gebhart/patrepeval huggingface dataset:
Hydrophobic Mesoporous Silica Particles Modified With Nonfluorinated Alkyl Silanes (2021)

This work reports the preparation of hydrophobic mesoporous silica particles (MSPs) modified with nonfluorinated alkyl silanes. Alkyl silanes were grafted onto the surface of the MSPs as a function of the length of nonfluorinated alkyl chains such as propyltriethoxysilane (C<sub>3</sub>), octyltriethoxysilane (C<sub>8</sub>), dodecyltriethoxysilane (C<sub>12</sub>), and octadecyltriethoxysilane (C<sub>18</sub>). Moreover, the grafting of the different alkyl silanes onto the surface of MSPs to make them hydrophobic was demonstrated using different conditions such as by changing the pH (0, 4, 6, 8, and 13), solvent type (protic and aprotic), concentration of silanes (0, 0.12, 0.24, 0.36, 0.48, and 0.60 M), reaction time (1, 2, 3, and 4 days), and reaction temperature (25 and 40 °C). The contact angles of the alkyl silane-modified MSPs were increased as a function of the alkyl chain lengths in the order of C<sub>18</sub> > C<sub>12</sub> > C<sub>8</sub> > C<sub>3</sub>, and the contact angle of C<sub>18</sub>-modified MSPs was 4 times wider than that of unmodified MSPs. The unmodified MSPs had a contact angle of 25.3°, but C<sub>18</sub>-modified MSPs had a contact angle of 102.1°. Furthermore, the hydrophobicity of the nonfluorinated alkyl silane-modified MSPs was also demonstrated by the adsorption of a hydrophobic lecithin compound, which showed the increase of lecithin adsorption as a function of the alkyl chain lengths. The cross-linking ratios of the modified silanes on the MSPs were confirmed by solid-state <sup>29</sup>Si-MAS nuclear magnetic resonance (NMR) measurement. Consequently, the hydrophobic modification on MSPs using nonfluorinated alkyl silanes was best preferred in a protic solvent, with a reaction time of ∼24 h at 25 °C and at a high concentration of silanes.
&lt;title&gt;Highly linear photoreceiver design for application to ultrahigh-bandwidth photonic A/D converters&lt;/title&gt; (2000)

Analog-to-digital converters operating at unprecedented speeds and resolutions are presently under development using a combination of photonics and electronics techniques. These systems impose stringent performance constraints on the photoreceivers used for photonic - electronic conversion, particularly in regard to linearity and noise. Photodetectors must accommodate optical pulses with very high input powers iwthout saturation, and the pulse input energy must be accurately determined. This paper presents design considerations and simulations of photodetectors and associated preamplifiers to meet these goals.
Triamidotriazacyclononane Complexes of Group 3 Metals. Synthesis and Crystal Structures (2003)

Reaction of yttrium and lanthanide trichlorides (Ln = La, Eu, Yb) with 1 equiv of the trisodium salt of 1,4,7-tris(dimethylsilylaniline)-1,4,7-triazacyclononane (Na(3)[(SiMe(2)NPh)(3)-tacn](THF)(2)) gives good yields of the compounds [M[(SiMe(2)NPh)(3)-tacn]] (M = Y (1), Eu (3), Yb (4)) and [La[(SiMe(2)NPh)(3)-tacn](THF)] (2). Reduction of 3 with Na/Hg followed by recrystallization in the presence of diglyme yielded crystals of [Eu[(SiMe(2)NPh)(3)-tacn]][Na(diglyme)(2)] (5). Synthesis of the uranium(III) complex [U[(SiMe(2)NPh)(3)-tacn]] (6) is achieved by reaction of 1 equiv of Na(3)[(SiMe(2)NPh)(3)-tacn](THF)(2) with uranium triiodide. The U(IV) complexes, [U[(SiMe(2)NPh)(3)-tacn]X] (X = Cl (7); I (8)), were prepared via oxidation of 6 with benzyl chloride or I(2), but salt metathesis from UCl(4) provided a higher yield route for 7. The solid-state structures of 1-7 were determined by single-crystal X-ray diffraction. The ligand [(SiMe(2)NPh)(3)-tacn] generates a trigonal prismatic coordination environment for the metal center in the neutral complexes 1, 3, 4, and 6 and the ionic 5. In 2 the six nitrogen atoms of the ligand are in a trigonal prismatic configuration with the oxygen atom of the THF capping one of the triangular faces of the trigonal prism. In 7 the coordination geometry around the uranium atom is best described as bicapped trigonal bipyramidal.
Pre-diagnostic plasma lipid levels and the risk of amyotrophic lateral sclerosis (2020)

