bluuebunny/crossref_metadata_2025 huggingface dataset:
Bionic Mineralized 3D‐Printed Scaffolds with Enhanced In Situ Mineralization for Cranial Bone Regeneration
Authors: Wang Ling , Li Dongxuan , Huang Yawen , Mao Ruiqi , Zhang Boqing , Luo Fengxiong , Gu Peiyang , Song Ping , Ge Xiang , Lu Jian , Yang Xusheng , Fan Yujiang , Zhang Xingdong , Wang Kefeng
Published: October 2023

In situ mineralization is a promising strategy to mimic the physicochemical properties of biominerals and is widely applied in the field of bone repair. Given the high requirement for substance exchange in cranial bone regeneration, in situ mineralized organic–inorganic hybrid materials exhibit advantages. However, the integration of remarkable mineral content, mechanical properties, and osteogenic properties also remains a major challenge. Herein, enhanced in situ mineralization through combining the enzymatic and anion‐boosted mineralization is applied to promote the mineralization efficiency, mineral content, and mechanical properties. Based on the results of computational calculations and in vitro mineralization experiments, the mechanism of mineralization enhancement is investigated from the perspectives of nucleation sites and the saturation of in situ mineralization. Anionic polyaspartic acid (pAsp) can increase the saturation of in situ mineralization; enzymatic mineralization shows high efficiency, with minerals of low crystallinity. The changes in the properties of the minerals effectively enhance the biological properties of 3D‐printed scaffolds, as confirmed by cell proliferation/differentiation experiments in vitro and in cranial bone regeneration in vivo. This strategy provides a new thinking for the preparation of bionic mineralized scaffolds for cranial bone repair, and can greatly promote the efficiency of bone regeneration.
Active Site Engineering in Reticular Covalent Organic Frameworks for Photocatalytic CO2 Reduction
Authors: Rath Bibhuti Bhusan , Krause Simon , Lotsch Bettina Valeska
Published: October 2023

Photochemical CO2 reduction using ubiquitous sunlight akin to natural photosynthesis is an effective approach for conversion of renewable energy into useful chemical feedstock. Driven by the need for earth‐abundant, inexpensive, and sustainable photocatalysts with practical applicability, covalent organic frameworks (COFs) have emerged as a new generation of molecularly defined semiconductors with tunable optoelectronic properties. These reticular frameworks with highly ordered, porous and crystalline structures can be tailor‐made by covalently combining organic building blocks to target specific functions. To date, numerous COFs have been reported, which show promising activity for photocatalytic CO2 reduction allowing to derive structure–property–function relationships. In this review, the different reported strategies are comprehensively analyzed and categorized for active site engineering in COF photocatalysts and the synthetic rationale and resulting catalytic activity for each approach are discussed. The recent advancements in terms of tailored photocatalyst design are then critically assessed, aspects of advanced materials characterization are analyzed, and future perspectives and challenges for the field are highlighted.
Insertion of Urea Moieties for One‐Component Strong yet Tough, Self‐Healing Polyurea Protective Materials
Authors: Zhang Zhipeng , Qian Lu , Huang Guanyu , Chen Cong , Cheng Jianfeng , Yao Xiaohu , Ma Chunfeng , Zhang Guangzhao
Published: October 2023

Polyurea has gained increasing attention in civil engineering, flexible electronics, and other emerging fields. However, owing to the rapid polymerization, tailoring their mechanical properties of polyurea for different applications remains challenging. Herein, a novel strategy is proposed for the insertion of urea moieties to prepare one‐component robust, mechanically tunable, and healable polyurea. First, the prepared latent curing agent, isophorone diisocyanate (IPDI), and NCO‐terminated prepolymer (PPGTD) are mixed. Due to the large difference in the reactivity of the ─NCO groups in IPDI and PPGTD, IPDI first reacts with the deblocked amino groups to form continuous urea moieties. The resulting urea moieties are inserted into the polyurea. This strategy provides a tremendous improvement in strength (500% increase), storage modulus (532% increase), and toughness (281% increase). Additionally, the as‐prepared polyurea exhibits excellent self‐healing, impact resistance, high transparency (>90%), and high dielectric constant (≈4.5). Thus, it can be used as a protective film and flexible substrate for electronic devices. Furthermore, the polyurea exhibits good versatility, which can be laminated with alumina ceramic sheets to form impact composites. This work opens up a promising avenue for the design and fabrication of polyurea material for flexible electronics and provides new insights into engineering anti‐impact materials.
A Dose‐Dependent Spatiotemporal Response of Angiogenesis Elicited by Zn Biodegradation during the Initial Stage of Bone Regeneration
Authors: Tan Junlong , Li Shuang , Sun Chaoyang , Bao Guo , Liu Meijing , Jing Zehao , Fu Hanwei , Sun Yanhua , Yang Qingmin , Zheng Yufeng , Wang Xiaogang , Yang Hongtao
Published: October 2023

Zinc (Zn) plays a crucial role in bone metabolism and imbues biodegradable Zn‐based materials with the ability to promote bone regeneration in bone trauma. However, the impact of Zn biodegradation on bone repair, particularly its influence on angiogenesis, remains unexplored. This study reveals that Zn biodegradation induces a consistent dose‐dependent spatiotemporal response in angiogenesis,both in vivo and in vitro. In a critical bone defect model, an increase in Zn release intensity from day 3 to 10 post‐surgery is observed. By day 10, the CD31‐positive area around the Zn implant significantly surpasses that of the Ti implant, indicating enhanced angiogenesis. Furthermore,angiogenesis exhibits a distance‐dependent pattern closely mirroring the distribution of Zn signals from the implant. In vitro experiments demonstrate that Zn extraction fosters the proliferation and migration of human umbilical vein endothelial cells and upregulates the key genes associated with tube formation, such as HIF‐1α and VEGF‐A, peaking at a concentration of 22.5 µM. Additionally, Zn concentrations within the range of 11.25−45 µM promote the polarization of M0‐type macrophages toward the M2‐type, while inhibiting polarization toward the M1‐type. These findings provide essential insights into the biological effects of Zn on bone repair, shedding light on its potential applications.
Multifunctional, Hybrid Materials Design via Spray‐Drying: Much more than Just Drying
Authors: Wintzheimer Susanne , Luthardt Leoni , Cao Kiet Le Anh , Imaz Inhar , Maspoch Daniel , Ogi Takashi , Bück Andreas , Debecker Damien P. , Faustini Marco , Mandel Karl
Published: October 2023

Spray‐drying is a popular and well‐known “drying tool” for engineers. This perspective highlights that, beyond this application, spray‐drying is a very interesting and powerful tool for materials chemists to enable the design of multifunctional and hybrid materials. Upon spray‐drying, the confined space of a liquid droplet is narrowed down, and its ingredients are forced together upon “falling dry.” As  detailed in this article, this enables the following material formation strategies either individually or even in combination: nanoparticles and/or molecules can be assembled; precipitation reactions as well as chemical syntheses can be performed; and templated materials can be designed. Beyond this, fragile moieties can be processed, or “precursor materials” be prepared. Post‐treatment of spray‐dried objects eventually enables the next level in the design of complex materials. Using spray‐drying to design (particulate) materials comes with many advantages—but also with many challenges—all of which are outlined here. It is believed that multifunctional, hybrid materials, made via spray‐drying, enable very unique property combinations that are particularly highly promising in myriad applications—of which catalysis, diagnostics, purification, storage, and information are highlighted.
Microfluidic Platforms for Real‐Time In Situ Monitoring of Biomarkers for Cellular Processes
Authors: Lou Chengming , Yang Hongru , Hou Ying , Huang Haina , Qiu Jichuan , Wang Chunhua , Sang Yuanhua , Liu Hong , Han Lin
Published: October 2023

Cellular processes are mechanisms carried out at the cellular level that are aimed at guaranteeing the stability of the organism they comprise. The investigation of cellular processes is key to understanding cell fate, understanding pathogenic mechanisms, and developing new therapeutic technologies. Microfluidic platforms are thought to be the most powerful tools among all methodologies for investigating cellular processes because they can integrate almost all types of the existing intracellular and extracellular biomarker‐sensing methods and observation approaches for cell behavior, combined with precisely controlled cell culture, manipulation, stimulation, and analysis. Most importantly, microfluidic platforms can realize real‐time in situ detection of secreted proteins, exosomes, and other biomarkers produced during cell physiological processes, thereby providing the possibility to draw the whole picture for a cellular process. Owing to their advantages of high throughput, low sample consumption, and precise cell control, microfluidic platforms with real‐time in situ monitoring characteristics are widely being used in cell analysis, disease diagnosis, pharmaceutical research, and biological production. This review focuses on the basic concepts, recent progress, and application prospects of microfluidic platforms for real‐time in situ monitoring of biomarkers in cellular processes.
Soft Wearable Haptic Display and Flexible 3D Force Sensor for Teleoperated Surgical Systems
Authors: Thai Mai Thanh , Davies James , Nguyen Chi Cong , Phan Phuoc Thien , Hoang Trung Thien , Ji Adrienne , Zhu Kefan , Sharma Bibhu , Nicotra Emanuele , Vo‐Doan Tat Thang , Phan Hoang‐Phuong , Lovell Nigel Hamilton , Do Thanh Nho
Published: October 2023

Haptic (touch) is important for effective interaction with the surroundings. In teleoperated surgical systems, its absence leads to reduced perception, making delicate tasks difficult and resulting in unexpected damage to surrounding tissues. To enhance safety, a force‐feedback system and haptic device are needed. However, existing haptic prototypes are associated with rigid, bulky, and heavy components, making effective communication with the skin problematic. This paper presents a teleoperated endoscopic surgical system with an integrated 3D force sensor and real‐time haptic feedback. A surgical robotic arm is remotely controlled by a soft haptic glove incorporated 3‐axis cutaneous device and a finger kinesthetic module. The 3D force sensor is constructed from hydraulic filament soft sensors that can induce pressure change under strain. To enable precise motion, the haptic glove is operated by a feedforward controller and a master‐slave architecture. Experiments with human subjects (n= 15) show that cutaneous and kinesthetic feedback significantly improves the user's performance (9.4 out of 10) compared to no haptic feedback (2.27 out of 10). Finally, subjects rank the new system as highly wearable, comfortable, and effective, which is expected to bridge a gap in the surgical field and support the future development of advanced teleoperated systems.
Hybrid Bionic Nerve Interface for Application in Bionic Limbs
Authors: Cho Youngjun , Jeong Hyung Hwa , Shin Heejae , Pak Changsik John , Cho Jeongmok , Kim Yongwoo , Kim Donggeon , Kim Taehyeon , Kim Hoijun , Kim Sohee , Kwon Soonchul , Hong Joon Pio , Suh Hyunsuk Peter , Lee Sanghoon
Published: October 2023

Intuitive and perceptual neuroprosthetic systems require a high degree of neural control and a variety of sensory feedback, but reliable neural interfaces for long‐term use that maintain their functionality are limited. Here, a novel hybrid bionic interface is presented, fabricated by integrating a biological interface (regenerative peripheral nerve interface (RPNI)) and a peripheral neural interface to enhance the neural interface performance between a nerve and bionic limbs. This interface utilizes a shape memory polymer buckle that can be easily implanted on a severed nerve and make contact with both the nerve and the muscle graft after RPNI formation. It is demonstrated that this interface can simultaneously record different signal information via the RPNI and the nerve, as well as stimulate them separately, inducing different responses. Furthermore, it is shown that this interface can record naturally evoked signals from a walking rabbit and use them to control a robotic leg. The long‐term functionality and biocompatibility of this interface in rabbits are evaluated for up to 29 weeks, confirming its promising potential for enhancing prosthetic control.
Automatic zone management definition in Mediterranean environment for Triticum durum
Authors: Orsini Roberto , Fiorentini Marco , Zenobi Stefano , Santilocchi Rodolfo , Deligios Paola A. , Ledda Luigi
Published: October 2023

Precision agriculture (PA) is an agronomic management that allows the parsimonious use of agronomic inputs according to the crop's actual spatiotemporal needs. The most important agronomic practice of PA is the site‐specific management (SSM) of agronomic inputs. To apply SSM, the number and location of homogeneous zones must be defined. Nowadays, many approaches are used to define the number of zones in an arbitrary and constant way, such as high‐, medium‐, and low‐input zones, without a priori statistical analysis. Two combined field experiments were carried out on durum wheat (Triticum turgidum subsp. durum Desf.) in central Italy to agronomically validate an automatic approach aimed at defining the number and position of the homogeneous zones using multispectral images. For both sites, at stem elongation and anthesis, the dry biomass per square meter and Soil Plant Analysis Development (SPAD) readings were measured, while at crop maturity the yield was measured. This approach uses multispectral images as source data and uses the gap statistic index to determine the correct number of zones. The management zones created were well‐fitted with the experimental design of both sites, and the validation was made by the statistical analysis performed on yield data, SPAD, dry biomass, and normalized difference red edge index with an average difference of 40.2%, 28.5%, 57.5%, and 37.4%, respectively, between the management zones. The approach could be scaled by using the multitemporal multispectral images provided by satellite constellation, which enables farms and societies to take advantage of all the economic and environmental benefits of PA.
Biocultural correlates of gross motor coordination in prepubescent children: A cross‐sectional study
Authors: da Silva Lima Braulio Patrick , Giudicelli Bruno Barbosa , dos Santos Pinheiro Ingrid Kelly Alves , Santos Douglas Henrique Bezerra , Magalhães Kleberton Carlos Silva , dos Santos Henrique Rafael , da Silva Danilo Rodrigues Pereira , Silva Manuel João Coelho e , de Oliveira Luz Leonardo Gomes
Published: October 2023

Aim

This study aimed to explore the association of gross motor coordination (GMC) with a matrix of biocultural factors in prepubescent children, taking into account weight status, somatic maturation, sociodemographic variables, and type of school.

Methods

One hundred twenty‐nine prepubescent children, of both sexes, aged between 8.00 and 8.99, were assessed for GMC (Körperkoordinationstest Für Kinder ‐ KTK), weight status, biological maturation (predicted mature stature), sex, mother's education level and type of school. Binary logistic regression was used to examine the relationship between higher values of KTK and associated biocultural factors.

Results

Normoponderal children are more likely to attain better total KTK scores than those with overweight or obesity (OR: 2.942; LC 95%: 1.189, 7.280). In addition, children who are more advanced in terms of biological maturation exhibited significantly lower odds of being in the high KTK category than their less advanced peers (OR: 0.670; LC 95%: 0.474,0.946). Sex, mother's education level and the type of school are not associated with higher performance on KTK.

Conclusion

Weight status and biological maturation are associated with motor competence in prepubescent children. Future studies should consider additional correlates to better understand the complex interactions between biological, psychosocial and behavioral factors in the prediction of motor competence.
Validation of predictive equations to estimate resting metabolic rate of females and males across different activity levels
Authors: Prado‐Nóvoa Olalla , Howard Kristen R. , Laskaridou Eleni , Reid Glen R. , Zorrilla‐Revilla Guillermo , Marinik Elaina L. , Davy Brenda M. , Speakman John R. , Davy Kevin P.
Published: October 2023

Objectives

Using equations to predict resting metabolic rate (RMR) has yielded different degrees of validity, particularly when sex and different physical activity levels were considered. Therefore, the purpose of the present study was to determine the validity of several different predictive equations to estimate RMR in female and male adults with varying physical activity levels.

Method

We measured the RMR of 50 adults (26 females and 24 males) evenly distributed through activity levels varying from sedentary to ultra‐endurance. Body composition was measured by dual X–ray absorptiometry and physical activity was monitored by accelerometry. Ten equations to predict RMR were applied (using Body Mass [BM]: Harris & Benedict, 1919; Mifflin et al., 1990 [MifflinBM]; Pontzer et al., 2021 [PontzerBM]; Schofield, 1985; FAO/WHO/UNU, 2004; and using Fat‐Free Mass (FFM): Cunningham, 1991; Johnstone et al., 2006; Mifflin et al., 1990 [MifflinFFM]; Nelson et al. 1992; Pontzer et al., 2021 [PontzerFFM]). The accuracy of these equations was analyzed, and the effect of sex and physical activity was evaluated using different accuracy metrics.

Results

Equations using BM were less accurate for females, and their accuracy was influenced by physical activity and body composition. FFM equations were slightly less accurate for males but there was no obvious effect of physical activity or other sample parameters. PontzerFFM provides higher accuracy than other models independent of the magnitude of RMR, sex, activity levels, and sample characteristics.

Conclusion

Equations using FFM were more accurate than BM equations in our sample. Future studies are needed to test the accuracy of RMR prediction equations in diverse samples.
Neonatal abstinence syndrome and other neonatal outcomes for the infants of women experiencing incarceration: A retrospective cohort study
Authors: Bell Megan F. , Kelty Erin , Segal Leonie , Dennison Susan , Kinner Stuart A. , Dawe Sharon , Spittal Matthew J. , Preen David B.
Published: October 2023

Substance use during pregnancy is associated with poor neonatal outcomes. Women incarcerated during pregnancy may have a history of substance use, and their babies may be at risk of neonatal abstinence syndrome (NAS). This study examines the incidence of NAS and other outcomes in infants born to currently or formerly incarcerated women. Infants born between 1985 and 2011 in Western Australia were divided into three mutually exclusive groups: born to women incarcerated during pregnancy (n = 708); born within 9–24 months of the mother's release from prison (n = 651); and born to women who were never incarcerated (n = 17,712). The impact of the timing of incarceration during pregnancy was also examined. Neonatal outcomes (NAS, preterm birth, low birthweight, infant mortality and admission to special care nursery) were compared using logistic regression. Infants born to currently or recently incarcerated women had higher odds of all adverse outcomes than infants in the nonexposed group. Infants born to women incarcerated during the second or third trimester (but not the month of birth) had poorer outcomes than infants born to women incarcerated during the month of birth. The findings show that babies born to currently or formerly incarcerated women are equally likely to experience adverse neonatal outcomes. Enhanced maternal healthcare must be provided during incarceration and after release.
Post‐Synthetic Ensembling Design of Hierarchically Ordered FAU‐type Zeolite Frameworks for Vacuum Gas Oil Hydrocracking
Authors: Kumar Parsapur Rajesh , Hengne Amol M. , Melinte Georgian , Refa Koseoglu Omer , Hodgkins Robert Peter , Bendjeriou‐Sedjerari Anissa , Lai Zhiping , Huang Kuo‐Wei
Published: October 2023

Zeolites hold importance as catalysts and membranes across numerous industrial processes that produce most of the world's fuels and chemicals. In zeolite catalysis, the rate of molecular diffusion inside the micropore channels defines the catalyst's longevity and selectivity, thereby influencing the catalytic efficiency. Decreasing the diffusion pathlengths of zeolites to the nanoscopic level by fabricating well‐organized hierarchically porous architecture can efficiently overcome their intrinsic mass‐transfer limitations without losing hydrothermal stability. We report a rational post‐synthetic design for synthesizing hierarchically ordered FAU‐type zeolites exhibiting 2D‐hexagonal (P6mm) and 3D‐cubic (Ia
d) mesopore channels. The synthesis involves methodical incision of the parent zeolite into unit‐cell level zeolitic fragments by in situ generated base and bulky surfactants. The micellar ensembles formed by these surfactant‐zeolite interactions are subsequently reorganized into various ordered mesophases by tuning the micellar curvature with ion‐specific interactions (Hofmeister effect). Unlike conventional crystallization, which offers poor control over mesophase formation due to kinetic constraints, crystalline mesostructures can be developed under dilute, mild alkaline conditions by controlled reassembly. The prepared zeolites with nanometric diffusion pathlengths have demonstrated excellent yields of naphtha and middle‐distillates in vacuum gas oil hydrocracking with decreased coke deposition.
Rapid imaging in the field followed by photogrammetry digitally captures the otherwise lost dimensions of plant specimens
Authors: James Nicole , Adkinson Alex , Mast Austin
Published: October 2023

Premise

We recognized the need for a customized imaging protocol for plant specimens at the time of collection for the purpose of three‐dimensional (3D) modeling, as well as the lack of a broadly applicable photogrammetry protocol that encompasses the heterogeneity of plant specimen geometries and the challenges introduced by processes such as wilting.

Methods and Results

We developed an equipment list and set of detailed protocols describing how to capture images of plant specimens in the field prior to their deformation (e.g., with pressing) and how to produce a 3D model from the image sets in Agisoft Metashape Professional.

Conclusions

The equipment list and protocols represent a foundation on which additional improvements can be made for specimen geometries outside of the range of the six types considered, and an easy entry into photogrammetry for those who have not previously used it.
Embryonic microinjection of ribonucleoprotein complex (Cas9+sgRNA) of white gene in melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae) produced white eye phenotype
Authors: Pradhan Sanjay Kumar , Karuppannasamy Ashok , Sujatha Parvathy Madhusoodanan , Nagaraja Bhargava Chikmagalur , Narayanappa Anu Cholenahalli , Chalapathi Pradeep , Dhawane Yogi , Bynakal Shivanna , Riegler Markus , Maligeppagol Manamohan , Ramasamy Asokan
Published: October 2023

Melon fly, Zeugodacus cucurbitae (Coquillett) is a major pest of cucurbitaceous crops, and causes substantial yield losses and economic costs. CRISPR/Cas9 is a rapid and effective site‐specific genome editing tool for the generation of genetic changes that are stable and heritable. The CRISPR/Cas9 tool uses synthetically designed single guide RNA (sgRNA) that is complementary to the target gene and guides the Cas9 enzyme to perform nuclease activity by making double‐strand breaks in the target DNA sequences. This tool can be effectively exploited to improve traits critical for the management of insect pests by targeting specific genes encoding these traits without the need of extensive genetic information. The white gene is an important gene responsible for the transport of body pigment precursor molecules. In this study, we produced effective mutagenesis of the white gene of Z. cucurbitae using the CRISPR/Cas9 tool with double sgRNA to target multiple sites of white to increase the efficiency in the generation of frame‐shift mutations resulting in the white eye phenotype in adults. This was achieved through embryonic microinjection of the ribonucleoprotein (RNP) complex in the pre‐blastoderm embryo stage 1 h after embryo laying. Our success with the production of a white eye mutant fly by CRISPR/Cas9 mutagenesis is important for the research on gene function and protein‐level modifications in melon fly and forms the basis for the development of new genetic control strategies such as precision guided sterile insect technique (pgSIT) for this pest of economic significance.
1,2,4‐Triazines and Calcium Carbide in the Catalyst‐Free Synthesis of 2,3,6‐Trisubstituted Pyridines and Their D‐, 13C‐, and Doubly D2‐13C2‐Labeled Analogues
Authors: Voronin Vladimir V. , Polynski Mikhail V. , Ledovskaya Maria S.
Published: October 2023

A novel synthetic approach to 2,3,6‐trisubstituted pyridines, their 4,5‐dideuterated derivatives, 4,5‐13C2‐ and doubly‐labeled D2‐13C2‐pyridines has been developed using catalyst‐free [4+2] cycloaddition of 1,2,4‐triazines and in situ generated acetylene or labeled acetylene. Calcium carbide and water or deuterium oxide were used for the in situ generation of acetylene and dideuteroacetylene. Calcium carbide‐13C2 in the mixture with water or deuterium oxide was applied as 13C2‐acetylene and D2‐13C2‐acetylene source.
177Lu Radiolabelled AIE Dots for Multimodal Imaging Guided Photothermal/Radiopharmaceutical Tumor Therapy
Authors: Huang Haoying , Yu Kaiwu , Husamelden Elkawad , Zhang Hong , Mao Zhengwei , Liu Shunjie , Zhang Qinghua , Tian Mei , Zhang Haoke , He Qinggang
Published: October 2023

Aggregation‐induced emission luminogens (AIEgens) in the second near‐infrared region (NIR‐II,1000‐1700 nm) have shown tremendous potential as theragnostic probe for tumor multimodal diagnostic imaging and combined treatment owing to their programmable optical, structural and functional properties. Herein, we presented a radionuclide 177Lu‐labeled AIEgen, 177Lu‐2TT‐oC6B dots, for NIR‐II fluorescence and SPECT/CT imaging‐guided tumor photothermal and radiopharmaceutical therapy. Intriguingly, 177Lu‐2TT‐oC6B self‐assembled into 10 nm dots, exhibited high NIR‐II fluorescence quantum yield (QY, 1.34 %) and unprecedented photothermal conversion efficiency (PCE, 70.3 %) in vitro, furtherly performed extremely long blood circulation (T1/2=52.4 h), persistent tumor accumulation and retention in tumor (NIR‐II SNR=5.56; SPECT SNR=36.59) via intravenous administration in vivo. Furthermore, upon NIR light activation and 177Lu irradiation, 177Lu‐2TT‐oC6B demonstrated great application potential in synergistic photothermal/radiopharmaceutical tumor therapy.
Metal Ion‐controlled Growth of Different Metal‐Organic Framework Micro/nanostructures for Enhanced Supercapacitor Performance
Authors: Wang Xiaoju , Hang Xinxin , Zhang Guangxun , An Yang , Liu Bei , Pang Huan
Published: October 2023

We report a metal ion‐modulated effective strategy to achieve different metal‐organic framework (MOF) micro/nanostructures using different metal precursors like CoCl2 ⋅ 6H2O, CoCl2 ⋅ 6H2O and NiCl2 ⋅ 6H2O, and NiCl2 ⋅ 6H2O with pyridine‐3,5‐dicarboxylate (3,5‐pdc). The structural characterizations confirm that different morphological structures, hollow microsphere, hierarchical nanoflower, and solid nanosphere are for Co‐(3,5‐pdc), Co0.19Ni0.81‐(3,5‐pdc), and Ni‐(3,5‐pdc), respectively. These different MOF micro/nanostructures correlate with the coordination ability of Co and Ni with 3,5‐pdc. Benefitting from the synergistic effect of the alloying metal nodes of Co and Ni producing rapid and rich redox reactions and the hierarchical nanoflower with higher surface area enabling excellent ion kinetics, the Co0.19Ni0.81‐(3,5‐pdc) exhibits higher specific capacitance of 515 F g−1/273 C g−1at 0.5 A g−1 than that of Ni‐(3,5‐pdc) (290 F g−1/153.7 C g−1) and Co‐(3,5‐pdc) (132 F g−1/67 C g−1), good rate capability and cycling stability. Moreover, the asymmetric supercapacitor device (Co0.19Ni0.81‐(3,5‐pdc)//AC) assembled from Co0.19Ni0.81‐(3,5‐pdc) and activated carbon (AC) achieves a maximum energy density of 42.6 Wh kg−1 at a power density of 277.3 W kg−1.
The Role of Surface Coating in P’2‐Na0.67Mn0.67Ni0.33O2: Enhancing Capacity and Stability of Layered Cathodes for Sodium‐ion Batteries
Authors: Brugnetti Gabriele , Pianta Nicolò , Ferrara Chiara , Tribbia Michele , Zampardi Giorgia , La Mantia Fabio , Goikolea Eider , Ruiz de Larramendi Idoia , Lezama Luis , Rojo Teofilo , Ruffo Riccardo
Published: October 2023

P’2‐Na0.67Mn0.67Ni0.33O2 (NMNO) is one of the most promising cathodic materials for new generation sodium‐ion batteries (SIBs). One drawback that is preventing its commercialization is however the high instability in the potential window 2.5–4.5 V vs. Na+/Na, caused by degradation reactions affecting the material's structure and composition. Herein we propose a strategy to overcome this weak spot introducing the surface coating of the material particles with inert magnesium oxide, that has been chosen as coating agent because of its low molecular weight. This protective layer is able to reduce the structural instability of the material without modifying the mixed conduction properties and thus globally stabilizing the electrochemical performances. In fact, the electrode of NMNO coated with 7 % of MgO, after an initial stabilization, was able to deliver over 90 mAh g−1 of reversible specific capacity at a current value of 50 mA g−1, with a capacity retention of 70 % after 250 cycles, to be compared with the 30 mAh g−1 of the uncoated material. The effect of the coating on the particles surface is here investigated with differential electrochemical mass spectrometry, to analyze the influence of the treatment on the electrode/electrolyte interphase.
Über die Kette: Pt, H2 (1atm)/HCl, Hg2Cl2 (s)/Hg in organischen Lösungsmitteln und ihren Gemischen mit Wasser III. Pt, H2 (1 atm)/HCl (m), Glykol (x), H2O (100 ‐ x), Hg2Cl2 (s)/Hg
Authors: Schwabe K. , Hertzsch R.
Published: October 2023

Im Rahmen der Versuchsreihe zum Studium des Mediumeinflusses wurde die Kette Pt, H2 (1atm)/HCl (m), Glykol (x), H2O (100 ‐ x), Hg2Cl2/Hg mit den Lösungsmittelzusammensetzungen x = 19,25, 50, 00 und 77,91 Gewichtsprozent Glykol in Wasser untersucht. Aus den bei den verschiedenen Gewichtsmolaritäten m der Salzsäure gemessenen EMK‐Werten werden Standardpotentiale, Aktivitätskoeffizienten und Mediumeffekte ermittelt und vergleichend diskutiert.
Adsorptionsmessungen an den Systemen Schwefel‐Platin und Schwefel‐Gold mittels einer Strömungsmethode
Authors: Bechtold E.
Published: October 2023

Eine neue, auf der gaschromatographischen Frontalanalyse beruhende Methode zur Messung der Adsorption von Schwefel wird beschrieben. Als Schwefelentwickler und Schwefeldetektor dient je eine elektrochemische Festkörperkette Pt/Ag/AgJ/Ag2S/Pt. Messungen an Platin‐ und Goldfolien ergaben bei 400–500°C bzw, bei 300–500 °C und Partialdrucken von 10−9 bis 5 · 10−8 bzw. 10−9 bis 10−5 atm S2 eine konstante, in beiden Fallen gleiche, adsorbierte Schwefelmenge von 1,1 · 10−9 mol S je cm2 der makroskopischen Oberfläche.
Die Lösungsmittelabhängigkeit der 1H‐NMR‐Spektren von einfachen Polymethin‐Merocyanin‐Farbstoffen. I. Der Einfluß der diamagnetischen Anisotropie des Lösungsmittels
Authors: Radeglia R. , Dahne S.
Published: October 2023

Die chemischen Verschiebungen der Protonen von \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm (CH}_{\rm 3} {\rm)}_{\rm 2} {\rm N}\mathop {{\rm (CH)}_{\rm n} {\rm O}}\limits^{\ldots{\rm (n + 3)\pi }\ldots} $\end{document} mit n = 1, 3, 5, 7 wurden in benzolhaltigen Lösungsmittelgemischen gemessen. Es wird ein einfaches Assoziationsmodell diskutiert, welches die Beeinflussung der chemischen Verschiebungen der Methinprotonen durch die magnetische Anisotropie von assoziierten Benzolmolekülen zu erklären gestattet. Die Grenzen dieses Modells werden aufgezeigt.
Konstanten der indirekten Kernspinkopplung der Methyl‐und Athylphosphoniumionen
Authors: Dreeskamp H. , Elser H. , Schumann C.
Published: October 2023

Die Konstanten der indirekten Kernspinkopplung zwischen Protonen und Phosphor wurden in der Reihe aller Methylphosphoniumionen gemessen. Durch Analyse der Spektren bei mehreren Meßfrequenzen ergaben sich ungleiche Vorzeichen der Kopplung über eine Bindung und der geminalen Kopplung über zwei Bindungen. Ein Alternieren des Vorzeichens der Kopplungskonstanten über eine, zwei und drei Bindungen wurde durch Doppelresonanzexperimente am Triäthylphosphoniumion bestätigt. Allgemein sind Größe und Vorzeichen der Kopplung zwischen Protonen und Heteroatom über mehrere Bindungen um Faktoren gegenüber der Kopplung über eine Bindung verändert, die in guter Näherung allein vom Alkylrest abhängen. Die schon früher aufgezeigte empirische Gesetzmäßigkeit wird mit diesen Daten und Beobachtungen an Tetraäthylsilan und Triathylbleihydrid weiter bekräftigt und ihre Bedeutung für eine theoretische Interpretation der indirekten Kernspinkopplung aufgezeigt.
Unimolekulare Reaktionen
Authors: Troe J.
Published: October 2023

Systeme unimolekularer Reaktionen mit verschiedenen Aktivierungsformen, mit thermischer, optischer, chemischer, sekundärer Aktivierung und Aktivierung durch Elektronenstoß, werden einander gegenübergestellt. Es wird der Zusammenhang zwischen den jeweils experimentell zugänglichen Größen und den sich während der Reaktion einstellenden Besetzungen von Molekülzuständen sowie den Eigenschaften der beteiligten mikroskopischen Elementarprozesse angedeutet. Formeln der statistischen Theorie von Zerfallsgeschwindigkeiten und Theorien thermischer unimolekularer Reaktionen werden erläutert.
Gas‐Phase Elementary Chemical Reactions
Authors: Johnston Harold S.
Published: October 2023

Different levels of the field of chemical kinetics are related to each other by the following outline:

Practical chemical systems

Elementary chemical reactions

Elementary chemical‐physical reactions

Elementary physical reactions

Time‐dependent quantum mechanics

The theory of practical chemical kinetics is manipulation of rate constants of elementary chemical reactions by Bodenstein's steady‐state method. The experiments of elementary chemical reactions are the elements of the theory of practical chemical kinetics. The field of elementary chemical reactions has now become so mature that it is worthwhile to produce handbooks of data on the rate constants of elementary reactions in terms of appropriate macroscopic variables, k(T), k(T, M), or k(T, [M]). Complex rate phenomena can be understood in terms of the elementary steps, and new rate phenomena can be predicted from sets of elementary reactions. In this way tables of elementary rate constants and the theory of elementary chemical reactions can make an important contribution to other areas of chemistry, including chemical problems of the most practical sort.

Theories of elementary chemical reactions are forced to make extensive (plausible) assumptions about potential‐energy functions, suitable coordinates, reaction cross sections, and molecular distribution functions. Direct experiments with molecular beams and new optical techniques are capable of giving actual observed data where the theory of elementary chemical reactions has traditionally been forced to make assumptions. Workers in these new fields need, perhaps, to be urged to keep a sympathetic eye on the “old‐fashioned” theories of elementary chemical reactions and to design some of the new experiments to confirm, or to deny, or to improve the postulates of these theories.

The theory of elementary chemical‐physical and elementary physical reactions is fundamental, many‐particle quantum mechanics. Useful, approximate solutions for extremely simple systems can be carried out. For large atoms or molecules as reactants, there is considerable room for the development of effective new theoretical techniques in calculating elementary reaction rates.

The field of chemical kinetics has a unity and a connectedness across its various levels of abstraction that should be understood and appreciated by all of its practitioners.
Exchange Stabilization in the Hydrogen Atom Recombination Reaction with Hydrogen Atoms as Third Bodies
Authors: Hurle I. R. , Mackey P. , Rosenfeld J. L. J.
Published: October 2023

Recent experiments in a shock tube on the dissociation of hydrogen in hydrogen/argon mixtures at temperatures between 2600 and 7000 °K have led to an evaluation of the rate constants for the six processes

magnified image

The result for the three‐atom recombination rate constant, k‐2, are of particular interest, as they indicate that a maximum value for k‐2 occurs at about 3000 °K. The reality of this novel behaviour is confirmed by a recent estimate at room temperature of an upper bound significantly below the shock‐tube values at 3000 °K.

It is proposed that the temperature‐dependence of this rate constant may be explained by the collisional stabilization of orbiting pairs of hydrogen atoms, by exchange with a third atom. Provided the vibrational mode is adiabatic during the exchange such a process requires activation energy, which explains the initial positive temperature‐dependence. As the temperature is further increased, however, the energy redistribution on exchange is no longer adequate to produce a stable molecule, and thus the rate constant acquires a negative temperature‐dependence at higher temperatures. A simple model gives semi‐quantitative agreement with experiment for the detailed variation of k−2 with temperature.
Berechnung des unimolekularen Zerfalls von Chlorkohlenwasserstoffen nach der Rice‐Ramsperger‐Kassel‐Marcus‐Theorie
Authors: Heydtmann H.
Published: October 2023

Die Druckabhängigkeit der relativen Geschwindigkeitskonstanten erster Ordnung k1/k1,∞ wurde für den unimolekularen Zerfall des äthylchlorids, des t‐Butylchlorids und zweier deuterierter äthylchloride nach der RRKM‐Theorie berechnet. Die Lage des Abfallbereiches relativ zur Druckskala und die Gestalt der Kurven ist so wenig von der Annahme einzelner Schwingungsfrequenzen für den hypothetischen Übergangszustand abhängig, daß detaillierte Aussagen über den Reaktionsweg nicht möglich erscheinen. Aussichtsreicher ist die Konstruktion konsistenter Modelle des Übergangszustandes für deuterierte und nichtdeuterierte Moleküle als Grundlage von Berechnungen und deren Vergleich mit experimentellen Daten. Der Einfluß der Temperatur und verschiedener Behandlungsweisen der inneren Rotation auf k1/k1,∞ wird gezeigt. Die Kopplung der inneren mit den äußeren Rotationsfreiheitsgraden wird berücksichtigt, die Annahme starker Stöße und die übliche Vernachlässigung eines Tunneleffektes werden kritisiert.
Die Photolyse des Ammoniaks bei 2062 Å in Gegenwart von Äthylen und von Propan
Authors: Schurath U. , Schindler R. N.
Published: October 2023

Aminoradikale, die in der Photolyse von Ammoniak in Gegenwart von Äthylen oder von Propan erzeugt wurden, bilden bei Reaktion mit Alkylradikalen die entsprechenden Amine. Aus der Temperaturabhängigkeit der Produktbildung kann geschlossen werden, daß die Reaktion (7) bei Raumtemperatur unbedeutend ist.

Der wichtigste Primärschritt in der Photolyse von Hydrazin bei 2062 Å ist auf Grund dieser Untersuchung Prozeß (1) .
Generalized Boltzmann Equation of Nuclear Magnetic Resonance for Spins in Intramolecular Reactions The Description of Chemical Processes by Dirac's Exchange Operator
Authors: Heidberg Joachim
Published: October 2023

The term due to chemical processes in the equation of motion for the spin density matrix can be expressed by means of Dirac's exchange operate also for asymmetric intramolecular reactions in which nuclei move about without necessarily exchanging positions. Therewith the effect of arbitrary intramolecular and intermolecular chemical processes at any scalar couplings between the spins and any reaction rates can be considered from a unified methodical point of view. It becomes evident that chemical processes which can be described by Dirac's exchange operator are not necessarily correlated exchange processes. An example is discussed in detail, and the connection with the adiabatic equation of Gutowsky and Saika for an asymmetric doublet is shown.
Ein Verfahren zur direkten Untersuchung von Atom‐Radikal‐Reaktionen. Die Geschwindigkeit der Reaktion O + CN → CO + N
Authors: Reinhardt K. , Wagner H. Gg. , Wolfrum J.
Published: October 2023

Es wird eine experimentelle Anordnung zur direkten Untersuchung von Reaktionen zwischen Atomen und Radikalen beschrieben. Hierbei werden Radikale durch Blitzlichtphotolyse in einem Strömungssystem bei einem hohen Überschuß von Atomen erzeugt. Die absolute Geschwindigkeit von Atom‐Radikal‐Reaktionen wird anschließend durch kinetische Spektroskopie direkt bestimmt. Für die Geschwindigkeit der Reaktion

ergab sich
Luminescence of Co(III) and Cr(III) in K3CrxCo1–x(CN)6 Mixed crystals: Energy transfer and quenching processes
Authors: Kirk Alexander D. , Ludi Andreas , Schläfer Hans L.
Published: October 2023

A complete series of mixed crystals of K3[Cr(CN)6] and K3[Co(CN)6] has been prepared by a precipitation technique and shown by crystallographic examination to have the orthorhombic structure. Room temperature studies of the intensity dependence of chromium and cobalt emissions with wavelength, intensity and chromium concentration have been made on tablets formed from these materials. In addition the lifetimes of the chromium emission have been measured. It is found that no significant energy transfer occurs between the cobalt and chromium systems and that a dramatic quenching of the chromium emission begins at about 15% chromium. The nature of this chromium/chromium quenching is discussed in terms of a statistical treatment of short range interactions between ions on adjacent lattice sites.
Die Überführungswärme der Kationen in α‐Ag2S
Authors: Weiss K.
Published: October 2023

Für das kationen‐ und elektronenleitende α‐Ag2S wird bei unterdrücktem Kationenfluß der anisotherme Elektronenfluß (Polarisationsstrom) abgeleitet. Aus Messungen des anisothermen Polarisationsstromes kann man die Summe der Überführungswärmen von fehlgeordneten Kationen und Elektronen abschätzen. Die Überführungswärme der Kationen Q wird aus der zum Soret‐Effekt des silbergesättigten Silbersulfides zugeordneten Polarisationsspannung berechnet. Zum Vergleich wird Q aus der ionischen und elektronischen Thermokraft sowie der Entropie der Elektronen in α‐Ag2S berechnet; die Zahlenwerte beider Berechnungen stimmen befriedigend überein. Bei 300 °C ist Q* negativ und von der Größenordnung einiger kcal mol−‐1.
Flow method with integrating observation for very fast irreversible reactions
Authors: Gerischer H. , Holzwarth J. , Seifert D. , Strohmaier L.
Published: October 2023

The continuous flow method, with observation along the concentration profile in the direction of flow, has previously been used to measure the rate constants of very rapid irreversible reactions up to 107 1 mol−1 sec−1. Improvements in the cell design and in the monitoring facilities now permit the study of reactions with rate constants greater than 109 1 mol−1 sec−1. The rate constants of eight electron transfer reactions of transition metal complexes are reported in this article.
Schwefelkohlenstoffoxydation II. Zur Oxydation von Carbonylsulfid
Authors: Homann K. H. , Krome G. , Wagner H. Gg.
Published: October 2023

Die Oxydation von COS mit O2 läßt sich durch die in Teil I dieser Arbeit untersuchten Elementarreaktionen quantitativ beschreiben. Experimentell bestimmte Konzentrationsprofile der Anfangs‐ Zwischen‐ und Endprodukte in Abhängigkeit von der Reaktionszeit werden mitgeteilt und mit den über die Elementarreaktionen berechneten Profilen verglichen.
Elektronenspinresonanz kurzlebiger Radikale aus einigen Aminosäuren und Amiden
Authors: Paul H. , Fischer H.
Published: October 2023

Kohlenstoffradikale werden in wäßriger Lösung aus Aminosäuren und Amiden erzeugt und durch Elektronenspinresonanz nachgewiesen. Die Struktur der aus Aminosäuren gebildeten Radikale hängt vom pH‐Wert der Lösungen ab. Aus den Aufspaltungsparametern von Radikalen vom Typ folgt, daß diese Radikale vermutlich nichtebene Bindungsstrukturen besitzen. Radikale vom Typ sind dagegen wahrscheinlich eben. Eine Berechnung von Spinpopulationen in diesen Radikalen gestattet, aus den Aufspaltungsparametern der Stickstoffatome die Polarisationskonstante Q zu −3,3 G ≤ Q ≤ −2,3 G abzuschätzen.
Investigation of the partial segregation of the components in low density supersonic jets by means of molecular beam sampling technique. I. number density distribution of the components perpendicular to the jet axis for binary systems
Authors: Aurich V. , Schügerl K.
Published: October 2023

The number density distributions of the components in binary systems were measured perpendicular to the jet axis in low density supersonic jets by means of molecular beam sampling technique. The distributions of the segregation parameters perpendicular to the jet axis were evaluated for different distances from the nozzle throat, different nozzle diameters, stagnation pressures and gas mixtures. At high source Reynolds numbers the heavy component is enriched along the axis of the jet. For low Reynolds numbers a ring‐shaped structure of the jet with alternating enriching of the heavy component as function of the distance from the jet axis is found.

Addition of heavy component to the light gas causes an increase of its perpendicular temperature in the jet.

The mechanism of the segregation is discussed.
Vergiftungsversuche an Eisenkatalysatoren für die Ammoniaksynthese. III. Vergiftung mit H2O
Authors: Brill R. , Hensel J. , Schaefer H.
Published: October 2023

Die partielle homogene Vergiftung von Eisenkontakten für die Ammoniaksynthese mit Wasserdampf wird beschrieben. Es wurde beobachtet, daß sich die Aktivierungsenergie der Ammoniaksynthese nach partieller Vergiftung mit Wasser nicht verändert. Der Mechanismus der Wasservergiftung wird diskutiert.
Space charge limited currents in liquid benzene
Authors: Kleinheins G.
Published: October 2023

The current‐voltage characteristics of liquid benzene are interpreted by making use of the theory of space charge limited currents. Small deviations from theory can easily be explained by additional ion currents originating from impurities or self‐dissociation of benzene. It will be shown by several independent experiments that charge carrier injection, which is the basic assumption for the applicability of this theory, does in fact exist. Moreover, these experiments show that the charge carriers in question must be protons or defect electrons. Since their mobility has already been evaluated, the injection concentration of these carriers can be calculated from current‐voltage measurements.