bluuebunny/crossref_metadata_2025_split huggingface dataset:
Principles and practice of HIV‐protease inhibitor pharmacoenhancement
Authors: Moyle GJ , Back D 
Published: July 2002

Continually maintaining maximally suppressive drug concentrations represents a key defence against the emergence of resistance. If drug levels fall and replication occurs, the opportunity for mutant virus to be selected occurs. It has been increasingly recognized that variability in the pharmacokinetics of antiretrovirals, particularly protease inhibitors (PIs), means that drug exposure is not always optimal, giving the virus a chance to replicate.A significant number of patients receiving PIs two or three times daily will have trough (Ctrough or Cmin) plasma concentrations, which are close to, or below, the plasma protein binding‐corrected inhibitory concentration (IC50 or IC95) during the dosing interval. It is primarily in this context that therapeutic drug monitoring of PIs has been proposed as an aid to patient management, to ensure that patients maintain adequate drug concentrations throughout the dosing interval. Ideally, an antiretroviral drug will have a pharmacokinetic (PK) profile that maintains drug levels well above the viral inhibitory concentration throughout the entire dosing interval.Beneficial drug–drug interactions have been shown to improve PI pharmacokinetics. Ritonavir (RTV) inhibits the key enzymes that limit the bioavailability or speed the metabolism of other PIs. It is therefore increasingly used for boosting and maintaining PI plasma concentrations. At low (100 mg twice a day) doses it acts as a pharmacoenhancer of indinavir (IDV), amprenavir, saquinavir, lopinavir and to a more limited degree nelfinavir. Using a pharmacoenhancer with a PI results in increased exposure to the PI, higher Cmin levels, and in most cases prolonged elimination half‐lives.The long‐term clinical benefits of PK enhancing are unknown as are the long‐term toxicities, although the incidence of nephrolithiasis with IDV appears increased when IDV is combined with low‐dose RTV in HIV‐infected patients. Head‐to‐head clinical comparisons of boosted PI regimens will help answer some of the questions that remain with regard to PK enhancement.
Hippocampal Volume and Glucose Metabolism in Temporal Lobe Epileptic Foci
Authors: Theodore William H. , Gaillard William D. , De Carli Charles , Bhatia Sanjiv , Hatta Junko 
Published: July 2002

Summary:  Purpose: Reports conflict on the relation of glucose metabolism to hippocampal volume in temporal lobe foci. Previous studies usually have used side‐side ratios rather than regional metabolic rates.Methods: We measured hippocampal volume and glucose metabolism in 37 patients with temporal epileptogenic zones identified by ictal video‐EEG telemetry. Metabolic rates were normalized to global brain mean.Results: Both 18‐fluoro‐2‐deoxyglucose‐PET and volumetric MRI lateralized the epileptic focus determined by ictal video‐EEG. There were significant correlations between left‐right metabolic asymmetry and hippocampal formation volume left‐right ratios. Comparisons between normalized metabolism and hippocampal formation volume, ignoring the side of the epileptic focus, showed significant relations between left hippocampal volume and left inferior lateral temporal metabolism, right hippocampus and right inferior mesial temporal, and left hippocampus and left inferior mesial temporal metabolism. In contrast, when normalized metabolism was compared with hippocampal volume in the epileptic focus, no relation was found.Conclusions: Our study suggests that the relation between hippocampal volume and glucose metabolism breaks down in epileptic foci and that hypometabolism is not dependent on neuronal loss. It is consistent with data suggesting that hypometabolism is an independent predictor of surgical outcome.
Polymerized complex synthesis and intergranular coupling of Bi-Pb-Sr-Ca-Cu-O superconductors characterized by complex magnetic susceptibility
Authors: Kakihana Masato , Yoshimura Masahiro , Mazaki Hiromasa , Yasuoka Hiroshi , Börjesson Lars 
Published: July 2002

