bluuebunny/crossref_metadata_2025 huggingface dataset:
CRISPR/Cas9‐mediated knockout of a male accessory glands‐specific gene takeout1 decreases the fecundity of Zeugodacus cucurbitae female
Authors: Wang Yun , Xu Hui‐Qian , Han Hong‐Liang , Chen Dong , Jiang Hongbo , Smagghe Guy , Wang Jin‐Jun , Wei Dong
Published: April 2024

BACKGROUND

The melon fly, Zeugodacus cucurbitae (Coquillett), is an invasive Tephritidae pest with robust fertility. The male accessory glands (MAGs) form a vital organ that ensures insect reproductive efficiency. Most of the secreted proteins by MAGs exhibit a male bias expression. Takeout, one of these proteins, is abundantly present in the MAGs of many insects.

RESULTS

In this study, we identified 32 takeout genes in Z. cucurbitae. The phylogenetic analysis and multiple sequence alignment results showed that Zctakeout1 is the most related homolog to the MAGs‐specific takeout in Tephritidae. The real‐time quantitative PCR results showed that Zctakeout1 was exclusively expressed in the male adult stage, and its expression level gradually increased with the increase in age and then remained stable at the sexually matured stage. The distribution among tissues demonstrated the specific expression of Zctakeout1 in the MAGs, and fluorescence immunohistochemical results confirmed the presence of Zctakeout1 in close proximity to binuclear cells of the mesoderm epidermal MAGs. In continuation, CRISPR/Cas9‐mediated genome editing was employed, resulting in successfully generating a homozygous strain with an +8 bp insertion. The mating experiments with the Zctakeout1−/− males resulted in significant reductions in both the mating rate and egg production of females.

CONCLUSION

These findings prove that the MAGs‐specific Zctakeout1 is essential in regulating fecundity in female Z. cucurbitae fruit flies. Our data suggests its utilization in future essential insect‐specific gene‐directed sterility insect technique (SIT) by the genetic manipulation to keep these important Tephritidae populations under control. © 2024 Society of Chemical Industry.
Relevance of amphiphilicity and helicity on the antibacterial action of a histatin 5‐derived peptide
Authors: Peggion Cristina , Panetta Valeria , Lastella Luana , Formaggio Fernando , Ricci Antonio , Oancea Simona , Hilma Geta , Biondi Barbara
Published: April 2024

Peptide dhvar4, derived from the active domain of our salivary peptide histatin 5, bears a Phe residue in the middle of its hydrophilic face when folded into an α‐helix. We then synthesized an analog with this Phe replaced by Lys and two analogs preserving Phe but bearing two and three α‐aminoisobutyric acid (Aib) residues to stabilize the helical structure. The aim of this design was to verify which of the two features is more favorable to the biological activity. We performed a conformational study by means of circular dichroism and nuclear magnetic resonance, made antibacterial tests, and assessed the stability of the peptides in human serum. We observed that amphiphilicity is more important than helix stability, provided a peptide can adopt a helical conformation in a membrane‐mimetic environment.
Using eLearning to improve and retain the knowledge of community health workers in maternal and neonatal health in Rwanda: A cohort study
Authors: Sangwa Yves , Ndaruhutse Victor , Radeny Samson , Ndatimana Dieudonne , Niragire François , Rutayisire Erigene , Mukamana Beatrice , Uwamariya Josee , Kabanda Clovis , Nyirafaranga Angelique , Uzayisenga Marie Chantal , Kanakuze Chris Adrien , Gasamagera Jean Claude , Umunyana Jacqueline , Mazimpaka Christian
Published: April 2024

Background

In Rwanda, community health workers (CHWs) serve a crucial function in providing community‐based maternal and neonatal health (CBMNH) services. However, limited access to continuous training affects their confidence and ability to execute their roles effectively. This study aimed at evaluating the impact of eLearning on enhancing and maintaining CHWs’ knowledge of CBMNH.

Methods

This cohort study, conducted from April to October 2021 in two Rwandan districts, evaluated knowledge acquisition and retention among 36 CHWs participating in an eLearning course. Knowledge scores were measured using a structured questionnaire administered pre‐training, post‐training and at a 6‐month follow‐up. Descriptive analysis and paired t‐tests were used to assess mean score differences.

Results

There was improvement in CHWs’ performance scores following eLearning training, with an average increase from 86.5% to 98.2%. The improvement was sustained at a 6‐month follow‐up. Statistical significance was found between age category and CHWs’ pre‐ and post‐test performance (p = 0.01, p = 0.04 respectively), and between years of experience and pre‐test scores (p = 0.02).

Conclusions

The results of this study suggest that eLearning is an effective method for enhancing and retaining CHWs’ knowledge of CBMNH. The findings support the use of eLearning as a valuable strategy for strengthening the capacity of CHWs in Rwanda and other countries with similar contexts.
Evaluation of novel pyridoxal isonicotinoyl hydrazone (PIH) derivatives as potential anti‐tuberculosis agents: An in silico investigation
Authors: Hossain Md. Shamim , Al Abbad Sanaa S. , Alsunaidi Zainab H. A. , Rahman Shofiur , Alodhayb Abdullah N. , Hossain Md. Mainul , Poirier Raymond A. , Uddin Kabir M.
Published: April 2024

This investigation employed computational methodologies to assess the therapeutic potential of derivatives (1–16) of pyridoxal isonicotinoyl hydrazone (PIH) as potential treatments for tuberculosis. Various computational techniques, including molecular dynamics simulation, molecular docking, density functional theory, and global chemical descriptors, were employed to analyze the interactions between the ligands and target proteins. Docking results indicated that ligands 6, 7, 8, and rifampin exhibited binding affinities of −8.4, −7.4, −9.2, and − 7.2 kcal mol−1, respectively, against mycobacterium tuberculosis enoyl acyl carrier protein reductase (INHA), with ligand 8 demonstrating superior inhibition. Molecular dynamics (MD) simulations were utilized to assess the stability of protein‐ligand interactions. Remarkably, the Root Mean Square Deviation (RMSD) of the INHA‐ligand 8 complex remained minimal, with peak values at .40, .56, .37, and .50 nm at temperatures of 300, 305, 310, and 320 K, respectively. This suggests superior stability compared to the reference drug rifampin and INHA complex, which exhibited an RMSD range of .2 to .8 nm at 300 K. Furthermore, analysis using Frontier Molecular Orbital (FMO) revealed that the Egap value of ligand 8 (4.407 eV) is lower than all the reference drugs except rifampin. This comprehensive theoretical analysis positions ligand 8 as a promising candidate for anti‐tuberculosis drug development, underscoring the need for further exploration through in vitro and in vivo studies.
Measurement of Charge State Dynamics in Nitrogen−Vacancy Centers Based on Microwave‐Pulses‐Assisted Longitudinal Relaxations Balancing of Spin Qutrit
Authors: Li Mingxin , Yuan Heng , Bian Guodong , Fan Pengcheng , Wang Sixian , Shen Jihongbo , Geng Jianpei , Zhang Jixing
Published: April 2024

The nitrogen−vacancy (NV) center in diamond gains its versatility when negatively charged (NV−) but is mediocre when neutrally charged. Particularly, the charge states of NV centers are convertible under optical pumping and during the dark intervals, whose dynamics are mixed with the NV−s’ spin polarizations and relaxations, making them difficult to detect. Here, a microwave‐pulses‐assisted charge state dynamics (CSD) measurement method of NV centers in the dark time (DT) is proposed. The microwave pulses are designed to manipulate the populations of the NV−s’ ground state spin triplets (qutrit) to the equilibrium state before the DT. Thus, the longitudinal relaxations of the qutrit are balanced, and pure CSD can be detected. Interestingly, in an annealed bulk diamond, not only the traditional tunneling‐induced fast exponential CSD are observed, but also a slow and long‐term recharging process, which is probably attributed to the exchanging of the electrons between NV centers and the high‐energy‐level charge traps such as vacancy clusters. Furthermore, results demonstrate a 40% increase in NV−s’ contrast by properly extending the recharging DT. These results are significant for the in‐depth study of the NV centers’ CSD and can improve the sensing abilities of the NV− ensemble.
Recommencement of atezolizumab with associated pulmonary sarcoid‐like reaction
Authors: Tam Khai , Wallace Michael , Mulrennan Siobhain
Published: April 2024

An 81 year old male with Child‐Pugh A cirrhosis and metastatic hepatocellular carcinoma (HCC) treated with 3‐weekly atezolizumab and bevacizumab developed a pulmonary sarcoid‐like reaction (SLR) after 5 months. Atezolizumab, an immune checkpoint inhibitor, was identified as the likely culprit. He was treated with prednisolone, resulting in improvement, and was successfully rechallenged with both atezolizumab and bevacizumab.
Mineral changes in the rhizospheres of conifer plantations for a weathered subtropical soil
Authors: Hummes Ana P. , Inda Alberto V. , Olk Daniel C. , Bortoluzzi Edson C.
Published: April 2024

Tree species can have great impacts on soil. Since the rhizosphere is more responsive to external inputs than the surrounding bulk soil, we investigated the rhizosphere effect of the exotic slash pine and the native araucaria in long‐term conifer monocultures in southern Brazil. Araucaria trees in a natural section of a nearby mixed araucaria forest were taken as the control. We assessed physical, chemical, and mineralogical properties of the underlying subtropical highly weathered soil. We did not find rhizosphere effects for most chemical and physical soil attributes, yet principal component analysis clearly distinguished the effects of the exotic and native conifers on rhizosphere properties by separating slash pine cluster from reforested and native araucaria clusters. Reductions in silt and sand contents under slash pine reforestation led to increases in clay and well‐crystallized iron oxides contents. The clay mineralogy comprised kaolinite, mica/illite, and hydroxy‐interlayered minerals, with kaolinite enrichment in the rhizospheres of both araucaria sites, mica/illite depletion in the rhizospheres of both araucaria and pine monocultures, and prevalence of well‐crystallized iron oxyhydroxides in the slash pine rhizosphere. This study demonstrates a tendency toward increasing soil weathering in the conifer monocultures, potential negative impacts of the faster growing slash pine reforestation on soil organic carbon, available P, and total K possibly by mica/illite depletion, while araucaria had lower impacts on soil properties. These results show long‐term potential loss of soil fertility and quality, which should be considered when monitoring soil changes in human modified ecosystems.
Interfacial Growth of Large Area Single‐Crystalline Silver Sheets Through Ambient Microdroplets
Authors: Sarkar Depanjan , Som Anirban , Unni Keerthana , Manna Sujan , Thalappil Pradeep
Published: April 2024

