gebhart/patrepeval huggingface dataset:
Developmental changes in brain serotonin synthesis capacity in autistic and nonautistic children (1999)

Serotonin content, serotonin uptake sites, and serotonin receptor binding measured in animal studies are all higher in the developing brain, compared with adult values, and decline before puberty. Furthermore, a disruption of synaptic connectivity in sensory cortical regions can result from experimental increase or decrease of brain serotonin before puberty. The purpose of the present study was to determine whether brain serotonin synthesis capacity is higher in children than in adults and whether there are differences in serotonin synthesis capacity between autistic and nonautistic children. Serotonin synthesis capacity was measured in autistic and nonautistic children at different ages, using alpha[11C]methyl-L-tryptophan and positron emission tomography. Global brain values for serotonin synthesis capacity (K complex) were obtained for autistic children (n = 30), their nonautistic siblings (n = 8), and epileptic children without autism (n = 16). K-complex values were plotted according to age and fitted to linear and five-parameter functions, to determine developmental changes and differences in serotonin synthesis between groups. For nonautistic children, serotonin synthesis capacity was more than 200% of adult values until the age of 5 years and then declined toward adult values. Serotonin synthesis capacity values declined at an earlier age in girls than in boys. In autistic children, serotonin synthesis capacity increased gradually between the ages of 2 years and 15 years to values 1.5 times adult normal values and showed no sex difference. Significant differences were detected between the autistic and epileptic groups and between the autistic and sibling groups for the change with age in the serotonin synthesis capacity. These data suggest that humans undergo a period of high brain serotonin synthesis capacity during childhood, and that this developmental process is disrupted in autistic children.
Novel transfer RNAs that are active in Escherichia coli (1992)

Many of the mammalian mitochondrial tRNAs contain significant nucleotide deletions in the dihydrouridine (D) stem or T psi C stem, so that they cannot fold into the canonical cloverleaf structure. This suggests that alternative forms and shapes are possible for a mitochondrial tRNA that functions in the specialized translational apparatus of the mammalian mitochondria. The question of whether significant structural alterations may be accommodated by a bacterial protein synthesis machinery, such as in Escherichia coli, is unanswered. In this work, all but ten positions in the gene for the 76-nucleotide coding sequence of an E. coli amber suppressor tRNA were permuted and screened for biological activity in vivo. Sequence analysis of a collection of biologically active variants established that many have unusual structures that include base-pair mismatches in helical stems, substitutions of normally conserved bases, and deletions. Independent mutations were obtained that weaken base pairs or tertiary interactions that normally stabilize the coaxial stacking of the D and anticodon stems, suggesting that the translational apparatus can accommodate considerable flexibility in this part of the molecule. The results demonstrate the capacity of the bacterial protein synthetic apparatus to accommodate altered tRNA structures that are not represented by any naturally occurring tRNAs.
Extensive neurite outgrowth and active synapse formation on self-assembling peptide scaffolds (2000)

A new type of self-assembling peptide (sapeptide) scaffolds that serve as substrates for neurite outgrowth and synapse formation is described. These peptide-based scaffolds are amenable to molecular design by using chemical or biotechnological syntheses. They can be tailored to a variety of applications. The sapeptide scaffolds are formed through the spontaneous assembly of ionic self-complementary beta-sheet oligopeptides under physiological conditions, producing a hydrogel material. The scaffolds can support neuronal cell attachment and differentiation as well as extensive neurite outgrowth. Furthermore, they are permissive substrates for functional synapse formation between the attached neurons. That primary rat neurons form active synapses on such scaffold surfaces in situ suggests these scaffolds could be useful for tissue engineering applications. The buoyant sapeptide scaffolds with attached cells in culture can be transported readily from one environment to another. Furthermore, these peptides did not elicit a measurable immune response or tissue inflammation when introduced into animals. These biological materials created through molecular design and self assembly may be developed as a biologically compatible scaffold for tissue repair and tissue engineering.
ChemInform Abstract: Progress in the Synthesis of Chiral Heterocyclic Natural Products: Epothilone B and Tartrolon B (2000)

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.
Enhanced intracellular delivery and multi‐target gene silencing triggered by tripodal RNA structures (2012)

The data obtained in the present study provide an example of synthetic multi-functional RNA structures that enable multiple gene interference in mammalian cells, which could become powerful tools for an efficient combinatorial iRNA strategy.
Fluorescence Modified Chitosan-Coated Magnetic Nanoparticles for High-Efficient Cellular Imaging (2009)

Labeling of cells with nanoparticles for living detection is of interest to various biomedical applications. In this study, novel fluorescent/magnetic nanoparticles were prepared and used in high-efficient cellular imaging. The nanoparticles coated with the modified chitosan possessed a magnetic oxide core and a covalently attached fluorescent dye. We evaluated the feasibility and efficiency in labeling cancer cells (SMMC-7721) with the nanoparticles. The nanoparticles exhibited a high affinity to cells, which was demonstrated by flow cytometry and magnetic resonance imaging. The results showed that cell-labeling efficiency of the nanoparticles was dependent on the incubation time and nanoparticles' concentration. The minimum detected number of labeled cells was around 10(4) by using a clinical 1.5-T MRI imager. Fluorescence and transmission electron microscopy instruments were used to monitor the localization patterns of the magnetic nanoparticles in cells. These new magneto-fluorescent nanoagents have demonstrated the potential for future medical use.
Detection of replicative intermediates of hepatitis C viral RNA in liver and serum of patients with chronic hepatitis C. (1991)

The hepatitis C virus is a positive stranded hepatotropic RNA virus. We describe a method of detecting positive and negative strands of hepatitis C viral RNA using the polymerase chain reaction. We tested serum and liver tissue from nine patients with chronic hepatitis C. The positive RNA strand of HCV was detected in the sera and livers of all nine, the negative strand was detected in the livers of eight (89%), and in the sera of five (55%). Titers of both strands of HCV RNA were determined by serial endpoint dilutions. The amount of the negative strand in the serum and liver was usually 10-100 times less than the positive strand. Predigestion of serum with ribonucleases did not alter the detection of the negative strand. This suggests that the negative strand found in the serum may be protected from digestion by being associated with virions.
Large-Scale Order Dispatch in On-Demand Ride-Hailing Platforms (2018)

We present a novel order dispatch algorithm in large-scale on-demand ride-hailing platforms. While traditional order dispatch approaches usually focus on immediate customer satisfaction, the proposed algorithm is designed to provide a more efficient way to optimize resource utilization and user experience in a global and more farsighted view. In particular, we model order dispatch as a large-scale sequential decision-making problem, where the decision of assigning an order to a driver is determined by a centralized algorithm in a coordinated way. The problem is solved in a learning and planning manner: 1) based on historical data, we first summarize demand and supply patterns into a spatiotemporal quantization, each of which indicates the expected value of a driver being in a particular state; 2) a planning step is conducted in real-time, where each driver-order-pair is valued in consideration of both immediate rewards and future gains, and then dispatch is solved using a combinatorial optimizing algorithm. Through extensive offline experiments and online AB tests, the proposed approach delivers remarkable improvement on the platform's efficiency and has been successfully deployed in the production system of Didi Chuxing.
Investigation of postoxidation thermal treatments of Si/SiO2 interface in relationship to the kinetics of amorphous Si suboxide decomposition (1998)

Interfacial Si suboxides (SiOx, x&amp;lt;2) are detrimental to transistor performance and are typically minimized during postoxidation anneals. To study the kinetics of SiOx decomposition, thick films (∼2000 Å) of amorphous Si:O:H alloys (0.7&amp;lt;x&amp;lt;1.4) were deposited by remote plasma enhanced chemical vapor deposition and subjected to rapid thermal anneals. Films were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, ellipsometry, photoluminescence (PL), and transmission electron microscopy. At temperatures &amp;gt;500 °C initially there is a rapid segregation into amorphous Si (a-Si) surrounded by a SiO2 shell which acts as a diffusion barrier decelerating the reaction. Phenomenological modeling of kinetics with a one-dimensional Avrami–Erofe’ve treatment gives an upper limit for a-Si lateral growth rates of 1.2 Å/s at 900 °C with an activation energy of 120 kJ/mol. PL, Raman, transmission electron microscopy and ellipsometry confirm this segregation model in the amorphous state. Due to the rapid initial decomposition and relatively large diffusion coefficients, a simple kinetic hindrance explanation for the 4–8 Å of SiOx at the SiO2/Si interface is unlikely.
Hypoxia in the tumorigenesis of gliomas and as a potential target for therapeutic measures (2006)

In this article, the author provides a brief description of the role of hypoxia in the tumorigenesis of gliomas and suggests potential ways of exploiting this role to design treatment modalities. Tumor hypoxia predicts the likelihood of metastases, tumor recurrence, resistance to chemotherapy and radiation therapy, invasive potential, and decreased patient survival for many human malignancies. Various methods of measurement of tumor hypoxia are discussed, including direct measurement and imaging methods. The role of hypoxia-responsive molecules, especially hypoxia-inducible factor-1 (HIF-1), in glioma tumorigenesis is explored. Treatment modalities regulated by hypoxia are proposed and some potential strategies reviewed. The progression of a low-grade astrocytoma to a glioblastoma multiforme may be mediated by hypoxia-induced phenotypic changes and subsequent clonal selection of cells that overexpress hypoxia-responsive molecules, such as HIF-1. In this model, intratumoral hypoxia causes genetic changes that produce a microenvironment that selects for cells of a more aggressive phenotype.
Strip: a soft real-time main memory database for open systems (1997)

Traditionally, real-time systems have been used in control applications, such as plant control and flight control. These applications have stringent timing requirements and missing even a single deadline can be disastrous. Currently, however, there is interest in real-time capabilities from other types of applications. Many problems in telecommunications, program trading, and multimedia delivery require systems that are cognizant of the temporal aspects of both data and transactions. Traditional hard real-time systems, which require very predictable execution times and mostly periodic workloads, do not map well to these event driven applications. This dissertation considers the database facilities that are needed by the new class of applications requiring soft real-time constraints, focusing on two problem in particular. The first problem is how to integrate soft real-time databases (SRTDBs) into distributed systems composed of real-time and non-real-time database systems. Supporting d...
Human-powered wearable computing (1996)

Batteries add size, weight, and inconvenience to present-day mobile computers. This paper explores the possibility of harnessing the energy expended during the user's everyday actions to generate power for his or her computer, thus eliminating the impediment of batteries. An analysis of power generation through leg motion is presented in depth, and a survey of other methods such as generation by breath or blood pressure, body heat, and finger and limb motion is also presented.
Automated Workflow Improves Speed and Precision of S/TEM Process Monitoring for 22 nm FinFET Structures (2013)

Abstract Recent developments in automated image acquisition and metrology using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have significantly improved the speed, precision, and usability of these techniques for controlling advanced semiconductor device manufacturing processes. As device dimensions have continued to shrink, these techniques may be needed to replace scanning electron microscopy (SEM) for the smallest critical dimension (CD) measurements. This article describes the use of automated S/TEM in a high-throughput CD-metrology workflow to support process development and control and explains how automated sample-preparation, data-acquisition, and metrology tools increase both throughput and data quality.
Toxicogenomics of drug delivery systems: Exploiting delivery system-induced changes in target gene expression to enhance siRNA activity (2007)

Synthetic siRNAs are typically formulated with drug delivery systems (DDS) that improve cellular uptake for optimal gene silencing activity. Here, we show that two PAMAM dendrimer DDS, differing only in their structural architecture, elicit many different gene expression changes in human cells including opposing effects on the expression of epidermal growth factor receptor (EGFR), a gene targeted for silencing by siRNA. Despite providing similar improvements in siRNA uptake, these two formulations led to a approximately 10-fold variation in anti-EGFR siRNA activity. These data show that gene expression changes induced by DDS, separate from their ability to enhance cell uptake, determine 'apparent' siRNA potency and thus offer the possibility of tailoring delivery system-siRNA combinations for additive or synergistic effects on gene silencing.
An 800 bit/s vector quantization LPC vocoder (1982)

An 800 bit/s vector quantization linear predictive coding (LPC) vocoder has been developed. The recently developed LPC vector quantization theory is applied to reduce the bit rate for LPC coefficients coding by a factor of four. Branch search techniques and separation of voiced and unvoiced codebooks are applied for better algorithm efficiency. Differential coding is applied to reduce the bit rate for the pitch and gain parameters by one third. Formal subjective evaluation shows that the 800 bit/s vocoder preserves most of the intelligibility of an LPC system. It is also robust under different transmission error and acoustic conditions. Informal listening comparisons show the quality to be acceptable and sometimes very close to 2400 bit/s LPC speech. The computational cost of the 800 bit/s vocoder is equivalent to or even lower than the 2400 bit/s LPC-10. Compatibility with any LPC-10 vocoder is guaranteed because the 800 bit/s design only differs in the quantization and encoding algorithms. Further bit rate reduction can be achieved by removing frame to frame redundancy in the code.
Synthesis and Characterization of Polyisoprene/Polybutadiene A2B2 Star Copolymers (1996)

Two routes for the synthesis of star block copolymers having exactly two arms of polyisoprene (PI) and two of polybutadiene (PB) are described. The first route starts by condensing one molecule of silicon tetrachloride with two of poly(isoprenyl)lithium which has been end-capped by a few units of styrene. The second route starts by linking two poly(isoprenyllithium) chains with one molecule of silicon tetrachloride at a suitably reduced temperature. Both routes are completed by reaction of the two-armed intermediate (PI)2SiCl2 with an excess of poly(butadienyllithium). The resulting (PI)2Si(PB)2 star polymer was purified by fractionation. The reaction steps were monitored by size exclusion chromatography and the products characterized by low-angle laser light scattering, osmometry, and NMR.
Synthesis and biological evaluation of phosphate triester alkyl lysophospholipids (ALPs) as novel potential anti-neoplastic agents. (1994)

Phosphate triester derivatives of the anti-neoplastic alkyl lysophospholipids (ALP) have been prepared as novel potential therapeutic agents. In particular, simple, symmetrical phosphate triesters have been prepared, using phosphorochloridate chemistry. The compounds have been fully characterized by a range of techniques, and assayed for their inhibition of DNA synthesis by mammalian cells in culture. The compounds are generally inhibitory towards DNA synthesis in the micromolar range. However, the magnitude of the effect varies greatly with the phosphate structure. In particular, there is a clear trend towards decreasing activity with increasing alkyl chain length. Thus, short-chain dialkyl phosphate esters appear more effective than the reference compound hexadecyl phosphatidyl choline.
The Assessment of Bioavailable Androgen Levels from the Serum Free Testosterone Level (1991)

Recently, it has been concluded that measurement of the serum free testosterone level is crucial for evaluating male gonadal function. However, the extent of the decline of serum free testosterone levels with aging and the actual levels in male infertility have not yet been clearly defined. In this study, the clinical significance of serum free testosterone levels was evaluated in a total of 248 subjects, including 120 healthy adult males (54 males aged 20-39, 26 males aged 40-59 and 41 males aged more than 60), 94 infertile males, 28 male hemodialysis patients, and 6 patients with Klinefelter's syndrome. Since the serum free testosterone levels correlate significantly with serum LH and FSH levels among 120 normal adult males, it appears that free testosterone has a biological action on the organ. In the subjects aged over 60, serum free testosterone levels were significantly decreased compared with the decrease of serum total testosterone. Thus, biologically active androgen levels decreased with aging. Serum free testosterone levels tended to decrease significantly from 40 years onwards. In infertile males, serum total testosterone levels were equal to those in normal adult males, but their serum free testosterone levels were significantly lower. This decrease of serum free testosterone may be one of the causes of their hypospermatogenesis. In male hemodialysis patients, serum total and free testosterone levels were not lower than in normal adult males. It is considered that the decline of percentage of serum free testosterone levels in aged males and infertile males was caused by increased serum sex hormone binding globulin (SHBG) levels. Several workers have shown that the production of SHBG is regulated by sex steroid hormones. In this study, however, serum SHBG levels were not correlated with the E2/T ratio. We concluded that measurement of the serum free testosterone level is of value in the endocrinological evaluation of male gonadal function.
Detection of elevated levels of α-synuclein oligomers in CSF from patients with Parkinson disease (2010)

