gebhart/patrepeval huggingface dataset:
Proton NMR studies of a biosynthetic lacto-ganglio hybrid glycosphingolipid: confirmation of structure, interpretation of anomalous chemical shifts, and evidence for interresidue amide-amide hydrogen bonding (1992)

Glycosphingolipids bearing GlcNAc beta 1----3 and GalNAc beta 1----4 linked to beta-Gal of lactosylceramide (lacto-ganglio hybrids), first isolated from a murine myelogenous leukemia cell line [Kannagi, R., Levery, S. B., & Hakomori, S. (1984) J. Biol. Chem. 259, 8444-8451], have since been found as normal components of mullet roe and English sole liver. In order to clarify the biosynthetic pathways responsible for its occurrence both as a product of normal tissues and as a possible mammalian cancer-associated antigen, the lacto-ganglio hybrid core structure LcGg4Cer was synthesized from Lc3Cer using a GalNAc beta 1----4 transferase preparation from English sole liver. A preliminary characterization of the enzyme, which may be identical to the GalNAc T-1 responsible for synthesis of GM2 ganglioside, is presented. The enzymatically synthesized product was analyzed by 1- and 2-D 1H NMR spectroscopy, confirmining its primary structure as GalNAc beta 1----4-(GlcNAc beta 1----3)Gal beta 1----4Glc beta 1----1Cer. In addition to assigning all nonexchangeable glycosyl proton resonances, measurements of several properties of the amide NH protons, including chemical shift, coupling constants, exchange rates, and temperature shift coefficients, were obtained and compared to those in the simpler constituent triglycosylceramides, Lc3- and Gg3Cer. An approximate three-dimensional structure for LcGg4Cer is proposed, consistent with all data obtained, which should be useful in discussing the results of 1H NMR analysis of compounds containing this core tetrasaccharide. The structure is characterized by an unusual arrangement of terminal N-acetylhexosamine residues, resulting in a pi-H hydrogen-bonding interaction between their acetamido groups.
Chiral‐magic angle of nanoimprint meta‐device (2023)

The magic angle of Twistronics has attracted a lot of attention because of its peculiar electrical characteristics. Moiré patterns formed by the superlattice of a twisted bilayer change overall physical properties. Circular dichroism can also be manipulated through the generated moiré pattern. Here, we report a polymer-based twisted bilayer meta-device fabricated by multilayer nanoimprint technology and study the magic angle of chirality. The superlattice of the bilayer meta-device creates moiré patterns and brings unique chiral optical responses. The bilayer nanoimprint technology is developed for metasurfaces with relative twist angles. Via the twist angle control, polymer materials with a low refractive index can manipulate the electric field of the light and reveal the chiral magic angle. Moreover, the shape of the meta-atoms plays a key role in chiral magic angle tuning. The chirality engineering by the reported nanoimprint technology and chiral meta-devices may contribute to applications in chiral imaging, biomedical sensing, lasing, and tunable optical devices.
Existence of an adenosine 5'-triphosphate dependent proton translocase in bovine neurosecretory granule membrane (1982)

The addition of ATP to bovine neurohypophysial secretory granules suspended in isotonic sucrose medium induces a positive polarization, delta psi, of their interior without affecting their internal pH. In KCl-containing media, ATP failed to generate large delta psi but induced a pH gradient (delta pH; interior acidic). These observations are consistent with the existence in the neurosecretory granule membrane of an ATP-dependent inward electrogenic H+ translocase (H+ pump), capable in KCl-containing media of acidifying the granule matrix by H+-Cl- cotransport. The delta psi and delta pH generated by the H+ pump, defined as the ATP-induced changes sensitive to the H+ ionophore carbonyl cyanide m-chlorophenylhydrazone (CCCP), were blocked by N,N'-dicyclohexylcarbodiimide, an inhibitor of all H+ pumps, and were insensitive to oligomycin, a mitochondrial ATPase inhibitor. In sucrose medium, measurements were complicated by a Donnan equilibrium reflecting the presence in the granule of peptide hormones and neurophysins which resulted in a CCCP-resistant resting delta pH. In KCl-containing media, the Donnan equilibrium was destroyed since the membrane is permeable to cations, but under these conditions a CCCP-resistant K+-diffusion potential was observed. The ATP-induced delta psi was also monitored by the extrinsic fluorescent probe bis(3-phenyl-5-oxoisoxazol-4-yl)pentamethine oxonol. The hypothesis of a granule H+ pump is further supported by the presence of an oligomycin-resistant ATPase in the preparation and the ultrastructural localization of such an activity on the granule membrane. The H+ pump has been found in both newly formed and aged neurosecretory granules. Its possible physiological function is discussed with reference to that of chromaffin granules, with which it has many similarities.
59. The influence of solvents and other factors on the rotation of optically active compounds. Part XXXVIII. Asymmetric solvent action (continued) (1940)

T. S. Patterson and C. Buchanan, J. Chem. Soc., 1940, 290 DOI: 10.1039/JR9400000290
Cylindrocyclin A, a New Cytotoxic Cyclopeptide from Cylindrocarpon sp. (2007)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Production of ACAT1 56-kDa isoform in human cells via trans-splicing involving the ampicillin resistance gene (2013)

Trans-splicing, a process involving the cleavage and joining of two separate transcripts, can expand the transcriptome and proteome in eukaryotes. Chimeric RNAs generated by trans-splicing are increasingly described in literatures. The widespread presence of antibiotic resistance genes in natural environments and human intestines is becoming an important challenge for public health. Certain antibiotic resistance genes, such as ampicillin resistance gene (Amp(r)), are frequently used in recombinant plasmids. Until now, trans-splicing involving recombinant plasmid-derived exogenous transcripts and endogenous cellular RNAs has not been reported. Acyl-CoA:cholesterol acyltransferase 1 (ACAT1) is a key enzyme involved in cellular cholesterol homeostasis. The 4.3-kb human ACAT1 chimeric mRNA can produce 50-kDa and 56-kDa isoforms with different enzymatic activities. Here, we show that human ACAT1 56-kDa isoform is produced from an mRNA species generated through the trans-splicing of an exogenous transcript encoded by the antisense strand of Amp(r) (asAmp) present in common Amp(r)-plasmids and the 4.3-kb endogenous ACAT1 chimeric mRNA, which is presumably processed through a prior event of interchromosomal trans-splicing. Strikingly, DNA fragments containing the asAmp with an upstream recombined cryptic promoter and the corresponding exogenous asAmp transcripts have been detected in human cells. Our findings shed lights on the mechanism of human ACAT1 56-kDa isoform production, reveal an exogenous-endogenous trans-splicing system, in which recombinant plasmid-derived exogenous transcripts are linked with endogenous cellular RNAs in human cells, and suggest that exogenous DNA might affect human gene expression at both DNA and RNA levels.
Supplementary Movie 4 from <i>In Vivo</i> Imaging of Drug-Induced Mitochondrial Outer Membrane Permeabilization at Single-Cell Resolution (2023)

&lt;p&gt;AVI file, 353KB, Time lapse image sequence of PANC-1 pancreatic cancer cells treated with TRAIL, showing the fluorescent IMS-RP MOMP reporter. The cell with the asterisk undergoes MOMP during this image sequence. (The asterisk is offset because the cell moves during the sequence.)&lt;/p&gt;
Trends in gynecologic cancer mortality in East Asian regions (2014)

Although uterine cancer mortality rates are declining in East Asia, additional effort is warranted to reduce the burden of gynecologic cancer in the future, through the implementation of early detection programs and the use of optimal therapeutic strategies.
Occurrence of multiple flame fronts in reheat combustors (2018)

Reheat flames are mainly stabilized by autoignition processes. In this paper their unsteady response to temperature fluctuations is investigated. To this end, a simple one dimensional duct is considered as an analytic surrogate model of a reheat combustion chamber. A chemistry-based correlation for the autoignition delay time is used to predict the flame position. In order to analyze the flame response to temperature fluctuations, the inlet boundary condition is harmonically excited. Depending on the amplitude and frequency of excitation, nonlinear phenomena are observed, in particular the co-existence of multiple flame fronts at different axial locations. The analytic formulation of the problem allows us to predict the onset of nonlinearities and to evaluate maps separating the linear from the nonlinear behavior, as function of the system parameters. Amplitude and frequency thresholds triggering different nonlinear properties of the system are identified. Verification of the obtained results for different excitation states is made by comparison to previously conducted Large Eddy Simulations of a simplified reheat combustor geometry represented by a backward-facing step. The simplified model is able to correctly predict the appearance of nonlinear phenomena as observed in the simulations suggesting that the governing factors are well represented.
Stepwise strategy for generating osteoblasts from human pluripotent stem cells under fully defined xeno-free conditions with small-molecule inducers (2020)

Clinically relevant human induced pluripotent stem cell (hiPSC) derivatives require efficient protocols to differentiate hiPSCs into specific lineages. Here we developed a fully defined xeno-free strategy to direct hiPSCs toward osteoblasts within 21 days. The strategy successfully achieved the osteogenic induction of four independently derived hiPSC lines by a sequential use of combinations of small-molecule inducers. The induction first generated mesodermal cells, which subsequently recapitulated the developmental expression pattern of major osteoblast genes and proteins. Importantly, Col2.3-Cherry hiPSCs subjected to this strategy strongly expressed the cherry fluorescence that has been observed in bone-forming osteoblasts <i>in vivo</i>. Moreover, the protocol combined with a three-dimensional (3D) scaffold was suitable for the generation of a xeno-free 3D osteogenic system. Thus, our strategy offers a platform with significant advantages for bone biology studies and it will also contribute to clinical applications of hiPSCs to skeletal regenerative medicine.
Fluconazole Coadministration Concurrent with Cyclophosphamide Conditioning May Reduce Regimen-Related Toxicity Postmyeloablative Hematopoietic Cell Transplantation (2007)

In a previous study comparing fluconazole and itraconazole administered as antifungal prophylaxis in hematopoietic cell transplant (HCT) recipients, we found that fluconazole administration concurrent with cyclophosphamide (CY)-based conditioning was associated with fewer early toxicities compared to itraconazole. Fluconazole inhibits cytochrome P450 2C9, which is involved with the activation of CY, and so might provide protection from CY-related toxicities. To investigate this further, we compared CY and CY-metabolite data from patients who received fluconazole (n = 56) concurrent with CY-containing conditioning and in patients who did not (n = 17). The fluconazole group had greater exposure to CY, and lower peak serum concentration of CY-metabolite 4-hydroxycyclophosphamide. In a separate cohort, we examined outcomes in patients randomized to receive either fluconazole (n = 152) or placebo (n = 147) concurrent with CY-containing conditioning in a prior randomized trial. Patients who received fluconazole experienced less hepatic and renal toxicity, and had lower mortality. No difference in relapsed malignancy was apparent. These data support the hypothesis that fluconazole, when coadministered with CY, decreases CY-related toxicities by inhibiting cytochrome P450 2C9 metabolism.
Integrating adaptive on-chip storage structures for reduced dynamic power (2003)

Energy efficiency in microarchitectures has become a necessity. Significant dynamic energy savings can be realized for adaptive storage structures such as caches, issue queues, and register files by disabling unnecessary storage resources. Prior studies have analyzed individual structures and their control. A common theme to these studies is exploration of the configuration space and use of system IPC as feedback to guide reconfiguration. However when multiple structures adapt in concert, the number of possible configurations increases dramatically, and assigning causal effects to IPC change becomes problematic. To overcome this issue, we introduce designs that are reconfigured solely on local behavior. We introduce a novel cache design that permits direct calculation of efficient configurations. For buffer and queue structures, limited histogramming permits precise resizing control. When applying these techniques we show energy savings of up to 70% on the individual structures, and savings averaging 30% overall for the portion of energy attributed to these structures with an average of 2.1% performance degradation.
What is the signal in noise? (2004)

Visual perception is limited by the strength of the neural signals, and by noise; however, little is known about what aspects of the input noise the human visual system is sensitive to, i.e., what is the signal in noise? To investigate this question we asked observers to discriminate differences in the strength of one-dimensional white noise. We measured their response consistency and classification images and compared the results with an ideal energy detector. The double-pass technique enabled us to partition the loss of efficiency into contributions from consistent and random noise, and the results show that random noise reduces human efficiency by about a factor of 2.25 over the approximately forty-fold range of noise levels tested. Consistent noise produces an additional efficiency reduction of about 20% at high noise and by a factor of 10–15 at near threshold noise levels. Consistent noise can be further partitioned into template noise and computational noise (which produces consistent responses not attributable to a mismatched template), by measuring the observer's classification image based on the noise energy at each frequency, and computing how the ideal observer would perform with the human observer's template. We found that the human template is bandpass, independent of the frequency range, suggesting that it is not simply the convolution of the stimulus with the observer's CSF. This template is surprisingly efficient. Template efficiency varies from about 50% at low noise levels to close to 80% at high. Computational noise produces minimal loss of efficiency at high noise levels and a nearly 6–10 fold loss at near threshold noise levels. Our results show that at high noise levels the human observer is mainly limited by random noise. At low noise levels the human observer gives surprisingly consistent responses, with a well-matched template, but with large computational inefficiency.
A Framework of a Surface Generation Model in Fast Tool Servo (FTS) Machining of Optical Microstructures (2007)

In this paper, a framework of surface generation model in the fast tool servo (FTS) machining of optical microstructures will be described. The integrated model is totally composed of a tool path generator (TPG), a surface topography model (STM) and an optimization model (OM). To develop the tool path generator, two parts should be involved. The first part is the tool path generated based on cutting conditions such as the feed rate and spindle speed, the geometry of optical microstructures, and diamond tool geometry. Another part is the synchronized motion generated by the tool actuation of the FTS at a bandwidth higher than the rotational frequency of the spindle. The surface topography model will be generated based on the TPG and used to predict the technological aspects of FTS machining. It takes into the account the kinematic and dynamic characteristics of the cutting process. The former includes the tool path generated by the tool path generator. The later includes the relative vibration between the tool and the workpiece caused by the axial error motion of the spindle as well as the synchronized motion of the FTS system. The optimization model will be undertaken by an iterative algorithm, which will be developed based on the TPG and STM. The OM will be expected to output the verified tool path, the suggested optimum cutting conditions, and the diagrams with predicted cutting performance characteristic and process parameters being investigated. Eventually, the successful development of this surface generation model can contribute for the knowledge of ultra-precision machining with FTS and the further development of the performance of the machining system.
The New Color Image Processing Techniques for Hardcopy (1989)

This paper addresses to provide some of the new image processing techniques for color hardcopy. The first requirement for high quality color imaging, is how to reproduce a continuous tone. In the actual printing systems, we often encounter the false contours caused by a lack of gray levels or a jump of dot density. Here, we present a tone smoothing method using an improved pseudo-noise modulation as a countermeasure for such a printer with discontinuities in gray scale reproduction. The second requirement is to get the correct color rendition. We discuss two models on color correction and show the practical applications for full color printing. As the third requirement, a function to adjust color-tone as you like, will be needed for the future hardcopies and we shortly discuss the color adjusting problem based on human color perception. Lastly, we report our latest works on the new color coding technique, which can reconstruct a full color image from a single color image by utilizing the strong correlation characteristics among RGB signals.
Microbial therapeutics: New opportunities for drug delivery (2019)

With >40 clinical trials underway, we are nearing the first FDA-approved live microbial therapeutic. Here, Giovanni Traverso, MIT and Harvard Medical School Assistant Professor, and colleagues Miguel Jimenez and Institute Professor Robert Langer from MIT discuss the significant challenges of administering live microorganisms to patients and the opportunities for drug delivery of these new complex therapeutics.
Ultrafast laser scribing of transparent conductive oxides in Cu(In,Ga)Se2 solar cells via laser lift-off process: the control of laser-induced damage (2017)

For higher cell-to-module efficiency in Cu(In,Ga)Se<sub>2</sub> (CIGS) thin-film solar cells, it is important to reduce the loss of active area due to integrated connection. The integrated connection contains three scribing processes: P1 (back contact insulation), P2 (electrical connection) and P3 (transparent conductive oxide, shortly TCO front contact insulation). In this work, we focused on ultrashort-pulse laser scribing (&lambda;=1034 nm, &Delta;&tau;=300 fs) of TCO via lift-off process as damage-less P3 scribing of CIGS thin-film solar cells. The lift-off of TCO was caused by laser ablation of only an upper part of CIGS light-absorbing layer. The dependence of lift-off behavior on the laser pulse energy and TCO film thickness has been investigated. It was observed that the lift-off of TCO formed a heat-affected zone (HAZ) with a thickness up to 250 nm beneath the trench bottom, where the CIGS experienced to melt. Further, thinner TCO film required lower laser energy threshold for the TCO lift-off, which is favorable to higher solar cell efficiency due to smaller HAZ. Using the TCO liftoff as P3, a submodule with an active area of approximately 3.5 cm<sup>2</sup> made by all laser scribing exhibited the conversion efficiency of 11.6 %. After post-annealing at 85 &deg;C for 15 h in vacuum for recovering laser-induced damages, the efficiency was successfully improved to 15.0 %, which is comparable to mechanically-scribed one.
Barriers, Incentives and Facilitators for Adoption of Universal Design Practices by Consumer Product Manufacturers (1998)

As electronic technologies become more integrated into education and employment, the ability to access and use these new technologies becomes critical to people with disabilities (40 million people in the U.S. alone) if they are to be able to participate in these environments. A key strategy for ensuring access to these emerging technologies is the practice of universal design - designing products so that they can be directly used by as many people as possible. Universal design is a practice that depends on the standard, mass-market product manufacturers for its implementation. Although there are key examples of universal design practices in the electronic and communication industries, they do not represent the majority of current practice. Little is known or documented about the reasons why universal design is, or is not, practiced. This paper reports on the first phase of a three-year project to explore the practice of universal design of products, including key factors, motivators, disincentives, and barriers to its practice, as well as what activities external to the company would facilitate (or hinder) practice within companies.
Experimental Characterization of a Two-Phase Heatsink (2015)

There is a continuous trend to increase power density in power electronics while traditional cooling methods like heat sinks cannot cope with this increase anymore. Cooling with two-phase thermosyphons allows to cool higher heat density without pump. Standard ther-mosyphon technology only works in vertical position because it uses gravity to move the phase changing fluid and has a fixed shape that cannot retrofit heatsinks in current product designs. This is a limitation for many products that would need a complete redesign to accommodate for a new air flow configuration. Hence, there is a need for thermosyphons working in vertical and possibly horizontal orientations and that can retrofit heatsinks, with performances allowing increase in power density. This article presents the experimental characterization of a new type of thermosyphon to fulfill these constraints.
ChemInform Abstract: Antitumor Agents. Synthesis and Biological Evaluation of New Compounds Related to Podophyllotoxin, Containing the 2,3‐Dihydro‐1,4‐benzodioxin System. (2001)

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.