bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conditional Mutagenesis of Gata6 in SF1-Positive Cells Causes Gonadal-Like Differentiation in the Adrenal Cortex of Mice
Authors: Pihlajoki Marjut , Gretzinger Elisabeth , Cochran Rebecca , Kyrönlahti Antti , Schrade Anja , Hiller Theresa , Sullivan Laura , Shoykhet Michael , Schoeller Erica L. , Brooks Michael D. , Heikinheimo Markku , Wilson David B. 
Published: March 2013

AbstractTranscription factor GATA6 is expressed in the fetal and adult adrenal cortex and has been implicated in steroidogenesis. To characterize the role of transcription factor GATA6 in adrenocortical development and function, we generated mice in which Gata6 was conditionally deleted using Cre-LoxP recombination with Sf1-cre. The adrenal glands of adult Gata6 conditional knockout (cKO) mice were small and had a thin cortex. Cytomegalic changes were evident in fetal and adult cKO adrenal glands, and chromaffin cells were ectopically located at the periphery of the glands. Corticosterone secretion in response to exogenous ACTH was blunted in cKO mice. Spindle-shaped cells expressing Gata4, a marker of gonadal stroma, accumulated in the adrenal subcapsule of Gata6 cKO mice. RNA analysis demonstrated the concomitant upregulation of other gonadal-like markers, including Amhr2, in the cKO adrenal glands, suggesting that GATA6 inhibits the spontaneous differentiation of adrenocortical stem/progenitor cells into gonadal-like cells. Lhcgr and Cyp17 were overexpressed in the adrenal glands of gonadectomized cKO vs control mice, implying that GATA6 also limits sex steroidogenic cell differentiation in response to the hormonal changes that accompany gonadectomy. Nulliparous female and orchiectomized male Gata6 cKO mice lacked an adrenal X-zone. Microarray hybridization identified Pik3c2g as a novel X-zone marker that is downregulated in the adrenal glands of these mice. Our findings offer genetic proof that GATA6 regulates the differentiation of steroidogenic progenitors into adrenocortical cells.
Exendin-4 Protects Hypoxic Islets From Oxidative Stress and Improves Islet Transplantation Outcome
Authors: Padmasekar M. , Lingwal N. , Samikannu B. , Chen C. , Sauer H. , Linn T. 
Published: March 2013

AbstractOxidative stress produced during pancreatic islet isolation leads to significant β-cell damage. Homeostatic cytokines secreted subsequently to islet transplantation damage β-cells by generating oxygen free radicals. In this study, exendin-4, a glucagon-like peptide-1 analog improved islet transplantation outcome by increasing the survival of diabetic recipient mice from 58% to 100%. We hypothesized that this beneficial effect was due to the ability of exendin-4 to reduce oxidative stress. Further experiments showed that it significantly reduced the apoptotic rate of cultured β-cells subjected to hypoxia or to IL-1β. Reduction of apoptotic events was confirmed in pancreatic islet grafts of exendin-4–treated mice. Exendin-4 enhanced Akt phosphorylation of β-cells and insulin released from them. It even augmented insulin secretion from islets cultivated at hypoxic conditions. Exposure to hypoxia led to a decrease in the activation of Akt, which was reversed when β-cells were pretreated with exendin-4. Moreover, exendin-4 increased the activity of redox enzymes in a hypoxia-treated β-cell line and reduced reactive oxygen species production in isolated pancreatic islets. Recovery from diabetes in mice transplanted with hypoxic islets was more efficient when they received exendin-4. In conclusion, exendin-4 rescued islets from oxidative stress caused by hypoxia or due to cytokine exposure. It improved the outcome of syngenic and xenogenic islet transplantation.
High-Fat Diet-Mediated Lipotoxicity and Insulin Resistance Is Related to Impaired Lipase Expression in Mouse Skeletal Muscle
Authors: Badin Pierre-Marie , Vila Isabelle K. , Louche Katie , Mairal Aline , Marques Marie-Adeline , Bourlier Virginie , Tavernier Geneviève , Langin Dominique , Moro Cedric 
Published: March 2013

