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1.
J Agric Food Chem ; 72(11): 5944-5954, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38466638

RESUMO

The objective of this study was to investigate the mechanism underlying nitric oxide (NO)-induced hypoxia-inducible factor-1α (HIF-1α) and its impact on yak muscle tenderness during post-mortem aging. The Longissimus thoracis et lumborum (LTL) muscle of yak were incubated at 4 °C for 0, 3, 6, 9, 12, 24, and 72 h after treatment with 0.9% saline, NO activator, or a combination of the NO activator and an HIF-1α inhibitor. Results indicated that elevated NO levels could increase HIF-1α transcription to achieve stable expression of HIF-1α protein (P < 0.05). Additionally, elevated NO triggered HIF-1α S-nitrosylation, which further upregulated the activity of key glycolytic enzymes, increased glycogen consumption, accelerated lactic acid accumulation, and decreased pH (P < 0.05). These processes eventually improved the tenderness of yak muscle during post-mortem aging (P < 0.05). The results demonstrated that NO-induced activation of HIF-1α S-nitrosylation enhanced glycolysis during post-mortem aging and provided a possible pathway for improving meat tenderness.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia , Óxido Nítrico , Animais , Bovinos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Ácido Láctico/metabolismo
2.
Small ; 20(1): e2304776, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37658502

RESUMO

Efficient artificial photosynthesis of disulfide bonds holds promises to facilitate reverse decoding of genetic codes and deciphering the secrets of protein multilevel folding, as well as the development of life science and advanced functional materials. However, the incumbent synthesis strategies encounter separation challenges arising from leaving groups in the ─S─S─ coupling reaction. In this study, according to the reaction mechanism of free-radical-triggered ─S─S─ coupling, light-driven heterojunction functional photocatalysts are tailored and constructed, enabling them to efficiently generate free radicals and trigger the coupling reaction. Specifically, perovskites and covalent organic frameworks (COFs) are screened out as target materials due to their superior light-harvesting and photoelectronic properties, as well as flexible and tunable band structure. The in situ assembled Z-scheme heterojunction MAPB-M-COF (MAPbBr3 = MAPB, MA+ = CH3 NH2 + ) demonstrates a perfect trade-off between quantum efficiency and redox chemical potential via band engineering management. The MAPB-M-COF achieves a 100% ─S─S─ coupling yield with a record photoquantum efficiency of 11.50% and outstanding cycling stability, rivaling all the incumbent similar reaction systems. It highlights the effectiveness and superiority of application-oriented band engineering management in designing efficient multifunctional photocatalysts. This study demonstrates a concept-to-proof research methodology for the development of various integrated heterojunction semiconductors for light-driven chemical reaction and energy conversion.

3.
J Ovarian Res ; 16(1): 180, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37644593

RESUMO

BACKGROUND: C-X-C motif chemokine ligand 9 (CXCL9), which is involved in the pathological processes of various human cancers, has become a hot topic in recent years. We developed a radiomic model to identify CXCL9 status in ovarian cancer (OC) and evaluated its prognostic significance. METHODS: We analyzed enhanced CT scans, transcriptome sequencing data, and corresponding clinical characteristics of CXCL9 in OC using the TCIA and TCGA databases. We used the repeat least absolute shrinkage (LASSO) and recursive feature elimination(RFE) methods to determine radiomic features after extraction and normalization. We constructed a radiomic model for CXCL9 prediction based on logistic regression and internal tenfold cross-validation. Finally, a 60-month overall survival (OS) nomogram was established to analyze survival data based on Cox regression. RESULTS: CXCL9 mRNA levels and several other genes involving in T-cell infiltration were significantly relevant to OS in OC patients. The radiomic score (rad_score) of our radiomic model was calculated based on the five features for CXCL9 prediction. The areas under receiver operating characteristic (ROC) curves (AUC-ROC) for the training cohort was 0.781, while that for the validation cohort was 0.743. Patients with a high rad_score had better overall survival (P < 0.001). In addition, calibration curves and decision curve analysis (DCA) showed good consistency between the prediction and actual observations, demonstrating the clinical utility of our model. CONCLUSION: In patients with OC, the radiomics signature(RS) of CT scans can distinguish the level of CXCL9 expression and predict prognosis, potentially fulfilling the ultimate purpose of precision medicine.


Assuntos
Neoplasias Ovarianas , Humanos , Feminino , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/genética , Bases de Dados Factuais , Nomogramas , Medicina de Precisão , RNA Mensageiro , Quimiocina CXCL9/genética
4.
J Mater Chem B ; 11(26): 6123-6130, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37340824

RESUMO

Sonodynamic therapy (SDT) has emerged as a promising treatment approach of solid tumors given its deep tissue penetration, non-invasiveness, few side effects, and negligible drug resistance. Herein, we report the first polythiophene derivative-based sonosensitizer (PT2) containing a quaternary ammonium salt and dodecyl chains with better ultrasound stability than that of traditional sonosensitizers, such as Rose Bengal and chlorin e6. PT2 was encapsulated by folic acid-containing polyethylene glycol. The obtained nanoparticles (PDPF NPs) exhibited excellent biocompatibility, cancer cell-targeting capacity, and accumulated mainly in the lysosomes and plasma membranes of cells. These NPs could generate singlet oxygen and superoxide anions simultaneously under ultrasound irradiation. In vitro and in vivo experimental results demonstrated that PDPF NPs could induce cancer-cell death through apoptosis and necrosis, inhibit DNA replication, and ultimately achieve tumor depletion upon US irradiation. These findings revealed that polythiophene could serve as an efficacious sonosensitizer for enhanced US treatment of deep-seated tumors.


Assuntos
Nanopartículas , Terapia por Ultrassom , Terapia por Ultrassom/métodos , Linhagem Celular Tumoral , Membrana Celular , Lisossomos
5.
J Mater Chem B ; 10(47): 9848-9854, 2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36409302

RESUMO

Phototherapeutic agents with near-infrared (NIR) fluorescence, strong reactive oxygen species generation and photothermal conversion capabilities are highly desirable for use in cancer therapy. Herein, a water-soluble NIR croconaine dye (TCR) with a thiophene-croconaine rigid core and two symmetric alkyl chains was designed and synthesized. TCR exhibits intense NIR absorption and fluorescence that peaked at 780 and 815 nm, respectively, with a high molar extinction coefficient of 1.19 × 105 M-1 cm-1. Moreover, TCR has a high photothermal conversion efficiency of 77% and is capable of generating hydroxyl radicals (OH˙) under 735 nm laser irradiation. Based on these outstanding properties, TCR has proven its application in NIR fluorescence imaging-guided synergistic photothermal/photodynamic therapy of cancer.


Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Tiofenos/farmacologia , Água , Imagem Óptica
6.
Front Endocrinol (Lausanne) ; 13: 995972, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36246907

RESUMO

Glucose-6-phosphate isomerase (GPI) plays an important part in gluconeogenesis and glycolysis through the interconversion of d-glucose-6-phosphate and d-fructose-6-phosphate, and its clinical significance still remains unclear in breast cancer (BRCA). We analyzed the expressions of GPI in BRCA patients to determine prognostic values. Our results showed that the expression levels of GPI were upregulated in BRCA patients, and a high GPI expression is correlated with poor overall survival (OS) in BRCA. At the same time, a high GPI expression is correlated with poor clinicopathological characteristics, such as stage III, over 60 years old, N3, HER2 negative, and estrogen receptor (ER) positive. Further analysis of the influence of GPI on the prognosis of BRCA suggested that 50 genes and 10 proteins were positively correlated with GPI, and these genes and proteins were mainly involved in cell cycle signaling pathways. In addition, in this study, we observed that GPI was closely related to N 6-methyladenosine (m6A) RNA methylation modification and immune cell infiltration and ferroptosis-related gene expression in BRCA, and there was a difference in m6A RNA methylation alterations, immune cell infiltration, and ferroptosis-related gene expression between the high GPI expression group and the low GPI expression group. Finally, we found that GPI in BRCA had 2.6% gene alterations, and BRCA patients with gene alteration of GPI had a poor prognosis in disease-free survival (DFS). Altogether, our work strongly suggested that GPI may serve as a new prognostic biomarker for BRCA patients.


Assuntos
Neoplasias da Mama , Biomarcadores , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Feminino , Glucose-6-Fosfato , Glucose-6-Fosfato Isomerase/análise , Glucose-6-Fosfato Isomerase/genética , Glucose-6-Fosfato Isomerase/metabolismo , Humanos , Pessoa de Meia-Idade , Prognóstico , RNA , Receptores de Estrogênio
7.
Front Plant Sci ; 13: 926941, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35937380

RESUMO

Lignocellulose is a major component of plant litter and plays a dominant role in regulating the process of litter decomposition, but we lack a global perspective on plant litter initial lignocellulose concentration. Here, we quantitatively assessed the global patterns and drivers of litter initial concentrations of lignin, cellulose, and hemicellulose using a dataset consisting of 6,021 observations collected from 795 independent publications. We found that (1) globally, the median concentrations of leaf litter lignin, cellulose, and hemicellulose were 20.3, 22.4, and 15.0% of litter mass, respectively; and (2) litter initial concentrations of lignin, cellulose, and hemicellulose were regulated by phylogeny, plant functional type, climate, and soil properties, with mycorrhizal association and lifeform the dominant predictors. These results clearly highlighted the importance of mycorrhizal association and lifeform in controlling litter initial lignocellulose concentration at the global scale, which will help us to better understand and predict the role of lignocellulose in global litter decomposition models.

8.
J Phys Chem Lett ; 13(34): 7939-7946, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35980815

RESUMO

The regulation of photochemical properties of phototheranostics, especially the absorption, fluorescence, singlet oxygen (1O2) generation, and photothermal conversion efficiency, is a hot research topic. Here, we designed and synthesized four boron dipyrromethene (BODIPY) derivatives with high absorption coefficients and intense fluorescence in the near-infrared (NIR) region. The substituted electron-donating group significantly improved 1O2 generation and fluorescence of BODIPYs, whereas the electron-withdrawing group boosts photothermal conversion. These hydrophobic BODIPYs were further coated with DSPE-PEG-2000 to form water dispersible nanoparticles (NPs). Among these BODIPY NPs, the B-OMe-NPs with methoxyl substituted at the meso-position showed the highest 1O2 generation, a photothermal conversion efficiency of 66.5%, and an NIR fluorescence peak at 809 nm. In vitro and in vivo experiments demonstrated that B-OMe-NPs might be used for NIR fluorescent and photoacoustic imaging-guided photodynamic and photothermal therapy of cancer.


Assuntos
Nanopartículas , Neoplasias , Técnicas Fotoacústicas , Boro , Compostos de Boro/química , Células HeLa , Humanos , Nanopartículas/química , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Terapia Fototérmica , Porfobilinogênio/análogos & derivados
9.
Sci Rep ; 12(1): 8896, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614183

RESUMO

Forkhead-box-P family include FOXP1/2/3/4 and its clinical significance still remains unclear in breast cancer (BRCA). We analysed the expressions of FOXPs in BRCA patients to determine diagnostic and prognostic values. Our results indicated that the transcriptional levels of FOXP3/4 were up-regulated in BRCA patients, but FOXP2 were down-regulated. No statistically significant correlation were found between the expression levels of FOXPs in Pathologic stage. FOXP2/3 had a significantly high AUC value in the detection of breast cancer, with 96.8% or 95.7% in accuracy respectively. Our study also suggested that BRCA patients with high transcription levels of FOXP1/2/4 were significantly associated with longer Overall Survival (OS). In contrast, BRCA patients with high transcription level of FOXP3 was not statistically related with OS. Our work revealed that FOXPs were closely related to the alteration of extensive immune checkpoints in breast invasive carcinoma. Additionally, FOXP3 has a significant positive correlation with PDCD1, CD274, CTLA4 and TMB in breast cancer, and FOXP3 expression showed a statistically significant correlation with infiltration of immune cells. Finally, we found that FOXP3 expression predicted the breast cancer cells response to anticancer drugs. Altogether, our work strongly suggested that FOXPs could serve as a biomarker for tumor detection, therapeutic design and prognosis.


Assuntos
Neoplasias da Mama , Biomarcadores Tumorais/genética , Neoplasias da Mama/metabolismo , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Prognóstico , Proteínas Repressoras
10.
J Hematol Oncol ; 15(1): 29, 2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35303900

