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1.
Opt Express ; 31(6): 9729-9738, 2023 Mar 13.
Article in English | MEDLINE | ID: mdl-37157536

ABSTRACT

We present what we belive to be a new band design in which self-assembled InAs quantum dots (QD) are embedded in InGaAs quantum wells (QW) to fabricate broadband single-core quantum dot cascade lasers (QDCLs) operating as frequency combs. The hybrid active region scheme was exploited to form upper hybrid QW/QD energy states and lower pure QD energy states, which expanded the total laser bandwidth by up to 55 cm-1 due to a broad gain medium provided by the inherent spectral inhomogeneity of self-assembled QDs. The continuous-wave (CW) output power of these devices was as high as 470 mW with optical spectra centered at ∼7 µm, which allowed CW operation at temperatures up to 45 °C . Remarkably, measurement of the intermode beatnote map revealed a clear frequency comb regime extending over a continuous 200 mA current range. Moreover, the modes were self-stabilized with intermode beatnote linewidths of approximately 1.6 kHz. Furthermore, what we believe to be a novel π-shaped electrode design and coplanar waveguide transition way were used for RF signal injection. We found that RF injection modified the laser spectral bandwidth by up to 62 cm-1. The developing characteristics indicate the potential for comb operation based on QDCLs as well as the realization of ultrafast mid-infrared pulse.

2.
Opt Express ; 30(20): 36783-36790, 2022 Sep 26.
Article in English | MEDLINE | ID: mdl-36258600

ABSTRACT

Increasing the power of a quantum cascade laser by widening laser ridges will lead to the degradation of the beam quality because of the operation of high-order transverse modes. We report on a phase-locked array scheme of terahertz quantum cascade laser (THz QCL) utilizing Talbot effect. By adjusting the absorbing boundary width of each ridge in the array, stable operation of the fundamental supermode is realized. A five-element array shows 4 times power amplification than that of a single ridge device. Due to the large power amplification efficiency, stable mode selection, and simple fabricating process, the phase-locked array scheme is very promising to further improve the performance of THz QCL.

3.
Plant Physiol ; 180(3): 1660-1676, 2019 07.
Article in English | MEDLINE | ID: mdl-31079035

ABSTRACT

Partial root-zone irrigation (PRI), a water-saving technique, improves water uptake in hydrated roots by inducing specific responses that are thought to be regulated by signals originating from leaves; however, this signaling is poorly understood. Using a split-root system and polyethylene glycol 6000 to simulate PRI in cotton (Gossypium hirsutum), we showed that increased root hydraulic conductance (L) and water uptake in the hydrated roots may be due to the elevated expression of cotton plasma membrane intrinsic protein (PIP) genes. Jasmonate (jasmonic acid [JA] and jasmonic acid-isoleucine conjugate [JA-Ile]) content and the expression of three JA biosynthesis genes increased in the leaves of the PRI plants compared with those of the polyethylene glycol-free control. JA/JA-Ile content also increased in the hydrated roots, although the expression of the three JA genes was unaltered, compared with the control. The JA/JA-Ile contents in leaves increased after the foliar application of exogenous JA and was followed by an increase in both JA/JA-Ile content and L in the hydrated roots, whereas the silencing of the three JA genes had the opposite effect in the leaves. Ring-barking the hydrated hypocotyls increased the JA/JA-Ile content in the leaves but decreased the JA/JA-Ile content and L in the hydrated roots. These results suggested that the increased JA/JA-Ile in the hydrated roots was mostly transported from the leaves through the phloem, thus increasing L by increasing the expression of GhPIP in the hydrated roots under PRI. We believe that leaf-derived JA/JA-Ile, as a long-distance signal, positively mediates water uptake from the hydrated roots of cotton under PRI.


Subject(s)
Agricultural Irrigation/methods , Cyclopentanes/metabolism , Gossypium/metabolism , Oxylipins/metabolism , Plant Leaves/metabolism , Plant Roots/metabolism , Water/metabolism , Biological Transport , Biosynthetic Pathways/genetics , Gene Expression Regulation, Plant , Gossypium/genetics , Isoleucine/metabolism , Plant Leaves/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Roots/genetics
4.
J Exp Bot ; 67(8): 2247-61, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26862153

ABSTRACT

Non-uniform root salinity increases the Na(+)efflux, water use, and growth of the root in non-saline side, which may be regulated by some form of signaling induced by the high-salinity side. However, the signaling and its specific function have remained unknown. Using a split-root system to simulate a non-uniform root zone salinity in Gossypium hirsutum L., we showed that the up-regulated expression of sodium efflux-related genes (SOS1, SOS2, PMA1, and PMA2) and water uptake-related genes (PIP1 and PIP2) was possibly involved in the elevated Na(+) efflux and water use in the the roots in the non-saline side. The increased level of indole acetic acid (IAA) in the non-saline side was the likely cause of the increased root growth. Also, the abscisic acid (ABA) and H2O2 contents in roots in the non-saline side increased, possibly due to the increased expression of their key biosynthesis genes, NCED and RBOHC, and the decreased expression of ABA catabolic CYP707A genes. Exogenous ABA added to the non-saline side induced H2O2 generation by up-regulating the RBOHC gene, but this was decreased by exogenous fluridone. Exogenous H2O2 added to the non-saline side reduced the ABA content by down-regulating NCED genes, which can be induced by diphenylene iodonium (DPI) treatment in the non-saline side, suggesting a feedback mechanism between ABA and H2O2.Both exogenous ABA and H2O2 enhanced the expression of SOS1, PIP1;7 ,PIP2;2, and PIP2;10 genes, but these were down-regulated by fluridone and DPI, suggesting that H2O2 and ABA are important signals for increasing root Na(+) efflux and water uptake in the roots in the non-saline side.


Subject(s)
Abscisic Acid/metabolism , Gossypium/metabolism , Hydrogen Peroxide/metabolism , Plant Roots/metabolism , Salinity , Signal Transduction , Sodium/metabolism , Water/metabolism , Biological Transport/drug effects , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Gossypium/genetics , Indoleacetic Acids/metabolism , Isopentenyladenosine/analogs & derivatives , Isopentenyladenosine/metabolism , Models, Biological , Onium Compounds/pharmacology , Plant Roots/drug effects , Plant Roots/growth & development , Signal Transduction/drug effects
5.
Protein Expr Purif ; 127: 81-87, 2016 11.
Article in English | MEDLINE | ID: mdl-27426133

ABSTRACT

Quorum-sensing related promoter srfA (PsrfA) was used to construct autoinducible expression system for production of recombinant proteins in Bacillus subtilis. PsrfA was prominent in the unique property of inducer-free activity that is closely correlated with cell density. Here, using green fluorescent protein (GFP) as the reporter protein, PsrfA was optimized by shortening its sequences and changing the nucleotides at the conserved regions of -35 -15 and -10 regions, obtaining a library of PsrfA derivatives varied in the strength of GFP production. Among all the promoter mutants, the strongest promoter P10 was selected and the strength in GFP expression was 150% higher than that of PsrfA. Heterologous protein of aminopeptidase and nattokinase could be overexpressed by P10, the activities of which were 360% and 50% higher than that of PsrfA, respectively. These results suggested that the enhanced promoter P10 could be used to develop autoinducible expression system for overexpression of heterologous proteins in B. subtilis.


Subject(s)
Bacillus subtilis/genetics , Bacterial Proteins/genetics , Gene Expression , Mutation , Peptide Synthases/genetics , Promoter Regions, Genetic , Bacillus subtilis/metabolism , Bacterial Proteins/metabolism , Green Fluorescent Proteins/biosynthesis , Green Fluorescent Proteins/genetics , Peptide Synthases/metabolism , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics
6.
Am J Clin Nutr ; 120(3): 737-745, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39009137

