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1.
Nature ; 632(8024): 287-293, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39020170

RESUMO

Compressing the optical field to the atomic scale opens up possibilities for directly observing individual molecules, offering innovative imaging and research tools for both physical and life sciences. However, the diffraction limit imposes a fundamental constraint on how much the optical field can be compressed, based on the achievable photon momentum1,2. In contrast to dielectric structures, plasmonics offer superior field confinement by coupling the light field with the oscillations of free electrons in metals3-6. Nevertheless, plasmonics suffer from inherent ohmic loss, leading to heat generation, increased power consumption and limitations on the coherence time of plasmonic devices7,8. Here we propose and demonstrate singular dielectric nanolasers showing a mode volume that breaks the optical diffraction limit. Derived from Maxwell's equations, we discover that the electric-field singularity sustained in a dielectric bowtie nanoantenna originates from divergence of momentum. The singular dielectric nanolaser is constructed by integrating a dielectric bowtie nanoantenna into the centre of a twisted lattice nanocavity. The synergistic integration surpasses the diffraction limit, enabling the singular dielectric nanolaser to achieve an ultrasmall mode volume of about 0.0005 λ3 (λ, free-space wavelength), along with an exceptionally small feature size at the 1-nanometre scale. To fabricate the required dielectric bowtie nanoantenna with a single-nanometre gap, we develop a two-step process involving etching and atomic deposition. Our research showcases the ability to achieve atomic-scale field localization in laser devices, paving the way for ultra-precise measurements, super-resolution imaging, ultra-efficient computing and communication, and the exploration of light-matter interactions within the realm of extreme optical field localization.

2.
Nature ; 624(7991): 282-288, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38092911

RESUMO

Miniaturized lasers play a central role in the infrastructure of modern information society. The breakthrough in laser miniaturization beyond the wavelength scale has opened up new opportunities for a wide range of applications1-4, as well as for investigating light-matter interactions in extreme-optical-field localization and lasing-mode engineering5-19. An ultimate objective of microscale laser research is to develop reconfigurable coherent nanolaser arrays that can simultaneously enhance information capacity and functionality. However, the absence of a suitable physical mechanism for reconfiguring nanolaser cavities hinders the demonstration of nanolasers in either a single cavity or a fixed array. Here we propose and demonstrate moiré nanolaser arrays based on optical flatbands in twisted photonic graphene lattices, in which coherent nanolasing is realized from a single nanocavity to reconfigurable arrays of nanocavities. We observe synchronized nanolaser arrays exhibiting high spatial and spectral coherence, across a range of distinct patterns, including P, K and U shapes and the Chinese characters '' and '' ('China' in Chinese). Moreover, we obtain nanolaser arrays that emit with spatially varying relative phases, allowing us to manipulate emission directions. Our work lays the foundation for the development of reconfigurable active devices that have potential applications in communication, LiDAR (light detection and ranging), optical computing and imaging.

3.
J Cardiothorac Vasc Anesth ; 38(2): 437-444, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38105126

RESUMO

OBJECTIVES: It is unknown whether there is a difference in pulmonary outcome in different intraoperative ventilation modes for cardiac surgery with cardiopulmonary bypass (CPB). The aim of this trial was to determine whether patients undergoing cardiac surgery with CPB could benefit from intraoperative optimal ventilation mode. DESIGN: This was a single-center, prospective, randomized controlled trial. SETTING: The study was conducted at a single-center tertiary-care hospital. PARTICIPANTS: A total of 1,364 adults undergoing cardiac surgery with CPB participated in this trial. INTERVENTIONS: Patients were assigned randomly (1:1:1) to receive 1 of 3 ventilation modes: volume-controlled ventilation (VCV), pressure-controlled ventilation (PCV), and pressure-controlled ventilation-volume guaranteed (PCV-VG). All arms of the study received the lung-protective ventilation strategy. MEASUREMENTS AND MAIN RESULTS: The primary outcome was a composite of postoperative pulmonary complications (PPCs) within the first 7 postoperative days. Pulmonary complications occurred in 168 of 455 patients (36.9%) in the PCV-VG group, 171 (37.6%) in the PCV group, and 182 (40.1%) in the VCV group, respectively. There was no statistical difference in the risk of overall pulmonary complications among groups (p = 0.585). There were no significant differences in the severity grade of PPCs within 7 days, postoperative ventilation duration, intensive care unit stay, postoperative hospital stay, or 30-day postoperative mortality. CONCLUSIONS: Among patients scheduled for cardiac surgery with CPB, intraoperative ventilation mode type did not affect the risk of postoperative pulmonary complications.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Respiração Artificial , Adulto , Humanos , Respiração Artificial/efeitos adversos , Estudos Prospectivos , Pulmão , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia
4.
Hepatobiliary Pancreat Dis Int ; 23(1): 77-82, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37087368

