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1.
FASEB J ; 37(3): e22779, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36723798

RESUMEN

Preeclampsia is a gestational disease characterized by two major pathological changes-shallow trophoblast invasion and impaired spiral artery remodeling. Atrial natriuretic peptide (ANP) is a kind of peptide hormone that regulates blood pressure, while the lack of active ANP participates in preeclampsia pathogenesis. However, the underlying mechanism of how ANP modulates trophoblasts function remains unclarified. Here, we performed isobaric tags for relative and absolute quantification (iTRAQ) in ANP-treated HTR-8/SVneo cells and identified Protein Kinase 3 (PKN3) as the downstream factor of ANP, which was downregulated in preeclamptic placenta. Chromatin immunoprecipitation analysis and luciferase assays showed that NFYA was one of the transcription factors for the PKN3 promoter, which was also regulated by ANP treatment in HTR-8/SVneo cells. Transmission electron microscopy and Western Blotting in HTR-8/SVneo cells indicated that ANP inhibited autophagy via AMPK-mTORC1 signaling, while excess autophagy was observed in preeclamptic placenta. The increased expression of PKN3 and enhanced cell invasion ability in HTR-8/SVneo cells induced by ANP could be abolished by autophagy activation or transfection with PKN3 shRNA or NFYA shRNA or NPR-A shRNA via regulating the invasion-related genes and the epithelial mesenchymal transition molecules. Our results demonstrated that ANP could enhance trophoblast invasion by upregulating PKN3 via NFYA promotion through autophagy inhibition in an AMPK/mTORC1 signaling-dependent manner.


Asunto(s)
Preeclampsia , Femenino , Humanos , Embarazo , Proteínas Quinasas Activadas por AMP/metabolismo , Autofagia , Línea Celular , Movimiento Celular , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Placenta/metabolismo , Preeclampsia/metabolismo , ARN Interferente Pequeño/metabolismo , Trofoblastos/metabolismo , Factor Natriurético Atrial
2.
Surg Endosc ; 37(5): 4088-4096, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36997652

RESUMEN

BACKGROUND: An innovative instrument for laparoscopy using indocyanine green (ICG) allows easy detection of sentinel lymph nodes (SLNs) in lateral pelvic lymph nodes (LPLNs). Here, we investigated the safety and efficacy of lateral pelvic SLN biopsy (SLNB) using ICG fluorescence navigation in advanced lower rectal cancer and evaluated the sensitivity and specificity of this technique to predict the status of LPLN. METHODS: From April 1, 2017 to December 1, 2020, we conducted lateral pelvic SLNB using ICG fluorescence navigation during laparoscopic total mesorectal excision and lateral pelvic lymph node dissection (LLND) in 23 patients with advanced low rectal cancer who presented with LPLN but without LPLN enlargement. Data regarding clinical characteristics, surgical and pathological outcomes, lymph node findings, and postoperative complications were collected and analyzed. RESULTS: We successfully performed the surgery using fluorescence navigation. One patient underwent bilateral LLND and 22 patients underwent unilateral LLND. The lateral pelvic SLN were clearly fluorescent before dissection in 21 patients. Lateral pelvic SLN metastasis was diagnosed in 3 patients and negative in 18 patients by frozen pathological examination. Among the 21 patients in whom lateral pelvic SLN was detected, the dissected lateral pelvic non-SLNs were all negative. All dissected LPLNs were negative in two patients without fluorescent lateral pelvic SLN. CONCLUSION: This study indicated that lateral pelvic SLNB using ICG fluorescence navigation shows promise as a safe and feasible procedure for advanced lower rectal cancer with good accuracy, and no false-negative cases were found. No metastasis in SLNB seemed to reflect all negative LPLN metastases, and this technique can replace preventive LLND for advanced lower rectal cancer.


Asunto(s)
Neoplasias del Recto , Ganglio Linfático Centinela , Humanos , Biopsia del Ganglio Linfático Centinela/métodos , Verde de Indocianina , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/cirugía , Ganglios Linfáticos/patología , Ganglio Linfático Centinela/diagnóstico por imagen , Ganglio Linfático Centinela/cirugía , Ganglio Linfático Centinela/patología , Colorantes , Escisión del Ganglio Linfático , Neoplasias del Recto/diagnóstico por imagen , Neoplasias del Recto/cirugía , Neoplasias del Recto/patología
3.
Acta Pharmacol Sin ; 42(4): 624-632, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32704040

RESUMEN

The mechanism underlying the resistance of cancer cells to chemotherapeutic drug varies with different cancer cells. Recent evidence shows that lysosomal function is associated with drug resistance of cancer cells. Artesunate, a derivative of artemisinin, displays broad antitumor activity and direct cytotoxicity on various tumor cells. Our previous study shows that artesunate increases autophagosome accumulation, while significantly decreases autolysosome number in cancer cells, suggesting that artesunate might impair the lysosomal function. In this study, we investigated the effects of artesunate on lysosomal function and its relationship with chemotherapeutic drug resistance in cancer cells. We found that the lysosomal function was significantly enhanced in two drug-resistant (A549/TAX and A549/DDP) cells. Furthermore, we showed that the enhanced lysosomal function by overexpression of transcription factor EB (TFEB) significantly increased MCF-7 cells resistance to doxorubicin (DOX), whereas the decreased lysosomal function by TFEB-knockdown or lysosome inhibitor chloroquine increased MCF-7 cells sensitivity to DOX. Treatment of A549/TAX cells with artesunate (2.5-50 µM) dose-dependently inhibited lysosomal function and the clearance of dysfunctional mitochondria, and induced cell apoptosis. Moreover, we demonstrated that artesunate exerted more potent inhibition on the resistant (A549/TAX and MCF-7/ADR) cells with higher activity of lysosomal function. Our results suggest that artesunate or other inhibitors of lysosomal function would be potential in the treatment of cancer cells with drug resistance caused by the enhanced lysosomal function.


Asunto(s)
Antineoplásicos/farmacología , Artesunato/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Lisosomas/efectos de los fármacos , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Catepsinas/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cloroquina/farmacología , Cromanos/farmacología , Doxorrubicina/farmacología , Sinergismo Farmacológico , Técnicas de Silenciamiento del Gen , Humanos , Paclitaxel/farmacología
4.
World J Surg Oncol ; 18(1): 159, 2020 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-32635945

RESUMEN

BACKGROUND: To evaluate the feasibility and safety of a new surgical method, complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction in right-transverse colon cancer. METHODS: We retrospectively analyzed and compared the data of consecutive patients with right-transverse colon cancer who underwent complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction (n = 23) and conventional complete laparoscopic extended right hemicolectomy (n = 34) in our hospital between October 2017 to May 2019, respectively. RESULTS: The overall operation time of the ileocecal junction-preserved group was significantly shorter than that of the control group (p = 0.048). There was no difference in the number of harvested lymph nodes, metastatic lymph nodes, and rate of metastatic lymph nodes (p > 0.05). The ileocecal junction-preserved group showed shorter time of first flatus, lower frequency of postoperative diarrhea, and shorter duration of postoperative hospitalization. Furthermore, it also showed that the defecation frequency was lower in the ileocecal junction-preserved group than the control group on the 1st, 3rd, and 6th month (p < 0.05), and the number of patients who defecated at night or defecated four times or more a day was less in the ileocecal junction-preserved group than control group on the 1st month (p < 0.05). CONCLUSION: The complete laparoscopic extended right hemicolectomy with preservation of the ileocecal junction promises as a safe and feasible surgical procedure for right-transverse colon cancer, associated with earlier recovery of bowel function, shorter operation time, and similar pathological outcomes when compared to the conventional laparoscopic procedure.


Asunto(s)
Colon Transverso , Neoplasias del Colon , Laparoscopía , Colectomía , Colon Transverso/cirugía , Neoplasias del Colon/cirugía , Estudios de Factibilidad , Humanos , Escisión del Ganglio Linfático , Pronóstico , Estudios Retrospectivos , Resultado del Tratamiento
5.
BMC Surg ; 20(1): 102, 2020 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-32404083

RESUMEN

BACKGROUND: To retrospectively evaluate the feasibility and safety of intraoperative assessment of bowel perfusion in totally laparoscopic surgery for colon cancer using indocyanine green fluorescence imaging (IGFI). METHODS: From October 2017 to June 2019, consecutive patients with colon cancer who underwent totally laparoscopic surgery were enrolled retrospectively and grouped into the IGFI group (n = 84) and control group (n = 105). In the IGFI group, indocyanine green (ICG) was injected intravenously, and the bowel perfusion was observed using a fluorescence camera system prior to and after completion of the anastomosis. RESULTS: The two groups were demographically comparable. The IGFI group exhibited a significantly shorter operative time (p = 0.0374) while intraoperative blood loss did not significantly differ among the groups (p = 0.062). In the IGFI group, average time to perfusion fluorescence was 48.4 ± 14.0 s after ICG injection, and four patients (4.8%) were required to choose a more proximal point of resection due to the lack of adequate fluorescence at the point previously selected. There were no differences in terms of pathological outcomes, postoperative recovery and the postoperative complication rates between the groups (p>0.05). CONCLUSION: IGFI shows promise as a safe and feasible tool to assess bowel perfusion during a totally laparoscopic surgery for colon cancer and may reduce the operative time.


Asunto(s)
Neoplasias del Colon/cirugía , Verde de Indocianina , Laparoscopía/métodos , Anciano , Anastomosis Quirúrgica/métodos , Fuga Anastomótica/etiología , Femenino , Fluorescencia , Humanos , Intestinos/cirugía , Masculino , Persona de Mediana Edad , Tempo Operativo , Perfusión , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos
6.
Front Microbiol ; 13: 1015913, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36338084

RESUMEN

Natural pigments are playing important roles in our daily lives. They not only make products colorful but also provide various health benefits for humans. In addition, Pycnoporus genus, listed as food- and cosmetic-grade microorganism, is one of the promising organisms for developing natural pigments. In this study, a new fungal strain with high efficiency in producing intense orange pigments was isolated and identified as Pycnoporus sanguineus SYBC-L7. Different agro-industrial wastes were applied to evaluate the growth and pigment production of strain SYBC-L7. SYBC-L7 can grow rapidly and effectively produce pigments using wood chips as substrate in solid-state fermentation (SSF). Culture conditions were also optimized for value-added pigments production and the optimum production conditions were glucose as carbon source, ammonium tartrate as nitrogen source, initial pH 6.0, and relative humidity of 65%. Pigment components, cinnabarinic acid, tramesanguin, and 2-amino-9-formylphenoxazone-1-carbonic acid were confirmed by liquid chromatography-mass spectrometry. Meanwhile, an agar plate diffusion assay was performed to evaluate the antimicrobial activity of the pigment. These pigments showed more significant inhibition of Gram-positive than Gram-negative bacteria. The results showed that Pycnoporus sanguineus SYBC-L7 was able to cost-effectively produce intense natural orange pigments with antibacterial activity in SSF, which is the basis of their large-scale production and application.

7.
Front Surg ; 9: 1076874, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36684242

RESUMEN

Background: Recently, totally laparoscopic (TLAP) surgery has suggested its potential on ileostomy reversal. This study aimed to compare the short-term outcomes between TLAP and traditional open ileostomy reversal. Patients and methods: From September 2016 to September 2021, 107 eligible patients underwent TLAP (n = 48) or open (n = 59) loop ileostomy reversal were retrospectively enrolled. Surgical parameters, postoperative recovery and complications were identified and compared between TLAP technique vs. open surgery. Results: The operation time and estimated blood loss showed no obvious difference between TLAP and open group. However, TLAP reversal significantly decreased the incision length (4.5cm vs. 6cm, P < 0.001). Furthermore, patients underwent TLAP surgery showed quicker first ground activities (1 day vs. 2 days, P < 0.001), faster first flatus passage (2 days vs. 3 days, P = 0.004) and shorter postoperative stay (5 days vs. 7 days, P = 0.007). More importantly, postoperative complications were significantly reduced after TLAP reversal (3 cases vs. 10 cases, P = 0.026). Further logistic regression analyses also indicated the TLAP technique was associated with lower incidence of complications (OR=3.316, CI, 1.118-9.835; P = 0.031). Conclusions: TLAP surgery is competitive in promoting postoperative recovery as well as reducing complications compared to the traditional open ileostomy reversal.

8.
Artículo en Inglés | MEDLINE | ID: mdl-33727939

RESUMEN

As a reproductive endocrine disease, polycystic ovary syndrome (PCOS) has influenced billions of women during childbearing age worldwide. Owing to its complex etiology and ambiguous pathogenesis, there is still not a specific method to cure it. Clinical treatments, such as hormone therapy and surgical treatment, have side effects. Therefore, it is essential and urgent to seek alternative treatment to solve these problems. The satisfactory efficacy of complementary and alternative medicine (CAM), such as traditional Chinese medicine (TCM), immunotherapy, medicinal foods, vitamin therapy, diet therapy, psychotherapy, spa, and oxygen therapy, in treating PCOS, has aroused an increasing number of medical workers' concern and gradually become the mainstream. This paper reviews the application of CAM in the treatment of PCOS, especially from the perspective of TCM. Meanwhile, the limitations of the literature about CAM in the treatment of PCOS are mentioned and analyzed as well.

9.
Updates Surg ; 73(2): 561-567, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32980964

RESUMEN

Reversal of loop ileostomy after colorectal surgery in obese patients can be challenging and total laparoscopic (TLAP) approach may be beneficial. This study aims to compare short-term outcomes of TLAP and open approaches in obese patients undergoing loop ileostomy reversal after laparoscopic-assisted colorectal surgery. A retrospective review was performed for consecutive patients who underwent laparoscopic-assisted colorectal surgery previously and underwent loop ileostomy reversal between January 2017 and April 2020. TLAP and open cases performed in obese patients were identified and compared for the following outcomes: baseline characteristics, operative outcomes, postoperative recovery, and postoperative complications. TLAP or open-loop ileostomy reversal was performed on 30 and 34 patients, respectively. TLAP approach was associated with a similar operation time and blood loss compared with an open approach (P > 0.05). The median length of incision for stoma removal was significantly shorter in the TLAP group than in the open group (6.5 cm vs. 8.5 cm; P < 0.05), and a lower incidence of incisional infection was also noted in the TLAP group (6.7% vs. 26.5%; P < 0.05). The groups were comparable as regards the time to ground activities and length of hospitalization (P > 0.05), but the time to first flatus was decreased (2.0 vs. 3.0 days; P < 0.05). This retrospective study demonstrated that TLAP loop ileostomy reversal may have a satisfactory short-term outcome for obese patients after laparoscopic-assisted colorectal surgery, with a shorter incisional length and a lower incidence of incisional infection as well as an earlier time to first flatus.


Asunto(s)
Laparoscopía , Estomas Quirúrgicos , Humanos , Ileostomía , Obesidad/complicaciones , Obesidad/cirugía , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Resultado del Tratamiento
10.
Onco Targets Ther ; 13: 11571-11582, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33204110

RESUMEN

PURPOSE: The molecular mechanism of perineural invasion (PNI) in stage II colorectal cancer (CRC) remains not to be defined clearly. This study aims to identify the genomic aberrations related to PNI in stage II CRC. PATIENTS AND METHODS: Using array-based comparative genomic hybridization (array-CGH), primary tumor tissues and paracancerous normal tissues of stage II CRC with PNI and without PNI were analyzed. We identified genomic aberrations by using Genomic Workbench and MD-SeeGH and validated the aberrations of selected genes by real-time polymerase chain reaction (PCR). Gene ontology (GO) and pathway analysis were performed to determine the most likely biological effects of these genes. RESULTS: The most frequent gains in stage II CRC were at 7q11.21-q11.22, 8p11.21, 8p12-p11.23, 8q11.1-q11.22, 13q12.13-q12.2, and 20q11.21-q11.23 and the most frequent losses were at 17p13.1-p12, 8p23.2, and 118q11.2-q23. Four high-level amplifications at 8p11.23-p11.22, 18q21.1, 19q11-q12, and 20q11.21-q13.32 and homozygous deletions at 20p12.1 were discovered in Stage II CRC. Gains at 7q11.21-q22.1, 16p11.2, 17q23.3-q25.3, 19p13.3-p12, and 20p13-p11.1, and losses at 11q11-q12.1, 11p15.5-p15.1, 18p11.21, and 18q21.1-q23 were more commonly found in patients with PNI by frequency plot comparison together with detailed genomic analysis. It is also observed that gains at 8q11.1-q24.3, 9q13-q34.3, and 13q12.3-q13.1, and losses at 8p23.3-p12, 17p13.3-p11.2, and 21q22.12 occurred more frequently in patients without PNI. Further validation showed that the expression of FLT1, FBXW7, FGFR1, SLC20A2 and SERPINI1 was significantly up-regulated in the NPNI group compared to the PNI group. GO and pathway analysis revealed some genes enriched in specific pathways. CONCLUSION: These involved genomic changes in the PNI of stage II CRC may be useful to reveal the mechanisms underlying PNI and provide candidate biomarkers.

14.
Ying Yong Sheng Tai Xue Bao ; 23(8): 2129-34, 2012 Aug.
Artículo en Zh | MEDLINE | ID: mdl-23189689

RESUMEN

From January 2008 to January 2009, a field experiment was conducted to investigate the effects of simulated nitrogen (N) deposition (0, 5, 15, and 30 g N x m(-2) x a(-1)) on the soil enzyme activities in a Betula luminifera plantation in Rainy Area of West China. As compared with the control (0 g N x m(-2) x a(-1)), simulated N deposition stimulated the activities of soil hydrolases (beta-fructofuranosidase, cellulase, acid phosphatase, and urease) significantly, but depressed the activities of soil oxidases (polyphenol oxidase and peroxidase). These results suggested that the increased exogenous inorganic N could stimulate soil microbial activity and increase the demands of both B. luminifera and soil microbes for C and P, whereas the depress of soil polyphenol oxidase and peroxidase activities under N addition could inhibit the degradation of litter and promote its accumulation in soil, leading to the increase of soil C storage in the B. luminifera plantation ecosystem.


Asunto(s)
Betula/crecimiento & desarrollo , Hidrolasas/metabolismo , Nitrógeno/análisis , Oxidorreductasas/metabolismo , Suelo/química , Betula/química , Carbono/análisis , China , Simulación por Computador , Ecosistema , Peroxidasa/metabolismo , Hojas de la Planta/química , Lluvia/química
15.
Ying Yong Sheng Tai Xue Bao ; 22(4): 829-36, 2011 Apr.
Artículo en Zh | MEDLINE | ID: mdl-21774300

RESUMEN

From January 2008 to February 2009, a field experiment was conducted in Rainy Area of West China to understand the effects of nitrogen (N) deposition on the soil respiration in a Bambusa pervariabilis x Dendrocala mopsi plantation. Four treatments were installed, i. e., no N added (control), 5 g N m(-2) a(-1) (low-N), 15 g N m(-2) a(-1) (medium-N), and 30 g N m(-2) a(-1) (high-N), and soil respiration rate was determined by infra-red CO2 analyzer. In the plantation, soil respiration rate had an obvious seasonal change, with the maximum in July and the minimum in January. In control plot, the annual cumulative soil respiration was (389 +/- 34) g m(-2) a(-1). Soil respiration rate had significant positive exponential relationships with soil temperature at 10 cm depth and air temperature, and significant positive linear relationships with soil microbial biomass carbon (MBC) and nitrogen (MBN). Simulated N deposition promoted soil respiration significantly, with significant differences between the low- and medium-N and the control but no significant difference between high-N and the control. In control plot, surface soil (0-20 cm) MBC and MBN were 0.460 and 0.020 mg g(-1), respectively. In N-added plots, both the MBC and the MBN had significant increase. The fine root density in surface soil was 388 g m(-2), which was less affected by simulated N deposition. The soil respiration Q10 value calculated from soil temperature at 10 cm depth and air temperature was 2.66 and 1.87, respectively, and short-term N deposition had lesser effects on the Q10 value. The variation of soil respiration in the plantation was mainly controlled by temperature and soil microbial biomass, and simulated N deposition could increase the CO2 emission via increasing soil microbial biomass.


Asunto(s)
Bambusa/crecimiento & desarrollo , Dióxido de Carbono/metabolismo , Ecosistema , Nitrógeno/análisis , Suelo/análisis , Bambusa/metabolismo , China , Simulación por Computador , Contaminantes Ambientales/análisis , Transpiración de Plantas/fisiología , Agua/metabolismo
16.
Ying Yong Sheng Tai Xue Bao ; 21(7): 1649-55, 2010 Jul.
Artículo en Zh | MEDLINE | ID: mdl-20879519

RESUMEN

From December 2007 to November 2008, an in situ experiment was conducted to study the effects of simulated nitrogen deposition on the soil respiration in a Neosinocalamus affinis plantation in Rainy Area of West China. Four treatments were installed, i.e., 0 (CK), 50, 150, and 300 kg N x hm(-2) x a(-1), and soil respiration rate was measured by infrared gas analyzer. In the test plantation, soil respiration rate had a distinct seasonal fluctuation, with the highest (3.36 +/- 0.20 micromol x m(-2) x s(-1)) by the end of July and the lowest by the end of February (0.33 +/- 0.07 micromol x m(-2) x s(-1)). There was a significant exponential relationship (P<0.001) between soil respiration rate and soil temperature, and the temperature at 10 cm soil depth explained 91.6% of the seasonal change of soil respiration. However, less relationship was observed between soil respiration rate and soil moisture content (R2 = 0.0758). From June to November 2008, the contribution of root respiration to total soil respiration ranged from 46% to 59%. The annual release amount of CO2 in treatments 50, 150, and 300 kg x hm(-2) x a(-1) was 23.6% , 46.7%, and 50.5% lower than that in CK (2.17 x 10(4) kg x hm(-2)), and the Q10 value of soil respiration rate in treatments 0, 50, 150, and 300 kg x hm(-2) x a(-1) was 3.72, 3.51, 2.95, and 2.71, respectively.


