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1.
Neuropsychiatr Dis Treat ; 20: 69-81, 2024.
Article in English | MEDLINE | ID: mdl-38249525

ABSTRACT

Purpose: The Coronavirus disease 2019 (COVID-19) remains a global public health concern. Many people have been forced to change their lifestyles, which has led to psychological and sleep problem. This study aims to investigate the psychological health problems and factors among patients in the Fangcang Shelter Hospital (FSH) during the COVID-19 pandemic. Patients and Methods: A Cross-Sectional survey was conducted to investigate the sleep, anxiety, depression and stress disorders of 2628 asymptomatic and mild patients treated in FSH of Zhengzhou, Henan Province, from 30 October to 6 December 2022, by scanning a WeChat two-dimensional code. Sociodemographic data and influencing factors in FSH were collected, Insomnia Severity Index (ISI), 9-item Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Impact of Event Scale-Revised (IES-R) were administered. Descriptive statistics, t-tests or analysis of variance, Spearman or Pearson correlation analysis, and multivariate regression analysis were used to explore the relationships between different variables and their impact on psychological health indicators. Results: The proportions of patients with insomnia, depressive disorder, anxiety, and stress disorders were 33.49%, 35.80%, 31.74%, and 43.57%, respectively. Spearman correlation analysis demonstrated that factors such as gender, higher education level, positive nucleic acid test results, longer illness duration, underlying diseases, and extended electronic device use were associated with elevated psychological distress scores. Notably, within FSH, extended exposure to light, a noisy environment, and sleep schedule management significantly impacted the prevalence of insomnia, depression, anxiety, and stress disorders (p<0.01). Multivariable binary logistic regression analysis identified higher education level, light exposure, noisy environment, sleep management, and electronic device usage as the primary risk factors for psychological distress. Conclusion: Patients in FSH face psychological distress influenced by sociodemographic factors, environment, and lifestyle, highlighting the need for integrated psychological support in healthcare, particularly in temporary medical facilities during crises.

2.
Mar Pollut Bull ; 167: 112336, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33865038

ABSTRACT

To improve our knowledge of the factors regulating Phaeocystis globosa colony formation, the effects of the diatom Ditylum brightwellii on P. globosa colony development were investigated using co-culture and cell-free filtrate approaches. The co-culture experiments showed the moderate abundance of D. brightwellii significantly increased the number and size of colonies, whereas a dramatically decreased effect from high abundance of D. brightwellii. The low abundance of D. brightwellii promoted early formation of P. globosa colony. The cell-free filtrate experiments indicated that culture-filtrates from the exponential phase of D. brightwellii were stimulatory for P. globosa colony formation with more and bigger colonies formed, whereas an inhibitory effect from its senescence phase filtrates. D. brightwellii may influence P. globosa colony formation by regulating the growth of P. globosa solitary cells. Our results suggest that D. brightwellii influences P. globosa colony development, but its effects vary according to its concentrations and growth phases.


Subject(s)
Diatoms , Haptophyta , Nutrients
3.
Bioresour Technol ; 289: 121681, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31247531

ABSTRACT

This study was conducted to evaluate the potential of the marine diatom Phaeodactylum tricornutum in nutrient removal coupled with biodiesel production using different ratios of mixed municipal wastewater (MW) and seawater (SW) as the growth medium. The results indicated that P. tricornutum exhibited high nutrient removal efficiency with the ratios of MW: SW = 1:1 and MW: SW = 2:1, e.g. 87.7-89.9% for chemical oxygen demand (COD), 82.2-86.7% for total nitrogen (TN), 96.0-97.0% for total phosphorus, and 76.9-84.2% for ammonium (NH3-N). Significantly higher biomass and lipid productivity were obtained with aeration. The highest lipid productivity of P. tricornutum was 54.76 mg/L/day, which was obtained with a two-step cultivation using the ratio of MW: SW = 1:1 by diluting half of the mixture and bubbling with 5% CO2 during the second step. These results suggested that the marine diatom P. tricornutum exhibited great potential for using mixed wastewater for wastewater treatment and biodiesel production.


