gebhart/patrepeval huggingface dataset:
Average Blood Flow and Oxygen Uptake in the Human Brain during Resting Wakefulness: A Critical Appraisal of the Kety—Schmidt Technique (1993)

The Kety-Schmidt technique can be regarded as the reference method for measurement of global average cerebral blood flow (average CBF) and global average cerebral metabolic rate of oxygen (average CMRO2). However, in the practical application of the method, diffusion equilibrium for inert gas tracer between the brain and its venous blood is not reached. As a consequence, normal values for CBF and CMRO2 of 54 ml 100 g-1 min-1 and 3.5 ml 100 g-1 min-1 obtained with the Kety-Schmidt technique are an overestimation of the true values. Using the Kety-Schmidt technique we have performed 57 measurements of CBF and CMRO2 during EEG-verified wakeful rest in young normal adults. In order to estimate the equilibrium values for CBF and CMRO2, a simple computer-based simulation model was employed to quantitate the systematic overestimation caused by incomplete tracer equilibrium. When correcting the measured data, we find that the true average values for CBF and CMRO2 in the healthy young adult are approximately 46 ml 100 g-1 min-1 and approximately 3.0 ml 100 g-1 min-1. Previous studies have suggested that some of the variation in CMRO2 values could be ascribed to differences in cerebral venous anatomy. However in the present study, no correlation between CMRO2 and cerebral venous anatomy as imaged by magnetic resonance angiography could be established. Our data show that the interindividual variation of CMRO2 is 11% (coefficient of variation).
Design of a high-speed vertical transition in LTCC for interposers suitable for packaging photonic integrated circuits (2016)

The packaging of high speed Photonic Integrated Circuits (PICs) should maintain the electrical signal integrity. The standard packaging of high speed PICs relies on wire bonds. This is not desirable because wire bonds degrade the quality of the electrical signal. The research presented in this paper proposes to replace wire bonds with an interposer with multilevel transmission lines. By attaching the PIC by flip chip onto the interposer, the use of wire bonds is avoided. The main concern for designing an interposer with multilevel transmission lines is the vertical transition, which must be designed to avoid return and radiation losses. In this paper, a novel design of a high speed vertical transition for Low Temperature Co-fired Ceramic (LTCC) is presented. The proposed vertical transition is simpler than others recently published in the literature, due to eliminating the need for additional ceramic layers or air cavities. A LTCC board was fabricated with several variations of the presented transition to find the optimal dimensions of the structure. The structures were fabricated then characterized and have a 3 dB bandwidth of 37 GHz and an open eye diagram at 44 Gbps. A full wave electromagnetic simulation is described and compared with good agreement to the measurements. The results suggest that an LTCC board with this design can be used for 40 Gbps per channel applications. Keywords: Photonics packaging, Low Temperature Co-Fired Ceramics.
Hemopexin is synthesized in peripheral nerves but not in central nervous system and accumulates after axotomy. (1992)

In adult mammals, injured axons regrow over long distances in peripheral nerves but fail to do so in the central nervous system. Analysis of molecular components of tissue environments that allow axonal regrowth revealed a dramatic increase in the level of hemopexin, a heme-transporting protein, in long-term axotomized peripheral nerve. In contrast, hemopexin did not accumulate in lesioned optic nerve. Sciatic nerve and skeletal muscle, but not brain, were shown to be sites of synthesis of hemopexin. Thus, hemopexin expression, which can no longer be considered to be liver-specific, correlates with tissular permissivity for axonal regeneration.
The effect of engineering surface loops on the thermal stability of Bacillus subtilis neutral protease (1994)

Using genetic techniques the contribution of surface loops to the thermal stability of Bacillus subtilis neutral protease (NP-sub) was studied. Mutations were designed to make the surface of NP-sub more similar to the surface of more thermostable neutral proteases such as thermolysin (TLN). The mutations included the replacement of an irregular loop by a shorter variant and the introduction of a ten-residue beta-hairpin. In general, these drastic mutations had little effect on the production and activity of NP-sub, indicating the feasibility of major structural rearrangements at the surface of proteins. In the most stable mutant, exhibiting an increase in thermal stability of 1.1 degree C, approximately 10% of the surface of NP-sub was modified. Several NP-sub variants carrying multiple mutations were constructed. Non-additive effects on thermal stability were observed, which were interpreted on the basis of a model for thermal inactivation, that emphasizes the importance of local unfolding processes for thermal stability.
Advances in Urological Laparoscopy (1995)

Despite the time-consuming and costly nature of laparoscopy, the decreased morbidity and brief convalescence that are the hallmarks of minimally invasive surgery are evident and well documented. Further dissemination of laparoscopic skills through postgraduate urology training programs and during urology residency is of the utmost importance.
3D Moments from Near-Duplicate Photos (2022)

We introduce 3D Moments, a new computational photography effect. As input we take a pair of near-duplicate photos, i.e., photos of moving subjects from similar viewpoints, common in people's photo collections. As output, we produce a video that smoothly interpolates the scene motion from the first photo to the second, while also producing camera motion with parallax that gives a heightened sense of 3D. To achieve this effect, we represent the scene as a pair of feature-based layered depth images augmented with scene flow. This representation enables motion interpolation along with independent control of the camera viewpoint. Our system produces photorealistic space-time videos with motion parallax and scene dynamics, while plausibly recovering regions occluded in the original views. We conduct extensive experiments demonstrating superior performance over baselines on public datasets and in-the-wild photos. Project page: https://3d-moments.github.io/.
Accelerated Exponential Fitting for Rapid Relaxation Time Mapping (2006)

Introduction Mapping of relaxation times such as T1 and T2 generally involves the fitting of an exponential function to the evolution of the signal intensity in each pixel of a time series of images. The prevalent method employed for this purpose, the Levenberg-Marquardt method, pursues a non-linear least squares approach [1]. For applications that require a rapid mapping, its high computational complexity is a limiting factor, however. Other, faster methods have been devised, but they prove less accurate. For instance, a linear regression leads to an unstable estimation in the presence of noise, and a numerical integration to a systematic overestimation [2]. To decrease computational complexity while conserving accuracy, the present work suggests to solve the non-linear regression problem by searching for a real root of a polynomial in a small interval, and it demonstrates this approach on T2 * mapping. Methods Let sk denote the samples of signal intensity taken at k∆t, where k = 0 ... N-1. The best fit of a monoexponential decay to this time series in a least squares sense is given by the minimum of the error function
Chiral phosphine oxides in present-day organocatalysis (2010)

The design and synthesis of new chiral Lewis bases is a field of extraordinary activity; in this context, while N-oxides derived from both N-heterocyclic systems and aliphatic amines have found widespread applications in organocatalysis, quite surprisingly phosphine oxides have been used less frequently. This contribution will highlight the relatively few examples of stereoselective transformations organocatalyzed by chiral phosphine oxides, discussing the different proposed reaction mechanisms and identifying topics for future investigation in what can be most certainly defined as an "Emerging Area".
The Computational Difficulty of Solving Cryptographic Primitive Problems Related to the Discrete Logarithm Problem (2005)

To the authors' knowledge, there are not many cryptosystems proven to be as difficult as or more difficult than the discrete logarithm problem. Concerning problems related to the discrete logarithm problem, there are problems called the double discrete logarithm problem and the e-th root of the discrete logarithm problem. These two problems are likely to be difficult and they have been utilized in cryptographic protocols such as verifiable secret sharing scheme and group signature scheme. However, their exact complexity has not been clarified, yet. Related to the e-th root of the discrete logarithm problem, we can consider a square root of the discrete logarithm problem. Again, the exact complexity of this problem has not been clarified, yet. The security of cryptosystems using these underlying problems deeply depends on the difficulty of these underlying problems. Hence it is important to clarify their difficulty. In this paper we prove reductions among these fundamental problems and show that under certain conditions, these problems are as difficult as or more difficult than the discrete logarithm problem modulo a prime.
Dynamic of ON and OFF chromatic adaptation (2019)

Introduction: Zaidi et al (Current Biology, 2012) devised a time varying chromatic adaptation paradigm that used two hemifields modulating in opposite (ON and OFF) directions in cardinal axes. The present study assessed the dynamics of ON and OFF chromatic adaptation separately under different background chromaticities and identified which process determined the dynamics of adaptation with simultaneous ON and OFF modulations. Methods: Two stimulus types were used: one consisted of two hemifields (subtending 3.6°) complementarily modulated to opposite ends of a cardinal axis (simultaneous ON/OFF) and the other was only one of the two hemi-fields modulated along one end (either ON or OFF) of a given cardinal axis (L+M-, l=L/(L+M)- and s=S/(L+M)-axis). Modulation was half a cycle of a sinusoid (1/32Hz), starting and finishing on the mean background chromaticity. Nine backgrounds (20cd/m2) were set: one achromatic (EEW), 2 reddish (+l), 2 greenish (−l), 2 bluish (+s) and 2 yellowish (−s). The task was to report the time to reach the identity point, that is, when the stimulus had the same color as the background. Results: Compared with the ON stimuli, the time at the identity point occurrence for the OFF stimuli was shorter in the L+M and s directions, particularly with the EEW, bluish and yellowish backgrounds. Relative to the EEW background, the identity times with complementary modulations in the s-axis was decreased by the yellowish backgrounds and increased by the bluish backgrounds. Finally, the identity times with complementary modulations were equal or larger than the slower mechanism tested separately for the ON and OFF stimuli for all backgrounds. Conclusions: The ON and OFF adaptations in the L+M and s directions have different dynamics and the slower mechanism determined adaptation with simultaneous ON and OFF modulations.
Regulatory effect of hydrogen on nitrogenase activity of the blue-green alga (cyanobacterium) Nostoc muscorum (1980)

Preincubation of the blue-green alga (cyanobacterium) Nostoc muscorum under an atmosphere of argon plus acetylene in the light led to a greater than fourfold increase of light-induced hydrogen evolution and to a 50% increase of acetylene reduction, as compared to cells that had not been preconditioned. The basic and the increased hydrogen evolution were both due to nitrogenase activity. Furthermore, after preincubation the hydrogen uptake, usually observed with unconditional cells, was abolished. Nostoc preincubated under acetylene evolved hydrogen in the light even in the presence of nitrogen for at least 2 h, with a 15-fold increase as compared to the unconditioned cells. These acetylene effects could be completely abolished by the presence of hydrogen during acetylene preincubation. These findings indicate that the hydrogen concentration in N. muscorum cells plays a role in regulation of nitrogenase activity.
Comparative analysis of inductor concepts for high peak load low duty cycle operation (2014)

In this work a compact-model-based inductor design procedure is presented. The losses, temperatures, and the total cost of ownership (TCO) of an inductor are expressed analytically. All geometric dependencies are summarized in a set of parameters which are calculated using finite element analysis (FEA). Therefore the model does not depend on the actual inductor geometry, instead it only relies on a generalized set of parameters which contain all geometric information. Different inductor geometries only result in different values of parameters. The dynamic thermal model is verified using time dependent FEA, the high frequency winding loss model is verified by measurements. The inductor model is then used to study the effect of changes in inductor geometry on the performance of the device. It is shown that for applications requiring high peak but low average load substantial cost reductions are achieved if the inductor's geometry is optimized and the right inductor topology is selected.
ChemInform Abstract: The Potential for Using Carbocyclic Nucleosides for the Treatment of AIDS. Part 1. Preparation of Some Analogues for Azidothymidine (AZT). (1991)

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.
Early nasopharyngeal microbial signature associated with severe influenza in children: a retrospective pilot study (2017)

A few studies have highlighted the importance of the respiratory microbiome in modulating the frequency and outcome of viral respiratory infections. However, there are insufficient data on the use of microbial signatures as prognostic biomarkers to predict respiratory disease outcomes. In this study, we aimed to evaluate whether specific bacterial community compositions in the nasopharynx of children at the time of hospitalization are associated with different influenza clinical outcomes. We utilized retrospective nasopharyngeal (NP) samples (n=36) collected at the time of hospital arrival from children who were infected with influenza virus and had been symptomatic for less than 2 days. Based on their clinical course, children were classified into two groups: patients with mild influenza, and patients with severe respiratory or neurological complications. We implemented custom 16S rRNA gene sequencing, metagenomic sequencing and computational analysis workflows to classify the bacteria present in NP specimens at the species level. We found that increased bacterial diversity in the nasopharynx of children was strongly associated with influenza severity. In addition, patients with severe influenza had decreased relative abundance of Staphylococcus aureus and increased abundance of Prevotella (including P. melaninogenica), Streptobacillus, Porphyromonas, Granulicatella (including G. elegans), Veillonella (including V. dispar), Fusobacterium and Haemophilus in their nasopharynx. This pilot study provides proof-of-concept data for the use of microbial signatures as prognostic biomarkers of influenza outcomes. Further large prospective cohort studies are needed to refine and validate the performance of such microbial signatures in clinical settings.
Two-Phase Scheduling and Leakage-Based Precoding in Wireless Cellular Networks (2013)

We consider the downlink of a wireless cellular network where the base stations are equipped with multiple antennas and operate in the same frequency band. Since scheduling changes the spatial transmit signal processing with each time slot, information from neighboring base stations is required for data encoding. This can, in theory, be accomplished by a high-capacity backhaul network through which the base stations exchange channel state information (CSI) and other control signals. In reality, however, the temporal granularity of the scheduler does not allow for timely distribution of CSI among base stations. We propose a two-phase scheduler which optimizes the precoding in the first phase and allows the users to feed back their instantaneous interference power in the second phase. For the single-user case, we present a practical scheme that combines two-phase scheduling with precoders that maximize the signal-to-leakage-plus-noise ratio. If the users feed back the interference power together with a supported rate, communication between base stations can be limited to integers. By comparing the performance to multi-user two-phase scheduling with dirty paper coding and to algorithms that share CSI among base stations we show that two-phase scheduling is a technically and practically feasible solution to deal with non-stationary intercell interference.
Transcriptional repressor CopR: Amino acids involved in forming the dimeric interface (2000)

Plasmid pIP501 encoded transcriptional repressor CopR is one of the two regulators of plasmid copy number. It acts as a transcriptional repressor at the essential repR promoter. Furthermore, CopR prevents convergent transcription from the repR and the antisense promoter, thereby indirectly increasing the amount of antisense-RNA, the second regulatory component. CopR binds as a dimer to a nearly palindromic operator with the consensus sequence 5'CGTG. Previously, a CopR structural model was built and used to identify amino acids involved in DNA binding. These data showed that CopR is a HTH protein belonging to the lambda repressor superfamily and allowed the identification of two amino acids involved in specific DNA recognition. Here, we describe site-directed mutagenesis in combination with EMSA, dimerization studies using sedimentation equilibrium, and CD measurements to verify the model predictions concerning amino acids involved in dimerization. With this approach, the dimeric interface could be located between amino acids I44 and L62. F5 located at the N-terminus is additionally required for proper folding, and could, therefore, not be unequivocally assigned to the dimeric interface. CD measurements at protein concentrations well below K(Dimer) revealed that the monomer of CopR is folded.
Modular Routes to 1,3-Dithian-2-ones and 1,2-Dithiolanes (2022)

Convergent routes to 1,3-dithian-2-ones based on the radical addition of xanthates to alkenes possessing a suitably located (latent) leaving group are described. These can be converted into 1,2-dithiolanes by base-mediated hydrolysis and oxidation. A broad variety of functional groups can be introduced, and the process is modular, uses inexpensive starting materials and reagents, and is atom economical, because both sulfur atoms of the xanthate end up in the products.
Synthesis of LiMnO2 with α ‐ NaMnO2‐Type Structure by a Mixed‐Alkaline Hydrothermal Reaction (1998)

A metastable form of with ‐type structure (layered‐) was synthesized directly from by hydrothermal reaction at 220°C using aqueous mixed‐alkaline solutions such as or LiCl‐KOH. Relatively highly crystallized samples could be obtained by a one‐step process, compared with that of an ion‐exchanged sample obtained previously. Magnetization data between 83 and 500 K show that manganese ions are present as 3+ in high‐spin state and a broad maximum is observed ca. 250 K, suggesting a yield of antiferromagnetic ordering below room temperature. Preliminary electrochemical tests using coin‐type cells in which lithium metal was used as negative electrode material show that about 100 mAh/g specific capacity remained at the eighth cycle between 2.0 and 4.3 V, whereas the initial charge capacity reached ca. 210 mAh/g up to 4.3 V.
Chitosan-Based Nanoparticles Against Viral Infections (2021)

Viral infections, in addition to damaging host cells, can compromise the host immune system, leading to frequent relapse or long-term persistence. Viruses have the capacity to destroy the host cell while liberating their own RNA or DNA in order to replicate within additional host cells. The viral life cycle makes it challenging to develop anti-viral drugs. Nanotechnology-based approaches have been suggested to deal effectively with viral diseases, and overcome some limitations of anti-viral drugs. Nanotechnology has enabled scientists to overcome the challenges of solubility and toxicity of anti-viral drugs, and can enhance their selectivity towards viruses and virally infected cells, while preserving healthy host cells. Chitosan is a naturally occurring polymer that has been used to construct nanoparticles (NPs), which are biocompatible, biodegradable, less toxic, easy to prepare, and can function as effective drug delivery systems (DDSs). Furthermore, chitosan is Generally Recognized as Safe (GRAS) by the US Food and Drug Administration (U.S. FDA). Chitosan NPs have been used in drug delivery by the oral, ocular, pulmonary, nasal, mucosal, buccal, or vaginal routes. They have also been studied for gene delivery, vaccine delivery, and advanced cancer therapy. Multiple lines of evidence suggest that chitosan NPs could be used as new therapeutic tools against viral infections. In this review we summarize reports concerning the therapeutic potential of chitosan NPs against various viral infections.
SYNTHESIS AND ELECTROSPINNING OF A NOVEL FLUORESCENT POLYMER PMMA-PM FOR QUENCHING-BASED OPTICAL SENSING (2002)

ABSTRACT This work presents the synthesis of a new fluorescent polymer and its applicability for optical sensing using the electrospinning technique for the fabrication of nanofibrous membrane sensors. A new fluorescent monomer was first synthesized by coupling reactions between methacryloyl chloride and a pyrene derivative, 1-pyrene butanol. Fluorescent polymers containing different ratios of pyrene were then obtained by the copolymerization of this monomer with methylmethacrylate using 2,2′-azobisisobutyronitrile as the initiator. These polymers show distinct and well-defined fluorescence that is characteristic of the pyrene chromophores. Quenching-based optical chemical sensors were then fabricated by the electrospinning technique. The preliminary results show that these sensors have an order of magnitude higher sensitivity to the target analyte 2, 4-dinitro toluene than sensors formed from continuous thin films. This is believed to be due to the higher surface area to volume ratio of the electrospun nanofibrous membranes. The quenching behavior follows Stern-Volmer bimolecular quenching kinetics. The synthesis, characterization, electrospinning fabrication, and sensing capability of these polymers are discussed.
TP53 Mutations Predict Sensitivity to Adjuvant Gemcitabine in Patients with Pancreatic Ductal Adenocarcinoma: Next-Generation Sequencing Results from the CONKO-001 Trial (2020)

In CONKO-001, the benefit from adjuvant gemcitabine was confined to the <i>TP53</i>mut patient group. This potentially clinical relevant observation needs to be confirmed in independent prospective studies. The sensitivity of TP53mut PDAC to gemcitabine in CONKO-001 provides a lead for further mechanistic investigations.