ABSTRACT

BACKGROUND: Optimal gestational weight change (GWC) is little known among pregnant women with gestational diabetes mellitus (GDM). OBJECTIVES: This study aimed to explore the optimal GWC ranges for women with GDM and validate these ranges compared with the Institute of Medicine (IOM) guidelines. METHODS: A population-based cohort study using natality data from the National Center for Health Statistics in the United States included 1,338,460 mother-infant pairs with GDM from 2014 to 2020. Poisson regression models were performed to identify GWC ranges (GDM targets) associated with acceptable risks (<10% increase) for a severity-weighted composite outcome including preterm birth (PTB) <37 wk, large for gestational age (LGA, birthweight >90th percentile) and small for gestational age (SGA, birthweight <10th percentile). These targets were validated in individual outcomes including PTB, LGA, SGA, hypertensive disorders of pregnancy, neonatal intensive care unit admission, and neonatal respiratory morbidity, and compared with the IOM guidelines using logistic regression models with population-attributable fractions (PAFs) calculated. RESULTS: The severity-weighted composite outcome had a U-shaped or a J-shaped relationship with GWC across body mass index categories. The GDM targets were 14.1 to 20.3 kg, 9.0 to 17.0 kg, 4.8 to 13.8 kg, -0.8 to 10.8 kg, -2.4 to 8.2 kg, and -8.3 to 6.0 kg for underweight, normal weight, overweight, class 1 obesity, class 2 obesity, and class 3 obesity, respectively. GWC outside the GDM or the IOM targets was associated with increased adverse perinatal outcomes in validation analyses. PAFs indicated that the IOM guidelines reduced a similar or higher proportion of adverse perinatal outcomes compared with the GDM targets for women with GDM, except for those with class 2 and 3 obesity. CONCLUSIONS: The IOM guidelines are generally applicable for women with GDM, except for women with moderate and severe obesity. The optimal GWC ranges for women with GDM and moderate to severe obesity may be lower than the IOM guidelines.


Subject(s)
Diabetes, Gestational , Gestational Weight Gain , Pregnancy Outcome , Humans , Female , Pregnancy , Diabetes, Gestational/epidemiology , United States/epidemiology , Adult , Cohort Studies , Infant, Newborn , Birth Weight , Body Mass Index , Premature Birth/epidemiology , Infant, Small for Gestational Age
7.
Appl Microbiol Biotechnol ; 97(19): 8495-503, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23893327

ABSTRACT

Biologically active ß-1,3-oligosaccharides with rapidly growing biomedical applications are produced from hydrolysis of curdlan polysaccharide. The water-insoluble curdlan impedes its hydrolysis efficiency which is enhanced by our newly developed alkali-neutralization treatment process to increase the stability of curdlan suspension to more than 20 days, while the untreated control settled within 5 min. A putative double-layer structure model comprising of a compact core and a hydrated outer layer was proposed to describe the treated curdlan particles based on sedimentation and scanning electron microscopy observation. This model was verified by single- and two-step acid hydrolysis, indicative of the reduced susceptibility to hydrolysis when close to the compact core. Electrospray ionization-mass spectrometry, thin-layer chromatography analyses, and effective HPLC procedure led to the development of improved process to produce purified individual ß-1,3-oligosaccharides with degrees of polymerization from 2 to 10 and potential for biomedical applications from curdlan hydrolyzate. Our new curdlan oligosaccharide production process offers an even better alternative to the previously published processes.


Subject(s)
Acids/chemistry , Alkalies/chemistry , Oligosaccharides/isolation & purification , beta-Glucans/chemistry , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Hydrolysis , Microscopy, Electron, Scanning , Spectrometry, Mass, Electrospray Ionization , Water
8.
Micromachines (Basel) ; 14(2)2023 Feb 18.
Article in English | MEDLINE | ID: mdl-36838173

ABSTRACT

The present study proposes a terahertz quantum cascade laser frequency comb (THz QCL FC) with a semi-insulated surface plasma waveguide characterized by a low threshold current density, high power and a wide current dynamic range. The gain dispersion value and the nonlinear susceptibility were optimized based on the combination of a hybrid bound-to-continuum active region with a semi-insulated surface plasmon waveguide. Without any extra dispersion compensator, stable frequency comb operation within a current dynamic range of more than 97% of the total was revealed by the intermode beat note map. Additionally, a total comb spectral emission of about 300 GHz centered around 4.6 THz was achieved for a 3 mm long and 150 µm wide device. At 10 K, a maximum output power of 22 mW was obtained with an ultra-low threshold current density of 64.4 A·cm-2.

9.
J Exp Bot ; 63(5): 2105-16, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22200663

ABSTRACT

A new split-root system was established through grafting to study cotton response to non-uniform salinity. Each root half was treated with either uniform (100/100 mM) or non-uniform NaCl concentrations (0/200 and 50/150 mM). In contrast to uniform control, non-uniform salinity treatment improved plant growth and water use, with more water absorbed from the non- and low salinity side. Non-uniform treatments decreased Na(+) concentrations in leaves. The [Na(+)] in the '0' side roots of the 0/200 treatment was significantly higher than that in either side of the 0/0 control, but greatly decreased when the '0' side phloem was girdled, suggesting that the increased [Na(+)] in the '0' side roots was possibly due to transportation of foliar Na(+) to roots through phloem. Plants under non-uniform salinity extruded more Na(+) from the root than those under uniform salinity. Root Na(+) efflux in the low salinity side was greatly enhanced by the higher salinity side. NaCl-induced Na(+) efflux and H(+) influx were inhibited by amiloride and sodium orthovanadate, suggesting that root Na(+) extrusion was probably due to active Na(+)/H(+) antiport across the plasma membrane. Improved plant growth under non-uniform salinity was thus attributed to increased water use, reduced leaf Na(+) concentration, transport of excessive foliar Na(+) to the low salinity side, and enhanced Na(+) efflux from the low salinity root.


Subject(s)
Gossypium/physiology , Sodium Chloride/pharmacology , Sodium-Hydrogen Exchangers/metabolism , Water/physiology , Biological Transport/physiology , Gossypium/growth & development , Gossypium/metabolism , Phloem/growth & development , Phloem/metabolism , Phloem/physiology , Photosynthesis/physiology , Plant Bark/growth & development , Plant Bark/metabolism , Plant Bark/physiology , Plant Leaves/growth & development , Plant Leaves/metabolism , Plant Leaves/physiology , Plant Roots/growth & development , Plant Roots/metabolism , Plant Roots/physiology , Plant Transpiration/physiology , Plants, Genetically Modified , Potassium/analysis , Potassium/metabolism , Salinity , Seedlings/growth & development , Seedlings/metabolism , Seedlings/physiology , Sodium/analysis , Sodium/metabolism , Stress, Physiological/physiology
10.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 30(1): 222-226, 2022 Feb.
Article in Zh | MEDLINE | ID: mdl-35123631

ABSTRACT

OBJECTIVE: To establish a stable mouse model of acquired aplastic anemia. METHODS: Female BALB/C mice aged 6 months were intraperitoneally injected with cyclophosphamide and cyclosporine for 14 days. The number of peripheral blood cells, the concentration of hemoglobin, the number of bone marrow nucleated cells, bone marrow smear, bone marrow pathological sections and other indexes were observed. RESULTS: In BALB/C mice injected intraperitoneally with cyclophosphamide and cyclosporine, the number of peripheral blood cells and the concentration of hemoglobin were significantly decreased, especially the white blood cells and platelets. Bone marrow smear showed a significant decrease in the number of nucleated cells and bone marrow hyperplasia. Bone marrow pathology showed decreased hematopoietic cells and increased non-hematopoietic cells such as adipocytes. CONCLUSION: The mouse model with intraperitoneal injection of cyclophosphamide and cyclosporine can meet the diagnostic criteria of acquired aplastic anemia, which can be used as a mouse model for the study of the pathogenesis and treatment of acquired aplastic anemia.


Subject(s)
Anemia, Aplastic , Animals , Bone Marrow , Cyclophosphamide , Cyclosporine , Female , Mice , Mice, Inbred BALB C
11.
J Sci Food Agric ; 91(13): 2463-70, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21823126

ABSTRACT

BACKGROUND: Although the volatiles present in mushrooms and fungi have been investigated by many researchers, including Antrodia camphorata in submerged fermentation, there are few data available regarding changes in volatile compounds during fermentation. Our research has revealed that solid state fermentation of A. camphorata is highly odiferous compared with submerged cultures and the odor changed with increasing culture time. Therefore the aim of this study was to investigate the changes in volatile compound composition of A. camphorata during solid state fermentation. RESULTS: Altogether, 124 major volatile compounds were identified. The volatile compounds produced by A. camphorata during growth in solid state fermentation were quite different. Oct-1-en-3-ol, octan-3-one and methyl 2-phenylacetate were predominant in exponential growth phase production, while the dominant volatiles produced in stationary phase were octan-3-one and methyl 2-phenylacetate. In stationary phase, lactone compounds in A. camphorata, such as 5-butyloxolan-2-one, 5-heptyloxolan-2-one, 6-heptyloxan-2-one, contributed greatly to peach and fruit-like flavor. Terpene and terpene alcohol compounds, such as 1-terpineol, L-linalool, T-cadinol, (E, E)-farnesol, ß-elemene, cis-α-bisabolene and α-muurolene, made different contributions to herbal fresh aroma in A. camphorata. Nineteen volatile sesquiterpenes were detected from solid state fermentation of A. camphorata. The compounds 5-n-butyl-5H-furan-2-one, ß-ionone, (-)-caryophyllene oxide, aromadendrene oxide, diepi-α-cedrene epoxide, ß-elemene, α-selinene, α-muurolene, azulene, germacrene D, γ-cadinene and 2-methylpyrazine have not hitherto been reported in A. camphorata. CONCLUSION: The preliminary results suggest that the aroma-active compounds produced by A camphorata in solid state fermentation might serve as an important source of natural aroma compounds for the food and cosmetic industries or antibiotic activity compounds. The sesquiterpenes could be identified as possible taxonomic markers for A. camphorata.


Subject(s)
Antrodia/metabolism , Food Preservation , Hyphae/metabolism , Volatile Organic Compounds/metabolism , Antrodia/growth & development , Antrodia/ultrastructure , Fatty Alcohols/chemistry , Fatty Alcohols/metabolism , Fermentation , Gas Chromatography-Mass Spectrometry , Hyphae/growth & development , Hyphae/ultrastructure , Panicum/metabolism , Phenylacetates/chemistry , Phenylacetates/metabolism , Seeds/metabolism , Solid Phase Microextraction , Terpenes/chemistry , Terpenes/metabolism , Time Factors , Volatile Organic Compounds/chemistry
12.
Plant Physiol Biochem ; 164: 92-100, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33975148

ABSTRACT

Apical hook formation is essential for the emergence and stand establishment of cotton plants. Searching for agronomic measures to regulate apical hook formation and clarifying its mechanism are important for full stand establishment in cotton. In this study, cotton seeds were sown at varying seeding rates or depths in sand to determine if and how apical hook formation was regulated by seeding rates or depths. The results showed that deep seeding or low seeding rates increased mechanical pressure and then increased ethylene content by increasing GhACO1 and GhACS2 expression to improve apical hook formation. Silencing of the GhACO1 and GhACS2 genes or exogenous application of 1-methylcyclopropene (1-MCP) decreased the ethylene content and inhibited apical hook formation in the cotton seedlings. Deep seeding, a low seeding rate, or 1-amino cyclopropane-1-carboxylic acid (ACC) treatment increased the expression of GhHLS1 and GhPIF3 genes, but their expression was decreased in theVIGS-ACO1 and VIGS-ACS2 seedlings. Silencing of the GhHLS1 and GhPIF3 genes inhibited apical hook formation, although the expression of GhACO1 and GhACS2 was unchanged. GhPIF3 may act upstream of GhHLS1, as the expression of GhPIF3 in the VIGS-HLS1 seedlings was unchanged, while the expression of GhHLS1 in the VIGS-PIF3 seedlings decreased. These results suggested that raised mechanical pressure could increase ethylene content by inducing GhACO1 and GhACS2 gene expression, which promoted apical hook formation by increasing the expression of GhHLS1. Therefore, adjusting the mechanical pressure through changing the seeding depth or seeding rate is an important means to regulate apical hook formation and emergence.