Superconducting Bi-Pb-Sr-Ca-Cu-O ceramics have been synthesized by the polymerized complex method at the Bi1.8Pb0.2Sr2Ca2Cu3Oy, Bi1.6Pb0.4Sr2Ca2Cu3Oy and Bi1.68Pb0.32Sr1.75Ca1.82Cu2.83Oy compositions. The polymerized complex method includes three important major steps: (1) formation of stable citrate complexes uniformly dispersed into ethyleneglycol and water, (2) fabrication of polymerized complexes which are formed through dehydration (or esterification) between ethyleneglycol and metal-citrate complexes, and (3) pyrolysis of the polymerized complex precursor and the subsequent heat treatments for producing the Bi-Pb-Sr-Ca-Cu-O superconductor. The present technique offers more convenient and easier fabrication of (Bi,Pb)2Sr2Ca2Cu3Oy superconductors compared with other more elaborate preparation procedures based on wet-chemical techniques, as it eliminates many steps such as ageing, filtration, washing, and pH control. ‘‘X-ray-clean’’ (Bi,Pb)-2223 superconductors have been obtained for all the three compositions after sintering at 850 °C in air for 94–235 h, depending upon the nominal composition of the starting batch. Noticeable is that a small deficiency of Sr, Ca, and Cu relative to the ideal stoichiometric composition of the (Bi,Pb)2Sr2Ca2Cu3Oy significantly accelerates the formation of the (Bi,Pb)-2223 phase.
Complex magnetic susceptibility measurements show that Tc(onset) of the bulk (Bi,Pb)-2223 phase remains almost constant at around 108 K, independent of the compositions. However, it is stressed that low-level and/or amorphous impurity phases possibly concentrated on grain boundaries can have dramatic effects on the overall magnetic properties even for materials which look like very ‘‘clean’’ by x-ray diffraction. The best superconducting properties were obtained with samples with a nominal composition of Bi1.6Pb0.4Sr2Ca2Cu3Oy after sintering in air at 850 °C for 180–280 h. The onset temperature of superconducting transition obtained by complex susceptibility was 108.0 K and the transition width (10%–90%) of full diamagnetism was 5.2 K for a measuring field of 100 mOe.
State mixing and vibrational predissociation in large molecule van der Waals complexes: t
r
a
n
s-stilbene–X complexes where X=He, H2, Ne, and Ar
Authors: DeHaan David O. , Holton Alicia L. , Zwier Timothy S. 
Published: July 2002

We report a detailed study of vibrational predissociation and intramolecular–intermolecular state mixing in the first excited singlet state of trans-stilbene van der Waals complexes with helium, hydrogen, neon, and argon. We present evidence that the helium atom in stilbene–He and the H2 molecule in stilbene–H2 possess very low frequency van der Waals bending levels involving delocalization of the complexed species over both phenyl rings. In stilbene–He, the mode-selective, strong coupling of the out-of-plane phenyl ring modes with the pseudotranslation van der Waals modes leads to a dramatic, inhomogeneous broadening of the transitions to several times their breadth in in-plane vibrations. The observed dispersed fluorescence spectra give product state distributions and internal clock lifetime estimates which can only be made consistent with direct lifetime measurements by assuming extensive state mixing of the intramolecular levels with the van der Waals levels in which the states accessed by the laser are actually only about 30% intramolecular in character. We conclude that in these complexes the processes of intramolecular–intermolecular state mixing (static IVR) and vibrational predissociation are not independent processes but are
closely tied to one another. In fact, the vibrational product state distributions observed for the out-of-plane phenyl ring levels can best be interpreted as reflecting the percentage van der Waals character in the initially prepared state. In stilbene–H2 the mode selective coupling exhibits itself as a splitting of the out-of-plane transitions into a set of 5–6 closely spaced transitions separated by only about 1 cm−1. The sequence of transitions is suggestive of an in-plane potential for H2 motion which is nearly flat across the entire length of the stilbene molecule with a small barrier presented by the ethylenic carbons through which the H2 molecule can tunnel. Dispersed fluorescence spectra from these levels point to a two-tiered coupling scheme with the bound van der Waals levels. In contrast, the out-of-plane phenyl transitions in stilbene–Ne and stilbene–Ar possess unusual shifts, but the transitions are narrow once again. In these cases the complexed atom appears to be largely localized over a single phenyl ring.
State mixing and internal rotation predissociation in large-molecule van der Waals complexes: p-methyl-t
r
a
n
s-stilbene–X where X=He, H2
Authors: Zwier Timothy S. 
Published: July 2002

