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1.
Molecules ; 28(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36985658

RESUMO

The flavonoids in Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum) have high medicinal value. However, because of slow growth and harsh ecological environments, T. hemsleyanum is currently an endangered species. In light of this, we present a detailed hairy root induction procedure as a promising alternative to true roots with medicinal value. The percentage of explants induced by Agrobacterium rhizogenes (A. rhizogenes) to produce hairy roots out of the total number of explants infected (induction rate 1) was 95.83 ± 7.22%, and the proportion of hairy roots that contained Rol B fragments among all the hairy roots with or without Rol B fragments (positive rate) was 96.57 ± 1.72%. The transformation was further confirmed by the expression of the GUS protein. A high-productive hairy root line was screened for the comparative profiling of six flavonoids with true roots using high-performance liquid chromatography (HPLC). The contents of (+)-catechin, (-)-epicatechin, neochlorogenic acid, luteolin-6-C-glucoside, and orientin were 692.63 ± 127.24, 163.34 ± 31.86, 45.95 ± 3.46, 209.68 ± 6.03, and 56.82 ± 4.75 µg/g dry weight (DW) of 30-day-old hairy roots, respectively, which were higher than those of 3-year-old true roots. Hairy roots have stronger antioxidant activity than true roots. Overall, the hairy roots of T. hemsleyanum could serve as promising alternative sources for the production of flavonoids with medicinal uses.


Assuntos
Catequina , Vitaceae , Flavonoides/metabolismo , Raízes de Plantas/metabolismo , Catequina/metabolismo
2.
Opt Express ; 30(5): 8222-8233, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35299568

RESUMO

In this article, we report a low-threshold random laser enhanced by TiN nanoparticles (NPs) suspended randomly in gain solutions. Results show that the random laser with TiN NPs has a lower threshold than the random laser with TiO2 NPs and the underlying mechanisms are discussed in detail. The localized surface plasmon resonance of individual TiN NPs increases the pump efficiency and strengthens the fluorescence amplification efficiency of the DCM. The multiple scattering of integral TiN NPs extends the dwelling time of light in random systems, which provides more possibilities for the light amplification in the gain medium. Then, the random laser threshold as a function of the number density of TiN NPs is studied. Results show that the optimum number density of TiN NPs for the lowest-threshold random lasers is about 1.468 × 1012ml-1. When we substitute the ethanol solution with the nematic liquid crystal (NLC), the random laser threshold can be further decreased to 5.11 µJ/pulse, which is about 7.7 times lower than that of DCM dye solution with TiN NPs under the same conditions. These findings provide a cost-effective strategy for the realization of low-threshold random lasers with high-quality.

3.
Sensors (Basel) ; 22(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36236397

RESUMO

Obtaining good measurement performance with meter wave radar has always been a difficult problem. Especially in low-elevation areas, the multipath effect seriously affects the measurement accuracy of meter wave radar. The generalized multiple signal classification (MUSIC) algorithm is a well-known measurement method that dose not require decorrelation processing. The polarization-sensitive array (PSA) has the advantage of polarization diversity, and the polarization smoothing generalized MUSIC algorithm demonstrates good angle estimation performance in low-elevation areas when based on a PSA. Nevertheless, its computational complexity is still high, and the estimation accuracy and discrimination success probability need to be further improved. In addition, it cannot estimate the polarization parameters. To solve these problems, a polarization synthesis steering vector MUSIC algorithm is proposed in this paper. First, the MUSIC algorithm is used to obtain the spatial spectrum of the meter wave PSA. Second, the received data are properly deformed and classified. The Rayleigh-Ritz method is used to decompose the angle to realize the decoupling of polarization and the direction of the arrival angle. Third, the geometric relationship and prior information of the direct wave and the reflected wave are used to continue dimension reduction processing to reduce the computational complexity of the algorithm. Finally, the geometric relationship is used to obtain the target height measurement results. Extensive simulation results illustrate the accuracy and superiority of the proposed algorithm.

4.
Int Orthop ; 46(5): 1145-1154, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35124710

RESUMO

BACKGROUND: Over the last 20 years, suprapatellar (SP) intramedullary nailing has gained considerable attention for treating tibia fractures and is believed to improve fracture alignments, decrease anterior knee pain, and facilitate intraoperative fluoroscopy. However, it is associated with various concerns, including the need to make another infrapatellar (IP) incision to remove the nail. AIMS: This study was aimed at developing a new technique for the removal of SP tibial nails through an SP approach using a cannulated extraction system. The efficiency of the novel SP approach was compared to that of the traditional IP approach for the removal of SP tibial nails. PATIENTS AND METHODS: This was a retrospective cohort study from a prospectively collected clinical registry. The data for 69 consecutive patients who received surgery to remove a previous SP intramedullary nail using an SP approach (n = 30, SP cohort) or an IP approach (n = 39, IP cohort) were analyzed. Intra-operative evaluations included intraoperative blood loss, operation time, and changes in the surgical procedures. At six months follow-up, post-operative Lysholm knee score, visual analog scale (VAS) score, and the active range of motion (ROM) of the affected knee and complications were assessed. RESULTS: Patients in the SP cohort exhibited an increased post-operative Lysholm knee score (ß, 2.6; 95% confidence interval [CI], 0.6 to 4.6; P = 0.012), decreased post-operative VAS score (ß, - 0.7; 95% CI, - 1.1 to - 0.2; P = 0.004), and increased operation time (ß, 9.8 minutes; 95% CI, 5.7 to 14.0 minutes; P < 0.001) compared with those treated with the IP approach after adjustment for baseline characteristics. There were no statistically significant differences in blood loss, post-operative ROM, or complications between the two cohorts. CONCLUSIONS: Compared with the IP technique, the SP approach for the removal of an SP tibial nail was independently associated with an increased post-operative Lysholm knee score and decreased VAS score, although the surgery was longer in duration. The novel technique offers a reliable and minimally invasive option for the removal of an SP tibial nail.


Assuntos
Fixação Intramedular de Fraturas , Fraturas da Tíbia , Pinos Ortopédicos , Estudos de Coortes , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/métodos , Humanos , Estudos Retrospectivos , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
5.
J Orthop Traumatol ; 23(1): 53, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36443615

RESUMO

BACKGROUND: Malalignment is a common event during the intramedullary nailing (IMN) of distal tibia fractures (DTFs). Although it is reported that the semi-extended IMN techniques such as suprapatellar (SP) and parapatellar (PP) approaches may be superior in preventing malalignment, the application of these techniques is concerning owing to the intra-articular involvement. We thus developed an extra-articular semi-extended infrapatellar (SEIP) approach which utilizes the infrapatellar (IP) space while maintaining the knee in a semi-extended position. However, there are no studies on the safety and efficacy of SEIP in treating DTFs. Therefore, in this study, the SEIP technique was examined, particularly in terms of the potential alignment improvement of DTFs, and this technique was compared with the traditional hyperflexed infrapatellar (HFIP) procedure. MATERIALS AND METHODS: This randomized clinical trial (RCT) compared IMN malalignment while correcting extraarticular and nondisplaced intra-articular DTFs between April 2018 and June 2021 using the HFIP and SEIP techniques at a level I trauma center in China. The study participants were clinically and radiographically examined for at least 12 months of follow-ups. Intraoperative fluoroscopy time, operation time, blood loss, hospitalization duration, functional ankle score, and complications were assessed as well. RESULTS: Among the 88 recruited participants, 45 (51%) underwent traditional HFIP IMN and 43 (49%) underwent SEIP IMN. Malalignment occurred in 9 patients (20.0%) from the HFIP cohort and in 2 patients (4.7%) from the SEIP cohort (P value = 0.030). In addition, the SEIP IMN technique significantly reduced the intraoperative fluoroscopy time, operation time, and improved the postoperative ankle function compared to the HFIP IMN technique. However, the intraoperative blood loss, hospitalization duration, infection, delay union, and nonunion remained the same between the two cohorts. CONCLUSIONS: In summary, we demonstrated that the SEIP IMN provides markedly enhanced alignment of extraarticular and nondisplaced intra-articular DTFs compared to the traditional HFIP IMN procedure. The described technique represents an effective option for IMN of DTFs. LEVEL OF EVIDENCE: Level 2. Trial registration The Chinese Clinical Trial Registry, ChiCTR2100043673. Registered 26 February 2021, retrospectively registered, http://www.chictr.org.cn/showprojen.aspx?proj=122263.


Assuntos
Fraturas do Tornozelo , Fixação Intramedular de Fraturas , Fraturas da Tíbia , Humanos , Tíbia , Fraturas da Tíbia/cirurgia , Articulação do Tornozelo
6.
Inorg Chem ; 60(23): 17699-17704, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34739254

RESUMO

A novel family of three types of charged (0, -1, -2) ligands based phosphorescent iridium(III) complexes with different carboxyl-containing dianionic (-2) ligands have been synthesized. Their single-crystal structures show that all neutral complexes (Ir1, Ir2, and Ir3) show a trans-N^N configuration between dianionic (-2) and monoanionic (-1) ligands, which is in contrast with the trans-N^C configuration in cationic complex Ir4, which has an interesting hydrogen bond in the solid state. Notably, Ir4 shows higher luminescence efficiency and an obvious blue shift emission relative to those in Ir1, Ir2, and Ir3. DFT calculations demonstrate that all neutral complexes (Ir1, Ir2, and Ir3) exhibit ligand-to-ligand charge transfer (LLCT) excited state character from the dianionic (-2) ligand to the neutral (0) ligand, which are completely different from the cationic complex Ir4 that exhibits an LLCT excited state from the monoanionic (-1) ligand to the neutral (0) ligand. Considering better solubility, Ir1 was eventually used in solution-processed OLED and achieved moderate efficiency (6.6%, 14.3 cd A-1, 2.8 lm W-1) with an orange light displaying CIEx,y coordinates of (0.53, 0.46). This work provides a new strategy to construct three types of charged (0, -1, -2) ligands based phosphorescent iridium(III) complexes and extends the range of iridium complex luminescent materials.

7.
Int Orthop ; 45(10): 2719-2726, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33559052

RESUMO

PURPOSE: The semi-extended tibial intramedullary nailing method would enable easier and improved reductions for tibial fractures as well as facilitate fluoroscopic imaging; however, its in-articular nature remains controversial. The aim of this study was to compare the clinical and functional outcomes of the semi-extended infrapatellar (SEIP) approach and hyper-flexed infrapatellar (HFIP) approach for intramedullary nailing to treat tibial shaft fractures. METHODS: This study involved the retrospective analysis of the medical records of patients with tibial shaft fractures that were fixed through either the SEIP approach or the HFIP approach of intramedullary nailing and who were admitted to a level 1 trauma centre. The minimum patient follow-up period was 12 months and the clinical and functional outcomes were estimated at the 12-month visit. RESULTS: Of the 80 patients whose medical records were analyzed, 40 (50%) underwent SEIP nailing and the remaining 40 (50%) underwent the traditional HFIP nailing. Compared with the HFIP group, patients in the SEIP group had a higher Lysholm knee score (median, 92 [interquartile range, 88-95] vs median, 88 [interquartile range, 81-92]; p = .01), a shorter intra-operative fluoroscopy time (median, 93 [interquartile range, 78-105] s, vs median, 136 [interquartile range, 110-157] s; p < .001), and operation time (mean, 88.1 [SD, 17.8] min vs mean, 98.7 [SD, 19.3] min; p = .01). The VAS score was significantly lower in the SEIP group (median, 0; interquartile range, 0-0) than in the HFIP group (median, 0; interquartile range, 0-2) (p = .03). There were two cases (5%) in the SEIP group and 10 cases (25%) in the HFIP group of moderate AKP (p = .03). Meanwhile, there was no significant difference in malalignment, nonunion, delayed union, infection, and other complications, as well as SF-36 physical and mental scores. CONCLUSION: We found that the SEIP approach to tibia intramedullary nailing was superior to the HFIP approach based on the intra-operative and post-operative outcomes. Thus, this novel technique provides an infrapatellar option for semi-extended tibial nailing.


Assuntos
Fixação Intramedular de Fraturas , Fraturas da Tíbia , Pinos Ortopédicos , Humanos , Estudos Retrospectivos , Tíbia/diagnóstico por imagem , Tíbia/cirurgia , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
8.
BMC Microbiol ; 18(1): 53, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29866035

RESUMO

BACKGROUND: Pu-erh tea is a traditional Chinese tea and produced by natural solid-state fermentation. Several studies show that the natural microbiota influence caffeine level in pu-erh tea. Our previous research also found that the caffeine declined significantly (p < 0.05) in the fermentation, which suggested that the caffeine level could be influenced by specific strains. The purpose of this study was to isolate and identify microorganisms for caffeine degradation, and this research explored the degradation products from caffeine and optimal condition for caffeine degradation. RESULTS: 11 Fungi were isolated from pu-erh tea fermentation and 7 strains could survive in caffeine solid medium. Two superior strains were identified as Aspergillus niger NCBT110A and Aspergillus sydowii NRRL250 by molecular identification. In the substrate tests with caffeine, A. niger NCBT110A could use caffeine as a potential carbon source while glucose is absent, A. sydowii NRRL250 could degrade 600 mg/L caffeine completely in a liquid medium. During the degradation product analysis of A. sydowii NRRL250, theophylline and 3-methlxanthine were detected, and the level of theophylline and 3-methlxanthine increased significantly (p < 0.05) with the degradation of caffeine. The single factor analysis showed that the optimum conditions of caffeine degradation were 1) substrate concentration of 1200 mg/L, 2) reaction temperature at 30 °C, and 3) pH of 6. In the submerged fermentation of tea infusion by A. sydowii NRRL250, 985.1 mg/L of caffeine was degraded, and 501.2 mg/L of theophylline was produced. CONCLUSIONS: Results from this research indicate that Aspergillus sydowii NRRL250 was an effective strain to degrade caffeine. And theophylline and 3-methlxanthine were the main caffeine degradation products.


Assuntos
Aspergillus/crescimento & desenvolvimento , Cafeína/química , Chá/microbiologia , Aspergillus/classificação , Aspergillus/isolamento & purificação , Aspergillus niger/crescimento & desenvolvimento , Aspergillus niger/isolamento & purificação , Biodegradação Ambiental , Fermentação , Especificidade por Substrato , Chá/química , Teofilina/metabolismo , Xantinas/metabolismo
9.
Zhongguo Zhong Yao Za Zhi ; 41(2): 160-166, 2016 Jan.
Artigo em Zh | MEDLINE | ID: mdl-28861957

RESUMO

In the wake of on-the-spot investigation into Chinese major production bases in Fujian, Zhejiang, Jiangxi, Taiwan, Guangxi and Yunnan provinces, and based on relevant literature, the paper systematically elaborates the current researches of botanical origin, major cultivation type, seedling propagation technique as well as cultivation mode of Jinxianlian. The way of seedling breeding mainly includes aseptic seed culture, in vitro propagation, artificial seed and bioreactor propagation, etc. And the planting model mainly includes protected cultivation modes, bionic wild cultivation modes and pot cultivation modes, etc. Further discussions have also been conducted to tackle significant problems existing in the production process of Jinxianlian, based on personal studies of the authors. It has made considerable contributions for the betterment of Jinxianlian's development and improvement.


Assuntos
Produção Agrícola/tendências , Orchidaceae/crescimento & desenvolvimento , China , Orchidaceae/química , Plântula/química , Plântula/crescimento & desenvolvimento , Sementes/química , Sementes/crescimento & desenvolvimento
10.
Zhongguo Zhong Yao Za Zhi ; 41(3): 553-558, 2016 Feb.
Artigo em Zh | MEDLINE | ID: mdl-28868881

RESUMO

The current status of the domestic manufacturing and sales markets of Anoectochilus roxburghii were investigated and analyzed in the study. Some problems in the A. roxburghii industry were revealed and a variety of sustainable development countermeasures were also proposed. The main problems of A. roxburghii industry are the lack of protection for wild resources, the lag in the speed of variety breeding, the insufficient research on the quality systems, the low level of industry and product innovation capability, as well as the relatively low market cognition and brand competence. Therefore, strengthening the protection for breeding resources, establishing a dynamic monitoring system, promoting the variety breeding, constructing a propagation system for improved varieties, enhancing the quality of medicinal herbs, accelerating the adjustment of product structure, upgrading the industry technology, strengthening brand competence and expanding the market, will be the effective methods to realize the sustainable development of A. roxburghii industry.


Assuntos
Orchidaceae/crescimento & desenvolvimento , Plantas Medicinais/crescimento & desenvolvimento , Cruzamento , China , Conservação dos Recursos Naturais , Orchidaceae/química , Plantas Medicinais/química
11.
Plant Mol Biol ; 88(4-5): 325-40, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25616735

RESUMO

The artemisinic aldehyde double bond reductase (DBR2) plays an important role in the biosynthesis of the antimalarial artemisinin in Artemisia annua. Artemisinic aldehyde is reduced into dihydroartemisinic aldehyde by DBR2. Artemisinic aldehyde can also be oxidized by amorpha-4,11-diene 12-hydroxylase and/or aldehyde dehydrogenase 1 to artemisinic acid, a precursor of arteannuin B. In order to better understand the effects of DBR2 expression on the flow of artemisinic aldehyde into either artemisinin or arteannuin B, we determined the content of dihydroartemisinic aldehyde, artemisinin, artemisinic acid and arteannuin B content of A. annua varieties sorted into two chemotypes. The high artemisinin producers (HAPs), which includes the '2/39', 'Chongqing' and 'Anamed' varieties, produce more artemisinin than arteannuin B; the low artemisinin producers (LAPs), which include the 'Meise', 'Iran#8', 'Iran#14', 'Iran#24' and 'Iran#47' varieties, produce more arteannuin B than artemisinin. Quantitative PCR showed that the relative expression of DBR2 was significantly higher in the HAP varieties. We cloned and sequenced the promoter of the DBR2 gene from varieties of both the LAP and the HAP groups. There were deletions/insertions in the region just upstream of the ATG start codon in the LAP varities, which might be the reason for the different promoter activities of the HAP and LAP varieties. The relevance of promoter variation, DBR2 expression levels and artemisinin biosynthesis capabilities are discussed and a selection method for HAP varieties with a DNA marker is suggested. Furthermore, putative cis-acting regulatory elements differ between the HAP and LAP varieties.


Assuntos
Artemisia annua/genética , Artemisia annua/metabolismo , Artemisininas/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Antimaláricos/metabolismo , Artemisia annua/classificação , Sequência de Bases , DNA de Plantas/genética , Genes de Plantas , Plantas Medicinais/classificação , Plantas Medicinais/genética , Plantas Medicinais/metabolismo , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Especificidade da Espécie
12.
Planta ; 242(5): 1167-74, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26105653

RESUMO

MAIN CONCLUSION: Chinese medicinal herbs have a similar appearance and are easily confused, complicating identification via traditional methods. This study provided a scientific approach, based on DNA barcoding, to accurately and rapidly identify Anoectochilus roxburghii and its adulterants. This technology complements traditional methods of identification of medicinal herbs. A comparison of the DNA barcodes matK, psbA-trnH and ITS2 was performed to verify that the ITS2 sequence is an effective marker for rapidly and accurately identifying A. roxburghii and its closely related species. Genomic DNA extracted from A. roxburghii and its adulterants were used as templates and the ITS2 sequence was amplified using PCR amplification and sequencing. Species identification was conducted using BLAST1 and neighbor-joining trees. The 12 samples were successfully classified into four species based on the ITS2 sequence. The ITS2 sequence length of A. roxburghii was 253 bp. The average intra-specific genetic distance of A. roxburghii was 0.0021, markedly lower than the inter-specific genetic distance between A. roxburghii and its adulterants (0.0380). Our findings illustrate that ITS2 sequence can accurately and efficiently distinguish A. roxburghii and its adulterants. In addition, the results provided reference for molecular identification of other Chinese herbal medicine.


Assuntos
DNA de Plantas/genética , DNA Espaçador Ribossômico/genética , Orchidaceae/genética , Código de Barras de DNA Taxonômico , Análise de Sequência de DNA
13.
J Phys Chem A ; 119(46): 11313-9, 2015 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-26492566

RESUMO

The state-selective photodissociation of diacetylene (C4H2) was studied in the wavelength range of 127.5-164.4 nm by high-resolution Rydberg H atom time-of-flight spectroscopy measurements. In the wavelength region, two Rydberg series nR and nR' were state-selectively excited using tunable vacuum-ultraviolet laser radiation. In all photolysis wavelengths, two decay channels with different dissociation dynamics were observed. In one channel, the characteristic and isotropic translational energy distributions with a peak around 1800 cm(-1) can be found, suggesting statistical dissociation through internal conversion (IC) from the Rydberg state to the ground state and then dissociation on the ground-state surface. In contrast to this, in the second channel, nonstatistical and anisotropic translational energy distributions were observed, possibly through IC to the excited repulsive state. The vibrational progressions of C4H (A(2)Π) products have also been observed and assigned to the CCC bend and C≡C stretch progressions in the second channel at 3R Rydberg states.

14.
J Chem Phys ; 143(18): 184302, 2015 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-26567657

RESUMO

Photodissociation dynamics of HOD from the B̃ state has been studied using H/D atom Rydberg "tagging" time-of-flight technique. Both the OD + H and OH + D channels have been investigated. Product kinetic energy distributions, internal state distributions of the OD/OH product, as well as the OD/OH quantum state specific angular anisotropy parameters have been determined. Overall, the photodissociation dynamics of HOD via the B̃ state is qualitatively similar to that of the H2O and D2O, with quantitative differences arising probably from the change in masses. At different photolysis energies, similar rovibrational distributions and state-resolved angular distributions have been observed for the OH/OD(X) product, while remarkable differences have been observed in the rovibrational distributions and state-resolved angular distributions of the OH/OD(A) product.

15.
Biomater Sci ; 12(8): 2019-2032, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38469672

RESUMO

Organic fluorescent materials (OFMs) play a crucial role in the development of biosensors, enabling the extraction of biochemical information within cells and organisms, extending to the human body. Concurrently, OFM biosensors contribute significantly to the progress of modern medical and biological research. However, the practical applications of OFM biosensors face challenges, including issues related to low resolution, dispersivity, and stability. To overcome these challenges, scientists have introduced interactive elements to enhance the order of OFMs. Highly-ordered assembled OFMs represent a novel material type applied to biosensors. In comparison to conventional fluorescent materials, highly-ordered assembled OFMs typically exhibit robust anti-diffusion properties, high imaging contrast, and excellent stability. This approach has emerged as a promising method for effectively tracking bio-signals, particularly in the non-invasive monitoring of chronic diseases. This review introduces several highly-ordered assembled OFMs used in biosensors and also discusses various interactions that are responsible for their assembly, such as hydrogen bonding, π-π interaction, dipole-dipole interaction, and ion electrostatic interaction. Furthermore, it delves into the various applications of these biosensors while addressing the drawbacks that currently limit their commercial application. This review aims to provide a theoretical foundation for designing high-performance, highly-ordered assembled OFM biosensors suitable for practical applications. Additionally, it sheds light on the evolving trends in OFM biosensors and their application fields, offering valuable insights into the future of this dynamic research area.


Assuntos
Técnicas Biossensoriais , Técnicas Biossensoriais/métodos
16.
ACS Omega ; 9(1): 1738-1747, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222557

RESUMO

A novel oxidative cross-coupling of benzo[b]thiophene 1,1-dioxides with arylboronic acids was reported. The efficient reaction occurred at the C2-position via C-H activation, followed by Pd(II)-catalyzed arylation. Furthermore, a series of C2-arylated products with significant photoluminescence properties have been synthesized and characterized, which illustrates the potential applications of our method in the aggregation-induced emission field.

17.
Plant Mol Biol ; 81(1-2): 119-38, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23161198

RESUMO

Artemisinin derivatives are effective anti-malarial drugs. In order to design transgenic plants of Artemisia annua with enhanced biosynthesis of artemisinin, we are studying the promoters of genes encoding enzymes involved in artemisinin biosynthesis. A 1,151 bp promoter region of the cyp71av1 gene, encoding amorpha-4,11-diene 12-hydroxylase, was cloned. Alignment of the cloned promoter and other cyp71av1 promoter sequences indicated that the cyp71av1 promoter may be different in different A. annua varieties. Comparison to the promoter of amorpha-4,11-diene synthase gene showed a number of putative cis-acting regulatory elements in common, suggesting a co-regulation of the two genes. The cyp71av1 promoter sequence was fused to the ß-glucuronidase (GUS) reporter gene and two varieties of A. annua and Nicotiana tabacum were transformed. In A. annua, GUS expression was exclusively localized to glandular secretory trichomes (GSTs) of leaf primordia and top expanded leaves. In older leaves, there is a shift of expression to T-shaped trichomes (TSTs). Only TSTs showed GUS staining in lower leaves and there is no GUS staining in old leaves. GUS expression in flower buds was specifically localized to GSTs. The recombinant promoter carries the cis-acting regulatory elements required for GST-specific expression. The cyp71av1 promoter shows activity in young tissues. The recombinant promoter was up to 200 times more active than the wild type promoter. GUS expression in transgenic N. tabacum was localized to glandular heads. Transcript levels were up-regulated by MeJA. Wound responsiveness experiment showed that the cyp71av1 promoter does not appear to play any role in the response of A. annua to mechanical stress.


Assuntos
Artemisia annua/genética , Artemisia annua/metabolismo , Artemisininas/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Antimaláricos/metabolismo , Sequência de Bases , DNA de Plantas/genética , Expressão Gênica , Genes de Plantas , Glucuronidase/genética , Glucuronidase/metabolismo , Redes e Vias Metabólicas , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Folhas de Planta/metabolismo , Folhas de Planta/ultraestrutura , Plantas Geneticamente Modificadas , Sesquiterpenos Policíclicos , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência do Ácido Nucleico , Sesquiterpenos/metabolismo , Nicotiana/genética , Nicotiana/metabolismo
18.
Sci Rep ; 13(1): 10951, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37414877

RESUMO

In this work, we investigate the yield criterion of nanoporous materials by using homogenization approach and Steigmann-Ogden surface model. The representative volume element is proposed as an infinite matrix containing a tiny nanovoid. The matrix is incompressible, rigid-perfectly plastic, von Mises materials and nanovoids are dilute and equal in size. First, the constitutive of microscopic stress and microscopic strain rate is established based on the flow criterion. Secondly, according to the Hill's lemma, the relationship between the macroscopic equivalent modulus and the microscopic equivalent modulus is established by homogenization approach. Thirdly, the macroscopic equivalent modulus containing the Steigmann-Ogden surface model including surface parameters, porosity and nanovoid radius is derived from the trial microscopic velocity field. Finally, an implicit macroscopic yield criterion for nanoporous materials is developed. For surface modulus, nanovoids radius and porosity studies are developed through extensive numerical experiments. The research results in this paper have reference significance for the design and manufacture of nanoporous materials.

19.
Chem Commun (Camb) ; 59(58): 8969-8972, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37381946

RESUMO

The effective imaging of endogenous HNO is highly crucial for pathology research and medical development due to its important pharmacological activity in biological systems. Here, a ratiometric photoacoustic probe in response to HNO was rationally developed to effectively assess HNO prodrug release and liver injury in vivo.


Assuntos
Técnicas Fotoacústicas , Pró-Fármacos , Óxidos de Nitrogênio , Corantes Fluorescentes , Pró-Fármacos/farmacologia , Técnicas Fotoacústicas/métodos , Imagem Óptica/métodos , Fígado/diagnóstico por imagem
20.
Biosensors (Basel) ; 13(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37185569

RESUMO

Highly bio-compatible organic semiconductors are widely used as biosensors, but their long-term stability can be compromised due to photo-degradation and structural instability. To address this issue, scientists have developed organic semiconductor nanoparticles (OSNs) by incorporating organic semiconductors into a stable framework or self-assembled structure. OSNs have shown excellent performance and can be used as high-resolution biosensors in modern medical and biological research. They have been used for a wide range of applications, such as detecting small biological molecules, nucleic acids, and enzyme levels, as well as vascular imaging, tumor localization, and more. In particular, OSNs can simulate fine particulate matters (PM2.5, indicating particulate matter with an aerodynamic diameter less than or equal to 2.5 µm) and can be used to study the biodistribution, clearance pathways, and health effects of such particles. However, there are still some problems that need to be solved, such as toxicity, metabolic mechanism, and fluorescence intensity. In this review, based on the structure and design strategies of OSNs, we introduce various types of OSNs-based biosensors with functional groups used as biosensors and discuss their applications in both in vitro and in vivo tracking. Finally, we also discuss the design strategies and potential future trends of OSNs-based biosensors. This review provides a theoretical scaffold for the design of high-performance OSNs-based biosensors and highlights important trends and future directions for their development and application.


Assuntos
Técnicas Biossensoriais , Nanopartículas , Pontos Quânticos , Distribuição Tecidual , Técnicas Biossensoriais/métodos , Semicondutores
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