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1.
Physiol Plant ; 176(3): e14358, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38783511

RESUMEN

Soil salinity is a major environmental constraint affecting the sustainability and profitability of agricultural production systems. Salinity stress tolerance has been present in wild crop relatives but then lost, or significantly weakened, during their domestication. Given the genetic and physiological complexity of salinity tolerance traits, agronomical solutions may be a suitable alternative to crop breeding for improved salinity stress tolerance. One of them is optimizing fertilization practices to assist plants in dealing with elevated salt levels in the soil. In this review, we analyse the causal relationship between the availability of boron (an essential metalloid micronutrient) and plant's adaptive responses to salinity stress at the whole-plant, cellular, and molecular levels, and a possibility of using boron for salt stress mitigation. The topics covered include the impact of salinity and the role of boron in cell wall remodelling, plasma membrane integrity, hormonal signalling, and operation of various membrane transporters mediating plant ionic and water homeostasis. Of specific interest is the role of boron in the regulation of H+-ATPase activity whose operation is essential for the control of a broad range of voltage-gated ion channels. The complex relationship between boron availability and expression patterns and the operation of aquaporins is also discussed.


Asunto(s)
Boro , Salinidad , Suelo , Boro/metabolismo , Suelo/química , Adaptación Fisiológica/genética , Tolerancia a la Sal/genética , Plantas/metabolismo , Plantas/genética , Regulación de la Expresión Génica de las Plantas
2.
Angew Chem Int Ed Engl ; 63(7): e202318390, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38117040

RESUMEN

Luban locks with mortise and tenon structure have structural diversity and architectural stability, and it is extremely challenging to synthesize Luban lock-like structures at the molecular level. In this work, we report the cocrystallization of two structurally related atom-precise fcc silver nanoclusters Ag110 (SPhF)48 (PPh3 )12 (Ag110 ) and Ag14 (µ6 -S)(SPhF)12 (PPh3 )8 (Ag14 ). It is worth noting that the Ag110 cluster is the first compound to simulate the complex Luban lock structure at the molecular level. Meanwhile, Ag110 is the largest known fcc-based silver nanocluster, so far, there is no precedent for fcc silver nanocluster with more than 100 silver atoms. DFT calculations show that Ag110 is a 58-electron superatom with an electronically closed shell1S2 1P6 1D10 2S2 1F14 2P6 1G18 . Ag110 ⋅Ag14 can rapidly catalyze the reduction of 4-nitrophenol within 4 minutes. In addition, Ag110 presents clear structural evidence to reveal the critical size and mechanism of the transformation of metal core from fcc stacking to quasi-spherical superatom. This research work provides an important structural model for studying the nucleation mechanism and structural assembly of silver nanoclusters.

3.
Inorg Chem ; 62(12): 4990-4998, 2023 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-36921355

RESUMEN

Photochromic viologen-based materials have emerged as one of the most promising candidates for the development of X-ray light detection applications, including medical diagnosis and treatment, environmental radiation inspection, and industrial crack detection. However, the design and construction of low-dose X-ray-sensitive complexes remains an immense challenge, especially for the in-depth dissection of their response mechanisms. Herein, by using N,N'-4,4'-bipyridiniodipropionate (CV) as functional sensitive structural units and cadmium as heavy atoms, two cadmium-viologen complexes with one-dimensional chained structures, namely, [Cd2Cl4(CV)(H2O)2]n (1) and [CdBr2(CV)]n (2), have been constructed, which exhibit a remarkable and selective photochromic response to low-dose X-ray radiation detection. Compound 1 is visually sensitive to both X-ray and UV light due to the more accessible photoinduced electron transfer (ET) pathways, while compound 2 only shows a slight color-changing process in response to UV light, in conformity with UV-vis absorbance analyses and kinetic studies. Surprisingly, compound 2 has longer ET pathways than 1, but not in response to high-energy X-ray light, seeming to contradict the previous phenomena. On further analysis, the key point in achieving X-ray-sensitive behavior should be a good balance among the electron donor-acceptor distance, intermolecular interaction, and X-ray absorbing capacity, as verified by density functional theory (DFT) and X-ray absorption strength calculations, X-ray photoelectron spectra, electron paramagnetic resonance measurements, and independent gradient model analysis. In particular, compound 1 is unprecedentedly sensitive to soft X-ray radiation, accompanied by an X-ray detection limit of as low as 2.91 Gy. These findings push forward the further development of low-dose X-ray sensing materials.

4.
Opt Lett ; 47(14): 3507-3510, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35838714

RESUMEN

A 3D-printed all-dielectric metasurface is presented in this Letter which can generate an accelerating beam with a circularly symmetric non-spreading transverse profile that can propagate along arbitrary convex trajectories. The curved trajectory is mapped to the corresponding direct-space spatial phases by the basic cube units with different geometrical heights. The required phase distribution is derived in detail based on the enveloping theory of differential geometry and the Bessel beam generation method. A metasurface with a preset trajectory is simulated and measured to demonstrate the validity of the phase distribution calculated by the proposed theory. The full-wave simulation and measurement results verify that the Bessel-like beam whose intensity follows a curved (off-axis) trajectory can be produced by the proposed metasurface. The generated hybrid beam merges the advantages of non-accelerating and accelerating diffractive-free beams. Therefore, the proposed metasurface has great potential in ultrahigh-speed communication, secure communication, near-field imaging, wireless energy transmission applications, and so on. The all-dielectric characteristic provides the proposed metasurface with the competitive advantages of low cost and easy large-scale processing.

5.
Opt Lett ; 46(21): 5441-5444, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34724496

RESUMEN

In this Letter, a metasurface combined with emerging 3D printing technology is proposed. The proposed metasurface regards the simple cube as the unit cell, and the height of the cube is the only variable. A nearly linear transmission phase range covering 360° operating at 20 GHz is obtained when the height is regulated in [2.26 mm, 11.20 mm]. Therefore, the proposed unit cell can be adopted to any metasurface with various functions. Taking the generation of a non-diffractive Bessel beam as an example, two metasurfaces composed of 30×30 units with different focusing directions are designed based on non-diffractive theory and the generalized law of refraction. Two prototypes are 3D printed and measured by a near-field scanning system. The measured results validate our design with satisfactory focusing and beam deflection performance. Additionally, the 3D printed metasurface has lower cost and a shorter processing cycle, and avoids metal loss. Therefore, a 3D printed metasurface is an excellent candidate that can be applied in millimeter wave or even higher frequency bands.

6.
Inorg Chem ; 60(20): 15136-15140, 2021 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-34612632

RESUMEN

One-dimensional (1D) organic-inorganic hybrid lead halides with unique core-shell quantum wire structures and splendid photoluminescence properties have been considered one of the most promising high-efficiency broadband emitters. However, studies on the broadband emissions in 1D purely face-shared lead iodide hybrids are still rare so far. Herein, we report on a new 1D lead iodide hybrid, (2cepyH)PbI3 (2cepy = 1-(2-chloroethyl)pyrrolidine), characterized with face-sharing PbI6 octahedral chains. Upon UV photoexcitation, this material shows broadband yellow emissions originating from the self-trapped excitons associated with distorted Pb-I lattices on account of the strong exciton-phonon coupling, as proved by variable-temperature emission spectra. Moreover, experimental and calculated results reveal that (2cepyH)PbI3 is an indirect bandgap semiconductor, the band structures of which are governed by inorganic parts. Our work represents the first broadband emitter based on a 1D face-shared lead iodide hybrid and opens a new way to obtain the novel broadband emission materials.

