Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 423
Filtrar
1.
Mol Plant ; 15(1): 125-137, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34896639

RESUMO

Crop plant architecture is an important agronomic trait that contributes greatly to crop yield. Tiller angle is one of the most critical components that determine crop plant architecture, which in turn substantially affects grain yield mainly owing to its large influence on plant density. Gravity is a fundamental physical force that acts on all organisms on earth. Plant organs sense gravity to control their growth orientation, including tiller angle in rice (Oryza sativa). This review summarizes recent research advances made using rice tiller angle as a research model, providing insights into domestication of rice tiller angle, genetic regulation of rice tiller angle, and shoot gravitropism. Finally, we propose that current discoveries in rice can shed light on shoot gravitropism and improvement of plant tiller/branch angle in other species, thereby contributing to agricultural production in the future.

2.
Sci Total Environ ; 803: 150012, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34525708

RESUMO

Thermal desorption coupled with different detectors is an important analysis method for ambient carbonaceous aerosols. However, it is unclear how the compounds coexisting in both the gas and particle phases affect carbonaceous aerosol concentrations and measurements during thermal desorption. We observed matrix effects leading to a redistribution of different OC fractions (OC1 to OC4) during the thermal desorption process. These factors led to the formation of OC with low volatility (OC4), mainly from high-volatility OC (OC1 and OC2). Laboratory studies further indicated that ammonium promotes such matrix effects by transforming OC in the particle phase. Therefore, in addition to providing insights into the chemical evolution of OC during haze events, we argue that thermal-desorption-based OC measurements should be used with caution, which is an important step towards a more accurate measurement of OC in the ambient atmosphere.


Assuntos
Poluentes Atmosféricos , Compostos de Amônio , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
3.
Prep Biochem Biotechnol ; : 1-5, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34871519

RESUMO

Effect of temperature on synthesis of Clavulanic acid (CA) and impurity substance G during fermentation by Streptomyces clavuligerus were investigated. Results show that fermentation at 24 °C is the most favorable for CA synthesis though the fermentation duration was 20-30 hours longer than fermentation at 26 and 28 °C. Meanwhile, the impurity substance G was only 110 mg/L in the end broth of fermentation at 24 °C, which was significantly lower than 148 and 180 mg/L of fermentation at 26 and 28 °C, respectively. Correlation of specific growth rate and CA synthesis was statistically analyzed based on data of 10 batches of industrial fermentation. Two temperature-shift strategies were investigated in 50 L fermenter. Fermentation with 26-24 °C temperature strategy achieved 5097 mg/L CA titer, meanwhile the fermentation duration was shortened 24 hours comparing with fermentation at constant 24 °C. Fermentation with 26-24 °C control strategy was validated in a 60 m3 industrial fermenter, in which 4960 mg/L of CA was achieved while impurity G substance was decreased to titer 65 mg/L from 200 to 300 mg/L of normal production.

4.
Mar Pollut Bull ; 174: 113256, 2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34923403

RESUMO

Nowadays, people have known more about the distribution features on the surface of beaches. However, the understanding on the microplastics (Mps) distribution in the vertical direction on beaches is still lacking. This study analysed the vertical distribution of Mps from five beaches, with one long core [Shilaoren Beach (C1), 8 m] and four short cores [Aoshan Beach (C2); Liuqinghewan Beach (C3); Bathing Beach No. 3 (C4); and Golden Beach (C5); approximately 70 cm]. An increasing trend of Mps from bottom to top layers were observed with an average of 16.6 ± 4.8 Mps/25 g d.w. in C1. Conversely, a fluctuating trend was found in C2-C5, with an average Mps abundance on the 70 cm depth to be 6.7, 7.1, 11.1 and 7.0 Mps/25 g d.w., respectively. These Mps were mainly comprised of fibres (>98%) and few were fragments. Mps were not uniformly distributed within all cores, and this variation was due to changes in Mps sources, hydrodynamics and sedimentation process in the beach environment. Although the vertical accumulation of Mps is not as stable as the other sedimentary environments, it still presents the increasing trend in the 8-m core from the bottom to the top, which is consistent with the plastic production history in China since 1950. Therefore, the 8-m core has been deposited on the beach in the recent 70 years. Thus, this study provides a valuable example for tracing the sedimentation history on the beach, which can help in understanding the sediment deposit and transport processes with time on beaches.

5.
J Sci Food Agric ; 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34741310

RESUMO

BACKGROUND: Garlic (Allium sativum L.), whose bioactive components are mainly organosulfur compounds (OSCs), is a herbaceous perennial widely consumed as a green vegetable and a condiment. Yet, the metabolic enzymes involved in the biosynthesis of OSCs are not identified in garlic. RESULTS: Here, a full-length transcriptome of purple garlic was generated via PacBio and Illumina sequencing, to characterize the garlic transcriptome and identify key proteins mediating the biosynthesis of OSCs. Overall, 22.56 Gb of clean data were generated, resulting in 454 698 circular consensus sequence (CCS) reads, of which 83.4% (379 206) were identified as being full-length non-chimeric reads - their further transcript clustering facilitated identification of 36 571 high-quality consensus reads. Once corrected, their genome-wide mapping revealed that 6140 reads were novel isoforms of known genes, and 2186 reads were novel isoforms from novel genes. We detected 1677 alternative splicing events, finding 2902 genes possessing either two or more poly(A) sites. Given the importance of serine O-acetyltransferase (SERAT) in cysteine biosynthesis, we investigated the five SERAT homologs in garlic. Phylogenetic analysis revealed a three-tier classification of SERAT proteins, each featuring a serine acetyltransferase domain (N-terminal) and one or two hexapeptide transferase motifs. Template-based modeling showed that garlic SERATs shared a common homo-trimeric structure with homologs from bacteria and other plants. The residues responsible for substrate recognition and catalysis were highly conserved, implying a similar reaction mechanism. In profiling the five SERAT genes' transcript levels, their expression pattern varied significantly among different tissues. CONCLUSION: This study's findings deepen our knowledge of SERAT proteins, and provide timely genetic resources that could advance future exploration into garlic's genetic improvement and breeding. © 2021 Society of Chemical Industry.

6.
Environ Sci Technol ; 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34806377

RESUMO

The understanding at a molecular level of ambient secondary organic aerosol (SOA) formation is hampered by poorly constrained formation mechanisms and insufficient analytical methods. Especially in developing countries, SOA related haze is a great concern due to its significant effects on climate and human health. We present simultaneous measurements of gas-phase volatile organic compounds (VOCs), oxygenated organic molecules (OOMs), and particle-phase SOA in Beijing. We show that condensation of the measured OOMs explains 26-39% of the organic aerosol mass growth, with the contribution of OOMs to SOA enhanced during severe haze episodes. Our novel results provide a quantitative molecular connection from anthropogenic emissions to condensable organic oxidation product vapors, their concentration in particle-phase SOA, and ultimately to haze formation.

7.
Stem Cell Res ; 56: 102542, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34619645

RESUMO

Central precocious puberty (CPP) refers to a pediatric endocrine disease in which boys have secondary sexual characteristics before the age of 9 and girls before the age of 8. In this study, we generated an induced pluripotent stem cell line FDCHi006-A from the Peripheral blood cell of a typical central precocious patient who was only 7 years old. This iPSC line showed full pluripotency, normal karyotype and differentiation capacity without integrating vectors. It provides a useful model to study the underlying molecular mechanisms of CPP.


Assuntos
Células-Tronco Pluripotentes Induzidas , Puberdade Precoce , Criança , Feminino , Humanos , Masculino
8.
Metabolites ; 11(9)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34564445

RESUMO

To avoid the widespread resistance of commercial fungicides, new broad-spectrum botanical fungicides need to be developed. In previous bioactive screening assays, extracts of Artemisia ordosica Krasch. (A. ordosica) had highly antifungal activities, but the responsible phytochemicals were unidentified. In this study, active compounds of A. ordosica extracts were identified using a bioassay-guided method, and antifungal assays were performed in vitro and in vivo. The bioactive compounds were dissolved in petroleum ether, and the best antifungal fraction contained four compounds: trans-dehydromatricaria ester (TDDE), 7, 4-demetylnringenin, capillarin, and stearic acid. Among them, TDDE exhibited the highest antifungal activity against six pathogenic fungi and five bacteria. It exhibited significant fungicidal activity against Thanatephorus cucumeris and Botrytis cinerea with EC50 values of 0.464 µg/mL and 1.4 µg/mL, respectively. The living tissue bioassay results showed that the relative protection effects (RPE) of TDDE on tomato leaves, tomato fruit, and strawberry leaves infected with B. cinerea reached 76.78%, 86.2%, and 80.89%, respectively. In pot experiments, the RPE on tomato and strawberry plants infected with B. cinerea reached 84.11% and 96.37%, respectively. Morphological and physiological examination showed that TDDE had significant inhibitory effects on mycelial growth, including increased top offshoot, contorted hyphal tips, and extravasated cytochylema. Meanwhile, bactericidal activities of TDDE were significantly higher than kanamycin and streptomycin in five bacteria, and the plant tissue experiments further demonstrated that it had an 88.31% RPE on walnut leaves infected with Xanthomonas campestris pv. jugiandis, 72.18% RPE on potato infected with Erwinia carotovora subsp. carotovora, and 82.50% RPE on kiwifruit branches infected with Pseudomonas syringae pv. actinidiae. The active compounds isolated from A. ordosica in this study show great potential value for developing broad-spectrum fungicides, and also provide an important way to identify and isolate new bioactive products from medicinal plants.

9.
ACS Synth Biol ; 10(10): 2628-2638, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34549587

RESUMO

Rational design and modification of autotrophic bacteria to efficiently produce high-value chemicals and biofuels are crucial for establishing a sustainable and economically viable process for one-carbon (C1) source utilization, which, however, remains a challenge in metabolic engineering. In this study, autotrophic Clostridium ljungdahlii was metabolically engineered to efficiently co-produce three important bulk chemicals, isopropanol, 3-hydroxybutyrate (3-HB), and ethanol (together, IHE), using syngas (CO2/CO). An artificial isopropanol-producing pathway was first constructed and optimized in C. ljungdahlii to achieve an efficient production of isopropanol and an unexpected product, 3-HB. Based on this finding, an endogenous active dehydrogenase capable of converting acetoacetate to 3-HB was identified in C. ljungdahlii, thereby revealing an efficient 3-HB-producing pathway. The engineered strain was further optimized to reassimilate acetic acid and synthesize 3-HB by introducing heterologous functional genes. Finally, the best-performing strain was able to produce 13.4, 3.0, and 28.4 g/L of isopropanol, 3-HB, and ethanol, respectively, in continuous gas fermentation. Therefore, this work represents remarkable progress in microbial production of bulk chemicals using C1 gases.

10.
Asian J Surg ; 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34366190

RESUMO

Robotic gastrectomy (RG) shows potential as an alternative to open gastrectomy (OG), the gold standard in the surgical management of gastric cancer (GC). This meta-analysis was conducted to compare the short-term efficacy and safety of RG versus OG for GC.A systematic literature search was conducted on RG with OG for GC in randomized and semi-randomized controlled trials and observational studies. Published materials and conference papers in English and trace references included in the literature were manually searched. The retrieval period was set to end in February 2021. The quality of the included studies was evaluated, and meta-analysis was conducted using the software STATA 15.1. Eleven studies with 6693 patients were included. Major blood loss (weighted mean differences (WMD) = -114.63, 95 % CI, -182.37-46.88, P = 0.001), hospital stay (WMD = -2.21, 95 % CI, -4.32-0.09, P = 0.041), and postoperative complications (odds ratio (OR) = OR = 0.57, 95 % CI, 0.35-0.93, P = 0.025) were fewer in the RS group, and R0 resection (odds ratio (OR) = 6.26, 95 % CI, 2.733-14.35, P = 0.000) occurred more frequently in the RG group than in the OG group. But positive lymph nodes (WMD = -2.09, 95 % CI,-3.73-0.45, P = 0.012) occurred less frequently in the RG group than in the OG group, and operative time was longer in the RG group than in the OG group (WMD = 83.21, 95 % CI, 19.88-146.55, P = 0.010). RG not only provides a technique for the treatment of GC but is also safe and feasible. This finding needs to be verified by multicenter, large-sample randomized controlled trials in the future.

