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1.
BMC Public Health ; 24(1): 655, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429684

RESUMO

BACKGROUND: Colorectal cancer (CRC) is a global health issue with noticeably high incidence and mortality. Microsimulation models offer a time-efficient method to dynamically analyze multiple screening strategies. The study aimed to identify the efficient organized CRC screening strategies for Shenzhen City. METHODS: A microsimulation model named CMOST was employed to simulate CRC screening among 1 million people without migration in Shenzhen, with two CRC developing pathways and real-world participation rates. Initial screening included the National Colorectal Polyp Care score (NCPCS), fecal immunochemical test (FIT), and risk-stratification model (RS model), followed by diagnostic colonoscopy for positive results. Several start-ages (40, 45, 50 years), stop-ages (70, 75, 80 years), and screening intervals (annual, biennial, triennial) were assessed for each strategy. The efficiency of CRC screening was assessed by number of colonoscopies versus life-years gained (LYG). RESULTS: The screening strategies reduced CRC lifetime incidence by 14-27 cases (30.9-59.0%) and mortality by 7-12 deaths (41.5-71.3%), yielded 83-155 LYG, while requiring 920 to 5901 colonoscopies per 1000 individuals. Out of 81 screening, 23 strategies were estimated efficient. Most of the efficient screening strategies started at age 40 (17 out of 23 strategies) and stopped at age 70 (13 out of 23 strategies). Predominant screening intervals identified were annual for NCPCS, biennial for FIT, and triennial for RS models. The incremental colonoscopies to LYG ratios of efficient screening increased with shorter intervals within the same test category. Compared with no screening, when screening at the same start-to-stop age and interval, the additional colonoscopies per LYG increased progressively for FIT, NCPCS and RS model. CONCLUSION: This study identifies efficient CRC screening strategies for the average-risk population in Shenzhen. Most efficient screening strategies indeed start at age 40, but the optimal starting age depends on the chosen willingness-to-pay threshold. Within insufficient colonoscopy resources, efficient FIT and NCPCS screening strategies might be CRC initial screening strategies. We acknowledged the age-dependency bias of the results with NCPCS and RS.


Assuntos
Neoplasias Colorretais , Detecção Precoce de Câncer , Humanos , Adulto , Idoso , Detecção Precoce de Câncer/métodos , Colonoscopia , Fatores de Risco , Neoplasias Colorretais/prevenção & controle , Sangue Oculto , Análise Custo-Benefício , Programas de Rastreamento/métodos
2.
J Asian Nat Prod Res ; 26(2): 228-236, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38193237

RESUMO

A novel [1, 2, 4]triazolo[5,1-b]quinazoline fluorescent probe (VIi) for Fe3+ was developed, featuring with rapid response (< 5 s) and specific selectivity to Fe3+, low detection limit (1.3 × 10-5 M), as well as the ability to resist interference of chelating agent (e.g. EDTA). VIi-based fluorescent test paper can quickly recognize Fe3+ under irradiation at the wavelength of 365 nm. The fluorescence probe VIi has potential application prospects for the detection of Fe3+ in real circumstance.


Assuntos
Corantes Fluorescentes , Quinazolinas , Espectrometria de Fluorescência , Íons
3.
Mol Pharm ; 20(5): 2402-2414, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37015025

RESUMO

Overexpression of fibroblast activation protein (FAP) in cancer-associated fibroblasts in a wide variety of tumors enables a highly selective targeting strategy using FAP inhibitors (FAPIs). Quinoline-based FAPIs labeled with radionuclides have been widely developed for tumor-targeted nuclear medicine imaging. However, the short retention time of FAPIs at the tumor site limits their application in radionuclide therapy. In this study, a novel FAPI-04 dimer was synthesized and labeled with radionuclides to prolong the retention time in tumors for imaging and therapy. To prepare the FAPI-04 dimer complex, DOTA-Suc-Lys-(FAPI-04)2, we used Fmoc-Lys(Boc)-OH as the linker to conjugate two FAPI-04 structures by an amide reaction. The resulting product was further modified by DOTA groups to allow for conjugation with radioactive metals. Both [68Ga]Ga-(FAPI-04)2 and [177Lu]Lu-(FAPI-04)2 showed a radiochemical purity of >99% and remained stable in vitro. In vivo, micro-PET images of SKOV3, A431, and H1299 xenografts revealed that the tumor uptake of [68Ga]Ga-(FAPI-04)2 was about twice that of [68Ga]Ga-FAPI-04 and that the accumulation of [68Ga]Ga-(FAPI-04)2 at the tumor site did not significantly decrease even 3h after injection. The tumor-abdomen ratio of [68Ga]Ga-(FAPI-04)2 images was significantly higher than that of [18F]F-FDG images. For radionuclide therapy, [177Lu]Lu-(FAPI-04)2 effectively retarded tumor growth and displayed good tolerance. In conclusion, the DOTA-Suc-Lys-(FAPI-04)2 design enhanced its uptake in FAP-expressing tumors, improved its retention time at the tumor site, and produced high-contrast imaging in xenografts after radionuclide labeling. Furthermore, it showed a noticeable antitumor effect. DOTA-Suc-Lys-(FAPI-04)2 provides a new approach for applying FAPI derivatives in tumor theranostics.


Assuntos
Neoplasias , Quinolinas , Humanos , Medicina de Precisão , Radioisótopos de Gálio , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada
4.
Thromb J ; 21(1): 9, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36691024

RESUMO

BACKGROUND: Portal vein thrombosis is a common complication of liver cirrhosis and hepatocellular carcinoma; however, few studies have reported its long-term clinical prognosis. This study aimed to establish and validate easy-to-use nomograms for predicting gastrointestinal bleeding, portal vein thrombosis resolution, and mortality of patients with portal vein thrombosis. METHODS: This multicenter retrospective cohort study included 425 patients with portal vein thrombosis who were divided into training (n = 334) and validation (n = 91) sets. Prediction models were developed using multivariate Cox regression analysis and evaluated using the consistency index and calibration plots. RESULTS: Predictors of gastrointestinal bleeding included a history of gastrointestinal bleeding, superior mesenteric vein thrombosis, red color sign observed during endoscopy, and hepatic encephalopathy. Meanwhile, predictors of resolution of portal vein thrombosis included a history of abdominal infection, C-reactive protein and hemoglobin levels, and intake of thrombolytics. Predictors of death included abdominal infection, abdominal surgery, aspartate aminotransferase level, hepatic encephalopathy, and ascites. All models had good discriminatory power and consistency. Anticoagulation therapy significantly increased the probability of thrombotic resolution without increasing the risk of bleeding or death. CONCLUSIONS: We successfully developed and validated three prediction models that can aid in the early evaluation and treatment of portal vein thrombosis.

5.
BMC Pregnancy Childbirth ; 23(1): 719, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37817070

RESUMO

BACKGROUND: Pre-eclampsia (PE) is a common condition in pregnancy; however, methods for early diagnosis and effective treatment options are lacking. Ferroptosis is a newly identified iron-dependent cell death pathway. The aim of this study was to investigate the role of ferroptosis-related genes in PE, the underlying mechanism, and their potential diagnostic value using a bioinformatics approach. METHODS: We downloaded the GSE48424 and GSE98224 datasets from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between PE and healthy pregnancy samples were identified in the GSE48424 dataset and subjected to weighted gene co-expression network analysis; the most relevant modules were intersected with known ferroptosis-related genes to distinctly identify the role of ferroptosis in PE. We further searched transcription factors and microRNAs that are predicted to regulate these ferroptosis-related genes, and patients in the GSE48424 dataset were divided into two groups according to high or low expression of the key ferroptosis-related genes associated with PE. To obtain robust key ferroptosis-related genes in PE, we validated their expression levels in the external dataset GSE98224. Finally, the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay was utilized to access the expression of these genes in the PE and normal blood samples. RESULTS: Six ferroptosis-related genes involved in PE were obtained by overlapping 3661 genes most associated with PE, 565 DEGs between PE and normal samples, and 259 known ferroptosis-related genes. Among these genes, patients with PE displaying lower expression levels of NOS2 and higher expression levels of PTGS2 had a higher ferroptosis potential index. The expression pattern of NOS2 was consistent in the GSE48424 and GSE98224 datasets. RT-qPCR data confirmed that NOS2 expression was more significantly elevated in patients with PE than in those with a normal pregnancy. CONCLUSIONS: Our study explored the diagnostic value of ferroptosis-related genes in PE, and identified NOS2 as the key gene linking ferroptosis and PE, suggesting a new candidate biomarker for early PE diagnosis.


Assuntos
Ferroptose , Óxido Nítrico Sintase Tipo II , Pré-Eclâmpsia , Feminino , Humanos , Gravidez , Biomarcadores , Biologia Computacional , Óxido Nítrico Sintase Tipo II/genética , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/genética
6.
Int J Mol Sci ; 24(7)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37047285

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease around the world; however, its pathogenesis remains unclear so far. Recent advances have shown that DNA damage and repair deficiency play an important role in the pathophysiology of PD. There is growing evidence suggesting that DNA damage is involved in the propagation of cellular damage in PD, leading to neuropathology under different conditions. Here, we reviewed the current work on DNA damage repair in PD. First, we outlined the evidence and causes of DNA damage in PD. Second, we described the potential pathways by which DNA damage mediates neurotoxicity in PD and discussed the precise mechanisms that drive these processes by DNA damage. In addition, we looked ahead to the potential interventions targeting DNA damage and repair. Finally, based on the current status of research, key problems that need to be addressed in future research were proposed.


Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Doença de Parkinson/metabolismo , Doenças Neurodegenerativas/genética , Dano ao DNA , Reparo do DNA
7.
Int J Mol Sci ; 24(10)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37239999

RESUMO

DNA damage and defective DNA repair are extensively linked to neurodegeneration in Parkinson's disease (PD), but the underlying molecular mechanisms remain poorly understood. Here, we determined that the PD-associated protein DJ-1 plays an essential role in modulating DNA double-strand break (DSB) repair. Specifically, DJ-1 is a DNA damage response (DDR) protein that can be recruited to DNA damage sites, where it promotes DSB repair through both homologous recombination and nonhomologous end joining. Mechanistically, DJ-1 interacts directly with PARP1, a nuclear enzyme essential for genomic stability, and stimulates its enzymatic activity during DNA repair. Importantly, cells from PD patients with the DJ-1 mutation also have defective PARP1 activity and impaired repair of DSBs. In summary, our findings uncover a novel function of nuclear DJ-1 in DNA repair and genome stability maintenance, and suggest that defective DNA repair may contribute to the pathogenesis of PD linked to DJ-1 mutations.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Humanos , Reparo do DNA por Junção de Extremidades , Dano ao DNA , Mutação , Instabilidade Genômica , Poli(ADP-Ribose) Polimerase-1/genética
8.
PLoS Pathog ; 16(4): e1008457, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32251420

RESUMO

The retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), including RIG-I and melanoma differentiation-associated gene 5 (MDA5), sense cytoplasmic viral RNA and initiate innate antiviral responses. How RIG-I and MDA5 are differentially regulated remains enigmatic. In this study, we identified the guanylate-binding protein (GBP) and zinc-finger FYVE domain-containing protein ZFYVE1 as a negative regulator of MDA5- but not RIG-I-mediated innate antiviral responses. ZFYVE1-deficiency promoted MDA5- but not RIG-I-mediated transcription of downstream antiviral genes. Comparing to wild-type mice, Zfyve1-/- mice were significantly protected from lethality induced by encephalomyocarditis virus (EMCV) that is sensed by MDA5, whereas Zfyve1-/- and Zfyve1+/+ mice were comparable to death induced by vesicular stomatitis virus (VSV) that is sensed by RIG-I. Mechanistically, ZFYVE1 interacted with MDA5 but not RIG-I. ZFYVE1 bound to viral RNA and decreased the ligand binding and oligomerization of MDA5. These findings suggest that ZFYVE1 acts as a specific negative regulator of MDA5-mediated innate immune responses by inhibiting its ligand binding and oligomerization.


Assuntos
Infecções por Cardiovirus/imunologia , Proteína DEAD-box 58/imunologia , Vírus da Encefalomiocardite/fisiologia , Helicase IFIH1 Induzida por Interferon/imunologia , Proteínas de Membrana/imunologia , Animais , Infecções por Cardiovirus/genética , Infecções por Cardiovirus/virologia , Proteína DEAD-box 58/genética , Vírus da Encefalomiocardite/genética , Humanos , Imunidade Inata , Helicase IFIH1 Induzida por Interferon/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
Mov Disord ; 37(1): 196-200, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34612548

RESUMO

BACKGROUND: Emerging evidence indicates that the apolipoprotein E (APOE) ε4 exacerbates α-synuclein pathology. OBJECTIVE: To determine whether APOE ε4 contributes to motor progression in early Parkinson's disease (PD). METHODS: Longitudinal data were obtained from 384 patients with PD divided into APOE ε4 carriers (n = 85) and noncarriers (n = 299) in the Parkinson's Progression Marker Initiative. Participants underwent yearly motor assessments over a mean follow-up period of 78.9 months. Repeated measures and linear mixed models were used to test the effects of APOE ε4. RESULTS: The motor progression was significantly more rapid in patients with PD carrying APOE ε4 than in noncarriers (ß = 0.283, P = 0.026, 95% confidence interval: 0.033-0.532). Through subgroup analysis, we found that the effect of APOE ε4 was significant only in patients with high amyloid ß burden (ß = 0.761, P < 0.001, 95% confidence interval: 0.0356-1.167). CONCLUSIONS: APOE ε4 may be associated with rapid motor progression in PD. © 2021 International Parkinson and Movement Disorder Society.


Assuntos
Apolipoproteína E4 , Doença de Parkinson , Peptídeos beta-Amiloides/metabolismo , Apolipoproteína E4/genética , Progressão da Doença , Genótipo , Humanos , Doença de Parkinson/genética , Doença de Parkinson/fisiopatologia
10.
J Org Chem ; 86(14): 9299-9305, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34181422

RESUMO

Brønsted acid-catalyzed direct C(sp2)-H alkylation of N-heteroaromatics with cyclic ethers via a cross-dehydrogenative coupling reaction in the presence of benzoyl peroxide was developed. This methodology successfully provided an easy access to a variety of alkyl-substituted quinoxaline, benzoimidazole, pyrazine, pyrimidine, quinoline, isoquinoline, and pyridine derivatives in up to 94% yield under metal-free conditions.

11.
J Immunol ; 203(1): 259-268, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31127032

RESUMO

The dynamic regulations of ubiquitination and deubiquitination play important roles in TGF-ß-activated kinase 1 (TAK1)-mediated NF-κB activation, which regulates various physiological and pathological events. We identified ubiquitin-specific protease (USP)19 as a negative regulator of TNF-α- and IL-1ß-triggered NF-κB activation by deubiquitinating TAK1. Overexpression of USP19 but not its enzymatic inactive mutant inhibited TNF-α- and IL-1ß-triggered NF-κB activation and transcription of downstream genes, whereas USP19 deficiency had the opposite effects. Usp19-/- mice produced higher levels of inflammatory cytokines and were more susceptible to TNF-α- and IL-1ß-triggered septicemia death compared with their wild-type littermates. Mechanistically, USP19 interacted with TAK1 in a TNF-α- or IL-1ß-dependent manner and specifically deconjugated K63- and K27-linked polyubiquitin chains from TAK1, leading to the impairment of TAK1 activity and the disruption of the TAK1-TAB2/3 complex. Our findings provide new insights to the complicated molecular mechanisms of the attenuation of the inflammatory response.


Assuntos
Endopeptidases/metabolismo , Inflamação/imunologia , MAP Quinase Quinase Quinases/metabolismo , NF-kappa B/metabolismo , Sepse/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Suscetibilidade a Doenças , Endopeptidases/genética , Células HEK293 , Humanos , Tolerância Imunológica , Interleucina-1beta/metabolismo , Camundongos , Camundongos Knockout , Ligação Proteica , RNA Interferente Pequeno/genética , Fator de Necrose Tumoral alfa/metabolismo , Ubiquitinação
12.
Proc Natl Acad Sci U S A ; 115(49): 12483-12488, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30442668

RESUMO

The proinflammatory cytokine IL-1ß plays critical roles in inflammatory and autoimmune diseases. IL-1ß signaling is tightly regulated to avoid excessive inflammatory response. In this study, we identified the E3 ubiquitin ligase membrane-associated RING-CH-type finger 3 (MARCH3) as a critical negative regulator of IL-1ß-triggered signaling. Overexpression of MARCH3 inhibited IL-1ß-triggered activation of NF-κB as well as expression of inflammatory genes, whereas MARCH3 deficiency had the opposite effects. MARCH3-deficient mice produced higher levels of serum inflammatory cytokines and were more sensitive to inflammatory death upon IL-1ß injection or Listeria monocytogenes infection. Mechanistically, MARCH3 was associated with IL-1 receptor I (IL-1RI) and mediated its K48-linked polyubiquitination at K409 and lysosomal-dependent degradation. Furthermore, IL-1ß stimulation triggered dephosphorylation of MARCH3 by CDC25A and activation of its E3 ligase activity. Our findings suggest that MARCH3-mediated IL-1RI degradation is an important mechanism for attenuating IL-1ß-triggered inflammatory response.


