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1.
J Healthc Eng ; 2021: 6556266, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34721825

RESUMO

This study aimed to detect and diagnose the lung nodules as early as possible to effectively treat them, thereby reducing the burden on the medical system and patients. A lung computed tomography (CT) image segmentation algorithm was constructed based on the deep learning convolutional neural network (CNN). The clinical data of 69 patients with lung nodules diagnosed by needle biopsy and pathological comprehensive diagnosis at hospital were collected for specific analysis. The CT image segmentation algorithm was used to distinguish the nature and volume of lung nodules and compared with other computer aided design (CAD) software (Philips ISP). 69 patients with lung nodules were treated by radiofrequency ablation (RFA). The results showed that the diagnostic sensitivity of the CT image segmentation algorithm based on the CNN was obviously higher than that of the Philips ISP for solid nodules <5 mm (63 cases vs. 33 cases) (P < 0.05); it was the same result for the subsolid nodule <5 mm (33 case vs. 5 cases) (P < 0.05) that was slightly higher for solid and subsolid nodules with a diameter of 5-10 mm (37 cases vs. 28 cases) (P < 0.05). In addition, the CNN algorithm can reach all detection for calcified nodules and pleural nodules (7 cases; 5 cases), and the diagnostic sensitivities were much better than those of Philips ISP (2 cases; 3 cases) (P < 0.05). Patients with pulmonary nodules treated by RFA were in good postoperative condition, with a half-year survival rate of 100% and a one-year survival rate of 72.4%. Therefore, it could be concluded that the CT image segmentation algorithm based on the CNN could effectively detect and diagnose the lung nodules early, and the RFA could effectively treat the lung nodules.

2.
Cell Death Dis ; 12(11): 1069, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34759275

RESUMO

Mounting studies have substantiated that abrogating autophagy contributes to cardiac hypertrophy (CH). Sirtuin 1 (SIRT1) has been reported to support autophagy and inhibit CH. However, the upstream regulation mechanism behind the regulation of SIRT1 level in CH remains unclear. Circular RNAs (circRNAs) are vital modulators in diverse human diseases including CH. This study intended to investigate the regulatory mechanism of circRNA on SIRT1 expression in CH. CH model was established by angiotensin II (Ang II) fusion or transverse aortic constriction (TAC) surgery and Ang II treatment on hiPSC-CMs and H9c2 cells in vitro. Our results showed that circ-SIRT1 (hsa_circ_0093884) expression was downregulated in Ang II-treated hiPSC-CMs, and confirmed that its conserved mouse homolog circ-Sirt1 (mmu_circ_0002354) was expressed at low levels in Ang II-treated H9c2 cells and TAC-induced mice model. Functionally, circ-SIRT1/circ-Sirt1 attenuated Ang II-induced CH and induced autophagy in hiPSC-CMs and H9c2 cardiomyocytes. Mechanistically, circ-SIRT1 could upregulate its host gene SIRT1 at the post-transcriptional level by sponging miR-3681-3p/miR-5195-3p and stabilized SIRT1 protein at the post-translational level by recruiting USP22 to induce deubiquitination on SIRT1 protein. Further, SIRT1 knockdown could rescue the effect of circ-SIRT1 upregulation on Ang II-induced CH and autophagy in vitro and in vivo. In conclusion, we first uncovered that circ-SIRT1 restrains CH via activating SIRT1 to promote autophagy, indicating circ-SIRT1 as a promising target to alleviate CH.

3.
Proc Natl Acad Sci U S A ; 118(43)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34675074

RESUMO

Most genetic changes have negligible reversion rates. As most mutations that confer resistance to an adverse condition (e.g., drug treatment) also confer a growth defect in its absence, it is challenging for cells to genetically adapt to transient environmental changes. Here, we identify a set of rapidly reversible drug-resistance mutations in Schizosaccharomyces pombe that are caused by microhomology-mediated tandem duplication (MTD) and reversion back to the wild-type sequence. Using 10,000× coverage whole-genome sequencing, we identify nearly 6,000 subclonal MTDs in a single clonal population and determine, using machine learning, how MTD frequency is encoded in the genome. We find that sequences with the highest-predicted MTD rates tend to generate insertions that maintain the correct reading frame, suggesting that MTD formation has shaped the evolution of coding sequences. Our study reveals a common mechanism of reversible genetic variation that is beneficial for adaptation to environmental fluctuations and facilitates evolutionary divergence.

4.
Anal Chem ; 93(39): 13326-13333, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34569226

RESUMO

Current ambient ionization sources for mass spectrometry (MS) are typically connected to gas cylinders, high-voltage supply, injection pump, and other accessory equipment, which hinder the popularization of MS in the field of on-site detection. Here, we developed a wireless pocket-size "MasSpec Pointer" (weights 65 g) based on arc discharge powered by a 3.7 V polymer Li battery for ambient ionization MS. A high voltage of 5600 V and 20 kHz was generated from the boost coil to penetrate air and form a plasma. The relative standard deviation (RSD) of the high-voltage pulses is 3.8%, leading to a stable discharge and a good quantification performance. A mini diaphragm pump was used to cool the plasma from ∼600 to ∼40 °C and to blow the plasma into a jet, which facilitates sampling. MasSpec Pointer can work well at both positive- and negative-ion modes without any modification and can quickly test gaseous, liquid, or solid samples. The limit of detection of this device for atrazine (an agrochemical) is lower than 0.1 ng/mL. MasSpec Pointer has shown its ability to pinpoint the double-bond location of fatty acid isomers without derivatization reagents or light illumination. Agrochemicals from the surface of an apple and daily chemicals from the surface of a finger were detected successfully using MasSpec Pointer coupled with a miniature mass spectrometer. We believe the "point-and-shoot" device coupled with mini-MS brings the hope for an age of detecting chemicals on-site by nonprofessionals.


Assuntos
Espectrometria de Massas
5.
Front Public Health ; 9: 705488, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568256

RESUMO

Aims: Non-communicable diseases (NCD) drag the NCD patients' families to the abyss of poverty. Medical insurance due to weak control over medical expenses and low benefits levels, may have actually contributed to a higher burden of out-of-pocket payments. By making a multi-dimensional calculation on catastrophic health expenditure (CHE) in Heilongjiang Province over 10 years, it is significant to find the weak links in the implementation of medical insurance to achieve poverty alleviation. Methods: A logistic regression was undertaken to predict the determinants of catastrophic health expenditure. Results: The average CHE of households dropped from 18.9% in 2003 to 14.9% in 2013. 33.2% of the households with three or more NCD members suffered CHE in 2013, which was 7.2 times higher than the households without it (4.6%). The uninsured households with cardiovascular disease had CHE of 12.0%, which were nearly 10% points lower than insured households (20.4-22.4%). For Medical Insurance for Urban Employees Scheme enrolled households, the increasing number of NCD members raised the risk of impoverishment from 3.4 to 20.0% in 2003, and from 0.3 to 3.1% in 2008. Households with hospital in-patient members were at higher risk of CHE (OR: 3.10-3.56). Conclusions: Healthcare needs and utilization are one of the most significant determinants of CHE. Households with NCD and in-patient members are most vulnerable groups of falling into a poverty trap. The targeting of the NCD groups, the poorest groups, uninsured groups need to be primary considerations in prioritizing services that are contained in medical insurance and poverty alleviation.


Assuntos
Seguro , Doenças não Transmissíveis , China/epidemiologia , Gastos em Saúde , Humanos , Doenças não Transmissíveis/epidemiologia , Pobreza
6.
Biomed Res Int ; 2021: 9066938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34540999

