bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circadian Programmes in Cyanobacteria
Authors: Cohen Susan E 
Published: November 2021

Abstract

Cyanobacteria are bacteria that express circadian (daily) rhythms. In rhythmic environments, the fitness of cyanobacteria is improved when this clock is operational and when its circadian period is similar to the period of the environmental cycle. In cyanobacteria, three key proteins (KaiA, KaiB and KaiC) form a core molecular clockwork that orchestrates rhythmic outputs including global rhythms of gene expression, cell division, compaction of the chromosome and metabolism. KaiA, KaiB and KaiC form a multiprotein nanomachine that can reconstitute a circadian oscillator
in vitro
, and this oscillator appears to function as a posttranslational oscillator (PTO)
in vivo
.
In vivo
, an extended clock network allows the core oscillator to synchronize with the environment and relate temporal information to clock‐controlled activities. Models of the complete
in vivo
system have important implications for our understanding of circadian clocks in higher organisms, including mammals.

Key Concepts

Prokaryotic cyanobacteria have a circadian timekeeping system that enhances fitness.

These cells exhibit pervasive circadian regulation of gene expression.

A circadian rhythm of the phosphorylation of the central clock protein KaiC can be reconstituted
in vitro
with three proteins derived from cyanobacteria (KaiA, KaiB and KaiC) and ATP.

KaiA, KaiB and KaiC are the only circadian clock proteins for which the 3D structure of full‐length proteins is known.

Structural, biochemical and biophysical methods have been used to study the mechanism by which KaiC is rhythmically phosphorylated and dephosphorylated.

Rhythmic associations of the extended clock network with the KaiABC oscillator help to coordinate rhythmic outputs.
Molecular Clock: Testing
Authors: Mello Beatriz , Kumar Sudhir , Battistuzzi Fabia Ursula 
Published: November 2021

AbstractThe molecular clock hypothesis originally rested on the assumption of rate constancy across lineages of a phylogeny, which would produce an approximately steady rate of accumulation of deoxyribonucleic acid or amino acid changes through time. This assumption has been questioned on the basis of increasingly large data sets, which have shown significant variability of evolutionary rates in lineages. To address this issue, tests have been developed to examine whether rates of molecular evolution vary significantly among taxonomic groups or phylogenetic lineages. Two major types of tests exist: those based on comparisons of genetic distances and those based on likelihood ratios. The first ones compare genetic distances between two species (or groups of species) relative to an outgroup; the latter ones compare maximum likelihood values for the same phylogeny calculated with and without the constant rate assumption. In those cases where the rate constancy assumption is violated, modern molecular clocks (relaxed clocks) are now being applied to implement rate heterogeneity in the time estimation process.Key ConceptsEvolutionary rates among lineages can be constant or variable.The first molecular clock methods developed (strict, or global, clocks) assumed constant rates.Many datasets have been shown to violate the rate constancy assumption.Testing for rate constancy is a key step before estimating times.Parametric and nonparametric rate tests are available.Variable rates may follow different distributions (autocorrelated or uncorrelated).While autocorrelation seems more common, it is advisable to test for the best fitting distribution.
Human Evolution: Early Radiations
Authors: Wood Bernard A , McRae Ryan T 
Published: November 2021

Abstract

We interpret the early radiations within the hominin clade as including all of the taxa in genera other than
Homo
. While the taxa in
Australopithecus
,
Kenyanthropus
and
Paranthropus
are almost certainly hominins, others in the genera
Ardipithecus
,
Orrorin
and
Sahelanthropus
may not be hominins but belong in one or more closely related clades. All of the taxa in
Australopithecus
,
Kenyanthropus
and
Paranthropus
have brain sizes one third (or less) to one half the average size of later
Homo
, postcranial skeletons that combine adaptations for bipedalism with retention of upper limbs adapted for climbing, and postcanine teeth that are relatively larger than those of chimpanzees and bonobos, covered by enamel that is thicker than that seen in chimpanzees and bonobos. Some (e.g.
Paranthropus boisei
) have exceptionally large postcanine teeth with hyper‐thick enamel cusps.

Key Concepts

Morphological and genetic features separate humans from our closest relatives in the genus
Pan

The earliest potential hominins retain many ‘ape‐like’ features such as arms adapted for climbing

All early hominins have chewing teeth that are relatively larger, and with thicker enamel, than in the genus
Pan

By the time of
Australopithecus afarensis
, hominins were fully bipedal

A radiation of megadont and hyper‐megadont hominins (
Paranthropus
) is found in eastern and southern Africa
Superior Antidegeneration Hierarchical Nanoengineered Wicking Surfaces for Boiling Enhancement
Authors: Li Jiaqi , Zhao Yongyi , Ma Jingcheng , Fu Wuchen , Yan Xiao , Rabbi Kazi Fazle , Miljkovic Nenad 
Published: November 2021

AbstractMicro‐ and nano‐structured surfaces having high wicking capability enable excellent liquid transport efficiency and have great promise in water desalination, atmospheric water harvesting, biomedical device development, and electronics thermal management applications. However, the poorly understood degeneration of surface wickability during exposure to air represents the main hindrance to societal application of structured surfaces. Here, the authors investigate wicking degeneration on structured surfaces and elucidate the importance of environmental volatile organic compound adsorption from air. Based on their developed mechanistic understanding, the authors design a highly scalable, cost‐effective, and hierarchical structure having both superior wicking capability and antidegeneration performance. Year‐long continuous surface wickability measurements demonstrate a 4100% higher surface wickability durability of this structure when compared to widely used single‐tier surface structures. Pool boiling tests coupled with in situ and in‐liquid optical microscopy are used to characterize the effect of wicking degradation on boiling heat transfer performance. This work demonstrates the previously unidentified coexistence of several dry areas underneath individual bubbles during boiling on highly wicking structured surfaces, resulting in significant augmentation of the three‐phase contact line length. In addition, this work outlines design guidelines for the fabrication of surface wicking structures having high performance and durability.
Reprogramming Tumor‐Associated Macrophages via ROS‐Mediated Novel Mechanism of Ultra‐Small Cu2−xSe Nanoparticles to Enhance Anti‐Tumor Immunity
Authors: Zheng Yanhui , Han Yaobao , Wang Tingting , Liu Hanghang , Sun Qiao , Hu Shijun , Chen Jianquan , Li Zhen 
Published: November 2021

AbstractReprogramming tumor‐associated macrophages (TAMs) from tumor‐supportive M2 phenotype to anti‐tumor M1 phenotype holds great promise in tumor immunotherapy. However, there are few reports on the remodeling of TAMs by inorganic nanoparticles due to their unclear intrinsic polarization mechanism. In this article, a novel signaling pathway of repolarizing TAMs into M1‐like macrophages is reported to boost anti‐tumor immunity using ultra‐small Cu2−xSe nanoparticles (CS NPs). The mechanism is totally different from the conventional ROS‐mediated polarization mechanism. It is revealed that CS NPs can effectively generate ROS in the macrophages to trigger auto‐ubiquitination of tumor necrosis factor receptor‐associated factor 6 (TRAF6), which activates the interferon regulatory factor 5 (IRF5) to facilitate the expression of its downstream gene interleukin‐23 (IL‐23), and eventually remodels the TAMs into M1‐like macrophages. It is shown that CS NPs can significantly inhibit the growth of melanoma tumor (B16F10) by repolarizing TAMs into M1‐like macrophages, and enhance the adaptive anti‐tumor immunity by inducing the infiltration of CD8+ T cells. Moreover, it is found that CS NPs can also effectively inhibit the recurrence of distal tumor. The study shows the novel macrophage polarization mechanism for TAMs‐targeted cancer immunotherapy, and demonstrates the great potential of ultra‐small Cu2−xSe nanoparticles in cancer immunotherapy.
Toward Stable and Efficient Perovskite Light‐Emitting Diodes
Authors: Yang Dexin , Zhao Baodan , Yang Tao , Lai Runchen , Lan Dongchen , Friend Richard H. , Di Dawei 
Published: November 2021

AbstractMetal halide perovskites (MHPs) are a promising class of materials for next‐generation display and lighting applications. Since the first demonstration of bright electroluminescence (EL) from perovskite light‐emitting diodes (PeLEDs) in 2014, the EQEs of these devices increased from below 1% to more than 20% in merely four years. Despite the meteoritic rise of device efficiencies that placed the new LED technology in the spotlight, many scientific and technical challenges remain, preventing PeLEDs from advancing further into practical applications. The success of inorganic III‐V LEDs, or commercial LED technologies in general, lies in the ability to demonstrate the reliable generation of blue EL. For PeLEDs, high operational stability and efficient blue EL remain to be some of the most pressing goals. To accelerate further developments in these areas, the recent progress in the research of PeLEDs is reviewed. The authors attempt to establish preliminary connections between the degradation mechanisms and the strategies for improvements, exemplified by a selection of recent representative works in the field. Lessons learned from organic LEDs and perovskite solar cells point toward some of the most important directions. This progress report serves as a catalyst for further interdisciplinary research involving materials scientists, chemists, and physicists working together to realize operationally stable PeLEDs.
Untethered Microrobots for Active Drug Delivery: From Rational Design to Clinical Settings
Authors: Liu Dong , Wang Ting , Lu Yuan 
Published: November 2021

AbstractRecent advances of untethered microrobots, which navigate the complex regions in vivo for therapeutics, have presented promising multiple applications on future healthcare. Microrobots used for active drug delivery system (DDS) have been demonstrated for advanced targeting distribution, improved delivery efficiency, and reduced systemic side effects. In this review, the therapeutic benefits of active DDS are presented compared to the traditional passive DDS, which illustrate the historical reasons for choosing active DDS. An integrated 5D radar chart analysis model containing the core capabilities of the active DDS is innovatively proposed. It would be a practical tool for measurement and mapping of the field of active delivery, followed by the evolutions and bottlenecks of each technical module. The comprehensive consideration of microrobots before clinical application is also discussed from the aspects of robot ethics, dosage, quality control and stability control in actual production. Gastrointestinal and blood administration, as two major clinical scenes of drug delivery, are discussed in detail as examples of the potential bedside applications of active DDS. Finally, combined with the reported analysis model, the current status and future outlook from the translation prospect to the clinical scenes of microrobots are provided.
Fluorine‐Free Nanoporous Low‐k Dielectric Film Covalently Grafted on Si via Aryldiazonium Chemistry
Authors: Cao Liangliang , Wu Yunwen , Hang Tao , Li Ming 
Published: November 2021

AbstractFluorine‐free nanoporous low‐k dielectric film containing polyhedral oligomeric silsesquioxanes (POSS) cage nanostructure is covalently grafted onto a p‐Si(100) surface via aryldiazonium chemistry, in an open environment without any inert gas protection. The method is based on two‐step reduction of aryldiazonium salts. First, 4‐nitrobenzene diazonium tetrafluoroborate (NBD) is reduced and a polynitrophenyl (PNP) passivation layer is formed on the p‐Si(100) surface, in an aqueous media with hydrofluoric acid being added. Second, NBD is reduced by electrons provided by external pulse power supply, and initiates octavinylsilsesquioxane polymerizing to form the film, which is composed of PNP and massive POSS cage, leading to a low k value. The average dielectric constant of the film is 2.12 at the range of 600 to 1700 nm wavelength, much lower than some low‐k materials reported by recent literature and traditional materials. The prepared films completely cover the Si substrate and are compact and thickness controllable. In particular, the k value can be controlled though the concentration of NBD. The low‐k properties imply they will be suitable to be utilized as high‐performance dielectric materials in future higher frequency communication field.
Epitaxial III–V/Si Vertical Heterostructures with Hybrid 2D‐Semimetal/Semiconductor Ambipolar and Photoactive Properties
Authors: Chen Lipin , Léger Yoan , Loget Gabriel , Piriyev Mekan , Jadli Imen , Tricot Sylvain , Rohel Tony , Bernard Rozenn , Beck Alexandre , Le Pouliquen Julie , Turban Pascal , Schieffer Philippe , Levallois Christophe , Fabre Bruno , Pedesseau Laurent , Even Jacky , Bertru Nicolas , Cornet Charles 
Published: November 2021

AbstractHybrid materials taking advantage of the different physical properties of materials are highly attractive for numerous applications in today's science and technology. Here, it is demonstrated that epitaxial bi‐domain III–V/Si are hybrid structures, composed of bulk photo‐active semiconductors with 2D topological semi‐metallic vertical inclusions, endowed with ambipolar properties. By combining structural, transport, and photoelectrochemical characterizations with first‐principle calculations, it is shown that the bi‐domain III–V/Si materials are able within the same layer to absorb light efficiently, separate laterally the photo‐generated carriers, transfer them to semimetal singularities, and ease extraction of both electrons and holes vertically, leading to efficient carrier collection. Besides, the original topological properties of the 2D semi‐metallic inclusions are also discussed. This comb‐like heterostructure not only merges the superior optical properties of semiconductors with good transport properties of metallic materials, but also combines the high efficiency and tunability afforded by III–V inorganic bulk materials with the flexible management of nano‐scale charge carriers usually offered by blends of organic materials. Physical properties of these novel hybrid heterostructures can be of great interest for energy harvesting, photonic, electronic or computing devices.
Polysulfide Catalytic Materials for Fast‐Kinetic Metal–Sulfur Batteries: Principles and Active Centers
Authors: Cheng Menghao , Yan Rui , Yang Zhao , Tao Xuefeng , Ma Tian , Cao Sujiao , Ran Fen , Li Shuang , Yang Wei , Cheng Chong 
Published: November 2021

AbstractBenefiting from the merits of low cost, ultrahigh‐energy densities, and environmentally friendliness, metal–sulfur batteries (M–S batteries) have drawn massive attention recently. However, their practical utilization is impeded by the shuttle effect and slow redox process of polysulfide. To solve these problems, enormous creative approaches have been employed to engineer new electrocatalytic materials to relieve the shuttle effect and promote the catalytic kinetics of polysulfides. In this review, recent advances on designing principles and active centers for polysulfide catalytic materials are systematically summarized. At first, the currently reported chemistries and mechanisms for the catalytic conversion of polysulfides are presented in detail. Subsequently, the rational design of polysulfide catalytic materials from catalytic polymers and frameworks to active sites loaded carbons for polysulfide catalysis to accelerate the reaction kinetics is comprehensively discussed. Current breakthroughs are highlighted and directions to guide future primary challenges, perspectives, and innovations are identified. Computational methods serve an ever‐increasing part in pushing forward the active center design. In summary, a cutting‐edge understanding to engineer different polysulfide catalysts is provided, and both experimental and theoretical guidance for optimizing future M–S batteries and many related battery systems are offered.
Usefulness of An Anal Sphincter Injury Mouse Model by Means of a Balloon Catheter and a New Method of Evaluating Anal Sphincter Function
Authors: Yukimoto Ryohei , Miyoshi Norikatsu , Fujino Shiki , Mori Ryota , Ogino Takayuki , Takahashi Hidekazu , Uemura Mamoru , Mizushima Tsunekazu , Doki Yuichiro , Eguchi Hidetoshi 
Published: November 2021

AbstractBackgroundThe incidence of fecal incontinence is ~2%, and the associated symptoms significantly impact daily life. New treatment methods including electrical stimulation and regenerative therapy using stem cells for fecal incontinence have been reported. We explored the usefulness of an anal sphincter injury mouse model by means of a balloon catheter and focused on the defecation status of mice as a novel method for evaluating anal function. We examined the utility of the mouse model of anal sphincter injury and the efficacy of electrical stimulation as a treatment modality using this model.MethodsA 10‐mm balloon catheter was used to create an anal sphincter injury model in mice. Sphincter function was evaluated in the noninjured (n = 4), injured (n = 4), noninjured electrical stimulation (n = 4), and injured electrical stimulation (n = 4) groups. Defecation status (defecation frequency in 24 h and fecal weight per stool) and pathological evaluation were used for comparison.ResultsThe defecation frequency increased and the fecal weight per stool decreased significantly in the anal sphincter injury model. Pathological evaluation revealed that anal sphincter tears occurred the day after the injury. Meanwhile, the defecation frequency improved on d 7, and the fecal weight per stool gradually normalized to that of the control group and exhibited significant sphincter muscle hypertrophy in the electrical stimulation group.ConclusionAnal sphincter injury using a balloon catheter in mice allowed us to create a uniform model. The evaluation of defecation status in mice is a useful method for comparatively evaluating anal function.
Genetic variants of PON1, GSTM1, GSTT1, and locus 9p21.3, and the risk for premature coronary artery disease in Yucatan, Mexico
Authors: García‐González Igrid , Pérez‐Mendoza Gerardo , Solís‐Cárdenas Alberto , Flores‐Ocampo Jorge , Herrera‐Sánchez Luis Fernando , Mendoza‐Alcocer Renan , González‐Herrera Lizbeth 
Published: November 2021

AbstractObjectiveGenetic variants of PON1, rs70587, rs662, rs854560, GSTM1, and GSTT1 and two single nucleotide polymorphisms (SNP) at 9p21.3 locus, rs1333049, and rs2383207; were evaluated in association with the risk for premature coronary artery disease (CAD) in a population of Yucatan, Mexico. These genes are involved in the inactivation of pro‐oxidants and pro‐inflammatory mediators, lipid and xenobiotic metabolism, detoxification of reactive oxygen species, and regulation of cellular proliferation playing key roles in the pathogenesis of atherosclerosis.MethodsWe conducted a matched case–control study with 98 CAD cases and 101 healthy controls. Genotyping of PON1 and 9p21.2 SNP was performed by real time‐PCR and for GSTM1 and GSTT1 with multiplex‐PCR. Odds ratios (OR) were calculated to estimate association and generalized multifactor dimensionality reduction (GMDR) algorithm to identify gene–gene and gene–environment interactions.ResultsThe distribution of all allele/genotype frequencies in controls was within Hardy–Weinberg expectations (p > .05) except for GSTM1. The allele/genotype frequencies of the GSTT1 null were significantly higher in CAD cases than in controls, suggesting association with higher risk for developing CAD. The other SNPs did not show any significant independent association with premature CAD. GMDR revealed a significant interaction between GSTT1 and LL55 genotype. Likewise, the body mass index (BMI) and smoking also showed an interaction with GSTT1.ConclusionThe GSTT1 null allele/genotype is associated with an increased risk of developing premature CAD, the effect of which is not modified by cardiovascular risk factors in the population of Yucatan.
Trends of cigarette smoking and smokeless tobacco use among US firefighters and law enforcement personnel, 1992–2019
Authors: Phan Lilianna , McNeel Timothy S. , Jewett Bambi , Moose Katherine , Choi Kelvin 
Published: November 2021

AbstractBackgroundPrevious studies indicate tobacco use was more prevalent among firefighters and law enforcement personnel than in the US adult population. Trends of smoking and smokeless tobacco (SLT) use among these first responders are unknown. We examined trends in current smoking and SLT use among US firefighters and law enforcement personnel and compared smoking and SLT use prevalence in firefighters and law enforcement personnel to US adults in non‐first‐responder occupations.MethodsTrends of smoking and SLT use prevalence among firefighters, law enforcement personnel, and adults in other occupations were assessed by fitting joinpoint regression models using the 1992–2019 Tobacco Use Supplement to the Current Population Survey (TUS‐CPS). We used multivariable logistic regression models adjusted for demographics to examine associations between occupation and smoking and SLT use status using the 2018–2019 TUS‐CPS data. Analyses were conducted in 2021.ResultsFrom 1992 to 2019, the smoking prevalence declined overall (all p's < 0.01). Though SLT use prevalence among adults in non‐first‐responder occupations declined (annual percentage change [APC] = −1.2%; 95% confidence interval [CI] = −1.7% to −0.7%), no changes were shown among firefighters and law enforcement personnel which suggests SLT use may be increasing among firefighters over time. In 2018–2019, firefighters (adjusted odds ratio [AOR] = 3.4; 95% CI = 1.7 to 6.8) and law enforcement personnel (AOR = 3.2; 95% CI = 2.1 to 4.7) were more likely than adults in non‐first‐responder occupations to use SLT.ConclusionsWhile smoking prevalence declined overall, SLT use is higher among firefighters and law enforcement personnel and may be increasing over time among firefighters. Research should examine reasons for SLT use by first responders. Comprehensive tobacco policies and SLT‐specific cessation programs are needed for first responders.