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1.
Fish Shellfish Immunol ; 144: 109274, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38072135

RESUMO

Interferon-gamma (IFN-γ) is an inflammatory cytokine that plays a crucial role in regulating both innate and cell-mediated immune responses by binding to a receptor complex made up of IFNGR1 and IFNGR2. In this study, the complete cDNA of IFN-γ and IFNGR1 from Nibea albiflora were cloned and functionally characterized (named NaIFN-γ and NaIFNGR1), whose complete cDNA sequences were 1593 bp and 2792 bp, encoding 201 and 399 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis showed that the concluded amino acids sequences of NaIFN-γ and NaIFNGR1 shared high identity with their teleost orthologues including the IFN-γ signature and nuclear localization signal (NLS) motif in NaIFN-γ and FN Ⅲ domain in NaIFNGR1. Real-time PCR showed that NaIFN-γ and NaIFNGR1 constitutively expressed in all tested tissues, such as the head-kidney, spleen, liver, kidney, gill, muscle, blood, and intestine with the highest expression of NaIFN-γ and NaIFNGR1 appearing in the liver and gill, respectively. After experiencing stimulation with Polyinosinic-polycytidylic acid (Poly (I:C)), Vibrio alginolyticus (V. alginolyticus) or Vibrio parahaemolyticus (V. parahaemolyticus), NaIFN-γ and NaIFNGR1 mRNA were up-regulated with the time-dependent model. Due to the presence of a nuclear localization signal (NLS), the subcellular localization revealed that NaIFN-γ dispersed throughout the cytoplasm and nucleus. NaIFNGR1, as a member of Cytokine receptor family B, was primarily expressed on the cell membrane. When NaIFN-γ and NaIFNGR1 were co-transfected, their fluorescence signals overlapped on the membrane of HEK 293T cells indicating the potential interaction between IFN-γ and IFNGR1. The GST-pull-down results further showed that NaIFN-γ could directly interact with the extracellular region of NaIFNGR1, further confirming the affinity between IFN-γ and IFNGR1. Taken together, the results firstly demonstrated that the NaIFN-γ ligand-receptor system existed in N.albiflora and played a pivotal part in N.albiflora's immune response against pathogenic bacterial infections, which contributed to the better understanding of the role of IFN-γ in the immunomodulatory mechanisms of teleost.


Assuntos
Interferon gama , Perciformes , Animais , Sinais de Localização Nuclear/genética , Sequência de Aminoácidos , Filogenia , DNA Complementar , Aminoácidos/genética
2.
J Anim Breed Genet ; 140(3): 330-342, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36789788

RESUMO

White coat pigmentation is a striking phenotype of many domesticated species and has various genetic controls. The Tianzhu White yak, an indigenous breed with a complete white coat, has fascinated Tibetans for centuries. However, the genetic basis of this trait remains unknown. Here, we conducted population genomics analysis and genome-wide association study based on the whole-genome sequencing data of 38 white and 59 non-white-coated yak. The results revealed the presence of KIT-linked Cs alleles characterized by the translocations between chromosomes 6 and 29 in all-white yak. Furthermore, structural variations showed additional duplications of the Cs alleles in white yak compared with colour-sidedness cattle. Interestingly, the Cs alleles associated with the white coat phenotype in yak were found to have introgressed from taurine cattle. Our findings unveil the shared genetic control of the white coat phenotype and its evolution in closely related bovine species.