Subject(s)
Diatoms/metabolism , Lipids/biosynthesis , Seawater/chemistry , Wastewater/chemistry , Ammonium Compounds/analysis , Biofuels , Biological Oxygen Demand Analysis , Biomass , Culture Media , Nitrogen/analysis , Phosphorus/analysis
4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 26(6): 1731-1737, 2018 Dec.
Article in Chinese | MEDLINE | ID: mdl-30501712

ABSTRACT

OBJECTIVE: To explore the relationship between HLA-A, -B, -C, -DRB1, -DQB1 gene polymorphism and aplastic anemia (AA)of 65 cases in Northern China. METHODS: The high resolution genotyping of HLA-A, -B, -C, -DRB1, -DQB1 alleles in 65 AA patients and 772 healthy controls was performed with polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO), the relationship between HLA-A, -B, -C, -DRB1, -DQB1 gene polymorphism and aplastic anemia was analyzed by Pearson Chi-square,Continuity Correction, Two-sided Fisher's Exact Test and Odds Ratio. RESULTS: The HLA-B*1302(10% vs 4.21%), B*3501(7.69% vs 3.89%), DRB1* 0701(10% vs 4.73%), DRB1*0901(19.23% vs 7.58%), DQB1*0202(9.23% vs 3.76%) gene frequency in AA patients was higher than those in health controls, the difference was statistically significant (P<0.05), the χ2 were 9.049, 4.336, 6.838, 20.974 and 8.968, OR ratio was 2.528, 2.061, 2.239, 2.904 and 2.605. However, the HLA-A*3303(1.54% vs 6.93%), DQB1*0302(1.54% vs 6.02%) gene frequency in AA patients was lower than those in healthy controls, the difference was statistically significant (P<0.05), the χ2 was 5.726 and 4.505, the OR ratio were 0.210 and 0.244. CONCLUSION: The polymorphism of HLA-A, -B, -DRB1, -DQB1 alleles is associate with AA in these patient cases, the HLA-B*1302, HLA-B*3501, HLA-DRB1*0701, HLA-DRB1*0901 and HLA-DQB1*0202 may be sensitive genes to AA, while the HLA-A*3303 and HLA-DQB1*0302 may be protective genes on AA.


Subject(s)
Anemia, Aplastic , HLA Antigens/genetics , Polymorphism, Genetic , Alleles , Anemia, Aplastic/genetics , China , Gene Frequency , Genetic Predisposition to Disease , Humans
5.
Poult Sci ; 97(10): 3429-3434, 2018 Oct 01.
Article in English | MEDLINE | ID: mdl-29889282

ABSTRACT

Uncharacteristically large spreading area on a flat surface of broken egg negatively affects egg quality assessment and reduces eggs' economic value. In this study, we investigated the heredity of the egg content spreading area as well as the relationships between the egg content spreading area and egg quality traits and properties. We measured the total egg content spreading area (TECA), outer thin albumen area (OTAA), inner thick albumen area (ITAA), yolk area (YA), and egg quality traits for 1414 newly laid eggs from 487 27-wk-old White Leghorn pure line pullets. The genetic parameters of egg content spreading areas were estimated. The phenotypic and genetic correlations between egg content spreading area and egg quality traits were analyzed. The differences in the properties of eggs with similar egg weight but markedly different TECA were also analyzed. The heritability estimates for TECA, OTAA, ITAA, and YA were low to moderate, with values of 0.214, 0.176, 0.340, and 0.280, respectively. Egg weight was related to TECA with a phenotypic correlation of 0.450 (P < 0.01) and a genetic correlation of 0.349. A high genetic correlation (-0.731) was found between TECA and Haugh unit. In eggs with larger TECA, the weight and total solid content of outer thin albumen (OTA) and moisture content of inner thick albumen (ITA) were significantly higher, whereas the weight and total solid content of ITA was markedly lower, but no differences (P > 0.05) were found in the pH of OTA and ITA, moisture content of OTA, as well as the eggshell strength, thickness, and non-destruction and fracture deformation between eggs with similar egg weight but markedly different TECA. These results suggest that the egg content spreading area can be regulated via the direct selection strategy or indirect selection of the ratio of OTA to ITA in the breeding program.


