Artykuły w czasopismach: „620/.5”

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Beika, Masatomo, Yoshinori Harada, Takeo Minamikawa, Yoshihisa Yamaoka, Noriaki Koizumi, Yasutoshi Murayama, Hirotaka Konishi i in. "Accumulation of Uroporphyrin I in Necrotic Tissues of Squamous Cell Carcinoma after Administration of 5-Aminolevulinic Acid". International Journal of Molecular Sciences 22, nr 18 (19.09.2021): 10121. http://dx.doi.org/10.3390/ijms221810121.

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5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence is widely used for the intraoperative detection of malignant tumors. However, the fluorescence emission profiles of the accompanying necrotic regions of these tumors have yet to be determined. To address this, we performed fluorescence and high-performance liquid chromatography (HPLC) analyses of necrotic tissues of squamous cancer after 5-ALA administration. In resected human lymph nodes of metastatic squamous cell carcinoma, we found a fluorescence peak at approximately 620 nm in necrotic lesions, which was distinct from the PpIX fluorescence peak at 635 nm for viable cancer lesions. Necrotic lesions obtained from a subcutaneous xenograft model of human B88 oral squamous cancer also emitted the characteristic fluorescence peak at 620 nm after light irradiation: the fluorescence intensity ratio (620 nm/635 nm) increased with the energy of the irradiation light. HPLC analysis revealed a high content ratio of uroporphyrin I (UPI)/total porphyrins in the necrotic cores of murine tumors, indicating that UPI is responsible for the 620 nm peak. UPI accumulation in necrotic tissues after 5-ALA administration was possibly due to the failure of the heme biosynthetic pathway. Taken together, fluorescence imaging of UPI after 5-ALA administration may be applicable for the evaluation of tumor necrosis.

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MANMUAN, Suwisit, Punyo YOYKAEW, Piyachat THUETONG, Patchraporn ASIPONG i Nattanicha RIANTONG. "Potentiating Effect of Oxymatrine and 5-fluorouracil on Cell Survival and Inhibition of Cancer Metastasis in SW-620 Colorectal Cancer Cells". Walailak Journal of Science and Technology (WJST) 15, nr 2 (4.09.2017): 117–30. http://dx.doi.org/10.48048/wjst.2018.3388.

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Colorectal cancer (CRC) is the most common cancer in the world, beginning in the cell lining of the colon and rectum. 5-fluorouracil (5-FU) is a first-line therapy for colorectal cancer patients. However, the response rate of 5-FU in advanced colorectal cancer patients is only 10 - 15 %, and can fail due to drug resistance. Therefore, the development of a new anticancer compound for improving the response rate or for reversing resistance to 5-FU is urgently needed. Oxymatrine is a major component of Sophora flavescens. Recently, many pharmacological effects have been exhibited. The objectives of the present study were to investigate the anticancer activity of oxymatrine, as well as to potentiate the effect of oxymatrine with 5-FU on cell viability, colony-forming, cell migration, cell invasion, and determined MMP-9 protein expression in SW-620 colorectal cancer cells. The results demonstrated that oxymatrine significantly inhibited the cell viability of SW-620 cells after 24, 48, and 72 h treatments. Oxymatrine and 5-FU interaction was synergistically greater in inhibiting the cell survival of SW-620 cells than 5-FU was alone. Oxymatrine also decreased colony formation, cell migration, and cell invasion through reducing the level of MMP-9 protein in SW-620 cells. These first findings elucidated an efficacious anticancer agent, which is derived from natural sources, which could be used to overcome 5-FU resistance in colorectal cancer, and may be beneficial for patients with colorectal cancer who are treated with 5-FU.

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KUO, FUENG-LIN, JOHN B. CAREY i STEVEN C. RICKE. "UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium". Journal of Food Protection 60, nr 6 (1.06.1997): 639–43. http://dx.doi.org/10.4315/0362-028x-60.6.639.

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The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P < .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P < .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.

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Jachimowicz-Jankowska, Paulina. "Sebastian Gajewski, Postępowanie o świadczenia emerytalno-rentowe. Studium z zakresu postępowania administracyjnego, seria Monografie Prawnicze, Wydawnictwo C.H. Beck, Warszawa 2020". Studia Prawa Publicznego, nr 1 (45) (15.03.2024): 201–20. http://dx.doi.org/10.14746/spp.2024.1.45.9.

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Sebastian Gajewski, Postępowanie o świadczenia emerytalno-rentowe. Studium z zakresu postępowania administracyjnego, seria Monografie Prawnicze, Wydawnictwo C.H. Beck, Warszawa 2020, ss. 636, ISBN 978-83-8198-620-5

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Chen, Jishi, Yanze Pan, Zonghua Wang i Peng Zhao. "The fluorescence properties of tiara like structural thiolated palladium clusters". Dalton Transactions 46, nr 38 (2017): 12964–70. http://dx.doi.org/10.1039/c7dt02836a.

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A series of tiara like structural Pd_n(SR)_2n (5 ≤ n ≤ 20) nanoclusters exhibit emission at 620 nm with excitation at around 268 nm. Their emission is due to ligand to metal charge transfer.

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Ambrož, Martin, Markéta Šmatová, Michaela Šadibolová, Eva Pospíšilová, Pavlína Hadravská, Michaela Kašparová, Veronika Hanušová Skarková, Věra Králová i Lenka Skálová. "Sesquiterpenes α-humulene and β-caryophyllene oxide enhance the efficacy of 5-fluorouracil and oxaliplatin in colon cancer cells". Acta Pharmaceutica 69, nr 1 (1.03.2019): 121–28. http://dx.doi.org/10.2478/acph-2019-0003.

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Abstract The present study is designed to find out if sesquiterpenes, α-humulene (HUM), valencene (VAL), β-caryphyllene-oxide (CAO) and trans-nerolidol (NER), are able to improve the antiproliferative effect of classical cytostatic drugs, 5-fluorouracil (FU) and oxaliplatin (1,2-diaminocyclohexaneoxalato-platinum, OxPt), in colon cancer cell lines Caco-2 and SW-620. In addition, the possible mechanisms of sesquiterpene action are studied. The results show significant ability of HUM and especially of CAO to enhance the anti-proliferative effects of FU and OxPt in cancer cell lines Caco-2 and SW-620. On the other hand, VAL and NER are ineffective. The action of CAO could be partly based on its ability to disrupt the mitochondrial membrane potential and to activate initiator caspases, but other mechanisms are probably also involved. Based on these results, CAO seems to have the potential for combination therapy of colon cancers and deserves further study.

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Chen, S. C., T. H. Sun, C. L. Chang, Chih Long Shen, G. P. Lin, K. T. Huang, S. L. Ou i Po Cheng Kuo. "The Effect of Thickness on the Magnetic Anisotropy and Magnetic Properties of Single-Layered FePt Films by In Situ Annealing". Advanced Materials Research 123-125 (sierpień 2010): 507–10. http://dx.doi.org/10.4028/www.scientific.net/amr.123-125.507.

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The FePt films with various thicknesses of 5 to 50 nm are deposited on Si(100) substrate without any underlayer by in-situ annealing at substrate temperature (Ts) of 620°C. A strong (001) texture of L10 FePt film is obtained and presents high perpendicular magnetic anisotropy as the film thickness increases to 30 nm. Further increasing the thickness to above 30 nm, the (111) orientation of L10 FePt is enhanced greatly, indicating that the quality of perpendicular magnetic anisotropy degrades when the FePt film is thicker than 30 nm. The single-layered FePt film with thickness of 30 nm by in-situ depositing at 620°C shows good perpendicular magnetic properties (perpendicular coercivity of 14.0 kOe, saturation magnetization of 473 emu/cm3 and perpendicular squareness of 0.96, respectively), which reveal its significant potential as perpendicular magnetic recording media for high-density recording.

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Yoshida-Yoneda, E., Y. Tache, H. P. Kosoyan i J. Y. Wei. "Peripheral bombesin decreases gastric vagal efferent activity in part through vagal pathways in rats". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 266, nr 6 (1.06.1994): R1868—R1875. http://dx.doi.org/10.1152/ajpregu.1994.266.6.r1868.

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The influence of intravenous (iv) bombesin on multiunit activities recorded from the ventral gastric branch of the vagus was investigated in urethan-anesthetized rats. Consecutive injections of bombesin (0.062, 0.62, 6.2, 62, and 620 pmol iv) decreased dose dependently gastric vagal efferent discharges to 79.8 +/- 4.9, 68.3 +/- 10.2, 47.0 +/- 6.7, 41.6 +/- 4.7, and 36.5 +/- 8.9%, respectively, from preinjection levels. Saline injection had no effect. Bombesin (62 pmol iv) reduced cervical vagal efferent discharges to 25 +/- 6% before and 67 +/- 5% after bilateral cervical vagotomy distal to the recording site. Bombesin (62 and 620 pmol iv) increased gastric vagal afferent discharges by 45 and 93%, respectively. These data show that systemic injection of bombesin potently decreases gastric and cervical vagal efferent activity in part through vagal-dependent mechanisms that may involve the increase in gastric vagal afferent activity.

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Lei, Bing, Xin Wu i Wei Liu. "A New Copper(I) Iodide Based Organic-Inorganic Hybrid Structure with Red Emission". Crystals 11, nr 6 (24.05.2021): 594. http://dx.doi.org/10.3390/cryst11060594.

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A new organic-inorganic hybrid structure based on copper (I) iodide staircase chain 1D-Cu2I2(5-chloropyrimidine)2 (1) has been synthesized by a slow-diffusion method. It emits red emission peaking at 620 nm. The internal quantum yield (IQY) measured for this compound is 6.5% under 360 nm excitation. This compound exhibits potential as a non-rare-earth light-emitting phosphor alternative.

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Wen, Hui, Wen Qin, Guangzhong Yang i Yanshen Guo. "Design and Synthesis of Arylamidine Derivatives as Serotonin/Norepinephrine Dual Reuptake Inhibitors". Molecules 24, nr 3 (30.01.2019): 497. http://dx.doi.org/10.3390/molecules24030497.

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To improve the in vivo antidepressant activity of previously reported serotonin (5-HT) and norepinephrine (NE) dual reuptake inhibitors, three series of arylamidine derivatives were designed and synthesized. The in vitro 5-HT and NE reuptake inhibitory activities of these compounds were evaluated, and compound II-5 was identified as the most potent 5-HT (IC50 = 620 nM) and NE (IC50 = 10 nM) dual reuptake inhibitor. Compound II-5 exhibited potent antidepressant activity in the rat tail suspension test and showed an acceptable safety profile in a preliminary acute toxicity test in mice. Our results show that these arylamidine derivatives exhibit potent 5-HT/NE dual reuptake inhibition and should be explored further as antidepressant drug candidates.

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Fernández, Eduardo J., Peter G. Jones, Antonio Laguna, José M. López-de-Luzuriaga, Miguel Monge, Manuel Montiel, M. Elena Olmos i Javier Pérez. "Luminescent Gold(I)-Thallium(I) Arrays through N-Bidentate Building Blocks". Zeitschrift für Naturforschung B 59, nr 11-12 (1.12.2004): 1379–86. http://dx.doi.org/10.1515/znb-2004-11-1203.

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Heteropolynuclear gold(I)-thallium(I) complexes of the type [TlLn][Au(C6F5)2] (L = py (2), 2,2’- bipy (3), 1,10-phen (4) or 4,4’-bipy and THF (5); n = 1, 2) have been obtained from reactions of the corresponding N-donor ligands with the precursor {Tl[Au(C6F5)2]}n (1). The crystal structures of complexes 3 - 5 have been determined by X-ray diffraction showing one- (3, 4) or three-dimensional (5) arrays. All complexes are photoluminescent in the solid state at RT and at 77 K. The strong visible emissions of complexes 2 - 5 are displayed over a wide range of wavelengths (460 - 620 nm) depending on the environment of the thallium(I) centres and on the nature of the N-donor ligand.

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Pang, Hui, Wen Guan Zhang i Sheng Min Zhao. "Non-Dopant Electroluminescent Devices Based on Benzoxazinone Derivative as Strong Fluorescence in Solid Film". Advanced Materials Research 399-401 (listopad 2011): 1151–55. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.1151.

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The orange fluorescent compound 2-[2-(p-toluenesulphonylamino)-5-chlorophenyl]-6- chloro-4H-3,1-benzoxazin-4-one (Cl-TSB) was synthesized by reacting 2-amino-5-chlorobenzoic acid with p-toluenesulphonyl chloride. The strong photoluminescent peak was at 544 nm in solid film. HOMO and LUMO energy levels were calculated -5.00 and -1.82 eV. The multilayer organic light-emitting devices (OLEDs) ITO/NPB/Cl-TSB/BCP/TPBi or Alq3/LiF/Al were fabricated. The electroluminescent peaks of all devices were at ca. 620 nm with luminance of over 100 cd/m2. The characteristics of devices demonstrated that Cl-TSB was an orange emitter suitable for OLED.

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İnal, Ali, Tulay Akman, Sebnem Yaman, Selcuk Cemil Ozturk, Caglayan Geredeli, Mehmet Bilici, Mevlude İnanc i in. "Pathologic and Clinical Characteristics of Elderly Patients With Breast Cancer: A Retrospective Analysis of a Multicenter Study (Anatolian Society of Medical Oncology)". International Surgery 99, nr 1 (1.01.2014): 2–7. http://dx.doi.org/10.9738/intsurg-d-13-00010.

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Abstract There is very little information about breast cancer characteristics, treatment choices, and survival among elderly patients. The purpose of this multicenter retrospective study was to examine the clinical, pathologic, and biologic characteristics of 620 breast cancer patients age 70 years or older. Between June 1991 and May 2012, 620 patients with breast cancer, recruited from 16 institutions, were enrolled in the retrospective study. Patients had smaller tumors at diagnosis; only 15% of patients had tumors larger than 5 cm. The number of patients who had no axillary lymph node involvement was 203 (32.7%). Ninety-three patients (15.0%) had metastatic disease at diagnosis. Patients were characterized by a higher fraction of pure lobular carcinomas (75.3%). The tumors of the elderly patients were also more frequently estrogen receptor (ER) positive (75.2%) and progesterone receptor (PR) positive (67.3%). The local and systemic therapies for breast cancer differed according to age. An association between age and overall survival has not been demonstrated in elderly patients with breast cancer. In conclusion, the biologic behavior of older patients with breast cancer differs from younger patients, and older patients receive different treatments.

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Zalov, A. Z., K. O. Iskenderova, Z. G. Askerova i A. B. Hajiyeva. "SPECTROPHOTOMETRIC STUDY OF NICKEL (II) COMPLEXES WITH 2- HYDROXYTHIOLPHENOL AND ITS DERIVATIVES IN THE PRESENCE OF HYDROPHOBIC AMINES". Chemical Problems 19, nr 4 (2021): 224–31. http://dx.doi.org/10.32737/2221-8688-2021-4-224-231.

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The complexation reactions of nickel (II) with 2-hydroxythiophenol and its derivatives (2,5- dihydroxythiophenol, 2-hydroxy-5-chlorothiophenol, 2-hydroxy-5-bromothiophenol, and 2-hydroxy-5- iodothiophenol) in the presence of hydrophobic amines were studied by spectrophotometric methods. Aniline and N, N-dimethylaniline were used as hydrophobic amines. It found that mixed-ligand complexes (MLC) are formed in a weakly acidic medium (pH 2.3-8.0). The maximum in the light absorption spectrum of the complexes is observed at λ = 620-650 nm. The molar coefficients of light absorption are (4.1-4.3)×104 . The best extractants were chloroform, dichloroethane and carbon tetrachloride. With a single extraction with chloroform, 97.8-98.4% of nickel is extracted in the form of MLC. Based on the data obtained, photometric methods for the determination of nickel in various objects were developed.

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Goodsell, David S. "The Molecular Perspective: Histone Deacetylase". Stem Cells 21, nr 5 (wrzesień 2003): 620–21. http://dx.doi.org/10.1634/stemcells.21-5-620.

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Tapia, Alejandro, José Cheel, Cristina Theoduloz, Jaime Rodríguez, Guillermo Schmeda-Hirschmann, Andre Gerth, Dirk Wilken i in. "Free Radical Scavengers from Cymbopogon citratus (DC.) Stapf Plants Cultivated in Bioreactors by the Temporary Immersion (TIS) Principle". Zeitschrift für Naturforschung C 62, nr 5-6 (1.06.2007): 447–57. http://dx.doi.org/10.1515/znc-2007-5-620.

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The biomass production of Cymbopogon citratus shoots cultivated in bioreactors according to the temporary immersion (TIS) principle was assessed under different growth conditions. The effect of gassing with CO2-enriched air, reduced immersion frequency, vessel size and culture time on total phenolic and flavonoid content and free radical scavenging effect of the methanolic extracts was measured. From the TIS-culture of C. citratus, seven compounds were isolated and identified as caffeic acid (1), chlorogenic acid (2), neochlorogenic acid (3), p-hydroxybenzoic acid (4), p-hydroxybenzoic acid 3-O-β-d-glucoside (5), glutamic acid (6) and luteolin 6-C-fucopyranoside (7). The occurrence of compounds 1-7 and their variability in C. citratus grown under different TIS conditions was determined by HPLC. The free radical scavenging effect of the methanolic extract and compounds was measured by the discoloration of the free radical 1,1- diphenyl-2-picrylhydrazyl (DPPH). The main metabolites in 6- and 8-week-old cultures, both in 5 and 10 l vessels, were chlorogenic acid (2) (100D113 mg%) and neochlorogenic acid (3) (80 - 119 mg%), while in the cultures with CO2-enriched air and reduced immersion frequency the main compound detected in the extracts was glutamic acid (6) (400 and 670 mg% for the green and white biomass and 619 and 630 mg% for the green and white biomass, respectively). The most active compounds, as free radical scavengers, in the DPPH discoloration assay were caffeic acid (1), chlorogenic acid (2), neochlorogenic acid (3) and the flavonoid luteolin 6-C-fucopyranoside (7).

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Goo, Tae Won, Eun Young Yun, Sung Wan Kim, Kwang Ho Choi, Seok Woo Kang, Kee-Sun Shin, Kweon Yu i O.-Yu Kwon. "Domain a′ of Bombyx mori Protein Disulfide Isomerase Has Chaperone Activity". Zeitschrift für Naturforschung C 63, nr 5-6 (1.06.2008): 435–39. http://dx.doi.org/10.1515/znc-2008-5-620.

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Protein disulfide isomerase (PDI) is an endoplasmic reticulum (ER)-localized multifunctional enzyme that can function as a disulfide oxidase, a reductase, an isomerase, and a chaperone. The domain organization of PDI is abb′xa′c, with two catalytic (CxxC) motifs and a KDEL ER retention motif. The members of the PDI family exhibit differences in tissue distribution, specificity, and intracellular localization. We previously identified and characterized the PDI of Bombyx mori (bPDI) as a thioredoxin-like protein that shares primary sequence homology with other PDIs. Here we compare the reactivation of inactivated rRNase and sRNase by bPDI and three bPDI mutants, and show that bPDI has mammalian PDI-like activity. On its own, the N-terminal a domain does not retain this activity, but the a′ domain does. This is the first report of chaperone activity only in the a′ domain, but not in the a domain.

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Xiang, Fu, Liqing Li, Wenwen Jin i Longjiang Yu. "Effect of DNA Methylation on 18S rRNA Gene Sequences during Culture of Taxus chinensis Cells". Zeitschrift für Naturforschung C 64, nr 5-6 (1.06.2009): 418–20. http://dx.doi.org/10.1515/znc-2009-5-620.

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Cell suspension culture has rapidly become an alternative source of taxol, an anticancer compound. To investigate the role of DNA methylation in the cultural course of Taxus chinensis cells, analyses of 18S rRNA gene sequences of cultured T. chinensis cells and related species were conducted. The phylogenetic analysis of 18S rRNA gene sequences indicated that HG-1 (the cultured T. chinensis cells), like T. mairei (the natural variety of T. chinensis), should be a new variety of T. chinensis, and cell culture can change the 18S rRNA gene sequence at the level of species despite 18S rRNA is the most conserved gene. The analyses of the CpG and TpG+CpA relative abundance and GC content of the 18S rRNA gene sequences made clear that DNA methylation contributed to changes of the 18S rRNA gene sequence of HG-1 at the level of species, which can make HG-1 to become a new variety of T. chinensis.

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Wang, Jiahu, i Vedene H. Smith. "Ab initio Study of the Electric Field Gradients in SCl2". Zeitschrift für Naturforschung A 48, nr 5-6 (1.06.1993): 699–702. http://dx.doi.org/10.1515/zna-1993-5-620.

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Abstract The electric field gradients (EFG) in SCl2 have been computed with both self-consistent-field (SCF) and configuration-interaction (Cl) methods. The predicted EFG, along with the nuclear quadrupole moment QN of 35Cl and 37Cl from other sources, allows us to compare theoretical quadrupole coupling constants with new experimental results. The best values obtained agree with the experiment within 3%. It has been found that the principal axis of the coupling tensor does not coincide with the S-Cl internuclear axis, and the tilt angle has been predicted close to that from experiment.

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Palmer, Michael H. "17O Nuclear Quadrupole Coupling in Molecular and Lattice Systems by ab initio Calculation of Electric Field Gradients". Zeitschrift für Naturforschung A 51, nr 5-6 (1.06.1996): 442–50. http://dx.doi.org/10.1515/zna-1996-5-620.

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Abstract We present ab initio Hartree-Fock calculations of electric field gradients, which are related to experimental determinations of nuclear quadrupole coupling constants. The nucleus of special interest is 17O but other nuclei in the molecules, especially 14N, 2H and 33S are included. The calculations were performed (a) as single molecules either at the SCF and MP2 correlated levels, (b) as clusters of molecules about a test site, or (c) as lattice calculations computed in the unit cell environment. The basis sets are triple zeta valence plus polarisation in (a). Because of limitations in exponent range in (c), the bases in both (b) and (c), where comparison was sought, are DZ at the SCF level.

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Elerman, Y., H. Kara i A. Elmali. "Relation between Magnetic, Spectroscopic and Structural Properties of Binuclear Copper(II) Complexes of Pentadentate Schiff-base Ligand, Semi-empirical and ab-initio Calculations". Zeitschrift für Naturforschung A 58, nr 5-6 (1.06.2003): 363–72. http://dx.doi.org/10.1515/zna-2003-5-620.

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The synthesis and characterization of [Cu2(L1)(3,5 prz)] (L1=1,3-Bis(2-hydroxy-3,5-chlorosalicylideneamino) propan-2-ol) 1 and of [Cu2(L2)(3,5 prz)] (L2=1,3-Bis(2-hydroxy-bromosalicylideneamino) propan-2-ol) 2 are reported. The compounds were studied by elemental analysis, infrared and electronic spectra. The structure of the Cu2(L1)(3,5 prz)] complex was determined by x-ray diffraction. The magnetochemical characteristics of these compounds were determined by temperaturedependent magnetic susceptibility measurements, revealing their antiferromagnetic coupling. The superexchange coupling constants are 210 cm−1 for 1 and 440 cm−1 for 2. The difference in the magnitude of the coupling constants was explained by the metal-ligand orbital overlaps and confirmed by ab-initio restricted Hartree-Fock (RHF) calculations. In order to determine the nature of the frontier orbitals, Extended Hückel Molecular Orbital (EHMO) calculations are also reported.

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Chen, Pei-Chung. "Physiology of Nitrogen Fixation in Two New Strains of Anabaena". Zeitschrift für Naturforschung C 40, nr 5-6 (1.06.1985): 406–8. http://dx.doi.org/10.1515/znc-1985-5-620.

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Abstract Two different cyanobacteria, Anabaena CH 1 and CH2, were isolated from Taiwan paddy soils. Both strains can grow well with daily dilution method. Anabaena CH1 shows a blue-green color and Anabaena CH2 a green brownish one. Nitrogenase activity decreased as cultures were transferred from light to dark. When a darkened culture was placed again into the light, nitrogenase activity recovered within two hours, but not in the presence of chloramphenicol. Energy supply for nitrogenase within both strains was different. Nitrogenase activity of Anabaena CH1 was light-dependent and oxygen in heterocyst was exhausted through oxyhydrogen reaction. Except photosynthesis, respiration may be used as energy source for nitrogenase in Anabaena CH2. Respiration was the major one to protect nitrogenase against oxygen.

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Chersi, Alberto, Richard A. Houghten, Francesco Chillemi, Romano Zito i Dora Centis. "Specificity of Rabbit Antibodies Elicited by Related Synthetic Peptides". Zeitschrift für Naturforschung C 41, nr 5-6 (1.06.1986): 613–17. http://dx.doi.org/10.1515/znc-1986-5-620.

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Three 17-residue peptides, presenting from 65% to 70% sequence homology, and one endecapeptide, with no apparent homology with the first three, were chemically synthesized and investigated in their ability to elicit rabbit antipeptide antibodies.The complex crossreactivities of the antisera were investigated by testing the binding of the antibodies to the intact peptides, to their enzymatic fragments, and by the use of specific immunoadsorbents.Antipeptide antibodies may or may not crossreact with related “parent” peptides, this depending upon number, distribution, and localization of amino acid differences in low or high antigenicity regions of the immunogen.Related peptides may elicit antibodies that crossreact almost completely, and therefore not specific for one or the other “parent” peptide. Those the selective recognition of closely related structures.

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Westerhausen, Matthias, i Wolfgang Schwarz. "Neuartige Synthese und Molekülstruktur von Benzylkalium (thf) [KCH2C6H5]2 / Novel Synthesis and Molecular Structure of Benzyl Potassium (thf)[KCH2C6H5]2". Zeitschrift für Naturforschung B 53, nr 5-6 (1.06.1998): 625–27. http://dx.doi.org/10.1515/znb-1998-5-620.

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Abstract The reaction of potassium with hexamethyldi-stannane in a refluxing solvent mixture of toluene and tetrahydrofuran (ratio 10:1) yields the red tetrahydrofuran adduct of benzyl potassium (thf)[KCH2C6H5]2 due to the metalation of toluene by the potassium trimethylstannanide intermediate. The solid state structure of (thf)[KCH2C6H5]2 contains dimers with only one potassium coordinated to a tetrahydrofuran molecule. These dimers form a polymer through benzyl bridging with shortest K-C distances at 292 pm.