Assuntos
Doenças dos Bovinos , Translocação Genética , Animais , Bovinos/genética , Doenças dos Bovinos/genética , Estudo de Associação Genômica Ampla/veterinária , Genômica , Cor de Cabelo/genética , Fenótipo , Proteínas Proto-Oncogênicas c-kit/metabolismo
3.
Nano Lett ; 22(14): 5997-6003, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35839083

RESUMO

As a lattice interference effect, moiré superlattices feature a magnification effect that they respond sensitively to both the extrinsic mechanical perturbations and intrinsic atomic reconstructions. Here, using scanning tunneling microscopy and spectroscopy, we observe that long-wavelength WS2 superlattices are reconstructed into various moiré morphologies, ranging from regular hexagons to heavily deformed ones. We show that a dedicated interplay between the extrinsic nonuniform heterostrain and the intrinsic atomic reconstruction is responsible for this interesting moiré structure evolution. Importantly, the interplay between these two factors also introduces a local inhomogeneous intralayer strain within a moiré. Contrary to the commonly reported electronic modulation that occurred at the valence band edge due to interlayer hybridization, we find that this local intralayer strain induces a strong modulation at K point of the conduction band, reaching up to 300 meV in the heavily deformed moiré. Our microscopic explorations provide valuable information in understanding the intriguing physics in TMD moirés.

4.
Glob Chang Biol ; 28(11): 3651-3664, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35231142

RESUMO

Belowground plant traits play important roles in plant diversity loss driven by atmospheric nitrogen (N) deposition. However, the way N enrichment shapes plant microhabitats by patterning belowground traits and finally determines aboveground responses is poorly understood. Here, we investigated the rhizosheath trait of 74 plant species in seven N-addition simulation experiments across multiple grassland ecosystems in China. We found that rhizosheath formation differed among plant functional groups and contributed to changes in plant community composition induced by N enrichment. Compared with forb species, grass and sedge species exhibited distinct rhizosheaths; moreover, grasses and sedges expanded their rhizosheaths with increasing N-addition rate which allowed them to colonize belowground habitats. Grasses also shaped a different microenvironment around their roots compared with forbs by affecting the physicochemical, biological, and stress-avoiding properties of their rhizosphere soil. Rhizosheaths act as a "biofilm-like shield" by the accumulation of protective compounds, carboxylic anions and polysaccharides, determined by both plants and microorganisms. This enhanced the tolerance of grasses and sedges to stresses induced by N enrichment. Conversely, forbs lacked the protective rhizosheaths which renders their roots sensitive to stresses induced by N enrichment, thus contributing to their disappearance under N-enriched conditions. This study uncovers the processes by which belowground facilitation and trait matching affect aboveground responses under conditions of N enrichment, which advances our mechanistic understanding of the contribution of competitive exclusion and environmental tolerance to plant diversity loss caused by N deposition.


Assuntos
Pradaria , Nitrogênio , Biomassa , Ecossistema , Plantas , Poaceae , Solo/química
5.
Artigo em Inglês | MEDLINE | ID: mdl-29193300

RESUMO

The green rice leafhopper, Nephotettix cincticeps, is a major rice pest in Southeast Asia and Southern China. Novel control strategies must be explored to control the rice pest. Behavior or fitness regulation of insect by modulating the Troponin C (TnC) may be a novel strategy in the comprehensive management of the insect pest. However, characterizations and functions of TnC, especially regarding effect of its RNA interference-mediated gene knockdown on the behavior or fitness of N. cincticeps remain unknown. Here, we successfully cloned and characterized TnC gene from N. cincticeps (Nc-TnC). We demonstrated that Nc-TnC ubiquitously transcribed at all development stages and special tissues in adult insects, with relative higher levels at the adult stage and in the intestinal canal. Microinjection- or oral membrane feeding-based transient knockdown of Nc-TnC adversely affected the performance or fitness, such as the decreased survival, feeding capacity, weight, and fecundity of N. cincticeps. Furthermore, we revealed that the expression of Nc-TnC was suppressed by its interaction with rice dwarf virus-encoded nonstructural protein 10, which ultimately affected detrimentally the corresponding parameters of the performance or fitness of N. cincticeps. In conclusion, our data deepen understanding of Nc-TnC functions during the development of and viral infection in N. cincticeps. It imply Nc-TnC may serve as a potential target for N. cincticeps control in future.


Assuntos
Hemípteros/fisiologia , Reoviridae/fisiologia , Troponina C/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Feminino , Aptidão Genética , Hemípteros/virologia , Controle de Insetos , Larva/metabolismo , Estágios do Ciclo de Vida , Interferência de RNA , Análise de Sequência de DNA
6.
Environ Sci Technol ; 49(4): 2066-72, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25606710

RESUMO

China is seeking to unlock its shale gas in order to curb its notorious urban air pollution, but robust assessment of the impact on PM2.5 pollution of replacing coal with natural gas for winter heating is lacking. Here, using a whole-city heating energy shift opportunity offered by substantial reductions in coal combustion during the heating periods in Urumqi, northwest China, we conducted a four-year study to reveal the impact of replacing coal with natural gas on the mass concentrations and chemical components of PM2.5. We found a significant decline in PM2.5, major soluble ions and metal elements in PM2.5 in January of 2013 and 2014 compared with the same periods in 2012 and 2011, reflecting the positive effects on air quality of using natural gas as a heating fuel throughout the city. This occurred following complete replacement with natural gas for heating energy in October 2012. The weather conditions during winter did not show any significant variation over the four years of the study. Our results indicate that China and other developing nations will benefit greatly from a change in energy source, that is, increasing the contribution of either natural gas or shale gas to total energy consumption with a concomitant reduction in coal consumption.


Assuntos
Poluição do Ar/prevenção & controle , Ar/normas , Conservação de Recursos Energéticos/métodos , Calefação/métodos , Gás Natural/análise , Material Particulado/análise , Poluição do Ar/análise , China , Cidades , Carvão Mineral/análise , Monitoramento Ambiental , Metais/análise , Tamanho da Partícula , Material Particulado/química , Estações do Ano , Tempo (Meteorologia)
7.
Oecologia ; 177(1): 65-72, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25407621

RESUMO

Species composition and productivity are influenced by water and N availability in semi-arid grasslands. To assess the effects of increased N deposition and water supply on plant species composition and productivity, two field experiments with four N addition treatments, and three N and water combination treatments were conducted in alpine grassland in the mid Tianshan mountains, northwest China. When considering N addition alone, aboveground biomass (AGB) of forbs (F(AGB)) responded less to N addition than AGB of grasses (G(AGB)). G(AGB) increased as an effect of N combined with water addition but F(AGB) did not show such an effect, reflecting a stronger response of grasses to the interaction of water availability and N than forbs. Under all treatments, N allocation to the aboveground tissue did not change for either forbs or grasses. N deposition and water addition did not alter species richness in the present study. These results suggest that N addition generally promoted AGB but had little effect on species richness in wet years. Snowfall in winter combined with rainfall in the early growing season likely plays a critical role in regulating plant growth of the subsequent year in the alpine grassland.


Assuntos
Poluição do Ar , Biomassa , Clima , Pradaria , Nitrogênio/metabolismo , Plantas , Água/metabolismo , China , Ecologia , Desenvolvimento Vegetal , Plantas/metabolismo , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , Especificidade da Espécie , Abastecimento de Água
8.
Materials (Basel) ; 17(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38730791

