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91.
Analysis of the nucleotide sequence in the 5' flanking region of bacteriophage T4 gene 25 revealed three potential Shine and Dalgarno sequences, SD1, SD2 and SD3, with a spacing of 8, 17 and 27 nucleotides from the initiation codon of this gene, respectively. Results of our experiments in the bacteriophage T7 expression system clearly demonstrate that the SD3 sequence is required for efficient expression of gene 25. We propose the existence of a stem-loop structure that includes SD1 and SD2 sequences and brings the SD3 sequence to a favourable spacing with the initiation codon of gene 25. Since the predicted secondary structure in the translational initiation region of gene 25 is relatively unstable and the SD3 sequence, GAGG, is more typical than the SD1 sequence, GAG, we suggest that this structure could control the level of gene expression. 相似文献
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94.
Checking the reliability of software is an ever growing challenge. Fully automatic tools that attempt to cover the entire state space often fail because of state explosion. We present instead a toolset that employs some less-ambitious but useful methods to assist in software debugging. The toolset provides an automatic translation of the code into visual flowcharts, allowing the user to interactively select execution paths. It assists the user by calculating path conditions and exploring the neighborhood of the paths. It also allows the user to interactively step through the execution of the program, directed by temporal formulas interpreted over finite sequences. We will show several different ways of using these capabilities for debugging sequential and concurrent programs. 相似文献
95.
Multiplex systems are examined in the time and frequency domains for their utility in applications to biological studies. The continuous-wave FM is shown to fit best the requirements of genuine signal reproduction, reasonable construction and reliability. 相似文献
96.
Orna Barash Nir Peled Fred R. Hirsch Hossam Haick 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(22):2618-2624
A highly sensitive and fast‐response array of sensors based on gold nanoparticles, in combination with pattern recognition methods, can distinguish between the odor prints of non‐small‐cell lung cancer and negative controls with 100% accuracy, with no need for preconcentration techniques. Additionally, preliminary results indicate that the same array of sensors might serve as a better tool for understanding the biochemical source of volatile organic compounds that might occur in cancer cells and appear in the exhaled breath, as compared to traditional spectrometry techniques. The reported results provide a launching pad to initiate a bedside tool that might be able to screen for early stages of lung cancer and allow higher cure rates. In addition, such a tool might be used for the immediate diagnosis of fresh (frozen) tissues of lung cancer in operating rooms, where a dichotomic diagnosis is crucial to guide surgeons. 相似文献
97.
A novel approach to the synthesis of a low-cost proton-exchange membrane (PEM) based on the single-step preparation of a functionalized ceramic powder containing surface-anchored sulfonic acid (SASA) and a polymer binder, is presented for the first time. The added value of this technique, compared with earlier work published by our group, is the adoption of a direct, single-step synthesis, as opposed to a multiple-step synthesis. The latter requires an oxidation step, in order to convert the thiol group into a sulfonic group. SASA powders of different compositions have been prepared and characterized by means of Brunaur–Emmet–Teller (BET), thermogravimetric analysis–differential thermal analysis (TGA–DTG), differential scanning calorimeter (DSC), Fourier transformation infrared (FT-IR), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and electrochemical techniques. The lowest equivalent weight measured for SASA powders is 1281 g equiv.−1. The ionic conductivity of a 100-μm-thick membrane is measured ex situ at room temperature (25 ± 3 °C) and the highest proton conductivity is 48 mS cm−1. The typical pore size, for the SASA powders is less than 10 nm and ranges from 2 to 50 nm for the SASA-based membranes. The membranes are thermally stable up to 250 °C. 相似文献
98.
Michal Taler Irit Gil-Ad Iris Brener Shay Henry Hornfeld Abraham Weizman 《International journal of molecular sciences》2022,23(5)
Some selective serotonin reuptake inhibitors (SSRIs), primarily sertraline, demonstrate anti-proliferative activity in malignant cell-lines and in xenografted mouse models of colorectal tumor. There is, however, a paucity of comparative studies on the anti-tumor effects of SSRIs. We compared the in vitro and in vivo effects of sertraline and citalopram on murine 4T1 breast cancer. Grafted mice were used to determine the rate of tumor growth and survival as well as the impact of stress and antidepressant treatment on tumor progression and mortality and on pro-inflammatory cytokines. Sertraline, in the micromolar range, but not citalopram, induced a significant in vitro concentration-dependent inhibition of murine 4T1 cell proliferation and splenocyte viability. In contrast, sertraline (10 mg/kg/d), enhanced in vivo tumor growth. Contrary to the study’s hypothesis, chronic mild stress did not modify tumor growth in grafted mice. The in vitro effects of sertraline on tumor growth seem to be the opposite of its in vivo effects. The impact of sertraline treatment on humans with breast cancer should be further investigated. 相似文献
99.
Eli Varon Gaddi Blumrosen Moshe Sinvani Elina Haimov Shlomi Polani Michal Natan Irit Shoval Avi Jacob Ayelet Atkins David Zitoun Orit Shefi 《International journal of molecular sciences》2022,23(4)
Photodynamic therapy (PDT) and photothermal therapy (PTT) are promising therapeutic methods for cancer treatment; however, as single modality therapies, either PDT or PTT is still limited in its success rate. A dual application of both PDT and PTT, in a combined protocol, has gained immense interest. In this study, gold nanoparticles (AuNPs) were conjugated with a PDT agent, meso-tetrahydroxyphenylchlorin (mTHPC) photosensitizer, designed as nanotherapeutic agents that can activate a dual photodynamic/photothermal therapy in SH-SY5Y human neuroblastoma cells. The AuNP-mTHPC complex is biocompatible, soluble, and photostable. PDT efficiency is high because of immediate reactive oxygen species (ROS) production upon mTHPC activation by the 650-nm laser, which decreased mitochondrial membrane potential (∆ψm). Likewise, the AuNP-mTHPC complex is used as a photoabsorbing (PTA) agent for PTT, due to efficient plasmon absorption and excellent photothermal conversion characteristics of AuNPs under laser irradiation at 532 nm. Under the laser irradiation of a PDT/PTT combination, a twofold phototoxicity outcome follows, compared to PDT-only or PTT-only treatment. This indicates that PDT and PTT have synergistic effects together as a combined therapeutic method. Our study aimed at applying the AuNP-mTHPC approach as a potential treatment of cancer in the biomedical field. 相似文献
100.
Pushkar Dolores; Basevitz Paul; Arbuckle Tannis; Nohara-LeClair Michiko; Lapidus Steven; Peled Maya 《Canadian Metallurgical Quarterly》2000,15(2):361
This study investigated social behavior in older adults with varying levels of off-target verbosity (OTV). After screening 455 adults in Phase 1, 198 individuals were selected to participate in both a get-acquainted conversation and an experimental cues situation and to complete social and cognitive measures. Higher OTV participants had lower cognitive inhibitory scores, talked more, were less interested in their partners, and focused more on themselves. Their conversational partners were less satisfied. Age and cognitive functioning were not related to OTV scores or conversational style for low and mid-range participants. Although high-OTV individuals talked less when exposed to social cues signalling boredom, they spoke more relative to other participants. Self-reported social behavior had little relation with OTV and conversational style, but higher OTV individuals were less accurate in judging videotaped social interactions. Gender differences in conversational behavior are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献