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1.
J Am Chem Soc ; 145(40): 22031-22040, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37774121

RESUMO

The selective functionalization of C(sp3)-H bonds has emerged as a transformative approach for streamlining synthetic routes, offering remarkable efficiency in the preparation and modification of complex organic molecules. However, the direct enantioselective transformation of hydrocarbons to medicinally valuable chiral molecules remains a significant challenge that has yet to be addressed. In this study, we adopt an atom transfer radical coupling (ATRC) strategy to achieve the asymmetric functionalization of C(sp3)-H bonds in hydrocarbons. This approach involves intermolecular H atom transfer (HAT) between a hydrocarbon and an alkoxy radical, leading to the formation of a carbon-centered radical. The resulting radical adds to alkenes, generating a new radical species that is intercepted by a chiral copper-mediated C-O bond coupling. By employing this method, we can directly access valuable chiral lactones bearing a quaternary stereocenter with high efficiency and excellent enantioselectivity. Importantly, ATRC exhibits great potential as a versatile platform for achieving stereoselective transformations of hydrocarbons.

2.
MedComm (2020) ; 4(2): e229, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36891351

RESUMO

Interleukin 37 (IL-37), a member of the IL-1 family, is considered a suppressor of innate and adaptive immunity and, hence is a regulator of tumor immunity. However, the specific molecular mechanism and role of IL-37 in skin cancer remain unclear. Here, we report that IL-37b-transgenic mice (IL-37tg) treated with the carcinogenic 7,12-dimethylbenzoanthracene (DMBA)/12-o-tetradecylphorbol-13-acetate (TPA) exhibited enhanced skin cancer and increased tumor burden in the skin by inhibiting the function of CD103+ dendritic cells (DCs). Notably, IL-37 induced rapid phosphorylation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), and via single immunoglobulin IL-1-related receptor (SIGIRR), inhibited the long-term Akt activation. Specifically, by affecting the SIGIRR-AMPK-Akt signaling axis, which is related to the regulation of glycolysis in CD103+DCs, IL-37 inhibited their anti-tumor function. Our results show that a marked correlation between the CD103+DC signature (IRF8, FMS-like tyrosine kinase 3 ligand, CLEC9A, CLNK, XCR1, BATF3, and ZBTB46) and chemokines C-X-C motif chemokine ligand 9, CXCL10, and CD8A in a mouse model with DMBA/TPA-induced skin cancer. In a word, our results highlight that IL-37 as an inhibitor of tumor immune surveillance through modulating CD103+DCs and establishing an important link between metabolism and immunity as a therapeutic target for skin cancer.

3.
Biomolecules ; 13(1)2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36671543

RESUMO

The pollen coat is the outermost domain of the pollen grain and is largely derived from the anther tapetum, which is a secretory tissue that degenerates late in pollen development. By being localised at the interface of the pollen-stigma interaction, the pollen coat plays a central role in mediating early pollination events, including molecular recognition. Amongst species of the Brassicaceae, a growing body of data has revealed that the pollen coat carries a range of proteins, with a number of small cysteine-rich proteins (CRPs) being identified as important regulators of the pollen-stigma interaction. By utilising a state-of-the-art liquid chromatography/tandem mass spectrometry (LC-MS/MS) approach, rich pollen coat proteomic profiles were obtained for Arabidopsis thaliana, Arabidopsis lyrata, and Brassica oleracea, which greatly extended previous datasets. All three proteomes revealed a strikingly large number of small CRPs that were not previously reported as pollen coat components. The profiling also uncovered a wide range of other protein families, many of which were enriched in the pollen coat proteomes and had functions associated with signal transduction, cell walls, lipid metabolism and defence. These proteomes provide an excellent source of molecular targets for future investigations into the pollen-stigma interaction and its potential evolutionary links to plant-pathogen interactions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Brassica , Arabidopsis/metabolismo , Proteoma/metabolismo , Cisteína/metabolismo , Proteômica , Cromatografia Líquida , Espectrometria de Massas em Tandem , Pólen/metabolismo , Brassica/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
4.
Asian J Androl ; 25(2): 179-183, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36537376

RESUMO

Management and treatment of terminal metastatic castration-resistant prostate cancer (mCRPC) remains heavily debated. We sought to investigate the efficacy of programmed cell death 1 (PD-1) inhibitor plus anlotinib as a potential solution for terminal mCRPC and further evaluate the association of genomic characteristics with efficacy outcomes. We conducted a retrospective real-world study of 25 mCRPC patients who received PD-1 inhibitor plus anlotinib after the progression to standard treatments. The clinical information was extracted from the electronic medical records and 22 patients had targeted circulating tumor DNA (ctDNA) next-generation sequencing. Statistical analysis showed that 6 (24.0%) patients experienced prostate-specific antigen (PSA) response and 11 (44.0%) patients experienced PSA reduction. The relationship between ctDNA findings and outcomes was also analyzed. DNA-damage repair (DDR) pathways and homologous recombination repair (HRR) pathway defects indicated a comparatively longer PSA-progression-free survival (PSA-PFS; 2.5 months vs 1.2 months, P = 0.027; 3.3 months vs 1.2 months, P = 0.017; respectively). This study introduces the PD-1 inhibitor plus anlotinib as a late-line therapeutic strategy for terminal mCRPC. PD-1 inhibitor plus anlotinib may be a new treatment choice for terminal mCRPC patients with DDR or HRR pathway defects and requires further investigation.


Assuntos
Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Resultado do Tratamento , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Estudos Retrospectivos
5.
Org Lett ; 25(1): 210-214, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36534618

RESUMO

The diverse functionalization of 1,3-butadiene provides wide applicability toward the synthesis of abundant and useful allylic compounds. Here, we describe a three-component and redox-neutral assembly of readily available C═X compounds, 1,3-butadiene, and various nucleophiles by merging photoredox and nickel catalysis, enabling the rapid synthesis of structurally diverse homoallyl amines and homoallylic alcohols.


Assuntos
Butadienos , Níquel , Oxirredução , Catálise
6.
Angew Chem Int Ed Engl ; 62(4): e202211631, 2023 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-36399016

RESUMO

Allylamines are important building blocks in the synthesis of bioactive compounds. The direct coupling of allylic C-H bonds and commonly available amines is a major synthetic challenge. An allylic C-H amination of 1,4-dienes has been accomplished by palladium catalysis. With aromatic amines, branch-selective allylic aminations are favored to generate thermodynamically unstable Z-allylamines. In addition, more basic aliphatic cyclic amines can also engage in the reaction, but linear dienyl allylic amines are the major products.


Assuntos
Compostos Alílicos , Alilamina , Aminação , Paládio/química , Compostos Alílicos/química , Aminas/química , Catálise
7.
Materials (Basel) ; 15(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36234090

RESUMO

Si3N4 ceramics with a microscale rice leaf structure (MRLS) and titanium alloy were connected via brazing, and the influence of the surface microstructure on the ceramic connection was analyzed. MRLS fabrication is an efficient and high-degree-of-freedom method that can be used to change a material's surface morphology and wettability. The MRLS was obtained at a laser power of 110 W, with line spacings of 100 and 50 µm. The laser-treated surface included nanoparticles and micro particles, exhibiting a coral-like structure after agglomeration. When the MRLS was used to braze the titanium alloy, no defects were observed at the brazing interface, and the formation was excellent. Throughout the brazed joint, the MRLS remained intact and formed a strong metallurgical bond with the brazing filler metal. A finite element analysis was performed to study the cross-sectional morphology after joint fracture; from the load-time curve, it was found that the MRLS on the surface not only helped improve the mechanical occlusion and brazing area at the interface, but also helped generate compressive stress on the Si3N4 side. Crack propagation was hindered, thereby increasing the joint strength.