Subject(s)
Arabidopsis , Ethylenes , Gene Expression Regulation, Plant , Gossypium/genetics , Seedlings
13.
BMC Bioinformatics ; 11: 31, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-20074382

ABSTRACT

BACKGROUND: Biochemical networks play an essential role in systems biology. Rapidly growing network data and versatile research activities call for convenient visualization tools to aid intuitively perceiving abstract structures of networks and gaining insights into the functional implications of networks. There are various kinds of network visualization software, but they are usually not adequate for visual analysis of complex biological networks mainly because of the two reasons: 1) most existing drawing methods suitable for biochemical networks have high computation loads and can hardly achieve near real-time visualization; 2) available network visualization tools are designed for working in certain network modeling platforms, so they are not convenient for general analyses due to lack of broader range of readily accessible numerical utilities. RESULTS: We present LucidDraw as a visual analysis tool, which features (a) speed: typical biological networks with several hundreds of nodes can be drawn in a few seconds through a new layout algorithm; (b) ease of use: working within MATLAB makes it convenient to manipulate and analyze the network data using a broad spectrum of sophisticated numerical functions; (c) flexibility: layout styles and incorporation of other available information about functional modules can be controlled by users with little effort, and the output drawings are interactively modifiable. CONCLUSIONS: Equipped with a new grid layout algorithm proposed here, LucidDraw serves as an auxiliary network analysis tool capable of visualizing complex biological networks in near real-time with controllable layout styles and drawing details. The framework of the algorithm enables easy incorporation of extra biological information, if available, to influence the output layouts with predefined node grouping features.


Subject(s)
Computational Biology/methods , Software , Systems Biology/methods , Databases, Factual , Models, Biological , Proteome/analysis
14.
Ann Palliat Med ; 9(3): 766-773, 2020 May.
Article in English | MEDLINE | ID: mdl-32312067

ABSTRACT

BACKGROUND: This study was to explore the potential mechanism of naprapathy in treating neuropathic pain (NP) after brachial plexus injury (BPI). METHODS: Totally 72 rats were randomly divided into normal group, model control group, and naprapathy group (n=24 per group). A right upper-limb chronic NP model was established, and naprapathy was administered at C5-T1 Jiaji Points on 4th day after modeling. Naprapathy was performed for 15 min once daily with a frequency of 60 per minute. The treatment was applied for altogether 28 days. Cold pain threshold and mechanical pain threshold were measured 1 day before modeling, 3 days after modeling, and 7, 14, 21 and 28 days after naprapathy; 7, 14, 21 and 28 days after naprapathy, rats were killed and the ß-endorphin expression and γ-aminobutyric acid (GABA) content were detected in the thalamus. RESULTS: After 14-day treatment, there was significant difference of mechanical pain threshold between the naprapathy group and the normal group (P<0.05); after treatment for 21 and 28 days, there was no significant difference between the naprapathy group and the normal group (P>0.05); after 28-day naprapathy, there was significant difference of ß-EP expression between the normal group and the naprapathy group (P<0.05), while the difference between model control group and naprapathy group was statistically significant (P<0.05). After 14-day treatment, there was significant difference of GABA content between the model control group and the naprapathy group (P<0.05). After 28-day treatment, significant difference was also found between the model control group and the naprapathy group (P<0.05). CONCLUSIONS: After naprapathy, chronic NP is attenuated in rats with BPI, which might be ascribed to the upregulation of ß-endorphin and GABA.


Subject(s)
Brachial Plexus , Neuralgia , Animals , Brachial Plexus/injuries , Neuralgia/drug therapy , Pain Threshold , Rats , Rats, Sprague-Dawley
15.
J Thorac Dis ; 11(7): 3146-3155, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31463143

ABSTRACT

Pulmonary echinococcosis is a zoonotic parasitic disease caused by the larval stage of cestodes belonging to the genus echinococcus, which is the top killer of residents in pastoral areas and requires more attention. Prevention is the top priority; screening is another important strategy. Surgery is still the preferred treatment for pulmonary echinococcosis. Fortunately, the Chinese government has equipped each county hospital with CT machines. In the foreseeable future, the screening for pulmonary echinococcosis will begin in many areas including Tibet, which will allow us to cure early pulmonary echinococcosis in a more minimally-invasive way.