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25

Burns, Peter C., i Frank C. Hawthorne. "The crystal structure of sinkankasite, a complex heteropolyhedral sheet mineral". American Mineralogist 80, nr 5-6 (1.06.1995): 620–27. http://dx.doi.org/10.2138/am-1995-5-620.

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26

Bonazzi, Paola, Silvio Menchetti i Thomas Reinecke. "Solid solution between piemontite and androsite-(La), a new mineral of the epidote group from Andros Island, Greece". American Mineralogist 81, nr 5-6 (1.06.1996): 735–42. http://dx.doi.org/10.2138/am-1996-5-620.

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27

Finch, Robert J., i Rodney C. Ewing. "Clarkeite; new chemical and structural data". American Mineralogist 82, nr 5-6 (1.06.1997): 607–19. http://dx.doi.org/10.2138/am-1997-5-620.

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28

Effenberger, H., G. Giester, W. Krause i H. J. Bernhardt. "Tschortnerite, a copper-bearing zeolite from the Bellberg volcano, Eifel, Germany". American Mineralogist 83, nr 5-6 (1.06.1998): 607–17. http://dx.doi.org/10.2138/am-1998-5-620.

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29

Zhang, Jianzhong, i Richard J. Reeder. "Comparative compressibilities of calcite-structure carbonates; deviations from empirical relations". American Mineralogist 84, nr 5-6 (1.06.1999): 861–70. http://dx.doi.org/10.2138/am-1999-5-620.

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30

Wang, Liping, Roland C. Rouse, Eric J. Essene, Donald R. Peacor i Youxue Zhang. "Carmichaelite, a new hydroxyl-bearing titanate from Garnet Ridge, Arizona". American Mineralogist 85, nr 5-6 (maj 2000): 792–800. http://dx.doi.org/10.2138/am-2000-5-620.

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31

Hervig, Richard L., Gordon M. Moore, Lynda B. Williams, Simon M. Peacock, John R. Holloway i Kurt Roggensack. "Isotopic and elemental partitioning of boron between hydrous fluid and silicate melt". American Mineralogist 87, nr 5-6 (maj 2002): 769–74. http://dx.doi.org/10.2138/am-2002-5-620.

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32

Johnson, Elizabeth A., i George R. Rossman. "The concentration and speciation of hydrogen in feldspars using FTIR and1H MAS NMR spectroscopy". American Mineralogist 88, nr 5-6 (maj 2003): 901–11. http://dx.doi.org/10.2138/am-2003-5-620.

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33

Frindt, Stephen, i Ilmari Haapala. "Anorogenic Gross Spitzkoppe granite stock in central western Namibia: Part II. Structures and textures indicating crystallization from undercooled melt". American Mineralogist 89, nr 5-6 (maj 2004): 857–66. http://dx.doi.org/10.2138/am-2004-5-620.

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34

Bertrand, Martine, Barbara Bereza i Esther Dujardin. "Evidence for Photoreduction of NADP+ in a Suspension of Lysed Plastids from Etiolated Bean Leaves". Zeitschrift für Naturforschung C 43, nr 5-6 (1.06.1988): 443–48. http://dx.doi.org/10.1515/znc-1988-5-620.

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It has been investigated if photoreduction of NADP+ (detected by absorption spectroscopy) may take place in lysed plastids within minutes of exposure to light. This process was made possible by removal of oxidants from the reaction mixture. Lysed plastids were suspended in a medium containing NADP+ , catalase, glucose oxidase and glucose; exposure to light simultaneously to addition of ferredoxin and ferredoxin-NADP+ reductase, resulted in increased absorbance in the band around 340 n m , while addition of 3-phosphoglycerate resulted in the disappearance of this band. Ferredoxin and ferredoxin-NADP+ reductase are only effective when photoactivation takes place before their addition to the medium.

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35

Hauska, Günter, Edelgard Herold, Claudia Huber, Wolfgang Nitschke i Danuse Sofrova. "Stigmatellin Affects Both Hemes of Cytochrome b in Cytochrome b6f/bc1-Complexes". Zeitschrift für Naturforschung C 44, nr 5-6 (1.06.1989): 462–67. http://dx.doi.org/10.1515/znc-1989-5-620.

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Abstract Stigmatellin causes spectral changes of both hemes of cytochrome b or b6 in cytochrome bc1/b6f-complexes. It also affects the redox potentials of all three hemes, including cytochrome c l and f, in addition to the dramatic rise of the redox potential it exerts on the Rieske FeS-center. We conclude that stigmatellin changes the overall conformation of the complexes.

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36

Pawlowski, Piotr, i Magdalena Fikus. "Shear Deformation Of The Spherical Shell Acted On By An External Alternating Electric Field: Possible Applications To Cell Deformation Experiments". Zeitschrift für Naturforschung C 46, nr 5-6 (1.06.1991): 487–94. http://dx.doi.org/10.1515/znc-1991-5-620.

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Shape deformation of the thin, area non-compressible spherical shell separating two different media, subjected to an external, alternating, homogeneous electric field is considered. The function relating shape deformation of the shell to the shear stress in its plane is presented. Shear stress develops as a result of Maxwell stress acting on both shell surfaces. All media are considered as lossy. The theoretical model predicts that the shear stress reaches its maximal value at the shell “equator” in relation to the field direction. The magnitude of the shear stress depends on the strength and frequency of the electric field, on the geometric parameters of the shell, and on the electric parameters of the system studied. The foregoing was applied to an analysis of cell deformation, e.g., an erythrocyte in an electric field. The analysis predicts that the maximal shear stress in the membrane develops at field frequencies close tof = 107 Hz. This is comparable to the electrocompression stress of the same membrane, maximal at the cell “pole”. At lower frequencies, compression predominates over shear stress

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37

Joeken, Stephan, i Jürgen Schnakenberg. "Monte Carlo Simulation of Shot Noise Analysis for Reconstructing Elementary Events: Quantum Bumps in Photoreceptor Cells". Zeitschrift für Naturforschung C 48, nr 5-6 (1.06.1993): 519–28. http://dx.doi.org/10.1515/znc-1993-5-620.

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Abstract Shot noise analysis is a frequently applied method for reconstructing elementary events from experimental data of noisy signals. The subject of this paper is the reconstruction of single photon responses in photoreceptors, the so-called quantum bumps, from experimental data which have been obtained at high light intensities where the quantum bumps can no longer be observed as individual events. The application of this method requires some basic prerequisites which are very likely not satisfied in photoreceptor cells. This situation makes the results of the method questionable. In order to estimate the reliability of shot noise reconstruction in photoreceptors we directly compare the reconstruction results with well known input parameters by using a simulation model for the elementary mechanisms in the cell membrane which cause the response to light stimulation. The comparison shows that the reconstruction method starts to yield errors already at low intensities if only a few percent of the light con trolled ionic channels in the cell membrane are open on average. The errors of the method become about 100 percent in the light intensity regime between 10 percent open channels and the onset of bump speck contact on the membrane. The anticipation that the reconstruction method yields single channel events at high light intensities is disproved at least for physiologically realistic intensities.

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38

Ömür, L., i Ayşe Kuruüzüm. "Notes: Determination of the Cytotoxicity of Rumex crispus during the Vegetation Period Using a Brine Shrimp Bioassay". Zeitschrift für Naturforschung C 50, nr 5-6 (1.06.1995): 461–62. http://dx.doi.org/10.1515/znc-1995-5-620.

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The percentage of anthraquinone glycosides in the roots of Rumex crispus L. (Polygonaceae) is significantly greater than in other parts of the plant. The roots of R. crispus in different vegetation stages were investigated with regard to anthraquinone glycoside content. Their toxicity towards shrimp were also tested during the vegetation period. The data showed that the percentage of anthraquinone glycosides as well as the toxic effect on the shrimp increased during the vegetation period.

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39

Hefetz, Abraham, Timo Taghizadehr i Wittko Francke. "The Exocrinology of the Queen Bumble Bee Bombus terrestris (Hymenoptera: Apidae, Bombini)". Zeitschrift für Naturforschung C 51, nr 5-6 (1.06.1996): 409–22. http://dx.doi.org/10.1515/znc-1996-5-620.

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Abstract Chemical analyses are presented of prominent exocrine glands of queen Bombus terrestris including mandibular, labial and hypopharyngeal glands in the head, Dufour’s gland and tarsal glands. A plethora of about 500 substances were identified belonging to various aliphatic compounds including hydrocarbons, various classes of esters, alcohols, methyl ketones and fatty acids. A group of chiral hydroxy acids and their butanoic acid esters are reported for the first time in bees.

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40

Ganeva, Roumiana L., i Lyuben M. Tzvetkov. "Effect of Cisplatin Alone and in Combination with γ-Radiation on the Initiation of DNA Synthesis in Friend Leukemia Cells". Zeitschrift für Naturforschung C 52, nr 5-6 (1.06.1997): 405–7. http://dx.doi.org/10.1515/znc-1997-5-620.

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The effect of the anticancer drug cisplatin (alone and in combination with γ-radiation) on the initiation of DNA synthesis in Friend leukemia cells was studied. A method for isolation of DNA fractions containing the origins of replication was used. It was found that cisplatin decreased the rate of the initiation of DNA synthesis. The mild γ-radiation has previously been observed to inhibit the initiation of DNA synthesis. In the present investigation the combination of cisplatin and γ-radiation showed additive effects without synergism on the initiation of DNA biosynthesis.

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41

Kleszczyńska, H., M. Oświęcimska, S. Witek i S. Przestalski. "Inhibition of Lipid Peroxidation in the Erythrocyte Membrane by Quaternary Morpholinium Salts with Antioxidant Function". Zeitschrift für Naturforschung C 53, nr 5-6 (1.06.1998): 425–30. http://dx.doi.org/10.1515/znc-1998-5-620.

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Abstract The antioxidant activity of five new compounds from a group of quaternary ammonium salts with antioxidant function has been investigated. The effect of the compounds on the degree of lipid oxidation in the erythrocyte membrane subjected to UV radiation was studied. It was found that all the salts used decreased oxidation of the lipids in the erythrocyte membrane. The antioxidant activity of the ammonium salts studied increased with their alkyl chain length. Three compounds with the longest alkyl chains were the most active antioxidants, and their antioxidant properties were comparable to those of a flavonoid extracted from haw thorn. The antioxidant effectiveness of the ten-carbon alkyl chain compound was comparable with that of the known antioxidant 3,5-di-t-butyl-4-hydroxytoluene (BHT). The least effective antioxidant studied proved to be the eight-carbon alkyl chain compound. The effect of these compounds on fluidity of the erythrocyte membrane has been studied, and for all an increase of fluidity of the membrane was observed. The changes in erythrocyte ghosts fluidity depended both on concentration and type of compound. A fluorimetric study also indicated that rigidity of the erythrocyte membrane increased with degree of its oxidation, but with antioxidants present membrane rigidity increased less.

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42

Kuczera, Janina, Teresa E. Krai, Marian Podolak i Stanisław Przestalski. "A Joint Effect of Cationic and Anionic Amphiphilic Compounds on the Desorption of Calcium Ions from Lecithin Liposome Membranes". Zeitschrift für Naturforschung C 54, nr 5-6 (1.06.1999): 429–37. http://dx.doi.org/10.1515/znc-1999-5-620.

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Abstract The aim of the work was to determine the synergism and antagonism of mixtures of the cationic amphiphilic compounds: N-benzyl-N,N-dimethyl-N-tetradecylammonium chloride (BD TA), N-benzyl-N,N-dimethyl-N-dodecylammonium chloride (BDDA), N-methyl-N-te-tradecyl-morpholinium bromide (MTM), N,N,N-trimethyl-N-tetradecylammonium bromide (TMTA) and those of tripropyltin chloride in a mixture with amphiphilic anionic compounds (a homologous series of sodium alkylsulfonates with n = 2, 4, 6, 8, 10, 12 and 14 alkyl carbon atoms) in the process of calcium ion desorption from liposome lecithin membranes. Radioactive labels and spin labels were used in the investigations. All compounds studied caused an increase in the kinetic rate constant of calcium ion desorption from liposome membranes with increasing concentration. In case of mixtures containing cationic and anionic compounds both synergism and antagonism were observed. It was shown that the regulatory effect depended on the properties of both cationic and anionic compounds. A mixture of the most effective cationic compound (BDTA) with each of the anionic compounds decreased the effect. Mixtures of the remaining ammonium com pounds with sodium alkylsulfonates produced both synergism and antagonism. Anionic com pounds with short chains increased, and with longer chains decreased efficiency, while com pounds with comparable chains caused totally blocked desorption. A mixture of an organometallic compound having three short chains with anionic compounds gave a reversed effect: short-chain compounds caused a decreased and those with long-chains -increased efficiency of tripropyltin chloride. Studies with spin labels supported the conclusion that the most important factor responsi ble for the regulatory effect is the molecular shape of the complexes formed in a mixture of both groups of compounds -a factor that determines membrane packing density

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43

Roussis, Vassilios, Constantinos Vagias, Christina Tsitsimpikou i Nina Diamantopoulou. "Chemical Variability of the Volatile Metabolites from the Caribbean Corals of the Genus Gorgonia". Zeitschrift für Naturforschung C 55, nr 5-6 (1.06.2000): 431–41. http://dx.doi.org/10.1515/znc-2000-5-620.

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The chemical composition of the investigated gorgonians showed a high level of individual variation and the colonies, according to their major contributors, were assigned to 10 distinct chemical profiles, among which A , C, E , and G were them ost abundant ones. From the metabolites identified in the present study, either by means of GC /MS or using NMR techniques after conventional separation procedures, the novel cyclic ether 5,10-epoxymuurolane is found in significant quantities in D and I chemical profiles. Furanotriene, isofuranotriene and furanodiene could be referred as the most common metabolites of the genus, since they are found in 6 out of 10 chemical profiles. Isosericenine is, also, a significant contributor of H and I chemical profiles. A number of sesquiterpene hydrocarbons, such as curzerene, bicyclogermacrene, valencene, β-bourbonene and β -elemene, along with the oxygenated sesquiterpenes elemanolide and furoventalene, are present at varying concentrations in the majority of the chemical profiles. Metabolites of high discriminant value are: α-himachalene for the K chemical profile, α -santalene and its oxygenated derivatives for the G chemical profile and the three geometrical isomers of germacrone for the F chemical profile. Several chemical profiles show ed narrow geographic distribution. Most of the chemical profiles are located in the north, while F inhabits mainly southern sites and the others are equally distributed. Finally, 91 % of the chemical profiles of the gorgonian colonies appeared to grow in all depths, while 9 % did not inhabit deep -water environments. Most chemical profiles are less frequent at higher water depths with the exception of chemical profiles A and C.

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44

Kiderlen, Albrecht F., Oliver Kayser, Daneel Ferreira i Herbert Kolodziej. "Tannins and Related Compounds: Killing of Amastigotes of Leishmania donovani and Release of Nitric Oxide and Tumour Necrosis Factor a in Macrophages in vitro". Zeitschrift für Naturforschung C 56, nr 5-6 (1.06.2001): 444–54. http://dx.doi.org/10.1515/znc-2001-5-620.

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The antileishmanial and immunomodulatory potencies of a series of 28 polyphenols were evaluated in terms of extra- and intracellular leishmanicidal activity and macrophage activation for release of nitric oxide (NO), tumour necrosis factor (TNF) and interferon (IFN)- like properties. For this, several functional bioassays were employed including an in vitro model for leishmaniasis in which murine bone marrow-derived macrophages (BMMΦ) were infected with the obligate intracellular parasite Leishmania donovani, an extracellular Leishmania proliferation assay, a fibroblast-lysis assay (TNF-activity), and a biochemical assay for NO. Except for gallic acid, its methyl ester, shikimic acid and catechin (EC50 25.8-67.9 nᴍ) all polyphenols tested significantly inhibited the intracellular survival of L. donovani amastigotes (EC50 0.4 -13.9 nᴍ) when compared with the clinically used agent, sodium stibogluconate (EC50 10.6 nᴍ). In contrast, none of the samples proved to be directly toxic for the extracellular promastigote form of the parasite. Noteworthy, the phenolic samples showed only moderate or no cytotoxicity against the murine host cells (EC50 10 to >144 nᴍ). Although NO is an important effector molecule in macrophage microbicidal activity, the inducing potential of the test compounds for its release was found to be very moderate ranging from 7-54 μm (IFN-γ/LPS 119 μm). On the other hand, inhibition of NO production had no apparent effect on intracellular leishmanicidal activity of polyphenols. Their in vitro TNFinducing potential producing 50% lysis in murine L929 cells increased in the order of simple phenols and flavanols (34-48 U/ml) < A-type proanthocyanidins (53 -80 U/ml) < B-type proanthocyanidins (64-200 U/ml) < hydrolyzable tannins (287-350 U/ml) at the host cell subtoxic concentration of 50 μg/ml. Furthermore, gallic acid and some hydrolyzable tannins showed appreciable IFN-like activities ( 14-23 U/ml) as reflected by inhibition of the cytopathic effect of encephalomyocarditis virus on fibroblast L 929 cells. The results provide a rational basis for the recorded anti-infectious efficacy of traditionally used herbal medicines containing tannins in vivo, in the light of both only moderate direct antimicrobial activities of distinct polyphenols in vitro and the limited knowledge on their uptake in humans.

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45

Smith, Stella, Franck Cantet, Fabrice Angelini, Armelle Marais, Francis Mégraud, Ekkhehard Bayerdöffer i Stephan Miehlke. "Discriminatory Power of RAPD,PCR-RFLP and Southern Blot Analyses of ureCD or ureA Gene Probes on Helicobacter pylori Isolates". Zeitschrift für Naturforschung C 57, nr 5-6 (1.06.2002): 516–21. http://dx.doi.org/10.1515/znc-2002-5-620.

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The genetic diversity of 33 Nigerian Helicobacter pylori isolates were studied using RAPD, PCR-RFLP and Southern blot analysis of ureA or ureCD gene probes. RAPD was able to distinguish the following number of isolates using the primers 3880 : 5ʹ-AAGAGCCCGT-3ʹ (28), 3881 :5ʹ-AACGCGCAAC-3ʹ (33) and OPH8 :5ʹ-GAAACACCCC-3ʹ (25). Southern blot analysis using the ureCD probe was also able to distinguish the 12 isolates tested into ten different patterns. The PCR-RFLP technique distinguished all 33 isolates into six types. In conclusion, considering typeability, discriminatory power, and convenience, RAPD with the 3881 primer was considered the most useful technique.

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46

Yang, Qing, Qiuhui Hu, Osamu Yamatoc, Keun-Woo Lee i Teruhiko Yoshihara. "Organosulfur Compounds from Garlic (Allium sativum) Oxidizing Canine Erythrocytes". Zeitschrift für Naturforschung C 58, nr 5-6 (1.06.2003): 408–12. http://dx.doi.org/10.1515/znc-2003-5-620.

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Abstract The sulfurous acid ester, trans-sulfurous acid allyl ester 3-allylsulfanyl-allyl ester 8, along with two known thiosulfinates was isolated from the aqueous ethanol extract of garlic (Allium sativum). The chemical structure of 8 was determined on the basis of spectroscopic data including high resolution mass and two-dimensional NMR techniques. All of these compounds induced methemoglobin formation in a canine erythrocyte suspension in vitro resulting in the oxidation of canine erythrocytes. This is the first report of sulfurous acid ester showing oxidant activity in canine erythrocytes.

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47

Šarlauskas, Jonas, Aušra Nemeikaitė-Cėnienė, Žilvinas Anusevičius, Lina Misevičienė, Audronė Marozienė, Arvydas Markevicius i Narimantas Čėnas. "Enzymatic Redox Properties of Novel Nitrotriazole Explosives Implications for their Toxicity". Zeitschrift für Naturforschung C 59, nr 5-6 (1.06.2004): 399–404. http://dx.doi.org/10.1515/znc-2004-5-620.

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The toxicity of conventional nitroaromatic explosives like 2,4,6-trinitrotoluene (TNT) is caused by their enzymatic free radical formation with the subsequent oxidative stress, the formation of alkylating nitroso and/or hydroxylamino metabolites, and oxyhemoglobin oxidation into methemoglobin. In order to get an insight into the mechanisms of toxicity of the novel explosives NTO (5-nitro-1,2,4-triazol-3-one) and ANTA (5-nitro-1,2,4-triazol-3-amine), we examined their reactions with the single-electron transferring flavoenzymes NADPH: cytochrome P-450 reductase and ferredoxin:NADP+ reductase, two-electron transferring flavoenzymes mammalian NAD(P)H:quinone oxidoreductase (DT-diaphorase), and Enterobacter cloacae NAD(P)H:nitroreductase, and their reactions with oxyhemoglobin. The reactivity of NTO and ANTA in the above reactions was markedly lower than that of TNT. The toxicity of NTO and ANTA in bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK) was partly prevented by desferrioxamine and the antioxidant N,N′-diphenyl-p-phenylene diamine, and potentiated by 1,3-bis-(2-chloroethyl)-1-nitrosourea. This points to the involvement of oxidative stress in their cytotoxicity, presumably to the redox cycling of free radicals. The FLK cell line cytotoxicity and the methemoglobin formation in isolated human erythrocytes of NTO and ANTA were also markedly lower than those of TNT, and similar to those of nitrobenzene. Taken together, our data demonstrate that the low toxicity of nitrotriazole explosives may be attributed to their low electron-accepting properties.

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48

Kosar, Müberra, Zeynep Tunalier, Temel Özek, Mine Kürkcüoglu i K. Hüsnü Can Baser. "A Simple Method to Obtain Essential Oils from Salvia triloba L. and Laurus nobilis L. by Using Microwave-assisted Hydrodistillation". Zeitschrift für Naturforschung C 60, nr 5-6 (1.06.2005): 501–4. http://dx.doi.org/10.1515/znc-2005-5-620.

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A microwave-assisted hydrodistillation protocol was modified to extract essential oils from leaves of Salvia triloba L. and Laurus nobilis L. The essential oils of these plants are generally obtained by hydrodistillation or steam distillation. The volatile compounds obtained by microwave-assisted hydrodistillation and hydrodistillation methods were analyzed by GC and GC/MS. Both distillation methods and analytical results were compared. 1,8-Cineole (46.8-54.2%) was the main component in the leaf oils of both samples. Although the distillation was accomplished in a shorter time, oil yields and 1,8-cineole contents were slightly higher in the microwave- assisted hydrodistillation compared to usual hydrodistillation. Microwave-assisted hydrodistillation appears to be an effective method for the production of essential oils.

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49

Peters, Swaantje, Thomas Lamah, Despina Kokkinou, Karl-Ulrich Bartz-Schmidt i Ulrich Schraermeyer. "Melanin Protects Choroidal Blood Vessels against Light Toxicity". Zeitschrift für Naturforschung C 61, nr 5-6 (1.06.2006): 427–33. http://dx.doi.org/10.1515/znc-2006-5-620.

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Low ocular pigmentation and high long-term exposure to bright light are believed to increase the risk of developing age-related macular degeneration (ARMD). To investigate the role of pigmentation during bright light exposure, cell damage in retinae and choroids of pigmented and non-pigmented rats were compared. Pigmented Long Evans (LE) rats and non-pigmented (albino) Wistar rats were exposed to high intensity visible light from a cold light source with 140,000 lux for 30 min. Control animals of both strains were not irradiated. The animals had their pupils dilated to prevent light absorbance by iris pigmentation. 22 h after irradiation, the rats were sacrificed and their eyes enucleated. Posterior segments, containing retina and choroid, were prepared for light and electron microscopy. Twenty different sections of specified and equal areas were examined in every eye. In albino rats severe retinal damage was observed after light exposure, rod outer segments (ROS) were shortened and the thickness of the outer nuclear layer (ONL) was significantly diminished. Choriocapillaris blood vessels were obstructed. In wide areas the retinal pigment epithelium (RPE) was absent in albino rats after irradiation. In contrast, LE rats presented much less cell damage in the RPE and retina after bright light exposure, although intra-individual differences were observed. The thickness of the ONL was almost unchanged compared to controls. ROS were shortened in LE rats, but the effect was considerably less than that seen in the albinos. Only minimal changes were found in choroidal blood vessels of pigmented rats. The RPE showed certain toxic damage, but cells were not destroyed as in the non-pigmented animals. The number of melanin granules in the RPE of LE rats was reduced after irradiation. Ocular melanin protects the retina and choroid of pigmented eyes against light-induced cell toxicity. Physical protection of iris melanin, as possible in eyes with non-dilated pupils, does not seem to play a major role in our setup. Biochemical mechanisms, like reducing oxidative intracellular stress, are more likely to be responsible for melanin-related light protection in eyes with dilated lens aperture.

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50

Schmid, Hoenes, Vatter i Hessling. "Antimicrobial Effect of Visible Light—Photoinactivation of Legionella rubrilucens by Irradiation at 450, 470, and 620 nm". Antibiotics 8, nr 4 (15.10.2019): 187. http://dx.doi.org/10.3390/antibiotics8040187.

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Despite the high number of legionella infections, there are currently no convincing preventive measures. Photoinactivation with visible light is a promising new approach and the photoinactivation sensitivity properties of planktonic Legionella rubrilucens to 450, 470, and 620 nm irradiation were thus investigated and compared to existing 405 nm inactivation data for obtaining information on responsible endogenous photosensitizers. Legionella were streaked on agar plates and irradiated with different doses by light emitting diodes (LEDs) of different visible wavelengths. When irradiating bacterial samples with blue light of 450 nm, a 5-log reduction could be achieved by applying a dose of 300 J cm−2, whereas at 470 nm, a comparable reduction required about 500 J cm−2. For red irradiation at 620 nm, no inactivation could be observed, even at 500 J cm−2. The declining photoinactivation sensitivity with an increasing wavelength is consistent with the assumption of porphyrins and flavins being among the relevant photosensitizers. These results were obtained for L. rubrilucens, but there is reason to believe that its inactivation behavior is similar to that of pathogenic legionella species. Therefore, this photoinactivation might lead to new future concepts for legionella reduction and prevention in technical applications or even on or inside the human body.

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