bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of decompressive craniectomy on intracranial pressure and cerebrospinal compensation following traumatic brain injury
Authors: Timofeev Ivan , Czosnyka Marek , Nortje Jurgens , Smielewski Peter , Kirkpatrick Peter , Gupta Arun , Hutchinson Peter 
Published: January 2008

Object
Decompressive craniectomy is an advanced treatment option for intracranial pressure (ICP) control in patients with traumatic brain injury. The purpose of this study was to evaluate the effect of decompressive craniectomy on ICP and cerebrospinal compensation both within and beyond the first 24 hours of craniectomy.

Methods
This study was a retrospective analysis of the physiological parameters from 27 moderately to severely head-injured patients who underwent decompressive craniectomy for progressive brain edema. Of these, 17 patients had undergone prospective digital recording of ICP with estimation of ICP waveform–derived indices. The pressure-volume compensatory reserve (RAP) index and the cerebrovascular pressure reactivity index (PRx) were used to assess those parameters. The values of parameters prior to and during the 72 hours after decompressive craniectomy were included in the analysis.

Results
Decompressive craniectomy led to a sustained reduction in median (interquartile range) ICP values (21.2 mm Hg [18.7; 24.2 mm Hg] preoperatively compared with 15.7 mm Hg [12.3; 19.2 mm Hg] postoperatively; p = 0.01). A similar improvement was observed in RAP. A significantly lower mean arterial pressure (MAP) was needed after decompressive craniectomy to maintain optimum cerebral perfusion pressure (CPP) levels, compared with the preoperative period (99.5 mm Hg [96.2; 102.9 mm Hg] compared with 94.2 mm Hg [87.9; 98.9 mm Hg], respectively; p = 0.017). Following decompressive craniectomy, the PRx had positive values in all patients, suggesting acquired derangement in pressure reactivity.

Conclusions
In this study, decompressive craniectomy led to a sustained reduction in ICP and improvement in cerebral compliance. Lower MAP levels after decompressive craniectomy are likely to indicate a reduced intensity of treatment. Derangement in cerebrovascular pressure reactivity requires further studies to evaluate its significance and influence on outcome.
Biomechanical comparison of single- and dual-lead pedicle screws in cadaveric spine
Authors: Jacob Arun T. , Ingalhalikar Aditya V. , Morgan John H. , Channon Scott , Lim Tae-Hong , Torner James C. , Hitchon Patrick W. 
Published: January 2008

ObjectThe pedicle screw (PS) is the cornerstone of spinal instrumentation, and its failure often entails additional surgery. Screw pullout is one of the most common reasons for screw failure, particularly in the elderly population. In this study the authors undertook a biomechanical comparison of the maximum pullout force (MPF) required for single- and dual-lead PSs in cadaver vertebrae.MethodsRadiographs of 40 cadaveric vertebrae (T11–L5) were obtained, and bone mineral density (BMD) was measured in the lateral plane using dual–x-ray absorptiometry with a bone densitometer. One screw of each design was implanted for side-by-side comparison. Vertebrae were potted and mounted on an MTS test frame for accurate measurement of MPF. A total of 80 PSs were tested, 40 each of single- and dual-lead design types.ResultsThe average MPF for dual-lead screws (533.89 ± 285.7 N) was comparable to that of single-lead screws (524.90 ± 311.6 N) (p = 0.3733). The BMD had a significant correlation with MPF for both dual-lead (r = 0.56413, p < 0.0001) and single-lead screws (r = 0.56327, p < 0.0001).ConclusionsBarring the effect of BMD, this in vitro biomechanical test showed no significant difference in MPF between single- and dual-lead PSs. Dual-lead PSs can be used to achieve a faster insertion time, without compromising pullout force.
Delayed-onset neurological deficit following correction of severe thoracic kyphotic deformity
Authors: Keyoung H. Michael , Kanter Adam S. , Mummaneni Praveen V. 
Published: January 2008

