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1.
Am J Epidemiol ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38949483

RESUMO

Dementia incidence is lower among Asian Americans than Whites, despite higher prevalence of type 2 diabetes, a well-known dementia risk factor. Determinants of dementia, including type 2 diabetes, have rarely been studied in Asian Americans. We followed 4,846 Chinese, 4,129 Filipino, 2,784 Japanese, 820 South Asian, and 123,360 non-Latino White members of a California-based integrated healthcare delivery system from 2002-2020. We estimated dementia incidence rates by race/ethnicity and type 2 diabetes status, and fit Cox proportional hazards and Aalen additive hazards models for the effect of type 2 diabetes (assessed 5 years before baseline) on age of dementia diagnosis controlling for sex/gender, educational attainment, nativity, height, race/ethnicity, and a race/ethnicity*diabetes interaction. Type 2 diabetes was associated with higher dementia incidence in Whites (hazard ratio [HR] 1.46, 95% confidence interval [CI] 1.40-1.52). Compared with Whites, the estimated effect of diabetes was larger in South Asians (2.26 [1.48-3.44]), slightly smaller in Chinese (1.32 [1.08-1.62]) and Filipino (1.31 [1.08-1.60]), and similar in Japanese (1.44 [1.15-1.81]) individuals. Heterogeneity in this association across Asian subgroups may be related to type 2 diabetes severity. Understanding this heterogeneity may inform prevention strategies to prevent dementia for all racial and ethnic groups.

2.
Am J Epidemiol ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38973744

RESUMO

Literature shows heterogeneous age-standardized dementia incidence rates across US Asian American, Native Hawaiian, and Pacific Islanders (AANHPI), but no estimates of population-representative dementia incidence exist due to lack of AANHPI longitudinal probability samples. We compared harmonized characteristics between AANHPI Kaiser Permanente Northern California members (KPNC cohort) and the target population of AANHPI 60+ with private or Medicare insurance using the California Health Interview Survey. We used stabilized inverse odds of selection weights (sIOSW) to estimate ethnicity-specific crude and age-standardized dementia incidence rates and cumulative risk by age 90 in the target population. Differences between the KPNC cohort and target population varied by ethnicity. sIOSW eliminated most differences in larger ethnic groups; some differences remained in smaller groups. Estimated crude dementia incidence rates using sIOSW (versus unweighted) were similar in Chinese, Filipinos, Pacific Islanders and Vietnamese, and higher in Japanese, Koreans, and South Asians. Unweighted and weighted age-standardized incidence rates differed for South Asians. Unweighted and weighted cumulative risk were similar for all groups. We estimated the first population-representative dementia incidence rates and cumulative risk in AANHPI ethnic groups. We encountered some estimation problems and weighted estimates were imprecise, highlighting challenges using weighting to extend inferences to target populations.

3.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33602823

RESUMO

Many cancers evade immune rejection by suppressing major histocompatibility class I (MHC-I) antigen processing and presentation (AgPP). Such cancers do not respond to immune checkpoint inhibitor therapies (ICIT) such as PD-1/PD-L1 [PD-(L)1] blockade. Certain chemotherapeutic drugs augment tumor control by PD-(L)1 inhibitors through potentiation of T-cell priming but whether and how chemotherapy enhances MHC-I-dependent cancer cell recognition by cytotoxic T cells (CTLs) is not entirely clear. We now show that the lysine acetyl transferases p300/CREB binding protein (CBP) control MHC-I AgPPM expression and neoantigen amounts in human cancers. Moreover, we found that two distinct DNA damaging drugs, the platinoid oxaliplatin and the topoisomerase inhibitor mitoxantrone, strongly up-regulate MHC-I AgPP in a manner dependent on activation of nuclear factor kappa B (NF-κB), p300/CBP, and other transcription factors, but independently of autocrine IFNγ signaling. Accordingly, NF-κB and p300 ablations prevent chemotherapy-induced MHC-I AgPP and abrogate rejection of low MHC-I-expressing tumors by reinvigorated CD8+ CTLs. Drugs like oxaliplatin and mitoxantrone may be used to overcome resistance to PD-(L)1 inhibitors in tumors that had "epigenetically down-regulated," but had not permanently lost MHC-I AgPP activity.


Assuntos
Apresentação de Antígeno/imunologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Antígenos de Histocompatibilidade Classe I/imunologia , Inibidores de Checkpoint Imunológico/farmacologia , NF-kappa B/metabolismo , Neoplasias/tratamento farmacológico , Fatores de Transcrição de p300-CBP/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linfócitos T CD8-Positivos , Proliferação de Células , Quimioterapia Combinada , Humanos , Imunoterapia/métodos , Camundongos , NF-kappa B/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Oxaliplatina/farmacologia , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Fatores de Transcrição de p300-CBP/genética
4.
Plant Dis ; 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326934

RESUMO

The small tree species Rhamnella franguloides, belonging to the genus Rhamnella in the tribe Rhamneae Hook. f. of Rhamnaceae (Hauenschild et al. 2016), is an important medicinal plant commonly used for making tea in China. In August 2023, leaf spot symptoms were observed on R. franguloides in Shangyao county, Yantai, Shandong, China, with a disease incidence of 45-65%. Initially appearing as small dark brown spots on the tip lesions, they later expanded and merged into irregular-shaped brown necrotic lesions with yellowish halos. To isolate pathogen, 20 symptomatic tissue fragments (5 × 5 mm) from ten sampling randomly plants were surface sterilized, placed on potato dextrose agar (PDA) plates, and incubated at 25°C in darkness for 3 days to obtain colonies.10 purified isolates with similar morphological characteristics were obtained by single-spore isolation from the colonies. The representative isolate MR13 was chosen for morphological and molecular analysis. The colonies On PDA medium initially appear as a circular yellow-brown ring with white round margins, ultimately turning into olive green with fluffy aerial hyphae. The conidiophores displayed brown pigmentation, solitary or branched, producing abundant short chains of conidia. The conidia were typically obclavate to obpyriform or ellipsoid in shape, 22.5-64.5 × 12.5-23.6µm in size, with a short conical beak at the apex, zero to three longitudinal septa and one to five transverse septa. Based on cultural and morphological characteristics, the fungus was identified as Alternaria spp (Simmons 2007). Due to morphological traits, five genes (the internal transcribed spacer [ITS], actin [ACT], plasma membrane ATPase [ATP], Alternaria major allergen [Alt a1] and histone 3 [H3]) form MR13 were amplified using primer pairs ITSI / ITS4, ACTDF1/R1, ATPDF1 / ATPDRI, Alt-for / Alt-rev, and H3-1a/1b, respectively (Hong et al. 2005; Lawrence et al. 2013; Lousie and Donaldson 1995). BLASTn analysis failed to confirm the identification of MR13 species based on ITS, ACT, ATP and Alt a1(ITS, OR668512; ACT, OR676918; ATP, OR676917; Alt a1, OR676919). The phylogenetic tree showed that it was closely related to Alternaria alternate, A. tenuissima, and A. destruens. The H3 sequence (OR676920) exhibited 100% similarity to A. tenuissima (OR485421). The phylogenetic tree constructed solely with H3 further confirmed MR13 as A. tenuissima. Pathogenicity tests were conducted by introducing the fungus onto healthy R. franguloides leaves in the field. Fifty leaves (five per plant) were treated with a 20ml suspension containing around 1x10^4 spores/ml, while an equal number of control samples were sprayed with distilled water. Transparent plastic bags were used to cover the treated leaves for 48 hours and maintain humidity. After fourteen days of inoculation, consistent leaf spotting symptoms were observed. In contrast, the control leaves showed no sign of infection. The fungal pathogen was successfully reisolated and identified as A. tenuissima through morphological and sequence analysis, fulfilling Koch's postulates. To our knowledge, this is the first report of A. tenuissima causing leaf spot disease on R. franguloides in China. Identifying the disease's causal agent is crucial for developing effective management strategies.

5.
BMC Surg ; 24(1): 154, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745320

RESUMO

BACKGROUND: Hemifacial spasm (HFS) is most effectively treated with microvascular decompression (MVD). However, there are certain challenges in performing MVD for HFS when the vertebral artery (VA) is involved in compressing the facial nerve (VA-involved). This study aimed to introduce a "bridge-layered" decompression technique for treating patients with VA-involved HFS and to evaluate its efficacy and safety to treat patients with HFS. METHODS: A single-center retrospective analysis was conducted on the clinical data of 62 patients with VA-involved HFS. The tortuous trunk of VA was lifted by a multi-point "bridge" decompression technique to avoid excessive traction of the cerebellum and reduce the risk of damage to the facial-acoustic nerve complex. To fully decompress all the responsible vessels, the branch vessels of VA were then isolated using the "layered" decompression technique. RESULTS: Among the 62 patients, 59 patients were cured immediately after the surgery, two patients were delayed cured after two months, and one had occasional facial muscle twitching after the surgery. Patients were followed up for an average of 19.5 months. The long-term follow-up results showed that all patients had no recurrence of HFS during the follow-up period, and no patients developed hearing loss, facial paralysis, or other permanent neurological damage complications. Only two patients developed tinnitus after the surgery. CONCLUSION: The "bridge-layered" decompression technique could effectively treat VA-involved HFS with satisfactory safety and a low risk of hearing loss. The technique could be used as a reference for decompression surgery for VA-involved HFS.


Assuntos
Espasmo Hemifacial , Cirurgia de Descompressão Microvascular , Artéria Vertebral , Humanos , Espasmo Hemifacial/cirurgia , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Artéria Vertebral/cirurgia , Adulto , Cirurgia de Descompressão Microvascular/métodos , Resultado do Tratamento , Idoso , Descompressão Cirúrgica/métodos , Seguimentos
6.
J Org Chem ; 88(11): 7141-7151, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37167441

RESUMO

Regioselective functionalization of unprotected carbohydrates at a secondary OH group in the presence of primary OH groups based on the commonly used organotin-mediated reaction has been improved. We found that the preactivation of the dibutylstannylene acetal intermediate with tetrabutylammonium bromide in toluene is a key to the improved condition for the efficient, high-yielding, and regioselective tosylation, benzoylation, or benzylation of unprotected carbohydrates. The counteranion of tetrabutylammonium ion with a weak coordination ability plays a crucial role in the improved regioselective reactions. A convenient access to the intermediates of synthetic value is also demonstrated in the organotin-mediated regioselective tosylation of unprotected carbohydrates, followed by the nucleophilic inversion reaction to give sulfur-containing and azide-modified carbohydrates.

7.
BMC Pediatr ; 23(1): 142, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-36997989

RESUMO

OBJECTIVE: Studies have shown that obesity has a significant impact on poor surgical outcomes. However, the relationship between obesity and pediatric epilepsy surgery has not been reported. This study aimed to explore the relationship between obesity and complications of pediatric epilepsy surgery and the effect of obesity on the outcome of pediatric epilepsy surgery, and to provide a reference for weight management of children with epilepsy. METHODS: A single-center retrospective analysis of complications in children undergoing epilepsy surgery was conducted. Body mass index (BMI) percentiles were adjusted by age and used as a criterion for assessing obesity in children. According to the adjusted BMI value, the children were divided into the obese group (n = 16) and nonobese group (n = 20). The intraoperative blood loss, operation time, and postoperative fever were compared between the two groups. RESULTS: A total of 36 children were included in the study, including 20 girls and 16 boys. The mean age of the children was 8.0 years old, ranging from 0.8 to 16.9 years old. The mean BMI was 18.1 kg/m2, ranging from 12.4 kg/m2 to 28.3 kg/m2. Sixteen of them were overweight or obese (44.4%). Obesity was associated with higher intraoperative blood loss in children with epilepsy (p = 0.04), and there was no correlation between obesity and operation time (p = 0.21). Obese children had a greater risk of postoperative fever (56.3%) than nonobese children (55.0%), but this was statistically nonsignificant (p = 0.61). The long-term follow-up outcomes showed that 23 patients (63.9%) were seizure-free (Engel grade I), 6 patients (16.7%) had Engel grade II, and 7 patients (19.4%) had Engel grade III. There was no difference in long-term seizure control outcomes between obese and nonobese groups (p = 0.682). There were no permanent neurological complications after surgery. CONCLUSION: Compared with nonobese children with epilepsy, obese children with epilepsy had a higher intraoperative blood loss. It is necessary to conduct early weight management of children with epilepsy as long as possible.


Assuntos
Epilepsia , Obesidade Infantil , Masculino , Feminino , Humanos , Criança , Lactente , Pré-Escolar , Adolescente , Estudos Retrospectivos , Obesidade Infantil/complicações , Perda Sanguínea Cirúrgica , Sobrepeso/complicações , Epilepsia/complicações , Epilepsia/cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Índice de Massa Corporal , Resultado do Tratamento
8.
Neurosurg Rev ; 46(1): 174, 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37442820

RESUMO

When early lateral spread response (LSR) loss before decompression in HFS surgery happens, the value of intraoperative monitoring of LSR for locating neurovascular conflicts and confirming adequate decompression was considered to be reduced. This study aimed to identify preoperative parameters predicting early LSR loss and figure out the impact of early LSR loss on prognosis. Hemifacial spasm (HFS) patients who received microvascular decompression (MVD) under intraoperative electrophysiological monitoring during the period of March 2013-January 2021 were reviewed retrospectively. The patients were divided into two groups according to the disappearance of their LSR before or after decompression. Preoperative clinical and radiological predictors for early LSR loss were evaluated using logistic regression. The relationship between early LSR loss and surgical outcomes was statistically analyzed. A total of 523 patients were included in the study, and the disappearance of their LSR before decompression occurred in 129 patients. In the multivariate analysis, three independent factors predicting early LSR loss were identified: (1) smaller vessel compression; (2) milder nerve deviation; (3) lower posterior fossa crowdedness index (PFCI, calculated as hindbrain volume (HBV)/the posterior fossa volume (PFV) using 3D Slicer software). The median follow-up time was about five years, and no significant differences in the spasm relief and complication rates were found between the 2 groups. Smaller responsible vessels, milder nerve deviation, and more spacious posterior cranial fossa are associated with early LSR loss. However, early LSR loss seems to have no significant adverse effect on MVD outcomes in skilled hands.


Assuntos
Espasmo Hemifacial , Cirurgia de Descompressão Microvascular , Humanos , Espasmo Hemifacial/cirurgia , Resultado do Tratamento , Estudos Retrospectivos , Prognóstico
9.
J Med Virol ; 94(6): 2519-2527, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35075669

RESUMO

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus affecting human health globally. G-quadruplex secondary structures attract great attention as potential targets for antiviral strategy. In this study, we show that the CHIKV genome possesses several conserved potential G-quadruplex sequences. G-quadruplex ligands BRACO-19 and TMPyP4 could stabilize the CHIKV G-quadruplex and inhibit the transcription of constructs containing CHIKV G-quadruplex sequences. Importantly, BRACO-19 and TMPyP4 suppress CHIKV replication. Our study not only reinforces the presence of viral G-quadruplex sequences but also suggests that targeting G-quadruplex structure could represent a novel strategy to inhibit CHIKV.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Animais , Antivirais/farmacologia , Vírus Chikungunya/genética , Humanos , Ligantes , Replicação Viral
10.
Int J Mol Sci ; 23(24)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36555119

RESUMO

Oligonucleotides (OGNs) are relatively new modalities that offer unique opportunities to expand the therapeutic targets. Reliable and high-throughput bioanalytical methods are pivotal for preclinical and clinical investigations of therapeutic OGNs. Liquid chromatography-mass spectrometry (LC-MS) is now evolving into being the method of choice for the bioanalysis of OGNs. Ion paring reversed-phase liquid chromatography (IP-RPLC) has been widely used in sample preparation and LC-MS analysis of OGNs; however, there are technical issues associated with these methods. IP-free methods, such as hydrophilic interaction liquid chromatography (HILIC) and anion-exchange techniques, have emerged as promising approaches for the bioanalysis of OGNs. In this review, the state-of-the-art IP-RPLC-MS bioanalytical methods of OGNs and their metabolites published in the past 10 years (2012-2022) are critically reviewed. Recent advances in IP-reagent-free LC-MS bioanalysis methods are discussed. Finally, we describe future opportunities for developing new methods that can be used for the comprehensive bioanalysis of OGNs.


