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1.
Plant Cell ; 36(2): 383-403, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-37847118

RESUMEN

The Casparian strip (CS) is a ring-like lignin structure deposited between endodermal cells that forms an apoplastic barrier to control the selective uptake of nutrients in vascular plants. However, the molecular mechanism of CS formation in rice (Oryza sativa), which possesses one CS each in the endodermis and exodermis, is relatively unknown. Here, we functionally characterized CS INTEGRITY FACTOR1 (OsCIF1a, OsCIF1b), OsCIF2, and SCHENGEN3 (OsSGN3a, OsSGN3b) in rice. OsCIF1s and OsCIF2 were mainly expressed in the stele, while OsSGN3s localized around the CS at the endodermis. Knockout of all three OsCIFs or both OsSGN3s resulted in a discontinuous CS and a dramatic reduction in compensatory (less localized) lignification and suberization at the endodermis. By contrast, ectopic overexpression of OsCIF1 or OsCIF2 induced CS formation as well as overlignification and oversuberization at single or double cortical cell layers adjacent to the endodermis. Ectopic co-overexpression of OsCIF1 and SHORTROOT1 (OsSHR1) induced the formation of more CS-like structures at multiple cortical cell layers. Transcriptome analysis identified 112 downstream genes modulated by the OsCIF1/2-OsSGN3 signaling pathway, which is involved in CS formation and activation of the compensatory machinery in native endodermis and nonnative endodermis-like cell layers. Our results provide important insights into the molecular mechanism of CIF-mediated CS formation at the root endodermal and nonendodermal cell layers.


Asunto(s)
Arabidopsis , Oryza , Arabidopsis/genética , Oryza/genética , Raíces de Plantas/metabolismo , Pared Celular/metabolismo , Péptidos/metabolismo , Transducción de Señal/genética
2.
Chemistry ; 29(42): e202301080, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37169722

RESUMEN

Two novel poly(3,5-diamide substituted phenylacetylene)s bearing L- or D-alanine residues with a long alkyl chain were synthesized. In low polar or apolar solvents, the polymers adopted contracted cis-cisoid helix showing strong yellow fluorescence, which was transferred to stretched cis-transoid helix by adding polar solvents or decreasing temperature, accompanied with the disappearance of fluorescence. The critical conformational transition temperature could be readily tuned in a wide range by altering the content of polar solvent, and the conformational variation at molecular level could be directly read out via the change in fluorescent property. The synergistical participation of amide and ester groups in the formation of intramolecular hydrogen bonds accelerated the conformational transition rate, resulting in remarkable reduction of hysteresis. Moreover, the polymers displayed switchable CPL performance and the luminescent dissymmetry factor could be stepwise amplified by forming chiral aggregates or liquid crystalline structure. This study may open a new avenue for the development of controllable helical structure-based smart CPL materials.

3.
Biol Lett ; 19(7): 20230203, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37465912

RESUMEN

The ability to discriminate relative quantities, one of the numerical competences, is considered an adaptive trait in uncertain environments. Besides humans, previous studies have reported this capacity in several non-human primates and birds. Here, we test whether red-eared sliders (Trachemys scripta elegans) can discriminate different relative quantities. Subjects were first trained to distinguish different stimuli with food reward. Then, they were tested with novel stimulus pairs to demonstrate how they distinguished the stimuli. The results show that most subjects can complete the initial training and use relative quantity rather than absolute quantity to make choices during the testing phase. This study provides behavioural evidence of relative quantity discrimination in a reptile species and suggests that such capacity may be widespread among vertebrates.


Asunto(s)
Tortugas , Animales , Humanos , Aprendizaje
4.
Transp Res Part C Emerg Technol ; 152: 104188, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37305559

RESUMEN

The COVID-19 pandemic has hit the airline industry hard, leading to heterogeneous epidemiological situations across markets, irregular flight bans, and increasing operational hurdles. Such a melange of irregularities has presented significant challenges to the airline industry, which typically relies on long-term planning. Given the growing risk of disruptions during epidemic and pandemic outbreaks, the role of airline recovery is becoming increasingly crucial for the aviation industry. This study proposes a novel model for airline integrated recovery problem under the risk of in-flight epidemic transmission risks. This model recovers the schedules of aircraft, crew, and passengers to eliminate possible epidemic dissemination while reducing airline operating costs. To account for the high uncertainty with respect to in-flight transmission rates and to prevent overfitting of the empirical distribution, a Wasserstein distance-based ambiguity set is utilized to formulate a distributionally robust optimization model. Aimed at tackling computation difficulties, a branch-and-cut solution method and a large neighborhood search heuristic are proposed in this study based on an epidemic propagation network. The computation results for real-world flight schedules and a probabilistic infection model suggest that the proposed model is capable of reducing the expected number of infected crew members and passengers by 45% with less than 4% increase in flight cancellation/delay rates. Furthermore, practical insights into the selection of critical parameters as well as their relationship with other common disruptions are provided. The integrated model is expected to enhance airline disruption management against major public health events while minimizing economic loss.

5.
Transp Policy (Oxf) ; 118: 10-19, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35125681

RESUMEN

The devastating impact of COVID-19 on aviation is unprecedented and undoubted in the recent sci-entific literature, with many studies having dissected different facets of COVID-19-induced changes to the industry. A few studies have stepped further and highlighted that the COVID-19 pandemic could have positive long-term impacts on aviation. Given that traditional air carriers are known to be reluctant for performing high-risk experiments outside their business-as-usual, parts of hope for a better aviation future rests on novel players entering the industry. The pandemic - against common perception and odds - might have created a rare opportunity for airline startups to enter the market. In this study, we first dissect the impact of the COVID-19 pandemic on aviation and how it possibly created a breeding ground for new airlines. We propose a framework of eight facets, STARTUPS, covering flight Suspensions, Talents, Aircraft, Recovery, Travel demand, Uniquity, Policy making, and Strategy. Moreover, we analyze the business model and markets of 46 airline startups, established or becoming active during the pandemic. Our study is concluded with a dis-cussion on the risk factors for airline startups during the COVID-19 pandemic and induced policy challenges. Our analysis, we believe, is complementary to existing studies on COVID-19, leveraging a novel perspective on the pandemic and the aviation industry.

6.
Transp Policy (Oxf) ; 127: 203-217, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36092947

RESUMEN

The impact of the COVID-19 pandemic is unprecedented in airline history, with irregular flight bans, the inability for accurate demand estimation, several turns in the epidemiological evolution, and a wide range of downstream effects on all aviation stakeholders. While most airlines have increasingly entered a recovery stage, compared to the utmost disruption around April 2020, the airline business is far from back-to-normality. Throughout the past two years, recurrent statements have been made regarding the existence of so-called ghost flights, where airlines operate nearly empty aircraft on markets with insufficient demand, partially with the aim to avoid losing precious airport slots. This study investigates the extent of such abnormal market service during the COVID-19 pandemic through an explorative, data-driven analysis, based on actual load factor data of European airlines for the years 2017 to 2021. We break down the observed deviations by airlines, markets, and airports. We find that low-cost carriers are most-likely to have performed abnormal flights during the pandemic; and that abnormal flights have mostly occurred on frequently-served markets. In addition, we show that airline responses, in terms of departure and yield changes, are largely heterogeneous across the 24 airlines in this study. Our study is the first one to shed light on the important issue of load factor deviations, and we hope that our findings can contribute to a better understanding of the existence of abnormal flights during the pandemic, as well as deriving appropriate policies for dealing with the ubiquitous threat and impact of ghost flights in the future.

7.
BMC Plant Biol ; 21(1): 132, 2021 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-33750309

RESUMEN

BACKGROUND: Tartary buckwheat seed development is an extremely complex process involving many gene regulatory pathways. MicroRNAs (miRNAs) have been identified as the important negative regulators of gene expression and performed crucial regulatory roles in various plant biological processes. However, whether miRNAs participate in Tartary buckwheat seed development remains unexplored. RESULTS: In this study, we first identified 26 miRNA biosynthesis genes in the Tartary buckwheat genome and described their phylogeny and expression profiling. Then we performed small RNA (sRNA) sequencing for Tartary buckwheat seeds at three developmental stages to identify the miRNAs associated with seed development. In total, 230 miRNAs, including 101 conserved and 129 novel miRNAs, were first identified in Tartary buckwheat, and 3268 target genes were successfully predicted. Among these miRNAs, 76 exhibited differential expression during seed development, and 1534 target genes which correspond to 74 differentially expressed miRNAs (DEMs) were identified. Based on integrated analysis of DEMs and their targets expression, 65 miRNA-mRNA interaction pairs (25 DEMs corresponding to 65 target genes) were identified that exhibited significantly opposite expression during Tartary buckwheat seed development, and 6 of the miRNA-mRNA pairs were further verified by quantitative real-time polymerase chain reaction (qRT-PCR) and ligase-mediated rapid amplification of 5' cDNA ends (5'-RLM-RACE). Functional annotation of the 65 target mRNAs showed that 56 miRNA-mRNA interaction pairs major involved in cell differentiation and proliferation, cell elongation, hormones response, organogenesis, embryo and endosperm development, seed size, mineral elements transport, and flavonoid biosynthesis, which indicated that they are the key miRNA-mRNA pairs for Tartary buckwheat seed development. CONCLUSIONS: Our findings provided insights for the first time into miRNA-mediated regulatory pathways in Tartary buckwheat seed development and suggested that miRNAs play important role in Tartary buckwheat seed development. These findings will be help to study the roles and regulatory mechanism of miRNAs in Tartary buckwheat seed development.


Asunto(s)
Fagopyrum/crecimiento & desarrollo , Fagopyrum/genética , MicroARNs/fisiología , ARN Mensajero/fisiología , ARN de Planta/fisiología , Semillas/crecimiento & desarrollo , Evolución Molecular , Perfilación de la Expresión Génica , Reacción en Cadena de la Ligasa , MicroARNs/genética , Filogenia , Desarrollo de la Planta/genética , ARN de Planta/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Semillas/genética
8.
Transp Res Part A Policy Pract ; 152: 203-215, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34664004

RESUMEN

After more than a year with COVID-19, it becomes increasingly clear that certain variants of concern have the potential to be game changers, determining the future of our aviation. These variants pose significant health threats and possibly undermine ongoing vaccination efforts. Recent research showed that flight bans on the initial SARS-CoV-2 outbreak in January 2020 were implemented too late and therefore, turned out to be largely ineffective, enabling a swift turn into a fully-blown pandemic. In this study, we investigate the following question: How effective were existing flight bans against the newly emerged variants of concern? In other words: Do airlines and countries happen to repeat the same mistake again? We analyze the spread of the three most prevalent variants of concern right now: B.1.1.7 (known as the UK variant), B.1.351 (known as the South African variant), and P.1 (known as the Brazilian variant). We find that many countries, again, implemented flights bans once the mutated virus had enough time to be imported via air transportation. To support our empirical analysis further, we designed and implemented a compartmental network spreading model on top of worldwide flight data for the years 2020 and 2021. We observe that the model predictions are rather accurate and confirm our findings. Overall, we hope that our study encourages air transportation stakeholders and policy makers to avoid repeating earlier mistakes in the future, with the ultimate goal to overcome COVID-19 entirely.

9.
Transp Res Part C Emerg Technol ; 129: 103218, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36313400

RESUMEN

The advent of COVID-19 is a sensible reminder of the vulnerability of our society to pandemics. We need to be better prepared for finding ways to stem such outbreaks. Except from social distancing and wearing face masks, restricting the movement of people is one important measure necessary to control the spread. Such decisions on the lock-down/reduction of movement should be made in an informed way and, accordingly, modeled as an optimization problem. We propose the Early-stage Transportation Lock-down and Quarantine Problem (TLQP), which can help to decide which parts of the transportation infrastructure of a country should be restricted in early stages. On top of the network-based Susceptible-Exposed-Infectious-Recovered (SEIR) model, we establish a decision recommendation framework, which considers the lock-down of cross-border traffic, internal traffic, and movement inside individual populations. The combinatorial optimization problem aims to find the best set of actions which minimize the social cost of a lock-down. Given the inherent intractability of this problem, we develop a highly-efficient heuristic based on the Effective Distance (ED) path and the Cost-Effective Lazy Forward (CELF) algorithm. We perform and report experiments on the global spread of COVID-19 and show how individual countries may protect their population by taking appropriate measures against the threatening pandemic. We believe that our study contributes to the orchestration of measures for dealing with current and future epidemic outbreaks.

