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1.
J Am Chem Soc ; 145(19): 10491-10496, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37141000

RESUMO

Strained cyclic allenes are a class of in situ-generated fleeting intermediates that, despite being discovered more than 50 years ago, has received significantly less attention from the synthetic community compared to related strained intermediates. Examples of trapping strained cyclic allenes that involve transition metal catalysis are especially rare. We report the first annulations of highly reactive cyclic allenes with in situ-generated π-allylpalladium species. By varying the ligand employed, either of two isomeric polycyclic scaffolds can be obtained with high selectivity. The products are heterocyclic and sp3-rich and bear two or three new stereocenters. This study should encourage the further development of fragment couplings that rely on transition metal catalysis and strained cyclic allenes for the rapid assembly of complex scaffolds.

2.
Nature ; 618(7966): 748-754, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37075803

RESUMO

Since 18251, compounds with the molecular formula C6H6-most notably benzene-have been the subject of rigorous scientific investigation2-7. Of these compounds, 1,2,3-cyclohexatriene has been largely overlooked. This strained isomer is substantially (approximately 100 kcal mol-1) higher in energy compared with benzene and, similar to its relatives benzyne and 1,2-cyclohexadiene, should undergo strain-promoted reactions. However, few experimental studies of 1,2,3-cyclohexatriene are known8-12. Here we demonstrate that 1,2,3-cyclohexatriene and its derivatives participate in a host of reaction modes, including diverse cycloadditions, nucleophilic additions and σ-bond insertions. Experimental and computational studies of an unsymmetrical derivative of 1,2,3-cyclohexatriene demonstrate the potential for highly selective reactions of strained trienes despite their high reactivity and short lifetimes. Finally, the integration of 1,2,3-cyclohexatrienes into multistep syntheses demonstrates their use in rapidly assembling topologically and stereochemically complex molecules. Collectively, these efforts should enable further investigation of the strained C6H6 isomer 1,2,3-cyclohexatriene and its derivatives, as well as their application in the synthesis of important compounds.

3.
Resuscitation ; 174: 35-41, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35314211

RESUMO

AIM: Cerebral oxygenation (rSO2) is not routinely measured during pediatric cardiopulmonary resuscitation (CPR). We aimed to determine whether higher intra-arrest rSO2 was associated with return of spontaneous circulation (ROSC) and survival to hospital discharge. METHODS: Prospective, single-center observational study of cerebral oximetry using near-infrared spectroscopy (NIRS) during pediatric cardiac arrest from 2016 to 2020. Eligible patients had ≥30 s of rSO2 data recorded during CPR. We compared median rSO2 and percentage of rSO2 measurements above a priori thresholds for the entire event and the final five minutes of the CPR event between patients with and without ROSC and survival to discharge. RESULTS: Twenty-one patients with 23 CPR events were analyzed. ROSC was achieved in 17/23 (73.9%) events and five/21 (23.8%) patients survived to discharge. The median rSO2 was higher for events with ROSC vs. no ROSC for the overall event (62% [56%, 70%] vs. 45% [35%, 51%], p = 0.025) and for the final 5 minutes of the event (66% [55%, 72%] vs. 43% [35%, 44%], p = 0.01). Patients with ROSC had a higher percentage of measurements above 50% during the final five minutes of CPR (100% [100%, 100%] vs. 0% [0%, 29%], p = 0.01). There was no association between rSO2 and survival to discharge. CONCLUSIONS: Higher cerebral rSO2 during CPR for pediatric cardiac arrest was associated with higher rates of ROSC but not with survival to discharge.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca , Parada Cardíaca Extra-Hospitalar , Reanimação Cardiopulmonar/métodos , Circulação Cerebrovascular , Criança , Parada Cardíaca/terapia , Humanos , Parada Cardíaca Extra-Hospitalar/terapia , Oximetria/métodos , Estudos Prospectivos , Espectroscopia de Luz Próxima ao Infravermelho
4.
J Am Chem Soc ; 143(25): 9338-9342, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34143634

RESUMO

We report Pd-catalyzed annulations of in situ generated strained cyclic allenes. This methodology employs aryl halides and cyclic allene precursors as the reaction partners in order to generate fused heterocyclic products. The annulation proceeds via the formation of two new bonds and an sp3 center. Moreover, both diastereo- and enantioselective variants of this methodology are validated, with the latter ultimately enabling the rapid enantioselective synthesis of a complex hexacyclic product. Studies leveraging transition metal catalysis to intercept cyclic allenes represent a departure from the more common, historical modes of cyclic allene trapping that rely on nucleophiles or cycloaddition partners. As such, this study is expected to fuel the development of reactions that strategically merge transition metal catalysis and transient strained intermediate chemistry for the synthesis of complex scaffolds.


Assuntos
Alcadienos/química , Compostos Heterocíclicos com 3 Anéis/síntese química , Acetatos/química , Catálise , Ciclização , Indóis/química , Iodobenzenos/química , Compostos Organometálicos/química , Paládio/química , Piridinas/química , Estereoisomerismo
5.
JMIR Res Protoc ; 7(3): e9, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29547386

RESUMO

[This corrects the article DOI: 10.2196/resprot.6886.].

6.
JMIR Res Protoc ; 6(1): e5, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-28100441

RESUMO

BACKGROUND: Some 222 million women worldwide have unmet needs for contraception; they want to avoid pregnancy, but are not using a contraceptive method, primarily because of concerns about side effects associated with most available methods. Expanding contraceptive options-particularly fertility awareness options that provide women with information about which days during their menstrual cycles they are likely to become pregnant if they have unprotected intercourse-has the potential to reduce unmet need. Making these methods available to women through their mobile phones can facilitate access. Indeed, many fertility awareness applications have been developed for smartphones, some of which are digital platforms for existing methods, requiring women to enter information about fertility signs such as basal body temperature and cervical secretions. Others are algorithms based on (unexplained) calculations of the fertile period of the menstrual cycle. Considering particularly this latter (largely untested) group, it is critical that these apps be subject to the same rigorous research as other contraceptive methods. Dynamic Optimal Timing, available via the Dot app as a free download for iPhone and Android devices, is one such method and the only one that has published the algorithm that forms its basis. It combines historical cycle data with a woman's own personal cycle history, continuing to accrue this information over time to identify her fertile period. While Dot has a theoretical failure rate of only 3 in 100 for preventing pregnancy with perfect use, its effectiveness in typical use has yet to be determined. OBJECTIVE: The study objective is to assess both perfect and typical use to determine the efficacy of the Dot app for pregnancy prevention. METHODS: To determine actual use efficacy, the Institute for Reproductive Health is partnering with Cycle Technologies, which developed the Dot app, to conduct a prospective efficacy trial, following 1200 women over the course of 13 menstrual cycles to assess pregnancy status over time. This paper outlines the protocol for this efficacy trial, following the Standard Protocol Items: Recommendations for Intervention Trials checklist, to provide an overview of the rationale, methodology, and analysis plan. Participants will be asked to provide daily sexual history data and periodically answer surveys administered through a call center or directly on their phone. RESULTS: Funding for the study was provided in 2013 under the United States Agency for International Development Fertility Awareness for Community Transformation project. Recruitment for the study will begin in January of 2017. The study is expected to last approximately 18 months, depending on recruitment. Findings on the study's primary outcomes are expected to be finalized by September 2018. CONCLUSIONS: Reproducibility and transparency, important aspects of all research, are particularly critical in developing new approaches to research design. This protocol outlines the first study to prospectively test both the efficacy (correct use) and effectiveness (actual use) of a pregnancy prevention app. This protocol and the processes it describes reflect the dynamic integration of mobile technologies, a call center, and Health Insurance Portability and Accountability Act-compliant study procedures. Future fertility app studies can build on our approaches to develop methodologies that can contribute to the evidence base around app-based methods of contraception. CLINICALTRIAL: ClinicalTrials.gov NCT02833922; https://clinicaltrials.gov/ct2/show/NCT02833922 (Archived be WebCite at http://www.webcitation.org/6nDkr0e76).

7.
Clin Infect Dis ; 46(11): e119-23, 2008 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-18426374

RESUMO

Historically, untreated disseminated coccidioidomycosis during pregnancy was thought to be associated with 100% maternal fatality and 50% fetal mortality and was the leading cause of maternal deaths in areas of endemicity. As recently as 1995, therapeutic abortions and early deliveries were advocated in certain contexts. This report describes an unrecognized case of disseminated coccidioidomycosis diagnosed at the time of placental examination in a woman who completed her pregnancy without significant maternofetal complications. This case suggests that abortion and early delivery may not be necessary, because the possibility of an uncomplicated pregnancy exists. It is likely that other similar cases exist but remain underreported or underdiagnosed because of the mild, nondescript nature of the illness and low clinical suspicion. Although this mother and infant had good clinical outcomes, thorough travel histories and consideration of the associated travel-related diseases are important because of the possibility of serious, potentially avoidable clinical consequences.


Assuntos
Coccidioidomicose/epidemiologia , Coccidioidomicose/transmissão , Placenta/microbiologia , Adulto , Coccidioidomicose/diagnóstico , Feminino , Humanos , Morbidade , Gravidez , Complicações Infecciosas na Gravidez/microbiologia
8.
Cytojournal ; 3: 8, 2006 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-16584551

RESUMO

BACKGROUND: Mammary sclerosing lobular hyperplasia is an uncommon benign lesion of adolescent and young women. Fine-needle aspiration cytology of mammary sclerosing lobular hyperplasia is said to show characteristic features that include an absence of stromal fragments. CASE PRESENTATION: In this article, we describe a case of sclerosing lobular hyperplasia that occurred in the right breast of a 12-year-old girl. Fine-needle aspiration cytology showed some fibroadenoma-like features including the presence of stromal fragments, while branched tubular fragments were not seen. The diagnosis of sclerosing lobular hyperplasia was made on histologic examination that showed preserved acinar architecture with lobular hyperplasia and sclerosis of intralobular and interlobular stroma. CONCLUSION: Fine-needle aspiration cytology features of mammary sclerosing lobular hyperplasia are not diagnostic and overlap with those of fibroadenoma; however, a distinction between the two benign entities is of no clinical significance. The definitive diagnosis of sclerosing lobular hyperplasia requires histopathologic evaluation.

9.
Clin Chem ; 47(10): 1769-75, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11568085

RESUMO

BACKGROUND: Carbohydrate-deficient transferrin (CDT) is used as a serum marker for heavy drinking. We compared a new Bio-Rad %CDT TIA assay with the CDTect assay; we also compared both to gamma-glutamyltransferase (GGT) as markers of heavy drinking. METHODS: Serum samples of well-defined alcoholics (n = 404) and matched (age, race, and gender) social drinkers (204) from 10 clinical centers were assayed with both CDT assays. Both assays use microcolumn separation after iron saturation, followed by enzyme immunoassay (CDTect) or turbidimetric immunoassay (Bio-Rad %CDT). In the latter, CDT is expressed as a percentage of total transferrin. RESULTS: The slope and intercept [95% confidence intervals (CIs)] for linear regression of results obtained by the %CDT-TIA (as percentage) and CDTect (units/L) assays were 0.091 (0.088-0.097) and 0.70% (0.54-0.86%), respectively (S(y/x) =1.30%; r = 0.848). The areas under the ROC curves (95% CIs) for CDTect and Bio-Rad %CDT TIA were 0.89 (0.86-0.92) and 0.88 (0.85-0.91), respectively, for men (P, not significant) and 0.76 (0.72-0.80) and 0.72 (0.68-0.76) for women (P, not significant). When CDT (CDTect or Bio-Rad %CDT) was combined with GGT (either one positive), the clinical sensitivity in men was 90% for both assays, and specificities were 81% and 84%, respectively; sensitivities in women were 75% and 76%, respectively, and specificities were 87% and 91%. CONCLUSION: The new Bio-Rad %CDT TIA assay compares favorably to the widely studied CDTect assay in the detection of alcohol-use disorders.


Assuntos
Alcoolismo/diagnóstico , Transferrina/análise , gama-Glutamiltransferase/sangue , Adulto , Biomarcadores/sangue , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Nefelometria e Turbidimetria , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Transferrina/análogos & derivados
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