bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of different forms of titanium oxide on titanium surface: Effects on apatite deposition
Authors: Rohanizadeh R. , Al‐Sadeq M. , LeGeros R. Z.
Published: September 2004

Methods of preparing different types of titanium oxide (TiO2) and their effects on apatite deposition and adhesion on titanium surfaces were investigated. Forty‐eight commercially pure titanium (Ti) discs were divided into four groups (12 per group) and each group was subjected to the following treatments: Group 1, heat treatment at 750°C; Group 2, oxidation in H2O2 solution followed by heat treatment; Group 3, dipping in rutile/gelatin slurry; and Group 4, dipping in anatase/gelatin slurry. Surface‐treated Ti discs were immersed in a supersaturated calcium phosphate solution to allow apatite deposition. Results showed that the percentage of area covered by deposited apatite was highest in Group 4 compared to the other groups. Apatite deposited on Ti discs pretreated in H2O2 solution (Group 2) demonstrated the highest adhesion to the titanium substrate. Results from this study indicated that surface treatment method affects the type of TiO2 layer formed (anatase or rutile) and affects apatite deposition and adhesion on the Ti surface. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 343–352, 2004
Properties of crosslinked protein matrices for tissue engineering applications synthesized by multiphoton excitation
Authors: Basu Swarna , Campagnola Paul J.
Published: September 2004

We demonstrate the fabrication of model scaffolds and extracellular matrices using multiphoton excited photochemistry. This method is three‐dimensional in nature and has excellent biocompatibility. Crosslinked matrices were fabricated from the proteins fibrinogen, fibronectin, and concanavalin A using two‐photon rose bengal photoactivation and the relatives rates were determined. Immunofluorescence labeling of fibrinogen and fibronectin indicated retention of bioactivity following the multiphoton crosslinking process. Using the fluorescence recovery after photobleaching method, we measured the lateral mobility of fluorescent dyes of different mass and chemistry in order to model the behavior of therapeutic agents and bioactive molecules and found diffusion coefficients within these fabricated structures to be on the order of 10−9–10−10 cm2/s, or approximately three to four orders of magnitude slower than in free solution. The precise diffusion coefficients can be smoothly tuned by varying the laser exposure during the fabrication of the matrix, which results in both an increase in crosslink density as well as protein concentration in the matrix. Terminal crosslink density is achieved at integrated high exposure dose and the relative fabrication rates were determined for these proteins. For all the proteins, the range of diffusion coefficients between the threshold for fabrication and the terminal limit is correlated with the change in matrix mesh size as determined by Flory‐Rehner swelling analysis. Both normal Fickian as well as hindered anomalous diffusion is observed depending on specific molecular interactions of the tracer dyes and protein host. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 359–368, 2004
Using quaternions to calculate RMSD
Authors: Coutsias Evangelos A. , Seok Chaok , Dill Ken A.
Published: September 2004

A widely used way to compare the structures of biomolecules or solid bodies is to translate and rotate one structure with respect to the other to minimize the root‐mean‐square deviation (RMSD). We present a simple derivation, based on quaternions, for the optimal solid body transformation (rotation‐translation) that minimizes the RMSD between two sets of vectors. We prove that the quaternion method is equivalent to the well‐known formula due to Kabsch. We analyze the various cases that may arise, and give a complete enumeration of the special cases in terms of the arrangement of the eigenvalues of a traceless, 4 × 4 symmetric matrix. A key result here is an expression for the gradient of the RMSD as a function of model parameters. This can be useful, for example, in finding the minimum energy path of a reaction using the elastic band methods or in optimizing model parameters to best fit a target structure. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1849–1857, 2004
Prediction of pKa shifts in proteins using a combination of molecular mechanical and continuum solvent calculations
Authors: Kuhn Bernd , Kollman Peter A. , Stahl Martin
Published: September 2004

The prediction of pKa shifts of ionizable groups in proteins is of great relevance for a number of important biological phenomena. We present an implementation of the MM‐GBSA approach, which combines molecular mechanical (MM) and generalized Born (GB) continuum solvent energy terms, to the calculation of pKa values of a panel of nine proteins, including 69 individual comparisons with experiment. While applied so far mainly to the calculation of biomolecular binding free energies, we show that this method can also be used for the estimation of protein pKa shifts, with an accuracy around 1 pKa unit, even for strongly shifted residues. Our analysis reveals that the nonelectrostatic terms that are part of the MM‐GBSA free energy expression are important contributors to improved prediction accuracy. This suggests that most of the previous approaches that focus only on electrostatic interactions could be improved by adding other nonpolar energy terms to their free energy expression. Interestingly, our method yields best accuracy at protein dielectric constants of εint = 2–4, which is in contrast to previous approaches that peak at higher εint ≥ 8. An important component of our procedure is an intermediate minimization step of each protonation state involving different rotamers and tautomers as a way to explicitly model protein relaxation upon (de)protonation. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1865–1872, 2004
Systematic study of vibrational frequencies calculated with the self‐consistent charge density functional tight‐binding method
Authors: Witek Henryk A. , Morokuma Keiji
Published: September 2004

We present a detailed study of harmonic vibrational frequencies obtained with the self‐consistent charge density functional tight‐binding (SCC‐DFTB) method. Our testing set comprises 66 molecules and 1304 distinct vibrational modes. Harmonic vibrational frequencies are computed using an efficient analytical algorithm developed and coded by the authors. The obtained results are compared to experiment and to other theoretical findings. Scaling factor for the SCC‐DFTB method, determined by minimization of mean absolute deviation of scaled frequencies, is found to be 0.9933. The accuracy of the scaled SCC‐DFTB frequencies is noticeably better than for other semiempirical methods (including standard DFTB method) and approximately twice worse than for other well established scaled ab initio quantum chemistry methods (e.g., HF, BLYP, B3LYP). Mean absolute deviation for the scaled SCC‐DFTB frequencies is 56 cm−1, while standard deviation is 82 cm−1, and maximal absolute deviation is as large as 529 cm−1. Using SCC‐DFTB allows for substantial time savings; computational time is reduced from hours to seconds when compared to standard ab initio techniques. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1858–1864, 2004
Brood care in freshwater crayfish and relationship with the offspring's sensory deficiencies
Authors: Vogt Günter , Tolley Laura
Published: September 2004

Prolonged brood care is one of the evolutionary clues for the successful colonization of freshwater habitats by freshwater crayfish (Astacida). By means of macrophotography, light microscopy, and scanning electron microscopy we investigated all phases of brood care in freshwater crayfish, with particular emphasis on the morphological structures involved. We selected the recently discovered parthenogenetic marbled crayfish (species identity not yet known) as a model organism due to its fast reproduction and high resistance to handling stress. In order to examine if there is a causal relationship between brood care and the developmental status of the offspring's sensory apparatus, we additionally investigated major sense organs of juvenile Stages 1–5 in comparison with those of the adults. Brood care in the marbled crayfish is characterized by initial and final “active” phases dominated by specific maternal or juvenile behavior and a medial “passive” phase based more on the action of temporarily developed structures rather than on behavior. The most remarkable feature of this period, which includes permanent carrying of the eggs and the first two juvenile stages under the mother's abdomen, is safeguarding of hatching by a telson thread that keeps the helpless newborn hatchlings linked to the egg cases on the maternal pleopods and thus prevents them from being lost. Further important transient structures are the recurved hooks on the first pereiopods of Stage 1 and 2 juveniles that are used to firmly attach these nonfeeding stages to the mother's abdomen. In hatchlings all sense organs necessary for an independent life, such as eyes, olfactory aesthetascs, gustatory fringed setae, hydrodynamic receptor hairs, and statocysts are not developed or are underdeveloped, making brood care indispensable. Most of these sense organs appear in Stage 2 juveniles, but only from Stage 3, the first freelancing and feeding stage, are all sense organs well developed and operating, thus reducing brood care in this final period to temporary provisioning of shelter. Brooding of the eggs and postembryonic brood care are to some extent also found in other freshwater Decapoda like freshwater crabs and aeglid anomurans, but safeguarding of hatching is confined to the Astacida only. This sophisticated mode of passive brood care is unique in the animal kingdom and is apparently related to the sensory deficiencies of the first juvenile stage. J. Morphol. 262:566–582, 2004. © 2004 Wiley‐Liss, Inc.
Morphology of the kidney in the West African caecilian, Geotrypetes seraphini (Amphibia, Gymnophiona, Caeciliidae)
Authors: Møbjerg N. , Jespersen Å. , Wilkinson M.
Published: September 2004

This study deals with the morphology and ultrastructure of the mesonephros in adult caecilians of the species Geotrypetes seraphini. Based on serial sections in paraffin and araldite, nephrons are reconstructed and the cellular characteristics of different nephron segments described. The long and slender mesonephric kidneys of G. seraphini are broadest caudally and taper toward the front, where the organs are divided into smaller segmental divisions. Two nephron types can be distinguished on the basis of their connections to the coelom and their position within the nephric tissue: ventral nephrons connect to the coelom via a ciliated peritoneal funnel, whereas medial nephrons lack this connection. Both nephron types are composed of a filtration unit, the Malpighian corpuscle, and a renal tubule, which can be divided into six morphologically distinct segments: neck segment, proximal tubule, intermediate segment, early distal tubule, late distal tubule, and collecting tubule. Collecting tubules merge and form a branch system that opens into collecting ducts. Collecting ducts empty into the Wolffian duct. Proximal tubules of nephrons in the frontal divisions are morphologically different from the proximal tubules of more caudal kidney regions. Distal tubule subdivision is only clearly recognizable at the electron microscopic level. The length of each nephron segment is calculated from a ventral nephron with a total length of ∼3.8 mm, and the course of the segments within the nephric tissue is reported. The number of nephrons was estimated at 1,700 units in each kidney. The segmentation and ultrastructure of the mesonephric nephrons in G. seraphini are discussed in relation to nephron descriptions from other caecilians and we further discuss the evolutionary origin of the amphibian nephron. J. Morphol. 262:583–607, 2004. © 2004 Wiley‐Liss, Inc.
Renal organs of cephalopods: A habitat for dicyemids and chromidinids
Authors: Furuya Hidetaka , Ota Mitsunori , Kimura Ritsuko , Tsuneki Kazuhiko
Published: September 2004

The renal organs of 32 species of cephalopods (renal appendage of all cephalopods, and renal and pancreatic appendages in decapods) were examined for parasite fauna and for histological comparison. Two phylogenetically distant organisms, dicyemid mesozoans and chromidinid ciliates, were found in 20 cephalopod species. Most benthic cephalopods (octopus and cuttlefish) were infected with dicyemids. Two pelagic cephalopod species, Sepioteuthis lessoniana and Todarodes pacificus, also harbored dicyemids. Chromidinid ciliates were found only in decapods (squid and cuttlefish). One dicyemid species was found in branchial heart appendages of Rossia pacifica. Dicyemids and chromidinids occasionally occurred simultaneously in Euprymna morsei, Sepia kobiensis, S. peterseni, and T. pacificus. The small‐sized cephalopod species, Idiosepius paradoxus and Octopus parvus, harbored no parasites. Comparative histology revealed that the external surface of renal organs varies morphologically in various cephalopod species. The small‐sized cephalopod species have a simple external surface. In contrast, the medium‐ to large‐sized cephalopod species have a complex external surface. In the medium‐ to large‐sized cephalopod species, their juveniles have a simple external surface of the renal organs. The external surface subsequently becomes complicated as they grow. Dicyemids and chromidinids attach their heads to epithelia or insert their heads into folds of renal appendages, pancreatic appendages, and branchial heart appendages. The rugged and convoluted external surface provides a foothold for dicyemids and chromidinids with a conical head. They apparently do not harm these tissues of their host cephalopods. J. Morphol. 262:629–643, 2004. © 2004 Wiley‐Liss, Inc.
Ontogeny of the palatoquadrate and adjacent lateral cranial wall of the endocranium in prehatching Alligator mississippiensis (Archosauria: Crocodylia)
Authors: Klembara Jozef
Published: September 2004

The purpose of this article is to gain insight into the ossification sequence of the palatoquadrate and the adjacent lateral cranial wall of prehatching Alligator mississippiensis, a process about which there is almost no published information. Results were obtained by studying serial histological sections of the series of ontogenetic stages and enlarged wax‐plate models of several stages. The cartilage of the palatoquadrate starts to ossify endochondrally in the quadrate portion of the pars pterygoquadrata palatoquadrati in Stage 6A. In this stage, a bone, called the lamina palatoquadrati anterior here, appears at and close to the anteromedial wall of the cartilaginous pterygoid portion of the pars pterygoquadrata. The lamina palatoquadrati anterior ossifies in membrane. Later in ontogeny, the lamina palatoquadrati anterior spreads into the cavum epiptericum and sheathes the posterior portion of the trigeminal ganglion laterally. The jaw adductor muscles insert at the outer surface of the lamina palatoquadrati anterior. The lamina palatoquadrati anterior is a new structure not previously recorded in crocodylians or any other Recent reptile. The topology, mode of ossification, and functional anatomy of the lamina palatoquadrati anterior correspond to those of the membranous ossification of the alisphenoid of marsupials. Another bone, called the lamina prootici anterior here, spreads in membrane from the anterolateral wall of the prootic portion of the otic capsule into the prootic fenestra, above the trigeminal ganglion. The lamina prootici anterior represents a structure not recorded previously in crocodylians. It contributes to the orbitotemporal braincase wall. J. Morphol. 262:644–658, 2004. © 2004 Wiley‐Liss, Inc.
Structure of long bones in mammals
Authors: Locke Michael
Published: September 2004

Techniques for staining (silver, osmium, metal sulfides, ink) and microphotography (epi‐illumination) of polished bone surfaces have been developed to visualize the three‐dimensional structure of the shafts of mammalian long bones. Bone is a two‐compartment system with capillaries and some kinds of connective tissue in one compartment separated from fibers of bone collagen, often forming lamellae, in the other. Laminar bone consists of stacks of lamellae separated by vascular spaces containing capillary network sheets. It is deposited at the periosteal and endosteal surfaces. Osteonic bone, well described in the literature, consists of cylinders of lamellae with central vascular spaces. The primary structure of the shafts of mammalian long bones is laminar and laminae often remain as the main component. Secondary osteons are a replacement within laminae. As laminar bones mature, some of the irregular longitudinal capillary spaces in the network sheets enlarge and become less crooked to form secondary osteons. Parts of the random networks become ordered longitudinal ones, resulting in collapse of those network spaces not converted to osteons. The residual capillaries become bloodless, making the surviving network spaces difficult to resolve. This may account for them being overlooked in descriptions of bone structure. For example, laminar bone occurs with osteonic bone in the human femur, although it is rarely figured. Nearly mature bones switch the kind of primary bone deposited at the peripheral (periosteal) surface from laminar to primary osteonic. J. Morphol. 262:546–565, 2004. © 2004 Wiley‐Liss, Inc.
Comparative vibrational analysis of thyronine hormones using infrared and Raman spectroscopy and density functional theory calculations
Authors: Álvarez Rosa M. S. , Farías Ricardo N. , Hildebrandt Peter
Published: September 2004

The molecular structures of L‐thyroxine (T4), 3,5,3′‐triiodo‐L‐thyronine (T3) and 3,5‐diiodo‐L‐thyronine (T2) were investigated by means of vibrational spectroscopy and density functional theory calculations using the B3LYP hybrid functional and the SDD effective core potential basis set, suitable for heavy atoms. The experimental data were obtained from FT‐IR and Raman spectra of the thyroid hormones in the crystalline state. The combined experimental and theoretical approach allows a consistent assignment for most of the fundamental modes in the range between 100 and 1650 cm−1. It was found that, in general, the modes are largely localized in the individual rings and in the linkage connecting both rings. Hence it was possible to identify bands that are dominated by the internal coordinates of the ether bridge and the CI stretchings. These bands are considered to be sensitive spectral markers for monitoring conformational changes of the hormones after insertion into phospholipid bilayers. Copyright © 2004 John Wiley & Sons, Ltd.
Optimization of a high‐performance liquid chromatography system by artificial neural networks for separation and determination of antioxidants
Authors: Wang Huaiwen , Liu Weimin
Published: September 2004

A high‐performance liquid chromatography (HPLC) system was used to determine the antioxidants tert‐butyl‐hydroquinone (TBHQ), tert‐butylhydroxyanisole (BHA), and 3,5‐di‐tert‐butylhydroxytoluene (BHT) simultaneously in oils. The paper presents a new methodology for the optimized separation of antioxidants in oils based on the coupling of experimental design and artificial neural networks. The orthogonal design and the artificial neural networks with extended delta‐bar‐delta (EDBD) learning algorithm were employed to design the experiments and optimize the variables. The response function (Rf) used was a weighted linear combination of two variables related to separation efficiency and retention time, according to which the optimized conditions were obtained. The above‐mentioned antioxidants in rapeseed oils were separated and determined simultaneously under optimized conditions by HPLC with UV detection at 280 nm. Linearity was obtained over the range of 10–200 μg/mL with recoveries of 98.3% (TBHQ), 98.1% (BHT), and 96.2% (BHA).
Preparation and characterization of alkylated polymethacrylate monolithic columns for micro‐HPLC of proteins
Authors: Li Yan , Zhang Jian , Xiang Rong , Yang Yanhui , Horváth Csaba
Published: September 2004

Protein separations were carried out by micro‐high performance liquid chromatography (micro‐HPLC) with surface alkylated monolithic columns, which were prepared by in situ copolymerization of glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) in the presence of dodecanol and toluene as porogens. First, glycidyl groups at the surface of the porous monolith were hydrolyzed with sulfuric acid. The hydroxyl groups thus formed were then reacted with n‐alkyl chloride to form alkylated stationary phase. Separation performance for proteins on columns with C18 and C8 stationary phases was compared. The results showed that a poly(GMA‐EGDMA) support derivatized with octadecyl moieties could achieve much better resolution than one with octyl groups. A protein mixture was separated with the octadecylated poly‐(GMA‐EGDMA) monolithic column, and the effluent peaks were collected and analyzed by matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI‐TOF MS). The physical properties of the monolithic columns such as column morphology, surface area, mesopore size distribution, and column permeability were further characterized by scanning electron microscopy (SEM), multipoint BET nitrogen adsorption/desorption, and Darcy's law, respectively.
Deterrmination of anthocyanins and related components in red wines by micro‐ and capillary HPLC
Authors: Dugo Paola , Favoino Olinda , Lo Presti Maria , Luppino Rosario , Dugo Giovanni , Mondello Luigi
Published: September 2004

Anthocyanins and derived components of red wines were determined by microHPLC using a 1 mm ID HPLC column coupled on‐line with an MS detector equipped with an ESI (ElectroSpray Ionisation) source. The use of microcolumn HPLC greatly enhanced detection performance, allowing direct identification of components present in the fraction. Nineteen anthocyanins were detected. Fifteen were identified, two were tentatively identified, and only the aglycon of the remaining two components was certainly identified. Six anthocyanin‐derived pigments, supposedly formed during wine maturation, were also investigated and found in a wine sample. The analysis of red wine anthocyanins was also carried out by injecting a large sample volume onto a 0.32 mm ID HPLC column, using the column focusing technique, in order to decrease the limit of detection and quantification of components present in a very small amounts.
Organic polymer monoliths as stationary phases for capillary HPLC
Authors: Svec Frantisek
Published: September 2004

Modern rigid porous polymer monoliths were conceived as a new class of stationary phases in classical columns in the early 1990s and later extended to the capillary format. These monolithic materials are typically prepared using a simple molding process carried out within the confines of the capillary. Polymerization of a mixture comprising monomers, initiator, and porogenic solvent affords macroporous materials with large through‐pores that enable applications in a rapid flow‐through mode. Since all the mobile phase must flow through the monolith, convection considerably accelerates mass transport within the monolithic separation medium and improves the separations. As a result, monolithic columns perform well even at very high flow rates. Various mechanisms including thermally and UV initiated free radical polymerization as well as ring opening metathesis copolymerizations were demonstrated for the preparation of monolithic capillary columns. The versatility of these preparation techniques was demonstrated by their use with hydrophobic (styrene, divinylbenzene, butyl methacrylate, ethylene dimethacrylate), hydrophilic (2‐hydroxyethyl methacrylate, methacrylamide, methylenebisacrylamide), ionizable (vinylsulfonic acid, 2‐acrylamido‐2‐methyl‐propanesulfonic acid), and tailor‐made (norborn‐2‐ene, 1,4,4a,5,8,8a‐hexahydro‐1,4,5,8‐exo,endo‐dimethanonaphthalene) monomers. Variation of polymerization conditions enables control of the porous properties of the monolith over a broad range and mediates the hydrodynamic properties of the monolithic columns. The applications of polymer‐based monolithic capillary columns are demonstrated for numerous separations in the μHPLC mode.
Separation, pre‐concentration, and HPLC analysis of methylxanthines in urine samples
Authors: Zydroń Mirosława , Baranowski Jacek , Baranowska Irena
Published: September 2004

An SPE method, using RP18 phases, for the simultaneous extraction of caffeine, theobromine, theophylline, paraxanthine, 1‐methylxanthine, 3‐methylxanthine, 7‐methylxanthine, 1‐methyluric acid, 1,3‐dimethyluric acid, 1,7‐dimethyluric acid, and 1,3,7‐trimethyluric acid from urine has been developed. Besides a gradient HPLC system for the analysis of the compounds of interest on a LiChrosorb RP‐18 (7 μm) column with mobile phase containing 0.05% aq. solution of trifluoroacetic acid and acetonitrile has been elaborated. The procedure has been successfully applied to the analysis of methylxanthines and methyluric acids in urine of patients with chronic asthma treated with theophylline and in urine of healthy subjects.
Photon echoes in strong magnetic fields
Authors: Reshetov V A , Yevseyev I V
Published: September 2004

The polarization properties of photon echoes in strong
magnetic field, when the action of this field during the time of
propagation of the exciting pulses and the echo signal through the
resonant gaseous medium cannot be neglected, are studied
theoretically. The photon echo polarization in strong magnetic
field cannot be described by the polarization vector but rather by
the polarization matrix. The degree of the photon echo
polarization decreases with the increase of the magnetic field
strength. The dependence of the photon echo intensity on the
magnetic field strength was also analyzed numerically. In strong
magnetic field the fast oscillations of this intensity appear to
be damping and modulated by the slower ones. The spectrum of these
oscillations depend also on the spectra of the exciting pulses, so
that in case of small area of the first exciting pulse its
temporal shape may be reconstructed from the oscillations of the
echo intensity versus the magnetic field strength.
Analysis of the timing jitter of dispersion-managed solitons controlled by
filters
Authors: Sousa M H , Ferreira M F S
Published: September 2004

Using a variational approach, an exact analytical
expression is derived for the variance of the timing jitter of a
dispersion-managed soliton in the presence of lumped narrow-band
filters. The asymptotic timing jitter shows a linear dependence
with distance, which is in contrast with the cubic dependence in
the unfiltered case. We show that the suppression of the timing
can be achieved by choosing conveniently the position and the
strength of the optical filter.
High-contrast dark resonance in σ+ - σ- optical field
Authors: Kargapoltsev S V , Kitching J , Hollberg L , Taichenachev A V , Velichansky V L , Yudin V I
Published: September 2004

The amplitude of Λ resonance in alkali atoms is
limited by perturbing cycling transitions in the case of D2 line
or by existence of additional trapping states in the case of D1
line. We propose to eliminate these extra trapping states by using
two counter-propagating bichromatic fields of orthogonal circular
polarizations. The experiment is in accordance with the
theoretical proposal. The result refers to small-size cells and is
important for applications in miniaturized atomic clocks.
Nonlinear refractive index of ceramic laser media and perspectives of their
usage in a high-power laser-driver
Authors: Senatsky Yu , Shirakawa A , Sato Y , Hagiwara J , Lu J , Ueda K , Yagi H , Yanagitani T
Published: September 2004

At the recent years a technology of ceramic laser media
on the base of crystals with a cubic symmetry has been developed.
The perspective of the usage of ceramic materials in many
different applications including high - power short pulse lasers
stimulates the work on the systematic study of the properties of
these new laser media. A nonlinear refractive index, n2 was
studied for several garnet and sesquioxide laser ceramics using
Z-scan method. n2 indices in the range of (2-6) × 10-13
were measured for YAG, Y2O3, Lu2O3, and Sc2O3
ceramic samples. These data together with the other laser and
spectroscopic parameters of several Nd3+ and Yb3+ doped
crystals of a cubic symmetry were used to estimate the properties
of laser ceramics for the application in a high-power
pulsed-repetitive laser - driver for inertial confinement fusion
(ICF) program. A high heat conductivity of ceramic materials is a
profitable characteristic for this application as compared to
glasses, which are used now for experiments in ICF at single shots
regime. Compared to single crystals, ceramic elements provide
laser designers with a variety of new design options for the
projects of laser-drivers.
Polarization-independent wavelength conversion using a single-ring fiber
laser with a semiconductor optical amplifier
Authors: Xu Xiao-Feng , Wei Jue , Kang Zhu-Hui , Jiang Yun , Zhu Wei-Zhong , Gao Jin-Yue
Published: September 2004

Polarization-Independent Wavelength Conversion has been
demonstrated using four-wave mixing in a single-ring fiber laser
with a semiconductor optical amplifier. We developed a novel
scheme employing a reflecting fiber grating, in which widely
wavelength-tunable and counterpropagating pump waves are provided.
Optical properties of gold nanoparticles at laser radiation
wavelengths for laser applications in nanotechnology and medicine
Authors: Pustovalov V K , Babenko V A
Published: September 2004

Investigations of laser interaction with metal (gold)
nanoparticles is of a great interest for laser applications in
nanotechnology, engineering, and medicine. The first problem of
laser interaction is to determine the optical properties of metal
nanoparticles, that determines following photophysical and
photochemical processes. The calculation of efficiency factors of
absorption, scattering and extinction for spherical gold
nanoparticles with radiuses in the range 5-100 nm and for some
laser wavelengths is performed. The estimation of absorbed laser
radiation energy by gold nanoparticles, their maximal temperatures
and comparison with experimental data is made. The importance of
the use of correct values of optical parameters of nanoparticles
is demonstrated.
Laser-exited fluorescence from normal and abnormal human thyroid cells: a pilot study
Authors: Jaliashvili Z V , Medoidze T D , Melikishvili Z G , Mardaleishvili K M , Ramsden J J
Published: September 2004

The fluorescence spectra have been measured from endogenous (native) fluorophores in normal, diseased and tumor thyroid tissues. They were found to be sufficiently different for the technique to be used as the basis for tumor diagnosis.
Laser welding of HTSC ceramics
Authors: Mikhailova G N , Mikhailov B P , Troitskii A V
Published: September 2004

The technology of laser welding of high temperature
superconducting ceramics Bi(2223) was developed and investigated.
CW CO2 laser (λ = 10.6 μm) with maximum power
of 100 W was used as a source of laser radiation. Then thermal
annealing was applied for Bi(2223) phase repairing.
Microstructure, chemical and phase composition of material in the
welded field were investigated. Properties of HTSC ceramics were
fully repaired (T
c ≈ 110 K) at optimal
conditions of laser welding and thermal annealing. Proposed method
opens wide capabilities for formation the reliable mechanical and
electrical contacts between different constructive elements of
HTSC ceramics devices having large dimensions or complex shape.
Impact of tacrolimus versus cyclosporine in hepatitis C virus-infected liver transplant recipients on recurrent hepatitis: A prospective, randomized trial
Authors: Martin Paul , Busuttil Ronald W. , Goldstein Robert M. , Crippin Jeffrey S. , Klintmalm Goran B. , Fitzsimmons William E. , Uleman Carol
Published: September 2004

Hepatitis C virus (HCV)-induced cirrhosis is the commonest indication for orthotopic liver transplantation, but HCV recurrence is nearly universal and may worsen patient / graft outcomes. The frequency and severity of HCV recurrence has apparently increased in recent years, raising concern about a possible role for newer immunosuppression regimens in this increase, including potentially tacrolimus. We randomized 79 patients to receive tacrolimus or cyclosporine as primary immunosuppressant posttransplantation. A pathologist blinded to treatment reviewed serial liver biopsies. Month 12 cumulative probabilities of histological hepatitis C recurrence for tacrolimus- and cyclosporine-treated patients were .38 and .54 (P = .19) and failure / death were .25 and .28, respectively (P = .789). Although cyclosporine-treated patients had significantly larger increases in median serum HCV RNA levels (months 1, 6, and 12), no significant differences were observed between the two treatment arms in histologically-diagnosed HCV recurrence / survival rates. In conclusion, choice of calcineurin inhibitors does not impact severity of recurrent HCV. (Liver Transpl 2004;10:1258-1262.)
Fulminant and fatal gas gangrene of the stomach in a healthy live liver donor
Authors: Miller Charles , Florman Sander , Kim-Schluger Leona , Lento Patrick , De La Garza Julia , Wu Josephine , Xie Boxun , Zhang Wandi , Bottone Edward , Zhang David , Schwartz Myron
Published: September 2004

A 57-year-old male with a history of hypercholesterolemia and anxiety but otherwise in good health volunteered to donate the right lobe of his liver to his brother. The operation was performed uneventfully, without transfusion. Postoperatively he did well, until he developed tachycardia, profound hypotension, and coffee ground emesis on postoperative day 3. Despite resuscitative measures, he arrested and expired. Autopsy demonstrated gas gangrene of the stomach as the underlying cause of the hemorrhage and numerous colonies of Gram-positive bacilli were identified. Subsequent polymerase chain reaction (PCR) analysis identified these bacteria to be Clostridium perfringens (C. perfringens) type D. This patient’s death was devastating, both to his family and his medical team. The impact of his death has transcended that of an individual occurrence. In conclusion, herein we present the facts and discuss this extraordinary example of florid clostridial infection and toxin-mediated shock. It was completely unexpected and probably unpreventable, and its cause was almost inconceivable. (Liver Transpl 2004;10:1315-1319.)
Outcomes of liver transplantation in HIV-infected individuals: The impact of HCV and HBV infection
Authors: Norris Suzanne , Taylor Chris , Muiesan Paolo , Portmann Bernard C. , Knisely Alex S. , Bowles Matthew , Rela Mohamed , Heaton Nigel , O’Grady John G.
Published: September 2004

Liver transplantation (LT) in human immunodeficiency virus (HIV)-positive individuals is considered to be an experimental therapy with limited reported worldwide experience, and little long-term survival data. Published data suggest that the short-term outcome is encouraging in selected patients. Here, we report our experience in 14 HIV-infected liver allograft recipients, and compare outcomes between those coinfected with hepatitis C virus (HCV) and the non-HCV group. A total of 14 HIV-infected patients (12 male, 2 female, age range 26-59 years) underwent LT between January 1995 and April 2003. Indications for LT were HCV (n = 7), hepatitis B virus (HBV; n = 4), alcohol-induced liver disease (n = 2), and seronegative hepatitis (n = 1); 3 patients presented with acute liver failure. At LT, CD4 cell counts (T-helper cells that are targets for HIV) ranged from 124 to 500 cells/μL (mean 264), and HIV viral loads from <50 to 197,000 copies/mL. Nine of 12 patients were exposed to highly active antiretroviral therapy (HAART) before LT. In the non-HCV group (n = 7), all patients are alive, all surviving more than 365 days (range 668-2,661 days). No patient has experienced HBV recurrence, and graft function is normal in all 7 patients. However, 5 of 7 HCV-infected patients died after LT at 95-784 days (median 161 days). A total of 4 patients died of complications due to recurrent HCV infection and sepsis, despite antiviral therapy in 3 of them. A total of 3 patients experienced complications relating to HAART therapy. In conclusion, outcome of LT in HIV-infected patients with HBV or other causes of chronic liver disease indicates that LT is an acceptable therapeutic option in selected patients. However, longer follow-up in larger series is required before a conclusive directive can be provided for HCV / HIV coinfected patients requiring LT. (Liver Transpl 2004;10:1271-1278.)
The influence of portoenterostomy on transplantation for biliary atresia
Authors: Visser Brendan C. , Suh Insoo , Hirose Shinjiro , Rosenthal Philip , Lee Hanmin , Roberts John P. , Hirose Ryutaro
Published: September 2004

After portoenterostomy (PE) for biliary atresia (BA), many patients suffer progressive deterioration of liver function and ultimately require liver transplantation. We retrospectively reviewed a single center’s experience with pediatric liver transplantation for BA from 1988 to 2002. Sixty-six patients underwent 69 liver transplants for BA. Forty-two (63%) patients had previously undergone Kasai PE, 11 (17%) biliary appendicoduodenostomy (BAD), and 13 (20%) had no prior biliary drainage (NBD). The BAD procedure offered only short-term biliary drainage—the mean interval between PE and transplant was more than twice that for Kasai patients than for BAD patients (132 versus 49 weeks). The transplants included 11 cadaveric partial, 27 cadaveric whole, and 31 living related transplants. Three patients required retransplant. Prior PE did not increase the incidence of major perioperative complications or unplanned reexploration. After transplant, the 1-, 5-, and 10-year actuarial graft survival rates were 87%, 86%, and 80%, respectively. The 1-, 5-, and 10-year actuarial patient survival rates were 91%, 89%, and 83%. PE remains an important bridge to transplant. In conclusion, transplantation for BA offers excellent long-term graft and patient survival. (Liver Transpl 2004;10:1279-1286.)
Sirolimus-based immunosuppression for liver transplantation in the presence of extended criteria for hepatocellular carcinoma
Authors: Kneteman Norman M. , Oberholzer José , Al Saghier Mohammed , Meeberg Glenda A. , Blitz Maurice , Ma Mang M. , Wong Winnie W.S. , Gutfreund Klaus , Mason Andrew L. , Jewell Larry D. , Shapiro James A.M. , Bain Vincent G. , Bigam David L.
Published: September 2004

An increasing number of patients with hepatocellular carcinoma (HCC) are undergoing evaluation for listing for liver transplantation. Criteria for selection require ongoing review for suitability. A consecutive series of 40 patients with HCC within the standard Milan criteria (single tumors n = 19 <5 cm, or up to 3 tumors <3 cm) and beyond (Extended Criteria; single tumors n = 21 <7.5 cm, multiple tumors <5 cm) underwent liver transplant with a sirolimus-based immunosuppressive protocol designed to minimize exposure to calcineurin inhibitors and steroids. At 44.3 ± 19.3 months (mean ± standard deviation) follow-up, 1- and 4-year survivals (Kaplan-Meier) are 94.1 ± 5.7% and 87.4 ± 9.3%, in the Milan group, respectively, and 90.5 ± 6.4% and 82.9 ± 9.3% in the Extended Criteria group, respectively. Five patients died during follow-up, only 1 from recurrent HCC. Five tumor recurrences have occurred at median 17 (mean 22 ± 17) months posttransplant, 1 in the Milan group and 4 in the Extended Criteria group. Median survival in the patients with recurrent tumor is 42 months (mean 45 ± 25), and the median postrecurrence survival is 15.5 months (mean 23 ± 16). The rate of patients who were alive and free of tumor at 1 and 4 years is 94.1 ± 5.7% and 81.1 ± 9.9%, respectively, in the Milan group and is 90.5 ± 6.4% and 76.8 ± 10.5%, respectively, in the Extended Criteria group. Five patients had sirolimus discontinued for toxicity, while 24 of 35 surviving patients have sirolimus monotherapy immunosuppression. In conclusion, the Milan criteria for liver transplantation in the presence of HCC can be carefully extended without compromising outcomes. This sirolimus based immunosuppression protocol appears to have beneficial effects on tumor recurrence and survival with an acceptable rate of rejection and toxicity. (Liver Transpl 2004;10:1301-1311.)
One-year protocol liver biopsy can stratify fibrosis progression in liver transplant recipients with recurrent hepatitis C infection
Authors: Firpi Roberto J. , Abdelmalek Manal F. , Soldevila-Pico Consuelo , Cabrera Roniel , Shuster Jonathan J. , Theriaque Douglas , Reed Alan I. , Hemming Alan W. , Liu Chen , Crawford James M. , Nelson David R.
Published: September 2004

