bluuebunny/crossref_metadata_2025_split huggingface dataset:
Existence and Multiplicity Results for a Class of Coupled Quasilinear Elliptic Systems of Gradient Type
Authors: Candela Anna Maria , Salvatore Addolorata , Sportelli Caterina 
Published: March 2021

AbstractThe aim of this paper is investigating the existence of one or more weak solutions of the coupled quasilinear elliptic system of gradient type\textup{(P)}{-div⁡(A⁢(x,u)⁢|∇⁡u|p1-2⁢∇⁡u)+1p1⁢Au⁢(x,u)⁢|∇⁡u|p1=Gu⁢(x,u,v)in Ω,-div⁡(B⁢(x,v)⁢|∇⁡v|p2-2⁢∇⁡v)+1p2⁢Bv⁢(x,v)⁢|∇⁡v|p2=Gv⁢(x,u,v)in Ω,u=v=0on ∂⁡Ω,\left\{\begin{aligned} \displaystyle-\operatorname{div}(A(x,u)|\nabla u|^{p_{1% }-2}\nabla u)+\frac{1}{p_{1}}A_{u}(x,u)|\nabla u|^{p_{1}}&\displaystyle=G_{u}(% x,u,v)&&\displaystyle\phantom{}\text{in~{}${\Omega}$,}\\ \displaystyle-\operatorname{div}(B(x,v)|\nabla v|^{p_{2}-2}\nabla v)+\frac{1}{% p_{2}}B_{v}(x,v)|\nabla v|^{p_{2}}&\displaystyle=G_{v}(x,u,v)&&\displaystyle% \phantom{}\text{in~{}${\Omega}$,}\\ \displaystyle u=v&\displaystyle=0&&\displaystyle\phantom{}\text{on ${\partial% \Omega}$,}\end{aligned}\right.whereΩ⊂ℝN{\Omega\subset\mathbb{R}^{N}}is an open bounded domain,p1{p_{1}},p2>1{p_{2}>1}andA⁢(x,u){A(x,u)},B⁢(x,v){B(x,v)}are𝒞1{\mathcal{C}^{1}}-Carathéodory functions onΩ×ℝ{\Omega\times\mathbb{R}}with partial derivativesAu⁢(x,u){A_{u}(x,u)}, respectivelyBv⁢(x,v){B_{v}(x,v)}, whileGu⁢(x,u,v){G_{u}(x,u,v)},Gv⁢(x,u,v){G_{v}(x,u,v)}are given Carathéodory maps defined onΩ×ℝ×ℝ{\Omega\times\mathbb{R}\times\mathbb{R}}which are partial derivatives of a functionG⁢(x,u,v){G(x,u,v)}. We prove that, even if the coefficients make the variational approach more difficult, under suitable hypotheses functional𝒥{{\mathcal{J}}}, related to problem (P), admits at least one critical point in the “right” Banach spaceX. Moreover, if𝒥{{\mathcal{J}}}is even, then (P) has infinitely many weak bounded solutions. The proof, which exploits the interaction between two different norms, is based on a weak version of the Cerami–Palais–Smale condition, a “good” decomposition of the Banach spaceXand suitable generalizations of the Ambrosetti–Rabinowitz Mountain Pass Theorems.
Sharp Hardy Identities and Inequalities on Carnot Groups
Authors: Flynn Joshua , Lam Nguyen , Lu Guozhen 
Published: March 2021

Abstract
In this paper we establish general weighted Hardy identities for several subelliptic settings including Hardy identities on the Heisenberg group, Carnot groups with respect to a homogeneous gauge and Carnot–Carathéodory metric, general nilpotent groups, and certain families of Hörmander vector fields. We also introduce new weighted uncertainty principles in these settings. This is done by continuing the program initiated by [N. Lam, G. Lu and L. Zhang, Factorizations and Hardy’s-type identities and inequalities on upper half spaces, Calc. Var. Partial Differential Equations 58 2019, 6, Paper No. 183; N. Lam, G. Lu and L. Zhang, Geometric Hardy’s inequalities with general distance functions, J. Funct. Anal. 279 2020, 8, Article ID 108673] of using the Bessel pairs introduced by [N. Ghoussoub and A. Moradifam, Functional Inequalities: New Perspectives and New Applications, Math. Surveys Monogr. 187, American Mathematical Society, Providence, 2013] to obtain Hardy identities. Using these identities, we are able to improve significantly existing Hardy inequalities in the literature in the aforementioned subelliptic settings. In particular, we establish the Hardy identities and inequalities in the spirit of [H. Brezis and J. L. Vázquez, Blow-up solutions of some nonlinear elliptic problems, Rev. Mat. Univ. Complut. Madrid 10 1997, 443–469] and [H. Brezis and M. Marcus, Hardy’s inequalities revisited. Dedicated to Ennio De Giorgi, Ann. Sc. Norm. Super. Pisa Cl. Sci. (4) 25 1997, 1–2, 217–237] in these settings.
Large Energy Bubble Solutions for Schrödinger Equation with Supercritical Growth
Authors: Guo Yuxia , Liu Ting 
Published: March 2021

Abstract
We consider the following nonlinear Schrödinger equation involving supercritical growth:

{

-

Δ
⁢
u

+

V
⁢

(
y
)

⁢
u

=

Q
⁢

(
y
)

⁢

u

2
*

-
1

+
ε

in
⁢

ℝ
N

,

u
>
0

,

u
∈

H
1

⁢

(

ℝ
N

)

,

\left\{\begin{aligned} &\displaystyle{-}\Delta u+V(y)u=Q(y)u^{2^{*}-1+% \varepsilon}&&\displaystyle\phantom{}\text{in }\mathbb{R}^{N},\\ &\displaystyle u>0,\quad u\in H^{1}(\mathbb{R}^{N}),\end{aligned}\right.{}

where

2
*

=

2
⁢
N

N
-
2

{2^{*}=\frac{2N}{N-2}}

is the critical Sobolev exponent,

N
≥
5

{N\geq 5}

, and

V
⁢

(
y
)

{V(y)}

and

Q
⁢

(
y
)

{Q(y)}

are bounded nonnegative functions in

ℝ
N

{\mathbb{R}^{N}}

. By using the finite reduction argument and local Pohozaev-type identities, under some suitable assumptions on the functions V and Q, we prove that for

ε
>
0

{\varepsilon>0}

is small enough, problem

(
*
)

{(*)}

has large number of bubble solutions whose functional energy is in the order

ε

-

N
-
4

(

N
-
2

)

2

.

{\varepsilon^{-\frac{N-4}{(N-2)^{2}}}.}
Diversity and composition of algal epiphytes on the Mediterranean seagrass Cymodocea nodosa: a scale-based study
Authors: Tsioli Soultana , Papathanasiou Vasillis , Rizouli Anastasia , Kosmidou Maria , Katsaros Christos , Papastergiadou Eva , Küpper Frithjof C. , Orfanidis Sotiris 
Published: March 2021

Abstract

Cymodocea nodosa, a typical marine angiosperm species in the Mediterranean Sea, hosts a range of epiphytic algae. Epiphyte abundance varies at different spatial scales, yet epiphyte diversity and community composition are poorly understood. This study explores the epiphytes on C. nodosa from two reference meadows (Thasos, Vrasidas) and one anthropogenically stressed meadow (Nea Karvali) in the northern Aegean Sea (Kavala Gulf, Greece). A nested destructive sampling design at three spatial scales (metres, hundreds of metres, kilometres) and stereoscopic/microscopic observations were used. Light microscopy revealed a total of 19 taxa of macroalgae populating the leaves of C. nodosa. The most commonly encountered taxa with highest cover (%) were Hydrolithon cruciatum and Feldmannia mitchelliae. DNA sequencing (18S rDNA) confirms the presence of a number of dinoflagellate and red algal epiphytes, and this represents the first application of DNA metabarcoding to study the diversity of seagrass epiphytes. Epiphytic communities studied at species/taxon and functional (Ecological Status Groups) levels separated the reference low-stressed meadows from the degraded one, with the functional approach having higher success. The ecological evaluation index classified the studied meadows into different Ecological Status Classes according to anthropogenic stress.
Evaluating chronic kidney disease in rural South Africa: comparing estimated glomerular filtration rate using point-of-care creatinine to iohexol measured GFR
Authors: Currin Sean , Gondwe Mwawi , Mayindi Nokthula , Chipungu Shingirai , Khoza Bongekile , Khambule Lungile , Snyman Tracy , Tollman Stephen , Fabian June , George Jaya 
Published: March 2021

Abstract

Objectives
The prevalence of chronic kidney disease is rising rapidly in low- and middle-income countries. Serum creatinine and estimation of glomerular filtration rate (GFR) are critical diagnostic tools, yet access to centralised laboratory services remains limited in primary care resource-limited settings. The aim of this study was to evaluate point-of-care (POC) technologies for serum creatinine measurement and to compare their performance to a gold standard measurement using iohexol measured GFR (mGFR).

