Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 481
Filtrar
1.
Opt Lett ; 48(3): 526-529, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36723522

RESUMO

Air lasing induced by laser filamentation opens a new route for research on atmospheric molecular physics and remote sensing. The generation of air lasing is composed of two processes, i.e., building up optical gain of air molecules in femtosecond time scale and emitting coherent radiation in picosecond time scale. Here, we focus on the emission mechanisms of N2 + air lasing and reveal, by examining the intensities and temporal profiles of N2 + lasing at 391 nm generated respectively in a time-varying polarization-modulated and a linearly polarized pump laser field under different nitrogen gas pressures, that the N2 + lasing can emit through either triggered super-radiance or seed amplification. We find that the two pressure-sensitive factors, i.e., the dipole dephasing time T2 and the population inversion density n, determine which of these two mechanisms dominates the N2 + lasing emission process, enabling manipulation of the transition from triggered super-radiance to seed amplification or vice versa. Our findings clarify the emission mechanism of N2 + lasing under different pressures and provide a deeper understanding of N2 + air lasing not only in the establishment of optical gain but also in the lasing emission process.

2.
Adv Sci (Weinh) ; : e2205262, 2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-36709476

RESUMO

Glutathione S-transferase pi (GSTP1), a phase II detoxification enzyme, is known to be overexpressed and mediates chemotherapeutic resistance in lung cancer. However, whether GSTP1 supports cancer stem cells (CSCs) and the underlying mechanisms in lung adenocarcinoma (LUAD) remain largely unknown. This study unveiled that GSTP1 is upregulated in lung CSCs and supports tumor self-renewal, metastasis, and resistance to targeted tyrosine kinase inhibitors of LUAD both in vitro and in vivo. Mechanistically, CaMK2A (calcium/calmodulin-dependent protein kinase 2 isoform A)/NRF2 (nuclear factor erythroid 2-related factor 2)/GSTP1 is uncovered as a regulatory axis under hypoxia. CaMK2A increased GSTP1 expression through phosphorylating the Sersine558 residue of NRF2 and promoting its nuclear translocation, a novel mechanism for NRF2 activation apart from conventional oxidization-dependent activation. Upregulation of GSTP1 in turn suppressed reactive oxygen species levels and supported CSC phenotypes. Clinically, GSTP1 analyzed by immunohistochemistry is upregulated in a proportion of LUAD and serves as a prognostic marker for survival. Using patient-derived organoids from an ALK-translocated LUAD, the therapeutic potential of a specific GSTP1 inhibitor ezatiostat in combination treatment with the ALK inhibitor crizotinib is demonstrated. This study demonstrates GSTP1 to be a promising therapeutic target for long-term control of LUAD through targeting CSCs.

3.
Environ Pollut ; 320: 121101, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36669720

RESUMO

Understanding particle size distribution and size-resolved gas-particle partitioning of semi-volatile organic compounds (SVOCs) is important for characterizing their fate in atmosphere. However, the size-resolved gas-particle partitioning characteristics of SVOCs has not been adequately considered. To address this issue, the present study collected gaseous and size-fractioned particulate samples both in and outside of schools, offices, and residences in three districts of different urbanization levels in a megacity, Guangzhou, South China during two seasons. Typical SVOCs, including 15 polycyclic aromatic hydrocarbons (PAHs), six organophosphate esters and seven phthalic acid esters were measured. Emission sources, physicochemical properties, and environmental conditions at the sampling sites considerably impacted the spatiotemporal distribution patterns and particle size distribution of target SVOCs. Not all observed gas-particle partition coefficients (Kp) of target SVOCs were negatively correlated with subcooled liquid-vapor pressures (PL0), probably because certain factors, such as the non-exchangeable part of the particle-bound SVOCs, were not considered in traditional gas-particle partition theories. Particle size was an important factor affecting gas-particle partitioning. Adsorption was the dominant mechanism for PAHs with high molecular weight in different particle modes. A new model was established to predict size-resolved Kp of PAHs with high molecular weight based on PL0 and particle size.

4.
Transl Psychiatry ; 13(1): 16, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658152

RESUMO

Aerobic exercise effectively relieves anxiety disorders via modulating neurogenesis and neural activity. The molecular mechanism of exercise-mediated anxiolysis, however, remains incomplete. On a chronic restrain stress (CRS) model in adolescent mice, we showed that 14-day treadmill exercise profoundly maintained normal neural activity and axonal myelination in the medial prefrontal cortex (mPFC), in association with the prevention of anxiety-like behaviors. Further interrogation of molecular mechanisms revealed the activation of the mechanistic target of the rapamycin (mTOR) pathway within mPFC under exercise training. At the upstream of mTOR, exercise-mediated brain RNA methylation inhibited the expression of Fragile X mental retardation protein (FMRP) to activate the mTOR pathway. In summary, treadmill exercise modulates an FMRP-mTOR pathway to maintain cortical neural activity and axonal myelination, contributing to improved stress resilience. These results extended our understanding of the molecular substrate of exercise-mediated anxiolytic effect during adolescent period.


Assuntos
Proteína do X Frágil de Retardo Mental , Condicionamento Físico Animal , Estresse Psicológico , Serina-Treonina Quinases TOR , Animais , Camundongos , Axônios/metabolismo , Encéfalo/metabolismo , Proteína do X Frágil de Retardo Mental/genética , Serina-Treonina Quinases TOR/metabolismo , Ansiedade
5.
iScience ; 26(1): 105740, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36594014

RESUMO

The function of the cancer-associated lncRNA Malat1 during aging is as-of-yet uncharacterized. Here, we show that Malat1 interacts with Nucleophosmin (NPM) in young mouse brain, and with Lamin A/C, hnRNP C, and KAP1 with age. RNA-seq and RT-qPCR reveal a persistent expression of Malat1_2 (the 3'isoform of Malat1) in Malat1Δ1 (5'-1.5 kb deletion) mouse retinas and brains at 1/4th level of the full-length Malat1, while Malat1_1 (the 5'isoform) in Malat1Δ2 (deletion of 3'-conserved 5.7 kb) at a much lower level, suggesting an internal promoter driving the 3' isoform. The 1774 and 496 differentially expressed genes in Malat1Δ2 and Malat1Δ1 brains, respectively, suggest the 3' isoform regulates gene expression in trans and the 5' isoform in cis. Consistently, Malat1Δ2 mice show increased age-dependent retinal oxidative stress and corneal opacity, while Malat1Δ1 mice show no obvious phenotype. Collectively, this study reveals a physiological function of the lncRNA Malat1 3'-isoform during the aging process.

6.
Org Lett ; 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36717216

RESUMO

In this new procedure, amide-containing indolo[2,1-a]isoquinoline scaffolds were prepared by palladium-catalyzed carbonylative cyclization of alkene-tethered indoles with nitroarenes. By using Mo(CO)6 as the CO source and reductant and nitroarenes as the nitrogen source, this reaction produced various amide-containing indolo[2,1-a]isoquinoline derivatives in good yields in general. Furthermore, the late-stage modifications of bioactive molecules using this protocol were demonstrated as well.

7.
Chem Mater ; 35(2): 755-763, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36711054

RESUMO

High carrier mobility is critical to improving thermoelectric performance over a broad temperature range. However, traditional doping inevitably deteriorates carrier mobility. Herein, we develop a strategy for fine tuning of defects to improve carrier mobility. To begin, n-type PbTe is created by compensating for the intrinsic Pb vacancy in bare PbTe. Excess Pb2+ reduces vacancy scattering, resulting in a high carrier mobility of ∼3400 cm2 V-1 s-1. Then, excess Ag is introduced to compensate for the remaining intrinsic Pb vacancies. We find that excess Ag exhibits a dynamic doping process with increasing temperatures, increasing both the carrier concentration and carrier mobility throughout a wide temperature range; specifically, an ultrahigh carrier mobility ∼7300 cm2 V-1 s-1 is obtained for Pb1.01Te + 0.002Ag at 300 K. Moreover, the dynamic doping-induced high carrier concentration suppresses the bipolar thermal conductivity at high temperatures. The final step is using iodine to optimize the carrier concentration to ∼1019 cm-3. Ultimately, a maximum ZT value of ∼1.5 and a large average ZT ave value of ∼1.0 at 300-773 K are obtained for Pb1.01Te0.998I0.002 + 0.002Ag. These findings demonstrate that fine tuning of defects with <0.5% impurities can remarkably enhance carrier mobility and improve thermoelectric performance.

8.
Artigo em Inglês | MEDLINE | ID: mdl-36631619

RESUMO

Bidens pilosa L. has been confirmed to be a potential Cd hyperaccumulator by some researchers, but the dynamic and real-time uptake of Cd2+ influx by B. pilosa root apexes was a conundrum up to now. The aim of our study was to investigate the effects of salinity and pH variations on the characteristics of Cd2+ influx around the root apexes of B. pilosa. The tested seedlings of B. pilosa were obtained by sand culture experiments in a greenhouse after 1 month from germination, and the Cd2+ influxes from the root apex of B. pilosa under Cd treatments with different salinity and pH levels were determined with application of non-invasive micro-test technology (NMT). The results showed that Cd2+ influxes at 300 µm from the root tips decreased under Cd treatments with 5 mM and 10 mM NaCl, as compared to Cd stress alone. However, Cd treatments with 2.5 mM NaCl had little effect on the net Cd2+ influxes, as compared to Cd treatments alone. Importantly, Cd treatments at pH = 4.0 markedly increased Cd2+ influxes in roots, and Cd treatment at pH = 7.0 had no significant effect on the net Cd2+ influxes compared to Cd treatments at pH = 5.5. Results also showed that Cd treatments with 10 mM NaCl significantly decreased concentrations of chlorophyll (Chl) a and b in leaves and root vigor of B. pilosa relative to Cd treatments alone, while there were no significant differences between Cd treatments with 2.5 mM NaCl and Cd treatments alone. But root vigor was inhibited significantly under Cd treatments with 5 mM and 10 mM NaCl. A significant increase of root vigor was observed in Cd treatments at pH = 4.0, as compared to pH = 5.5. The Cd treatments with high and medium concentrations of NaCl inhibited the uptake of Cd by B. pilosa roots and affected the Chl and root vigor further. But the Cd treatments at pH = 4.0 could promote the Cd uptake and root vigor. Our results revealed the uptake mechanisms of B. pilosa as a potential phytoremediator under different salinity and pH levels combined with Cd contamination and provided a new idea for screening ideal hyperaccumulator and constructing evaluation system.

9.
Sci Total Environ ; : 161721, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36682571

RESUMO

Microbial electrolysis cell coupled with anaerobic digestion (MEC-AD) is currently encountering constraints on electromethanogenesis. The electrode configuration modification can be a simple yet efficient way to improve electromethanogenesis. This study evaluated two coaxial electrode configurations (large anode and small cathode: A10C1; small anode and large cathode: A1C10) using carbon felt as the electrode material. At an external voltage of 1.7 V, CH4 content was found exclusively higher in A1C10 (11 % and 13 % higher for acetate-fed and cow manure-fed, respectively) than that of the control reactors. Consequently, CH4 production was 13 % and 29 % higher in acetate-fed and CM-fed A1C10, respectively. The strengthened electromethanogenesis was attributed to the enrichment of interspecies hydrogen transfer microbes (i.e., Mesotoga and Bathyarchaeia). The coaxial configuration with a large cathode surface area demonstrated a viable stereotype in MEC-AD for improved waste treatment and energy recovery.

10.
Phys Med Biol ; 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36634371

RESUMO

OBJECTIVE: Proton therapy as the next generation radiation-based cancer therapy offers dominant advantages over conventional radiation therapy due to the utilization of the Bragg peak; however, range uncertainty in beam delivery substantially mitigates the advantages of proton therapy. This work reports using protoacoustic measurements to determine the location of proton Bragg peak deposition within a water phantom in real time during beam delivery. APPROACH: In protoacoustics, proton beams have a definitive range, depositing a majority of the dose at the Bragg peak; this dose is then converted to heat. The resulting thermoelastic expansion generates a 3D acoustic wave, which can be detected by acoustic detectors to localize the Bragg peak. MAIN RESULTS: Protoacoustic measurements were performed with a synchrocyclotron proton machine over the exhaustive energy range from 45.5MeV to 227.15MeV in clinic. It was found that the amplitude of the acoustic waves is proportional to proton dose deposition, and therefore encodes dosimetric information. With the guidance of protoacoustics, each individual proton beam (7pC/pulse) can be directly visualized with sub-millimeter (<0.7 mm) resolution using single beam pulse for the first time. SIGNIFICANCE: The ability to localize the Bragg peak in real-time and obtain acoustic signals proportional to dose within tumors could enable precision proton therapy and hope to progress towards in-vivo measurements.