16.
Micromachines (Basel) ; 10(5)2019 May 13.
Article in English | MEDLINE | ID: mdl-31086010

ABSTRACT

ß-Ga2O3, characterized with high n-type conductivity, little lattice mismatch with III-Nitrides, high transparency (>80%) in blue, and UVA (400-320 nm) as well as UVB (320-280 nm) regions, has great potential as the substrate for vertical structure blue and especially ultra violet LEDs (light emitting diodes). Large efforts have been made to improve the quality of III-Nitrides epilayers on ß-Ga2O3. Furthermore, the fabrication of vertical blue LEDs has been preliminarily realized with the best result that output power reaches to 4.82 W (under a current of 10 A) and internal quantum efficiency (IQE) exceeds 78% by different groups, respectively, while there is nearly no demonstration of UV-LEDs on ß-Ga2O3. In this review, with the perspective from materials to devices, we first describe the basic properties, growth method, as well as doping of ß-Ga2O3, then introduce in detail the progress in growth of GaN on (1 0 0) and (-2 0 1) ß-Ga2O3, followed by the epitaxy of AlGaN on gallium oxide. Finally, the advances in fabrication and performance of vertical structure LED (VLED) are presented.

17.
J Exp Bot ; 59(6): 1295-304, 2008.
Article in English | MEDLINE | ID: mdl-18375935

ABSTRACT

Leaf senescence varies greatly among cotton cultivars, possibly due to their root characteristics, particularly the root-sourced cytokinins and abscisic acid (ABA). Early-senescence (K1) and late-senescence (K2) lines, were reciprocally or self-grafted to examine the effects of rootstock on leaf senescence and endogenous hormones in both leaves and xylem sap. The results indicate that the graft of K1 scion onto K2 rootstock (K1/K2) alleviated leaf senescence with enhanced photosynthetic (Pn) rate, increased levels of chlorophyll (Chl) and total soluble protein (TSP), concurrently with reduced malondialdehyde (MDA) contents in the fourth leaf on the main-stem. The graft of K2 scion onto K1 rootstock enhanced leaf senescence with reduced Pn, Chl, and TSP, and increased MDA, compared with their respective self-grafted control plants (K1/K1 and K2/K2). Reciprocally grafted plants differed significantly from their self-grafted control plants in levels of zeatin and its riboside (Z+ZR), isopentenyl and its adenine (iP+iPA), and ABA, but not in those of dihydrozeatin and its riboside (DHZ+DHZR) in leaves in late season, which was consistent with variations in leaf senescence between reciprocally and self-grafted plants. The results suggest that leaf senescence is closely associated with reduced accumulation of Z+ZR, and iP+iPA rather than DHZ+DHZR, or enhanced ABA in leaves of cotton. Genotypic variation in leaf senescence may result from the difference in root characteristics, particularly in Z+ZR, iP+iPA, and ABA which are regulated by the root system directly or indirectly.


Subject(s)
Abscisic Acid/metabolism , Cytokinins/metabolism , Gossypium/physiology , Plant Growth Regulators/metabolism , Plant Roots/metabolism , Xylem/metabolism , Abscisic Acid/isolation & purification , Biomass , Chlorophyll/biosynthesis , Cytokinins/isolation & purification , Cytokinins/pharmacology , Gossypium/genetics , Photosynthesis , Plant Growth Regulators/isolation & purification , Plant Leaves/physiology , Plants, Genetically Modified , Time Factors
18.
Sci Rep ; 7(1): 2879, 2017 06 06.
Article in English | MEDLINE | ID: mdl-28588258

ABSTRACT

Non-uniform salinity alleviates salt damage through sets of physiological adjustments in Na+ transport in leaf and water and nutrient uptake in the non-saline root side. However, little is known of how non-uniform salinity induces these adjustments. In this study, RNA sequencing (RNA-Seq) analysis shown that the expression of sodium transport and photosynthesis related genes in the non-uniform treatment were higher than that in the uniform treatment, which may be the reason for the increased photosynthetic (Pn) rate and decreased Na+ content in leaves of the non-uniform salinity treatment. Most of the water and nutrient transport related genes were up-regulated in the non-saline root side but down-regulated in roots of the high-saline side, which might be the key reason for the increased water and nutrient uptake in the non-saline root side. Furthermore, the expression pattern of most differentially expressed transcription factor and hormone related genes in the non-saline root side was similar to that in the high-saline side. The alleviated salt damage by non-uniform salinity was probably attributed to the increased expression of salt tolerance related genes in the leaf and that of water and nutrient uptake genes in the non-saline root side.


Subject(s)
Gene Expression Regulation, Plant , Gossypium/physiology , Plant Roots/genetics , Plant Roots/metabolism , Salinity , Sodium/metabolism , Water/metabolism , Biological Transport , Computational Biology/methods , Databases, Genetic , Gene Expression Profiling , Gene Ontology
19.
PLoS One ; 12(9): e0185075, 2017.
Article in English | MEDLINE | ID: mdl-28953908

ABSTRACT

Cotton is sensitive to waterlogging stress, which usually results in stunted growth and yield loss. To date, the molecular mechanisms underlying the responses to waterlogging in cotton remain elusive. Cotton was grown in a rain-shelter and subjected to 0 (control)-, 10-, 15- and 20-d waterlogging at flowering stage. The fourth-leaves on the main-stem from the top were sampled and immediately frozen in liquid nitrogen for physiological measurement. Global gene transcription in the leaves of 15-d waterlogged plants was analyzed by RNA-Seq. Seven hundred and ninety four genes were up-regulated and 1018 genes were down-regulated in waterlogged cotton leaves compared with non-waterlogged control. The differentially expressed genes were mainly related to photosynthesis, nitrogen metabolism, starch and sucrose metabolism, glycolysis and plant hormone signal transduction. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis indicated that most genes related to flavonoid biosynthesis, oxidative phosphorylation, amino acid metabolism and biosynthesis as well as circadian rhythm pathways were differently expressed. Waterlogging increased the expression of anaerobic fermentation related genes, such as alcohol dehydrogenase (ADH), but decreased the leaf chlorophyll concentration and photosynthesis by down-regulating the expression of photosynthesis related genes. Many genes related to plant hormones and transcription factors were differently expressed under waterlogging stress. Most of the ethylene related genes and ethylene-responsive factor-type transcription factors were up-regulated under water-logging stress, suggesting that ethylene may play key roles in the survival of cotton under waterlogging stress.


Subject(s)
Gene Expression Profiling , Gene Expression Regulation, Plant/drug effects , Gossypium/genetics , Gossypium/physiology , Plant Leaves/genetics , Stress, Physiological/drug effects , Water/pharmacology , Carbohydrate Metabolism/drug effects , Carbon/metabolism , Down-Regulation/drug effects , Gossypium/drug effects , Gossypium/metabolism , Nitric Oxide/biosynthesis , Nitric Oxide/metabolism , Sequence Analysis, RNA , Solubility , Stress, Physiological/genetics
20.
Photochem Photobiol ; 91(1): 42-7, 2015.
Article in English | MEDLINE | ID: mdl-25376103

ABSTRACT

ß-Ga2O3 nanorod was first directly prepared by the microwave irradiation hydrothermal way without any subsequent heat treatments, and its characterizations were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), UV-Vis diffuse reflection spectroscopy techniques, and also its photocatalytic degradation for perfluorooctanoic acid (PFOA) was investigated. XRD patterns revealed that ß-Ga2O3 crystallization increased with the enhancement of microwave power and the adding of active carbon (AC). PFOA, as an environmental and persistent pollutant, is hard decomposed by hydroxyl radicals (HO·); however, it is facilely destroyed by ß-Ga2O3 photocatalytic reaction in an anaerobic atmosphere. The important factors such as pH, ß-Ga2O3 dosage and bubbling atmosphere were researched, and the degradation and defluorination was 98.8% and 56.2%, respectively. Reductive atmosphere reveals that photoinduced electron may be the major reactant for PFOA. Furthermore, the degradation kinetics for PFOA was simulated and constant and half-life was calculated, respectively.

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