RESUMO

BACKGROUND: Chimeric antigen receptor (CAR)-T cell therapy has demonstrated remarkable success in the treatment of hematologic malignancies, while the success has not yet been replicated in solid tumors. To some extent, the disappointing results can be attributed to the paucity and heterogeneity of target antigens in solid tumors since adequate antigens are the cornerstone for CAR-T cells to recognize and attack tumor cells. METHODS: We established a target-redirected universal CAR-T (TRUE CAR-T) cell therapeutic modality, in which exogenous antigens are loaded onto fusogenic nanoparticles to achieve in situ modification of cell membrane in solid tumors, providing targets for subsequent CAR-T cell therapy. The modification effect was evaluated by flow cytometry and confocal microscopic imaging. The in vivo metabolism and biodistribution of fusogenic antigen loaded nanoparticles (F-AgNPs) was explored using near infrared living imaging. Then F-AgNPs mediated in situ antigen modification were cooperated with corresponding CAR-T cell therapy, and its antitumor efficacy was evaluated using immune function experiments and further investigated in different tumor models. RESULTS: Using F-AgNPs, exogenous antigens were selectively modified onto tumor cell membranes through membrane fusion, spread deeper into tumor tissues through intercellular lipid transfer, further activating corresponding CAR-T cells and mediating antitumor immune responses towards multiple types of tumor cells, despite of their inherent antigen profiles. The cooperative treatment of F-AgNPs and CAR-T cell therapy successfully suppressed tumor proliferation and prolonged survival in both subcutaneous and peritoneally disseminated tumor models. CONCLUSION: The fusogenic nanoparticle-based in situ antigen modification overcome the limitation of target antigens paucity and heterogeneity in solid tumors, improving the efficacy and broadening the applications of CAR-T cells, thus establishing a novel TRUE CAR-T cell therapeutic modality with universal application and translational potential in immunotherapies for solid tumors.


Assuntos
Neoplasias , Receptores de Antígenos Quiméricos , Antígenos de Neoplasias , Terapia Baseada em Transplante de Células e Tecidos , Humanos , Imunoterapia Adotiva/métodos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Gastroenterol Rep (Oxf) ; 9(4): 339-349, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34567566

RESUMO

BACKGROUND: Approximately 10% of patients with gastric cancer (GC) have a genetic predisposition toward the disease. However, there is scant knowledge regarding germline mutations in predisposing genes in the Chinese GC population. This study aimed to determine the spectrum and distribution of predisposing gene mutations among Chinese GC patients known to have hereditary high-risk factors for cancer. METHODS: A total of 40 GC patients from 40 families were recruited from seven medical institutions in China. Next-generation sequencing was performed on 171 genes associated with cancer predisposition. For probands carrying pathogenic/likely pathogenic germline variants, Sanger sequencing was applied to validate the variants in the probands as well as their relatives. RESULTS: According to sequencing results, 25.0% (10/40) of the patients carried a combined total of 10 pathogenic or likely pathogenic germline variants involving nine different genes: CDH1 (n = 1), MLH1 (n = 1), MSH2 (n = 1), CHEK2 (n = 1), BLM (n = 1), EXT2 (n = 1), PALB2 (n = 1), ERCC2 (n = 1), and SPINK1 (n = 2). In addition, 129 variants of uncertain significance were identified in 27 patients. CONCLUSIONS: This study indicates that approximately one in every four Chinese GC patients with hereditary high risk factors may harbor pathogenic/likely pathogenic germline alterations in cancer-susceptibility genes. The results further indicate a unique genetic background for GC among Chinese patients.

12.
Ying Yong Sheng Tai Xue Bao ; 32(4): 1154-1162, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33899383

RESUMO

To understand the nutrient use strategies of 11 tree species in a subtropical common-garden, we measured the specific leaf area, nitrogen (N) and phosphorus (P) resorption and stoichiometric characteristics of leaves in August 2019. The results showed that the specific leaf area, N and P concentrations in mature and senescent leaves of evergreen broadleaved (Lindera communis, Cinnamomum camphora, Schima superba, Castanopsis carlesii, Michelia macclurei and Elaeocarpus decipiens) and coniferous species (Cunninghamia lanceolata and Pinus massoniana) were lower than those of deciduous broadleaved species (Liquidambar formosana, Sapindus mukorossi and Liriodendron chinense). In contrast, C:N and C:P in mature leaves of evergreen broadleaved and coniferous species were significantly higher than those of deciduous broadleaved species. Except for C. carlesii, the N:P of all the species were lower than 14. Compared with other tree species, N and P resorption efficiencies of S. mukorossi were higher than 50% based on both mass and leaf area. Although P resorption efficiency of P. massoniana, C. lanceolata and C. camphora were higher than 50%, N and P resorption efficiency of M. macclurei were the lowest with only 15%-30%. In addition, specific leaf area of mature leaves was significantly positively correlated with N and P concentrations, but negatively correlated with C:N and C:P. In the common-garden, evergreen broadleaved species such as C. carlesii and L. communis, and coniferous species such as P. massoniana might belong to the slow investment species with lower specific leaf area, N and P concentrations, displaying relatively efficient in N and P resorption and utilization in comparison with other species. In contrast, deciduous broadleaved species such as S. mukoraiensis might be the fast investment species with low N and P use efficiency. Interestingly, tree species being restricted by N availability did not exhibit higher N resorption efficiency in the common-garden. Similarly, C. carlesii, the only P-restricted species here, did not exhibit higher P resorption efficiency. Our results provided scientific support for afforestation practice in the mid-subtropics.