11.
Ear Nose Throat J ; : 1455613221115142, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36651145

RESUMO

Nodular fasciitis(NF) is a proliferative disease of fibroblasts and myofibroblasts that generally affects subcutaneous tissue, muscle tissue, and fascia. NF usually occurs in young adults aged 20-40 and is more common in the upper extremities and relatively rare in the region of the head and neck. Here, we report on two patients with NF in the ear and nose. Under general anesthesia, the masses of NF were completely resected along the safety margin. The patients recovered well after surgery and there was no recurrence after more than half a year of follow-up.

12.
Bioresour Technol ; 369: 128461, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36503086

RESUMO

Solid-state anaerobic digestion (SSAD) is vulnerable to excess volatile fatty acids (VFA), mainly acetate and propionate. The co-effects of VFAs and microbial dynamics under VFA accumulation were investigated in SSAD of pig manure and corn straw. Adding 2 and 4 mg/g acetate or propionate caused initial increases in total VFAs, followed by decreases after day 6, resulting in 'mild' VFA accumulation, while adding 6 mg/g caused similarly increased VFAs, but with no subsequent decrease, causing 'severe' VFA accumulation and poor methanation performance. Mild propionate accumulation promoted acetate consumption, whereas acetate accumulation inhibited propionate degradation by affecting crucial redox reactions. Under severe VFA accumulation, hydrolysis and acidification mainly conducted by acid-tolerant Clostridium sp. exacerbated VFA inhibition, causing a competition between Methanosarcina and Methanosaeta, and impairments of acetoclastic and hydrogenotrophic methanogenesis and interspecies formate transfer. This study provides new insights into mechanisms of VFA accumulation in SSAD, and its effects on methanogenesis.


Assuntos
Microbiota , Propionatos , Animais , Suínos , Propionatos/metabolismo , Anaerobiose , Reatores Biológicos , Metano/metabolismo , Ácidos Graxos Voláteis/metabolismo , Acetatos , Redes e Vias Metabólicas
13.
Environ Res ; 216(Pt 3): 114670, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36341794

RESUMO

The global expansion of cyanobacterial blooms poses a major risk to the safety of freshwater resources. As a result, many explorations have been performed at a regional scale to determine the underlying impact mechanism of cyanobacterial blooms for one or several waterbodies. However, two questions still need to be answered quantitatively at a global scale to assist the water management. One is to specify which factors were often selected as the driving forces of cyanobacterial blooms, and the other is to estimate their quantitative relationships. For that, this paper applied a systematic literature review for 41 peer-reviewed studies published before May 2021 and a statistical meta-analysis based on the Pearson's or Spearman's correlation coefficients from 27 studies. These results showed that the water quality, hydraulic conditions, meteorological conditions and nutrient levels were often considered the driving forces of cyanobacterial blooms in global freshwater systems. Among these, meteorological conditions and nutrient level had the highest probability of being chosen as the driving force. In addition, knowledge of the quantitative relationships between these driving forces and cyanobacterial blooms was newly synthesized based on the correlation coefficients. The results indicated that, at a global scale, meteorological conditions were negatively related to cyanobacterial blooms, and other driving forces, such as water quality, hydraulic conditions and nutrient levels, were positively related to cyanobacterial blooms. In addition, the measurement indicators of these driving forces had diverse forms. For example, the nutrient level can be measured by the concentration of different forms of nitrogen or phosphorus, which may lead to different results in correlation analysis. Thus, a subgroup meta-analysis was necessary for the subdivided driving forces and cyanobacterial blooms, which had a better accuracy. Overall, the synthesized knowledge can help guide advanced cyanobacteria-centered water management, especially when the necessary cyanobacterial data of targeting waterbodies are inaccessible.


