Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
1.
Plant Cell Environ ; 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38828861

ABSTRACT

Cadmium (Cd) is a toxic metal that poses serious threats to human health. Rice is a major source of dietary Cd but how rice plants transport Cd to the grain is not fully understood. Here, we characterize the function of the ZIP (ZRT, IRT-like protein) family protein, OsZIP2, in the root-to-shoot translocation of Cd and intervascular transfer of Cd in nodes. OsZIP2 is localized at the plasma membrane and exhibited Cd2+ transport activity when heterologously expressed in yeast. OsZIP2 is strongly expressed in xylem parenchyma cells in roots and in enlarged vascular bundles in nodes. Knockout of OsZIP2 significantly enhanced root-to-shoot translocation of Cd and alleviated the inhibition of root elongation by excess Cd stress; whereas overexpression of OsZIP2 decreased Cd translocation to shoots and resulted in Cd sensitivity. Knockout of OsZIP2 increased Cd allocation to the flag leaf but decreased Cd allocation to the panicle and grain. We further reveal that the variation of OsZIP2 expression level contributes to grain Cd concentration among rice germplasms. Our results demonstrate that OsZIP2 functions in root-to-shoot translocation of Cd in roots and intervascular transfer of Cd in nodes, which can be used for breeding low Cd rice varieties.

2.
J Exp Bot ; 73(6): 1766-1774, 2022 03 15.
Article in English | MEDLINE | ID: mdl-34864981

ABSTRACT

Molybdenum (Mo) is an essential element for almost all living organisms. After being taken up into the cells as molybdate, it is incorporated into the molybdenum cofactor, which functions as the active site of several molybdenum-requiring enzymes and thus plays crucial roles in multiple biological processes. The uptake and transport of molybdate is mainly mediated by two types of molybdate transporters. The homeostasis of Mo in plant cells is tightly controlled, and such homeostasis likely plays vital roles in plant adaptation to local environments. Recent evidence suggests that Mo is more than an essential element required for plant growth and development; it is also involved in local adaptation to coastal salinity. In this review, we summarize recent research progress on molybdate uptake and transport, molybdenum homeostasis network in plants, and discuss the potential roles of the molybdate transporter in plant adaptation to their local environment.


Subject(s)
Membrane Transport Proteins , Molybdenum , Biological Transport , Membrane Transport Proteins/metabolism , Molybdenum/metabolism
3.
Appl Microbiol Biotechnol ; 98(8): 3679-89, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24190495

ABSTRACT

The expression efficiency was improved for the recombinant single-chain variable fragment (scFv) against clenbuterol (CBL) obtained from mouse and expressed in the methylotrophic yeast Pichia pastoris GS115, by redesigning and synthesizing the DNA sequence encoding for CBL-scFv based on the codon bias of P. pastoris. The codons encoding 124 amino acids were optimized, in which a total of 156 nucleotides were changed, and the G+C ratio was simultaneously decreased from 53 to 47.2 %. Under the optimized expression conditions, the yield of the recombinant CBL-scFv (41 kDa) antibodies was 0.223 g L⁻¹ in shake culture. Compared to the non-optimized control, the expression level of the optimized recombinant CBL-scFv based on preferred codons in P. pastoris demonstrated a 2.35-fold higher yield. Furthermore, the recombinant CBL-scFv was purified by Ni-NTA column chromatography, and the purity was 95 %. The purified CBL-scFv showed good CBL recognition by a competitive indirect enzyme-linked immunoassay. The average concentration required for 50 % inhibition of binding and the limit of detection for the assay were 5.82 and 0.77 ng mL⁻¹, respectively.


Subject(s)
Clenbuterol/immunology , Codon , Pichia/genetics , Single-Chain Antibodies/immunology , Single-Chain Antibodies/metabolism , Animals , Base Composition , Chromatography, Affinity , Enzyme-Linked Immunosorbent Assay , Gene Expression , Mice , Molecular Sequence Data , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Sequence Analysis, DNA , Single-Chain Antibodies/genetics , Single-Chain Antibodies/isolation & purification
4.
Huan Jing Ke Xue ; 45(6): 3421-3432, 2024 Jun 08.
Article in Zh | MEDLINE | ID: mdl-38897763

ABSTRACT

Addressing the issue of carbon emissions in the transportation sector, this research constructed various predictive models using multiple machine learning algorithms based on panel data from 30 provinces in China from 2005 to 2019. The study aimed to identify the optimal machine learning algorithm and key factors influencing the carbon emissions of transportation, providing potent references for policymakers and decision-makers to reduce carbon emissions and promote the sustainable development of the transportation sector. Initially, drawing from the concept of the fixed effects model, we included the heterogeneity differences among provinces as an important factor. We further employed a combined method of Pearson's correlation coefficient and Spearman's rank correlation coefficient to screen 18 factors influencing transportation carbon emissions. We then made a preliminary selection of seven common machine learning algorithms and used the screened factors as explanatory variables for model training. The three algorithms with the best performance were further optimized and trained. Subsequently, we utilized the K-fold cross-validation method; plotted learning curves to test the performance of each predictive model; and used MSE, MAE, R2, and MAPE as evaluation indicators to determine the best predictive model. SHAP values were chosen to calculate the importance of each explanatory variable in the optimal predictive model. The results indicated that the multicollinearity among the seven factors of provincial differences, total consumption of social goods, urban green space area, freight turnover, number of private cars, transportation industry output, and permanent population was weak, and all passed the significance test. They could be used as explanatory variables in the prediction model of transportation carbon emissions. The prediction results of the Random Forest and XGBoost algorithms were both outstanding, with R2 values above 0.97 and errors below 10 %, showing no signs of overfitting or underfitting. Among them, the XGBoost algorithm performed the best, whereas the KNN algorithm performed poorly. The importance ranking of the explanatory variables was as follows:provincial differences > total consumption of social goods > number of private cars > permanent population > freight turnover > urban green space area > transportation industry output. A comprehensive analysis of relevance and importance showed that provincial differences were an indispensable variable in the prediction of transportation carbon emissions. In conclusion, this study provides a new approach to the governance of carbon emissions in the transportation industry, and the results can serve as a reference for policymakers and decision-makers. In future policy design and decision-making, the distinctive factors of each province should not be overlooked. Measures targeted at specific regions need to be formulated to promote the sustainable development of the transportation industry.

5.
Ying Yong Sheng Tai Xue Bao ; 34(6): 1474-1482, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37694408

ABSTRACT

The rapid urbanization adversely affects landscape pattern of mountainous cities. It is of great practical significance to explore the spatial and temporal evolution of ecological networks in mountainous areas to achieve regional ecological security. Taking Qianshan City in Anhui Province as an example, based on the land use data in 2012 and 2020, we simulated the land use situation in 2036 with PLUS model, and constructed the ecological networks in 2020 and 2036, respectively. We further analyzed its spatial and temporal evolution characteristics and explored the optimization path of ecological network. The results showed that the scale of various land use types in Qianshan City would change little from 2020 to 2036. The construction land would be centered on the built-up area, expanding in a point and block shape to the surrounding area. The ecological space would be continuously squeezed and encroached. The overall complexity and connectivity of ecological networks in Qianshan City would increase. The number and area of ecological source sites would increase, expanding spatially to the southwest and northeast. The overall density and number of ecological corridors would increase, with a lack of ecological corridor connections in the east-west direction, which need urgent improvement. The stability of ecological networks could be improved through three major measures, including protection and restoration of source sites, optimization and cultivation of corridors, and zoning control.


Subject(s)
City Planning , Urbanization , Cities , Computer Simulation
6.
Zhonghua Nei Ke Za Zhi ; 49(4): 309-12, 2010 Apr.
Article in Zh | MEDLINE | ID: mdl-20627037

ABSTRACT

OBJECTIVE: To study the incidence of osteopenia in patients with initial systemic lupus erythematosus (SLE). Investigate the levels of the vitamin D (VitD) endocrine system in peripheral blood of SLE patients and its relation to bone mineral density (BMD). Analyse the relationship between the estrogen receptor (ER) and BMD and evaluate the role of ER in the pathogenesis osteopenia. METHODS: Serum levels of 25-OH VitD(3) and 1,25-(OH)(2) VitD(3) were detected by enzyme linked immunosorbent assay. The gene expression levels of VitD receptor (VDR) and ER were determined by real-time PCR. BMD measurements in the lumbar spine (L1-L4) and left proximal femur (femoral neck) were performed using dual X-ray absorptiometry before treatment. RESULTS: The initial SLE patients had significantly lower BMD values, and higher frequency of bone loss at both sites of measurement compared with normal controls (P < 0.05). The levels of 25-OH VitD(3) and 1,25-(OH)(2) VitD(3) were lower in the initial SLE patients than normal controls (P < 0.01 both). There is no difference in the levels of 25-OH VitD(3) and 1,25-(OH)(2) VitD(3) between the osteopenia SLE group and the normal BMD SLE group (P > 0.05, P > 0.05). There are no correlations between the VitD and BMD in initial SLE patients (P > 0.05 both). The expressions of VDR gene were significantly increased in the initial SLE patients compared with the normal controls (P < 0.01). There was no difference in VDR gene expression between osteopenia SLE group and normal BMD SLE group (P > 0.05). The VDR gene expression does not correlate with the bone mass (P > 0.05). The levels of ER-beta gene expression are higher in the initial SLE group than the normal controls (P < 0.01). CONCLUSIONS: The incipient SLE patients may have lower BMD than expected. SLE patients present abnormal VitD endocrine system and higher ER-beta mRNA expression than those in normal controls, but these weren't concerned with osteopenia.


Subject(s)
Bone Density , Cholecalciferol/blood , Estrogen Receptor beta/metabolism , Lupus Erythematosus, Systemic/metabolism , Adolescent , Adult , Bone Diseases, Metabolic/complications , Case-Control Studies , Child , Estrogen Receptor beta/genetics , Female , Gene Expression , Humans , Lupus Erythematosus, Systemic/complications , Male , Middle Aged , RNA, Messenger/genetics , Receptors, Calcitriol/metabolism , Young Adult
7.
Environ Toxicol Pharmacol ; 40(3): 698-703, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26410088

ABSTRACT

Investigation of organochlorine pesticides residues (important environmental contamination causing malignant transformation) in breast cancer patients is valuable to understanding their roles in breast cancer. 75 invasive ductal carcinoma (IDC) patients were enrolled with control of 79 benign breast diseases patients and control of 80 healthy women. Morning fasting blood specimens and adipose tissue specimens beside the primary lesion were detected with gas chromatograph. In blood specimens, both levels of ß-HCH and PCTA were higher in IDC than those in both controls (both p<0.05), and increasingly higher among the three IDC degrees. In adipose tissue specimens, all levels of ß-HCH, PCTA and pp'-DDE were higher in IDC than those in control (all p<0.05) and increasingly higher among three IDC degrees. The levels of ß-HCH, PCTA in both blood specimens and adipose tissue specimens were higher in estrogen receptor (ER) positive IDC than those in ER negative IDC (all p<0.05). The higher level of organochlorine pesticides residues in blood and adipose tissue specimens of IDC infers its association with IDC, but the details remains to reveal, and this study may helpful in this field.


Subject(s)
Adipose Tissue/chemistry , Breast Neoplasms/blood , Carcinoma, Ductal, Breast/blood , Hydrocarbons, Chlorinated/toxicity , Adult , Aged , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/metabolism , Carcinoma, Ductal, Breast/pathology , Chlorobenzenes/blood , Dichlorodiphenyl Dichloroethylene/blood , Female , Hexachlorocyclohexane/blood , Humans , Middle Aged , Receptors, Estrogen/metabolism
8.
Fen Zi Xi Bao Sheng Wu Xue Bao ; 40(4): 245-52, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17966462

ABSTRACT

The aim of this study was to establish whether early prepubertal Sannen dairy goat could provide a large source of ova for SCNT. The effects of different hormonal treatments including untreated control, FSH alone, estadiol plus progesterone (E2-P4), and E2-P4 and FSH (E2-P4-FSH) on ovary size, follicle number and size were studied using the early prepubertal goats aged 39-60 days. Then prepubertal goats aged 39-120 days were categorized into three groups to study the effect of age on recruited follicle number. The meiotic competence of oocytes derived from > or =3 mm follicles recovered from the early prepubertal goats treated with E2-P4-FSH was compared with those treated with FSH alone. Finally, the development competence of the ova from the early goats treated with E2-P4-FSH was evaluated by SCNT. The E2-P4-FSH treatment produced the largest ovaries, the highest numbers of total follicles and follicles > or =3 mm diameter compared with the other treatments. The number of > or =3 mm follicles per goat treated with E2-P4-FSH was significantly higher for those in the age groups 39-60 days than those in the age groups 61-90 days and 91-120 days. The FSH alone treatment resulted in a lower proportion matured ova in vitro within 27 hr than from those goats treated with E2-P4-FSH. Ova derived from the early prepubetal goats resulted in lower rate of blastocyst in SCNT (15.3% versus 22.1%, P < 0.01) than that of adult goat However, the number of ova recovered per goat was substantially greater for the prepubertal goats (108 +/- 10.3 Versus 28 +/- 5.0). Consequently, the younger goats produced significantly more blastocyst (7.1 +/- 2.7 versus 4.2 +/- 1.4) per head. It was concluded that early pubertal goats treated with E2-P4-FSH could provide a relatively high number of developmentally competent ova for SCNT studies.


Subject(s)
Oocytes/drug effects , Ovarian Follicle/drug effects , Animals , Cell Size/drug effects , Estradiol/pharmacology , Female , Follicle Stimulating Hormone/pharmacology , Goats , Oocytes/cytology , Ovarian Follicle/cytology , Ovary/cytology , Ovary/drug effects , Progesterone/pharmacology , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL