gebhart/patrepeval huggingface dataset:
High‐Resolution Patterning of Hydrogels in Three Dimensions using Direct‐Write Photofabrication for Cell Guidance (2009)

Abstract The development of three‐dimensional, spatially defined neuronal cultures that mimic chemical and physical attributes of native tissue is of considerable interest for various applications, including the development of tailored neuronal networks and clinical repair of damaged nerves. Here, the use of multiphoton excitation to photocrosslink protein microstructures within three‐dimensional, optically transparent hydrogel materials, such as those based on hyaluronic acid, is reported. Multiphoton excitation confines photocrosslinking to a three‐dimensional voxel with submicron spatial resolution, enabling fabrication of protein matrices with low‐ to sub‐micrometer feature sizes by scanning the focus of a laser relative to the reagent solution. These methods can be used to create complex three‐dimensional architectures that provide both chemical and topographical cues for cell culture and guidance, providing for the first time a means to direct cell adhesion and migration on size scales relevant to in vivo environments. Using this approach, guidance of both dorsal root ganglion cells (DRGs) and hippocampal neural progenitor cells (NPCs) along arbitrary, three‐dimensional paths is demonstrated.
Aziridine-Functionalized Mesoporous Silica Membranes on Polymeric Hollow Fibers: Synthesis and Single-Component CO2 and N2 Permeation Properties (2014)

The synthesis of aziridine-functionalized mesoporous silica membranes on polymeric hollow fibers is described, and their single-component CO2 and N2 permeation properties are investigated under both dry and humid conditions to elucidate the unusual permeation mechanisms observed in these membranes. Hollow fiber-supported mesoporous silica membranes are amine-functionalized with aziridine to yield hyperbranched aminopolymers within the membrane pores. The effects of the hyperbranched polymers in the mesopores on gas transport properties are investigated by single-component gas permeation measurements. The hyperbranched aminosilica membrane shows counterintuitive N2-selective (over CO2) permeation during operation under dry conditions. Further characterization of the permeation behavior reveals the effects of strong adsorption of CO2 under dry permeation conditions, leading to reduced CO2 diffusivity because of CO2-induced amine cross-linking in the mesopores. On the other hand, the hyperbranched aminosilica membrane shows CO2-selective properties under humid conditions. Water molecules cause a lower degree of amine cross-linking and thus allow facilitated transport of CO2. This first study of hollow fiber-supported hyperbranched aminosilica membranes indicates that they can be tuned to have N2- or CO2-selective permeation properties under the conditions employed.
ChemInform Abstract: New Chiral Brominating and Chlorinating Agents, e.g. (II), (IV). (1994)

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.
Functional Photonic Switching Device by Vertical and Direct Integration of Six Heterojunction Phototransistors and Two Laser Diodes (1993)

Much interest has been emerging in optical signal processing and optical computing. In these fields, various functional devices are greatly demanded. A vertical and direct integration of a light-receiving device and a light-emitting device is an attractive method to achieve these functional devices [1–5]. The integrated device exhibits not only the simple combined characteristics of constituent devices but also the more elevated characteristics due to their internal optical couplings. For example, the integrated device composed of four heterojunction phototransistors (HPTs) and one laser diode (LD) offers the functions of light-controlled optical bistability, light-controlled optical thresholding, and optical tristability [6].
Werner syndrome: association of premature aging and cancer predisposition (2013)

Introduction Werner syndrome (WS) is a rare autosomal recessive disorder in humans characterized by segmental premature aging. Somatic cells from WS individuals show low replicative capacity, hypersensitivity to DNA-damaging agents, increased genome instability, and altered telomere maintenance (1). The incidence of sarcomas is significantly higher in WS patients than in normal individuals (1). Genetic evidence indicates that WS is caused by loss of function mutations in the WRN gene, which encodes a protein that belongs to the RecQ family of DNA helicases. Polymorphisms in WRN have been demonstrated to be associated with breast cancer (2) and soft tissue sarcomas (3,4). The WRN gene has been cloned and the properties of WS cells and WRN protein have been studied extensively. Nevertheless, the pathophysiology of WS and the cellular and molecular mechanisms involved in WS pathogenesis remain poorly understood. Because WS is a progerioid disease, it is used as a model system to better understand the process of aging in humans. The exact biological role of WRN remains unknown. However, it has been proposed that it plays roles in the response to DNA damage. In particular, WRN may promote rescue of stalled replication forks and help resolve recombination intermediates in cells experiencing replicative stress. WRN also plays a role in telomere replication and alternative lengthening of telomeres. Thus, loss of function mutations in WRN could disrupt DNA replication and DNA-damage processing, resulting in accumulation of DNA double-strand breaks (DSBs) and recombination intermediates. These events could activate cell-cycle checkpoints resulting in senescence, apoptosis, or genetic instability leading to cellular transformation. These molecular endpoints could ultimately lead to features of premature aging and/or increased cancer susceptibility (Figure 35.1). This chapter discusses how WRN may contribute to genome stability and reduce cancer susceptibility.
Passively damped vibration welding system and method (2023)

A vibration welding system includes a controller, welding horn, an anvil, and a passive damping mechanism (PDM). The controller generates an input signal having a calibrated frequency. The horn vibrates in a desirable first direction at the calibrated frequency in response to the input signal to form a weld in a work piece. The PDM is positioned with respect to the system, and substantially damps or attenuates vibration in an undesirable second direction. A method includes connecting the PDM having calibrated properties and a natural frequency to an anvil of an ultrasonic welding system. Then, an input signal is generated using a weld controller. The method includes vibrating a welding horn in a desirable direction in response to the input signal, and passively damping vibration in an undesirable direction using the PDM.
Computers in optics education: principles and basic models (1992)

Modern optics looks like a quickly growing tree with its numerous branches rushed upwards and its branched top (Fig. 1) . According to this analogy the problems of the optics education are to interest young talented people in a ripe fruit of that tree, to help them reach the low branches of the tree and to show them the way to the top. There areplenty of ways leading to the fruit-bearing top, and every teacher who works hard in this or that field of optics has his optimal algorithm of reaching the top.
Planar Thin-Film Servo Write Head for Magnetic Tape Recording (2012)

We present a planar thin-film servo write head for writing timing-based servo patterns. The planar head operates at low current ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\sim}100$</tex></formula> mA) with nanosecond switching times. The planar head can handle dc current, enabling trailing-edge writing. Magnetic force microscopy measurements of the transitions written by the planar head and a conventional commercial servo write head on longitudinal metal particle and nonoriented barium ferrite media were made to assess the quality of the written transitions. The transition response width PW50 is found to be independent of the tape velocity during write for the planar head. For the conventional head, PW50 is larger and increases with the tape write velocity. The reduced PW50 results in larger readback signal amplitude and hence an improved track-follow performance. The faster switching capability of the planar head enables formatting at higher tape velocity.
P2‐136: Heme oxygenase‐1 promotes proteosomal degradation of tau and alpha‐synuclein in human neuroblastoma cells (2008)

HO-1 is a stress-responsive enzyme that degrades heme to free iron, carbon monoxide and biliverdin (bilirubin precursor). HO-1 protein is over-expressed in Alzheimer (AD) and Parkinson (PD) brain and co-localizes, respectively, to tau-containing neurofibrillary tangles (NFT) and α-synuclein-laden Lewy bodies in affected neurons.Attenuated proteasomal activity has been implicated in the accumulation of and aggregation of insoluble forms of tau and α-synuclein in these conditions. The effects of transient transfection of human (h) HO-1 cDNA on levels of co-transfected wild-type (WT) and mutant (P301L) tau and WT and mutant (A30P) α-synuclein were measured by Western blotting in M17 human neuroblastoma cells in the presence or absence of the HO competitive inhibitor, tin mesoporphyin (SnMP) or proteasome inhibitor, lactacystin. In some experiments, deferoxamine, methylene blue and bilirubin were administered to delineate the role(s) of iron, CO and bilirubin, respectively, in altered tau and α-synuclein metabolism. hHO-1 transfection (∼3–4 fold increase in HO activity) significantly decreased expression levels of both wild type tau and P301L mutant tau. These effects were attenuated by administration of SnMP, lactacystin or deferoxamine (but not methylene blue or bilirubin). hHO-1 transfection similarly diminished endogenous and transgenic WT α-synuclein levels, effects reversed by SnMP, lactacystin, deferoxamine or methylene blue (but not bilirubin). HO-1 transfection did not significantly impact A30P levels in these cells. In sporadic AD and PD, induction of neuronal HO-1 may confer neuroprotection by stimulating proteasomal degradation of tau or α-synuclein, respectively. Conversely, failure of HO-1 to suppress mutant (A30P) α-synuclein may predispose to familial PD.
Quinolizidine alkaloid biosynthesis: incorporation of [1-amino-15N,1-13C]cadaverine into sparteine (1983)

Three [1-amino-15N,1-13C]cadaverine (4) units are incorporated to about the same extent into sparteine (5); the presence of only two 13C–15N doublets in the 13C{1H} n.m.r. spectrum of sparteine indicates that two of these units are transformed into the outer rings of sparteine in a specific fashion.
Photonic Crystal Nanobeam Cavities for Tunable Filter and Router Applications (2012)

We investigate the suitability of photonic crystal nanobeam cavities for interconnect applications. Owing to their small footprint, exactly the same as that of an optical waveguide, as well as ultrahigh quality factor resonances that they support, nanobeam cavities are attractive candidates for realization of densely integrated on-chip optical networks. We discus tunability of these filters using thermo-optic, electromechanic, and optomechanic effects, and we compare different reconfiguration strategies in terms of tuning hold power, tuning efficiency, and maximum operating frequency.
Role of p73 in Alzheimer disease: lack of association in mouse models or in human cohorts (2013)

Our results fail to support P73 as a contributor to AD pathogenesis.
Development and Structure/Property Relationship of New Electron Accepting Polymers Based on Thieno[2′,3′:4,5]pyrido[2,3-g]thieno[3,2-c]quinoline-4,10-dione for All-Polymer Solar Cells (2015)

Several electron accepting polymers having weak accepting–strong accepting (WA-SA) and strong accepting–strong accepting (SA-SA) monomer alternation were synthesized for studies of structure/property relationship in all-polymer solar cells. Two kinds of cyclic amide monomers, 4,10-bis(2-butyloctyl)-thieno[2′,3′:5,6]pyrido[3,4-g]thieno-[3,2-c]isoquinoline-5,11-dione (TPTI) and 5,11-bis(2-butyloctyl)-thieno[2′,3′:4,5]pyrido[2,3-g]thieno[3,2-c]quinoline-4,10-dione (TPTQ), were synthesized as weak accepting monomers (WA). Difluorinated TPTQ (FTPTQ) and well-known perylene diimide (PDI) monomers were synthesized as strong electron accepting monomers (SA). By using 1-chloronaphthalene (CN) as a cosolvent, the morphology of the polymer blended films can be finely tuned to achieve better ordering toward face-on mode and favorable phase separation between electron donor and acceptor, resulting in significant enhancement of short circuit current (Jsc) and fill factor (FF). The fluorination in the TPTQ unit reduced the dipole moment of the D–A complex and gave a negative effect on a polymer system. PFP showed worse electron accepting property with lower electron mobility than PQP. It is reasoned that the internal polarization plays an important role in the design of electron accepting polymers. As a result, PQP having TPTQ monomer exhibited the best photovoltaic performance with power conversion efficiency (PCE) of 3.52% (Voc = 0.71 V, Jsc = 8.57 mA/cm2, FF = 0.58) at a weight ratio of PTB7-Th:PQP = 1:1, under AM 1.5G.
A practical illustration of the importance of realistic individualized treatment rules in causal inference (2007)

The effect of vigorous physical activity on mortality in the elderly is difficult to estimate using conventional approaches to causal inference that define this effect by comparing the mortality risks corresponding to hypothetical scenarios in which all subjects in the target population engage in a given level of vigorous physical activity. A causal effect defined on the basis of such a static treatment intervention can only be identified from observed data if all subjects in the target population have a positive probability of selecting each of the candidate treatment options, an assumption that is highly unrealistic in this case since subjects with serious health problems will not be able to engage in higher levels of vigorous physical activity. This problem can be addressed by focusing instead on causal effects that are defined on the basis of realistic individualized treatment rules and intention-to-treat rules that explicitly take into account the set of treatment options that are available to each subject. We present a data analysis to illustrate that estimators of static causal effects in fact tend to overestimate the beneficial impact of high levels of vigorous physical activity while corresponding estimators based on realistic individualized treatment rules and intention-to-treat rules can yield unbiased estimates. We emphasize that the problems encountered in estimating static causal effects are not restricted to the IPTW estimator, but are also observed with the G-computation estimator, the DR-IPTW estimator, and the targeted MLE. Our analyses based on realistic individualized treatment rules and intention-to-treat rules suggest that high levels of vigorous physical activity may confer reductions in mortality risk on the order of 15-30%, although in most cases the evidence for such an effect does not quite reach the 0.05 level of significance.
5-Azacytosine Compounds In Medicinal Chemistry: Current Stage And Future Perspectives (2012)

This review summarizes the basic milestones of the research of 5-azacytosine nucleosides chronologically from their discovery and anticancer activity identification, through to subsequent unveiling of their mechanism of action based on DNA hypomethylation and tumor-suppressor gene reactivation, to the final US FDA approval of 5-azacytidine (Vidaza(®)) and 2'-deoxy-5-azacytidine (Dacogen(®)) for the treatment of myelodysplastic syndromes. 5,6-dihydro-2'-deoxy-5-azacytidine, a compound with anti-HIV activity through lethal mutagenesis, representing a unique mechanism of action among existing anti-retroviral drugs, is discussed together with quite recent discovery of its so far unexpected hypomethylation activity. Special attention is paid to 5-azacytosine acyclic nucleoside analogues and phosphonomethyl derivatives with the emphasis on the new potent anti-DNA virus agent (S)-1-[3-hydroxy-2-(phosphonomethoxy)propyl]-5-azacytosine and its prodrug forms. Considering the potential pharmaceutical applications, 5-azacytosine and 5,6-dihydro-5-azacytosine appear to be so far the most effective cytosine mimics for the design of novel antiviral and anti-tumor drug candidates.
Feasibility study of low-swing clocking (2004)

This paper evaluates the feasibility of low-swing clocking under no performance degradation constraint. We consider flip-flops, logic and clock distribution network in our analysis. The preferred flip-flop topologies for low-swing clocking (low-V/sub Clk/) are different from those normally used in a full-swing (high-V/sub Clk/) design. Clock buffers are redesigned to accommodate reduced drive current under low-V/sub Clk/. In order to maintain performance, logic and flip-flops must absorb increase in clock skew due to low-V/sub Clk/. In a 64-bit ALU design, the optimal low-V/sub Clk/ design point is at the minimum energy-delay product (EDP) point of the high-V/sub Clk/ design, with no delay or energy penalty in the ALU itself. A 43% energy reduction achieved in the clock distribution network results in a 13% overall energy savings due to low-V/sub Clk/, assuming that the clocking energy is 40% of the total energy tinder high-V/sub Clk/. For performance targets of at least one FO4 inverter delay better than the min-EDP point, low-swing clocking becomes ineffective because of a high energy cost in logic that is spent to absorb increase in flip-flop delay and clock skew. Finally, low-V/sub Clk/ cannot achieve the peak performance of the high-V/sub Clk/ design due to slower flip-flops and higher clock uncertainty at low-V/sub Clk/.
Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices (2017)

Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2)-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish) rat model. Female ACI rats were given either control diet (AIN 93M) or diet supplemented with 7.5% (<i>w</i>/<i>w</i>) of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold) enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA) in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα). The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92 days in control group. At the end of the study (25 weeks), the tumor incidence was 96% in the control group compared with only 70% in the caraway group. A significant reduction in tumor volume (661 ± 123 vs. 313 ± 81 mm³) and tumor multiplicity (4.2 ± 0.4 vs. 2.5 ± 0.5 tumors/animal) was also observed in the caraway group compared with the control group. Together, our data show dietary caraway can significantly delay and prevent the hormonal mammary tumorigenesis by modulating different cellular and molecular targets.
Characterizing the small RNA transcriptome associated with COPD and ILD using next-generation sequencing (2012)

Background Despite the increasing public health burden associated with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD), the molecular mechanisms responsible for the pathogenesis of these diseases remain unclear. The goal of this study was to comprehensively profile the lung small RNA transcriptome via next-generation sequencing, and elucidate microRNAs that might contribute to COPD and ILD pathogenesis.
Characteristics of ethylene propylene diene monomer rubber/organoclay nanocomposites resulting from different processing conditions and formulations (2004)

Abstract Several parameters which affect the nanocomposite formation in a sulfur‐cured ethylene propylene diene rubber (EPDM) containing 10 phr organoclay (montmorillonite modified with octadecylamine; MMT–ODA), were investigated. The parameters varied were linked to processing (mixer type, temperature) and rubber recipe (compatibilizer, accelerator). Increasing temperature and high shear mixing (internal mixer instead of open mill) improved the mechanical performance of the rubber nanocomposites. A more pronounced effect was achieved by using polar EPDM rubbers (maleic anhydride and glycidyl methacrylate grafted version) as compatibilizer. Among the accelerators, zinc diethyldithiocarbamate proved to be most suitable. The microstructure of the rubber/organoclay systems was studied by X‐ray diffraction, transmission electron microscopy and scanning electron microscopy. Organoclay intercalation/exfoliation was accompanied by its more or less severe confinement (reaggregation, deintercalation). This was traced to a partial or full removal of the ODA intercalant from the clay galleries via the formation of a zinc complex in which amine groups of the ODA and sulfur participated. Copyright © 2004 Society of Chemical Industry