Assuntos
Cunninghamia , Árvores , China , Nitrogênio/análise , Fósforo , Folhas de Planta/química
13.
Int J Nanomedicine ; 15: 10059-10073, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33335394

RESUMO

INTRODUCTION: Vertical bone augmentation without osseous walls to support the stability of clots and bone grafts remains a challenge in dental implantology. The objectives of this study were to confirm that cortical perforation of the recipient bed is necessary and to evaluate whether nanohydroxyapatite (nHA) block grafts coated with recombinant human vascular endothelial growth factor165 (rhVEGF165) and cortical perforation can improve vertical bone regeneration. MATERIALS AND METHODS: We prepared nHA blocks coated with or without rhVEGF165 on the rabbit calvarium through cortical perforation, and designated the animals as the nonperforated group (N-nHA), rhVEGF165 group (NV-nHA), perforated group (P-nHA) and rhVEGF165 on perforated group (PV-nHA). Micro-computed tomography (micro-CT) and fluorescence microscopy were selected to evaluate parameters of vertical bone regeneration at 4 and 6 weeks. RESULTS: The ratio of the newly formed bone volume to the titanium dome volume (BV/TV) and the bone mineral density (BMD) were significantly higher in the PV-nHA group than in the N-nHA group at 4 and 6 weeks, as determined using micro-CT. The fluorescence analysis showed slightly greater increases in new bone regeneration (NB%) and vertical height (VH%) gains in the P-nHA group than in the N-nHA group. Greater increases in NB% and VH% were observed in groups treated with rhVEGF165 and perforation than in the blank groups, with significant differences detected at 4 and 6 weeks (N-nHA compared with PV-nHA, p<0.05). A greater VH% that was observed at the midline of the block in the PV-nHA group than in the other three groups at both time points (0.75±0.53% at 4 weeks and 0.83±0.42% at 6 weeks). CONCLUSION: According to the present study, cortical perforation is necessary and nHA blocks coated with rhVEGF165 and decoration could work synergistically to improve vertical bone regeneration by directly affecting primary osteoblasts and promoting angiogenesis and osteoinduction.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Durapatita/farmacologia , Regeneração Tecidual Guiada/métodos , Nanoestruturas/química , Crânio/efeitos dos fármacos , Crânio/fisiologia , Fator A de Crescimento do Endotélio Vascular/química , Animais , Durapatita/química , Osteoblastos/efeitos dos fármacos , Porosidade , Coelhos , Proteínas Recombinantes/química , Crânio/citologia , Crânio/diagnóstico por imagem , Titânio/química , Microtomografia por Raio-X
14.
Cancer Manag Res ; 12: 863-870, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32104068

RESUMO

OBJECTIVE: The use of hepatic artery infusion (HAI) as a regional therapy against liver metastasis has rarely been reported in gastric cancer. This study aimed to evaluate the efficacy and safety of HAI oxaliplatin plus oral S-1 chemotherapy in first-line palliative therapy for gastric cancer with multiple liver metastases (GCLM). METHODS: We reviewed the records of five patients with GCLM who received HAI oxaliplatin (70-80 mg/m2 2 hrs d1,15) administered via a port-catheter system and S-1 with oral (35-40 mg/m2 twice daily for d1-14, 28 days for one cycle). Follow-up examination and efficacy evaluation were executed periodically. RESULTS: Until the 4th cycle response evaluation, the local effective rate and control rate were 40% and 80%, respectively; only one patient developed progression. HAI chemotherapy had a better local control against liver metastases (median progression-free survival: hepatic, 8.8 months vs. extrahepatic, 6.2 months), accompanied by less systemic toxicity, decreased tumour markers and symptomatic relief. CONCLUSION: HAI oxaliplatin plus oral S-1 chemotherapy can be considered as a new choice of first-line treatment for GCLM, which is also a good approach for controlling extrahepatic lesions with less adverse events.