To assess whether pre-diagnostic lipid levels are associated with Amyotrophic lateral sclerosis (ALS) risk. <i>Methods:</i> We conducted a matched case-control study nested in five large prospective US cohorts (the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the Women's Health Initiative), and identified 275 individuals who developed ALS during follow-up and had provided blood samples before disease diagnosis. For each ALS case, we randomly selected two controls who were alive at the time of the case diagnosis and matched on cohort, birth year (±1 year), sex, race/ethnicity, fasting status, and time of blood draw. We measured total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels in the plasma samples, and used conditional logistic regression to estimate associations between lipid levels and ALS risk. <i>Results:</i> Higher levels of HDL-C were associated with higher ALS risk in an analysis adjusted for the matching factors (risk ratio [RR] Q4 vs. Q1: 1.78, 95% confidence interval [CI]: 1.18-2.69, <i>p</i> trend: 0.007). The estimate remained similar in a multivariable analysis additionally adjusted for body mass index, physical activity, smoking, alcohol intake, plasma urate levels, and use of cholesterol-lowering drugs (RR Q4 vs. Q1: 1.71, 95% CI: 1.07-2.73, <i>p</i> trend: 0.02). Plasma levels of TC, LDL-C, and TG were not associated with ALS risk. <i>Conclusions:</i> Higher pre-diagnostic HDL-C levels, but not levels of other lipids, were associated with a higher risk of ALS.
Synthesis of Three Novel Fluorine-18 Labeled Analogues of <scp>l</scp>-Deprenyl for Positron Emission Tomography (PET) studies of Monoamine Oxidase B (MAO-B) (2011)

The aim in this project was to synthesize and to study fluorine-18 labeled analogues of l-deprenyl which bind selectively to the enzyme monoamine oxidase B (MAO-B). Three fluorinated l-deprenyl analogues have been generated in multistep organic syntheses. The most promising fluorine-18 compound N-[(2S)-1-[(18)F]fluoro-3-phenylpropan-2-yl]-N-methylprop-2-yn-1-amine (4c) was synthesized by a one-step fluorine-18 nucleophilic substitution reaction. Autoradiography on human brain tissue sections demonstrated specific binding for compound 4c to brain regions known to have a high content of MAO-B. In addition, the corresponding nonradioactive fluorine-19 compound (13) inhibited recombinant human MAO-B with an IC(50) of 170.5 ± 29 nM but did not inhibit recombinant human MAO-A (IC(50) > 2000 nM), demonstrating its specificity. Biodistribution of 4c in mice showed high initial brain uptake leveling at 5.2 ± 0.04%ID/g after 2 min post injection. In conclusion, compound 4c is a specific inhibitor of MAO-B with high initial brain uptake in mice and is, therefore, a candidate for further investigation in PET.
Response Profiles of Retinal Ganglion Cells to Sinusoidal Electric Stimulation vary for Low vs. High Frequencies (2020)

Microelectronic retinal prostheses electrically stimulate retinal neurons with the goal of restoring vision in patients blinded by outer retinal degeneration. Despite some success in clinical trials, the quality of vision elicited by these devices is still limited. To improve the performance of retinal prostheses, our group studied how retinal neurons respond to electric stimulation. Our previous work showed that responses of retinal ganglion cells (RGCs) are frequency-dependent and different types of RGCs can be preferentially activated with a specific frequency and current amplitude. In the present study, we systemically examined responses of RGCs to sinusoidal electric stimulation with varying frequencies and amplitudes. We found that ON sustained alpha RGCs show distinct stimulus-response relationships to low and high frequency stimulation. For example, RGCs showed monotonic response curves to 500 Hz sinusoidal stimulation, whereas they showed non-monotonic response curves to 2000 Hz stimulation. We also described how increasing stimulus frequency gradually changed the response curves of RGCs.
Spectroscopic Studies of the Modification of Crystalline Si(111) Surfaces with Covalently-Attached Alkyl Chains Using a Chlorination/Alkylation Method (2001)

A two-step procedure, involving radical-initiated chlorination of the Si surface with PCl5 followed by reaction of the chlorinated surface with alkyl-Grignard or alkyl-lithium reagents, has been developed to functionalize crystalline (111)-oriented H-terminated Si surfaces. The surface chemistry that accompanies these reaction steps has been investigated using X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), temperature programmed desorption spectroscopy (TPDS), high-resolution electron energy loss spectroscopy (HREELS), infrared (IR) spectroscopy in both glancing transmission (TIR) and attenuated total multiple internal reflection (ATR) modes, ellipsometry, and contact angle goniometry. The XPS data show the appearance of the Cl signal after exposure to PCl5 and show its removal, and concomitant appearance of a C 1s signal, after the alkylation step. Auger electron spectra, in combination with TPD spectroscopy, demonstrate the presence of Cl after the chlorination process and its subsequent loss after thermal desorption of Si−Cl fragments due to heating the Si surface to 1200 K. High-resolution XP spectra of the Si 2p region show a peak corresponding to Si−Cl bond formation after the chlorination step, and show the subsequent disappearance of this peak after the alkylation step. IR spectra show the loss of the perpendicularly polarized silicon monohydride (Si−H) vibration at 2083 cm-1 after the chlorination step, whereas HREELS data show the appearance of vibrations due to Si−Cl stretches upon chlorination of the Si surface. The HREELS data furthermore show the disappearance of the Si−Cl stretch and the appearance of a Si−C vibration at 650 cm-1 after alkylation of the Si surface. Ellipsometric measurements indicate that the thickness of the alkyl overlayer varies monotonically with the length of the alkyl group used in the reactant. Contact angle and IR measurements indicate that the packing of alkyl groups in the monolayers produced by this method is less dense than that found in alkylthiol monolayers on Au. As determined by XPS, the alkylated surfaces show enhanced resistance to oxidation by various wet chemical treatments, compared to the H-terminated Si surface. The two-step reaction sequence thus provides a simple approach to functionalization of (111)-oriented, H-terminated silicon surfaces using wet chemical methods.
Structure‒function studies of tryptophan mutants of equinatoxin II, a sea anemone pore-forming protein (2000)

Equinatoxin II (EqtII) is a eukaryotic cytolytic toxin that avidly creates pores in natural and model lipid membranes. It contains five tryptophan residues in three different regions of the molecule. In order to study its interaction with the lipid membranes, three tryptophan mutants, EqtII Trp45, EqtII Trp116/117 and EqtII Trp149, were prepared in an Escherichia coli expression system [here, the tryptophan mutants are classified according to the position of the remaining tryptophan residue(s) in each mutated protein]. They all possess a single intrinsic fluorescent centre. All mutants were less haemolytically active than the wild-type, although the mechanism of erythrocyte damage was the same. EqtII Trp116/117 resembles the wild-type in terms of its secondary structure content, as determined from Fourier-transform infrared (FTIR) spectra and its fluorescent properties. Tryptophans at these two positions are buried within the hydrophobic interior of the protein, and are transferred to the lipid phase during the interaction with the lipid membrane. The secondary structure of the other two mutants, EqtII Trp45 and EqtII Trp149, was altered to a certain extent. EqtII Trp149 was the most dissimilar from the wild-type, displaying a higher content of random-coil structure. It also retained the lowest number of nitrogen-bound protons after exchange with 2H2O, which might indicate a reduced compactness of the molecule. Tryptophans in EqtII Trp45 and EqtII Trp149 were more exposed to water, and also remained as such in the membrane-bound form.
Long-Term Analytical Performance of Hemostasis Field Methods as Assessed by Evaluation of the Results of an External Quality Assessment Program for Antithrombin (2002)

This linear regression model is useful for assessing the total error, random error, and bias for hemostasis field methods. The LCV(a) and ACD for measurement on a long-term time-scale appear to be useful for assessing the long-term analytical performance.
Recanalization, reperfusion, and recirculation in stroke (2017)

Recirculation, from arterial inflow routes through venous outflow pathways, was conceptualized in stroke research 50 years ago. As new technologies were developed, blocked arteries could be reopened, capillaries could be reperfused, and the use of recanalization and reperfusion grew to dominate therapeutic strategies. These approaches overwhelmingly focused on restoration of arterial and capillary inflow, but not on veins even though venous disorders may initiate or exacerbate brain injury. In this commentary, we advance the term "recirculation" after "recanalization" and "reperfusion" as a primary concept of stroke pathophysiology that targets the restoration of both the arterial and venous cerebral circulations.
Ion-Exchange and Cation Solvation Reactions in Ti<sub>3</sub>C<sub>2</sub> MXene (2016)

Ti3C2 and other two-dimensional transition metal carbides known as MXenes are currently being explored for many applications involving intercalated ions, from electrochemical energy storage, to contaminant sorption from water, to selected ion sieving. We report here a systematic investigation of ion exchange in Ti3C2 MXene and its hydration/dehydration behavior. We have investigated the effects of the presence of LiCl during the chemical etching of the MAX phase Ti3AlC2 into MXene Ti3C2Tx (T stands for surface termination) and found that the resulting MXene has Li+ cations in the interlayer space. We successfully exchanged the Li+ cations with K+, Na+, Rb+, Mg2+, and Ca2+ (supported by X-ray photoelectron and energy-dispersive spectroscopy) and found that the exchanged material expands on the unit-cell level in response to changes in humidity, with the nature of expansion dependent on the intercalated cation, similar to behavior of clay minerals; stepwise expansions of the basal spacing were observed, with changes consistent with the size of the H2O molecule. Thermogravimetric analysis of the dehydration behavior of these materials shows that the amounts of H2O contained at ambient humidity correlates simply with the hydration enthalpy of the intercalated cation, and that the diffusion of the exiting H2O proceeds with kinetics similar to clays. These results have implications for understanding, controlling, and exploiting structural changes and H2O sorption in MXene films and powders utilized in applications involving ions, such as electrochemical capacitors, sensors, reverse osmosis membranes, or contaminant sorbents.
Design, Fabrication, and Characteristics of a MEMS Micromirror With Sidewall Electrodes (2010)

This paper presents a 2-DOF silicon-on-insulator (SOI) microelectromechanical systems (MEMS) mirror with sidewall (SW) electrodes. The biaxial MEMS mirror with SW is actuated by electrostatic actuators. The dimension of mirror plate is 1000¿m × 1000¿m, with a thickness of 35 ¿m. The analytical modeling, fabrication process, and performance characteristics are described. This paper analyzes the effects of the three-end single crystal serpentine torsion bar width and the bottom and SW electrodes on the performance of the mirror. A new fabrication process based on SOI wafer, hybrid bulk/surface micromachined technology, and a high-aspect-ratio shadow mask is presented. In comparison to previous fabrication processes and the Optical iMEMS process, the process is novel, easily understood, and simple to realize. The measured maximum angular deflection achieved is ±11°(mechanical angle) at a static operating voltage and is ± 21°(mechanical angle) at resonance frequency driving. This mirror is well suited for applications where these characteristics are critical, such as in confocal or endoscopic scanning elements
Assessing variation in response to anti-VEGFR TKI AV-951 across a population of genetically defined tumor populations to dissect phenotypic and genetic context of sensitivity and resistance (2007)

B6 Clinical development of antiangiogenic therapies of cancer have been largely empirical, resulting in high failure rates, long time lines and significant exposure of patients to inappropriate or ineffective therapies. The observed variation in clinical antiangiogenic drug response across tumor types is likely underpinned by extensive and complex genetic variation across tumor types, subtypes and individuals. Traditional preclinical models of human xenografts have been of limited predictive utility in that successful inhibition of a particular xenograft tumor provides little insight into which clinical population is more likely to respond to treatment. In addition, extensive variation in genetic background across different cell lines, the lack of sufficient numbers of well characterized cell lines and the inappropriate cell culture context remain as significant hurdles for the effort to dissect genetic context of response and discovery of biomarkers.  To address these challenges, we have created an alternate approach for preclinical antiangiogenic response prediction and biomarker discovery. Using novel ES cell based chimeric approach, a large population of more than 100 genetically engineered murine breast tumors were generated, in which defined genetic alterations, i.e., HER2 overexpression & INK4A-/-, are allowed to be combined with spontaneous genetic alterations to more accurately model human cancer populations. Characterization of this tumor population revealed a surprising degree of variation in key parameters such as angiogenesis, microvasculature, VEGF expression, microarray gene expression and chromosomal gain/loss by array CGH.  Having developed methodology to expend and archive these tumors, we have now begun testing various antiangiogenic agents including AV-951 (formerly KRN-951), a pan VEGF receptor inhibitor currently in clinical development. Pilot pharmacological testing showed dramatic variation in drug response to AV-951 across tumors in the population, identifying both responsive and resistant tumors. Among resistant tumors, we have observed two different phenotypes. One resistant class exhibits reduction in vascularity, but continued tumor proliferation, whereas another class appears to maintain angiogenenic features despite treatment with AV-951.  We are currently working to correlate the phenotypic and genetic variation with responsiveness to AV-951 in an effort to use this population based model to identify and validate anti-angiogenesis response biomarkers.
An active haemovigilance programme characterizing the safety profile of 7437 platelet transfusions prepared with amotosalen photochemical treatment (2008)

Background An active haemovigilance programme was implemented to survey adverse events (AE) associated with transfusion of platelets photochemically treated with amotosalen and ultraviolet A (PCT‐PLT). The results of 5106 transfusions have already been reported. Here we report the results of an additional 7437 PCT‐PLT transfusions. Methods The focus of this ongoing haemovigilance programme is to document all AEs associated with PCT‐PLT transfusion. Data collected for AEs include: time of event after starting transfusion, clinical descriptions, vital signs, results from radiographs and bacterial cultures, event severity (Grade 0–4) and causal relationship to PCT‐PLT transfusion. Results One thousand four hundred patients (mean 60 years, range 1–96) received PCT‐PLT transfusions. The majority of the patients (53·4%) had haematology–oncology diseases and required conventional chemotherapy (44·8%) or stem cell transplantation (8·6%). Sixty‐eight PCT‐PLT transfusions were associated with AE. Acute transfusion reactions (ATR), classified as an AE possibly related, probably related, or related to PCT‐PLT transfusions were infrequent ( n = 55, 55/7437 = 0·7%) and most were of Grade 1 severity. Thirty‐nine patients (39/1400 = 2·8%) experienced one or more ATRs. The most frequently reported signs/symptoms were chills, fever, urticaria, dyspnoea, nausea and vomiting. Five AEs were considered severe (≥ Grade 2); however, no causal relationship to PCT‐PLT transfusion was found. Repeated exposure to PCT‐PLT did not increase the likelihood of an ATR. No cases of transfusion‐related acute lung injury and no deaths due to PCT‐PLT transfusions were reported. Conclusions Routine transfusion of PCT‐PLT is well‐tolerated in a wide range of patients. ATRs related to PCT‐PLT transfusion were infrequent and most were of mild severity.
A Two-element Interferometer for Millimeter-wave Solar Flare Observations (2023)

Abstract In this paper, we present the design and implementation of a two-element interferometer operating in the millimeter-wave band (39.5–40 GHz) for observing solar radio emissions through nulling interference. The system is composed of two 50 cm aperture Cassegrain antennas installed on a common equatorial mount, with a separation of 230 wavelengths. The cross-correlation of the received signals effectively cancels out the quiet solar component of the high flux density (∼3000 sfu) that reduces the detection limit due to atmospheric fluctuations. The system performance is as follows: the noise factor of the analog front end in the observation band is less than 2.1 dB, system sensitivity is approximately 12.4 K (∼34 sfu) with an integration time constant of 0.1 ms (default), the frequency resolution is 153 kHz, and the dynamic range is ≥30 dB. Through actual testing, the nulling interferometer observes a quiet Sun with a low level of output fluctuations (up to 50 sfu) and has a significantly lower radiation flux variability (up to 190 sfu) than an equivalent single-antenna system, even under thick cloud cover. As a result, this new design can effectively improve observation sensitivity by reducing the impact of atmospheric and system fluctuations during observation.