gebhart/patrepeval huggingface dataset:
A new envelope predistortion linearization architecture for handset power amplifiers (2005)

The paper proposes a new envelope predistortion linearization architecture that utilizes low power analog components to correct intermodulation distortion (IMD) in RF power amplifiers (PAs). Log amps and phase detectors are used at the input and output of the PA to estimate the instantaneous complex gain. The outputs of the log amps and phase detector are fed back to a voltage controlled variable attenuator (VVA) and phase shifter (VVP), respectively, to correct any errors in the gain due to AM-AM or AM-PM distortion. As opposed to traditional envelope feedback approaches, this architecture achieves greater bandwidth by only feeding the distortion components back. Moreover, the distortion components are not added to the input signal as feedback, but they are used to predistort the input signal in a multiplicative manner. This architecture also allows correction of envelope memory effects that may occur in the PA. A behavioral model for Class-AB PA has been developed. The architecture has been verified by means of computer simulation using behavioral models extracted from a VVA, a VVP, and a 0.5 W GaAs HFET PA. For a cdmaOne signal with a bandwidth of 1.2288 MHz, the simulation shows an ACPR peak improvement of more than 10 dB over an output power dynamic range of 6 dB.
Angiotensin II inhibits rat arterial KATP channels by inhibiting steady‐state protein kinase A activity and activating protein kinase Ce (2001)

We used whole-cell patch clamp to investigate steady-state activation of ATP-sensitive K+ channels (KATP) of rat arterial smooth muscle by protein kinase A (PKA) and the pathway by which angiotensin II (Ang II) inhibits these channels. Rp-cAMPS, an inhibitor of PKA, did not affect KATP currents activated by pinacidil when the intracellular solution contained 0.1 mM ATP. However, when ATP was increased to 1.0 mM, inhibition of PKA reduced KATP current, while the phosphatase inhibitor calyculin A caused a small increase in current. Ang II (100 nM) inhibited KATP current activated by the K+ channel opener pinacidil. The degree of inhibition was greater with 1.0 mM than with 0.1 mM intracellular ATP. The effect of Ang II was abolished by the AT1 receptor antagonist losartan. The inhibition of KATP currents by Ang II was abolished by a combination of PKA inhibitor peptide 5-24 (5 microM) and PKC inhibitor peptide 19-27 (100 microM), while either alone caused only partial block of the effect. In the presence of PKA inhibitor peptide, the inhibitory effect of Ang II was unaffected by the PKC inhibitor Go 6976, which is selective for Ca2+-dependent isoforms of PKC, but was abolished by a selective peptide inhibitor of the translocation of the epsilon isoform of PKC. Our results indicate that KATP channels are activated by steady-state phosphorylation by PKA at normal intracellular ATP levels, and that Ang II inhibits the channels both through activation of PKCepsilon and inhibition of PKA.
Characterization of a Mycobacterium tuberculosis insertion sequence belonging to the IS3 family (1990)

A repetitive element (IS986), previously isolated from Mycobacterium tuberculosis and shown to detect multiple restriction fragment-length polymorphisms (RFLPs), has been sequenced. It consists of a potential insertion sequence of 1358bp, with 30-bp inverted repeat ends. IS986 has four potentially significant open reading frames (ORFs): ORFa1, ORFa2 and ORFb on one strand and ORFc on the complementary strand. The sequences of the potential translated products identify IS986 as a member of the IS3 family, with an apparent frameshift between ORFa1 and ORFa2. IS986 has potential as a highly specific probe for detection and typing of M. tuberculosis, as well as for transposon mutagenesis of mycobacteria. The sequence of IS986 is virtually identical to that of another recently described element, IS6110 (Thierry et al., 1990).
Electron Crystallography of Biological Macromolecules (1985)

Machine learning (ML) is transforming all areas of science. The complex and time-consuming calculations in molecular simulations are particularly suitable for an ML revolution and have already been profoundly affected by the application of existing ML ...Read More
Ghost imaging of a moving target with an unknown constant speed (2014)

We report a method for ghost imaging of a moving target with an unknown constant speed. By both numerical simulations and experiments, it is shown that by matching the calculated signal to the recorded data, the unknown speed can be correctly retrieved and the target image can be reconstructed. We suppose that this work is a good start of addressing the related problems and will find its applications in ghost imaging remote sensing.
Clinical experience with a new biocompatible phosphorylcholine-coated coronary stent. (1999)

This initial clinical experience indicates that the implantation of stents coated with phosphorylcholine appears to be safe and efficacious in the treatment of complex coronary lesions and is associated with an extremely low target vessel revascularization rate.
The leukocyte common antigen (CD45): a putative receptor-linked protein tyrosine phosphatase. (1988)

A major protein tyrosine phosphatase (PTPase 1B) has been isolated in essentially homogeneous form from the soluble and particulate fractions of human placenta. Unexpectedly, partial amino acid sequences displayed no homology with the primary structures of the protein Ser/Thr phosphatases deduced from cDNA clones. However, the sequence is strikingly similar to the tandem C-terminal homologous domains of the leukocyte common antigen (CD45). A 157-residue segment of PTPase 1B displayed 40% and 33% sequence identity with corresponding regions from cytoplasmic domains I and II of human CD45. Similar degrees of identity have been observed among the catalytic domains of families of regulatory proteins such as protein kinases and cyclic nucleotide phosphodiesterases. On this basis, it is proposed that the CD45 family has protein tyrosine phosphatase activity and may represent a set of cell-surface receptors involved in signal transduction. This suggests that the repertoire of signal transduction mechanisms may include the direct control of an intracellular protein tyrosine phosphatase, offering the possibility of a regulatory balance with those protein tyrosine kinases that act at the internal surface of the membrane.
Lessons in Quality: Learning from the Japanese (1994)

Attempts to demonstrate that total quality management (TQM) can be successfully transferred to service industries as well as manufacturing industries. In profit‐making services, TQM can lead not only to reduced costs and greater profit margins but also to greater market share through better orientation to customers’ needs. Highlights the Japanese approach to service quality which is an integral part of the organization rather than just an add‐on programme. Illustrates the condition needed to institute a TQM programme successfully in the service industry and concludes with the thought that without these conditions, TQM merely becomes another panacea doomed to failure.
α-Chemokine receptor blockade reduces high mobility group box 1 protein-induced lung inflammation and injury and improves survival in sepsis (2005)

High mobility group box 1 (HMGB1) protein, a late mediator of lethality in sepsis, can induce acute inflammatory lung injury. Here, we identify the critical role of alpha-chemokine receptors in the HMGB1-induced inflammatory injury and show that alpha-chemokine receptor inhibition increases survival in sepsis, in a clinically relevant time frame. Intratracheal instillation of recombinant HMGB1 induces a neutrophilic leukocytosis, preceded by alveolar accumulation of the alpha-chemokine macrophage inflammatory protein-2 and accompanied by injury and increased inflammatory potential within the air spaces. To investigate the role of alpha-chemokine receptors in the injury, we instilled recombinant HMGB1 (0.5 microg) directly into the lungs and administered a subcutaneous alpha-chemokine receptor inhibitor, Antileukinate (200 microg). alpha-Chemokine receptor blockade reduced HMGB1-induced inflammatory injury (neutrophils: 2.9 +/- 3.2 vs. 8.1 +/- 2.4 x 10(4) cells; total protein: 120 +/- 48 vs. 311 +/- 129 microg/ml; reactive nitrogen species: 2.3 +/- 0.3 vs. 3.5 +/- 1.3 microM; and macrophage migration inhibitory factor: 6.4 +/- 4.2 vs. 37.4 +/- 15.9 ng/ml) within the bronchoalveolar lavage fluid, indicating that HMGB1-induced inflammation and injury are alpha-chemokine mediated. Because HMGB1 can mediate late septic lethality, we administered Antileukinate to septic mice and observed increased survival (from 58% in controls to 89%) even when the inhibitor treatment was initiated 24 h after the induction of sepsis. These data demonstrate that alpha-chemokine receptor inhibition can reduce HMGB1-induced lung injury and lethality in established sepsis and may provide a novel treatment in this devastating disease.
Suicide-inhibitory bifunctionally linked substrates (SIBLINKS) as phospholipase A2 inhibitors. Mechanistic implications. (1991)

Novel phospholipids that function as mechanism-based inhibitors for phospholipase A2 (PLA2) are described. PLA2-catalyzed hydrolysis of the sn-2 ester of these suicide-inhibitory bifunctionally linked substrates (SIBLINKS) followed by a cyclization reaction generates a cyclic anhydride at the active site of the enzyme which leads to inhibition. Structure/activity relationships for the SIBLINKS substituents in the sn-1 and sn-2 position are delineated. Time courses and efficiency of SIBLINKS inhibition are reported and compared for extracellular PLA2s obtained from Naja naja naja, porcine pancreas, bee venom, Crotalus atrox and Crotalus adamanteus. SIBLINKS-inhibited PLA2s cannot process either monomeric or micellar substrates consistent with inhibition at the catalytic site. Some SIBLINKS efficiently inactivate 1 mol of N. naja naja and C. adamanteus PLA2/6-10 mol of SIBLINKS hydrolyzed. Inhibition of N. naja naja PLA2 can be reversed by hydroxylamine, suggesting that a tyrosine residue is acylated.
Ernst Levy, Forgotten Genius, Vol. 4: A Selection of Unpublished Concert and Studio Recordings (2015)

Ernst Levy, Forgotten Genius, Vol. 4: A Selection of Unpublished Concert and Studio Recordings. Marston 57072-2 (2 CD). Gary Galo reviewed the previous installments of this series begun in 1998 by Marston. (1) This volume gathers both concert and commercial recordings. Most originated in Cambridge, MA, perhaps made in the same venue, although it is unspecified in the accompanying documentation. Levy (1895-1981) was a Swiss Jew who settled in the U.S. in 1941 and taught for the next twenty-six years at several universities, including The New England Conservatory, University of Chicago and MIT. He studied with two celebrated pianists, Raul Pugno and Egon Petri, and the composer Hans Huber. Levy himself authored fifteen symphonies (1920-1967), many choral works, chamber music, various pieces for solo instruments, etc. His teaching career began during World War I at the Berne Conservatory; he went to Paris in 1921 and remained there until 1940, when he escaped to Switzerland until he could travel to Lisbon to embark for the U.S. As a pianist, Levy performed in New York, where he was praised for his technique at the same time as idiosyncratic qualities in his interpretations were noted. He was the object of a devoted coterie of listeners, particularly in the Boston area. In my teens, I remember ads for his series of Unicorn LPs (made at the then brand new Kresge Auditorium at MIT) as they appeared in the pages of High Fidelity. I probably also read the accompanying reviews; however, at that time my attention was focused on such pianists as Schnabel, Kempff, Backhaus, Rachmaninoff, Richter, Gieseking, Godowsky, Grainger, Moiseiwitsch, Casadesus, Cortot and Rubinstein. They pushed Levy to the fringes and I never listened to a single one of his LPs. Nor have I heard the earlier installments in this series. Thus, my reactions to this set of two CDs are those of a tabula rasa. CD 1 opens with a group of four Haydn Sonatas. HV XVI, nos. 6 (G) and 30 (A) were recorded in Basel in 1952; the others, HV XVI nos. 34 (e) and 48 (C), are from a concert in Cambridge in March 1955. They are musically unexceptionable but definitely dated. After Haydn comes Schubert, the Sonata in A, D. 664 or, as many of us once knew it, Op. 120. From the opening measures of the Allegro moderato, Levy utterly lacks the poise or exquisite lyricism of Myra Hess's famous 1928 Columbia recording. Passages and octaves are often clumsy and unbalanced and Levy seems impatient with the material, inclined to hurry things along to no interpretative benefit. The Andante's lyric phrases, especially, are encumbered with pointless agogic touches. The finale lacks elegance, suppleness or correct proportion and has the same little squats and bends. It all seems rather provincial. All the more pleasant a surprise, therefore, is the Franck Prelude, Chorale, and Fugue that follows. …
Quantitative angiographic blood-flow measurement using pulsed intra-arterial injection (1999)

A technique for quantitative blood-flow measurement using a novel pulsed injection of radiographic contrast agent is reported. A pressurized source of contrast agent is interrupted by a rotary valve at rates ranging from 1 to 30 Hz, producing well-defined boli at the end of a catheter. The position of these boli can be recorded by a digital radiographic system and analyzed by one of several previously reported techniques, to produce quantitative measurements of blood velocity and flow rate throughout the cardiac cycle. The contrast-agent flow wave form produced by the pulsed injector has been measured with an electromagnetic flow meter, for driving pressures ranging from 600 to 1500 kPa. Excellent modulation of the contrast agent is observed for injection frequencies up to 20 Hz, through catheters up to 100 cm in length. Preliminary in vitro angiographic flow measurements have been performed using an x-ray image intensifier, coupled to a linear photodiode array as the digital detector. Both constant flow and pulsatile human blood-flow wave forms were simulated within a 6.4-mm-diam straight tube and monitored with an electromagnetic flow meter. These experiments indicate that the pulsed injector can be used to provide estimates of arterial blood flow over the entire cardiac cycle (including reverse flow), to within about +/-11%, following injection of less than 10 ml of iodinated contrast agent.
Fractionation Protocol for the Isolation of Polypeptides from Plant Biomass (1998)

A fractionation protocol for the isolation of a highly purified polypeptide fraction from plant biomass is described. The procedure dereplicates ubiquitous substance classes known to interfere with bioassays often used in natural product-based drug discovery programs. The protocol involves pre-extraction with dichloromethane, extraction with ethanol (50%), removal of tannins with polyamide, removal of low-molecular-weight components with size-exclusion chromatography over Sephadex G-10, and final removal of salts and polysaccharides with solid-phase extraction using reversed-phase cartridges. The method has been applied to the aerial parts of Viola arvensis, resulting in the isolation of a peptide fraction that on further separation yielded a novel 29-residue macrocyclic polypeptide named varv peptide A, cyclo(-TCVGGTCNTPGCSCSWPVCTRNGLPVCGE-).
Synthesis and Structure–Activity Relationships of Lapacho Analogues. 2. Modification of the Basic Naphtho[2,3-b]furan-4,9-dione, Redox Activation, and Suppression of Human Keratinocyte Hyperproliferation by 8-Hydroxynaphtho[2,3-b]thiophene-4,9-diones (2014)

The basic structure of linearly anellated lapacho quinones, naphtho[2,3-b]furan-4,9-dione (7), was modified in the search for novel agents against keratinocyte hyperproliferation. The synthesis and structure-activity relationships of several heterocycle-fused naphthoquinones as well as a full range of 2- and 7-substituted derivatives of one of these, 8-hydroxynaphtho[2,3-b]thiophene-4,9-dione (8a), are described. Out of a total of 71 analogues, particularly 2-thenoyl-substituted 26l, 2-nicotinoyl-substituted 26m, and 2-oxadiazole-substituted 35a compared favorably with the antipsoriatic agent anthralin. Their potency for suppression of keratinocyte hyperproliferation, which was evaluated using HaCaT cells as a model, was combined with comparably low membrane-damaging effects toward keratinocytes, as established by the release of lactate dehydrogenase activity from the cytoplasm of the cells. With respect to the mechanism of action, redox activation of lapacho quinones by one- and two-electron reduction in isolated enzymatic assays was studied, and their potential to generate superoxide was confirmed in the keratinocyte-based hyperproliferation assay.
A Comparative Examination of the Clinical Outcome and Histological Appearance of Cryopreserved and Fresh Split-Thickness Skin Grafts (2016)

The clinical use of frozen, human allogeneic skin grafts is considered a suitable alternative to freshly harvested allogeneic skin grafts when the latter are not available. However, limited functional and histological information exists regarding the effects of cryopreservation on allogeneic skin grafts, especially those across mismatched histocompatibility barriers. Thus, we performed a side-by-side comparative study of fresh vs frozen skin grafts, across both minor and major histocompatibility barriers, in a miniature swine model. Since porcine skin shares many physical and immunological properties with human skin, our findings have relevance to current clinical practices involving allogeneic grafting and may support future, temporary wound therapies involving frozen xenografts, comprised genetically modified porcine skin. Four miniature swine underwent harvest and grafting of split-thickness skin, with and without cryopreservation, in order to observe autologous grafts and grafts across minor and major histocompatibility barriers. A biopsy of the grafts was done at regular intervals for study of architecture, vascularization, and outcomes. All grafts vascularized without technical complications. Differences were noted in the early appearance of some fresh vs frozen grafts, but no significant difference was observed in overall survival times in any of the experimental groups. These results demonstrate that despite early observable differences in the healing process, cryopreservation and thawing does not significantly affect long-term graft survival or time to rejection, thus supporting the clinical and experimental use of fresh and frozen split-thickness skin grafts as comparable and interchangeable.
THE WNT SIGNALING PATHWAY IN DEVELOPMENT AND DISEASE (2004)

Tight control of cell-cell communication is essential for the generation of a normally patterned embryo. A critical mediator of key cell-cell signaling events during embryogenesis is the highly conserved Wnt family of secreted proteins. Recent biochemical and genetic analyses have greatly enriched our understanding of how Wnts signal, and the list of canonical Wnt signaling components has exploded. The data reveal that multiple extracellular, cytoplasmic, and nuclear regulators intricately modulate Wnt signaling levels. In addition, receptor-ligand specificity and feedback loops help to determine Wnt signaling outputs. Wnts are required for adult tissue maintenance, and perturbations in Wnt signaling promote both human degenerative diseases and cancer. The next few years are likely to see novel therapeutic reagents aimed at controlling Wnt signaling in order to alleviate these conditions.
“Sliding kinetics” of single-walled carbon nanotubes on self-assembled monolayer patterns: Beyond random adsorption (2006)

We present the experimental results and theoretical model describing new adsorption kinetics of single-walled carbon nanotubes (swCNTs) onto self-assembled monolayer (SAM) including their sliding motion. The adsorption behavior of swCNTs on large-size SAM patterns is similar to the Langmuir isotherm, while that on nanoscale patterns shows a significant deviation which can be explained by the sliding motion of adsorbed nanotubes. The "sliding chamber" experiment confirms that swCNTs can align along the SAM patterns by sliding motion right above the SAM surfaces. This result provides new scientific insights regarding the adsorption kinetics of one-dimensional nanostructures, and, from a practical point of view, it can be an important guideline to design SAM patterns to assemble carbon nanotubes and nanowires into desired device structures.
Comparison of carrier recovery techniques in M-QAM digital communication systems (2002)

In digital wireless systems the frequency uncertainty between the transmitter and the receiver can take large values. The carrier recovery loop must be able to acquire lock in the presence of phase noise on the synthesized carrier. However, high level modulation formats such as 16, 32 and 64 QAM require very small steady state phase jitter. Unfortunately, these requirements are often incompatible in carrier recovery circuits. Practically, acquisition aiding techniques such as frequency sweeping or frequency detectors are the main solution to this problem. This paper addresses decision feedback carrier recovery loops for coherent demodulation of the 16 QAM signal format. Two types of decision-directed phase detector referred as basic or original phase detector (PD) and phase-frequency detector (PFD) are used in order to extend the acquisition range of the loop. Extensive and realistic simulation tests are performed to investigate the acquisition behavior of both phase detectors in the presence of phase noise. The best performance is obtained with the PFD structure. Compared with the original phase detector, the PFD structure leads to a 15-fold increase of the loop acquisition range.
Enhancing effect of thyroxine on tumor growth and metastases in syngeneic mouse tumor systems. (1979)

We studied the effect of thyroxine treatment on tumor growth and metastases resulting from tumor implants on the hind feet of mice in two syngeneic systems. In control, untreated A/Jax mice, tumor Sarcoma 1 at Day 14 after implantation had average tumor weight of 582 +/- 60 (S.D.) mg and showed an incidence of 57% metastases to regional popliteal nodes and 5% metastases to thymus. In contrast, the thyroxine-treated group (40 microgram/mouse s.c., 5 times/week for 1 month) had an average tumor weight of 808 +/- 56 mg (p less than 0.001), and metastases to popliteal nodes and thymus were 90 and 35%, respectively. In another syngeneic tumor system, Lewis fibrosarcoma was implanted in C57BL/6J mice, and the tumor weight and metastatic index (derived from the number and size of the pulmonary tumor foci) were determined at Day 28. Again, the synthetic L-thyroxine treated group showed a significant enhancement tumor growth and metastatic index. The mean tumor weight in the treated group was 385 +/- 26 mg (control, 694 +/- 25 mg; p less than 0.005) and metastatic index was 84 +/- 29 (control, 30 +/- 25; p less than 0.001). Induced hypothyroidism (treatment with 131I, 100 microCi/mouse i.p.) showed the reverse effect on both tumor systems. These results suggest that both tumor systems are dependent on thyroid hormones for their growth and spread.