RESUMO

The peroxisome proliferator-activated receptor (PPAR) α/γ-adenosine 5'-monophosphate- (AMP-) activated protein kinase- (AMPK-) sirtuin-1 (SIRT1) pathway and fatty acid metabolism are reported to be involved in influenza A virus (IAV) replication and IAV-pneumonia. Through a cell-based peroxisome proliferator responsive element- (PPRE-) driven luciferase bioassay, we have investigated 145 examples of traditional Chinese medicines (TCMs). Several TCMs, such as Polygonum cuspidatum, Rheum officinale Baillon, and Aloe vera var. Chinensis (Haw.) Berg., were found to possess high activity. We have further detected the anti-IAV activities of emodin (EMO) and its analogs, a group of common important compounds of these TCMs. The results showed that emodin and its several analogs possess excellent anti-IAV activities. The pharmacological tests showed that emodin significantly activated PPARα/γ and AMPK, decreased fatty acid biosynthesis, and increased intracellular ATP levels. Pharmaceutical inhibitors, siRNAs for PPARα/γ and AMPKα1, and exogenous palmitate impaired the inhibition of emodin. The in vivo test also showed that emodin significantly protected mice from IAV infection and pneumonia. Pharmacological inhibitors for PPARα/γ and AMPK signal and exogenous palmitate could partially counteract the effects of emodin in vivo. In conclusion, emodin and its analogs are a group of promising anti-IAV drug precursors, and the pharmacological mechanism of emodin is linked to its ability to regulate the PPARα/γ-AMPK pathway and fatty acid metabolism.


Assuntos
Emodina/uso terapêutico , Vírus da Influenza A/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Células A549 , Adenilato Quinase/efeitos dos fármacos , Adenilato Quinase/metabolismo , Animais , China , Cães , Emodina/análogos & derivados , Emodina/metabolismo , Ácidos Graxos/metabolismo , Humanos , Vírus da Influenza A/patogenicidade , Metabolismo dos Lipídeos , Células Madin Darby de Rim Canino , Medicina Tradicional Chinesa/métodos , PPAR alfa/efeitos dos fármacos , PPAR alfa/metabolismo , PPAR gama/efeitos dos fármacos , PPAR gama/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/efeitos dos fármacos , Sirtuína 1/metabolismo
7.
Am J Chin Med ; 49(7): 1577-1622, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34559620

RESUMO

Schisandra sphenanthera Rehd. et Wils (S. sphenanthera) is a single species of Schisandra genus, Magnoliaceae family, and it is a famous medicinal herb mostly growing in southern China, China Taiwan and Vietnam. S. sphenanthera is usually used for the treatments of hepatitis, Alzheimer's disease, renal transplantation, osteoporosis, and insomnia. In present studies, approximately 310 natural constituents have been isolated from S. sphenanthera, including lignans, triterpenes, volatile oils, and polysaccharides, which were mainly obtained from the fruits and stems of S. sphenanthera. Pharmocological studies have shown that the extracts and monomeric compounds of S. sphenanthera possessed wide-range bioactivities, such as antitumor, anti-oxidant, anti-inflammatory, osteoblastic, immune regulation, neuroprotective, kidney protection, hepatoprotective, and antiviral activities. However, resource availability, quality control measures, in-depth in vivo pharmacological study, and clinical application are still insufficient and deserve further studies. This review systematically summarized literatures on the botany, phytochemistry, pharmacology, development utilization, and clinical application of S. sphenanthera, in hopes of provide a useful reference for researchers for further studies of this plant.

8.
BMC Public Health ; 21(1): 1500, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344328

RESUMO

BACKGROUND: To explore the psychological status and vulnerability characteristics of medical staff with the progress of the epidemic. METHODS: This study investigated the prevalence of mental problems of 2748 medical staff in four stages. The PHQ-9 (Patient Health Questionnaire), GAD-7 (Generalized Anxiety Disorder questionnaire), SSS (Somatization Symptom Checklist), Pittsburgh sleep quality index, and PCL-C (Self-rating scale for post-traumatic stress disorder) were used for the psychological evaluation, and univariate logistic standardised analysis, and multivariate logistic regression for data analysis. RESULTS: The prevalence of mental problems showed a statistically significant difference. In Stage 1, mild anxiety and mild depression reached the highest value of 41.4 and 40.72% respectively. Between 4 and 17 March that of mild depression rose from 16.07 to 26.7%, and between 17 and 26 March the prevalence of mild anxiety increased from 17.28 to 20.02%. Female, unmarried, and working in Wuhan are the risk factors of mental health of medical staff (P < 0.05). CONCLUSION: The psychological status of the medical staff has changed dynamically. Stage 1 and the latter period of Stages 2 and 3 are the high-risk stages. Female and unmarried are the dangerous characteristics of psychological vulnerability.


