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1.
Int J Biol Macromol ; 278(Pt 1): 134605, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39127281

RESUMO

ABC transporters are a highly conserved membrane protein class that promote the transport of substances across membranes. Under drought conditions, insects primarily regulate the content of cuticular hydrocarbon (CHC) to retain water and prevent evaporative loss. Involvement of ABC transporter protein G (ABCG) subfamily genes in insect CHC transport has been relatively understudied. In this study, we demonstrated that ABCG4 gene in Acyrthosiphon pisum (ApABCG4) is involved in CHC transport and affects drought tolerance by regulating CHC accumulation. ApABCG4 is strongly expressed in the abdominal cuticle and embryonic stages of A. pisum. Effective silencing of ApABCG4 was achieved using RNAi, and the silencing duration was analyzed. ApABCG4 silencing resulted in a significant decrease in the total and component contents of the CHC and cuticular waxy coatings of A. pisum. Nevertheless, the internal hydrocarbon content remained unchanged. The lack of cuticular hydrocarbons significantly reduced the drought tolerance of A. pisum, shortening its survival time under drought stress. Drought stress caused significant upregulation of ApABCG4. Molecular docking showed that ApABCG4 has a high binding affinity for nine n-alkanes of CHC through electrostatic interactions. These results indicate that ApABCG4 is a novel RNAi target with key applications in aphid biological control.

2.
Water Res ; 265: 122263, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39180953

RESUMO

Recent climate warming and associated glacier retreat have dramatically changed the environmental conditions and microbial inhabitants of proglacial lakes. However, our understanding of the effects of climate warming and glacial influence on microbial biodiversity in these lakes remain relatively limited. Here, we studied bacterioplankton communities in 22 proglacial lakes on the Tibetan Plateau, spanning a range of nearly 7 °C in mean annual temperature (MAT), and examined the effects of climate and glaciers on their biodiversity by a space-to-time substitution. MAT emerged as the primary environmental driver of bacterioplankton biodiversity compared to glacial influence, increasing species richness and decreasing ß-diversity. We identified 576 low-MAT (cold-preferred) species and 2,088 high-MAT (warm-preferred) species, and found that low-MAT species are less environmentally adapted, with their numbers declining as temperature increased. These results advance our understanding of temperature-driven bacterioplankton dynamics by disentangling the contrasting responses and adaptations of cold-preferred and warm-preferred species. Our findings highlight the vulnerability of cold-specialist taxa and the potential biodiversity losses associated with climate warming in the rapidly changing proglacial lakes.

3.
J Zhejiang Univ Sci B ; : 1-16, 2024 Jul 09.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38993075

RESUMO

Grooming, as an evolutionarily conserved repetitive behavior, is common in various animals, including humans, and serves essential functions including, but not limited to, hygiene maintenance, thermoregulation, de-arousal, stress reduction, and social behaviors. In rodents, grooming involves a patterned and sequenced structure, known as the syntactic chain with four phases that comprise repeated stereotyped movements happening in a cephalocaudal progression style, beginning from the nose to the face, to the head, and finally ending with body licking. The context-dependent occurrence of grooming behavior indicates its adaptive significance. This review briefly summarizes the neural substrates responsible for rodent grooming behavior and explores its relevance in rodent models of neuropsychiatric disorders and neurodegenerative diseases with aberrant grooming phenotypes. We further emphasize the utility of rodent grooming as a reliable measure of repetitive behavior in neuropsychiatric models, holding promise for translational psychiatry. Herein, we mainly focus on rodent self-grooming. Allogrooming (grooming being applied on one animal by its conspecifics via licking or carefully nibbling) and heterogrooming (a form of grooming behavior directing towards another animal, which occurs in other contexts, such as maternal, sexual, aggressive, or social behaviors) are not covered due to space constraints.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 321: 124710, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38936207

RESUMO

As a unconventional oil, perilla oil is much more expensive than conventional oils since it has the highest content of α-linolenic acid among vegetable oils. Thus the adulteration of perilla oil is serious, which needs to be solved. In this study, the single component oil in perilla oil blends were first quantitatively analyzed by ultraviolet-visible (UV-vis) spectroscopy combined with chemometric methods. Soybean oil and palm oil were added into perilla oil to form binary and ternary perilla oil blends. Partial least squares (PLS), back propagation-artificial neural network (BP-ANN), support vector regression (SVR) and extreme learning machine (ELM) were compared and the best model was selected for calibration. In order to improve the prediction performance of the calibration model, ten preprocessing methods and five variable selection methods were investigated. Results show that PLS was the best calibration method for binary and ternary perilla oil blends. For binary perilla oil blends, the correlation coefficients of prediction (Rp) obtained by PLS were both above 0.99, which does not need preprocessing and variable selection. For ternary perilla oil blends, after the best continuous wavelet transform (CWT) preprocessing and discretized whale optimization algorithm (WOA) variable selection, the Rp values obtained by the best model CWT-WOA-PLS were all above 0.97. This research provides a common framework for calibration of perilla oil blends, which maybe a promising method for quality control of perilla oil in industry.

5.
Angew Chem Int Ed Engl ; : e202405920, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38945829

RESUMO

The practical application of lithium-sulfur batteries with high theoretical energy density and readily available cathode active materials is hampered by problems such as sulfur insulation, dramatic volume changes, and polysulfide shuttling. The targeted development of novel binders is the most industrialized solution to the problem of sulfur cathodes. Herein, an aqueous conductive emulsion binder with the sulfonate-containing hard elastic copolymer core and the conjugate polymer shell, which is capable of forming a bicontinuous mesoscopic interpenetrating polymer network, is synthesized and investigated. Not only can the elastic skeleton formed by the copolymer bind the active substance under drastic volume changes, but also the rich ester and cyanide groups in it can effectively capture lithium polysulfide. Meanwhile, the conducting skeleton consisting of poly(3,4-ethylenedioxythiophene) both provides the additional charge conduction pathways and acts as the redox intermediates, significantly accelerating the kinetic process of lithium polysulfide conversion. Based on the synergistic effect of the above mechanisms, the use of the prepared binder on the sulfur carbon cathode significantly improves the rate performance and cycle stability of lithium sulfur batteries.

6.
Materials (Basel) ; 17(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38930316

RESUMO

Conventional plasma electrolytic oxidation treatments produce oxide coatings with micron-scale discharge pores, resulting in insulation and wear and corrosion resistance far below that expected of highly dense Al2O3 coatings. The introduction of cathodic polarization during the plasma electrolytic oxidation process, especially when the applied cathode-to-anode current ratio (Rpn) is greater than 1, triggers a unique plasma discharge phenomenon known as "soft sparking". The soft spark discharge mode significantly improves the densification of the anode ceramic layer and facilitates the formation of the high-temperature α-Al2O3 phase within the coating. Although the soft spark discharge phenomenon has been known for a long time, the growth behavior of the coating under its discharge mode still needs to be studied and improved. In this paper, the growth behavior of the coating before and after soft spark discharge is investigated with the help of the micro-morphology, phase composition and element distribution of a homemade fixture. The results show that the ceramic layer grows mainly along the oxide-electrolyte direction before the soft spark discharge transformation; after the soft spark discharge, the ceramic layer grows along the oxide-substrate direction. It was also unexpectedly found that, under soft spark discharge, the silicon element only exists on the outside of the coating, which is caused by the large size and slow migration of SiO32-, which can only enter the ceramic layer and participate in the reaction through the discharge channel generated by the strong discharge. In addition, it was also found that the relative phase content of α-Al2O3 in the coating increased from 0.487 to 0.634 after 10 min of rotary spark discharge, which is an increase of 30.2% compared with that before the soft spark discharge transition. On the other hand, the relative phase content of α-Al2O3 in the coating decreased from 0.487 to 0.313 after 20 min of transfer spark discharge, which was a 55.6% decrease compared to that before the soft spark discharge transformation.

7.
Materials (Basel) ; 17(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38893885

RESUMO

In this study, we successfully employed the plasma electrolytic oxidation (PEO) technique to create a uniform white ceramic layer on the surface of the 6061 aluminum alloy using K2ZrF6 and Na2WO4 as colorants. A scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS) and X-ray diffraction (XRD) were used to characterize the coatings, and we used an electrochemical workstation to test their corrosion protection properties. The corrosion resistance of the coatings was analyzed using potentiodynamic polarization curves. The results showed that K2ZrF6 addition whitened the coating with ZrO2 as the main phase composition, inhibiting Al substrate depletion and enhancing coating corrosion resistance. A small amount of Na2WO4 decreased the coating's L* value, successfully constructing ceramic coatings with L* (coating brightness) values ranging from 70 to 86, offering broad application prospects for decorative coatings.