AbstractElevated expression/activity of adipose triglyceride lipase (ATGL) and/or reduced activity of hormone-sensitive lipase (HSL) in skeletal muscle are causally linked to insulin resistance in vitro. We investigated here the effect of high-fat feeding on skeletal muscle lipolytic proteins, lipotoxicity, and insulin signaling in vivo. Five-week-old C3H mice were fed normal chow diet (NCD) or 45% kcal high-fat diet (HFD) for 4 weeks. Wild-type and HSL knockout mice fed NCD were also studied. Whole-body and muscle insulin sensitivity, as well as lipolytic protein expression, lipid levels, and insulin signaling in skeletal muscle, were measured. HFD induced whole-body insulin resistance and glucose intolerance and reduced skeletal muscle glucose uptake compared with NCD. HFD increased skeletal muscle total diacylglycerol (DAG) content, protein kinase Cθ and protein kinase Cϵ membrane translocation, and impaired insulin signaling as reflected by a robust increase of basal Ser1101 insulin receptor substrate 1 phosphorylation (2.8-fold, P &lt; .05) and a decrease of insulin-stimulated v-Akt murine thymoma viral oncogene homolog Ser473 (−37%, P &lt; .05) and AS160 Thr642 (−47%, P &lt;.01) phosphorylation. We next showed that HFD strongly reduced HSL phosphorylation at Ser660. HFD significantly up-regulated the muscle protein content of the ATGL coactivator comparative gene identification 58 and triacylglycerol hydrolase activity, despite a lower ATGL protein content. We further show a defective skeletal muscle insulin signaling and DAG accumulation in HSL knockout compared with wild-type mice. Together, these data suggest a pathophysiological link between altered skeletal muscle lipase expression and DAG-mediated insulin resistance in mice.
Loss of integration is associated with reduced resistance to oxidative stress
Authors: Costantini David , Monaghan Patricia , Metcalfe Neil 
Published: March 2013

Summary
One cellular mechanism thought to be particularly important as a constraint on lifespan and life-history strategies is oxidative stress. Susceptibility to oxidative stress is influenced by a number of antioxidant defences, whose effectiveness depends on the synergistic and competitive interactions among them (biochemical integration). It is generally assumed that exposure to oxidative stress is detrimental, but it is also possible that low level oxidative stress has a positive effect on integration, and therefore carries some benefits. Using three experimental groups of zebra finches (control, mild and high flight activity), we tested whether exercise-induced oxidative stress altered the integration of the pro-oxidant/antioxidant system by manipulating levels of flight activity, known to generate oxidative stress in birds. We show for the first time that a short-term high level of physical activity leads to a reduction in integration among components of the blood antioxidant defences, associated with a reduced resistance to oxidative stress. We found no evidence of improved integration in the antioxidant defences at low levels of oxidative stress exposure, suggesting that improved integration is not the route whereby any benefits of low level stress exposure occur. These findings point to a reduction in biochemical integration as a potential mechanism explaining a reduced resistance to oxidative stress induced by short-term stressors.
An Expeditious and Solvent-Free Synthesis of Substituted Pyrroles Using Sulfated Anatase-Titania as a Solid Acid Catalyst
Authors: Ravi Krishnaswamy , Krishnakumar Balu , Swaminathan Meenakshisundaram 
Published: March 2013

Abstract
Sulfated anatase-titania (TiO2–SO42−) has been used as a solid acid catalyst for the synthesis of substituted pyrroles from γ-diketone and aromatic/aliphatic (acyclic and cyclic) primary amines by simple physical grinding. This sulfated titania gives an excellent yield with less reaction time and is an inexpensive, easily recyclable nanocatalytic material for this reaction. Higher catalytic activity of TiO2–SO42− is due to its increased Brønsted acidity.
Studies of Composite Cathode Material LiFePO4–Li3V2(PO4)3 and It’s Precursor FeVO4·xH2O
Authors: Zheng Jun-chao , Zhang Bao , Yang Zhan-hong , Ou Xing , Zhang Jia-feng 
Published: March 2013

Abstract
As both iron and vanadium sources, the spherical amorphous FeVO4·xH2O powders are synthesized through an aqueous precipitation method by using Fe(NO3)3, NH4VO3, and ammonia water as starting materials. The effects of pH value of precursor solution on the Fe/V molar ratio is studied, it is found that when the pH is 4, the Fe/V molar ration is 1.004, it is close to 1. The FeVO4·xH2O powders are preheat treated at 600 °C for 12 h in air to obtain triclinic FeVO4. The FeVO4 powders are homogeneously mixed with Li2CO3, NH4H2PO4, and oxalic acid with stoichiometric ratio, and then sinter at 750 °C for 12 h in argon atmosphere to obtain LiFePO4–Li3V2(PO4)3 composite material. The structural properties, particle morphology, and electrochemical performance of composite cathode material LiFePO4–Li3V2(PO4)3 were studied. The FeVO4 not only plays as the main reactant to form LiFePO4 and Li3V2(PO4)3, but also as the dopants doping LiFePO4–Li3V2(PO4)3. The LiFePO4–Li3V2(PO4)3 composite cathode shows good electrochemical performance, and its discharge capacity is about 138.7 mA h g−1 at 1 C rate after 100 cycles, which retains 93.3% of it’s theoretical capacity (148.6 mA h g−1) for composite cathode material LiFePO4–Li3V2(PO4)3 in the voltage range of 2.5–4.5 V.
Odd–Even Effect in the Surface Structure of Alkyloxy-Substituted Anthraquinone on HOPG Observed by Scanning Tunneling Microscope
Authors: Tamaki Yoshinori , Muto Kosuke , Miyamura Kazuo 
Published: March 2013

Abstract
Self-assembled adlayers of a series of anthraquinone derivatives, 2-alkoxyanthraquinone (n-ant, n = 14, 15, 16, 17, 18, 20, and 22) where n stands for the alkyl (CnH2n+1) chain length, on highly oriented pyrolytic graphite (HOPG) surface are investigated by scanning tunneling microscope (STM). Anthraquinone derivatives are found to form C–H···O hydrogen-bonded dimers. However, the self-assembled 2D pattern of monolayer depends on the parity (odd/even) of carbon atoms and the length of the alkyl chains. When n is even in number, the aggregating structure in the monolayer is interdigitated lamellar structure. The specific feature of these lamellae is the propagation of dislocations. The frequency of dislocation increased as the alkyl chain elongated. However, when n is odd in number, molecules adopt different conformation (type B) and the aggregating structure changes drastically. This indicates that the orientation of the terminal methyl of the alkyl group induces the surface structural change, i.e., the odd–even effect.
The Atiyah–Patodi–Singer signature formula for measured foliations
Authors: Antonini Paolo 
Published: March 2013

Abstract

Given a compact manifold with boundary X
0 endowed with a foliation

ℱ
0

${\mathcal {F}_0}$

transverse to the boundary, and which
admits a holonomy invariant transverse measure Λ,
we define three types of signature for the pair (foliation, boundary foliation): the analytic signature, denoted by

σ

Λ
,
an

(

X
0

,
∂

X
0

)

${\sigma _{\Lambda ,\operatorname{an}}(X_0,\partial X_0)}$

, is the leafwise L2
-Λ-index of the signature operator on the extended manifold X obtained by attaching cylindrical ends to the boundary; the Hodge signature

σ

Λ
,
Hodge

(

X
0

,
∂

X
0

)

${\sigma _{\Lambda ,\operatorname{Hodge}}(X_0,\partial X_0)}$

is defined using the natural representation of the Borel groupoid

ℛ

${\mathcal {R}}$

of X on the field of square integrable harmonic forms on the leaves; and
the de Rham signature,

σ

Λ
,
dR

(

X
0

,
∂

X
0

)

${\sigma _{\Lambda ,\operatorname{dR}}(X_0,\partial X_0)}$

, defined using the natural representation
of the Borel groupoid

ℛ
0

${\mathcal {R}_0}$

of X
0 on the field of the L2
-relative de Rham spaces of the leaves. We prove that
these three signatures coincide

σ

Λ
,
an

(

X
0

,
∂

X
0

)

=

σ

Λ
,
Hodge

(

X
0

,
∂

X
0

)

=

σ

Λ
,
dR

(

X
0

,
∂

X
0

)

.

$ \sigma _{\Lambda , \operatorname{an}}(X_0,\partial X_0)=
\sigma _{\Lambda ,\operatorname{Hodge}}(X_0,\partial X_0)=\sigma _{\Lambda ,\operatorname{dR}}(X_0,\partial X_0). $

As a consequence of the index formula we proved in [Bull. Sci. Math. (2010), DOI 10.1016/
j.bulsci.2010.10.003], we finally obtain the Atiyah–Patodi–Singer
signature formula for measured foliations:

σ

Λ
,
dR

(

X
0

,
∂

X
0

)

=

〈
L

(
T

ℱ
0

)

,

C
Λ

〉

+
1
/
2

[

η
Λ

(

D

ℱ
∂

)

]

.

$ \sigma _{\Lambda ,\operatorname{dR}}(X_0,\partial X_0)=\langle L(T\mathcal {F}_0),C_{\Lambda }\rangle +1/2[\eta _{\Lambda }(D^{\mathcal {F}_{\partial }})]. $
Heat kernel for fractional diffusion operators with perturbations
Authors: Wang Feng-Yu , Zhang Xi-Cheng 
Published: March 2013

Abstract
Let L be an elliptic differential operator on a complete connected Riemannian manifold M such that the associated heat kernel has two-sided Gaussian
bounds as well as a Gaussian type gradient estimate. Let

L

(
α
)

${L^{(\alpha )}}$

be the α-stable subordination of L for

α
∈
(
1
,
2
)

${\alpha \in (1,2)}$

. We
found some classes

𝕂

α

γ
,
β

(
β
,
γ
∈

[
0
,
α
)

)

${\mathbb {K}_{\alpha }^{\gamma ,\beta } (\beta ,\gamma \in [0,\alpha ))}$

of
time-space functions containing the Kato class, such that for any
measurable functions

b
:
[
0
,
∞
)
×
M
→
T
M

${b: [0,\infty )\times M\rightarrow TM}$

and

c
:
[
0
,
∞
)
×
M
→
M

${c: [0,\infty )\times M\rightarrow M}$

with

|
b
|
,
c

∈

𝕂

α

1
,
1

${|b|, c\in \mathbb {K}_{\alpha }^{1,1}}$

, the operator

L

b
,
c

(
α
)

(
t
,
x
)

:
=

L

(
α
)

(
x
)

+

〈
b

(
t
,
x
)

,
∇
·

〉

+
c

(
t
,
x
)

,

(
t
,
x
)

∈

[
0
,
∞
)

×
M
,

$
L_{b,c}^{(\alpha )}(t,x):= L^{(\alpha )}(x)+ \langle b(t,x),\nabla \cdot \,\rangle +c(t,x),\quad (t,x)\in [0,\infty )\times M,\vspace*{-1.42262pt}
$

has a unique heat kernel

p

b
,
c

(
α
)

(
t
,
x
;
s
,
y
)

${p_{b,c}^{(\alpha )}(t,x;s,y)}$

,

0
≤
s
<
t

${0\le s&lt;t}$

,

x
,
y
∈
M

${x,y\in M}$

, which is jointly continuous and satisfies

t
-
s

C

{
ρ

(
x
,
y
)

∨

(
t
-
s
)

1
α

}

d
+
α

≤

p

b
,
c

(
α
)

(
t
,
x
;
s
,
y
)

≤

C
(
t
-
s
)

{
ρ

(
x
,
y
)

∨

(
t
-
s
)

1
α

}

d
+
α

$
\frac{t-s}{C\lbrace \rho (x,y)\vee (t-s)^{\frac{1}{\alpha }}\rbrace ^{d+\alpha }}\le p_{b,c}^{(\alpha )}(t,x;s,y)\le \frac{C(t-s)}{\lbrace \rho (x,y)\vee (t-s)^{\frac{1}{\alpha }}\rbrace ^{d+\alpha }}\vspace*{-1.42262pt}
$

and

|

∇
x

p

b
,
c

(
α
)

(
t
,
x
;
s
,
y
)

|
≤

C

(
t
-
s
)

α
-
1

α

{
ρ

(
x
,
y
)

∨

(
t
-
s
)

1
α

}

d
+
α

,

0
≤
s
<
t
,

x
,
y
∈
M
,

$ \big |\nabla _x p_{b,c}^{(\alpha )}(t,x; s,y)\big |\le \frac{C(t-s)^{\frac{\alpha -1}{\alpha }}}{\lbrace \rho (x,y)\vee (t-s)^{\frac{1}{\alpha }}\rbrace ^{d+\alpha }},\quad 0\le s&lt;t,\; x,y\in M,\vspace*{-1.42262pt}
$

for some constant C > 1, where ρ is the Riemannian distance. The estimate of

∇
y

p

b
,
c

(
α
)

${\nabla _yp^{(\alpha )}_{b,c}}$

and the Hölder continuity of

∇
x

p

b
,
c

(
α
)

${\nabla _x p_{b,c}^{(\alpha )}}$

are also considered. The resulting estimates of the gradient and its Hölder continuity are new even in the standard case where

L
=
Δ

${L=\Delta }$

on ℝ
d
and b, c are time-independent.
Wear Evaluation of Pack Boronized AISI 1060 Steel
Authors: Fernandes F. A. P. , Heck S. C. , Totten G. E. , Casteletti L. C. 
Published: March 2013

Abstract
Boronizing is used to obtain very high hardness and wear resistance on ferrous and non-ferrous materials and some super alloys. The process can be carried out in solid, liquid, or gaseous medium. In this work, samples of AISI 1060 steel were treated by the pack boriding method during 2 and 4 h at 900 and 1000°C. Optical microscopy, x-ray diffraction, and micro-hardness analyses were conducted and wear tests were performed using a micro-wear machine with a fixed-ball configuration. The pack boriding resulted in the formation of layers with high hardness and wear resistance. All the borided layers presented top hardness around 2000 HV (Vickers pyramid number). Raising time and temperature of treatment increased the layer thickness. X-ray diffraction patterns showed the presence of only Fe2B for samples treated at 900°C for 2 and 4 h. The samples borided at 1000°C for 2 and 4 h presented layers composed by a mixture of Fe2B and FeB. The wear resistance of the samples borided at 1000°C was higher than that borided at 900°C, probably because of the difference in chemical composition.
Study of Magnetization Behavior of Glass-Coated Amorphous Ferromagnetic Microwires
Authors: Su Fei , Wang Xiaoyan 
Published: March 2013

Abstract
In this paper, two relevant problems are investigated. First, the residual stresses within glass-coated amorphous ferromagnetic microwires (AFMWs) subjected to thermal expansion mismatch and magnetostriction effect are analyzed using the finite element method; the effects of various design parameters (e.g., the thickness of the glass cover) on the residual stress are discussed as well. Then, based on the theory of micromagnetics, the magnetization states of AFMWs under the collective effects of stress and external axial magnetic field are analyzed. It has been found that the magnetization of AFMWs with negative saturation magnetostriction from −0.1 × 10−6 to −0.3 × 10−6 is sensitive to stress change, and external magnetic field of the proper amplitude can help to increase this sensitivity. This study should provide guidance on the optimal design of glass-coated AFMWs and their potential applications in tunable microwave composites and stress sensors.
Implant–Buccal Plate Distance as Diagnostic Parameter: A Prospective Cohort Study on Implant Placement in Fresh Extraction Sockets
Authors: Capelli Matteo , Testori Tiziano , Galli Fabio , Zuffetti Francesco , Motroni Alessandro , Weinstein Roberto , Del Fabbro Massimo 
Published: March 2013

Background:The aim of this study is to investigate contour changes around immediate implants in fresh extraction sockets when different grafting procedures are performed, based on the distance between the external implant collar and the bony surface on the buccal plate (I‐BP). A secondary aim is to assess the esthetic outcome via the implant esthetic score (IAS).Methods:This prospective cohort study was performed in three centers. Suitable patients to undergo implant placement in fresh extraction sockets were selected. Periodontal biotype, horizontal and vertical peri‐implant bone defects, and dehiscences were assessed. Depending on I‐BP, two types of grafting procedures were performed. In group A (I‐BP <4 mm), only the peri‐implant gap was grafted during the surgical phase (internal grafting [IG]), whereas group B (I‐BP ≥4 mm) received both internal and external grafting (IEG). Master casts of the sites, made before implant placement and after 1 year of loading, were optically scanned. A computerized analysis of the contour changes at the involved sites was performed by superimposing the scanned models.Results:A total of 20 patients (eight males and 12 females) were recruited, and 20 non‐submerged implants were placed in fresh extraction sockets. No implant failed during the observation period. The mean follow‐up was 25 months (range: 12 to 37 months). After 1 year of loading, group A showed a slight decrease in mean buccal volume, whereas group B had an increase in volume (P= 0.02). IAS was higher for group B than group A.Conclusions:When implants are placed immediately after tooth extraction, I‐BP may represent a useful diagnostic parameter in choosing the most appropriate grafting procedure (IG versus IEG). In clinical cases in which the distance between implant surface and the buccal plate is <4 mm, the combination of internal and external grafting (IEG) is recommended to maintain the volume and the contour of the ridge and achieve a successful esthetic outcome.
Mowing Height and Genotype Influence on Carbohydrate Content of Buffalograss
Authors: Peterson K. W. , Wegner C. J. , Amundsen K. L. , Gaussoin R. E. , Schacht W. H. , Horst G. L. , Shearman R. C. 
Published: March 2013

ABSTRACTDetermination of total nonstructural carbohydrate levels in turf‐type buffalograss [Buchloë dactyloides (Nutt.) Engelm.] genotypes as influenced by mowing height has not been previously investigated. The objectives of this study were to determine the influence of buffalograss genotype and mowing height on total nonstructural sugar and starch content during the growing season. The study was conducted at the John Seaton Anderson Turfgrass Research Facility located near Mead, NE. Cultivars Legacy and Prestige along with selections NE‐2979 and NE‐2964 from the buffalograss breeding program at the University of Nebraska were studied. The genotypes were mowed at 1.6 and 5.0 cm. Sugar and starch content trends were similar, but differences in carbohydrate concentration among genotypes were observed. NE‐2964 exhibited the greatest sugar content, 6.37% at 5‐cm mowing height, and NE‐2979 the lowest sugar content, 1.75% at 5‐cm mowing height. Legacy exhibited the greatest starch content, 12.6% at 5‐cm mowing height, and NE‐2979 the lowest starch content, 1.3% at 5‐cm mowing height. Surprisingly, mowing height had little effect on sugar or starch levels of buffalograss. Genotype was the greatest source of variation for sugar and starch content, indicating that different genotypes partition or allocate carbohydrates differently. These results show the seasonal carbohydrate content variations among buffalograss genotypes and provide some insight as to why those changes occur.
Diversity of Maize Kernels from a Breeding Program for Protein Quality: I. Physical, Biochemical, Nutrient, and Color Traits
Authors: Jaradat Abdullah A. , Goldstein Walter 
Published: March 2013

ABSTRACTIt is a challenge to breed maize (Zea mays L.) varieties with enhanced levels of protein, oil, starch, and essential amino acid contents while maintaining competitive agronomic capability. We used multivariate statistical procedures to quantify total diversity and its components for 31 physical, biochemical, nutrient, and color traits of 1348 accessions from 13 maize populations. The germplasm belonged to stiff and non‐stiff stalk heterotic groups at different stages of inbreeding and with opaque or translucent kernel endosperm. Cluster, principal components, and variance components analyses resulted in separating populations and traits into statistically different groups and helped to identify physical and color traits that may be useful for selecting accessions with high protein, amino acid, oil, and nutrient contents. We identified correlative relationships between groups of biochemical and nutrient traits linked to certain populations or physical or kernel color traits. Diversity analysis revealed variable relationships between and within total diversity and its components depending on kernel physical, biochemical, nutrient, and color traits. Sources of variation in and amount of variation attributed to total diversity for each of these traits were identified and quantified. Populations and genotypes within populations were identified as sources of variation for multiple kernel quality traits that can be used in developing high‐quality maize varieties.