Our results demonstrate that levels of α-synuclein oligomers in CSF and the oligomers/total-α-synuclein ratio can be useful biomarkers for diagnosis and early detection of PD.
Synthesis and Characterization of Zwitterionic Block Copolymers (1998)

Zwitterionic poly(2-(dimethylamino)ethyl methacrylate-block-methacrylic acid) (PDMAEMA-block-PMAA) copolymers are synthesized by group transfer polymerization using 2-tetrahydropyranyl methacrylate (THPMA) as a protected monomer for the acid block. Subsequent thermolysis led to quantitative removal of the tetrahydropyranyl groups, but control experiments indicated significant broadening of the molecular weight distribution (MWD) of a PDMAEMA homopolymer under the same conditions. Hence this deprotection route was considered unsatisfactory. Acid hydrolysis of the block copolymers under mild conditions also led to quantitative removal of the THP groups, as judged by 1H NMR spectroscopy. This deprotection chemistry was adopted as our preferred route, since it did not lead to MWD broadening of the same PDMAEMA homopolymer. A series of zwitterionic blocks were synthesized with good control over both molecular weight and copolymer composition. The aqueous solubility vs. pH behavior of these copolymers was determined by acid titration. Finally, the reversible micellization of these copolymers in aqueous media was examined using dynamic light scattering and variable temperature 1H NMR spectroscopy.
Application of Mid-Infrared Transmission Spectrometry to the Direct Determination of Glucose in Whole Blood (1998)

The capability of FT-IR transmission spectrometry was examined for the direct determination of glucose in whole blood without any sample preparation. For these investigations, the whole blood samples were automatically aspirated by a syringe pump into the transmission cell. Infrared spectra were recorded in the 1500–900 cm −1 range. Despite the high water background absorption and the complex blood matrix, significant spectral changes due to different glucose concentrations were observed. Chemometric (partial least-squares) models were applied for the determination of glucose. A standard error of calibration of 13.8 mg/dL was obtained by using a partial least-squares calibration model containing five ranks. The residues for an independent test set were less than 15 mg/dL.
Single-Molecule DNA Amplification and Analysis in an Integrated Microfluidic Device (2001)

Stochastic PCR amplification of single DNA template molecules followed by capillary electrophoretic (CE) analysis of the products is demonstrated in an integrated microfluidic device. The microdevice consists of submicroliter PCR chambers etched into a glass substrate that are directly connected to a microfabricated CE system. Valves and hydrophobic vents provide controlled and sensorless loading of the 280-nL PCR chambers; the low volume reactor, the low thermal mass, and the use of thin-film heaters permit cycle times as fast as 30 s. The amplified product, labeled with an intercalating fluorescent dye, is directly injected into the gel-filled capillary channel for electrophoretic analysis. Repetitive PCR analyses at the single DNA template molecule level exhibit quantized product peak areas; a histogram of the normalized peak areas reveals clusters of events caused by 0, 1, 2, and 3 viable template copies in the reactor and these event clusters are shown to fit a Poisson distribution. This device demonstrates the most sensitive PCR possible in a microfabricated device. The detection of single DNA molecules will also facilitate single-cell and single-molecule studies to expose the genetic variation underlying ensemble sequence and expression averages.