bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Imidazole Derivative Complexes That Catalyze the Thermal Decomposition of AP, CL‐20, and BNFFO
Authors: Li Haibo , Zhang Weijing , Wei Zhenghe , Xia Lianghong , Long Maohao , Li Zhimin , Zhang Tonglai
Published: April 2022

In this study, three energetic complexes, namely Cu(1‐MIM)2(N3)2 (1) (1‐MIM=1‐methylimidazole), [Cu(1‐VIM)2(N3)2]n (2) (1‐VIM=1‐vinylimidazole), and Cu(2‐MIM)3(N3)2 (3) (2‐MIM=2‐methylimidazole), were synthesized via a simple and mild method. The complexes were characterized by single‐crystal X‐Ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The thermal behavior and sensitivity of the complexes were analyzed by DSC, TG, and BAM methods, and their catalytic performances with respect to AP (ammonium perchlorate), CL‐20 (hexanitrohexaazaisowurtzitane), and BNFFO (3,4‐dinitrofurazanfuroxan) thermal decomposition were studied by differential scanning calorimetry (DSC). The obtained results indicate that complex 1 exhibits the best catalytic performance for AP thermal decomposition, as it reduces the decomposition (high‐temperature) peak temperature by 101.0 °C compared to pure AP. Moreover, this complex alters the shape of the decomposition peak, which suggests that it speeds up the decomposition process and renders it more intense. In terms of CL‐20 and BNFFO thermal decomposition, complex 3 shows the best catalytic performance, and it reduces the peak decomposition temperatures by 18.4 and 108.2 °C, respectively, compared to the pure samples. The activation energies of the AP/complex, CL‐20/complex, and BNFFO/complex mixtures were calculated using the Kissinger and Ozawa equations. Considering that the calculated values are lower than those corresponding to the pure substrates, the complexes can be employed as combustion catalysts for composite propellants.
Artificial neural networks model for predicting the behavior of different injection pressure characteristics powered by blend of biofuel‐nano emulsion
Authors: Elumalai P. V. , Krishna Moorthy R. , Parthasarathy M. , Samuel Olusegun David , Owamah Hilary I. , Saleel C Ahamed , Enweremadu Christopher C. , Sreenivasa Reddy M. , Afzal Asif
Published: April 2022

This investigation deals with the usage of graphene oxide (GO) nanoparticles with orange peel biodiesel in a conventional CI engine. The different fuel blends used for this experiment are biodiesel 10% + diesel 80% + ethanol 5% + surfactant 5% + GO 50 ppm (B10), biodiesel 20% + diesel 70% + ethanol 5% + surfactant 5% + GO 50 ppm (B20), biodiesel 50% + diesel 40% + ethanol 5% + surfactant 5% + GO 50 ppm (B50) and B100. The addition of ethanol has dual benefits for improving the vaporization of fuel blends and reduction of oxides of nitrogen (NOx) emission. Span80 and Tween80 were chosen as surfactants based on hydrophilic‐lipophilic balance numbers. It is useful for improving the homogeneity of immiscible fuel blends. From this study, the injection pressure (IP) was varied from 180, 200 to 220 bar for better atomization characteristics of nano additive biodiesel blend. The experimental results indicated that an increase in the percentages of biodiesel beyond 20% in the blend, NOx increases, and hydrocarbon (HC) and carbon dioxide (CO) emissions were found to be decreased. It is also observed that the highest brake thermal efficiency (BTE) was found for fuel 20 at the IP of 220 bar. The addition of nano additive has a great influence on fuel droplets and reduction of NOx emission levels. B20 blend was found to higher cylinder pressure and heat release rate when compared to other nano additive blends. Finally, indicated that the nano additive B20 blend is a better alternative to conventional fuel in unmodified CI engines. The RMSE value for the BTE, brake‐specific energy consumption (BSEC), CO, HC, NOx, and smoke is obtained to be 0.036, 0.0216, 0.044, 0.041, 0.0446, and 0.0435, respectively. The mean absolute percentage error value for the BTE, BSEC, CO, HC, NOx, and smoke is obtained to be 1.12, 0.84, 3.04, 4.12, 1.71, and 0.97, respectively.
Parametric and sensitivity analysis of metal hydride hydrogen storage systems for development of novel design charts
Authors: Tiwari Saurabh , Sharma Pratibha
Published: April 2022

Hydrogen storage is the biggest challenge towards the widespread utilization of hydrogen as an energy carrier. One of the methods is solid‐state storage of hydrogen in the metal hydride, which is safe, volumetrically efficient, and involves an optimal set of operating conditions. However, designing reactors for metal hydride storage involves much thermal management since the absorption and desorption are exothermic and endothermic reactions, respectively. Many optimization and simulations are involved before arriving at a suitable metal hydride reactor design for a particular application. This study focuses on developing easy‐to‐use design charts to evaluate reaction fractions inside the metal hydride bed for various combinations of parameters. First, the parameters affecting the reaction fraction are selected, and the range for each of these parameters is defined. The dependence of each parameter on the reaction fraction is analysed, maintaining the mean value of the remaining parameters. The LaNi5 is used as a metal hydride for this study. A two‐dimensional (2‐D) mathematical model is developed to evaluate the effect of these parameters on reaction fraction. Further, based on this detailed parametric study, a sensitivity analysis has been carried out to determine the most significant parameters. It was observed from this parametric and sensitivity analysis that among the considered parameters, the volume of the reactor (amount of hydrogen to be stored) and length to diameter ratio have a more dominant effect on the reaction fraction followed by supply pressure and thermal conductivity of metal hydride. However, the external temperature of heat transfer fluid (ie, the ambient temperature) does not significantly affect the reaction fraction. Hence, this parameter is assumed to be constant in developing design charts. Also, based on this analysis, the range of parameters is redefined for design charts. Further, this 2‐D mathematical model and parametric and sensitivity analysis are used to develop the design charts. These design charts use the most sensitive parameters and demonstrate the effect of all the other parameters on the reaction fraction. Finally, the method of using these design charts and their accuracy is explained for reaction fraction evaluation for a particular set of parameters. These charts are easy‐to‐use and accurate for the quick preliminary reaction fraction estimation for metal hydride hydrogen storage system.
Antinociceptive activity of theCaesalpinia eriostachysBenth. ethanolic extract, fractions, and isolated compounds in mice
Authors: Kim Hyun‐Yong , Lee Hee Jung , Zuo Guanglei , Hwang Seung Hwan , Park Jeong Seok , Hong Jae Seung , Kim Kang Hyuk , Soto Montero Silvia , Yi Dong‐Keun , Lee Jeong Tae , Suh Hong‐Won , Lim Soon Sung
Published: April 2022

Caesalpinia eriostachysBenth. (CE) is native to the Mexico and multiple effects have been observed from several plants belonging to the same family. CE was subjected to extraction with 95% ethanol, and the components were isolated through column chromatography. The structure of the compound was elucidated based on nuclear magnetic resonance (NMR) spectral data, electron ionization–mass (EI‐MS) spectroscopy, and liquid chromatography–mass (LC‐MS) spectroscopy. In vivo antinociceptive studies were conducted using writhing, 5% formalin, tail‐flick, hot‐plate, and von Frey filament tests. The ethanolic extract showed a significant effect in the acetic acid‐induced pain model and nociceptive behavior in the formalin model (second phase). In hot‐plate test and tail‐flick test, the results showed no difference compared to the control group. The results suggest that the ethanolic extract may act peripherally to reduce pain. In the streptozotocin (STZ)‐induced pain model, the ethanolic extract showed significant effect in the von Frey test model. Then‐Hex (Hexane) and MC (Methylene chloride) fractions and isolated compounds, ellagic acid and agathisflavone, showed increased effect. Based on these results, we confirmed that the CE ethanolic extract and their compounds, ellagic acid and agathisflavone, have antinociceptive effect on diabetes mellitus‐induced pain. Furthermore, the results of this study might be valuable for identifying compounds with antinociceptive activity from natural products.
Methylation classifiers: Brain tumors, sarcomas, and what's next
Authors: Koelsche Christian , von Deimling Andreas
Published: April 2022

Tumor classification has evolved over the last decades with technical progress contributing much to our current concepts. Among diagnostic hallmarks, novelties were immunostaining, Fluorescence in situ hybridization, Sanger sequencing followed by massive parallel DNA sequencing, and recently, epigenetic analyses have entered the stage. Although each of these techniques was revolutionary and, in some way, also disruptive in certain diagnostic fields, it took years to decades for broad implementation into standard pathological‐diagnostic algorithms. In contrast, DNA methylation profiling has been accepted in short time as a game changer with lasting impact on brain tumor classification and with potential for classification of other tumor types. This review provides a brief introduction in DNA methylation‐based tumor classification. We present why DNA methylation signatures are attractive diagnostic biomarkers, discuss present achievements and future aims and explain the integration of methylation‐based classifiers in diagnostic procedure. Finally, we provide an outlook on the challenges and opportunities associated with DNA methylation‐based tumor profiling.
Multimodal brain deficits shared in early‐onset and adult‐onset schizophrenia predict positive symptoms regardless of illness stage
Authors: Feng Aichen , Luo Na , Zhao Wentao , Calhoun Vince D. , Jiang Rongtao , Zhi Dongmei , Shi Weiyang , Jiang Tianzi , Yu Shan , Xu Yong , Liu Sha , Sui Jing
Published: April 2022

Incidence of schizophrenia (SZ) has two predominant peaks, in adolescent and young adult. Early‐onset schizophrenia provides an opportunity to explore the neuropathology of SZ early in the disorder and without the confound of antipsychotic mediation. However, it remains unexplored what deficits are shared or differ between adolescent early‐onset (EOS) and adult‐onset schizophrenia (AOS) patients. Here, based on 529 participants recruited from three independent cohorts, we explored AOS and EOS common and unique co‐varying patterns by jointly analyzing three MRI features: fractional amplitude of low‐frequency fluctuations (fALFF), gray matter (GM), and functional network connectivity (FNC). Furthermore, a prediction model was built to evaluate whether the common deficits in drug‐naive SZ could be replicated in chronic patients. Results demonstrated that (1) both EOS and AOS patients showed decreased fALFF and GM in default mode network, increased fALFF and GM in the sub‐cortical network, and aberrant FNC primarily related to middle temporal gyrus; (2) the commonly identified regions in drug‐naive SZ correlate with PANSS positive significantly, which can also predict PANSS positive in chronic SZ with longer duration of illness. Collectively, results suggest that multimodal imaging signatures shared by two types of drug‐naive SZ are also associated with positive symptom severity in chronic SZ and may be vital for understanding the progressive schizophrenic brain structural and functional deficits.
Impact of the Act‐Belong‐Commit campaign on mental health help‐seeking behaviour
Authors: Drane Catherine F. , Jalleh Geoffrey , Lin Chad , Donovan Robert J.
Published: April 2022

Issue addressed

Despite the high prevalence of mental ill‐health amongst Australians, many people do not seek help for their mental ill‐health. A delay in help‐seeking is associated with poorer outcomes. This study investigated the extent to which the Act‐Belong‐Commit mental health promotion campaign prompted people to seek information or professional help for mental ill‐health.

Methods

A sample of 1200 respondents took part in two state‐wide surveys (n = 600 each). Participants aware of the Act‐Belong‐Commit campaign were asked questions related to information‐seeking and help‐seeking behaviours because of the campaign.

Results

Of those aware of the campaign, 8% stated that the campaign prompted them to seek information and 4% stated that the campaign prompted them to seek help for a mental health problem. Those with a mental illness experience (MIE) were significantly more likely than those without to report that the campaign prompted them to look for information (12% vs 6%) and seek help for a mental health problem (9.5% vs 1.2%). Extrapolating these results to the total adult population of Western Australia indicated that around 120 000 adults had sought mental health information, and around 60 000 had sought help as a result of the campaign.

Conclusions

The campaign not only initiated the seeking of information or professional help for a mental health problem amongst those with no prior thoughts of such, but also prompted those who were already thinking about seeking information or getting help to act sooner than they otherwise would.

So what?

Although previous research suggests that mental health literacy interventions have limited impact on help‐seeking, the presented data show that the Act‐Belong‐Commit approach can have a significant impact on help‐seeking, particularly amongst those with a MIE, which could yield substantial social and economic return on investment benefits if intensified at both the media and community grass roots levels.
Association of vitamin D status with COVID‐19 disease severity in pediatric patients: A retrospective observational study
Authors: Heidari Solmaz , Mohammadi Shooka , Fathi Mohammadreza , Cigary Shayan , Alisamir Mohsen , Mirkarimi Mohammadreza , Aminzadeh Majid
Published: April 2022

Background and Aims

Vitamin D deficiency is associated with increased vulnerability to respiratory infections. This study aimed to determine the potential relationships between coronavirus disease 2019 (COVID‐19) severity, serum vitamin D concentrations, and some inflammatory markers among pediatric COVID‐19 patients in Iran.

Methods

A retrospective study was conducted among hospitalized pediatric COVID‐19 cases in Abuzar Hospital (Ahvaz, Iran) for 6 months. The COVID‐19 diagnosis was based on the real‐time reverse transcription‐polymerase chain reaction technique. Demographic and clinical data of patients were recorded. Patients with serum vitamin D levels lower than 20 ng/ml were assigned as Group 1 and those with serum vitamin D concentrations equal to or more than 20 ng/ml were considered as Group 2.

Results

A total of 144 patients were enrolled. Their mean age was 80  ±  49 months (range: 1–16 years). Patients in Group 1 had significantly lower levels of serum vitamin D, calcium, and lymphocytes, as well as higher fibrinogen, d‐dimer, and C‐reactive protein (CRP) levels compared with those in Group 2 (p < 0.001). In addition, they had a significantly higher dry cough, fever, chest radiographic findings, respiratory rate, and longer hospital length of stay than patients in Group 2. Serum concentrations of vitamin D were positively correlated with levels of serum calcium, lymphocytes, and neutrophils but negatively correlated with CRP, fibrinogen, and
d‐dimer values. Furthermore, patients with moderate or severe courses of COVID‐19 had significantly higher inflammatory markers (CRP,
d‐dimer, and fibrinogen), as well as lower levels of serum calcium, vitamin D, lymphocytes, and neutrophils than those with mild COVID‐19 (p < 0.001). In the multivariate analysis, fibrinogen level on admission was detected as the independent predictor of severe COVD‐19 (odds ratio = 1.06, 95% confidence interval: 1.03–1.09; p < 0.001).

Conclusion

This study indicated associations between the severity of COVID‐19, serum vitamin D concentrations, and some inflammatory markers in pediatric COVID‐19 patients.
Mesenchymal stromal cells promote the proliferation of basal stem cells and efficient epithelization in organotypic models of wound healing
Authors: Paganelli Alessia , Benassi Luisa , Rossi Elena , Tarentini Elisabetta , Magnoni Cristina
Published: April 2022

Adipose derived mesenchymal stromal cells (ADSCs) represent a fascinating tool in the scenario of wound healing and regenerative medicine. Recent data already demonstrated that ADSCs could exert a stimulatory action on epithelial cells through secretion of soluble factors. The aim of the present study was to assess how ADSCs guide wound re‐epithelization in vitro in the presence of keratinocytes. We used an organotypic model of wound healing and we seeded keratinocytes on a ADSC‐induced dermal matrix. Conventional hematoxylin–eosin stain and immunohistochemistry staining for Ki67, p63 and pan‐keratins were performed at different timepoints. Histological sections of organotypic cultures showed complete coverage of the ADSC‐induced matrix by keratinocytes. Proliferation of basal stem cells was found to be the main mechanism responsible for epithelization of the dermis. In conclusion, ADSC do not only stimulate dermal regeneration through collagen deposition but also promote epithelization.

Highlights

Mesenchymal stromal cells (MSCs) are widely used in regenerative medicine and wound healing.

MSCs do not only stimulate dermal regeneration through collagen deposition but also promote epithelization.

MSCs directly target the basal stem cell niche and promote its proliferation, migration and subsequent differentiation.
Structure of edges of embedded graphs with minimum degree two
Authors: Čekanová Katarína , Maceková Mária , Soták Roman
Published: April 2022

The weight of an edge is the degree‐sum of its end‐vertices. An edge is an ‐edge if and . In 1955, Kotzig proved that every 3‐connected plane graph contains an edge of weight at most 13. Later, Borodin proved the existence of such an edge in plane graphs with minimum degree at least three. If we consider a graph embedded on a surface with nonpositive Euler characteristic, minimum degree at least three and sufficiently large number of vertices, then the existence of an edge of weight at most 15 can be proved. In this paper we consider graphs with minimum degree two, minimum face degree at least three, embedded on a surface with nonpositive Euler characteristic. We prove that every connected graph with sufficiently large number of vertices, minimum degree two and minimum face degree at least , embedded on a surface with nonpositive Euler characteristic, contains an edge of type , , or if , , or if , or if , if , if , and if . We will also discuss the quality of our results.
Cutaneous metastasectomy: Is there a role in breast cancer? A systematic review and overview of current treatment modalities
Authors: Huang Samantha , Parekh Vishwas , Waisman James , Jones Veronica , Yuan Yuan , Vora Nayana , Li Richard , Jung Jae , Kruper Laura , Abdulla Farah , Fong Yuman , Li Wai‐Yee
Published: April 2022

Cutaneous metastases (CM) are neoplastic lesions involving the dermis or subcutaneous tissues, originating from another primary tumor. Breast cancer is commonest primary solid tumor, representing 24%–50% of CM patients. There is no “standard of care” on management. In particular, the role of surgery in the treatment of cutaneous metastases from breast carcinoma (CMBC) remains controversial. This systematic review evaluates the role of cutaneous metastasectomy in breast cancer and provides an overview of existing treatment types.
Knowledge management, agile management, and the use of foreign languages—A theoretical analysis illustrated with the cases of Russia and Portugal
Authors: Tomé Eduardo , Gromova Elizaveta , Hatch Andrew
Published: April 2022

In this article, we analyze the link between knowledge management and the use of foreign languages. In a globalized world, the mastery of foreign languages is a factor of business creation and business success. Of course, not all the national languages have the same international importance, and this is a double‐edge relation. In this context, we relate foreign languages, business, KM, productivity, and agile business. After a theoretical analysis, we address two different countries—Portugal and Russia. We conclude that investment in foreign languages is higher in Portugal than in Russia, probably due to the fact that Russia still sees itself as a superpower, whereas Portugal, (even if Portuguese is a language spoken worldwide), sees itself as a European Union member. As a consequence, and particularly in the last decade, Portugal has become more international (business is done in Portuguese, English, French, or Spanish), whereas in Russia, the language is still seen as a big barrier to entry. In accordance with this situation, Portugal saw its level of knowledge‐related activities to grow more than Russia. This increase in turn led to a higher increase in economic and social standards and a higher increase in the level of agile related activities. These results mean that even when a country has as large a continental dimension, as Russia, it is useful to become global in linguistic terms.
Nitrogen addition mediates the effect of soil microbial diversity on microbial carbon use efficiency under long‐term tillage practices
Authors: Zhang Mengni , Li Shengping , Wu Xueping , Zheng Fengjun , Song Xiaojun , Lu Jinjing , Liu Xiaotong , Wang Bisheng , Abdelrhmana Ahmed Ali , Degré Aurore
Published: April 2022

Tillage practices can influence soil microbial carbon use efficiency (CUE), which is critical for carbon cycling in terrestrial ecosystems. The effect of tillage practices could also be regulated by nitrogen (N) addition. However, the soil microbial mechanism relating to N fertilizer effect on microbial CUE under no‐tillage (zero‐tillage) is still unclear. We investigated how N fertilizer regulates the effect of tillage management on microbial CUE through changing microbial properties and further assessed the impact of microbial CUE on particulate (POC) and mineral‐associated organic matter carbon (MAOC). For this we used a 16‐year field experiment with no‐tillage (NT) and conventional tillage (CT), both of which combined with 105 (N1), 180 (N2), and 210 kg N ha−1 (N3) N application. We found that microbial CUE increased with increasing N application rate. NT increased microbial CUE compared with CT in the 0–10 cm. The bacterial and fungal diversities of NT were higher than CT and N application decreased their diversities in 0–10 cm. The partial least squares path model showed that bacterial and fungal diversity had a significant influence on microbial CUE. Furthermore, POC and MAOC under NT were higher than CT and they also increased with increasing N application rate. It suggested that increasing microbial CUE induced by N application had the potential to increase POC and MAOC. Overall, this study highlights that N addition can alter the effect of soil microbial diversity on CUE, which further improves our understanding to explain and predict the fractions of SOC (i.e., POC and MAOC) in tillage systems.
Hybrid‐Mode‐Family Kerr Optical Parametric Oscillation for Robust Coherent Light Generation on Chip
Authors: Zhou Feng , Lu Xiyuan , Rao Ashutosh , Stone Jordan , Moille Gregory , Perez Edgar , Westly Daron , Srinivasan Kartik
Published: April 2022

Optical parametric oscillation (OPO) using the third‐order nonlinearity () in integrated photonics platforms is an emerging approach for coherent light generation, and has shown great promise in achieving broad spectral coverage with small device footprints and at low pump powers. However, current nanophotonic OPO devices use pump, signal, and idler modes of the same transverse spatial mode family. As a result, such single‐mode‐family OPO (sOPO) is inherently sensitive in dispersion and can be challenging to scalably fabricate and implement. In this work, a novel scheme is proposed using different families of transverse spatial modes for pump, signal, and idler, which is termed as hybrid‐mode‐family OPO (hOPO). The hOPO shows unprecedented robustness in dispersion versus device geometry, pump frequency, and temperature. Moreover, the hOPO is capable of generating a few milliwatts of output signal power with a conversion efficiency of 8 and without competitive processes. This hOPO scheme is an important counterpoint to the existing sOPO approach, and is particularly promising as a robust method to generate coherent on‐chip visible and infrared light sources.
Dual‐Band Organic Photodetectors for Dual‐Channel Optical Communications
Authors: Lan Zhaojue , Lau Ying Suet , Cai Linfeng , Han Jiayin , Suen Chun Wai , Zhu Furong
Published: April 2022

The dual‐band organic photodetectors (OPDs) detect incoming light selectively in two different bands. This work demonstrates a bias‐switchable dual‐band OPD, achieving a fast‐switching speed of over 1000 times per second and a −3 dB cutoff frequency of > 100 kHz for high‐speed optical communications in two distinct bands, e.g., near‐infrared (NIR) and visible light. Visible‐blind NIR detection with a high responsivity of 435 mA W–1is realized for the OPDs operated under a small reverse bias of −1.0 V. NIR‐blind visible light detection with a responsivity of 325 mA W–1is obtained for the OPDs operated under a low forward bias of 1.0 V. Dual‐channel NIR/visible optical communication technique has been demonstrated, providing an opportunity for a plethora of applications in information electronics and the Internet‐of‐Things.
Nondestructive optical feedback systems for use during infrared laser sealing of blood vessels
Authors: Giglio Nicholas C. , Fried Nathaniel M.
Published: April 2022

Objectives

High‐power infrared lasers are capable of sealing blood vessels during surgery. A real‐time diagnostic feedback system utilizing diffuse optical transmission is characterized by nondestructive identification of vessel seals.

Materials and Methods

For real‐time diffuse optical transmission experiments, two approaches were studied. First, a low‐power (1.2 mW) visible aiming beam (635 nm) was used for diagnostics, co‐aligned with the therapeutic high‐power infrared beam (1470 nm). Second, the 1470 nm beam was used simultaneously for both therapy and diagnostics. For both studies, the 1470‐nm laser delivered 5 W for 5 seconds for unsuccessful seals (control) versus 30 W for 5 seconds for successful seals, using a linear beam profile (8.4 × 2 mm). Diffuse optical transmission signals were correlated with vessel burst pressures measured using a standard burst pressure setup.

Results

Diffuse optical transmission studies using the low‐power, 635‐nm aiming beam were promising. A decrease in the visible transmitted signal of 59 ± 11% was measured for successful seals versus 23 ± 8% for failed seals (p = 5.4E−8). The use of the high‐power, 1470‐nm infrared laser for simultaneous therapeutics and diagnostics proved inconsistent and unreliable, due in part to the dynamic and rapid changes in water content and absorption during the seal.

Conclusions

A low‐power, visible aiming beam, integrated with the therapeutic high‐power infrared diode laser, may be used as a real‐time diagnostic system for indicating successful laser seals, based on significant changes in optical scattering and diffuse optical transmission between native and coagulated compressed vessels. With further development, this simple and inexpensive optical feedback system may be integrated into a laparoscopic device for laser de‐activation upon successful vessel sealing.
Wholly Biobased Polyamide Thermoplastic Elastomer‐Cellulose Nanocomposites
Authors: Nurhamiyah Yeyen , Yoon Sungkwon , Chen Biqiong
Published: April 2022

Polymers play a prominent role in daily lives; however, there is a growing concern on the depleting fossil resources triggering the research for sustainable alternatives. Here, novel wholly biobased nanocomposites are prepared from polyamide 36,36 (PA36,36) thermoplastic elastomer and cellulose nanocrystals (CNCs). Further, the influence of CNC addition and CNC loading on the morphological features, thermal and mechanical properties of PA36,36 is studied. The presence of CNC in PA36,36 affects the thermal degradation of PA36,36. The additions of 10 and 30 wt% CNCs to the PA36,36 improve the tensile strength and Young's modulus by up to 700% and 750% to 9.6 and 6.8 MPa, respectively, while still maintaining relatively high elongation at break values. The hardness of the polymer increases significantly after the inclusion of CNC. The PA36,36/CNC nanocomposites also show relatively good resilience when exposed to 100% strain. Overall, these biobased thermoplastic elastomer nanocomposites can be potential alternatives for some existing rubbers with low or medium hardness.
Upgrading the mechanical properties of marine structural steel by enhancement of acicular ferrite formation
Authors: Amer A.E. , Hong S.H. , Shash A.Y.
Published: April 2022

This work reports the results of an investigation of the effect of magnesium addition on microstructure evolution, acicular ferrite formation together with the change in the mechanical properties of micro‐alloyed steel plates. The investigated steel is subjected to high heat input (4.5 kJ mm−1) simulating the thermal cycle of heat affected zones, conducted by induction heating in a computer controlled weld thermal cycle simulator. Both magnesium and magnesium free steel samples have carbon and aluminum contents of 0.08 wt.% and 0.009 wt.%, respectively, are investigated. The change in microstructure, hardness and crack tip opening displacement fracture toughness properties due to magnesium addition is evaluated, and compared with the other steel having the same chemical compositions but without Magnesium. The fracture toughness tests reveal the increase of magnesium steel‘s crack tip opening displacement values. In contrast, the hardness measuring presents the decrease of its hardness due to the decrease of martensite volume fraction and reduction in ferrite grain size. Optical and transmission electron microscopy observations detect some microstructural morphology that can affect the mechanical properties of such steels. Hence, the improved toughness of magnesium containing steel are attributed to both the generation of acicular ferrite nucleated within the matrix, refined microstructure and the bainite dominated microstructure in steel.
Transverse displacements of cracked beams on Pasternak soil
Authors: Imamović D. , Skrinar M.
Published: April 2022

The response analysis of cracked beams resting on elastic foundations can be conveniently and satisfactorily addressed by applying the simplified crack model within the 1D finite element model. For the very commonly implemented Winkler's soil model, the exact transverse displacements’ interpolation functions, the stiffness matrix, as well as the corresponding load‐vector for the linearly distributed continuous transverse load were recently presented in closed symbolic forms. This paper upgrades the existing 1D finite element solution to the more realistic Pasternak soil model. The derivation implements the exact Winkler soil model transverse displacements’ functions as interpolation functions of the Pasternak soil model. In this way, a complementary stiffness matrix is obtained which upgrades the existing Winkler solution into an approximate Pasternak soil model solution. Also this matrix is derived in closed symbolic form and it can be easily added to the existing finite element solutions. The implementation and the quality of the results are being presented through a comparative case study to support the discussed approach.
A new guardian map and boundary theorems applied to the stabilization of initialized fractional control systems
Authors: López‐Rentería Jorge A. , Aguirre‐Hernández Baltazar , Fernández‐Anaya Guillermo
Published: April 2022

In the present work, some generalizations of the boundary crossing theorem and the zero exclusion principle are given for fractional order initialized systems. A new guardian map for the maximal stability interval is proposed as well as its relation with the boundary theorems is established. An extension of the technique for linear time invariant fractional order initialized systems to determinate the maximal stability interval is derived from the guardian map defined as a monoparametric pseudo‐polynomials family. This technique is essentially the task of locating the zeros of the family of characteristic pseudo‐polynomials of a linear fractional order system inside the stability region. Finally, an illustrative example is also provided to show the technique.
Cascade Path Augmentation Unet for bladder cancer segmentation in MRI
Authors: Yu Jie , Cai Lingkai , Chen Chunxiao , Fu Xue , Wang Liang , Yuan Baorui , Yang Xiao , Lu Qiang
Published: April 2022

Background

Treatment choices for patients with bladder cancer (BCa) are determined by the presence of muscular invasion. The precise segmentation of the inner and outer walls (IW and OW), as well as the bladder tumor (BT), is crucial for improving computer‐aided diagnosis of muscle‐invasive bladder cancer (MIBC).

Purpose

To propose a novel deep learning‐based model to improve the segmentation accuracy of the IW, OW, and BT, which can be useful in clinical practice.

Methods

We proposed a Cascade Path Augmentation Unet (CPA‐Unet) network to conduct multi‐regional segmentation of the bladder using 1545 T2‐weighted MRI scans. The model employs a cascade strategy to eliminate the redundant information in the background. Unet is used to segment the bladder from the background in the rough segmentation. The path augmentation structure is used in the fine segmentation to mine multi‐scale features. Additionally, the partial dense connection is adopted as the skip connection module to concatenate the low‐ and high‐level sematic features.

Results

The CPA‐Unet is trained using 1391 T2WI slices and tested using 154 T2WI slices. In comparison to previous deep learning‐based methods, the CPA‐Unet achieves superior segmentation results in terms of Dice similarity coefficient (DSC) and Hausdorff distance (HD) (IW: DSC = 98.19%, HD = 2.07 mm; OW: DSC = 82.24%, HD = 2.62 mm; BT: DSC = 87.40%, HD = 0.76 mm).

Conclusions

Our proposed CPA‐Unet network is capable of segmenting the bladder into its IW and OW, as well as tumors. The segmentation results provide a reliable and effective foundation for computer‐assisted clinical diagnosis of MIBC.
HDR prostate brachytherapy plan robustness and its effect on in‐vivo source tracking error thresholds: A multi‐institutional study
Authors: Poder Joel , Koprivec Dylan , Dookie Yashiv , Howie Andrew , Cutajar Dean , Damato Antonio L. , Côté Nicolas , Petasecca Marco , Bucci Joseph , Rosenfeld Anatoly
Published: April 2022

Purpose

The purpose of this study was to examine the effect of departmental planning techniques on appropriate in‐vivo source tracking error thresholds for high dose rate (HDR) prostate brachytherapy (BT) treatments, and to determine if a single in‐vivo source tracking error threshold would be appropriate for the same patient anatomy.

Methods

The prostate, rectum, and urethra were contoured on a single patient transrectal ultrasound (TRUS) dataset. Anonymized DICOM files were disseminated to 16 departments who created an HDR prostate BT treatment plan on the dataset with a prescription dose of 15 Gy in a single fraction. Departments were asked to follow their own local treatment planning guidelines. Source positioning errors were then simulated in the 16 treatment plans and the effect on dose–volume histogram (DVH) indices calculated. Change in DVH indices were used to determine appropriate in‐vivo source tracking error thresholds. Plans were considered to require intervention if the following DVH conditions occurred: prostate V100% < 90%, urethra D0.1cc > 118%, and rectumtt Dmax > 80%.

Results

There was wide variation in appropriate in‐vivo source tracking error thresholds among the 16 participating departments, ranging from 1 to 6 mm. Appropriate in‐vivo source tracking error thresholds were also found to depend on the direction of the source positioning error and the endpoint. A robustness parameter was derived, and found to correlate with the sensitivity of plans to source positioning errors.

Conclusions

A single HDR prostate BT in‐vivo source tracking error threshold cannot be applied across multiple departments, even for the same patient anatomy. The burden on in‐vivo source tracking devices may be eased through improving HDR prostate BT plan robustness during the plan optimisation phase.
Effects of Ambient Ammonia-Nitrogen Exposure on Uric Acid and Urea Metabolic Pathways and Tissue Distribution in the Swimming Crab Portunus trituberculatus
Authors: Zhang Xin , Ren Qin , Tong Ruixue , Pan Luqing
Published: April 2022

Ammonia-nitrogen (ammonia-N) is an important threat factor to the development of the crustacean breeding industry; however, information on nitrogen metabolism remains limited. In this study, effects of ammonia-N on the metabolic pathways and tissue distribution of nitrogenous wastes were investigated in swimming crabs Portunus trituberculatus. The results showed that ammonia content in the hemolymph of crabs exposed to 1- and 5-mg/L NH4Cl (ammonia-N concentrations were 1.36 and 5.31 mg/L, respectively) significantly (P < 0.05) increased with time. The expression of xanthine oxidase was significantly up-regulated in gills and muscles but was significantly down-regulated in the hepatopancreas of crabs exposed to 1- and 5-mg/L NH4Cl after 6–12 h. The expression of uricase was significantly up-regulated in gills and muscles at 3 h, whereas it was significantly down-regulated in hepatopancreas during 6–12 h but up-regulated again after 24 h. Moreover, the expression levels of carbamoyl phosphate synthetase III and arginase were significantly up-regulated in gills and muscles but significantly down-regulated in the hepatopancreas of crabs exposed to 5-mg/L NH4Cl after 6–12 h. Furthermore, under 5-mg/L NH4Cl stress, trace amounts of uric acid were detected, which significantly increased in hepatopancreas and hemolymph at 3 h, in muscles at 6–12 h, and in gills at 6–24 h. In addition, similar to hemolymph ammonia, urea was also significantly increased after NH4Cl exposure. Moreover, uric acid was mainly stored in muscles and urea was primarily synthesized in the hepatopancreas. This study provides a theoretical basis for further study on the nitrogen metabolism mechanism in crustaceans.
‘The ghost of environmental history’: Analysing the evolving governance of communal rangeland resources in Machubeni, South Africa
Authors: Falayi Menelisi , Gambiza James , Schoon Michael
Published: April 2022

The need to effectively govern and manage communal rangeland resources has become more important over the past two decades, given the extent of biodiversity loss caused by a myriad of drivers interacting at different scales.

Using in‐depth interviews, participant observations and historical information from organisational records, we analysed the application of governance objectives between 1947 and 2017 and their corresponding rangeland condition outcome in Machubeni (South Africa) communal lands.

The results show that while the application of governance objectives varied through time, there has been a steady degradation of local rangeland resources since apartheid, due to internal and external drivers of change. This reveals a disconnection between management and resource conditions, suggesting that a return to effective governance alone will not necessarily result in improved rangeland condition in Machubeni, but that more radical steps such as prolonged periods of resting, reseeding and building individual and group agency, are needed. These findings can help practitioners working in post‐colonial territories to design effective rangeland management models.

Read the freePlain Language Summaryfor this article on the Journal blog.
Design of a Transparent System for Mutual Coupling Reduction of Microstrip Array Antennas with Confined Water
Authors: Rohaninezhad Mohammadreza , Ghayekhloo Alireza , Afsahi Majid , Denidni Tayeb A.
Published: April 2022

Herein, a new method for minimizing mutual coupling of an antenna array with confined water is proposed. In multiantenna systems, mutual coupling reduction is needed to sustain array signal processing efficiency. There are currently a variety of ways to suppress coupling, including defected ground, electromagnetic (EM) bandgaps, and advanced structures. The water absorption characteristic is devised in this innovative approach to minimize mutual coupling without a permanent alteration in the structure. Surface current between two antennas is cancelled using permittivity and water depth in a new configuration. A plexi‐glass confined water is added between the propagating elements to achieve this aim. The rectangular microstrip patch of transparent conducting components serves as the antenna array. Using scattering theories, numerical EM calculations, and anechoic chamber tests, the suggested technique shows a 15 dB decrease in coupling at center frequency (7 GHz). Other propagating functions have also been improved. The suggested framework can be used in multifunction communication networks, aerial vehicle antennas, solar panels, and naval communications because of its optical transparency.
Trivial and Topological Bound States in Bilayer Graphene Quantum Dots and Rings
Authors: Benchtaber Nassima , Sánchez David , Serra Llorenç
Published: April 2022

Herein, two different types of confinement in bilayer graphene by top and bottom gating with symmetrical microelectrodes are discussed and compared. Trivial confinement corresponds to the same polarity of all top gates, which is opposed to that of all bottom ones. Topological confinement requires the polarity of part of the top–bottom pairs of gates to be reversed. It is shown that the main qualitative difference between trivial and topological bound states manifests itself in the magnetic field dependence. The finding is illustrated with an explicit calculation of the energy spectrum for quantum dots and rings. Trivial confinement shows bunching of levels into degenerate Landau bands, with a non‐centered gap, while topological confinement shows no field‐induced gap and a sequence of state branches always crossing zero energy.
In vitro fertilization using sperm activated by ML‐2–3 isolated from Morinda lucida Bentham leaves
Authors: Ohta Tomoe , Uto Takuhiro , Shoyama Yukihiro , Sakyiamah Maxwell Mamfe , Appiah Alfred Ampomah , Tanaka Hiromitsu
Published: April 2022

Purpose

ML‐2–3 is a novel tetracyclic iridoid derived from Morinda lucida Bentham leaves. This compound has anti‐trypanosomal and anti‐leishmanial effects. In this study, the authors investigated effects of ML‐2–3 on in vitro fertilization (IVF) rates, motility, and acrosome reaction of the mouse sperm.

Methods

IVF was performed using sperm from BALB/cByJJcl mice treated with ML‐2–3. Computer‐assisted sperm analysis (CASA) was performed on the sperm of C57BL/6J mice to investigate sperm motility. The effect of ML‐2–3 on the acrosome reaction was examined by observing the fluorescence of sperm labeled with the acrosin‐EGFP transgene.

Results

ML‐2–3 improved IVF in BALB/cByJJcl mice with low fertilization rates. The optimum concentration of ML‐2–3 in sperm pre‐culture medium was 20 µM, and no significant toxicity of ML‐2–3 was observed in developing embryos at this concentration. ML‐2–3 affected sperm motility but not the acrosome reaction. ML‐2–3 increased the IVF rate of mouse sperm that had been refrigerated for 3 days.

Conclusions

ML‐2–3 can improve the outcome of IVF and motility without inducing the acrosome reaction in mice. These effects of ML‐2–3 on sperm behaviors are different from those of the similar drugs.
Fertilization, embryo culture, and clinical results using low lactate embryo culture medium for pre‐culture, insemination, and beyond
Authors: Kobanawa Masato
Published: April 2022

Purpose

We focused on the metabolism of oocytes in pre‐culture and insemination and compared these results between our existing fertilization medium, GEMS Fertilisation Medium (GEMS group) (Merck BioPharma) and Continuous Single Culture Medium—NX Complete (CSCM‐NXC group) (FUJIFILM Irvine Scientific).

Methods

Patients under 42 years of age were received controlled ovarian stimulation and oocytes were retrieved. Those were pre‐cultured and fertilized with either GEMS fertilization medium or CSCM‐NXC. After fertilization was confirmed, embryos were cultured using CSCM‐NXC in both groups. The embryos were cryopreserved at blastocyst stage (3BB or more, Gardner classification) and then transferred in HRT cycles.

Results

The fertilization rate of both groups was the same, but the 3PN rate was significantly lower in the CSCM‐NXC group. In terms of embryo culture results, the CSCM‐NXC group had a significantly higher rate of good quality blastocysts, high‐grade embryos, and embryos with a high degree of expansion.

Conclusions

The use of CSCM‐NXC, a low lactate embryo culture medium, from pre‐culture and for insemination, increases the energy metabolic efficiency of oocytes and cumulus cells, making it possible to supply sufficient energy ATP for fertilization and early division, which is thought to promote good embryonic development.
Early Literacy in Everyday Settings: Creating an Opportunity to Learn for Low‐income Young Children
Authors: Neuman Susan B. , Knapczyk Jillian
Published: April 2022

Persistent concerns about income and social inequality have raised questions about how to address opportunity gaps in access to literacy learning for low‐income young children. Recognizing the need to strengthen learning opportunities, this study examines how specially designed hybrid spaces within the ‘everyday’ place of a neighborhood laundromat might support children’s literacy development. Twenty laundromats in high‐poverty neighborhoods from a large urban city participated in the research: 10 in which small spaces were reconfigured to create literacy‐related play settings; 10, in which remained “business as usual” control sites. Conducted over two phases, the 7‐month study examined changes in children’s literacy activities resulting from the physical design changes alone, and subsequent changes when combined with a trusted messenger, a public librarian, who assisted in their activities. Results indicated that these hybrid spaces dramatically increased children’s time on literacy‐related activities, especially when given adult assistance, averaging 47‐minutes per child of sustained activity. These results suggest that intentionally‐designed everyday spaces may play an important role in increasing young children’s access to resources and opportunity to learn.
Highly Efficient and Reusable Polymer Supported Palladium Catalyst for Copper Free Sonogashira Reaction in Water
Authors: Sruthi Pambingal Rajan , Nimmi Puthan Purayil , Babu Sukumaran Santhosh , Anas Saithalavi
Published: April 2022

Development of a novel, greener and efficient heterogeneous catalytic system for copper free Sonogashira reaction in water is described. This novel catalyst can be easily prepared by a simple method through synthetic modification of nitrile group in Polyacrylonitrile (PAN) using monoethanolamine (MEA) followed by its complexation with palladium chloride (PdCl2). The resulting polymer Pd complex (mPAN‐Pd) was characterized by means of Fourier Transform Infrared Spectroscopy (FTIR), Energy‐Dispersive X‐ray Spectroscopy (EDAX), Inductively Coupled Mass Spectrometry (ICP‐MS) and X‐ray Photo Electron Spectroscopy (XPS) analyses. mPAN‐Pd was then explored as highly efficient heterogeneous catalyst for Sonogashira coupling reaction under copper and ligand free conditions in water affording the corresponding coupling products up to 97 % isolated yield. Moreover, the catalyst was recovered by simple filtration after the reaction and reused for next 5 cycles with excellent stability and activity. This is the first report on the use of ethanolamine modified PAN Pd (II) complex as an efficient heterogeneous catalyst for a coupling reaction.