bluuebunny/crossref_metadata_2025 huggingface dataset:
Passive acoustic mapping with absolute time‐of‐flight information and delay‐multiply‐sum beamforming
Authors: Lu Shukuan , Su Ruibo , Wan Chunye , Guo Shifang , Wan Mingxi
Published: January 2023

Background

Passive acoustic mapping (PAM) is showing increasing application potential in monitoring ultrasound therapy by spatially resolving cavitation activity. PAM with the relative time‐of‐flight information leads to poor axial resolution when implemented with ultrasound diagnostic transducers. Through utilizing the absolute time‐of‐flight information preserved by the transmit‐receive synchronization and applying the common delay‐sum (DS) beamforming algorithm, PAM axial resolution can be greatly improved in the short‐pulse excitation scenario, as with active ultrasound imaging. However, PAM with the absolute time‐of‐flight information (referred as AtPAM) suffers from low imaging resolution and weak interference suppression when the DS algorithm is applied.

Purpose

This study aims to propose an enhanced AtPAM algorithm based on delay‐multiply‐sum (DMS) beamforming, to address the shortcomings of the DS‐based AtPAM algorithm.

Methods

In DMS beamforming, the element signals delayed by the absolute time delays are first processed with a signed square‐root operation and then multiplied in pairs and finally summed, the resulting beamformed output is further band‐pass filtered. The performances of DS‐ and DMS‐based AtPAMs are compared by experiments, in which an ultrasound diagnostic transducer (a linear array) is employed to passively sense the wire signals generated by an unfocused ultrasound transducer and the cavitation signals generated by a focused therapeutic ultrasound transducer in a flow phantom. The AtPAM image quality is assessed by main‐lobe width (MLW), intensity valley value (IVV), area of pixels (AOP), signal‐to‐interference ratio (SIR), and signal‐to‐noise ratio (SNR).

Results

The single‐wire experimental results show that compared to the DS algorithm, the DMS algorithm leads to an enhanced AtPAM image with a decreased transverse MLW of 0.15 mm and an improved SIR and SNR of 31.50 and 18.77 dB. For the four‐wire images, the transverse (axial) IVV is decreased by 18.37 dB (13.11 dB) and the SIR (the SNR) is increased by 26.13 dB (18.47 dB) when using the DMS algorithm. The cavitation activity is better highlighted by DMS‐based AtPAM, which decreases the AOP by 0.81 mm2 (–10‐dB level) and 4.43 mm2 (–20‐dB level) and increases the SIR and SNR by 20.14 and 10.48 dB respectively. The pixel distributions of AtPAM images of both wires and cavitation activity also indicate a better suppression of the DMS algorithm in sidelobe and noise.

Conclusions

The experimental results illustrate that the DMS algorithm can improve the image quality of AtPAM compared to the DS algorithm. DMS‐based AtPAM is beneficial for detecting cavitation activity during short‐pulse ultrasound exposure with high resolution, and further for monitoring short‐pulse ultrasound therapy.
3D‐EPI blip‐up/down acquisition (BUDA) with CAIPI and joint Hankel structured low‐rank reconstruction for rapid distortion‐free high‐resolution T2* mapping
Authors: Chen Zhifeng , Liao Congyu , Cao Xiaozhi , Poser Benedikt A. , Xu Zhongbiao , Lo Wei‐Ching , Wen Manyi , Cho Jaejin , Tian Qiyuan , Wang Yaohui , Feng Yanqiu , Xia Ling , Chen Wufan , Liu Feng , Bilgic Berkin
Published: January 2023

Purpose

This work aims to develop a novel distortion‐free 3D‐EPI acquisition and image reconstruction technique for fast and robust, high‐resolution, whole‐brain imaging as well as quantitative mapping.

Methods

3D Blip‐up and ‐down acquisition (3D‐BUDA) sequence is designed for both single‐ and multi‐echo 3D gradient recalled echo (GRE)‐EPI imaging using multiple shots with blip‐up and ‐down readouts to encode B0 field map information. Complementary k‐space coverage is achieved using controlled aliasing in parallel imaging (CAIPI) sampling across the shots. For image reconstruction, an iterative hard‐thresholding algorithm is employed to minimize the cost function that combines field map information informed parallel imaging with the structured low‐rank constraint for multi‐shot 3D‐BUDA data. Extending 3D‐BUDA to multi‐echo imaging permits mapping. For this, we propose constructing a joint Hankel matrix along both echo and shot dimensions to improve the reconstruction.

Results

Experimental results on in vivo multi‐echo data demonstrate that, by performing joint reconstruction along with both echo and shot dimensions, reconstruction accuracy is improved compared to standard 3D‐BUDA reconstruction. CAIPI sampling is further shown to enhance image quality. For mapping, parameter values from 3D‐Joint‐CAIPI‐BUDA and reference multi‐echo GRE are within limits of agreement as quantified by Bland–Altman analysis.

Conclusions

The proposed technique enables rapid 3D distortion‐free high‐resolution imaging and mapping. Specifically, 3D‐BUDA enables 1‐mm isotropic whole‐brain imaging in 22 s at 3T and 9 s on a 7T scanner. The combination of multi‐echo 3D‐BUDA with CAIPI acquisition and joint reconstruction enables distortion‐free whole‐brain mapping in 47 s at 1.1 × 1.1 × 1.0 mm3 resolution.
Diffusion sampling schemes: A generalized methodology with nongeometric criteria
Authors: Rodríguez‐Galván Justino R. , París Guillem , Tristán‐Vega Antonio , Alberola‐López Carlos
Published: January 2023

Purpose

The aim of this paper is to show that geometrical criteria for designing multishell ‐space sampling procedures do not necessarily translate into reconstruction matrices with high figures of merit commonly used in the compressed sensing theory. In addition, we show that a well‐known method for visiting k‐space in radial three‐dimensional acquisitions, namely, the Spiral Phyllotaxis, is a competitive initialization for the optimization of our nonconvex objective function.

Theory and Methods

We propose the gradient design method WISH (WeIghting SHells) which uses an objective function that accounts for weighted distances between gradients within M‐tuples of consecutive shells, with ranging between 1 and the maximum number of shells . All the ‐tuples share the same weight . The objective function is optimized for a sample of these weights, using Spiral Phyllotaxis as initialization. State‐of‐the‐art General Electrostatic Energy Minimization (GEEM) and Spherical Codes (SC) were used for comparison. For the three methods, reconstruction matrices of the attenuation signal using MAP‐MRI were tested using figures of merit borrowed from the Compressed Sensing theory (namely, Restricted Isometry Property —RIP— and Coherence); we also tested the gradient design using a geometric criterion based on Voronoi cells.

Results

For RIP and Coherence, WISH got better results in at least one combination of weights, whilst the criterion based on Voronoi cells showed an unrelated pattern.

Conclusion

The versatility provided by WISH is supported by better results. Optimization in the weight parameter space is likely to provide additional improvements. For a practical design with an intermediate number of gradients, our results recommend to carry out the methodology here used to determine the appropriate gradient table.
A multiaxial inertial macroelement for bridge abutments
Authors: Gorini Davide Noè , Callisto Luigi , Whittle Andrew J. , Sessa Salvatore
Published: January 2023

This paper proposes a multiaxial macroelement for bridge abutments that can be included in the global structural model of a bridge to carry out nonlinear dynamic analyses with very much smaller computational effort than can be achieved using continuum representations of embankment and foundation soil behaviour. The proposed macroelement derives a constitutive force–displacement relationship within a rigorous thermodynamic framework and includes important features of non‐linearity and directional coupling in characterizing the interactions of the abutment with the soil. In a dynamic analysis, the frequency‐dependent response of the system is simulated through the combination of the macroelement with appropriate participating masses. The calibration procedure of the macroelement is based on the assessment of its ultimate capacity and of its response at small displacements, and it is shown that these ingredients can be derived through standardised procedures. In the paper, the macroelement response is validated against the results of fully coupled continuum numerical analyses for a reference soil–abutment system, under both static and seismic loading conditions. We show that the two models achieve similar predictions of maximum and permanent abutment deformations (less than 10–14% difference, respectively) for a suite of three‐axis seismic loading events.
Case study of a special burial resulting from obstetric death at the Sanbulijia site, Shandong Province, China
Authors: Guo Lin , Qi Gaohua , Feng Xiaotian , Peng Yu , Mao Xiaowei , Yang Zhangqiaochu , Zeng Wen , Zhao Yongsheng
Published: January 2023

Many young women were believed to die due to pregnancy and childbirth in the past, yet few cases of pregnant female burials have been reported in bioarcheological literature. Therefore, this paper reports the burial of an adult female (H49‐1) and her infant (H49‐2), who were buried together in an early Western Zhou pit at the Sanbulijia site, Jiaodong Peninsula, Shandong Province, China. It is the first reported case of obstetric death in thePre‐Qin Period in Shandong Province. The mother–child relationship was proved by ancient DNA evidence and archeological context. The infant's remains were placed between the adult's lower legs. Skeletal histological evidence suggests that the infant died during or shortly after childbirth. Sacroiliac fusion of individual H49‐1 may have resulted in dystocia. Furthermore, a special postmortem burial ritual—pit burial, was carried out for both the infant and the mother. H49 is the first Zhou Dynasty pit burial (multiple burial) with an exact radiocarbon date in the Shandong Peninsula. The case under review suggests that both the adult and the infant may have died due to special events, which may be related to obstetric death.
Fire impact on mechanically failed graphite/epoxy composites
Authors: Boushab Dounia , Ouidadi Hasnaa , Mote Aniket , Priddy Matthew , Kundu Santanu , Pittman Charles U. , Grunlan Jaime , Wang Qingsheng , Lacy Thomas
Published: January 2023

Aircraft crashes often initiate or accompany fire incidents. Post‐crash fires, in particular, can mask or destroy critical fractographic failure features necessary for accident reconstruction. As a first step in developing a coherent strategy for composite aircraft post‐crash forensic analysis, a series of vertical flame tests were performed on mechanically failed Cytec T40‐800/Cycom® 5215 graphite/epoxy unnotched compression, short beam strength, and in‐plane shear specimens. Visual inspection and scanning electron microscopy were used to examine the specimens fracture surfaces before and after fire testing. The fire‐induced damage included matrix decomposition, melt dripping, char, soot, delamination, and residual thickness increases. The composite thermal degradation was significantly influenced by the specimen stacking sequence, the fracture surface morphology, and the total available free surface area. In addition, microscopic inspection showed that char layers impeded heat conduction and oxygen transfer to the interior of the specimens resulting in less thermal damage to the underlying plies. Moreover, burned specimens with more available free surface area sustained more thermal degradation and fire combustion damage for a given fire exposure duration. Exposed fiber bundles from the fracture surfaces were susceptible to severe thinning and thermal oxidation, which destroyed critical fractographic failure features necessary for accident reconstruction.
Thermal properties of lauric acid/high‐density polyethylene form‐stabilized phase change materials doped with hybrid carbon nanofillers
Authors: Zhang Huan , Fu Tingwei , Wang Wenze , Fang Guiyin
Published: January 2023

The form‐stabilized phase change materials (PCMs) comprised of lauric acid (LA), high‐density polyethylene (HDPE) and graphene nanoplates‐carbon nanofibers (GNP‐CNF) hybrid fillers were synthesized by melt blending method in this work, and the effects of GNP‐CNF mass ratio on thermal properties were investigated. The results from FT‐IR and XRD reveal that LA, HDPE, GNP and CNF were integrated with each other in a physical manner. The LA/HDPE/GNP‐CNF composites possess melting points very close to that of pure LA, with melting latent heats of 113.83–119.84 J/g. Thermal conductivity results indicate that the effect of GNP is better than that of CNF at the same content. The synergistic effect of hybrid carbon fillers can achieve higher thermal conductivity value compared to a single GNP or CNF. The synergistic thermal conductivity improvement mechanism is also analyzed. The sample SN2 (GNP: CNF is 1.7:0.3) exhibits the best thermal conductivity of 0.759 W/(m·K), with 2.73 times that of SN0. It also presents satisfactory thermal stability and reliability, allowing it to have promising applications in thermal energy storage.
Low‐temperature 3D printing and curing process of continuous fiber‐reinforced thermosetting polymer composites
Authors: Xiao Hong , He Qian , Duan Yugang , Wang Jie , Qi Yao , Ming Yueke , Zhang Chenping , Zhu Yansong
Published: January 2023

The reported work has developed a methodology of printing and curing continuous fiber‐reinforced thermosetting polymer composites (CFRTPCs) with excellent mechanical properties at low temperatures. First, to print and cure CFRTPCs at low temperatures, a thermosetting polymer system was proposed, consisting of phenol based epoxy resin and curing agent (F‐44/2E4MZ). The rheological properties of the polymer system were analyzed to determine a reasonable printing temperature. Second, the non‐linear Vyazovkin integral method was applied to establish the model‐free kinetics (MFK) of the resin system. MFK can predict the curing degree curves at the characteristic temperatures obtained by extrapolation. Reasonable curing process parameters were determined by analyzing the predicted curing degree curves. Then, CFRTPC samples were prepared with the low‐temperature 3D printing process and the low‐temperature curing process, and the fiber content was found to be 53 wt.%. At last, the mechanical property measurements revealed that the tensile and flexural strengths were 1012 MPa and 929 MPa, respectively. This work can further expand the potential applications of 3D printed CFRTPCs in aerospace and defense industries which require high mechanical properties and temperature safety simultaneously.
Evaluation of the efficacy and safety of romosozumab (evenity) for the treatment of osteoporotic vertebral compression fracture in postmenopausal women: A systematic review and meta‐analysis of randomized controlled trials (CDM‐J)
Authors: Huang Wenbo , Nagao Masashi , Yonemoto Naohiro , Guo Sen , Tanigawa Takeshi , Nishizaki Yuji
Published: January 2023

Purpose

Osteoporotic vertebral compression fracture (OVCF) is a common fragile fracture resulting from osteoporosis. We compared the efficacy and safety of romosozumab and commonly used osteoporosis drug treatments for the treatment of OVCF in postmenopausal women.

Methods

Through searching and screening five databases, we included randomized controlled trials (RCTs) published through June 18, 2021 comparing different treatments. Following the Preferred Reporting Items for Systematic Reviews statement, the main objective was to evaluate the mean difference and risk ratio of the treatment effect. The primary measures of romosozumab efficacy used in this study were vertebral, non‐vertebral, and clinical fracture events, and secondary outcomes were bone mineral density (BMD) changes at the lumbar spine, total hip, and femoral neck and the incidence of adverse events (AEs),

Results

Nine RCTs including 12 796 participants were included in the analysis, and romosozumab was compared with placebo, alendronate, and teriparatide in the treatment of osteoporosis in postmenopausal women. The incidence of fractures, low BMD, and AEs was analyzed. Compared with the controls, three doses of romosozumab were linked to evident advantages in the treatment of low BMD and fractures but associated with increased hypersensitivity and injection site reaction risks. Furthermore, fewer AEs were observed in the romosozumab arms (210 mg: risk ratio = 0.96, 95% confidence interval = 0.93–0.99; 140 mg: risk ratio = 0.28, 95% confidence interval = 0.08–0.98) than in the alendronate and placebo arms.

Conclusions

Our meta‐analysis revealed the evident advantages of romosozumab in the treatment of osteoporosis and low BMD in postmenopausal women and increased risks of hypersensitivity and injection site reactions.
Computational study of the alcoholysis for organophosphorus pesticides: The reaction of phoxim with methanol
Authors: Chen Rong , Luo Xiaoling , Liang Guoming
Published: January 2023

The alcoholysis process for one of organophosphorus pesticides, phoxim, was systematically examined by using the M06‐2X/6–311++G(d,p) and MP2/6–311++G(d,p)//M06‐2X/6–311++G(d,p) levels. Two possible alcoholysis mechanisms, P–OR1, P–OEt rupture channels together with the concerted and stepwise steps, were theoretically evaluated. The catalytic role of an extra methanol was also simulated. Furthermore, the influence of solvent on water was also taken into consideration for the M06‐2X/6–311++G(d,p) level of theory. Our predicted results show convincingly that the P–OEt disintegration pathway is slightly more favorable than the P–OR removal channel. The stepwise pathway is calculated to be more prominent than the concerted one for all reactions. It can be observed that the methanol‐assisted alcoholysis is more easier to take place than the direct alcoholysis. Solvent effect does not have remarkable effect on the reaction mechanism.
Improving methods for evaluating potassium availability in vineyard soils
Authors: Fiola Jaclyn C. , Stewart Ryan D. , Evanylo Greg K.
Published: January 2023

Vineyard soils often contain mineralogy that can confound predictions of plant‐available potassium (K). Too little or too much K uptake into wine‐grape (Vitis varieties) tissues can negatively affect fruit chemistry, making it important to have soil tests that accurately quantify plant‐available K. Our goal was to determine the best soil sampling, processing, and extraction methods for predicting K availability in vineyard soils. We sampled soil and grapevine tissue in 39 vineyard blocks from 22 vineyards in Virginia, Maryland, and New Jersey. Plant tissue sampling included petioles at bloom and both petioles and leaf blades at veraison. Soil samples were collected from 0 to 10‐ and 0 to 38‐cm depths. We tested three soil extraction methods—Mehlich 1, Mehlich 3, and sodium tetraphenylboron (NaTPB)—on both oven‐dried and field‐moist samples. The different sampling, processing, and extracting procedures produced distinct K concentrations, with shallow 0–10 cm samples and NaTPB extraction resulting in higher K concentrations than their counterparts. Upon drying, three soils fixed K and 24 samples released K. Whole leaf (petiole plus leaf blade) samples collected at veraison had the best relationships with most soil K concentrations. The best soil testing method for predicting tissue K concentration in whole leaves at veraison was Mehlich 1 extractions of field‐moist soils from 0 to 38‐cm depth. This sampling combination appears to be best suited for growers to use when assessing K concentrations in vineyard soils.
Controllable synthesis of Pt nanoparticles on graphene oxide nanosheets and its application for electrochemical determination of dopamine
Authors: Zhang Xinjin , Yan Bo , Peng Lei , Zhao Jie , Zheng Jianbin
Published: January 2023

Establishing effective strategies to improve the performance of catalyst is a major area of interest within the field of electrochemical detection. In this paper, the nanocomposites of Pt catalyst with different morphologies decorated GO surface were successfully synthesized. The feature and diversity of Pt nanoparticles were confirmed by transmission electron microscope. The electrocatalytic performance and electroactive area of various modified electrodes were examined by cyclic voltammetry. According to Randles‐Sevick equation, the active area of electrode modified with the shape of concave cube Pt nanoparticles is the largest. Moreover, compared with the other common stable planes, the concave cube Pt nanoparticles bound by high‐index facets have the strongest current response. Furthermore, dopamine can be detected by amperometry at a typical working potential of 0.2 V (versus SCE) with a detection limit of 0.74 μM (at the signal‐to‐noise ratio of 3), over two wide linear ranges (3 μM–0.7 mM and 0.7 mM–4 mM). The sensing electrode also exhibited good reproducibility, stability and selectivity for dopamine determination.
Synthesis of Novel 5‐Oxo‐1,2,4‐Oxadiazole Derivatives as Antitubercular Agents and Their Molecular Docking Study toward Enoyl Reductase (InhA) Enzyme
Authors: Reddy B. Raja Sekhara , Babu K Sudakar , Mulakayala Naveen , Gajulapalli V. Pratap Reddy
Published: January 2023

An analogue of novel 3‐(1‐(4‐(benzoyl) benzyl)‐1H‐indol‐5‐yl)‐1,2,4‐oxadiazol‐5(4H)‐ones were synthesized in good yields (80–90 %), and its anti‐tubercular (anti‐TB) activity was investigated. All synthesized compounds (7 a–u) showed significant deterioration in the proliferation of the Mycobacterium tuberculosis H37Rv strain. A structure‐activity relationship (SAR) study was performed to identify compounds with mixed anti‐tubercular profiles. These compounds′ minimum inhibitory concentration (MIC) ranged between 0.78 and 25 μg/mL, comparable to standard drugs such as Ethambutol. Moreover, the derivative (7 l) (MIC of 0.78 μg/mL), amongst other 5‐oxo‐1,2,4‐oxadiazole, conferred anti‐TB activity more efficiently than Ethambutol (MIC of 1.56 μg/mL) when tested against all bacterial strains. Additionally, molecular docking studies were used against the mycobacterial enoyl reductase (InhA) enzyme to understand the binding modes of the potent compounds (7 l) and (7 m). Also evaluated were these molecules for in silico ADMET and drug similarity features. Thus, this study identified novel 5‐oxo‐1,2,4‐oxadiazoles as potential targets against tuberculosis. Further optimization of the molecule (7 l) could increase potency and aid in creating newer and better targets against M. tuberculosis.
Water‐Assisted Passerini Reactions under Mechanochemical Activation: A Simple and Straightforward Access to Oxindole Derivatives
Authors: Salami Sodeeq Aderotimi , Smith Vincent J. , Krause Rui W. M.
Published: January 2023

A protocol based on the Passerini Multi‐Component reaction (MCR) has been developed for facile, efficient, environmentally benign and atom economical synthesis of a small library of biologically important oxindole derivatives employing isatin, benzoic acid and substituted isocyanides. In contrast to the conventional approach, which requires the use of toxic organic solvents, Passerini reactions were completed in 10–15 minutes under mechanochemical conditions with excellent yields. The protocol described below allows the modular synthesis of diverse compounds under green chemistry principles, specifically in favourable environmental conditions, with great atom economy, shorter reaction time, cleaner reactions with improved yields, and experimental simplicity.
An Efficient Synthesis of Rivaroxaban
Authors: Lin Xiaoyu , Li Nanlian , Zhu Chenlong , Sun Bingfeng
Published: January 2023

An efficient synthesis of rivaroxaban has been accomplished by a sequence spanning five steps from 4‐morpholinoaniline and (S)‐2‐(oxiran‐2‐ylmethyl)isoindoline‐1,3‐dione with an overall yield of 44 %. This synthesis is concise, environmentally benign and cost‐effective, providing a good basis for the development of a new process for rivaroxaban.
An Oxidative Enzyme Boosting Mechanical and Optical Performance of Densified Wood Films
Authors: Koskela Salla , Wang Shennan , Li Lengwan , Zha Li , Berglund Lars A. , Zhou Qi
Published: January 2023

Nature has evolved elegant ways to alter the wood cell wall structure through carbohydrate‐active enzymes, offering environmentally friendly solutions to tailor the microstructure of wood for high‐performance materials. In this work, the cell wall structure of delignified wood is modified under mild reaction conditions using an oxidative enzyme, lytic polysaccharide monooxygenase (LPMO). LPMO oxidation results in nanofibrillation of cellulose microfibril bundles inside the wood cell wall, allowing densification of delignified wood under ambient conditions and low pressure into transparent anisotropic films. The enzymatic nanofibrillation facilitates microfibril fusion and enhances the adhesion between the adjacent wood fiber cells during densification process, thereby significantly improving the mechanical performance of the films in both longitudinal and transverse directions. These results improve the understanding of LPMO‐induced microstructural changes in wood and offer an environmentally friendly alternative for harsh chemical treatments and energy‐intensive densification processes thus representing a significant advance in sustainable production of high‐performance wood‐derived materials.
Reactivation of Anticancer Immunity by Resetting Interorgan Crosstalk in Immune‐Suppressive Cells with a Nanoparticulated Anti‐Inflammatory Drug
Authors: Doi Mizuki , Tanaka Hiroki , Ohoto Takara , Miura Naoya , Sakurai Yu , Hatakeyama Hiroto , Akita Hidetaka
Published: January 2023

The reactivation of anticancer immunity is a fundamental principle in cancer immunotherapy as evidenced by the use of immune checkpoint inhibitors (ICIs). While treatment with the ICIs is shown to have remarkable and durable therapeutic effects in the responders, the low objective response rate (<40%) continues to be a major problem. Since myeloid‐derived suppressor cells (MDSCs), heterogenous cells with strong immunosuppressive activity that originate in the hematopoietic system, suppress the anticancer immunity via parallel immune checkpoint‐dependent and independent pathways, these cells are potential targets for improving the efficacy of cancer immunotherapy. In this study, it is demonstrated that MDSCs can be depleted by delivering synthetic glucocorticoid dexamethasone to phagocytic cells in the spleen using a lipid nanoparticle. Since the interaction of nanoparticles with T cells is intrinsically poor, this strategy also enables the “detargeting” from T cells, thus avoiding the nonspecific suppression of cytotoxic immune responses against cancer cells. In addition to the direct anticancer effect of the nanoparticulated dexamethasone, their synergistic anticancer effect with ICIs is also reported.
Water as a Modifier in a Hybrid Coordination Network Glass
Authors: Sørensen Søren S. , Ren Xiangting , Du Tao , Traverson Ayoub , Xi Shibo , Jensen Lars R. , Bauchy Mathieu , Horike Satoshi , Wang John , Smedskjaer Morten M.
Published: January 2023

Chemical diversification of hybrid organic–inorganic glasses remains limited, especially compared to traditional oxide glasses, for which property tuning is possible through addition of weakly bonded modifier cations. In this work, it is shown that water can depolymerize polyhedra with labile metal–ligand bonds in a cobalt‐based coordination network, yielding a series of nonstoichiometric glasses. Calorimetric, spectroscopic, and simulation studies demonstrate that the added water molecules promote the breakage of network bonds and coordination number changes, leading to lower melting and glass transition temperatures. These structural changes modify the physical and chemical properties of the melt‐quenched glass, with strong parallels to the “modifier” concept in oxides. It is shown that this approach also applies to other transition metal‐based coordination networks, and it will thus enable diversification of hybrid glass chemistry, including nonstoichiometric glass compositions, tuning of properties, and a significant rise in the number of glass‐forming hybrid systems by allowing them to melt before thermal decomposition.
Synthesis of Thermally Stable and Highly Luminescent Cs5Cu3Cl6I2 Nanocrystals with Nonlinear Optical Response
Authors: Jang Changhee , Kim Kangyong , Nho Hak‐Won , Lee Seung Min , Mubarok Hanif , Han Joo Hyeong , Kim Hyeonjung , Lee Dongryeol , Jang Yangpil , Lee Min Hyung , Kwon Oh‐Hoon , Kwak Sang Kyu , Im Won Bin , Song Myoung Hoon , Park Jongnam
Published: January 2023

Low‐dimensional Cu(I)‐based metal halide materials are gaining attention due to their low toxicity, high stability and unique luminescence mechanism, which is mediated by self‐trapped excitons (STEs). Among them, Cs5Cu3Cl6I2, which emits blue light, is a promising candidate for applications as a next‐generation blue‐emitting material. In this article, an optimized colloidal process to synthesize uniform Cs5Cu3Cl6I2 nanocrystals (NCs) with a superior quantum yield (QY) is proposed. In addition, precise control of the synthesis parameters, enabling anisotropic growth and emission wavelength shifting is demonstrated. The synthesized Cs5Cu3Cl6I2 NCs have an excellent photoluminescence (PL) retention rate, even at high temperature, and exhibit high stability over multiple heating–cooling cycles under ambient conditions. Moreover, under 850‐nm femtosecond laser irradiation, the NCs exhibit three‐photon absorption (3PA)‐induced PL, highlighting the possibility of utilizing their nonlinear optical properties. Such thermally stable and highly luminescent Cs5Cu3Cl6I2 NCs with nonlinear optical properties overcome the limitations of conventional blue‐emitting nanomaterials. These findings provide insights into the mechanism of the colloidal synthesis of Cs5Cu3Cl6I2 NCs and a foundation for further research.
Controllable CO2 Reduction or Hydrocarbon Oxidation Driven by Entire Solar via Silver Quantum Dots Direct Photocatalysis
Authors: Xue Ruiting , Ge Peng , Xie Jun , Hu Ziyuan , Wang Xikui , Li Peiqi
Published: January 2023

The current solar‐chemical‐industry based on semiconductor photocatalyst is impractical. Metal catalysts are extensively employed in thermal‐ and electro‐catalysis industries, but unsuitable for direct‐driven photocatalysis. Herein, silver quantum dots (Ag‐QDs) are synthesized on support via an in situ photoreduction method, and in situ photocatalysis temperature programmed dynamics chemisorption desorption analyses are designed to demonstrate that Ag‐QDs should be the actual photocatalytic sites. The surface plasmon resonance of Ag‐QDs could harvests entire visible solar, and the plasmon‐driven charge‐transfer exhibits opposite directions at the interface when supports are different. Consequently, Ag‐QDs could be alternatively regulated as oxidation or reduction active centers. Furthermore, Ag‐QDs excite electron tunneling transfer with adsorbate, which does not generate high‐energy free‐radical intermediates. As a result, the efficiencies of hydrocarbon photooxidation and CO2 photoreduction are improved in several orders of magnitude. Evidently, the Ag‐QDs direct photocatalytic technology greatly promotes solar‐chemical‐industry applications.
Boosting Electrochemical Catalysis and Nonenzymatic Sensing Toward Glucose by Single‐Atom Pt Supported on Cu@CuO Core–Shell Nanowires
Authors: Zhao Yuanmeng , Jiang Yunhao , Mo Yan , Zhai Yueming , Liu Juejing , Strzelecki Andrew C. , Guo Xiaofeng , Shan Changsheng
Published: January 2023

It is critical to develop high‐performance electrocatalyst for electrochemical nonenzymatic glucose sensing. In this work, a single‐atom Pt supported on Cu@CuO core–shell nanowires (Pt1/Cu@CuO NWs) for electrochemical nonenzymatic glucose sensor is designed. Pt1/Cu@CuO NWs exhibit excellent electrocatalytic oxidation toward glucose with 70 mV lower onset potential (0.131 V) and 2.4 times higher response current than Cu NWs. Sensors fabricated using Pt1/Cu@CuO NWs also show high sensitivity (852.163 µA mM−1 cm−2), low detection limit (3.6 µM), wide linear range (0.01–5.18 µM), excellent selectivity, and great long‐term stability. The outstanding sensing performance of Pt1/Cu@CuO NWs, investigated by experiments and density functional theory (DFT) calculations, is attributed to the synergistic effect between Pt single atoms and Cu@CuO core–shell nanowires that generates strong binding energy of glucose on the nanowires. The work provides a new pathway for exploring highly active SACs for electrochemical nonenzymatic glucose sensor.
Heterocyclic Modulated Electronic States of Alkynyl‐Containing Conjugated Microporous Polymers for Efficient Oxygen Reduction
Authors: Zhao Zijie , Wang Binbin , You Zhihu , Zhang Qiankun , Song Weichen , Long Xiaojing
Published: January 2023

The oxygen reduction reaction (ORR) is a key process in green energy conversion technology. Heteroatom doping has been proven to be a prospective strategy to prepare metal‐free carbon‐based electrocatalysts, but such methods often suffer from uncontrollable catalyst frameworks and imprecise active sites. Herein, an organic heterocyclic strategy is adopted to modulate the charge redistribution of alkynyl‐containing conjugated microporous polymers (CMPs) by introducing varied five‐membered heterocyclic structures. Among these CMPs, the S, 2N‐containing thiadiazole heterocyclic molecule (CMP‐Tdz) with carbonized alginate materials (CCA) displays a remarkable quasi‐four‐electron‐transfer ORR pathway, exhibiting an excellent half‐wave potential (E1/2) of 0.77 V, coupled with superior methanol tolerance and electrochemical stability, which are among the highest performance in the metal‐free organic catalytic material systems. Density functional theory calculations prove that the high catalytic performance of these catalysts originates from the sp‐hybridized C atom (site–2) which is activated by their adjacent heterocyclic structures. Importantly, the five‐membered heterocyclic structures can also modulate the local charge distribution, and increase dipole moment, with significantly improved catalytic kinetics. This incorporation of chemically designed heterocyclic‐containing alkynyl‐CMPs provides a new approach to developing efficient metal‐free carbon‐based electrocatalysts for fuel cells.
2D Covalent Organic Frameworks Based on Heteroacene Units
Authors: Guo Fu , Zhang Weifeng , Yang Shuai , Wang Liping , Yu Gui
Published: January 2023

Covalent organic frameworks (COFs) are a unique new class of porous materials that arrange building units into periodic ordered frameworks through strong covalent bonds. Accompanied with structural rigidity and well‐defined geometry, heteroacene‐based COFs have natural advantages in constructing COFs with high stability and crystallinity. Heteroacene‐based COFs usually have high physical and chemical properties, and their extended π‐conjugation also leads to relatively low energy gap, effectively promoting π‐electron delocalization between network units. Owing to excellent electron‐withdrawing or ‐donating ability, heteroacene units have incomparable advantages in the preparation of donor–acceptor type COFs. Therefore, the physicochemical robust and fully conjugated heteroacene‐based COFs solve the problem of traditional COFs lacking π–π interaction and chemical stability. In recent years, significant breakthroughs are made in this field, the choice of various linking modes and building blocks has fundamentally ensured the final applications of COFs. It is of great significance to summarize the heteroacene‐based COFs for improving its complexity and controllability. This review first introduces the linkages in heteroacene‐based COFs, including reversible and irreversible linkages. Subsequently, some representative building blocks are summarized, and their related applications are especially emphasized. Finally, conclusion and perspectives for future research on heteroacene‐based COFs are presented.
Exciton diffusion and dissociation in organic and quantum‐dot solar cells
Authors: He Dan , Zeng Miao , Zhang Zhenzhen , Bai Yang , Xing Guichuan , Cheng Hui‐Ming , Lin Yuze
Published: January 2023

For the process of photovoltaic conversion in organic solar cells (OSCs) and quantum‐dot solar cells (QDSCs), three of four steps are determined by exciton behavior, namely, exciton generation, exciton diffusion, and exciton dissociation. Therefore, it is of great importance to regulate exciton behavior in OSCs and QDSCs for achieving high power conversion efficiency. Due to the rapid development in materials and device fabrication, great progress has been made to manage the exciton behavior to achieve prolonged exciton diffusion length and improved exciton dissociation in recent years. In this review, we first introduce the parameters that affect exciton behavior, followed by the methods to measure exciton diffusion length. Then, we provide an overview of the recent advances with regard to exciton behavior investigation in OSCs and QDSCs, including exciton lifetime, exciton diffusion coefficient, and exciton dissociation. Finally, we propose future directions in deepening the understanding of exciton behavior and boosting the performance of OSCs and QDSCs.
Optical Amplification at 637 and 1067 nm Based on Organic Molecule AQ(PhDPA)2 and NdIII Complex Codoped Polymer Waveguides
Authors: Huang Yuyang , Man Yi , Xie Guohua , Wang Ce , Zhang Baoping , Xu Hui , Fu Hongyan , Zhu Jiyun , Lv Ziyue , Ying Leiying , Xia Feng , Zhang Dan
Published: January 2023

Based on the molecular energy transfer mechanism, relative gains at 1067 and 637 nm wavelengths are achieved in thermally activated delayed fluorescence molecule AQ(PhDPA)2 and Nd complex with chelating phosphine oxide as ligands codoped polymer waveguides, with the excitation of low‐power UV light‐emitting diodes (LEDs) instead of traditional semiconductor lasers as pump sources. For AQ(PhDPA)2‐Nd(DBTTA)3(DBFDPO) (DBTTA = dibenzotetrathienoacene, DBFDPO = 4,6‐bis (diphenylphosphoryl) dibenzofuran) ‐codoped polymethylmethacrylate (PMMA), and AQ(PhDPA)2‐Nd(DBTTA)3(FDPO) (FDPO = 9,9‐bis (diphenylphosphorylphenyl) fluorene)‐codoped PMMA polymers with a mass ratio of 1:4 respectively, when they are spin‐coated as upper claddings, the relative gains of 2.2 and 1.8 dB cm−1 at 1067 nm are obtained in evanescent‐field waveguides with cross‐section of 4 × 8 µm2 under excitation of 300 mW 405 nm LED, and the gains of 3.9 and 4.9 dB cm−1 at 637 nm are achieved with pumping of 530 mW 450 nm LED respectively. By growing a 100 nm‐thick aluminum reflector with the waveguides, the optical gain at 1067 and 637 nm can be enhanced to 3.5 and 6.1 dB cm−1, corresponding to AQ(PhDPA)2‐Nd(DBTTA)3(DBFDPO) and AQ(PhDPA)2‐Nd(DBTTA)3(FDPO)‐codoped PMMA polymers, respectively.
High‐Voltage MXene‐Based Supercapacitors: Present Status and Future Perspectives
Authors: Zhu Yuanyuan , Ma Jiaxin , Das Pratteek , Wang Sen , Wu Zhong‐Shuai
Published: January 2023

As an emerging class of 2D materials, MXene exhibits broad prospects in the field of supercapacitors (SCs). However, the working voltage of MXene‐based SCs is relatively limited (typically ≤ 0.6 V) due to the oxidation of MXene electrode and the decomposition of electrolyte, ultimately leading to low energy density of the device. To solve this issue, high‐voltage MXene‐based electrodes and corresponding matchable electrolytes are developed urgently to extend the voltage window of MXene‐based SCs. Herein, a comprehensive overview and systematic discussion regarding the effects of electrolytes (aqueous, organic, and ionic liquid electrolytes), asymmetric device configuration, and material modification on the operating voltage of MXene‐based SCs, is presented. A deep dive is taken into the latest advances in electrolyte design, structure regulation, and high‐voltage mechanism of MXene‐based SCs. Last, the future perspectives on high‐voltage MXene‐based SCs and their possible development directions are outlined and discussed in depth, providing new insights for the rational design and realization of advanced next‐generation MXene‐based electrodes and high‐voltage electrolytes.
A numerical perspective for CFRP‐wrapped thin‐walled steel cylinders
Authors: Aydin Abdulkadir Cüneyt , Maali Mahyar , Kiliç Mahmut , Bayrak Bariş , Akarsu Oğuzhan
Published: January 2023

The failure of steel cylindrical shells with carbon fiber‐reinforced polymers (CFRP) under hydrostatic pressure is studied in this article by experimental tests and the finite element method. Simulations were performed for 12 cylindrical shells with different dent numbers, dent depths, and two perfect models with and without CFRP. The finite element models are built to simulate the buckling behavior. The nonlinear stabilization method is preferred to simulate the buckling behavior. The finite element results agree well with the corresponding experimental tests and theories. A parametric study is conducted, and the number, depth, width of dents, and the effects of CFRPs on the critical buckling pressure are discussed. The dents are placed symmetrically around the cylinder with a thickness of tc (thickness of cylinder) and 2tc mm. The initial and overall buckling load decreased with increasing amplitude for dent numbers with different dent depths on all models. The results show that the number and depth of dents generally have a negative effect on the buckling strength, while CFRPs increase the critical buckling strength and are effective in repair as a retrofitting concept.
Outcome of laser photocoagulation in monochorionic diamniotic twin pregnancy complicated by Type‐II selective fetal growth restriction
Authors: Nassr A. A. , Hessami K. , Corroenne R. , Sanz Cortes M. , Donepudi R. , Espinoza J. , Yamamoto R. , Stirnemann J. , Ishii K. , Belfort M. A. , Chmait R. H. , Shamshirsaz A. A.
Published: January 2023

Objectives

To evaluate the outcome of monochorionic diamniotic (MCDA) twins complicated by Type‐II selective fetal growth restriction (sFGR) who underwent fetoscopic laser photocoagulation and to validate a previously proposed subclassification system for Type‐II sFGR in a large multicenter cohort.

