Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
1.
Nat Commun ; 15(1): 3017, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589414

RESUMEN

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically considered but not probed experimentally. Here, we report the observation of a nonlinear optical diode effect (NODE) in the magnetic Weyl semimetal CeAlSi, where the magnetization introduces a pronounced directionality in the nonlinear optical second-harmonic generation (SHG). We demonstrate a six-fold change of the measured SHG intensity between opposite propagation directions over a bandwidth exceeding 250 meV. Supported by density-functional theory, we establish the linearly dispersive bands emerging from Weyl nodes as the origin of this broadband effect. We further demonstrate current-induced magnetization switching and thus electrical control of the NODE. Our results advance ongoing research to identify novel nonlinear optical/transport phenomena in magnetic topological materials and further opens new pathways for the unidirectional manipulation of light.

3.
Gen Hosp Psychiatry ; 87: 92-102, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38382421

RESUMEN

OBJECTIVE: Poor sleep quality is common in patients with cancer, but the prevalence rates varied widely across studies. This systematic review and meta-analysis examined the pooled prevalence of poor sleep quality among patients with cancer. METHODS: Systematic literature searches were independently conducted in the major databases (Web of Science, PubMed, EMBASE and PsycINFO). Studies that reported the prevalence of poor sleep quality in patients with cancer were analyzed using a random effects model. Funnel plots and Egger's tests were used to assess publication bias. Statistical analyses were performed using R software. RESULTS: A total of 59 epidemiological studies involving 16,223 patients were included. The pooled prevalence of poor sleep quality in patients with cancer was 57.4% [95% confidence interval (CI): 53.3% - 61.6%]. Additionally, three comparative studies with 372 patients and 412 healthy controls were included. Compared to healthy controls, patients with cancer had a significantly higher risk for poor sleep quality [odd ratio (OR) = 3.0; 95%CI: 1.2-7.2; P < 0.05]. Subgroup analyses of the studies revealed that studies from Middle East & North Africa region and low income countries, and on gynecological cancer as well as those with a lower cut-off value of sleep quality (all P < 0.01) reported a higher prevalence of poor sleep quality. Meta-regression analyses showed that higher prevalence of poor sleep quality was associated with higher prevalence of comorbid depression (P < 0.05) and anxiety (P < 0.01), but was associated with a lower education level (P < 0.05) and alcohol use ratio (P < 0.05). CONCLUSION: Poor sleep quality is common among patients with cancer. Considering the overall high prevalence rate and negative impact of poor sleep quality, appropriate measures to identify and improve poor sleep quality are needed to enhance the clinical outcomes in this group.


Asunto(s)
Neoplasias , Calidad del Sueño , Humanos , Prevalencia , Comorbilidad , Consumo de Bebidas Alcohólicas , Neoplasias/epidemiología
4.
Schizophr Res ; 264: 407-415, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38241784

RESUMEN

OBJECTIVE: Poor sleep quality is common in patients with schizophrenia but estimated prevalence rates in this population have been mixed. This systematic review and meta-analysis examined the prevalence of poor sleep quality in schizophrenia samples and moderators of prevalence from epidemiological studies as well as the risk of poor sleep quality in schizophrenia patients based on case-control studies. METHODS: Both international (PubMed, Web of Science, PsycINFO, EMBASE) and Chinese databases [Chinese Nation knowledge Infrastructure (CNKI) and WANFANG] were systematically searched. Studies that estimated the prevalence of poor sleep quality in schizophrenia were analyzed using a random effects model. Funnel plots and Egger's tests were used to assess publication bias. Statistical analyses were performed using R software. RESULTS: In total, 23 epidemiological studies and nine case-control studies were included. Based on the epidemiological studies, the pooled overall prevalence of poor sleep quality was 63.4 % [95 % confidence interval (CI): 57.0 %-69.9 %]. Additionally, based on the nine case-control studies, schizophrenia patients had a significantly higher risk for poor sleep quality compared to healthy controls [odd ratio (OR) = 4.5; 95%CI: 2.4-8.3; P < 0.0001]. CONCLUSION: Poor sleep quality is common among schizophrenia patients. Considering negative outcomes caused by poor sleep quality, regular screening on poor sleep quality should be conducted and effective interventions should be provided to those in need.


Asunto(s)
Esquizofrenia , Humanos , Esquizofrenia/epidemiología , Calidad del Sueño , Estudios de Casos y Controles , Proyectos de Investigación , Prevalencia
5.
J Am Chem Soc ; 146(5): 3396-3404, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38266485

RESUMEN

Covalent organic frameworks (COFs), with the features of flexible structure regulation and easy introduction of functional groups, have aroused broad interest in the field of photocatalysis. However, due to the low light absorption intensity, low photoelectron conversion efficiency, and lack of suitable active sites, it remains a great challenge to achieve efficient photocatalytic aerobic oxidation reactions. Herein, based on reticular chemistry, we rationally designed a series of three-motif molecular junction type COFs, which formed dual photosensitizer coupled redox molecular junctions containing multifunctional COF photocatalysts. Significantly, due to the strong light adsorption ability of dual photosensitizer units and integrated oxidation and reduction features, the PY-BT COF exhibited the highest activity for photocatalytic aerobic oxidation. Especially, it achieved a photocatalytic benzylamine conversion efficiency of 99.9% in 2.5 h, which is much higher than that of the two-motif molecular junctions with only one photosensitizer or redox unit lacking COFs. The mechanism of selective aerobic oxidation was studied through comprehensive experiments and density functional theory calculations. The results showed that the photoinduced electron transfer occurred from PY and then through triphenylamine to BT. Furthermore, the thermodynamics energy for benzylamine oxidation on PY-BT COF was much lower than that for others, which confirmed the synergistic effect of dual photosensitizer coupled redox molecular junction COFs. This work provided a new strategy for the design of functional COFs with three-motif molecular junctions and also represented a new insight into the multifunctional COFs for organic catalytic reactions.

6.
J Tradit Complement Med ; 13(6): 600-610, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38020551

RESUMEN

Background and aim: The purpose of this study is to explore whether the Xiaozheng pill (XZP) has the effect of anti-hyperplasia of mammary glands (HMG) and to identify the related signaling pathways. Experimental procedure: We analyzed the effective chemical components of the XZP, as well as the key chemical components, key proteins, main biological processes, and pathways in the treatment of HMG; Secondly, the levels of Estradiol (E2), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Progesterone (P), Raf/ERK/ELK and HIF-1α/bFGF pathways related proteins were detected; Finally, the effect of XZP on metabolites was analyzed by metabolomics. Results and conclusion: In this study, we identified key targets and pathways for XZP therapy of HMG, including EGFR, VEGFA, ER, and Ras signaling pathways. Animal experiments show that XZP can reduce the levels of E2, LH, and FSH and increase the expression of P in HMG mice. XZP can restore the normal structure of breast tissue and reduce ERα, ERß, and PR expression in breast tissue. In addition, metabolomics results show that XZP also regulates HMG metabolites, including HIF-1α and metabolic pathways. The Western blot results showed that XZP intervention can reduce the protein expression of p-Raf1, Raf1, p-ERK1/2, ERK1/2, ELK, HIF-1α, and bFGF in the breast tissue of HMG mice. XZP may eliminate abnormal breast hyperplasia through inhibition of apoptosis and angiogenesis, which may be linked with the regulation of the Raf/ERK/ELK and HIF-1α/bFGF signaling pathways in HMG mice. These results suggest that XZP treatment may be beneficial for the management of HMG.

7.
Angew Chem Int Ed Engl ; 62(44): e202311999, 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37709724

RESUMEN

The high local electron density and efficient charge carrier separation are two important factors to affect photocatalytic activity, especially for the CO2 photoreduction reaction. However, the systematic studies on the structure-functional relationship regarding the above two factors based on precisely structure model are rarely reported. Herein, as a proof-of-concept, we developed a new strategy on the evaluation of local electron density by controlling the relative electron-deficient (ED) and electron-rich (ER) intensity of monomer at a molecular level based on three rational-designed vinylene-linked sp2 carbon-covalent organic frameworks (COFs). As expected, the as-prepared vinylene-linked sp2 carbon-conjugated metal-covalent organic framework (MCOFs) (VL-MCOF-1) with molecular junction exhibited excellent activities for CO2 -to-HCOOH conversion (283.41 µmol g-1 h-1 ) and high selectivity of 97.1 %, much higher than the VL-MCOF-2 and g-C34 N6 -COF, which is due to the synergistic effect of the multi-electronic metal clusters (Cu3 (PyCA)3 ) (PyCA=pyrazolate-4-carboxaldehyde) as strong ER roles and cyanopyridine units as ED roles and active sites, as well as the boosted photo-induced charge separation efficiency of vinyl connection and increased light utilization ability. These results not only provide a strategy for regulating the electron-density distribution of photocatalysts at the molecular level but also offers profound insights for metal clusters-based COFs to effective CO2 conversion.

8.
World J Clin Cases ; 11(23): 5440-5446, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37637688

RESUMEN

BACKGROUND: Although norepinephrine injection is commonly used in emergency situations, it is associated with risks for elderly patients with spasmodic liver pain. This study explores the safety and effectiveness of mebendazole injection, an alternative treatment option, for the emergency management of spasmodic abdominal pain, while minimizing adverse reactions, in elderly patients. AIM: To explore the development of norepinephrine injection and the adverse reactions of this drug in emergency elderly patients with spasmodic liver pain. METHODS: The control group consisted of 56 elderly patients visiting our hospital from January 2021 to December 2021. After hospital admission, the control group was intravenously administered tolopin. The experimental group consisted of 56 emergency patients with spasmodic abdominal pain who visited our hospital until June 2022. After hospital admission, the experimental group was intravenously administered toloxazole. The two groups were treated for 3 d. The disappearance of clinical symptoms was observed before and after the treatment, and the difference in adverse reactions between the two groups was compared. RESULTS: The pain of the wife, fire, diarrhea, drowning, and surrounding time disappeared in the experimental group. No statistical difference was observed between the experimental and control groups in visual pain analog scale (VAS) scores before and after the treatment (P > 0.05). The VAS scores of abdominal pain severity after 0.5 h, 1.0 h, and after 6.0 h of treatment were significantly lower for the experimental group than for the control group. After the treatment, the therapeutic effect in the experimental group was higher and statistically significant than that in the control group (P < 0.05). The probability of adverse reactions before the treatment was lower in the experimental group than in the control group. CONCLUSION: During emergency, mebendazole injection exhibited a good therapeutic value when used for the clinical treatment of elderly patients with spasmodic stomach pain. It accelerated the disappearance of clinical symptoms such as stomach pain, reduced the stomach weight, and improved clinical activity. Reducing and promoting the frequency of high treatment safety with mebendazole injection is worthwhile.

9.
Sleep Med Rev ; 71: 101840, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37647751

RESUMEN

Poor sleep quality is prevalent among members of the military but rates of poor sleep quality vary between studies. This study examined the global prevalence of poor sleep quality in military personnel and veterans as well as possible moderators of prevalence differences between studies. PubMed, EMBASE, Web of Science, and PsycINFO were systematically searched from their inception dates to September 1, 2022. Studies were included if they were conducted on military personnel and/or veterans and prevalence estimates of poor sleep quality could be generated from assessments with standardized tools. A random-effects model was used to calculate the pooled prevalence and its 95% confidence intervals (CIs). Fifty-nine studies (N = 28,100) were included for analysis with sample sizes ranging from 14 to 8481. Two studies were rated as "high quality" (3.39%), while 57 were rated as "moderate quality" (96.61%). The overall pooled prevalence of poor sleep quality in military personnel and veterans was 69.00% (95% CI: 62.33-75.30%); pooled rates were 57.79% (95% CI: 49.88-65.50%) and 82.88% (95% CI: 74.08-90.21%) for active duty personnel and veterans, respectively. Subgroup analyses indicated study region, study design, sampling method, Pittsburg Sleep Quality Index cut-off values, and service type moderated prevalence of poor sleep quality. Meta-regression analyses indicated sample size, mean age, depression and posttraumatic stress disorder (PTSD) were associated with prevalence differences between studies. Poor sleep quality was more common in both active duty military personnel and veterans who were older and those who reported PTSD or depression. Regular monitoring of sleep quality and sleep hygiene should be promoted in this population. More relevant studies in middle- and low-income countries should also be conducted.

10.
Clin Transl Med ; 13(7): e1338, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37488671

RESUMEN

BACKGROUND: Recurrent bladder cancer is the most common type of urinary tract malignancy; nevertheless, the mechanistic basis for its recurrence is uncertain. Innovative technologies such as single-cell transcriptomics and spatial transcriptomics (ST) offer new avenues for studying recurrent tumour progression at the single-cell level while preserving spatial data. METHOD: This study integrated single-cell RNA (scRNA) sequencing and ST profiling to examine the tumour microenvironment (TME) of six bladder cancer tissues (three from primary tumours and three from recurrent tumours). FINDINGS: scRNA data-based ST deconvolution analysis revealed a much higher tumour heterogeneity along with TME in recurrent tumours than in primary tumours. High-resolution ST analysis further identified that while the overall natural killer/T cell and malignant cell count or the ratio of total cells was similar or even lower in the recurrent tumours, a higher interaction between epithelial and immune cells was detected. Moreover, the analysis of spatial communication reveals a marked increase in activity between cancer-associated fibroblasts (CAFs) and malignant cells, as well as other immune cells in recurrent tumours. INTERPRETATION: We observed an enhanced interplay between CAFs and malignant cells in bladder recurrent tumours. These findings were first observed at the spatial level.


Asunto(s)
Fibroblastos Asociados al Cáncer , Neoplasias de la Vejiga Urinaria , Humanos , Transcriptoma , Fibroblastos , Vejiga Urinaria , Microambiente Tumoral
11.
Angew Chem Int Ed Engl ; 62(31): e202307632, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37280179

RESUMEN

In this work, we innovatively assembled two types of traditional photosensitizers, that is pyridine ruthenium/ferrum (Ru(bpy)3 2+ /Fe(bpy)3 2+ ) and porphyrin/metalloporphyrin complex (2HPor/ZnPor) by covalent linkage to get a series of dual photosensitizer-based three-dimensional metal-covalent organic frameworks (3D MCOFs), which behaved strong visible light-absorbing ability, efficient electron transfer and suitable band gap for highly efficient photocatalytic hydrogen (H2 ) evolution. Rubpy-ZnPor COF achieved the highest H2 yield (30 338 µmol g-1 h-1 ) with apparent quantum efficiency (AQE) of 9.68 %@420 nm, which showed one of the best performances among all reported COF based photocatalysts. Furthermore, the in situ produced H2 was successfully tandem used in the alkyne hydrogenation with ≈99.9 % conversion efficiency. Theoretical calculations reveal that both the two photosensitizer units in MCOFs can be photoexcited and thus contribute optimal photocatalytic activity. This work develops a general strategy and shows the great potential of using multiple photosensitive materials in the field of photocatalysis.

12.
Science ; 381(6654): 181-186, 2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37319246

RESUMEN

Quantum geometry in condensed-matter physics has two components: the real part quantum metric and the imaginary part Berry curvature. Whereas the effects of Berry curvature have been observed through phenomena such as the quantum Hall effect in two-dimensional electron gases and the anomalous Hall effect (AHE) in ferromagnets, the quantum metric has rarely been explored. Here, we report a nonlinear Hall effect induced by the quantum metric dipole by interfacing even-layered MnBi2Te4 with black phosphorus. The quantum metric nonlinear Hall effect switches direction upon reversing the antiferromagnetic (AFM) spins and exhibits distinct scaling that is independent of the scattering time. Our results open the door to discovering quantum metric responses predicted theoretically and pave the way for applications that bridge nonlinear electronics with AFM spintronics.

13.
Asian J Surg ; 46(9): 3529-3541, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37330302

RESUMEN

BACKGROUND: Melatonin is a neurohormone involved in diverse physiological processes, including regulation of circadian rhythm, oncogenesis and immune function. More attention are focused on the molecular events surrounding the occurrence of abnormally expressed lncRNAs leading to breast cancer. The purpose of this study was to evaluate the role of melatonin-related lncRNAs in the clinical management of BRCA patients and their immune responses. METHODS: The transcriptome data and clinical data of BRCA patients were acquired from TCGA database. A total of 1103 patients were randomly assigned to either training set or validation set. A melatonin-related lncRNA signature was constructed in the training set and verified in the validation set. Functional analysis, immune microenvironment and drug resistance analysis associated to melatonin-related lncRNAs were performed by utilizing GO&KEGG, ESTIMATE and TIDE analysis. A nomogram based on the signature score and clinical characteristics was established, which was calibrated to increase prediction probability of 1-year, 3-year and 5-year survival for BRCA patients. RESULTS: BRCA patients were divided into two signature groups based on a 17-melatonin-related lncRNA signature. High-signature patients had worse prognosis than low-signature patients (p < 0.001). Univariate and multivariate Cox regression analysis proved that the signature score was an independent prognostic factor for BRCA patients. Functional analysis indicated that high-signature BRCA involved in regulation of processing and maturation of mRNA and misfolded protein response. Remarkably, immune microenvironment analysis showed that the proportion of tumor-infiltrating M2 macrophage and the expression of CTLA4 were significantly higher in high-signature BRCA. The calibration curves for the probability of invasive BRCA showed optimal agreement between the probability as predicted by the nomogram and the actual probability. CONCLUSIONS: A novel melatonin-related lncRNA signature was considered as an independent prognostic indicator for BRCA patients. Melatonin-related lncRNAs were potentially associated with tumor immune microenvironment and might be therapeutic targets for BRCA patients.


Asunto(s)
Neoplasias de la Mama , Melatonina , ARN Largo no Codificante , Humanos , Femenino , Pronóstico , Nomogramas , Microambiente Tumoral
14.
Psychiatry Clin Neurosci ; 77(10): 541-549, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37350640

RESUMEN

AIMS: Hikikomori is a common phenomenon reported in Japan and many other countries. However, the broad trends of the research publications on hikikomori are unclear. Therefore, this study examined the patterns of research on hikikomori using bibliometric analysis. METHODS: Relevant publications were searched in Web of Science. Bibliometric analyses were performed with CiteSpace, R and VOSviewer. RESULTS: In total, 297 publications on hikikomori met the eligibility criteria. The International Journal of Social Psychiatry (IF = 10.461) published the most papers (K = 17, or 5.7%) on hikikomori. Takahiro A. Kato from Kyushu University (41; 13.8%; H-index = 18) was the most influential author, while Takahiro A. Kato (total link strength [TLS]: 235), Alan R. Teo (TLS: 157), and Masaru Tateno (TLS: 153) separately had the strongest research collaboration with other researchers. Of all countries that published on hikikomori, Japan had the highest number of publications (K = 91). The keywords "United States" and "psychiatric diagnosis" received the most attention between 2013 and 2015, whereas "health" and "autism spectrum disorder" received the most attention in 2021 and 2022. CONCLUSIONS: Peer-reviewed research publications on hikikomori are growing rapidly and the research trends in this field are also changing.


Asunto(s)
Trastorno del Espectro Autista , Fobia Social , Humanos , Bibliometría , Japón
15.
Nat Mater ; 22(5): 583-590, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36894774

RESUMEN

Using circularly polarized light to control quantum matter is a highly intriguing topic in physics, chemistry and biology. Previous studies have demonstrated helicity-dependent optical control of chirality and magnetization, with important implications in asymmetric synthesis in chemistry; homochirality in biomolecules; and ferromagnetic spintronics. We report the surprising observation of helicity-dependent optical control of fully compensated antiferromagnetic order in two-dimensional even-layered MnBi2Te4, a topological axion insulator with neither chirality nor magnetization. To understand this control, we study an antiferromagnetic circular dichroism, which appears only in reflection but is absent in transmission. We show that the optical control and circular dichroism both arise from the optical axion electrodynamics. Our axion induction provides the possibility to optically control a family of [Formula: see text]-symmetric antiferromagnets ([Formula: see text], inversion; [Formula: see text], time-reversal) such as Cr2O3, even-layered CrI3 and possibly the pseudo-gap state in cuprates. In MnBi2Te4, this further opens the door for optical writing of a dissipationless circuit formed by topological edge states.

16.
Front Psychiatry ; 14: 1145409, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36923522

RESUMEN

Background: A growing number of studies has implicated oxidative stress in the pathophysiology of psychiatric disorders including schizophrenia. The aim of this study was to explore the field of schizophrenia and oxidative stress-related research from a bibliometric perspective. Methods: All relevant publications on schizophrenia and oxidative stress were obtained from Web of Science Core Collection (WOSCC) database from its inception date to November 8, 2022. VOSviewer software was used to examine co-authorships and co-occurring keywords. R software was used to present the main characteristics of publications and cooperation frequency among countries. CiteSpace was used to investigate keywords with the strongest citation bursts. Results: A total of 3,510 publications on schizophrenia and oxidative stress were included. The United States had the largest number of publications (26.1%), and international collaborations. University of Melbourne was the most productive institution, while Schizophrenia Research was the most productive journal in this field. Apart from "schizophrenia" and "oxidative stress", the terms "prefrontal cortex", "brain" and "nitric oxide" were among the most frequently used keywords. Conclusions: In conclusion, research on the association between oxidative stress and schizophrenia has received growing attention in the academic literature that is expected to continue its upward trajectory during the next two decades. Existing research suggests there has been a transition from research focused on pathways to animal models, and subsequently to clinical applications. Intervention studies on oxidative stress and schizophrenia are likely to be an important focus of related work in the near future.

17.
Front Psychiatry ; 14: 1086638, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36937736

RESUMEN

Background: Depression commonly occurs in heart failure patients, and negatively influences quality of life and disease prognosis. This study explored heart failure and depression-related research from a bibliometric perspective. Methods: Relevant publications were searched on June 24, 2022. The Bibliometrix package in R was used to conduct quantitative analyses including the trends in publications, and related countries, articles, authors and keywords. VOSviewer software was used to conduct the visualization map on co-word, co-author, and institution co-authorship analyses. CiteSpace software was used to illustrate the top keywords with citation burst. Results: A total of 8,221 publications in the heart failure and depression-related research field were published between 1983 and 2022. In this field, the United States had the most publications (N = 3,013; 36.65%) and highest total citation (N = 149, 376), followed by China, Germany, Italy and Japan. Author Moser and Duke University were the most productive author and institution, respectively. Circulation is the most influential journal. Apart from "heart failure" and "depression," "quality of life," "mortality" and "myocardial infarction" were the most frequently used keywords in this research area; whereas more recently, "self care" and "anxiety" have been used more frequently. Conclusion: This bibliometric analysis showed a rapid growth of research related to heart failure and depression from 1989 to 2021, which was mostly led by North America and Europe. Future directions in this research area include issues concerning self-care and anxiety about heart failure. As most of the existing literature were published in English, publications in other languages should be examined in the future.

18.
Hortic Res ; 10(2): uhac279, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36793757

RESUMEN

Caffeine is an important functional component in tea, which has the effect of excitement and nerve stimulation, but excessive intake can cause insomnia and dysphoria. Therefore, the production of tea with low-caffeine content can meet the consumption needs of certain people. Here, in addition to the previous alleles of the tea caffeine synthase (TCS1) gene, a new allele (TCS1h) from tea germplasms was identified. Results of in vitro activity analysis showed that TCS1h had both theobromine synthase (TS) and caffeine synthase (CS) activities. Site-directed mutagenesis experiments of TCS1a, TCS1c, and TCS1h demonstrated that apart from the 225th amino acid residue, the 269th amino acid also determined the CS activity. GUS histochemical analysis and dual-luciferase assay indicated the low promoter activity of TCS1e and TCS1f. In parallel, insertion and deletion mutations in large fragments of alleles and experiments of site-directed mutagenesis identified a key cis-acting element (G-box). Furthermore, it was found that the contents of purine alkaloids were related to the expression of corresponding functional genes and alleles, and the absence or presence and level of gene expression determined the content of purine alkaloids in tea plants to a certain extent. In summary, we concluded TCS1 alleles into three types with different functions and proposed a strategy to effectively enhance low-caffeine tea germplasms in breeding practices. This research provided an applicable technical avenue for accelerating the cultivation of specific low-caffeine tea plants.

19.
J Nat Med ; 77(2): 397-402, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36689084

RESUMEN

Two new ß-carboline alkaloids, anemonilins A and B (1-2), and two known ß-carboline alkaloids, flazine (3) and 4-(9H-ß-carbolin-l-yl)-4-oxo-butyric acid (4), were isolated from the roots of Anemone altaica. The structures of the isolated compounds were elucidated with spectroscopic and spectrometric methods (1D and 2DNMR, HRESIMS). Compounds 2 and 4 significantly attenuated the growth inhibition induced by lipopolysaccharide (LPS) in normal rat kidney tubule epithelioid (NRK52e) cells (p < 0.05 or p < 0.01). Furthermore, compound 2 significantly reduced the apoptosis (p < 0.05) and the caspase-3/9 expression of NRK52e cells induced by LPS.


Asunto(s)
Alcaloides , Anemone , Ratas , Animales , Lipopolisacáridos/farmacología , Alcaloides/química , Carbolinas/química , Estructura Molecular
20.
Fitoterapia ; 165: 105396, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36526219

RESUMEN

Phytochemical investigation of the 95% ethanol extract from Pinus yunnanensis Franch resin induced the isolation of six previously unreported diterpenoids pinuyunnanacids K - N, P - Q, a nor-diterpenoid with a novel skeleton pinuyunnanacid O and six known analogues. Their structures were elucidated by spectroscopic analysis and computational methods, including nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, calculated NMR chemical shifts method and electronic circular dichroic (ECD) spectra. All the compounds were analyzed for anti-inflammatory activity through western blotting and cell viability, compounds 2, 10 and 12 significantly downregulated the protein expression of iNOS at the concentration of 40 µM. At the same time, compounds 10 and 12 decreased the expression of COX-2 in LPS-treated RAW264.7 (leukemia cells in mouse macrophage) cells at the concentration of 40 µM.


Asunto(s)
Diterpenos , Pinus , Ratones , Animales , Estructura Molecular , Diterpenos/farmacología , Diterpenos/química , Espectroscopía de Resonancia Magnética , Antiinflamatorios/farmacología , Antiinflamatorios/química , Resinas de Plantas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...