gebhart/patrepeval huggingface dataset:
Posterior capsular opacification prevention: IOL design and material (1999)

Posterior capsular opacification (PCO) occurs in up to 50% of eyes following cataract extraction1 and its treatment with Nd:YAG capsulotomy is not without complications. PCO also has important implications in the developing world,2 where it may increasingly become a significant cause of treatable blindness.

Central to the pathogenesis of PCO is the concept that, following cataract surgery, lens epithelial cells (LECs) migrating from the equator of the capsular bag undergo myofibroblastic or fibroblastic-like change (so called fibrous pseudometaplasia) behind the optic of the intraocular lens (IOL) implant. In order to study the molecular biology of LECs a number of culture methods have been developed. Although many studies have been limited to LECs from animals, it has recently been possible to culture human LECs with both their capsular bag,3 and in a serum free culture medium from age related cataract which closer represents in vitro conditions.4 These cell culture models have been used to assess the pathophysiology of PCO and, in particular, LECs migration, proliferation, and strategies to inhibit these processes.

Anti-inflammatory drugs, cytotoxins, antimetabolites, and immunotoxins have all been employed in vitro and in vivo to destroy or suppress LECs.5 Despite attempts at specifically targeting LECs—for example, by utilising monoclonal antibodies, toxic side effects remain the principal limitation in the use of such agents.

With the recognition of the role of LECs in PCO, a wide variety of techniques have also been directed at attempting to remove residual cells during surgery. These have included simple aspiration, capsule polishing, ultrasound aspiration, cryocoagulation, and osmolysis.5 The fact that none of these techniques has been utilised as a routine surgical procedure reflects the difficulty in totally removing all LECs. Attempts to remove LECs …
An aminotransferase from Lactococcus lactis initiates conversion of amino acids to cheese flavor compounds (1997)

The enzymatic degradation of amino acids in cheese is believed to generate aroma compounds and therefore to be involved in the complex process of cheese flavor development. In lactococci, transamination is the first step in the degradation of aromatic and branched-chain amino acids which are precursors of aroma compounds. Here, the major aromatic amino acid aminotransferase of a Lactococcus lactis subsp. cremoris strain was purified and characterized. The enzyme transaminates the aromatic amino acids, leucine, and methionine. It uses the ketoacids corresponding to these amino acids and alpha-ketoglutarate as amino group acceptors. In contrast to most bacterial aromatic aminotransferases, it does not act on aspartate and does not use oxaloacetate as second substrate. It is essential for the transformation of aromatic amino acids to flavor compounds. It is a pyridoxal 5'-phosphate-dependent enzyme and is composed of two identical subunits of 43.5 kDa. The activity of the enzyme is optimal between pH 6.5 and 8 and between 35 and 45 degrees C, but it is still active under cheese-ripening conditions.
MMC05-1: An Adaptive FEC Scheme to Reduce Bursty Losses in a 802.11 Network (2006)

One of the challenges that video transmission over wireless networks (such as IEEE 802.11) must face is the packet loss that can heavily decrease the received video quality. What makes the challenge more difficult is the bursty nature of wireless losses. Many video decoders can mask the effects of small amounts of random packet loss, however, most are unable to successfully hide the effects of burst losses (periods with high loss data rate). Forward error correction (FEC) is a technique extensively adopted to increase error resilience. In unicast transmission, the FEC redundancy is usually added adaptively on the basis of a loss pattern feedback. In many cases the loss pattern is represented through a very simple statistics: the average packet error rate (PER). This paper proposes a technique to adaptively introduce FEC redundancy that exploits a feedback scheme based on a 4-state Markov model to describe the loss pattern. The model allows us to obtain a description of the loss pattern in terms of burst and gap length and density. The feedback is based on the RTCP extended Report - IP Video Metrics Report Blocks that includes statistics on error patterns, such as the average PER, burst length and density. Our simulation results show that the proposed method smoothes out the burst losses and outperforms solutions based on the average PER.
REAKTİF BOYARMADDELERLE BOYANMIŞ PAMUKLU KUMAŞLARIN RENK ÖZELLİKLERİNİN CIELAB VE HUNTER SİSTEMLERİ KULLANILARAK FARKLI AYDINLATICILAR ALTINDA DEĞERLENDİRİLMESİ (2010)

Bu çalışmada reaktif boyarmaddeler ile boyanmış pamuklu kumaşların renk özellikleri D65, A ve F11 aydınlatıcıları altında CIELAB ve Hunter sistemleri ile hesaplanarak değerlendirilmiştir. Kumaş numuneleri dört farklı reaktif boyarmadde (siyah, sarı, kırmızı ve mavi) ile on ayrı boyama konsantrasyonunda boyanmış ve boyanmış numunelerin renk koordinatları bir reflektans spektrofotometresi ile ölçülmüştür. Sonuç boyamaların renk koordinatları ve renk farklılıkları CIELAB ve Hunter sistemlerine göre hesaplanmış ve elde edilen sonuçlar boyamaların renkleri ile ilişkili olarak tartışılmıştır. CIELAB ve Hunter sistemlerine göre hesaplanan renk sonuçlarının elde edilen renklerin farklılıklarına göre hassas olduğu bulunmuştur. Renk koordinatları Hunter sistemine göre hesaplandığında siyah, sarı, kırmızı ve mavi renklerin aydınlatıcı seçimine hassas olduğu görülmüştür. Hesaplanan en yüksek renk koordinatları farkı sarı renkte elde edilmiştir
Robust and high-quality time-domain audio watermarking based on low-frequency amplitude modification (2006)

This work proposes a method of embedding digital watermarks into audio signals in the time domain. The proposed algorithm exploits differential average-of-absolute-amplitude relations within each group of audio samples to represent one-bit information. The principle of low-frequency amplitude modification is employed to scale amplitudes in a group manner (unlike the sample-by-sample manner as used in pseudonoise or spread-spectrum techniques) in selected sections of samples so that the time-domain waveform envelope can be almost preserved. Besides, when the frequency-domain characteristics of the watermark signal are controlled by applying absolute hearing thresholds in the psychoacoustic model, the distortion associated with watermarking is hardly perceivable by human ears. The watermark can be blindly extracted without knowledge of the original signal. Subjective and objective tests reveal that the proposed watermarking scheme maintains high audio quality and is simultaneously highly robust to pirate attacks, including MP3 compression, low-pass filtering, amplitude scaling, time scaling, digital-to-analog/analog-to-digital reacquisition, cropping, sampling rate change, and bit resolution transformation. Security of embedded watermarks is enhanced by adopting unequal section lengths determined by a secret key.
Electrical Transport and Network Percolation in Graphene and Boron Nitride Mixed-Platelet Structures (2016)

Percolating network of mixed 2D nanomaterials (2DNs) can leverage the unique electronic structures of different 2DNs, their interfacial doping, manipulable conduction pathways, and local traps. Here, we report on the percolation mechanism and electro-capacitive transport pathways of mixed-platelet network of hexagonal boron nitride (hBN) and reduced graphene oxide (rGO), two isostructural and isoelectronic 2DNs. The transport mechanism is explained in terms of electron hopping through isolated hBN defect traps between rGO (possibly via electron tunneling/hopping through "funneling" points). With optical bandgaps of 4.57 and 4.08 eV for the hBN-domains and 2.18 eV for the rGO domains, the network of hBN with rGO exhibits Poole-Frenkel emission-based transport with mean hopping gap of 1.12 nm (∼hBN trilayer) and an activation barrier of ∼15 ± 0.7 meV. Further, hBN (1.7 pF) has a 6-fold lower capacitance than 1:1 hBN:rGO, which has a resistance 2 orders of magnitude higher than that of rGO (1.46 MΩ). These carrier transport results can be applied to other multi-2DN networks for development of next-generation functional 2D-devices.
Mechanism of mutation at the aprt locus in Chinese hamster ovary cells: analysis of heterozygotes and hemizygotes. (1983)

A two-step model to explain the high frequency of mutation at the diploid adenine phosphoribosyltransferase (aprt) locus in CHO cells has been proposed previously (Simon et al., Mol. Cell. Biol. 2:1126-1133, 1982). This model indicates that two distinct classes of aprt heterozygotes can be isolated. Class 1 heterozygotes, the most abundant class, were defined as those which arose spontaneously and were capable of undergoing mutation to the APRT- phenotype only at a low frequency (putative point mutation). Class 2 heterozygotes arose from a mutation and gave rise at a high frequency to APRT- cells. This high-frequency event has been identified as a deletion of the wild-type allele (A. E. Simon and M. W. Taylor, Proc. Natl. Acad. Sci. U.S.A. 80:810-814, 1983). In this paper we report further analysis of class 1 heterozygotes with respect to genetic structure, gene products, and karyotype. Our study indicated that class 1 heterozygotes contain two different types of mutants. About half have only one copy of the aprt gene and an unaltered karyotype, indicating that a deletion (similar to the high-frequency second-step event observed for class 2 heterozygotes) rather than a loss of the chromosome was responsible for the generation of the aprt+/- genotype. The remainder of the previously designated class 1 heterozygotes still contained two copies of the aprt gene (within the limits of the quantitation technique used) and arose presumably by a point mutation. One of this group, D423, was characterized with respect to aprt gene products and found to produce an electrophoretic variant in addition to the wild-type protein. APRT- mutants derived from D423 retained the same number of aprt gene copies as D423 and still synthesized a protein that comigrated with wild type, unlike APRT- mutants derived from class 2 heterozygotes. D423 and the other heterozygotes with two aprt genes therefore did not fit into either class 1 or 2 and are now designated class 3. The model we present suggests that only one of the two aprt alleles present in wild-type cells can undergo the deletion.
Assembling of fiber collimators for photonic devices (2003)

Packaging and assembly covers almost 80% of the overall cost of any fiber-optic device. It is thus a demanding issue to lower the cost of fiber-optic alignment and attachment process. This work presents the development of automated packaging using adhesives, i.e., alignment and attachment of 8-channel fiber collimators for photonic devices. The optimal fiber-lens arrayed coupling and alignment are first determined, and the tolerances for all 3 linear (x, y, z) and 3 angular (pitch, roll and yaw) misalignments are obtained. The fiber and lens attachments using three different UV-curing adhesives of different properties are performed. The entire process of arrayed fiber-lens alignment and attachment is automated using AutoAlign/spl trade/. Optical tests are performed to determine the coupling loss of the assembled collimators as well as the coupling loss induced by the attachment process. The results show that the overall coupling loss of the assembled devices is well below 2 dB, and the assembly yield is found to be extremely high and consistent.
RELIEF Study: First Consolidated European Data (2000)

The RELIEF study (Reflux assEssment and quality of life improvement with micronized Flavonoids in chronic venous insufficiency [CVI]) is a prospective, controlled, multicenter, international study performed in patients with or without venous reflux. This study was conducted between March 1997 and December 1998 in 23 countries worldwide with the participation of more than 10,000 patients suffering from CVI. The European countries, the subject of this report, were represented by the Czech and Slovak Republics, Hungary, Poland, Russia, and Spain. The principal aims of the study were: 1. To validate the first quality-of-life scale specific to chronic venous insufficiency (CMVIQ) in different languages and to assess the evolution of quality of life in patients suffering from CVI, with or without venous reflux, treated with micronized purified flavonoid fraction (MPFF*) (1,000 mg/day). 2. To collect international epidemiologic data on venous reflux assessed with pocket Doppler and photoplethysmography. 3. To assess the evolution of symptoms and signs with a specific emphasis on edema through validated Leg-O-Meter measurement (heaviness, pain, cramps, sensation of swelling, edema) in patients suffering from CVI and treated with MPFF, 1,000 mg/day, during 6 months. The first country-by-country statistical analysis and the European consolidated analysis are now available. The CIVIQ questionnaires adapted to each participating country have been validated with highly significant validity and reproducibility (p<0.0001). All dimensions have demonstrated a highly significant and evolving improvement during the study. The results show several interesting findings concerning the epidemiologic data and, of these, two were particularly interesting: - More than 50% of patients suffering from CVI (class 0 to 4 of the CEAP classification) were reflux-free, which means that they were suffering from functional CVI. Patient distribution between the different classes of the CEAP classification changed in a statistically significant manner after 6 months' treatment with MPFF; the number of patients in the more severe classes decreased to the benefit of the less severe classes. Symptoms such as pain, leg heaviness, sensation of swelling, and cramps were significantly improved (p=0.0001). This was associated with a significant decrease in edema, when present, measured by leg circumferences with the Leg-O-Meter (p=0.0001). In conclusion, the European results of the RELIEF study showed the perfect validity and reproducibility of CIVIQ questionnaire adaptations, and the positive progression of quality-of-life scores on MPFF treatment. This progression was paralleled by clinical improvement of patients reflected not only by assessment of CVI symptoms and signs but also by evolution of the CEAP classification.
Emerging themes in the computational design of novel enzymes and protein–protein interfaces (2012)

Recent years have seen the first applications of computational protein design to generate novel catalysts, binding pairs of proteins, protein inhibitors, and large oligomeric assemblies. At their core these methods rely on a similar hybrid energy function, composed of physics-based and database-derived terms, while different sequence and conformational sampling approaches are used for each design category. Although these are first steps for the computational design of novel function, crystal structures and biochemical characterization already point out where success and failure are likely in the application of protein design. Contrasting failed and successful design attempts has been used to diagnose deficiencies in the approaches and in the underlying hybrid energy function. In this manner, design provides an inherent mechanism by which crucial information is obtained on pressing areas where focused efforts to improve methods are needed. Of the successful designs, many feature pre-organized sites that are poised to perform their intended function, and improvements often result from disfavoring alternative functionally suboptimal states. These rapid developments and fundamental insights obtained thus far promise to make computational design of novel molecular function general, robust, and routine.
D<sub>1</sub> dopamine receptor stimulation increases GluR1 phosphorylation in postnatal nucleus accumbens cultures (2002)

Postsynaptic interactions between dopamine and glutamate receptors in the nucleus accumbens are critical for acute responses to drugs of abuse and for neuroadaptations resulting from their chronic administration. We tested the hypothesis that D(1) dopamine receptor stimulation increases phosphorylation of the AMPA receptor subunit GluR1 at the protein kinase A phosphorylation site (Ser845). Nucleus accumbens cell cultures were prepared from postnatal day 1 rats. After 14 days in culture, GluR1 phosphorylation was measured by western blotting using phosphorylation site-specific antibodies. The D(1) receptor agonist SKF 81297 increased Ser845 phosphorylation in a concentration- dependent manner, with marked increases occurring within 5 min. This was prevented by the D(1) receptor antagonist SCH 23390 and the protein kinase A inhibitor H89, and reproduced by forskolin. The D(2) receptor agonist quinpirole attenuated the response to D(1) receptor stimulation. Neither D(1) nor D(2) receptor agonists altered GluR1 phosphorylation at Ser831, the site phosphorylated by protein kinase C and calcium/calmodulin-dependent protein kinase II. In other systems, phosphorylation of GluR1 at Ser845 is associated with enhancement of AMPA receptor currents. Thus, the present results suggest that AMPA receptor transmission in the nucleus accumbens may be augmented by concurrent D(1) receptor stimulation.
Id1 Restrains p21 Expression to Control Endothelial Progenitor Cell Formation (2007)

Loss of Id1 in the bone marrow (BM) severely impairs tumor angiogenesis resulting in significant inhibition of tumor growth. This phenotype has been associated with the absence of circulating endothelial progenitor cells (EPCs) in the peripheral blood of Id1 mutant mice. However, the manner in which Id1 loss in the BM controls EPC generation or mobilization is largely unknown. Using genetically modified mouse models we demonstrate here that the generation of EPCs in the BM depends on the ability of Id1 to restrain the expression of its target gene p21. Through a series of cellular and functional studies we show that the increased myeloid commitment of BM stem cells and the absence of EPCs in Id1 knockout mice are associated with elevated p21 expression. Genetic ablation of p21 rescues the EPC population in the Id1 null animals, re-establishing functional BM-derived angiogenesis and restoring normal tumor growth. These results demonstrate that the restraint of p21 expression by Id1 is one key element of its activity in facilitating the generation of EPCs in the BM and highlight the critical role these cells play in tumor angiogenesis.
Achieving conductive high Al-content AlGaN alloys for deep UV photonics (2007)

