) nitrogen groups at the margins of the coal's carbon matrix during diagenesis. On average, it has a δ 15 N value of + 8.0‰, much higher than that of total coal nitrogen (+ 3.9‰ on average). This is related mainly to the higher δ 15 N values of N-5 and N-6 than the quaternary nitrogen group (N-Q) within the carbon matrix.