Assuntos
Cianobactérias , Eutrofização , Água Doce/microbiologia , Qualidade da Água , Fósforo/análise , Lagos/microbiologia
14.
Phys Chem Chem Phys ; 25(3): 2012-2018, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36541670

RESUMO

In recent years, a new two-dimensional carbon material, graphdiyne (GDY), has attracted extensive attention in the field of energy storage, due to its unique topological and electronic structures, high charge mobility, and excellent electron transport properties. However, the disappearance of the density of states near the Fermi level leads to a low quantum capacitance (CQ) of pristine GDY, which limits its application in supercapacitors. Here, we propose doping and metal atom adsorption to be efficient ways to increase the CQ of GDY. Based on first-principles density functional theory, the effects of doping B, N, P, and S atoms and adsorbing Au, Ag, Cu, Ti, and Al atoms on the CQ of GDY are systematically investigated. The results show that the CQ of GDY can be significantly improved by introducing doping/adsorption, which could be a potential cathode material and anode material for supercapacitors. Our work provides an effective way for GDY to be applied as an efficient electrode material for supercapacitors.

15.
Zhongguo Zhong Yao Za Zhi ; 47(20): 5584-5590, 2022 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-36471976

RESUMO

Danzhi Xiaoyao Powder is a classical prescription for anxiety. This study aims to analyze the effect of this medicine on mitochondrial morphology and function of anxiety rats and explore the mechanism of it against anxiety. Specifically, uncertain empty bottle drinking water stimulation(21 days) was employed to induce anxiety in rats. The elevated plus-maze test and open field test were respectively performed on the 7 th, the 14 th, and the 21 st days of the stimulation, so as to detect the anxiety-related protein index brain-derived neurotrophic factor(BDNF) and evaluate the anxiety level of animals. On this basis, the effect of this prescription on anxiety rats was preliminarily evaluated. After the behavioral test on the 21 st day, rats were killed and the brain tissues were separated for the observation of the mitochondrial morphology and the determination of mitochondrial function-related indicators and the adenosine 5'-monophosphate-activated protein kinase(AMPK) level. The results showed that Danzhi Xiaoxiao Powder could alleviate the anxiety-like behavior of rats, significantly increase the percentage of time in open arm in elevated plus-maze test and the ration of activity time in the central area of the field, dose-dependently raise the activity levels of respiratory chain complex Ⅰ,Ⅱ,Ⅲ and Ⅳ and the adenosine triphosphate(ATP) content, and elevate the levels of BDNF and phosphorylated AMPK(p-AMPK). Clear structure and intact morphology of mitochondrial cristae in medial prefrontal cortex cells and amygdala were observed in the Danzhi Xiaoyao Powder group. In summary, Danzhi Xiaoyao Powder exerts therapeutic effect on anxiety, and the mechanism is the likelihood that p-AMPK protects the structure and maintains the function of mitochondria.


Assuntos
Proteínas Quinases Ativadas por AMP , Fator Neurotrófico Derivado do Encéfalo , Ratos , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Pós , Ansiedade/tratamento farmacológico , Mitocôndrias
17.
Anim Genet ; 2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36478437

RESUMO

microRNAs (miRNAs) are well known to be important in mammalian female fertility. However, the genetic regulation of miRNAs associated with female fertility remains largely unknown. Here, we report that two single-nucleotide variants (SNVs) in the miR-23a promoter strongly influence miR-23a transcription and function in granulosa cell (GC) apoptosis. Two novel SNVs, g.-283G>C and g.-271C>T, were detected in the porcine miR-23a promoter by pooled-DNA sequencing. Furthermore, SNVs in the promoter region influenced miR-23a transcription in porcine GCs by altering its promoter activity. Functionally, SNVs in the promoter strongly influenced miR-23a regulation of early apoptosis in porcine GCs cultured in vitro. In addition, a preliminary association analysis showed that the combined genotypes of the two SNVs, rather than a single SNV, were tentatively associated with sow fertility traits in a Large White population. Overall, our findings suggest that the SNVs g.-283G>C and g.-271C>T in the miR-23a promoter are causal variants affecting GC apoptosis and miR-23a may be a potential small-molecule nonhormonal drug for regulating female fertility.

18.
Neurotrauma Rep ; 3(1): 522-533, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36479365

RESUMO

Spinal cord injury (SCI) leads to cardiovascular dysregulation, including persistent low blood pressure (BP), orthostatic hypotension, and autonomic dysreflexia, leading to daily BP instability that may not be adequately recognized. We compared mean systolic BP, diastolic BP, and heart rate from awake and asleep measurements over a 24-h period among persons with chronic SCI (n = 33; 30 cervical injuries and three upper thoracic injuries), ambulatory/non-injured (Ambulatory-NI; n = 13), and non-injured (NI) in a wheelchair (n = 9). Stability of awake BP was evaluated by deviation of systolic BP from 115 mmHg and percent of systolic BP measurement within and outside of 90-140 mmHg. Variability over 24 h was compared using coefficient of variation and average real variability. Awake hyper- and hypotensive events (change in systolic BP ±20 mmHg from the median) were compared to symptoms reported by the participants corresponding to BP events. Participants with SCI had a lower percentage of awake systolic BP measurements within 90-140 mmHg than Ambulatory-NI and a greater deviation below 115 mmHg. Coefficient of variation and successive differences of awake systolic and diastolic BP were greater in SCI than Ambulatory-NI. Finally, all SCI participants had hyper- and/or hypotensive events and 88% experienced the BP events asymptomatically. In conclusion, participants with SCI had significantly greater BP instability compared with NI, with many hyper- and hypotensive events occurring without symptoms. Clinical management of BP instability, regardless of symptoms, should be a priority after SCI to reduce the risk of cardiovascular disease and improve quality of life.

19.
BMC Infect Dis ; 22(1): 944, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36527077

RESUMO

BACKGROUND: Transmission-blocking vaccines (TBVs) target the sexual stages of malaria parasites to reduce or interrupt the transmission cycle in human and mosquito populations. The genetic diversity of TBVs candidate antigens, Pvs25 and Pvs28, in Plasmodium vivax could provide evidence for the development of TBVs. METHODS: Dry blood spots from P. vivax patients were collected from Dandong, Suining, Hainan, Nyingchi, Tengchong, and Yingjiang in China. The pvs25 and pvs28 genes were amplified and sequenced. The genetic diversity of pvs25 and pvs28 were analyzed using DNASTAR, MEGA6, and DnaSP 5.0 programs. RESULTS: A total of 377 samples were collected, among which 324 and 272 samples were successfully amplified in the pvs25 and pvs28 genes, respectively. Eight haplotypes were identified in Pvs25, for which the predominant mutation was I130T with 100% prevalence. A variety of 22 haplotypes in Pvs28 were identified. The number of GSGGE/D repeats of Pvs28 was a range of 4-8, among which, high (7-8) and low (4-5) copy numbers of tandem repeats were found in haplotypes H2 and H17, respectively. The nucleotide diversity of pvs28 (π = 0.00305 ± 0.00061) was slightly higher than that of pvs25 (π = 0.00146 ± 0.00007), thus they were not significantly different (P > 0.05). The Tajima's D value of pvs25 was positive whereas pvs28 was negative, which indicated that both genes were affected by natural selection. CONCLUSION: The genetic diversity of pvs25 and pvs28 genes in China was relatively limited, which provided valuable information for TBVs design and optimization.


Assuntos
Vacinas Antimaláricas , Malária Vivax , Animais , Humanos , Plasmodium vivax , Vacinas Antimaláricas/genética , Antígenos de Protozoários/genética , DNA de Protozoário/genética , Antígenos de Superfície/genética , Polimorfismo Genético , Malária Vivax/prevenção & controle , Malária Vivax/parasitologia , Proteínas de Protozoários/genética , Variação Genética
20.
Molecules ; 27(24)2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36557890

RESUMO

We describe the carbonylation of a series of mono and dihydroxy derivatives of polyfluorinated alkylbenzenes and benzocycloalkenes with OH groups at benzylic positions using carbon monoxide in the presence of a superacid (TfOH, a TfOH-SbF5 mixture, or a FSO3H-SbF5 mixture). It was shown that the superacid-catalyzed addition of CO to various primary and secondary polyfluorinated alcohols and diols gives the corresponding mono- and dicarboxylic acids or lactones. The efficiency of various superacids depending on alcohol structure was evaluated, and FSO3H-SbF5 yielded the best results in most transformations. The addition of CO to secondary 1-arylalkan-1-ols containing vicinal fluorine atoms was found to be accompanied by elimination of HF with the formation of α,ß-unsaturated aryl-carboxylic acids. In contrast to primary and secondary alcohols, conversion of tertiary perfluoro-1,1-diarylalkan-1-ols into carbonylation products is not complete, and the resulting carboxylic acids are easily decarboxylated after water treatment of the reaction mixture.


Assuntos
Ácidos Dicarboxílicos , Etanol , Estrutura Molecular , Monóxido de Carbono
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...