Asunto(s)
Bambusa/crecimiento & desarrollo , Dióxido de Carbono/metabolismo , Contaminantes Ambientales/análisis , Nitrógeno/análisis , Suelo/análisis , China , Simulación por Computador , Ecosistema , Transpiración de Plantas/fisiología , Lluvia , Estaciones del Año , Agua/metabolismo
17.
Ying Yong Sheng Tai Xue Bao ; 20(11): 2588-93, 2009 Nov.
Artículo en Zh | MEDLINE | ID: mdl-20135987

RESUMEN

An in situ experiment was conducted to study the effects of simulated nitrogen deposition on the litter decomposition in Neosinocalamus affinis stands in rainy area of West China. Four treatments were installed, i.e., null N (CK, 0 kg x hm(-2) x a(-1)), low N (LN, 50 kg x hm(-2) x a(-1)), medium N (MN, 150 kg x hm(-2) x a(-1)), and high N (HN, 300 kg x hm(-2) x a(-1)). Among the litters, leaf had the highest decomposition rate, followed by sheath, and twig, with a remaining rate after decomposing for 15 months being 26.38%, 46.18%, and 54.54%, respectively (P < 0.01). Leaf litter decomposed faster during the first 2 months and the 7th-10th month, while the decomposition of sheath and twig was faster from the 5th to the 8th month. It took 2.573 years to decompose 95% of leaf litter mass, 1.686 years and 3.319 years shorter than that of sheath and twig, respectively. After 15 months decomposition of leaf litter, no significant differences were observed among different treatments. To decompose 95% of sheath litter needed 2.679-4.259 years, being the longest in CK and the shortest in treatment MN. After decomposing for 15 months, the decomposition rate of twig litter was in the order MN > HN > LN > CK, and significant difference existed between treatments MN and LN. Nitrogen deposition had obvious promotion effect on the litter decomposition in the N. affinis stands, but this effect decreased with increasing deposited N concentration and time extension.


Asunto(s)
Contaminantes Ambientales/análisis , Nitrógeno/análisis , Hojas de la Planta/metabolismo , Poaceae/metabolismo , Lluvia , China , Simulación por Computador , Árboles/metabolismo
18.
Ying Yong Sheng Tai Xue Bao ; 20(12): 2943-8, 2009 Dec.
Artículo en Zh | MEDLINE | ID: mdl-20353060

RESUMEN

From November 2007 to May 2009, a simulation test was conducted in a Pleioblastus amarus plantation in Rainy Area of West China to study the effects of nitrogen deposition on the activities of soil enzymes. Four treatments were installed, i.e., control (0 g N x m(-2) x a(-1)), low nitrogen (5 g N x m(-2) x a(-1)), medium nitrogen (15 g N x m(-2) x a(-1)), and high nitrogen (30 g N x m(-2) x a(-1)). Half year after N deposition, 0-20 cm soil samples were collected monthly, and the activities of peroxidase, polyphenol oxidase, cellulase, sucrase, urease, and acid phosphatase were determined. All test enzyme activities had apparent, seasonal variation, with the peak of cellulase, suerase, and acid phosphatase activities in spring, of urease activity in autumn, and of peroxidase and polyphenol oxidase activities in winter. Nitrogen deposition stimulated the activities of polyphenol oxidase, sucrase, urease, and acid phosphatase, inhibited cellulase activity, but had no significant effects on peroxidase activity. The test P. amurus plantation ecosystem was N-limited, and nitrogen deposition stimulated the decomposition of soil organic matter by microbe-enzyme system.


Asunto(s)
Nitrógeno/análisis , Peroxidasa/metabolismo , Poaceae/crecimiento & desarrollo , Suelo/análisis , Ureasa/metabolismo , Celulasa/metabolismo , China , Simulación por Computador , Ecosistema , Modelos Teóricos , Lluvia
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