Subject(s)
Chickens/physiology , Eggs/analysis , Ovum/physiology , Animals , Chickens/genetics , Heredity
6.
Bioprocess Biosyst Eng ; 41(8): 1213-1224, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29789928

ABSTRACT

Microalgae are considered as attractive feedstocks for biofuel production nowadays because of their high lipid contents and easy cultivation. In the present study, two diatoms, Thalassiosira weissflogii and Chaetoceros muelleri, were cultured under various nutrient-limitation conditions to explore their comprehensive lipid accumulation profiles for further commercialization. In T. weissflogii, the highest neutral lipid accumulation and highest lipid productivity (14.28 mg L-1 day-1) were both recorded under P-limitation. In C. muelleri, the highest lipid content (35.03% of dry cell weight), highest neutral lipid accumulation, and highest lipid productivity (29.07 mg L-1 day-1) were all recorded under N-limitation. Besides, the predominant fatty acids of T. weissflogii and C. muelleri were myristic acid (C14:0), palmitic acid (C16:0), and palmitoleic acid (C16:1), with the amounts of 58.4-74.4 and 74.1-87.7% of the total fatty acids, respectively. Moreover, nutrient limitations led to a lower proportion of polyunsaturated fatty acids (PUFA) than that of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) in both species. The ratios of (SFA + MUFA) to PUFA were from 1.65 to 3.01 in T. weissflogii, and up to 3.61 to 8.59 in C. muelleri. Our results suggested the feasibility of C. muelleri as biodiesel feedstock due to its more suitable fatty acid composition and higher lipid productivity compared to T. weissflogii.


Subject(s)
Diatoms/growth & development , Fatty Acids/biosynthesis , Stress, Physiological , Species Specificity
7.
PLoS One ; 12(9): e0184849, 2017.
Article in English | MEDLINE | ID: mdl-28910417

ABSTRACT

Diatoms are important components of marine ecosystems and contribute greatly to the world's primary production. Despite their important roles in ecosystems, the molecular basis of how diatoms cope with oxidative stress caused by nutrient fluctuations remains largely unknown. Here, an isobaric tags for relative and absolute quantitation (iTRAQ) proteomic method was coupled with a series of physiological and biochemical techniques to explore oxidative stress- and cell fate decision-related cellular and metabolic responses of the diatom Thalassiosira pseudonana to nitrate (N) and inorganic phosphate (P) stresses. A total of 1151 proteins were detected; 122 and 56 were significantly differentially expressed from control under N- and P-limited conditions, respectively. In N-limited cells, responsive proteins were related to reactive oxygen species (ROS) accumulation, oxidative stress responses and cell death, corresponding to a significant decrease in photosynthetic efficiency, marked intracellular ROS accumulation, and caspase-mediated programmed cell death activation. None of these responses were identified in P-limited cells; however, a significant up-regulation of alkaline phosphatase proteins was observed, which could be the major contributor for P-limited cells to cope with ambient P deficiency. These findings demonstrate that fundamentally different metabolic responses and cellular regulations are employed by the diatom in response to different nutrient stresses and to keep the cells viable.