RESUMO

BACKGROUND: Early systemic anticoagulation (SAC) is a common practice in acute necrotizing pancreatitis (ANP), and its impact on in-hospital clinical outcomes had been assessed. However, whether it affects long-term outcomes is unknown. This study aimed to evaluate the effect of SAC on 90-day readmission and other long-term outcomes in ANP patients. METHODS: During January 2013 and December 2018, ANP patients admitted within 7 days from the onset of abdominal pain were screened. The primary outcome was 90-day readmission after discharge. Cox proportional-hazards regression model and mediation analysis were used to define the relationship between early SAC and 90-day readmission. RESULTS: A total of 241 ANP patients were enrolled, of whom 143 received early SAC during their hospitalization and 98 did not. Patients who received early SAC experienced a lower incidence of splanchnic venous thrombosis (SVT) [risk ratio (RR) = 0.40, 95% CI: 0.26-0.60, P < 0.01] and lower 90-day readmission with an RR of 0.61 (95% CI: 0.41-0.91, P = 0.02) than those who did not. For the quality of life, patients who received early SAC had a significantly higher score in the subscale of vitality (P = 0.03) while the other subscales were all comparable between the two groups. Multivariable Cox regression model showed that early SAC was an independent protective factor for 90-day readmission after adjusting for potential confounders with a hazard ratio of 0.57 (95% CI: 0.34-0.96, P = 0.04). Mediation analysis showed that SVT mediated 37.0% of the early SAC-90-day readmission causality. CONCLUSIONS: The application of early SAC may reduce the risk of 90-day readmission in the survivors of ANP patients, and reduced SVT incidence might be the primary contributor.


Assuntos
Pancreatite Necrosante Aguda , Trombose Venosa , Humanos , Readmissão do Paciente , Estudos Retrospectivos , Pancreatite Necrosante Aguda/diagnóstico , Pancreatite Necrosante Aguda/tratamento farmacológico , Qualidade de Vida , Fatores de Risco , Trombose Venosa/tratamento farmacológico , Anticoagulantes/efeitos adversos
5.
Fa Yi Xue Za Zhi ; 40(2): 118-127, 2024 Apr 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-38847025

RESUMO

In the study of age estimation in living individuals, a lot of data needs to be analyzed by mathematical statistics, and reasonable medical statistical methods play an important role in data design and analysis. The selection of accurate and appropriate statistical methods is one of the key factors affecting the quality of research results. This paper reviews the principles and applicable principles of the commonly used medical statistical methods such as descriptive statistics, difference analysis, consistency test and multivariate statistical analysis, as well as machine learning methods such as shallow learning and deep learning in the age estimation research of living individuals, and summarizes the relevance and application prospects between medical statistical methods and machine learning methods. This paper aims to provide technical guidance for the age estimation research of living individuals to obtain more scientific and accurate results.


Assuntos
Aprendizado de Máquina , Humanos , Determinação da Idade pelo Esqueleto/métodos , Análise Multivariada , Determinação da Idade pelos Dentes/métodos
6.
J Pediatr ; 253: 165-172.e1, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36181871

RESUMO

OBJECTIVE: The objective of this study was to document the practices and preferences of neonatal care stakeholders regarding location and duration of care for newborns with low illness acuity. STUDY DESIGN: We developed a survey instrument that comprised 14 questions across 2 global scenarios and 7 specific clinical conditions. The latter included apnea of prematurity, gestational age for neonatal intensive care unit admission, jaundice, neonatal opioid withdrawal, thermoregulation, and sepsis evaluation. Respondents reported their current practice and preferences for an alternative approach. We administered the survey to individuals in the membership email distribution lists of the American Academy of Pediatrics Section on Neonatal-Perinatal Medicine, the National Association of Neonatal Nurses, and the Vermont Oxford Network. RESULTS: Of 2284 respondents, 53% believed that infants were, in general, admitted to a higher level of care than was required, and only 13% reported that the level of care was too low. Length of stay was perceived to be generally too long by 46% of respondents and too short by 21%. Across 10 specific clinical questions, there was substantial variability in current practice and up to 35% of respondents reported discordance between current and preferred practice. These respondents preferred a lower level of care in 8 of 10 scenarios. CONCLUSIONS: A multidisciplinary sample of US clinicians reported significant variation in the level and duration of care for infants with low illness acuity. Among individuals reporting discordance between current and preferred practice, a majority believed that current management could be accomplished in a lower level of care location.


Assuntos
Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Lactente , Recém-Nascido , Humanos , Criança , Idade Gestacional , Cuidados Críticos , Inquéritos e Questionários
7.
J Psycholinguist Res ; 52(1): 75-100, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34783943

RESUMO

The present study attempted to explore the abstract priming effects from mathematical equations to Mandarin Chinese structure NP1 + You + NP2 + Hen + AP in an on-line comprehension task with the aim to figure out the mechanism that underlying these effects. The results revealed that compared with baseline priming conditions, participants tended to choose more high-attachment options in high-attachment priming conditions and more low-attachment priming options in low-attachment priming conditions. Such difference had reached a significant level, which provided evidence for the shared structural representation across mathematical and linguistic domains. Additionally, the fixations sequences during arithmetic calculations reflected those equations were processed hierarchically and could be extracted in parallel instead of being scanned in a sequentially left-to-right order. Our results have provided some evidence for the Representational Account.


Assuntos
Tecnologia de Rastreamento Ocular , Humanos , Compreensão , Linguística
8.
Fa Yi Xue Za Zhi ; 39(1): 7-12, 2023 Feb 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-37038849

RESUMO

OBJECTIVES: To explore the difference in CT values between pulmonary thromboembolism and postmortem clot in postmortem CT pulmonary angiography (CTPA) to further improve the application value of virtual autopsy. METHODS: Postmortem CTPA data with the definite cause of death from 2016 to 2019 were collected and divided into pulmonary thromboembolism group (n=4), postmortem clot group (n=5), and control group (n=5). CT values of pulmonary trunk and left and right pulmonary artery contents in each group were measured and analyzed statistically. RESULTS: The average CT value in the pulmonary thromboembolism group and postmortem clot group were (168.4±53.8) Hu and (282.7±78.0) Hu, respectively, which were lower than those of the control group (1 193.0±82.9) Hu (P<0.05). The average CT value of the postmortem clot group was higher than that of the pulmonary thromboembolism group (P<0.05). CONCLUSIONS: CT value is reliable and feasible as a relatively objective quantitative index to distinguish pulmonary thromboembolism and postmortem clot in postmortem CTPA. At the same time, it can provide a scientific basis to a certain extent for ruling out pulmonary thromboembolism deaths.