RESUMO

In order to address the issue of hole collapse, which frequently arises when boring piles are being constructed in intricate marine strata, this paper discusses the influence of the slurry ratio on the slurry performance as well as the mechanism of slurry wall protection. It performs this by means of theoretical analysis, laboratory ratio testing, engineering analogies, numerical simulation, and field testing. Our findings demonstrate that adding sodium polyacrylate and sodium carboxymethyl cellulose can enhance mud's viscosity, contribute to flocculation, and improve the connection between mud and soil layers. Refering similar engineering cases, three optimization schemes are proposed for achieving a mud ratio that offers wall protection in complex marine strata. Furthermore, the particle flow model of slurry viscous fluid is established. The collapse of holes in the sand layer is reflected in the uneven radial displacement of hole walls and the invasion of mud particles. Increasing the viscosity of mud gradually transforms the uneven radial deformation of pore walls in the sand layer into a uniform radial deformation, whereas increasing the proportion of mud significantly decreases the radial displacement of hole walls. Additionally, when the mud pressure in the hole is 300 kPa and 600 kPa, the wall protection effect is better, and there is no particle penetration by substances such as sand. It is found that a high mud pressure can promote the diffusion of mud particles into the sand layer, while low mud pressure cannot balance the pressure on deep soil. The results of the field tests show that the ratio of water-clay-bentonite-CMC-Na-sodium carbonate = 700:110:90:1.5:0.5 used (where the mass percentage of each material is 77.8% water, 12.2% clay, 10% bentonite, 0.16% CMC-Na, and 0.05% sodium carbonate) can effectively prevent hole collapse and reduce the thickness of the sand layer at the bottom of the hole by 50%.

9.
Front Med (Lausanne) ; 11: 1361777, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725470

RESUMO

Background: High altitudes are characterized by low-pressure oxygen deprivation. This is further exacerbated with increasing altitude. High altitudes can be associated with reduced oxygenation, which in turn, can affect labor, as well as maternal and fetal outcomes. Epidural anesthesia can significantly relieve labor pain. This study aimed to assess the effects of elevation gradient changes at high altitude on the analgesic effect of epidural anesthesia, labor duration, and neonatal outcomes. Methods: We divided 211 women who received epidural anesthesia into groups according to varying elevation of their residence (76 in Xining City, mean altitude 2,200 m; 63 in Haibei Prefecture, mean altitude 3,655 m; and 72 in Yushu Prefecture, mean altitude 4,493 m). The analgesic effect was assessed using a visual analog scale (VAS). Labor duration was objectively recorded. The neonatal outcome was assessed using Apgar scores and fetal umbilical artery blood pH. Results: VAS scores among the three groups did not differ significantly (p > 0.05). The neonatal Apgar scores in descending order were: Xining group > Haibei group > Yushu group (p < 0.05). The stage of labor was similar among the three groups (p > 0.05). Fetal umbilical artery blood pH in descending order were: Xining group > Haibei group > Yushu group (p < 0.05). Conclusion: Elevation gradient changes in highland areas did not affect the efficacy of epidural anesthesia or labor duration. However, neonatal outcomes were affected.

10.
Sci Total Environ ; 924: 171572, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38461998

RESUMO

Nitrous oxide (N2O) is the third most important greenhouse gas, and can damage the atmospheric ozone layer, with associated threats to terrestrial ecosystems. However, to date it is unclear how extreme precipitation and nitrogen (N) input will affect N2O emissions in temperate desert steppe ecosystems. Therefore, we conducted an in-situ in a temperate desert steppe in the northwest of Inner Mongolia, China between 2018 and 2021, in which N inputs were combined with natural extreme precipitation events, with the aim of better understanding the mechanism of any interactive effects on N2O emission. The study result showed that N2O emission in this desert steppe was relatively small and did not show significant seasonal change. The annual N2O emission increased in a non-linear trend with increasing N input, with a much greater effect of N input in a wet year (2019) than in a dry year (2021). This was mainly due to the fact that the boost effect of high N input (on June 17th 2019) on N2O emission was greatly amplified by nearly 17-46 times by an extreme precipitation event on June 24th 2019. In contrast, this greatly promoting effect of high N input on N2O emission was not observed on September 26th 2019 by a similar extreme precipitation event. Further analysis showed that soil NH4+-N content and the abundance of ammonia oxidizing bacteria (amoA (AOB)) were the most critical factors affecting N2O emission. Soil moisture played an important indirect role in regulating N2O emission, mainly by influencing the abundance of amoA (AOB) and de-nitrification functional microorganisms (nosZ gene). In conclusion, the effect of extreme precipitation events on N2O emission was greatly increased by high N input. Furthermore, in this desert steppe, annual N2O flux is co-managed through soil nitrification substrate concentration (NH4+-N), the abundance of soil N transformation functional microorganisms and soil moisture. Overall, it was worth noting that an increase in extreme precipitation coupled with increasing N input may significantly increase future N2O emissions from desert steppes.


Assuntos
Ecossistema , Nitrogênio , Nitrogênio/análise , Microbiologia do Solo , Nitrificação , Solo/química , Óxido Nitroso/análise
11.
Dalton Trans ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38915258

RESUMO

A heterostructure composed of ZIF-67-derived nitrogen and cobalt-doped carbon enfolded silicon (C@Si) nanoparticles anchored on 2D MXene layers was constructed for boosting the performance of lithium-ion batteries (LIBs). The heterostructure anode demonstrated a high initial discharge capacity of 3021 mA h g-1 at 0.2 A g-1, retaining outstanding cycling stability with a reversible capacity of 520 mA h g-1 at 2000 mA g-1, and the coulombic efficiency remained above 97% after 500 cycles. The introduced Ti3C2 nanosheets and the cobalt-doped carbon can not only contribute to the interfacial transfer of Li+ and electrons but also buffer the volume expansion of Si.

12.
ACS Nano ; 18(11): 7937-7944, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38441035

RESUMO

Strongly correlated states commonly emerge in twisted bilayer graphene (TBG) with "magic-angle" (1.1°), where the electron-electron (e-e) interaction U becomes prominent relative to the small bandwidth W of the nearly flat band. However, the stringent requirement of this magic angle makes the sample preparation and the further application facing great challenges. Here, using scanning tunneling microscopy (STM) and spectroscopy (STS), we demonstrate that the correlation-induced symmetry-broken states can also be achieved in a 3.45° TBG, via engineering this nonmagic-angle TBG into regimes of U/W > 1. We enhance the e-e interaction through controlling the microscopic dielectric environment by using a MoS2 substrate. Simultaneously, the width of the low-energy van Hove singularity (VHS) peak is reduced by enhancing the interlayer coupling via STM tip modulation. When partially filled, the VHS peak exhibits a giant splitting into two states flanked by the Fermi level and shows a symmetry-broken LDOS distribution with a stripy charge order, which confirms the existence of strong correlation effect in our 3.45° TBG. Our result demonstrates the feasibility of the study and application of the correlation physics in TBGs with a wider range of twist angle.

13.
Nanoscale ; 16(16): 8028-8035, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38546273

RESUMO

Two-dimensional (2D) chromium-based self-intercalated materials Cr1+nX2 (0 ≤ n ≤ 1, X = S, Se, Te) have attracted much attention because of their tunable magnetism with good environmental stability. Intriguingly, the magnetic and electrical properties of the materials can be effectively tuned by altering the coverage and spatial arrangement of the intercalated Cr (ic-Cr) within the van der Waals gap, contributing to different stoichiometries. Several different Cr1+nX2 systems have been widely investigated recently; however, those with the same stoichiometric ratio (such as Cr1.25Te2) were reported to exhibit disparate magnetic properties, which still lacks explanation. Therefore, a systematic in situ study of the mechanisms with microscopy techniques is in high demand to look into the origin of these discrepancies. Herein, 2D self-intercalated Cr1+nSe2 nanoflakes were synthesized as a platform to conduct the characterization. Combining scanning transmission electron microscopy (STEM) and scanning tunneling microscopy (STM), we studied in depth the microscopic structure and local electronic properties of the Cr1+nSe2 nanoflakes. The self-intercalation mechanism of ic-Cr and local stoichiometric-ratio variation in a Cr1+nSe2 ultrathin nanoflake is clearly detected at the nanometer scale. Scanning tunneling spectroscopy (STS) measurements indicate that Cr1.5Se2/Cr2Se2 and Cr1.25Se2 exhibit conductive and semiconductive behaviors, respectively. The STM tip manipulation method is further applied to manipulate the microstructure of Cr1+nSe2, which successfully produces clean zigzag-type boundaries. Our systematic microscopy study paves the way for the in-depth study of the magnetic mechanism of 2D self-intercalated magnets at the nano/micro scale and the development of new magnetic and spintronic devices.

14.
Adv Mater ; 36(14): e2312425, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38146671

RESUMO

2D transition metal dichalcogenides (TMDCs) are considered as promising materials in post-Moore technology. However, the low photoluminescence quantum yields (PLQY) and single carrier polarity due to the inevitable defects during material preparation are great obstacles to their practical applications. Here, an extraordinary defect engineering strategy is reported based on first-principles calculations and realize it experimentally on WS2 monolayers by doping with IIIA atoms. The doped samples with large sizes possess both giant PLQY enhancement and effective carrier polarity modulation. Surprisingly, the high PL emission maintained even after one year under ambient environment. Moreover, the constructed p-n homojunctions shows high rectification ratio (≈2200), ultrafast response times and excellent stability. Meanwhile, the doping strategy is universally applicable to other TMDCs and dopants. This smart defect engineering strategy not only provides a general scheme to eliminate the negative influence of defects, but also utilize them to achieve desired optoelectronic properties for multifunctional applications.

15.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 8): m1058-9, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22904731

RESUMO

In the title compound, [Ni(C(20)H(13)O(5)P)(C(12)H(10)N(2))(H(2)O)](n), the Ni(II) cation is coordinated by three O atoms from two 5-(diphenyl-phosphino-yl)isophthalate anions, two N atoms from two 1,2-bis-(pyridin-4-yl)ethene ligands and one water mol-ecule in a distorted octa-hedral geometry. Both 1,2-bis-(pyridin-4-yl)ethene and 5-(diphenyl-phosphino-yl)iso-phthal-ate bridge the Ni(II) cations to form polymeric layers parallel to (001). In the crystal, O-H⋯O hydrogen bonding links layers into a three-dimensional supra-molecular structure.

16.
Plants (Basel) ; 11(13)2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35807730

RESUMO

The semiparasitic weed Pedicularis kansuensis Maxim. has rapidly spread in the alpine grasslands of northern China over the past twenty years and has caused serious ecological problems. In order to effectively halt the spread of this weed, a thorough understanding of the dormancy type and the seed-germination ecology of P. kansuensis is required. We have conducted a series of experiments to investigate the effects of plant growth regulators (gibberellin (GA3) and strigolactone synthesis (GR24)), as well as different abiotic (temperature, light, cold stratification, and drought) and biotic (aqueous extracts of three native dominant plants) factors on the seed-germination characteristics of P. kansuensis. The seed-germination percentages ranged from 2% to 62% at all of the temperatures that were examined, with the highest occurring at 25/10 °C. The light conditions did not significantly affect the germination percentage. The seed germination was greatly improved after two to eight weeks of cold stratification. The seed germination decreased dramatically with an increasing polyethylene glycol (PEG-6000) concentration, from 55% to 0%, under 10% and 20% PEG-6000. The seed germination was improved at a proper concentration of GA3, GR24, and the aqueous extracts of Festuca ovina L., Stipa purpurea L., and Leymus secalinus (Georgi) Tzvel. Furthermore, in the pot experiment, the seedling emergence of P. kansuensis was also improved by the cultivation of these three dominant grasses. These findings indicate that the dormancy type of P. kansuensis seeds is non-deep physiological dormancy, and such findings will help in paving the way for the creation of effective weed management strategies, based on a thorough knowledge of germination ecology.

