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1.
Funct Integr Genomics ; 23(3): 257, 2023 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-37522982

RESUMEN

In recent years, the potassium voltage-gated channel subfamily D (KCND) channels, particularly KCND2 (also known as Kv4.2), have been suggested to play a role in a variety of cancers, but their role in breast cancer has not yet been revealed. We analyzed RNA sequencing data from The Cancer Genome Atlas database and the Genotype-Tissue Expression database to investigate the differential expression of KCND2 in breast cancer and normal breast tissue. In addition, we leveraged GO and KEGG analysis techniques to gain a better understanding of the potential functional enrichment of 500 genes related to KCND2. Our findings were validated using collected tissue samples and clinical data from hospitals showed that KCND2 is a crucial independent factor in the prognosis of breast cancer patients. The higher the expression of KCND2, the shorter the survival time of breast cancer patients. Colony formation assay confirmed that KCND2 promotes the proliferation of breast cancer cells, whereas transwell assay and wound healing assay verified that KCND2 promoted breast cancer invasion and migration. In addition, 5-Ethynyl-2'-deoxyuridine (EdU) and flow cytometry revealed that KCND2 affected the cycle changes of breast cancer cells and contributed to the G1/S phase transition of breast cancer cells. Overall, our study demonstrates that KCND2 holds a promising potential as a significant target for breast cancer diagnosis and therapy.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/genética , Pronóstico , Carcinogénesis , Proliferación Celular , Línea Celular Tumoral , Canales de Potasio Shal/genética , Canales de Potasio Shal/metabolismo
2.
Phys Rev Lett ; 131(10): 103002, 2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37739370

RESUMEN

We investigate the 2^{3}S_{1}-2^{3}P_{J} (J=0, 1, 2) transitions in ^{6}Li^{+} using the optical Ramsey technique and achieve the most precise values of the hyperfine splittings of the 2^{3}S_{1} and 2^{3}P_{J} states, with smallest uncertainty of about 10 kHz. The present results reduce the uncertainties of previous experiments by a factor of 5 for the 2^{3}S_{1} state and a factor of 50 for the 2^{3}P_{J} states, and are in better agreement with theoretical values. Combining our measured hyperfine intervals of the 2^{3}S_{1} state with the latest quantum electrodynamic (QED) calculations, the improved Zemach radius of the ^{6}Li nucleus is determined to be 2.44(2) fm, with the uncertainty entirely due to the uncalculated QED effects of order mα^{7}. The result is in sharp disagreement with the value 3.71(16) fm determined from simple models of the nuclear charge and magnetization distribution. We call for a more definitive nuclear physics value of the ^{6}Li Zemach radius.

3.
Appl Opt ; 60(21): 6097-6102, 2021 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-34613273

RESUMEN

Laser frequency stabilization plays an important role in high-precision spectroscopic measurements. Since high-accuracy commercial wavemeters became available, wavemeter-based frequency stabilization has found a broad application due to its convenience, flexibility, and wide applicability. However, such stabilization schemes frequently suffer from long-term drift, since the accuracy of the wavelength measurement of a wavemeter is affected by ambient temperature fluctuation. In this work, we demonstrate that such long-term drift can be suppressed by regularly calibrating the frequency of a wavemeter-locked laser utilizing an optical frequency comb, which has much better long-term stability. Under this dual-referenced locking scheme, the Allan deviation is reduced to 3.5 E-12 at 4000 s for a fiber laser operated at 548 nm, which when used in the optical Ramsey spectroscopic measurement of 7Li+, reduces the standard deviation by as much as 40%, compared to the case when only wavemeter locking is applied.

4.
J Nanosci Nanotechnol ; 19(6): 3420-3428, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30744769

RESUMEN

In this study, we describe a novel method for preparing Y2O3@CaO ceramic cores with anti-hydration performance and high-interface stability against interface reaction of Ti-6Al-4V alloys. The effect of Y2O3 coating on microstructure, mechanical, anti-hydration properties of ceramic cores and interface reaction with Ti-6Al-4V alloys was studied. The results show that the surface charge of Y2O3 and CaO are opposite at the pH value of 13, which might result in an electrostatic force and become the main driving force of Y2O3 particles absorb on the surface of CaO particles. The Y2O3 coating improved the anti-hydration properties of the CaO-based ceramic cores after sintering at 1450 °C. Meanwhile, the flexural strength improved from 11.2 to 18.8 MPa. At last, the interaction between the ceramic cores and Ti-6Al-4V metal were studied by centrifugal investment casting. Y2O3 coating can effectively reduce the interface reaction and the thickness of the interaction layer in the casting was less than 10 µm. The results suggest that the Y2O3@CaO ceramic with anti-hydration performance provide excellent mechanical and high-interface stability against interface reaction of Ti-6Al-4V alloys.