✓There are many potential risks associated with spinal deformity correction procedures including transient and/or permanent neurological deficits. Typically, neurological deficits caused by the surgical correction of spinal kyphosis occur acutely during surgery or immediately after surgery. Delayed postoperative neurological deficits are extremely rare.
The authors report a case of delayed neurological deficit that occurred 48 hours after surgical correction of thoracic hyperkyphosis. An 18-year-old man with myotonic dystrophy presented with a 110° T7–L1 kyphosis. The patient underwent an uneventful two-stage correction procedure of the hyperkyphotic deformity. First, anterior discectomies and fusion were performed from T-7 to L-1 using rib autograft, and all segmental vessels were preserved. Subsequently, on the same day, the patient underwent posterior Smith–Petersen osteotomies and T7–L2 pedicle screw fixation. Intact somatosensory and motor evoked potentials were maintained throughout both operations. Postoperatively, he remained neurologically intact without sequelae for nearly 48 hours. On postoperative Day 2, the patient developed delayed monoplegia of the left leg and sensory level loss below T-10.
Medical management enabled complete reversal of the patient's monoplegia and sensory loss. At 2-year follow-up, the patient had no adverse neurological sequelae.
In this case, a delayed postoperative neurological deficit occurred following spinal hyperkyphosis correction. The authors discuss the possible etiological mechanisms behind this complication and suggest strategies for its management.
Adaptive robust H∞ state feedback control for linear uncertain systems with time‐varying delay
Authors: Ye Dan , Yang Guang Hong 
Published: January 2008

AbstractThis paper considers the problem of adaptive robust H∞ state feedback control for linear uncertain systems with time‐varying delay. The uncertainties are assumed to be time varying, unknown, but bounded. A new adaptive robust H∞ controller is presented, whose gains are updating automatically according to the online estimates of uncertain parameters. By combining an indirect adaptive control method and a linear matrix inequality method, sufficient conditions with less conservativeness than those of the corresponding controller with fixed gains are given to guarantee robust asymptotic stability and H∞ performance of the closed‐loop systems. A numerical example and its simulation results are given to demonstrate the effectiveness and the benefits of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.
Efficient homocoupling reactions of halide compounds catalyzed by manganese (II) chloride
Authors: Yuan Yu , Bian Yubo 
Published: January 2008

AbstractA new efficient homocoupling reaction was reported in one pot by a combination of metallic magnesium and a catalytic amount of manganese (II) chloride. Various aromatic and alkyl halides underwent homocoupling smoothly, affording the corresponding symmetrical homocoupling compounds in moderate to good yields. The readily available MnCl2, the mild reaction conditions and the operational simplicity and practicability allow for an easy and practical procedure for the purpose of carboncarbon bond formation. Copyright © 2007 John Wiley & Sons, Ltd.
Recent advances in spirochalcogenurane stereochemistry—A mini review
Authors: Allenmark Stig 
Published: January 2008

AbstractA summary of the present knowledge of the stereochemistry of the hypervalent spirochalcogenuranes, especially the role of the central atom (S, Se, Te) for the chemical and configurational stability and the chiroptical and X‐ray crystallographic techniques available for the determination of absolute configuration, is given. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Tracking Receptors by Imaging Single Molecules: Figure 1.
Authors: Cognet Laurent , Lounis Brahim , Choquet Daniel 
Published: January 2008

INTRODUCTIONThis article describes imaging techniques using single optical labels, ranging from fluorescent dyes to scattering particles, for the study of the movement of individual or small assemblies of membrane proteins. These techniques have been used to track the movements of different types of plasma membrane proteins, such as neurotransmitter receptors and adhesion proteins. They can be used to probe the degree of interaction between membrane proteins and cytoplasmic stabilizing elements in live cells.
Speciation problems in the Papilio machaon group of butterflies (Lepidoptera: Papilionidae)
Authors: CLARKE Sir CYRIL (A.) , LARSEN TORBEN B. 
Published: January 2008

Abstract. The taxonomic and genetic relationships between P.machaon rathjensi Warnecke from the west side of southern Arabia and P.machaon muetingi Seyer from the east are discussed, together with suggestions of their relationship to P.machaon saharae Oberthiir from the northern Hejaz, Sinai and desert North Africa. It is concluded that though P.m.rathjensi and P.m.saharae are subspecifically distinct, they are very closely related to each other, and both should be regarded as specifically distinct from the rest of the machaon complex.The remainder of the machaon complex in its turn presents a somewhat similar problem. Thus P.machaon gorganus Fruhstorfer and P.hospiton Géné are normally regarded as good species, but Fl caterpillars have been found in the wild and the cross can be readily produced in captivity with no upset in the sex ratio. Furthermore, recently we have obtained sparse F2 offspring between the two species.We therefore suggest that the entire P.machaon complex is in a labile state as regards speciation throughout its range and the relationships between the various forms are not easily expressed through the traditional species and subspecies concepts. Our tentative conclusions are that the status of P.machaon and P.hospiton as distinct species probably remains valid. The saharaelrathjensi complex might be considered distinct from P.machaon using the biological species concept, while their genetics indicate a more conservative approach. However, more important than the exact status of the taxa in question is the fact that the P.machaon complex illustrates evoluton in action, the end result of which cannot be predicted.
OPTICAL ROTATORY DISPERSION OF SOME DEHYDROGENASES*
Authors: JIRGENSONS B. 
Published: January 2008

SummaryThe optical rotatory dispersion of solutions of alcohol dehydrogenase (AD), glyceralde‐hyde‐3‐phosphate dehydrogenase (GAPD), glutamic dehydrogenase (GAD), and malic dehydrogenase (MD) was investigated. The b, values of the native dehydrogenases were found to be between ‐170 and ‐450. GAD and MD were studied also with the short wave length ultraviolet light, and they both displayed strong Cotton effects at 230–245 mµ. The solutions of native GAD were found to be dextrorotatory, however, they became levorotatory on denaturation with alkali, urea, or sodium decyl sulfate. According to the rotatory dispersion data, the dehydrogenases belong to the α‐helical globular proteins, although it seems premature to make quantitative estimates of the a‐helix content from the rotatory dispersion data alone.
SENSIBILISIERTE PHOTOOXIDATION DURCH METHYLENBLAU, THIOPYRONIN UND PYRONIN — II. PHYSIKOCHEMISCHE GRUNDLAGEN DER PHOTODYNAMISCHEN WIRKUNG VON THIOPYRONIN
Authors: BERG H. , GOLLMICK F. A. , JACOB H.‐E. , TRIEBEL H. 
Published: January 2008

Abstract— The physical‐chemical properties of thiopyronine which result in its outstanding photodynamic effectiveness (in comparison to methylene blue and pyronine) are: (1) High velocity of free radical generation (kinetics followed by spectroscopy after flash photolysis). (2) High velocity of reoxidation of free radical (rate constant determined by kinetic spectroscopy under aerobic conditions). (3) Fairly positive reduction potential of oxidized free radical (from polarographic analysis of redox behavior). (4) Irreversible oxidation behavior of leuco‐thiopyronin in contrast to leuco‐methylene blue (the structure of leuco‐thiopyronin was elucidated by NMR‐analysis). (5) Fairly high equilibrium constant for complex formation with DN A (determination by high sensitive pulse‐polarography).From the sedimentation behavior and T‐jump relaxation of in vitro photodynamically treated DNA it is shown that not only does guanine photooxidation take place but also single‐ and double‐strand breaks can occur. The mechanism of this phenomenon is not yet elucidated.
FLASH PHOTOLYSIS STUDY OF ALIPHATIC AMINO ACIDS AND PEPTIDES IN AQUEOUS SOLUTION*
Authors: Mittal L. J. , Mittal J. P. , Hayon E. 
Published: January 2008

Abstract— The intermediates produced in the photolysis of oxygen‐free aqueous solutions of a number of aliphatic amino acids and peptides were observed spectrophotometrically using the fast‐reaction technique of flash photolysis. Included among the compounds examined are the N‐acetyl derivatives of glycine, alanine, sarcosine, glutamic acid and glycylglycine; the esters and amides of these N‐acetyl compounds; diketopiperazines; the amino acids glycine, alanine and β‐alanine; and finally the oligopeptides di‐, tri‐ and tetraglycine. The direct optical excitation of these compounds was found to lead primarily to a photo‐induced decarboxylation reaction:The transient spectra of the radicals produced have been identified. The quantum yields of these processes were found to be directly proportional to the pKa of the carboxyl groups of the corresponding ground‐state molecules, and hence to the concentration of the non‐ionized carboxylic acids. The φ's of these processes for the ionized acids were close to zero. The dependence of φ upon pH is correlated to the absorption spectra of these compounds. The quantum yields of the corresponding esters were lower but independent of pH. No intermediates were observed from excitation of the amine derivatives. Other photolytic reactions are suggested. The photo‐decarboxylation of alanine and diglycine were found to be monophotonic, while that of N‐acetyl alanine, N‐acetyl diglycine, and tetraglycine were found to be biphotonic. A triplet excited state precursor is indicated for the latter group of compounds. These and other results are discussed.
THE TRANS → CIS PHOTOISOMERIZATION OF PROTONATED RETINYL SCHIFF BASES
Authors: Donahue Jean M. , Waddell Walter H. 
Published: January 2008

AbstractSchiff bases were prepared from all‐trans‐retinal (I) and pyrrolidine perchlorate (II) and from I and n‐butyl amine, protonated with anhydrous hydrogen chloride gas, Ill. Initial quantum yields of trans→ cis photoisomerization (Φ°PI) were determined and primary photoproducts and product ratios were measured in aerated methanol. Φ°PI of all‐trans‐III is independent of excitation energy. All analyses were made using high‐pressure liquid chromatographic (LC) methods. It was necessary to hydrolize the Schiff bases to corresponding retinals prior to LC analysis.
A PHOTORECEPTOR SYSTEM REGULATING in vivo AND in vitro PHOSPHORYLATION OF A PEA PLASMA MEMBRANE PROTEIN
Authors: Short Timothy W. , Porst Markus , Brigg Winslow R. 
Published: January 2008

AbstractWe have continued to characterize the blue light‐regulated phosphorylation of a 120 kDa pea plasma membrane protein thought to be involved in sensory transduction for phototropism (Short and Briggs, 1990, Plant Physiol.92, 179–185). By incubating pea stem sections in 32P‐phosphate, we show that the 120 kDa protein is phosphorylated in vivo only after blue light irradiation and that the photosensitive fluence range matches that for phototropism. Blue light induces phosphorylation of the protein in vitro as well, but the fluences required to elicit the response are at least 30‐fold higher. Triton solubilization of the plasma membrane vesicles does not further alter the fluence‐response relationship. Very little turnover was detected over 20 min phosphorylation time courses or by pulse‐chase experiments on unirradiated, blue light pulse‐irradiated, or continuously irradiated membranes. Experiments with a dark period intervening between irradiation and addition of adenosine triphosphate show the light‐induced change to persist for several minutes at 30°C. Agents that disrupt the normal photochemistry of flavins preferentially inhibit the light‐induced enhancement of phosphorylation, suggesting a flavin chromophore. However, exogenous free flavins do not affect the sensitivity of the response. Staphylococcus aureus V‐8 proteolysis of the phosphorylated protein from membranes subjected to a range of fluences before phosphorylation shows that the radiolabel on each of three peptides increases in proportion to the phosphorylation level of the undigested polypeptide. These studies may be valuable for assessing the nature of the photoreceptor and for unravelling the early sensory transduction steps in phototropism.
PHOTOOXIDATION AND ELECTRON‐TRANSFER PROCESSES IN FREE‐BASE TETRAPHENYLPORPHIN PROBED BY RESONANCE RAMAN SPECTROSCOPY
Authors: Saini G. S. S. , Chaudhury N. K. , Verma A. L. 
Published: January 2008

AbstractWe report here the resonance Raman studies of photooxidation of free base tetraphenylporphin (H2TPP) in the presence of external electron acceptors such as CCl4 and chloranil under selective laser irradiation. From the dependence of photooxidation on the concentration of electron acceptors, polarity of solvents, excitation lines and temperatures, we have inferred that a weak triplet exciplex formed between the excited H2TPP and electron acceptor in non‐polar solvents serves as transient species and the light‐induced intermolecular charge transfer from H2TPP to the electron acceptor is the primary process involved in photooxidation. Observation of partial photooxidation in the rigid matrix at low temperatures has been interpreted to be due to long‐range quantum mechanical electron tunneling process. Almost complete photooxidation is observed in a soft matrix as the donor and acceptor molecules can attain favorable relative orientation and separation for electron transfer during the excited state lifetime of the exciplex.
MITOCHONDRIAL DNA SYNTHESIS IN NON‐GROWTH CONDITION (LIQUID HOLDING) IN Saccharomyces cerevisiae. RELATION WITH GROWTH STAGES and MITOCHONDRIAL DNA REPAIR AFTER UV‐IRRADIATION
Authors: Heude Martine 
Published: January 2008

Abstract— The synthesis of DNA as measured by incorporation of [14C]adenine in Saccharomyces cerevisiae liquid held in non‐growth conditions was followed in controls and UV‐irradiated cells. The incorporation into mitochondrial DNA relative to total DNA was higher in these conditions than that observed in growth medium, especially in liquid held stationary phase cells. The absolute amount of mitochondrial DNA synthesized during liquid holding was larger in exponential than in stationary phase cells and increased after UV‐irradiation.The data reported here are discussed in relation to the effects of liquid holding on the UV‐induction of rho− mutants, such effects depending upon the growth stage of the cells at the time of irradiation. A correlation has been found between the initial ability of the cells to synthesize mitochondrial DNA in liquid holding conditions and their capacity to repair UV‐induced lesions in this DNA. We propose the hypothesis that the opposite effects of liquid holding on the UV‐induction of rho− mutants observed in exponential versus stationary phase cells are not due to the action of different repair pathways, but result essentially from quantitative differences in mtDNA synthesis.
CONFIGURATIONAL PHOTOISOMERIZATION OF BILIRUBIN IN VITRO–II. A COMPARATIVE STUDY OF PHOTOTHERAPY FLUORESCENT LAMPS AND LASERS
Authors: Agati Giovanni , Fusi Franco , Pratesi Riccardo 
Published: January 2008

Abstract— A comparative investigation of configurational photoisomerization of bilirubin (Z.Z‐BR) bound to human serum albumin (HSA) in vitro produced by fluorescent lamps currently employed in phototherapy of neonatal jaundice has been carried out by using a fast absorbance technique. Photoequilibrium Z, E‐BR concentrations and rise‐times are reported. Similar measurements effected with monochromatic laser lines in the blue‐green spectral region are presented for comparison purposes.Narrow‐spectrum fluorescent lamps (violet, special‐blue, filtered‐green) produce Z,E‐BR concentrations at photoequilibrium almost equal to those obtained with monochromatic lines. The photoequilibrium rise‐times, however, strongly depend on the spectral bandwidth of the excitation light. Special‐blue, daylight and green lamps produce Z,E‐BR concentrations = 34,31, and 12%, respectively. For green lamps, the intense UV‐blue‐Hg lines are responsible for more than 50% of Z,E‐BR concentration. Green light is found to be quite ineffective in forming Z,E isomers and very efficient in causing Z,E‐BR to revert to native Z.Z‐BR. Moreover, simultaneous irradiation of BR solution with special‐blue and green fluorescent lamps produces almost complete inhibition of the Z→E reaction at suitable green/blue intensity ratio.On the basis of these results a possible mechanism is presented to explain the clinical success of fluorescent green lamp phototherapy and the greater production of structural BR isomers recently reported for green than that for white lamps.
PICOSECOND LASER SPECTROSCOPY AND OPTICALLY DETECTED MAGNETIC RESONANCE ON A MODEL PHOTOSYNTHETIC SYSTEM
Authors: Hala J. , Searle G. F. W. , Schaafsma T. J. , Hoek A. van , Pancoska P. , Blaha K. , Vacek K. 
Published: January 2008

AbstractFluorescence‐detected magnetic resonance of triplets in zero magnetic field (FDMR), fluorescence fading (FF) due to triplet‐formation, both at 4.2 K, and prompt fluorescence decay kinetics (FDK) at room temperature have been measured for free pheophorbide‐a (f‐Pheo) and bound (b‐Pheo) to a synthetic polypeptide (L‐Lys‐L‐Ala‐L‐Ala)n, dissolved in dimethylformamide (DMF). Fluorescence decay kinetics measurements of f‐Pheo in DMF yielded 1‐5 ns lifetimes, for b‐Pheo in DMF a ~ 50 ps decay‐component was found emitting at 730–750 nm. Zero‐field splitting parameters |D| and |E| of the lowest triplet state T1 were determined from FDMR spectra as (337 and 24) 10‐4 cm‐1 for f‐Pheo and (359 and 25) 10‐4 cm‐1 for b‐Pheo, both in DMF. Decay rate constants of the three spin levels of T1 of b‐Pheo (Kx= 1200 50 s‐1, ky= 440 25 s‐1, kz= 80 5 s‐1) and relative steady‐state populations (Nx= 28 2%, Ny= 47 2%, Nz= 26 2%) determined from FF curves predict a fluorescence decrease at the D–E and D + E FDMR transitions, whereas experimentally a fluorescence increase is observed. The FDMR sign‐inversion results from singlet‐singlet energy transfer from b‐Pheo monomers to their aggregates, followed by fast intersystem crossing to T1. These results indicate that aggregates are formed by two or more b‐Pheo molecules at different positions on the folded polypeptide chain. This situation resembles that in chlorophyll‐proteins, containing low‐lying traps, resulting from interaction of chromophores with other chromophores and with the protein environment.
THE USE OF SPIN LABEL OXIMETRY IN THE STUDY OF PHOTODYNAMIC INACTIVATION OF CHINESE HAMSTER OVARY CELLS
Authors: Ankel Else , Felix Christopher C. , Kalyanaraman B. 
Published: January 2008

AbstractSpin label oximetry has been used to study the effects of photosensitizer hematoporphyrin on oxygen consumption in Chinese hamster ovary cells. These measurements demonstrate that, in the presence of the sensitizer, there occurs (i) an increase in total oxygen consumption during irradiation and (ii) a decrease in oxygen consumption following irradiation. These results are attributed to the effects of photosensitized oxygen consumption and decreased cellular respiration due to cell inactivation. Thus the inhibition of oxygen consumption after irradiation was shown to correlate with decreased cell survival measured in cell culture experiments. Possible mechanisms of inactivation and extensions of the oximetric approach are discussed.