Assessing the Impact of Flip Angle and on Image Quality and reliability of Ernst Angle optimization across Varied Conditions in Magnetic Resonance Imaging

This study investigates the significance of flip angle, an imaging parameter, in enhancing Magnetic Resonance image quality under various imaging conditions. It specifically explores the extent to which the Ernst angle, an optimal flip angle, optimizes image quality under different imaging parameters. The investigation begins with a theoretical derivation of the Ernst angle, assuming steady state imaging conditions. Then multiple studies that examine the effect of flip angle on signal-to-noise ratio (SNR), a key indicator of image quality, in different areas of the human body (blood, liver, and brain), are analysed. The study compares the results of these studies and compares their respective optimal flip angles with the Ernst angle. The findings reveal that flip angle plays a crucial role in enhancing SNR and image quality. However, the Ernst angle only optimizes SNR under steady state conditions and when using a spoiled gradient echo (GRE) sequence. Therefore, further investigations are necessary to determine the optimal flip angle under different imaging conditions to optimize SNR and enhance overall image quality.Comment: 23 pages, 5152 word

Neutrophil and endothelial cell-mediated inflammation in abdominal sepsis

Sepsis is defined as a life-threatening condition caused by a dysregulated host response to infection. Neutrophils are themost abundant innate immune cells of the body and play a key role in septic pathogenesis. During sepsis activatedneutrophils release web-like traps decorated with various cellular proteins known as neutrophil extracellular traps(NET). The primary task of NET and NET-associated proteins are to kill pathogens; however, excessive accumulationof NET is known to cause tissue damage. Endothelial cells are important for regulating vascular permeability andbarrier functions; however, during sepsis endothelial cells get activated and contribute to tissue damage andorgan failure. The four original studies included in this thesis aimed to investigate new mechanisms involved information of NET, lung injury and pulmonary endothelial cell activation in abdominal sepsis. In study I, we havefound that c-Abl kinase regulate NET formation through ROS signaling pathway. Blocking of c-Abl kinase notonly inhibited NET formation but also reduced inflammation and tissue damage in sepsis. In study II, weinvestigated the role of actin-related protein 2/3 complex (Arp2/3 complex) and found that it regulates neutrophiltrap expulsion both in vivo and in vitro. Inhibition of Arp2/3 complex not only reduced the neutrophil infiltration inbronchoalveolar space, but also alleviated lung damage in abdominal sepsis. In study III, we investigated the roleof S100A9, a pro-inflammatory alarmin, in regulating inflammation and tissue damage in abdominal sepsis.Inhibition of S100A9 by a specific inhibitor, ABR-238901, decreased sepsis-induced neutrophil activation,cytokine formation as well as damage to the lung tissue. In study IV, we examined global transcriptomic changesin a subgroup of lung endothelial cells during sepsis. We found that sepsis caused transcriptomic changes ofgenes related to regulation of coagulation, vascular permeability as well as wound healing and lipid metabolic incapillary endothelial cells. In contrast, postcapillary venules were found to be more enriched with genes related tochemotaxis, cell-cell adhesion of integrins, chemokine biosynthesis, regulation of actin polymerization andneutrophil homeostasis after sepsis. Together, these results demonstrated that targeting c-Abl, Arp2/3 complex,S100A9 or endothelial functions could be useful targets to ameliorate neutrophil mediated tissue injury in sepsis

The Role of Online Peer-to-Peer Lending in Crisis Response: Evidence from Kiva

Online peer-to-peer (P2P) lending, a new form of microfinance, has been touted as to its prominent potential for reducing world poverty. Although a growing body of research has been devoted to examining online P2P lending, how such platforms actually make a difference in curbing poverty has yet to be fully explored. The Ebola outbreak of 2014 provides us a unique empirical opportunity to explore such broader impacts of online P2P lending. We investigate how the demand and supply sides of P2P lending platforms react to an unpredictable crisis. Employing a difference-in-difference identification strategy with data from Kiva.org, we conduct country- and loan-level estimations. Results show upward trends on both demand and supply sides of P2P lending; borrowers request more financial capital and lenders are more active in their lending behaviors in the post-crisis period. We extend online P2P lending literature by investigating the influences of “off-platform shocks on within-platform behaviors

A New Fusion Method of Table Tennis Sensor Information System

We have collected Table Tennis Training data by sensor System to improve training level. Table Tennis Sensor System analytical methods must be better designed, including definitions, analysis principles, and Information Fusion to avoid inconsistent vocabulary and potentially incorrect interpretation of training data. A continuing problem for Information Fusion of Table Tennis Sensor (TTS) is to develop efficient information unit. Many experts see information fusion as an important solution. The quality of TTS information fusion include establishing and maintaining a database of Table Tennis training information, searching for applicable information to be fused in a design, as well as adapting information toward a proper structure. In this paper, a new Data Vector Model (DVM) method is suggested here for training data classification and fusion of Table Tennis training data. We found that this new method gives a higher accuracy in training data selection and fusion process of TTS compared to the existing formal methods. We can improve the level of Table Tennis training by this method

Determination of erlotinib in rabbit plasma by liquid chromatography mass spectrometry

A sensitive and selective liquid chromatography mass spectrometry (LC–MS) method for determination of erlotinib in rabbit plasma was developed. After addition of midazolam as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographic separation was achieved on a Zorbax SB-C18 (2.1 × 150 mm, 5 μm) column with acetonitrile-0.1 % formic acid as mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 394→336 for erlotinib and m/z 326→291 for the IS. Calibration plots were linear over the range of 5-2000 ng/mL for erlotinib in plasma. Lower limit of quantification (LLOQ) for erlotinib was 5 ng/mL. Mean recovery of erlotinib from plasma was in the range 84.5-95.7 %. CV of intra-day and interday precision were both less than 12 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of erlotinib in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Determination of erlotinib in rabbit plasma by liquid chromatography mass spectrometry

A sensitive and selective liquid chromatography mass spectrometry (LC–MS) method for determination of erlotinib in rabbit plasma was developed. After addition of midazolam as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographic separation was achieved on a Zorbax SB-C18 (2.1 × 150 mm, 5 μm) column with acetonitrile-0.1 % formic acid as mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 394→336 for erlotinib and m/z 326→291 for the IS. Calibration plots were linear over the range of 5-2000 ng/mL for erlotinib in plasma. Lower limit of quantification (LLOQ) for erlotinib was 5 ng/mL. Mean recovery of erlotinib from plasma was in the range 84.5-95.7 %. CV of intra-day and interday precision were both less than 12 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of erlotinib in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Development and Validation of Liquid Chromatography-Mass Spectrometry Method for Determination of Febuxostat in Rat Plasma and its Application

A selective liquid chromatography-mass spectrometry (LC–MS) method for determination of febuxostat in rat plasma was developed and validated. After addition of midazolam as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation, and chromatography involved Agilent SB-C18 column (2.1 x150 mm, 5 μm) using 0.1% formic acid in water and acetonitrile as a mobile phase with gradient elution. Detection involved positive ion mode electrospray ionization (ESI), and selective ion monitoring (SIM) mode was used for quantification of target fragment ions m/z 317 for febuxostat and m/z 326 for midazolam (internal standard, IS). The assay was linear over the range of 10-2000 ng/mL for febuxostat, with a lower limit of quantitation (LLOQ) of 10 ng/mL for febuxostat. Intra- and inter-day RSDs were less than 15% and the accuracies were in the range of 93.8-111.9% for febuxostat. This developed method was successfully applied to determinate of febuxostat in rat plasma for pharmacokinetic study.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Puerarin Induces Mitochondria-Dependent Apoptosis in Hypoxic Human Pulmonary Arterial Smooth Muscle Cells

Background: Pulmonary vascular medial hypertrophy in hypoxic pulmonary arterial hypertension (PAH) is caused in part by decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs). Puerarin, an isoflavone purified from the Chinese medicinal herb kudzu, ameliorates chronic hypoxic PAH in animal models. Here we investigated the effects of puerarin on apoptosis of hypoxic human PASMCs (HPASMCs), and to determine the possible underlying mechanisms. Methodology/Principal Findings: HPASMCs were cultured for 24 h in normoxia or hypoxia (5 % O2) conditions with and without puerarin. Cell number and viability were determined with a hemacytometer or a cell counting kit. Apoptosis was detected with a TUNEL test, rhodamine-123 (R-123) fluorescence, a colorimetric assay, western blots, immunohistochemical staining and RT-PCR. Hypoxia inhibited mitochondria-dependent apoptosis and promoted HPASMC growth. In contrast, after puerarin (50 mM or more) intervention, cell growth was inhibited and apoptosis was observed. Puerarin-induced apoptosis in hypoxic HPASMCs was accompanied by reduced mitochondrial membrane potential, cytochrome c release from the mitochondria, caspase-9 activation, and Bcl-2 down-regulation with concurrent Bax up-regulation. Conclusions/Significance: Puerarin promoted apoptosis in hypoxic HPASMCs by acting on the mitochondria-dependent pathway. These results suggest a new mechanism of puerarin relevant to the management of clinical hypoxic pulmonar

Riemannian Surface on Carbon Anodes Enables Li-Ion Storage at −35 °C

Since sluggish Li$^{+}$ desolvation leads to severe capacity degradation of carbon anodes at subzero temperatures, it is urgently desired to modulate electron configurations of surface carbon atoms toward high capacity for Li-ion batteries. Herein, a carbon-based anode material (O-DF) was strategically synthesized to construct the Riemannian surface with a positive curvature, which exhibits a high reversible capacity of 624 mAh g$^{-1}$ with an 85.9% capacity retention at 0.1 A g$^{-1}$ as the temperature drops to −20 °C. Even if the temperature drops to −35 °C, the reversible capacity is still effectively retained at 160 mAh g$^{-1}$ after 200 cycles. Various characterizations and theoretical calculations reveal that the Riemannian surface effectively tunes the low-temperature sluggish Li$^{+}$ desolvation of the interfacial chemistry via locally accumulated charges of non-coplanar sp$^{x}$ (2 < x < 3) hybridized orbitals to reduce the rate-determining step of the energy barrier for the charge-transfer process. Ex-situ measurements further confirm that the sp$^{x}$-hybridized orbitals of the pentagonal defect sites should denote more negative charges to solvated Li$^{+}$ adsorbed on the Riemannian surface to form stronger Li–C coordinate bonds for Li$^{+}$ desolvation, which not only enhances Li-adsorption on the curved surface but also results in more Li$^{+}$ insertion in an extremely cold environment

Determination of erlotinib in rabbit plasma by liquid chromatography mass spectrometry

A sensitive and selective liquid chromatography mass spectrometry (LC–MS) method for determination of erlotinib in rabbit plasma was developed. After addition of midazolam as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographic separation was achieved on a Zorbax SB-C18 (2.1 × 150 mm, 5 μm) column with acetonitrile-0.1 % formic acid as mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 394→336 for erlotinib and m/z 326→291 for the IS. Calibration plots were linear over the range of 5-2000 ng/mL for erlotinib in plasma. Lower limit of quantification (LLOQ) for erlotinib was 5 ng/mL. Mean recovery of erlotinib from plasma was in the range 84.5-95.7 %. CV of intra-day and interday precision were both less than 12 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of erlotinib in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire