bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasminogen and Plasminogen Activators Protect against Renal Injury in Crescentic Glomerulonephritis
Authors: Kitching A. Richard , Holdsworth Stephen R. , Ploplis Victoria A. , Plow Edward F. , Collen Désiré , Carmeliet Peter , Tipping Peter G.
Published: July 2002

The plasminogen/plasmin system has the potential to affect the outcome of inflammatory diseases by regulating accumulation of fibrin and other matrix proteins. In human and experimental crescentic glomerulonephritis (GN), fibrin is an important mediator of glomerular injury and renal impairment. Glomerular deposition of matrix proteins is a feature of progressive disease. To study the role of plasminogen and plasminogen activators in the development of inflammatory glomerular injury, GN was induced in mice in which the genes for these proteins had been disrupted by homologous recombination. Deficiency of plasminogen or combined deficiency of tissue type plasminogen activator (tPA) and urokinase type plasminogen activator (uPA) was associated with severe functional and histological exacerbation of glomerular injury. Deficiency of tPA, the predominant plasminogen activator expressed in glomeruli, also exacerbated disease. uPA deficiency reduced glomerular macrophage infiltration and did not significantly exacerbate disease. uPA receptor deficiency did not effect the expression of GN. These studies demonstrate that plasminogen plays an important role in protecting the glomerulus from acute inflammatory injury and that tPA is the major protective plasminogen activator.
Type II and III Receptors for Immunoglobulin G (IgG) Control the Presentation of Different T Cell Epitopes from Single IgG-complexed Antigens
Authors: Amigorena Sebastian , Lankar Danielle , Briken Volker , Gapin Laurent , Viguier Mireille , Bonnerot Christian
Published: July 2002

T cell receptors on CD4+ lymphocytes recognize antigen-derived peptides presented by major histocompatibility complex (MHC) class II molecules. A very limited set of peptides among those that may potentially bind MHC class II is actually presented to T lymphocytes. We here examine the role of two receptors mediating antigen internalization by antigen presenting cells, type IIb2 and type III receptors for IgG (FcγRIIb2 and FcγRIII, respectively), in the selection of peptides for presentation to T lymphocytes. B lymphoma cells expressing recombinant FcγRIIb2 or FcγRIII were used to assess the presentation of several epitopes from two different antigens. 4 out of the 11 epitopes tested were efficiently presented after antigen internalization through FcγRIIb2 and FcγRIII. In contrast, the 7 other epitopes were efficiently presented only when antigens were internalized through FcγRIII, but not through FcγRIIb2. The capacity to present these latter epitopes was transferred to a tail-less FcγRIIb2 by addition of the FcγRIII-associated γ chain cytoplasmic tail. Mutation of a single leucine residue at position 35 of the γ chain cytoplasmic tail resulted in the selective loss of presentation of these epitopes. Therefore, the nature of the receptor that mediates internalization determines the selection of epitopes presented to T lymphocytes within single protein antigens.
Selective Expression of a Stable Cell Surface Molecule on Type 2 but Not Type 1 Helper T Cells
Authors: Xu Damo , Chan Woon Ling , Leung Bernard P. , Huang Fang-ping , Wheeler Rachel , Piedrafita David , Robinson John H. , Liew Foo Y.
Published: July 2002

T helper cell type 1 (Th1) and 2 (Th2) are central to immune regulation. However, no stable cell surface marker capable of distinguishing and separating these two subsets of CD4+ cells has yet been found. Using differential display PCR, we have identified a gene encoding a cell membrane bound molecule, originally designated ST2L, T1, DER4, or Fit, expressed constitutively and stably on the surface of murine Th2s, but not Th1s even after stimulation with a range of immunological stimuli. Antibody against a peptide derived from ST2L strongly and stably labeled the surface of cloned Th2s but not Th1s, and Th2s but not Th1s derived from naive T cells of ovalbumin T cell receptor–α/β transgenic mice. Three-color single cell flow cytometric analysis shows that cell surface ST2L coexpressed with intracellular interleukin (IL)-4, but not with interferon (IFN)-γ. The antibody selectively lysed Th2s in vitro in a complement-dependent manner. In vivo, it enhanced Th1 responses by increasing IFN-γ production and decreasing IL-4 and IL-5 synthesis. It induced resistance to Leishmania major infection in BALB/c mice and exacerbated collagen-induced arthritis in DBA/1 mice. Thus, ST2L is a stable marker distinguishing Th2s from Th1s and is also associated with Th2 functions. Hence, it may be a target for therapeutic intervention.
Physical and Functional Association of the Major Histocompatibility Complex Class I Heavy Chain α3 Domain with the Transporter Associated with Antigen Processing
Authors: Kulig Kimary , Nandi Dipankar , Bacik Igor , Monaco John J. , Vukmanovic Stanislav
Published: July 2002

CD8+ T lymphocytes recognize antigens as short, MHC class I-associated peptides derived by processing of cytoplasmic proteins. The transporter associated with antigen processing translocates peptides from the cytosol into the ER lumen, where they bind to the nascent class I molecules. To date, the precise location of the class I-TAP interaction site remains unclear. We provide evidence that this site is contained within the heavy chain α3 domain. Substitution of a 15 amino acid portion of the H-2Db α3 domain (aa 219-233) with the analogous MHC class II (H-2IAd) β2 domain region (aa 133-147) results in loss of surface expression which can be partially restored upon incubation at 26°C in the presence of excess peptide and β2-microglobulin. Mutant H-2Db (Db219-233) associates poorly with the TAP complex, and cannot present endogenously-derived antigenic peptides requiring TAP-dependent translocation to the ER. However, this presentation defect can be overcome through use of an ER targeting sequence which bypasses TAP-dependent peptide translocation. Thus, the α3 domain serves as an important site of interaction (directly or indirectly) with the TAP complex and is necessary for TAP-dependent peptide loading and class I surface expression.
Cd4+ T Cells from Lupus-Prone Mice Are Hyperresponsive to T Cell Receptor Engagement with Low and High Affinity Peptide Antigens
Authors: Vratsanos George S. , Jung Sungsoo , Park Yeong-Min , Craft Joe
Published: July 2002

Polyclonal CD4+ T cell activation is characteristic of spontaneous lupus. As a potential explanation for this phenotype, we hypothesized that T cells from lupus-prone mice are intrinsically hyperresponsive to stimulation with antigen, particularly to those peptide ligands having a low affinity for the T cell receptor (TCR). To test this hypothesis, we backcrossed the α and β chain genes of the AND TCR specific for amino acids 88–104 of pigeon cytochrome C (PCC) to the Fas-intact MRL/Mp+Fas-lpr and to the H-2k–matched control backgrounds B10.BR and CBA/CaJ (MRL.AND, B10.AND, and CBA.AND, respectively), and assessed naive CD4+ TCR transgenic T cell activation in vitro after its encounter with cognate antigen and lower affinity altered peptide ligands (APLs). MRL.AND T cells, compared with control B10.AND and CBA.AND cells, proliferated more when stimulated with agonist antigen. More strikingly, MRL.AND T cells proliferated significantly more and produced more interleukin 2 when stimulated with the APLs of PCC 88–104, having lower affinity for the transgenic TCR. These results imply that one of the forces driving polyclonal activation of α/β T cells in lupus is an intrinsically heightened response to peptide antigen, particularly those with low affinity for the TCR, independent of the nature of the antigen-presenting cell and degree of costimulation.
Legionella pneumophila Is Internalized by a Macropinocytotic Uptake Pathway Controlled by the Dot/Icm System and the Mouse Lgn1 Locus✪
Authors: Watarai Masahisa , Derre Isabelle , Kirby James , Growney Joseph D. , Dietrich William F. , Isberg Ralph R.
Published: July 2002

The products of the Legionella pneumophila dot/icm genes enable the bacterium to replicate within a macrophage vacuole. This study demonstrates that the Dot/Icm machinery promotes macropinocytotic uptake of L. pneumophila into mouse macrophages. In mouse strains harboring a permissive Lgn1 allele, L. pneumophila promoted formation of vacuoles that were morphologically similar to macropinosomes and dependent on the presence of an intact Dot/Icm system. Macropinosome formation appeared to occur during, rather than after, the closure of the plasma membrane about the bacterium, since a fluid-phase marker preloaded into the macrophage endocytic path failed to label the bacterium-laden macropinosome. The resulting macropinosomes were rich in GM1 gangliosides and glycosylphosphatidylinositol-linked proteins. The Lgn1 allele restrictive for L. pneumophila intracellular replication prevented dot/icm-dependent macropinocytosis, with the result that phagosomes bearing the microorganism were targeted into the endocytic network. Analysis of macrophages from recombinant inbred mouse strains support the model that macropinocytotic uptake is controlled by the Lgn1 locus. These results indicate that the products of the dot/icm genes and Lgn1 are involved in controlling an internalization route initiated at the time of bacterial contact with the plasma membrane.
Intracellular pH Regulation in Cultured Astrocytes from Rat Hippocampus
Authors: Bevensee Mark O. , Weed Regina A. , Boron Walter F.
Published: July 2002

We studied the regulation of intracellular pH (pHi) in single cultured astrocytes passaged once from the hippocampus of the rat, using the dye 2′,7′-biscarboxyethyl-5,6-carboxyfluorescein (BCECF) to monitor pHi. Intrinsic buffering power (βI) was 10.5 mM (pH unit)−1 at pHi 7.0, and decreased linearly with pHi; the best-fit line to the data had a slope of −10.0 mM (pH unit)−2. In the absence of HCO3−, pHi recovery from an acid load was mediated predominantly by a Na-H exchanger because the recovery was inhibited 88% by amiloride and 79% by ethylisopropylamiloride (EIPA) at pHi 6.05. The ethylisopropylamiloride-sensitive component of acid extrusion fell linearly with pHi. Acid extrusion was inhibited 68% (pHi 6.23) by substituting Li+ for Na+ in the bath solution. Switching from a CO2/HCO3−-free to a CO2/HCO3−-containing bath solution caused mean steady state pHi to increase from 6.82 to 6.90, due to a Na+-driven HCO3− transporter. The HCO3−-induced pHi increase was unaffected by amiloride, but was inhibited 75% (pHi 6.85) by 400 μM 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS), and 65% (pHi 6.55–6.75) by pretreating astrocytes for up to ∼6.3 h with 400 μM 4-acetamide-4′-isothiocyanatostilbene-2,2′-disulfonic acid (SITS). The CO2/HCO3−-induced pHi increase was blocked when external Na+ was replaced with N-methyl-d-glucammonium (NMDG+). In the presence of HCO3−, the Na+-driven HCO3− transporter contributed to the pHi recovery from an acid load. For example, HCO3− shifted the plot of acid-extrusion rate vs. pHi by 0.15–0.3 pH units in the alkaline direction. Also, with Na-H exchange inhibited by amiloride, HCO3− increased acid extrusion 3.8-fold (pHi 6.20). When astrocytes were acid loaded in amiloride, with Li+ as the major cation, HCO3− failed to elicit a substantial increase in pHi. Thus, Li+ does not appear to substitute well for Na+ on the HCO3− transporter. We conclude that an amiloride-sensitive Na-H exchanger and a Na+-driven HCO3− transporter are the predominant acid extruders in astrocytes.
Hopf algebras of types 𝑈_{𝑞}(𝑠𝑙_{𝑛})’ and 𝑂_{𝑞}(𝑆𝐿_{𝑛})’ which give rise to certain invariants of knots, links and 3-manifolds
Authors: Gelaki Shlomo , Westreich Sara
Published: July 2002

In this paper we determine when Lusztig’s

U
q

(
s

l
n

)
′

U_q(sl_n)’

has all the desired properties necessary to define invariants of knots, links and 3-manifolds. Specifically, we determine when it is ribbon, unimodular and factorizable. We also compute the integrals and distinguished elements involved.
Values of Gaussian hypergeometric series
Authors: Ono Ken
Published: July 2002

Let

p
p

be prime and let

G
F
(
p
)

GF(p)

be the finite field with

p
p

elements. In this note we investigate the arithmetic properties of the Gaussian hypergeometric functions
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="Subscript 2 Baseline upper F 1 left-parenthesis x right-parenthesis equals Subscript 2 Baseline upper F 1 left-parenthesis StartLayout 1st Row 1st Column phi comma 2nd Column a m p semicolon phi 2nd Row 1st Column Blank 2nd Column a m p semicolon epsilon EndLayout vertical-bar x right-parenthesis and Subscript 3 Baseline upper F 2 left-parenthesis x right-parenthesis equals Subscript 3 Baseline upper F 2 left-parenthesis StartLayout 1st Row 1st Column phi comma 2nd Column a m p semicolon phi comma 3rd Column a m p semicolon phi 2nd Row 1st Column Blank 2nd Column a m p semicolon epsilon comma 3rd Column a m p semicolon epsilon EndLayout vertical-bar x right-parenthesis comma">

2

F

1

(
x
)

=

2

F

1

(

ϕ
,

a
m
p
;
ϕ

a
m
p
;
ϵ

|

x
)

and

3

F

2

(
x
)

=

3

F

2

(

ϕ
,

a
m
p
;
ϕ
,

a
m
p
;
ϕ

a
m
p
;
ϵ
,

a
m
p
;
ϵ

|

x
)

,

\begin{equation*} _{2}F_{1}(x) = _{2}F_{1} \left ( \begin {matrix}\phi , & \phi \\ & \epsilon \end{matrix} | x \right ) \;\;\text {and}\;\; _{3}F_{2}(x)= _{3}F_{2} \left ( \begin {matrix}\phi , & \phi , & \phi \\ & \epsilon , & \epsilon \end{matrix} | x \right ), \end{equation*}

where

ϕ
\phi

and

ϵ
\epsilon

respectively are the quadratic and trivial characters of

G
F
(
p
)

GF(p)

. For all but finitely many rational numbers

x
=
λ

x=\lambda

, there exist two elliptic curves

2

E

1

(
λ
)

_{2}E_{1}(\lambda )

and

3

E

2

(
λ
)

_{3}E_{2}(\lambda )

for which these values are expressed in terms of the trace of the Frobenius endomorphism. We obtain bounds and congruence properties for these values. We also show, using a theorem of Elkies, that there are infinitely many primes

p
p

for which

2

F

1

(
λ
)

_{2}F_{1}(\lambda )

is zero; however if

λ
≠
−
1
,
0
,

1
2

\lambda \neq -1,0, \frac {1}{2}

or

2
2

, then the set of such primes has density zero. In contrast, if

λ
≠
0

\lambda \neq 0

or

1
1

, then there are only finitely many primes

p
p

for which

3

F

2

(
λ
)
=
0

_{3}F_{2}(\lambda ) =0

. Greene and Stanton proved a conjecture of Evans on the value of a certain character sum which from this point of view follows from the fact that

3

E

2

(
8
)

_{3}E_{2}(8)

is an elliptic curve with complex multiplication. We completely classify all such CM curves and give their corresponding character sums in the sense of Evans using special Jacobsthal sums. As a consequence of this classification, we obtain new proofs of congruences for generalized Apéry numbers, as well as a few new ones, and we answer a question of Koike by evaluating

3

F

2

(
4
)

_{3}F_{2}(4)

over every

G
F
(
p
)

GF(p)

.
Bayesian adaptive sequence alignment algorithms.
Authors: Zhu J , Liu J S , Lawrence C E
Published: July 2002

The selection of a scoring matrix and gap penalty parameters continues to be an important problem in sequence alignment. We describe here an algorithm, the 'Bayes block aligner, which bypasses this requirement. Instead of requiring a fixed set of parameter settings, this algorithm returns the Bayesian posterior probability for the number of gaps and for the scoring matrices in any series of interest. Furthermore, instead of returning the single best alignment for the chosen parameter settings, this algorithm returns the posterior distribution of all alignments considering the full range of gapping and scoring matrices selected, weighing each in proportion to its probability based on the data. We compared the Bayes aligner with the popular Smith-Waterman algorithm with parameter settings from the literature which had been optimized for the identification of structural neighbors, and found that the Bayes aligner correctly identified more structural neighbors. In a detailed examination of the alignment of a pair of kinase and a pair of GTPase sequences, we illustrate the algorithm's potential to identify subsequences that are conserved to different degrees. In addition, this example shows that the Bayes aligner returns an alignment-free assessment of the distance between a pair of sequences.
Identifying good diagnostic gene groups from
gene expression profiles using the concept of
emerging patterns
Authors: Li Jinyan , Wong Limsoon
Published: July 2002

Motivations and Results: Gene groups that are significantly related to a disease can be detected by conducting a series of gene expression experiments. This work is aimed at discovering special types of gene groups that satisfy the following property. In each group, its member genes are found to be one-to-one contained in pre-determined intervals of gene expression level with a large frequency in one class of cells but are never found unanimously in these intervals in the other class of cells. We call these gene groups emerging patterns, to emphasize the patterns' frequency changes between two classes of cells. We use effective discretization and gene selection methods to obtain the most discriminatory genes. We also use efficient algorithms to derive the patterns from these genes. According to our studies on the ALL/AML dataset and the colon tumor dataset, some patterns, which consist of one or more genes, can reach a high frequency of 90%, or even 100%. In other words, they nearly or fully dominate one class of cells, even though they rarely occur in the other class. The discovered patterns are used to classify new cells with a higher accuracy than other reported methods. Based on these patterns, we also conjecture the possibility of a personalized treatment plan which converts colon tumor cells into normal cells by modulating the expression levels of a few genes.

Contact: jinyan@krdl.org.sg; limsoon@krdl.org.sg

* To whom correspondence should be addressed.
Continuation and maintenance therapy in depression
Authors: Paykel E S
Published: July 2002

This paper reviews longer term treatment for unipolar depression. Antidepressant continuation for prevention of early relapse has been routine for many years. Recent evidence supports a longer period of 9 months to 1 year after remission. Antidepressants are also effective in maintenance treatment for recurrent depression, and are indicated where there is clear risk of further episodes. Antidepressant withdrawal after continuation and maintenance should always be gradual, over a minimum of 3 months and longer after longer maintenance periods, to avoid withdrawal symptoms or rebound relapse. Trials of interpersonal therapy in the prevention of recurrence show some benefit, but effects are weaker than those of drug and additional benefit in combination is limited. There is better evidence for effects of cognitive therapy in preventing relapse and an emerging indication for its addition to antidepressants, particularly where residual symptoms are present.
Simulations of neuromuscular control in lamprey swimming
Authors: Ekeberg Örjan , Grillner Sten
Published: July 2002

The neuronal generation of vertebrate locomotion has been extensively studied in the lamprey. Models at different levels of abstraction are being used to describe this system, from abstract nonlinear oscillators to interconnected model neurons comprising multiple compartments and a Hodgkin–Huxley representation of the most relevant ion channels. To study the role of sensory feedback by simulation, it eventually also becomes necessary to incorporate the mechanical movements in the models. By using simplifying models of muscle activation, body mechanics, counteracting water forces, and sensory feedback through stretch receptors and vestibular organs, we have been able to close the feedback loop to enable studies of the interaction between the neuronal and the mechanical systems. The neuromechanical simulations reveal that the currently known network is sufficient for generating a whole repertoire of swimming patterns. Swimming at different speeds and with different wavelengths, together with the performance of lateral turns can all be achieved by simply varying the brainstem input. The neuronal mechanisms behind pitch and roll manoeuvres are less clear. We have put forward a ‘crossed–oscillators’ hypothesis where partly separate dorsal and ventral circuits are postulated. Neuromechanical simulations of this system show that it is also capable of generating realistic pitch turns and rolls, and that vestibular signals can stabilize the posture during swimming.
Elastin as a self–organizing biomaterial: use of recombinantly expressed human elastin polypeptides as a model for investigations of structure and self–assembly of elastin
Authors: Keeley F. W. , Bellingham C. M. , Woodhouse K. A.
Published: July 2002

Elastin is the major extracellular matrix protein of large arteries such as the aorta, imparting characteristics of extensibility and elastic recoil. Once laid down in tissues, polymeric elastin is not subject to turnover, but is able to sustain its mechanical resilience through thousands of millions of cycles of extension and recoil. Elastin consists of
ca
. 36 domains with alternating hydrophobic and cross–linking characteristics. It has been suggested that these hydrophobic domains, predominantly containing glycine, proline, leucine and valine, often occurring in tandemly repeated sequences, are responsible for the ability of elastin to align monomeric chains for covalent cross–linking. We have shown that small, recombinantly expressed polypeptides based on sequences of human elastin contain sufficient information to self–organize into fibrillar structures and promote the formation of lysine–derived cross–links. These cross–linked polypeptides can also be fabricated into membrane structures that have solubility and mechanical properties reminiscent of native insoluble elastin. Understanding the basis of the self–organizational ability of elastin–based polypeptides may provide important clues for the general design of self–assembling biomaterials.
A variable speed translating couch technique for total body irradiation
Authors: Chrétien Mario , Côté Carl , Blais Roger , Brouard Lucie , Roy‐Lacroix Lise , Larochelle Marie , Roy René , Pouliot Jean
Published: July 2002

We have developed a variable speed translating patient couch system for the delivery of total body irradiation (TBI). For a whole body Rando‐type phantom, dose variation at mid‐plane relative to the prescription point (navel) can be as high as 15% (neck or legs) with a constant velocity. By taking into account variations in body thickness, the intensity modulation radiation therapy, resulting from variable velocities, effectively delivers a uniform dose distribution at mid plane. The couch control user interface, technical aspects and dose planning optimization procedure for determining velocity distribution are described.
Leaf position verification during dynamic beam delivery: A comparison of three applications using electronic portal imaging
Authors: Partridge Mike , Evans Philip M. , van Herk Marcel , Ploeger Lennert S. , Budgell Geoffrey J. , James Hayley V.
Published: July 2002

The use of a dynamic multileaf collimator (MLC) to deliver intensity‐modulated beams presents a problem for conventional verification techniques. The use of electronic portal imaging to track MLC leaves during beam delivery has been shown to provide a solution to this problem. An experimental comparison of three different verification systems, each using a different electronic portal imaging technology, is presented. Two of the systems presented are commercially available imagers with in‐house modifications, with the third system being an in‐house built experimental system. The random and systematic errors present in each of the verifications systems are measured and presented, together with the study of the effects of varying dose rate and leaf speed on verification system performance. The performance of the three systems is demonstrated to be very similar, with an overall accuracy in comparing measured and prescribed collimator trajectories of approximately Systematic errors in the percentage delivered dose signal provided by the accelerator are significant and must be corrected for good performance of the current systems. It is demonstrated that, with suitable modifications, commercially available portal imaging systems can be used to verify dynamic MLC beam delivery.
Control of oral closure in lingual stop consonant production
Authors: Löfqvist Anders , Gracco Vincent L.
Published: July 2002

Previous work has shown that the lips are moving at a high velocity when the oral closure occurs for bilabial stop consonants, resulting in tissue compression and mechanical interactions between the lips. The present experiment recorded tongue movements in four subjects during the production of velar and alveolar stop consonants to examine kinematic events before, during, and after the stop closure. The results show that, similar to the lips, the tongue is often moving at a high velocity at the onset of closure. The tongue movements were more complex, with both horizontal and vertical components. Movement velocity at closure and release were influenced by both the preceding and the following vowel. During the period of oral closure, the tongue moved through a trajectory of usually less than 1 cm; again, the magnitude of the movement was context dependent. Overall, the tongue moved in forward–backward curved paths. The results are compatible with the idea that the tongue is free to move during the closure as long as an airtight seal is maintained. A new interpretation of the curved movement paths of the tongue in speech is also proposed. This interpretation is based on the principle of cost minimization that has been successfully applied in the study of hand movements in reaching.
Transporting objects without contact using flexural traveling waves
Authors: Hashimoto Yoshiki , Koike Yoshikazu , Ueha Sadayuki
Published: July 2002

Near-field acoustic levitation is successfully applied to transport objects without contact. Planar objects having a weight greater than 10 kgf can be stably levitated near a vibrating plate. An experimental apparatus has been fabricated to measure the transportation speed and transient characteristics.
Acoustic evidence for dynamic formant trajectories in Australian English vowels
Authors: Watson Catherine I. , Harrington Jonathan
Published: July 2002

The extent to which it is necessary to model the dynamic behavior of vowel formants to enable vowel separation has been the subject of debate in recent years. To investigate this issue, a study has been made on the vowels of 132 Australian English speakers (male and female). The degree of vowel separation from the formant values at the target was contrasted to that from modeling the formant contour with discrete cosine transform coefficients. The findings are that, although it is necessary to model the formant contour to separate out the diphthongs, the formant values at the target, plus vowel duration are sufficient to separate out the monophthongs. However, further analysis revealed that there are formant contour differences which benefit the within-class separation of the tense/lax monophthong pairs.
The Second Electroviscous Effect in Polymer Latices
Authors: Krieger Irvin M. , Eguiluz Miguel
Published: July 2002

Free electrolyte was removed by ion exchange from monodisperse polystyrene latex. Non-Newtonian viscosities were measured at volume fractions from 0.05 to 0.50, at various electrolyte concentrations. Electrolytes included HCl, K2SO4, MgSO4, Al2(SO)4)3, and Th(NO3)4. Deionized latices exhibited yield stresses τ0 which decreased with the diminishing volume fraction and with increasing electrolyte concentration. The effect of added electrolyte upon the viscosity of a freshly mixed dispersion depended upon its equivalent concentration (normality) and was independent of the chemical nature or valence types of the ions. Limiting viscosities η1 at high shear rates were independent of electrolyte content. At intermediate electrolyte levels, variation of shear stress τ with shear rate γ̇ followed Casson's equation τ1/2=τ01/2+η11/2γ̇1/2.
X-ray powder diffraction study of synthetic Palmierite, K2Pb(SO4)2
Authors: Tissot Ralph G. , Rodriguez Mark A. , Sipola Diana L. , Voigt James A.
Published: July 2002

Palmierite (K2Pb(SO4)2) has been prepared via a chemical synthesis method. Intensity differences were observed when X-ray powder data from the newly synthesized compound were compared to the published powder diffraction card (PDF) 29-1015 for Palmierite. Investigation of these differences indicated the possibility of preferred orientation and/or chemical inhomogeneity affecting intensities, particularly those of the basal (00l) reflections. Annealing of the Palmierite was found to reduce the effects of preferred orientation. Electron microprobe analysis confirmed K:Pb:S as 2:1:2 for the for the annealed Palmierite powder. Subsequent least-squares refinement and Rietveld analysis of the annealed powder showed peak intensities very close to that of a calculated Palmierite pattern (based on single crystal data), yet substantially higher than many of the PDF 29-1015 published intensities. Further investigation of peak intensity variation via calculated patterns suggested that the intensity discrepancies between the annealed sample and those found in PDF 29-1015 were potentially due to chemical variation in the K2Pb(SO4)2composition. X-ray powder diffraction and crystal data for Palmierite are reported for the annealed sample. Palmierite is trigonal/hexagonal with unit cell parametersa=5.497(1) Å,c=20.864(2) Å, space groupR-3m(166), andZ=3.
Grief as a Superpower
Authors: Daum Rachel
Published: November 2022

In this narrative medicine essay, a medical student’s first code blue ripped open the scab covering her unresolved grief for her father, who died when she was 5 years old, an experience that demonstrated how profoundly she loved her father.
FDG-PET Positivity and Overall Survival in Renal Cell Carcinoma
Authors: Ferdinandus Justin , Maríc Ines , Darr Christopher , Kesch Claudia , Bartel Timo , Fendler Wolfgang Peter , Grünwald Viktor
Published: November 2022

This cohort study examines positron emission tomography in renal cell carcinoma and its association with overall survival among adults.
Effect of source location on contaminant dispersion pattern and occupants inhaled air quality in lecture room under displacement ventilation
Authors: Essa Aya , Yamanaka Toshio , Kobayashi Tomohiro , Choi Narae
Published: November 2022

Displacement ventilation (DV) is considered an energy saving air conditioning system and is especially recommended for classrooms for providing cool clean air in the occupied zone. However, in the current pandemic situation, ventilation systems should be assessed in terms of infection‐spread prevention as well. Hence, this study aims at assessing the efficiency of displacement ventilation in minimizing infection spread in lecture halls through investigating the effect of source position on the contaminant concentration distribution. The settings of a mid‐size DV lecture hall in Osaka University, Japan was chosen as a case‐study. Ten single‐contaminant‐source cases were simulated using CFD software. The cases were analyzed in terms of temperature distribution, contaminant diffusion pattern and vertical distribution, and breathing air quality using indices, such as local air quality index and scale of ventilation efficiency. The results demonstrated a considerable variation between cases in terms of contaminant distribution pattern, number of occupants affected, average inhaled‐air quality, and diffusion radius. Accordingly, given the ventilation system design, best and worst case‐scenarios were pointed out and factors affecting the variation were highlighted and further investigated to conclude the impact of each factor.
Trade‐Off between Second‐ and Third‐Order Nonlinearities, Ultrafast Free Carrier Absorption and Material Damage in Silicon Nanoparticles
Authors: Rudenko Anton , Han Aoxue , Moloney Jerome V.
Published: November 2022

Reaching the optimal second‐ and third‐order nonlinear conversion efficiencies while avoiding undesirable free carrier absorption losses and material damage in ultrashort laser‐excited nanostructures is a challenging obstacle in all‐dielectric ultrafast nanophotonics. In order to elucidate the main aspects of this problem, a multi‐physical model is developed, coupling nonlinear Maxwell equations supplied by surface and bulk nonlinearities with free carrier hydrodynamic equations for electron–hole plasma kinetics and electron‐ion transfer for silicon. The maximum feasible efficiencies for a single spherical particle supporting different electric and magnetic resonances are compared, and the harmonic yields are further optimized by tuning lattice resonances in a periodic arrangement of nanoparticles. Results support the dominant role of magnetic dipole and quadrupole contributions in the enhancement of the third harmonic and the electric dipole for the second harmonic, as well as the possibility to further improve the conversion of both harmonics simultaneously at least by two orders of magnitude by designing properly the resonant metasurface.
All‐Optical Digital Logic Based on Unidirectional Modes
Authors: Xu Jie , Luo Yamei , Xiao Sanshui , Kang Fengwen , Tsakmakidis Kosmas L.
Published: November 2022

Standard electronic computing based on nanoelectronics and logic gates has upended our lives in a profound way. However, suffering from, both, Moore's law and Joule's law, further development of logic devices based solely on electricity has gradually stuck in the mire. All‐optical logic devices are believed to be a potential solution for such a problem. This work proposes an all‐optical digital logical system (AODLS) based on unidirectional (one‐way propagation) modes in the microwave regime. In a Y‐shaped module of the AODLS, the basic seven logic gates, including OR, AND, NOT, NOR, NAND, XOR, and XNOR gates, are achieved for continuous broadband operation relying on the existence of unidirectional electromagnetic signals. Extremely large extinction and contrast ratios are found in these logic gates. The idea of “negative logic” is used in designing the AODLS. Moreover, the authors further demonstrate that the AODLS can be assembled to multi‐input and/or multi‐output logical functionalities, which is promising for parallel computation. Besides, numerical simulations perfectly fit with and corroborate the theoretical analyses presented here. The low‐loss, broadband, and robust characteristics of this system are outlined and studied in some detail. The AODLS consisting of unidirectional structures may open a new route for all‐optical calculation and integrated optical circuits.
A Group Recommendation Algorithm Based on Dividing Subgroup
Authors: Jia Junjie , Chen Si , Shang Tianyue
Published: November 2022

With the rapid development of Internet technology and social networks, traditional personalized recommendation systems have been unable to provide effective recommendation services for groups composed of multiple users. In order to content the needs of group users, the current group recommendation algorithm mainly uses users’ consensus preferences instead of personal preferences for group recommendation, which can only content the preferences of most users and ignore the preferences of a few cold users. In order to improve the fairness of group recommendation, a group recommendation algorithm based on dividing subgroups is proposed. The algorithm introduces the comprehensive trust between users to divide the group into different subgroups, and obtains the initial subgroup recommendation list according to the average strategy. The PageRank idea is used to set the weight of subgroups and assign the number of recommended items to subgroups to generate the group recommendation list. The experimental results show that the algorithm in this paper can content the user's personalized recommendation needs to the greatest extent under the premise of improving the group fair recommendation service.
A New In Situ Prepared MOF‐Natural Polymer Composite Electrolyte for Solid Lithium Metal Batteries with Superior High‐ Rate Capability and Long‐Term Cycling Stability at Ultrahigh Current Density
Authors: Guan Jiazhu , Feng Xinping , zeng Qinghui , Li Zhenfeng , Liu Yu , Chen Anqi , Wang Honghao , Cui Wei , Liu Wei , Zhang Liaoyun
Published: November 2022

Lithium metal batteries hold promise for energy storage applications but suffer from uncontrolled lithium dendrites. In this study, a new composite membrane based on modified natural polymer and ZIF‐67 is designed and prepared by the in situ composite method for the first time. Among them, a modified natural polymer composed of lithium alginate (LA) and polyacrylamide (PAM) can be obtained by electrospinning. Importantly, the polar functional groups of natural polymers can interact by hydrogen bonding and MOFs can construct lithium‐ion transport channels. Consequently, compared with LA‐PAM electrolyte without MOF, the electrochemical stability window of ZIF‐67‐LA‐PAM electrolyte becomes wider from 4.5 to 5.2 V, and the lithium‐ion transference number (tLi+) enhances from 0.326 to 0.627 at 30°C. It is worth noting that the symmetric cells with ZIF‐67‐LA‐PAM have superior stable cycling performance at 40 and 100 mA cm−2, and a high rate at 10C and 20C for LFP cells. Besides, the cell with NCM811 high‐voltage cathode can run stably for 400 cycles with an initial discharge capacity of 136.1 mAh g−1 at 0.5C. This work provides an effective method for designing and preparing MOF‐natural polymer composite electrolytes and exhibits an excellent application prospect in high‐energy‐density lithium metal batteries.
Temporal dynamics predict symptom onset and cognitive decline in familial frontotemporal dementia
Authors: Whiteside David J. , Malpetti Maura , Jones P. Simon , Ghosh Boyd C. P. , Coyle‐Gilchrist Ian , van Swieten John C. , Seelaar Harro , Jiskoot Lize , Borroni Barbara , Sanchez‐Valle Raquel , Moreno Fermin , Laforce Robert , Graff Caroline , Synofzik Matthis , Galimberti Daniela , Masellis Mario , Tartaglia Maria Carmela , Finger Elizabeth , Vandenberghe Rik , de Mendonça Alexandre , Tagliavini Fabrizio , Butler Chris R. , Santana Isabel , Ber Isabelle Le , Gerhard Alexander , Ducharme Simon , Levin Johannes , Danek Adrian , Otto Markus , Sorbi Sandro , Pasquier Florence , Bouzigues Arabella , Russell Lucy L. , Rohrer Jonathan D. , Rowe James B. , Rittman Timothy ,   The GENFI consortium
Published: November 2022

Introduction

We tested whether changes in functional networks predict cognitive decline and conversion from the presymptomatic prodrome to symptomatic disease in familial frontotemporal dementia (FTD).

Methods

For hypothesis generation, 36 participants with behavioral variant FTD (bvFTD) and 34 controls were recruited from one site. For hypothesis testing, we studied 198 symptomatic FTD mutation carriers, 341 presymptomatic mutation carriers, and 329 family members without mutations. We compared functional network dynamics between groups, with clinical severity and with longitudinal clinical progression.

Results

We identified a characteristic pattern of dynamic network changes in FTD, which correlated with neuropsychological impairment. Among presymptomatic mutation carriers, this pattern of network dynamics was found to a greater extent in those who subsequently converted to the symptomatic phase. Baseline network dynamic changes predicted future cognitive decline in symptomatic participants and older presymptomatic participants.

Discussion

Dynamic network abnormalities in FTD predict cognitive decline and symptomatic conversion.

Highlights

We investigated brain network predictors of dementia symptom onset

Frontotemporal dementia results in characteristic dynamic network patterns

Alterations in network dynamics are associated with neuropsychological impairment

Network dynamic changes predict symptomatic conversion in presymptomatic carriers

Network dynamic changes are associated with longitudinal cognitive decline
Supercritical CO2‐assisted extrusion foaming: A suitable process to produce very lightweight acrylic polymer micro foams
Authors: Haurat Margaux , Sauceau Martial , Baillon Fabien , Barbenchon Louise Le , Pedros Matthieu , Dumon Michel
Published: November 2022

A strategy of CO2‐assisted extrusion foaming of PMMA‐based materials was established to minimize both foam density and porosities dimension. First a highly CO2‐philic block copolymer (MAM: PMMA‐PBA‐PMMA) was added in PMMA in order to improve CO2 saturation before foaming. Then the extruding conditions were optimized to maximize CO2 uptake and prevent coalescence. The extruding temperature reduction led to an increase of pressure in the barrel, favorable to cell size reduction. With the combination of material formulation and extruding strategy, very lightweight homogeneous foams with small porosities have been produced. Lightest PMMA micro foams (ρ = 0.06 g cm−3) are demonstrated with 7 wt% CO2 at 130°C and lightest blend micro foams (ρ = 0.04 g cm−3) are obtained at lower temperature (110°C, 7.7 wt% CO2). If MAM allows a reduction of Tfoaming, it also allows a much better cell homogeneity, an increase in cell density (e.g., from 3.6 107 cells cm−3 to 2 to 6 108 cells cm−3) and an overall decrease in cell size (from 100 to 40 μm). These acrylic foams produced through scCO2‐assisted extrusion has a much lower density than those ever produced in batch (ρ ≥ 0.2 g cm−3).
Microstructural tuning and band gap engineering of calcium hydroxides: a novel approach by pH variation
Authors: Akash  , Harish  , Kumar Vipin , Mishra Rajneesh Kumar , Gwag Jin Seog , Singhal Rahul , Mukhopadhyay Anoop Kumar , Kumar Pushpendra
Published: November 2022

Here we report a simple, inexpensive, energy benign, yet novel pH‐driven chemical precipitation technique to achieve microstructural and band gap engineering of calcium hydroxide nanoparticles (CHNPs). The chemical precipitation route involved the use of 0.4–1.6 M Ca(NO3)2.4H2O solutions as the precursor and 1 M NaOH solution as the precipitator. The simple variation in precursor molarity induces a pH change from about 12.4 to 11.3 in the reactant solution. The CHNPs characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and ultraviolet–visible (UV–Vis) spectroscopy techniques confirm a jump of nanocrystallite size from ~50–70 nm with a concomitant reduction of direct optical band gap energy from ~5.38–5.26 eV. The possible mechanisms that could be operative behind obtaining microstructurally tuned (MT)‐CHNPS and band gap engineering (BGE) are discussed from both theoretical and physical process perspectives. Furthermore, the implications of these novel results for possible futuristic applications are briefly hinted upon.
Heed OCR's guidance to prevent discrimination related to pregnancy
Authors: Lyerly Eric
Published: November 2022

Following a general uptick in complaints of pregnancy‐related discrimination submitted to the Office for Civil Rights, a new resource clarifies the legal responsibilities of colleges and universities in this area. The recently published document provides guidance for avoiding discrimination involving pregnancy and related conditions under Title IX (bit.ly/3TsbJHm).
Review recent rulings involving retaliation
Authors: Lyerly Eric
Published: November 2022

An overview of the key topics faced by campus administrators with citations to noteworthy cases, statutes, regulations, and additional sources.
Identifying determinants of refurbished apparel adoption: An attribution theory perspective
Authors: Sharma Himanshu
Published: November 2022

Environmental pollution is wreaking havoc on countries all over the world today. Environmental issues are compelling governments, businesses, and consumers to collaborate to mitigate environmental damage. The concept of remanufacturing or refurbishing products has recently gained popularity. This study attempted to identify the determinants of intention to adopt refurbished apparel (IARA). Attribution Theory classified the set of independent variables into two categories namely intrinsic (customer behavior, customer value, and green awareness) and extrinsic (government policies, technological advancements, and reverse logistics). An econometric model was proposed to validate the association between the dependent variable (IARA) and these independent variables. Logistic regression is applied to a survey‐based dataset of 210 respondents. The findings significantly validate the association of internal and external variables with IARA. In addition, it was inferred that the internal variables have greater impact than the external variables.
In‐Plate Chemical Synthesis of Isopeptide‐Linked SUMOylated Peptide Fluorescence Polarization Reagents for High‐Throughput Screening of SENP Preferences
Authors: Huppelschoten Yara , Mukhopadhyay Rishov , Buchardt Jens , Nielsen Thomas E. , Vertegaal Alfred C. O. , Ovaa Huib , van der Heden van Noort Gerbrand J.
Published: November 2022

Small ubiquitin‐like modifiers (SUMOs) are conjugated to protein substrates in cells to regulate their function. The attachment of SUMO family members SUMO1‐3 to substrate proteins is reversed by specific isopeptidases called SENPs (sentrin‐specific protease). Whereas SENPs are SUMO‐isoform or linkage type specific, comprehensive analysis is missing. Furthermore, the underlying mechanism of SENP linkage specificity remains unclear. We present a high‐throughput synthesis of 83 isopeptide‐linked SUMO‐based fluorescence polarization reagents to study enzyme preferences. The assay reagents were synthesized via a native chemical ligation‐desulfurization protocol between 11‐mer peptides containing a γ‐thiolysine and a SUMO3 thioester. Subsequently, five recombinantly expressed SENPs were screened using these assay reagents to reveal their deconjugation activity and substrate preferences. In general, we observed that SENP1 is the most active and nonselective SENP while SENP6 and SENP7 show the least activity. Furthermore, SENPs differentially process peptides derived from SUMO1‐3, who form a minimalistic representation of diSUMO chains. To validate our findings, five distinct isopeptide‐linked diSUMO chains were chemically synthesized and proteolysis was monitored using a gel‐based read‐out.
Long‐term (>5‐year) survivors among unresectable or metastatic cancer patients treated with zoledronate‐activated killer cells: Seven case reports
Authors: Yamaguchi Yoshiyuki
Published: November 2022

We are conducting an adoptive immunotherapy (AIT) trial using zoledronate‐activated killer cells for patients in Japan with incurable cancer. We have encountered seven long‐term survivors. Since such long survival may be very rare in cancer treatment, we present the details and a discussion of a possible role of AIT.
Do coronary stents suffer long‐term deterioration after repeated intracoronary lithotripsy for rebel underexpansion treatment?
Authors: Valencia Jose , Herrero‐Brocal Marta , Torres‐Mezcua Fernando , Pineda Javier , Ruiz‐Nodar Juan Miguel
Published: November 2022

Coronary intravascular lithotripsy (IVL) is the latest developed technique available for stent underexpansion treatment, although it is unclear if this therapy causes stent structure damage. We present the case of a patient with severe, refractory stent underexpansion after primary angioplasty, which was resolved with a double session of IVL. Elective angiographic and optical coherence tomography (OCT) follow‐up was performed 1 year after the procedure, which demonstrated the absence of any damage in the stent platform. Paradoxically, the study revealed a critical restenotic lesion in an area distant from the one of interest. Review of the first OCT after the primary procedure revealed 78% underexpansion in that area, which went by unnoticed and could be the cause of restenosis. Repeated IVL therapy may be helpful in cases of rebel stent underexpansion, and it conveys the impression of being safe in the long term in relation to the integrity and effectiveness of the drug‐eluting coronary stents.