8.
Nanomaterials (Basel) ; 12(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36296847

RESUMO

Laser fabrication of metallic superhydrophobic surfaces (SHSs) for anti-frosting has recently attracted considerable attention. Effective anti-frosting SHSs require the efficient removal of condensed microdroplets through self-propelled droplet jumping, which is strongly influenced by the surface morphology. However, detailed analyses of the condensate self-removal capability of laser-structured surfaces are limited, and guidelines for laser processing parameter control for fabricating rationally structured SHSs for anti-frosting have not yet been established. Herein, a series of nanostructured copper-zinc alloy SHSs are facilely constructed through ultrafast laser processing. The surface morphology can be properly tuned by adjusting the laser processing parameters. The relationship between the surface morphologies and condensate self-removal capability is investigated, and a guideline for laser processing parameterization for fabricating optimal anti-frosting SHSs is established. After 120 min of the frosting test, the optimized surface exhibits less than 70% frost coverage because the remarkably enhanced condensate self-removal capability reduces the water accumulation amount and frost propagation speed (<1 µm/s). Additionally, the material adaptability of the proposed technique is validated by extending this methodology to other metals and metal alloys. This study provides valuable and instructive insights into the design and optimization of metallic anti-frosting SHSs by ultrafast laser processing.

9.
Artigo em Inglês | MEDLINE | ID: mdl-35958909

RESUMO

Renal fibrosis could lead to chronic kidney disease (CKD) developing into the end-stage with its pathological manifestation is the deposition of extracellular matrix (ECM). Danggui Shaoyao San (DSS) is one of the widely used herbal formulas in ancient China, which has been proven to have efficacy in the treatment of CKD. The experiment employed TGF-ß1 to stimulate the NRK-52E cells to establish a renal fibrosis model. With rapamycin (RAPA) used as the positive control, we detected the expression of fibronectin (FN), caspase-3, and autophagy-related proteins in the NRK-52E cells treated with DSS by Western blot and immunofluorescence assay. In order to further verify autophagy-promoting effects of DSS, we adopted 3-MA to inhibit autophagy. The experiment has found that DSS can lower the protein levels of FN and caspase-3 in the NRK-52E cells induced by TGF-ß1. After TGF-ß1 stimulation, the expression of LC3 II/I and Beclin 1 has decreased, and the protein levels of mTOR and p62 have increased. Consistent with rapamycin, DSS has significantly reduced these effects of TGF-ß1. It has also been found that DSS can increase the expression of LC3 II/I and Beclin 1 proteins and can reduce the level of mTOR in cells treated with 3-MA, suggesting that DSS can promote autophagy. In conclusion, DSS has been proved to reduce the apoptosis and fibrosis of NRK-52E cells induced by TGF-ß1, which may be achieved by promoting autophagy.

10.
Eur J Med Res ; 27(1): 162, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36045455

RESUMO

BACKGROUND: Knee osteoarthritis, a common degenerative joint disease, has been widely treated by electroacupuncture in recent years. However, there are too many parameters of the treatment currently, resulting in various applications in clinical practice. This study aims to summarize the optimal stimulation parameters of electroacupuncture for knee osteoarthritis in clinical studies by applying data mining techniques. METHODS: Four databases including Pubmed, Cochrane Library, Embase, and Web of Science were searched for clinical studies on electroacupuncture treating knee osteoarthritis from 2012 to 2021. A database was established by Microsoft Excel 2020 and analyzed by R Version 4.1.1. RESULTS: Forty-six articles were included according to the established criteria. The most used electroacupuncture stimulation parameters were 0.30 mm × 40 mm needle, continuous wave, low frequency of current (mainly 2 Hz), stimulation duration for 30 min per treatment, and frequency of treatment for once a day. Eighteen acupoints were mentioned and the most used ones include Dubi (ST35), Liangqiu (ST34), Neixiyan (EX-LE4), Xuehai (SP10), Yanglingquan (GB34), and Yinlingquan (SP9), and those most generally used acupoints are closely arranged on the Stomach Channel of Foot Yangming. Cluster analysis showed two groups, one for obligatory acupoints and one for adjunctive ones. The association analysis showed the most supported acupoint pair was Liangqiu (ST34) and Xuehai (SP10). CONCLUSIONS: Continuous wave, low frequency of current (2 Hz), 30-min stimulation, and local acupoint selection are frequently used for electroacupuncture treating knee osteoarthritis. Due to the limitations of this study, further research and more standardized, multi-centered, and large-sample clinical trials should be conducted to provide more convincing evidence.


