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41.
Simultaneous detection and quantitation of organic impurities in methamphetamine by ultra‐high‐performance liquid chromatography–tandem mass spectrometry,a complementary technique for methamphetamine profiling 下载免费PDF全文
The analysis of organic impurities plays an important role in the impurity profiling of methamphetamine, which in turn provides valuable information about methamphetamine manufacturing, in particular its synthetic route, chemicals, and precursors used. Ultra‐high‐performance liquid chromatography – tandem mass spectrometry (UHPLC – MS/MS) is ideally suited for this purpose due to its excellent sensitivity, selectivity, and wide linear range in multiple reaction monitoring (MRM) mode. In this study, a dilute‐and‐shoot UHPLC – MS/MS method was developed for the simultaneous identification and quantitation of 23 organic manufacturing impurities in illicit methamphetamine. The developed method was validated in terms of stability, limit of detection (LOD), lower limit of quantification (LLOQ), accuracy, and precision. More than 100 illicitly prepared methamphetamine samples were analyzed. Due to its ability to detect ephedrine/pseudoephedrine and its high sensitivity for critical target markers (eg, chloro‐pseudoephedrine, N‐cyclohexylamphetamine, and compounds B and P), more impurities and precursor/pre‐precursors were identified and quantified versus the current procedure by gas chromatography – mass spectrometry (GC – MS). Consequently, more samples could be classified by their synthetic routes. However, the UHPLC – MS/MS method has difficulty in detecting neutral and untargeted emerging manufacturing impurities and can therefore only serve as a complement to the current method. Despite this deficiency, the quantitative information acquired by the presented UHPLC – MS/MS methodology increased the sample discrimination power, thereby enhancing the capacity of methamphetamine profiling program (MPP) to conduct sample‐sample comparisons. 相似文献
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Organic cation transporter 3: Keeping the brake on extracellular serotonin in serotonin-transporter-deficient mice 下载免费PDF全文
Nicole L. Baganz Rebecca E. Horton Alfredo S. Calderon W. Anthony Owens Jaclyn L. Munn Lora T. Watts Nina Koldzic-Zivanovic Nathaniel A. Jeske Wouter Koek Glenn M. Toney Lynette C. Daws 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(48):18976-18981
Mood disorders cause much suffering and are the single greatest cause of lost productivity worldwide. Although multiple medications, along with behavioral therapies, have proven effective for some individuals, millions of people lack an effective therapeutic option. A common serotonin (5-HT) transporter (5-HTT/SERT, SLC6A4) polymorphism is believed to confer lower 5-HTT expression in vivo and elevates risk for multiple mood disorders including anxiety, alcoholism, and major depression. Importantly, this variant is also associated with reduced responsiveness to selective 5-HT reuptake inhibitor antidepressants. We hypothesized that a reduced antidepressant response in individuals with a constitutive reduction in 5-HTT expression could arise because of the compensatory expression of other genes that inactivate 5-HT in the brain. A functionally upregulated alternate transporter for 5-HT may prevent extracellular 5-HT from rising to levels sufficiently high enough to trigger the adaptive neurochemical events necessary for therapeutic benefit. Here we demonstrate that expression of the organic cation transporter type 3 (OCT3, SLC22A3), which also transports 5-HT, is upregulated in the brains of mice with constitutively reduced 5-HTT expression. Moreover, the OCT blocker decynium-22 diminishes 5-HT clearance and exerts antidepressant-like effects in these mice but not in WT animals. OCT3 may be an important transporter mediating serotonergic signaling when 5-HTT expression or function is compromised. 相似文献
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Malaria-specific transgenic CD4(+) T cells protect immunodeficient mice from lethal infection and demonstrate requirement for a protective threshold of antibody production for parasite clearance 总被引:6,自引:0,他引:6 下载免费PDF全文
Stephens R Albano FR Quin S Pascal BJ Harrison V Stockinger B Kioussis D Weltzien HU Langhorne J 《Blood》2005,106(5):1676-1684
T cells are important in the immune response to malaria, both for their cytokines and their help for antibody production. To look at the relative importance of these roles, a T-cell receptor (TCR) transgenic mouse has been generated carrying a TCR specific for an epitope of the merozoite surface protein 1 (MSP-1) of the malaria parasite, Plasmodium chabaudi. In adoptive transfer experiments, malaria-specific CD4(+) T cells expand and produce interferon gamma (IFN-gamma) early in infection, but the population contracts quickly despite prolonged persistence of the parasite. MSP-1-specific CD4(+) cells can protect immunodeficient mice from lethal infection; however, the parasite is only completely cleared in the presence of B cells showing that T helper cells are critical. Levels of malaria-specific antibody and the speed of their production clearly correlate with the time of resolution of infection, indicating that a critical threshold of antibody production is required for parasite clearance. Furthermore, T cells specific for a shed portion of MSP-1 are able to provide help for antibody to the protective region, which remains bound to the infected erythrocyte, suggesting that MSP-1 has all of the components necessary for a good vaccine. 相似文献
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Starla M. Weaver Jaclyn N. Portelli Aileen Chau Irene Cristofori Laura Moretti Jordan Grafman 《Brain imaging and behavior》2014,8(3):420-434
Recovery after Traumatic Brain Injury (TBI) is variable, even for patients with similar severity of brain injury. Recent research has highlighted the contribution that genetic predisposition plays in determining TBI outcome. This review considers the potential for genetic polymorphisms to influence recovery of cognitive and social processes following TBI. Limitations and considerations that researchers should make when assessing the potential impact of polymorphisms on TBI outcome are also discussed. Understanding the genetic factors that support neuroplasticity will contribute to an understanding of the variation in outcome following injury and help to identify potential targets for rehabilitation. 相似文献
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Choice of Vein‐Harvest Technique for Coronary Artery Bypass Grafting: Rationale and Design of the REGROUP Trial 下载免费PDF全文
Marco A. Zenati MD MSc J. Michael Gaziano MD MPH Joseph F. Collins ScD Kousick Biswas PhD Jennifer M. Gabany MSN CRNP CCRC Jacquelyn A. Quin MD MPH Jerene M. Bitondo PA‐C Faisal G. Bakaeen MD Rosemary F. Kelly MD A. Laurie Shroyer PhD Deepak L. Bhatt MD MPH 《Clinical cardiology》2014,37(6):325-330
The Randomized Endo‐vein Graft Prospective (REGROUP) trial ( ClinicalTrials.gov NCT01850082) is a randomized, intent‐to‐treat, 2‐arm, parallel‐design, multicenter study funded by the Cooperative Studies Program (CSP No. 588) of the US Department of Veterans Affairs. Cardiac surgeons at 16 Veterans Affairs (VA) medical centers with technical expertise in performing both endoscopic vein harvesting (EVH) and open vein harvesting (OVH) were recruited as the REGROUP surgeon participants. Subjects requiring elective or urgent coronary artery bypass grafting using cardiopulmonary bypass with use of ≥1 saphenous vein graft will be screened for enrollment using pre‐established inclusion/exclusion criteria. Enrolled subjects (planned N = 1150) will be randomized to 1 of the 2 arms (EVH or OVH) after an experienced vein harvester has been assigned. The primary outcomes measure is the rate of major adverse cardiac events (MACE), including death, myocardial infarction, or revascularization. Subject assessments will be performed at multiple times, including at baseline, intraoperatively, postoperatively, and at discharge (or 30 days after surgery, if still hospitalized). Assessment of leg‐wound complications will be completed at 6 weeks after surgery. Telephone follow‐ups will occur at 3‐month intervals after surgery until the participating sites are decommissioned after the trial's completion (approximately 4.5 years after the full study startup). To assess long‐term outcomes, centralized follow‐up of MACE for 2 additional years will be centrally performed using VA and non‐VA clinical and administrative databases. The primary MACE outcome will be compared between the 2 arms, EVH and OVH, at the end of the trial duration. 相似文献
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Chithiravel Sundaresan Pierre Josse Mrio C. Vebber Jaclyn Brusso Jianping Lu Ye Tao Salima Alem Benoît H. Lessard 《RSC advances》2022,12(16):10029
Silicon phthalocyanines as ternary additives are a promising way to increase the performance of organic photovoltaics. The miscibility of the additive and the donor polymer plays a significant role in the enhancement of the device performance, therefore, ternary additives can be designed to better interact with the conjugated polymer. We synthesized N-9′-heptadecanyl-2,7-carbazole functionalized SiPc ((CBzPho)2-SiPc), a ternary additive with increased miscibility in poly[N-90-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT). The resulting additive was included into PCDTBT and [6,6]-phenyl C71 butyric acid methyl ester as bulk (PC71BM) heterojunction OPV devices as a ternary additive. While the (CBzPho)2-SiPc demonstrated strong EQE >30% contribution in the range of 650–730 nm, the overall performance was reduced because (CBzPho)2-SiPc acted as a hole trap due to its high-lying HOMO energy level. This study demonstrates the importance of the solubility, miscibility, and energy level engineering of the ternary additive when designing organic photovoltaic devices.Silicon phthalocyanines with carbazole axial functional groups were synthesized to improve the miscibility in PCDTBT and for use as ternary additives in organic photovoltaics. 相似文献