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1.
Nat Immunol ; 25(2): 268-281, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38195702

RESUMO

Melanoma cells, deriving from neuroectodermal melanocytes, may exploit the nervous system's immune privilege for growth. Here we show that nerve growth factor (NGF) has both melanoma cell intrinsic and extrinsic immunosuppressive functions. Autocrine NGF engages tropomyosin receptor kinase A (TrkA) on melanoma cells to desensitize interferon γ signaling, leading to T and natural killer cell exclusion. In effector T cells that upregulate surface TrkA expression upon T cell receptor activation, paracrine NGF dampens T cell receptor signaling and effector function. Inhibiting NGF, either through genetic modification or with the tropomyosin receptor kinase inhibitor larotrectinib, renders melanomas susceptible to immune checkpoint blockade therapy and fosters long-term immunity by activating memory T cells with low affinity. These results identify the NGF-TrkA axis as an important suppressor of anti-tumor immunity and suggest larotrectinib might be repurposed for immune sensitization. Moreover, by enlisting low-affinity T cells, anti-NGF reduces acquired resistance to immune checkpoint blockade and prevents melanoma recurrence.


Assuntos
Melanoma , Receptor de Fator de Crescimento Neural , Humanos , Receptor de Fator de Crescimento Neural/genética , Receptor de Fator de Crescimento Neural/metabolismo , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Tropomiosina , Melanoma/terapia , Receptor trkA/genética , Receptor trkA/metabolismo , Citoproteção , Inibidores de Checkpoint Imunológico , Células T de Memória , Terapia de Imunossupressão , Imunoterapia , Receptores de Antígenos de Linfócitos T
2.
Genes Dev ; 37(19-20): 929-943, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37932012

RESUMO

The mismatch repair (MMR) deficiency of cancer cells drives mutagenesis and offers a useful biomarker for immunotherapy. However, many MMR-deficient (MMR-d) tumors do not respond to immunotherapy, highlighting the need for alternative approaches to target MMR-d cancer cells. Here, we show that inhibition of the ATR kinase preferentially kills MMR-d cancer cells. Mechanistically, ATR inhibitor (ATRi) imposes synthetic lethality on MMR-d cells by inducing DNA damage in a replication- and MUS81 nuclease-dependent manner. The DNA damage induced by ATRi is colocalized with both MSH2 and PCNA, suggesting that it arises from DNA structures recognized by MMR proteins during replication. In syngeneic mouse models, ATRi effectively reduces the growth of MMR-d tumors. Interestingly, the antitumor effects of ATRi are partially due to CD8+ T cells. In MMR-d cells, ATRi stimulates the accumulation of nascent DNA fragments in the cytoplasm, activating the cGAS-mediated interferon response. The combination of ATRi and anti-PD-1 antibody reduces the growth of MMR-d tumors more efficiently than ATRi or anti-PD-1 alone, showing the ability of ATRi to augment the immunotherapy of MMR-d tumors. Thus, ATRi selectively targets MMR-d tumor cells by inducing synthetic lethality and enhancing antitumor immunity, providing a promising strategy to complement and augment MMR deficiency-guided immunotherapy.


Assuntos
Linfócitos T CD8-Positivos , Reparo de Erro de Pareamento de DNA , Animais , Camundongos , Reparo de Erro de Pareamento de DNA/genética , Mutações Sintéticas Letais , DNA , Imunoterapia
3.
Cell ; 151(5): 927-9, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23178113

RESUMO

An unexpected role for a Mediator subunit, MED12, in resistance to multiple anticancer agents is revealed by Huang et al. Loss of MED12 confers drug resistance by activating transforming growth factor b (TGF-b) signaling. Inhibition of the TGF-b pathway resensitizes cells to therapeutic drugs, suggesting a new combinatorial cancer treatment.

4.
Small ; 20(25): e2310158, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38573962

RESUMO

The integration of one-selector-one-resistor crossbar arrays requires the selectors featured with high nonlinearity and bipolarity to prevent leakage currents and any crosstalk among distinct cells. However, a selector with sufficient nonlinearity especially in the frame of device miniaturization remains scarce, restricting the advance of high-density storage devices. Herein, a high-performance memory selector is reported by constructing a graphene/hBN/WSe2 heterostructure. Within the temperature range of 300-80 K, the nonlinearity of this selector varies from ≈103 - ≈104 under forward bias, and increases from ≈300 - ≈105 under reverse bias, the highest reported nonlinearity among 2D selectors. This improvement is ascribed to direct tunneling at low bias and Fowler-Nordheim tunneling at high bias. The tunneling current versus voltage curves exhibit excellent bipolarity behavior because of the comparable hole and electron tunneling barriers, and the charge transport polarity can be effectively tuned from N-type or P-type to bipolar by simply changing source-drain bias. In addition, the conceptual memory selector exhibits no sign of deterioration after 70 000 switching cycles, paving the way for assembling 2D selectors into modern memory devices.

5.
New Phytol ; 242(5): 1996-2010, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38571393

RESUMO

The conquest of land by plants was concomitant with, and possibly enabled by, the evolution of three-dimensional (3D) growth. The moss Physcomitrium patens provides a model system for elucidating molecular mechanisms in the initiation of 3D growth. Here, we investigate whether the phytohormone ethylene, which is believed to have been a signal before land plant emergence, plays a role in 3D growth regulation in P. patens. We report ethylene controls 3D gametophore formation, based on results from exogenously applied ethylene and genetic manipulation of PpEIN2, which is a central component in the ethylene signaling pathway. Overexpression (OE) of PpEIN2 activates ethylene responses and leads to earlier formation of gametophores with fewer gametophores produced thereafter, phenocopying ethylene-treated wild-type. Conversely, Ppein2 knockout mutants, which are ethylene insensitive, show initially delayed gametophore formation with more gametophores produced later. Furthermore, pharmacological and biochemical analyses reveal auxin levels are decreased in the OE lines but increased in the knockout mutants. Our results suggest that evolutionarily, ethylene and auxin molecular networks were recruited to build the plant body plan in ancestral land plants. This might have played a role in enabling ancient plants to acclimate to the continental surfaces of the planet.


Assuntos
Bryopsida , Etilenos , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Proteínas de Plantas , Etilenos/metabolismo , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Bryopsida/crescimento & desenvolvimento , Bryopsida/genética , Bryopsida/efeitos dos fármacos , Bryopsida/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Células Germinativas Vegetais/metabolismo , Células Germinativas Vegetais/crescimento & desenvolvimento , Células Germinativas Vegetais/efeitos dos fármacos , Mutação/genética
6.
Hepatology ; 77(6): 1998-2015, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36815382

RESUMO

BACKGROUND AND AIMS: Liver fibrosis results from the accumulation of myofibroblasts (MFs) derived from quiescent HSCs, and yes-associated protein (YAP) controls this state transition. Although fibrosis is also influenced by HSC death and senescence, whether YAP regulates these processes and whether this could be leveraged to treat liver fibrosis are unknown. APPROACH AND RESULTS: YAP activity was manipulated in MF-HSCs to determine how YAP impacts susceptibility to pro-apoptotic senolytic agents or ferroptosis. Effects of senescence on YAP activity and susceptibility to apoptosis versus ferroptosis were also examined. CCl 4 -treated mice were treated with a ferroptosis inducer or pro-apoptotic senolytic to determine the effects on liver fibrosis. YAP was conditionally disrupted in MFs to determine how YAP activity in MF-HSC affects liver fibrosis in mouse models. Silencing YAP in cultured MF-HSCs induced HSC senescence and vulnerability to senolytics, and promoted ferroptosis resistance. Conversely, inducing HSC senescence suppressed YAP activity, increased sensitivity to senolytics, and decreased sensitivity to ferroptosis. Single-cell analysis of HSCs from fibrotic livers revealed heterogeneous sensitivity to ferroptosis, apoptosis, and senescence. In mice with chronic liver injury, neither the ferroptosis inducer nor senolytic improved fibrosis. However, selectively depleting YAP in MF-HSCs induced senescence and decreased liver injury and fibrosis. CONCLUSION: YAP determines whether MF-HSCs remain activated or become senescent. By regulating this state transition, Yap controls both HSC fibrogenic activity and susceptibility to distinct mechanisms for cell death. MF-HSC-specific YAP depletion induces senescence and protects injured livers from fibrosis. Clarifying determinants of HSC YAP activity may facilitate the development of novel anti-fibrotic therapies.


Assuntos
Cirrose Hepática , Senoterapia , Camundongos , Animais , Cirrose Hepática/patologia , Fígado/patologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Morte Celular , Células Estreladas do Fígado/metabolismo
7.
Hepatology ; 78(4): 1209-1222, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37036206

RESUMO

BACKGROUND AND AIMS: Senescent hepatocytes accumulate in parallel with fibrosis progression during NASH. The mechanisms that enable progressive expansion of nonreplicating cell populations and the significance of that process in determining NASH outcomes are unclear. Senescing cells upregulate thrombomodulin-protease-activated receptor-1 (THBD-PAR1) signaling to remain viable. Vorapaxar blocks the activity of that pathway. We used vorapaxar to determine if and how THBD-PAR1 signaling promotes fibrosis progression in NASH. APPROACH AND RESULTS: We evaluated the THBD-PAR1 pathway in liver biopsies from patients with NAFLD. Chow-fed mice were treated with viral vectors to overexpress p16 in hepatocytes and induce replicative senescence. Effects on the THBD-PAR1 axis and regenerative capacity were assessed; the transcriptome of p16-overexpressing hepatocytes was characterized, and we examined how conditioned medium from senescent but viable (dubbed "undead") hepatocytes reprograms HSCs. Mouse models of NASH caused by genetic obesity or Western diet/CCl 4 were treated with vorapaxar to determine effects on hepatocyte senescence and liver damage. Inducing senescence upregulates the THBD-PAR1 signaling axis in hepatocytes and induces their expression of fibrogenic factors, including hedgehog ligands. Hepatocyte THBD-PAR1 signaling increases in NAFLD and supports sustained hepatocyte senescence that limits effective liver regeneration and promotes maladaptive repair. Inhibiting PAR1 signaling with vorapaxar interrupts this process, reduces the burden of 'undead' senescent cells, and safely improves NASH and fibrosis despite ongoing lipotoxic stress. CONCLUSION: The THBD-PAR1 signaling axis is a novel therapeutic target for NASH because blocking this pathway prevents accumulation of senescing but viable hepatocytes that generate factors that promote maladaptive liver repair.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Receptor PAR-1/metabolismo , Trombomodulina/metabolismo , Hepatócitos/metabolismo , Fígado/patologia , Fibrose , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
8.
EMBO Rep ; 23(12): e55191, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36256516

RESUMO

Autophagy has emerged as the prime machinery for implementing organelle quality control. In the context of mitophagy, the ubiquitin E3 ligase Parkin tags impaired mitochondria with ubiquitin to activate autophagic degradation. Although ubiquitination is essential for mitophagy, it is unclear how ubiquitinated mitochondria activate autophagosome assembly locally to ensure efficient destruction. Here, we report that Parkin activates lipid remodeling on mitochondria targeted for autophagic destruction. Mitochondrial Parkin induces the production of phosphatidic acid (PA) and its subsequent conversion to diacylglycerol (DAG) by recruiting phospholipase D2 and activating the PA phosphatase, Lipin-1. The production of DAG requires mitochondrial ubiquitination and ubiquitin-binding autophagy receptors, NDP52 and optineurin (OPTN). Autophagic receptors, via Golgi-derived vesicles, deliver an autophagic activator, EndoB1, to ubiquitinated mitochondria. Inhibition of Lipin-1, NDP52/OPTN, or EndoB1 results in a failure to produce mitochondrial DAG, autophagosomes, and mitochondrial clearance, while exogenous cell-permeable DAG can induce autophagosome production. Thus, mitochondrial DAG production acts downstream of Parkin to enable the local assembly of autophagosomes for the efficient disposal of ubiquitinated mitochondria.


Assuntos
Ubiquitina-Proteína Ligases , Ubiquitina , Ubiquitina-Proteína Ligases/genética , Lipídeos
9.
Br J Nutr ; : 1-34, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38826079

RESUMO

This study was conducted to investigate whether methionyl-tRNA synthetase (MetRS) is a mediator of Met-induced crop milk protein synthesis via the janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5) signalling pathway in breeding pigeons. In Experiment 1, a total of 216 pairs of breeding pigeons were divided into 3 groups (control, Met-deficient, and Met-rescue groups). In Experiments 2 and 3, forty pairs of breeding pigeons from each experiment were allocated into 4 groups. The 2nd experiment included a control group and 3 MetRS inhibitor (REP8839) groups. The 3rd experiment included a Met-deficient group, Met-sufficient group, REP8839 + Met-deficient group, and REP8839 + Met-sufficient group. Experiment 1 showed that Met supplementation increased crop development, crop milk protein synthesis, the protein expression of MetRS and JAK2/STAT5 signalling pathway, and improved squab growth. Experiment 2 showed that crop development, crop milk protein synthesis, and the protein expression of MetRS and the JAK2/STAT5 signalling pathway were decreased, and squab growth was inhibited by the injection of 1.0 mg/kg BW REP8839, which was the selected dose for the 3rd experiment. These results showed that Met supplementation increased crop development, crop milk protein synthesis, and the expression of MetRS and JAK2/STAT5 signalling pathway and rescued squab growth after the injection of REP8839. Moreover, the Co-IP results showed that there was an interaction between MetRS and JAK2. Taken together, these findings indicate that MetRS mediates Met-induced crop milk protein synthesis via the JAK2/STAT5 signalling pathway, resulting in improved squab growth in breeding pigeons.

10.
Cell ; 139(4): 658-60, 2009 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-19914161

RESUMO

TGF-beta ligands induce phosphorylation of receptor-activated Smads at both the C-terminal tail and the linker region. Two papers from Massagué and colleagues (Alarcón et al., 2009; Gao et al., 2009) reveal a dual role for this linker phosphorylation, which is required for activation of Smads and for their degradation.


Assuntos
Proteínas Smad/metabolismo , Ativação Transcricional , Animais , Camundongos , Fosforilação , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Smad/química , Proteínas Smad/genética
11.
Sensors (Basel) ; 24(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38544079

RESUMO

Crowd counting is an important task that serves as a preprocessing step in many applications. Despite obvious improvement reported by various convolutional-neural-network-based approaches, they only focus on the role of deep feature maps while neglecting the importance of shallow features for crowd counting. In order to surmount this issue, a dilated convolutional-neural-network-based cross-level contextual information extraction network is proposed in this work, which is abbreviated as CL-DCNN. Specifically, a dilated contextual module (DCM) is constructed by importing cross-level connection between different feature maps. It can effectively integrate contextual information while conserving the local details of crowd scenes. Extensive experiments show that the proposed approach outperforms state-of-the-art approaches using five public datasets, i.e., ShanghaiTech part A, ShanghaiTech part B, Mall, UCF_CC_50 and UCF-QNRF, achieving MAE 52.6, 8.1, 1.55, 181.8, and 96.4, respectively.

12.
Ann Bot ; 132(6): 1073-1088, 2023 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-37751161

RESUMO

BACKGROUND AND AIMS: Morphological matching between flower and pollinator traits has been documented in diverse plant lineages. Indeed, the matching of corolla tube length and pollinator tongue length has been cited repeatedly as a classic case of coevolution. However, there are many possible evolutionary routes to trait matching. Our aim here is both to review the evolutionary mechanisms of plant-pollinator trait matching and to investigate a specific case of trait matching/mismatching in a genus of alpine gingers. METHODS: Roscoea gingers with long corolla tubes in the western Himalayas have pollinators with correspondingly long tongues, but the match between corolla tube and pollinator tongue lengths is not seen in the eastern Himalayas. Six floral traits were measured, including corolla tube depth, an internal trait controlling pollinator access to nectar. We calculated coefficients of variation and phylogenetically controlled correlation patterns of these traits in six Roscoea species in order to gain possible insights into stabilizing selection and modularization of these traits. KEY RESULTS: The distal (nectar-containing) portion of the corolla tube exhibited lower coefficients of variations than did the basal portion. This is consistent with the hypothesis that pollinators mediate stabilizing selection on the distal, but not basal, portion of the corolla tube. This result, combined with phylogenetic data, suggests that the elevated liquid level of nectar in the distal tube evolved subsequent to dispersal into the eastern Himalayan region and loss of long-tongue pollinators. After accounting for phylogeny, corolla tube length, anther length, style length and labellum width were all intercorrelated. Corolla-tube depth was not part of this covariational module, however, suggesting separate adaptation to short-tongued pollinators. CONCLUSIONS: The reduction in functional corolla tube depth in the Roscoea appears to be related to the loss of long-tongued pollinators associated with dispersal to the eastern Himalayas and pollination by short-tongued pollinators. The apparent mismatch between floral tubes and pollinator tongues is a case of cryptic trait matching between flowers and pollinators, underscoring the importance of combining floral anatomy with pollination ecology in assessing plant-pollinator trait matching.


Assuntos
Néctar de Plantas , Zingiber officinale , Filogenia , Flores/anatomia & histologia , Polinização , Plantas
13.
J Org Chem ; 88(3): 1493-1503, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36631394

RESUMO

The treatment of 2-alkenylanilines with phenyliodine(III) diacetate (PIDA) and LiBr or KI in HFIP was found to afford the corresponding 3-haloindoles via cascade oxidative cyclization/halogenation encompassing oxidative C-N/C-X (X = Br, I) bond formations. A plausible mechanism involving the in situ formation of the reactive AcO-X (X = Br, I) from the reaction of PIDA and LiBr/KI was postulated.

14.
Chaos ; 33(3): 033123, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37003839

RESUMO

Inter-network combat and intra-network cooperation among structured systems are likely to have been recurrent features of human evolutionary history; however, little research has investigated the combat mechanism between structured systems that the adversarial interactions will cause the disability of agents and agents are prone to seek cooperation with neighbors. Hence, the current study has proposed a two-network combat game model and designed the corresponding rules of how to attack, how to be disabled, how to cooperate, and how to win. First, within the framework of our model, we have simulated the combat among four common network structures-the Erdos-Rényi (ER) random network, the grid graph, the small-world network, and the scale-free network. We found that the grid network always holds the highest winning percentage, while the ER random graph is most likely to lose when combating with the other three network structures. For each structure, we have also simulated the combat between the same network structures with different generating parameters. The simulations reveal that the small-world property and heterogeneity can promote winning a combat. Besides, by broadening and deepening cooperation, we have found that broader cooperation helps defeat the opposite system on grid and scale-free networks, yet hinders it on ER and Watts-Strogatz (WS) networks, while deeper cooperation can benefit to winning except on scale-free networks. These findings inform our understanding of the effects of structure and cooperation in a combat.


Assuntos
Evolução Biológica , Teoria dos Jogos , Humanos
15.
Chem Soc Rev ; 51(12): 4902-4927, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35638386

RESUMO

Water is a colossal reservoir of clean energy as it adsorbs thirty-five percent of solar energy reaching the Earth's surface. More than half of the adsorbed energy turns into latent heat for water evaporation, driving the water cycle of the Earth.1 Yet, only very limited energy in the water cycle is harvested by current industrial technologies. The past decade has witnessed the emergence of hydrovoltaic technology, which generates electricity from nanomaterials by direct interaction with water and enables energy harvesting from the water cycle such as from rain, waves, flows, moisture and natural evaporation. Years of efforts have been committed to improve the conversion efficiency of hydrovoltaic devices through chemical synthesis of advanced nanomaterials and innovative design of device structures. Further development of this field, however, still requires in-depth understanding of hydrovoltaic mechanisms and boosting of the electrical outputs for wider applications. Here, we present a tutorial review of different mechanisms of generating electricity from droplets, flows, natural evaporation and ambient moisture by analyzing basic interactions at various water-material interfaces. Key aspects in raising the output power of hydrovoltaic devices are then discussed in terms of material synthesis, structural design, and device optimization. We also provide an outlook on the potential applications of this technology ranging from sensors, power suppliers to multifunctional systems as well as on the scientific and technological challenges in transforming its potential into practical utility. The prospects of this emerging field are considered for future endeavor.


Assuntos
Nanoestruturas , Energia Solar , Eletricidade , Nanoestruturas/química , Água
16.
J Environ Manage ; 337: 117756, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-36934497

RESUMO

Anaerobic digestion (AD) can not only treat organic waste, but also recycle energy. However, high-solids AD of kitchen waste usually failed due to excessive acidification. In this study, the effect of activated carbon (AC) on kitchen waste AD performance was investigated under high-solids conditions (total solids contents = 15%). The results showed that efficiencies of acidogenesis and methanogenesis were promoted in presence of moderate concentration (50 g/L > AC >5 g/L), but high concentration (AC >70 g/L) weakened AD performance. Moreover, AC addition enhanced the methane production rate from 66.0 mL/g VS to 231.50 mL/g VS, i.e., up to 250.7%. High-throughput sequencing results demonstrated that the abundance of electroactive DMER64 increased from less than 1%-29.7% (20 g/L AC). As AC gradually increased,aceticlastic methanogenesis changed to hydrogenotrophic pathway. Predicted functional analysis indicated that AC can enhance abundances of energy and inorganic ion metabolism, resulting in high methane production.


Assuntos
Reatores Biológicos , Carvão Vegetal , Anaerobiose , Pós , Metano , Esgotos
17.
Angew Chem Int Ed Engl ; 62(24): e202301026, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37002926

RESUMO

Due to the intrinsic inertness of alkanes, strong oxidative conditions are typically required to enable their C(sp3 )-H functionalization. Herein, a paired electrocatalysis strategy was developed by integrating oxidative catalysis with reductive catalysis in one cell without interference, in which earth-abundant iron and nickel are employed as the anodic and cathodic catalysts, respectively. This approach lowers the previously high oxidation potential required for alkane activation, enabling electrochemical alkane functionalization at the ultra-low oxidation potential of ≈0.25 V vs. Ag/AgCl under mild conditions. Structurally diverse alkenes, including challenging all-carbon tetrasubstituted olefins, can be accessed using readily available alkenyl electrophiles.

18.
BMC Plant Biol ; 22(1): 113, 2022 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-35279080

RESUMO

BACKGROUND: Many seed plants produce winged diaspores that use wind to disperse their seeds. The morphology of these diaspores is directly related to the seed dispersal potential. The majority of winged diaspores have flat wings and only seeds; however, some angiosperms, such as Firmiana produce winged fruit with a different morphology, whose seed dispersal mechanisms are not yet fully understood. In this study, we observed the fruit development of F. simplex and determined the morphological characteristics of mature fruit and their effects on the flight performance of the fruit. RESULTS: We found that the pericarp of F. simplex dehisced early and continued to unfold and expand during fruit development until ripening, finally formed a spoon-shaped wing with multiple alternate seeds on each edge. The wing caused mature fruit to spin stably during descent to provide a low terminal velocity, which was correlated with the wing loading and the distribution of seeds on the pericarp. When the curvature distribution of the pericarp surface substantially changed, the aerodynamic characteristics of fruit during descent altered, resulting in the inability of the fruit to spin. CONCLUSIONS: Our results suggest that the curved shape and alternate seed distribution are necessary for the winged diaspore of F. simplex to stabilize spinning during wind dispersal. These unique morphological characteristics are related to the early cracking of fruits during development, which may be an adaptation for the wind dispersal of seeds.


Assuntos
Frutas/anatomia & histologia , Frutas/crescimento & desenvolvimento , Malvaceae/anatomia & histologia , Malvaceae/crescimento & desenvolvimento , Dispersão de Sementes , Sementes/anatomia & histologia , Sementes/crescimento & desenvolvimento , China , Fenótipo , Vento
19.
Opt Express ; 30(6): 9892-9903, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299402

RESUMO

In this paper, phase-locking dynamics of 2D VCSEL hexagonal array with an integrated Talbot cavity are numerically investigated based on rate equations aiming at achieving high brightness output. The processes of wavelength synchronization and phase locking under different fill factors ff and fractional Talbot cavity lengths L were addressed comprehensively. Different supermodes of phase-locked VCSEL array were then analyzed from both near-field and far-field pattern, and proved to be well matched with the results of coupled-mode theory. With appropriate configuration the Talbot-VCSEL system can operate in a full in-phase mode eventually, which is beneficial for determining the parameter interval corresponding to the most expected single narrow-lobe far-field pattern. Furthermore, the simulation results also indicate that, considering the parametric interactions the distribution of optical feedback from the fractional Talbot cavity should be consistent as much as possible to facilitate the realization of phase-locked state. Our study could provide a theoretical support to obtain the full in-phase coupled VCSEL array with high performance.

20.
Microb Pathog ; 170: 105686, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35917986

RESUMO

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has proven to be an urgent threat to human health. Proteomics (TMT/LC-MS/MS) and bioinformatics approaches were employed to explore the potential mechanisms underlying carbapenem resistance. Proteomic profiling of CRKP and susceptible KP (sKP) isolates revealed the involvement of outer membrane, beta-lactam resistance pathway, and two-component systems (TCSs) in carbapenem resistance. 27 CRKP strains and 27 susceptible Klebsiella pneumoniae strains were isolated from inpatients at the Second Xiangya Hospital, China to verify the mechanisms. Modified carbapenem inactivation method (mCIM) and PCR of common carbapenem resistance genes confirmed that 77.8% (21/27) of CRKP isolates were carbapenemase-producing. Porin decrease in CRKP isolates was found by SDS-PAGE and mRNA levels of major porins (OmpK35 and OmpK36). RT-qPCR detection of two-component systems (envZ, ompR, phoP, phoQ, baeS and baeR) revealed down-regulation of EnvZ-OmpR, PhoPQ, BaeSR TCSs. Expression of the TCSs, except ompR, were closely correlated with OMPs with the R-value >0.7. Together, this study reaffirmed the significance of the ß-lactam resistance pathway in CRKP based on proteomic analysis. OmpK35/36 porin reduction and the controversial downregulation of EnvZ-OmpR, PhoPQ, and BaeSR TCSs were confirmed in carbapenem resistance of Klebsiella pneumoniae.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Klebsiella , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Carbapenêmicos/metabolismo , Carbapenêmicos/farmacologia , Cromatografia Líquida , Regulação para Baixo , Humanos , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Porinas/genética , Porinas/metabolismo , Proteômica , Espectrometria de Massas em Tandem , beta-Lactamases/metabolismo
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