10.
Transp Policy (Oxf) ; 114: 104-115, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34566279

RESUMEN

While COVID-19 has devastating effects on aviation, several recent studies have highlighted the potential of the pandemic-induced break for rethinking air transportation, hopefully orchestrating changes towards the construction of a more pandemic-resilient aviation system. Here, pandemic-resilient means that aviation stakeholders can sustain the impact of an epidemic or pandemic outbreak through a more informed reallocation of their resources and more collaborative decision making, while being able to minimize the impacts of external events. Our study contributes to the literature by discussing the challenges associated with technological innovation and education of aviation professionals, on the way towards pandemic-resilient aviation. We discuss issues surrounding technologies for smarter aircraft, smarter airports, and smarter airlines. While technology ensures long-term competitiveness and sustainability, an often-ignored source of challenges are human resources and education. COVID-19 has uncovered and magnified the effects of severe concerns with the current aviation education system, which need to be solved by extended skill sets, modern technology, and better career perspectives. Without properly addressing these technological and educational challenges, the aviation industry likely misses an distinct opportunity for restructuring towards pandemic-resilient aviation.

11.
Transp Policy (Oxf) ; 105: 115-123, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33776252

RESUMEN

COVID-19 is one of the most impactful pandemics in recent history, not only in terms of direct casualties but also regarding socio-economic impact. The goal of our study is to investigate the degree of synchronization between the number of confirmed cases in specific countries, on one hand, and how/at which stage these countries adapted their air transportation operations, on the other hand. We investigate the global air transportation system as a network of countries whose edges represent the existence of direct flights. Aggregated analysis of this country network and its evolving dynamics leads to novel insights regarding the synchronization with the number of confirmed cases; finding that most country borders were likely closed too late. We believe and hope that our analysis leads to a more efficient/effective prevention and control of future epidemics.

12.
Transp Policy (Oxf) ; 110: 394-401, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34608363

RESUMEN

COVID-19 has been a major setback for air transportation; many airlines had to request for bailouts and the international flights connectivity is only restarting slowly. Accordingly, many aviation stakeholders put hopes into the ongoing process of vaccination, with the expectation that a high degree of vaccination will push the envelope for a return to normalcy. One prerequisite for reviving international air connectivity is the introduction of verification documents, also called "vaccination passports". These passports, however, come with several challenges which need to be overcome in order to enable recovery. In this study, we propose a framework covering five important aspects and policy challenges concerning the introduction of vaccination passports for a return of aviation, covering the topics: Competition, Epidemiology, Technology, Ethics, and Politics. Neglecting to appropriately address these challenges will likely not only delay the recovery, but possibly miss an important opportunity before new disastrous events appear on the horizon.

13.
Nanotechnology ; 30(13): 135502, 2019 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-30572322

RESUMEN

Detection of Fe3+ ion is essential for human health because it is an important element of hemoglobin, which carries oxygen to cells in the body. Here, a 3,3',5,5'-tetramethylbenzidine (TMB) functionalized NaYF4: Yb3+, Er3+@NaYF4 composite upconversion probe was developed, and demonstrated Fe3+ sensing ability with high sensitivity and selectivity. The red emission of upconversion nanoparticles (UCNPs) has a higher penetration depth in tissue than green light and works within the biological window. The obtained hydrophobic NaYF4: Yb3+, Er3+@NaYF4 nanoparticles were treated with HCl to achieve hydrophilic ligand-free nanoparticles with non-saturated metal ions on their surface. Then, a Fe3+ responsive TMB-UNCPs composite luminescence probe was formed through linking TMB onto the ligand-free UCNPs by a coordination bond between the NH2 groups in TMB and the metal ions on the UCNPs. Due to the efficient fluorescence resonance energy transfer from UCNPs to Fe3+-TMB, the obtained probe shows high sensitivity for detecting Fe3+ in the range of 0-100 µM with a detection limit of 0.217 µM. And the color change of the detection system can also be easily recognized by the naked eye. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) experiments and the bioimaging experiments show promising prospects in tissue imaging.

14.
Matern Child Health J ; 23(10): 1371-1381, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31236826

RESUMEN

OBJECTIVES: Group prenatal care (GPC), an alternative to individual prenatal care (IPC), is becoming more prevalent. This study aimed to describe the attendance and reasons of low attendance among pregnant women who were randomly assigned to receive GPC or IPC and explore the maternal characteristics associated with low-attendance. METHODS: This study was a descriptive study among Medically low risk pregnant women (N = 992) who were enrolled in an ongoing prospective study. Women were randomly assigned to receive CenteringPregnany GPC (N = 498) or IPC (N = 994) in a single clinical site The attendance frequency and reason for low-attendance (i.e. ≤ 5/10 sessions in GPC or ≤ 5 visits in IPC) were described separately in GPC and IPC. Multivariable logistic regressions were performed to explore the associations between maternal characteristics and low-attendance. RESULTS: On average, women in GPC attended 5.32 (3.50) sessions, with only 6.67% attending all 10 sessions. Low-attendance rate was 34.25% in GPC and 10.09% in IPC. The primary reasons for low-attendance were scheduling barriers (23.19%) and not liking GPC (16.43%) in GPC but leaving the practice (34.04%) in IPC. In multivariable analysis, lower perceived family support (P = 0.01) was positively associated with low-attendance in GPC, while smoking in early pregnancy was negatively associated low-attendance (P = 0.02) in IPC. CONCLUSIONS FOR PRACTICE: Scheduling challenges and preference for non-group settings were the top reasons for low-attendance in GPC. Changes may need to be made to the current GPC model in order to add flexibility to accommodate women's schedules and ensure adequate participation. TRIAL REGISTRATION: NCT02640638 Date Registered: 12/20/2015.


Asunto(s)
Atención Prenatal/métodos , Factores Raciales/estadística & datos numéricos , Cumplimiento y Adherencia al Tratamiento/psicología , Adulto , Femenino , Humanos , Modelos Logísticos , Satisfacción del Paciente , Embarazo , Mujeres Embarazadas/etnología , Mujeres Embarazadas/psicología , Atención Prenatal/estadística & datos numéricos , Estudios Prospectivos , South Carolina , Encuestas y Cuestionarios , Cumplimiento y Adherencia al Tratamiento/etnología , Cumplimiento y Adherencia al Tratamiento/estadística & datos numéricos
15.
Lipids Health Dis ; 17(1): 281, 2018 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-30545386

RESUMEN

BACKGROUND: Several meta-analyses have demonstrated that the rs662 polymorphism in Paraoxonase 1 gene (PON1) gene is associated with coronary heart disease (CHD). However, it is still uncertain whether this polymorphism is associated with the plasma levels of oxidized low-density lipoprotein (Ox-LDL) and lipids. This meta-analysis is aimed to clarify the relationships between the rs662 polymorphism and plasma levels of Ox-LDL and lipids. METHODS: By searching in PubMed, Google Scholar, Web of Science, Cochrane Library, Wanfang, VIP and CNKI databases, 5 studies (1369 subjects) and 85 studies (46,740 subjects) were respectively identified for Ox-LDL association analysis and lipid association analysis. Standardized mean difference (SMD) was used to estimate the effects of the rs662 polymorphism on plasma Ox-LDL and lipid levels. RESULTS: The carriers of the variant R allele had higher levels of Ox-LDL (SMD = 0.23, 95% CI = 0.10-0.36, P <  0.01), triglyceride (TG) (SMD = 0.06, 95% CI = 0.01-0.11, P = 0.02), total cholesterol (TC) (SMD = 0.04, 95% CI = 0.00-0.07, P = 0.05) and low-density lipoprotein cholesterol (LDL-C) (SMD = 0.04, 95% CI = 0.00-0.08, P = 0.04) than the non-carriers. CONCLUSIONS: This meta-analysis suggests that the association between the PON1 rs662 polymorphism and CHD may partly be mediated by abnormal Ox-LDL and lipid levels caused by the R allele.


Asunto(s)
Arildialquilfosfatasa/genética , Enfermedad Coronaria/genética , Lípidos/genética , Lipoproteínas LDL/genética , Alelos , Enfermedad Coronaria/sangre , Enfermedad Coronaria/patología , Femenino , Estudios de Asociación Genética , Genotipo , Humanos , Lípidos/sangre , Lipoproteínas LDL/sangre , Masculino , Polimorfismo de Nucleótido Simple , Triglicéridos/sangre , Triglicéridos/genética
16.
BMC Pregnancy Childbirth ; 17(1): 118, 2017 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-28403832

RESUMEN

BACKGROUND: In the United States, preterm birth (PTB) before 37 weeks gestational age occurs at an unacceptably high rate, and large racial disparities persist. To date, medical and public health interventions have achieved limited success in reducing rates of PTB. Innovative changes in healthcare delivery are needed to improve pregnancy outcomes. One such model is CenteringPregnancy group prenatal care (GPNC), in which individual physical assessments are combined with facilitated group education and social support. Most existing studies in the literature on GPNC are observational. Although the results are promising, they are not powered to detect differences in PTB, do not address the racial disparity in PTB, and do not include measures of hypothesized mediators that are theoretically based and validated. The aims of this randomized controlled trial (RCT) are to compare birth outcomes as well as maternal behavioral and psychosocial outcomes by race among pregnant women who participate in GPNC to their counterparts in individual prenatal care (IPNC) and to investigate whether improving women's behavioral and psychosocial outcomes will explain the potential benefits of GPNC on birth outcomes and racial disparities. METHODS/DESIGN: This is a single site RCT study at Greenville Health System in South Carolina. Women are eligible if they are between 14-45 years old and enter prenatal care before 20 6/7 weeks of gestational age. Eligible, consenting women will be randomized 1:1 into GPNC group or IPNC group, stratified by race. Women allocated to GPNC will attend 2-h group prenatal care sessions according to the standard curriculum provided by the Centering Healthcare Institute, with other women due to deliver in the same month. Women allocated to IPNC will attend standard, traditional individual prenatal care according to standard clinical guidelines. Patients in both groups will be followed up until 12 weeks postpartum. DISCUSSION: Findings from this project will provide rigorous scientific evidence on the role of GPNC in reducing the rate of PTB, and specifically in reducing racial disparities in PTB. Establishing the improved effect of GPNC on pregnancy and birth outcomes can change the way healthcare is delivered, particularly with populations with higher rates of PTB. TRIAL REGISTRATION: NCT02640638 Date Registered: 12/20/2015.


Asunto(s)
Atención Posnatal/organización & administración , Resultado del Embarazo/epidemiología , Atención Prenatal/organización & administración , Calidad de la Atención de Salud , Femenino , Humanos , Periodo Posparto , Embarazo , Nacimiento Prematuro/epidemiología , South Carolina , Resultado del Tratamiento , Estados Unidos
17.
Nanotechnology ; 27(34): 345703, 2016 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-27418592

RESUMEN

Upconversion nanoparticles (UCNPs) hold promise as near-infrared light converters to enhance the efficiency of solar cells. However, the prevalent use of UCNPs in solar cells is restricted by their poor electrical conductivity and low emission efficiency. Here reduced graphene oxide (rGO)-NaYF4:Yb(3+)/Er(3+) composites are proposed to achieve good electrical conductivity due to the high charge carrier mobility of rGO. Composites of rGO and UCNPs combined by a chemical bond are in situ synthesized by the hydrothermal method, followed by a reduction process. The contact of UCNPs with rGO is proved by SEM, and the binding between the rGO-UCNP composites is confirmed by Fourier transform infrared spectroscopy. The composites are doped into the photoanode of a solar cell. As anticipated, electrochemical impedance spectroscopy confirms the good electrical conductivity of the in situ synthesized rGO-UCNPs. Furthermore, the use of rGO-UCNPs in solar cells enables an enhancement in short-circuit current density and overall efficiency by about 10%. These findings reveal that the combination of UCNPs with rGO opens up new opportunities of extending the use of UCNPs in the area of solar energy harvesting.

18.
Zhongguo Zhong Yao Za Zhi ; 41(23): 4400-4407, 2016 Dec.
Artículo en Zh | MEDLINE | ID: mdl-28933119

RESUMEN

This paper aimed to establish animal models which are suitable for the activity found, efficacy evaluation of herbs resistant to acute liver injury with syndrome of liver depression and spleen deficiency and new drug research and development based on corresponding of formula and syndrome. The symptoms that are suitable for evaluating the rat models of acute liver injury with syndrome of liver depression and spleen deficiency were extracted according to the evolution rule of the etiology and pathogenesis in traditional Chinese medicine and the modern pathological mechanism. Xiaoyao pill and silibin meglumine tablets were used as drug counter evidence for models in accordence with the principle of consistence of prescription and syndrome. Rats model were fed with high-lipid and low-protein fodder of different proportion and induced by intraperitoneal injection with pig serum, intragastric administration with edible alcohol once a day for 7 days. Daily record of body weight, daily food intake and daily water intake were conducted day after day in experimental session. Symptoms were also observed and evaluated by score at the same time. The contents of ALT, AST, PA, TBIL and TBA in serum were detected and histopathological changes of liver were checked at the ending of experiment. Obvious acute liver injury occurred to all rats in model groups at 1 week following model induction. Both main symptoms and secondary symptoms were consistent with syndrome manifestation of liver depression and spleen deficiency. Compared with normal control group, the activity of ALT,AST and contents of TBIL,TBA in serum increased and the content of PA decreased. Liver tissue pathological morphology showed inflammatory cells infiltration, eosinophilic or eosinophilic adipose change in hepatocytes of rats in model groups. All the above lesions manifestation could be improved by drug counterevidence. By the disproof of medicine, rat models of acute liver injury with syndrome of liver depression and spleen deficiency could be induced by fed with high-lipid and low-protein fodder which contained 89.5% cornstarch, 10% lard and 0.5% cholesterol, intraperitoneal injected with pig serum, intragastric administrated with edible alcohol for 7 days. The rat models with a low mortality could be induced in a short time and animal status were similar to syndrome performance of patients. So the rats models are suitable for the activity found, efficacy evaluation and drug discovery of herbs resistant to acute liver injury with syndrome of liver depression and spleen deficiency, and also can be used in the research of correlation between prescription and syndrome and its mechanism.


Asunto(s)
Modelos Animales de Enfermedad , Hepatopatías/fisiopatología , Animales , Hepatocitos/patología , Hígado/fisiopatología , Medicina Tradicional China , Ratas , Bazo/fisiopatología
19.
Artículo en Inglés | MEDLINE | ID: mdl-38526658

RESUMEN

Heart attacks, also known as myocardial infarctions (MIs), are one of the main reasons people die from cardiovascular diseases (CVDs) worldwide. Neferine, an alkaloid derived from Nelumbo nucifera seeds, has garnered interest due to its purported medicinal effects. In the current research, we induced MI in rats using the ß-adrenergic agonist isoproterenol to investigate whether neferine can improve cardiac dysfunction. The rats were separated into four groups: control, isoproterenol (ISO), and two treatment groups received neferine at doses of 10 or 20 mg/kg once daily for 28 days. On days 27 and 28, the groups undergoing treatment were administered with an ISO injection. Results showed that pretreatment with neferine strongly protected against changes in lipid profiles and cardiac functional markers in ISO-administered rats. Neferine attenuated histopathologic changes, collagen deposition, and myocardial fibrosis in rats administered ISO. Neferine pretreatment significantly inhibited the oxidative stress, inflammatory, and apoptotic markers in the heart of ISO-injected rats. This was achieved through Nrf2/Keap1/ARE signaling stimulation, TLR4/NF-κB/MAPK-mediated signaling inhibition, and activation of the intrinsic apoptotic pathway. Using CB-Dock-2, researchers determined that neferine has a high binding affinity with protein receptors that are pivotal in several biological processes. In conclusion, the study provides strong evidence that pretreatment with neferine protects rats from ISO-induced heart damage.

20.
Eur J Med Chem ; 267: 116195, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38330868

RESUMEN

Parkinson's disease (PD) is a common neurodegenerative disease. The clinical symptoms of PD are usually related to motor symptoms, including postural instability, rigidity, bradykinesia, and resting tremors. At present, the pathology of PD is not yet clear. Therefore, revealing the underlying pathological mechanism of PD is of great significance. A variety of bioactive molecules are produced during the onset of Parkinson's, and these bioactive molecules may be a key factor in the development of Parkinson's. The emerging fluorescence imaging technology has good sensitivity and high signal-to-noise ratio, making it possible to deeply understand the pathogenesis of PD through these bioactive molecules. Currently, fluorescent probes targeting PD biomarkers are widely developed and applied. This article categorizes and summarizes fluorescent probes based on different PD biomarkers, systematically introduces their applications in the pathological process of PD, and finally briefly elaborates on the challenges and prospects of these probes. We hope that this review will provide in-depth reference insights for designing fluorescent probes, and contribute to study of the pathogenesis and clinical treatment of PD.


Asunto(s)
Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/tratamiento farmacológico , Colorantes Fluorescentes , Biomarcadores
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