Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; 20(12): e2307072, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37940616

RESUMO

Discovering new deep ultraviolet (DUV) nonlinear optical (NLO) materials is the current research hotspot. However, how to perfectly integrate several stringent performances into a crystal is a great challenge because of the natural incompatibility among them, particularly wide band gap and large NLO coefficient. To tackle the challenge, a boron-rich closed-loop strategy is supposed, based on which a new barium borate, Ba4B14O25, is designed and synthesized successfully via the high-temperature solid-state melting method. It features a highly polymeric 3D geometry with the closed-loop anionic framework [B14O25]8- constructed by the fundamental building blocks [B14O33]24-. The high-density π-conjugated [BO3]3- groups and the fully closed-loop B-O-B connections make Ba4B14O25 possess excellent NLO properties, including short UV cutoff edge (<200 nm), large second harmonic generation response (3.0 × KDP) and phase-matching capability, being a promising DUV-transparent NLO candidate material. The work provides a creative design strategy for the exploration of DUV NLO crystals.

2.
Inorg Chem ; 61(5): 2686-2694, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35068146

RESUMO

A new phase-matchable nonlinear-optical material, Na3Ti3O3(SeO3)4F, has been achieved by a facile hydrothermal reaction. The anionic skeleton displays a honeycombed 3D structure with Ti6Se6 12-member polyhedral ring tunnels along the c axis. Na3Ti3O3(SeO3)4F presents a strong second-harmonic-generation (SHG) response of about 6 × KDP, which is twice that of its isostructural Ag compound. Interestingly, the band gap of Na3Ti3O3(SeO3)4F is also broader than that of the isomorph. Also, the powder laser-induced damage threshold of Na3Ti3O3(SeO3)4F is even 5.5 times larger than that of Ag3Ti3O3(SeO3)4F. Theoretical calculations revealed that the fully filled Ag 4d and empty Ag 5s states have made the difference in the band gap and SHG response of the two isostructural compounds. Our work has provided a practical way of improving the SHG efficiency and band gap simultaneously, which is usually considered to be a pair of negatively correlated parameters.

3.
Inorg Chem ; 61(12): 4801-4805, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35285612

RESUMO

The first examples of zirconium fluoroantimonites, namely, K3ZrF4(SbF4)(SbF5) and K8(ZrF6)(Sb2Zr2F20), have been successfully synthesized by facial hydrothermal reactions. K3ZrF4(SbF4)(SbF5) features a unique 1D (ZrSb2F13)3- double-chain structure, while K8(ZrF6)(Sb2Zr2F20) displays a special 0D construction composed of Zr2Sb2F20 tetranuclear clusters and isolated ZrF6 octahedra. The two fluorides can exhibit a broad transparency range with almost no absorption peaks from ultraviolet to near-IR. For K8(ZrF6)(Sb2Zr2F20), a phase transformation was found before decomposition. The band structures, density of states, and linear-optical properties for the title compounds were also obtained.

4.
Front Plant Sci ; 14: 1107277, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36818881

RESUMO

Introduction: Seed dormancy (SD) significantly decreases under high temperature (HT) environment during seed maturation, resulting in pre-harvest sprouting (PHS) damage under prolonged rainfall and wet weather during wheat harvest. However, the molecular mechanism underlying HT-mediated SD remains elusiveSeed dormancy (SD) significantly decreases under high temperature (HT) environment during seed maturation, resulting in pre-harvest sprouting (PHS) damage under prolonged rainfall and wet weather during wheat harvest. However, the molecular mechanism underlying HT-mediated SD remains elusive. Methods: Here, the wheat landrace 'Waitoubai' with strong SD and PHS resistance was treated with HT from 21 to 35 days post anthesis (DPA). Then, the seeds under HT and normal temperature (NT) environments were collected at 21 DPA, 28 DPA, and 35 DPA and subjected to whole-transcriptome sequencing. Results: The phenotypic data showed that the seed germination percentage significantly increased, whereas SD decreased after HT treatment compared with NT, consistent with the results of previous studies. In total, 5128 mRNAs, 136 microRNAs (miRNAs), 273 long non-coding RNAs (lncRNAs), and 21 circularRNAs were found to be responsive to HT, and some of them were further verified through qRT-PCR. In particular, the known gibberellin (GA) biosynthesis gene TaGA20ox1 (TraesCS3D02G393900) was proved to be involved in HT-mediated dormancy by using the EMS-mutagenized wheat cultivar Jimai 22. Similarly, a novel gene TaCDPK21 (TraesCS7A02G267000) involved in the calcium signaling pathway was validated to be associated with HT-mediated dormancy by using the EMS mutant. Moreover, TaCDPK21 overexpression in Arabidopsis and functional complementarity tests supported the negative role of TaCDPK21 in SD. We also constructed a co-expression regulatory network based on differentially expressed mRNAs, miRNAs, and lncRNAs and found that a novel miR27319 was located at a key node of this regulatory network. Subsequently, using Arabidopsis and rice lines overexpressing miR27319 precursor or lacking miR27319 expression, we validated the positive role of miR27319 in SD and further preliminarily dissected the molecular mechanism of miR27319 underlying SD regulation through phytohormone abscisic acid and GA biosynthesis, catabolism, and signaling pathways. Discussion: These findings not only broaden our understanding of the complex regulatory network of HT-mediated dormancy but also provide new gene resources for improving wheat PHS resistance to minimize PHS damage by using the molecular pyramiding approach.

5.
Medicine (Baltimore) ; 100(5): e23971, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33592851

RESUMO

BACKGROUND: The purpose of this study is to explore the association between extravascular lung water (EVLW) and prognosis of sepsis (PS). METHODS: We will carry out comprehensive literature search in electronic databases (PUBMED/MEDLINE, EMBASE, CENTRAL, WorldSciNet, PsycINFO, Allied and Complementary Medicine Database, CBM, and CNKI) and additional sources. All electronic databases will be searched from their initial to the present without language restrictions. Case-controlled studies reporting the association between EVLW and PS will be evaluated for inclusion. Outcomes of interest will include mortality rate, extravascular lung water index, pulmonary vascular permeability index, blood lactate clearance, oxygenation index, blood gas analysis, PaO2/FiO2, cardiac output index, global end diastolic volume index, intrathoracic blood volume index, systemic resistance index, acute physiology and chronic health scoring system II, and infection-related organ failure scoring system. Study quality will be evaluated using Newcastle-Ottawa Tool, and statistical analysis will be performed utilizing RevMan 5.4 software. RESULTS: This study will summarize the most recent evidence to investigate the association between EVLW and PS. CONCLUSIONS: The results of this study will provide an exhaustive view of the association between EVLW and PS. STUDY REGISTRATION OSF: osf.io/vhnxw.


Assuntos
Água Extravascular Pulmonar/metabolismo , Sepse/mortalidade , Sepse/fisiopatologia , APACHE , Gasometria , Pressão Sanguínea , Permeabilidade Capilar , Débito Cardíaco , Estudos de Casos e Controles , Humanos , Ácido Láctico/sangue , Escores de Disfunção Orgânica , Consumo de Oxigênio , Prognóstico , Circulação Pulmonar , Projetos de Pesquisa , Medição de Risco , Fatores de Risco , Revisões Sistemáticas como Assunto
6.
Nat Prod Res ; 35(6): 945-950, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31135215

RESUMO

Premna fulva Craib, locally known as "Zhangu" in China, is a kind of traditional medicinal plant. A phytochemical investigation on this plant led to the isolation of a novel flavonoid glycoside along with three known analogues. The chemical structure of the new compound was determined by spectral and chemical analysis as apigenin 8-C-ß-D-xylopyranoside (1). Compound 1 showed weak inhibitory activities in vitro against to four tumor cell lines (HL-60, Bcap37, SMMC7721, and P388) with IC50 values of 12.58, 19.31, 31.02, and 48.19 µg/mL, respectively. The result might be helpful to explain the application of P. fulva in Traditional Chinese Medicine.[Figure: see text].


Assuntos
Flavonoides/farmacologia , Glicosídeos/farmacologia , Lamiaceae/química , Antineoplásicos Fitogênicos/farmacologia , Apigenina/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , China , Flavonoides/química , Glicosídeos/química , Humanos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Plantas Medicinais/química , Proibitinas , Espectroscopia de Prótons por Ressonância Magnética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA