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1.
Front Microbiol ; 15: 1344831, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38585697

RESUMO

Rice serves as a staple food across various continents worldwide. The rice plant faces significant threats from a range of fungal, bacterial, and viral pathogens. Among these, rice false smut disease (RFS) caused by Villosiclava virens is one of the devastating diseases in rice fields. This disease is widespread in major rice-growing regions such as China, Pakistan, Bangladesh, India, and others, leading to significant losses in rice plantations. Various toxins are produced during the infection of this disease in rice plants, impacting the fertilization process as well. This review paper lightens the disease cycle, plant immunity, and infection process during RFS. Mycotoxin production in RFS affects rice plants in multiple ways, although the exact phenomena are still unknown.

2.
J Toxicol Environ Health A ; 87(10): 421-427, 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38551405

RESUMO

Vascular dementia (VD) a heterogenous group of brain disorders in which cognitive impairment is attributable to vascular risk factors and cerebrovascular disease. A common phenomenon in VD is a dysfunctional cerebral regulatory mechanism associated with insufficient cerebral blood flow, ischemia and hypoxia. Under hypoxic conditions oxygen supply to the brain results in neuronal death leading to neurodegenerative diseases including Alzheimer's (AD) and VD. In conditions of hypoxia and low oxygen perfusion, expression of hypoxia-inducible factor 1 alpha (HIF-1α) increases under conditions of low oxygen and low perfusion associated with upregulation of expression of hypoxia-upregulated mitochondrial movement regulator (HUMMR), which promotes anterograde mitochondrial transport by binding with trafficking protein kinesin 2 (TRAK2). Schisandrin B (Sch B) an active component derived from Chinese herb Wuweizi prevented ß-amyloid protein induced morphological alterations and cell death using a SH-SY5Y neuronal cells considered an AD model. It was thus of interest to determine whether Sch B might also alleviate VD using a rat bilateral common carotid artery occlusion (BCAO) dementia model. The aim of this study was to examine the effects of Sch B in BCAO on cognitive functions such as Morris water maze test and underlying mechanisms involving expression of HIF-1α, TRAK2, and HUMMR levels. The results showed that Sch B improved learning and memory function of rats with VD and exerted a protective effect on the hippocampus by inhibition of protein expression of HIF-1α, TRAK2, and HUMMR factors. Evidence indicates that Sch B may be considered as an alternative in VD treatment.


Assuntos
Demência Vascular , Lignanas , Neuroblastoma , Compostos Policíclicos , Ratos , Humanos , Animais , Demência Vascular/tratamento farmacológico , Demência Vascular/etiologia , Demência Vascular/metabolismo , Aprendizagem em Labirinto/fisiologia , Hipóxia , Cognição , Hipocampo , Oxigênio/farmacologia , Ciclo-Octanos
3.
Luminescence ; 39(1): e4618, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37937696

RESUMO

The interactions between drugs and proteins play a pivotal role in determining the pharmacological effects and disposition of drugs within the human body. This study focuses on exploring the interaction between nitrendipine and lysozyme/human serum albumin. Spectroscopic analysis indicated a compound static quenching, indicative of the formation of stable complexes between the drug and proteins. The addition of vitamin C or naringin resulted in a decrease of the binding constant between nitrendipine and lysozyme/human serum albumin. The presence of these compounds may disrupt the interactions between the drug and proteins, potentially leading to an increased concentration of free nitrendipine in the bloodstream. Nitrendipine binds more easily to human serum albumin at 310 K, and human serum albumin has an average binding site ratio with nitrendipine approximately 0.1 higher than that with lysozyme. Vitamin C has a greater impact on the binding constant of nitrendipine to human serum albumin and lysozyme. Compared to the binary system of proteins with the drug, the ternary system with the addition of vitamin C at 310 K reduces the binding constants of lysozyme and human serum albumin by 85%. In conclusion, this study explores the significance of considering drug-protein interactions in understanding drug behavior and potential drug-food interactions.


Assuntos
Flavanonas , Nitrendipino , Albumina Sérica Humana , Humanos , Ácido Ascórbico , Sítios de Ligação , Dicroísmo Circular , Simulação de Acoplamento Molecular , Muramidase/metabolismo , Ligação Proteica , Conformação Proteica , Albumina Sérica Humana/química , Espectrometria de Fluorescência , Termodinâmica
4.
Plants (Basel) ; 12(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37653869

RESUMO

Maize, as a glycophyte, is hypersensitive to salinity, but the salt response mechanism of maize remains unclear. In this study, the physiological, biochemical, and molecular responses of two contrasting inbred lines, the salt-tolerant QXH0121 and salt-sensitive QXN233 lines, were investigated in response to salt stress. Under salt stress, the tolerant QXH0121 line exhibited good performance, while in the sensitive QXN233 line, there were negative effects on the growth of the leaves and roots. The most important finding was that QXH0121 could reshift Na+ from shoots into long roots, migrate excess Na+ in shoots to alleviate salt damage to shoots, and also improve K+ retention in shoots, which were closely associated with the enhanced expression levels of ZmHAK1 and ZmNHX1 in QXH0121 compared to those in QXN233 under salt stress. Additionally, QXH0121 leaves accumulated more proline, soluble protein, and sugar contents and had higher SOD activity levels than those observed in QXN233, which correlated with the upregulation of ZmP5CR, ZmBADH, ZmTPS1, and ZmSOD4 in QXH0121 leaves. These were the main causes of the higher salt tolerance of QXH0121 in contrast to QXN233. These results broaden our knowledge about the underlying mechanism of salt tolerance in different maize varieties, providing novel insights into breeding maize with a high level of salt resistance.

6.
Bioeng Transl Med ; 8(3): e10459, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37206236

RESUMO

Prevention and early intervention are the current focus of treatment for Alzheimer's disease (AD). An increase in reactive oxygen species (ROS) is a feature of the early stages of AD, thus suggesting that the removal of excess ROS can be a viable method of improving AD. Natural polyphenols are able to scavenge ROS and thus promising for treating AD. However, some issues need to be addressed. Among them, important are that most polyphenols are hydrophobic, have low bioavailability in the body, are easily degraded, and that single polyphenols have insufficient antioxidant capacity. In this study, we employed two polyphenols, resveratrol (RES) and oligomeric proanthocyanidin (OPC), and creatively grafted them with hyaluronic acid (HA) to form nanoparticles to address the aforementioned issues. Meanwhile, we strategically grafted the nanoparticles with the B6 peptide, enabling the nanoparticles to cross the blood-brain barrier (BBB) and enter the brain for AD treatment. Our results illustrate that B6-RES-OPC-HA nanoparticles can significantly scavenge ROS, reduce brain inflammation, and improve learning and memory ability in AD mice. B6-RES-OPC-HA nanoparticles have the potential to prevent and alleviate early AD.

7.
Org Lett ; 25(9): 1458-1463, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36856674

RESUMO

Using dichloromethane (DCM) as the C1 feedstock, the first Pd(0)-catalyzed synthesis of aryl-methylene ether motifs from hydrobenzoxazoles (hydrothiazoles) has been reported. This protocol has exhibited an ample substrate scope (38 examples) and wide functional group tolerance. Aryl-methylene ether adducts have been successfully engaged in coupling with isocyanate to provide bis-iminoisoindolinones. In this reaction, DCM has served as a twofold electrophile for reaction with hydrobenzoxazoles via double C-Cl bond cleavage.

8.
Food Res Int ; 158: 111536, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35840233

RESUMO

This work developed novel bi-phasic gel systems containing a hydrogel (κ-carrageenan) and an oleogel, and investigated the roles of different oleogelators (glycerol monostearate-GMS and beeswax-BW) on the structures of the bigels. Stable bigels were obtained via a facile blending approach by carefully controlling the mixing temperature. Microstructural observation indicated that GMS-based bigels were of oil-in-water type, and BW-based bigels were of water-in-oil type. In GMS-based bigels, both water holding capacity and oil holding capacity after freeze-thawing were enhanced with the increase in GMS content. The bigel with 8% (w/w) GMS had water holding capacity and oil holding capacity of 94.81% and 93.13%, respectively. In BW-based bigels, oil holding capacity was also increased (from 36.98% to 88.39%), but separation of oleogel and hydrogel was detected after centrifugation. Textural and rheological analysis revealed that gel strength of the bigels were gradually increased with the increase in oleogelator content, and BW-based bigels were much stronger than GMS-based ones. Moreover, BW-based bigels had higher relaxation degree. DSC analysis found that thermodynamic stability of the bigels were increased with the increase in oleogelator content. Temperature sweep rheological analysis indicated that GMS-based bigels were not able to fully recover their original structure and gel strength after heating-cooling cycle due to the nature of the crystals formed in bigels. This study offered profound structural information about the bigels as affected by different oleogelators, which was also useful for the development of novel functional products.


Assuntos
Hidrogéis , Compostos Orgânicos , Hidrogéis/química , Compostos Orgânicos/química , Reologia , Água
9.
Front Microbiol ; 13: 884469, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35694310

RESUMO

Rhizoctonia solani is a pathogen that causes considerable harm to plants worldwide. In the absence of hosts, R. solani survives in the soil by forming sclerotia, and management methods, such as cultivar breeding, crop rotations, and fungicide sprays, are insufficient and/or inefficient in controlling R. solani. One of the most challenging problems facing agriculture in the twenty-first century besides with the impact of global warming. Environmentally friendly techniques of crop production and improved agricultural practices are essential for long-term food security. Trichoderma spp. could serve as an excellent example of a model fungus to enhance crop productivity in a sustainable way. Among biocontrol mechanisms, mycoparasitism, competition, and antibiosis are the fundamental mechanisms by which Trichoderma spp. defend against R. solani, thereby preventing or obstructing its proliferation. Additionally, Trichoderma spp. induce a mixed induced systemic resistance (ISR) or systemic acquired resistance (SAR) in plants against R. solani, known as Trichoderma-ISR. Stimulation of every biocontrol mechanism involves Trichoderma spp. genes responsible for encoding secondary metabolites, siderophores, signaling molecules, enzymes for cell wall degradation, and plant growth regulators. Rhizoctonia solani biological control through genes of Trichoderma spp. is summarized in this paper. It also gives information on the Trichoderma-ISR in plants against R. solani. Nonetheless, fast-paced current research on Trichoderma spp. is required to properly utilize their true potential against diseases caused by R. solani.

10.
Opt Express ; 30(2): 2143-2155, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35209361

RESUMO

Based on the full wave simulation and the Maxwell stress tensor theory, we demonstrate an enhanced transverse optical gradient force acting on Rayleigh particles immersed in a simple optical field formed by two linearly polarized plane waves. The optical gradient force acting on a conventional dielectric particle can be enhanced by two orders of magnitude via coating an extremely thin silver shell, whose thickness is only about one-tenth of the dielectric core. The analytical results based on the multipole expansion theory reveal that the enhanced optical gradient force comes mostly from the interaction between the incident field and the electric quadrupole excited in the core-shell particle. It is worth noting that the force expression within the dipole approximation commonly used for Rayleigh particles is invalid in our situation, even the particle is within the Rayleigh regime. In addition, both the optical potential energy and the optical trapping stiffness for the core-shell particle exhibit a great enhancement by two orders of magnitude stronger than a conventional dielectric particle and thus is favorable to a stable optical trapping. These results may extend the application range of optical tweezers and enrich optical manipulation techniques.

11.
Spectrochim Acta A Mol Biomol Spectrosc ; 272: 120982, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35139470

RESUMO

The interaction mechanisms of nimodipine with pepsin, trypsin, α-chymotrypsin, lysozyme and human serum albumin were investigated by multispectral and molecular docking methods. Vitamin C and naringin were the main active components of grapefruit juice, and nimodipine was the typical drug that interacts with this juice. Fluorescence spectroscopy was used to study the interaction of nimodipine with five proteinases (pepsin, trypsin, α-chymotrypsin, lysozyme and human serum albumin) and the effects of vitamin C and naringin on these interactions. The fluorescence quenching results showed that nimodipine can quench the intrinsic fluorescence of these five proteinases by a static quenching procedure. Nimodipine binds to pepsin and α-chymotrypsin, through hydrogen bonding and van der Waals forces, whereas it binds to trypsin, lysozyme and human serum albumin mainly by hydrophobic interactions. The microenvironment of the five proteinases changed. The probability of nonradiative energy transfer between the five proteinases and nimodipine was high. Both vitamin C and naringin reduced the binding constant of nimodipine to the four proteinases (except α-chymotrypsin) and might increase the concentration of free nimodipine. Thus, vitamin C or naringin in fruits or foods could increase the blood concentration of free nimodipine and perhaps a reduction in nimodipine dose was needed.


Assuntos
Ácido Ascórbico , Nimodipina , Sítios de Ligação , Flavanonas , Humanos , Simulação de Acoplamento Molecular , Peptídeo Hidrolases , Ligação Proteica , Espectrometria de Fluorescência , Termodinâmica
12.
Chemosphere ; 296: 133773, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35114264

RESUMO

Phytopathogenic bacteria cause severe economic losses in agricultural production worldwide. The spread rates, severity, and emerging plant bacterial diseases have become serious threat to the sustainability of food sources and the fruit industry. Detection and diagnosis of plant diseases are imperative in order to manage plant diseases in field conditions, greenhouses, and food storage conditions as well as to maximize agricultural productivity and sustainability. To date, various techniques including, serological, observation-based, and molecular methods have been employed for plant disease detection. These methods are sensitive and specific for genetic identification of bacteria. However, these methods are specific for genetic identification of bacteria. Currently, the innovative biosensor-based disease detection technique is an attractive and promising alternative. A biosensor system involves biological recognition and transducer active receptors based on sensors used in plant-bacteria diagnosis. This system has been broadly used for the rapid diagnosis of plant bacterial pathogens. In the present review, we have discussed the conventional methods of bacterial-disease detection, however, the present review mainly focuses on the applications of different biosensor-based techniques along with point-of-care (POC), robotics, and cell phone-based systems. In addition, we have also discussed the challenges and limitations of these techniques.


Assuntos
Bactérias , Técnicas Biossensoriais , Bactérias/genética , Técnicas Biossensoriais/métodos , Doenças das Plantas , Plantas/microbiologia , Tecnologia
13.
Opt Lett ; 47(23): 6241-6244, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37219217

RESUMO

Based on the multipole expansion theory, we show that a transverse optical torque acting on a dipolar plasmonic spherical nanoparticle can be anomalously enhanced in two plane waves with linear polarization. Compared with a homogeneous Au nanoparticle, the transverse optical torque acting on an Au-Ag core-shell nanoparticle with an ultra-thin shell thickness can be dramatically enhanced by more than two orders of magnitude. Such enhanced transverse optical torque is dominated by the interaction between the incident optical field and the electric quadrupole excited in the dipolar core-shell nanoparticle. It is thus noted that the torque expression based on the dipole approximation usually used for dipolar particles is not available even in our dipolar case. These findings deepen the physical understanding of the optical torque (OT) and may have applications in optically driven rotation of plasmonic microparticles.

14.
Opt Express ; 29(16): 25377-25387, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34614870

RESUMO

We rigorously calculate the conservative gradient force (GF) and the non-conservative scattering force (SF) associated with the optical tweezers (the single beam optical trap). A wide range of parameters are considered, with particle size ranging from the Rayleigh to Mie regime (radius ∼3 µm), dielectric constant ranging from metallic (large and negative) to high dielectrics (large and positive), numerical aperture (NA) ranging from 0.5 to 1.33, and different polarizations. The trap depth associated with GF can reach 123 and 168 kBT per mW for a 0.5 µm-radius polystyrene particle illuminated by a 1064 nm Gaussian beam with NA = 0.9 and 1.3, respectively. This indicates that unless at a low beam power or with a small NA, the Brownian fluctuations do not play a role in the stability. The transverse GF orthogonal to beam propagation always dominates over the transverse SF. While the longitudinal SF can be larger than the longitudinal GF when the scattering is strong, the NA is small, or when absorption is present, optical trapping under these conditions is difficult. Generally speaking, absorption reduces GF and enhances SF, while increasing a dielectric constant enhances GF slightly but boosts SF significantly owing to stronger scattering. These results verify previous experimental observations and explain why optical tweezers are so robust across such a wide range of conditions. Our quantitative calculations will also provide a guide to future studies.

15.
J Anal Methods Chem ; 2021: 2174667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34381625

RESUMO

Eupatorium fortunei Turcz. is a widely used Chinese herbal medicine in China. In this study, a gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) method was developed and validated to simultaneously determine the contents of p-cymene, thymol, neryl acetate, and ß-caryophyllene in roots, stems, and leaves of Eupatorium fortunei Turcz. harvested at different growth periods. All four constituents could be detected in leaves, three could be detected in stems except ß-caryophyllene, and only thymol could be detected in roots. The order of the total contents of four constituents in different parts was leaves > stems > roots. It indicated that the leaves could be the proper medicinal parts of Eupatorium fortunei Turcz. The content of four constituents in leaves varied a lot among different growth periods and showed an M-shaped change trend with the growth of Eupatorium fortunei Turcz. The four constituents accumulated to the highest values in early July followed by mid-September. Accordingly, the best harvest time of Eupatorium fortunei Turcz. is early July and mid-September.

16.
J Ethnopharmacol ; 268: 113644, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33264660

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: QingYan Formula has been traditionally used to tonify kidney and benefit essence, and QingYan Formula 70% ethanol extracts (QYFE) showed estrogen-like effect on reproductive system in our previous studies. However, there were no reports of QYFE on bone. AIM OF THE STUDY: This study offered preliminary insight of QYFE into the pharmacodynamics and mechanism of anti-bone osteoporosis in ovariectomized rats. MATERIALS AND METHODS: OVX rats were orally administrated QYFE or estradiol valerate (EV) for 12 weeks. We investigated the pharmacodynamic effects of QYFE on anti-bone loss in OVX rats, and also investigated the role of QYFE in promoting osteogenesis and inhibiting osteoclast differentiation. RESULTS: QYFE administration significantly reduced the degree of high bone turnover, dose-dependently repaired the damaged microstructure of trabecular and cortical bone by Hematoxylin-Eosin (HE) staining and micro-computed tomography (micro-CT), and reduced the number of femur osteoclasts by TRAP staining. QYFE enhanced the proliferation and activity of alkaline phosphatase (ALP), the phosphorylation levels of extracellular regulated kinase (ERK) and Akt in MG-63 cells, which was inhibited by ICI 182 780. Moreover, in RAW264.7 cells, QYFE inhibited osteoclasts differentiation, reduced the number of osteoclasts, decreased the activity of TRAP enzyme during formation, down-regulated the protein expression of p-ERK inhibited by ICI 182 780 and p-Akt not inhibited by ICI 182 780. CONCLUSION: This experiment demonstrated that QYFE had a definite anti-bone loss effect and had potential effect on postmenopausal osteoporosis. The molecular mechanism was related to the activation of estrogen receptor (ER)-dependent mitogen-activated protein kinase kinase (MEK)/ERK and phosphoinositide 3-kinase (PI3K)/Akt signal pathways in osteoblast, down-regulation protein expressions of ER-dependent p-ERK and ER-independent p-Akt in osteoclast.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Osteoporose Pós-Menopausa/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Estrogênio/metabolismo , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Osteoporose Pós-Menopausa/etiologia , Osteoporose Pós-Menopausa/prevenção & controle , Ovariectomia/efeitos adversos , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley
17.
Cancer Med ; 10(3): 999-1011, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33382529

RESUMO

BACKGROUND: Despite numerous chimeric antigen receptor T-cell (CAR-T) trials conducted in China, no CAR-T has been registered in the country. Furthermore, China law and regulations restrict the export of patient material for CAR-T manufacture abroad. Relma-cel (JWCAR029), an anti-CD19 product produced with a commercial-ready process in China, was evaluated in the first prospective, single-arm, multicenter, pivotal study of CAR-T therapy conducted under Chinese IND to support an NMPA-accepted BLA submission in relapsed/refractory (r/r) LBCL (NCT04089215). METHODS: Patients were randomized to receive either 100 × 106 (low dose, n = 27) or 150 × 106 (high dose, n = 32) CAR+ T-cells as a single infusion following lymphodepleting chemotherapy (fludarabine 25 mg/m2 and cyclophosphamide 250 mg/m2 daily × 3), and then, monitored for efficacy and safety outcomes and pharmacokinetics. The primary endpoint was ORR at 3 months, as assessed by the investigators. Secondary endpoints included DOR, PFS, OS, and adverse event frequency/severity and cell expansion kinetics. RESULTS: As of the data cutoff on 17 June 2020, 68 patients were enrolled, and 59 were treated. Among the 58 efficacy-evaluable patients, the primary endpoint of 3 month ORR was 60.3% (95% CI, 46.6-73.0), excluding the null hypothesis rate of 20%. Any grade and severe grade CRS occurred in 47.5% and 5.1%, respectively, and any grade and severe grade neurotoxicity events occurred in 20.3% and 5.1%. CONCLUSIONS: Relma-cel met the primary endpoint analysis and demonstrated a high rate of durable responses and low rate of CAR-T-associated toxicities in patients with r/r LBCL in a multicenter trial supporting regulatory submission in China.


Assuntos
Antígenos CD19/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Imunoterapia Adotiva/métodos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Compostos Orgânicos/uso terapêutico , Terapia de Salvação , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Linfoma Difuso de Grandes Células B/imunologia , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/imunologia , Recidiva Local de Neoplasia/patologia , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida , Adulto Jovem
18.
Phys Rev Lett ; 125(7): 073901, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32857552

RESUMO

Lateral optical forces in a direction perpendicular to light propagation have attracted increasing interest in recent years. Up to now, all lateral forces can be attributed to the symmetry breaking in the lateral directions caused by either the morphology of the scatterer geometry or the optical fields impinging on the scatterer. Here we demonstrate, both numerically and analytically, that when an isotropic scatterer breaks the electric-magnetic symmetry, a new type of anomalous lateral force can be induced along the direction of translational invariance where the illumination striking the scatterer has no propagation, field gradient, or spin density vortex (Belinfante's spin momentum). Our analytical results are rigorous for an arbitrary size scatterer, ensuring the universality of our conclusion. Furthermore, the electric-magnetic symmetry-breaking-induced lateral force is comparable in magnitude to other components of the optical force and reversible in direction for different polarizations of the illuminating light, rendering it capable of practical optical manipulation as well as enriching the understanding of light-matter interaction.

19.
Opt Lett ; 45(16): 4515-4518, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32796997

RESUMO

Based on the concepts of conservative and non-conservative optical forces (COF and NCOF), we analyze the physical mechanism of longitudinal chirality sorting along the direction of light propagation in some simple optical fields. It is demonstrated, both numerically and analytically for particle of arbitrary size, that the sorting relies solely on the NCOF, which switches its direction when particle chirality is reversed. For particles larger than half of the optical wavelength λ, the NCOF far surpasses its counterpart COF, enabling the longitudinal chirality sorting. When the particle is much smaller than λ, however, the COF outweighs the NCOF, destroying the sorting mechanism. A scenario is thus proposed that totally eliminates the COF while leaving the sorting NCOF unchanged, extending the applicability of longitudinal chirality sorting to small particles.

20.
Aging (Albany NY) ; 11(12): 4032-4049, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31219800

RESUMO

The reproductive tissues are negatively influenced by estrogens in hormone therapy. Qingyan formula ethanol extract (QYFE)'s estrogenic effects and safety on reproductive tissues after long-term administration and its mechanism via estrogen receptor (ER) pathway haven't been studied. Here, we characterized its estrogenic effects using ovariectomized rats together with in vitro studies for further molecular characterization. Ovariectomized rats were treated with QYFE at doses of 0.7, 1.4, and 2.8g/kg for 12 weeks. The results showed QYFE has a potent estrogenic activity, as indicated by restoring the disappeared estrous cycle, antagonizing the atrophy of uterus, vagina and mammary gland, and the estrogen decline in circulation caused by ovariectomy. In addition, QYFE upregulated ERα and ERß expressions and had a less stimulatory effect on PCNA and ki-67 antigen in reproductive tissues compared with estradiol valerate. QYFE components can bind to ERα and ERß, significantly increased ERα/ß-ERE luciferase reporter gene expression, upregulated the expressions of ERs, PR and pS2 in MCF-7 cells at protein and gene level. All these activities were significantly inhibited by the ER antagonist ICI182,780. QYFE's estrogenic activity maybe mediated by stimulating biosynthesis of estrogen and increasing the quantity of ERs in target tissue and via active ER to ERE-independent gene regulation.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glândulas Suprarrenais , Animais , Neoplasias da Mama , Linhagem Celular Tumoral , Estradiol/sangue , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Feminino , Humanos , Antígeno Ki-67/genética , Antígeno Ki-67/metabolismo , Glândulas Mamárias Humanas , Ovariectomia , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Regulação para Cima/efeitos dos fármacos , Útero , Vagina/efeitos dos fármacos
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