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1.
Neurochem Res ; 48(3): 956-966, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36402927

RESUMO

Ferroptosis is characterized by excessive accumulation of iron and lipid peroxides, which are involved in ischemia, reperfusion-induced organ injury, and stroke. Propofol, an anesthetic agent, has neuroprotective effects due to its potent antioxidant, anti-ischemic, and anti-inflammatory properties. However, the relationship between propofol and ferroptosis is still unclear. In the current study, we elucidated the role of ferroptosis in the neuroprotective effect of propofol in mouse brains subjected to cerebral ischemia reperfusion injury (CIRI). Ferroptosis was confirmed by Western blotting assays, transmission electron microscopy, and glutathione assays. Propofol regulated Nrf2/Gpx4 signaling, enhanced antioxidant potential, inhibited the accumulation of lipid peroxides in CIRI-affected neurons, and significantly reversed CIRI-induced ferroptosis. Additionally, Gpx4 inhibitor RSL3 and Nrf2 inhibitor ML385 attenuated the effects of propofol on antioxidant capacity, lipid peroxidation, and ferroptosis in CIRI-affected neurons. Our data support a protective role of propofol against ferroptosis as a cause of cell death in mice with CIRI. Propofol protected against CIRI-induced ferroptosis partly by regulating the Nrf2/Gpx4 signaling pathway. These findings may contribute to the development of future therapies targeting ferroptosis induced by CIRI.


Assuntos
Propofol , Traumatismo por Reperfusão , Animais , Camundongos , Propofol/farmacologia , Propofol/uso terapêutico , Fator 2 Relacionado a NF-E2 , Antioxidantes , Peróxidos Lipídicos , Traumatismo por Reperfusão/tratamento farmacológico , Modelos Animais de Doenças , Transdução de Sinais , Morte Celular
2.
Acta Pharmacol Sin ; 44(11): 2296-2306, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37316630

RESUMO

Current therapy for acute myeloid leukemia (AML) is largely hindered by the development of drug resistance of commonly used chemotherapy drugs, including cytarabine, daunorubicin, and idarubicin. In this study, we investigated the molecular mechanisms underlying the chemotherapy drug resistance and potential strategy to improve the efficacy of these drugs against AML. By analyzing data from ex vivo drug-response and multi-omics profiling public data for AML, we identified autophagy activation as a potential target in chemotherapy-resistant patients. In THP-1 and MV-4-11 cell lines, knockdown of autophagy-regulated genes ATG5 or MAP1LC3B significantly enhanced AML cell sensitivity to the chemotherapy drugs cytarabine, daunorubicin, and idarubicin. In silico screening, we found that chloroquine phosphate mimicked autophagy inactivation. We showed that chloroquine phosphate dose-dependently down-regulated the autophagy pathway in MV-4-11 cells. Furthermore, chloroquine phosphate exerted a synergistic antitumor effect with the chemotherapy drugs in vitro and in vivo. These results highlight autophagy activation as a drug resistance mechanism and the combination therapy of chloroquine phosphate and chemotherapy drugs can enhance anti-AML efficacy.


Assuntos
Idarubicina , Leucemia Mieloide Aguda , Humanos , Idarubicina/farmacologia , Idarubicina/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Daunorrubicina/farmacologia , Daunorrubicina/uso terapêutico , Citarabina/farmacologia , Citarabina/uso terapêutico , Autofagia , Cloroquina/farmacologia , Cloroquina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
3.
Angew Chem Int Ed Engl ; 62(17): e202300396, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-36849867

RESUMO

PbS quantum dots (QDs) are promising building blocks for solution-processed short-wavelength infrared (SWIR) devices. The recently developed direct synthesis of semi-conductive PbS QD inks has substantially simplified the preparation processing and reduced the material cost, while facing the challenge to synthesize large-size QDs with absorption covering the SWIR region. Herein, we for the first time realize a low-cost, scalable synthesis of SWIR PbS QD inks after an extensive investigation of the reaction kinetics. Finally, based on these PbS SWIR QD inks, the solar cell demonstrates a record-high power conversion efficiency (PCE) of 1.44 % through an 1100 nm cutoff silicon filter and the photodetector device shows a low dark current density of 2×10-6  A cm-2 at -0.8 V reverse bias with a high external quantum efficiency (EQE) of 70 % at ≈1300 nm. Our results realize the direct synthesis of low-cost and scalable SWIR QD inks and may accelerate the industrialization of consumer SWIR technologies.

4.
Acta Pharmacol Sin ; 43(1): 220-228, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33782542

RESUMO

Checkpoint kinase 1 inhibitors (CHK1i) have shown impressive single-agent efficacy in treatment of certain tumors, as monotherapy or potentiators of chemotherapy in clinical trials, but the sensitive tumor types and downstream effectors to dictate the therapeutic responses to CHK1i remains unclear. In this study we first analyzed GDSC (Genomics of Drug Sensitivity in Cancer) and DepMap database and disclosed that hematologic malignancies (HMs) were relatively sensitive to CHK1i or CHK1 knockdown. This notion was confirmed by examining PY34, a new and potent in-house selective CHK1i, which exhibited potent anti-HM effect in vitro and in vivo, as single agent. We demonstrated that the downregulation of c-Myc and its signaling pathway was the common transcriptomic profiling response of sensitive HM cell lines to PY34, whereas overexpressing c-Myc could partially rescue the anticancer effect of PY34. Strikingly, we revealed the significant correlations between downregulation of c-Myc and cell sensitivity to PY34 in 17 HM cell lines and 39 patient-derived cell (PDC) samples. Thus, our results demonstrate that HMs are more sensitive to CHK1i than solid tumors, and c-Myc downregulation could represent the CHK1i efficacy in HMs.


Assuntos
Proteínas de Ligação a DNA/antagonistas & inibidores , Regulação para Baixo/efeitos dos fármacos , Neoplasias Hematológicas/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Fatores de Transcrição/antagonistas & inibidores , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Quinase 1 do Ponto de Checagem/deficiência , Quinase 1 do Ponto de Checagem/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/patologia , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
J Mol Evol ; 88(2): 202-209, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31919584

RESUMO

Drug-resistant Mycobacterium tuberculosis (M. tuberculosis) has become an increasingly serious public health problem and has complicated tuberculosis (TB) treatment. Levofloxacin (LOF) is an ideal anti-tuberculosis drug in clinical applications. However, the detailed molecular mechanisms of LOF-resistant M. tuberculosis in TB treatment have not been revealed. Our study performed transcriptome and methylome sequencing to investigate the potential biological characteristics of LOF resistance in M. tuberculosis H37Rv. In the transcriptome analysis, 953 differentially expressed genes (DEGs) were identified; 514 and 439 DEGs were significantly downregulated and upregulated in the LOF-resistant group and control group, respectively. The KEGG pathway analysis revealed that 97 pathways were enriched in this study. In the methylome analysis, 239 differentially methylated genes (DMGs) were identified; 150 and 89 DMGs were hypomethylated and hypermethylated in the LOF-resistant group and control group, respectively. The KEGG pathway analysis revealed that 74 pathways were enriched in this study. The overlap study suggested that 25 genes were obtained. It was notable that nine genes expressed downregulated mRNA and upregulated methylated levels, including pgi, fadE4, php, cyp132, pckA, rpmB1, pfkB, acg, and ctpF, especially cyp132, pckA, and pfkB, which were vital in LOF-resistant M. tuberculosis H37Rv. The overlapping genes between transcriptome and methylome could be essential for studying the molecular mechanisms of LOF-resistant M. tuberculosis H37Rv. These results may provide informative evidence for TB treatment with LOF.


Assuntos
Farmacorresistência Bacteriana/genética , Epigenoma , Levofloxacino/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Transcriptoma , Antibacterianos/farmacologia , Metilação de DNA , Genes Bacterianos
6.
Nanotechnology ; 31(22): 225204, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32059199

RESUMO

In recent years, organic-inorganic hybrid perovskites have attracted wide attention due to their excellent optoelectronic properties in the application of optoelectronic devices. In the manufacturing process of perovskite solar cells, perovskite films inevitably have residual stress caused by non-stoichiometry components and the external load. However, their effects on the structural stability and photovoltaic performance of perovskite solar cells are still not clear. In this work, we investigated the effects of external strain on the structural stability and optoelectronic properties of tetragonal MAPbI3 by using the first-principles calculations. We found that the migration barrier of I- ion increases in the presence of compressive strain and decreases with tensile strain, indicating that the compressive strain can enhance the structural stability of halide perovskites. In addition, the light absorption and electronic properties of MAPbI3 under compressive strain are also improved. The variations of the band gap under triaxial and biaxial strains are consistent within a certain range of strain, resulting from the fact that the band edge positions are mainly influenced by the Pb-I bond in the equatorial plane. Our results provide useful guidance for realizing the commercial applications of MAPbI3-based perovskite solar cells.

7.
Molecules ; 25(1)2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31947824

RESUMO

Herein, we design and synthesize an array of benzofuro[3,2-c]quinolines starting from 3-(2-methoxyphenyl)quinolin-4(1H)ones via a sequential chlorination/demethylation, intramolecular cyclization pathway. This sequential transformation was efficient, conducted under metal-free and mild reaction conditions, and yielded corresponding benzofuro[3,2-c]quinolines in high yields. In vitro biological evaluation indicated that such type of compounds showed excellent antileukemia activity and selectivity, and therefore may offer a promising hit compound for developing antileukemia compounds.


Assuntos
Antineoplásicos , Desenho de Fármacos , Leucemia , Quinolinas , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Leucemia/tratamento farmacológico , Leucemia/metabolismo , Leucemia/patologia , Quinolinas/síntese química , Quinolinas/química , Quinolinas/farmacologia
8.
Appl Microbiol Biotechnol ; 102(3): 1357-1366, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29199353

RESUMO

Paenibacillus elgii B69 produces a new xylose-containing exopolysaccharide (EPS) that effectively removes the pollutants from wastewater through flocculation. However, information about the biosynthesis of this EPS is limited. In this study, sequence analysis showed six putative glycosyltransferases (GTs) genes in polysaccharide gene clusters involved in glycosidic linkages of repeating units. Each gene was deleted and phenotypes were examined to understand the functions of these genes. Two of the genes were deleted successfully to encode a priming glucose GT and a side-chain xylose GT, but other genes were unsuccessfully deleted because of the accumulation of toxic intermediate products. The six genes were cloned and expressed in Escherichia coli, and the corresponding enzymes were purified. The activity of GTs was analyzed through mass spectrometry by using the purified membrane fraction as a lipid carrier receptor after a hexasaccharide repeated unit was reconstructed in vitro. The specificities of six different GTs and the building order of the hexasaccharide were characterized. This study provided a basis for future research on the biosynthetic pathway of EPS in Paenibacillus or other genera.


Assuntos
Glicosiltransferases/metabolismo , Paenibacillus/enzimologia , Polissacarídeos Bacterianos/biossíntese , Vias Biossintéticas , Escherichia coli/genética , Deleção de Genes , Técnicas de Inativação de Genes , Genes Bacterianos , Glicosídeos/química , Glicosiltransferases/genética , Espectrometria de Massas , Família Multigênica , Paenibacillus/genética , Fenótipo , Águas Residuárias/microbiologia , Xilose/química
9.
Am J Physiol Endocrinol Metab ; 310(3): E225-37, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26646098

RESUMO

Salidroside (SAL) is a phenylethanoid glycoside isolated from the medicinal plant Rhodiola rosea. R. rosea has been reported to have beneficial effects on diabetic nephropathy (DN) and high-glucose (HG)-induced mesangial cell proliferation. Given the importance of caveolin-1 (Cav-1) in transcytosis of albumin across the endothelial barrier, the present study was designed to elucidate whether SAL could inhibit Cav-1 phosphorylation and reduce the albumin transcytosis across glomerular endothelial cells (GECs) to alleviate diabetic albuminuria as well as to explore its upstream signaling pathway. To assess the therapeutic potential of SAL and the mechanisms involved in DN albuminuria, we orally administered SAL to db/db mice, and the effect of SAL on the albuminuria was measured. The albumin transcytosis across GECs was explored in a newly established in vitro cellular model. The ratio of albumin to creatinine was significantly reduced upon SAL treatment in db/db mice. SAL decreased the albumin transcytosis across GECs in both normoglycemic and hyperglycemic conditions. SAL reversed the HG-induced downregulation of AMP-activated protein kinase and upregulation of Src kinase and blocked the upregulation Cav-1 phosphorylation. Meanwhile, SAL decreased mitochondrial superoxide anion production and moderately depolarized mitochondrial membrane potential. We conclude that SAL exerts its proteinuria-alleviating effects by downregulation of Cav-1 phosphorylation and inhibition of albumin transcytosis across GECs. These studies provide the first evidence of interference with albumin transcytosis across GECs as a novel approach to the treatment of diabetic albuminuria.


Assuntos
Albuminas/efeitos dos fármacos , Albuminúria/metabolismo , Caveolina 1/efeitos dos fármacos , Nefropatias Diabéticas/metabolismo , Células Endoteliais/efeitos dos fármacos , Glucosídeos/farmacologia , Glomérulos Renais/efeitos dos fármacos , Fenóis/farmacologia , Transcitose/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Albuminas/metabolismo , Animais , Caveolina 1/metabolismo , Creatinina/metabolismo , Células Endoteliais/metabolismo , Glucose/metabolismo , Técnicas In Vitro , Glomérulos Renais/metabolismo , Células Mesangiais/efeitos dos fármacos , Células Mesangiais/metabolismo , Camundongos , Fosforilação/efeitos dos fármacos , Quinases da Família src/efeitos dos fármacos , Quinases da Família src/metabolismo
10.
Bioorg Med Chem Lett ; 26(10): 2544-2546, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-27061156

RESUMO

To find a new lead compound with high biological activity, a series of N-substituted benzoyl-1,2,3,4-tetrahydroquinolyl-1-carboxamide were designed using linking active substructures method. The target compounds were synthesized from substituted benzoic acid by four steps and their structures were confirmed by (1)H NMR, IR spectrum and elemental analysis. The in vitro bioassay results indicated that some target compounds exhibited excellent fungicidal activities, and the position of the substituents played an important role in fungicidal activities. Especially, compound 5n, exhibited better fungicidal activities than the commercial fungicide flutolanil against two tested fungi Valsa mali and Sclerotinia sclerotiorum, with EC50 values of 3.44 and 2.63mg/L, respectively. And it also displayed good in vivo fungicidal activity against S. sclerotiorum with the EC50 value of 29.52mg/L.


Assuntos
Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Ascomicetos/efeitos dos fármacos , Técnicas de Química Sintética , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Fungicidas Industriais/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrofotometria Infravermelho , Relação Estrutura-Atividade
11.
Lancet Oncol ; 15(6): 612-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24742740

RESUMO

BACKGROUND: The combination of stent insertion and single high-dose brachytherapy is a feasible and safe palliative treatment regimen in patients with unresectable oesophageal cancer. We aimed to further assess the efficacy of this treatment strategy compared to a conventional covered stent in patients with dysphagia caused by unresectable oesophageal cancer. METHODS: In this multicentre, single-blind, randomised, phase 3 trial, we enrolled patients with unresectable oesophageal cancer from 16 hospitals in China. We included adult patients (aged ≥ 20 years) with progressive dysphagia, unresectable tumours due to extensive lesions, metastases, or poor medical condition, and with clear consciousness, cooperation, and an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-3. Eligible patients were randomly assigned (in 1:1 ratio, no stratification) to receive either a stent loaded with (125)iodine radioactive seeds (irradiation group) or a conventional oesophageal stent (control group). The primary endpoint was overall survival. Survival analyses were done in a modified intention-to-treat group. This study is registered with ClinicalTrials.gov, number NCT01054274. FINDINGS: Between Nov 1, 2009, and Oct 31, 2012, 160 patients were randomly assigned to receive treatment with either an irradiation stent (n=80) or a conventional stent (n=80). During a median follow-up of 138 days (IQR 72-207), 148 stents (73 in the irradiation group and 75 in the control group) were successfully placed into the diseased oesophagus in 148 participants. Median overall survival was 177 days (95% CI 153-201) in the irradiation group versus 147 days (124-170) in the control group (p=0.0046). Major complications and side-effects of the treatment were severe chest pain (17 [23%] of 73 patients in the irradiation group vs 15 [20%] of 75 patents in the control group), fistula formation (six [8%] vs five [7%]), aspiration pneumonia (11 [15%] vs 14 [19%]), haemorrhage (five [7%] vs five [7%]), and recurrent dysphagia (21 [28%] vs 20 [27%]). INTERPRETATION: In patients with unresectable oesophageal cancer, the insertion of an oesophageal stent loaded with (125)iodine seeds prolonged survival when compared with the insertion of a conventional covered self-expandable metallic stent.


Assuntos
Adenocarcinoma/radioterapia , Braquiterapia/métodos , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/radioterapia , Stents , Adenocarcinoma/mortalidade , Idoso , Braquiterapia/instrumentação , Carcinoma de Células Escamosas/mortalidade , Neoplasias Esofágicas/mortalidade , Feminino , Humanos , Radioisótopos do Iodo/uso terapêutico , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Método Simples-Cego
12.
J Mol Cell Cardiol ; 72: 85-94, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24594319

RESUMO

Tumor necrosis factor-α (TNF-α) is an established pro-atherosclerotic factor, but the mechanism is not completely understood. We explored whether TNF-α could promote atherosclerosis by increasing the transcytosis of lipoproteins (e.g., LDL) across endothelial cells and how NF-κB and PPAR-γ were involved in this process. TNF-α significantly increased the transcytosis of LDL across human umbilical vein endothelial cells (HUVECs) and stimulated an increase of subendothelial retention of LDL in vascular walls. These effects of TNF-α were substantially blocked not only by transcytosis inhibitors, but also by NF-κB inhibitors and PPAR-γ inhibitors. In ApoE(-/-) mice, both NF-κB and PPAR-γ inhibitors alleviated the early atherosclerotic changes promoted by TNF-α. NF-κB and PPAR-γ inhibitors down-regulated the transcriptional activities of NF-κB and PPAR-γ induced by TNF-α. Furthermore, cross-binding activity assay revealed that NF-κB and PPAR-γ could form an active transcription factor complex containing both the NF-κB P65 subunit and PPAR-γ. The increased expressions of LDL transcytosis-related proteins (LDL receptor and caveolin-1, -2) stimulated by TNF-α were also blocked by both NF-κB inhibitors and PPAR-γ inhibitors. TNF-α promotes atherosclerosis by increasing the LDL transcytosis across endothelial cells and thereby facilitating LDL retention in vascular walls. In this process, NF-κB and PPAR-γ are activated coordinately to up-regulate the expression of transcytosis-related proteins. These observations suggest that inhibitors of either NF-κB or PPAR-γ can be used to target atherosclerosis.


Assuntos
Aterosclerose/genética , Lipoproteínas LDL/metabolismo , NF-kappa B/metabolismo , PPAR gama/metabolismo , Transcitose/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Anilidas/farmacologia , Animais , Aterosclerose/induzido quimicamente , Aterosclerose/patologia , Aterosclerose/prevenção & controle , Benzamidas/farmacologia , Caveolina 1/antagonistas & inibidores , Caveolina 1/genética , Caveolina 1/metabolismo , Caveolina 2/antagonistas & inibidores , Caveolina 2/genética , Caveolina 2/metabolismo , Alcaloides de Cinchona/farmacologia , Filipina/farmacologia , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Lipoproteínas LDL/antagonistas & inibidores , Camundongos , Camundongos Knockout , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , Nitrilas/farmacologia , PPAR gama/antagonistas & inibidores , PPAR gama/genética , Prolina/análogos & derivados , Prolina/farmacologia , Piridinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores de LDL/antagonistas & inibidores , Receptores de LDL/genética , Receptores de LDL/metabolismo , Transdução de Sinais , Sulfonas/farmacologia , Tiocarbamatos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
13.
Acta Neurochir (Wien) ; 156(11): 2209-13, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25223746

RESUMO

BACKGROUND: A coordinate system was previously developed to identify landmarks on the skull surface to help locate the transverse-sigmoid sinus junction in order to reduce surgical morbidity in retrosigmoid craniotomy; however, in practice we found that this system has important flaws. OBJECTIVE: To develop and evaluate a novel reference coordinate system to precisely locate the inferomedial point of the transverse-sigmoid sinus junction (IMTS) and evaluate the effect of gender and skull side (left or right). METHODS: Forty-two adult skulls (84 sides) were obtained for analyses. The X-axis was defined by point A (where the upper edge of the zygomatic arch joins with the frontal process of the zygomatic bone) and point B (where the upper edge of the zygomatic arch blends posterosuperiorly into the supramastoid crest). The Y-axis was defined by the line perpendicular to the X-axis and extending across the tip of the mastoid. The x and y coordinates of IMTS (IMTS-x and IMTS-y) were measured in this coordinate system. RESULTS: There were 20 male skulls and 22 female skulls. The mean IMTS-x measurements were significantly higher on the right side compared with the left side in both males and females. For the left skull side, the mean IMTS-y measurements were significantly lower in females compared with males. CONCLUSION: This novel reference coordinate system may be a reliable and practical method for identifying the IMTS during retrosigmoid craniotomy. There are significant differences in location of the axes with regard to gender and skull side.


Assuntos
Pontos de Referência Anatômicos , Processo Mastoide/anatomia & histologia , Crânio/anatomia & histologia , Seios Transversos/anatomia & histologia , Zigoma/anatomia & histologia , Adulto , Cavidades Cranianas/anatomia & histologia , Cavidades Cranianas/cirurgia , Craniotomia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Crânio/cirurgia , Seios Transversos/cirurgia
14.
ScientificWorldJournal ; 2014: 259139, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25097872

RESUMO

The cloud platform provides various services to users. More and more cloud centers provide infrastructure as the main way of operating. To improve the utilization rate of the cloud center and to decrease the operating cost, the cloud center provides services according to requirements of users by sharding the resources with virtualization. Considering both QoS for users and cost saving for cloud computing providers, we try to maximize performance and minimize energy cost as well. In this paper, we propose a distributed parallel genetic algorithm (DPGA) of placement strategy for virtual machines deployment on cloud platform. It executes the genetic algorithm parallelly and distributedly on several selected physical hosts in the first stage. Then it continues to execute the genetic algorithm of the second stage with solutions obtained from the first stage as the initial population. The solution calculated by the genetic algorithm of the second stage is the optimal one of the proposed approach. The experimental results show that the proposed placement strategy of VM deployment can ensure QoS for users and it is more effective and more energy efficient than other placement strategies on the cloud platform.


Assuntos
Algoritmos , Armazenamento e Recuperação da Informação/métodos
15.
Sci Total Environ ; 932: 173035, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38719031

RESUMO

Sea-to-air emissions of very short-lived brominated halocarbons (VSLBrHs) are known to contribute to 30 % of stratospheric and tropospheric ozone depletion. However, empirical data on their occurrence in open ocean are scarce, which makes it difficult to estimate the significant contribution of open ocean releases to the global budget of halocarbons. This study was conducted in 2022 to explore the spatial variations of VSLBrHs and their controlling factors in the western tropical Pacific Ocean (WTPO). The findings highlighted that high biological productivity and the resulting dissolved organic matter (DOM) as well as upwelling dynamics significantly influenced the distribution and production of VSLBrHs in seawater, with atmospheric levels primarily governed by oceanic emissions. Based on the simultaneous observation of seawater and atmospheric concentrations, the mean sea-to-air fluxes of CH2Br2, CHBr3, CHBrCl2, and CHBr2Cl were estimated to be 1.01, 6.65, 9.31, and 7.25 nmol m-2 d-1, respectively. Sea-to-air fluxes of these gases in the upwelling regions were 9.0, 4.6, 2.9, and 6.8 times those in the non-upwelling regions, respectively. Additionally, in-situ incubation experiments revealed that the enzymatic mediated biosynthesis pathways of VSLBrHs were enhanced under temperature and light-induced stress and in waters rich in humus-like substances. Therefore, we tentatively concluded that abundant photothermal conditions and the existence of upwelling in the WTPO made it a potential hotspot for the emission of VSLBrHs. This study offers critical insights into the environmental dynamics of VSLBrHs emissions and underscores the importance of regional oceanic conditions in influencing atmospheric greenhouse gas compositions.

16.
Se Pu ; 42(8): 805-811, 2024 Aug.
Artigo em Zh | MEDLINE | ID: mdl-39086250

RESUMO

Tobacco flavor, an important tobacco additive, is an essential raw material in cigarette production that can effectively improve the quality of tobacco products, add aroma and taste, and increase the suction flavor. The quality consistency of tobacco flavors affects the quality stability of branded cigarettes. Therefore, the quality control of tobacco flavors is a major concern for cigarette and flavor manufacturers. Physical and chemical indices, odor similarity, and sensory efficacy are employed to evaluate the quality of tobacco flavors, and the analysis of chemical components in tobacco flavors is usually conducted using gas chromatography (GC) and high performance liquid chromatography (HPLC). However, because the composition of tobacco flavors is complex, their quality cannot be fully reflected using a single component or combination of components. Therefore, establishing an objective analytical method for the quality control of tobacco flavors is of extreme importance. Chromatographic fingerprint analysis is routinely used for the discriminative analysis of tobacco flavors. Chromatographic fingerprints refer to the general characteristics of the concentration profiles of different chemical compounds. In the daily procurement process, fingerprints established by GC and HPLC are effective for the evaluation and identification of tobacco flavors. However, given continuous improvements in aroma-imitation technology, some flavors with high similarity cannot be directly distinguished using existing methods. In this study, a method for the determination of organic acids and inorganic anions in tobacco flavors based on ion chromatography (IC) was developed to ensure the quality consistency of tobacco flavors. A 1.0 g sample of tobacco flavors and 10 mL of deionized water were mixed and vibrated for 30 min. The aqueous sample solution was passed through a 0.45 µm membrane filter and RP pretreatment column in succession to eliminate interferences and then subjected to IC. Standard solutions containing nine organic acids and seven inorganic anions were used to identify the anions in the tobacco flavors, and satisfactory reproducibility was obtained. The relative standard deviations (RSDs) for retention times and peak areas were <0.71% and <6.02%, respectively. The chromatographic fingerprints of four types of tobacco flavors (samples A-D) from five different batches were obtained. Nine tobacco flavor samples from different manufacturers (samples AY1-AY3, BY1-BY2, CY1-CY2, DY1-DY2) were also analyzed to obtain their chromatographic fingerprints. Hierarchical cluster and similarity analyses were used to evaluate the quality of tobacco flavors from different manufacturers. Hierarchical clustering refers to the process of subdividing a group of samples into clusters that exhibit a high degree of intracluster similarity and intercluster dissimilarity. The dendrograms obtained using SPSS 12.0 indicated good quality consistency among the samples in different batches. Samples AY3, BY2, CY2, and DY1 clustered with the batches of standard tobacco flavors. Therefore, hierarchical cluster analysis can effectively distinguish the quality of products from different manufacturers. The Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine (version 2.0) was used to evaluate the similarity between the standard tobacco flavors and products from different manufacturers. Among the samples analyzed, samples AY3, BY2, CY2, and DY1 showed the highest similarity values (>97.7%), which was consistent with the results of the hierarchical cluster analysis. This finding indicates that IC combined with chromatographic fingerprint analysis could accurately determine the quality of tobacco flavors. GC combined with ultrasonic-assisted liquid-liquid extraction was also used to analyze the tobacco flavors and verify the accuracy of the proposed method. Compared with GC coupled with ultrasonic-assisted liquid-liquid extraction, IC demonstrated more significant quality differences among certain tobacco flavors.


Assuntos
Nicotiana , Controle de Qualidade , Nicotiana/química , Aromatizantes/análise , Produtos do Tabaco/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Gasosa/métodos , Cromatografia por Troca Iônica/métodos
17.
J Fungi (Basel) ; 10(5)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38786665

RESUMO

This study investigates the effects of forest aging on ectomycorrhizal (EcM) fungal community and foraging behavior and their interactions with plant-soil attributes. We explored EcM fungal communities and hyphal exploration types via rDNA sequencing and investigated their associations with plant-soil traits by comparing younger (~120 years) and older (~250 years) temperate forest stands in Northeast China. The results revealed increases in the EcM fungal richness and abundance with forest aging, paralleled by plant-soil feedback shifting from explorative to conservative nutrient use strategies. In the younger stands, Tomentella species were prevalent and showed positive correlations with nutrient availability in both the soil and leaves, alongside rapid increases in woody productivity. However, the older stands were marked by the dominance of the genera Inocybe, Hymenogaster, and Otidea which were significantly and positively correlated with soil nutrient contents and plant structural attributes such as the community-weighted mean height and standing biomass. Notably, the ratios of longer-to-shorter distance EcM fungal exploration types tended to decrease along with forest aging. Our findings underscore the integral role of EcM fungi in the aging processes of temperate forests, highlighting the EcM symbiont-mediated mechanisms adapting to nutrient scarcity and promoting sustainability in plant-soil consortia.

18.
J Surg Res ; 185(1): 388-98, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23743186

RESUMO

BACKGROUND: It was previously reported that propofol, an intravenously administered hypnotic and anesthetic agent, protects organs from ischemia-reperfusion (I/R) injury. However, the underlying mechanisms are largely unknown. Glycogen synthase kinase 3ß (GSK-3ß) is known to play an important role in the oxidative stress-induced apoptosis. In this study, we investigated the role of GSK-3ß and mitochondrial permeability transition pore (MPTP) in the protective effects of propofol against hepatic I/R injury. MATERIALS AND METHODS: The left and median hepatic artery and the portal vein branches were blocked by no-damage artery clips to create the model of partial ischemia (70%), and liver lobes were subjected to warm ischemia for 30, 60, 90 min, respectively. Reperfusion of 120 min was then initiated by the removal of clamp. The MPTP opening was assessed by measuring mitochondrial large amplitude swelling and mitochondrial membrane potential. RESULTS: Pretreatment with propofol in conditions of hepatic I/R inhibits the apoptosis of hepatocytes as evidenced by decreased terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. Importantly, propofol suppressed the mitochondrial GSK-3ß by promoting or preserving its phosphorylation at Ser9, thus restraining the opening of MPTP and preventing the mitochondrial swell and mitochondrial membrane potential collapse. CONCLUSIONS: Propofol protects liver from I/R injury by sustaining the mitochondrial function, which is possibly involved with the modulation of MPTP and GSK-3ß.


Assuntos
Anestésicos Intravenosos/farmacologia , Quinase 3 da Glicogênio Sintase/metabolismo , Fígado/efeitos dos fármacos , Propofol/farmacologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta , Fígado/enzimologia , Fígado/patologia , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/patologia
19.
3D Print Addit Manuf ; 10(4): 711-722, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37609587

RESUMO

The finite element (FE) method is used to characterize the thermal gradient, solidification rate, and molten pool sizes of Ti-6Al-4V plates in the process of selective laser melting (SLM). The results are verified by using the computational fluid dynamics (CFD) simulation. The proposed FE model contains a series of toolpath information that is directly converted from a G-code file, including hatch spacing, laser power, layer thickness, dwell time, and scanning speed generated by using Slic3r software from a CAD file. A proposed multi-layer, multi-track FE model is used to investigate the influence of the laser power, scanning speed, and scanning path on the microstructure in the Ti-6Al-4V plate built via SLM. The processing window is also determined based on the proposed FE model. The FE results indicate that, with a decrease in the laser power and an increase in the scanning speed, the morphology of the crystal grains, showing fully columnar crystals, gradually deviates from the fully equiaxed region. The formed grains are dependent on the laser power, scanning speed, and deposition position, but they are not sensitive to the scanning path, and with the deposition from the bottom layer to the top layer, the size of the formed grains is gradually increasing, which shows a good agreement with the experimental results.

20.
Front Cell Dev Biol ; 11: 1199519, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37261074

RESUMO

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are emerging as the leading causes of liver disease worldwide. These conditions can lead to cirrhosis, liver cancer, liver failure, and other related ailments. At present, liver transplantation remains the sole treatment option for end-stage NASH, leading to a rapidly growing socioeconomic burden. Kupffer cells (KCs) are a dominant population of macrophages that reside in the liver, playing a crucial role in innate immunity. Their primary function includes phagocytosing exogenous substances, presenting antigens, and triggering immune responses. Moreover, they interact with other liver cells during the pathogenesis of NAFLD, and this crosstalk may either delay or exacerbate disease progression. Stimulation by endogenous signals triggers the activation of KCs, resulting in the expression of various inflammatory factors and chemokines, such as NLRP3, TNF-α, IL-1B, and IL-6, and contributing to the inflammatory cascade. In the past 5 years, significant advances have been made in understanding the biological properties and immune functions of KCs in NAFLD, including their interactions with tissue molecules, underlying molecular mechanisms, signaling pathways, and relevant therapeutic interventions. Having a comprehensive understanding of these mechanisms and characteristics can have enormous potential in guiding future strategies for the prevention and treatment of NAFLD.

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