6,999 research outputs found
Aminosilanetrithiol RSi(SH)(3): an experimental and quantum-chemical study
No full textAn interesting aminosilanetrithiol RSi(SH)(3) (R = N(SiMe3)-2,6-iPr(2)C(6)H(3)) has been prepared by the reaction of lithium aminosilanetrithiolate {RSi[SLi(THF)](3)}(2) with MeCOOH. Theoretical calculations indicate that the LP(N) -> sigma (Si-S) and LP(S) -> sigma (Si-S) electron donations remarkably contribute to the stabilization of the Si(SH)(3) part of the molecule. RSi(SH)(3) is the first example of a stable molecule containing three SH groups attached to one element
Measurement of the differential and double-differential Drell-Yan cross sections in proton-proton collisions at root s=7 TeV
No full textMeasurements of the differential and double-differential Drell-Yan cross sections are presented using an integrated luminosity of 4.5 (4.8) fb−1 in the dimuon (dielectron) channel of proton-proton collision data recorded with the CMS detector at the LHC at s√ = 7 TeV. The measured inclusive cross section in the Z-peak region (60–120 GeV) is σ(ℓℓ) = 986.4 ± 0.6 (stat.) ± 5.9 (exp. syst.) ± 21.7 (th. syst.) ± 21.7 (lum.) pb for the combination of the dimuon and dielectron channels. Differential cross sections dσ/dm for the dimuon, dielectron, and combined channels are measured in the mass range 15 to 1500 GeV and corrected to the full phase space. Results are also presented for the measurement of the double-differential cross section d2σ/dm d|y| in the dimuon channel over the mass range 20 to 1500 GeV and absolute dimuon rapidity from 0 to 2.4. These measurements are compared to the predictions of perturbative QCD calculations at next-to-leading and next-to-next-to-leading orders using various sets of parton distribution functions
The D-SPECT SH reconstruction protocol: improved quantification of small left ventricle volumes.
No full textBACKGROUND
Due to spatial resolution limitations, conventional NaI-SPECT typically overestimates the left ventricular (LV) ejection fraction (EF) in patients with small LV volumes. The purpose of this study was to explore the clinical application value of the small heart (SH) reconstruction protocol embedded in the postprocessing procedure of D-SPECT.
METHODS
We retrospectively analyzed patients who undergo both D-SPECT and echocardiography (Echo) within one week. Patients with small LV volume were defined as those with a rest end-systolic volume (rESV) ≤ 25 mL and underwent reconstruction using the standard (SD) reconstruction protocol. The SH protocol was deemed successful in correcting the LVEF value if it decreased by 5% or more compared to the SD protocol. The ROC curve was used to calculate the optimal cutoff value of the SH protocol. LVEF, ESV and EDV were computed with SD and SH, respectively. Echo was performed as a reference, and Echo-LVEF, ESV, and EDV were calculated using the Teichholz formula. One-way ANOVA was used to compare these parameters among the three groups.
RESULTS
The final study included 209 patients (73.21% female, age 67.34 ± 7.85 years). Compared with the SD protocol, the SH protocol significantly decreased LVEF (67.43 ± 7.38% vs. 71.30 ± 7.61%, p 17 mL (AUC = 0.651, sensitivity = 78.43%, specificity = 45.57%, p = 0.001). In the subgroup of rESV > 17 mL, there was no significant difference in LVEF (61.84 ± 4.67% vs. 62.83 ± 2.85%, p = 0.481) between the SH protocol and Echo, and no significant difference was observed in rESV (26.92 ± 3.25 mL vs. 27.94 ± 7.96 mL, p = 0.60) between the SH protocol and Echo.
CONCLUSION
This pilot study demonstrated that the SH reconstruction protocol was able to effectively correct the overestimation of LVEF in patients with small LV volumes. Particularly, in the rESV > 17 mL subgroup, the time and computing power waste could be reduced while still ensuring the accuracy of the LVEF value and image quality
Wellesly Sh. W. to Mr. James Meredith (2 October 1962)
No full textSigned by Wellesly Sh. W.https://egrove.olemiss.edu/mercorr_pro/1531/thumbnail.jp
Location verification for future wireless vehicular networks: Research directions and challenges
No full textVehicle location information obtained through the global navigation satellite system (GNSS) will play a pivotal role in emerging vehicular networks. This vital information is, however, susceptible to a host of unwanted manipulations, especially if a malicious entity is involved. The most obvious example of such manipulations is the forwarding by a malicious vehicle of false GNSS locations to other members of the network. Such events can lead to poor operational outcomes for the vehicular network, and in extreme cases even lead to catastrophic safety violations. Here, we highlight research efforts pursued in the past few years that have attempted to address this weakness in vehicular networks. We also discuss the importance of location verification in the wake of emerging wireless technologies, such as those being proposed for beyond 5G (B5G) wireless vehicular networks. In particular, we detail an opportunity to conduct location reporting and verification simultaneously with the aid of mmWave technology and discuss how emerging machine learning (ML) techniques will provide for location verification solutions where reliability levels will be commensurate with that required by the vehicular network paradigm. We close by discussing the potential enhancements for location verification within a future combined B5G-ML architecture
Effets d'un traitement chronique par la morphine sur le protéome des cellules de neuroblastome humain SH-SY5Y
No full textAfin de mieux comprendre les adaptations cellulaires induites suite à une prise chronique de morphine, une stratégie de type protéomique différentielle combinant les techniques d'électrophorèse et de spectrométrie de masse a été entreprise dans des cellules de neuroblastome humain sh-sy5y surexprimant le récepteur mop. l'étude globale des modifications induites par la morphine sur le protéome total a permis d'identifier environ 50 protéines impliquées dans des processus tels que l'organisation du cytosquelette, le trafic vésiculaire, la dégradation des protéines et la signalisation cellulaire. de plus, nous avons montré qu'un traitement chronique à la morphine entraînait la dégradation par le protéasome de sous-unités de protéines g; la dégradation deg étant étroitement corrélée à la sensibilisation de l'adénylyl cyclase, un phénomène impliqué dans la dépendance à la morphine. nos travaux suggèrent ainsi que le protéasome est impliqué dans les effets à long terme de la morphine
"Hong lou meng" yan jiu zi liao fen lei suo yin 1630-2009
No full text"Hong lou meng" yan jiu zi liao fen lei suo yin shi yi bu an lei shu li jian suo li dai "Hong lou meng"y an jiu zi liao pian mu di gong ju sh
Draft Genome Sequence of Vibrio owensii Strain SH-14, Which Causes Shrimp Acute Hepatopancreatic Necrosis Disease
No full textWe sequenced Vibrio owensii strain SH-14, which causes serious acute hepatopancreatic necrosis disease (AHPND) in shrimp. Sequence analysis showed a large extrachromosomal plasmid, which encoded pir toxin genes and shared highly sequence similarity with the one observed in AHPND-causing Vibrio parahaemolyticus strains. The results suggest that this plasmid appears to play an important role in shrimp AHPND
SMA-SH: Modified styrene maleic acid copolymer for functionalization of lipid nanodiscs
No full textChallenges in purification and subsequent functionalization of membrane proteins often complicate their biochemical and biophysical characterization. Purification of membrane proteins generally involves replacing the lipids surrounding the protein with detergent molecules, which can affect protein structure and function. Recently, it was shown that styrene–maleic acid copolymers (SMA) can dissolve integral membrane proteins from biological membranes into nanosized discs. Within these nanoparticles, proteins are embedded in a patch of their native lipid bilayer that is stabilized in solution by the amphipathic polymer that wraps the disc like a bracelet. This approach for detergent-free purification of membrane proteins has the potential to greatly simplify purification but does not facilitate conjugation of functional compounds to the membrane proteins. Often, such functionalization involves laborious preparation of protein variants and optimization of labeling procedures to ensure only minimal perturbation of the protein. Here, we present a strategy that circumvents several of these complications through modifying SMA by grafting the polymer with cysteamine. The reaction results in SMA that has solvent-exposed sulfhydrils (SMA-SH) and allows tuning of the coverage with SH groups. Size exclusion chromatography, dynamic light scattering, and transmission electron microscopy demonstrate that SMA-SH dissolves lipid bilayer membranes into lipid nanodiscs, just like SMA. In addition, we demonstrate that, just like SMA, SMA-SH solubilizes proteoliposomes into protein-loaded nanodiscs. We covalently modify SMA-SH-lipid nanodiscs using thiol-reactive derivatives of Alexa Fluor 488 and biotin. Thus, SMA-SH promises to simultaneously tackle challenges in purification and functionalization of membrane proteins.BN/Marie-Eve Aubin-Tam LabBN/Andreas Engel La
Omega-3 fatty acid eicospentaenoic acid attenuates MPP+-induced neurodegeneration in fully differentiated human SH- SY5Y and primary mesencephalic cells
No full textEicosapentaenoic acid ( EPA), a neuroactive omega-3 fatty acid, has been demonstrated to exert neuroprotective effects in experimental models of Parkinson's disease ( PD), but the cellular mechanisms of protection are unknown. Here, we studied the effects of EPA in fully differentiated human SH-SY5Y cells and primary mesencephalic neurons treated with MPP+. In both in-vitro models of PD, EPA attenuated an MPP+-induced reduction in cell viability. EPA also prevented the presence of electron-dense cytoplasmic inclusions in SH-SY5Y cells. Then, possible mechanisms of the neuroprotection were studied. In primary neurons, EPA attenuated an MPP+-induced increase in Tyrosine-related kinase B (TrkB) receptors. In SH-SY5Y cells, EPA down-regulated reactive oxygen species and nitric oxide. This antioxidant effect of EPA may have been mediated by its inhibition of neuronal NADPH oxidase and cyclo-oxygenase-2 ( COX-2), as MPP+ increased the expression of these enzymes. Furthermore, EPA prevented an increase in cytosolic phospholipase A2 ( cPLA2), an enzyme linked with COX-2 in the potentially pro-inflammatory arachidonic acid cascade. Lastly, EPA attenuated an increase in the bax:bcl-2 ratio, and cytochrome c release. However, EPA did not prevent mitochondrial enlargement or a decrease in mitochondrial membrane potential. This study demonstrated cellular mechanisms by which EPA provided neuroprotective effects in experimental P
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