Methods
POC creatinine was measured using iSTAT® and StatSensor® devices in capillary and venous whole blood, and laboratory creatinine was measured using the compensated kinetic Jaffe method in 670 participants from a rural area in South Africa. GFR estimating equations Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease (CKD-EPI and MDRD) for POC and laboratory creatinine were compared to iohexol mGFR.

Results
Calculated GFR for laboratory and POC creatinine measurements overestimated GFR (positive bias of 1.9–34.1 mL/min/1.73 m2). However, all POC devices had less positive bias than the laboratory Jaffe method (1.9–14.7 vs. 34.1 for MDRD, and 8.4–19.9 vs. 28.6 for CKD-EPI). Accuracy within 30% of mGFR ranged from 0.56 to 0.72 for POC devices and from 0.36 to 0.43 for the laboratory Jaffe method. POC devices showed wider imprecision with coefficients of variation ranging from 4.6 to 10.2% compared to 3.5% for the laboratory Jaffe method.

Conclusions
POC estimated GFR (eGFR) showed improved performance over laboratory Jaffe eGFR, however POC devices suffered from imprecision and large bias. The laboratory Jaffe method performed poorly, highlighting the need for laboratories to move to enzymatic methods to measure creatinine.
Evaluation of the automated LIAISON® SARS-CoV-2 TrimericS IgG assay for the detection of circulating antibodies
Authors: Bonelli Fabrizio , Blocki Frank A. , Bunnell Tina , Chu Edward , De La O Arriel , Grenache David G. , Marzucchi Ginevra , Montomoli Emanuele , Okoye Lilian , Pallavicini Luca , Streva Vincent A. , Torelli Alessandro , Wagner Aaron , Zanin Davide , Zierold Claudia , Wassenberg James J. 
Published: March 2021

Abstract

Objectives
COVID-19 has brought about tests from many manufacturers. While molecular and rapid antigen tests are targeted for early diagnosis, immunoassays have a larger role in epidemiological studies, understanding longitudinal immunity, and in vaccine development and response.

Methods
The performance of the LIAISON® SARS-CoV-2 TrimericS IgG assay was evaluated against the Beckman ACCESS SARS-CoV-2 IgG assay in New Mexico, and against the Siemens ADVIA Centaur COV2G assay in New York. Discordant samples were parsed using a microneutralization assay.

Results
A SARS-CoV-2 antibody positivity rate of 23.8% was observed in the samples tested in New York (September 2020), while in the same month the positivity rate was 1.5% in New Mexico. Positive and negative agreement were 67.6% (95% CI 49.5–82.6%) and 99.8% (95% CI 99.5–99.9%), respectively, with the Beckman test, and 98.0% (95% CI 95.7–99.3%) and 94.8% (95% CI 93.4–96.0%), respectively, with the Siemens test. Receiver operating characteristic analysis for the detection of SARS-CoV-2 antibodies discloses an AUC, area under the curve, of 0.996 (95% CI 0.992–0.999) for the LIAISON® SARS-CoV-2 TrimericS IgG assay. The criterion associated to the Youden Index was determined to be >12.9 kAU/L with a sensitivity of 99.44% and a specificity of 99.82%.

Conclusions
The LIAISON® SARS-CoV-2 TrimericS IgG assay is highly sensitive and specific. The balance of these parameters, without emphasis on high specificity alone, is particularly important when applied to high prevalence populations, where a highly sensitive assay will result in reporting a lower number of false negative subjects.
Continuous reference intervals for leukocyte telomere length in children: the method matters
Authors: Lesmana Analia , Tian Pei , Karlaftis Vasiliki , Hearps Stephen , Monagle Paul , Ignjatovic Vera , Elwood Ngaire 
Published: March 2021

Abstract

Objectives
Children with very short telomeres commonly develop bone marrow failure and other severe diseases. Identifying the individuals with short telomeres can improve outcome of bone marrow transplantation, with accurate diagnosis requiring the use of age-matched reference intervals (RIs). This study aimed to establish RIs for telomere length (TL) in children using three commonly used methods for TL measurement.

Methods
Healthy children aged 30 days to 18 years were recruited for assessment using age as a continuous variable. Venous blood samples were collected and leukocyte TL was measured using terminal restriction fragment (TRF) analysis, quantitative PCR (QPCR) and flow cytometry with fluorescence in situ hybridization (Flow-FISH). Fractional polynomial model and quantile regression were performed to generate continuous RIs. Factors that might contribute to variation in TL, such as gender, were also examined.

Results
A total of 212 samples were analyzed. Continuous RIs are presented as functions of age. TRF analysis and QPCR showed significant negative correlation between TL and age (r=−0.28 and r=−0.38, p<0.001). In contrast, Flow-FISH showed no change in TL with age (r=−0.08, p=0.23). Gender did not have significant influence on TL in children.

Conclusions
This study provides three options to assess TL in children by establishing method-specific continuous RIs. Choosing which method to use will depend on several factors such as amount and type of sample available and required sensitivity to age-related change.
Smoothed-Adaptive Perturbed Inverse Iteration for Elliptic Eigenvalue Problems
Authors: Giani Stefano , Grubišić Luka , Heltai Luca , Mulita Ornela 
Published: March 2021

Abstract
We present a perturbed subspace iteration algorithm to approximate the lowermost eigenvalue cluster of an elliptic eigenvalue problem. As a prototype, we consider the Laplace eigenvalue problem posed in a polygonal domain. The algorithm is motivated by the analysis of inexact (perturbed) inverse iteration algorithms in numerical linear algebra. We couple the perturbed inverse iteration approach with mesh refinement strategy based on residual estimators. We demonstrate our approach on model problems in two and three dimensions.
Residues on affine Grassmannians
Authors: Florence Mathieu , Gille Philippe 
Published: March 2021

Abstract
Given a linear group G over a field k, we define a notion of
index and residue of an element

g
∈

G
⁢

(

k
⁢

(

(
t
)

)

)

{g\in G(k(\kern-1.707165pt(t)\kern-1.707165pt))}

.
The index

r
⁢

(
g
)

{r(g)}

is a rational number and the residue a group homomorphism

res

(
g
)

:

𝔾
a

⁢
or
⁢

𝔾
m

→
G

{\mathop{\rm res}\nolimits(g):\mathbb{G}_{a}\text{ or }\mathbb{G}_{m}\to G}

.
This provides an alternative proof of Gabber’s theorem
stating that G has no subgroups isomorphic to

𝔾
a

{\mathbb{G}_{a}}

or

𝔾
m

{\mathbb{G}_{m}}

iff

G
⁢

(

k
⁢

[

[
t
]

]

)

=

G
⁢

(

k
⁢

(

(
t
)

)

)

{G(k[\kern-1.13811pt[t]\kern-1.13811pt])=G(k(\kern-1.707165pt(t)\kern-1.707165%
pt))}

.
In the case of a reductive group, we offer an explicit connection
with the theory of affine Grassmannians.
Ring-opening polymerization
Authors: Penczek Stanislaw , Pretula Julia , Slomkowski Stanislaw 
Published: March 2021

Abstract
Ring-opening polymerization is defined by IUPAC (Penczek, S., Moad, G. (2008). Glossary of the terms related to kinetics, thermodynamics, and mechanisms of polymerization. (IUPAC Recommendations 2008), Pure and Applied Chemistry, 80(10), 2163–2193) as (cit.) “Ring-opening polymerization (ROP): Polymerization in which a cyclic monomer yields a monomeric unit that is either acyclic or contains fewer rings than the cyclic monomer”. The large part of the resulting polymerizations is living/controlled; practically all belong to chain polymerizations. After the introduction, providing basic information on chain polymerizations, the paper presents the concise overview of major classes of monomers used in ROP, including cyclic ethers, esters, carbonates, and siloxanes as well as cyclic nitrogen, phosphorus, and sulfur containing monomers. There are discussed also thermodynamics, kinetic polymerizability, and major mechanisms of ROP. Special attention is concentrated on polymers prepared by ROP on industrial scale.
Higher differentiability results for solutions to a class of non-autonomous obstacle problems with sub-quadratic growth conditions
Authors: Gentile Andrea 
Published: March 2021

Abstract
We establish some higher differentiability results of integer and fractional order for solutions to non-autonomous obstacle problems of the form

min
⁡

{

∫
Ω

f
⁢

(
x
,

D
⁢
v
⁢

(
x
)

)

:

v
∈

𝒦
ψ

⁢

(
Ω
)

}

,

\min\biggl{\{}\int_{\Omega}f(x,Dv(x)):v\in\mathcal{K}_{\psi}(\Omega)\biggr{\}},

where the function f satisfies p-growth conditions with respect to the gradient variable, for

1
<
p
<
2

{1<p<2}

, and

𝒦
ψ

⁢

(
Ω
)

{\mathcal{K}_{\psi}(\Omega)}

is the class of admissible functions

v
∈

u
0

+

W
0

1
,
p

⁢

(
Ω
)

{v\in u_{0}+W^{1,p}_{0}(\Omega)}

such that

v
≥
ψ

{v\geq\psi}

a.e. in Ω, where

u
0

∈

W

1
,
p

⁢

(
Ω
)

{u_{0}\in W^{1,p}(\Omega)}

is a fixed boundary datum.
Here we show that a Sobolev or Besov–Lipschitz regularity assumption on the gradient of the obstacle ψ transfers to the gradient of the solution, provided the partial map

x
↦

D
ξ

⁢
f
⁢

(
x
,
ξ
)

{x\mapsto D_{\xi}f(x,\xi)}

belongs to a suitable Sobolev or Besov space.
The novelty here is that we deal with sub-quadratic growth conditions with respect to the gradient variable, i.e.

f
⁢

(
x
,
ξ
)

≈

a
⁢

(
x
)

⁢

|
ξ
|

p

{f(x,\xi)\approx a(x)\lvert\xi\rvert^{p}}

with

1
<
p
<
2

{1<p<2}

, and where the map a belongs to a Sobolev or Besov–Lipschitz space.
Microwave-assisted reactions: Efficient and versatile one-step synthesis of 8-substituted xanthines and substituted pyrimidopteridine-2,4,6,8-tetraones under controlled microwave heating
Authors: Mekheimer Ramadan Ahmed , Hayallah Alaa M. , Moustafa Moustafa Sherief , Al-Mousawi Saleh Mohammed , Abd-Elmonem Mohamed , Mostafa Sara M. , Abo Elsoud Fatma A. , Sadek Kamal Usef 
Published: March 2021

Abstract
We report herein a simple and efficient one-step synthesis of 8-substituted xanthines and substituted pyrimidopteridine-2,4,6,8-tetraones via reaction of 1,3-dimethyl-5,6-diaminouracil 1 with activated double bond systems 2 assisted by controlled microwave irradiation. The obtained heterocycles are privileged biologically relevant scaffolds.
Specific heat capacity of wood between −140 and 50 °C in dry and wet state
Authors: Nopens Martin , Sazama Uta , Krause Andreas , Fröba Michael 
Published: March 2021

Abstract
Specific heat capacity of wood is an important material property for fundamental research and timber technology. However, the existing database for heat capacity values is limited, especially for data below 0 °C. Therefore, the aim of this study was to investigate the specific heat capacity of wood with different moisture contents (dry, below and above fibre saturation) in lower temperature. Beech (Fagus sylvatica) and scots pine (Pinus sylvestris) were investigated via differential scanning calorimetry (DSC), equipped with a liquid nitrogen-cooling device, using the sapphire standard. Specific heat capacity for beech and pine were linear within the investigated temperature region. Values above 0 °C are in agreement with existing literature. Both species showed similar results. Based on the obtained results the specific heat capacity for bound water was calculated. The presented results are an important step for increasing the database of wood heat capacity. These findings enable future research for calculating heat-flux, diffusion and moisture transfer in wood.
Predicting strength of Finnish birch veneers based on three different failure criteria
Authors: Pramreiter Maximilian , Bodner Sabine C. , Keckes Jozef , Stadlmann Alexander , Feist Florian , Baumann Georg , Maawad Emad , Müller Ulrich 
Published: March 2021

AbstractThe use of wood in high-performance composites based on laminated veneer products, plywood or wood hybrid elements thereof requires accurate prediction of strength of each individual ply. Previous research has shown that one dominating factor influencing the strength of birch veneers is the fibre orientation. The present study investigates the validity of the failure criteria after Tsai-Hill, Hoffmann and Kollmann for thin birch veneers under tensile loading. The fibre orientation in- and out-of-plane was measured by means of wide-angle X-ray scattering. Tensile strength and threshold values were determined in laboratory experiments. Pearson correlation between the predicted strength and actual strength ranged from 0.836 up to 0.883. Best correlation (r = 0.883) was achieved for Kollmann using a combined angle between in- and out-of-plane fibre orientation. It was shown that the failure criteria commonly used for manmade fibre reinforced composites are also applicable for thin birch veneers.
Investigating the relationship between insulin resistance and adipose tissue in a randomized Tehrani population
Authors: Mirzay Razzaz Jalaledin , Moameri Hossein , Akbarzadeh Zahra , Ariya Mohammad , Hosseini Seyed ali , Ghaemi Alireza , Osati Saeed , Ehrampoush Elham , Homayounfar Reza 
Published: March 2021

Abstract

Objectives
Insulin resistance is the most common metabolic change associated with obesity. The present study aimed to investigate the relationship between insulin resistance and body composition especially adipose tissue in a randomized Tehrani population.

Methods
This study used data of 2,160 individuals registered in a cross-sectional study on were randomly selected from among subjects who were referred to nutrition counseling clinic in Tehran, from April 2016 to September 2017. Insulin resistance was calculated by homeostasis model assessment formula. The odds ratio (95% CI) was calculated using logistic regression models.

Results
The mean age of the men was 39 (±10) and women were 41 (±11) (the age ranged from 20 to 50 years). The risk of increased HOMA-IR was 1.03 (95% CI: 1.01–1.04) for an increase in one percent of Body fat, and 1.03 (95% CI: 1.00–1.05) for an increase in one percent of Trunk fat. Moreover, the odds ratio of FBS for an increase in one unit of Body fat percent and Trunk fat percent increased by 1.05 (adjusted odds ratio [95% CI: 1.03, 1.06]) and 1.05 (95% CI: 1.02, 1.08). Also, the risk of increased Fasting Insulin was 1.05 (95% CI: 1.03–1.07) for an increase in one unit of Body fat percent, and 1.05 (95% CI: 1.02–1.08) for an increase in one unit of Trunk fat percent.

Conclusions
The findings of the present study showed that there was a significant relationship between HOMA-IR, Fasting blood sugar, Fasting Insulin, and 2 h Insulin with percent of Body fat, percent of Trunk fat.
STAT3 promotes peritoneal metastasis of gastric cancer by enhancing mesothelial-mesenchymal transition
Authors: Yang Hongkui , Xu Wenjun 
Published: March 2021

Abstract
Signal transducer and activator of transcription 3 (STAT3) is a widely-reported oncogene in many human cancers, but its role in the peritoneal metastasis of gastric cancer (GC) has yet to be studied. The expression level of STAT3 in GC patient tissues was assessed. Stable shRNA knockdown (KD) of STAT3 was established in GC cell line AGS, followed by examination of its effect on AGC cell viability and proliferation, xenograft tumor growth, metastatic potential, mesothelial-to-mesenchymal transition (MMT)-related properties and peritoneal metastasis in a mouse model. The specific STAT3 inhibitor BP1-102 was also employed to verify findings from STAT3 KD experiments. Expression of activated STAT3 was upregulated in GC patient tumor tissues, and further elevated among patients diagnosed with peritoneal metastasis. STAT3 deactivation suppressed viability and proliferation of GC cells in vitro, as well as GC tumorigenesis in vivo. Furthermore, the metastatic properties and production of MMT-inducing factors of GC cells in vitro were also dependent on STAT3 activation. Importantly, STAT3 KD significantly compromised peritoneal metastasis of GC in vivo. STAT3 activation contributes to peritoneal metastasis of GC by promoting MMT, warranting further investigation to explore its potential for GC treatment, in particular among peritoneal metastasis patients.