bluuebunny/crossref_metadata_2025 huggingface dataset:
Are Guidelines Needed for the Diagnosis and Management of Incipient Alzheimer's Disease and Mild Cognitive Impairment?
Authors: Palmer Katie , Musicco Massimo , Caltagirone Carlo
Published: August 2010

Current research is aiming to push the boundaries of the point at which a diagnosis of Alzheimer Disease (AD) can be made. Clinical syndromes such as Mild Cognitive Impairment (MCI) and various clinical and biological markers of AD may help to identify people in the early stage of AD, before a full dementia syndrome is present. In the first part of this paper, we discuss whether MCI represents incipient AD, and examine some of the methods currently used in research to identify AD patients in the preclinical phase. In the second part, we discuss whether specific guidelines are needed for the diagnosis and management of MCI and incipient AD, and consider the potential impact of this on clinical practice and public health from the perspective of patients, caregivers, and healthcare providers.
Scavenger Receptors and Their Potential as Therapeutic Targets in the Treatment of Cardiovascular Disease
Authors: Stephen Sam L. , Freestone Katie , Dunn Sarah , Twigg Michael W. , Homer-Vanniasinkam Shervanthi , Walker John H. , Wheatcroft Stephen B. , Ponnambalam Sreenivasan
Published: August 2010

Scavenger receptors act as membrane-bound and soluble proteins that bind to macromolecular complexes and pathogens. This diverse supergroup of proteins mediates binding to modified lipoprotein particles which regulate the initiation and progression of atherosclerotic plaques. In vascular tissues, scavenger receptors are implicated in regulating intracellular signaling, lipid accumulation, foam cell development, and cellular apoptosis or necrosis linked to the pathophysiology of atherosclerosis. One approach is using gene therapy to modulate scavenger receptor function in atherosclerosis. Ectopic expression of membrane-bound scavenger receptors using viral vectors can modify lipid profiles and reduce the incidence of atherosclerosis. Alternatively, expression of soluble scavenger receptors can also block plaque initiation and progression. Inhibition of scavenger receptor expression using a combined gene therapy and RNA interference strategy also holds promise for long-term therapy. Here we review our current understanding of the gene delivery by viral vectors to cells and tissues in gene therapy strategies and its application to the modulation of scavenger receptor function in atherosclerosis.
Fertilization Rate and Number of Embryos on Day 2 after Intrauterine and Deep Intrauterine Insemination Using Frozen-Thawed Boar Semen in Multiparous Sows
Authors: Buranaamnuay Kakanang , Panyaboriban Yodchai , Tummaruk Padet , Techakumphu Mongkol
Published: August 2010

The present study determines fertilization rate and number of embryos on Day 2 after intrauterine insemination (IUI) and deep intrauterine insemination (DIUI) using frozen-thawed (FT) boar semen in multiparous sows. Twelve crossbred Landrace × Yorkshire multiparous sows were included. The sows were inseminated at 24 h after oestrus detection and reinseminated every 12 h until ovulation took place. The inseminations were conducted using IUI with2×109 FT sperm per dose (n=6) and DIUI with1×109 FT sperm per dose (n=6). The sows were slaughtered at45.1±7.2 h after ovulation. Embryos and unfertilized oocytes were flushed from the oviducts. IUI yielded a better fertilization rate than DIUI (66.0% versus 31.0%,P<.001). The number of embryos was13.5±2.7and6.6±3.2embryos/sow in IUI and DIUI groups, respectively (P=.08). The proportion of sows having unilateral fertilization was higher in the DIUI (3/5) than the IUI group (1/6). In conclusion, IUI with at least2×109total number of FT boar spermatozoa is recommended.
A Generalized Poisson Transform of an Lp-Function over the Shilov Boundary of the
n-Dimensional Lie Ball
Authors: El Wassouli Fouzia
Published: August 2010

Let 𝒟 be the n-dimensional Lie ball and let
𝔅(S) be the space of hyperfunctions on the Shilov
boundary S of 𝒟. The aim of this paper is to give a
necessary and sufficient condition on the generalized Poisson transform
Pl，λf of an element f in the space
𝔅(S) for f to be in
Lp(S), 1 < p < 1. Namely, if
F is the Poisson transform of some f ∈
𝔅(S) (i.e., F = Pl，λf ), then for any l ∈ ℤ and ， ∈
C such that , we show
that f ∈ Lp(S) if and only if f satisfies
the growth condition
Becoming a Co-Survivor—Reflections From the ICU
Authors: Burns Courtney Julia
Published: May 2024

This essay describes what the author learned from being in the intensive care unit with her father during multiple cardiac arrests and surgery.
Dual Checkpoint Inhibition in Melanoma With ≥1% PD-L1—Time to Reassess the Evidence
Authors: Donia Marco , Prasad Vinay
Published: May 2024

This Viewpoint discusses use of anti–PD-1 monotherapy as the primary treatment option for patients with treatment-naive metastatic melanoma staining positive for PD-L1 over dual checkpoint inhibition therapy.
High Toughness Laminated Composites Fabricated from Ti3Al(Si)C2 Filled Preceramic Paper and Nb Foils: Formation Mechanism and Influence of Laminate Architecture
Authors: Kashkarov Egor Borisovich , Krotkevich Dmitriy , Abdulmenova Anastasia , Tolkachev Oleg , Travitzky Nahum
Published: May 2024

In this work high strength and tough metal‐ceramic laminated composites are fabricated by spark plasma sintering (SPS) of Ti3Al(Si)C2 MAX‐phase filled preceramic papers (TAC) and ductile Nb foils. The sintering is carried out at 1250 °C and 50 MPa for 5–20 min. Various stacking techniques are used to obtain Nb/TAC laminated composites with different architectures. SPS results in the formation of reaction layer (RL) with a complex composition, which changes the thickness insignificantly with increasing sintering time. The possible formation mechanism of RL is discussed. The bending strength of Nb/TAC composites is decreased from 410 to 350 MPa when lowering the thickness of ceramic layer. The maximum fracture toughness of 10.2 MPa·m1/2 is achieved for the composite with similar individual layers thickness. The toughening is explained by complex fracture mechanisms associated with deflection and branching of cracks at interfaces, delamination, plastic deformation of Nb layers, multiple cracking and crack deflection in ceramic TAC layers.
Design and Development of Ti–Zr–Nb–Ta–Ag High Entropy Alloy for Bioimplant Applications
Authors: Hussein Mohamed Abdrabou , Abdul Azeem Mohammed , Kumar Arumugam Madhan , Ankah Nestor
Published: May 2024

A new non‐equiatomic 35Ti–35Zr–20Nb–5Ta–5Ag at% high entropy alloy (HEA) is designed by combining the HEA concept with the properties required for bioimplants. Mechanical alloying is used to synthesize the HEA, which is then compacted at 550 and 700 MPa and sintered at 1300 °C. The phases, microstructure, and mechanical properties are investigated, and in vitro corrosion properties are studied in a simulated body fluid. After 20 h of mechanical alloying, a single body‐centered cubic (BCC) phase with a nanocrystalline size of 3.6 nm was formed. After sintering, the microstructure is composed of dual‐phase BCC structures: the major BCC 1 phase, the grain boundary BCC 2 phase, and the ultra‐fine equiaxed phase. The results of the micro‐indentation test indicate that the elastic modulus of the HEA is 84.4 ± 8.7 and 113.2 ± 13.36 GPa, and its Vickers microhardness is 3.47 ± 0.1 and 5.35 ± 0.2 GPa when it was compacted at 550 and 700 MPa respectively. The corrosion resistance tests reveal that HEA compacted at 700 MPa has higher corrosion resistance than commercial Ti6Al4V alloy. The developed Ti–Zr–Nb–Ta–Ag HEA has improved corrosion resistance and a lower elastic modulus, making it a potential candidate for bioimplant applications.
Powder Aerosol Deposition and Polymers: Is There Hope for a Common Future?
Authors: Thiel Marc Christopher , Lienkamp Karen
Published: May 2024

Polymer–ceramic composites (PCCs) are promising functional materials with applications in energy technology, microelectronics, sensor technology, protective coatings, wastewater treatment or for biomedical purposes. Unfortunately, ceramics require high‐temperature sintering, while polymers only have a limited thermal stability. Therefore, PCC fabrication is quite complex and requires strict process control. This severely limits the efficiency and economy of the process and the reproducibility of the desired materials properties. Powder aerosol deposition (PAD) is a spray‐coating process in which ceramic powders are accelerated by a pressure difference using a carrier gas. They are then deposited as nanocrystalline, dense coatings onto a substrate without the need for additional sintering. In the current PAD research, the focus is ceramic powders. Yet there are also examples of polymer and ceramic particles that have been codeposited. Much of this works is trial‐and‐error, and a general concept for deposition of PCCs by PAD is not yet available. This review revisits the fundamentals of PAD and the most important process parameters that were studied experimentally and in silico. It connects these with recent work on the combination of polymers and ceramics in the PAD process to highlight and evaluate the future of this field from a polymer science perspective.
Π‐Bridge Modulations in D–π–A Conjugated Microporous Polymers to Facilitate Charge Separation and Transfer Kinetics for Efficient Photocatalysis
Authors: Li Chunlei , Xu Hetao , Xiong Hao , Xia Shuling , Peng Xu , Xu Fei , Chen Xiong
Published: May 2024

The burgeoning field of conjugated microporous polymers (CMPs) has generated widespread interest due to their potential as photocatalysts for hydrogen production from water. Nevertheless, their photocatalytic performance is sometimes hindered by inadequate charge separation and transfer, coupled with rapid charge recombination. Herein, a strategy to enhance photocatalytic performance via the customization of π‐bridges through the modulation of heteroatoms in a series of donor‐π‐acceptor (D‐π‐A) CMPs is proposed. This affords optimized energy levels and improved charge separation and transfer, thus boosting photocatalytic efficiency. Among various heteroatom substitutions, S‐doped CMP (10 mg) demonstrates the highest photocatalytic hydrogen evolution rate of 203 µmol h−1 (AQY450nm = 7.4%) under visible light irradiation. Subsequent experimental analysis reveals its superior photocatalytic performance can be largely related to its minimized exciton binding energy, facilitated charge transfer efficiency, and impeded charge recombination among these heteroatom‐doped D‐π‐A CMPs. This research paves the way for the rational design and modification of organic semiconductors for advanced solar‐driven photocatalysis by promoting charge separation and transfer.
Ultrasound‐Responsive Aligned Piezoelectric Nanofibers Derived Hydrogel Conduits for Peripheral Nerve Regeneration
Authors: Xu Dongyu , Fu Siqi , Zhang Hui , Lu Weicheng , Xie Jingdun , Li Jilai , Wang Huan , Zhao Yuanjin , Chai Renjie
Published: May 2024

Nerve guidance conduits (NGCs) are considered as promising treatment strategy and frontier trend for peripheral nerve regeneration, while their therapeutic outcomes are limited by the lack of controllable drug delivery and available physicochemical cues. Herein, novel aligned piezoelectric nanofibers derived hydrogel NGCs with ultrasound (US)‐triggered electrical stimulation (ES) and controllable drug release for repairing peripheral nerve injury are proposed. The inner layer of the NGCs is the barium titanate piezoelectric nanoparticles (BTNPs)‐doped polyvinylidene fluoride‐trifluoroethylene [BTNPs/P(VDF‐TrFE)] electrospinning nanofibers with improved piezoelectricity and aligned orientation. The outer side of the NGCs is the thermoresponsive poly(N‐isopropylacrylamide) hybrid hydrogel with bioactive drug encapsulation. Such NGCs can not only induce neuronal‐oriented extension and promote neurite outgrowth with US‐triggered wireless ES, but also realize the controllable nerve growth factor release with the hydrogel shrinkage under US‐triggered heating. Thus, the NGC can positively accelerate the functional recovery and nerve axonal regeneration of rat models with long sciatic nerve defects. It is believed that the proposed US‐responsive aligned piezoelectric nanofibers derived hydrogel NGCs will find important applications in clinic neural tissue engineering.
Localized Surface Plasmon Resonance Optical Biosensor for Simple Detection of Deoxyribonucleic Acid Mismatches
Authors: Lugongolo Masixole Yvonne , Ombinda‐Lemboumba Saturnin , Hlekelele Lerato , Nyokana Nontsikelelo , Mthunzi‐Kufa Patience
Published: May 2024

Optical biosensors are optical technologies that evaluate changes in the refractive index as they monitor non‐covalent molecular interactions in real time. These make use of unsophisticated, label‐free analytical approaches, which do not require dyes to produce a visible signal. In this study, the efficiency of localized surface plasmon resonance (LSPR) biosensor in detecting a single nucleotide mismatch in deoxyribonucleic acid is examined. The detection is based on the hybridization of a target DNA at 100 ng μL−1 with a complementary biotinylated probe as well as a partially complementary biotinylated with one nucleotide mismatch probe on a gold‐coated surface. Both probes are used at a concentration of 0.1 μm. The LSPR exhibited sensitivity by differentiating sample M+ from sample C+ through varying transmission intensities of 0.28 and 0.26 μA, respectively. Based on these findings, this approach demonstrates a great potential due to its ability to distinguish samples that differ with a single base pair, and its efficiency will be explored in the development of a point‐of‐care device as a simpler and cost‐effective approach for detection of various biologically and medically significant mutations such as antimicrobial resistance mutations. More work is underway to determine the robustness of the LSPR biosensor using the biotin–neutravidin approach.
A Thermally Reconfigurable Photonic Switch Utilizing Drop Cast Vanadium Oxide Nanoparticles on Silicon Waveguides
Authors: Tanyi Gregory , Peace Daniel , Taha Mohammed , Cheng Elliot , Hiep Dinh Xuan , Ren Guanghui , Lim Christina , Mitchell Arnan , Unnithan Ranjith R.
Published: May 2024

Photonic switches play a vital role in optical communications and computer networks for establishing and releasing connections of optical signals. With the growing demand for ultra‐compact switches in high‐speed optical computing and communications, thermally reconfigurable optical switches have gained significant attention. These switches offer simplicity, ease of fabrication, and leverage a wide range of thermo‐optic materials. Silicon remains an ideal platform for making photonic devices including the switches due to its compatibility with complementary metal‐oxide‐semiconductor (CMOS) technology and cost‐effectiveness. The article presents a drop cast sub‐stoichiometric vanadium oxide (VO2−x) nanoparticles combined with a silicon ridge waveguide to make a compact thermally reconfigurable optical switch with low transition temperature and accelerated phase transition. Furthermore, the design achieves high modulation depth in addition to its scalability and simplicity. This study demonstrates the potential of solution‐based VO2−x nanoparticles in combination with silicon waveguides for efficient optical switch design for various applications.
Reducing Peptidoglycan Crosslinking by Chemical Modulator Reverts β‐lactam Resistance in Methicillin‐Resistant Staphylococcus aureus
Authors: Kim Ji‐Hoon , Lee Yunmi , Kim Inseo , Chang JuOae , Hong Subin , Lee Na Kyung , Shum David , Baek Seongeun , Kim Wooseong , Jang Soojin , Lee Wonsik
Published: May 2024

Small molecule can be utilized to restore the effectiveness of existing major classes of antibiotics against antibiotic‐resistant bacteria. In this study, it is demonstrated that celastrol, a natural compound, can modify the bacterial cell wall and subsequently render bacteria more suceptible to β‐lactam antibiotics. It is shown that celastrol leads to incomplete cell wall crosslinking by modulating levels of c‐di‐AMP, a secondary messenger, in methicillin‐resistant Staphylococcus aureus (MRSA). This mechanism enables celastrol to act as a potentiator, effectively rendering MRSA susceptible to a range of penicillins and cephalosporins. Restoration of in vivo susceptibility of MRSA to methicillin is also demonstrated using a sepsis animal model by co‐administering methicillin along with celastrol at a much lower amount than that of methicillin. The results suggest a novel approach for developing potentiators for major classes of antibiotics by exploring molecules that re‐program metabolic pathways to reverse β‐lactam‐resistant strains to susceptible strains.
Clearfield upland rice intercropped with Urochloa ruziziensis for grain, increased revenue and environmental preservation
Authors: de Sousa Santos Fenelon Lourenço , Nascente Adriano Stephan , Lacerda Mabio Chisley , Calil Francine Neves
Published: May 2024

Intercropping perennial forage grasses into cereal crops is an alternative to recover degraded pastures. However, the intercrop of forage grasses, such as Urochloa ruziziensis (R. Germ. and C. M. Evard) Crins (Congo grass), can lead to losses in cereal yield. Therefore, it is necessary to develop management strategies that allow forage grass establishment without major losses in cereal yield in intercropping. The objective was to study the agronomic and economic impacts of intercropping U. ruziziensis into a Clearfield upland rice (Oryza sativa L.) cultivar in the state of Goiás, Brazil, in two growing seasons. Treatments included forage grass seeds sowing method (broadcast or incorporation to the soil) and sowing times (at rice sowing, 20 days after emergence [DAE], and 45 DAE of rice). Also, imazapyr + imazapic herbicide was applied to restrict the competitive effect on rice yield. Monocropping control plots were also evaluated. Grain yield was measured on rice. Forage grass dry matter yield was measured at 30, 60, and 90 days after harvesting (DAH) of rice. Crude protein content was analyzed at 90 DAH. Profitability was calculated for each cropping system relative to rice monocropping. Intercropping of rice and U. ruziziensis sowed at 45 DAE provided the highest grain yield relative to other assessed intercropping treatments as well as rice monocropping. Concurrent sowing of rice and incorporated U. ruziziensis seeding provided the greatest economic return. This reformed cropping system improved land and pasture output, which can reduce the pressure to convert more land to agricultural use.
FI‐Net: Rethinking Feature Interactions for Medical Image Segmentation
Authors: Ding Yuhan , Liu Jinhui , He Yunbo , Huang Jinliang , Liang Haisu , Yi Zhenglin , Wang Yongjie
Published: May 2024

To solve the problems of existing hybrid networks based on convolutional neural networks (CNN) and Transformers, we propose a new encoder–decoder network FI‐Net based on CNN‐Transformer for medical image segmentation. In the encoder part, a dual‐stream encoder is used to capture local details and long‐range dependencies. Moreover, the attentional feature fusion module is used to perform interactive feature fusion of dual‐branch features, maximizing the retention of local details and global semantic information in medical images. At the same time, the multi‐scale feature aggregation module is used to aggregate local information and capture multi‐scale context to mine more semantic details. The multi‐level feature bridging module is used in skip connections to bridge multi‐level features and mask information to assist multi‐scale feature interaction. Experimental results on seven public medical image datasets fully demonstrate the effectiveness and advancement of our method. In future work, we plan to extend FI‐Net to support 3D medical image segmentation tasks and combine self‐supervised learning and knowledge distillation to alleviate the overfitting problem of limited data training.
Three‐dimensional telomere profiling predicts risk of progression in smoldering multiple myeloma
Authors: Kumar Shaji , Rajkumar S. Vincent , Jevremovic Dragan , Kyle Robert A. , Shifrin Yulia , Nguyen Michelle , Husain Zahabiya , Alikhah Asieh , Jafari Anita , Mai Sabine , Anderson Kenneth , Louis Sherif
Published: May 2024

Smoldering multiple myeloma (SMM) is a precursor stage that precedes multiple myeloma (MM). SMM is heterogenous with nearly 40% of patients progressing to MM in the first 5 years. The high rate of progression of SMM patients highlights the need for early intervention, which underscores the importance of identifying SMM patients with the highest risk of progression. Several risk stratification models showed utility in identifying high‐risk SMM patients; however, these systems showed limited sensitivity. To date, identifying high‐risk SMM patients remains an important clinical need. In this study, we present the 3‐dimensional telomere profiling as a structural biomarker capable of stratifying SMM patients as a function of genomic instability. Quantifying telomere dysfunction using the TeloView technology showed utility in risk stratification of cancer patients, particularly hematological malignancies. In this study, we analyzed 168 SMM patients. We report an AUC in ROC analysis of 0.8 using a subset of the patients as a training dataset. We then conducted a blind validation on a different cohort and demonstrated a positive predictive value of 85% and negative predictive value of 73%, with sensitivity and specificity of 83% and 76%, respectively. We examined the correlation between the TeloView prediction and the 20‐2‐20 scoring system, and cytogenetic abnormalities. We report a correlation of 53% with the 20‐2‐20 scores and over 60% correlation with cytogenetic abnormalities. The result of this study presents the telomere profiling as an effective biomarker able to stratify SMM patients to their respective risk groups with high sensitivity and specificity.
Changes needed to reduce risk of musculoskeletal disorders
Authors: Macdonald Wendy A. , Oakman Jodi
Published: May 2024

Musculoskeletal disorders (MSDs) are the main contributor to disability levels, which are rising as populations age. Workplace hazard exposures are a major source of this problem, and current workplace risk management practices require substantial changes to tackle it more effectively. Most importantly, the current focus of risk management on “manual handling” tasks must broaden to encompass the whole job. This is necessary because a wide range of psychosocial hazards, most of which operate across the whole job rather than particular tasks, are significant contributors to risk. To ensure that risk‐control actions are effective, a recurring risk management cycle that includes worker participation and addresses risk from both biomechanical and psychosocial hazards will be essential. Legislation that mandates workplace management of psychosocial hazards would be helpful. Amendment by regulatory bodies of MSD‐related guidance and codes of practice so that they reflect current research evidence would also be helpful in communicating the need for change to workplace stakeholders.
Neuropsychological functioning of adults with PTEN hamartoma tumor syndrome
Authors: Oldenboom Carmen , Drissen Meggie M. C. M. , van Dongen Linde C. M. , Kleefstra Tjitske , Prins Judith B. , Egger Jos I. M. , Hoogerbrugge Nicoline
Published: May 2024

PTEN hamartoma tumor syndrome (PHTS) might be associated with a distinct cognitive and psychological profile. However, previous studies are limited, predominantly based on small and pediatric cohorts, likely affected by selection bias, and show a broad range of findings. We aimed to characterize the neuropsychological functioning of adults with PHTS. A total of 40 participants, with intellectual disability as exclusion criterium, completed an extensive clinical neuropsychological assessment including cognitive tasks, questionnaires, and a clinical diagnostic interview. The cognitive tasks and questionnaire data were categorized as below and above average based on 1.5 SD. About 80% of participants showed an average level of intelligence. In addition, 30% and 24% of participants scored below average on immediate memory recall and speed of information processing, respectively. Furthermore, about 25% reported above average scores on the majority of the questionnaires, indicating psychological distress, signs of alexithymia, and cognitive complaints. Personality of participants was characterized by inflexibility, social withdrawal, and difficulties in recognizing and describing their own emotions. Adults with PHTS demonstrate a heterogeneous yet distinct neuropsychological profile that is characterized by slower information processing, psychological problems, and specific personality traits. These findings provide directions on how to optimize the care and daily lives of adults with PHTS.
Pathogenicity and transcriptomic profiling reveals immunology molecular hallmarks after CA10 virus infection
Authors: Peng Wanjun , Wu Jing , Zhao Binbin , Zhang Lihong , Chen Xin , Wei Xiaohui , Rong Na , Han Yunlin , Liu Jiangning
Published: May 2024

Background

Hand, foot and mouth disease (HFMD) is a common infectious disease caused by viral infection by a variety of enteroviruses, with coxsackievirus A 10 (CA10) having become more prevalent in recent years.

Methods

In this study, models of CA10 infection were established in 7‐day‐old Institute of Cancer Research (ICR) mice by intraperitoneal injection to analyze the pathogenicity of the virus. RNA sequencing analysis was used to screen the differentially expressed genes (DEGs) after CA10 infection. Coxsackievirus A 16 (CA16) and enterovirus 71 (EV71) infections were also compared with CA10.

Results

After CA10 virus infection, the mice showed paralysis of the hind limbs at 3 days post infection and weight loss at 5 days post infection. We observed viral replication in various tissues and severe inflammatory cell infiltration in skeletal muscle. The RNA‐sequencing analysis showed that the DEGs in blood, muscle, thymus and spleen showed heterogeneity after CA10 infection and the most up‐regulated DEGs in muscle were enriched in immune‐related pathways. Compared with CA16 and EV71 infection, CA10 may have an inhibitory effect on T helper (Th) cell differentiation and cell growth. Additionally, the common DEGs in the three viruses were most enriched in the immune system response, including the Toll‐like receptor pathway and the nucleotide‐binding and oligomerization domain (NOD)‐like pathway.

Conclusions

Our findings revealed a group of genes that coordinate in response to CA10 infection, which increases our understanding of the pathological mechanism of HFMD.
Vollständig anorganische sp‐Kettenliganden: Isoelektronische B/N‐Analoga von E. O. Fischers Alkinylcarbinen
Authors: Walther Luis , Radacki Krzysztof , Dewhurst Rian D. , Bertermann Rüdiger , Finze Maik , Braunschweig Holger
Published: May 2024

Borylierung eines wolframgebundenen N2‐Liganden und anschließende Halogenidabstraktion ermöglichen den Zugang zu einem kationischen Komplex mit einem bisher beispiellosen linearen NNBR‐Liganden. Dieser Komplex geht [3+2] Cycloadditionen mit Aziden ein und eine unerwartete Kettenverlängerungsreaktion mit einem Iminoboran, was zu einem Komplex mit einer fünfatomigen B/N‐Kette führt. Diese beiden [NNBR]‐haltigen Komplexe, anorganische Analoga von E. O. Fischers Alkinylcarbinen, sind sehr seltene Beispiele für Moleküle, die rein anorganische Ketten von sp‐hybridisierten Atomen enthalten.
Effiziente Cu‐katalysierte Tandem‐Klicksynthese von mehrfach zuckermodifizierten Oligonukleotiden
Authors: Tölke Annika J. , Gaisbauer Julia F. , Gärtner Yasmin V. , Steigenberger Barbara , Holovan Anna , Streshnev Filip , Schneider Sabine , Müller Markus , Carell Thomas
Published: May 2024

Nukleinsäuren in Form von siRNA, Antisense‐Oligonukleotiden oder mRNA werden derzeit als neue vielversprechende Modalitäten in der pharmazeutischen Industrie erforscht. Insbesondere der Erfolg von mRNA‐Impfstoffen gegen SARS‐CoV‐2 sowie die erfolgreiche Entwicklung der ersten zuckermodifizierten siRNA‐Therapeutika haben das Feld beflügelt. Die Entwicklung von Nukleinsäuretherapeutika erfordert eine effiziente Chemie, um Oligonukleotide mit chemischen Strukturen zu verknüpfen, die die Stabilität verbessern, die Aufnahme in die Zellen fördern oder eine spezifische Adressierung ermöglichen. Für die derzeit verwendeten siRNA‐Therapeutika hat sich die Modifizierung des 3′‐Endes der Oligonukleotide mit Triple‐N‐Acetylgalactosamin (GalNAc)3 als wichtig erwiesen. Diese Modifikation wird derzeit durch eine umständliche, mehrstufige Synthese und anschließende Beladung auf das Trägermaterial erreicht. Hier berichten wir über die Entwicklung eines bifunktionellen, klickreaktiven Linkers, der die Modifizierung von Oligonukleotiden in einer Tandem‐Klickreaktion mit multiplen Zuckern, unabhängig von der Position innerhalb des Oligonukleotids, mit bemerkenswerter Effizienz und in einer Ein‐Topf Reaktion ermöglicht.
Strong and Tough MXene Bridging‐induced Conductive Nacre
Authors: Yan Jia , Zhou Tianzhu , Yang Xinyu , Zhang Zejun , Li Lei , Zou Zhaoyong , Fu Zhengyi , Cheng Qunfeng
Published: May 2024

Nacre is a classic model, providing an inspiration for fabricating high‐performance bulk nanocomposites with the two‐dimensional platelets. However, the “brick” of nacre, aragonite platelet, is an ideal building block for making high‐performance bulk nanocomposites. Herein, we demonstrated a strong and tough conductive nacre through reassembling aragonite platelets with bridged by MXene nanosheets and hydrogen bonding, not only providing high mechanical properties but also excellent electrical conductivity. The flexural strength and fracture toughness of the obtained conductive nacre reach ~282 MPa and ~6.3 MPa m1/2, which is 1.6 and 1.6 times higher than that of natural nacre, respectively. These properties are attributed to densification and high orientation degree of the conductive nacre, which is effectively induced by the combined interactions of hydrogen bonding and MXene nanosheets bridging. The crack propagations in conductive nacre are effectively inhibited through crack deflection with hydrogen bonding, and MXene nanosheets bridging between aragonite platelets. In addition, our conductive nacre also provides a self‐monitoring function for structural damage and offers exceptional electromagnetic interference shielding performance. Our strategy of reassembling the aragonite platelets exfoliated from waste nacre into high‐performance artificial nacre, provides an avenue for fabricating high‐performance bulk nanocomposites through the sustainable reutilization of shell resources.
Strong Swelling and Symmetrization in Siliceous Zeolites due to Hydrogen Insertion at High Pressure
Authors: Santoro Mario , Rouquette Jérôme , Fabbiani Marco , di Renzo Francesco , Coasne Benoît , Dong Weiwei , Glazyrin Konstantin , Haines Julien
Published: May 2024

Hydrogen and helium saturate the 1D pore systems of the high‐silica (Si/Al>30) zeolites Theta‐One (TON), and Mobile‐Twelve (MTW) at high pressure based on x‐ray diffraction, Raman spectroscopy and Monte Carlo simulations. In TON, a strong 22 % volume increase occurs above 5 GPa with a transition from the collapsed P21 to a symmetrical, swelled Cmc21 form linked to an increase in H2 content from 12 H2/unit cell in the pores to 35 H2/unit cell in the pores and in the framework of the material. No transition and continuous collapse of TON is observed in helium indicating that the mechanism of H2 insertion is distinct from other fluids. The insertion of hydrogen in the larger pores of MTW results in a strong 11 % volume increase at 4.3 GPa with partial symmetrization followed by a second volume increase of 4.5 % at 7.5 GPa, corresponding to increases in hydrogen content from 43 to 67 and then to 93 H2/unit cell. Flexible 1D siliceous zeolites have a very high H2 capacity (1.5 and 1.7 H2/SiO2 unit for TON and MTW, respectively) due to H2 insertion in the pores and the framework, in contrast to other atoms and molecules, thereby providing a mechanism for strong swelling.
Hidden Impurities Generate False Positives in Single Atom Catalyst Imaging
Authors: Allasia Nicolò , Collins Sean Michael , Ramasse Quentin Mathieu , Vilé Gianvito
Published: May 2024

Single‐atom catalysts (SACs) are an emerging class of materials, leveraging maximum atom utilization and distinctive structural and electronic properties to bridge heterogeneous and homogeneous catalysis. Direct imaging methods, such as aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy, are commonly applied to confirm the atomic dispersion of active sites. However, interpretations of data from these techniques can be challenging due to simultaneous contributions to intensity from impurities introduced during synthesis processes, as well as any variation in position relative to the focal plane of the electron beam. To address this matter, this paper presents a comprehensive study on two representative SACs containing isolated nickel or copper atoms. Spectroscopic techniques, including X‐ray absorption spectroscopy, were employed to prove the high metal dispersion of the catalytic atoms. Employing scanning transmission electron microscopy imaging combined with single‐atom‐sensitive electron energy loss spectroscopy, we scrutinized thin specimens of the catalysts to provide an unambiguous chemical identification of the observed single‐atom species and thereby distinguish impurities from active sites at the single‐atom level. Overall, the study underscores the complexity of SACs characterization and establishes the importance of the use of spectroscopy in tandem with imaging at atomic resolution to fully and reliably characterize single‐atom catalysts.
On Tautomerism and Amphoterism: An In‐Depth Structural and Physicochemical Characterization of Ammeline and Some of Its Salts
Authors: Koller Thaddäus J. , Endraß Simon M. J. , Rösch Markus , Witthaut Kristian , Klapötke Thomas M. , Schnick Wolfgang
Published: May 2024

Ammeline is a simple, readily available, molecular compound, which has been known for nearly 200 years. Despite that, no proper structural characterization of ammeline has been conducted so far. For this reason, the prevalent tautomeric form of ammeline in the solid remained unknown to this date. In the course of this study, its crystal structure was finally established by single‐crystal X‐ray diffraction. In this structure, ammeline is exclusively found as its 4,6‐diamino‐1,3,5‐triazin‐2(1H)‐one tautomer and adopts layered structure with an exceptionally high hydrogen bond density. Ammeline shows an interesting amphoteric behavior. Therefore, the synthesis and structural characterization of some of its salts were carried out to investigate the influence of the protonation degree on its molecular structure. In particular, the crystal structure of silver ammelinate monohydrate was solved as the first reported structure containing deprotonated ammeline. Moreover, the crystal structures of three different modifications of ammelinium perchlorate were elucidated and the transformation conditions between them were studied. Lastly, the crystal structure of ammelinediium diperchlorate monohydrate, containing unprecedented doubly protonated ammeline, was determined. The products’ thermal behavior was studied by differential thermal analysis and thermogravimetric analysis. The perchlorate salts were additionally examined for their potential as insensitive high‐energy‐density materials.
Chemoenzymatic Synthesis of 2‐Aryl Thiazolines from 4‐Hydroxybenzaldehydes Using Vanillyl Alcohol Oxidases
Authors: Zhang Haowen , Xie Shuhan , Yang Jun , Ye Ning , Gao Feng , Gallou Fabrice , Gao Lei , Lei Xiaoguang
Published: May 2024

Nitrogen heterocycles are commonly found in bioactive natural products and drugs. However, the biocatalytic tools for nitrogen heterocycle synthesis are limited. Herein, we report the discovery of vanillyl alcohol oxidases (VAOs) as efficient biocatalysts for the one‐pot synthesis of 2‐aryl thiazolines from various 4‐hydroxybenzaldehydes and aminothiols. The wild‐type biocatalyst features a broad scope of 4‐hydroxybenzaldehydes. Though the scope of aminothiols is limited, it could be improved via semi‐rational protein engineering, generating a variant to produce previously inaccessible cysteine‐derived bioactive 2‐aryl thiazolines using the wild‐type VAO. Benefiting from the derivatizable functional groups in the enzymatic products, we further chemically modified these products to expand the chemical space, offering a new chemoenzymatic strategy for the green and efficient synthesis of structurally diverse 2‐aryl‐thiazoline derivatives to prompt their use in drug discovery and catalysis.
Enantioselective Synthesis of Cyclopentenes by (3+2) Annulation via a 2‐Carbon Phosphonium
Authors: Seitz Antonia , Maddigan‐Wyatt Jeremy T. , Cao Jing , Breugst Martin , Lupton David W.
Published: May 2024

Herein we report a catalytic enantioselective (3+2) annulation, in which a vinyl phosphonium intermediate serves as the 2‐carbon component. The reaction involves an α‐umpolung β‐umpolung coupling sequence, enabled by β‐haloacrylates and chiral enantioenriched phosphepine catalysts. The reaction shows good generality, providing access to an array of cyclopentenes, with mechanistic studies supporting stereospecific formation of the vinyl phosphonium intermediate which, then undergoes annulation with turn over limiting catalyst elimination. Beyond defining a new approach to cyclopentenes, these studies demonstrate that β‐haloacrylates can replace ynoates in reaction designs that require exclusive umpolung coupling at the α‐ and β‐positions.
Effect of concave‐wall jets with circumferential multi‐inlet on liquid–solid separation
Authors: Zhang Jing , Jiang Zhexuan , Hou Wenhao , Jian Aibo , Li Yaxia , Tian Zhiguo , Gong Bin
Published: May 2024

This study combined numerical simulation and experiment to explore the influence of the concave‐wall jets with uniformly distributed tangential inlets in the cyclone separator on the liquid–solid separation characteristics and equipment. The results show that as the number of tangential inlets increases, the superposition effect of particle trajectories and flow fields becomes more significant. The superimposed flow field enhances the circumferential flow velocity of the fluid, causing the distribution of the jet along the radial and spanwise directions to shrink, greatly improving the uniformity of particle distribution and turbulent kinetic energy along the circumference, and effectively reducing the impact of particles on local areas near the jet inlet. Since the superposition of circumferential multi‐inlet jets enhances the swirling flow, the local disturbance and wall erosion effects near the jet inlet were reduced. Compared with double inlets, the flow rates of three inlets and four inlets were increased by 50% and 100%, respectively, the maximum turbulent kinetic energy increased by 14.5% and 56.2%, and the maximum escape time of particles was shortened by 3.2 and 3.3 s, respectively, the maximum erosion rates were reduced by 38.4% and 23.6%, respectively, and the separation efficiency and material handling capacity were significantly improved. This study supplemented the theory of concave‐wall jets' superposition characteristics and provided a theoretical basis for applying circumferential multi‐inlet devices in liquid–solid separation equipment.
Supercapacitor performance enhancement with the BaS3:Cu2S:Mn2S trichalcogenide semiconductor synthesized via dithiocarbamate precursors
Authors: Ahmad Khuram Shahzad , Jaffri Shaan Bibi , Makawana Bhumikaben , Gupta Ram K. , Ashraf Ghulam Abbas , Alotaibi Nouf H.
Published: May 2024

Due to its potential uses, including e‐vehicles, electrochemical energy storage has attracted a lot of interest from the scientific community and energy stakeholders. With the usage of the novel semiconductor chalcogenide BaS3:Cu2S:Mn2S, which is synthesized by chelating with diethyldithiocarbamate ligand, the current work seeks to enhance the performance of charge‐storage devices. An energy band gap of 2.57 eV was found for this semiconductor, which showed remarkable photoactivity. The chalcogenide that was produced had favorable crystallinity, with an average crystallite size of 26.92 nm and mixed crystalline phases. Additionally, metallic sulfide linkages were identified using infrared spectroscopy, and they were reported to range from 400 to 845 cm−1. Thermal breakdown in two steps was verified using thermogravimetric analysis. Particles with different forms and a rod‐like fusion suggested a higher volume–surface area ratio and many locations. The electrochemical performance of the BaS3:Cu2S:Mn2S was evaluated using a traditional three‐electrode setup with a background electrolyte of 1‐M KOH. BaS3:Cu2S:Mn2S is a great electrode material for energy storage applications, with a specific power density of 10 618 W kg−1 and a specific capacitance of up to 694 F g−1. The same series resistance (Rs) = 0.46 Ω further supported this remarkable electrochemical performance.
Advancing the science and practice of rare plant conservation with the Center for Plant Conservation Reintroduction Database
Authors: Bellis Joe , Albrecht Matthew A. , Maschinski Joyce , Osazuwa‐Peters Oyomoare , Stanley Tina , Heineman Katherine D.
Published: May 2024

Premise

Reintroductions or translocations are an increasingly important activity to recover and conserve at‐risk plant species. Yet because many are not published in the scientific literature, learning from previous attempts may often require considerable time and effort. The Center for Plant Conservation Reintroduction Database (CPCRD; https://saveplants.org/reintroduction-database/), a new centralized and standardized repository of U.S.‐based plant reintroductions, aims to improve the efficiency and effectiveness of accessing data on rare plant reintroductions.

Methods

The CPCRD is the product of multiple efforts to assemble information on rare plant reintroductions in the United States. The database comprises a wealth of standardized data on the key stages of a reintroduction, from the planning and implementation phases, to monitoring and management techniques.

Results

The CPCRD is a dynamic resource, allowing data contributors to continually update their entries as projects progress. While contributions are ongoing, the CPCRD currently includes 460 projects involving 201 plant taxa, spanning diverse growth forms, ecosystems, and regions.

Discussion

The CPCRD and its well‐documented and monitored projects provide a valuable practical resource for conservation practitioners, and have supported multiple scientific studies and contributed to the internationally recognized Center for Plant Conservation Best Practices Guidelines.
An improved Bayesian filter for nonlinear systems under multistep randomly delayed and lost measurements
Authors: Zhang Wenbo , Cheng Guorui , Song Shenmin
Published: May 2024

This article addresses the Bayesian filtering problem for a class of nonlinear systems under multistep randomly delayed and lost measurements. A new measurement model is established that can characterize the random delay and loss of measurement data. First, an augmented Gaussian mixture filter framework is developed in the case of random delay of measurement data; the posterior probability density function after state augmentation is calculated by marginalizing over delay variables to extract accurate information from delayed measurements. The implementation of the filter is transformed into the computation of nonlinear numerical integrals. Second, under the proposed framework, novel expressions of the mean and covariance are generated by propagating the measurement taken at the previous moment in the event of no new measurement being received. Finally, we present two simulation examples for estimating system states, and the results demonstrate the effectiveness and superiority of our proposed filter.
Objective measurement of movement variability using wearable sensors predicts ASD outcomes in infants at high likelihood for ASD and ADHD
Authors: Wilson Rujuta B. , Vangala Sitaram , Reetzke Rachel , Piergies Antonia , Ozonoff Sally , Miller Meghan
Published: May 2024

Early motor delays and differences are common among children with autism spectrum disorder (ASD) and attention‐deficit/hyperactivity disorder (ADHD). Yet, little work has shown whether there are early atypical motor signs that differentiate these groups. Quantitative measures of movement variability hold promise for improving the identification of subtle and specific differences in motor function among infants and toddlers at high likelihood for ASD and ADHD. To this end, we created a novel quantitative measure of movement variability (movement curvature) and conducted a preliminary investigation as to whether this measure improves outcome predictions. We used a wearable triaxial accelerometer to evaluate continuous motion‐based activity in infants at high and low likelihood for ASD and ADHD at 12, 18, 24, and 36 months of age. At 36 months, participants were categorized into three outcome groups: ASD (n = 19), ADHD concerns (n = 17), and a comparison group (n = 82). We examined group differences in movement curvature and whether movement curvature is predictive of a later ASD or ADHD concerns classification. We found that movement curvature was significantly lower in infants with later ASD diagnosis at 18, 24, and 36 months of age compared to infants with either ADHD concerns or those in the comparison group. Movement curvature was also a significant predictor of ASD at 18, 24, and 36 months (AUC 0.66–0.71; p = 0.005–0.039) and when adjusting for high ASD likelihood at 18 and 24 months (AUC 0.90, p = 0.05–0.019). These results indicate that lower movement curvature may be a feature of early motor differences in infants with later ASD diagnosis as early as 18 months of age.
Arsenic Treatment Using Electrolytic Ferrous Reagent to Replace Bulk Ferric Chloride
Authors: Dozortsev Vladimir , Sanchez Roy
Published: May 2024

Key Takeaways

As federal maximum contaminant level (MCL) recommendations for arsenic in drinking water are being reviewed, US utilities are preparing for more stringent regulations.

If faced with reducing its treated water's arsenic concentration to 5 μg/L, the City of Alamosa, Colo., would need to increase its ferric chloride dose—raising supply, cost, and operational concerns.

To avoid these issues, the city explored a new technology that generates a ferrous reagent via an in situ electrolytic process to replace bulk ferric chloride.

The electrolytic ferrous reagent removed arsenic to below 5 μg/L, reduced permeate manganese levels, and improved effluent quality with a far lower coagulant dose.
Exploring teachers' strategies for navigating compulsory digital transformations in Danish primary and lower secondary schools
Authors: Laursen Ronni
Published: May 2024

This study employs Bourdieu's theory of practice to analyse 31 interviews with teachers, principals and administrators. I explore the strategies teachers use to handle the mandatory enactment of a Learning Management System (LMS) in Danish primary and lower secondary schools. Teachers are categorised into three groups: those mainly focused on teaching, those with digital responsibilities and those representing the Danish Teachers' Union. The findings reveal three distinct strategies adopted by these groups of teachers. Firstly, teachers solely focused on teaching developed a strategy of resistance, avoiding the use of the LMS in their daily teaching. In contrast, the other two groups of teachers responded to the changes by accumulating either digital or managerial capital to enhance their skills. This latter strategy positioned them as key figures in the eyes of local management, preparing them for advancement. Furthermore, since enhancing skills entails collaborating closely with management, it naturally leads these teachers to support the enactment of the LMS through their actions in the schools. The findings contribute to theoretical development and provide insights into teachers' practices when required to enact change in school.