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This study investigates the effects of grazing intensity and spatial scale on the important values, interspecific relationships, and community stability of desert steppe plant communities in Siziwang Banner, Inner Mongolia, China. Using vegetation data collected at three spatial scales (50 m × 50 m, 25 m × 25 m, and 2.5 m × 2.5 m) under two grazing conditions (no grazing and heavy grazing), we employed ecological statistics, including variance ratio analysis, χ 2 tests, and the Jaccard index, to analyze species interactions and community structure. The results indicated that the important values of species vary with both spatial scale and grazing intensity; for example, Stipa breviflori and Chenopodium aristatum exhibited significantly higher important values in heavily grazed areas. Larger spatial scales enhanced the dominance of Cleistogenes songorica and Chenopodium aristatum, while smaller scales favored Stipa breviflori and Caragana stenophylla. Furthermore, interspecific associations were stronger in heavy grazing conditions. The community demonstrated consistent instability; however, no grazing areas were more stable than heavily grazed ones. These findings highlight that species importance, interspecific relationships, and community stability are closely linked to grazing intensity and spatial scale, emphasizing the critical role of sustainable grazing management in maintaining the long-term stability and resilience of desert steppe ecosystems. By emphasizing the need for targeted and sustainable management strategies, this study aims to contribute to the restoration and preservation of these vital ecosystems. [ABSTRACT FROM AUTHOR]

Due to climate change and global warming, the frequency of sandstorms in northern China is increasing. Stipa breviflora, a dominant species in Eurasian grasslands, can help prevent desertification from becoming more serious. Studies on S. breviflora cover a wide range of fields. To the best of our knowledge, the present study is the first to sequence, assemble, and annotate the S. breviflora genome. In total, 2,781,544 contigs were assembled, and 2,600,873 scaffolds were obtained, resulting in a total length of 649,849,683 bp. The number of scaffolds greater than 1 kb was 70,770. We annotated the assembled genome (>121 kb), conducted a selective sweep analysis, and ultimately succeeded in assembling the Matk gene of S. breviflora. More importantly, our research identified 26 scaffolds that may be responsible for the drought tolerance of S. breviflora Griseb. In summary, the data obtained regarding S. breviflora will be of great significance for future research. [ABSTRACT FROM AUTHOR]

Ecological restoration has a positive impact on global climate change. How plant-soil stores carbon in degraded grassland ecological restoration requires long-term monitoring and support. To reveal the dynamics of plant-soil carbon storage in the succession process of ecological restoration, compare the effects of artificial interference and natural restoration, and determine the impact of climate change and biodiversity on vegetation soil carbon storage, we conducted a study in National Grassland Natural Park, which is located on the southern foot of the Yinshan Mountains in Hohhot, Inner Mongolia, China. Based on long restoration chronosequences (2012–2022), using a space-for-time substitution approach and one-way ANOVA tests, Pearson correlation and structural equation modeling were used to investigate the interactions among these various factors. The results indicated that the carbon storage of aboveground vegetation first increased, and then, decreased with time. The underground root carbon storage and soil carbon storage at 0–10 cm and 20–30 cm first increased, then decreased, and finally, stabilized. The highest soil carbon storage (0–30 cm) was 102.11 t/ha in 2013, which accounted for 96.61% of the total organic carbon storage. The Shannon–Wiener index, individual number of species, and surface root carbon storage (0–10 cm) significantly increased the carbon storage of surface soil (0–10 cm) (p < 0.05). Compared to natural restoration, artificial restoration over seven years decreased soil carbon storage at 0–30 cm and underground root carbon storage at 0–10 cm (p < 0.05). Consequently, combining artificial restoration with natural restoration can help in establishing a more stable ecosystem faster and in increasing the carbon storage of the ecosystem. It is an effective management measure to promote grassland restoration in arid areas. Also, climate (MAT, MAP) change was closely correlated with plant-soil carbon storage. [ABSTRACT FROM AUTHOR]

A high stocking rate can intensify wind erosion in grasslands, and strong wind can carry away soil surface particles, soil carbon (C), and nitrogen (N), which leads to soil barrenness. In this research, the dust flux, total carbon (TC) and total nitrogen (TN) contents, and fluxes of aeolian sediment were determined in the nongrowing season (mid‐October to mid‐April of the following year) and growing season (mid‐April to mid‐October) from 2017 to 2020 at a continuous grazing gradient experiment platform established in 2004 in a desert steppe in Inner Mongolia, China. The results were as follows: (1) As the stocking rate increased, fluxes of aeolian sediment at 10 cm (H10), 30 cm (H30), and 100 cm (H100) were greatly increased (p < 0.05). Aeolian sediment fluxes followed the order control (CK) < light stocking rate (LG) < moderate stocking rate (MG) < heavy stocking rate (HG). (2) The TC and TN contents of aeolian sediment decreased with an increase in stocking rate, and higher grazing intensity resulted in a difference in TC content, which decreased between the two seasons. The TC flux/aeolian sediment flux increased with an increase in stocking rate, and the ratio of TC flux increased between two seasons due to the influence of heavy grazing. Grazing disturbance had little effect on TN flux. As grazing intensity increased, wind erosion resulted in an increase in soil available carbon loss, and this loss was more severe in the nongrowing season. (3) The C/N ratio increased with increase in aeolian sediment flux. The aeolian sediment flux and C/N showed an inverse relationship with the increase in grazing intensity. Regression lines for the two seasons showed an intersecting trend, and the intersection points moved backward as height increased, indicating that higher stocking rates could reduce the influence of grassland vegetation on C/N. As height increased, the regression intercept increased, indicating that the loss of wind‐eroded soil changed from a low C/N loss to a high C/N loss. In general, high stocking rates aggravated soil wind erosion, resulting in more C pool loss than N loss in terms of soil elements and more available C loss in the nongrowing season. In the nongrowing season, vegetation characteristics are poor, coupled with grazing interference, and wind erosion in the nongrowing season is serious in general; however, the change law of C and N in wind‐eroded soil is directly related to its particle size. C and N content in fine particles is higher, and C content in soil is much higher than N, so the TC loss is relatively large; therefore, reducing the intensity of grazing can reduce the occurrence of soil wind erosion, and implementing measures to protect grassland in spring and other periods vulnerable to wind erosion would be conducive to the sustainable usage of grassland resources. [ABSTRACT FROM AUTHOR]

Cleistogenes songorica, as a clustered grass, is the main grassland flora of the Stipa breviflora desert grassland. Some studies have shown that the constructive species of S. breviflora (sparse cluster type) is prone to cluster fragmentation; however, research on C. songorica is relatively rare. Then will the C. songorica plant population (dense cluster type) also have cluster fragmentation under the influence of intense grazing? To answer this question, we used variance analysis and geo‐statistical methods. The spatial distribution of C. songorica in S. breviflora desert steppe in Inner Mongolia was measured under four grazing intensities (no grazing, CK, 0 sheep·ha−1·half year−1; light grazing, LG, 0.93 sheep·ha−1·half year−1; moderate grazing, MG, 1.82 sheep·ha−1·half year−1; and heavy grazing, HG, 2.71 sheep·ha−1·half year−1) and four scales (10 cm × 10 cm, 20 cm × 20 cm, 25 cm × 25 cm, 50 cm × 50 cm). We then analyzed C. songorica whether fragmentation was present. The results showed that increased grazing intensity is associated with increased density and decreased height, coverage, and standing crop of C. songorica. The spatial distribution of C. songorica was affected by structural factors, and spatial heterogeneity decreased with increased spatial scale. With increased grazing intensity and spatial scale, the patch area of C. songorica gradually increased and tended toward band distribution. In summary, increased grazing intensity and spatial scale led to weakened heterogeneity of C. songorica spatial distribution and increased consistency. [ABSTRACT FROM AUTHOR]

Dominant species play a principal role in controlling and maintaining ecosystem stability. Stipa breviflora is the dominant species in desert steppe. Changes in the stability of a plant population will further affect the stability of the broader habitat, such as the desert steppe. In the desert steppe ecosystem, it is not clear what level of grazing intensity is best for improving the grazing tolerance and stability of the vegetation. And, the study of this question should involve a multi-dimensional, comprehensive analysis. This study will utilize variance analysis, plant population stability, and trade-off index to study S. breviflora, the dominant species in the desert steppe in Inner Mongolia, and its performance under four grazing intensities (control, CK, 0 sheep·ha−1·half year−1; light grazing, LG, 0.93 sheep·ha−1·half year−1; moderate grazing, MG, 1.82 sheep·ha−1·half year−1; and heavy grazing, HG, 2.71 sheep·ha−1·half year−1) over six scales (5 cm × 5 cm; 10 cm × 10 cm; 20 cm × 20 cm; 25 cm × 25 cm; 50 cm × 50 cm; and 100 cm × 100 cm). The characteristics of the population stability of S. breviflora were explored. The results showed that the response of S. breviflora's stability to heavy grazing was multidimensional. Heavy grazing reduced the population stability of S. breviflora. Across different dimensions, base coverage was the first of the population stability metrics of S. breviflora to destabilize, followed by projection coverage, density, and height. Heavy grazing also affected the trade-offs of S. breviflora's population stability across different dimensions. In general, the trade-off degree decreased as the grazing intensity increased, and it increased as the scale increased. [ABSTRACT FROM AUTHOR]

Antler velvet polypeptide (VAP) is a prominent bioactive component of antler velvet. Whereas uncharacterized crude extracts have typically been used in pharmacological studies, in this study, the velvet polypeptide was isolated and purified by acid water extraction, ethanol precipitation, ammonium sulfate fractionation and precipitation, and chromatography, progressively. Human umbilical vein endothelial cells (HUVECs) were induced with [H.sub.2][O.sub.2] followed purified polypeptide treatment. Cell viability was evaluated by MTT assay. The apoptosis of cells was detected by fluorescence microscopy and flow cytometry. A cell analyzer was used to measure the mitochondrial membrane potential. The intracellular reactive oxygen species (ROS) levels were determined by flow cytometry. Oxidative stress related biochemical parameters were detected, and the expression of apoptosis-related proteins was examined by Western blot analysis. The results indicated that a 7.0 kDa polypeptide (VAP II) was isolated from antler velvet. VAP II enhanced cell viability, decreased cell apoptosis, reversed depolarization of mitochondrial membrane potential, decreased ROS levels, inhibited oxidative stress, and regulated the downstream signaling apoptotic cascade expression caused by [H.sub.2][O.sub.2]. The protective effects of VAP II on HUVECs suggests a potential strategy for the treatment of cardiovascular disease. Key words: antler velvet polypeptides, oxidative stress, antioxidant, apoptosis. Le polypeptide de bois de velours (VAP pour << antler velvet polypeptide >>) est un important compose bioactif des bois de velours. Alors que des extraits bruts non caracterises ont habituellement ete utilises dans le cadre d'etudes pharmacologiques, dans cette etude, nous avons isole et purifie le polypeptide de velours par une extraction acide-eau, la precipitation dans l'ethanol ainsi que le fractionnement et la precipitation a l'aide de sulfate d'ammonium, avec le passage progressif dans une colonne de chromatographie. Nous avons obtenu des cellules HUVEC (pour << human umbilical vein endothelial cells >>) par une induction l'aide de [H.sub.2][O.sub.2] suivie d'un traitement de purification des polypeptides. Nous avons evalue la viabilite des cellules l'aide du test MTT. Nous avons decele les cellules apoptotiques a l'aide de la microscopie par fluorescence et de la cytometrie en flux. Nous avons utilise un analyseur de cellules pour mesurer le potentiel des membranes mitochondriales. Nous avons mesure les derives reactifs de l'oxygene (ou ROS pour << reactive oxygen species >>) intracellulaires par cytometrie en flux. Nous avons detecte les parametres biochimiques lies au stress oxydatif et etudie l'expression des proteines liees a l'apoptose a l'aide de la technique d'immunobuvardage de Western. Les resultats ont revele l'isolation d'un polypeptide de 7,0 kDa (VAP II) partir de bois de velours. Le VAP II pourrait entrainer une augmentation de la viabilite des cellules, une attenuation de l'apoptose cellulaire, la depolarisation inverse du potentiel des membranes mitochondriales, diminuer les taux de ROS, inhiber le stress oxydatif et assurer la regulation de l'expression de la cascade de la signalisation apoptotique causee par le [H.sub.2][O.sub.2] en aval. Les effets protecteurs du VAP II contre les lesions des cellules HUVEC ont permis d'obtenir une strategie eventuelle dans le traitement de la maladie cardiovasculaire. [Traduit par la Redaction] Mots-cles : polypeptide de bois de velours, stress oxydatif, antioxydant, apoptose., Introduction There has recently been a surge of interest in the benefits from the natural products used in traditional and herbal medicines. To date, the majority of studies conducted worldwide [...]

Leymus chinensis is a widely distributed species of Eurasian grasslands that is well adapted to a range of environmental conditions. In this study, we measured soil and plant chemical elements to examine the basis of the ecological adaptations of L. chinensis to temperate steppe. We sampled leaves of L. chinensis and soil layers at different latitudes in temperate steppe for three consecutive years from 2012 to 2014. One-way analysis of variance and linear regression were used to analyze the variation in foliar nitrogen (N) and phosphorus (P) contents and the N:P ratio in L. chinensis. The correlations between the foliar N:P ratio and the variation in soil total nitrogen (TN) and total P contents with latitudinal gradient were measured to explore the homeostasis stoichiometry of foliar N and P in L. chinensis. With increasing latitude, both the foliar N and P contents of L. chinensis showed parabolic trends with significant negative correlations. The population of L. chinensis was limited by N, and the soil TN content showed a significant increasing trend with the increase in the foliar N:P ratio. The variation in the foliar N:P ratio of L. chinensis was determined through the variation in the soil N content. In different latitude intervals, the foliar N, P, and N:P ratio of L. chinensis showed absolute stability and strong internal stability, and the values of HN:P were high and similar in different latitudes. In conclusion, the population of L. chinensis in the temperate steppe is highly adaptable; and, thus, can maintain a dominant position in the variable environment and has a wide distribution range. [ABSTRACT FROM AUTHOR]

Microwaves may exert adverse biological effects on the cardiovascular system at the integrated system and cellular levels. However, the mechanism underlying such effects remains poorly understood. Here, we report a previously uncharacterized mechanism through which microwaves damage myocardial cells. Rats were treated with 2450 MHz microwave radiation at 50,100,150, or 200 mW/[cm.sup.2] for 6 min. Microwave treatment significantly enhanced the levels of various enzymes in serum. In addition, it increased the malondialdehyde content while decreasing the levels of antioxidative stress enzymes, activities of enzyme complexes I-IV, and ATP in myocardial tissues. Notably, irradiated myocardial cells exhibited structural damage and underwent apoptosis. Furthermore, Western blot analysis revealed significant changes in expression levels of proteins involved in oxidative stress regulation and apoptotic signaling pathways, indicating that microwave irradiation could induce myocardial cell apoptosis by interfering with oxidative stress and cardiac energy metabolism. Our findings provide useful insights into the mechanism of microwave-induced damage to the cardiovascular system. Key words: microwave radiation, myocardial cell, oxidative stress, energy metabolism. Les micro-ondes pourraient avoir des effets biologiques nefastes sur le systeme cardiovasculaire: dans son integrite comme au niveau cellulaire. Cependant, on connait toujours peu leurs mecanismes sous-jacents. Dans ces travaux, nous rapportons un mecanisme encore jamais caracterise qui mene a des lesions des cellules myocardiques. A cet effet, nous avons administre a des rats des rayonnements de micro-ondes de 2450 MHz a 50,100, 150 ou 200 mW/[cm.sup.2] pendant 6 min, ce qui a entraine une augmentation marquee des taux seriques de divers enzymes. Cette intervention a aussi entraine une augmentation des taux de malondialdehyde ainsi qu'une diminution des taux des enzymes du stress oxydatif, de l'activite des enzymes des complexes I a IV et des taux d'ATP dans le tissu myocardique. Mais surtout, les cellules myocardiques irradiees presentaient des dommages structurels et subissaient l'apoptose. En fait, l'analyse par buvardage de Western a revele la presence de modifications importantes des taux d'expression des proteines jouant un role dans les voies de signalisation de la regulation du stress oxydatif et de l'apoptose, ce qui indique que l'irradiation par les micro-ondes peut induire l'apoptose dans les cellules myocardiques en interferant avec le stress oxydatif et le metabolisme energetique cardiaque. En somme, nos resultats donnent une idee concrete du mecanisme responsable des dommages causes par les micro-ondes au systeme cardiovasculaire. [Traduit par la Redaction] Mots-cles: rayonnement de micro-ondes, cellule myocardique, stress oxydatif, metabolisme energetique., Introduction Microwaves are electromagnetic waves with wavelengths ranging from 1 mm to 1 m and frequencies between 300 MHz and 300 GHz (Gupta 2014; Shahin et al. 2013). Microwave technology [...]

New therapeutic approaches are needed to improve the survival rate from pancreatic cancer, one of the most lethal human malignancies. In this study, JF305 cells were treated with microwaves at doses of 2.5, 5.0,10.0,15.0, and 20.0 mW/[cm.sup.2] for 20 min. The inhibition of JF305 cell proliferation was tested using the MTT assay. Apoptotic cells were detected with Hoechst 33258 staining and a Nucleo-Counter NC-3000. The expression of apoptosis-related proteins was examined with Western blot. The results showed that microwaves inhibited the growth of JF305 cells in a dose-dependent manner, and caused morphological changes in apoptotic body formation. The percentages of apoptosis detected using annexin V-fluorescein isothiocyanate (FITC) were 4.0%, 10.0%, 12.0%, and 30.0% with the dosage of microwave (0, 5.0,10.0, and 20.0 mW/[cm.sup.2]), respectively. Treatment with microwaves increased the activity of caspase-9 and caspase-3, down-regulated the expression of Bcl-2, and up-regulated the expression of Bax and CytoC. In addition, the expression level of p65 was increased whereas the level of IκBα down-regulated. Those results suggest that microwaves inhibit cell growth and induce apoptosis in JF305 cells through an NF-κB-regulated mitochondria-mediated pathway. Key words: anticancer, microwave, JF305 cells, apoptosis. De nouvelles approches therapeutiques sont requises afin d'ameliorer le taux de survie des patients atteints du cancer du pancreas, un des cancers les plus letaux chez l'humain. Dans cette etude, les cellules JF305 ont ete traitees par des microondes a des doses de 2,5, 5,0, 10,0, 15,0 et 20,0 mW/[cm.sup.2] pendant 20 minutes. L'inhibition de la proliferation des cellules JF305 a ete testee a l'aide d'un dosage au MTT. Les cellules en apoptose ont ete detectees par une coloration au Hoechst 33258 sur un Nucleo-Counter NC-3000. L'expression de proteines reliees a l'apoptose a ete examinee par buvardage Western. Les resultats ont montre que les microondes peuvent inhiber la croissance des cellules JF305 en fonction de la dose et causer des changements morphologiques dans la formation de corps apoptotiques. Les pourcentages de cellules en apoptose detectes par l'Annexine V-FITC etaient respectivement de 4,0, 10,0, 12,0 et 30,0 % en fonction de la dose de microondes (0, 5,0, 10,0, et 20,0 mW/[cm.sup.2]). Le traitement aux microondes accroissait l'activite de la caspase-9 et de la caspase-3, regulait a la baisse l'expression de Bcl-2 et regulait a la hausse l'expression de Bax et CytoC. En plus, le niveau d'expression de p65 etait accru alors que celui de IκBα etait diminue. Ces resultats suggerent que les microondes inhibent la croissance cellulaire et induisent l'apoptose des cellules JF305 par l'intermediaire d'une voie mitochondriale regulee par NF-κB. [Traduit par la Redaction] Mots-cles: anti-cancer, microonde, cellules JF305, apoptose., Introduction Pancreatic cancer is one of the most lethal human malignancies, with a mortality rate of up to 96%. Pancreatic adenocarcinoma is locally invasive and is surrounded by a dense [...]

Leymus chinensis is a primary plant in the meadow steppe and typical steppe of China. With global warming and increasing grazing intensity, grassland degradation is being exacerbated. To better protect the L. chinensis grassland in this area and provide a theoretical basis for restoring it, this paper compared the germinable seed bank in the soil and the germination characteristics of L. chinensis (including initial germination time, duration of germination, germination termination time, germination dynamics, and germination index) in free-grazing and enclosed areas. At the same time, combining information about the density of L. chinensis on the ground and previous research results, a comprehensive analysis was conducted. The major results were: (1) there was no significant difference in the number of germinable seeds in the soil between the free-grazing area and the enclosed area, and these seeds were mainly concentrated in the 0–2 cm soil layer. (2) The free-grazing area resulted in a significant increase in the number of germinable L. chinensis seeds and advanced the initial germination time. (3) The number of soil germinated seeds and the number of L. chinensis germinated seeds decreased with the increase in soil depth. (4) Livestock grazing behaviours increased seed burial, thus improving the L. chinensis germination rate. At the same time, the L. chinensis seed bearing percentage and seed quality and the number of germinable L. chinensis seeds were significantly higher in the free-grazing area than in the enclosed area. However, this result still needs to be further explored. [ABSTRACT FROM AUTHOR]

Root traits are often used to predict the ecological adaptations of plants. Water and nutrient availability together with fragment size are likely to affect the adaptative capacity of Stipa breviflora and help plants spread and explore new sites, while the effects of water, nutrients and fragment size on S. breviflora's root traits have rarely been studied in combination. Here, a standard Taguchi L8(27) array design was conducted with four single factors, water (W), nitrogen (N), phosphorus (P) and fragment size (C), and three interactions (N × P, N × W and P × W). Each of the four factors had two levels (1 = low level and 2 = high level). This study found that water was the most important contributor influencing S. breviflora root growth, followed by N and P, respectively. W2 and P2 additions both promoted root growth, whereas N2 addition significantly inhibited root growth. Though C2 had higher values of total root length, surface area, volume, number of tips and biomass than C1, its root growth rate was lower than C1, and its small size fragment had a higher capacity of root growth under low N addition. These findings suggest that clonal fragmentation may enhance the adaptation of S. breviflora in low nitrogen habitats, and that nitrogen is one of the limiting factors influencing their growth and distribution. [ABSTRACT FROM AUTHOR]

Induction of apoptosis in tumor cells has become the major focus of anti-tumor therapeutics development. Juglone, a major chemical constituent of Juglans mandshurica Maxim, possesses several bioactivities, including anti-tumor. In the present study, HeLa cells were incubated with juglone at various concentrations. The proliferation inhibition of juglone on HeLa cells was tested by the MTT assay. Occurrence of apoptosis was detected by Hoechst 33258 staining, flow cytometry, and transmission electron microscopy. The expression of apoptotic-related proteins was examined by Western blot. The results showed that juglone inhibits the growth of HeLa cells in dose--dependent manner. Topical morphological changes of apoptotic body formation after juglone treatment were observed. The percentages of early apoptosis of Annexin V-FITC were 5.23%, 7.95%, 10.69%, and 20.92% with the concentrations of juglone (12.5, 25, 50, and 100 (µmol/L), respectively. After cells were treated with juglone at the different dose for 24 h, the expression of Bcl-2 was significantly down-regulated and the expression of Bax was significantly up-regulated compared with the control. These events paralleled with activation of caspase-9, -8, -3, and PARP cleavage. The results suggest that juglone may be effective for the treatment of HeLa cells. Key words: anticancer, juglone, HeLa cells, apoptosis, cytotoxicity, caspases, early apoptosis. L'induction de l'apoptose des cellules tumorales est devenu un element central du developpement de therapies anti-tumorales. La juglone, la constituante chimique principale de Juglans mandshurica Maxim, possede plusieurs activites biologiques dont une activite anti-tumorale. Dans cette etude, des cellules HeLa ont ete incubees avec differentes concentrations de juglone. L'inhibition de la proliferation des cellules HeLa par la juglone a ete mesuree par le dosage de MTT. L'apoptose a ete detectee par une coloration au Hoechst 33258, par cytometrie de flux et par microscopie electronique a transmission. L'expression de proteines reliees a l'apoptose a ete examinee par buvardage Western. Les resultats ont montre que la juglone inhibe la croissance des cellules HeLa de facon dependante de la concentration. Des changements morphologiques locaux dans la formation de corps apoptotiques a la suite du traitement a la juglone ont ete observes. Les pourcentages d'apoptose precoce detectes par la coloration a l'annexine V-FITC etaient de 5,23 %, 7,95 %, 10,69 % et 20,92 % a des concentrations de 12,5 , 25 , 50 et 100 (µmol/L de juglone, respectivement. Apres que les cellules aient ete traitees aux differentes concentrations de juglone pendant 24 h, l'expression de Bcl-2 etait significativement diminuee et l'expression de Bax etait significativement regulee a la hausse comparativement aux controles. Ces evenements se deroulaient parallelement a l'activation des capsases 9, 8 et 3 ainsi qu'au clivage de la PARP. Ces resultats suggerent que la juglone peut etre efficace dans le traitement des cellules HeLa. Mots-cles : anti-cancer, juglone, cellules HeLa, apoptose, cytotoxicite, caspases, apoptose precoce. [Traduit par la Redaction], Introduction Human cervical cancer is a major mortality factor in the female population. HeLa cell (also Hela or hela cell) is a cell type in an immortal cell line used [...]

The stable carbon (C) isotope of soil CO2 efflux (δ13CO2e) is closely associated with soil C dynamics, which have a complex feedback relationship with climate. Three levels of warming (T0: ambient temperature (15.7 °C); T1: T0 + 2 °C; T2: T0 + 4 °C) were combined with three levels of increased precipitation (W0: ambient precipitation (245.2 mm); W1: W0 + 25%; W2: W0 + 50%) in order to quantify soil CO2 flux and its δ13CO2e values under nine treatment conditions (T0W0, T0W1, T0W2, T1W0, T1W1, T1W2, T2W0, T2W1, and T2W2) in desert steppe in an experimental beginning in 2015. A non-steady state chamber system relying on Keeling plots was used to estimate δ13CO2e. The temperature (ST) and moisture (SM) of soil as well as soil organic carbon content (SOC) and δ13C values (δ13Csoil) were tested in order to interpret variations in soil CO2 efflux and δ13CO2e. Sampling was carried out during the growing season in 2018 and 2019. During the experiment, the ST and SM correspondingly increased due to warming and increased precipitation. CO2 flux ranged from 37 to 1103 mg m−2·h−1, and emissions peaked in early August in the desert steppe. Warming of 2 °C to 4 °C stimulated a 14% to 30.9% increase in soil CO2 efflux and a 0.4‰ to 1.8‰ enrichment in δ13CO2e, respectively. Increased precipitation raised soil CO2 efflux by 14% to 19.3%, and decreased δ13CO2e by 0.5‰ to 0.9‰. There was a positive correlation between soil CO2 efflux and ST and SOC indicating that ST affected soil CO2 efflux by changing SOC content. Although the δ13CO2e was positively correlated with ST, it was negatively correlated to SM. The decline of δ13CO2e with soil moisture was predominantly due to intensified and increased diffusive fractionation. The mean δ13CO2e value (−20.2‰) was higher than that of the soil carbon isotope signature at 0–20 cm (δ13Csoil = −22.7‰). The difference between δ13CO2e and δ13Csoil (Δe-s) could be used to evaluate the likelihood of substrate utilization. 13C enriched stable C pools were more likely to be utilized below 20 cm under warming of 2 °C in the desert steppe. Moreover, the interaction of T × W neither altered the CO2 emitted by soil nor the δ13CO2e or Δe-s, indicating that warming combined with precipitation may alleviate the SOC oxidation of soil enriched in 13C in the desert steppe. [ABSTRACT FROM AUTHOR]

The gelatin film has great potential in biomedical applications, especially in wound healing. The combination of gelatin films and stem cells could further accelerate the skin regeneration. Although polysaccharide modification can improve the mechanical property and biological activity of gelatin films, information about the stability and cellular affinity is still limited. This study investigated the influence of polysaccharides on the stability and cellular affinity of gelatin films. Two kinds of gelatin‐polysaccharide composite films, including gelatin‐hyaluronic acid (G‐HA) and gelatin‐chitosan (G‐CS), were prepared in this study. It was found that G‐HA composite film had better short‐term and long‐term stability compared with G‐CS composite film. And G‐HA composite film also had better biological safety than G‐CS film. Moreover, the surface of G‐HA composite film supported the adhesion and growth of human umbilical cord Wharton's jelly‐derived mesenchymal stem cells (WJ MSCs) better than G‐CS film surface. These data illustrated that G‐HA composite film has better stability and cellular affinity compared with G‐CS film, which could be considered a promising delivery system of stem cells for further in vivo studies. Therefore, this work would be very helpful to optimize the preparation of gelatin‐polysaccharide composite films. [ABSTRACT FROM AUTHOR]

Understanding how grazing activity drives plant community structure or the distribution of specific species in a community remains a major challenge in community ecology. The patchiness or spatial aggregation of specific species can be quantified by analyzing their relative coordinates in the community. Using variance and geostatistical analysis methods, we examined the quantitative characteristics and spatial distribution of Stipa breviflora in a desert steppe in northern China under four different grazing intensities (no grazing, NG, light grazing, LG, moderate grazing, MG, and heavy grazing, HG) at three small spatial scales (10 × 10 cm, 20 × 20 cm, 25 × 25 cm). We found that grazing significantly increased cover, density, and proportion in standing crop of S. breviflora, but decreased height. The spatial distribution of S. breviflora was strongly dependent upon the sampling unit and grazing intensity. The patchiness of S. breviflora reduced with sampling scale, and spatial distribution of S. breviflora was mainly determined by structural factors. The intact clusters of S. breviflora were more fragmented with increasing grazing intensity and offspring clusters spread out from the center of the parent plant. These findings suggest that spatial aggregation can enhance the ability of S. breviflora to tolerate grazing and that smaller isolated clusters are beneficial to the survival of this dominant species under heavy grazing. [ABSTRACT FROM AUTHOR]

Ref.: Can. J. Physiol. Pharmacol. 92(4): 324-329 (2014). The statement informing that Wenhe Zhu and Wei Zhang contributed equally to this work was left out of the original published version. [...]

Gelatin hydrogel has great potential in regenerative medicine. The degradation of gelatin hydrogel is important to control the release profile of encapsulated biomolecules and regulate in vivo tissue repair process. As a plasticizer, PEG can significantly improve the mechanical property of gelatin hydrogel. However, how preparation parameters affect the degradation rate of gelatin-PEG composite hydrogel is still not clear. In this study, the significant effect factor, glutaraldehyde (GA) concentration, was confirmed by means of Plackett-Burman method. Then a mathematical model was built to predict the degradation rate of composite hydrogels under different preparation conditions using the response surface method (RSM), which was helpful to prepare the certain composite hydrogel with desired degradation rate. In addition, it was found that gelatin-PEG composite hydrogel surface well supported the adhesion and growth of human mesenchymal stem cells (MSCs). Moreover, PEG concentration not only could adjust hydrogel degradation more subtly, but also might increase the cross-linking degree and affect the cell migration. Therefore, these results would be useful to optimize the preparation of gelatin-PEG composite hydrogel for drug delivery or tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3149-3156, 2016. [ABSTRACT FROM AUTHOR]

The advances in cluster-assembled materials where clusters serve as building blocks have opened new opportunities to develop ever more sensitive gas sensors. Here, using density functional theory calculations, the structural and electronic properties of cluster-assembled nanowires based on M12N12 (M = Al and Ga) clusters and their application as gas sensors have been investigated. Our results show that the nanowires can be produced via the coalescence of stable M12N12 fullerene-like clusters. The M12N12-based nanowires have semiconducting electrical properties with direct energy gaps, and are particularly stable at room temperature for long enough to allow for their characterization and applications. Furthermore, we found that the CO, NO, and NO2 molecules are chemisorbed on the M12N12-based nanowires with reasonable adsorption energies and apparent charge transfer. The electronic properties of the M12N12-based nanowires present dramatic changes after the adsorption of the CO, NO, and NO2 molecules, especially their electric conductivity. However, the adsorption of NO2 on the Al12N12-based nanowire is too strong, indicating an impractical recovery time as NO2 sensors. In addition to this, due to reasonable adsorption energies, apparent charge transfer, change in the electric conductivity, and the short recovery time, the Al12N12-based nanowire should be a good CO and NO sensor with quick response as well as short recovery time, while the Ga12N12-based nanowire should be a promising gas sensor for CO, NO, and NO2 detection. [ABSTRACT FROM AUTHOR]

Background and Objective. It is important to guarantee the quality of stem cells. Serial passage is the main approach to expand stem cells. This study evaluated effects of serial passage on the biological characteristics of human umbilical cord Wharton’s jelly-derived MSCs (WJ MSCs). Methods. Biological properties of WJ MSCs in the early (less than 10 passages, P10), middle (P11–20), and late (more than P20) phases including cell proliferation, cell cycle, phenotype, senescence, oncogene expression, stemness marker expression, and differentiation capacity were evaluated using flow cytometry, real-time PCR, immunocytofluorescence, and western blot. Results. It was found that there were no significant differences in cell proliferation, cell cycle, phenotype, and stemness marker expression in different phases. However, the expression of senescence-related gene, p21, and oncogene, c-Myc, was significantly upregulated in the late phase, which had close relations with the obviously increased cell senescence. Moreover, cardiac differentiation capability of WJ MSCs decreased whereas the propensity for neural differentiation increased significantly in the middle phase. Conclusions. This study reveals that WJ MSCs in the early and middle phases are relatively stable, and effect of serial passage on the lineage-specific differentiation should be considered carefully. [ABSTRACT FROM AUTHOR]

• Temperature gradients were divided by the soil temperature from 2009 to 2019. • Increasing temperature advanced the flowering phenology of Stipa breviflora. • Not always advanced, a temporary delay occurs in average temperature gradient. • The Mann-Kendall tests the cumulative effect of long-term phenological break point. The sensitivity of plant phenology to climate change can be used as the basis for predicting change in plant species' growth and development period as they adapt to gradual increase in atmospheric temperature. However, it is not clear how the reproductive phenology of plants will respond to a continuous increase in temperature gradient, especially when the time series has break points due to interannual change. In this experiment, the flowering phenology of Stipa breviflora , an established species in the desert steppe of Siziwang Banner in northern China, was observed from 2009 to 2019. A no warming treatment and warming treatment (1.3 °C higher than no warming) were applied. Three temperature gradients were defined: the annual average temperature of the 0–10 cm soil layer in the no warming treatment plot from 2009 to 2019 was taken as the average temperature gradient (C2, 5.63 °C ± 1.09); a higher-than-average temperature gradient (C3, 6.93 °C ± 1.34), and a lower than the average temperature gradient (C1, 4.33 °C ± 1.87). The results showed that increasing temperature was an important driving factor that advanced the flowering phenology of S. breviflora. When high temperatures exceed plants' physiological thresholds (5.63 °C ± 1.09), plants exhibit a temporary delay. Based on a Mann-Kendall test, we found that reproductive phenology was advanced from 2009 to 2015, and delayed by a time break point from 2015 to 2018. After 2018, reproductive phenology continued to be advanced, which once again verified that reproductive phenology would not continue to be advanced in the process of climate warming, but would be temporarily delayed. Therefore, our study reveals the response strategy of S. breviflora to a continuous increase in global atmospheric temperature, and provides a theoretical basis for studying the response mechanism of the desert steppe ecosystem to climate warming. [ABSTRACT FROM AUTHOR]

Integration of perennial grass species into the current food production systems, especially in the agropastoral regions worldwide, may produce multiple benefits including, among others, a more stable productivity and a smaller eco-environmental footprint. However, one of the fundamental challenges facing the large-scale adoption of such grass species is their ability to withstand the vagaries of winter in these regions. Here, we present a comprehensive evaluation of the winter hardiness of 50 indigenous Chinese cultivars of alfalfa, a high-quality leguminous perennial grass, in comparison with six introduced U.S. cultivars in a multi-site field experiment in northern China. Our results reveal that indigenous cultivars have stronger winter hardiness than introduced cultivars. Cultivars native in the north performed better than southern cultivars, suggesting that suitability evaluation is an unavoidable step proceeding any regional implementations. Our results also show that the metric we used to assess alfalfa's winter hardiness, the average score index (ASI), produced more consistent results than another more-widely used metric of winter survival rate (WSR). These findings offer a systematic field evidence that supports regional cropping system adjustment and production system betterment to ensure food security under climate change in the region and beyond. [ABSTRACT FROM AUTHOR]