bluuebunny/crossref_metadata_2025_split huggingface dataset:
Volumetric analysis of the posterior cranial fossa in a family with four generations of the Chiari malformation Type I
Authors: Tubbs R. Shane , Hill Mark , Loukas Marios , Shoja Mohammadali M. , Oakes W. Jerry 
Published: January 2008

Object
Many authors have concluded that the Chiari malformation Type I (CM-I) is due to a smaller than normal posterior cranial fossa. In order to establish this smaller geometry as the cause of hindbrain herniation in a family, the authors of this paper performed volumetric analysis in a family found to have this malformation documented in 4 generations.

Methods
Members from this family found to have a CM-I by imaging underwent volumetric analysis of their posterior cranial fossa using the Cavalieri method.

Results
No member of this family found to have CM-I on preoperative imaging had a posterior fossa that was significantly smaller than that of age-matched controls.

Conclusions
The results of this study demonstrate that not all patients with a CM-I will have a reduced posterior cranial fossa volume. Although the mechanism for the development of hindbrain herniation in this cohort is unknown, this manifestation can be seen in multiple generations of a familial aggregation with normal posterior fossa capacity.
Have we made progress in preventing shunt failure? A critical analysis
Authors: Stein Sherman C. , Guo Wensheng 
Published: January 2008

Object
The goal of this study was to determine whether failure rates of hydrocephalus shunts have fallen over the years as a result of experience or technical improvements.

Methods
A structured search was performed of the English language literature for case series reporting failure rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to analyze failure rates statistically for temporal trends. Separate models were used for children (< 17 years old) and adults.

Results
In children, the shunt failure rate was 31.3% for the 1st year and 4.5% per year thereafter. There were no significant changes in either rate over time. Although 1st-year failure rates in adults have fallen slightly over time, late failure rates have risen.

Conclusions
Progress in preventing shunt failures has not been made over the last several decades. Any improvements made in shunt materials or insertion techniques have been overshadowed by biological and other factors.
Preliminary mechanistic information on disulfide‐bond formation and the role of hydrogen bonds by nanoelectrospray mass spectrometry
Authors: Jiang Honghai , Li Minfeng , Moy Marie A. , Gong Bing , Wood Troy D. 
Published: January 2008

AbstractThe formation of disulfide‐bonds is vital for the proper folding of most secreted proteins and the stabilization of the final protein structure, including many of medical importance. The determination of disulfide‐bonds is an important aspect of gaining a comprehensive understanding of the chemical structure of a protein. A long‐term goal of ours is to examine the mechanism of disulfide‐bond formation in aqueous solution and the potential role hydrogen bonds play in this process. Here, we report preliminary results from a method that utilizes the oxidizing power of iodine to generate disulfide bonds from synthesized model compounds, which is followed by nanoelectrospray ionization (nanoESI)‐ mass spectrometry (MS). By continuously monitoring the reaction mixture during disulfide formation, this nanoESI approach provides insight on the sequence of intermediate species formed, and how hydrogen‐bonding donor/acceptor pairs may promote disulfide bond formation. Copyright © 2008 John Wiley & Sons, Ltd.
Design of robust quadratic‐optimal controllers for uncertain singular systems using orthogonal function approach and genetic algorithm
Authors: Chen Shinn‐Horng , Ho Wen‐Hsien , Chou Jyh‐Horng 
Published: January 2008

AbstractThis paper discusses the robust‐optimal state feedback controller design problems of linear singular systems under the structured (elemental) parameter uncertainties by using the orthogonal function approach (OFA) and the hybrid Taguchi genetic algorithm (HTGA). A sufficient condition is proposed to ensure that the linear singular systems with the structured parameter uncertainties are regular, impulse free, and asymptotically stable. Based on the OFA, an algorithm only involving algebraic computation is derived in this paper and then is integrated with the HTGA to design the robust‐optimal state feedback controller of linear uncertain singular systems subject to robust stability constraint and the minimization of a quadratic performance index. A design example of a two degree of freedom mass–spring–damper system is given to demonstrate the applicability of the proposed approach. Copyright © 2008 John Wiley & Sons, Ltd.
Immunohistochemistry of Embryo Sections
Authors: Nagy Andras , Gertsenstein Marina , Vintersten Kristina , Behringer Richard 
Published: January 2008

INTRODUCTIONThis protocol describes how to localize an antigen in cells and tissues using embryo sections attached to glass slides. The method outlined here uses alkaline-phosphatase-coupled secondary antibody; horseradish-peroxidase-coupled secondary antibody can be used as an alternative.
Phenetic studies of African army ant queens of the genus Dorylus (Hymenoptera: Formicidae)
Authors: BARR DAVID , BOVEN JOSEF VAN , GOTWARD WILLIAM H. 
Published: January 2008

AbstractMultivariate analyses of queens of fourteen species of the Old World army ant genus Dorylus were undertaken to assist in clarifying the status of the six included subgenera. Results were compared with two similar studies based on major workers and males, respectively. Queens are phenetically less divergent than either of the other two phena examined, although similar sub‐generic relationships were observed. Taken together, these phenetic studies suggest that the subgenera Rhogmus and Alaopone are deserving of continued individual status, but that species of Anomma and Dorylus (s.s.) form one diverse taxon. A conservative classification would place Dichthadia and Typhlopone species together with the composite Dorylus (s.s.) ‐ Anomma taxon.
Description of the larval stages of Disenochus fractus Sharp and the origin of the Hawaiian platynine Carabidae (Coleoptera)
Authors: LIEBHERR JAMES K. 
Published: January 2008

AbstractThe larval stages of the Hawaiian Disenochus fractus Sharp are described, representing the first comprehensive larval description for any species of native Hawaiian Carabidae. Based on cladistic analysis using eleven characters of first‐instar larvae for twenty‐two platynine carabid species representing ten genera, D.fractus is most closely related to the Asian Platynus magnus Bates. This result supports Zimmerman's hypothesis that the Hawaiian Platynini are of Asian derivation. Synapomorphies supporting this relationship include: (1) smooth keel‐like egg bursters, (2) serrate margins on the mandibular terebrum and retinacular tooth, and (3) translucent lunules apicad from urogomphal setae UR4–7.
RADICAL PROCESSES IN LIPIDS. A LASER PHOTOLYSIS STUDY OF t‐BUTOXY RADICAL REACTIVITY TOWARD FATTY ACIDS
Authors: Small Richard D. , Scaiano Juan C. , Patterson L. K. 
Published: January 2008

Abstract—Laser photolysis techniques have been used to measure the reactivity of t‐butoxy radical (t‐BuO) toward various fatty acids. Eight compounds varying both in number and in the configuration of olefinic bonds were examined. It has been found that the rate constant for hydrogen abstraction from these compounds by t‐BuO may be related to the number of secondary, allylic, and doubly allylic hydrogens in each molecule by the equation: kr= [0.072[Hsec] + 0.518[Hallylic] + 2.716[Hdoubly allylic] x 106M‐1 s‐1.
INHIBITION AND RECOVERY OF DNA SYNTHESIS IN UV‐IRRADIATED CHINESE HAMSTER V‐79 CELLS†
Authors: Dahle Dan , Griffiths T. D. , Carpenter J. G. 
Published: January 2008

Abstract—DNA replication in UV‐irradiated Chinese hamster V‐79 cells was analyzed by measuring the incorporation of 14C‐thymidine into acid precipitable form and by DNA fiber autoradiography. As expected, UV exposure resulted in a rapid deceleration in the rate of thymidine incorporation, reaching a minimum rate 60–75 min following exposure to 2–10Jm‐2. After an additional 1–2h the rate of thymidine incorporation began to recover slowly, approaching the control rate within 10h following exposure to 10 Jm‐2 or less. The mechanism of the inhibition and recovery in thymidine incorporation was examined by DNA fiber autoradiography. The results indicate that UV radiation produces lesions in DNA which temporarily block chain growth of DNA that is synthesized during the first 5 h after exposure. Within 10 h after exposure, the lesions have either been repaired or modified (or the replicative enzymes altered) so that DNA chain growth is no longer impeded.
ACIDITY DEPENDENCE OF THE ABSORPTION AND FLUORESCENCE SPECTRA OF ISOFLAVONE AND 7‐HYDROXYISOFLAVONE
Authors: Wolfbeis Otto S. , Schipfer Rudolf 
Published: January 2008

Abstract‐The pH and H0 dependence of the absorption and fluorescence spectra of isoflavone and 7‐hydroxyisoflavone are reported. Isoflavone is fluorescent in acidic solution only, whereas 7‐hydroxyisoflavone is fluorescent in all acidity ranges under investigation. Ground and first excited singlet state pKa's have been determined spectrophotometrically and fluorimetrically, respectively. Excited state protolytic equilibration processes via a second order reaction (proton gain) are found to be too slow to compete efficiently with fluorescence. This is deduced from the close agreement between the pKa's of the conjugate acids obtained by absorption and fluorescence titrations. On the other hand, photodissociation of 7‐hydroxyisoflavone proceeds faster than its fluorescence decays. The experimental pKa(S1) is in fair agreement with the calculated one. 7‐Hydroxyisofiavone forms a phototautomer (or exciplex) in the pH 2 to H0‐1 acidity range, which is characterized by its long wavelength emission. Quantum efficiencies are given for isoflavone and 7‐hydroxyisoflavone in aqueous solutions of various acidities. Deuteration effects thereon are discussed.
PHOTOCHEMICAL DAMAGE TO DNA TREATED WITH CHLORPROMAZINE AND NEAR UV RADIATION UNDER AEROBIC AND ANAEROBIC CONDITIONS
Authors: Schothorst Albert A. , Suurmond Dick , Schouten Ron 
Published: January 2008

Abstract—Double stranded salmon sperm DNA in a chlorpromazine (CPZ) solution is damaged when irradiated with near UV light. The damage of irradiated DNA can be estimated by measuring the increase in extinction at 260 nm following incubation at 60°C of the DNA with formaldehyde. Moreover, DNA irradiated in the presence of CPZ or kept in the dark separate quite differently in an aqueous polymer two‐phase system. DNA irradiated in the presence of CPZ seemed to be susceptible to digestion by endonuclease S1, while the endonuclease of Neurospora crassa could not digest this DNA. Irradiation under aerobic conditions seemed to be less disastrous for DNA than under anaerobic conditions.
SINGLE‐STRAND BREAKS IN SUPERCOILED DNA INDUCED BY VACUUM‐UV RADIATION IN AQUEOUS SOLUTION
Authors: Takakura Kaoru , Ishikawa Mitsuo , Hidea Kotaro , Kobayashi Katsumi , Ito Atsushi , Ito Takashi 
Published: January 2008

AbstractWe studied the induction of single‐strand breaks in the DNA of plasmid pBR 322 by vacuum‐UV radiation above 145 nm in aqueous solutions in relation to the production of OH‐radicals in water. The similarity and dissimilarity were examined of the wavelength dependence between the two effects. The maximum of single strand breaks at 150 nm could be explained by the action of OH‐radicals derived from direct water photolysis: the maximum at 180 nm remains unexplained. There was no indication that the direct absorption of photon by the DNA molecule plays an important role in the production of single‐strand breaks.
PHOTOHEMOLYSIS OF HUMAN ERYTHROCYTES LABELED IN BAND 3 WITH EOSIN‐ISOTHIOCYANATE
Authors: Pooler John P. , Girotti Albert W. 
Published: January 2008

AbstractEosin‐isothiocyanate (EYNCS) is 50 to 100 times more effective in sensitizing delayed photo‐hemolysis of human erythrocytes than is eosin when matched for absorbance in the reaction medium. These dyes are equally efficient in generating singlet oxygen, a potent membrane oxidant. When cells are treated with sensitizer and washed extensively prior to illumination, EYNCS phototoxicity persists, while that of eosin is lost. SDS‐gel electrophoresis of membranes from EYNCS‐exposed cells shows a large fluorescence signal coincident with band 3 protein that is abolished by pretreatment with H2DIDS, the inhibitor of anion exchange by band 3. This treatment reduces the photohemolytic potency of EYNCS by over 90%. The marked enhancement of photohemolytic activity upon binding sensitizer to band 3 implicates band 3 itself as a site of photodamage leading to lysis.
PHOTOIONIZATION OF TRYPTOPHAN: AN ELECTRON SPIN RESONANCE INVESTIGATION
Authors: Hoebeke M. , Gandin E. , Lion Y. 
Published: January 2008

AbstractThe photoionization of tryptophan has been studied by ESR spectroscopy using the free radical scavenger 5, 5 dimethyl‐1‐pyrroline‐l‐oxide as a spin trap for hydrated electrons. A special set‐up has been devised to irradiate more than one aliquot of the bubbled aqueous solutions in the cavity without removing the ESR cell out of the cavity.Quantum yields of electrons production have been estimated as a function of irradiation wavelength. No photoionization threshold has been observed in these experiments.
WAVELENGTH DEPENDENCE FOR THE INDUCTION OF BACTERIOPHAGE LAMBDA BY ANTITUMOR AGENT GILVOCARCIN V
Authors: Elespuru Rosalie K. , Hitchins Victoria M. 
Published: January 2008

AbstractThe wavelength dependence for the induction of a lambda‐lacZ fusion phage of E. coli by photo‐activated gilvocarcin V was determined using a spot test or a quantitative assay for the lacZ gene product. Suspensions of bacteria and chemical were exposed to radiation of different wavelengths in the region 313‐546 nm, using a double grating monochromator. The prophage induction profiles generated were similar to the absorption spectrum of gilvocarcin V in this region, with a peak near 400 nm. The radiation fluence and chemical concentration required for threshold levels of prophage induction exhibited a nearly reciprocal relationship. These results have implications for the therapeutic use of gilvocarcins as antitumor agents.
THE PHOTOLYSIS OF TRYPTOPHAN WITH 337.1 nm LASER RADIATION
Authors: Borkman R. F. , Hibbard L. B. , Dillon James 
Published: January 2008

Abstract— Aqueous solutions of L‐tryptophan were photolyzed by exposure to 337.1 nm radiation from a pulsed nitrogen laser. These data were compared with results for the 290 nm conventional‐source photolysis of tryptophan. The progress of photolysis was monitored by fluorescence analysis of tryptophan. UV absorption spectroscopy, HPLC, TLC, and proton NMR spectroscopy. The loss of Trp was observed to be first order for 290 nm photolysis but of mixed order for 337.1 nm photolysis. Five photolysis products were detected by TLC analysis, including: N‐formylkynurenine. kynurenine, tryptamine (detected after 290 nm photolysis but not 337.1 nm photolysis) and two unknown products. The tryptophan‐containing peptides N‐acetyl‐tryptophanamide (NATA) and tryptophylglycine (Trp‐Gly) were also observed to photolyze upon 337.1 nm laser radiation demonstrating that this phenomenon is not restricted to free tryptophan monomer.Since Trp is not ordinarily thought to absorb U V radiation at wavelengths as long as 337.1 nm. a number of experiments were performed in an effort to determine the mechanism of photolysis at this wavelength. Evidence is presented which indicates that the 337.1 nm laser photolysis of Trp does not result from two photon absorption, dielectric breakdown, or other laser‐specific processes. Instead. it is concluded that this photolysis results either from a very weak absorption tail extending to 337.1 nm in tryptophan itself or from a reaction involving an impurity sensitizer which absorbs the 337.1 nm radiation. The sensitizing impurity. if present, could not. however, be removed by preparative HPLC and could not be detected by TLC or fluorescence analysis.
PYRIMIDINE DIMER FORMATION IN HUMAN SKIN
Authors: Freeman Steven E. , Gange Richard W. , Sutherland John C. , Sutherland Betsy M. 
Published: January 2008

AbstractCyclobutyl pyrimidine dimers are major photoproducts formed upon irradiation of DNA with ultraviolet light. We have developed a method for detecting as few as one pyrimidine dimer per million bases in about 50 ng of non‐radioactive DNA, and have used this method to quantitate dimer yields in human skin DNA exposed in situ to UV. We found that UVA radiation (320–400 nm) produces detectable levels of dimers in the DNA of human skin. We also measured UVB‐induced dimer yields in skin of individuals of differing sun sensitivity and found higher yields in individuals with higher UVB minimal erythema doses and greater sun sensitivity. These approaches should provide important information on damage induced in human skin upon exposure to natural or artificial sources of ultraviolet radiation.
PHYTOCHROME IN GREEN‐TISSUE: PARTIAL PURIFICATION and CHARACTERIZATION OF THE 118‐KILODALTON PHYTOCHROME SPECIES FROM LIGHT‐GROWN Avena sativa L.*
Authors: Tokuhisa James G. , Quail Peter H. 
Published: January 2008

Abstract—The predominant, immunochemically‐detectable phytochrome polypeptide rapidly extracted directly into boiling sodium dodecyl sulfate‐containing buffer from fresh or freeze‐dried green Avena tissue has an apparent molecular mass of 118 kilodaltons (kDa). This result indicates that the 118‐kDa phytochrome species obtained from green Avena by extraction and rapid processing under non‐denaturing conditions in previous studies was not derived by partial proteolysis of a larger polypeptide present in the cell. Additional data do, however, demonstrate the presence in green tissue homogenates of proteolytic activity that can cause a = 6‐kDa reduction in apparent molecular mass and a blue‐shift in the Pfr absorbance maximum of phytochrome during handling. This proteolytic activity contrasts with that previously encountered in etiolated tissue in that it is not inhibited by phenylmethylsulfonyl fluoride, but is inhibited by iodoacetamide and leupeptin. This result indicates that the activity is associated with a thiol‐like protease.A partial purification procedure that incorporates the use of iodacetamide and a novel chromatographic step is described for green‐tissue phytochrome. This procedure provides 50% recovery with a 90‐fold enrichment of phytochrome relative to the initial extract in which the chromoprotein is 0.003% of the total soluble protein. The final fraction is apparently free of proteolytic activity. Immunoblot analysis of this fraction demonstrates that the predominant immunoreactive band has a monomeric molecular mass of 118 kDa. Comigration of this band with a band exhibiting zinc‐induced fluorescence on blots of the partially purified preparations verifies that the 118‐kDa species is the principal tetrapyrrole‐bearing polypeptide present. Spectral properties of the final fraction are identical to those published for crude green‐tissue extracts, indicating the stability of the molecule's spectral properties throughout the procedure. Size exclusion chromatography under nondenaturing conditions shows that the 118‐kDa phytochrome species from green tissue comigrates with the dimeric, etiolated‐tissue molecule, and is therefore suggestive of similar quaternary structure. Together these data reinforce previous conclusions that the predominant phytochrome molecule present in the living cells of green tissue is resolvable as a 118‐kDa species, distinct from the well‐characterized 124‐kDa molecule from etiolated tissue (Tokuhisa et al., 1985, Planta 164, 321–332), and indicate that the partial purification protocol described here sustains the green‐tissue phytochrome in its native state throughout the procedure.
THE EPIDERMAL CELL KINETIC RESPONSE TO ULTRAVIOLET B IRRADIATION COMBINES REGENERATIVE PROLIFERATION AND CARCINOGEN ASSOCIATED CELL CYCLE DELAY
Authors: Olsen Wenche Marie , Kirkhus Bente 
Published: January 2008

Abstract—The cell cycle traverse of epidermal basal cells 24 h after in vivo exposure of ultraviolet B (UVB) irradiation was studied by immunochemical staining of incorporated bromodeoxyuridine (BrdU) and bivariate BrdU/DNA flow cytometric analysis. The results were compared with the cell kinetic patterns following topical application of the skin carcinogen methylnitrosourea (MNU) as well as the skin irritant cantharidin. Hairless mice were injected intraperitoneally with BrdU 24 h after treatment of their back skin with either a minimal erythema dose of UVB, or a single application of MNU or cantharidin dissolved in acetone. The cell cycle traverse of the BrdU‐labelled cohorts of epidermal basal cells were then followed for the subsequent 12 h. At 6 h after BrdU‐injection, when all labelled cells in the control group as well as in the cantharidin group had left the S phase, the bivariate distributions of the UVB‐exposed and the MNU group showed that BrdU‐positive cells were still present in S phase. Hence, UVB irradiation, similar to the carcinogen MNU, prolonged the S phase duration in some of the basal cells. At 12 h after pulse labelling, however, BrdU‐positive cells from UVB‐exposed mice were re‐entering S phase from Gl phase, indicating that UVB irradiation induced a shortening of the cell cycle time as well, similar to the response observed after cantharidin. The present data can not tell whether these cells also were delayed in S phase. Thus, the cell cycle traverse in hairless mouse epidermis 24 h after in vivo exposure to UVB seemed to be a combination of the cell kinetic effects following chemical skin carcinogens and skin irritants. UVB irradiation induced both a delay in transit time through S phase, probably due to DNA damage and subsequent repair, as well as a reduction in the total cell cycle time consistent with rapid regenerative proliferation.
THE PHOTOSENSITIZERS BENZOPHENOXAZINE and THIAZINES: COMPREHENSIVE INVESTIGATION OF PHOTOPHYSICAL and PHOTOCHEMICAL PROPERTIES
Authors: Becker Ralph S. , Chakravorti Sankar , Das Suresh 
Published: January 2008

AbstractEight differently substituted title dye compounds have been investigated regarding intersystem crossing, triplet state, fluorescence and singlet excited state pKa properties. In general, non‐halogenated oxazines and thiazines as well as a mono bromooxazine show very low triplet quantum yields, φT (lT 0.03) and relatively long triplet lifetimes (‐40 μs) in acidic methanol. The φT data correlate well with known singlet oxygen yields. In basic methanol no triplet transient is observed but a significant yield of a ground state transient protonated (base dye) form is produced with a short lifetime, ‐400 ns. Fluorescence can be seen simultaneously from both the excited base and the protonated base dye forms in basic methanol. For iodinated oxazine or thiazines, the triplet yield increases and can be as high as 0.5 (diiodo case) in acidic methanol. The triplet lifetimes are further shortened to ‐10 μs compared to the non‐iodinated derivatives above. The triplet yields of the iodo compounds are higher or equal to known singlet oxygen yields. In basic methanol triplet yields up to 0.2 can be seen, the triplet lifetime are shortened still further to 1 μs but no observable protonated form is produced (in distinction to the non‐iodinated cases). Consideration is given to the correlation of triplet and singlet oxygen yields, ground and excited pKa properties, spin‐orbit coupling and internal conversion properties, solvent effects, and phototherapeutic activity of these dyes.