11.
Front Microbiol ; 12: 703093, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34408734

RESUMO

The bacterial genus Streptomyces is an important source of antibiotics, and genome mining is a valuable tool to explore the potential of microbial biosynthesis in members of this genus. This study reports an actinomycete strain 135, which was isolated from Qinghai-Tibet Plateau in China and displayed broad antimicrobial activity. The fermentation broth of strain 135 displayed strong antifungal activity (>70%) against Sclerotinia sclerotiorum, Botrytis cinerea, Valsa mali, Phytophthora capsici, Glomerella cingulata, Magnaporthe grisea, Bipolaris maydis, Exserohilum turcicum in vitro, meanwhile possessed significant preventive and curative efficacy against S. sclerotiorum, Gaeumannomyces graminis, and P. capsici on rape leaves (54.04 and 74.18%), wheat (90.66 and 67.99%), and pepper plants (79.33 and 66.67%). X-14952B showed the greatest antifungal activity against S. sclerotiorum and Fusarium graminearum which the 50% inhibition concentration (EC50) were up to 0.049 and 0.04 µg/mL, respectively. Characterization of strain 135 using a polyphasic approach revealed that the strain displayed typical features of the genus Streptomyces. 16S rRNA gene sequencing and phylogenetic analysis demonstrated that the isolate was most closely related to and formed a clade with Streptomyces huasconensis HST28T (98.96% 16S rRNA gene sequence similarity). Average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) values in strain 135 and related type strains were both below the threshold of species determination (91.39 and 56.5%, respectively). OrthoANI values between strain 135 and related type strains are under the cutoff of determining species (<95%). The biosynthetic gene cluster (BGC) designated to X-14952B biosynthesis was identified through genome mining and the possible biosynthesis process was deduced.

12.
Front Med (Lausanne) ; 8: 724224, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34422872

RESUMO

Objective: HBV-related acute-on-chronic liver failure (HBV-ACLF) has a high mortality due to severe intrahepatic cholestasis and coagulation dysfunction, thus new treatment measures are urgently needed to improve the therapeutic effect. This study aimed to observe the efficacy of N-acetylcysteine (NAC) in the treatment of HBV-ACLF. Methods: The data of patients with HBV-ACLF admitted to West China Hospital from October 2019 to August 2020 were collected retrospectively, and they were divided into treatment group and control group according to whether they had received additional NAC treatment. The improvement of biochemistry, coagulation function and disease severity score after 14 days of hospitalization were analyzed between two groups. Results: A total of 90 HBV-ACLF patients were included, including 42 patients in treatment group and 48 patients in control group. Compared with baseline, serum TBil, DBil, TBA, GGT and ALP in two groups both decreased significantly, while PTA increased significantly. Interesting, the decrease of serum TBil, DBil and TBA and the increase of PTA in treatment group were all significantly than these in control group. Additionally, more patients in treatment group than control group changed from CTP grade C to grade B. Subgroup analysis of CTP grade C patients showed that the decrease of serum TBil, DBil and TBA and the increase of PTA in treatment group were significantly than these in control group. Conclusion: The NAC treatment may help to improve intrahepatic cholestasis and coagulation dysfunction of HBV-ACLF.

13.
Appl Biochem Biotechnol ; 193(12): 3936-3948, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34436750

RESUMO

Clavulanic acid (CA) is a naturally occurring antibiotic produced by Streptomyces clavuligerus. Statistical optimization of the fermentation medium for CA production by Streptomyces clavuligerus was carried out. Multiple carbon sources, glycerol, dextrin, and triolein, were considered simultaneously. A two-level fractional factorial design experiment was conducted to identify the significant components of medium on CA production. Statistical analysis of the results showed that soybean meal, dextrin, and triolein were the most significant medium ingredients on CA production. The optimal level of these screened components was obtained by RSM based on the result of a Box-Behnken design, in which the values of dextrin, soybean meal, and triolein in CA fermentation medium were 12.37 g/L, 39.75 g/L, and 26.98 ml/L, respectively. Using the proposed optimized medium, the model predicted 938 mg/L of CA level and via experimental rechecking the model, 946 mg/L of CA level was attained in shake flask fermentation, significantly high than 630 mg/L of original medium. The optimized medium was further verified in 50-L stirred fermenter, and compared with performance of original medium in parallel, CA titer was increased from 889 to 1310 mg/L; a 47% increase was achieved through medium optimization by statistical approaches.

14.
Appl Opt ; 60(20): 5953-5958, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34263817

RESUMO

We propose a new radial shearing speckle pattern interference system. The introduction of radial shearing and the four-step temporal phase shift are realized using a spatial light modulator to modulate the phase information of the light wavefront. The modulation mode of the spatial light modulator is controlled by programming, and thus the shearing information can be adjusted quickly and arbitrarily according to the actual measurement needs. The interference system no longer has the requirement of the defect direction in nondestructive testing and can simultaneously realize the accurate detection of defects in all directions. The basic principle of radial shearing speckle pattern interferometry and the introduction method of radial shearing are described, and the system feasibility and practicability are verified by experiments.

15.
Medicine (Baltimore) ; 100(28): e26556, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34260533

RESUMO

BACKGROUND: Currently, transcatheter aortic valve implantation (TAVI) as an effective and convenient intervention has been adopted extensively for patients with severe aortic disease. However, the efficacy and safety of TAVI have not yet been well evaluated and its noninferiority compared with traditional surgical aortic valve replacement (sAVR) still lack sufficient evidence. This meta-analysis was designed to comprehensively compare the noninferiority of TAVI with sAVR for patients with severe aortic disease. METHODS: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science up to October 1, 2020 was conducted for relevant studies that comparing TAVI and sAVR in the treatment of severe aortic disease. The primary outcomes were early, midterm and long term mortality. The secondary outcomes included early complications and other late outcomes. Two reviewers assessed trial quality and extracted the data independently. All statistical analyzes were performed using the standard statistical procedures provided in Review Manager 5.2. RESULTS: A total of 16 studies including 14394 patients were identified. There was no difference in 30-day, 1-year, 2-year, and 5-year all-cause or cardiovascular mortality as well as stroke between TAVI and sAVR. Regarding to the 30-day outcomes, compared with sAVR, TAVI experienced a significantly lower incidence of myocardial infarction (risk ratio [RR] 0.62; 95% confidence interval [CI] 0.40-0.97; 5441 pts), cardiogenic shock (RR 0.34; 95% CI 0.19-0.59; 1936 pts), acute kidney injury (AKI) > stage 2 (RR 0.37; 95% CI 0.25-0.54; 5371 pts), and new-onset atrial fibrillation (NOAF) (RR 0.29; 95% CI 0.24-0.35; 5371 pts) respectively, but higher incidence of permanent pacemaker implantation (RR 3.16; 95% CI 1.61-6.21; 5441 pts) and major vascular complications (RR 2.22; 95% CI 1.14-4.32; 5371 pts). Regarding to the 1- and 2-year outcomes, compared with sAVR, TAVI experienced a significantly lower incidence of NOAF, but higher incidence of neurological events, transient ischemic attacks (TIA), permanent pacemaker and major vascular complications respectively. Regarding to the 5-year outcomes, compared with sAVR, TAVI experienced a significantly lower incidence of NOAF, but higher incidence of TIA and reintervention respectively. CONCLUSIONS: Our analysis shows that TAVI was equal to sAVR in early, midterm and long term mortality for patients with severe aortic disease. In addition, TAVI may be favorable in reducing the incidence of both early, midterm and long term NOAF. However, pooled results showed superiority of sAVR in reducing permanent pacemaker implantation, neurological events, TIA, major vascular complications and reintervention.


Assuntos
Doenças da Aorta/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Doenças da Aorta/fisiopatologia , Comorbidade , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Marca-Passo Artificial , Complicações Pós-Operatórias/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodos
16.
Stem Cell Res Ther ; 12(1): 391, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34256842

RESUMO

BACKGROUND: Mesenchymal stem cells (MSCs) have to be expanded in vitro to reach a sufficient cell dose for the treatment of various diseases. During the process of expansion, some obstacles remain to be overcome. The purpose of this study was to investigate the effects of storage solutions and heterogeneity on the behavior of MSCs in vitro and in vivo. METHODS: Umbilical cord MSCs (UC-MSCs) of similar sizes within normal ranges were suspended in three different storage solutions, phosphate buffer solution, normal saline, and Dulbecco's modified Eagle medium. Then, the ultrastructure, viability, and safety of these cells were compared. Other two UC-MSC populations of different sizes were categorized based on their mean diameters. The ultrastructure, proliferation, immunosuppression, hepatic differentiation potential, and number of senescent cells were investigated and compared. The survival rates of mice after the infusion of UC-MSCs of different sizes were compared. RESULTS: For UC-MSCs suspended in different storage solutions, the cell apoptosis rates, ultrastructure, and survival rates of mice were similar, and no differences were observed. Cells with a diameter of 19.14 ± 4.89 µm were categorized as the larger UC-MSC population, and cells with a diameter of 15.58 ± 3.81 µm were categorized as the smaller population. The mean diameter of the larger UC-MSC population was significantly larger than that of the smaller UC-MSC population (p < 0.01). Smaller UC-MSCs had more powerful proliferation and immunosuppressive potential and a higher nucleus-cytoplasm ratio than those of large UC-MSCs. The number of cells positive for ß-galactosidase staining was higher in the larger UC-MSC population than in the smaller UC-MSC population. The survival rates of mice receiving 1 × 106 or 2 × 106 smaller UC-MSCs were 100%, both of which were higher than those of mice receiving the same amounts of larger UC-MSCs (p < 0.01). The cause of mouse death was explored and it was found that some larger UC-MSCs accumulated in the pulmonary capillary in dead mice. CONCLUSION: Different storage solutions showed no significant effects on cell behavior, whereas heterogeneity was quite prevalent in MSC populations and might limit cells application. Hence, it is necessary to establish a more precise standardization for culture-expanded MSCs.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Apoptose , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Camundongos , Cordão Umbilical
17.
DNA Cell Biol ; 40(8): 1101-1111, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34156283

RESUMO

Chronic myeloid leukemia (CML) is characterized by the formation of the BCR-ABL fusion gene. The BCR-ABL protein leads to an increased level of reactive oxygen species, which is a major cause of endogenous DNA double-strand breaks (DSBs). CML cells are prone to rely on a highly mutagenic alternative end-joining (Alt-EJ) pathway to cope with enhanced DSBs, which aggravates chromosomal instability. Hence, targeting dysregulated DNA repair proteins provides new insights into cancer treatment. In this study, we discovered the abnormal upregulation of Flap endonuclease 1 (FEN1) in CML, as well as FEN1's participation in the error-prone Alt-EJ repair pathway and its interplay with DNA Ligase1 and proliferating cell nuclear antigen in DSB repair. Knockdown of FEN1 by shRNA not only inhibited the proliferation and induced apoptosis but also enhanced the efficacy of imatinib (IM) in drug-resistant CML cell K562/G01. Moreover, excessive DSB accumulation was detected after FEN1 inhibition. In summary, our results demonstrated that FEN1 is a promising therapeutic target in CML treatment. This work extends the understanding of regulating abnormal DSB repair for cancer treatment.


Assuntos
Proliferação de Células , Reparo do DNA por Junção de Extremidades , Endonucleases Flap/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Antineoplásicos/toxicidade , Apoptose , Células Cultivadas , DNA Ligase Dependente de ATP/metabolismo , Resistencia a Medicamentos Antineoplásicos , Endonucleases Flap/metabolismo , Células HEK293 , Humanos , Mesilato de Imatinib/toxicidade , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Células THP-1
18.
Sci Total Environ ; 773: 145264, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33940722

RESUMO

The atmospheric oxidation capacity (AOC) and photochemical reactivity are of increasing concern owing to their roles in photochemical pollution. The AOC and OH reactivity were evaluated based on simultaneous measurements of volatile organic compounds (VOCs), trace gases and photolysis frequency during summer and winter campaigns at a suburban site in Xianghe. The AOC exhibited well-defined seasonal and diurnal patterns, with higher intensities during the summertime and daytime than during the wintertime and nighttime, respectively. The major reductants contributing to the AOC during the summertime were CO (41%) and alkenes (41%), whereas CO (40%) and oxygenated VOCs (OVOCs) (30%) dominated the AOC during the wintertime. The dominant oxidant contributor to the AOC during the daytime was OH (≥93%), while the contributions of O3 and NO3 (≥75%) to the AOC increased during the nighttime. High values during the wintertime and an increase at night were features of the speciated OH reactivity. Inorganic compounds (NOx and CO) dominated the speciated OH reactivity (76% and 85% during the summer and winter campaigns, respectively). Among VOCs, the dominant contributors were alkenes (12%) and OVOCs (7%) during the summer and winter campaigns, respectively. The ratio of NOx- and VOC-attributed OH reactivity indicated that O3 formation occurred under a VOC-limited regime during the summertime and that aromatics had the largest potential to form O3. Isoprene and m/p-xylene were the most important contributors to the AOC, OH reactivity and O3-forming among VOCs during the summertime, biogenic sources and secondary formation and industrial production were the main sources of these species. During the wintertime, hexanal and ethylene were the key VOC species contributing to the AOC and OH reactivity, and solvent usage and traffic-related emissions were the main contributing sources. We recommend that priority measures for the control of VOC species and sources should be taken when suitable. CAPSULE: This study focused on the similarities and differences in the AOC and speciated OH reactivity during summer and winter campaigns.

19.
Eur J Pharm Sci ; 163: 105868, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33951483

RESUMO

Ceftazidime is a third-generation cephalosporin with high activity against many pathogens. But the ambiguity and diversity of the dosing regimens in neonates and young infants impair access to effective treatment. Thus, we conducted a population pharmacokinetic study of ceftazidime in this vulnerable population and recommended a model-based dosage regimen to optimize sepsis therapy. Totally 146 neonates and young infants (gestational age (GA): 36-43.4 weeks, postnatal age (PNA): 1-81 days, current weight (CW): 900-4500 g) were enrolled based on inclusion and exclusion criteria. Ceftazidime bloods samples (203) were obtained using the opportunistic sampling strategy and determined by the high-performance liquid chromatography. The population pharmacokinetic-pharmacodynamic analysis was conducted by nonlinear mixed effects model (NONMEM). A one-compartment model with first-order elimination best described the pharmacokinetic data. Covariate analysis showed the significance of GA, PNA, and CW on developmental pharmacokinetics. Monte Carlo simulation was performed based on above covariates and minimum inhibitory concentration (MIC). In the newborns with PNA ≤ 3 days (MIC=8 mg/L), the dose regimen was 25 mg/kg twice daily (BID). For the newborns with PNA > 3 days (MIC=16 mg/L), the optimal dose was 30 mg/kg three times daily (TID) for those with GA ≤ 37 weeks and 40 mg/kg TID for those with GA > 37 weeks. Overall, on the basis of the developmental population pharmacokinetic-pharmacodynamic analysis covering the whole range of neonates and young infants, the evidence-based ceftazidime dosage regimens were proposed to optimize neonatal early-onset and late-onset sepsis therapy.


Assuntos
Sepse Neonatal , Sepse , Antibacterianos/uso terapêutico , Ceftazidima , Humanos , Lactente , Recém-Nascido , Testes de Sensibilidade Microbiana , Método de Monte Carlo , Sepse Neonatal/tratamento farmacológico , Sepse/tratamento farmacológico
20.
New Phytol ; 231(3): 1073-1087, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34042184

RESUMO

Rice (Oryza sativa) tiller angle is a key component for achieving ideal plant architecture and higher grain yield. However, the molecular mechanism underlying rice tiller angle remains elusive. We characterized a novel rice tiller angle mutant lazy2 (la2) and isolated the causative gene LA2 through map-based cloning. Biochemical, molecular and genetic studies were conducted to elucidate the LA2-involved tiller angle regulatory mechanism. The la2 mutant shows large tiller angle with impaired shoot gravitropism and defective asymmetric distribution of auxin. We found that starch granules in amyloplasts are completely lost in the gravity-sensing leaf sheath base cells of la2, whereas the seed development is not affected. LA2 encodes a novel chloroplastic protein that can interact with the starch biosynthetic enzyme Oryza sativa plastidic phosphoglucomutase (OspPGM) to regulate starch biosynthesis in rice shoot gravity-sensing cells. Genetic analysis showed that LA2 regulates shoot gravitropism and tiller angle by acting upstream of LA1 to mediate lateral auxin transport. Our studies revealed that LA2 acts as a novel regulator of rice tiller angle by specifically regulating starch biosynthesis in gravity-sensing cells, and established the framework of the starch-statolith-dependent rice tiller angle regulatory pathway, providing new insights into the rice tiller angle regulatory network.


Assuntos
Oryza , Regulação da Expressão Gênica de Plantas , Gravitropismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Amido
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...