Subject(s)
Diatoms/growth & development , Nitrates/metabolism , Phosphates/metabolism , Proteomics/methods , Aquatic Organisms , Diatoms/genetics , Diatoms/metabolism , Gene Expression Regulation , Oxidative Stress , Photosynthesis , Reactive Oxygen Species/metabolism , Stress, Physiological
8.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 25(3): 885-889, 2017 Jun.
Article in Chinese | MEDLINE | ID: mdl-28641654

ABSTRACT

OBJECTIVE: To investigate the efficacy and clinical safety of posaconazoleon primary antifungal prophylaxis against invasive fungal disease (IFD) in patients with stem cell transplantation. METHODS: At the start from preconditioning regimen, 45 patients without IFD were administered with posaconazoleon until neutrophils greater than 0.5×109/L, 35 patients treated with micafungin were enrolled in control group. The incidence, risk factors of IFD and side effects of medicines were evaluated. RESULTS: Of the total 80 patients, 13(16%) had IFD within 100 days after allo-HSCT. The overall survival was significantly different between patients with or without IFD by Kaplan-Meier survival curve analysis (P<0.05). Out of the 45 cases in posaconazoleon group, IFD occurred in 4 cases (9%). In contrast, the incidence of IFD in control group was 26%(9 out of 35) (P<0.05). The risk factors of IFD and side effects were not significantly different between 2 groups(P>0.05). CONCLUSION: The primary prevention efficancy of IFD by posaconazoleon after allo-HSCT is much better than that of micafungin with well tolerability and satisfactory efficacy.


Subject(s)
Antifungal Agents/therapeutic use , Hematopoietic Stem Cell Transplantation , Mycoses/prevention & control , Triazoles/therapeutic use , Humans , Incidence , Stem Cell Transplantation
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 24(6): 1817-1823, 2016 Dec.
Article in Chinese | MEDLINE | ID: mdl-28024500

ABSTRACT

OBJECTIVE: To analyse the feasibility and compare differences between hematopoietic reconstitution and prognosis of patients with severe aplastic anemia(SAA) after matched sibling donor (MSD) or haploidentical family donor (HFD) hematopoietic stem cell transplantation (HSCT) using the modified FC/ATG conditioning. METHODS: The clinical data of 56 patients with SAA who received HSCT in First Affiliated Hospital of Chinese PLA General Hospital from January 2011 to June 2016 were analyzed retrospectively. The hematopoietic reconstitution, graft verus host disease (GVHD), transplantation related toxicity (TRT) and prognosis after transplantation were compared. Furthermore, the modifed conditioning FC/ATG included low-dose cyclophosphamide (total dose 100 mg/kg), infustion of third-party donor-derived mesenchymal stem cells. RESULTS: All 56 patients with MSD-HSCT or HFD-HSCT achieved hematopoietic reconstitution. Among them, not only the recovery of neutrophils and platelets, but also the incidences of III-IV aGVHD, extensive cGVHD and TRT were not significantly different (the P value were 0.58, 0.61, 0.73, 0.73 and 0.67, respectively). After following-up for 32(2-66) months, 48 patients alive well, the 1-year overall survival rates were 86% in HFD-HSCT group and 89% in MSD-HSCT group, respectively (P=0.58). CONCLUSION: After HSCT using the modifed FC/ATG conditioning, patients with SAA achieved stable engraftment, low toxicity, mild GVHD and excellent outcomes. Furthermore, the HFD-HSCT achieved comparable outcomes to MSD-HSCT and may be served as an alternate therapy for patients with SAA.


Subject(s)
Anemia, Aplastic , Hematopoietic Stem Cell Transplantation , Blood Platelets , Cyclophosphamide , Graft vs Host Disease , HLA Antigens , Haplotypes , Humans , Incidence , Mesenchymal Stem Cells , Neutrophils , Prognosis , Retrospective Studies , Siblings , Tissue Donors , Transplantation Conditioning , Transplantation, Homologous
10.
Mar Pollut Bull ; 113(1-2): 362-370, 2016 Dec 15.
Article in English | MEDLINE | ID: mdl-27771098

ABSTRACT

Seasonal variations of phytoplankton assemblages were examined in a scallop culture sea area of Bohai Bay (China) with regard to some major physical and chemical variables. Samples were collected at three stations from July 2011 to September 2013. A total of 134 species belong to 4 phyla were identified, of which 104 were diatoms, 27 were dinoflagellates, 1 was euglenophyte and 2 were chrysophytes. The cells abundance in autumn (55.44×103cells/L) was higher than that in summer (6.99×103cells/L), spring (3.46×103cells/L) and winter (2.69×103cells/L). The Shannon-Wiener diversity index was higher in summer (3.06), followed by spring (3.02) and winter (2.91), and low in autumn (1.40). Results of canonical correspondence analysis showed that phosphate, salinity, temperature, silicate and DIN/SiO2 ratio were the most important environmental factors influencing the variation of phytoplankton community structure. It is suggested that eutrophication resulted from scallop culture would cause a potential red tide risk.


Subject(s)
Aquaculture/methods , Diatoms/growth & development , Dinoflagellida/growth & development , Environmental Monitoring/methods , Pectinidae/growth & development , Phytoplankton/growth & development , Animals , Bays/chemistry , China , Eutrophication , Salinity , Silicon Dioxide/chemistry , Temperature
11.
J Proteome Res ; 13(12): 5510-23, 2014 Dec 05.
Article in English | MEDLINE | ID: mdl-25372880

ABSTRACT

Investigation of how diatoms cope with the rapid fluctuations in iron bioavailability in marine environments may facilitate a better understanding of the mechanisms underlying their ecological success, in particular their ability to proliferate rapidly during favorable conditions. In this study, using in vivo biochemical markers and whole-cell iTRAQ-based proteomics analysis, we explored the cellular responses associated with reactive oxygen species (ROS) production and cell fate decision during the early response to Fe limitation in the centric diatom Thalassiosira pseudonana. Fe limitation caused a significant decrease in Photosystem (PS) II photosynthetic efficiency, damage to the photosynthetic electron transport chain in PS I, and blockage of the respiratory chain in complexes III and IV, which could all result in excess ROS accumulation. The increase in ROS likely triggered programmed cell death (PCD) in some of the Fe-limited cells through synthesis of a series of proteins involved in the delicate balance between pro-survival and pro-PCD factors. The results provide molecular-level insights into the major strategies that may be employed by T. pseudonana in response to Fe-limitation: the reduction of cell population density through PCD to reduce competition for available Fe, the reallocation of intracellular nitrogen and Fe to ensure survival, and an increase in expression of antioxidant and anti-PCD proteins to cope with stress.


Subject(s)
Diatoms/metabolism , Iron/metabolism , Proteome/analysis , Proteomics/methods , Reactive Oxygen Species/metabolism , Adaptation, Physiological , Antioxidants/metabolism , Apoptosis/genetics , Chromatography, Liquid , Diatoms/genetics , Diatoms/ultrastructure , Electron Transport Complex III/genetics , Electron Transport Complex III/metabolism , Electron Transport Complex IV/genetics , Electron Transport Complex IV/metabolism , Gene Expression , Mass Spectrometry/methods , Microscopy, Electron, Transmission , Photosynthesis/genetics , Photosystem II Protein Complex/genetics , Photosystem II Protein Complex/metabolism , Proteome/genetics , Proteome/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Stress, Physiological
12.
J Agric Food Chem ; 62(48): 11628-36, 2014 Dec 03.
Article in English | MEDLINE | ID: mdl-25407701

ABSTRACT

A novel method allowing simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors (phenylalanine, tyrosine, creatine, creatinine, glucose) has been developed as a robust kinetic study tool by using ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A direct hydrochloric acid (HCl) extraction was applied to achieve the simultaneous extraction of all seven analytes, with the mean recoveries ranging from 60% to 120% at two concentration levels. Then, an Atlantis dC18 column selected from four different chromatographic columns was ultimately used to separate these compounds within 15 min. The limits of detection range of allseven analytes were calculated as 0.14-325.00 µg L(-1). The intra- and interday precision of the proposed method were less than 15.4 and 19.9%, respectively. The proposed method was successfully applied to depict the kinetic profiles of PhIP, 4'-OH-PhIP, and their precursors in pork model, reducing the analysis time and cost in the kinetic study.


Subject(s)
Chromatography, High Pressure Liquid/methods , Imidazoles/analysis , Meat/analysis , Tandem Mass Spectrometry/methods , Animals , Cooking , Creatine/analysis , Creatinine/analysis , Glucose/analysis , Hot Temperature , Phenylalanine/analysis , Swine , Tyrosine/analysis
13.
Bioresour Technol ; 161: 124-30, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24698739

ABSTRACT

The marine diatom Chaetoceros muelleri grown under air (0.03% CO2), 10%, 20%, and 30% CO2 conditions was evaluated to determine its potential for CO2 reduction coupled with biodiesel production. The results indicated that C. muelleri grows well with high CO2 aeration levels (10-20%) and is induced to accumulate lipids under 10-30% CO2. In particular, the highest values of the maximum biomass concentration (1.059gL(-1)), maximum specific growth rate (0.868d(-1)), maximum biomass productivity (0.272gL(-1)d(-1)), maximum CO2 biofixation (0.428gL(-1)d(-1)), and total lipid (43.40% dry weight) and neutral lipid contents were all obtained with 10% CO2 aeration. Moreover, the analysis of the fatty acid composition of C. muelleri revealed the predominance of C14-C18 fatty acids (>90%) and saturated and monounsaturated fatty acids (>80%) under all CO2 levels. The results suggest that C. muelleri has great potential to biodiesel production using flue gases.


Subject(s)
Biofuels , Carbon Dioxide/metabolism , Diatoms/metabolism , Fatty Acids/metabolism , Lipid Metabolism , Algal Proteins/metabolism , Biomass , Carbohydrate Metabolism , Carbon Cycle , Carbon Dioxide/administration & dosage , Diatoms/drug effects , Diatoms/growth & development , Microalgae/metabolism
14.
Mar Genomics ; 16: 29-38, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24406659

ABSTRACT

In this study a comparative proteomics approach involving a mass spectrometric analysis of synchronized cells was employed to investigate the cellular-level metabolic mechanisms associated with siliceous cell wall formation in the pennate diatom Pseudo-nitzschia multiseries. Cultures of P. multiseries were synchronized using the silicate limitation method. Approximately 75% of cells were arrested at the G2+M phase of the cell cycle after 48 h of silicate starvation. The majority of cells progressed to new valve synthesis within 5h of silicon replenishment. We compared the proteome of P. multiseries at 0, 4, 5, and 6h of synchronization progress upon silicon replenishment using two-dimensional gel electrophoresis. Forty-eight differentially expressed protein spots were identified in abundance (greater than two-fold change; P<0.005), some of which are predicted to be involved in intracellular trafficking, cytoskeleton, photosynthesis, lipid metabolism, and protein biosynthesis. Cytoskeleton proteins and clathrin coat components were also hypothesized to play potential roles in cell wall formation. The proteomic profile analysis suggests that P. multiseries most likely employs multiple synergistic biochemical mechanisms for cell wall formation. These results improve our understanding of the molecular mechanisms underlying silicon cell wall formation and enhance our understanding of the important role played by diatoms in silicon biogeochemical cycling.