8.
Materials (Basel) ; 17(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38893918

RESUMO

The correlation between negative pulse and the black electrolyte properties of magnesium alloy micro-arc oxidation and the treated area was investigated by introducing a negative pulse electric field. The physical phase composition, microstructure, elemental distribution, and content of the coating were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results showed that the introduction of negative pulses favored the generation of MgO and MgSiO3 contents in the coatings, and an increase in the MgO phase was found in the coatings formed in the failed electrolytes; the microporous size and microcracks of the coatings were gradually and significantly reduced; the average consumption of Cu ions was 0.0453 g/L·dm2, which is only 26% of that in the unipolar condition; the introduction of the negative pulses significantly improved the "anomalous consumption" of Cu ions. The introduction of negative pulse can significantly improve the "abnormal consumption" of copper ions, which is attributed to the change in the electric field by negative pulse, which makes the cathode-enriched Cu ions migrate to the anode and reduces the reduction and precipitation of Cu ions at the cathode.

9.
Molecules ; 29(10)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38792141

RESUMO

Ceramic fibers have the advantages of high temperature resistance, light weight, favorable chemical stability and superior mechanical vibration resistance, which make them widely used in aerospace, energy, metallurgy, construction, personal protection and other thermal protection fields. Further refinement of the diameter of conventional ceramic fibers to microns or nanometers could further improve their thermal insulation performance and realize the transition from brittleness to flexibility. Processing traditional two-dimensional (2D) ceramic fiber membranes into three-dimensional (3D) ceramic fiber aerogels could further increase porosity, reduce bulk density, and reduce solid heat conduction, thereby improving thermal insulation performance and expanding application areas. Here, a comprehensive review of the newly emerging 2D ceramic micro-nanofiber membranes and 3D ceramic micro-nanofiber aerogels is demonstrated, starting from the presentation of the thermal insulation mechanism of ceramic fibers, followed by the summary of 2D ceramic micro-nanofiber membranes according to different types, and then the generalization of the construction strategies for 3D ceramic micro-nanofiber aerogels. Finally, the current challenges, possible solutions, and future prospects of ceramic micro-nanofiber materials are comprehensively discussed. We anticipate that this review could provide some valuable insights for the future development of ceramic micro-nanofiber materials for high temperature thermal insulation.

10.
Hepatobiliary Surg Nutr ; 13(2): 198-213, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38617471

RESUMO

Background: Adequate evaluation of degrees of liver cirrhosis is essential in surgical treatment of hepatocellular carcinoma (HCC) patients. The impact of the degrees of cirrhosis on prediction of post-hepatectomy liver failure (PHLF) remains poorly defined. This study aimed to construct and validate a combined pre- and intra-operative nomogram based on the degrees of cirrhosis in predicting PHLF in HCC patients using prospective multi-center's data. Methods: Consecutive HCC patients who underwent hepatectomy between May 18, 2019 and Dec 19, 2020 were enrolled at five tertiary hospitals. Preoperative cirrhotic severity scoring (CSS) and intra-operative direct liver stiffness measurement (DSM) were performed to correlate with the Laennec histopathological grading system. The performances of the pre-operative nomogram and combined pre- and intra-operative nomogram in predicting PHLF were compared with conventional predictive models of PHLF. Results: For 327 patients in this study, histopathological studies showed the rates of HCC patients with no, mild, moderate, and severe cirrhosis were 41.9%, 29.1%, 22.9%, and 6.1%, respectively. Either CSS or DSM was closely correlated with histopathological stages of cirrhosis. Thirty-three (10.1%) patients developed PHLF. The 30- and 90-day mortality rates were 0.9%. Multivariate regression analysis showed four pre-operative variables [HBV-DNA level, ICG-R15, prothrombin time (PT), and CSS], and one intra-operative variable (DSM) to be independent risk factors of PHLF. The pre-operative nomogram was constructed based on these four pre-operative variables together with total bilirubin. The combined pre- and intra-operative nomogram was constructed by adding the intra-operative DSM. The pre-operative nomogram was better than the conventional models in predicting PHLF. The prediction was further improved with the combined pre- and intra-operative nomogram. Conclusions: The combined pre- and intra-operative nomogram further improved prediction of PHLF when compared with the pre-operative nomogram. Trial Registration: Clinicaltrials.gov Identifier: NCT04076631.

11.
Environ Toxicol Chem ; 43(7): 1677-1689, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38661489

RESUMO

Pesticide additives (PAs) are auxiliary ingredients added to the pesticide manufacturing and use processes, constituting 1% to 99% of the pesticide and often composed of benzene and chlorinated hydrocarbons. We selected three typical PAs, toluene, chloroform, and trichloroethylene, to evaluate their retention function toxicity and ecological risk in soil. Soil immobilization techniques and aquatic model organisms were used to demonstrate the effectiveness of the immobilized soil method to determine the ecological risk of chemicals. The 48-h median lethal concentrations of toluene, chloroform, and trichloroethylene alone in spiked soil on Daphnia magna were 10.5, 2.3, and 1.1 mg/L (medium, high, and high toxicity, respectively). The toxicity of the three-PA mixtures showed an antagonistic effect. The risk levels of toluene, chloroform, and trichloroethylene in the soil were evaluated as moderate to high, low to high, and high risk, respectively. The toxicity of two pesticide-contaminated sites in the Yangtze River Delta before and after remediation was successfully evaluated by immobilized soil technology. The toxicity of two soil sampling points was reduced from medium toxic to low toxic and no toxic, respectively, after remediation. The results of our study give a rationale for and prove the validity of the aquatic model organisms and soil immobilization techniques in assessing the soil retention functions toxicity of PAs. Environ Toxicol Chem 2024;43:1677-1689. © 2024 SETAC.


Assuntos
Daphnia , Recuperação e Remediação Ambiental , Praguicidas , Poluentes do Solo , Poluentes do Solo/toxicidade , Daphnia/efeitos dos fármacos , Animais , Praguicidas/toxicidade , Medição de Risco , Recuperação e Remediação Ambiental/métodos , Tolueno/toxicidade , Tolueno/análise , Tricloroetileno/toxicidade , Tricloroetileno/análise , Solo/química
12.
ACS Omega ; 9(10): 11658-11670, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38496992

RESUMO

Using traditional Chinese medicine residues as raw materials, different biochars (BC) were prepared through oxygen-limited pyrolysis at 300 °C, 500 °C, and 700 °C, and BC was ball-milled to produce ball-milled biochar (BMC). Using these adsorbents to adsorb the allelopathic autotoxic substance quercetin. The physical and chemical properties of various biochars derived from traditional Chinese medicine residues were characterized using the Brunauer-Emmett-Teller-N2 surface areas (BET), scanning electron microscopy (SEM), Fourier transform IR spectroscopy (FTIR), X-ray diffraction (XRD), and Raman spectroscopy (Raman). The study investigated the effects of the initial pH value, different humic acid concentrations, and multiple adsorption-desorption experiments on the removal of quercetin from the solution. The article discusses the adsorption mechanism of quercetin in solution by biochar from a traditional Chinese medicine residue, based on the results of adsorption kinetics and adsorption isotherm fitting. The findings indicate that increasing the pyrolysis temperature reduces the oxygen-containing functional groups of BC, enhances the aromaticity, and stabilizes the carbon structure. The pore structure of BMC becomes more complex after ball milling, which increases the number of oxygen-containing functional groups on the surface. Among the samples tested, BMC700 exhibits the best adsorption performance, with an adsorption capacity of 293.3 mg·g-1 at 318 K. The adsorption process of quercetin by BMC700 follows the pseudo-second-order kinetic model and the Freundlich adsorption isotherm model. The process is primarily a form of multimolecular layer adsorption. Its mechanism involves the pore-filling effect, hydrogen-bonding interaction, electrostatic interaction, and π-π coexistence, as well as the yoke effect. Additionally, they are highly recyclable and show promise in addressing continuous cropping issues.

13.
Plant Physiol Biochem ; 208: 108535, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38503187

RESUMO

Aluminum (Al) toxicity is the major constraint on plant growth and productivity in acidic soils. An adaptive mechanism to enhance Al tolerance in plants is mediated malate exudation from roots through the involvement of ALMT (Al-activated malate transporter) channels. The underlying Al tolerance mechanisms of stylo (Stylosanthes guianensis), an important tropical legume that exhibits superior Al tolerance, remain largely unknown, and knowledge of the potential contribution of ALMT genes to Al detoxification in stylo is limited. In this study, stylo root growth was inhibited by Al toxicity, accompanied by increases in malate and citrate exudation from roots. A total of 11 ALMT genes were subsequently identified in the stylo genome and named SgALMT1 to SgALMT11. Diverse responses to metal stresses were observed for these SgALMT genes in stylo roots. Among them, the expressions of 6 out of the 11 SgALMTs were upregulated by Al toxicity. SgALMT2, a root-specific and Al-activated gene, was selected for functional characterization. Subcellular localization analysis revealed that the SgALMT2 protein is localized to the plasma membrane. The function of SgALMT2 in mediating malate release was confirmed by analysis of the malate exudation rate from transgenic composite stylo plants overexpressing SgALMT2. Furthermore, overexpression of SgALMT2 led to increased root growth in transgenic stylo plants treated with Al through decreased Al accumulation in roots. Taken together, the results of this study suggest that malate secretion mediated by SgALMT2 contributes to the ability of stylo to cope with Al toxicity.


Assuntos
Alumínio , Fabaceae , Alumínio/toxicidade , Alumínio/metabolismo , Malatos/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Fabaceae/metabolismo
14.
HPB (Oxford) ; 26(6): 753-763, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38485565

RESUMO

BACKGROUND: Anatomical sectionectomy based on Takasaki's segmentation has shown advantages in hepatocellular carcinoma. However, whether this approach improves the survival of intrahepatic cholangiocarcinoma (ICC) remains unknown. METHODS: A series of 248 consecutive patients with solitary ICCs who underwent hepatectomy were studied retrospectively. The patients were classified into the groups of anatomical sectionectomy based on Takasaki's segmentation (TS group) and non-Takasaki's hepatectomy (NTH group). The bias between the two groups was minimized using propensity score matching (PSM). Recurrence-free survival (RFS) and overall survival (OS) were evaluated with Kaplan-Meier analysis. The Cox proportional hazards model was performed to determine the adverse risk factors associated with survival. RESULTS: After PSM, 67 pairs of patients were compared. Both the RFS and OS rates in the TS group were significantly better than those in the NTH group (23.2 % vs. 16.5 %, and 40.4 % vs. 27.3 %, P = 0.035 and 0.032, respectively). Multivariate analysis showed that NTH was independently associated with worse RFS and OS than TS. The stratified analysis demonstrated that the RFS and OS rates in the TS group with tumor stage I and tumor size ≥3 cm were significantly better than those in the NTH group, while the survival rates for ICC with stage I and tumor size <3 cm or stage II-III showed no significant difference. CONCLUSION: TS was associated with improved RFS and OS in patients with solitary ICC even after PSM. TS may be preferred particularly in patients with tumor stage I and tumor size ≥3 cm.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Hepatectomia , Pontuação de Propensão , Humanos , Colangiocarcinoma/cirurgia , Colangiocarcinoma/mortalidade , Colangiocarcinoma/patologia , Masculino , Feminino , Neoplasias dos Ductos Biliares/cirurgia , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/mortalidade , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estimativa de Kaplan-Meier
15.
Toxicology ; 504: 153787, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38522818

RESUMO

Cadmium (Cd) is a common heavy metal pollutant in the environment, and the widespread use of products containing Cd compounds in industry has led to excessive levels in the environment, which enter the animal body through the food chain, thus seriously affecting the reproductive development of animals. Related studies have reported that Cd severely affects spermatogonia development and spermatogenesis in animals. In contrast, the reproductive toxicity of Cd in males and its mechanism of action have not been clarified. Therefore, this paper reviewed the toxic effects of Cd on germ cells, spermatogonia somatic cells and hypothalamic-pituitary-gonadal axis (HPG axis) of male animals and its toxic action mechanisms of oxidative stress, apoptosis and autophagy from the perspectives of cytology, genetics and neuroendocrinology. The effects of Cd stress on epigenetic modification of reproductive development in male animals were also analyzed. We hope to provide a reference for the in-depth study of the toxicity of Cd on male animal reproduction.