5.
BMC Ophthalmol ; 19(1): 269, 2019 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-31888567

RESUMEN

BACKGROUND: Intraventricular silicone oil is a relatively rare complication resulted from silicone oil tamponade to treat retinal detachment. It is occasionally reported in previous literature. To the best of our knowledge, the long-term longitudinal comparisons of silicone oil both in the brain and in the postoperative eyeball based on CT/MRI were lacking, and intraventricular silicone oil accumulation beside lesions has been reported rarely. CASE PRESENTATION: A 63-year-old male patient underwent an intraocular tamponade with silicone oil in June 2009. Eight CT examinations and 2 MRI examinations were acquired between 2011 and 2018.The changes of silicone oil in the brain in CT/MRI as below: Silicone oil initially migration to bilateral lateral ventricular anterior horn was found in November 2011, it was aslo found at right side of suprasellar cisterna, and there was no change in location 6 h later; Silicone oil at the anterior horn of right lateral ventricle disappeared but remained at left lateral ventricle and right side of suprasellar cisterna in July 2014, and there was no change in location in a short-term reexamination. It was found at the middle of left lateral ventricle (adjacent to the real cause) in march 2018, but disappeared 3 months later, while remained at anterior horn of left lateral ventricular and right side of suprasellar cisterna all the time. There was no change in location in the next 2 follow-up (September and October in 2018). The CT values of silicone oil distributed throughout the brain were dynamically changed with time. CONCLUSION: It is important to recognize intraventricular silicone oil in a particular location.More important is to discover "the real murderer", which is the main cause of symptoms in the vicinity of special location. Moreover, the migration of silicone oil between eyeball and brain may not be always in a single direction.


Asunto(s)
Encefalopatías/diagnóstico por imagen , Ventrículos Cerebrales/diagnóstico por imagen , Endotaponamiento , Migración de Cuerpo Extraño/diagnóstico por imagen , Desprendimiento de Retina/cirugía , Aceites de Silicona , Encefalopatías/etiología , Estudios de Seguimiento , Migración de Cuerpo Extraño/etiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
6.
Appl Microbiol Biotechnol ; 101(9): 3769-3780, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28083652

RESUMEN

Eicosapentaenoic acid (EPA) is an essential polyunsaturated fatty acid for human beings. At present, the production of commercially available long-chain polyunsaturated fatty acids, mainly from wild-caught ocean fish, is struggling to meet the increasing demand for EPA. Production of EPA by microorganisms may be an alternative, effective and economical method. The oleaginous fungus Pythium splendens RBB-5 is a potential source of EPA, and thanks to the simple culture conditions required, high yields can be achieved in a facile manner. In the study, lipid metabolomics was performed in an attempt to enhance EPA biosynthesis in Pythium splendens. Synthetic, metabolic regulation and gene expression analyses were conducted to clarify the mechanism of EPA biosynthesis, and guide optimization of EPA production. The results showed that the Δ6 desaturase pathway is the main EPA biosynthetic route in this organism, and ∆6, ∆12 and Δ17 desaturases are the rate-limiting enzymes. All the three desaturase genes were separately introduced into the parent strain to increase the flow of fatty acids into the Δ6 desaturase pathway. Enhanced expression of these key enzymes, in combination with improved regulation of metabolism, resulted in a maximum yield of 1.43 g/L in the D12 transgenic strain, which represents a tenfold increase over the parent strain before optimization. This is the higher EPA production yield yet reported for a microbial system. Our findings may allow the production of EPA at an industrial scale, and the strategy employed could be used to increase the production of EPA or other lipids in oleaginous microorganisms.