Subject(s)
Aquatic Organisms/genetics , Cell Wall/metabolism , Diatoms/genetics , Aquatic Organisms/growth & development , Aquatic Organisms/metabolism , Cell Wall/genetics , Diatoms/growth & development , Diatoms/metabolism , Gene Expression Profiling , Gene Expression Regulation , Proteome , Silicon/metabolism
15.
J Proteome Res ; 13(2): 720-34, 2014 Feb 07.
Article in English | MEDLINE | ID: mdl-24372006

ABSTRACT

Silicon is a critical element for diatom growth; however our understanding of the molecular mechanisms involved in intracellular silicon responses are limited. In this study, an iTRAQ-LC-MS/MS quantitative proteomic approach was coupled with an established synchrony technique to reveal the global metabolic silicon-response in the model diatom Thalassiosira pseudonana subject to silicon starvation and readdition. Four samples, which corresponded to the time of silicon starvation, girdle band synthesis, valve formation, and right after daughter cell separation (0, 1, 5, 7 h), were collected for the proteomic analysis. The results indicated that a total of 1,831 proteins, representing 16% of the predicted proteins encoded by the T. pseudonana genome, could be identified. Of the identified proteins, 165 were defined as being differentially expressed proteins, and these proteins could be linked to multiple biochemical pathways. In particular, a number of proteins related to silicon transport, cell wall synthesis, and cell-cycle progress could be identified. In addition, other proteins that are potentially involved in amino acid synthesis, protein metabolism, and energy generation may have roles in the cellular response to silicon. Our findings provide a range of valuable information that will be of use for further studies of this important physiological response that is unique to diatoms.


Subject(s)
Proteomics , Silicon/chemistry , Stramenopiles/metabolism , Base Sequence , Chromatography, High Pressure Liquid , DNA Primers , Marine Biology , Microscopy, Fluorescence , Polymerase Chain Reaction , Spectrometry, Mass, Electrospray Ionization , Stramenopiles/chemistry
16.
Environ Pollut ; 159(12): 3784-92, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21807444

ABSTRACT

This study characterized the changes of nitric oxide (NO) production during the growth of Microcystis aerugrinosa, a cyanobacterium which usually cause cyanobacterial blooms. Results showed a drastic NO release accompanying with cell density and Chl-a content sharp rises when M. aerugrinosa grew from fifth day to sixth day. Moreover, high N:P ratio accelerated the cyanobacterial growth and NO burst. Sodium nitroprusside, an exogenous NO donor, promoted M. aerugrinosa growth with the optimal concentration of 0.1 mg/L. Experiments by supplementing with sodium nitrite and L-arginine demonstrated NO production in M. aerugrinosa cells was mainly through nitrate reductase (NR) pathway while minorly through NO synthase pathway. All these data suggested M. aerugrinosa produced increasing NO during its growth mainly by NR pathway, during which NO positively regulated the growth of M. aerugrinosa.


Subject(s)
Microcystis/growth & development , Microcystis/metabolism , Nitric Oxide/metabolism , Bacterial Proteins/metabolism , Microcystis/enzymology , Nitrate Reductase/metabolism
17.
Colloids Surf B Biointerfaces ; 85(2): 125-30, 2011 Jul 01.
Article in English | MEDLINE | ID: mdl-21397463

ABSTRACT

Surfaces of amphiphilic phosphorylcholine polymer (PC1036) prepared by spin-coating were characterized by spectroscopic ellipsometry, water contact angle and atomic force microscopy. The antifouling properties of the PC1036 films to marine benthic diatom Nitzschia closterium MMDL533 were also investigated. The results showed that the dry PC1036 film promoted the adhesion of N. closterium MMDL533 because the hydrophobic lauryl groups were present in the film surface. The 2 h-swelled PC1036 films had excellent anti-fouling properties with extremely low attachment densities and retention densities no matter what the annealing temperature was. The thickness of the coated films lower than 147 Å had a profound effect on the film anti-fouling properties. Otherwise, when the film thickness was higher than that value, there was no more improvement of diatom cell reduction observed. The annealing temperature had only a little effect on the film resistant to diatom adhesion, which might be attributed to two factors including the PC group packing densities in the outer PC layer and the equilibrated water volume fraction in the 2 h-swelled PC1036 films.