Assuntos
COVID-19 , Ansiedade/epidemiologia , China , Estudos Transversais , Depressão/epidemiologia , Feminino , Humanos , SARS-CoV-2 , Inquéritos e Questionários
9.
Sci Total Environ ; 799: 149420, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371411

RESUMO

Ultrafine particulates (UFPs) are considered one of the most hazardous of all air pollutants, which can be directly inhaled into the human body and cause direct damage to lung tissues. Lung fibroblasts (LF) play an important role in the structure and function of lung and there are few studies on primary cells at present. So, the article focuses on LF as the research objective and ultrafine carbon black (UFCB) and Pb-UFCB (loaded with lead) as a representative of UFPs to study the effect on LF. The results showed that UFCB and Pb-UFCB inhibited LF proliferation due to cell cycle arrested in the S phase, and induced apoptosis. Additionally, UFCB or Pb-UFCB could induce oxidative stress manifested as the increase of intracellular reactive oxygen species. The redox imbalance was further confirmed by measuring the changes of related enzymes, including the activity of superoxide dismutase and catalase and the level of reduced glutathione and malondialdehyde in cells. Moreover, the elevated lactate dehydrogenase in the culture medium indicated that cell membrane had been injured. And mitochondrial function was impaired by the imbalance of ATP synthesis and hydrolysis. In summary, both induced oxidative stress, which is the main driving force of LF early apoptosis, disruption of cell membrane integrity and mitochondrial function. Here, we provide a meaningful and challenging subject to explore the toxic effect and mechanism between UFPs and lung tissue at cellular levels, and theoretical basics for the possible changes of lung tissue function in vivo.


Assuntos
Chumbo , Fuligem , Animais , Apoptose , Fibroblastos , Pulmão , Camundongos , Mitocôndrias , Estresse Oxidativo , Tamanho da Partícula , Espécies Reativas de Oxigênio , Fuligem/toxicidade
10.
Angew Chem Int Ed Engl ; 60(43): 23225-23231, 2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34254412

RESUMO

The inhalation of atmospheric particles is deleterious to human health. However, as a complex mixture, tracing the behaviors of multiple components from real aerosol particles is crucial but unachievable by the existing methods. Here, taking advantage of the intrinsic fingerprints of elemental carbon (EC) and organic carbon (OC) in carbonaceous aerosol (CA) upon laser irradiation, we proposed a label-free mass spectrometry imaging method to visualize and quantify the deposition, translocation and component variation of CA in organs. With this method, the heterogeneous deposition, clearance and release behavior of CA in lung, that more OC was released in parenchyma and OC was cleared faster than EC, was observed. The translocation of CA to extrapulmonary organs including kidney, liver, spleen and even brain was also verified and quantified. By comparing the ratio of OC to EC, an organ-specific release behavior of OC from CA during circulation was revealed. In orthotopic lung and liver tumor, OC was found to penetrate more into tumor foci than EC. This technique provides deeper information for understanding the systemic health effects of aerosol particles.

11.
Anal Chem ; 93(26): 9158-9165, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34162204

RESUMO

Volatile organic compounds (VOCs) from exhaled breath (EB) are considered to be promising biomarkers for lung diseases. A convenient and sensitive point-of-care (POC) testing method for EB VOCs is essential. Here, we developed a POC test paper for the analysis of EB aldehydes, which are potential biomarkers for lung cancer. A probe molecule, 4-aminothiophenol (4-ATP), was anchored on a paper substrate to specifically capture gas-phase aldehydes through the Schiff base reaction. Meanwhile, thin-film reaction acceleration was utilized to increase capture efficiency. By directly coupling the test paper to a mass spectrometer through paper spray, high sensitivity (0.1 ppt) and a wide quantification linear range (from 10 ppt to 1 ppm) were obtained. Analysis of EB from lung cancer patients with the test paper showed a significant increase in several reported aldehyde markers compared to EB from healthy volunteers, indicating the potential of this method for sensitive, low-cost, and convenient lung cancer screening and diagnosis.


Assuntos
Neoplasias Pulmonares , Compostos Orgânicos Voláteis , Aldeídos , Testes Respiratórios , Detecção Precoce de Câncer , Expiração , Humanos , Neoplasias Pulmonares/diagnóstico , Espectrometria de Massas , Testes Imediatos
12.
Magn Reson Med ; 86(3): 1647-1661, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33821529

RESUMO

PURPOSE: To propose a reconstruction framework to generate accurate T1 maps for a fast MR T1 mapping sequence. METHODS: A deep learning-enhanced T1 mapping method with spatial-temporal and physical constraint (DAINTY) was proposed. This method explicitly imposed low-rank and sparsity constraints on the multiframe T1 -weighted images to exploit the spatial-temporal correlation. A deep neural network was used to efficiently perform T1 mapping as well as denoise and reduce undersampling artifacts. Additionally, the physical constraint was used to build a bridge between low-rank and sparsity constraint and deep learning prior, so the benefits of constrained reconstruction and deep learning can be both available. The DAINTY method was trained on simulated brain data sets, but tested on real acquired phantom, 6 healthy volunteers, and 7 atherosclerosis patients, compared with the narrow-band k-space-weighted image contrast filter conjugate-gradient SENSE (NK-CS) method, kt-sparse-SENSE (kt-SS) method, and low-rank plus sparsity (L+S) method with least-squares T1 fitting and direct deep learning mapping. RESULTS: The DAINTY method can generate more accurate T1 maps and higher-quality T1 -weighted images compared with other methods. For atherosclerosis patients, the intraplaque hemorrhage can be successfully detected. The computation speed of DAINTY was 10 times faster than traditional methods. Meanwhile, DAINTY can reconstruct images with comparable quality using only 50% of k-space data. CONCLUSION: The proposed method can provide accurate T1 maps and good-quality T1 -weighted images with high efficiency.


Assuntos
Aprendizado Profundo , Algoritmos , Artefatos , Encéfalo/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Imagens de Fantasmas
13.
Nat Commun ; 12(1): 1938, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33824331

RESUMO

The growing energy consumption and associated carbon emission of Bitcoin mining could potentially undermine global sustainable efforts. By investigating carbon emission flows of Bitcoin blockchain operation in China with a simulation-based Bitcoin blockchain carbon emission model, we find that without any policy interventions, the annual energy consumption of the Bitcoin blockchain in China is expected to peak in 2024 at 296.59 Twh and generate 130.50 million metric tons of carbon emission correspondingly. Internationally, this emission output would exceed the total annualized greenhouse gas emission output of the Czech Republic and Qatar. Domestically, it ranks in the top 10 among 182 cities and 42 industrial sectors in China. In this work, we show that moving away from the current punitive carbon tax policy to a site regulation policy which induces changes in the energy consumption structure of the mining activities is more effective in limiting carbon emission of Bitcoin blockchain operation.

15.
Global Health ; 17(1): 36, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33781274

RESUMO

BACKGROUND: The vulnerability of cardiovascular disease (CVD) patients' health abilities, combined with the severity of the disease and the overlapping risk factors, leads such people to bear the economic burden of the disease due to the medical services. We estimated the economic burden of CVD and identified the weak link in the design of the medical insurance. METHODS: Data from 5610 middle-aged and elderly with CVD were drawn from the 2015 wave of "China Health and Retirement Longitudinal Study" (CHARLS). The recommended method of the "World Health Organization" (WHO) was adopted to calculate "catastrophic health expenditure" (CHE), "impoverishment by medical expenses" (IME), and applied the treatment-effect model to analyze the determinants of CHE. RESULTS: The incidence of CHE was 19.9% for the elderly families with CVD members, which was 3.6% higher than for uninsured families (16.3%). Families with CVD combined with > 3 other chronic diseases (38.88%) were the riskiest factor for the high CHE in the new rural cooperative medical system (NCMS). Moreover, families with members > 75 years old (33.33%), having two chronic disease (30.74%), and families having disabled members (33.33%), hospitalization members (32.41%) were identified as the high risky determinants for the high CHE in NCMS. CONCLUSIONS: Elderly with physical vulnerabilities were more prone to CHE. The medical insurance only reduced barriers to accessing health resources for elderly with CVD; however it lacked the policy inclination for high-utilization populations, and had poorly accurate identification of the vulnerable characteristics of CVD, which in turn affects the economic protection ability of the medical insurance. The dispersion between the multiple medical security schemes leads to the existence of blind spots in the economic risk protection of individuals and families.

16.
Clin Respir J ; 15(6): 661-669, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33686798

RESUMO

INTRODUCTION AND OBJECTIVES: Pulmonary infarction (PI) shares similar symptoms and imaging presentations with community-acquired pneumonia (CAP), which might delay diagnosis and lead to devastating consequences. Noncontrast computed tomography (CT) is the first-line examination for the patients with the respiratory symptoms. This study aimed to investigate a radiomics method to differentiate PI from CAP using noncontrast-enhanced CT. METHODS: Noncontrast-enhanced CT images of 54 patients with PI and 64 patients with CAP were retrospectively selected. All patients were confirmed using computed tomography pulmonary angiography (CTPA). A radiomics model was built with 18 texture features that showed significant differences between PI and CAP patients. For comparison, a clinical model using clinical biomarkers and an integrated model combining the radiomics and clinical biomarkers were also generated. An experienced radiologist performed diagnoses using the noncontrast-enhanced CT images. The parameters of the models were generated using a training dataset of 61 patients, whereas the performance of the models was evaluated using receiver operating characteristic (ROC) analysis and Harrell's concordance index (C-index) applied to a separate validation dataset of 57 patients. RESULTS: The integrated model achieved the best performance (C-index 0.760, sensitivity 0.703, specificity 0.867, positive predictive value [PPV] 0.826, and negative predictive value [NPV] 0.765). The radiomics model was better than both the clinical model and the radiologist's interpretations (C-index 0.721, 0.707, 0.665, respectively; sensitivity 0.667, 0.630, 0.593; specificity 0.800, 0.785, 0.733; PPV 0.750, 0.739, 0.667; and NPV 0.727, 0.706, 0.667). CONCLUSIONS: Radiomics features generated from noncontrast-enhanced CT images allow PI to be differentiated from CAP with considerable accuracy. The radiomics-based method could provide useful information in clinical practice.


Assuntos
Pneumonia , Infarto Pulmonar , Humanos , Curva ROC , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
17.
Anal Bioanal Chem ; 413(4): 1099-1106, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33388931

RESUMO

We develop a capillary-paper spray (CPS) ion source which allows for sample separation in the capillary and enables rapid and sensitive paper spray (PS) mass spectrometry (MS) analysis of biofluids. The CPS employs a glass capillary to load liquid analytes, vertically standing at the rear of the PS. To further reduce the matrix effect, a nitrocellulose filter membrane is placed between the glass tube and chromatography paper to absorb proteins and other macromolecules, which is beneficial for the detection of the small molecules. Compared with the normal PS method, the CPS method markedly improves spray stability and prolongs analysis duration, and also generates significantly better signal intensities during the analysis of drugs, thus indicating its potential for clinical use. As a proof of concept, quantitative analysis of drugs (metformin hydrochloride and berberine hydrochloride) in serum is performed.


Assuntos
Berberina/análise , Hipoglicemiantes/análise , Espectrometria de Massas/instrumentação , Metformina/análise , Animais , Berberina/sangue , Bovinos , Desenho de Equipamento , Hipoglicemiantes/sangue , Metformina/sangue , Papel , Soro/química
18.
Sci Total Environ ; 767: 144252, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33429279

RESUMO

Tillage has a considerable effect on the soil ecosystem and its services, including microbial communities. Harnessing beneficial microbes is a sustainable way to optimizing crop management and agricultural production. Although diazotrophs play a major role in global biological nitrogen fixation, the effects of tillage on diazotrophic communities in the rhizosphere are not fully understood. In the present study, we investigated the diazotrophic community in wheat rhizosphere soil under different tillage treatments in a long-term experiment, i.e., plow tillage (considered as conventional tillage), chisel plow tillage (considered as conservation tillage), and zero tillage (considered as conservation tillage). Tillage led to a divergent distribution in the rhizosphere diazotrophic community and significant changes in community structure. Tillage caused specific responses from members/modules of the rhizosphere diazotrophic community co-occurrence network, and the relative abundance of keystone taxa was higher under conservation tillage than under conventional tillage. The increased abundance of tillage-sensitive modules under conservation tillage had a broad and significant positive correlation with rhizosphere nutrient availability, whereas the opposite was true for conventional tillage. Differences in nutrients under different tillage practices may lead to different assembly processes of diazotrophs. Overall, our findings indicate that tillage significantly affects the assembly and composition of the rhizosphere diazotrophic community, emphasizing the importance of improved substrate availability for rhizosphere diazotrophic modules under conservation tillage. This knowledge could deepen our understanding of the rhizosphere functional microbial community (e.g., biological nitrogen fixation).


Assuntos
Rizosfera , Triticum , Agricultura , Fixação de Nitrogênio , Solo , Microbiologia do Solo
19.
J Am Chem Soc ; 143(2): 1078-1087, 2021 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-33399468

RESUMO

Carbonyls and amines are yin and yang in organocatalysis as they mutually activate and transform each other. These intrinsically reacting partners tend to condense with each other, thus depleting their individual activity when used together as cocatalysts. Though widely established in many prominent catalytic strategies, aminocatalysis and carbonyl catalysis do not coexist well, and, as such, a cooperative amine/carbonyl dual catalysis remains essentially unknown. Here we report a cooperative primary amine and ketone dual catalytic approach for the asymmetric α-hydroxylation of ß-ketocarbonyls with H2O2. Besides participating in the typical enamine catalytic cycle, the chiral primary amine catalyst was found to work cooperatively with a ketone catalyst to activate H2O2 via an oxaziridine intermediate derived from an in-situ-generated ketimine. Ultimately, this enamine-oxaziridine coupling facilitated the highly controlled α-hydroxylation of several ß-ketocarbonyls in excellent yield and enantioselectivity. Notably, late-stage hydroxylation for peptidyl amide or chiral esters can also be achieved with high stereoselectivity. In addition to its operational simplicity and mild conditions, this cooperative amine/ketone catalytic approach also provides a new strategy for the catalytic activation of H2O2 and expands the domain of typical amine and carbonyl catalysis to include this challenging transformation.

20.
Curr Stem Cell Res Ther ; 16(5): 589-598, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32000654

RESUMO

Macrophage proliferation and skewed myelopoiesis-induced monocytosis, as well as neutrophils, enhance the generation of atherogenic inflammatory cells in a lesion area, leading to plaque formation and Cardiovascular Disease (CVD). Among all risk factors, accumulated data have shown that hyperlipidemia activates Hematopoietic Stem/Progenitor Cells (HSPCs) in the Bone Marrow (BM) niche. Recently, proliferation of Granulocyte-Monocyte Progenitors (GMPs) has been demonstrated to drive skewed myelopoiesis, while HSPCs remain quiescent. In this review, we discuss how HSPCs and GMPs participate in atherosclerosis of mice in terms of proliferation and cell mobilization from BM to peripheral blood and the lesion area. We also describe how the spleen, an extramedullary organ, is involved in skewed myelopoiesis and inflammation in atherosclerosis. We further summarize the clinical evidence of the relationship of HSPCs with coronary stenoses in patients with CVD. Ultimately, this review facilitates understanding the pathological roles of HSPCs and GMPs in atherosclerosis for future treatments.

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