bluuebunny/crossref_metadata_2025_split huggingface dataset:
Point Surveillance of <i>Staphylococcus aureus</i> Carriage among Medical Staff in Infectious Diseases Hospital, Kuwait
Authors: Dimitrov Tz. , Udo E.E. , Grover S. 
Published: May 2003

<i>Objective:</i> To investigate the carriage of <i>Staphylococcus aureus</i> among doctors and nurses in Infectious Diseases Hospital, Kuwait, following the detection of 3 cases of methicillin-resistant <i>S. aureus</i> (MRSA). <i>Materials and Methods:</i> A total of 260 nasal and throat swabs were obtained from 19 doctors and 111 nurses and cultured for the carriage of <i>S. aureus</i>. Forty-three <i>S. aureus</i> were identified based on their growth characteristics on mannitol-salt agar, catalase and tube coagulase and DNA hydrolysis. The isolates were tested for susceptibility to antibacterial agents and typed by phage typing; plasmid analysis and pulsed-field electrophoresis were carried out to determine their relatedness. <i>Results:</i> Of the 19 doctors, 4 (21%) had nasal carriage while only 1 of them had a throat carriage. Sixteen (14.4%) nurses carried <i>S. aureus</i> in their noses and 20 (18%) in their throats. The combined nasal carriage rate for both doctors and nurses was 15.8%, and combined throat carriage was 16.6%. None of them carried MRSA. The isolates were resistant to penicillin G (90%), tetracycline (23.3%), erythromycin (9.3%) and cadmium (100%). Typing of the isolates showed a variety of phage types, plasmid and pulsed-field gel electrophoresis patterns. <i>Discussion:</i> None of the doctors or nurses carried MRSA. Typing of the methicillin-susceptible strains that they carried demonstrated that the <i>S. aureus</i> were different, indicating an absence of a dominant clone capable of spreading. It is important to maintain a low carriage of <i>S. aureus</i> among health-care workers.
Treatment Options to Intensify Hemodialysis
Authors: Haag-Weber M. 
Published: May 2003

At present, three methods are practiced to intensify hemodialysis (HD): 3 times weekly, 8-hour HD, short daily HD and slow daily nocturnal HD. Three times weekly 8-hour dialysis increase both the dialysis dose and time. The longest experiences are in Tassin. Five-year survival in Tassin was better in all age groups compared with the major registries – Japan, EDTA and US Medicare and more obvious for older age groups. The data of Tassin show that increasing the dialysis time provides better blood pressure control, need for no or less antihypertensive drugs, less intradialytic complications, better middle molecule and phosphate clearance, better nutritional status, less requirement for erythropoietin and increased survival. These data of Tassin could be mainly confirmed in our dialysis center. The main difference to Tassin was that in our center most of the patients still need few antihypertensive drugs. The reasons for the difference are that in Tassin the patients are on very low sodium diet (<5 g/day) and in Tassin extracellular volume (ECV) is reduced as far as possible independent of residual renal function. The concept of our center was to preserve residual renal function and accept slightly higher ECV and few antihypertensive drugs. Another concept to intensify HD is short daily HD (6 times/week for 90–180 min). This form of dialysis is offered as in-center and home HD with and without dialysis partner. All studies demonstrated significant improvement of nutritional status, quality of life, control of blood pressure, phosphate and anemia. Survival of AV fistula even with daily double punctures was excellent. The most extensive form of dialysis is slow daily nocturnal dialysis (6 times/week for 8–10 h). This form of dialysis provides excellent urea, phosphate clearance and fourfold increase of β<sub>2</sub>-microglobulin clearance. Patients discontinue phosphate binders and several patients need phosphate addition to dialysis. Blood pressure control is excellent, all patients are off antihypertensive drugs. Improvement of nutrition, anemia, blood pressure and quality of life is even more pronounced compared to short daily HD or 3 times weekly 8-hour HD. Nocturnal dialysis was able to improve sleep apnea. Nocturnal dialysis is offered only as home HD with and without dialysis partner. Any patient who could be trained for home HD was eligible. Presence of co-morbidities was not a contraindication.
Vitamin C in Chronic Kidney Disease and Hemodialysis Patients
Authors: Deicher Robert , Hörl Walter H. 
Published: May 2003

Increments of oxidative stress have been addressed as one potential cause for the accelerated atherosclerosis of chronic kidney disease patients. Ascorbate represents one of the most prominent antioxidants both in plasma as well as intracellulary, exerting beneficial effects by an inhibition of lipid peroxidation and by reducing endothelial dysfunction. However, in the presence of transition metals like iron, ascorbate may give rise to an increased generation of oxidants, and ascorbylation may impose additional carbonyl stress to uremic patients. Unsupplemented dialysis patients have reportedly lower plasma levels of ascorbate in comparison to healthy controls, mostly due to a loss into the dialysate or, in case of not dialyzed patients, increased urinary losses. Currently, 60 mg of ascorbate are recommended for chronic kidney disease patients, and 1–1.5 g of oral ascorbate/week in case of suspected subclinical ascorbate deficiency or 300 mg parenteral ascorbate/dialysis session, respectively. Ascorbate’s role in modifying arterial blood pressure remains unclear, but anemic patients with functional iron deficiency might benefit from short-term, moderately dosed ascorbate supplements.
Role of activin A in murine mast cells: modulation of cell growth, differentiation, and migration
Authors: Funaba Masayuki , Ikeda Teruo , Ogawa Kenji , Murakami Masaru , Abe Matanobu 
Published: May 2003

Abstract
Activins, members of the transforming growth factor-β (TGF-β) superfamily, are potent growth and differentiation factors. Our previous studies revealed that activin A, a homodimer of inhibin/activin βA, was induced in mast cells and peritoneal macrophages in response to their activation. In the present study, we examined the roles of activin A in murine bone marrow-derived, cultured mast cell progenitors (BMCMCs), which expressed gene transcripts for molecules involved in activin signaling, suggesting that BMCMCs could be target cells of activin A. Treatment of activin A inhibited 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide uptake into BMCMCs in a dose-dependent manner. The IC50 concentration was 2.1 nM, which was less potent than 185 pM TGF-β1. Activin A treatment caused morphological changes toward the differentiated cells at 2 nM and up-regulated mRNA of mouse mast cell protease-1 (mMCP-1), a marker enzyme of mature mucosal mast cells, at 1 nM. Activin A also showed activity in inducing migration of BMCMCs; the optimal concentration for maximal migration was 10 pM, which was much lower than the concentrations to inhibit cell growth and to activate the mMCP-1 gene. Taking the present results together with our previous results, it is suggested that activin A secreted from activated immune cells recruits mast cell progenitors to sites of inflammation and that with increasing activin A concentration, the progenitors differentiate into mature mast cells. Thus, activin A may positively regulate the functions of mast cells as effector cells of the immune system.
5-Lipoxygenase knockout mice exhibit a resistance to pleurisy and lung injury caused by carrageenan
Authors: Cuzzocrea Salvatore , Rossi Antonietta , Serraino Ivana , Mazzon Emanuela , Di Paola Rosanna , Dugo Laura , Genovese Tiziana , Calabrò Barbara , Caputi Achille P , Sautebin Lidia 
Published: May 2003

Abstract
In the present study, by comparing the responses in wild-type (WT) mice and mice lacking [knockout (KO)] the 5-lipoxygenase (5-LO), we investigated the role played by 5-LO in the development of acute inflammation. When compared with carragenan-treated 5-LOWT mice, 5-LOKO mice, which had received carrageenan, exhibited a reduced degree of pleural exudation, polymorphonuclear cell migration. Lung myeloperoxidase activity, an index of neutrophil infiltration, was significantly reduced in 5-LOKO mice in comparison with 5-LOWT. Lung-tissue sections from carrageenan-treated 5-LOWT mice showed positive staining for intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, and E-selectin, which were mainly localized around vessels. The intensity and degree of ICAM-1, VCAM-1, P-selectin, and E-selectin were markedly reduced in tissue section from carrageenan-5-LOKO mice, which also improved the histological status of the inflamed lungs. Taken together, our results clearly demonstrate that 5-LO modulates neutrophil infiltration in the acute lung inflammation.
Synthesis, Structure and Catalytic Activity of a Seven-Coordinate Titanium(IV) Tris(pyridine-2-thiolate) Complex
Authors: Nakayama Yuushou , Miyamoto Kaoru , Ueyama Norikazu , Nakamura Akira 
Published: June 2003

Abstract
Reaction of TiCl4 with three equivalents of Me3SiSPy (SPy = pyridine-2-thiolate) cleanly gave a tris(thiolate) complex, TiCl(SPy)3·THF (1). The pentagonal bipyramidal geometry of 1 was revealed by X-ray crystallography. This complex showed catalytic activity for the polymerization of ethylene and styrene upon activation with methylaluminoxane.
One-Pot Formation of a Cyclobutane from the Double Photocycloaddition Reactions of 1,4-Diethynylbenzene to Some o-Quinones
Authors: Kim Sung Sik , Kim Ae Rhan , Mah Yoon Jung , Shim Sang Chul 
Published: June 2003

Abstract
A cyclobutane was produced in one pot, when irradiated 1,4-diethynylbenzene and some o-quinones, such as tetrahalo-1,2-benzoquinones, phenanthrenequinone and acenaphthenequinone, in dichloromethane with 300 nm UV light.
Easy Access to [60]Fulleroalkaloids via Photoinduced Reactions of Tertiary Amines with [60]Fullerene
Authors: Guo Li-Wei , Gao Xiang , Zhang Dan-Wei , Wu Shi-Hui , Wu Hou-Ming , Li Yong-Jiang 
Published: June 2003

Abstract
Photoinduced reactions of tertiary amines with [60]fullerene (C60) were successfully applied to the synthesis of [60]fulleroalkaloids. This method is easy and effective for constructing C60 derivatives containing natural alkaloids for the purpose of checking the influence of the carbon cage on the biological activities of the alkaloids. In this letter, the preparation and characterization of [60]fulleroscandine is reported.
Two-Dimensional Honeycomb Network Formed by Porphyrinatomanganese(III) and μ4-σ-Dimerized 7,7,8,8-Tetracyano-p-quinodimethane Dianion
Authors: Mikami Shinji , Sugiura Ken-ichi , Miller Joel S , Sakata Yoshiteru 
Published: June 2003

Abstract
An unprecedented layered (2-D) honeycomb supramolecular structure comprised of μ4-σ-dimerized 7,7,8,8-tetracyano-p-quinodimethane dianion bridging four S = 2 substituted Mn(III)porphyrins as demonstrated with meso-tetrakis(2,4,6-trimethylphenyl)porphyrinato has been structural characterized.
Photochemical Generation of Radical Species from α-Stannyl Ethers and Their Reaction with Conjugate Enones
Authors: Mikami Tetsuhiro , Harada Manabu , Narasaka Koichi 
Published: June 2003

Abstract
Photochemical reaction of α-stannyl ethers and conjugated enones proceeds in the presence of photosensitizers to give addition products of aryloxymethyl radicals to the enones.
Syntheses of Novel Cyclotriveratrylenophane Capsules and Their Supramolecular Complexes of Fullerenes
Authors: Matsubara Hiroshi , Oguri Shin-ya , Asano Kaori , Yamamoto Koji 
Published: June 2003

Abstract
Cyclotriveratrylenophanes were synthesized and their inclusion abilities for fullerenes were examined by UV spectroscopy. From the spectra, the association constants were determined using Rose and Drago method. Cyclotriveratrylene hosts showed shape-selective properties and large association constants up to 19400 ± 110 dm3mol−1 for C60 and 26500 ± 260 dm3mol−1 for C70
Novel Catalytic Oxidative Synthesis of Soluble Conductive Polymers of Poly(3-butoxycarbonyl-4-methylpyrrole)
Authors: Ohno Naonori , Toshima Naoki 
Published: June 2003

Abstract
A soluble conductive polymer, poly(3-butoxycarbonyl-4-methylpyrrole) was synthesized by catalytic oxidative polymerization of 3-butoxycarbonyl-4-methylpyrrole, where only a small amount of iron (III) chloride as a catalyst, and enough amount of oxygen as an oxidant were used. Addtion of BF3·Et2O to the reaction system can make the yield of the polymer remarkably increase.
Assembly of a Tetranuclear Mixed-Valence Manganese(II,III) Complex from a Binuclear Manganese(II) Complex by Photo-Irradiation
Authors: Tomida Shouichi , Matsushima Hideaki , Koikawa Masayuki , Tokii Tadashi 
Published: June 2003

Abstract
A tetranuclear mixed-valence manganese(II,III) complex, [Mn2(O)(Ph2MeCCOO)2(phen)2]2(PF6)2·10H2O (2), has been assembled from a binuclear manganese(II) complex, [Mn(Ph2MeCCOO)(phen)2]2(PF6)2·2MeCN (1) by use of a photo-induced oxidation reaction.
Preparation of Non-Stoichiometric Nd1−xMnO3−y by Coprecipitation Method
Authors: Uehara Motoki , Nagai Takuro , Yamazaki Atsushi , Takahashi Koichiro , Tsutsumi Sadao 
Published: June 2003

Abstract
The coprecipitate of carbonates was obtained by titrating an ammonium carbonate solution into an hydrochloric solution of MnO2 and Nd2O3 . The non-stoichiometric perovskite-type oxide, Nd1−xMnO3−y was synthesized by firing the coprecipitate in air without flowing. For the products of Nd1−xMnO3−y prepared at 1100 °C, the single phase showing the stable y/x value 1.5 was obtained in the x = 0.05 to 0.20 region, and a by-product Mn3O4 was appeared in x = 0.25.
Cyanodibenzo[1,4]dioxines: A New Family of Synthons for Substituted Dibenzo[1,4]dioxines
Authors: Eastmond Geoffrey C , Paprotny Jerzy 
Published: June 2003

Abstract
Cyanodibenzo[1,4]dioxines, previously unreported, are prepared quantitatively from catechols by nucleophilic fluorodisplacement from 2,3- and 3,4-difluorobenzonitriles, involving meta-fluorodisplacement, in DMF at 130 °C in the presence of potassium carbonate; the cyano-substituted dioxines can be transformed to other substituted dibenzo[1,4]dioxines.
Mixed Phthalocyaninato-Porphyrinato Europium(III) Triple-decker Sandwich Complexes Containing a Conjugated Dimeric Porphyrin Ligand
Authors: Arnold Dennis P , Jiang Jianzhuang 
Published: June 2003

Abstract
The first examples of triple-decker europium(III) sandwich complexes containing bis(octaethylporphyrinyl)butadiyne and phthalocyanine have been prepared by condensation of NiOEP-C4-OEPH2(H21) and Li2Pc with Eu(acac)3·H2O. The complexes (Pc)Eu(1)Eu(Pc) and (1)Eu(Pc)Eu(Pc) were characterized by NMR, IR, Raman, UV-vis, and mass spectra.
Reaction of Primary Selenoamides with Bisacyl Chlorides: Syntheses of 6-Hydroxy-1,3-selenazin-4-ones and Selenoanhydrides
Authors: Koketsu Mamoru , Hiramatsu Sohma , Ishihara Hideharu 
Published: June 2003

Abstract
The reaction of primary selenoamides with bisacyl chlorides in the presence of Et3N was investigated. By the reaction with malonyl chloride, 6-hydroxy-1,3-selenazin-4-ones were provided in high yield. By the reactions with succinyl chloride, glutaryl chloride, and phthaloyl chloride, the corresponding selenoanhydrides were obtained in moderate yields, respectively.
Tissue Based Enzymatic Determination of ATP in Human Erythrocyte Hemolysate Combined with Spectrophotometric Method
Authors: Kataoka Makoto , Teshima Norio , Kurihara Makoto , Kuwa Katsuhiko , Kawashima Takuji 
Published: June 2003

Abstract
A potato tissue based enzymatic determination of ATP combined with spectrophotometric detection is proposed. ATP can be hydrolyzed to give AMP via ADP and two moles of orthophosphate by apyrase (EC 3.6.1.5) contained in the potato tissue. The phosphate released is determined spectrophotometrically based on molybdenum blue formation (λmax = 712 nm). A linear calibration graph is obtained over the range 1.3 × 10−6–1.3 × 10−5 mol dm−3 ATP with a detection limit of 1.5 × 10−7 mol dm−3 (S/N = 3). The proposed method was successfully applied to the determination of ATP in human erythrocyte hemolysate.
Microcryoscopy of Water Employing Silver Iodide to Break Supercooling
Authors: Ogura Tetsuya , Salinas Maria Lorenza , Quiroz Cynthia Genoveva , Miyake Hiroyuki , Kojima Yoshitane 
Published: June 2003

Abstract
A microcryoscope for water has been successfully developed. A series of experiments using 25 μL samples were presented here. It was shown that microcryoscopes can be small sized employing a smaller thermistor and a folded Al-foil as container. AgI was employed to promote ice nucleation.
In vivo Simultaneous Monitoring by Pt-disk Microelectrodes of Intracerebral Hydrogen Peroxide and Dopamine in Rats
Authors: Yokoyama Hidekatsu , Kasai Nahoko , Matsue Tomokazu , Uchida Isamu , Ohya-Nishiguchi Hiroaki , Kamada Hitoshi 
Published: June 2003

Abstract
A technique was developed for simultaneous monitoring of temporal changes in hydrogen peroxide (H2O2) and dopamine (DA) levels by using Pt-disk microelectrodes (φ 30 μm). H2O2 and DA were determined by differential double-pulse amperometry (for H2O2; 1st step, 750 mV, 1000 ms; 2nd step, 1100 mV, 1000 ms: for DA; 1st step, 150 mV, 600 ms; 2nd step, 250 mV, 50 ms). The electrode for H2O2 or DA is capable of determining each target substance and these substances do not interfere with each other. For an in vivo application, the electrodes were implanted into the striatum of rats and used successfully to monitor intrastriatal changes in H2O2 and DA simultaneously after intraperitoneal injection of methamphetamine while the animals were moving freely.
Novel Approach to the Reaction Analysis of Non-UV-Absorbing Crown Ether with Alkali Metal Ions in Aqueous Solution by Capillary Zone Electrophoresis Using Indirect Photometric Detection
Authors: Takayanagi Toshio , Motomizu Shoji 
Published: June 2003

Abstract
A novel analysis method for complex formation reactions of such a non-UV-absorbing crown ether as 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6 ether, 18C6) with alkali metal ions was established through the mobility change in capillary zone electrophoresis. Alkali metal ions at their concentrations of 1 × 10−4 mol dm−3 were photometrically detected by using 1-ethylquinolinium ion as an indirect photometric reagent. The apparent electrophoretic mobility of alkali metal ions decreased along with the increase in the concentrations of 18C6 in migrating solutions. The complex formation constants analyzed and determined by using the mobility change agreed well with the reported values.
Calcium Phosphate Formation on Highly-oriented Collagen Fibrils
Authors: Yokogawa Yoshiyuki , Nagata Fukue , Toriyama Motohiro 
Published: June 2003

Abstract
Calcium phosphate formation on collagen fibrils was studied. Collagen fibrils deposited from a collagen solution were insolubilized by UV-irradiation. The collagen fibrils looked to be precipitated and arranged in one direction in a narrow space due to convection stream from bottom to top of test tube. Highly-oriented collagen fibrils precipitated were soaked in simulated body fluid (SBF) solution at 36.5 °C. After immersion of SBF solution at 36.5 °C for 3 days, calcium phosphate was formed on insolubilized collagen fibrils. In contrast, no calcium phosphate was formed on collagen fibrils without insolubilization treatment.
Crystal Field Effect on the Chemical Shift in Cu LIII XANES Spectra of Cu(II) Compounds
Authors: Shimizu Ken-ichi , Maeshima Hajime , Yoshida Hisao , Satsuma Atsushi , Hattori Tadashi 
Published: June 2003

Abstract
Chemical shifts of the 2p3/2→ 3d peaks in the Cu LIII XANES spectra of copper(II) compounds were correlated with the crystal field parameter, 10Dq, and were understood in terms of the simple crystal field concept.
On the Azide Effect Regenerating the Proton Channel of Mutated Bacteriorhodpsins
Authors: Koyama Koichi , Miyasaka Tsutomu 
Published: June 2003

Abstract
Effect of azide on proton transfer of bacteriorhodopsin (bR) mutants that lack the proton donor Asp-96 and/or proton acceptor Asp-85 was investigated by a photoelectrochemical method. In the presence of azide, D96N completely recovered the response profile of the wild type and D96N/D85N gave a very small current with the same amplitude as in D85N. On the contrary, D85N showed no azide effect. These results indicate that azide affects the process of shuttling protons from D96 to the Schiff base rather than does the proton transfer from the Schiff base to D85.
Electron Transfer Process of lonically Dimeric Cobalt Porphyrin Accompanied with Dissociation Equilibrium
Authors: Yamamoto Kimihisa , Nakazawa Sinsuke 
Published: June 2003

Abstract
The ionically dimeric cobalt porphyrin with a II-II valence state undergoes a stepwise two-electron transfer accompanied with dissociation equilibrium (Kd = 1.3 × 10−6 M) with redox potentials at −0.37 and −0.17 V vs. Fc/Fc+.
Synthesis, Structure, and Photochemistry of Tetrakis(trimethylsilyl)-p-benzoquinone
Authors: Sakamoto Kenkichi , Tsutsui Shinobu , Ebata Keisuke , Kabuto Chizuko , Sakurai Hideki 
Published: June 2003

Abstract
Tetrakis(trimethylsilyl)-p-benzoquinone (1) was obtained by oxidation of hexakis(trimethylsilyl)hydroquinone with pyridinium chlorochromate. X-Ray crystallographic analysis of 1 showed the quinone ring was distorted into a chair form by steric hindrance. Photolysis resulted in a rearrangement of the quinone ring and produced a ketene derivative.
Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel
Authors: Yamaguchi Kazuo , Kitabatake Takashi , Izawa Masashi , Fujiwara Tomomichi , Nishimura Hiroki , Futami Tatsuhiro 
Published: June 2003

Abstract
Silane coupling agents containing a carboxy group are not known because the chloro- or alkoxy group is reactive to the carboxylic acid. In this study, silane coupling agents bearing a 2-nitrobenzyl ester as a protecting group of carboxylic acid were synthesized and applied for surface modification of silica gel followed by uv irradiation under neutral conditions to generate carboxy groups on the surface.
Phosphorus Ylide Migration from Fe to a Phosphenium Phosphorus
Authors: Nakazawa Hiroshi , Kishishita Mitsuru , Nakamoto Tadahiro , Nakamura Norihiko , Ishiyama Takeshi , Miyoshi Katsuhiko 
Published: June 2003

Abstract
The reaction of a phosphorus ylide complex [(C5H4R)(CO)(CH2PR′3)Fe{PNN(Ome)}]BF4 (R = H, Me; R′ = Me, Et, Ph; PNN = PN(Me)CH2CH2Nme) with TMSOTf and then nBu4NBr gave [(C5H4R)(CO)BrFe{PNN(CH2PR′3)}]Otf through intramolecular migration of a cationic phosphorus ylide ligand from Fe to a cationic phosphenium phosphorus.
Novel Emitting Materials for Organic Electroluminescent Device: 1-Aryl-2,5-di(2-thienyl)pyrrole Derivatives Having an Electron-withdrawing Group
Authors: Yanai Hiroyuki , Yoshizawa Daisuke , Tanaka Satoshi , Fukuda Tatsuo , Akazome Motohiro , Ogura Katsuyuki 
Published: June 2003

Abstract
Since 1-aryl-2,5-di(2-thienyl)pyrrole derivatives having an electron-withdrawing group emit strong fluorescence, they could be utilized as an efficient dopant in the emitting layer of an organic EL device. Especially, 1-aryl-2,5-di(2-thienyl)pyrrole having a ketene dithioacetal S,S-dioxide group showed extremely high performance (the highest luminous efficiency: 5.9 cd/A).
A Spontaneous Aggregate Formed by Polypeptide-based Amphiphile in Water
Authors: Doi Tomokiyo , Kinoshita Takatoshi , Kamiya Hiroki , Tsujita Yoshiharu , Yoshimizu Hiroaki 
Published: June 2003

Abstract
In order to construct a molecular aggregate with well-defined structure, a novel amphiphile consisting of a phosphate head group and hydrophobic polypeptide tail was prepared. This amphiphilic polypeptide was soluble in water and spontaneously assembled to form a ribbon-like molecular aggregate. FT-IR and circular dichroism (CD) spectra showed that the aggregated polypeptide adopts an anti-parallel β-form conformation.