Subject(s)
Biofilms/growth & development , Biofouling , Phosphorylcholine/chemistry , Polymers/chemistry , Biofilms/drug effects , Diatoms/drug effects , Diatoms/physiology , Hydrophobic and Hydrophilic Interactions , Microscopy, Atomic Force , Phosphorylcholine/pharmacology , Polymers/pharmacology , Refractometry/methods , Seawater/microbiology , Temperature , Water/chemistry
18.
Colloids Surf B Biointerfaces ; 75(2): 550-6, 2010 Feb 01.
Article in English | MEDLINE | ID: mdl-19850452

ABSTRACT

The self-assembled monolayers (SAMs) with gradient surface free energies were prepared by surface grafting of a binary mixture of methyl and vinyl terminated trimethoxysilanes on hydrophilic glass slides followed by in situ oxidation of vinyl groups into carboxyl groups. Characterized by contact angles, the SAMs combined with freshly cleaned glass slides bearing hydroxyl groups were used to study the adhesion behavior of marine benthic diatom Nitzschia closterium MMDL533. The attachment densities were much higher on hydrophobic CH3-SAMs and lower on mixed SAMs with surface free energy of 40.1-50.4 mJ/m2. More gregarious adhesion had been found on hydrophobic CH3-SAMs. The percentage removal was in a narrow range of 63-80% on the engineered surfaces and was much lower with a value of 54% on the hydrophilic slides. Our studies have revealed some subtle but interesting differences in attachment and adhesion from the features reported for these benthic species, indicating the possible links to different diatom species.


Subject(s)
Diatoms/cytology , Seawater/microbiology , Cell Adhesion , Diatoms/isolation & purification , Formamides/chemistry , Hydrocarbons, Iodinated/chemistry , Silanes/chemistry , Surface Tension , Thermodynamics , Water/chemistry , Wettability
19.
Yi Chuan Xue Bao ; 32(3): 309-14, 2005 Mar.
Article in Chinese | MEDLINE | ID: mdl-15931793

ABSTRACT

According to the sequences of the gene nhaA coding for Na+ / H+ antiporter,a structural gene was cloned from Pseudomonas sp. cn4902 by PCR reaction with a set of primers. It was 1089 bp in length and codes for 362 amino acids sharing homology with the gene nhaA of E. coli K12 as high as 97.0%. It was inserted into plasmid pBV220 to form a high level expression reconstruction plasmid pBVA. So an overexpression 41 kD protein band could be found in the lane of transformant harbored with pBVA after SDS-PAGE electrophoresis. The detection of growth curve showed that the biomass of the transformant was 2.3 times over that of the control in the medium containing 1.0 mol/L NaCl. It was found that Na+ concentration in cytoplasm of the transformant was low to 60.4% of the control by the detection of atomic absorption spectrum. Evidence of SDS-PAGE electrophoresis of membrane proteins also showed that the NhaA was located in membrane. Purified NhaA was harvested and digested by FXa proteinase. The sequence of eight amino acids in N termination of NhaA protein was entirely identical with the polypeptide deduced from the nhaA gene. Then ten strains of transformant were continuously cultivated for 18 generations under 42 degrees C hot shock condition,all of their reconstructed plasmids were lost with the result that salt-tolerant-level went back to the original standard. In summary, all the experiments proved that the cloned gene is nhaA gene. The gene has been accepted in GenBank by the accession number AY643494.


Subject(s)
Bacterial Proteins/genetics , Pseudomonas/genetics , Sodium-Hydrogen Exchangers/genetics , Amino Acid Sequence , Bacterial Proteins/metabolism , Base Sequence , Cloning, Molecular , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Electrophoresis, Polyacrylamide Gel , Gene Expression Regulation, Bacterial , Molecular Sequence Data , Pseudomonas/metabolism , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Sodium/metabolism , Sodium-Hydrogen Exchangers/isolation & purification , Sodium-Hydrogen Exchangers/metabolism
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