Assuntos
Embolia Pulmonar , Trombose , Humanos , Autopsia , Embolia Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Angiografia , Cadáver
9.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(7): 739-744, 2023 Jul 15.
Artigo em Zh | MEDLINE | ID: mdl-37529957

RESUMO

OBJECTIVES: To explore the relationship between atherogenic index of plasma (AIP) and childhood asthma. METHODS: This retrospective study included 86 children with asthma admitted to the Changzhou Second People's Hospital Affiliated to Nanjing Medical University from July 2020 to August 2022 as the asthma group and 149 healthy children undergoing physical examination during the same period as the control group. Metabolic parameters including total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and blood glucose, as well as general information of the children such as height, weight, body mass index, presence of specific dermatitis, history of inhalant allergen hypersensitivity, family history of asthma, and feeding history, were collected. Multivariable logistic regression analysis was used to study the relationship between AIP, triglycerides, and high-density lipoprotein cholesterol and asthma. The value of AIP, triglycerides, and high-density lipoprotein cholesterol for predicting asthma was assessed using receiver operating characteristic (ROC) curve analysis. RESULTS: The AIP and triglyceride levels in the asthma group were significantly higher than those in the control group, while high-density lipoprotein cholesterol was significantly lower (P<0.05). However, there was no significant difference in total cholesterol and low-density lipoprotein cholesterol between the two groups (P>0.05). Before and after adjusting for height, weight, presence of specific dermatitis, history of inhalant allergen hypersensitivity, family history of asthma, feeding method, and blood glucose, multivariable logistic regression analysis showed that AIP, triglycerides, and high-density lipoprotein cholesterol were associated with asthma (P<0.05). ROC curve analysis showed that the optimal cutoff value for predicting asthma with AIP was -0.333, with a sensitivity of 80.2%, specificity of 55.0%, positive predictive value of 50.71%, and negative predictive value of 82.85%. The area under the curve (AUC) for AIP in predicting asthma was significantly higher than that for triglycerides (P=0.009), but there was no significant difference in AUC between AIP and high-density lipoprotein cholesterol (P=0.686). CONCLUSIONS: AIP, triglycerides, and high-density lipoprotein cholesterol are all associated with asthma. AIP has a higher value for predicting asthma than triglycerides and comparable value to high-density lipoprotein cholesterol.


Assuntos
Asma , Dermatite , Humanos , Criança , Estudos Retrospectivos , Glicemia , Triglicerídeos , HDL-Colesterol , LDL-Colesterol , Asma/etiologia , Fatores de Risco
10.
BMC Med ; 20(1): 481, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36522645

RESUMO

BACKGROUND: Inhaled NO is a selective pulmonary vasodilator proven to be therapeutic for patients with pulmonary artery hypertension (PAH). The most common NO delivery system in clinical practice is cylinder-based, but unfortunately limited by its high costs, complicated delivery, and the requirement of an extensive supply chain, leaving vast unmet medical needs globally. METHODS: To address the need for rapid, affordable, and safe production of nitric oxide (NO) for in-home inhalation therapy in patients with PAH. We developed a novel portable device to derive NO from a nitrite complex solution with a copper(II)-ligand catalyst, and further examined its effectiveness in a porcine model of PAH. This model was established by using female Bama miniature pig and induced by monocrotaline (MCT) administration. RESULTS: This generator could rapidly and safely produce therapeutic NO at concentrations ranging from 0 to 100 parts per million (ppm) with the least disproportionated nitrogen dioxide (NO2) and byproducts. It could effectively alleviate pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) in piglets with PAH, without causing major physiologic disruptions. CONCLUSIONS: Our electrochemical NO generator is able to produce the desired NO doses for pulmonary vasodilation in a safe and sustainable way, with low costs, which paves the way for its subsequent clinical trials in the patient with PAH and other common cardiopulmonary conditions with a high disease burden around the world.


Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Humanos , Animais , Feminino , Suínos , Óxido Nítrico/farmacologia , Óxido Nítrico/uso terapêutico , Artéria Pulmonar/fisiologia , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/tratamento farmacológico , Administração por Inalação , Terapia Respiratória
11.
J Chem Phys ; 157(17): 174303, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36347693

RESUMO

Maintaining stability of single-molecular junctions (SMJs) in the presence of current flow is a prerequisite for their potential device applications. However, theoretical understanding of nonequilibrium heat transport in current-carrying SMJs is a challenging problem due to the different kinds of nonlinear interactions involved, including electron-vibration and anharmonic vibrational coupling. Here, we overcome this challenge by accelerating Langevin-type current-induced molecular dynamics using machine-learning potential derived from density functional theory. We show that SMJs with graphene electrodes generate an order of magnitude less heating than those with gold electrodes. This is rooted in the better phonon spectral overlap of graphene with molecular vibrations, rendering harmonic phonon heat transport being dominant. In contrast, in a spectrally mismatched junction with gold electrodes, anharmonic coupling becomes important to transport heat away from the molecule to surrounding electrodes. Our work paves the way for studying current-induced heat transport and energy redistribution in realistic SMJs.

12.
Hepatobiliary Pancreat Dis Int ; 21(1): 63-68, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33478932

RESUMO

BACKGROUND: Current guidelines for the treatment of patients with necrotizing acute pancreatitis (NAP) recommend that invasive intervention for pancreatic necrosis should be deferred to 4 or more weeks from disease onset to allow necrotic collections becoming "walled-off". However, for patients showing signs of clinical deterioration, especially those with persistent organ failure (POF), it is controversial whether this delayed approach should always be adopted. In this study, we aimed to assess the impact of differently timed intervention on clinical outcomes in a group of NAP patients complicated by POF. METHODS: All NAP patients admitted to our hospital from January 2013 to December 2017 were screened for potential inclusion. They were divided into two groups based on the timing of initial intervention (within 4 weeks and beyond 4 weeks). All the data were extracted from a prospectively collected database. RESULTS: Overall, 131 patients were included for analysis. Among them, 100 (76.3%) patients were intervened within 4 weeks and 31 (23.7%) underwent delayed interventions. As for organ failure prior to intervention, the incidences of respiratory failure, renal failure and cardiovascular failure were not significantly different between the two groups (P > 0.05). The mortality was not significantly different between the two groups (35.0% vs. 32.3%, P = 0.83). The incidences of new-onset multiple organ failure (8.0% vs. 6.5%, P = 1.00), gastrointestinal fistula (29.0% vs. 12.9%, P = 0.10) and bleeding (35.0% vs. 35.5%, P = 1.00), and length of ICU (30.0 vs. 22.0 days, P = 0.61) and hospital stay (42.5 vs. 40.0 days, P = 0.96) were comparable between the two groups. CONCLUSION: Intervention within 4 weeks did not worsen the clinical outcomes in NAP patients complicated by POF.


Assuntos
Insuficiência de Múltiplos Órgãos/etiologia , Pancreatite Necrosante Aguda/complicações , Doença Aguda , Adulto , Idoso , Feminino , Doença Enxerto-Hospedeiro , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/terapia , Necrose , Pancreatite Necrosante Aguda/diagnóstico , Pancreatite Necrosante Aguda/terapia , Tempo para o Tratamento
13.
Nano Lett ; 21(16): 7005-7011, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34350759

RESUMO

The Mott state in 1T-TaS2 is predicted to host quantum spin liquids (QSLs). However, its insulating mechanism is controversial due to complications from interlayer coupling. Here, we study the charge transfer state in monolayer 1T-NbSe2, an electronic analogue to TaS2 exempt from interlayer coupling, using spectroscopic imaging scanning tunneling microscopy and first-principles calculations. Monolayer NbSe2 surprisingly displays two types of star of David (SD) motifs with different charge transfer gap sizes, which are interconvertible via temperature variation. In addition, bilayer 1T-NbSe2 shows a Mott collapse by interlayer coupling. Our calculation unveils that the two types of SDs possess distinct structural distortions, altering the effective Coulomb energies of the central Nb orbital. Our calculation suggests that the charge transfer gap, the same parameter for determining the QSL regime, is tunable with strain. This finding offers a general strategy for manipulating the charge transfer state in related systems, which may be tuned into the potential QSL regime.

14.
Fa Yi Xue Za Zhi ; 38(3): 350-354, 2022 Jun 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-36221829

RESUMO

OBJECTIVES: To reduce the dimension of characteristic information extracted from pelvic CT images by using principal component analysis (PCA) and partial least squares (PLS) methods. To establish a support vector machine (SVM) classification and identification model to identify if there is pelvic injury by the reduced dimension data and evaluate the feasibility of its application. METHODS: Eighty percent of 146 normal and injured pelvic CT images were randomly selected as training set for model fitting, and the remaining 20% was used as testing set to verify the accuracy of the test, respectively. Through CT image input, preprocessing, feature extraction, feature information dimension reduction, feature selection, parameter selection, model establishment and model comparison, a discriminative model of pelvic injury was established. RESULTS: The PLS dimension reduction method was better than the PCA method and the SVM model was better than the naive Bayesian classifier (NBC) model. The accuracy of the modeling set, leave-one-out cross validation and testing set of the SVM classification model based on 12 PLS factors was 100%, 100% and 93.33%, respectively. CONCLUSIONS: In the evaluation of pelvic injury, the pelvic injury data mining model based on CT images reaches high accuracy, which lays a foundation for automatic and rapid identification of pelvic injuries.


Assuntos
Algoritmos , Máquina de Vetores de Suporte , Teorema de Bayes , Mineração de Dados , Análise dos Mínimos Quadrados
15.
Proc Natl Acad Sci U S A ; 115(7): E1560-E1569, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29378943

RESUMO

E-cigarette smoke delivers stimulant nicotine as aerosol without tobacco or the burning process. It contains neither carcinogenic incomplete combustion byproducts nor tobacco nitrosamines, the nicotine nitrosation products. E-cigarettes are promoted as safe and have gained significant popularity. In this study, instead of detecting nitrosamines, we directly measured DNA damage induced by nitrosamines in different organs of E-cigarette smoke-exposed mice. We found mutagenic O6-methyldeoxyguanosines and γ-hydroxy-1,N2 -propano-deoxyguanosines in the lung, bladder, and heart. DNA-repair activity and repair proteins XPC and OGG1/2 are significantly reduced in the lung. We found that nicotine and its metabolite, nicotine-derived nitrosamine ketone, can induce the same effects and enhance mutational susceptibility and tumorigenic transformation of cultured human bronchial epithelial and urothelial cells. These results indicate that nicotine nitrosation occurs in vivo in mice and that E-cigarette smoke is carcinogenic to the murine lung and bladder and harmful to the murine heart. It is therefore possible that E-cigarette smoke may contribute to lung and bladder cancer, as well as heart disease, in humans.


Assuntos
Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Coração/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Nicotina/toxicidade , Nitrosaminas/toxicidade , Fumaça/efeitos adversos , Bexiga Urinária/efeitos dos fármacos , Animais , Carcinogênese/efeitos dos fármacos , Linhagem Celular , Sistemas Eletrônicos de Liberação de Nicotina , Humanos , Pulmão/metabolismo , Masculino , Camundongos , Mutação/efeitos dos fármacos , Nicotina/química , Nitrosaminas/química , Bexiga Urinária/metabolismo
16.
Proc Natl Acad Sci U S A ; 115(27): E6152-E6161, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29915082

