bluuebunny/crossref_metadata_2025 huggingface dataset:
Disparities in treatment and survival in early‐stage hepatocellular carcinoma in California
Authors: Gholami Sepideh , Kleber Kara T. , Perry Lauren M. , Abidalhassan Mustafa , McFadden Nikia R. , Bateni Sarah B. , Maguire Frances B. , Stewart Susan L. , Morris Cyllene , Chen Moon , Gaskill Cameron E. , Merkow Ryan P. , Keegan Theresa H.
Published: August 2023

Background and Objectives

Curative intent therapy is the standard of care for early‐stage hepatocellular carcinoma (HCC). However, these therapies are under‐utilized, with several treatment and survival disparities. We sought to demonstrate whether the type of facility and distance from treatment center (with transplant capabilities) contributed to disparities in curative‐intent treatment and survival for early‐stage HCC in California.

Methods

We performed a retrospective analysis of the California Cancer Registry for patients diagnosed with stage I or II primary HCC between 2005 and 2017. Primary and secondary outcomes were receipt of treatment and overall survival, respectively. Multivariable logistic regression and Multivariable Cox proportional hazards regression were used to evaluate associations.

Results

Of 19 059 patients with early‐stage HCC, only 36% (6778) received curative‐intent treatment. Compared to Non‐Hispanic White patients, Hispanic patients were less likely, and Asian/Pacific Islander patients were more likely to receive curative‐intent treatment. Our results showed that rural residence, public insurance, lower neighborhood SES, and care at non‐National Cancer Institute‐designated cancer center were associated with not receiving treatment and decreased survival.

Conclusions

Although multiple factors influence receipt of treatment for early‐HCC, our findings suggest that early intervention programs should target travel barriers and access to specialist care to help improve oncologic outcomes.
The microbial profile of infected endoprosthetic reconstructions after wide excision for patients with musculoskeletal tumors: A call for pathogen‐based practices
Authors: Trikha Rishi , Greig Danielle , Sekimura Troy , Geiger Erik J. , Wessel Lauren , Eckardt Jeffrey J. , Bernthal Nicholas M.
Published: August 2023

Background and Objectives

Periprosthetic infection is a devastating complication following endoprosthetic reconstruction. This study utilized a large database of endoprostheses to describe the incidence, risk factors, and microbial profile of such infections to better catalogue and understand these catastrophic events.

Methods

A retrospective review of endoprosthetic reconstructions for an oncologic indication from January 1, 1981 to December 31, 2020 was performed. Demographic, oncologic, procedural and outcome data was analyzed. Multivariable logistic regression was used to identify potential risk factors for infection with significance defined as p < 0.05.

Results

Forty four out of 712 (6.2%) reconstructions resulted in infection at a mean time of 39.9 ± 44.5 months. Revision surgery (odds ratio [OR] 6.14, p < 0.001) or having a postoperative wound complication (OR 7.67, p < 0.001) were significantly associated with infection. Staphylococcus aureus and Staphylococcus epidermidis were the most commonly cultured organisms at a rate of 34.1% (15/44) and 22.7% (10/44), respectively. Ten infections resulted in amputation; five due to antimicrobial‐resistant infections and three due to polymicrobial infections.

Conclusion

Understanding the microbial profile of patients undergoing endoprosthetic reconstruction is paramount. This study demonstrates a relatively high rate of polymicrobial and antibiotic‐resistant infections that portend worse outcomes, thus suggesting that pathogen‐specific infectious practices may be warranted.

Level of Evidence

Retrospective cohort study, level III.
Development of liquid chromatography‐triple quadrupole mass spectrometric method for the quantitative determination of a novel adjuvant, Imidazoquinoline gallamide in aluminum hydroxide gel‐Imidazoquinoline gallamide and COVAXIN
Authors: Nagendla Narendra Kumar , Subrahanyam Seetha Bala , Konda Satyanand , Mudiam Mohana Krishna Reddy
Published: August 2023

Imidazoquinoline gallamide is a toll‐like receptor 7/8 agonist, belongs to the imidazoquinoline class, has the potential to activate antigen‐presenting cells, and enhances immune response, primarily Th1 response. The COVAXIN is a whole virion inactivated Coronavirus disease 2019 vaccine formulated with this novel adjuvant called, aluminum hydroxide gel Imidazoquinoline gallamide, wherein, Imidazoquinoline gallamide is chemisorbed onto aluminum hydroxide gel. Herein, an analytical method based on liquid chromatography‐tandem mass spectrometry was developed to identify and quantify Imidazoquinoline gallamide in aluminum hydroxide gel Imidazoquinoline gallamide and COVAXIN. The multiple reaction monitoring transitions were optimized for Imidazoquinoline gallamide quantification are [M+H]+ ions with 512.24→343.19 m/z (quantifier ion) and 512.24→360.22 m/z (qualifier ion). The developed method was validated as per the international conference on harmonization quality2 revison1 guidelines. The method was linear in the range of 0.025–10 µg/mL with a coefficient of determination of 0.9985 and the limit of quantification is 0.025 µg/mL. The accuracy was in the range of 82–121 % and intra‐ and inter‐day precision was less than 7.1% and 5.39%, respectively. The expanded uncertainty results are 9.2% for Imidazoquinoline gallamide in the sample. The validated method was successfully applied to evaluate Imidazoquinoline gallamide concentration in every batch of COVAXIN.
Photonic Integrated Quantum Memory in Rare‐Earth Doped Solids
Authors: Zhou Zong‐Quan , Liu Chao , Li Chuan‐Feng , Guo Guang‐Can , Oblak Daniel , Lei Mi , Faraon Andrei , Mazzera Margherita , de Riedmatten Hugues
Published: August 2023

An optical quantum memory is a device that can store photonic quantum information and release it after a controlled time. It is an essential component for overcoming channel losses in large‐scale quantum networks. Optical quantum memories have been demonstrated with various physical systems including atomic gases, single atoms in optical cavities, and rare‐earth‐ion doped solids. Now, quantum memories are marching toward miniaturization and integration for large‐scale practical applications. Solid state systems stand as a natural choice due to the physical stability and ease of micro or nano fabrication using well‐established techniques. In the past decade, considerable efforts have been devoted to developing photonic integrated quantum memories, that is, quantum memories based on micro/nano‐photonic structures manufactured in solids. Remarkable performances have been achieved with integrated quantum memories, with the advantages of lower laser/electric power requirements, small volumes, large storage densities, and easy implementations. In this article, the basic concepts of optical quantum memories, the state‐of‐the‐art technologies for fabricating integrated quantum memories in rare‐earth ions doped crystals, and recent advances are introduced, and the roadmap for developing practically useful devices for applications in quantum networks is discussed.
Evidence Hub: A place to exchange medical knowledge and form communities
Authors: Hong Kenny , Bandaranayake Druvinka , Tsafnat Guy
Published: August 2023

Introduction

Medical knowledge is complex and constantly evolving, making it challenging to disseminate and retrieve effectively. To address these challenges, researchers are exploring the use of formal knowledge representations that can be easily interpreted by computers.

Methods

Evidence Hub is a new, free, online platform that hosts computable clinical knowledge in the form of “Knowledge Objects”. These objects represent various types of computer‐interpretable knowledge. The platform includes features that encourage advancing medical knowledge, such as public discussion threads for civil discourse about each Knowledge Object, thus building communities of interest that can form and reach consensus on the correctness, applicability, and proper use of the object. Knowledge Objects are maintained by volunteers and published on Evidence Hub under GPL 2.0. Peer review and quality assurance are provided by volunteers.

Results

Users can explore Evidence Hub and participate in discussions using a web browser. An application programming interface allows applications to register themselves as handlers of specific object types and provide editing and execution capabilities for particular object types.

Conclusions

By providing a platform for computable clinical knowledge and fostering discussion and collaboration, Evidence Hub improves the dissemination and use of medical knowledge.
Smart Antifouling and Self‐Cleaning Membrane for Effective Oil/Water Separation
Authors: Oral Nur , Basal Guldemet
Published: August 2023

A novel membrane consisting of cellulose acetate (CA) nanofibers and poly(N‐isopropylacrylamide) (PNIPAM) microparticles is successfully fabricated by simultaneous electrospinning and electrospraying. The CA/PNIPAM membrane has highly effective gravity‐driven separation performances for both oil/water mixtures and oil‐in‐water emulsions. It separates oil droplets from oil‐in‐water mixtures and oil‐water emulsions with rejection rates of 99.83% and 96%, respectively. In order to examine the contribution of PNIPAM particles, the performance of the CA/PNIPAM membrane is compared with the CA membrane. Increased hydrophilicity due to the inclusion of the PNIPAM particles between CA nanofibers results in a higher rejection ratio and superior antifouling performance. While the CA membrane becomes unusable after 10 cycles during the separation of the oil–water emulsion, the CA/PNIPAM membrane is still in good shape after 20 cycles. The self‐cleaning ability of the membrane is examined through the permeation flux below and above the lower critical solution temperature (LCST) of PNIPAM. The reversible thermo‐responsive flux variation proves that the pore sizes increase at temperatures above the LCST of PNIPAM. Moreover, when the lubricating oil–water emulsion is filtered through the membrane, the permeate changes from clear to turbid due to the nonretained oil particles as the temperature passes through the LCST.
Fiber‐Specific White Matter Alterations in Parkinson's Disease Patients with GBA Gene Mutations
Authors: Andica Christina , Kamagata Koji , Uchida Wataru , Saito Yuya , Takabayashi Kaito , Hagiwara Akifumi , Takeshige‐Amano Haruka , Hatano Taku , Hattori Nobutaka , Aoki Shigeki
Published: August 2023

Background

Patients with Parkinson's disease (PD) carrying GBA gene mutations (GBA‐PD) have a more aggressive disease course than those with idiopathic PD (iPD).

Objective

The objective of this study was to investigate fiber‐specific white matter (WM) differences in nonmedicated patients with early‐stage GBA‐PD and iPD using fixel‐based analysis, a novel technique to assess tract‐specific WM microstructural and macrostructural features comprehensively.

Methods

Fixel‐based metrics, including microstructural fiber density (FD), macrostructural fiber‐bundle cross section (FC), and a combination of FD and FC (FDC), were compared among 30 healthy control subjects, 16 patients with GBA‐PD, and 35 patients with iPD. Associations between FDC and clinical evaluations were also explored using multiple linear regression analyses.

Results

Patients with GBA‐PD showed significantly lower FD in the fornix and superior longitudinal fasciculus than healthy control subjects, and lower FC in the corticospinal tract (CST) and lower FDC in the CST, middle cerebellar peduncle, and striatal‐thalamo‐cortical pathways than patients with iPD. Contrarily, patients with iPD showed significantly higher FC and FDC in the CST and striatal‐thalamo‐cortical pathways than healthy control subjects. In addition, lower FDC in patients with GBA‐PD was associated with reduced glucocerebrosidase enzyme activity, lower cerebrospinal fluid total α‐synuclein levels, lower Montreal Cognitive Assessment scores, lower striatal binding ratio, and higher Unified Parkinson's Disease Rating Scale Part III scores.

Conclusions

We report reduced fiber‐specific WM density and bundle cross‐sectional size in patients with GBA‐PD, suggesting neurodegeneration linked to glucocerebrosidase deficiency, α‐synuclein accumulation, and poorer cognition and motor functions. Conversely, patients with iPD showed increased fiber bundle size, likely because of WM reorganization. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Sources of meaning in life among older adults during the COVID‐19 pandemic: A qualitative study
Authors: Kim Chanhee , Lee Min Hye , Kang Kyung Im
Published: August 2023

Aim

This study aims to explore the sources of meaning in life (MIL) and its impact on South Korean older adults during the coronavirus disease 2019 (COVID‐19) pandemic.

Design

This study had a qualitative descriptive study design.

Methods

The study participants included 18 older adults. Six focus group interviews were conducted. Data were analysed using content analysis.

Results

The subcategories ‘Continued learning and growth’, ‘Self‐transcending practices’ and ‘Efforts to maintain good health’ were extracted under the category ‘Sources of MIL for older adults’. Similarly, the subcategories ‘Tremendous changes brought about by the virus’ and ‘Varying patterns of adjustment to the pandemic’ were extracted under the category ‘Changes in the sources of MIL since the COVID‐19 outbreak’.

Public Contribution

Our study provides an in‐depth understanding of the changed sources of MIL for older adults during the COVID‐19 pandemic. The findings serve as useful guidance for planning interventions for older adults to lead meaningful lives during the COVID‐19 pandemic and post‐pandemic crises.
The role of the teacher and learning in clinical practicum scales: A psychometric testing of the Finnish versions
Authors: Strandell‐Laine Camilla , Haapa Toni , Timonen Leena , Suikkala Arja
Published: August 2023

Aim

To test the psychometric properties of the further developed Role of the Teacher (Tc2) and the new Learning in Clinical Practicum (LCP) scales in a sample of Finnish healthcare students.

Design

Psychometrical testing of the Tc2 and LCP scales.

Methods

A sample consisting of 1133 healthcare students completed the further developed Tc2 scale and the new LCP scale between January and June 2020. Statistical data analysis was performed using explorative factor analysis and Cronbach's alpha coefficient. The STROBE checklist for cross‐sectional studies was applied in reporting.

Results

Both the further developed Tc2 and the new LCP scales were shown to be valid and reliable. Explorative factor analysis confirmed a two‐factor solution for the Tc2 scale with a 76.3% explained variance and a one‐factor solution for the LCP scale with a 58.0% explained variance. The scales' internal consistency reliabilities were high (0.9).
Nurses' experiences of provision family‐centred care in the postresuscitation period: A qualitative study
Authors: Zali Mahnaz , Rahmani Azad , Powers Kelly , Hassankhani Hadi , Namdar‐Areshtanab Hossein , Gilani Neda
Published: August 2023

Aim

This study aimed to explore nurses' experiences of providing family‐centred care in the postresuscitation period.

Design

An exploratory‐descriptive qualitative design was used.

Methods

In this qualitative study, in‐depth, semi‐structured interviews were conducted with 22 nurses in three educational hospitals. There were six participants who completed follow‐up interviews to resolve questions generated during initial interviews. Data were analysed using conventional content analysis.

Results

Five main categories were extracted: continuous monitoring, facilitation of attendance, involvement in care, informing and emotional support. Despite the lack of organizational policies and guidelines, nurses explained how they work to provide family‐centred care for families, especially those they assessed as having less possibility of aggressive behaviour and those with a better understanding of their loved one's condition. To provide postresuscitation family‐centred care, nurses facilitated family attendance, involved them in some basic nursing care, and provided information and emotional support to the family members.

Conclusion

Nurses attempted to follow the basic principles of family‐centred care in the postresuscitation period. However, to improve the provision of care by nurses, it is necessary to embed family‐centred care principles in institutional policies and guidelines and to conduct training for nurses.

Implications for the Profession

Iranian nurses are interested in engaged families in the postresuscitation period. Correct implementations of such care that include all families need institutional policies and guidelines.

Patient or Public Contribution

No patient or public contribution.
Nurses' bereavement experiences of a deceased colleague due to COVID‐19: A phenomenological study
Authors: Najafi Fatemeh , Mardanian Dehkordi Leila , Khodayari Sajad , Jaafarpour Molouk , Nasrabadi Alireza Nikbakht
Published: August 2023

Aim

Healthcare workers have little time to mourn due to the intensification of the COVID‐19 pandemic. Although grief is a normal part of life and death, the circumstances surrounding the death can affect the grieving process. So far, the nurses' experience in mourn for a deceased colleague in the COVID‐19 pandemic has not been determined. Identifying these experiences can provide opportunities to formulate appropriate strategies to functionally adapt to death and promote mental health and well‐being during this crisis. This study aimed to understand the nurses' experiences in mourning for a deceased colleague due to COVID‐19.

Design

This was an interpretive phenomenological study.

Method

Participants included 10 nurses with the bereavement experience following the death of a colleague due to COVID‐19, who were selected through purposive sampling, and the data were collected through in‐depth and semi‐structured interviews and analysed using Diekelmann et al.'s (1989) approach.

Results

The nurses' bereavement experiences were in the form of eight themes: disbelief and amazement, acceptance with grief, lasting sadness, unsung laments, bringing back memories, impulse to leave the service, a professional myth and holy death. For nurses, mourning for the death of a colleague due to COVID‐19 is like a lasting sadness that begins with disbelief and amazement and changes to acceptance with sadness. From the fellow nurses' point of view, this type of death was perceived as a holy death, which along with countless unsung laments and memories brought to us the association of a professional legend, and that such a fate would be inevitable for us as well, it was a push to leave the service.

Public Contribution

Crisis managers and policymakers need to add protocols and training programs for resilience skills and healthy mourning.
Approximate optimal control design for quadrotors: A computationally fast solution
Authors: Yao Jie , Rafee Nekoo Saeed , Xin Ming
Published: August 2023

An approximate closed‐form optimal control design is proposed for the flight control of quadrotor unmanned aerial vehicles. The nonlinear dynamic equation is rewritten as a pseudo‐linear form without approximations. The quadratic cost function is modified by adding perturbation terms to the state weighting matrix. A co‐state, which is associated with the solution to the partial differential Hamilton–Jacobi–Bellman (HJB) equation, is approximated by a power series of an instrumental variable with symmetric matrices as the coefficients. The solution to the intractable HJB equation can be reduced to solving these coefficient matrices, which are in forms of a differential Riccati equation and a series of linear Lyapunov equations, These equations can be solved recursively and analytically. Specifically, the differential Riccati equation can be solved offline and only once, and the linear Lyapunov equations can be solved analytically. These approximations lead to a closed‐form suboptimal state feedback control law, which is computationally more efficient than the similar finite‐time state‐dependent Riccati equation (SDRE) technique that requires the solution of the state‐dependent differential Riccati equation at each time step and demands a high computational cost. The proposed control law is applied to the flight control design of quadrotors. Numerical simulations validate the effectiveness of the proposed optimal control technique with superior performance of control accuracy and robustness. It is compared favorably with the finite‐time SDRE technique in terms of computation efficiency and control effort, especially when onboard implementations and experiments are needed.
Recent progress in thermal and acoustic properties of natural fiber reinforced polymer composites: Preparation, characterization, and data analysis
Authors: Dev Barshan , Rahman Md. Ashikur , Repon Md. Reazuddin , Rahman Mohammed M. , Haji Aminoddin , Nawab Yasir
Published: August 2023

Natural fiber reinforced polymer composites (NFRPCs) have emerged as promising eco‐friendly alternatives over conventional synthetic fiber composites due to their inherent biodegradability, renewability, low environmental impact, and lightweight properties. It has been seen a significant growth in both invention and innovation in the field of NFRPCs. Natural fibers (NFs) reduce the cost of the material by 5%, the weight of the composite by 10%, and the energy required for production by 80%. In terms of thermal, and acoustic properties, NFs can successfully compete with synthetic fibers. As a result, the development of NFRPCs for industrial use has increased significantly in the past decade to meet the growing demands of industrial sectors. To improve the thermal and acoustic properties of NFRPCs, researchers have done a lot of investigation. The aim of the current review is to provide a comprehensive analysis of the existing literature on the thermal and acoustic properties of natural fiber reinforced polymer composites. Thermal properties such as thermal conductivity, TGA, DSC, DMA, and acoustic properties of natural fiber reinforced composites with several parameters, such as different fiber types, different matrix types, fiber weight ratio, fiber to matrix ratio, chemical treatment of fiber have been summarized and analyzed very concisely. This review also emphasizes a summary of different natural fibers, their chemical compositions, composite preparation, characterizations, and future research directions. This article enables the readers, researchers, and manufacturers to realize several opportunities about the latest developments in NFRPCs for the application of thermal and acoustic purposes.

Highlights

Natural fibers can successfully compete with synthetic fibers, in terms of thermal and acoustic properties.

Thermal properties of natural fiber reinforced composites including thermal conductivity, TGA, DSC, and DMA are summarized.

Acoustic properties of natural fiber reinforced polymer composites are discussed.

Composite materials made of treated fibers result better thermal stability than untreated fiber composites.

Sound absorption coefficient generally increases as fiber content increases.
Mechanical and thermal properties of high volume‐fraction carbon nanotube/epoxy composites, and property enhancement byUVozone treatment of carbon nanotubes
Authors: Kamae Toshiya , Drzal Lawrence T.
Published: August 2023

A new method to fabricate carbon nanotube/epoxy composites, consisting of well dispersed and highly concentrated CNTs in an epoxy resin, has been developed. In this method, multiwalled carbon nanotubes (MWNTs) were dispersed into water with the assistance of cationic polymers to form a MWNT sheet by filtration. An epoxy resin was impregnated into the MWNT sheet by vacuum assisted impregnation using a filtration system, followed by autoclave cure, resulting in a MWNT/epoxy composite with a MWNT content of 33 wt%. It was revealed that the composite has a tensile modulus of 8.37 GPa and a tensile strength of 130 MPa. An application of a UV ozone (UV/O3) treatment to the MWNTs increased the XPS O/C ratio from 0.03 to 0.10, resulting in the improvement of the tensile strength to 171 MPa. These results indicate the effectiveness of the UV/O3treated MWTNs for mechanical property enhancement.
Lubrication mechanism of polyimide/V2CTx MXene composites based on surface chemistry
Authors: Jin Lanyu , Wang Xinrui , Huang Yufei , Chen Guojing , Pang Haosheng , Yin Xuan , Chai Chunpeng
Published: August 2023

A series of polyimide (PI)/V2CTx MXene composites was synthesized via polyamide acids (PAA) and two‐dimensional (2D) V2CTx MXene obtained by etching precursor V2AlC. PI/V2CTx MXene composites with different mass ratios were obtained by blending and heating with PAA. The results showed that V2CTx MXene has excellent dispersion in PI. In particular, V2CTx MXene exhibited excellent friction reduction and anti‐wear properties as a solid lubricant additive, and the wear rate (WR) was reduced by 43.2% by incorporating only 0.8 wt% of V2CTx MXene in the pristine PI and 71.9% by incorporating 1.2 wt%. Scanning electron microscopy (SEM) and x‐ray photoelectron spectroscopy (XPS) analyses showed that the continuous transfer film consisting of a high proportion of tribo‐chemical products formed on the contact surface is significant to improve the lubrication performances of the PI composites. This work broadens the application of MXene in the field of tribology and contributes to energy conservation and sustainable development of human society.

Highlights

The tribological properties could be tuned by changing the ratio of PI to V2CTx MXene.

The WR of PI composites was reduced by 71.9% with incorporating 1.2 wt% of V2CTx MXene.

The formation of transfer films on the contact surface is significant for improving anti‐wear of PI.
Sodium alginate/polyethyleneimine/polydopamine@cellulose nanofiber composite aerogel as a novel adsorbent for Cr(VI) and dyes removal
Authors: Li Jun , Lei Lingling , Liu Zheng , Qiu Jinghong , Wang Haibo
Published: August 2023

In this work, a novel SA/PEI/PDA@CNF (SPCP) aerogel adsorbent was prepared for efficient hexavalent chromium (Cr(VI)) and dyes removal. Sodium alginate was used as the skeleton ingredient, nanocellulose fiber as the reinforcing agent, while polyethyleneimine provides functional groups, and polydopamine was added to improve the adsorption capacity of the aerogel toward cationic dyes. Several methods were used to characterize the SPCP aerogel, and thorough research showed that the aerogel's adsorption capacities for CR, Cr(VI), and MB were 1078.06, 2827.38, and 596.96 mg/g, respectively. In addition, it was established that the pseudo‐second‐order kinetics provides the most accurate way to the adsorption kinetic process while the Langmuir model provides the most accurate representation of the adsorption isotherm. Additionally, SPCP aerogel still retained exceptional adsorption capability after five adsorption‐desorption cycles. Thereupon, SPCP, this biomass composite aerogel exhibits notable benefits, such as high adsorption capacity, marvelous sustainability, cost‐effectiveness, and easy operation, which was considered to be a promising adsorbent for the wastewater treatment.
Nonlinear plasma surface modification of polylactide to promote interaction with fibroblasts
Authors: Kamalov Almaz , Ivanov Aleksey , Smirnova Natalia , Sokolova Maria , Kolbe Konstantin , Pavlov Andrey , Malafeev Konstantin , Yudin Vladimir
Published: August 2023

Surface modification of polylactide films was performed using a dielectric barrier discharge (DBD) with the aim of increasing proliferative activity of human fibroblasts on these films. It has been shown that during the plasma treatment of the polylactide film, nonlinear processes occur depending on the processing time. The effect of the dielectric barrier discharge on the modification of polylactide films was evaluated using IR spectroscopy, AFM, XPS, TSDC, and the wetting angle of the surface. The optimal processing time in DBD of polylactide films is 3 min for this installation, the proliferative activity increases by 10% compared to the original film. This treatment time provides an increased concentration of oxygen‐containing groups, optimal relief, and free surface energy of 55 mJ/m2 on the surface.

Highlights

The biocompatibility of the polylactide film was improved by 10% used DBD.

The optimal processing time of PLA films in DBD is 3 min.

The functionalization of the polylactide surface occurs non‐linearly.
A novel micromixer for efficient mixing and nano‐TATB preparation
Authors: Guo Yunyan , Zhou Jinqiang , Liu Shujie , An Chongwei , Wang Jingyu , Wu Bidong
Published: August 2023

Passive micromixers are widely used in the preparation of ultrafine explosives because of their efficient mixing and necessary safety. A novel passive micromixer was designed to prepare nano‐TATB. Computational fluid dynamics (CFD) is used to simulate the opening width (K), fluid velocity and mixing performance of the micromixer. The results show that the proposed micromixer has good mixing performance in the Reynolds number (Re) range of 0.1~100, and its pressure drop less than 28204 Pa at Re=100. A microfluidic recrystallization system was established and nano‐TATB was prepared by a new micromixer. The results show that the average particle size of the prepared TATB is 93.12 nm, and the particle size distribution ranges from 43 nm to 151.4 nm. The SEM test shows that TATB has better morphological characteristics. XRD results show that the crystal structure of TATB is consistent with that of raw materials. This study proves that the new micromixer has good mixing effect and the feasibility of preparing nano TATB. It also provides reference for the design of micromixer and refinement of other energetic materials.
Electrostatic hazards: Identifying the early warning signs to reduce explosion risk1
Authors: Ebadat Vahid , Cartwright Paul
Published: August 2023

Electrostatic discharges are known to cause many industrial fires and explosions each year. Yet it is quite usual to find that before an incident operatives have encountered signs that static electricity is present. These signs—the ‘early warning signs’—had their significance been appreciated, could have prevented many industrial fires or explosions. In this paper, we bring together evidence obtained from investigation of electrostatic incidents and group them by class of ‘manifestation’. We discuss how these classes/manifestations should be interpreted by reference to discharge types and their associated energy ranges. Finally, we discuss how we can go about assessing whether each static manifestation could lead to an electrostatically initiated fire or explosion as well as how they can be eliminated. The early warning signs of static electricity can be as apparently innocuous as dust patterns on plastic or a prickling feeling on the arms. They can also include unexpected corrosion in a glass‐lined vessel or even a pinhole leak from an insulating pipe; these in addition to the well‐recognized sparks and cracking sounds that present themselves as the more obvious face of hazardous static electricity. Waiting for an ‘early warning sign’ can never be a substitute for detailed hazard assessment work that focuses on the identification and elimination of all potential ignition sources. But it is worth noting that electrostatic sources of ignition are often considered to be more complicated to identify and eliminate than others, and consequently, they frequently elude the formal HAZOP or hazard study process. With electrostatic hazards, this makes vigilance by operatives and others that much more important, especially since electrostatic effects can easily be spotted and eliminated—if you know what to look for. A new proposed ‘classification’ that will be discussed in this paper can aid the understanding of hazardous static electricity and thus help reduce the risk of fire and explosion in industry.
Wind turbine gear reliability analysis considering dependent competing failure
Authors: Liu Yuanyuan , Gao Jianxiong , Yuan Yiping , Wang Shuo
Published: August 2023

To more precisely assess the reliability of wind turbine gears, a competing failure model is established with consideration given to the degradation of internal fatigue strength and external random shocks. Firstly, the nonlinear Gamma process is adopted to depict the degradation of fatigue strength, and the strength‐stress interference theory is used to establish the threshold of degradation failure that changes over time. Also, the non‐homogeneous Poisson process is employed to depict the arrival of the shock, and classification of the shocks. Secondly, the correlation between degradation and shock is described, while the effect of shocks on degradation is demonstrated as a sudden increase in the extent of degradation. Besides, the decline rate of residual strength curve is introduced to describe the change in intensity parameters of the Poisson process, and then the effect of degradation on shocks is described. Finally, the sun gear in the wind turbine gearbox is an example. Monte Carlo simulation is used to calculate the reliability of the dependent competing failure model. This is then compared with the conventional stress‐strength interference model. The results verify that when the relationship between degradation and the shock process is disregarded, the reliability of gears may be overestimated.
Transmission reliability evaluation of the wireless mobile ad hoc network considering the routing protocol and randomness of channel capacity
Authors: Wang Ning , He Jiatao , Xiang Shihu , Yang Jun
Published: August 2023

Due to the characteristics of self‐organization, flexibility, and low cost, Mobile ad hoc networks (MANETs) have been applied in many fields, such as disaster rescues and military actions. However, in reality, the successful route establishment based on routing protocols is the prerequisite of data transmission. Besides, the transmission reliability of MANETs is affected by resource constraints, such as channel capacity and energy, and environmental factors. Hence, how accurately modeling and evaluating the transmission reliability of MANETs is very important to ensure their application. Whereas, existing studies ignore the impact of routing protocols and do not fully consider the influence of some factors on transmission reliability, such as environmental randomness, channel capacity, and energy consumption. To solve the above problems, we first propose a signal‐to‐noise‐ratio‐Capacity connection model to better describe the characteristics of wireless links, and the probability of one hop connection is deduced considering the capacity demand randomness. Then, considering the influence of routing protocol on the MANET link establishment, we take the ad hoc on‐demand distance vector routing protocol as an example, and propose an evaluation algorithm of the MANET transmission reliability based on algebraic graph theory and Monte Carlo simulation. Finally, the effectiveness of the proposed method is demonstrated by a numerical example of an unmanned aerial vehicle search and rescue scene.
Sustainable urbanization and vulnerability to climate change in Africa: Accounting for digitalization and institutional quality
Authors: Yeyouomo Aurelien K. , Asongu Simplice A.
Published: August 2023

This study empirically examines the effect of sustainable urbanization on vulnerability to climate change over a sample of 52 African countries from 1996 to 2019. We use the two‐stage system generalized method of moments (GMM) empirical strategy and mediation analysis to assess direct and indirect impacts, respectively. The results of the direct analysis reveal that sustainable urbanization reduces vulnerability to climate change. The results of the indirect analysis also show that sustainable urbanization significantly reduces vulnerability to climate change through the channels of digitalization and institutional quality. The results also highlight that considering the direct effect of sustainable urbanization alone underestimates the impact of reducing vulnerability to climate change. The results are robust to an alternative indicator of vulnerability to climate and other estimation techniques. These results have important policy implications and provide evidence for the improvement of sustainable urbanization in terms of access to basic services or reduction of vulnerability to climate change.
After the startup: A collection to spur research about entrepreneurial growth
Authors: Combs James G. , Ketchen David J. , Terjesen Siri A. , Bergh Donald D.
Published: August 2023

Research Summary

Entrepreneurship researchers have made great strides toward understanding who discovers and/or creates opportunities, how they validate a business model, and how they attract resources, but far less is known about what happens next. Beyond gathering resources, how do entrepreneurs build a growing organization once customer enthusiasm has been demonstrated? What has been learned is fragmented across theoretical perspectives and activities related to growth. We describe a collection of articles that spotlight different theories and organize the articles according to key activities: (1) building internal resources and capabilities, (2) leveraging partnerships, (3) taking strategic actions, and (4) managing interactions among resources, partners, and actions. Juxtaposing these activities with theories from the collection, we offer a research agenda designed to spur research to fill gaps in understanding of how entrepreneurs successfully manage growth.

Managerial Summary

The period of an organization's development between the startup stage and becoming an established firm presents unique challenges. We spotlight a set of articles that have provided insights into how organizations can overcome these challenges. We then add our own perspective by providing research ideas that scholars can investigate in order to generate additional insights.
Declining science‐based startups: Strategic human capital and the value of working in startups versus established firms
Authors: Ding Yuheng , Åstebro Thomas , Braguinsky Serguey
Published: August 2023

Research Summary

We document that since 1997, the rate of startup formation has precipitously declined for firms operated by US PhD recipients in science and engineering. We explore how increasing knowledge complexity can be associated with fewer science‐based startups. The decline in startup formation is accompanied by an earnings decline, increasing work complexity in R&D, and more administrative work for science‐based founders. Founding a startup appears to have become increasingly harder over the past 20 years, while established firms are becoming more attractive workplaces for PhDs.

Managerial Summary

The increase in knowledge complexity has changed the balance of incentives between starting own business versus working for an incumbent firm in favor of the latter for PhDs. If maintaining a steady flow of new businesses in the high‐tech sector is important to keep the flow of commercialization of new ideas coming, managerial practitioners and policy makers may need to find ways to make the job of the founder more attractive. The findings in this article point to the importance of secularly increasing value of complementary assets in work practices, especially for founders and employees that are high value generators. Alternatively, the increasing dominance of a few very large tech firms that the increasing burden of knowledge is fueling could be just fine, and startups need not play an important role in economic development.
Reduction and Adsorption of Hexavalent Chromium by Iron Sulfide Loaded Biochar: Isotherms, Kinetics and Thermodynamics
Authors: Qhubu Mpho Cynthia , Lesaoana Mahadi , Nomngongo Philiswa Nosizo , Pakade Vusumzi Emmanuel
Published: August 2023

The removal of noxious Cr(VI) from water has gained worldwide attention. In this study, biochar derived from macadamia nut shells (MHP) was embedded with iron sulfide (FeS) nanoparticles produced through a solid‐phase reduction of pyrite. The MHP‐FeS composite was evaluated for the adsorption of Cr(VI) and its subsequent reduction to Cr(III). The scanning electron microscope images revealed that the particles were of irregular shape, while the energy dispersive spectroscopy results showed the existence of Fe, S, O, and C atoms. X‐ray diffraction peaks at 2=29.8°, 33.7°, 43.7°, and 53.1° were characteristic of the formation of FeS nanoparticles. A maximum Cr(VI) adsorption capacity of 4.95 mg/g was obtained at pH 3, 60 min, and 25 °C. The higher correlation coefficient (R2>0.873) and lower residual standard error (RSE=1.43) values pointed to the adsorption process favoring Langmuir and pseudo‐second‐order models. As per thermodynamic reaction calculations, the remediation process was spontaneous and endothermic. With further optimization, this material could be a potential adsorbent and reductant for Cr(VI) in water.
A Facile Regio‐ and Stereoselective Synthesis and Cholinesterase Inhibitory Activity of New Oxobenzothiophene Grafted Spiropyrrolidine/Pyrrolizidine Hybrids Employing Multicomponent 1,3‐Dipolar Cycloaddition Methodology
Authors: Raju Rajesh , Mani Suresh , Arumugam Natarajan , Almansour Abdulrahman I. , Suresh Kumar Raju , Premnath Dhanaraj , Perumal Karthikeyan
Published: August 2023

A stereo‐, regio‐ and chemoselective synthesis of a series of structurally diverse novel oxobenzothiophene embedded spirooxindolopyrrolidine/pyrrolizidine hybrid heterocycles were achieved in excellent yields by multicomponent 1,3‐dipolar cycloaddition reaction process. The 1,3‐dipole component employed was generated in situ from isatin and N‐methylglycine/L‐proline while the dipolarophile, ethyl 2‐(3‐oxobenzo[b]thiophen‐2(3H)‐ylidene)acetate was prepared from thiophenol in two good yielding steps. The formation of spiroheterocyclic hybrids occurred through the formation of two C=C and one C−N bonds in a single synthetic transformation. The compounds formed consists of three adjacent stereocenters, out of which two are spirocarbons. The synthesized spiro compounds were assayed for their AChE/BChE inhibitory activity and most of the spirocompounds showed promising cholinesterase inhibitory activity. Among them, spiropyrrolidine that substituted with chlorine atom on the oxindole ring displayed significant activity (4.16±0.09 μM) with respect to standard drug, galantamine (2.09±0.11 μM). Molecular modelling simulation was explored for the most potent compound that revealed interesting binding templates to the active site of enzyme.
Design, Synthesis, Antimicrobial and Docking Studies of Benzothiazoles Bearing Pyrazole and Pyrimidine Moieties
Authors: Tamam Esraa , Fadda Ahmed A. , El‐Sawy Eslam R. , Abdel‐Aziz Mohamed S. , Tawfik Eman H.
Published: August 2023

The reaction of enaminonitrile 2 with hydrazine hydrate yielded 5‐amino pyrazole derivative 4. Compound 4 reacted with ethyl acetoacetate, enaminone 8, chalcone 12, enaminonitrile 2, arylidene malononitrile 18, 3‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐3‐oxopropanenitrile 21 and phenacyl bromide to give the corresponding pyrazolopyrimidine derivatives 7, 11, 14, 17, 20, 23, and imidazopyrazole 25, respectively. The newly synthesized compounds were characterized by spectral and elemental analyses. The antimicrobial activities of the new compounds were tested against S. aureus, E. coli, and C. albicans. It was found that compound 23 exhibited the highest antimicrobial activity against the tested microorganisms. All tested compounds did not have antifungal activity against A. niger as a fungal strain. Utilizing drug‐likeness (ADME) and molecular docking the effectiveness of compound 23 towards G+ve and G‐ve bacteria has been studied. Accordingly, compound 23 is expected to have a high chance of oral bioavailability due to its compliance with Lipinski′s rule of five. In addition, it plays a critical role in the inhibition of bacterial S. Ribosome, dihydropteroate synthase, transpeptidase, and gyrase B. subunit proteins.
Lithiophilic Cu3Sn Modified Cu Foil as Current Collector for Stable Lithium Metal Anodes
Authors: Ma Kaiwen , Li Fangya , Li Xinbin , Liu Ting , Wang Ting , Wang Huanlei , Liu Shuai
Published: August 2023

The development of lithium metal battery is severely restricted by its uncontrolled dendrite growth and volume change. In this work, we designed a controllable lithiophilic Cu3Sn modified commercial Cu foil as current collector via simple industrial electroplating and heat treatment. As a Li‐reservoir substrate for efficient deposition/stripping of Li metal, the introduction of Cu3Sn not only increases multiple active sites for the deposition of Li, but also provides more transfer paths for lithium ions. The Li metal anodes prepared by molten Li on the Cu current collector with dispersed Cu3Sn active sites provide a uniform lithiophilic surface, which could effectively promote a uniform Li deposition/stripping and suppress the formation of lithium dendrites. As a result, the assembled symmetric battery is stable at a low over‐point position for 1600 h without short circuit at 1 mA cm−2 with 1 mAh cm−2, the full battery paired with LiFePO4 still maintains a high‐capacity retention rate of 97.1 % and a coulombic efficiency (CE) of 99.5 % after 400 cycles at a current density of 2 C. This work provides a facile and controllable strategy for the design of current collectors with high lithium affinity for stable lithium metal anode applications.
Synthesis of Nano‐zero‐valent Iron/Chitosan based on Bimetallic Nanoparticles for the Simultaneous Removal of Reactive Violet 5 and Reactive Blue 171 from Aquatic Media: Response Surface Methodology
Authors: Neishaboori Fahimehsadat Mostafavi , Sohrabi Mahmoud Reza , Motiee Fereshteh , Davallo Mehran
Published: August 2023

In this study, a nanostructure adsorbent was fabricated from mixed nanosized zero‐valent iron (nZVI), chitosan (CS), and copper (Cu) for the simultaneous removal of Reactive Violet 5 and Reactive Blue 171 from the aqueous media. The prepared adsorbent was characterized by scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Brunauer‐Emmett–Teller, Fourier transform infrared spectroscopy, and X‐ray diffraction. The impact of variables, including pH, adsorbing dosage, contact time, and temperature on the removal percentages of RV5 and RB171 dyes were simultaneously investigated using response surface methodology (RSM) based on a central composite design. The maximum removal efficiency (77.67 %) was obtained at a pH of 3, an adsorbent dosage of 0.3 g, a contact time of 15 min, and a temperature of 10 °C. The adsorption process fitted well with the Langmuir isotherm model with a coefficient of determination (R2) equal to 0.9996 and the pseudo‐second‐order kinetic model (R2=0.9988). Hence, it could be concluded that the process of adsorption mechanism is monolayer and chemical. The maximum adsorption capacity (qmax) was 50.25 mg g−1. In conclusion, nZVI‐CS‐Cu can be considered as an efficient and inexpensive adsorbent for dye removal from aqueous solutions, because its separation is quick and easy, it possesses high efficiency, and there is no secondary pollution.
Synthesis of 2’,4‐Dibromo‐2,4’‐bithiazole Using Novel Long‐range Halogen Dance Reaction
Authors: Arimitsu Kenji , Hirokawa Yoshimi , Ikegawa Yuriko , Tanba Akiko , Ueda Yuki , Kashihara Taiga , Atarashi Naruhiro , Yoshida Ryoto , Matsuo Yosuke , Maezaki Naoyoshi
Published: August 2023

This study presents a novel halogen dance reaction using 4,5‐dibromo‐2,4’‐bithiazole, which demonstrates a long‐range effect. The reaction involves the migration of a bromo group from the C5‐position to the C2’‐position of another thiazole ring when treated with lithium hexamethyldisilazide (LiHMDS), resulting in the formation of a non‐symmetric brominated bithiazole. In contrast, the base‐induced C2’‐bromination of 4‐bromobithiazole was found to be inefficient in synthesizing the desired brominated bithiazole due to its poor deprotonation selectivity.