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1.
Sci Total Environ ; 933: 172935, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38703859

RESUMEN

The deleterious impact of pollution point sources on the surrounding environment and human has long been a focal point of environmental research. When considering the local atmospheric dispersion of semi-volatile organic compounds (SVOCs) around the emission sites, it is essential to account the dynamic process for the gas/particle (G/P) partitioning, which involves the transition from an initial state to a steady state. In this study, we have developed a model that enables the prediction of the dynamic process for G/P partitioning of SVOCs, particularly considering the influence from emission. It is important to note that the dynamic processes of the concentrations of SVOCs in particle phase (CP) and in gas phase (CG) differ significantly. These differences arise due to the influence of two critical factors: particulate proportion of SVOCs in the emissions (ϕ0) and octanol-air partitioning coefficient (KOA). The validity of our model was assessed by comparing its predictions of the extremum value of the G/P partitioning quotient (KP) with the results obtained from the steady-state model. Remarkably, the characteristic time (tC), used to evaluate the timescale required for SVOCs to reach steady state, demonstrated different variations with KOA for CP and CG. Additionally, the values of tC were quite different for CP and CG, which were markedly influenced by ϕ0. For some SVOCs with high KOA values, it took approximately 35 h to reach steady state. Furthermore, it was found that the time to achieve 95 % of steady state (t95 ≈ 3tC) could reach approximately 105 h. This duration is sufficient for chemicals to disperse from their emission site to the surrounding areas. Therefore, it is crucial to consider the dynamic process of G/P partitioning in local atmospheric transport studies. Moreover, the influence of ϕ0 should be incorporated into future investigations examining the dynamic process of G/P partitioning.

2.
J Nanobiotechnology ; 22(1): 270, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769551

RESUMEN

Rheumatoid arthritis (RA) is a chronic autoimmune disease of yet undetermined etiology that is accompanied by significant oxidative stress, inflammatory responses,  and damage to joint tissues. In this study, we designed chondroitin sulfate (CS)-modified tragacanth gum-gelatin composite nanocapsules (CS-Cur-TGNCs) loaded with curcumin nanocrystals (Cur-NCs), which rely on the ability of CS to target CD44 to accumulate drugs in inflamed joints. Cur was encapsulated in the form of nanocrystals into tragacanth gum-gelatin composite nanocapsules (TGNCs) by using an inborn microcrystallization method, which produced CS-Cur-TGNCs with a particle size of approximately 80 ± 11.54 nm and a drug loading capacity of 54.18 ± 5.17%. In an in vitro drug release assay, CS-Cur-TGNCs showed MMP-2-responsive properties. During the treatment of RA, CS-Cur-TGNCs significantly inhibited oxidative stress, promoted the polarization of M2-type macrophages to M1-type macrophages, and decreased the expression of inflammatory factors (TNF-α, IL-1ß, and IL-6). In addition, it also exerted excellent anti-inflammatory effects, and significantly alleviated the swelling of joints during the treatment of gouty arthritis (GA). Therefore, CS-Cur-TGNCs, as a novel drug delivery system, could lead to new ideas for clinical therapeutic regimens for RA and GA.


Asunto(s)
Sulfatos de Condroitina , Curcumina , Gelatina , Nanocápsulas , Nanopartículas , Tragacanto , Curcumina/farmacología , Curcumina/química , Sulfatos de Condroitina/química , Gelatina/química , Animales , Nanocápsulas/química , Nanopartículas/química , Ratones , Tragacanto/química , Células RAW 264.7 , Estrés Oxidativo/efectos de los fármacos , Artritis Reumatoide/tratamiento farmacológico , Masculino , Tamaño de la Partícula , Antiinflamatorios/farmacología , Antiinflamatorios/química , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Liberación de Fármacos , Ratas
3.
J Hazard Mater ; 473: 134643, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38776815

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) have the capability for solar radiation absorption related to climate forcing. Herein, pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles in a cold megacity were comprehensively investigated. The mean concentrations of Σ18PAHs in all the 11 particle size ranges were 3.95 ± 4.77 × 104 pg/m3 and 2.17 ± 1.54 × 103 pg/m3 in heating period (HP) and non-heating period (NHP), respectively. Except for most PAHs with 2 and 3 benzene rings in NHP, most other PAHs showed a unimodal distribution pattern with the peak at 0.56-1.0 µm in both periods, which was caused by PAH emission sources. The PAH-related climate forcing was mainly caused by the solar radiation absorptions at ∼325 (∼330) nm and ∼365 nm. In general, the absorption intensities were higher in HP than NHP. The absorption intensity in the particle size range of 0.56-1.0 µm was the highest, and benzo[e]pyrene was the dominant contributor. In colder periods in HP, higher PAH concentrations caused more intensive PAH-related climate forcing. This study provided new insights for pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles, which will be useful for better understanding PAH-related climate forcing.

4.
Front Bioeng Biotechnol ; 12: 1329712, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38515621

RESUMEN

The failure of endogenous repair is the main feature of neurological diseases that cannot recover the damaged tissue and the resulting dysfunction. Currently, the range of treatment options for neurological diseases is limited, and the approved drugs are used to treat neurological diseases, but the therapeutic effect is still not ideal. In recent years, different studies have revealed that neural stem cells (NSCs) have made exciting achievements in the treatment of neurological diseases. NSCs have the potential of self-renewal and differentiation, which shows great foreground as the replacement therapy of endogenous cells in neurological diseases, which broadens a new way of cell therapy. The biological functions of NSCs in the repair of nerve injury include neuroprotection, promoting axonal regeneration and remyelination, secretion of neurotrophic factors, immune regulation, and improve the inflammatory microenvironment of nerve injury. All these reveal that NSCs play an important role in improving the progression of neurological diseases. Therefore, it is of great significance to better understand the functional role of NSCs in the treatment of neurological diseases. In view of this, we comprehensively discussed the application and value of NSCs in neurological diseases as well as the existing problems and challenges.

5.
World Neurosurg ; 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38537785

RESUMEN

OBJETIVE: This study aims to introduce the unilateral biplanar screw-rod fixation (UBSF) technique (a hybrid fixation technique: 2 sets of atlantoaxial screws were placed on the same side), which serves as a salvage method for traditional posterior atlantoaxial fixation. To summarize the indications of this technique and to assess its safety, feasibility, and clinical effectiveness in the treatment of odontoid fractures. METHODS: Patients with odontoid fractures were enrolled according to special criteria. Surgical duration and intraoperative blood loss were documented. Patients were followed up for a minimum of 12 months. X-ray and computerized tomography scans were conducted and reviewed at 1 day, and patients were asked to return for computerized tomography reviews at 3, 6, 9, and 12 months after surgery until fracture union. Recorded and compared the Neck Visual Analog Scale and Neck Disability Index presurgery and at 1 week and 12 months postsurgery. RESULTS: Between January 2016 and December 2022, our study enrolled 7 patients who were diagnosed with odontoid fractures accompanied by atlantoaxial bone or vascular abnormalities. All 7 patients underwent successful UBSF surgery, and no neurovascular injuries were recorded during surgery. Fracture union was observed in all patients, and the Neck Visual Analog Scale and Neck Disability Index scores improved significantly at 1 week and 12 months postoperative (P < 0.01). CONCLUSIONS: The UBSF technique has been demonstrated to be safe, feasible, and effective in treating odontoid fractures. In cases where the atlantoaxial bone or vascular structure exhibits abnormalities, it can function as a supplementary or alternative approach to the conventional posterior C1-2 fixation.

6.
Diabetes Metab Syndr Obes ; 17: 675-689, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38352234

RESUMEN

Purpose: To investigate the intestinal inflammatory response and the abundance of intestinal bacteria in rats with high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) and assess the intervention effects of taurine (TAU). Methods: Forty male Sprague-Dawley rats were randomly divided into five groups: group I, normal diet and normal saline gavage; group II, normal diet and TAU gavage; group III, HFD and normal saline gavage; group IV, HFD and TAU gavage (from the 1st week); group V, HFD and TAU gavage (from the 10th week). At the end of the 16th week, all the animals were sacrificed. Body weight, liver weight, liver function, and serum lipid levels were measured. The histopathologies of the liver and ileum were observed. The mRNA and protein expression levels of interleukin 17 (IL-17) and IL-10 in the ileum were detected by reverse transcription quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Three types of bacteria were detected in intestinal feces using the 16S rDNA qPCR method. Results: The ileal IL-17 level in group III was significantly higher than those in the other four groups (P < 0.01). The ileal IL-10 mRNA levels in group IV was significantly higher than those in groups III and V (P < 0.05), and IL-10 protein MOD levels in group III was significantly lower than those in the other four groups (P < 0.01). The numbers of Lactobacillus in group III were significantly lower than those in the other four groups (P < 0.01 or P < 0.05). The numbers of Bifidobacteria in groups IV and V were significantly increased compared with that in group III (P < 0.05). Conclusion: TAU may down-regulate the expression of IL-17, up-regulate the expression of IL-10 and regulate the intestinal flora, and alleviate the liver and intestinal damage in rats with HFD-induced NAFLD.

7.
Eur J Pharmacol ; 966: 176346, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38246329

RESUMEN

Cell transplantation has brought about a breakthrough in the treatment of nerve injuries, and the efficacy of cell transplantation compared to drug and surgical therapies is very exciting. In terms of transplantation targets, the classic cells include neural stem cells (NSCs) and Schwann cells, while a class of cells that can exist and renew throughout the life of the nervous system - olfactory ensheathing cells (OECs) - has recently been discovered in the olfactory system. OECs not only encircle the olfactory nerves but also act as macrophages and play an innate immune role. OECs can also undergo reprogramming to transform into neurons and survive and mature after transplantation. Currently, many studies have confirmed the repairing effect of OECs after transplantation into injured nerves, and safe and effective results have been obtained in clinical trials. However, the specific repair mechanism of OECs among them is not quite clear. For this purpose, we focus here on the repair mechanisms of OECs, which are summarized as follows: neuroprotection, secretion of bioactive factors, limitation of inflammation and immune regulation, promotion of myelin and axonal regeneration, and promotion of vascular proliferation. In addition, integrating the aspects of harvesting, purification, and prognosis, we found that OECs may be more suitable for transplantation than NSCs and Schwann cells, but this does not completely discard the value of these classical cells. Overall, OECs are considered to be one of the most promising transplantation targets for the treatment of nerve injury disorders.


Asunto(s)
Células-Madre Neurales , Traumatismos de la Médula Espinal , Humanos , Bulbo Olfatorio , Vaina de Mielina , Neuronas , Trasplante de Células/métodos , Regeneración Nerviosa , Neuroglía
8.
Neural Netw ; 172: 106093, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38228022

RESUMEN

Traffic Prediction based on graph structures is a challenging task given that road networks are typically complex structures and the data to be analyzed contains variable temporal features. Further, the quality of the spatial feature extraction is highly dependent on the weight settings of the graph structures. In the transportation field, the weights of these graph structures are currently calculated based on factors like the distance between roads. However, these methods do not take into account the characteristics of the road itself or the correlations between different traffic flows. Existing approaches usually pay more attention to local spatial dependencies extraction while global spatial dependencies are ignored. Another major problem is how to extract sufficient information at limited depth of graph structures. To address these challenges, we propose a Random Graph Diffusion Attention Network (RGDAN) for traffic prediction. RGDAN comprises a graph diffusion attention module and a temporal attention module. The graph diffusion attention module can adjust its weights by learning from data like a CNN to capture more realistic spatial dependencies. The temporal attention module captures the temporal correlations. Experiments on three large-scale public datasets demonstrate that RGDAN produces predictions with 2%-5% more precision than state-of-the-art methods.