15.
Front Pharmacol ; 11: 563433, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33536902

RESUMO

Psoriasis is a chronic inflammatory skin disease that is associated with multiple coexisting conditions. Extensive literature suggests that psoriasis is a T-cell-mediated condition, and its pathogenesis is related to dysfunction of the immune system. Myeloid-derived suppressor cells (MDSCs) are a group of heterogeneous myeloid cells that have suppressive effects on T cells. MDSCs are present at very low levels in healthy individuals but can substantially expand in tumours or inflammatory conditions. PSORI-CM02, a Chinese medical formula designed based on the Chinese medicine theory (Blood Stasis), has been prescribed extensively for psoriasis therapy and shows a stable clinical effect and safety. This study discusses the mechanisms of MDSCs involved in disease development and therapeutic progress. Our data provides evidence that monocytic myeloid-derived suppressor cells (M-MDSCs) play a role in IMQ-induced psoriatic dermatitis. Functional characterization and correlation analysis indicated that MDSCs are positively correlated with Th17 cells. PSORI-CM02 alleviated IMQ-induced psoriatic dermatitis and suppressed the proliferation of Th17 cells via M-MDSC-induced Arg1 upregulation, suggesting M-MDSCs could be a novel therapeutic target for psoriasis, and PSORI-CM02 exerted its effects via the perturbation of M-MDSCs and Th17 cell crosstalk.

16.
Sci Rep ; 8(1): 9373, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29921971

RESUMO

Canopy exchange is one of the most important processes involved in the internal transfer of elements in forest ecosystems. However, little information is available on how canopy exchange influences the input of base cations in subalpine forests. Therefore, the concentrations and fluxes of base cations in throughfall and stemflow were investigated from August 2015 to July 2016 (except for the frozen season) in a representative subalpine spruce plantation in the eastern Tibet Plateau. Our results showed that the mean concentrations of K, Ca, Na and Mg were higher in the stemflow than in the throughfall and precipitation. The total input fluxes of K, Ca, Na and Mg in the internal forest were lower than those in the non-forest. Moreover, the results from the canopy budget model indicated that the canopy exchange fluxes of K, Ca and Mg were higher than the dry deposition fluxes, and Ca and Mg were uptaken, whereas K was leached when precipitation passed through the canopy. Therefore, the results suggested that the input of base cations is mainly controlled by canopy exchange during precipitation in subalpine forest ecosystems, and the canopy could alter the sinks and sources of base cations from precipitation.

17.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 31(8): 1115-9, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26271987

RESUMO

OBJECTIVE: To prepare the monoclonal antibody (mAb) against human myoglobin (MYO) of high titer and specificity and develop double-antibody sandwich ELISA for detecting MYO in human serum samples. METHODS: The BALB/c mice were immunized with natural human MYO, and the hybridoma cell lines secreting anti-MYO mAb were established using cell fusion and hybridoma screening techniques. The characteristics of the mAb were identified after affinity purification from ascites. Then the best antibody pair was selected from mAb to establish a one-step sandwich ELISA method. Sixty human serum samples were detected by the homemade ELISA kit and the imported one, respectively. RESULTS: Nine strains of hybridoma cell lines stably secreted anti-MYO mAb. Four strains named 2M1, 3M4, 5M7 and 10M4 could secrete high-quality mAb and the titers of them were in the range of 1.0×10(6) to 2.6×10(6) (A450 value was about 1.0). Three antibody pairs (2M1/HRP-3M4, 5M7/HRP-3M4, 10M4/HRP-5M7) were selected by double-antibody sandwich ELISA. Among them, the 5M7/HRP-3M4 had higher sensitivity and larger linear range. The homemade ELISA kit had a larger linear range (25-1000 ng/mL) than the imported one (25-500 ng/mL) and showed high accuracies in detecting human serum samples, being 95% (19/20) in positive samples and 100% (40/40) in negative samples. CONCLUSION: With the anti-human MYO mAbs of high specificity and affinity, a one-step sandwich ELISA for detecting human MYO has been established successfully, which provides a basis for the development of domestic ELISA kit.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Mioglobina/sangue , Mioglobina/imunologia , Animais , Afinidade de Anticorpos/imunologia , Especificidade de Anticorpos/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Hibridomas , Camundongos Endogâmicos BALB C , Kit de Reagentes para Diagnóstico/normas , Reprodutibilidade dos Testes
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