Assuntos
Oligonucleotídeos , Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Oligonucleotídeos/química , Cromatografia de Fase Reversa , Íons
11.
Nanotechnology ; 33(8)2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34768252

RESUMO

The development of powerful terahertz (THz) emitters is the cornerstone for future THz applications, such as communication, medical biology, non-destructive inspection, and scientific research. Here, we report the THz emission properties and mechanisms of mushroom-shaped InAs nanowire (NW) network using linearly polarized laser excitation. By investigating the dependence of THz signal to the incidence pump light properties (e.g. incident angle, direction, fluence, and polarization angle), we conclude that the THz wave emission from the InAs NW network is induced by the combination of linear and nonlinear optical effects. The former is a transient photocurrent accelerated by the photo-Dember field, while the latter is related to the resonant optical rectification effect. Moreover, thep-polarized THz wave emission component is governed by the linear optical effect with a proportion of ∼85% and the nonlinear optical effect of ∼15%. In comparison, thes-polarized THz wave emission component is mainly decided by the nonlinear optical effect. The THz emission is speculated to be enhanced by the localized surface plasmon resonance absorption of the In droplets on top of the NWs. This work verifies the nonlinear optical mechanism in the THz generation of semiconductor NWs and provides an enlightening reference for the structural design of powerful and flexible THz surface and interface emitters in transmission geometry.

12.
Lab Invest ; 100(8): 1030-1041, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32238906

RESUMO

Talin and vinculin, both actin-cytoskeleton-related proteins, have been documented to participate in establishing bacterial infections, respectively, as the adapter protein to mediate cytoskeleton-driven dynamics of the plasma membrane. However, little is known regarding the potential role of the talin-vinculin complex during spotted fever group rickettsial and Ebola virus infections, two dreadful infectious diseases in humans. Many functional properties of proteins are determined by their participation in protein-protein complexes, in a temporal and/or spatial manner. To resolve the limitation of application in using mouse primary antibodies on archival, multiple formalin-fixed mouse tissue samples, which were collected from experiments requiring high biocontainment, we developed a practical strategic proximity ligation assay (PLA) capable of employing one primary antibody raised in mouse to probe talin-vinculin spatial proximal complex in mouse tissue. We observed an increase of talin-vinculin spatial proximities in the livers of spotted fever Rickettsia australis or Ebola virus-infected mice when compared with mock mice. Furthermore, using EPAC1-knockout mice, we found that deletion of EPAC1 could suppress the formation of spatial proximal complex of talin-vinculin in rickettsial infections. In addition, we observed increased colocalization between spatial proximity of talin-vinculin and filamentous actin-specific phalloidin staining in single survival mouse from an ordinarily lethal dose of rickettsial or Ebola virus infection. These findings may help to delineate a fresh insight into the mechanisms underlying liver specific pathogenesis during infection with spotted fever rickettsia or Ebola virus in the mouse model.


Assuntos
Citoesqueleto de Actina/metabolismo , Membrana Celular/metabolismo , Doença pelo Vírus Ebola/metabolismo , Fígado/metabolismo , Talina/metabolismo , Vinculina/metabolismo , Animais , Células Cultivadas , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Fígado/microbiologia , Fígado/virologia , Camundongos Knockout , Ligação Proteica , Rickettsia/fisiologia , Rickettsiose do Grupo da Febre Maculosa/metabolismo , Rickettsiose do Grupo da Febre Maculosa/microbiologia , Talina/química , Vinculina/química
13.
Mol Microbiol ; 111(6): 1529-1543, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30838726

RESUMO

Bacterial antibiotic resistance, a global health threat, is caused by plasmid transfer or genetic mutations. Quinolones are important antibiotics, partially because they are fully synthetic and resistance genes are unlikely to exist in nature; nonetheless, quinolone resistance proteins have been identified. The mechanism by which plasmid-borne quinolone resistance proteins promotes the selection of quinolone-resistant mutants is unclear. Here, we show that QnrB increases the bacterial mutation rate. Transcriptomic and genome sequencing analyses showed that QnrB promoted gene abundance near the origin of replication (oriC). In addition, the QnrB expression level correlated with the replication origin to terminus (oriC/ter) ratio, indicating QnrB-induced DNA replication stress. Our results also show that QnrB is a DnaA-binding protein that may act as an activator of DNA replication initiation. Interaction of QnrB with DnaA promoted the formation of the DnaA-oriC open complex, which leads to DNA replication over-initiation. Our data indicate that plasmid-borne QnrB increases bacterial mutation rates and that genetic changes can alleviate the fitness cost imposed by transmitted plasmids. Derivative mutations may impair antibiotic efficacy and threaten the value of antibiotic treatments. Enhanced understanding of how bacteria adapt to the antibiotic environment will lead to new therapeutic strategies for antibiotic-resistant infections.


Assuntos
Replicação do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Taxa de Mutação , DNA Bacteriano/metabolismo , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Perfilação da Expressão Gênica , Aptidão Genética , Mutação , Plasmídeos/genética , Quinolonas/farmacologia , Origem de Replicação , Sequenciamento Completo do Genoma
14.
Opt Express ; 28(21): 30675-30685, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33115063

RESUMO

We propose a switchable broadband and wide-angular terahertz asymmetric transmission based on a spiral metasurface composed of metal and VO2 hybrid structures. Results show that asymmetric transmission reaching up to 15% can be switched on or off for circularly polarized terahertz waves when the phase of VO2 transits from the insulting state to the conducting state or reversely. Strikingly, we find that relatively high asymmetric transmission above 10% can be maintained over a broad bandwidth of 2.6-4.0 THz and also over a large incident angular range of 0°-45°. We further discover that as the incident angle increases, the dominant chirality of the proposed metasurface with VO2 in the conducting state can shift from intrinsic to extrinsic chirality. We expect this work will advance the engineering of switchable chiral metasurfaces and promote terahertz applications.

15.
Phys Chem Chem Phys ; 22(7): 3849-3854, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32022047

RESUMO

Zeolitic imidazolate frameworks (ZIFs) represent a novel class of porous crystalline materials that have demonstrated potential as light harvesting materials for solar energy conversion. In order to facilitate their application in solar energy conversion, it is necessary to expand their absorption further into the realm of the solar spectrum. In this work, we report the incorporation of semiconductor cadmium sulfide nanowires (CdS NWs) into ZIF-67 (CdS@ZIF-67), where a broader region of the solar spectrum can be absorbed by CdS NWs and relayed to ZIF-67 through an energy transfer (EnT) process. Using steady-state emission and time resolved emission and absorption spectroscopy, we show that efficient EnT can occur from CdS NWs to ZIF-67 by selective excitation of CdS NWs. The EnT time is ∼729.9 ps, which corresponds to 71.2% EnT efficiency.

16.
Phys Chem Chem Phys ; 22(37): 21428-21435, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32944724

RESUMO

Tunable optical properties play an important role in the high performance of optoelectronic applications based on two-dimensional (2D) transition metal carbide and nitride (MXene) materials. Herein, the optical properties of functionalized MXene monolayers Sc2CT2 (T = O and OH) are investigated by strain engineering. The strain-dependent linear optical properties of Sc2CT2 possess broadband optical response due to the geometry and orbital overlap effect. The peaks from the second-order nonlinear coefficient elements d (d15, d16, and d31) at around half the band-gap exhibit a redshift for Sc2CO2 (blueshift for Sc2C(OH)2) with the increase of strain. The strain-dependent d reveals that Sc2CO2 with -1268 pm V-1 %-1 has a larger photoelastic coefficient than that of Sc2C(OH)2 with -574 pm V-1 %-1 at 1% strain. Meanwhile, the photoelastic tensors can not only be increased but also reduced with the increase of strain due to the dispersion relation. Moreover, the azimuthal angle-dependent second harmonic generation (SHG) from strained Sc2CT2 monolayers depends highly on the strained states and the pumping photon energy. The results pave the way for the tunable, broadband, and anisotropic applications of nonlinear optoelectronic devices based on MXenes based on strain engineering.

17.
Appl Opt ; 59(12): 3686-3691, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32400491

RESUMO

Chirality has received wide attention due to its promising applications in biopharmaceuticals, chemical detection, and polarized optoelectronic devices. Herein, metamaterials with layered Tai Chi patterns are proposed to get strong and tunable chirality. Based on the surface current distribution analysis, a coupling model considering both the magnetic and electric dipoles in the upper and bottom metallic structures is proposed to understand the circular dichroism. Accordingly, both an external chiral modulation by changing the incident angle and an internal chiral modulation by changing the twist angle are achieved. Incident-angle-dependent circular dichroism modulation exhibits a range of 0.44-0.62 and the twist-angle-dependent modulation range is ${-}{0.6 - 0.42}$-0.6-0.42, where the negative value means the polarity of the circular dichroism can also be tuned. This work deepens the understanding of angular-dependent chirality in metamaterials and expands the potential for terahertz polarization optoelectronic applications.