Asunto(s)
Difusión
9.
Eur J Pharmacol ; 963: 176238, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38072039

RESUMEN

Spinal cord injury (SCI) can lead to severe motor, sensory and autonomic nervous dysfunction, cause serious psychosomatic injury to patients. There is no effective treatment for SCI at present. In recent years, exciting evidence has been obtained in the application of cell-based therapy in basic research. These studies have revealed the fact that cells transplanted into the host can exert the pharmacological properties of treating and repairing SCI. Olfactory ensheathing cells (OECs) are a kind of special glial cells. The application value of OECs in the study of SCI lies in their unique biological characteristics, that is, they can survive and renew for life, give full play to neuroprotection, immune regulation, promoting axonal regeneration and myelination formation. The function of producing secretory group and improving microenvironment. This provides an irreplaceable treatment strategy for the repair of SCI. At present, some researchers have explored the possibility of treatment of OECs in clinical trials of SCI. Although OECs transplantation shows excellent safety and effectiveness in animal models, there is still lack of sufficient evidence to prove the effectiveness of their clinical application in clinical trials. There has been an obvious stagnation in the transformation of OECs transplantation into routine clinical practice, and clinical trials of cell therapy in this field are still facing major challenges and many problems that need to be solved. Therefore, this paper summarized and analyzed the clinical trials of OECs transplantation in the treatment of SCI, and discussed the problems and challenges of OECs transplantation in clinical trials.


Asunto(s)
Traumatismos de la Médula Espinal , Animales , Humanos , Traumatismos de la Médula Espinal/terapia , Trasplante de Células , Neuroglía , Bulbo Olfatorio , Regeneración Nerviosa , Médula Espinal
10.
J Biophotonics ; 17(1): e202300259, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37755063

RESUMEN

Tail artifact elimination is essential in optical coherence tomography angiography (OCTA) for the artifacts will prevent the reconstruction of the 3D vessel image. The tail artifacts of superficial vessels obscure the deep vascular signals and cause the signals at different depths to mix with each other. Most tail artifact elimination methods can shorten the tails but have difficulty in determining the lower boundary of the vessels. In this letter, we introduce a technique to extract vascular signals with more accurate vascular boundaries. With the help of structural image, our method can reconstruct the 3D image of the vascular network more precisely and perform better in deep areas. The images of vessels of palm are used to compare our new technique with previous common parts extraction method experimentally. The results show that our method removes the tail artifacts more thoroughly and has a significant advantage in imaging deep vessels.


Asunto(s)
Vasos Retinianos , Tomografía de Coherencia Óptica , Tomografía de Coherencia Óptica/métodos , Imagenología Tridimensional , Artefactos , Angiografía
11.
iScience ; 26(12): 108225, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38025770

RESUMEN

Pulmonary fibrosis frequently occurs in rheumatic conditions, particularly systemic sclerosis-associated interstitial lung disease (SSc-ILD). The pathology involves cell transformation into interstitial structures and collagen accumulation. CD4+LAG3+T cells, known for immune inhibition, are relevant in autoimmunity. This study investigates CD4+LAG3+T cells in SSc-ILD. Clinical analysis revealed a correlation between CD4+LAG3+T cells and interleukin-6 (IL-6) and erythrocyte sedimentation rate (ESR). Using primary human lung fibroblasts (pHLFs) and murine bone marrow-derived macrophages (BMDMs), we showed that CD4+LAG3+T cells secreted TGF-ß3 inhibits TGF-ß1-induced mesenchymal transformation, modulates cellular function, and reduces collagen release. In mouse models, CD4+LAG3+T cells exhibited potential in alleviating bleomycin-induced pulmonary fibrosis. This study emphasizes CD4+LAG3+T cells' therapeutic promise against fibrosis and proposes their role as biomarkers.

12.
World J Urol ; 41(11): 3097-3103, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37698634

RESUMEN

PURPOSE: This study aimed to compare the outcomes of vacuum-assisted dedusting lithotripsy (VADL) using flexible vacuum-assisted ureteral access sheath (FV-UAS) versus traditional flexible ureteroscopic lithotripsy (fURL) in patients with kidney or proximal ureteral calculi less than 3 cm in size. METHODS: A total of 371 patients who successfully underwent fURL treatment were enrolled. These patients were divided into traditional fURL group and VADL group. Outcomes of both groups were compared using 1:1 propensity score-matched analysis. Stratified analyses based on stone size and location were also conducted. RESULTS: Finally, 103 well-matched patients in each group were identified. No septic shock or death occurred. The immediate stone-free rate (SFR) and follow-up SFR of VADL group were significantly higher (78.6% vs. 50.5%, p < 0.001; 94.2%% vs. 75.7%, p < 0.001). No difference was observed in postoperative fever rate (2.9% vs. 3.9%, p = 1.000) and duration of lithotripsy (37.7 ± 20.1 min vs. 40.3 ± 18.9 min, p = 0.235). For patients with stones ≤ 2 cm in size, the immediate SFR and follow-up SFR in VADL group were higher (86.7% vs. 60.6%, p < 0.001; 96.0% vs. 83.1%, p = 0.010). The same trend was observed in the 2-3 cm subgroup (57.1% vs. 28.1%, p = 0.023; 89.3% vs. 59.4%, p = 0.009). Although the in situ fragmentation strategy was employed more frequently in VADL group for lower pole stones, the SFR was still higher. Subgroup analyses did not reveal any significant differences in either infectious complications or duration of lithotripsy. CONCLUSION: VADL technique can significantly improve the postoperative SFR for the patients with kidney or proximal ureteral stones less than 3 cm in size treated by flexible ureteroscope.


Asunto(s)
Cálculos Renales , Litotricia , Cálculos Ureterales , Humanos , Cálculos Ureterales/cirugía , Resultado del Tratamiento , Ureteroscopía/métodos , Litotricia/métodos , Riñón , Cálculos Renales/cirugía
14.
Arch Environ Contam Toxicol ; 85(2): 129-139, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37578493

RESUMEN

Health risks from exposure to contaminants are generally estimated by evaluating concentrations of the contaminants in environmental matrixes. However, accurate health risk assessment is difficult because of uncertainties regarding exposures. This study aims to utilize data on the concentrations of organophosphate flame retardants (OPFRs) in surface soil across China coupled with Monte Carlo simulations to compensate for uncertainties in exposure to evaluate the health risks associated with contamination of soil with this class of flame retardants. Results revealed that concentrations of ∑OPFRs were 0.793-406 ng/g dry weight (dw) with an average of 23.2 ng/g dw. In terms of spatial distribution, higher OPFRs concentrations were found in economically developed regions. Although the values of health risk of OPFRs in soil across China were below the threshold, the high concentrations of OPFRs in soil in some regions should attract more attentions in future. Sensitivity analysis revealed that concentrations of OPFRs in soil, skin adherence factor, and exposure duration were the most sensitive parameters in health risk assessment. In summary, the study indicated that the national scale soil measurement could provide unique information on OPFRs exposure and health risk assessment, which was useful for the management of soil in China and for better understanding of the environmental fate of OPFRs in the global perspective.


Asunto(s)
Monitoreo del Ambiente , Retardadores de Llama , Humanos , China , Retardadores de Llama/análisis , Método de Montecarlo , Organofosfatos/análisis , Medición de Riesgo , Suelo
16.
Trends Biotechnol ; 41(12): 1532-1548, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37365082

RESUMEN

Proteogenomics (PG) integrates the proteome with the genome and transcriptome to refine gene models and annotation. Coupled with single-cell (SC) assays, PG effectively distinguishes heterogeneity among cell groups. Affiliating spatial information to PG reveals the high-resolution circuitry within SC atlases. Additionally, PG can investigate dynamic changes in protein-coding genes in plants across growth and development as well as stress and external stimulation, significantly contributing to the functional genome. Here we summarize existing PG research in plants and introduce the technical features of various methods. Combining PG with other omics, such as metabolomics and peptidomics, can offer even deeper insights into gene functions. We argue that the application of PG will represent an important font of foundational knowledge for plants.


Asunto(s)
Proteogenómica , Genoma , Proteoma/genética , Transcriptoma
17.
J Hazard Mater ; 455: 131639, 2023 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-37196441

RESUMEN

The floating catkins generated by willow and poplar trees have been criticized for spreading germ and causing fire for decades. It has been found that catkins are with a hollow tubular structure, which made us wonder if the floating catkins can adsorb atmospheric pollutions. Thus, we conducted a project in Harbin, China to investigate whether and how willow catkins could adsorb atmospheric polycyclic aromatic hydrocarbons (PAHs). The results suggest that both the catkins floating in the air and on the ground preferred to adsorb gaseous PAHs rather than particulate PAHs. Moreover, 3- and 4-ring PAHs were the dominating compositions adsorbed by catkins, which significantly increased with exposure time. The gas/catkins partition (KCG) was defined, which explained why 3-ring PAHs are more easily adsorbed by catkins than by airborne particles when their subcooled liquid vapor pressure is high (log PL > -1.73). The removal loading of atmospheric PAHs by catkins were estimated as 1.03 kg/year in the center city of Harbin, which may well explain the phenomenon that levels of gaseous and total (particle + gas) PAHs are relatively low in the months with catkins floating reported in peer-reviewed papers.

18.
J Ethnopharmacol ; 312: 116454, 2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37059246

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Polyrhachis vicina Roger (P. vicina), a traditional Chinese medicinal animal, has been used to treat rheumatoid arthritis, hepatitis, cancer, and other conditions. Due to its anti-inflammatory properties, our previous pharmacological investigations have demonstrated that it is effective against cancer, depression, and hyperuricemia. Nevertheless, the key active components and targets of P. vicina in cancers are still unexplored. AIM OF THE STUDY: The study aimed to evaluate the pharmacological treatment mechanism of the active fraction of P. vicina (AFPR) in treating colorectal cancer (CRC) and to further reveal its active ingredients and key targets. METHODS: To examine the inhibitory impact of AFPR on CRC growth, tumorigenesis assays, cck-8 assays, colony formation assays, and MMP detection were utilized. The primary components of AFPR were identified by GC-MS analysis. The network pharmacology, molecular docking, qRT-PCR, western blotting, CCK-8 assays, colony formation assay, Hoechst staining, Annexin V-FITC/PI double staining, and MMP detection were performed to pick out the active ingredients and potential key targets of AFPR. The function of Elaidic acid on necroptosis was investigated through siRNA interference and the utilization of inhibitors. Elaidic acid's effectiveness to suppress CRC growth in vivo was assessed using a tumorigenesis experiment. RESULTS: Studies confirmed that AFPR prevented CRC from growing and evoked cell death. Elaidic acid was the main bioactive ingredient in AFPR that targeted ERK. Elaidic acid greatly affected the ability of SW116 cells to form colonies, produce MMP, and undergo necroptosis. Additionally, Elaidic acid promoted necroptosis predominantly by activating ERK/RIPK1/RIPK3/MLKL. CONCLUSION: According to our findings, Elaidic acid is the main active component of AFPR, which induced necroptosis in CRC through the activation of ERK. It represents a promising alternative therapeutic option for CRC. This work provided experimental support for the therapeutic application of P. vicina Roger in the treatment of CRC.