7.
Sheng Li Xue Bao ; 72(3): 263-273, 2020 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-32572425

RESUMEN

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the adult central nervous system (CNS), however, it causes excitation in the immature CNS neurons. The shift from GABA-induced depolarization to hyperpolarization in postnatal brain is primarily due to progressive decrease in the expression of the Na+-K+-2Cl- symporter 1 (NKCC1) and increased expression of the K+-Cl- cotransporter 2 (KCC2). Unlike CNS neurons, both immature and mature neurons in the enteric nervous system (ENS) are depolarized by GABA. Molecular mechanisms by which GABA excites ENS neurons are unclear. It is understood, however, that the excitatory action depends on elevated intraneuronal Cl-. We aimed to test a hypothesis that high intracellular Cl- in ENS neurons is maintained by activity of the NKCCs. We found that NKCC2 immunoreactivity (IR) was expressed in the ENS of the rat colon on postnatal day 1 (P1). The expression level of NKCC2 continuously increased and reached a steady high level on P14 and maintained at that level in adulthood. NKCC1 IR appeared in ENS on P14 and maintained through adulthood. KCC2 IR was not detectable in the ENS in any of the developmental stages. Both NKCC1 IR and NKCC2 IR were co-expressed with GABAA receptors in ENS neurons. Exogenous GABA (1 mmol/L) caused membrane depolarization in the ENS neurons. The reversal potential of GABA-induced depolarization was about -16 mV. Blockade of NKCC by bumetanide (50 µmol/L) or furosemide (300 µmol/L) suppressed the depolarizing responses to GABA. Bumetanide (50 µmol/L) shifted the reversal potential of GABA-induced depolarization in the hyperpolarizing direction. Neither the KCC blocker DIOA (20 µmol/L) nor the Cl-/HCO3- exchanger inhibitor DIDS (200 µmol/L) suppressed GABA-evoked depolarization. The results suggest that ENS neurons continuously express NKCC2 since P1 and NKCC1 since P14, which contribute to the accumulation of Cl- in ENS neurons and GABA-evoked depolarization in neonate and adult ENS neurons. These results provide the first direct evidence for the contribution of both NKCC2 and NKCC1 to the GABAA-mediated depolarization.


Asunto(s)
Receptores de GABA-A , Simportadores , Animales , Bumetanida , Neuronas , Ratas , Ácido gamma-Aminobutírico
8.
Angew Chem Int Ed Engl ; 59(16): 6507-6512, 2020 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-31981465

RESUMEN

The only feasible access to non-face-centered cubic (FCC) copper was by physical vapor deposition under high vacuum. Now, non-FCC copper is observed in a series of alkynyl-protected Cu53 nanoclusters (NCs) obtained from solution-phase synthesis. Determined by single-crystal X-ray crystallography, the structures of Cu53 (C≡CPhPh)9 (dppp)6 Cl3 (NO3 )9 and its two derivatives reveal an ABABC stacking sequence involving 41 Cu atoms. It can be regarded as a mixed FCC and HCP structure, which gives strong evidence that Cu can be arranged in non-FCC lattice at ambient conditions when proper ligands are provided. Characterization methods including X-ray absorption fine structure, XPS, ESI-MS, UV/Vis, Auger spectroscopy, and DFT calculations were carried out. CuII was shown to successively coordinate with introduced ligands and changed to CuI after bonding with phosphine. The following addition of NaBH4 and the aging step further reduced it to the Cu53 NC.

9.
Biochem Biophys Res Commun ; 512(4): 902-907, 2019 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-30929914

RESUMEN

Resistance to adjuvant chemotherapy remains therapeutic challenge in nasopharyngeal carcinoma (NPC). In this work, we demonstrate that targeting eukaryotic translation initiation factor 4E (eIF4E) is a potential sensitizing strategy to overcome chemoresistance in NPC. We observe the aberrant activation of eIF4E and translational upregulation of eIF4E-regulated oncogenes in NPC cell after pro-longed exposure of cisplatin. Functional analysis demonstrates that eIF4E depletion effectively inhibits proliferation and induces apoptosis in cisplatin-resistant NPC cells. Consistently, eIF4E knockdown significantly enhances cisplatin efficacy in cisplatin-sensitive cells. We identify eIF4E as a therapeutically actionable targets by showing that ribavirin, an anti-viral drug, phenocopies the effects of eIF4E knockdown in NPC. We further demonstrate that ribavirin acts on chemoresistant NPC cells through suppressing eIF4E activity and oncogenic protein translation. Using two independent NPC xenograft mouse models, we show that ribavirin not only is effective in inhibiting chemoresistant NPC growth but also significantly augments the inhibitory effects of cisplatin efficacy in vivo without causing significant toxicity in mice. Taken together, our work shows an activation of eIF4E-mediated growth and survival mechanisms in response to chemotherapy and suggests that inhibition of eIF4E activity represents an attractive sensitizing strategy for NPC treatment. Our findings also suggest that ribavirin is a useful addition to the treatment armamentarium for NPC.


Asunto(s)
Resistencia a Antineoplásicos/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Carcinoma Nasofaríngeo/tratamiento farmacológico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Línea Celular Tumoral , Cisplatino/administración & dosificación , Cisplatino/farmacología , Factor 4E Eucariótico de Iniciación/antagonistas & inhibidores , Factor 4E Eucariótico de Iniciación/genética , Humanos , Ratones SCID , Terapia Molecular Dirigida/métodos , Carcinoma Nasofaríngeo/genética , Oncogenes , Fosforilación/efectos de los fármacos , Biosíntesis de Proteínas , Ribavirina/administración & dosificación , Ribavirina/farmacología , Serina/metabolismo
10.
Plant Physiol ; 177(3): 1254-1266, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29784768

RESUMEN

Boron (B) alleviates aluminum (Al) toxicity in higher plants; however, the underlying mechanisms behind this phenomenon remain unknown. Here, we used bromocresol green pH indicator, noninvasive microtest, and microelectrode ion flux estimation techniques to demonstrate that B promotes root surface pH gradients in pea (Pisum sativum) roots, leading to alkalization in the root transition zone and acidification in the elongation zone, while Al inhibits these pH gradients. B significantly decreased Al accumulation in the transition zone (∼1.0-2.5 mm from the apex) of lateral roots, thereby alleviating Al-induced inhibition of root elongation. Net indole acetic acid (IAA) efflux detected by an IAA-sensitive platinum microelectrode showed that polar auxin transport, which peaked in the root transition zone, was inhibited by Al toxicity, while it was partially recovered by B. Electrophysiological experiments using the Arabidopsis (Arabidopsis thaliana) auxin transporter mutants (auxin resistant1-7; pin-formed2 [pin2]) and the specific polar auxin transporter inhibitor1-naphthylphthalamic acid showed that PIN2-based polar auxin transport is involved in root surface alkalization in the transition zone. Our results suggest that B promotes polar auxin transport driven by the auxin efflux transporter PIN2 and leads to the downstream regulation of the plasma membrane-H+-ATPase, resulting in elevated root surface pH, which is essential to decrease Al accumulation in this Al-targeted apical root zone. These findings provide a mechanistic explanation for the role of exogenous B in alleviation of Al accumulation and toxicity in plants.


Asunto(s)
Aluminio/toxicidad , Boro/farmacología , Ácidos Indolacéticos/metabolismo , Pisum sativum/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Aluminio/farmacocinética , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico/efectos de los fármacos , Membrana Celular/metabolismo , Concentración de Iones de Hidrógeno , Mutación , Pisum sativum/metabolismo , Ftalimidas/farmacología , Proteínas de Plantas/metabolismo , Raíces de Plantas/química , Raíces de Plantas/metabolismo , ATPasas de Translocación de Protón/metabolismo
11.
J Exp Bot ; 70(21): 6349-6361, 2019 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-31420662

RESUMEN

The non-protein amino acid γ-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to salinity. However, the physiological rationale for this elevation remains elusive. This study compared electrophysiological and whole-plant responses of salt-treated Arabidopsis mutants pop2-5 and gad1,2, which have different abilities to accumulate GABA. The pop2-5 mutant, which was able to overaccumulate GABA in its roots, showed a salt-tolerant phenotype. On the contrary, the gad1,2 mutant, lacking the ability to convert glutamate to GABA, showed oversensitivity to salinity. The greater salinity tolerance of the pop2-5 line was explained by: (i) the role of GABA in stress-induced activation of H+-ATPase, thus leading to better membrane potential maintenance and reduced stress-induced K+ leak from roots; (ii) reduced rates of net Na+ uptake; (iii) higher expression of SOS1 and NHX1 genes in the leaves, which contributed to reducing Na+ concentration in the cytoplasm by excluding Na+ to apoplast and sequestering Na+ in the vacuoles; (iv) a lower rate of H2O2 production and reduced reactive oxygen species-inducible K+ efflux from root epidermis; and (v) better K+ retention in the shoot associated with the lower expression level of GORK channels in plant leaves.


Asunto(s)
Arabidopsis/fisiología , ATPasas de Translocación de Protón/metabolismo , Tolerancia a la Sal/fisiología , Ácido gamma-Aminobutírico/metabolismo , Arabidopsis/anatomía & histología , Biomasa , Supervivencia Celular , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Iones , Potenciales de la Membrana , Mutación/genética , Estrés Oxidativo , Epidermis de la Planta/metabolismo , Raíces de Plantas/citología , Brotes de la Planta/anatomía & histología , Potasio/metabolismo , Salinidad , Plantones/metabolismo , Sodio/metabolismo , Estrés Fisiológico , Transcripción Genética
12.
J Am Chem Soc ; 139(36): 12346-12349, 2017 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-28837326

RESUMEN

Determining the total structure of metal nanoparticles is vital to understand their properties. In this work, the first all-alkynyl-protected Ag nanocluster, Ag74(C≡CPh)44, was synthesized and structurally characterized by single crystal diffraction. Ag atoms are arranged in a Ag4@Ag22@Ag48 three shell structure and all 44 phenylethynyl ligands coordinated with Ag in a µ3 mode. In spite of being absent in nanocluster, 31P NMR study reveals that bidentate phosphine first reacts with Ag(I) to form a dinuclear complex, from which Ag atoms are then released to phenylethynyl ligands. This phosphine mediated strategy may find general application in synthesis of alkynyl-protected Ag nanoclusters.

13.
Clin Anat ; 30(8): 1029-1033, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28509338

RESUMEN

The location of perianal abscesses and the course of the fistula follow certain patterns, especially in the relationship between external and internal openings. However, it is still not clear how the contents of the ischioanal fossa, especially the fibrous network of fat tissue, affect the route for such diseases. Ten male adult cadavers were selected for the study. Seven horizontal transverse section planes from 1 cm above the pubic symphysis to the inferior border of the lesser trochanter of the femur were recorded after P45 sheet plastination. We observed characteristics of fiber distribution in the ischioanal fossa and its relationship with surrounding structures in every plane. There was a dense strip-type fiber connecting with junction fascia between the obturator internus and gluteus maximus muscles. Close to the levator ani, obturator internus, and gluteus maximus, the fibers were very dense and continuous with the fascia on the surfaces of these three muscles. The function of the fibrous network was considered to be not only the support of fat tissue in the fossa but also cushioning during physiological actions such as defecation. We hope that these morphological results could help to elucidate the passage of fistulae and the locations susceptible to perianal abscesses. Clin. Anat. 30:1029-1033, 2017. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Absceso/patología , Canal Anal/anatomía & histología , Isquion/anatomía & histología , Diafragma Pélvico/anatomía & histología , Sínfisis Pubiana/anatomía & histología , Tejido Adiposo , Enfermedades del Ano , Cadáver , Fémur , Humanos , Masculino
14.
Tumour Biol ; 37(4): 5645-51, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26581907

RESUMEN

The level of microRNA-93 (miR-93) in tumors has been recently reported to be negatively correlated with survival of lung cancer patients. Considering that the most devastating aspect of lung cancer is metastasis, which can be promoted by transforming growth factor-ß (TGF-ß)-induced epithelial-to-mesenchymal transition (EMT), we sought to determine whether miR-93 is involved in this process. Here, we report that a previously unidentified target of miR-93, neural precursor cell expressed developmentally downregulated gene 4-like (NEDD4L), is able to mediate TGF-ß-mediated EMT in lung cancer cells. miR-93 binds directly to the 3'-UTR of the NEDD4L messenger RNA (mRNA), leading to a downregulation of NEDD4L expression at the protein level. We next demonstrated that the downregulation of NEDD4L enhanced, while overexpression of NEDD4L reduced TGF-ß signaling, reflected by increased phosphorylation of SMAD2 in the lung cancer cell line after TGF-ß treatment. Furthermore, overexpression of miR-93 in lung cancer cells promoted TGF-ß-induced EMT through downregulation of NEDD4L. The analysis of publicly available gene expression array datasets indicates that low NEDD4L expression correlates with poor outcomes among patients with lung cancer, further supporting the oncogenic role of miR-93 in lung tumorigenesis and metastasis.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Neoplasias Pulmonares/genética , MicroARNs/genética , Factor de Crecimiento Transformador beta/genética , Ubiquitina-Proteína Ligasas/genética , Carcinogénesis/genética , Línea Celular Tumoral , Complejos de Clasificación Endosomal Requeridos para el Transporte/biosíntesis , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/patología , Masculino , MicroARNs/biosíntesis , Ubiquitina-Proteína Ligasas Nedd4 , Metástasis de la Neoplasia , Estadificación de Neoplasias , Proteína Smad2/biosíntesis , Ubiquitina-Proteína Ligasas/biosíntesis
15.
Langmuir ; 32(51): 13746-13751, 2016 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-27958759

RESUMEN

The phase transfer of nanoparticles (NPs) from water to organic solvents by an amphiphilic room-temperature ionic liquid (IL) was reported. The geminal IL modified with Pluronic P123 stabilizes a variety of NPs of different size and nature, such as Pd, Au, Ag, and SiO2 NPs. Their phase transfer into a hydrophobic environment was realized by raising the temperature and adding salts (such as NaCl and KBr), both of which have a common effect of breaking the hydrogen bonds of the IL with H2O. A more straightforward method of using an organic solvent working as a hydrogen bond donor (such as butyl alcohol) was then proposed. In this case, NaCl was no longer required. To further apply this strategy to the organic solvents that are generally incapable of forming hydrogen bonds (e.g., toluene), a small quantity of benzoic acid was added to the organic phase. By forming hydrogen bonds from benzoic acid to the IL, an even more facile approach was provided. FT-IR confirmed the hydrogen bonding between them. The phase-transfer protocol does not rely on coordination bonding of ligands with a specific metal and is capable of the phase transfer of objects with large sizes and different natures. Thus, it has the potential for wide application.

16.
Genomics ; 105(5-6): 296-303, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25666662

RESUMEN

The regulatory gene network of unicellular trichome development in Arabidopsis thaliana has been studied intensively, but that of multicellular remains unclear. In the present study, we characterized cucumber trichomes as representative multicellular and unbranched structures, but in a spontaneous mutant, mict (micro-trichome), all trichomes showed a micro-size and stunted morphologies. We revealed the transcriptome profile using Illumina HiSeq 2000 sequencing technology, and determined that a total of 1391 genes exhibited differential expression. We further validated the accuracy of the transcriptome data by RT-qPCR and found that 43 genes encoding critical transcription factors were likely involved in multicellular trichome development. These 43 candidate genes were subdivided into seven groups: homeodomain, MYB-domain, WRKY-domain, bHLH-domain, ethylene-responsive, zinc finger and other transcription factor genes. Our findings also serve as a powerful tool to further study the relevant molecular networks, and provide a new perspective for investigating this complex and species-specific developmental process.


Asunto(s)
Cucumis sativus/metabolismo , Perfilación de la Expresión Génica , Tricomas/genética , Tricomas/crecimiento & desarrollo , Tricomas/metabolismo
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(7): 2275-8, 2016 Jul.
Artículo en Zh | MEDLINE | ID: mdl-30036008

RESUMEN

LAMOST-DR1 is the first data released by Guoshoujing telescop, which has the largest number of stellar spectra in the world at present. The data set provides the data source for searching for special and rare celestial objects like cataclysmic variable stars.Meanwhile, it requires more advanced astronomical data processing methods and techniques. A data mining method for cataclysmic variable spectra in massive spectra data is proposed in this paper. Different types of celestial spectra show obvious difference in the feature space constructed with Laplacian Eigenmap method. The parameters of artificial neural network are optimized with particle swarm optimization method and the total LAMOST-DR1 data is processed. 7 cataclysmic variable star spectra are found in the experiment including 2 dwarf nova, 2 nova like variables and a highly polarized AM Her type. The newly found spectra enrich the current cataclysmic variable spectra library. The experiment is the first attempt of searching for cataclysmic variable star spectra with Guoshoujing telescope data and the results show that our approach is feasible in LAMOST data. This method is also applicable for mining other special celestial objects in sky survey telescope data.

18.
Neurol Sci ; 36(11): 2027-33, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26169757

RESUMEN

Lysophosphatidic acid (LPA) is a bioactive phospholipid that activates at least five known G-protein-coupled receptors (GPCRs): LPA1-LPA5. The nervous system is a major locus for LPA1 expression. LPA has been shown to regulate neuronal proliferation, migration, and differentiation during central nervous system development as well as neuronal survival. Furthermore, deficient LPA signaling has been implicated in several neurological disorders including neuropathic pain and schizophrenia. Parkinson's disease (PD) is a neurodegenerative movement disorder that results from the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc). The specific molecular pathways that lead to DA neuron degeneration, however, are poorly understood. The influence of LPA in the differentiation of mesenchymal stem cells (MSCs) into DA neurons in vitro and LPA1 expression in a 6-hydroxydopamine (6-OHDA) lesion model of PD in vivo were examined in the present study. LPA induced neuronal differentiation in 80.2 % of the MSC population. These MSCs developed characteristic neuronal morphology and expressed the neuronal marker, neuron-specific enolase (NSE), while expression of the glial marker, glial fibrillary acidic protein (GFAP), was absent. Moreover, 27.6 % of differentiated MSCs were positive for tyrosine hydroxylase (TH), a marker for DA neurons. In the 6-OHDA PD rat model, LPA1 expression in the substantia nigra was significantly reduced compared to control. These results suggest LPA signaling via activation of LPA1 may be necessary for DA neuron development and survival. Furthermore, reduced LPA/LPA1 signaling may be involved in DA neuron degeneration thus contributing to the pathogenesis of PD.


Asunto(s)
Neuronas Dopaminérgicas/fisiología , Lisofosfolípidos/metabolismo , Neurogénesis/fisiología , Trastornos Parkinsonianos/fisiopatología , Receptores del Ácido Lisofosfatídico/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Fármacos del Sistema Nervioso Central/administración & dosificación , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/patología , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Lisofosfolípidos/administración & dosificación , Masculino , Células Madre Mesenquimatosas/patología , Células Madre Mesenquimatosas/fisiología , Plexo Mientérico/metabolismo , Neurogénesis/efectos de los fármacos , Oxidopamina , Trastornos Parkinsonianos/patología , Fosfopiruvato Hidratasa/metabolismo , Ratas Sprague-Dawley , Transducción de Señal , Sustancia Negra/patología , Sustancia Negra/fisiopatología , Tirosina 3-Monooxigenasa/metabolismo
19.
Zhonghua Gan Zang Bing Za Zhi ; 23(3): 194-9, 2015 Mar.
Artículo en Zh | MEDLINE | ID: mdl-25938832

RESUMEN

OBJECTIVE: To investigate the roles of PI3K/Akt signaling in the unfolded protein response (UPR) and non-UPR signaling pathways of endoplasmic reticulum stress and apoptosis in hepatocytes under conditions of saturated fatty acid-induced steatosis. METHODS: A steatosis model of hepatocytes (L02 cell and HepG2 cell line) was induced by palmitate sodium saturated fatty acids.The hepatocytes were divided into normal control group,experimental group (treated with palmitate sodium) and intervention group (treated with palmitate sodium and LY294002, a PI3K/Akt inhibitor). Cell apoptosis was detected by flow cytometry with Annexin V/PI double-staining.Western blot analysis was used to examine the protein expression of GRP78, PI3K, P-PI3K,Akt, P-Akt, CHOP and Bax.The F test and t-test were used in statistical analyses. RESULTS: Flow cytometry showed that palmitate sodium induced cell apoptosis in steatotic hepatocytes;moreover, a significant increase in cell apoptosis was observed in the palmitate sodium-induced steatotic hepatocytes in the presence of LY294002.For the normal control group, the experimental group and the intervention group, the apoptosis ratios of L02 cells were 4.41 ± 0.78% vs. 6.01 ± 1.49% vs. 19.50 ± 2.53% after 24 hours of treatment,and 12.56 ± 2.78% vs. 29.72 ± 6.39% vs. 44.60 ± 4.17% after 48 hours of treatment in respectively (all P < 0.05),and of HepG2 cells were 11.16 ± 1.15% vs. 17.50 ± 6.83% vs. 30.41 ± 3.62% after 24 hours of treatment, and 22.37 ± 1.24% vs. 33.85 ± 5.79% vs. 48.56 ± 4.21% after 48 hours of treatment (all P < 0.05). Western blot analysis showed that expression of GRP78 was significantly upregulated in the palmitate sodium-induced steatosis hepatocytes, indicating activation of endoplasmic reticulum stress. In addition, the palmitate sodium treatment also activated the PI3K/Akt pathway,induced expression of CHOP and Bax of the UPR and non-UPR signaling pathways respectively. Moreover, Pretreatment with LY294002 inhibited the palmitate sodium induced-phosphorylation of PI3K and Akt, and promoted upregulation of CHOP and Bax induced by palmitate sodium. CONCLUSION: The PI3K/Akt pathway may be involved in regulation of the UPR and non-UPR signaling pathways of endoplasmic reticulum stress and may promote apoptosis of hepatocytes by enhancing the expression of CHOP and Bax protein in saturated fatty acid-induced steatotic hepatocytes.


Asunto(s)
Estrés del Retículo Endoplásmico , Transducción de Señal , Animales , Apoptosis , Línea Celular , Chaperón BiP del Retículo Endoplásmico , Hígado Graso , Proteínas de Choque Térmico , Hepatocitos , Humanos , Ácido Palmítico , Fosfatidilinositol 3-Quinasas , Fosforilación , Proteínas Proto-Oncogénicas c-akt , Respuesta de Proteína Desplegada , Regulación hacia Arriba
20.
Inorg Chem ; 53(15): 7870-5, 2014 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-25057907

RESUMEN

A new homonuclear single-chain magnet self-assembles as a one-dimensional coordination network of defective dicubane {Co(II)4} complexes linked by single Co(II) ions with the assistance of azido and picolinate ligands. Dominating intrachain ferromagnetic interactions, intrinsic Ising-like Co(II) anisotropy, and negligible interchain magnetic interactions lead to a thermally activated relaxation time of the magnetization below 8 K. Two thermally activated regimes above and below 3.5 K are observed with the following energy barriers: Δ(τ1)/k(B) = 66 K (τ0 = 3.7 × 10(-11) s) and Δ(τ2)/k(B) = 51 K (τ0 = 2.3 × 10(-9) s), respectively. The difference between the two energy barriers of the relaxation time, 15 K, agrees well with the experimental energy, Δ(ξ), to create a domain wall along the chain.

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