Assuntos
Inflamação/metabolismo , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Listeriose/patologia , Receptores Tipo I de Interleucina-1/metabolismo , Animais , Regulação da Expressão Gênica , Interleucina-1beta/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Listeria monocytogenes , Camundongos , Camundongos Knockout , Fosforilação , Receptores Tipo I de Interleucina-1/genética , Tirosina , Ubiquitinação
13.
Sensors (Basel) ; 21(18)2021 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-34577327

RESUMO

Toxic and nontoxic volatile organic compound (VOC) gases are emitted into the atmosphere from certain solids and liquids as a consequence of wastage and some common daily activities. Inhalation of toxic VOCs has an adverse effect on human health, so it is necessary to monitor their concentration in the atmosphere. In this work, we report on the fabrication of inorganic nanotube (INT)-tungsten disulfide, paper-based graphene-PEDOT:PSS sheet and WS2 nanotube-modified conductive paper-based chemiresistors for VOC gas sensing. The WS2 nanotubes were fabricated by a two-step reaction, that is oxide reduction and sulfurization, carried out at 900 °C. The synthesized nanotubes were characterized by FE-SEM, EDS, XRD, Raman spectroscopy, and TEM. The synthesized nanotubes were 206-267 nm in diameter. The FE-SEM results show the length of the nanotubes to be 4.5-8 µm. The graphene-PEDOT:PSS hybrid conductive paper sheet was fabricated by a continuous coating process. Then, WS2 nanotubes were drop-cast onto conductive paper for fabrication of the chemiresistors. The feasibility and sensitivity of the WS2 nanotube-modified paper-based chemiresistor were tested in four VOC gases at different concentrations at room temperature (RT). Experimental results show the proposed sensor to be more sensitive to butanol gas when the concentration ranges from 50 to 1000 ppm. The limit of detection (LOD) of this chemiresistor for butanol gas was 44.92 ppm. The WS2 nanotube-modified paper-based chemiresistor exhibits good potential as a VOC sensor with the advantages of flexibility, easy fabrication, and low fabrication cost.


Assuntos
Nanotubos , Compostos Orgânicos Voláteis , Dissulfetos , Humanos , Limite de Detecção , Tungstênio
14.
Int J Mol Sci ; 22(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34769113

RESUMO

The increasing numbers of infections caused by multidrug-resistant (MDR) pathogens highlight the urgent need for new alternatives to conventional antibiotics. Antimicrobial peptides have the potential to be promising alternatives to antibiotics because of their effective bactericidal activity and highly selective toxicity. The present study was conducted to investigate the antibacterial, antibiofilm, and anti-adhesion activities of different CTP peptides (CTP: the original hybrid peptide cathelicidin 2 (1-13)-thymopentin (TP5); CTP-NH2: C-terminal amidated derivative of cathelicidin 2 (1-13)-TP5; CTPQ: glutamine added at the C-terminus of cathelicidin 2 (1-13)-TP5) by determining the minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), propidium iodide uptake, and analysis by scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy). The results showed that CTPs had broad-spectrum antibacterial activity against different gram-positive and gram-negative bacteria, with MICs against the tested strains varying from 2 to 64 µg/mL. CTPs at the MBC (2 × MIC 64 µg/mL) showed strong bactericidal effects on a standard methicillin-resistant Staphylococcus aureus strain ATCC 43300 after co-incubation for 6 h through disruption of the bacterial membrane. In addition, CTPs at 2 × MIC also displayed effective inhibition activity of several S. aureus strains with a 40-90% decrease in biofilm formation by killing the bacteria embedded in the biofilms. CTPs had low cytotoxicity on the intestinal porcine epithelial cell line (IPEC-J2) and could significantly decrease the rate of adhesion of S. aureus ATCC 43300 on IPEC-J2 cells. The current study proved that CTPs have effective antibacterial, antibiofilm, and anti-adhesion activities. Overall, this study contributes to our understanding of the possible antibacterial and antibiofilm mechanisms of CTPs, which might be an effective anti-MDR drug candidate.


Assuntos
Catelicidinas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Timopentina , Biofilmes/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Testes de Sensibilidade Microbiana
15.
J Acoust Soc Am ; 141(4): 2882, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28464690

RESUMO

If an auditory scene consists of many spatially separated sound sources, how many sound sources can be processed by the auditory system? Experiment I determined how many speech sources could be localized simultaneously on the azimuth plane. Different words were played from multiple loudspeakers, and listeners reported the total number of sound sources and their individual locations. In experiment II the accuracy of localizing one speech source in a mixture of multiple speech sources was determined. An extra sound source was added to an existing set of sound sources, and the task was to localize that extra source. In experiment III the setup and task were the same as in experiment I, except that the sounds were tones. The results showed that the maximum number of sound sources that listeners could perceive was limited to approximately four spatially separated speech signals and three for tonal signals. The localization errors increased along with the increase of total number of sound sources. When four or more speech sources already existed, the accuracy in localizing an additional source was near chance.


Assuntos
Meio Ambiente , Exposição Ambiental/efeitos adversos , Ruído/efeitos adversos , Mascaramento Perceptivo , Localização de Som , Percepção da Fala , Estimulação Acústica , Audiometria da Fala , Limiar Auditivo , Feminino , Humanos , Masculino , Detecção de Sinal Psicológico
16.
Inorg Chem ; 55(11): 5095-7, 2016 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-27158986

RESUMO

Catenation based on homochiral metal-organic nanocages or nanotubes is realized in this work for the first time. A flexible enantiopure ligand is employed to assemble metal ions, with the structure-directing effect of an auxiliary ligand, a triangular-prism-like nanocage, and a nanotube successfully built. Further 0D → 3D catenation is achieved by interlocking the nanocages, and 1D → 3D catenation based on nanotubes is also presented. This work reveals extraordinary catenating architectures from molecular cages and tubes.

17.
Inorg Chem ; 55(13): 6355-7, 2016 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-27315193

RESUMO

Using lactic acid derivatives as chiral ligands, a pair of unprecedented homochiral metal-organic zeolites have been synthesized that feature zeotype CAN topology and have high porosity for enantioselective separation of racemates.

18.
Chemistry ; 21(28): 10236-40, 2015 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-26041141

RESUMO

Homochiral metal-organic frameworks (HMOFs) are efficient materials for enantioselective adsorption. However, the combination of size selectivity and enantioselectivity is still a major challenge in the field of HMOFs. Herein, two enantiomorphic HMOFs built from predesigned proline-derived ligands are presented. Both of them show multiple homochiral features: they contain four different helical chains and three types of helical channels. Due to the size effect of the helical channels, each HMOF can enantioselectively adsorb methyl lactate with high ee. The results reveal a new approach toward size-dependent enantioselective separation of racemic compounds by using HMOFs built from inexpensive proline derivatives.

19.
J Acoust Soc Am ; 138(5): 3293-310, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26627802

RESUMO

In four experiments listeners were rotated or were stationary. Sounds came from a stationary loudspeaker or rotated from loudspeaker to loudspeaker around an azimuth array. When either sounds or listeners rotate the auditory cues used for sound source localization change, but in the everyday world listeners perceive sound rotation only when sounds rotate not when listeners rotate. In the everyday world sound source locations are referenced to positions in the environment (a world-centric reference system). The auditory cues for sound source location indicate locations relative to the head (a head-centric reference system), not locations relative to the world. This paper deals with a general hypothesis that the world-centric location of sound sources requires the auditory system to have information about auditory cues used for sound source location and cues about head position. The use of visual and vestibular information in determining rotating head position in sound rotation perception was investigated. The experiments show that sound rotation perception when sources and listeners rotate was based on acoustic, visual, and, perhaps, vestibular information. The findings are consistent with the general hypotheses and suggest that sound source localization is not based just on acoustics. It is a multisystem process.


Assuntos
Movimentos da Cabeça , Modelos Neurológicos , Localização de Som/fisiologia , Aceleração , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Propriocepção/fisiologia , Rotação , Comportamento Espacial , Vestíbulo do Labirinto/fisiologia , Visão Ocular/fisiologia , Adulto Jovem
20.
Inorg Chem ; 53(22): 12199-204, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25361035

RESUMO

Two enantiopure organic ligands integrating flexible proline units and rigid isophthalate units have been rationally designed and employed for the construction of four homochiral porous metal-organic frameworks (MOFs), respectively. One pair of these MOFs is used as heterogeneous catalysts to construct ß-lactam derivatives by oxidative coupling reactions.


Assuntos
Cobre/química , Compostos Organometálicos/síntese química , Prolina/química , beta-Lactamas/síntese química , Catálise , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/química , Estereoisomerismo , beta-Lactamas/química
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