Asunto(s)
Vías Biosintéticas/genética , Ácido Eicosapentaenoico/metabolismo , Ácido Graso Desaturasas/metabolismo , Regulación Fúngica de la Expresión Génica , Pythium/metabolismo , Ácido Graso Desaturasas/genética , Pythium/genética
7.
Biotechnol Lett ; 39(6): 883-888, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28247196

RESUMEN

OBJECTIVES: To clone and express a diacylglycerol acyltransferase (DGAT) gene from Mortierella alpina in Saccharomyces cerevisiae and characterize oil production and fatty acid composition of the resulting recombinant RESULTS: A new, full-length cDNA, putatively encoding a DGAT, was cloned from M. alpina. We subsequently cloned the gene, except the transmembrane-encoding region, termed MaDGAT, its molecular mass was 31.3 kDa. MaDGAT shares 75% identity with a DGAT from Mortierella verticillata NRRL 6337. A recombinant vector expressing MaDGAT, pYES2-DGAT, was constructed and transformed into S. cerevisiae H1246, a neutral, lipid-deficient quadruple mutant. TLC analysis showed that the recombinant vector restored triacylglycerol biosynthesis and its content in the recombinant strain was 3.9%. CONCLUSION: MaDGAT is a novel DGAT gene and could increase TAG biosynthesis in M. alpina or other filamentous fungi, thereby promoting the synthesis of polyunsaturated fatty acids.


Asunto(s)
Diacilglicerol O-Acetiltransferasa/metabolismo , Proteínas Fúngicas/metabolismo , Mortierella/enzimología , Clonación Molecular , Diacilglicerol O-Acetiltransferasa/química , Diacilglicerol O-Acetiltransferasa/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Gotas Lipídicas/química , Gotas Lipídicas/metabolismo , Mortierella/genética , Filogenia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Triglicéridos/análisis , Triglicéridos/metabolismo
9.
Bioprocess Biosyst Eng ; 39(2): 315-21, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26658812

RESUMEN

Schizochytrium is a marine microalga that requires high concentrations of sea salt for growth, although problems arise with significant amounts of chloride ions in the culture medium, which corrodes the fermenters. In this work, we evaluated that cell growth and docosahexaenoic acid (DHA) production can be improved when using 1 % (w/v) sodium sulfate instead of 2 % (w/v) sea salt in the culture medium for Schizochytrium sp. S056. In practice, the use of sodium sulfate as the sodium salt led to chloride ion levels in the medium that can be completely removed, thus avoiding fermenter corrosion during Schizochytrium sp. S056 growth, reducing cost and increasing DHA production, and simplifying the disposal of fermentation wastewater. Additionally, we demonstrated that the osmolality of growth media did not play a crucial role in the production of DHA. These findings may be significantly important to companies involved in production of PUFAs by marine microbes.


Asunto(s)
Ácidos Docosahexaenoicos/biosíntesis , Microalgas/crecimiento & desarrollo , Cloruro de Sodio/farmacología , Estramenopilos/crecimiento & desarrollo , Sulfatos/farmacología
10.
Water Res ; 251: 121105, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38184913

RESUMEN

Microorganisms in wetland groundwater play an essential role in driving global biogeochemical cycles. However, largely due to the dynamics of spatiotemporal surface water-groundwater interaction, the spatiotemporal successions of biogeochemical cycling in wetland groundwater remain poorly delineated. Herein, we investigated the seasonal coevolution of hydrogeochemical variables and microbial functional genes involved in nitrogen, carbon, sulfur, iron, and arsenic cycling in groundwater within a typical wetland, located in Poyang Lake Plain, China. During the dry season, the microbial potentials for dissimilatory nitrate reduction to ammonium and ammonification were dominant, whereas the higher potentials for nitrogen fixation, denitrification, methane metabolism, and carbon fixation were identified in the wet season. A likely biogeochemical hotspot was identified in the area located in the low permeable aquifer near the lake, characterized by reducing conditions and elevated levels of Fe2+ (6.65-17.1 mg/L), NH4+ (0.57-3.98 mg/L), total organic carbon (1.02-1.99 mg/L), and functional genes. In contrast to dry season, higher dissimilarities of functional gene distribution were observed in the wet season. Multivariable statistics further indicated that the connection between the functional gene compositions and hydrogeochemical variables becomes less pronounced as the seasons transition from dry to wet. Despite this transition, Fe2+ remained the dominant driving force on gene distribution during both seasons. Gene-based co-occurrence network displayed reduced interconnectivity among coupled C-N-Fe-S cycles from the dry to the wet season, underpinning a less complex and more destabilizing occurrence pattern. The rising groundwater level may have contributed to a reduction in the stability of functional microbial communities, consequently impacting ecological functions. Our findings shed light on microbial-driven seasonal biogeochemical cycling in wetland groundwater.


Asunto(s)
Agua Subterránea , Microbiota , Contaminantes Químicos del Agua , Humedales , Estaciones del Año , Agua Subterránea/química , Carbono/metabolismo , Contaminantes Químicos del Agua/análisis
11.
Biotechnol Lett ; 35(3): 431-8, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23247564

RESUMEN

A new full-length cDNA (PsD6) putatively encoding a ∆(6)-desaturase was cloned from the eicosapentaenoic acid-producing fungus Pythium splendens RBB-5. PsD6 contained an open reading frame of 1380 bp encoding a protein of 459 amino acids. The deduced amino acid sequence showed high similarity to those of other ∆(6)-desaturases. A recombinant vector expressing PsD6 (pPIC3.5K-D6) was constructed and transformed into Pichia pastoris GS115. The heterologous expressed PsD6 in P. pastoris desaturated linoleic acid to γ-linolenic acid but not desaturated α-linolenic acid to stearidonic acid. The results indicated that PsD6 was a fatty acid ∆(6)-desaturase and it had a substrate specificity for linoleic acid.


Asunto(s)
Ácido Eicosapentaenoico/metabolismo , Linoleoil-CoA Desaturasa/genética , Linoleoil-CoA Desaturasa/metabolismo , Pythium/enzimología , Pythium/metabolismo , Biotransformación , Clonación Molecular , ADN de Hongos/química , ADN de Hongos/genética , Expresión Génica , Vectores Genéticos , Ácidos Linoleicos/metabolismo , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Pichia/genética , Pythium/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
12.
Sci Total Environ ; 868: 161728, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-36681342

RESUMEN

Dual nitrate stable isotopes combined with end-member mixing models are typically used to identify nitrate sources in fields of geochemistry and environmental science, which helps to quantitively depict the geochemical behaviors of nitrate and accurately control the sources of nitrate pollution in waters. Recently, various models with different computation principles, working efficiency, and operation difficulty have been developed and applied in the source apportionment of nitrate. In this paper, an end-member mixing model tool on Excel™, namely EMMTE, has been written with Visual Basic for Application (VBA) and built into a macro-enabled Excel™ spreadsheet. Monte Carlo simulation and constraint relative deviation between the observed and the predicted values were included in the working algorithm to solve the mass balance equation. After comparison with the internationally recognized Bayesian framework (mixing stable isotope analysis in R, MixSIAR) in different cases (three practical cases and one virtual case), the preliminary results showed that the contribution of various sources to groundwater nitrate calculated by EMMTE was highly consistent with that by MixSIAR and the performance of EMMTE seemed to be as good as that of MixSIAR as indicated by the higher goodness-of-prediction, lower root-mean-square error, and lower relative deviation. Therefore, EMMTE is applicable in the source apportionment of groundwater nitrate, and might also be extended to other water bodies and mixtures. It provides a simple, feasible, and user-friendly for front-line workers without experience with MixSIAR to quantitively source apportionment of nitrate in waters.

13.
Sci Total Environ ; 874: 162524, 2023 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-36868285

RESUMEN

Anthropogenic nitrogen (N) input has led to elevated levels of nitrate nitrogen (NO3--N) in the groundwater. However, insights into the responses of the microbial community and its N metabolic functionality to elevated NO3--N in suburban groundwater are still limited. Here, we explored the microbial taxonomy, N metabolic attributes, and their responses to NO3--N pollution in groundwaters from Chaobai River catchment (CR) and Huai River catchment (HR) in Beijing, China. Results showed that average NO3--N and NH4+-N concentrations in CR groundwater were 1.7 and 3.0 folds of those in HR. NO3--N was the dominant nitrogen specie both in HR and CR groundwater (over 80 %). Significantly different structures and compositions of the microbial communities and N cycling gene profiles were found between CR groundwater and HR groundwater (p < 0.05), with CR groundwater harboring significantly lower microbial richness and abundance of N metabolic genes. However, denitrification was the dominant microbial N cycling process in both CR and HR groundwater. Strong associations among NO3--N, NH4+-N, microbial taxonomic, and N functional attributes were found (p < 0.05), suggesting denitrifiers and Candidatus_Brocadia might serve as potential featured biomarkers for the elevated NO3--N and NH4+-N concentration in groundwater. Path analysis further revealed the significant effect of NO3--N on the overall microbial N functionality and microbial denitrification (p < 0.05). Collectively, our results provide field evidence that elevated levels of NO3--N and NH4+-N under different hydrogeologic conditions had a significant effect on the microbial taxonomic and N functional attributes in groundwater, with potential implications for improving sustainable N management and risk assessment of groundwater.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Nitrógeno/análisis , Nitratos/análisis , Desnitrificación , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Agua Subterránea/química , China
14.
Sci Total Environ ; 863: 160885, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36526179

RESUMEN

The composition and main sources of dissolved organic matter (DOM) in groundwater may change significantly under long-term anthropogenic groundwater recharge (AGR); however, the impact of AGR on quantitative sources of groundwater DOM has seldom been reported. This study evaluated the applicability of optical indices combined with mixing stable isotope analysis in R (MixSIAR) in end-member mixing analysis (EMMA) of groundwater DOM. Fluorescent indices, including C1%, C2%, and C3%, were more sensitive to AGR than other absorbance indices, as indicated by the significant difference between the dominant area of artificial groundwater recharged by surface water and the dominant area of natural groundwater recharged by atmospheric precipitation (NGRP). BIX-C1% was selected as the optimal dual index after the screening protocol of groundwater DOM for EMMA. Our results showed that DOM in the aquifer was mainly subject to autochthonous DOM and the contribution of background groundwater to AGRSW and NGRP groundwater accounted for 36.15% ± 32.41% and 55.46% ± 37.17% (p < 0.05), respectively. Therefore, AGR significantly changed the native DOM in the groundwater. In allochthonous sources of DOM, sewage and surface water contributed 29.54% ± 24.87% and 21.32% ± 28.08%, and 24.79% ± 15.56% and 15.21% ± 14.20% to AGRSW and NGRP groundwater, respectively. The contribution of surface water to AGRSW groundwater was significantly higher than that to NGRP groundwater (p < 0.05), indicating that AGR introduced significantly more DOM from surface water to groundwater. This study provides novel insights into the quantitative source apportionment of DOM in groundwater under long-term AGR, which will facilitate the environmental risk assessment of present AGR measures and the sustainable management of clean water.

15.
Wei Sheng Wu Xue Bao ; 52(5): 588-93, 2012 May 04.
Artículo en Zh | MEDLINE | ID: mdl-22803344

RESUMEN

OBJECTIVE: We constructed a recombinant Escherichia coli strain for butanol production by cloning the cDNA sequence of the key butanol synthetic pathway genes from Clostridium acetobutylicum ATCC824. METHODS: We amplified the genes of thil, adhE2 and BCS operon by PCR with C. acetobutylicum ATCC824 genome as a template. We constructed the recombinant strain E. coli pBAT (BCS operon-adhE2-thil/pTrc99a/MG1655). We used 0.1 mmol/l Isopropyl beta-D-thiogalactopyranoside (IPTG) to induce the recombinant E. coli pBAT for 5 h for recombinant protein expression. We measured acetyl-CoA acetyltransferase (THL), beta-hydroxybutyryl-CoA dehydrogenase (HBD), 3-hydroxybutyryl-CoA dehydratase (CRT), butyryl-CoA dehydrogenase (BCD) and butyraldehyde dehydrogenase (BYDH)/butanol dehydrogenase (BDH) activities in E. coli MG1655 and E. coli pBAT. The fermentation of E. coli pBAT was done in flask in aerobic, micro-aerobic and anaerobic mode separately. RESULTS: In the recombinant E. coli pBAT, THL activity was 0.160 U/mg protein, about 30 times higher than that of E. coli MG1655. HBD activity was 5 times higher than that of E. coli MG1655. CRT activity was 1.53 U/mg protein whereas not detectable in E. coli MG1655. BCD activity was about 32 times higher than that of E. coli MG1655. In addition, the results show that n-butanol could be produced under anaerobic and micro-aerobic conditions. The maximum n-buntanol concentration of 84 mg/l was detected in cultivation broth. CONCLUSION: The key genes of butanol synthetic pathway were expressed in E. coli and the recombinant strains would offer an alternative strategy for butanol biosynthesis.


Asunto(s)
1-Butanol/metabolismo , Clostridium acetobutylicum/enzimología , Clostridium acetobutylicum/genética , Proteínas de Escherichia coli/biosíntesis , Proteínas de Escherichia coli/genética , Escherichia coli/enzimología , Escherichia coli/genética , Clonación Molecular , Clostridium acetobutylicum/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Fermentación , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
16.
Sci Total Environ ; 839: 156187, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-35618121

RESUMEN

Although anthropogenic groundwater recharge (AGR) can either elevate or decline the concentration of nitrate in the phreatic aquifer with high hydraulic conductivity, the long-term impact of AGR on nitrate dynamics in the phreatic aquifer and its reason is seldom disclosed. In this study, the hydrogen and oxygen stable isotopes (δ2H-H2O and δ18O-H2O) combined with mixing stable isotope analysis in R (MixSIAR) were used to group the study area into the dominant area of AGR by surface water (AGRSW) and the dominant area of natural groundwater recharged by precipitation (NGRP). Hydrochemical parameters and multiple stable isotopes, including δ2H-H2O, δ18O-H2O, δ15N-NO3-, δ18O-NO3-, and δ13C-DIC, were applied to explore the impacts of AGR on the concentration, biogeochemical processes, and main sources of nitrate. The results showed that AGR by surface water with low nitrate content can reduce nitrate pollution in groundwater. The characteristic of δ18O-NO3- value revealed that nitrification was the primary biogeochemical process of nitrogen in groundwater. AGR may enhance nitrification as indicated by the δ18O-NO3- value closer to the nitrification theoretical line. Dual nitrate stable isotopes and MixSIAR revealed that chemical fertilizer (CF), soil nitrogen (SN), and surface water (SW) contributed 10.88%, 49.92%, and 27.64% to nitrate in AGRSW groundwater, respectively, which was significantly different from their contributions to NGRP groundwater (p < 0.05). Notably, AGR significantly increased the contribution of SW but decreased the contribution of CF and SN in groundwater. This study provided a basis and guidance for groundwater quality assessment and pollution control in the phreatic aquifer with high hydraulic conductivity.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Monitoreo del Ambiente/métodos , Fertilizantes/análisis , Nitratos/análisis , Nitrógeno/análisis , Isótopos de Nitrógeno/análisis , Óxidos de Nitrógeno/análisis , Isótopos de Oxígeno/análisis , Suelo/química , Agua/análisis , Contaminantes Químicos del Agua/análisis
17.
Curr Microbiol ; 62(4): 1315-20, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21221971

RESUMEN

In this study, an Agrobacteriurn tumefaciens-mediated transformation (ATMT) protocol was successfully developed for the genetic transformation of a taxol-producing fungus, Cladosporium cladosporioides MD2, and the co-cultivation conditions affecting the transformation efficiency were optimized. The optimal transformation conditions were that 1 ml of C. cladosporioides MD2 spore suspension (10(8) spores/ml) was mixed with an equal volume of A. tumefaciens cultures, which contained 400 µl of A. tumefaciens LBA4404 (OD(660) ≈ 0.6) and 600 µl LB medium that were used to make up difference in volume, and the mix cultures were supplemented with 300 µM acetosyringone (AS) and co-cultivated at 26°C and 50 rpm for 48 h. Stable transformants were obtained through analysis of the mitotic stability of inserted T-DNA and the presence of hygromycin resistance gene (hpt II). This study laid a fine groundwork for development of transgenic C. cladosporioides MD2 strains.


Asunto(s)
Agrobacterium tumefaciens/genética , Cladosporium/genética , Cladosporium/metabolismo , Paclitaxel/metabolismo , Transformación Genética , ADN Bacteriano/genética , Vectores Genéticos/genética
18.
Z Naturforsch C J Biosci ; 66(3-4): 173-81, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21630592

RESUMEN

The response surface methodology (RSM) involving central composite design (CCD) was employed to optimize the fermentation medium for the cell growth and schizophllan production by Schizophyllum commune CGMCC 5.113 in submerged culture at pH 6.5 and 26 degrees C. The four variables involved in this study were glucose, yeast extract, ammonium nitrate, and magnesium sulfate. The statistical analysis of the results showed that, in the range studied, glucose and yeast extract had a highly significant effect on schizophyllan production. The optimal medium for schizophyllan production calculated from the regression model of RSM was as follows: glucose, 18 g/l; yeast extract, 0.5 g/l; NH4NO3, 0.48 g/l; and MgSO4, 0.05 g/l, with a predicted maximum schizophyllan production of 11.74 g/l. These predicted values were experimentally validated. The excellent correlation between predicted and measured values justifies the validity of the response model. The results of bioreactor fermentation also show that the optimized medium enhanced schizophyllan production (12.80 g/l) by S. commune in a 5-1 fermenter.