Assuntos
Eletroacupuntura , Osteoartrite do Joelho , Pontos de Acupuntura , Mineração de Dados , Humanos , Osteoartrite do Joelho/terapia , Resultado do Tratamento
11.
Front Pharmacol ; 13: 764473, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35250555

RESUMO

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse reaction of chemotherapy. Many studies have confirmed that traditional Chinese medicine (TCM) has unique advantages for treating CIPN. However, there is no standard TCM prescription in clinical practice or objective outcome index, and similar efficacy varies. Therefore, in this study, a systematic review of randomized controlled trials (RCTs) was performed to evaluate the clinical efficacy of external treatment with Chinese herbal medicine (CHM) for CIPN. This analysis provides evidence-based medical support for the use of CHM for external treatment of CIPN. Methods: Relevant RCTs assessing CHM external treatment of CIPN were searched in nine electronic databases, including the China National Knowledge Infrastructure Database, China Biology Medicine Disc, China Science and Technology Journal Database, Wanfang Database, PubMed, Cochrane Library, MEDLINE, Web of Science, and OVID, from inception to July 2021. A meta-analysis was performed on these studies using RevMan5.3 software. Results: Based on the inclusion and exclusion criteria, 33 clinical studies were included, while 1,354 studies were screened out. There were 2,356 patients in total, including 1,208 in the treatment group and 1,148 in the control group. In the treatment group, peripheral neurotoxicity rate, total effect rate, KPS score, TCM syndrome score and efficacy, pain NRS score, and pain relief rate were significantly improved compared with those of the control group (p < 0.01). Furthermore, the peroneal and median nerve conduction velocities were also improved compared with those in the control group (p < 0.05). By creating a funnel plot for the incidence of peripheral neurotoxicity and the total effect rate, we showed that the left and right sides were symmetrical, and that the publication bias was low. Conclusion: CHM external treatment was found to be an effective method for treating CIPN as it significantly improved clinical symptoms and quality of life in patients with CIPN. Clinical Trial Registration: identifier ChiCTR1900024617.

12.
Signal Transduct Target Ther ; 7(1): 19, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35046386

RESUMO

Interleukin-37b (hereafter called IL-37) was identified as fundamental inhibitor of natural and acquired immunity. The molecular mechanism and function of IL-37 in colorectal cancer (CRC) has been elusive. Here, we found that IL-37 transgenic (IL-37tg) mice were highly susceptible to colitis-associated colorectal cancer (CAC) and suffered from dramatically increased tumor burdens in colon. Nevertheless, IL-37 is dispensable for intestinal mutagenesis, and CRC cell proliferation, apoptosis, and migration. Notably, IL-37 dampened protective cytotoxic T cell-mediated immunity in CAC and B16-OVA models. CD8+ T cell dysfunction is defined by reduced retention and activation as well as failure to proliferate and produce cytotoxic cytokines in IL-37tg mice, enabling tumor evasion of immune surveillance. The dysfunction led by IL-37 antagonizes IL-18-induced proliferation and effector function of CD8+ T cells, which was dependent on SIGIRR (single immunoglobulin interleukin-1 receptor-related protein). Finally, we observed that IL-37 levels were significantly increased in CRC patients, and positively correlated with serum CRC biomarker CEA levels, but negatively correlated with the CD8+ T cell infiltration in CRC patients. Our findings highlight the role of IL-37 in harnessing antitumor immunity by inactivation of cytotoxic T cells and establish a new defined inhibitory factor IL-37/SIGIRR in cancer-immunity cycle as therapeutic targets in CRC.


Assuntos
Carcinogênese/imunologia , Colite/imunologia , Neoplasias Colorretais/imunologia , Interleucina-1/imunologia , Proteínas de Neoplasias/imunologia , Receptores de Interleucina-1/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Carcinogênese/genética , Colite/genética , Colite/patologia , Neoplasias Colorretais/genética , Interleucina-1/genética , Camundongos , Camundongos Transgênicos , Proteínas de Neoplasias/genética , Receptores de Interleucina-1/genética
13.
Int J Clin Pharmacol Ther ; 60(1): 57-66, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34672254

RESUMO

OBJECTIVE: This study was conducted to assess the pharmacokinetic and safety profiles between a new oral formulation of terazosin hydrochloride capsule compared with the brand-name drug. MATERIALS AND METHODS: A randomized, open-label, single-dose, 2-period crossover study under fasting or fed conditions was conducted in healthy Chinese subjects. 24 individuals were selected, respectively. Each subject was randomized at the beginning to receive a 2-mg capsule of the test or the reference terazosin during the first period and then received the alternate formulation during the second period following a 1-week washout period. Blood samples were collected at pre-dose and up to 60 hours after administration. Plasma terazosin was quantified by a validated LC-MS/MS method. RESULTS: 48 healthy subjects were enrolled, and 47 completed the study. Cmax, AUC0-t, and AUC0-∞ were similar and the 90% CIs for the geometric mean ratios of these parameters between the two groups were all bounded within the predefined bioequivalence criterion of 80 - 125% under both fasting and fed conditions. Throughout the study period, a total of 30 treatment-emergent adverse events (TEAEs) were reported under fasting condition. 35 TEAEs were observed under fed conditions. No serious adverse event was observed. CONCLUSION: The test and reference formulations of terazosin were bioequivalent and well tolerated under both fasting and fed conditions.


Assuntos
Jejum , Espectrometria de Massas em Tandem , Área Sob a Curva , China , Cromatografia Líquida , Estudos Cross-Over , Voluntários Saudáveis , Humanos , Prazosina/análogos & derivados , Comprimidos , Equivalência Terapêutica
14.
Front Plant Sci ; 12: 765077, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956262

RESUMO

Grasslands provide key resource for the millions of people who are dependent on livestock in Tajikistan. Productivity and species richness (SR) are important characteristics of grassland ecosystems and are greatly affected by nutrient inputs. The effect that climate change might have on these characteristics remains unclear. Here, an in situ nitrogen (N) and phosphorus (P) fertilization experiment was conducted at four sites along with an elevational gradient (650, 1,100, 1,250, and 2,000 m) in western Tajikistan over 2 years (2018 and 2019) to examine the influences of nutrient availability and climate change on aboveground biomass (AGB) and SR; precipitation and temperature were also considered to analyze the responses. It demonstrated that enrichment with N, P, and their combinations significantly increased AGB along with an elevational gradient (p < 0.05). AGB increased as the concentrations of nutrients added increased. The maximum AGB, which was 2-fold higher compared with control, was observed when 90 kg N ha-1year-1 and 30 kg P ha-1year-1 were added. In addition, nitrogen addition alone stimulated greater AGB than P addition, although no significant difference was observed between these two treatments. Enrichment with N, P, and their combination had no significant effect on SR; however, SR significantly changed at different elevation. Elevation had direct effect on precipitation and temperature, which, in turn, resulted in variation in AGB and SR. Moreover, both nutrient and elevation had significant effect on AGB and SR, but there was no interaction effect of them. AGB and SR interacted with significant negative correlation. In the high-elevation area, plants grew better in the warmer year (2018); this indicates that grasslands in high mountain areas in Tajikistan might have higher productivity as the climate warms, which will positively affect the economic development of the country.

15.
Huan Jing Ke Xue ; 42(5): 2240-2250, 2021 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-33884793

RESUMO

To reveal the hydrochemical characteristics of karst wetland located in a subtropical area and at lower elevations in China, 27 surface water samples were collected during three periods (wet, normal, and dry) in the Huixian karst wetland to investigate the distributions, pollution, and irrigation application of 12 inorganic ions and 10 heavy metals. Based on their concentrations, the Nemerow index and the four evaluation systems of the sodium adsorption ratio (SAR), sodium concentration (SC), permeability index (PI), and residual sodium carbonate (RSC) were applied to evaluate the pollution characteristics and irrigation application. It was found that the water type in this area was Ca2+-HCO3- and weakly alkaline. Regarding the 12 inorganic ions and 10 heavy metals, NH4+ exceeded the Chinese standards for drinking water with an exceedance rate of 25.93%, and the exceedance rates of Al, Mn, and Hg were 11.11%, 44.44%, and 37.04%, respectively. The spatiotemporal scaling effect on inorganic ions was lower than that of heavy metals, and the distributions of the inorganic ions and heavy metals were in the order of wet period > normal period > dry period. However, the surface water quality in the Huixian karst wetland was generally well-protected based on the pollution assessment. The Nemerow index ranged from 0.75 to 2.69, which recognized the main pollution contributors as NH4+, Mn, Al, and Hg with the contamination grade from slight pollution to moderate pollution, especially in the core area during the wet period. According to the limits of standards for irrigation water quality and environmental quality for surface water, as well as the evaluation results of the SAR, SC, PI, and RSC, the surface water in the Huixian karst wetland was generally suitable for irrigation, and the water quality in the dry period was better than that in the wet and normal periods. The surface water from site PH1 during the normal period with 19.1 µg·L-1 of Hg and site FH8 during the wet period with 13.7 mg·L-1 of NH4+ were not suitable for agricultural irrigation.

16.
Huan Jing Ke Xue ; 42(1): 184-194, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372470

RESUMO

The concentrations of 10 metals (Cd, Cr, As, Al, Cu, Pb, Zn, Mn, Hg, and Fe) in 27 groundwater samples collected during different periods (wet, normal, and dry) in the Huixian Karst wetland, the largest subtropical low-altitude karst wetland in China, were detected and analyzed to investigate pollution and health risks. The pollution characteristics, distribution, and health risks of the metals in groundwater were revealed by a comprehensive pollution assessment, multivariate statistical analysis, and health risk assessment model, respectively. The results showed that the average concentrations of metals in groundwater were followed the order of Mn > Fe > Zn > Al > Hg > Cr > Cu > Cd > As > Pb. The maximum concentration of Mn (1022.00 µg·L-1) was found in the wet season, while that of Hg (42.40 µg·L-1) was found in the normal season, and both were over the corresponding standard limits. The results of the pollution assessment indicated that only Mn pollution reached level Ⅵ in the wet season, while Cd, Al, Zn, and Fe pollution were at the level of Ⅲ. Only the Hg pollution level reached level Ⅵ while Al pollution reached the level of Ⅲ in the normal water period. According to the above results, the water quality in the dry season was better than that in the wet and normal seasons in terms of the 10 metals. The concentrations of Zn, Cd, Mn, and Al in groundwater were affected by human activities, while the time-scale characteristics of these were not obvious. The concentrations of As, Fe, Cu, and Cr were all affected by human activities and the time-scale, while the concentrations of Hg and Pb were mainly manifested in time-scale characteristics. The results of the health risk assessment of the water due to drinking and the skin penetration pathway indicated that the total health risks followed the order of normal season > the wet season > the dry season. The carcinogenic risks caused by Cr for adults and children through drinking pathway in the wet season (8.03×10-5 a-1 and 8.76×10-5 a-1), normal season (1.15×10-4 a-1 and 1.26×10-4 a-1),and dry season (8.72×10-5 a-1 and 9.51×10-5 a-1) exceeded the maximum allowed level (5.0×10-5 a-1) in all periods. Hence, Cr was the main metal element that caused carcinogenic risks. For the sake of drinking water safety, the concentrations of Mn, Hg, and Cr in groundwater should be controlled before drinking.


Assuntos
Água Subterrânea , Metais Pesados , Poluentes Químicos da Água , Adulto , Criança , China , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Medição de Risco , Poluentes Químicos da Água/análise , Áreas Alagadas
17.
Angew Chem Int Ed Engl ; 58(47): 16806-16810, 2019 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-31475764

RESUMO

Branched selectivity in asymmetric allylic C-H alkylation is enabled by using 2-acylimidazoles as nucleophiles in the presence of a chiral phosphoramidite-palladium catalyst. A wide range of terminal alkenes, including 1,4-dienes and allylarenes, are nicely tolerated and provide chiral 2-acylimidazoles in moderate to high yields and with high levels of regio-, and enantio-, and E/Z-selectivities. Mechanistic studies using density-functional theory calculations suggest a nucleophile-coordination-enabled inner-sphere attack mode for the enantioselective carbon-carbon bond-forming event.

18.
Org Lett ; 21(17): 6720-6725, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31403315

RESUMO

Monodentate phosphorus ligands have been found to enable the palladium-catalyzed allylic C-H alkylation reaction of terminal alkenes with a wide variety of carbon nucleophiles. Moreover, an asymmetric allylic C-H alkylation of terminal alkenes with pyrazol-5-ones has been established in the presence of chiral phosphoramidite ligand and chiral phosphoric acid as co-catalyst. Mechanistic studies suggest that a ternary Pd(0) complex, coordinated with a monodentate phosphorus ligand, benzoquinone, and alkene, is most likely to be an active species.

19.
Chin Med J (Engl) ; 132(12): 1441-1447, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31205102

RESUMO

BACKGROUND: Diagnosis of heparin-induced thrombocytopenia (HIT) is challenging. This study aimed to compare the diagnostic performance of HIT expert probability (HEP) and 4T scores, and to evaluate the inter-observer reliability for the 4T score in a clinical setting. METHODS: This prospective study included HIT-suspected patients between 2016 and 2018. Three hematologists assessed the HEP and 4T scores. Correlations between scores and anti-platelet factor 4 (anti-PF4)/heparin antibodies were evaluated. Receiver operating characteristic curves and area under the curve (AUC) were used to assess the predictive accuracy of these two scoring models. The intraclass correlation coefficient (ICC) was used to assess the inter-observer agreement of 4T scores between residents and hematologists. RESULTS: Of the 89 subjects included, 22 (24.7%) were positive for anti-PF4/heparin antibody. The correlations between antibody titer and either HEP or 4T scores were similar (r = 0.392, P < 0.01 for the HEP score; r = 0.444, P < 0.01 for the 4T score). No significant difference in the diagnostic performance was displayed between these two scores (AUC for the HEP score: 0.778 vs. AUC for the 4T score: 0.741, P = 0.357). Only 72 4T scores were collected from the residents, with a surprisingly low percentage of observers (43.1%) presenting the four individual item scores which made up their 4T score. The AUC of 4T score assessed by residents and hematologists was 0.657 (95% confidence interval [CI]: 536-0.765) and 0.780 (95% CI: 0.667-0.869, P < 0.05), respectively. The ICC of 4T score between residents and hematologists was 0.49 (95% CI: 0.29-0.65, P < 0.01), demonstrating a fair inter-observer agreement. CONCLUSIONS: The HEP score does not display a better performance for predicting HIT than the 4T score. With the unsatisfactory completion rate, the inter-observer agreement of 4T score in a tertiary hospital is fair, underscoring the necessity for continuing education for physicians.


Assuntos
Heparina/toxicidade , Trombocitopenia/induzido quimicamente , Trombocitopenia/diagnóstico , Adulto , Idoso , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto , Estudos Prospectivos , Curva ROC , Centros de Atenção Terciária/estatística & dados numéricos
20.
J Am Chem Soc ; 141(27): 10616-10620, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31251608

RESUMO

An asymmetric allylic C-H alkylation of allyl ethers has been established by chiral phosphoramidite-palladium catalysis, affording a wide variety of functionalized chiral 2-acylimidazoles in moderate to high yields and with high levels of enantioselectivity. Moreover, this protocol could be applied to a concise asymmetric synthesis of a tachykinin receptor antagonist.

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