bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further extension of the Heinz-Kato-Furuta inequality
Authors: Uchiyama Mitsuru 
Published: July 2002

Let

T
T

be a bounded operator on a Hilbert space

H

,

\mathfrak {H},

and

A
,
B

A,B

positive definite operators. Kato has shown that if

‖
T
x
‖
≤
‖
A
x
‖

\Vert T x \Vert \leq \Vert A x \Vert

and

‖

T

∗

y
‖
≤
‖
B
y
‖

\Vert T^{*} y \Vert \leq \Vert B y \Vert

for all

x
,
y
∈

H

x, y \in \mathfrak {H}

, then

|

(
T
x
,
y
)

|

≤

|

|

f
(
A
)
x

|

|

|

|

g
(
B
)
y

|

|

,

|(Tx , y)| \leq ||f(A)x|| \; ||g(B)y||,

where

f
(
t
)
,
g
(
t
)

f(t), g(t)

are operator monotone functions defined on

[
0
,
∞
)

[0, \infty )

such that

f
(
t
)
g
(
t
)
=
t

f(t) g(t)=t

. Furuta has shown that

|

(
T

|

T

|

α
+
β
−
1

x
,
y
)

|

≤

|

|

A

α

x

|

|

|

|

B

β

y

|

|

,
where
0
≤
α
,
β
≤
1
,
1
≤
α
+
β
.

|(T|T|^{\alpha +\beta -1}x,y)|\leq ||A^{\alpha }x|| ||B^{\beta }y||, \text { where } 0 \leq \alpha ,\beta \leq 1, 1\leq \alpha + \beta .

Let

f
(
t
)
,
g
(
t
)

f(t), g(t)

be any continuous operator monotone functions, and set

h
(
t
)
=
f
(
t
)
g
(
t
)

/

t

h(t) = f(t) g(t) /t

for

t
>
0.

t >0.

We will show that

T
h
(

|

T

|

)

Th(|T|)

is well defined and

|

(
T
h
(

|

T

|

)
x
,
y
)

|

≤

|

|

f
(
A
)
x

|

|

|

|

g
(
B
)
y

|

|

.

|(T h(|T|)x,y)| \leq ||f(A)x|| \; ||g(B)y||.

Moreover, we will extend this result for unbounded closed operators densely defined on

H

.

\mathfrak {H}.
Analysis of base-pairing potentials between 16S rRNA and 5' UTR for translation initiation in various prokaryotes.
Authors: Osada Y , Saito R , Tomita M 
Published: July 2002

Abstract
MOTIVATION: It is well accepted that the 3' end of 16S rRNA is directly involved in prokaryotic translation initiation by pairing with the Shine-Dalgarno (SD) sequence, which is located in the ribosome-binding site of mRNA. According to Shine and Dalgarno, Escherichia coli 's 5' UTR has the pattern of 'AGGAGG' (SD sequence), which is complementary to the 3' end sequence of 16S rRNA. In this work, we systematically calculated free-energy values of the base pairing between the 3' end of 16S rRNA and the 5' UTR of mRNA, in order to analyze the base-pairing potentials in various prokaryotes. The free-energy values were then plotted over distances from the start codon to visualize the free-energy pattern of 5'UTRs. RESULTS: The average free-energy values fell sharply before the start codon in E. coli, which is consistent with the model that the 3' end of 16S rRNA base pairs with the SD sequence. Haemophilus influenzae, Bacillus subtilis and Helicobacter pylori show a similar pattern, suggesting that the organisms have basically the same mechanism of translation initiation as E. coli. Other eubacteria, such as Synechocystis PCC6803, Mycoplasma genitalium, Mycoplasma pneumoniae and Borrelia burgdorferi also show decreases in their free-energy values, although they are less evident. We also did the same analysis with a eukaryote genome as a control; no fall in free-energy values was observed between the 3' end of 18S rRNA and 5' UTRs of Saccharomyces cerevisiae, suggesting that this organism does not base pair in translation initiation. The three archaebacteria A. fulgidus, M. jannaschii and M. thermoautotrophicum show patterns similar to eubacteria, but not to S. cerevisiae, indicating that archaebacteria are closer to eubacteria than to eukaryotes with respect to the mechanism of translation initiation. From these observations, it appears that the shape of the curve produced by the algorithm can be used to predict the mechanism of translation initiation. AVAILABILITY: The C programs used in our analysis are available upon request.
V-SINEs: A New Superfamily of Vertebrate SINEs That Are Widespread in Vertebrate Genomes and Retain a Strongly Conserved Segment within Each Repetitive Unit
Authors: Ogiwara Ikuo , Miya Masaki , Ohshima Kazuhiko , Okada Norihiro 
Published: July 2002

We have identified a new superfamily of vertebrate short interspersed repetitive elements (SINEs), designated V-SINEs, that are widespread in fishes and frogs. Each V-SINE includes a central conserved domain preceded by a 5′-end tRNA-related region and followed by a potentially recombinogenic (TG)n tract, with a 3′ tail derived from the 3′ untranslated region (UTR) of the corresponding partner long interspersed repetitive element (LINE) that encodes a functional reverse transcriptase. The central domain is strongly conserved and is even found in SINEs in the lamprey genome, suggesting that V-SINEs might be ∼550 Myr old or older in view of the timing of divergence of the lamprey lineage from the bony fish lineage. The central conserved domain might have been subject to some form of positive selection. Although the contemporary 3′ tails of V-SINEs differ from one another, it is possible that the original 3′ tail might have been replaced, via recombination, by the 3′ tails of more active partner LINEs, thereby retaining retropositional activity and the ability to survive for long periods on the evolutionary time scale. It seems plausible that V-SINEs may have some function(s) that have been maintained by the coevolution of SINEs and LINEs during the evolution of vertebrates.[The sequences reported in this paper have been deposited in the DDBJ/GenBank database under accession nos.AB072981–AB073004. Supplemental figures are available online athttp://www.genome.org.]
Fine‐tuning function: Correlation of hinge domain interactions with functional distinctions between LacI and PurR
Authors: Swint‐Kruse Liskin , Larson Christopher , Pettitt B. Montgomery , Matthews Kathleen Shive 
Published: July 2002

AbstractLacI and PurR are highly homologous proteins. Their functional units are homodimers, with an N‐terminal DNA binding domain that comprises the helix‐turn‐helix (HTH), N‐linker, and hinge regions from both monomers. Hinge structural changes are known to occur upon DNA dissociation but are difficult to monitor experimentally. The initial steps of hinge unfolding were therefore examined using molecular dynamics simulations, utilizing a truncated, chimeric protein comprising the LacI HTH/N‐linker and PurR hinge. A terminal Gly‐Cys‐Gly was added to allow “dimerization” through disulfide bond formation. Simulations indicate that differences in LacI and PurR hinge primary sequence affect the quaternary structure of the hinge•hinge′ interface. However, these alternate hinge orientations would be sterically restricted by the core domain. These results prompted detailed comparison of recently available DNA‐bound structures for LacI and truncated LacI(1–62) with the PurR structure. Examination revealed that different N‐linker and hinge contacts to the core domain of the partner monomer (which binds effector molecule) affect the juxtapositions of the HTH, N‐linker, and hinge regions in the DNA binding domain. In addition, the two full‐length repressors exhibit significant differences in the interactions between the core and the C‐linker connection to the DNA binding domain. Both linkers and the hinge have been implicated in the allosteric response of these repressors. Intriguingly, one functional difference between these two proteins is that they exhibit opposite allosteric response to effector. Simulations and observed structural distinctions are correlated with mutational analysis and sequence information from the LacI/GalR family to formulate a mechanism for fine‐tuning individual repressor function.
A Magnetically Separable Pd Single‐Atom Catalyst for Efficient Selective Hydrogenation of Phenylacetylene
Authors: Zhao Linmin , Qin Xuetao , Zhang Xirui , Cai Xiangbin , Huang Fei , Jia Zhimin , Diao Jiangyong , Xiao Dequan , Jiang Zheng , Lu Ruifeng , Wang Ning , Liu Hongyang , Ma Ding 
Published: March 2022

AbstractSelective hydrogenation of alkynes to alkenes plays a crucial role in the synthesis of fine chemicals. However, how to achieve high selectivity and effective separation of the catalyst and substrate while obtaining high activity is the key for this reaction. In this work, a Pd single‐atom catalyst is anchored to the shell of magnetic core–shell particles that consist of a Ni‐nanoparticles core and a graphene sheets shell (Ni@G) for semi‐hydrogenation of phenylacetylene, delivering 93% selectivity to styrene at full conversion with a robust turnover frequency of 7074 h−1 under mild reaction conditions (303 K, 2 bar H2). Moreover, the catalyst can be recovered promptly from the liquid phase due to its magnetic separability, which makes it present good stability for enduring five cycles. Experimental and theoretical investigations reveal that H2 and substrates are activated by atomically dispersed Pd atoms and Ni@G hybrid support, respectively. The hydrogenation reaction occurs on the surface of Ni@G via hydrogen spillover from the metal to the support. Such a strategy opens an avenue for designing highly active, selective, and magnetically recyclable catalysts for selective hydrogenation in liquid reaction systems.
Tail‐To‐Tail Stereoselective Dimerization of Acrylate Derivatives via Iridium‐Catalyzed Vinylic sp2 C−H Activation
Authors: Kojima Masafumi , Sasaki Mio , Ito Mamoru , Shibata Takanori 
Published: March 2022

AbstractWe describe a cationic Ir‐catalyzed tail‐to‐tail dimerization of aryl acrylates starting from vinylic sp2 C−H activation, which gives industrially useful adipic acid ester derivatives in high yields. We further expanded the reaction to an enantioselective dimerization using aryl methacrylates and achieved the first example of catalytic asymmetric dimerization of acrylate derivatives.magnified image
Synthesis of 3‐Halogenated Quinolin‐2‐Ones from N‐Arylpropynamides via Hypervalent Iodine(III)−Mediated Umpolung Process
Authors: Li Xiaoxian , Zhang Beibei , Zhao Bingyue , Wang Xiaofan , Xu Lingzhi , Du Yunfei 
Published: March 2022

AbstractThe selective synthesis of 3‐halogenated quinolin‐2‐ones from N‐arylpropynamides was realized via umpolung process mediated by phenyliodine(III) diacetate (PIDA) and MX (LiCl, LiBr, CuI). Differing from most previous electrophilic cyclization/halogenation processes that afforded spiro[4,5]trienones, 3‐halogenated quinolin‐2‐ones were obtained through this method with high selectivity.magnified image
Tunable Tannic Acid–Zein Adhesives for Bonding Different Substrates
Authors: Schmidt Gudrun , Smith Kylie H. , Miles Logan J. , Gettelfinger Carissa K. , Hawthorne Jana A. , Fruzyna Erin C. , Wilker Jonathan J. 
Published: March 2022

AbstractPlant‐based, nontoxic and strong adhesives that can work on different substrates allow for better product recycling. Replacing synthetic adhesives with plant based ones that perform equally well may lead to a more sustainable ecosystem. Adhesives based on zein protein, derived from corn, can be made as strong as Super Glue. Unlike petroleum‐based adhesives, this plant protein is removable and degradable. Here, adhesives from the components zein and tannic acid function well on different substrates such as metals, plastics, and wood. This work presents the properties of selected adhesive formulations including bond strengths when the substrates are changed. To achieve near Super Glue strength, each substrate requires a different adhesive formulation. Temperature‐dependent curing, (potential of hydrogen) changes, and additional variables influence adhesion. Tack testing at room temperature is measured to provide comparisons between initial bonding and that achieved after curing. Adhesion to plastic substrates is less than wood or metal, but still plenty strong to measure. Aging of adhesive solutions as well as water resistance after curing is investigated. Infrared spectroscopy data are correlated with changes in color, age, and pH of adhesives. These new adhesives may lead to a sustainable and cleaner environment.
CeO2 Doping of Hf0.5Zr0.5O2 Thin Films for High Endurance Ferroelectric Memories
Authors: Yu Zhouchangwan , Saini Balreen , Liao Pei‐Jean , Chang Yu‐Kai , Hou Duen‐Huei , Nien Chih‐Hung , Shih Yu‐Chuan , Yeong Sai Hooi , Afanas'ev Valeri , Huang Fei , Baniecki John D. , Mehta Apurva , Chang Chih‐Sheng , Wong H.‐S. Philip , Tsai Wilman , McIntyre Paul C. 
Published: March 2022

AbstractFerroelectric switching is demonstrated in CeO2‐doped Hf0.5Zr0.5O2 (HZCO) thin films with application in back‐end‐of‐line compatible embedded memories. At low cerium oxide doping concentrations (2.0–5.6 mol%), the ferroelectric orthorhombic phase is stabilized after annealing at temperatures below 400 °C. HZCO ferroelectrics show reliable switching characteristics beyond 1011 cycles in TiN/HZCO/TiN capacitors, several orders of magnitude greater than identically processed Hf0.5Zr0.5O2 (HZO) capacitors, without sacrificing polarization and retention. Internal photoemission and photoconductivity experiments show that CeO2‐doping introduces in‐gap states in HZCO that are nearly aligned with TiN Fermi level, facilitating electron injection through these states. The enhanced average bulk conduction, which may lead to more uniform thermal dissipation in the HZCO films, delays irreversible degradation via breakdown that leads to device failure after repeated programming cycles.
Manipulating Strain in Transistors: From Mechanically Sensitive to Insensitive
Authors: Li Ming‐Zheng , Guo Liang‐Chao , Liu Gang , Yan Yan , Zhang Meng , Han Su‐Ting , Zhou Ye 
Published: March 2022

AbstractThe rapid development of flexible and stretchable materials has portrayed a bright future of flexible electronics in pursuing the concept of “Internet of Things.” Transistors, as one of the fundamental units in electronic devices, are being widely studied in exploring the possibility of increasing their flexibility and/or stretchability to fulfill the requirement in flexible electronics, from basic logic circuits to intelligent devices. However, the mechanical stimuli induced by bending and stretching activities can lead to unexpected performance degradations. Here, an in‐depth analysis of approaches to modulating the sensitivity of flexible and stretchable transistors, from a mechanically sensitive type to an insensitive type is demonstrated. Starting with the structural design, the mechanism of sensitivity modulation is explicitly analyzed, such as effects based on the modulation of dielectric capacitance, conductance of active channels, or contact resistance at interfaces in sensitive transistors and strain patterning technology applied to an insensitive type. The sensitivity modulation for transistors is further analyzed regarding material utilization based on different dimensional forms. Finally, the potential applications where flexible and stretchable transistors can be employed as an outlook are discussed.
Inverted Anode Structure for Long‐Life Lithium Metal Batteries
Authors: Li Dongdong , Xie Chuan , Gao Yuan , Hu Hong , Wang Lei , Zheng Zijian 
Published: March 2022

AbstractUnlimited growth of lithium dendrites is undesirable yet preventing this still remains a challenge for pursuing high‐energy battery systems. Serious safety hazards caused by short circuit and fire demand accurate control of the nucleation location of lithium deposition. Here, an inverted anode structure enabled by simple flipping of carbon fabric after lithium electrodeposition is reported. In contrast to traditional strategies of using regular upright structure, the inverted anode structure can guide a directional deposition of lithium to the bottom of the anode. The low nucleation barrier originating from the bottom lithium metal can induce a superior bottom‐up deposition process. Lithium dendrite issues can thus be significantly alleviated, and approximately twice the cycle life extension of the lithium metal anode is achieved. More importantly, the solid electrolyte interphase immersed in the inverted anode structure is extremely stable, resulting from the well supporting skeleton of the surrounding carbon fabric fibers. The assembled lithium metal batteries show excellent cycling stability with a capacity retention per cycle of 99.98%, i.e., the battery capacity still retains 82.3% after 750 charge/discharge cycles. This simple inversion strategy is universal and can be extended to other porous current collectors, such as thin conductive fabric, and offers great opportunities for next‐generation lithium‐based batteries.
A DNA‐Based Plasmonic Nanodevice for Cascade Signal Amplification
Authors: Liu Fengsong , Li Na , Shang Yingxu , Wang Yiming , Liu Qing , Ma Zhentao , Jiang Qiao , Ding Baoquan 
Published: March 2022

AbstractHere, we describe a DNA circuit‐aided, origami nanodevice‐based plasmonic system, which performs DNA‐regulated, cascade amplification of faint chemical/biological signals. In this system, two gold‐nanorods (GNRs) are co‐assembled onto a DNA lock‐containing, tweezer‐like DNA origami template. Logic circuits serve as recognition and amplification elements for specific messengers, producing DNA keys for driving conformational changes of the plasmonic nanodevices. In the presence of input signals including nucleic acids, adenosines, chiral tyrosinamides or specific receptors expressed by tumor cells, the plasmonic nanodevices can be activated to perform dynamic structural motions, reporting robust responses via plasmonic circular dichroism (CD) spectral changes. This DNA nanodevice‐based system provides a different design to enrich the strategies for constructing synthetic nanomachines, enabling the customized bottom‐up nanostructure construction for sensitive biological signaling.
Chemical Biology Tools for Protein Lysine Acylation
Authors: Xie Yusheng , Du Shubo , Liu Zhiyang , Liu Min , Xu Zhiqiang , Wang Xiaojie , Kee Jia Xuan , Yi Fan , Sun Hongyan , Yao Shao Q. 
Published: March 2022

AbstractLysine acylation plays pivotal roles in cell physiology, including DNA transcription and repair, signal transduction, immune defense, metabolism, and many other key cellular processes. Molecular mechanisms of dysregulated lysine acylation are closely involved in the pathophysiological progress of many human diseases, most notably cancers. In recent years, chemical biology tools have become instrumental in studying the function of post‐translational modifications (PTMs), identifying new “writers”, “erasers” and “readers”, and in targeted therapies. Here, we describe key developments in chemical biology approaches that have advanced the study of lysine acylation and its regulatory proteins (2016–2021). We further discuss the discovery of ligands (inhibitors and PROTACs) that are capable of targeting regulators of lysine acylation. Next, we discuss some current challenges of these chemical biology probes and suggest how chemists and biologists can utilize chemical probes with more discriminating capacity. Finally, we suggest some critical considerations in future studies of PTMs from our perspective.
Achieving 37.1% Green Electroluminescent Efficiency and 0.09 eV Full Width at Half Maximum Based on a Ternary Boron‐Oxygen‐Nitrogen Embedded Polycyclic Aromatic System
Authors: Cai Xinliang , Xue Jianan , Li Chenglong , Liang Baoyan , Ying Ao , Tan Yao , Gong Shaolong , Wang Yue 
Published: March 2022

AbstractHerein, a ternary boron‐oxygen‐nitrogen embedded polycyclic aromatic hydrocarbon with multiple resonance thermally activated delayed fluorescence (MR‐TADF), namely DBNO, is developed by adopting theparaboron‐π‐boron andparaoxygen‐π‐oxygen strategy. The designed molecule presents a vivid green emission with a high photoluminescence quantum yield (96 %) and an extremely narrow full width at half maximum (FWHM) of 19 nm/0.09 eV, which surpasses all previously reported green TADF emitters to date. In addition, the long molecular structure along the transition dipole moment direction endows it with a high horizontal emitting dipole ratio of 96 %. The organic light‐emitting diode (OLED) based on DBNO reveals a narrowband green emission with a peak at 504 nm and a FWHM of 24 nm/0.12 eV. Particularly, a significantly improved device performance is achieved by the TADF‐sensitization (hyperfluorescence) mechanism, presenting a FWHM of 27 nm and a maximum external quantum efficiency (EQE) of 37.1 %.
Operando Spectroscopy Unveils the Catalytic Role of Different Palladium Oxidation States in CO Oxidation on Pd/CeO2 Catalysts
Authors: Muravev Valery , Simons Jérôme F. M. , Parastaev Alexander , Verheijen Marcel A. , Struijs Job J. C. , Kosinov Nikolay , Hensen Emiel J. M. 
Published: March 2022

AbstractAiming at knowledge‐driven design of novel metal–ceria catalysts for automotive exhaust abatement, current efforts mostly pertain to the synthesis and understanding of well‐defined systems. In contrast, technical catalysts are often heterogeneous in their metal speciation. Here, we unveiled rich structural dynamics of a conventional impregnated Pd/CeO2 catalyst during CO oxidation. In situ X‐ray photoelectron spectroscopy and operando X‐ray absorption spectroscopy revealed the presence of metallic and oxidic Pd states during the reaction. Using transient operando infrared spectroscopy, we probed the nature and reactivity of the surface intermediates involved in CO oxidation. We found that while low‐temperature activity is associated with sub‐oxidized and interfacial Pd sites, the reaction at elevated temperatures involves metallic Pd. These results highlight the utility of the multi‐technique operando approach for establishing structure–activity relationships of technical catalysts.
Gold‐Catalyzed Desymmetric Lactonization of Alkynylmalonic Acids Enabled by Chiral Bifunctional P,N ligands
Authors: Lin Bijin , Yang Tilong , Zhang Dequan , Zhou Yang , Wu Liangliang , Qiu Jingfei , Chen Gen‐Qiang , Che Chi‐Ming , Zhang Xumu 
Published: March 2022

AbstractDue to the linear coordination nature of gold(I) catalysts, achieving high enantiocontrol in asymmetric gold catalysis is a great challenge. To improve the enantiocontrol of gold catalysis, an ion‐pairing strategy was therefore proposed. A series of bifunctional P,N ligands based on chiral spirocyclic and biaryl scaffolds were synthesized and applied in the gold(I)‐catalyzed desymmetric lactonization of alkynylmalonic acids. A wide range of chiral lactones containing an α‐position quaternary stereocenter were synthesized with high yields, excellent regioselectivity and enantioselectivity under mild reaction conditions. The synthetic utilities of the current reaction were demonstrated by gram‐scale synthesis and transformations of chiral lactones. The origin of enantioselectivity and the role of the alcohol additive were elucidated via control experiments and DFT calculations.
Metal‐Free Ring‐Opening Metathesis Polymerization with Hydrazonium Initiators**
Authors: Quach Phong K. , Hsu Jesse H. , Keresztes Ivan , Fors Brett P. , Lambert Tristan H. 
Published: March 2022

AbstractThe ring‐opening metathesis polymerization (ROMP) of cyclopropenes using hydrazonium initiators is described. The initiators, which are formed by the condensation of 2,3‐diazabicyclo[2.2.2]octane and an aldehyde, polymerize cyclopropene monomers by a sequence of [3+2] cycloaddition and cycloreversion reactions. This process generates short chain polyolefins (Mn≤9.4 kg mol−1) with relatively low dispersities (Đ≤1.4). The optimized conditions showed efficiency comparable to that achieved with Grubbs’ 2nd generation catalyst for the polymerization of 3‐methyl‐3‐phenylcyclopropene. A positive correlation between monomer to initiator ratio and degree of polymerization was revealed through NMR spectroscopy.