gebhart/patrepeval huggingface dataset:
Low-Cost MEMS Packaging Using Polymer-Based Air-Gaps (2014)

The improvements in microelectromechanical systems (MEMS) have been traditionally focused more on the functionality and sensitivity of devices. However, packaging of MEMS devices has become a bottleneck mainly due to a wide range of device dimensions and packages being device-specific. In this study, we present a low-cost, sacrificial polymer-based MEMS packaging using air-gaps. Air-gaps were fabricated with poly(propylene carbonate) (PPC) as the sacrificial material and Cyclotene 4026 (BCB) as the overcoat. BCB was found to provide excellent mechanical support for the air cavity during the decomposition of the sacrificial material at high temperature and after decomposition at room temperature. Initial results were found to be promising in terms of before-and-after resonant spectra changes, i.e. &lt;0.1% change in resonant frequency, and &lt;5.2% change in quality factor. Two possible schemes of air-gap MEMS packaging are presented: (i) air-gap structures with BCB overcoat cap, and (ii) air-gap structures without BCB overcoat cap. Both schemes utilize epoxy overmolding as the protective layer.
Does Freund's Adjuvant Denature Protein Antigens? EPR Studies of Emulsified Hemoglobin (1976)

Use of complete Freund's adjuvant for production of antibodies to study protein conformation is valid only if emulsification in adjuvant does not denature protein antigens. Using electron paramagnetic resonance to observe directly the protein in situ in the opaque emulsions, we demonstrate that hemoglobin is not denatured by emulsification or storage in adjuvant for 24 hr at 4 degrees C, conditions comparable to the usual handling of antigens before immunization.
Effect of leptin deficiency on metabolic rate inob/obmice (1999)

Reduced metabolic rate may contribute to weight gain in leptin-deficient (ob/ob) mice; however, available studies have been criticized for referencing O2 consumption (VO2) to estimated rather than true lean body mass. To evaluate whether leptin deficiency reduces energy expenditure, four separate experiments were performed: 1) NMR spectroscopy was used to measure fat and nonfat mass, permitting VO2 to be referenced to true nonfat mass; 2) dietary manipulation was used in an attempt to eliminate differences in body weight and composition between ob/ob and C57BL/6J mice; 3) short-term effects of exogenous leptin (0.3 mg. kg-1. day-1) on VO2 were examined; and 4) body weight and composition were compared in leptin-repleted and pair-fed ob/ob animals. ob/ob animals had greater mass, less lean body mass, and a 10% higher metabolic rate when VO2 was referenced to lean mass. Dietary manipulation achieved identical body weight in ob/ob and C57BL/6J animals; however, despite weight gain in C57BL/6J animals, percent fat mass remained higher in ob/ob animals (55 vs. 30%). Exogenous leptin increased VO2 in ob/ob but not control animals. Weight loss in leptin-repleted ob/ob mice was greater than in pair-fed animals (45 vs. 17%). We conclude, on the basis of the observed increase in VO2 and accelerated weight loss seen with leptin repletion, that leptin deficiency causes a reduction in metabolic rate in ob/ob mice. In contrast, these physiological studies suggest that comparison of VO2 in obese and lean animals does not produce useful information on the contribution of leptin to metabolism.
Atomic Layer Deposition of Tantalum Oxide and Tantalum Silicate from Chloride Precursors (2012)

Abstract The atomic layer deposition (ALD) of Ta 2 O 5 and TaSiO x from TaCl 5 , SiCl 4 , and H 2 O is reported. Both processes are influenced by the concomitant etching of Ta 2 O 5 and TaSiO x by TaCl 5 . The optimum deposition temperature is found to be 250 °C for both Ta 2 O 5 and TaSiO x . For lower deposition temperatures, the large Cl contamination leads to poor dielectric properties of the films, whereas higher temperatures lead to poor within‐wafer (WiW) thickness non‐uniformity due to etching. Si incorporation is limited to Si/(Si + Ta) ∼ 0.65 because of the slow adsorption kinetics of SiCl 4 on SiOH‐terminated surfaces. Under optimum conditions, amorphous films with good dielectric quality are obtained.
Genetic and Functional Analyses of SHANK2 Mutations Suggest a Multiple Hit Model of Autism Spectrum Disorders (2012)

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23-4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11-q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the "multiple hit model" for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.
Optical Transpose Interconnection System for Vertical Emitters (1997)

Optical interconnections have advantages over electrical interconnections in terms of speed, power, and density for high-speed links over distances on the order of centimeters 1 . In this paper, we are concerned with a particular interconnection pattern, the k -shuffle 2 . The optical transpose interconnection system 3 (OTIS) architecture provides this pattern using only a pair of lenslet arrays. Here, we describe a novel optical system design for implementing the OTIS architecture utilizing vertical emitters (OTIS-VE). In contrast, for high efficiency and power uniformity, earlier designs required individually directed transmitters. We carry out a Gaussian beam analysis to optimize the system parameters and to show that fabrication of the system is feasible.
A human protein required for the second step of pre-mRNA splicing is functionally related to a yeast splicing factor. (1997)

We have identified a human splicing factor required for the second step of pre-mRNA splicing. This new protein, hPrp18, is 30% identical to the yeast splicing factor Prp18. In HeLa cell extracts immunodepleted of hPrp18, the second step of pre-mRNA splicing is abolished. Splicing activity is restored by the addition of recombinant hPrp18, demonstrating that hPrp18 is required for the second step. The hPrp18 protein is bound tightly to the spliceosome only during the second step of splicing. hPrp18 is required for the splicing of several pre-mRNAs, making it the first general second-step splicing factor found in humans. Splicing activity can be restored to hPrp18-depleted HeLa cell extracts by yeast Prp18, showing that important functional regions of the proteins have been conserved. A 90-amino-acid region near the carboxyl terminus of hPrp18 is strongly homologous to yeast Prp18 and is also conserved in rice and nematodes. The homology identifies one region important for the function of both proteins and may define a new protein motif. In contrast to yeast Prp18, hPrp18 is not stably associated with any of the snRNPs. A 55-kD protein that cross-reacts with antibodies against hPrp18 is a constituent of the U4/U6 and U4/U6 x U5 snRNP particles.
A close look at temperature profiles during laser powder bed fusion using operando X-ray diffraction and finite element simulations (2023)

In laser powder bed fusion (LPBF), complex components are manufactured layer-by-layer via scanning the cross-sections of a 3D CAD model using a high intensity laser. Throughout this process, the material is exposed to temperature profiles that significantly differ from conventional manufacturing methods, and result in development of a unique and inhomogeneous microstructure and high levels of residual stresses in additively fabricated parts. The large temperature gradients and rapid cooling rates around the moving laser spot, and the overall heterogeneity of the temperature field need to be better understood in order to optimize the process parameters for increased production quality. In this study, operando X-ray diffraction (XRD) was employed to measure and compare temperature histories on the laser path under various processing conditions for Hastelloy X. Finite element thermal simulations were validated based on the acquired XRD data and then used as a supplementary tool to discuss the cooling behaviour and thermal heterogeneities across the geometry. The increase in the deposited energy density was qualitatively linked with higher temperature levels and slower cooling rates during LPBF. The melt-pool lengths showed strong sensitivity to the laser power and little variation with the scanning speed. Furthermore, even for a single set of parameters, large variations in the temperature field within the build were observed such that the cross-section edges located at higher build layers were exposed to markedly higher temperature levels.
Inappropriate shocks in single-chamber and subcutaneous implantable cardioverter-defibrillators: a systematic review and meta-analysis (2017)

A comprehensive review of the literature shows that 6.4% of patients with ICDs experienced their first IS annually. One of the 16 studies was better than predicted with the lowest reported rate (1.9%) and could not be explained by timing of the study or other covariates.
Loudspeaker Testing at the Production Line (2006)

Quality control in the mass production of transducers and electro-acoustical systems requires an objective technique for reliable selection of defective units. A new technique is presented for detecting defects which produce almost inaudible symptoms during testing but may degrade sound quality in the final application (e.g. loose particles in the gap). Here the regular distortion which is characteristic for good units is modeled and actively compensated in the measured signal of a device under test to reveal symptoms of irregular defects (meta-hearing technology). The paper shows ways to perform high-speed measurements close to the physical limits and how to cope with ambient noise in a production environment. Traditional and more advanced techniques for separating passed and failed units are compared and their integration into process control is discussed. Finally, the paper addresses cost effective implementation in a robust hardware, flexibility to customer’s needs, simple handling and other practical requirements.
Fluorescent Er2O3 doped lead silicate glass for optical amplifiers (1999)

A hot-pressing method is investigated for the fabrication of a planar optical waveguide amplifier. Therefore commercially available LaSFN15 produced by Schott is used as substrate and cladding material in combination with Er2O3 doped lead silicate glass as core material, synthesised by a hybrid sol-gel melting technique. The lead silicate glass is selected for its low melting temperature required for the waveguide processing. The core glass is adapted to the LaSFN15 with respect to the thermal expansion coefficient and the refractive index. The composition suited for the hot-pressing technology is evaluated to be 45 mole% PbO and 55 mole% SiO2. The influence of increasing Er2O3 content to these parameters is compensated by changing the molar ratio of PbO/SiO2. The optimal composition of the doped core glass is found out to be a glass containing around 3 wt.% Er2O3 because concentration quenching accurs above.
Low Incidence of Pump-Related Infections in Jarvik 2000 Ventricular Assist Device Recipients with a Subcostal Driveline Exit Site (2019)

Driveline infection has been a persistent problem with mechanical cardiac assist devices. The reported incidence of infection has been low in patients who receive a Jarvik 2000 continuous-flow left ventricular assist device when a skull-pedestal driveline exit site is used. We evaluated whether this is also true when a subcostal driveline exit site is used. We reviewed baseline demographic variables, postimplantation vital signs, laboratory values, and culture results in patients who underwent Jarvik 2000 implantation at our center from April 2000 through October 2009, including follow-up through June 2014. All patients had a subcostal driveline exit site. We defined device-related infection as a positive blood or wound culture associated with a medical or surgical device intervention. Event and time-to-event rates were calculated. Eighty-one patients received 89 Jarvik 2000 devices, all as bridges to transplantation. The median support duration was 69 days (interquartile range, 27-153 d; range, 2-2,249 d). Five superficial driveline infections and one incision-site infection occurred (0.002 events per patient-year of support). The median time from pump implantation to onset of driveline infection was 30 days; the incision-related infection occurred at 44 days. The Jarvik 2000 has a low incidence of infection when implanted with use of a subcostal driveline exit site. The incidence of pump infections is particularly low. Using a subcostal driveline exit site may be as effective in preventing infections as using a skull-pedestal driveline exit site. We detail our findings in this report.
High Speed and Large Area Coating by Silica Thin Film with Self-organized Two Dimensional Macro Pores (2004)

Self-organized two-dimensional polystyrene spheres (PSL) were fabricated on a glass substrate by using a capillary coater. The coating speed was 100cm/min and the coating area was over 5×5cm2. The Voronoi polygon analysis was carried out for evaluating quantitatively the regularity of spheres or pores. The ratio of hexagons in all polygons, that is ordering factor; VP6, is defined as the quantitative measure of hexagonal closed-packed structures. The maximum VP6 of PSL spheres by Voronoi polygon analysis was 0.99. After the PSL spheres were completely decomposed at 400°C, the VP6 of the silica thin film with the pores was 0.98.
High peak power 974 nm fiber source employing parametric wavelength conversion with HOM fibers (2016)

We utilize four-wave mixing in the LP0,7 mode of a multi-mode fiber to achieve spatially coherent monomode 16-kW peak-power pulses at 974nm, of interest for realizing power-scalable, compact blue lasers in a monolithic fiber geometry.
Limitations of Ligand-Only Approaches for Predicting the Reactivity of Covalent Inhibitors (2019)

Covalent inhibition has undergone a resurgence and is an important modern-day drug design and chemical biology approach. To avoid off-target interactions and to fine-tune reactivity, the ability to accurately predict reactivity is vitally important for the design and development of safer and more effective covalent drugs. Several ligand-only metrics have been proposed that promise quick and simple ways of determining covalent reactivity. In particular, we examine proton affinity and reaction energies calculated with the density functional B3LYP-D3/6-311+G**//B3LYP-D3/6-31G* method to assess the reactivity of a series of α,β-unsaturated carbonyl compounds that form covalent adducts with cysteine. We demonstrate that while these metrics correlate well with experiment for a diverse range of small reactive molecules these approaches fail for predicting the reactivity of drug-like compounds. We conclude that ligand-only metrics such as proton affinity and reaction energies do not capture determinants of reactivity in situ and fail to account for important factors such as conformation, solvation, and intermolecular interactions.
Chemical biology of mutagenesis and DNA repair: cellular responses to DNA alkylation (2009)

The reaction of DNA-damaging agents with the genome results in a plethora of lesions, commonly referred to as adducts. Adducts may cause DNA to mutate, they may represent the chemical precursors of lethal events and they can disrupt expression of genes. Determination of which adduct is responsible for each of these biological endpoints is difficult, but this task has been accomplished for some carcinogenic DNA-damaging agents. Here, we describe the respective contributions of specific DNA lesions to the biological effects of low molecular weight alkylating agents.
230. Neural Progenitor Cell Transduction with AAV Serotypes 1 and 4 (2004)

The mucopolysaccharidoses (MPS) and the ceroid lipofuscinoses (NCLs) are devastating childhood onset diseases. Some forms of MPS and all NCLs have a severe CNS component. MPS VII, or beta-glucuronidase deficiency, and late-infantile NCL, or tripeptidyl protease deficiency are due to mutations in mRNAs encoding soluble lysosomal enzymes. Prior work in our laboratory and others' demonstrated that overexpression of beta-glucurondiase or TPP-1 from transduced cells in brain can lead to enzyme activity in non-transduced cells remote from the injection site, and improvements in cellular pathology and behavioral deficits. This occurs through a process called cross-correction. We hypothesized that cross-correction could also occur from gene-corrected endogenous neural progenitor cells (NPCs). Transduction of endogenous NPCs with virus expressing beta-glucuronidase or TPP-1 may allow enzyme secretion at several sites: 1) in the SVZ (with enzyme secreted into the ventricular system); 2) during migration through the corpus callosum (with enzyme secreted along the extensive white matter tracts of the corpus callosum); and 3) from differentiated neurons in the olfactory bulb (OB). We tested AAV1 and AAV4 for their ability to target endogenous neural progenitors. AAV4 vector injected unilateral into the lateral ventricle of adult or P0 C57BL/6 mice resulted in highly specific transduction of ependymal cells along the ventricular wall. Only scattered transgene positive cells were observed in the rostral migratory stream (RMS) and olfactory bulb in tissues harvested from several days to 8 weeks after gene transfer, regardless of injection time. Transgene positive cells did not express neuronal cell marker, indicating that NPCs were not a major target of AAV4 transduction in vivo. In contrast to AAV4, transgene positive migrating neuroblasts and olfactory bulb neurons were obvious after unilateral intraventricular injection of AAV1. However, numbers remained too few to consider AAV1-transduced NPCs as a significant source of recombinant lysosomal enzymes. Thus, transduction of endogenous NPCs with AAV4 does not occur, and with AAV1 is limited, preclude the use of these vectors for therapeutic application via NPCs.
ChemInform Abstract: Oxidative Dehydrogenation of Propane on Vanadium Supported on Magnesium Silicates. (1993)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Assessments of Hollow Cathode Wear in the Xenon Ion Propulsion System (XIPS) by Numerical Analyses and Wear Tests (2008)

The standard approach presently followed by NASA to qualify electric propulsion for the required mission throughput has been based largely on life tests, which can be costly and time consuming. Revised electric propulsion lifequalification approaches are being formulated that combine analytical and/or computational methods with (shorter-duration) wear tests. As a model case, a wear test is being performed at JPL to assess the lifetime of the discharge hollow cathode in the Xenon Ion Propulsion System (XIPS(c)), a 25-cm ion engine developed by L-3 Communications Electron Technologies, Inc. for commercial applications. Wear and plasma data accumulated throughout this life-assessment program are being used to validate the existing 2-D hollow cathode code OrCa2D. We find that the OrCa2D steady-state solution predicts very well the time-averaged plasma data and the keeper voltage after 5500 hrs of operation in high-power mode. When the wave motion that occurs naturally in these devices is accounted for, based on an estimate of the maximum wave amplitude, the molybdenum-keeper erosion profile observed in the XIPS(c) discharge cathode is also reproduced within a factor of two of the observation. When the same model is applied to predict the erosion of a tantalum keeper we find that erosion is reduced by more than two orders of magnitude compared to the molybdenum keeper due the significantly lower sputtering yield of tantalum. A tantalum keeper would therefore allow keeper lifetimes that greatly exceed the present requirements for deep-space robotic missions considered by NASA. Moreover, such large reduction of the erosion renders the largest uncertainties in the models, which are associated with the wave amplitude estimates and the electron transport model, negligible.
High-throughput, multiplexed pushbroom hyperspectral microscopy (2008)

We describe a high-throughput hyperspectral microscope. The system replaces the slit of conventional pushbroom spectral imagers with a static coded aperture mask. We present the theoretical underpinnings of the aperture coded spectral engine and describe two proof-of-concept experimental implementations. Compared to a conventional pushbroom system, the aperture coded systems have 32 times greater throughput. Both systems have about a 1 nm spectral resolution over the spectral range of 550-665 nm. For the first design, the spatial resolution for the system is 5.4 microm while the spatial resolution for the second system ranges from 7.7 microm to 1.54 microm. We describe experimental results from proof-of-concept applications of the imager to hyperspectral microscopy.
Selective, zirconium-mediated cross-coupling of alkynes: the synthesis of isomerically pure 1,3-dienes and 1,4-diiodo-1,3-dienes (1989)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelective, zirconium-mediated cross-coupling of alkynes: the synthesis of isomerically pure 1,3-dienes and 1,4-diiodo-1,3-dienesStephen L. Buchwald and Ralph B. NielsenCite this: J. Am. Chem. Soc. 1989, 111, 8, 2870–2874Publication Date (Print):April 1, 1989Publication History Published online1 May 2002Published inissue 1 April 1989https://pubs.acs.org/doi/10.1021/ja00190a021https://doi.org/10.1021/ja00190a021research-articleACS PublicationsRequest reuse permissionsArticle Views1676Altmetric-Citations158LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts