bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synapses
Authors: Harrigan Jenna , Schweizer Felix E 
Published: April 2021

Abstract

Synapses are the connection sites between nerve cells and their targets, either other nerve cells or effector cells such as muscle. The transfer of information across synapses, called synaptic transmission, is a tightly regulated and modifiable process. Information is sent along axons in the form of electrical signals, called action potentials. Action potentials are rapid changes in the cell membrane that can propagate long distances. These changes in potential occur in response to ions that flow across the cell membrane. At electrical synapses, ions can pass directly into the postsynaptic cell through gap junctions and thus change the postsynaptic membrane potential. At chemical synapses, the electrical signal is converted to a chemical signal by triggering the release of neurotransmitter from the presynaptic cell. This neurotransmitter then binds to receptors on the postsynaptic cell to induce an appropriate reaction. The strength of a synapse can vary over time, a process called synaptic plasticity.

Key Concepts

Intercellular signalling between neurons is achieved at synapses.

At electrical synapses, current flows directly from one neuron to another through channels called gap junctions.

At chemical synapses, a neurotransmitter is released from the signal‐providing (presynaptic) neuron onto the signal‐receiving (postsynaptic) neuron.

Neurotransmitter molecules are concentrated in vesicles that fuse with the presynaptic membrane, either spontaneously or in response to a trigger, and release neurotransmitter.

Synaptic transmission is modulated by several cellular and biochemical pathways and neuronal network properties, and this plasticity of synapses underlies brain functions such as learning.

Natural and man‐made toxicants that disrupt neurotransmission via diverse synaptic targets are important tools in drug development and biological research.
Plant Endoplasmic Reticulum
Authors: Sparkes Imogen A 
Published: April 2021

Abstract

The plant endoplasmic reticulum (ER) is responsible for the synthesis and often storage of a large group of proteins and lipids that enter the secretory pathway. This multifunctional organelle, which also represents one of the calcium storage compartments in plant cells, has currently received considerable attention from the research community because of features unique to plants that make it particularly interesting for biotechnology. Here, the principles behind ER dynamics and interactions between the ER and organelles in plants, and the molecular factors that control the rapid remodelling and network configuration of the organelle are discussed. Correlations between ER morphology and function indicate the potential to enhance protein storage by merely increasing the capacity of the organelle through altering its shape.

Key Concepts

The endoplasmic reticulum in plants rapidly changes ‘shape’.

The ER is composed of a polygonal network of tubules and cisternae (sheets) that readily interconvert.

ER morphology is controlled by several molecular components; membrane shaping proteins, reticulons (RTNs), affect ER curvature, root hair defective 3 (RHD3) controls tubule fusion and is affected by lunapark.

ER network movement is driven by actin and myosin in plants.

The ER is physically connected to several organelles in plant cells.
Genome Organisation: Human
Authors: Kass David H , Batzer Mark A 
Published: April 2021

AbstractThe human nuclear genome is organised into a highly complex arrangement of two sets of 23 chromosomes comprised of various types of deoxyribonucleic acid (DNA) sequences. With less than 2% of the human genome consisting of protein‐encoding DNA sequence, the remainder of the 3 × 109 bp of the haploid genome consists of a multifaceted assortment of DNA sequence classifications. At the broadest level, the genome can be divided into single‐copy protein‐encoding genes, repetitive sequences and spacer DNA. Notably, the categories of repetitive sequences are profoundly intricate and may be further classified into functional or functionally related groups such as gene families and superfamilies, or groups with no known function such as satellite DNA and transposable elements. Their genomic organisation may be dispersed, within localised regions, and/or tandemly repeated. The generation of repetitive sequences results from a variety of mechanisms continually promoting a genome that is highly dynamic.Key ConceptsThe human genome is highly complex and dynamic.Only 2–4% of the three billion base pairs of the human genome consists of protein‐encoding genes, of which only a portion of that is translated into amino acids with some of the sequence being involved in regulation of gene expression.The human genome consists of single or low‐copy genes, moderately repetitive sequences and highly repetitive sequences initially determined utilising reassociation kinetics, with all three categories of DNA found throughout the genome.G‐band staining of chromosomes yield karyograms that define characteristic properties and organisation of the genome.Repetitive DNA sequences comprise a large proportion of the genome and may be dispersed and/or in tandem arrays.The repetitive sequences in the genome may be functional or serve no known function. Functional repetitive sequences may encode protein or RNA molecules.A large fraction of DNA sequences in the human genome have been generated via mechanisms such as unequal crossing over yielding either functional, or nonfunctional pseudogene, copies typically adjacent to each other, as well as by reverse transcription which yields retrocopies dispersed throughout the genome.Functional tandem repeats of DNA sequences are localised in certain chromosomal regions, for example the rRNA genes within nucleolar organiser regions (NORs), providing numerous copies of genes typically having general functions (e.g. protein synthesis).Telomeres are the sequences at the ends of the chromosomes that consist of tandemly repeated sequences associated with stability and maintenance of chromosome size after cell division.
Prostate Cancer
Authors: Mason Matthew M , Evans Christopher P 
Published: April 2021

Abstract

The prostate is a walnut‐sized gland located between the bladder and external urinary sphincter through which the urethra passes. The primary function of the prostate is to produce a slightly alkaline fluid that protects spermatozoa from the acidic environment found within the vaginal tract; hence, it is important in reproduction. Adenocarcinoma of the prostate is the second most commonly diagnosed cancer in men worldwide, with approximately 99% of cases occurring in men over the age of 50. Improvements in screening techniques and aggressive treatment have led to markedly improved survival rates over the past two decades. Treatment‐related side effects and ‘overtreatment’ of prostate cancer, however, have significantly impacted prostate cancer survivors and thus ignited a significant amount of controversy regarding prostate cancer screening.

Key Concepts

Prostate cancer is among the most frequent causes of cancer in men.

Hereditary prostate cancer has been associated with inherited mutations in many different genes including
BRCA1
,
BRCA2
,
ATM
and
CHEK2
.

Prostate‐specific antigen can be used to detect early‐stage prostate cancer and monitor response to treatment.

Treatment decisions for localised prostate cancer are complex and must take into account patient age, life expectancy, overall medical condition and patient preferences.

Treatment of localised prostate cancer mainly consists of active surveillance, radical prostatectomy or radiation therapy with androgen deprivation therapy.

Additional treatment modalities are being actively studied including cryosurgery, brachytherapy and high intensity focused ultrasound.
Trypanosomiases
Authors: Gibson Wendy 
Published: April 2021

Abstract

The human trypanosomiases are vector‐borne tropical diseases that occur in tropical Africa and South America and are caused by parasitic protozoa. Human African trypanosomiasis (or sleeping sickness) is caused by two subspecies of
Trypanosoma brucei
and is transmitted by the bite of the bloodsucking tsetse fly. Chagas disease occurs in Latin America and is caused by
Trypanosoma cruzi
. This parasite is transmitted by triatomine bugs, which acquire infection by feeding on infected blood, but pass the parasites on to the next host via their infected faeces. The human trypanosomiases are zoonoses and a range of wild and domestic mammals can act as reservoir hosts for the parasites. There are no vaccines for these diseases and control relies on drug treatment and limiting opportunities for transmission.

Key Concepts

Human African trypanosomiasis and Chagas disease are both caused by insect‐borne, parasitic trypanosomes, but the diseases and the parasite life cycles are completely different.

Control of the trypanosomiases relies on treatment of human patients and reduction of transmission, largely achieved through killing the insect vectors.

The human trypanosomiases are zoonotic diseases and a range of wild and domestic mammals act as reservoir hosts for the parasites.

Vector‐borne diseases with animal reservoirs have complex epidemiology and are difficult to control.

Elimination of Human African trypanosomiasis as a public health problem in sub‐Saharan Africa seems likely if current treatment, surveillance and tsetse control measures are maintained.

Animal reservoir hosts are more important in maintaining Human African trypanosomiasis in East Africa than West and Central Africa.

Eradication of Chagas disease is thwarted by the longevity of infection in humans, circulation of the parasite in a wide range of animal reservoir hosts and transmission by routes other than the insect vector.
Symmetry‐Broken Au–Cu Heterostructures and their Tandem Catalysis Process in Electrochemical CO2 Reduction
Authors: Jia Henglei , Yang Yuanyuan , Chow Tsz Him , Zhang Han , Liu Xiyue , Wang Jianfang , Zhang Chun‐yang 
Published: April 2021

AbstractSymmetry‐breaking synthesis of colloidal nanocrystals with desired structures and properties has aroused widespread interest in various fields, but the lack of robust synthetic protocols and the complex growth kinetics limit their practical applications. Herein, a general strategy is developed to synthesize the Au–Cu Janus nanocrystals (JNCs) through the site‐selective growth of Cu nanodomains on Au nanocrystals, which is directed by the substantial lattice mismatch between them, with the assistance of judicious manipulation of the growth kinetics. This strategy can work on Au nanocrystals with different architectures for the achievement of diverse asymmetric Au–Cu hybrid nanostructures. Of particular note, the obtained Au nanobipyramids (Au NBPs)‐based JNCs facilitate the conversion of CO2 to C2 hydrocarbon production during electrocatalysis, with the Faradaic efficiency and maximum partial current density being 4.1‐fold and 6.4‐fold higher than those of their monometallic Cu counterparts, respectively. The excellent electrocatalytic performances benefit from the special design of the Au–Cu Janus architectures and their tandem catalysis mechanism as well as the high‐index facets on Au nanocrystals. This research provides a new approach to synthesize various hybrid Janus nanostructures, facilitating the study of structure‐function relationship in the catalytic process and the rational design of efficient heterogeneous electrocatalysts.
Ohmic Dissipation‐Assisted Complex Amplitude Hologram with High Quality
Authors: Cheng Yang , Li Yongfeng , Wang He , Chen Hongya , Wan Weipeng , Wang Jiafu , Zheng Lin , Zhang Jieqiu , Qu Shaobo 
Published: April 2021

AbstractTailoring the phase and amplitude of electromagnetic waves has drawn great attention in the microwave, terahertz, and even optics domains. However, the existing method for simultaneous control of these two essential properties suffers from inadequate efficiency and narrow bandwidth, especially for microwave devices. Here, a strategy of overcoming this difficulty is proposed by introducing the ohmic sheet into a Fabry–Pérot‐like cavity. The arbitrary phase modulation can be realized by changing the geometric parameters and the orientation of elliptical split resonance ring; via changing the intensity of ohmic dissipation, the amplitude can be continuously adjusted from 0 to 1. Its most significant advantage is arbitrary wide‐band complex‐amplitude modulation without introducing cross‐polarization crosstalk and backward scattering field interference. To verify its feasibility, three phase‐amplitude holographic imaging ​prototypes at 12, 14, and 16 GHz are designed. Both the simulated and measured results manifest the excellent performances of the proposed metasurface, demonstrating the excellent performances with a remarkable signal‐to‐noise ratio and low root‐mean‐square error. This proposed strategy provides an alternative method to control the phase and amplitude arbitrarily, which not only realizes high‐quality holography but also paves a way for random beamforming and so on.
The Trityl‐Cation Mediated Phosphine Oxides Reduction
Authors: Laye Claire , Lusseau Jonathan , Robert Frédéric , Landais Yannick 
Published: April 2021

AbstractReduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)4]− as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes.magnified image
Chemoselective Peptide Backbone Diversification and Bioorthogonal Ligation by Ruthenium‐Catalyzed C−H Activation/Annulation
Authors: Song Liangliang , Ojeda‐Carralero Gerardo M. , Parmar Divyaakshar , González‐Martínez David A. , Van Meervelt Luc , Van der Eycken Johan , Goeman Jan , Rivera Daniel G. , Van der Eycken Erik V. 
Published: April 2021

AbstractThe field of peptide derivatization by metal‐catalyzed C−H activation has been mostly directed to modify the side chains, but poor attention has been given to the peptide backbone. Here we report a ruthenium‐catalyzed C−H activation/annulation process that can chemoselectively modify the peptide backbone producing functionalized isoquinolone scaffolds with high regioselectivity in a rapid and step‐economical manner. This strategy is characterized by racemization‐free conditions and the production of fluorescent peptides, and peptide conjugates to drugs, natural products and other peptide fragments, providing a chemical approach for the construction of novel peptide‐pharmacophore conjugates. Mechanistic studies suggest that amide bonds of peptide backbone act as the bidentate directing group to promote the C−H activation/annulation process. This report provides an unprecedented example of peptide backbone diversification and bioorthogonal ligation exploiting the power of ruthenium‐catalyzed C−H activation.magnified image
Carbon‐Coordinated Single Cr Site for Efficient Electrocatalytic N2 Fixation
Authors: Song Wei , Fu Ling , He Chaozheng , Xie Kun 
Published: April 2021

AbstractElectrocatalytic nitrogen reduction reaction (NRR) is a very promising method for ammonia (NH3) synthesis under ambient conditions, which can provide alternative routes to the traditional Haber–Bosch process and realize green NH3 synthesis. In this study, the electrocatalytic performance of chromium (Cr) atom anchored to graphyne (Cr@GY) is systematically investigated using density functional theory (DFT) calculations. The results show that Cr@GY is an efficient NRR electrocatalyst which can activate the inert N≡N bond sufficiently. In particular, the enzymatic mechanism is considered as the most positive catalytic pathway with the limiting potential of −0.52 V. More importantly, Cr@GY can restrict a competitive hydrogen evolution reaction (HER). The electronic properties including Bader charge, the charge difference density (CDD), the partial density of states (PDOS) and the crystal orbital Hamilton population (COHP) have been analyzed in detail. In addition, the co‐doping of B and N atoms in GY is beneficial to reduce the energy barrier of the potential‐determining step (PDS) and promote the smooth progress of the NRR. This work can provide theoretical guidance for the experimental synthesis of the single‐atom catalysts (SACs) with high activity and stability.
Ultramicroporous carbons featuring sub‐Ångstrom tunable apertures for the selective separation of light hydrocarbon
Authors: Du Shengjun , Wang Xingjie , Huang Jiawu , Kent Kirlikovali , Huang Baolin , Karam Idrees , Li Zhong , Xiao Jing 
Published: April 2021

AbstractSeparations of both C3 alkene/alkane and C4 alkadiene/alkenes are of great commercial significance as propylene and butadiene represent important feedstock chemicals, but the full extraction of them using carbon‐based separating agents has yet to be fully realized. Herein, derived from low‐cost starch precursors, we report a series of ultramicroporous starch‐based carbon materials (SC‐M; M = Na, K, Rb), with sub‐Ångstrom tunable ultramicropore apertures to separate the targeted gases with high purity. Among these materials, potassium derivative SC‐K can deliver high uptake capacities of propylene and butadiene (up to 2.20 and 2.36 mmol/g, respectively, at 100 kPa and 298 K) and superior selectivities due to a molecular‐sieving effect, as evidenced through adsorption isotherms and breakthrough experiments. Low heats of adsorption enable regeneration of SC‐M under mild conditions. To our knowledge, SC‐K represents the sole example of a porous carbon material that demonstrates potential for highly selective sieving‐driven separation of both C3 alkene/alkane and C4 alkadiene/alkenes.
Heterozygous missense variant in TRPC6 in a boy with rapidly progressive infantile nephrotic syndrome associated with diffuse mesangial sclerosis
Authors: Hanafusa Hiroaki , Hidaka Yoshihiko , Yamaguchi Tomomi , Shimojo Hisashi , Tsukahara Takanori , Murase Tsubasa , Matsuoka Daisuke , Chiba Nao , Shimada Shun , Morokawa Hirokazu , Omori Norio , Minoura Hironori , Nagano China , Takano Kyoko , Nakamura Katsuya , Wakui Keiko , Fukushima Yoshimitsu , Uehara Takeshi , Nakazawa Yozo , Iijima Kazumoto , Nozu Kandai , Kosho Tomoki 
Published: April 2021

AbstractTransient receptor potential channel C6 encoded by TRPC6 is involved in slit diaphragm formation in podocytes, and abnormalities of the TRPC6 protein cause various glomerular diseases. The first identified pathogenic variant of TRPC6 was found to cause steroid‐resistant nephrotic syndrome that typically developed in adulthood and then slowly led to end‐stage renal disease, along with a renal pathology of focal segmental glomerulosclerosis. Here, we report a patient with rapidly progressing infantile nephrotic syndrome and a heterozygous missense TRPC6 variant. The patient, a 2‐year‐old Japanese boy, developed steroid‐resistant nephrotic syndrome at age 11 months. His renal function deteriorated rapidly, and peritoneal dialysis was introduced at age 1 year and 6 months. His renal pathology, obtained at age 1 year and 1 month, was consistent with diffuse mesangial sclerosis (DMS). Clinical exome analysis and custom panel analysis for hereditary renal diseases revealed a reported heterozygous missense variant in TRPC6 (NM_004621.5:c.523C > T:p.Arg175Trp). This is the first report of a patient with a TRPC6‐related renal disorder associated with DMS.
Novel MYT1 variants expose the complexity of oculo‐auriculo‐vertebral spectrum genetic mechanisms
Authors: Zamariolli Malú , Burssed Bruna , Moysés‐Oliveira Mariana , Colovati Mileny , Bellucco Fernanda Teixeira da Silva , dos Santos Leonardo Caires , Alvarez Perez Ana Beatriz , Bragagnolo Silvia , Melaragno Maria Isabel 
Published: April 2021

AbstractOculo‐auriculo‐vertebral spectrum (OAVS) is a developmental disorder characterized by anomalies mainly involving the structures derived from the first and second pharyngeal arches. The spectrum presents with heterogeneous clinical features and complex etiology with genetic factors not yet completely understood. To date, MYT1 is the most important gene unambiguously associated with the spectrum and with functional data confirmation. In this work, we aimed to identify new single nucleotide variants (SNVs) affecting MYT1 in a cohort of 73 Brazilian patients diagnosed with OAVS. In addition, we investigated copy number variations (CNVs) encompassing this gene or its cis‐regulatory elements and compared the frequency of these events in patients versus a cohort of 455 Brazilian control individuals. A new SNV, predicted as likely deleterious, was identified in five unrelated patients with OAVS. All five patients presented hearing impairment and orbital asymmetry suggesting an association with the variant. CNVs near MYT1, located in its neighboring topologically associating domain (TAD), were found to be enriched in patients when compared to controls, indicating a possible involvement of this region with OAVS pathogenicity. Our findings highlight the genetic complexity of the spectrum that seems to involve more than one variant type and inheritance patterns.
Operator Transpose within Normal Ordering and its Applications for Quantifying Entanglement
Authors: Hu Liyun , Zhang Luping , Chen Xiaoting , Ye Wei , Guo Qin , Fan Hongyi 
Published: April 2021

AbstractPartial transpose is an important operation for quantifying entanglement. In this study, the (partial) transpose of any single (two‐mode) operator is investigated. Using the Fock basis expansion, it is found that the transposed operator of an arbitrary operator can be obtained by replacing with , rather than the c‐number within the normal ordering form. The transpose of the displacement and Wigner operators is also investigated, from which the relation of the Wigner function, characteristics function, and average values such as covariance matrix is constructed between the density operator and transposed density operator. These observations can be further extended to multi‐mode cases. As for the application, partial transpose of the two‐mode squeezed operator and the entanglement of the two‐mode squeezed vacuum through a laser channel is considered.
A Supramolecular Complex of C60–S with High‐Density Active Sites as a Cathode for Lithium–Sulfur Batteries
Authors: Xiang Jingwei , Shen Wangqiang , Guo Zezhou , Meng Jintao , Yuan Lixia , Zhang Yi , Cheng Zexiao , Shen Yue , Lu Xing , Huang Yunhui 
Published: April 2021

AbstractThe well‐known “shuttle effect” of the intermediate lithium polysulfides (LiPSs) and low sulfur utilization hinder the practical application of lithium–sulfur (Li–S) batteries. Herein, we describe a novel C60–S supramolecular complex with high‐density active sites for LiPS adsorption that was formed by a simple one‐step process as a cathode material for Li–S batteries. Benefiting from the cocrystal structure, 100 % of the C60 molecules in the complex can offer active sites to adsorb LiPSs and catalyze their conversion. Furthermore, the lithiated C60 cores promote internal ion transport inside the composite cathode. At a low electrolyte/sulfur ratio of 5 μL mg−1, the C60–S cathode with a sulfur loading of 4 mg cm−2 exhibited a high capacity of 809 mAh g−1 (3.2 mAh cm−2). The development of the C60–S supramolecular complex will inspire the invention of a new family of S/fullerenes as cathodes for high‐performance Li–S batteries and extend the application of fullerenes.