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1.
Adv Sci (Weinh) ; : e2405137, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39136047

RESUMEN

It is still a challenge to construct single-atom level reduction and oxidation sites in single-component photocatalyst by manipulating coordination configuration for photocatalytic water splitting. Herein, the atomically dispersed asymmetric configuration of six-coordinated Co-S2O4 (two exposed S atoms, two OH groups, and two Co─O─Zn bonds) suspending on ZnIn2S4 nanosheets verified by combining experimental analysis with theoretical calculation, is applied into photocatalytic water splitting. The Co-S2O4 site immobilized by Vs acts as oxidation sites to guide electrons transferring to neighboring independent S atom, achieving efficient separation of reduction and oxidation sites. It is worth mentioning that stabilized Co-S2O4 configuration show dynamic structure evolution to highly active Co-S1O4 configuration (one exposed S atom, one OH group, and three Co─O─Zn bonds) in reaction, which lowers energy barrier of transition state for H2O activization. Ultimately, the optimized photocatalyst exhibits excellent photocatalytic activity for water splitting (H2: 80.13 µmol g-1 h-1, O2: 37.81 µmol g-1 h-1) and outstanding stability than that of multicomponent photocatalysts due to dynamic and reversible evolution between stable Co-S2O4 configuration and active Co-S1O4 configuration. This work demonstrates new cognitions on immobilized strategy through vacancy inducing, manipulating coordination configuration, and dynamic evolution mechanism of single-atom level catalytic site in photocatalytic water splitting.

2.
J Phys Chem A ; 128(32): 6729-6738, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39109870

RESUMEN

This study elucidates the mechanisms and principles governing chemoselectivity in synthesizing two distinct N-heterocycles, benzimidazole thiazine and benzothiazole imidazole, through BF3•OEt2-catalyzed cyclization reactions of propargyl alcohols with benzimidazole thiols. Employing density functional theory calculations, we highlight the crucial role of fluorine source in influencing chemoselectivity. In DCM, BF3, as the catalytic center, coordinates with propargyl alcohol's hydroxyl group to form a precursor. Conversely, in DMF, [BF2•DMF]+, formed from DMF and BF3•OEt2, acts as the catalytic center, activating the propargyl alcohol's hydroxyl group. The mechanisms in both solvents involve sequential steps: B-O bond formation, C-O bond cleavage, S-C bond formation, hydrogen atom transfer (HAT), cyclization, and deprotonation. A notable difference is the HAT process: in DCM, it follows a 1,5-HAT process, while in DMF, BF4- formation from DMF and BF3•OEt2 provides a fluorine source and introduces steric hindrance, favoring a 1,6-HAT process and leading to unique chemoselectivity. This pioneering research showcases the impact of DMF on cyclization reactions, offering valuable insights for comprehending and designing reactions driven by fluorine sources. Crucially, our results propose an innovative reaction mechanism featuring lower potential energy surfaces, enhancing our understanding of the intricate interplay among reactants, catalysts, and solvents.

3.
Chin J Traumatol ; 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38637176

RESUMEN

PURPOSE: Traumatic brain injury (TBI), currently a major global public health problem, imposes a significant economic burden on society and families. We aimed to quantify and predict the incidence and severity of TBI by analyzing its incidence, prevalence, and years lived with disability (YLDs). The epidemiological changes in TBI from 1990 to 2019 were described and updated to provide a reference for developing prevention, treatment, and incidence-reducing measures for TBI. METHODS: A secondary analysis was performed on the incidence, prevalence, and YLDs of TBI by sex, age group, and region (n = 21,204 countries and territories) between 1990 and 2019 using the Global Burden of Diseases, Injuries, and Risk Factors Study 2019. Proportions in the age-standardized incidence rate due to underlying causes of TBI and proportions of minor and moderate or severe TBI were also reported. RESULTS: In 2019, there were 27.16 million (95% uncertainty intervals (UI): 23.36 - 31.42) new cases of TBI worldwide, with age-standardized incidence and prevalence rates of 346 per 100,000 population (95% UI: 298-401) and 599 per 100,000 population (95% UI: 573-627), respectively. From 1990 to 2019, there were no significant trends in global age-standardized incidence (estimated annual percentage changes: -0.11%, 95% UI: -0.18% - -0.04%) or prevalence (estimated annual percentage changes: 0.01%, 95% UI: -0.04% - 0.06%). TBI caused 7.08 million (95% UI: 5.00 - 9.59) YLDs in 2019, with age-standardized rates of 86.5 per 100,000 population (95% UI: 61.1 - 117.2). In 2019, the countries with higher incidence rates were mainly distributed in Central Europe, Eastern Europe, and Australia. The 2019 global age-standardized incidence rate was higher in males than in females. The 2019 global incidence of moderate and severe TBI was 182.7 per 100,000 population, accounting for 52.8% of all TBI, with falls and road traffic injuries being the main causes in most regions. CONCLUSIONS: The incidence of moderate and severe TBI was slightly higher in 2019, and TBI still accounts for a significant portion of the global injury burden. The likelihood of moderate to severe TBI and the trend of major injury under each injury cause from 1990 to 2019 and the characteristics of injury mechanisms in each age group are presented, providing a basis for further research on injury causes in each age group and the future establishment of corresponding policies and protective measures.

4.
Toxics ; 12(2)2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38393240

RESUMEN

1,4-dioxane is a potential carcinogen in water and is difficult to deal with due to its robust cycloether bond and complete miscibility with water. To remove 1,4-dioxane in an economically viable and environmentally friendly way, a series of carbon aerogels were synthesized as adsorbents for 1,4-dioxane. The experiment results showed that adsorption performances were closely related to the preparation conditions of carbon aerogels, such as the molar ratio, heating rate, pyrolysis temperature and residence time, which were carefully controlled. Scanning electron microscope analysis revealed the presence of a three-dimensional porous network structure in carbon aerogels. Brunauer-Emmett-Teller analysis results demonstrated an increase in specific surface area (673.89 m2/g) and total pore volume after carbonization, with an increase in mesoporous porosity and a decrease in microporosity. When considering each variable individually, the highest specific surface area of prepared carbon aerogels was achieved at a pyrolysis temperature of 800 °C, a holding time of 1 h, and a heating rate of 2 °C/min. Under optimal experimental conditions, the adsorption removal of 1,4-dioxane by carbon aerogels exceeded 95%, following quasi-second-order kinetics and Langmuir isothermal adsorption isotherms, indicating that monolayer adsorption on the surface of carbon aerogels occurred. The maximum adsorption capacity obtained was 67.28 mg/g at a temperature of 318 K, which was attributed to the presence of a large proportion of mesopores and abundant micropores simultaneously in carbon aerogels. Furthermore, with the interference of chlorinated solvents such as trichloroethylene (TCE), the removal efficiency of 1,4-dioxane had no obvious inhibition effect. Regeneration experiments showed that after five continuous cycles, the carbon aerogels still kept a comparable adsorption capacity, which illustrates its potential application in 1,4-dioxane-polluted water purification.

5.
Sci Adv ; 9(51): eadk1704, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-38117883

RESUMEN

Here, an Ir/Zn-cocatalyzed atroposelective [2+2+2] cycloaddition of 1,6-diynes and ynamines was developed, forging various functionalized C─N axially chiral indoles and pyrroles in generally good to excellent yields (up to 99%), excellent chemoselectivities, and high enantioselectivities (up to 98% enantiomeric excess) with wide substrate scope. This cocatalyzed strategy not only provided an alternative promising and reliable way for asymmetric alkyne [2+2+2] cyclotrimerization in an easy handle but also settled the issues of previous [Rh(COD)2]BF4-catalyzed system on the construction of C─N axial chirality such as complex operations, limited substrate scope, and low efficiency. In addition, control experiments and theoretical calculations disclosed that Zn(OTf)2 markedly reduced the barrier of migration insertion to significantly increase reaction efficiency, which was distinctly different from previous work on the Lewis acid for improving reaction yield through accelerating oxidative addition and reductive elimination.

6.
Nature ; 623(7987): 608-615, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37938768

RESUMEN

Cell therapies have yielded durable clinical benefits for patients with cancer, but the risks associated with the development of therapies from manipulated human cells are understudied. For example, we lack a comprehensive understanding of the mechanisms of toxicities observed in patients receiving T cell therapies, including recent reports of encephalitis caused by reactivation of human herpesvirus 6 (HHV-6)1. Here, through petabase-scale viral genomics mining, we examine the landscape of human latent viral reactivation and demonstrate that HHV-6B can become reactivated in cultures of human CD4+ T cells. Using single-cell sequencing, we identify a rare population of HHV-6 'super-expressors' (about 1 in 300-10,000 cells) that possess high viral transcriptional activity, among research-grade allogeneic chimeric antigen receptor (CAR) T cells. By analysing single-cell sequencing data from patients receiving cell therapy products that are approved by the US Food and Drug Administration2 or are in clinical studies3-5, we identify the presence of HHV-6-super-expressor CAR T cells in patients in vivo. Together, the findings of our study demonstrate the utility of comprehensive genomics analyses in implicating cell therapy products as a potential source contributing to the lytic HHV-6 infection that has been reported in clinical trials1,6-8 and may influence the design and production of autologous and allogeneic cell therapies.


Asunto(s)
Linfocitos T CD4-Positivos , Herpesvirus Humano 6 , Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos , Activación Viral , Latencia del Virus , Humanos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Ensayos Clínicos como Asunto , Regulación Viral de la Expresión Génica , Genómica , Herpesvirus Humano 6/genética , Herpesvirus Humano 6/aislamiento & purificación , Herpesvirus Humano 6/fisiología , Inmunoterapia Adoptiva/efectos adversos , Inmunoterapia Adoptiva/métodos , Encefalitis Infecciosa/complicaciones , Encefalitis Infecciosa/virología , Receptores Quiméricos de Antígenos/inmunología , Infecciones por Roseolovirus/complicaciones , Infecciones por Roseolovirus/virología , Análisis de Expresión Génica de una Sola Célula , Carga Viral
7.
bioRxiv ; 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37214906

RESUMEN

Infections with defined Herpesviruses, such as Pseudorabies virus (PRV) and Varicella zoster virus (VZV) can cause neuropathic itch, referred to as "mad itch" in multiple species. The underlying mechanisms involved in neuropathic "mad itch" are poorly understood. Here, we show that PRV infections hijack the RNA helicase DDX3X in sensory neurons to facilitate anterograde transport of the virus along axons. PRV induces re-localization of DDX3X from the cell body to the axons which ultimately leads to death of the infected sensory neurons. Inducible genetic ablation of Ddx3x in sensory neurons results in neuronal death and "mad itch" in mice. This neuropathic "mad itch" is propagated through activation of the opioid system making the animals "addicted to itch". Moreover, we show that PRV co-opts and diverts T cell development in the thymus via a sensory neuron-IL-6-hypothalamus-corticosterone stress pathway. Our data reveal how PRV, through regulation of DDX3X in sensory neurons, travels along axons and triggers neuropathic itch and immune deviations to initiate pathophysiological programs which facilitate its spread to enhance infectivity.

8.
Mol Ther Methods Clin Dev ; 27: 73-88, 2022 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-36186955

RESUMEN

A limitation for recombinant adeno-associated virus (rAAV)-mediated gene transfer into the central nervous system (CNS) is the low penetration of vectors across the human blood-brain barrier (BBB). High doses of intravenously delivered vector are required to reach the CNS, which has resulted in varying adverse effects. Moreover, selective transduction of various cell types might be important depending on the disorder being treated. To enhance BBB penetration and improve CNS cell selectivity, we screened an AAV capsid-shuffled library using an in vitro transwell BBB system with separate layers of human endothelial cells, primary astrocytes and/or human induced pluripotent stem cell-derived cortical neurons. After multiple passages through the transwell, we identified chimeric AAV capsids with enhanced penetration and improved transduction of astrocytes and/or neurons compared with wild-type capsids. We identified the amino acids (aa) from regions 451-470 of AAV2 associated with the capsids selected for neurons, and a combination of aa from regions 413-496 of AAV-rh10 and 538-598 of AAV3B/LK03 associated with capsids selected for astrocytes. A small interfering RNA screen identified several genes that affect transcytosis of AAV across the BBB. Our work supports the use of a human transwell system for selecting enhanced AAV capsids targeting the CNS and may allow for unraveling the underlying molecular mechanisms of BBB penetration.