18.
Sensors (Basel) ; 20(23)2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33266108

RESUMO

In visual tracking, the tracking model must be updated online, which often leads to undesired inclusion of corrupted training samples, and hence inducing tracking failure. We present a locality preserving correlation filter (LPCF) integrating a novel and generic decontamination approach, which mitigates the model drift problem. Our decontamination approach maintains the local neighborhood feature points structures of the bounding box center. This proposed tracking-result validation approach models not only the spatial neighborhood relationship but also the topological structures of the bounding box center. Additionally, a closed-form solution to our approach is derived, which makes the tracking-result validation process could be accomplished in only milliseconds. Moreover, a dimensionality reduction strategy is introduced to improve the real-time performance of our translation estimation component. Comprehensive experiments are performed on OTB-2015, LASOT, TrackingNet. The experimental results show that our decontamination approach remarkably improves the overall performance by 6.2%, 12.6%, and 3%, meanwhile, our complete algorithm improves the baseline by 27.8%, 34.8%, and 15%. Finally, our tracker achieves the best performance among most existing decontamination trackers under the real-time requirement.

19.
Int J Mol Sci ; 21(10)2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32429319

RESUMO

Sugar allocation is based on the source-to-sink and intracellular transport between different organelles, and sugar transporters are usually involved in these processes. Tonoplast sugar transporters (TST) are responsible for transporting sugar into vacuoles; however, the role of TSTs in root growth and the response to abiotic stress is poorly studied. Here, RNA analysis and promoter-ß-glucuronidase staining revealed that a melon TST1 gene (CmTST1) is highly expressed in the roots. The sugar feeding experiment results showed that the expression of CmTST1 in the roots was induced by a relatively high level of sucrose (6%), glucose (3%), and fructose (3%). The ectopic overexpression of CmTST1 in Arabidopsis improved the root and shoot growth of seedlings under high exogenous sugar stress. Furthermore, the ectopic expression of CmTST1 promoted the expression of plasma membrane-located sugar transporters. We proposed that CmTST1 plays a key role in importing sugar transport into the vacuoles of roots in response to metabolic demands to maintain cytosolic sugar homeostasis.


Assuntos
Cucurbitaceae/crescimento & desenvolvimento , Cucurbitaceae/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Açúcares/metabolismo , Vacúolos/metabolismo , Arabidopsis/genética , Cucurbitaceae/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana Transportadoras/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Plântula/metabolismo , Estresse Fisiológico
20.
Lab Invest ; 99(11): 1650-1660, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31253864

RESUMO

Understanding bacterial adhesion is challenging and critical to our understanding of the initial stages of the pathogenesis of endovascular bacterial infections. The vascular endothelial cell (EC) is the main target of Rickettsia, an obligately intracellular bacterium that causes serious systemic disease in humans and animals. But the mechanism(s) underlying bacterial adherence to ECs under shear stress from flowing blood prior to activation are unknown for any bacteria. Although host surface annexin a2 (ANXA2) has been identified to participate in efficient bacterial invasion of epithelial cells, direct evidence is lacking in the field of bacterial infections of ECs. In the present study, we employ a novel, anatomically based, in vivo quantitative bacterial-adhesion-to-vascular-EC system, combined with atomic force microscopy (AFM), to examine the role of endothelial luminal surface ANXA2 during rickettsial adherence to ECs. We also examined whether ANXA2 antibody affected binding of Staphylococcus aureus to ECs. We found that deletion of ANXA2 impeded rickettsial attachment to the ECs in vitro and blocked rickettsial adherence to the blood vessel luminal surface in vivo. The AFM studies established that EC surface ANXA2 acts as an adherence receptor for rickettsiae, and that rickettsial adhesin OmpB is the associated bacterial ligand. Furthermore, pretreatment of ECs with anti-ANXA2 antibody reduced EC surface-associated S. aureus. We conclude that the endothelial surface ANXA2 plays an important role in initiating pathogen-host interactions, ultimately leading to bacterial anchoring on the vascular luminal surface.


Assuntos
Anexina A2/fisiologia , Aderência Bacteriana/fisiologia , Células Endoteliais/microbiologia , Células Endoteliais/fisiologia , Animais , Anexina A2/deficiência , Anexina A2/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/fisiologia , Fenômenos Biomecânicos , Modelos Animais de Doenças , Interações entre Hospedeiro e Microrganismos/fisiologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Força Atômica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rickettsia/patogenicidade , Rickettsia/fisiologia , Infecções por Rickettsia/microbiologia , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/fisiologia
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