Asunto(s)
Schizophyllum/metabolismo , Sizofirano/biosíntesis , Biomasa , Reactores Biológicos , Medios de Cultivo , Fermentación
19.
Z Naturforsch C J Biosci ; 66(7-8): 429-33, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21950169

RESUMEN

A method was developed for rapid screening and isolation of eicosapentaenoic acid (EPA)-producing soil fungi through polymerase chain reaction (PCR) amplification. Genes coding for delta6 fatty acid desaturase and delta5 fatty acid desaturase were used as molecular markers for screening these EPA-producing fungi from soil. Three out of 65 soil fungi gave positive results through PCR amplification. Two out of these three strains were found to produce EPA when they had grown in 80 ml potato/dextrose liquid medium at (25 +/- 1) degrees C for 144 h. The EPA yields were 215.81 mg 1(-1) and 263.80 mg 1(-1), respectively. The other positive strain was detected to produce arachidonic acid (AA). This study indicates that molecular detection of genes encoding delta6 and delta5 desaturases is an efficient method for primary screening of EPA- or its related polyunsaturated fatty acids (PuFAs)-producing fungi, which can improve the screening efficiency prominently.


Asunto(s)
Ácido Eicosapentaenoico/biosíntesis , Hongos/metabolismo , Reacción en Cadena de la Polimerasa/métodos , Microbiología del Suelo , Secuencia de Bases , Cartilla de ADN , Hongos/genética , Hongos/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas
20.
Cancer Manag Res ; 13: 1853-1860, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33658849

RESUMEN

OBJECTIVE: To assess the clinical value of contrast-enhanced ultrasound (CEUS) technology in predicting axillary lymph nodes status before surgery, and to explore the feasibility of sentinel lymph nodes (SLNs) localization guided by CEUS combined with 125I implantation for breast cancer. METHODS: From August 2017 to February 2019, 115 patients were included in this prospective study. Before surgery, a microbubble (SonoVue) was injected intradermally next to the areola. The enhancement patterns of SLNs were recorded and 125I seeds were deployed into the enhanced nodes. Then, all patients underwent standard sentinel lymph node biopsy (SLNB) and all 125I seeds were found out guided by a gamma detector in surgery. The localization was considered successful if 125I seeds were implanted in/beside the nodes. RESULTS: SLNs in 103 cases were successfully identified, the success rate was 89.6% (103/115), 118 SLNs were detected in total. 125I seeds were deployed successfully in 99 cases, and all of the 125I-labeled SLNs were then successfully detected by combined method (radionuclides and blue dye). The accuracy of 125I seeds localization was 96.1% (99/103). Based on the enhancement patterns recorded, 34 cases were predicted to have SLNs metastasis (metastasis in 27 cases and no metastasis in 7 cases confirmed by postoperative pathology) and 65 cases were predicted to have no SLNs metastasis (metastasis in 5 cases and no metastasis in 60 cases by pathology). The positive predictive value and negtive predictive value of CEUS in assessing axillary status were 79.4% (27/34) and 92.3% (60/65), respectively. The axillary metastasis rate in CEUS combined with 125I seeds localization was 27.3% (27/99), while the metastasis rate in the combined method of SLNB was 32.3% (32/99). The sensitivity of 125I seeds localization was 84.4% (27/32), the false-negative rate was 15.6% (5/32), and the consistency evaluation was excellent (Kappa value=0.880, P<0.001). CONCLUSION: CEUS combined with 125I seeds implantation can locate SLNs accurately and has excellent consistency with the combined method. The enhancement patterns can provide helpful predicting information of axillary status preoperatively. However, more studies are needed to be carried out to verify our outcomes and explore the feasibility of applying CEUS technology in clinical work.

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