Methods

This retrospective multicenter cohort study included all MCDA twins complicated by Type‐II sFGR who underwent laser photocoagulation of placental anastomoses at four large tertiary fetal‐care centers between 2006 and 2020. Cases were subclassified according to a recently proposed system based on Doppler evaluation of the ductus venosus (DV) and middle cerebral artery (MCA) into Type‐IIA (normal DV flow and MCA peak systolic velocity (PSV) of the growth‐restricted fetus) or Type‐IIB (absent or reversed flow in the DV during atrial contraction and/or MCA‐PSV ≥ 1.5 multiples of the median of the growth‐restricted fetus). Demographic characteristics and pregnancy outcomes were compared between the groups. Data are presented as mean ± SD or n (%) as appropriate. P‐values < 0.05 were considered statistically significant.

Results

A total of 98 patients with MCDA twins met our inclusion criteria, with 56 subclassified as Type IIA and 42 as Type IIB. Demographic characteristics were similar between the groups; however, Type‐IIB cases had a significantly earlier gestational age at diagnosis and at laser surgery, as well as larger intertwin estimated fetal weight discordance, which may be a reflection of disease severity. Postnatal survival of the growth‐restricted fetus to 30 days of age was significantly lower in Type‐IIB compared to Type‐IIA cases (23.8% vs 46.4%; P = 0.034).

Conclusions

In MCDA twins complicated by Type‐II sFGR and treated with laser photocoagulation of placental anastomoses, preoperative Doppler assessment of the DV and MCA helped identify a subset of patients at increased risk of demise of the growth‐restricted fetus following intervention. This study provides valuable information for guiding surgical management and patient counseling. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
Visitors and observers otter‐ly influence the behavior and enclosure use of zoo‐housed giant otters
Authors: Brereton James E. , Jones Edward M. L. , McMillan Connor , Perkins Kerry
Published: January 2023

The potential impact of human presence on captive animal behavior has recently been the focus of considerable research interest, especially following 2020 and 2021 periods of enforced closure as a result of COVID‐19 opening restrictions. It is important to investigate whether human presence represents an enriching or stressful stimulus to a range of zoo‐housed species. In 2020, during an easing of lockdown restrictions, investigations of the “visitor effect” and “observer effect” were carried out, using the giant otter (Pteronura brasiliensis) as a model species. To investigate the impact of both visitor and observer presence, otter behavior and space use was recorded for a pair of on‐show and a pair of off‐show otters. Observations were conducted using either a human observer, or cameras, allowing the researchers to investigate otter behavior when no one was present at the exhibits. The Electivity Index was used to assess the otters' use of four enclosure zones. Overall, otter behavior was significantly impacted by observer presence, though the impact of an observer differed between individual otters. Visitors had a minimal effect on otter enclosure use, whereas observers had a greater impact, whereby otters used their pools less frequently and houses more frequently when observers were present. However, this change in zone use differed between individuals, with more dominant otters tending to make use of indoor zones more often when observers were present. Zoos should consider the potential impact of human presence on their animals and use both behavior and space use when conducting their investigations.
Bergbaukunde, quo vadis?
Authors: Tost Michael , Hartlieb Philipp , Heiss Christian , Knoll Birgit , Ladinig Tobias , Mayer Gerhard , Moser Peter , Prenner Michael , Sifferlinger Nikolaus , Tscharf Alexander
Published: January 2023

Um dem Klimawandel und dem zunehmenden Wettbewerb beim Zugang zu Ressourcen zu begegnen, hat die Europäische Union im sogenannten Green Deal weitreichende Transformationen in den Bereichen Energie und Digitalisierung sowie die Umstellung des Wirtschaftssystems hin zu einer inklusiven Kreislaufwirtschaft festgelegt. Aus Sicht des Bergbaus bedeuten diese Transformationen einen weiterhin wachsenden Rohstoffbedarf, der durch die Gewinnung mineralischer Rohstoffe aus primären Lagerstätten gedeckt werden muss. Gesteigerte Mengen mit „Business as usual“ würden allerdings auch die Umwelt- und Sozialauswirkungen des Bergbaus steigern, was vor allem in Europa und Österreich keine Option darstellt.

Aufgrund dieser Tatsachen ergibt sich Forschungsbedarf für neue und verbesserte Abbauverfahren und -planung ebenso wie für optimierte Prozesse und Maschinen. Im vorliegenden Artikel wird beschrieben, wie der Lehrstuhl für Bergbaukunde, Bergtechnik und Bergwirtschaft an der Montanuniversität Leoben mit seiner aktuellen Strategie, sowohl für die Forschung als auch für die Lehre, diese Herausforderungen als Chance nutzen möchte. Für den Forschungsbereich soll dabei die Nachhaltigkeit und Involvierung in die Gestaltung von Rohstoffpolitik den Rahmen bilden. Mit einer Fokussierung auf die Digitalisierung und den untertägigen Bergbau sowie der Stärkung der Bereiche Tagebau, Fördertechnik und Geoinformatik soll die Forschung für die anstehenden Transformationen zukunftssicher ausgerichtet werden. Die Lehre wird inhaltlich weiterhin eine ingenieurwissenschaftliche Grundausbildung mit Spezialisierung auf den Bergbau beinhalten, wobei die Digitalisierung eine zunehmend stärkere Rolle spielen wird.