Assuntos
Cádmio , Estresse Oxidativo , Reprodução , Animais , Masculino , Cádmio/toxicidade , Reprodução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Espermatogênese/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Apoptose/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos
18.
Bioresour Technol ; 396: 130419, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38325610

RESUMO

Effects of short hydraulic retention time (HRT) in wet weather and long HRT in dry weather on sludge properties, microbial community, and metabolomic of anammox granular system were studied. Results showed under equal nitrogen loading rate (0.4 kg N/(m3 · d)) conditions, an HRT of 4.41 h was beneficial for total nitrogen removal efficiency (78.9 %). The shorter the HRT, the lower the particle density (1.01±0.34 g/cm3), the lower the settling performance (1.18±0.28 cm/s), and the worse the biomass retention (1.04±0.18 g/L), but the higher the mechanical strength (85.22 Pa). Properly decreasing HRT could increase the permeability of anammox granules, ensuring their activity. Metabolomics analysis indicated that the activity of anaerobic ammonium oxidizing bacteria was promoted by stimulating the metabolic pathways of amino acids and glycerophospholipids. In summary, this research clarified the effect of wet/dry weather on anammox granular system and provided theoretical guidance for the application in engineering.


Assuntos
Compostos de Amônio , Oxidação Anaeróbia da Amônia , Reatores Biológicos/microbiologia , Esgotos/microbiologia , Compostos de Amônio/metabolismo , Bactérias Anaeróbias/metabolismo , Tempo (Meteorologia) , Nitrogênio/metabolismo , Oxirredução , Anaerobiose
19.
FEMS Microbiol Ecol ; 100(3)2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38378869

RESUMO

Different types of inlet water are expected to affect microbial communities of lake ecosystems due to changing environmental conditions and the dispersal of species. However, knowledge of the effects of changes in environmental conditions and export of microbial assemblages on lake ecosystems is limited, especially for glacier-fed lakes. Here, we collected water samples from the surface water of a glacier-fed lake and its two fed streams on the Tibetan Plateau to investigate the importance of glacial and non-glacial streams as sources of diversity for lake bacterial communities. Results showed that the glacial stream was an important source of microorganisms in the studied lake, contributing 45.53% to the total bacterial community in the lake water, while only 19.14% of bacterial community in the lake water was seeded by the non-glacial stream. Bacterial communities were significantly different between the glacier-fed lake and its two fed streams. pH, conductivity, total dissolved solids, water temperature and total nitrogen had a significant effect on bacterial spatial turnover, and together explained 36.2% of the variation of bacterial distribution among habitats. Moreover, bacterial co-occurrence associations tended to be stronger in the lake water than in stream habitats. Collectively, this study may provide an important reference for assessing the contributions of different inlet water sources to glacier-fed lakes.


Assuntos
Lagos , Microbiota , Humanos , Camada de Gelo , Tibet , Água
20.
Molecules ; 29(3)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38338399

RESUMO

The interaction between human serum albumin (HSA) and hispidin, a polyketide abundantly present in both edible and therapeutic mushrooms, was explored through multispectral methods, hydrophobic probe assays, location competition trials, and molecular docking simulations. The results of fluorescence quenching analysis showed that hispidin quenched the fluorescence of HSA by binding to it via a static mechanism. The binding of hispidin and HSA was validated further by synchronous fluorescence, three-dimensional fluorescence, and UV/vis spectroscopy analysis. The apparent binding constant (Ka) at different temperatures, the binding site number (n), the quenching constants (Ksv), the dimolecular quenching rate constants (Kq), and the thermodynamic parameters (∆G, ∆H, and ∆S) were calculated. Among these parameters, ∆H and ∆S were determined to be 98.75 kJ/mol and 426.29 J/(mol·K), respectively, both exhibiting positive values. This observation suggested a predominant contribution of hydrophobic forces in the interaction between hispidin and HSA. By employing detergents (SDS and urea) and hydrophobic probes (ANS), it became feasible to quantify alterations in Ka and surface hydrophobicity, respectively. These measurements confirmed the pivotal role of hydrophobic forces in steering the interaction between hispidin and HSA. Site competition experiments showed that there was an interaction between hispidin and HSA molecules at site I, which situates the IIA domains of HSA, which was further confirmed by the molecular docking simulation.


Assuntos
Pironas , Albumina Sérica Humana , Albumina Sérica , Humanos , Albumina Sérica Humana/química , Simulação de Acoplamento Molecular , Albumina Sérica/química , Dicroísmo Circular , Espectrometria de Fluorescência , Sítios de Ligação , Termodinâmica , Ligação Proteica
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