17.
Front Plant Sci ; 13: 1047670, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36570959

RESUMO

Invasive exotic plant species (IEPs) are widely distributed across the globe, but whether IEPs are drivers or passengers of habitat change in the invaded spaces remains unclear. Here, we carried out a vegetation and soil survey in 2018 and two independent field experiments (Pedicularis kansuensis removal in 2014 and 2015, and fertilization experiment since 2012) and found that the invasive annual P. kansuensis was at a disadvantage in light competition compared with perennial native grasses, but the successful invasion of P. kansuensis was due to the sufficient light resources provided by the reduced coverage of the native species. Conversely, nitrogen enrichment can effectively inhibit P. kansuensis invasion by increasing the photocompetitive advantage of the native species. sP. kansuensis invasion did not reduce species richness, but did increase plant community coverage, productivity and soil nutrients. Furthermore, the removal of P. kansuensis had little effect on the plant community structure and soil properties. Our results suggest that the passenger model perfectly explains the benign invasive mechanism of P. kansuensis. The invasion "ticket" of P. kansuensis is a spare ecological niche for light resources released by overgrazing.

18.
Sci Total Environ ; 804: 150172, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798732

RESUMO

Desert soils are an important sink of atmospheric methane (CH4) and regulate the global CH4 budget. However, it is still unclear how CH4 fluxes respond to precipitation changes in desert-steppe soils. Therefore, a two-year in situ control experiment was conducted to investigate the effect of precipitation changes on CH4 uptake in desert steppe of Inner Mongolia in northwest China and its driving mechanism. The result showed that this desert steppe was an important sink of CH4, with an annual uptake of 2.93 (2.64-3.22) kg C ha-1. It was found that CH4 uptake was reduced significantly for decreasing precipitation, especially in spring and summer. In contrast, an increasing trend of CH4 uptake was observed for increasing precipitation, although it was not statistically significant. Further analyses found that CH4 uptake was more sensitive to decreasing precipitation than increasing precipitation. This may be mainly due to the fact that only moderate water-filled pore space (WFPS) induced by precipitation promoted CH4 uptake, while too-high (>32%) or too-low WFPS inhibited its uptake. A structural equation model showed that the copy number of the pmoA functional gene was the most important factor affecting CH4 uptake. In contrast, soil moisture had a very important indirect effect on CH4 uptake, mainly through significantly affected soil porosity, the above-ground plant biomass and NO3--N content, further affected CH4 uptake. Overall, CH4 sinks in desert steppe was still mainly controlled by methane-oxidizing bacteria containing the key functional gene pmoA and WFPS. Therefore, precipitation plays an important role in regulating the intensity of CH4 sinks in desert steppe, while it is worth noting that too-little precipitation will significantly weaken CH4 sinks.


Assuntos
Metano , Methylococcaceae , China , Metano/análise , Estações do Ano , Solo
19.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 6): m804, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754680

RESUMO

In the title compound, [Zn(C(9)H(4)O(6))(C(12)H(12)N(2))(H(2)O)(2)], the Zn(II) atom is five-coordinated by two N atoms from a 4,4'-dimethyl-2,2'-bipyridine ligand, one O atom from a 5-carb-oxy-benzene-1,3-dicarboxyl-ate ligand and two water mol-ecules in a distorted trigonal-bipyramidal geometry. The complex mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds and partly overlapping π-π inter-actions [centroid-centroid distance = 4.017 (2) Å] into a three-dimensional supra-molecular network.

20.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 8): m1156, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22090913

RESUMO

In the crystal structure of the title compound, [MnCl(2)(C(14)H(14)N(4))(2)](n), the Mn(II) atom, lying on an inversion center, is coordinated by four N atoms from four 1,4-bis-(imidazol-1-ylmeth-yl)benzene (bimb) ligands and two Cl(-) anions in a distorted octa-hedral geometry. The bimb ligands bridge the Mn(II) atoms, forming a two-dimensional polymeric complex, which is composed of a 52-membered [Mn(4)(bimb)(4)] ring with distances of 7.7812 (2) and 27.4731 (9) Šbetween opposite metal atoms. Weak C-H⋯π inter-actions are present in the crystal structure.

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