Determinants of progression to cirrhosis in hepatitis C virus (HCV) infection have been well described in the immunocompetent population but remain poorly defined in liver transplant (LT) recipients. This cohort study determines the factors contributing to the development of fibrosis and its rate of progression in the allograft. Predictive factors analyzed include: demographics, host and donor factors, surgery-related variables (cold and warm ischemia time), rejection episodes, cytomegalovirus infection (CMV), and immunosuppression. Over 12 years, 842 adult LTs were performed at our institution; 358 for the indication of HCV. A total of 264 patients underwent protocol liver biopsies at month 4 and yearly after LT. Using the modified Knodell system of Ishak for staging fibrosis, the median fibrosis progression rate was .8 units/year (P < .001). Rapid fibrosis progression (>.8 units/year) was best identified by liver histology performed at 1 year. Donor age > 55 years was associated with rapid fibrosis progression and development of cirrhosis (P < .001). In contrast, donor age < 35 years was associated with slower progression of fibrosis (P = .003). Risk factors for graft loss due to recurrent HCV included recipient age > 35 years (P = .01), donor age > 55 years (P = .005), and use of female donor allografts (P = .03). In conclusion, fibrosis progression in HCV-infected LT recipients occurs at a rate of .8 units/year. Increased donor age has a major impact on disease progression, graft failure, and patient survival. A liver biopsy performed at 1 year posttransplant can help identify those patients more likely to develop progressive disease and may allow better targeting of antiviral therapy. (Liver Transpl 2004;10:1240-1247.)
Reliability of histopathologic assessment for the differentiation of recurrent hepatitis C from acute rejection after liver transplantation†
Authors: Regev Arie , Molina Enrique , Moura Rosana , Bejarano Pablo A. , Khaled Amr , Ruiz Phillip , Arheart Kris , Berho Mariana , Drachenberg Cinthia B. , Mendez Patricia , O’Brien Christopher , Jeffers Lennox , Tzakis Andreas , Schiff Eugene R.
Published: September 2004

Histopathologic assessment is considered essential for the differentiation of recurrent hepatitis C (RHC) from acute cellular rejection (ACR) after liver transplantation (LT); however, there is limited information regarding its reliability. The aim of this study was to determine the interobserver and intraobserver agreement of the histopathologic diagnosis of RHC vs. ACR, and to determine the reliability of specific histopathologic features for the differentiation of RHC from ACR. Liver biopsy specimens from 105 consecutive patients transplanted for hepatitis C virus (HCV)-related liver disease were studied retrospectively. All the biopsies were performed for evaluation of abnormal liver enzymes within the 1st year after LT. The slides were blindly coded and assessed by 5 liver-transplant pathologists, practicing at 3 medical centers. The pathologists were asked to render a diagnosis, and determine the severity of the disease. Four of the pathologists were asked to determine the presence and severity of 36 histopathologic features. A total of 34 of the samples were then blindly resubmitted to each of the 4 pathologists to determine the intraobserver agreement. There was a slight agreement (κ = .12) among the 5 pathologists on the histopathologic diagnosis. All 5 pathologists were in agreement on the diagnosis of RHC in only 5 patients (5%) and on the diagnosis of ACR in only 2 patients (2%). The best agreement among any 4 pathologists was fair (κ = .20). Slight to moderate agreement occurred on the main histological features considered to be important in the diagnosis of ACR. Intraobserver agreement ranged from slight (κ = .19) to moderate (κ = .42) among 4 pathologists. In conclusion, the histopathologic differentiation of RHC from ACR after LT had relatively low interobserver and intraobserver agreement rates, and hence showed low reliability. Histopathologic assessment should be used cautiously for the differentiation of RHC from ACR post-LT. (Liver Transpl 2004;10:1233-1239.)
Liver transplantation without steroid induction in HIV-infected patients
Authors: Rafecas Antonio , Rufí Gabriel , Figueras Juan , Fabregat Juan , Xiol Xavier , Ramos Emilio , Torras Jaime , Lladó Laura , Serrano Teresa
Published: September 2004

Until recently, human immunodeficiency virus (HIV) infection was considered an absolute contraindication for liver transplantation in Spain. We present the first 4 cases of liver transplantation (LT) carried out in our center in patients infected with HIV and coinfected by the hepatitis C virus (HCV), immunosuppressed with cyclosporine A (CyA) and basiliximab, but without steroids. The 4 patients were male, with a mean age of 38.25 ± 4.5 years. Mean time of HIV infection was 114 ± 62.3 months and all patients were receiving highly active antiretroviral therapy (HAART). HCV genotypes of the 4 patients were 4, 1b, 1b, and 1a. Two patients were classified as Child-Turcotte-Pugh C (10 and 11 points), 1 was B (8 points), and the patient with hepatocellular carcinoma was A (5 points). Immunosuppression consisted of basiliximab and monotherapy with CyA. There were no postoperative infections. With a follow-up of 17 ± 8 months, all patients are alive. There was only 1 acute rejection episode, and this was solved with steroid pulses. Three patients showed HCV recurrence with enzymatic and histological changes and were treated with interferon and ribavirin. One patient had negative HCV-ribonucleic acid after 6 months of treatment. In conclusion, HIV infection should not be considered an absolute contraindication for liver transplantation. The evolution of this type of patients will probably depend on the HCV infection. Immunosuppression without steroids may reduce opportunistic infection. (Liver Transpl 2004;10:1320-1323.)