Recent progresses in epitaxial growth and fundamental studies on electrical and optical properties of high Al-content AlGaN alloys with Si, Mg, and Zn doping are presented. For Si doped Al<sub>x</sub>Ga1-<sub>x</sub>N, the Si activation energy was determined for x = 0 up to 1, and the resistivity of n-Al<sub>x</sub>Ga1-<sub>x</sub>N was found to increases by one order of magnitude when Al content is increased by ~ 8%. From photoluminescence (PL) studies, three groups of deep impurity transitions were observed, related with deep level acceptors involving cation vacancy and its complexes: (VIII)<sup>3-</sup>, (VIII-complex)<sup>2</sup>, and (VIII-complex)<sup>1-</sup>, which are electron traps and compensating centers. By optimizing the growth processes to reduce the densities of cation vacancy and its complexes, the <i>n</i>-type conductivity of Al<sub>x</sub>Ga1-<sub>x</sub>N was significantly improved. A record low room temperature <i>n</i>-type resistivity of 0.0075 Ω•cm has been obtained for Al<sub>0.7</sub>Ga<sub>0.3</sub>N, and <i>n</i>-type conduction in pure AlN has also been achieved. We also review the electrical and optical measurement results of Mgdoped AlGaN and AlN. It was found that the overall material quality and conductivity of Mg-doped AlN are strongly correlated with the PL emission intensity of the nitrogen vacancy (V<sub>N</sub> <sup>3+</sup>) related transition. Improved conductivity was obtained by suppressing the V<sub>N</sub><sup>3+</sup> related emission line, which was attributed to the reduced hole compensation by V<sub>N</sub><sup>3+</sup>. With the identification of the emission peaks associated with V<sub>N</sub><sup>3+</sup> hole compensating centers, the <i>p</i>-type conductivity of high Al-content AlGaN alloys was improved by monitoring and suppressing the intensity of the V<sub>N</sub><sup>3+</sup> related emission lines. <i>P</i>-type conduction in Al<sub>x</sub>Ga1-<sub>x</sub>N (x > 0.7) was confirmed at elevated temperatures (> 700 K). The possibility of using Zn as an alternative <i>p</i>-type dopant was also studied. It was found that contrary to the calculation, the energy level of Zn acceptor in AlN was about 0.74 eV, which is 0.23 eV deeper than Mg level in AlN.
A miniaturized MMIC analog phase shifter using two quarter-wave-length transmission lines (2002)

This paper describes a miniaturized monolithic-microwave integrated-circuit (MMIC) analog phase shifter using two quarter-wave-length transmission lines. A conventional analog phase shifter employs an analog phase-shifter topology using a 3-dB 90/spl deg/ branch-line hybrid requiring four quarter-wave-length transmission lines. Thus, in the first stage of our study, we present a new analog phase-shifter topology using only two quarter-wave-length transmission lines. The phase shifter here has only one-half as many transmission tines as a conventional analog phase shifter using a 3-dB 90/spl deg/ branch-line hybrid, and the circuit can be miniaturized to less than one-fourth as compared to the conventional analog phase shifter. Furthermore, we show that the operating frequency range of the phase shifter is very wide and can obtain large phase variation with small capacitance variation. Next, an experimental Ku-band MMIC analog phase shifter is presented. A phase shift of more than 180/spl deg/ and an insertion loss of 3.6/spl plusmn/1.1 dB are obtained at the frequency range from 12 to 14 GHz. The chip size of the experimental MMIC phase shifter is less than 3.0 mm/sup 2/.
Synergistic effect of phosphorus, nitrogen, and silicon on flame‐retardant properties and char yield in polypropylene (2005)

Abstract In this study, several flame retardants (FRs), containing phosphorus, nitrogen, and silicon, were synthesized. These synthesized FRs were blended with polypropylene (PP) to obtain mixture samples. The flame‐retardant properties of these mixture samples were estimated by the limiting oxygen index (LOI) value and thermal stabilities were characterized by thermogravimetric analysis. The LOI values of these samples were improved from 17.0 to 26.0 and the char yield increased from 0 to 27 wt %. A comparison of these samples, with respect to their LOI values and carbon yield, showed that the FRs, which simultaneously contained phosphorus, nitrogen, and silicon elements, can provide materials with the best flame‐retardant properties, suggesting that there is a synergistic effect among the three elements on the flame‐retardant properties and char yield when they are used in PP. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 854–860, 2005