RESUMO

Tobacco smoke (TS) contains numerous cancer-causing agents, with polycyclic aromatic hydrocarbons (PAHs) and nitrosamines being most frequently cited as the major TS human cancer agents. Many lines of evidence seriously question this conclusion. To resolve this issue, we determined DNA adducts induced by the three major TS carcinogens: benzo(a)pyrene (BP), 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanoe (NNK), and aldehydes in humans and mice. In mice, TS induces abundant aldehyde-induced γ-hydroxy-propano-deoxyguanosine (γ-OH-PdG) and α-methyl-γ-OH-PdG adducts in the lung and bladder, but not in the heart and liver. TS does not induce the BP- and NNK-DNA adducts in lung, heart, liver, and bladder. TS also reduces DNA repair activity and the abundance of repair proteins, XPC and OGG1/2, in lung tissues. These TS effects were greatly reduced by diet with polyphenols. We found that γ-OH-PdG and α-methyl-γ-OH-PdG are the major adducts formed in tobacco smokers' buccal cells as well as the normal lung tissues of tobacco-smoking lung cancer patients, but not in lung tissues of nonsmokers. However, the levels of BP- and NNK-DNA adducts are the same in lung tissues of smokers and nonsmokers. We found that while BP and NNK can induce BPDE-dG and O6-methyl-dG adducts in human lung and bladder epithelial cells, these inductions can be inhibited by acrolein. Acrolein also can reduce DNA repair activity and repair proteins. We propose a TS carcinogenesis paradigm. Aldehydes are major TS carcinogens exerting dominant effect: Aldehydes induce mutagenic PdG adducts, impair DNA repair functions, and inhibit many procarcinogens in TS from becoming DNA-damaging agents.


Assuntos
Aldeídos/toxicidade , Benzo(a)pireno/toxicidade , Carcinógenos/toxicidade , Transformação Celular Neoplásica , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Neoplasias Pulmonares , Nitrosaminas/toxicidade , Poluição por Fumaça de Tabaco/efeitos adversos , Fumar Tabaco , Animais , Linhagem Celular , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Humanos , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Fumar Tabaco/efeitos adversos , Fumar Tabaco/patologia
17.
Fungal Genet Biol ; 142: 103415, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32497577

RESUMO

SNF1/AMPK protein kinases play important roles in fungal development and activation of catabolite-repressed genes. In this study, we characterized the role of SNF1 ortholog in Cordyceps militaris (CmSnf1). The vegetative growth of a CmSnf1 deletion mutant was (ΔCmSnf1) reduced by 42.2% with arabinose as a sole carbon source. Most strikingly, the ΔCmSnf1 produced only a few conidia and exhibited delayed conidial germination. We found that CmSnf1 was necessary for mycelium to penetrate the insect cuticle to form the fruiting body on silkworm pupae, consistent with the down-regulation of chitinase- and protease-encoding genes in ΔCmSnf1. However, cordycepin content increased by more than 7 times in culture supernatants. Correspondingly, the relative expression levels of cordycepin gene cluster members were also elevated. In particular, the expression of cns4 associated with cordycepin transfer was up-regulated >10-fold. Furthermore, transcriptional analysis showed that CmSnf1 regulated the expression of genes involved in cell autophagy and oxidative stress tolerance. We speculated that under environmental stress, both the ATG and SNF1 pathways might collaborate to sustain adverse environments. Our study provides an initial framework to probe the diverse function and regulation of CmSnf1 in C. militaris, which will shed more light on the direction of molecular improvement of medicinal fungi.


Assuntos
Cordyceps/genética , Micélio/genética , Proteínas Serina-Treonina Quinases/genética , Estresse Fisiológico/genética , Carbono/metabolismo , Cordyceps/patogenicidade , Carpóforos/genética , Carpóforos/metabolismo , Genoma Fúngico/genética
18.
Appl Microbiol Biotechnol ; 104(16): 6905-6917, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32566995

RESUMO

Formate can be efficiently produced via electrochemical or photochemical catalytic conversion of CO2, and it can be directly used as an organic carbon source by microorganisms. In theory, formate can be used as the sole carbon source for the microbial production of high-value-added chemicals. Consequently, the construction of efficient formate-assimilation pathways in microorganisms is essential for the utilization of cheap, renewable one-carbon compounds. This paper summarizes new methods of formate synthesis, as well as the natural formate utilization pathways of microorganisms with their advantages and disadvantages. Furthermore, it reviews recent progress in the design of utilization pathways for formate in microbial cells through metabolic engineering and synthetic biology. Besides, we also use the pathway-prediction algorithm comb-FBA to rationally design completely new one-carbon compounds utilization pathways. The pathway with the highest efficiency, named GAA, was corroborated by the in vitro experiments showing a carbon molar yield up to 88%. Finally, it discusses the main problems and challenges presently existing in the pathway design and strain improvement for microbial utilization of formate. KEY POINTS: • Natural and artificial design pathways of formate-assimilation was summarized. • Recent progresses in different hosts and approaches of using one-carbon compounds was reviewed. • Metabolic engineering and synthetic biology methods to improve formate utilization were discussed.


Assuntos
Bactérias/metabolismo , Carbono/metabolismo , Formiatos/metabolismo , Engenharia Metabólica/métodos , Algoritmos , Dióxido de Carbono/metabolismo , Engenharia Metabólica/tendências , Biologia Sintética
19.
Mediators Inflamm ; 2020: 5270508, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33132755

RESUMO

Radix Aconiti Lateralis Preparata (Fuzi) is a traditional Chinese medicine. Its alkaloids are both cardiotonic and cardiotoxic; however, the underlying mechanisms are unclear. Compatibility testing and processing are the primary approaches used to reduce the toxicity of aconite preparations. The purpose of this study was to compare the effects of crude Fuzi (CFZ), CFZ combined with Glycyrrhiza (Gancao) (CFZ+GC), and prepared materials of CFZ (PFZ) on heart failure (HF) in C57BL/6J mice and explore the potential mechanisms of action of CFZ. Transverse aortic constriction (TAC) was used to generate the HF state, and CFZ (1.5 g·mL-1), PFZ (1.5 g·mL-1), or CFZ+GC (1.8 g·mL-1) was orally administered to the HF-induced mice daily. For the subsequent 8 weeks, hemodynamic indicators, ventricular pressure indices, and mass indices were evaluated, and histopathological imaging was performed. CFZ, CFZ+GC, and PFZ significantly improved left ventricular function and structure and reduced myocardial damage. CFZ+GC was more effective than CFZ and PFZ, whereas CFZ had higher toxicity than CFZ+GC and PFZ. CFZ and CFZ+GC attenuated ischemia-induced inflammatory responses and also inhibited Toll-like receptor-4 (TLR4) and nuclear factor kappa beta (NF-κB) action in the heart. Moreover, mass spectrometry analysis revealed a decrease in the levels of toxic components of CFZ+GC, whereas those of the protective components were increased. This study suggested that GC reduces the toxicity and increases the efficacy of CFZ on HF induced by TAC. Furthermore, GC+CFZ reduces the risk of HF by ameliorating the inflammation response, which might be partially related to the inhibition of the TLR4/NF-κB pathway.


Assuntos
Aconitum/química , Glycyrrhiza/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Hemodinâmica/efeitos dos fármacos , Inflamação/tratamento farmacológico , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Remodelação Ventricular
20.
Anal Biochem ; 577: 82-88, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31029675

RESUMO

Biothiols play critical roles in many biological processes and their aberrant is related to a variety of syndromes. A simple and reliable colorimetric method is developed in this work for biothiols detection based on an oxidase mimic, a metal organic framework (MOF) MIL-53(Fe), and a peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB). In this design, MIL-53(Fe) is utilized to catalyze the conversion of TMB to a blue colored 3,3',5,5'-tetramethylbenzidine diimine, which can be read on a spectrophotometer at 652 nm. The oxidation-induced blue color generation can be efficiently inhibited by biothiols, thus a colorimetric analytical method is proposed for biothiols detection based on the above system. Under optimal conditions, a linear relationship in a range from 1 to 100 µM and a limit of detection (LOD) at 120 nM are achieved with Cys as a model target. The developed platform is further applied to evaluate cellular biothiols in normal (RWPE-1) and cancer (LNCap) cell lines, revealing that the overall biothiols level in LNCap is much higher than that in RWPE-1. This work renders a powerful tool for identifying cancer cells in a simple manner for biomedical diagnosis associated with biothiols.


Assuntos
Cisteína/análise , Glutationa/análise , Homocisteína/análise , Benzidinas/química , Linhagem Celular , Colorimetria/métodos , Humanos , Estruturas Metalorgânicas/química
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