9.
Nat Commun ; 13(1): 4887, 2022 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-36068211

RESUMEN

Wild yak (Bos mutus) and domestic yak (Bos grunniens) are adapted to high altitude environment and have ecological, economic, and cultural significances on the Qinghai-Tibetan Plateau (QTP). Currently, the genetic and cellular bases underlying adaptations of yak to extreme conditions remains elusive. In the present study, we assembled two chromosome-level genomes, one each for wild yak and domestic yak, and screened structural variants (SVs) through the long-read data of yak and taurine cattle. The results revealed that 6733 genes contained high-FST SVs. 127 genes carrying special type of SVs were differentially expressed in lungs of the taurine cattle and yak. We then constructed the first single-cell gene expression atlas of yak and taurine cattle lung tissues and identified a yak-specific endothelial cell subtype. By integrating SVs and single-cell transcriptome data, we revealed that the endothelial cells expressed the highest proportion of marker genes carrying high-FST SVs in taurine cattle lungs. Furthermore, we identified pathways which were related to the medial thickness and formation of elastic fibers in yak lungs. These findings provide new insights into the high-altitude adaptation of yak and have important implications for understanding the physiological and pathological responses of large mammals and humans to hypoxia.


Asunto(s)
Células Endoteliales , Genoma , Aclimatación/genética , Animales , Bovinos , Humanos , Mamíferos/genética , ARN , Transcriptoma/genética
10.
Zhen Ci Yan Jiu ; 47(8): 665-72, 2022 Aug 25.
Artículo en Chino | MEDLINE | ID: mdl-36036098

RESUMEN

OBJECTIVE: To observe the effect of moxibustion (Moxi) at acupoints of Governor Vessel on autophagy lysosomal function and lncRNA H19 in amyloid precursor protein/presenilin 1 (APP/PS1) double transgenic Alzheimer's disease (AD) mice, so as to explore its underlying mechanisms in relieving AD. METHODS: Fifty two male APP/PS1 double transgenic AD mice were randomly divided into model, Moxi, Moxi+inhibitor and medication (rapamycin) groups, with 13 mice in each group. Other 13 male C57BL/6J mice of the same age were selected as the control group. The mice of the Moxi group received aconite cake-separated Moxi stimulation at "Baihui" (GV20), "Dazhui"(GV14) and "Fengfu" (GV16), for 15 min, those of the Moxi+inhibitor group received intraperitoneal injection of 3-methyladenine (an inhibitor of PI3K for suppressing autophagy) 1.5 mg· kg-1 · d-1 on the basis of Moxi, and those of the medication group received intraperitoneal injection of rapamycin 2 mg· kg-1 · d-1. The treatment was conducted once daily for 2 weeks. The mouse's learning-memory ability was detected by Morris water maze tests. The hippocampus tissue was sampled for observing the formation of autophagy by using transmission electron microscope, detecting the expression of Aß_(1-42) protein with immunohistochemical staining, and for detecting the expression levels of long noncoding RNA H19 (lncRNA H19), mammalian target of rapamycin kinase (mTOR), nuclear transcription factor EB (TFEB), Cathepsin D and lysosome associated membrane protein-1 (LAMP1) genes and proteins as well as microtubule associated protein 1 light chain 3B (LC3B)-Ⅱ/LC3B-Ⅰand autophagy protein p62 protein by quantitative real-time PCR and Western blot, respectively. RESULTS: In contrast to the control group, the model group had an evident increase in the escape latency of Morris water maze test, and in the expression levels of Aß_(1-42) protein, lncRNA H19 mRNA, mTOR mRNA and protein, and p62 protein (P<0.05), and a significant decrease in the expression levels of TFEB, Cathepsin D, LAMP1 mRNAs and proteins and LC3B-Ⅱ/LC3B-Ⅰ (P<0.05). After the treatment and relevant to the model and Moxi+inhibitor groups, both the Moxi and medication groups had an obvious down-regulation in the levels of latency of Morris water maze, expression levels of Aß_(1-42) protein, lncRNA H19 mRNA, mTOR mRNA and protein, and p62 protein (P<0.05), and a significant up-regulation in the levels of TFEB, Cathepsin D, LAMP1 mRNAs and proteins and LC3B-Ⅱ/LC3B-Ⅰ (P<0.05). CONCLUSION: Moxi at acupoints of Governor Vessel can improve cognitive function of AD mice, which may be associated with its functions in inhibiting mTOR/TFEB pathway by down-regulating the expression of lncRNA H19, improving autophagy lysosomal function, promoting autophagy and clearing away Aß1-42 in the hippocampus.


Asunto(s)
Enfermedad de Alzheimer , Moxibustión , ARN Largo no Codificante , Péptidos beta-Amiloides , Precursor de Proteína beta-Amiloide , Animales , Autofagia , Catepsina D , Hipocampo , Lisosomas , Masculino , Mamíferos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Presenilina-1 , ARN Mensajero , Sirolimus , Serina-Treonina Quinasas TOR
11.
Sci Adv ; 8(4): eabl5220, 2022 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-35080973

RESUMEN

DNA methyltransferases (DNMTs) catalyze DNA methylation, and their functions in mammalian embryonic development and diseases including cancer have been extensively studied. However, regulation of DNMTs remains under study. Here, we show that CCAAT/enhancer binding protein α (CEBPA) interacts with the long splice isoform DNMT3A, but not the short isoform DNMT3A2. CEBPA, by interacting with DNMT3A N-terminus, blocks DNMT3A from accessing DNA substrate and thereby inhibits its activity. Recurrent tumor-associated CEBPA mutations, such as preleukemic CEBPAN321D mutation, which is particularly potent in causing AML with high mortality, disrupt DNMT3A association and cause aberrant DNA methylation, notably hypermethylation of PRC2 target genes. Consequently, leukemia cells with the CEBPAN321D mutation are hypersensitive to hypomethylation agents. Our results provide insights into the functional difference between DNMT3A isoforms and the regulation of de novo DNA methylation at specific loci in the genome. Our study also suggests a therapeutic strategy for the treatment of CEBPA-mutated leukemia with DNA-hypomethylating agents.

12.
J Am Chem Soc ; 144(1): 339-348, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-34935377

RESUMEN

A copper-catalyzed remote benzylic C-H functionalization strategy enabling 1,2-difunctionalization of alkenes with 2-methylbenzeneamides and nucleophiles, including alcohols, indoles, pyrroles, and the intrinsic amino groups, is reported, which is characterized by its redox-neutral conditions, exquisite site-selectivity, broad substrate scope, and wide utilizations of late-stage modifying bioactive molecules. This reaction proceeds through nitrogen-centered radical generation, hydrogen atom transfer, benzylic radical addition across the alkenes, single-electron oxidation, and carbocation electrophilic course cascades. While using external nucleophiles manipulates three-component alkene alkylalkoxylation and alkyl-heteroarylation with 2-methylbenzeneamides to access dialkyl ethers, 3-alkylindoles, and 3-alkylpyrroles, omitting the external nucleophiles results in two-component alkylamidation ([5+2] annulation) of alkenes with 2-methylbenzeneamides to benzo-[f][1,2]thiazepine 1,1-dioxides.

13.
Artículo en Inglés | MEDLINE | ID: mdl-34335843

RESUMEN

Huxie Huaji (HXHJ) Ointment is a famous traditional Chinese medicinal prescription and is commonly used for the clinical treatment of hepatocellular carcinoma by boosting immunity and detoxification. However, the scientific evidence for the effect of HXHJ Ointment on hepatocellular carcinoma and the underlying molecular mechanism are lacking. The present study aimed to identify the effects of HXHJ Ointment on hepatocellular carcinoma in vitro and in vivo as well as investigating the mechanistic basis for the anticancer effect of HXHJ ointment. First, liquid chromatography-mass spectrometry was used to verify the composition of HXHJ Ointment and quality control. Second, in vitro, Cell Counting Kit (CCK8) cell viability assay and Hoechst 33342 staining assay were performed to explain the cell apoptosis. The protein levels of tumor suppressor protein (p53), B-cell lymphoma 2 gene (Bcl-2), cytochrome C (Cyt-C), and aspartate proteolytic enzyme-3 (caspase-3) were examined by immunofluorescence. Finally, in vivo, hematoxylin and eosin (H&E) staining was used to observe the pathological changes in hepatocellular carcinoma samples. Western blots and immunohistochemistry were used to detect the anticancer properties of HXHJ ointment. The results in vitro showed that 20% HXHJ Ointment serum could significantly inhibit HepG2 cell proliferation, increased tumor suppressor gene p53, downregulated antiapoptotic protein Bcl-2, promoted the release of mitochondrial Cyt-C, activated caspase-3, and induced HepG2 cell apoptosis. Furthermore, in vivo experiments showed that HXHJ Ointment could effectively inhibit tumor growth in nude mice xenotransplanted with HepG2 cells, changed the morphology of tumor cells, and regulated the expression of apoptosis-related protein pathway p53/Bcl-2/Cyt-C/caspase-3. HXHJ Ointment can significantly inhibit the development of hepatocellular carcinoma, and its mechanism may be related to the regulation of p53/Bcl-2/Cyt-C/caspase-3 signaling pathway to induce cell mitochondrial apoptosis.

14.
Int J Gen Med ; 14: 1379-1387, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33907442

RESUMEN

OBJECTIVE: This study aims to investigate the feasibility of the horizontal rotary-cut technique in the removal of superficial benign breast tumors with a ≤1.0 cm distance between the upper margin of the tumor and the skin. PATIENTS AND METHODS: A total of 69 patients with superficial benign breast tumors received horizontal rotary-cut surgery between July 2018 and June 2019 (horizontal group). The rotary cutter groove was in the true lateral position of the tumor and the ultrasonic probe was vertical to the rotary cutter groove. The patients were compared with 33 patients who underwent the traditional vertical rotary-cut surgery between July 2017 and June 2018 (traditional group) regarding the aspects of operation time, intraoperative bleeding volume, postoperative skin ecchymosis, skin damage, and tumor residue. The rotary cutter groove was directly below the tumor and the ultrasonic probe was parallel to the rotary cutter groove in the traditional vertical rotary-cut surgery. RESULTS: The operation time in the horizontal group was significantly shorter than in the traditional group (7.7 ± 1.1 minutes vs 9.5 ± 1.3 minutes, with t = -7.458 and p = 0.000) and there was significantly less skin damage in the horizontal group than in the traditional group (0 cases vs 3 cases, with p = 0.032). The differences in intraoperative bleeding and postoperative skin ecchymosis between the two groups were not statistically significant (6.0 ± 1.3 mL vs 6.5 ± 1.5 mL, with t = -1.853 and p = 0.067; 4 cases vs 2 cases, with χ 2 = 0.003 and p = 0.958). Ninety-seven patients attended follow-ups for 6-30 (16.5 ± 4.5) months. No residues or recurrences were observed under ultrasound reviews in either group. CONCLUSION: In superficial benign breast tumor removal, the horizontal rotary-cut breast technique can help avoid skin injury, shorten the operation time, and reduce tumor residue more effectively compared with the traditional vertical rotary-cut technique. It has certain popularization and application values.

15.
Chem Commun (Camb) ; 57(30): 3684-3687, 2021 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-33725052

RESUMEN

We have developed a new radical-mediated alkoxypolyhaloalkylation of styrenes with polychloroalkanes and alcohols for the facile synthesis of complex polyhaloalkanes. 4-Methoxybenzenediazonium tetrafluoroborate is a good radical initiator for this transformation. This protocol is well applied to the late-stage functionalization of complex molecules, including vitamin E, estrone and cholesterol derivatives.

16.
Org Lett ; 23(3): 1000-1004, 2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33476163

RESUMEN

We have disclosed a new radical-mediated decarboxylative C(sp3)-N cross-coupling of diacyl peroxides with nitrogen nucleophiles. The primary and secondary alkyl radicals derived from corresponding diacyl peroxides were generated by copper catalysis or by merging copper catalysis and photoredox catalysis, respectively. Various N-alkyl nitrogen nucleophiles, including indazoles, triazoles, indoles, purine, carbazole, anilines, and sulfonamide, were provided with a broad substrate scope and good functional group tolerance.


Asunto(s)
Nitrógeno/química , Peróxidos/química , Compuestos de Anilina/química , Carbazoles/química , Catálisis , Cobre/química , Estructura Molecular
17.
Chem Commun (Camb) ; 56(90): 14055-14058, 2020 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-33103675

RESUMEN

We have developed a new oxidative decarboxylation of cinnamic acids with 4-alkyl-1,4-dihydropyridines to construct C(sp3)-C(sp2) bonds in the presence of copper catalyst and dicumyl peroxide (DCP). A variety of internal alkenes have been obtained with mild conditions, broad substrate scope and excellent functional group tolerance. This method has significant potential for application by using inexpensive and stable cinnamic acids instead of alkenyl halides and nitro-olefins.

18.
Org Lett ; 22(18): 7250-7254, 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-32852217

RESUMEN

A general, ideal atom utilization electrochemical technology to enable alkene alkoxyhalogenation and organohalide dehalogenation in one pot is presented. This technology is highlighted by convergent strategy integrating several reactions, such as alkene alkoxyhalogenation, organohalide dehalogenation, and dehalogenation deuteration. Experimental data suggest that alkenes have the lowest oxidation potential, which lead to anodic conversion of the C═C bond to the radical cation intermediates, and cathodic transformations of organohalides, including alkyl and aryl halides, as the nucleophilic halogen sources.

19.
Biomed J ; 43(4): 318-324, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32654885

RESUMEN

Aggressive tracing of contacts of confirmed cases is crucial to Taiwan's successful control of the early spread of COVID-19. As the pandemic lingers, an epidemiological investigation that can be conducted efficiently in a timely manner can help decrease the burden on the health personnel and increase the usefulness of such information in decision making. To develop a new tool that can improve the current practice of epidemiological investigation by incorporating new technologies in digital platform and knowledge graphs. To meet the various needs of the epidemiological investigation, we decided to develop an e-Outbreak Platform that provides a semi-structured, multifaceted, computer-aided questionnaire for outbreak investigation. There are three major parts of the platform: (1) a graphic portal that allows users to have an at-glance grasp of the functions provided by the platform and then choose the one they need; (2) disease-specific questionnaires that can accommodate different formats of the information, including text typing, button selection, and pull-down menu; and (3) functions to utilize the stored information, including report generation, statistical analyses, and knowledge graphs displaying contact tracing. When the number of outbreak investigation increases, the knowledge graphs can be extended to encompass other persons appearing in the same location at the same time, i.e., constituting a potential contact cluster. The information extracted can also be used to display the tracing on a map in animation. Overall, this system can provide a basis for further refinement that can be generalized to a variety of outbreak investigations.


Asunto(s)
Betacoronavirus/patogenicidad , Infecciones por Coronavirus/diagnóstico , Brotes de Enfermedades/prevención & control , Neumonía Viral/diagnóstico , Encuestas y Cuestionarios , COVID-19 , Femenino , Humanos , Masculino , Pandemias , SARS-CoV-2 , Taiwán
20.
Org Biomol Chem ; 18(25): 4843-4847, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32608447

RESUMEN

A simple and practical method for the synthesis of phosphoryl-substituted indolo[2,1-a]isoquinolin-6(5H)-ones and benzimidazo[2,1-a]isoquinolin-6(5H)-ones through manganese(iii)-promoted tandem phosphinoylation/cyclization of 2-arylindoles or 2-arylbenzimidazoles with disubstituted phosphine oxides was developed. In this transformation, new C-P bond and C-C bond were constructed simultaneously under silver-free conditions, exhibiting a broad substrate scope. It was noted that not only diarylphosphine oxides but also dialkyl and arylalkyl-phosphine oxides were compatible with the conditions.

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