The creation of micrometer‐sized sheets of silver at the air–water interface by direct deposition of electrospray‐generated silver ions (Ag+) on an aqueous dispersion of reduced graphene oxide (RGO), in ambient conditions, is reported. In the process of electrospray deposition (ESD), an electrohydrodynamic flow is created in the aqueous dispersion, and the graphene sheets assemble, forming a thin film at the air–water interface. The deposited Ag+ coalesce to make single‐crystalline Ag sheets on top of this assembled graphene layer. Fast neutralization of Ag+ forming atomic Ag, combined with their enhanced mobility on graphene surfaces, presumably facilitates the growth of larger Ag clusters. Moreover, restrictions imposed by the interface drive the crystal growth in 2D. By controlling the precursor salt concentration, RGO concentration, deposition time, and ion current, the dimensionality of the Ag sheets can be tuned. These Ag sheets are effective substrates for surface‐enhanced Raman spectroscopy (SERS), as demonstrated by the successful detection of methylene blue at nanomolar concentrations.
An Active Strategy Based on Different Droplet Removal Modes on Polydimethylsiloxane Magnetic Microstructures
Authors: Zhang Yang , Wu Chao , Gu Haoyu , Song Yingbin , Zhao Ruoxi , Zhang Dongjie , Xie Zhimin , Liu Yuyan , Cheng Zhongjun
Published: April 2024

The efficient removal of droplets on solid surfaces holds significant importance in the field of fog collection, condensation heat transfer, and so on. However, on current typical surfaces, droplets are characterized by a passive and single removal mode, contingent on the traction force (e.g., capillary force, Laplace pressure, etc.) generated by the surface's physics and chemistry design, posing challenges for enhancing the efficiency of droplet removal. In this paper, an effective active strategy based on different removal modes is demonstrated on magnetic responsive polydimethylsiloxane (PDMS) superhydrophobic microplates (RM‐MPSM). By regulating the parameters of microplates and droplet volume, different effective departure modes (top jumping and side departure) can be induced to facilitate the removal of droplets. Moreover, the removal volume of droplets through the side departure mode exhibits a significant reduction compared to that observed in the top jumping mode. The exceptional removal ability of RM‐MPSM demonstrates adaptability to diverse functional applications: efficient fog collection, removal of condensation droplets and micro‐particles. The efficient modes of droplet removal demonstrated in this work hold significant implications for broadening its application in many fields, such as droplet collection, heat transfer, and anti‐icing.
Dynamic Structures and Fast Transition Kinetics of Oxidized G‐Quadruplexes
Authors: Ji Jiahao , Sharma Arpit , Pokhrel Pravin , Karna Deepak , Pandey Shankar , Zheng Yao‐Rong , Mao Hanbin
Published: April 2024

8‐oxoguanines (8‐oxoG) in cells form compromised G‐quadruplexes (GQs), which may vary GQ mediated gene regulations. By mimicking molecularly crowded cellular environment using 40% DMSO or sucrose, here it is found that oxidized human telomeric GQs have stabilities close to the wild‐type (WT) GQs. Surprisingly, while WT GQs show negative formation cooperativity between a Pt(II) binder and molecularly crowded environment, positive cooperativity is observed for oxidized GQ formation. Single‐molecule mechanical unfolding reveals that 8‐oxoG sequence formed more diverse and flexible structures with faster folding/unfolding transition kinetics, which facilitates the Pt(II) ligand to bind the best‐fit structures with positive cooperativity. These findings offer new understanding on structures and properties of oxidized G‐rich species in crowded environments. They also provide insights into the design of better ligands to target oxidized G‐rich structures formed under oxidative cell stress.
Precise Construction of Nitrogen‐Enriched Porous Ionic Polymers as Highly Efficient Sulfur Dioxide Adsorbent
Authors: Chen Sen , Huang Shicheng , Yang Zhenglu , Suo Xian , Xing Huabin , Cui Xili
Published: April 2024

Porous ionic polymers with unique features have exhibited high performance in various applications. However, the fabrication of functional porous ionic polymers with custom functionality and porosity for efficient removal of low‐concentration SO2 remains challenging. Herein, a novel nitrogen‐enriched porous ionic polymer NH2Py‐PIP is prepared featuring high‐content nitrogen sites (15.9 wt.%), adequate ionic sites (1.22 mmol g−1), and a hierarchical porous structure. The proposed construction pathway relies on a tailored nitrogen‐functionalized cross‐linker NH2Py, which effectively introduces abundant functional sites and improves the porosity of porous ionic polymers. NH2Py‐PIP with a well‐engineered SO2‐affinity environment achieves excellent SO2/CO2 selectivity (1165) and high SO2 adsorption capacity (1.13 mmol g−1 at 0.002 bar), as well as enables highly efficient and reversible dynamic separation performance. Modeling studies further elucidate that the nitrogen sites and bromide anions collaboratively promote preferential adsorption of SO2. The unique design in this work provides new insights into constructing functional porous ionic polymers for high‐efficiency separations.
High‐Energy Symmetric Li‐Ion Battery Enabled by Binder‐Free FeOF‐MXene Heterostructure with Doubly Matched Capacity and Kinetics
Authors: Liang Huanyu , Zhu Chunliu , Tian Weiqian , Zhu Chunyan , Ma Yu , Hu Wei , Wu Jingyi , Chen Jingwei , Wang Rutao , Huang Minghua , Zhu Yue , Wang Huanlei
Published: April 2024

Fluorides are viewed as promising conversion‐type Li‐ion battery cathodes to meet the desired high energy density. FeOF is a typical member of conversion‐type fluorides, but its major drawback is sluggish kinetics upon deep discharge. Herein, a heterostructured FeOF‐MXene composite (FeOF‐MX) is demonstrated to overcome this limitation. The rationally designed FeOF‐MX electrode features a microsphere morphology consisting of closely packed FeOF nanoparticles, providing fast transport pathways for lithium ions while a continuous wrapping network of MXene nanosheets ensures unobstructed electron transport, thus enabling high‐rate lithium storage with enhanced pseudocapacitive contribution. In/ex situ characterization techniques and theoretical calculations, both reveal that the lithium storage mechanism in FeOF arises from a hybrid intercalation‐conversion process, and strong interfacial interactions between FeOF and MXene promote Li‐ion adsorption and migration. Remarkably, through demarcating the conversion‐type reaction with a controlled potential window, a symmetric full battery with prelithiated FeOF‐MX as both cathode and anode is fabricated, achieving a high energy density of 185.5 Wh kg−1 and impressive capacity retention of 88.9% after 3000 cycles at 1 A g−1. This work showcases an effective route toward high‐performance MXene engineered fluoride‐based electrodes and provides new insights into constructing symmetric batteries yet with high‐energy/power densities.
Interlayer Polymerization to Construct a Fully Conjugated Covalent Organic Framework as a Metal‐Free Oxygen Reduction Reaction Catalyst for Anion Exchange Membrane Fuel Cells
Authors: Chen Zhiwei , Fang Pengda , Zou Xiuyang , Shi Zheng , Zhang Jiamin , Sun Zhe , Guo Siyu , Yan Feng
Published: April 2024

Two‐dimensional (2D) covalent organic frameworks (COFs) have a multilayer skeleton with a periodic π‐conjugated molecular array, which can facilitate charge carrier transport within a COF layer. However, the lack of an effective charge carrier transmission pathway between 2D COF layers greatly limits their applications in electrocatalysis. Herein, by employing a side‐chain polymerization strategy to form polythiophene along the nanochannels, a conjugated bridge is constructed between the COF layers. The as‐synthesized fully conjugated COF (PTh‐COF) exhibits high oxygen reduction reaction (ORR) activity with narrowed energy band gaps. Correspondingly, PTh‐COF is tested as a metal‐free cathode catalyst for anion exchange membrane fuel cells (AEMFCs) which showed a maximum power density of 176 mW cm−2 under a current density of 533 mA cm−2. The density functional theory (DFT) calculation reveals that interlayer conjugated polythiophene optimizes the electron cloud distribution, which therefore enhances the ORR performance. This work not only provides new insight into the construction of a fully conjugated covalent organic framework but also promotes the development of new metal‐free ORR catalysts.
Mechanically Ultra‐Robust Fluorescent Elastomer for Elaborating Auxetic Composite
Authors: Li Jiawei , Zheng Zhiran , Ma Yaning , Dong Zhaoxing , Li Min‐Hui , Hu Jun
Published: April 2024

Fluorescent elastomers are predominantly fabricated through doping fluorescent components or conjugating chromophores into polymer networks, which often involves detrimental effects on mechanical performance and also makes large‐scale production difficult. Inspired by the heteroatom‐rich microphase separation structures assisted by intensive hydrogen bonds in natural organisms, an ultra‐robust fluorescent polyurethane elastomer is reported, which features a remarkable fracture strength of 87.2 MPa with an elongation of 1797%, exceptional toughness of 678.4 MJ m−3 and intrinsic cyan fluorescence at 445 nm. Moreover, the reversible fluorescence variation with temperature could in situ reveal the microphase separation of the elastomer in real time. By taking advantage of mechanical properties, intrinsic fluorescence and hydrogen bonds‐promoted interfacial bonding ability, this fluorescent elastomer can be utilized as an auxetic skeleton for the elaboration of an integrated auxetic composite. Compared with the auxetic skeleton alone, the integrated composite shows an improved mechanical performance while maintaining auxetic deformation in a large strain below 185%, and its auxetic process can be visually detected under ultraviolet light by the fluorescence of the auxetic skeleton. The concept of introducing hydrogen‐bonded heteroatom‐rich microphase separation structures into polymer networks in this work provides a promising approach to developing fluorescent elastomers with exceptional mechanical properties.
Solid‐State Anion Exchange Enabled by Pluggable vdW Assembly for In Situ Halide Manipulation in Perovskite Monocrystalline Film
Authors: Gao Weiqi , Liu Songlong , Chen Yang , Niu Kaixin , Lu Zheyi , Li Zhiwei , Zeng Zhiyao , Xiao Yulong , Zhai Yaxin , Liu Yuan , Wang Yiliu
Published: April 2024

The fabrication of perovskite single crystal‐based optoelectronics with improved performance is largely hindered by limited processing techniques. Particularly, the local halide composition manipulation, which dominates the bandgap and thus the formation of heterostructures and emission of multiple‐wavelength light, is realized via prevalent liquid‐ or gas‐phase anion exchange with the utilization of lithography, while the monocrystalline nature is sacrificed due to polycrystalline transition in exchange with massive defects emerging, impeding carrier separation and transportation. Thus, a damage‐free and lithography‐free solid‐state anion exchange strategy, aiming at in situ halide manipulation in perovskite monocrystalline film, is developed. Typically, CsPbCl3 working as medium to deliver halide is van der Waals (vdW) assembled to specific spots of CsPbBr3, followed by the removal of CsPbCl3 after anion exchange, with the halide composition in contact area modulated and monocrystalline nature of CsPbBr3 preserved. CsPbBr3‐CsPbBrxCl3‐x monocrystalline heterostructure has been achieved without lithography. Device based on the heterostructure shows apparent rectification behavior and improved photo‐response rate. Heterostructure arrays can also be constructed with customized medium crystal. Furthermore, the halide composition can be accurately tuned to enable full coverage of visible spectra. The solid‐state exchange enriches the toolbox for processing vulnerable perovskite and paves the way for the integration of monocrystalline perovskite optoelectronics.
Piezochromic Behavior of 2,4,6‐Triphenylpyrylium Tetrachloroferrate
Authors: Canasa Princess , King David , Cifligu Petrika , Lua Sanchez Adrian F. , Chen Si L. , Han Haesook , Malik Trimaan , Billinghurst Brant , Zhao Jianbao , Park Changyong , Rossman George R. , Pravica Michael , Bhowmik Pradip K. , Evlyukhin Egor
Published: April 2024

In advanced photonics, there is a growing interest in piezochromic luminescent materials that exhibit multicolor switching, driven by their potential applications in optical recording, memory, and sensors. Here, the piezochromic behavior of 2,4,6‐triphenylpyrylium tetrachloroferrate (Py‐FeCl4) under high pressures from 0 to 9 GPa is reported. The observed multicolor changing properties of Py‐FeCl4 (yellow–orange–red–maroon–black) are found to be fully reversible upon decompression to ambient conditions. The mechanism of Py‐FeCl4 piezochromism is investigated via Raman, infrared, and UV–vis spectroscopy combined with powder X‐ray Diffraction. The absence of structural phase transitions as well as the abrupt shifts of bandgap values together with characteristic Raman and IR peaks within 0‐9 GPa suggests that the Py‐FeCl4 multicoloring switching behavior is driven by an electron transfer between the inorganic FeCl4− anion and the organic pyrylium cation. The obtained results demonstrate that Py‐FeCl4 dye is a good candidate for developing high‐pressure sensing technologies designed to function in extreme environments. Moreover, due to the inherent role of molecular‐structure relationships in the pyrylium salt's photophysical properties, findings suggest the potential discovery of piezochromic behavior in other pyrylium compounds.
Benchtop Fabricated Nano‐Roughened Microstructured Electrodes for Electrochemical and Surface‐Enhanced Raman Scattering Sensing
Authors: González‐Martínez Eduardo , Beganovic Nadine E. , Moran‐Mirabal Jose M.
Published: April 2024

Tailoring a material's surface with hierarchical structures from the micro‐ to the nanoscale is key for fabricating highly sensitive detection platforms. To achieve this, the fabrication method should be simple, inexpensive, and yield materials with a high density of surface features. Here, using benchtop fabrication techniques, gold surfaces with hierarchically structured roughness are generated for sensing applications. Hierarchical gold electrodes are prepared on pre‐stressed polystyrene substrates via electroless deposition and amperometric pulsing. Electrodes fabricated using 1 mm H[AuCl₄] and roughened with 80 pulses revealed the highest electroactive surface area. These electrodes are used for enzyme‐free detection of glucose in the presence of bovine serum albumin and achieved a limit of detection of 0.36 mm, below glucose concentrations in human blood. The surfaces nanoroughened with 100 pulses also showed excellent surface‐enhanced Raman scattering (SERS) response for the detection of rhodamine 6G, with an enhancement factor of ≈2 × 106 compared to detection in solution, and for the detection of a self‐assembled monolayer of thiophenol, with an enhancement factor of ≈30 compared to the response from microstructured gold surfaces. It is envisioned that the simplicity and low fabrication cost of these gold‐roughened structures will expedite the development of electrochemical and SERS sensing devices.
Rational Design of Coordination Polymers Composited Hollow Multishelled Structures for Drug Delivery
Authors: Xiao Qian , Shang Lingling , Peng Yang , Zhang Ludan , Wei Yanze , Zhao Decai , Zhao Yasong , Wan Jiawei , Wang Yuguang , Wang Dan
Published: April 2024

Multifunctional drug delivery systems (DDS) are in high demand for effectively targeting specific cells, necessitating excellent biocompatibility, precise release mechanisms, and sustained release capabilities. The hollow multishelled structure (HoMS) presents a promising solution, integrating structural and compositional design for efficient DDS development amidst complex cellular environments. Herein, starting from a Fe‐based metal‐organic framework (MOF), amorphous coordination polymers (CP) composited HoMS with controlled shell numbers are fabricated by balancing the rate of MOF decomposition and shell formation. Fe‐CP HoMS loaded with DOX is utilized for synergistic chemotherapy and chemodynamic therapy, offering excellent responsive drug release capability (excellent pH‐triggered drug release 82% within 72 h at pH 5.0 solution with doxorubicin (DOX) loading capacity of 284 mg g−1). In addition to its potent chemotherapy attributes, Fe‐CP‐HoMS possesses chemodynamic therapy potential by continuously catalyzing H2O2 to generate ·OH species within cancer cells, thus effectively inhibiting cancer cell proliferation. DOX@3S‐Fe‐CP‐HoMS, at a concentration of 12.5 µg mL−1, demonstrates significant inhibitory effects on cancer cells while maintaining minimal cytotoxicity toward normal cells. It is envisioned that CP‐HoMS could serve as an effective and biocompatible platform for the advancement of intelligent drug delivery systems in the realm of cancer therapy.
Generalized Synthesis of Highly‐Dispersed, Ultrafine Transition Metal Nanoparticles on Silica Spheres for Enhanced Optical Absorption
Authors: Wei Qilin , Wu Siyu , Zuo Xiaobing , Sun Yugang
Published: April 2024

Robust synthesis of ultrafine metal nanoparticles (ufMNPs) below 5 nm with clean surfaces and strong optical absorption in the visible spectral range is challenging due to their instability originating from large surface‐to‐volume ratios. This work reports a general strategy involving two sequential steps: i) loading metal precursor ions onto the surface of silica nanospheres (SiOx NSs) by forming a uniform coating of metal oxyhydroxide [MOy(OH)z] through preferred surface acid–base reactions and ii) thermally reducing MOy(OH)z in forming gas at elevated temperatures to form ufMNPs evenly dispersed on the surface of SiOx NSs. The capability of this synthesis strategy is verified by loading ufMNPs of various transition metals and bimetallic combinations onto the SiOx NSs. The ufMNPs exhibit strong optical absorption enhanced by the optical scattering resonances in the SiOx NSs, which generate intense electric fields near the surface of the SiOx NSs. The SiOx NSs also support stabilizing the ufMNPs, which do not need additional organic capping reagents. The successful synthesis of SiOx‐NS‐supported ufMNPs with clean surfaces and enhanced optical absorption is promising for exploring the photocatalytic properties of ufMNPs.
Characterization of Functional Biohybrid Materials Based on Saccharomyces Cerevisiae Biomass
Authors: Hüsing Torben , Van Opdenbosch Daniel , Rühmann Broder , Zollfrank Cordt , Reuter Ellen , Sieber Volker
Published: April 2024

Biohybrid materials and engineered living materials (ELMs) are a dynamic field of research at the interface of material science and synthetic biology. Recently, microorganisms have been described as both functional and structural building blocks of such materials. Dry materials with bacteria as structural building block have previously not been investigated for their ability to retain catalytic activity. Herein, it is shown that Saccharomyces cerevisiae biomass can act as a structural building block in dry, macroscopic materials while simultaneously providing functionality. A benign method for the preparation of both coatings and free‐standing, flexible films is presented. Notably, free‐standing films can be prepared solely from biomass and plasticizers without the need for other additives. During the process, the integrity of the cells and the catalytic activity within is preserved, which is demonstrated by biocatalytic H2O2 degradation. The film‐forming properties of S. cerevisiae biomass and the influence of plasticizing and polymeric additives on the mechanical properties are investigated in detail and compared to related materials. The work presented is a first step toward new, mechanically strong microorganism‐based functional coatings and films.
Bond performance of NSM FRP–concrete interfaces with epoxy under chloride‐salt conditioned environments
Authors: Zhang Haixia , Sun Xingwu , Wang Ya
Published: April 2024

Concrete in coastal areas is susceptible to structural damage caused by corrosion and expansion of reinforcement. Near‐surface mounted (NSM) fiber‐reinforced polymer (FRP) bars have become effective for strengthening damaged reinforced concrete structures. The bonding performance of NSM FRP bars in concrete is a key factor limiting their application and promotion in civil engineering. In this study, the influences of the conditioned environment, such as the chloride salt concentration, immersion time, and bond length of the FRP bar, on the bonding performance were investigated experimentally. First, material properties in a conditioned environment were studied. Subsequently, the failure mode, bond stress–slip curve, and bond strength of the NSM FRP bar in concrete were investigated. Finally, the microstructure and chemical composition of the materials were revealed using scanning electron microscopy and energy‐dispersive spectroscopy (EDS) images of the materials under environmental conditions. The transfer mechanism of NSM FRP bars in concrete with epoxy was revealed. The results showed that the failure modes of the pullout specimens can be divided into epoxy splitting failure and basalt fiber‐reinforced polymer (BFRP) pulling failure. The chloride‐salt concentration was a critical factor affecting the bond properties, and the longer the bond length, the lower the bond strength. The microstructure clearly shows that the degradation of the bonding behavior at the interface of the NSM FRP bar in concrete in a conditioned environment is attributable primarily to the resin damage of the epoxy, resulting in pit corrosion. There was no significant damage to the fibers in the FRP bar, and the degradation was primarily due to resin matrix damage and interfacial debonding. The EDS results showed that the degradation of the epoxy resin and BFRP bars was caused by CO bond and SiO bond fractures, respectively.
The evolution of systems engineering as a transdiscipline
Authors: Pennotti Michael , Brook Peter , Rousseau David
Published: April 2024

Systems engineering's evolutionary trajectory has been far from linear, and its future direction is uncertain. We present an assessment and vision of how SE might evolve to enduringly be impactful and relevant, despite growing complexity and radical technological change. We discuss how SE started out focused on achieving technical objectives, then drifted towards a more process and methodology focus, and is now responding to calls to return to its roots under the banner of “attaining elegant solutions to complex problems.” We discuss how SE has always been a transdiscipline, although it was not always so recognized, and how SE is now increasingly recognizing and valuing its transdisciplinary nature. We present our view that the future of SE as an impactful and relevant engineering discipline lies in the strengthening of its transdisciplinarity and an increased focus on attaining elegant solutions to complex problems. We present a framework for understanding the nature of SE and the way in which it evolves in terms of its principles, methods and purposes. We show that SE is informed by, and informs many disciplines and social institutions in a dynamic ecology of discovery, achievement and vision. Lastly, we discuss the value of this framework, and show how it can serve as a basis for developing a common understanding of the value and potential of SE, and support institutions such as INCOSE as they engage in the wider social agenda of building a better and more sustainable world.
Ex Vivo Working Porcine Heart Model
Authors: Pigot Henry , Soltesz Kristian , Steen Stig
Published: April 2024

Ex vivo working porcine heart models allow for the study of a heart’s function and physiology outside the living organism. These models are particularly useful due to the anatomical and physiological similarities between porcine and human hearts, providing an experimental platform to investigate cardiac disease or assess donor heart viability for transplantation. This chapter presents an in-depth discussion of the model’s components, including the perfusate, preload, and afterload. We explore the challenges of emulating cardiac afterload and present a historical perspective on afterload modeling, discussing various methodologies and their respective limitations. An actively controlled afterload device is introduced to enhance the model’s ability to rapidly adjust pressure in the large arteries, thereby providing a more accurate and dynamic experimental model. Finally, we provide a comprehensive experimental protocol for the ex vivo working porcine heart model.
A trace inequality for Euclidean gravitational path integrals (and a new positive action conjecture)
Authors: Colafranceschi Eugenia , Marolf Donald , Wang Zhencheng
Published: April 2024

Abstract

The AdS/CFT correspondence states that certain conformal field theories are equivalent to string theories in a higher-dimensional anti-de Sitter space. One aspect of the correspondence is an equivalence of density matrices or, if one ignores normalizations, of positive operators. On the CFT side of the correspondence, any two positive operators A, B will satisfy the trace inequality Tr(AB) ≤ Tr(A)Tr(B). This relation holds on any Hilbert space $$ \mathcal{H} $$
H
and is deeply associated with the fact that the algebra B($$ \mathcal{H} $$
H
) of bounded operators on $$ \mathcal{H} $$
H
is a type I von Neumann factor. Holographic bulk theories must thus satisfy a corresponding condition, which we investigate below. In particular, we argue that the Euclidean gravitational path integral respects this inequality at all orders in the semi-classical expansion and with arbitrary higher-derivative corrections. The argument relies on a conjectured property of the classical gravitational action, which in particular implies a positive action conjecture for quantum gravity wavefunctions. We prove this conjecture for Jackiw-Teitelboim gravity and we also motivate it for more general theories.
Oriented matroids from triangulations of products of simplices
Authors: Celaya Marcel , Loho Georg , Yuen Chi Ho
Published: April 2024

We introduce a construction of oriented matroids from a triangulation of a product of two simplices. For this, we use the structure of such a triangulation in terms of polyhedral matching fields. The oriented matroid is composed of compatible chirotopes on the cells in a matroid subdivision of the hypersimplex, which might be of independent interest. In particular, we generalize this using the language of matroids over hyperfields, which gives a new approach to construct matroids over hyperfields. A recurring theme in our work is that various tropical constructions can be extended beyond tropicalization with new formulations and proof methods.
Laser powder bed fusion of NdFeB and influence of powder bed heating on density and magnetic properties
Authors: Genç Kübra , Toyting Sirapob , Galindo-Nava Enrique , Todd Iain , Mumtaz Kamran
Published: April 2024

Laser powder bed fusion (L-PBF) is an additive manufacturing technique that provides an opportunity to create complex NdFeB magnets, potentially enhancing their performance. L-PBF possesses its own processing challenges, such as porosity/cracks and thermal stresses due to rapid cooling. This study focused on optimizing the parameters and the use of elevated temperature (300–550 °C) powder bed heating to reduce defect generation. This paper includes a detailed process parameter investigation, which revealed samples with a maximum energy product, (BH)max, of 81 kJ/m3 (remanence, Br 0.72 T; coercivity, Hci 891 kA/m) without post/pretreatment, which are the highest (BH)max and Br for L-PBF-processed NdFeB commercial powder. It was observed that all the high-magnetism samples possessed high density, but not all the high-density samples possessed high magnetism. The SEM images and discussions are academically valuable since they clearly illustrate grain formation and morphology in the melt pool, areas where the literature provides limited discussion. Furthermore, this paper incorporates quantitative phase analyses, revealing that the magnetic properties increase with increasing volume fraction of the strong magnetic phase Nd2Fe14B. Another significant contribution of this paper is that it is the first study to investigate the effect of heated bed on L-PBF-NdFeB alloys. The density of the samples and Br can be improved with the use of elevated powder bed heating, while the Hc decreases. The (BH)max can also be improved from 55 to 84 kJ/m3 through elevated powder bed heating. The maximum magnetic properties obtained with the heated bed (400 °C) were as follows: Br, 0.76 T; Hci, 750 kA/m; and (BH)max, 84 kJ/m3.
Snacks from the sea: a cross-national comparison of consumer acceptance for crackers added with algae
Authors: Rabitti Noemi Sofia , Bayudan Simoun , Laureati Monica , Neugart Susanne , Schouteten Joachim Jietse , Apelman Linnea , Dahlstedt Sermin , Sandvik Pernilla
Published: April 2024

One of the main priorities of current food systems is to develop new and healthy foods to overcome food shortages considering consumer’s expectations. Algae are receiving increasing attention as nutritious and sustainable food, though studies are limited mainly to Arthrospira and Chlorella species and cross-national research is scant. This study aims to investigate European consumers’ liking and perception of crackers added with powders from Arthrospira platensis (green Spirulina), isolated proteins from Arthrospira platensis (blue Spirulina), Palmaria palmata, Saccharina latissima, Lithothamnium calcareum and a control cracker. Belgian, German, Italian, and Swedish participants (n = 413, 18–69 years, 59.8% females) evaluated cracker liking and perceived sensory attributes using the check-all-that-apply (CATA) task. Food neophobia, familiarity towards, and consumption of algae were also collected. Partial Least Squares Regression (PLSR) analyses showed that across all countries, Lithothamnium calcareum, blue Spirulina and the control samples were perceived as similar and were liked more than the other crackers. “Sweet”, “toasted bread”, and “bland” attributes were significant contributors to liking, while “off-flavor”, “fishy flavor”, “umami” and “speckled” contributed negatively. PLSR performed by country provided similar results except for Italians who liked the green Spirulina sample equally as the samples added with Lithothamnium calcareum, blue Spirulina, and the control. These cross-national differences can be ascribed to Italians’ lower food neophobia level. The present results suggest that Lithothamnium calcareum is the most promising algal species to be exploited in food formulations and that the use of isolated proteins from Spirulina (blue Spirulina) significantly reduces off-flavors, consequently improving consumers’ acceptance.
The combined effects of ocean warming and ocean acidification on Pacific cod (Gadus macrocephalus) early life stages
Authors: Slesinger Emily , Mundorff Samantha , Laurel Benjamin J. , Hurst Thomas P.
Published: April 2024

The eastern North Pacific is simultaneously experiencing ocean warming (OW) and ocean acidification (OA), which may negatively affect fish early life stages. Pacific cod (Gadus macrocephalus) is an economically and ecologically important species with demonstrated sensitivity to OW and OA, but their combined impacts are unknown. Through a ~ 9-week experiment, Pacific cod embryos and larvae were reared at one of six combinations of three temperatures (3, 6, 10 °C) and two CO2 levels (ambient: ~ 360 μatm; high: ~ 1560 μatm) in a factorial design. Both embryonic and larval mortality were highest at the warmest temperature. Embryonic daily mortality rates were lower under elevated CO2 and there was no effect of CO2 level on larval daily mortality rates. Growth rates of young larvae (0 to 11 days post-hatch) were faster at warmer temperatures and at high CO2 levels, but growth during the 11–28 days post-hatch interval increased by temperature alone. The condition of larvae decreased with age, but less markedly under high CO2 levels. However, at 6 °C, fish incubated in ambient CO2 remained in higher condition than fish in the high CO2 treatment throughout the experiment. Overall, temperature had the greater influence on Pacific cod early life stages across each measurement endpoint, while CO2 effects were more modest and inconsistent. Subtle developmental differences in larval Pacific cod could be magnified later in life and important in the context of recruitment. These results show the complexity of stage- and trait-specific responses to and value of investigating the combined effects of co-occurring climatic stressors.
When are females dominant over males in rats (Rattus norvegicus)?
Authors: Puentes-Escamilla Miguel A. , Schweinfurth Manon K. , Hemelrijk Charlotte K.
Published: April 2024

In group-living animals, males are assumed to be dominant over females when they are larger than females. Despite this, females have sometimes been proven to be dominant over some males via the winner-loser effect, which becomes stronger when the intensity of aggression in the group is higher. To test whether the winner-loser effect leads to (partial) female dominance in a species with a pronounced sexual dimorphism, we studied the hierarchy in 12 rat colonies (Rattus norvegicus) in which the rats could freely interact with their group members within a spacious area. To investigate the underlying mechanisms, we compared the empirical data to hypotheses generated by the agent-based model ‘DomWorld’. We show that females dominated on average 55% of the males, and occupied the alpha position in four colonies, in three of them they shared it with one or several males. Moreover, in line with the predictions of the computational model, females dominated a higher percentage of males when the intensity of aggression of the colony was higher. This shows that although females are only half as heavy as males, they dominate part of the males probably through the winner-loser effect. We suggest that this effect may be widespread in many other species and can be tested experimentally.

Significance statement

It is often assumed that males automatically dominate females because males are bigger and stronger than females in many species. However, the present study shows that females can dominate males due to the winner-loser effect. We used an agent-based computational model to generate specific hypotheses that we empirically tested in a large sample of rat colonies. Despite this species having a pronounced male-biased sex dimorphism, some females dominated males – with one female even occupying an unshared alpha position. Such partial female dominance was stronger in colonies with higher intensity of aggression. Here, defeated males may suffer a drastic decrease in their fighting capability and consequently give females more opportunities to surpass them in the hierarchy.
I need some space: solitary nesting Adélie penguins demonstrate an alternative breeding strategy at Cape Crozier
Authors: Cox A. M. , Khor D. J. , Elrod M. L. , Lescroël A. , Ballard G. , Schmidt A. E.
Published: April 2024

According to the ‘selfish herd’ hypothesis, most seabird species breed colonially so that individuals can decrease their risk of predation by forming compact groups. However, costs and benefits associated with colonial breeding may not be evenly distributed among individuals within a colony. At Adélie penguin colonies, individuals nesting on the periphery of subcolonies (distinct groups of nests) may experience higher rates of nest predation by south polar skuas, and thus the optimal aggregation pattern for Adélie penguins may be within groups that minimize the proportion of edge nests. Nevertheless, some penguins choose to nest solitarily, at significant distances from conspecifics. We tracked 50 of these “solitary-nesting” Adélie penguins at Cape Crozier, a large colony on Ross Island, during the 2021 nesting season and compared their breeding success to individuals nesting within subcolony boundaries. We found that both solitary and subcolony nests successfully raised chicks large enough to join crèches and left unattended by adults. However, chicks from solitary nests exhibited a rate of mortality more than six times higher during the transition from nest brooding/guarding to crèche stage. In the 2022 nesting season, we found that solitary nests which had previously hosted actively breeding penguins were more likely to be re-occupied. Solitary nesting therefore appears to be a less-successful alternative to breeding within subcolonies, but enough individuals could be successful with this approach to maintain the apparently disadvantageous behavior and effectively pioneer previously unused locations, possibly including eventual new colony locations.