In this paper we extend our study of state mixing and predissociation in large-molecule van der Waals complexes by considering the p-methyl-trans-stilbene–X complexes where X He, H2. The addition of the methyl group in the para position makes the two phenyl rings inequivalent but does not significantly change the ν37 vibrational frequency. It also introduces internal rotation levels as an added source of low frequency transitions which can be coupled to the van der Waals modes. The p-methyl-trans-stilbene molecule possesses two clear progressions on which we focus much of our attention: an internal rotation progression 2e→3a1 →4e, and a progression in ν37 activity: 3a1,37103a2, 3720. The p-methyl–He transitions built on the internal rotor levels exhibit narrow rotational band contours. Internal rotation predissociation from these levels appears to be efficient. The transitions in the ν37 progression in p-methyl–He show both increasing breadth and decreasing shift as one increases the out-of-plane vibrational excitation. The band contour of the 3720 0a1 transition is very
similar in breadth and shape to the 3720 transition in stilbene–He. This broadening can only be accounted for by assuming, as we did in trans-stilbene–He, that the He atom can move almost freely between the two phenyl rings. The corresponding transitions in p-methyl–H2 are no longer split (as they were in stilbene–H2 ), but the dispersed fluorescence spectra from levels below the dissociation limit show less resonance fluorescence and more broadening. We argue that the states carrying the absorption strength from the ground state involve a H2 molecule localized on a single phenyl ring while background van der Waals levels built on lower lying vibrational levels are delocalized. The enhanced state mixing in p-methyl–X is a consequence of two factors. First, the reduced symmetry of the p-methyl–X complex makes coupling with all van der Waals states allowed. Second, the internal rotor levels act as added base levels on which stacks of van der Waals levels can be built, thus increasing the overall density of van der Waals states at a given energy.
Experimental and neoclassical electron heat transport in the LMFP regime for the stellarators W7-A, L-2, and W7-AS
Authors: Maassberg H. , Burhenn R. , Gasparino U. , Kühner G. , Ringler H. , Dyabilin K. S. 
Published: July 2002

The electron energy balance is analyzed for equivalent low-density electron cyclotron resonance heated (ECRH) discharges with highly peaked central power deposition in the stellarators W7-A [Plasma Phys. Controlled Fusion 28, 43 (1986)], L-2 [Proceedings of the 6th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Berchtesgaden, 1976 (International Atomic Energy Agency, Vienna, 1977), Vol. 2, p. 115] and W7-AS [Proceedings of the 9th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Baltimore, 1982 (International Atomic Energy Agency, Vienna, 1983), Vol. 3, p. 141]. Within the long mean-free path (LMFP) collisionality regime in stellarators, the neoclassical electron heat diffusivity χe can overcome the ‘‘anomalous’’ one. The neoclassical transport coefficients are calculated by the dkes code (Drift Kinetic Equation Solver) [Phys. Fluids 29, 2951 (1986); Phys. Fluids B 1, 563 (1989)] for these configurations, and the particle and energy fluxes are estimated based on measured density and temperature profiles.
Neoclassical transport in the LMFP regime is minimum in W7-A and maximum in L-2, the standard configurations in W7-AS are in between. The radial electric field is estimated from the ambipolarity condition of only neoclassical particle fluxes. For these types of discharges in the quite different stellarator configurations, only the ‘‘electron root’’ exists in the innermost region, and, at the outer radii, only the ‘‘ion root.’’ In the region where both roots are found, a rather narrow shear layer in the poloidal plasma rotation is expected. Especially for W7-AS, a significant improvement of the neoclassical confinement is predicted in the ‘‘electron root’’ region. On the ‘‘ion root’’ side of the predicted ‘‘shear layer,’’ both the neoclassical energy and particle fluxes agree quite well with the experimental findings. At outer radii, the neoclassical fluxes are much lower. The predicted improvement for the ‘‘electron root’’ region is not found experimentally.
Injecting drug use and blood‐borne viruses: a comparison of rural and urban Victoria, 1990–95
Authors: AITKEN CAMPBELL , BROUGH RODGER , CROFTS NICK 
Published: July 2002

AbstractMost studies of injecting drug users (IDUs) have included only urban IDUs; information about rural IDUs is scarce. Recognizing this, the Victorian Injecting Drug Users Cohort Study (VICS) recruited IDUs from rural Victoria as well as Melbourne (population 3.2 million in 1995), capital city of the state of Victoria, Australia. Examination of data collected from IDUs living in Melbourne and the Western District (largest city: Warrnambool, pop. 27 734) revealed numerous differences in behaviour and serology. The primary drug for most Western District IDUs was amphetamines while Melbourne IDUs preferred heroin. Injecting and sharing frequencies were much lower in the rural sample. Hepatitis C antibody prevalence at first test was significantly higher in Melbourne IDUs, although this was clearly related to the difference in primary drugs; conversely, incidence among Western District amphetamine injectors was 16.2 per 100 person‐years (py) (during 18.5 py), yet no conversions occurred in metropolitan amphetamine injectors in 29.8 py. Western District IDUs were less educated and more likely to be unemployed and of aboriginal descent than metropolitan IDUs. Variation between populations of Victorian IDUs has implications for the delivery of IDU‐related health services; of particular concern is the possibility that hepatitis C has been spreading relatively rapidly among rural IDUs.
Gastritis in the alcoholic: relationship to gastric alcohol metabolism and Helicobacter pylori
Authors: Lieber Charles S. 
Published: July 2002

AbstractChronic gastritis is common in the alcoholic. It is characterized by histological inflammation of the gastric mucosa and is associated with variable symptomatology. Its etiology is still the subject of debate. Recently, a new alcohol dehydrogenase isoenzyme, called sigma ADH, absent from the liver but predominant in the upper GI tract, has been fully characterized, its gene cloned, and it appears to play a major role in gastric ethanol metabolism. Indeed, it has now been established, both in vivo in experimental animals and in vitro in cultured human gastric cells, that alcohol is metabolized in the gastric mucosa, resulting in the production of acetaldehyde, a toxic metabolite. In addition, Helicobacter pylori infection is common in the alcoholic, resulting in the breakdown of urea to ammonia, another toxic product. A number of studies carried out over the last 40 years revealed that antibiotic treatment eradicates ammonia production and results in histological and symptomatic improvement in the majority of patients with alcoholic gastritis. Non‐invasive tests for the detection of H. pylori are now available which will facilitate the large scale studies needed to confirm whether, in H. pylori ‐positive patients, antibiotics should become routine treatment for alcoholic gastritis.
Non‐word repetition and grammatical morphology: normative data for children in their final year of primary school
Authors: Simkin Zoë , Conti‐Ramsden Gina 
Published: July 2002

AbstractIt is likely that tests of phonological short‐term memory (non‐word repetition) and grammatical morphology (past tense, third‐person singular) are clinical markers for specific language impairment (SLI). The study provides normative data on three specific tests covering the aforementioned areas for 100 children attending the final year of primary schooling (10–11 year olds). Data from typically developing age controls can be used to provide a benchmark against which to compare the ability of language‐impaired children. This is particularly important given that the transition from primary to secondary schooling is a key stage in a child's education.
Spectroscopic Contributions to the Understanding of Hemoglobin Function: Implications for Structural Biology
Authors: Shulman Robert G. 
Published: July 2002

AbstractStructural biology is based on the assumption that structural determinations will explain macromolecular function. To examine the basis of these proposals, the structure/function connections in hemoglobin have been examined. Presently the Monod, Wyman, Changeux (MWC) model of hemoglobin function has great validity. In this model, ligand‐binding affinities are linked to quaternary structure, and it has been shown that the model describes the function accurately to a high first approximation. To see how this understanding developed, we review two sets of experimental studies in 1970‐71 that supported the applicability of MWC to hemoglobin oxygen binding. One set of data from NMR and ligand binding kinetics supported the quaternary‐linked nature of binding required by the MWC model. The other approach, by Perutz, proposed a structural basis for MWC, by suggesting that in one quaternary structure the binding of oxygen broke a salt bridge that caused a lowered quaternary‐linked affinity. However, experiments since that time, mostly by X‐ray crystallography of deoxygenated hemoglobin, have failed to show salt bridges breaking upon ligation, whereas affinities have remained low. This pattern of results shows that the small energies responsible for ligand‐binding affinities and reaction rates have not been identified by discrete structural features. Rather, thermodynamic and kinetic data from a variety of spectroscopic studies have played the central role in establishing the MWC model for hemoglobin.
Signaling by the Respiratory Burst in Macrophages
Authors: Forman Henry Jay , Torres Martine 
Published: July 2002

AbstractDuring phagocytosis or stimulation with a wide variety of agents, macrophages and other phagocytic cells produce reactive oxygen species (ROS) through activation of a multicomponent NADPH oxidase. ROS production through related NADPH oxidases has recently been demonstrated in several other cell types. Furthermore, the physiological generation of ROS production has now been clearly implicated in activating signaling pathways resulting in a broad array of physiological responses from cell proliferation to gene expression and apoptosis. This brief review suggests that: 1) hydrogen peroxide and superoxide, but not the hydroxyl radical, function as second messengers; 2) antioxidant enzymes function in the “turn‐off” phase of signal transduction; 3) the chemistry of thiols is critical in redox signaling; and 4) the primary physiological role of the respiratory burst in macrophages may be in redox signaling rather than microbicidal activity.
Numerical solution of the scalar double-well problem allowing microstructure
Authors: Carstensen Carsten , Plecháč Petr 
Published: July 2002

The direct numerical solution of a non-convex variational problem (

P
P

) typically faces the difficulty of the finite element approximation of rapid oscillations. Although the oscillatory discrete minimisers are properly related to corresponding Young measures and describe real physical phenomena, they are costly and difficult to compute. In this work, we treat the scalar double-well problem by numerical solution of the relaxed problem (

R
P

RP

) leading to a (degenerate) convex minimisation problem. The problem (

R
P

RP

) has a minimiser

u
u

and a related stress field

σ
=
D

W

∗
∗

(
∇

u

)

\sigma = DW^{**}(\nabla {u})

which is known to coincide with the stress field obtained by solving (

P
P

) in a generalised sense involving Young measures. If

u
h

u_h

is a finite element solution,

σ
h

:=
D

W

∗
∗

(
∇

u

h

)

\sigma _h:= D W^{**}(\nabla {u}_h)

is the related discrete stress field. We prove a priori and a posteriori estimates for

σ
−

σ
h

\sigma -\sigma _h

in

L

4

/

3

(
Ω
)

L^{4/3}(\Omega )

and weaker weighted estimates for

∇

u

−
∇

u

h

\nabla {u}-\nabla {u}_h

. The a posteriori estimate indicates an adaptive scheme for automatic mesh refinements as illustrated in numerical experiments.
Maximum excursion and stopping time record-holders for the problem: Computational results
Authors: e Silva Tomás 
Published: July 2002

This paper presents some results concerning the search for initial values to the so-called

3
x
+
1

3x+1

problem which give rise either to function iterates that attain a maximum value higher than all function iterates for all smaller initial values, or which have a stopping time higher than those of all smaller initial values. Our computational results suggest that for an initial value of

n
n

, the maximum value of the function iterates is bounded from above by

n
2

f
(
n
)

n^2 f(n)

, with

f
(
n
)

f(n)

either a constant or a very slowly increasing function of

n
n

. As a by-product of this (exhaustive) search, which was performed up to

n
=
3
⋅

2

53

≈
2.702
⋅

10

16

n=3 \cdot 2^{53}\approx 2.702 \cdot 10^{16}

, the

3
x
+
1

3x+1

conjecture was verified up to that same number.
Quantum affine algebras at roots of unity
Authors: Chari Vyjayanthi , Pressley Andrew 
Published: July 2002

Let

U

q

(

g

^

)

U_{q}(\hat {\mathfrak {g}})

be the quantized universal enveloping algebra of the affine Lie algebra

g

^

\hat {\mathfrak {g}}

associated to a finite-dimensional complex simple Lie algebra

g

\mathfrak {g}

, and let

U

q

r
e
s

(

g

^

)

U_{q}^{\mathrm {res}}(\hat {\mathfrak {g}})

be the

C

[
q
,

q

−
1

]

\mathbb {C}[q,q^{-1}]

-subalgebra of

U

q

(

g

^

)

U_{q}(\hat {\mathfrak {g}})

generated by the

q
q

-divided powers of the Chevalley generators. Let

U

ϵ

r
e
s

(

g

^

)

U_{\epsilon }^{\mathrm {res}}(\hat {\mathfrak {g}})

be the Hopf algebra obtained from

U

q

r
e
s

(

g

^

)

U_{q}^{\mathrm {res}}(\hat {\mathfrak {g}})

by specialising

q
q

to a non-zero complex number

ϵ
\epsilon

of odd order. We classify the finite-dimensional irreducible representations of

U

ϵ

r
e
s

(

g

^

)

U_{\epsilon }^{\mathrm {res}}(\hat {\mathfrak {g}})

in terms of highest weights. We also give a “factorisation” theorem for such representations: namely, any finite-dimensional irreducible representation of

U

ϵ

r
e
s

(

g

^

)

U_{\epsilon }^{\mathrm {res}}(\hat {\mathfrak {g}})

is isomorphic to a tensor product of two representations, one factor being the pull-back of a representation of

g

^

\hat {\mathfrak {g}}

by Lusztig’s Frobenius homomorphism

F
r

^

ϵ

:

U

ϵ

r
e
s

(

g

^

)
→
U
(

g

^

)

\hat {\mathrm {Fr}}_{\epsilon }:U_{\epsilon }^{\mathrm {res}}(\hat {\mathfrak {g}})\to U(\hat {\mathfrak {g}})

, the other factor being an irreducible representation of the Frobenius kernel. Finally, we give a concrete construction of all of the finite-dimensional irreducible representations of

U

ϵ

r
e
s

(

s
l

^

2

)

U_{\epsilon }^{\mathrm {res}}(\hat {sl}_{2})

. The proofs make use of several interesting new identities in

U

q

(

g

^

)

U_{q}(\hat {\mathfrak {g}})

.