Asunto(s)
Neoplasias Colorrectales , Necroptosis , Animales , Simulación del Acoplamiento Molecular , Sincalida , Neoplasias Colorrectales/tratamiento farmacológico , Carcinogénesis
19.
Huan Jing Ke Xue ; 44(4): 2052-2061, 2023 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-37040955

RESUMEN

Organic aggregates (OA) are the important circulation hub of matter and energy in aquatic ecosystems. However, the comparison studies on OA in lakes with different nutrient levels are limited. In this study, spatio-temporal abundances of OA and OA-attached bacteria (OAB) in oligotrophic Lake Fuxian, mesotrophic Lake Tianmu, middle-eutrophic Lake Taihu, and hyper-eutrophic Lake Xingyun were investigated in different seasons during 2019-2021 using a scanning electron microscope, epi-fluorescence microscope, and flow cytometry. The results showed that:① the annual average abundances of OA in Lake Fuxian, Lake Tianmu, Lake Taihu, and Lake Xingyun were 1.4×104, 7.0×104, 27.7×104, and 16.0×104 ind·mL-1, whereas the annual average abundances of OAB in the four lakes were 0.3×106, 1.9×106, 4.9×106, and 6.2×106 cells·mL-1. The ratios of OAB:total bacteria (TB) in the four lakes were 30%, 31%, 50%, and 38%, respectively. ② OA abundance in summer was significantly higher than that in autumn and winter; however, the ratio of OAB:TB in summer was approximately 26%, which was significantly lower than that in the other three seasons. ③ Lake nutrient status was the most important environmental factor that affected the abundance variations of OA and OAB, accounting for 50% and 68% of the spatio-temporal variations in OA and OAB abundances. ④ Nutrient and organic matters were enriched in OA, especially in Lake Xingyun; the proportions of particle phosphorous, particle nitrogen, and organic matters in this lake were as high as 69%, 59%, and 79%, respectively. Under the circumstance of future climate change and the expansion of lake algal blooms, the effects of algal-originated OA in the degradation of organic matters and nutrient recycling would be increased.


Asunto(s)
Ecosistema , Lagos , Estaciones del Año , Eutrofización , Fósforo
20.
Genome Res ; 33(3): 371-385, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36963844

RESUMEN

Alternative splicing (AS) regulates gene expression and increases proteomic diversity for the fine tuning of stress responses in plants, but the exact mechanism through which AS functions in plant stress responses is not thoroughly understood. Here, we investigated how AS functions in poplar (Populus trichocarpa), a popular plant for bioremediation, in response to lead (Pb) stress. Using a proteogenomic analysis, we determine that Pb stress induced alterations in AS patterns that are characterized by an increased use of nonconventional splice sites and a higher abundance of Pb-responsive splicing factors (SFs) associated with Pb-responsive transcription factors. A strong Pb(II)-inducible chaperone protein, PtHSP70, that undergoes AS was further characterized. Overexpression of its two spliced isoforms, PtHSP70-AS1 and PtHSP70-AS2, in poplar and Arabidopsis significantly enhances the tolerance to Pb. Further characterization shows that both isoforms can directly bind to Pb(II), and PtHSP70-AS2 exhibits 10-fold higher binding capacities and a greater increase in expression under Pb stress, thereby reducing cellular toxicity through Pb(II) extrusion and conferring Pb tolerance. AS of PtHSP70 is found to be regulated by PtU1-70K, a Pb(II)-inducible core SF involved in 5'-splice site recognition. Because the same splicing pattern is also found in HSP70 orthologs in other plant species, AS of HSP70 may be a common regulatory mechanism to cope with Pb(II) toxicity. Overall, we have revealed a novel post-transcriptional machinery that mediates heavy metal tolerance in diverse plant species. Our findings offer new molecular targets and bioengineering strategies for phytoremediation and provide new insight for future directions in AS research.


Asunto(s)
Arabidopsis , Populus , Proteogenómica , Empalme Alternativo , Proteómica , Populus/genética , Populus/metabolismo , Plomo/toxicidad , Plomo/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Factores de Transcripción/metabolismo , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
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