bluuebunny/crossref_metadata_2025 huggingface dataset:
Par protein localization during the early development of Mnemiopsis leidyi suggests different modes of epithelial organization in the metazoa
Authors: Salinas-Saavedra Miguel , Martindale Mark Q
Published: July 2020

In bilaterians and cnidarians, epithelial cell-polarity is regulated by the interactions between Par proteins, Wnt/PCP signaling pathway, and cell-cell adhesion. Par proteins are highly conserved across Metazoa, including ctenophores. But strikingly, ctenophore genomes lack components of the Wnt/PCP pathway and cell-cell adhesion complexes raising the question if ctenophore cells are polarized by mechanisms involving Par proteins. Here, by using immunohistochemistry and live-cell imaging of specific mRNAs, we describe for the first time the subcellular localization of selected Par proteins in blastomeres and epithelial cells during the embryogenesis of the ctenophoreMnemiopsis leidyi. We show that these proteins distribute differently compared to what has been described for other animals, even though they segregate in a host-specific fashion when expressed in cnidarian embryos. This differential localization might be related to the emergence of different junctional complexes during metazoan evolution.
Revealing architectural order with quantitative label-free imaging and deep learning
Authors: Guo Syuan-Ming , Yeh Li-Hao , Folkesson Jenny , Ivanov Ivan E , Krishnan Anitha P , Keefe Matthew G , Hashemi Ezzat , Shin David , Chhun Bryant B , Cho Nathan H , Leonetti Manuel D , Han May H , Nowakowski Tomasz J , Mehta Shalin B
Published: July 2020

We report quantitative label-free imaging with phase and polarization (QLIPP) for simultaneous measurement of density, anisotropy, and orientation of structures in unlabeled live cells and tissue slices. We combine QLIPP with deep neural networks to predict fluorescence images of diverse cell and tissue structures. QLIPP images reveal anatomical regions and axon tract orientation in prenatal human brain tissue sections that are not visible using brightfield imaging. We report a variant of U-Net architecture, multi-channel 2.5D U-Net, for computationally efficient prediction of fluorescence images in three dimensions and over large fields of view. Further, we develop data normalization methods for accurate prediction of myelin distribution over large brain regions. We show that experimental defects in labeling the human tissue can be rescued with quantitative label-free imaging and neural network model. We anticipate that the proposed method will enable new studies of architectural order at spatial scales ranging from organelles to tissue.
An analog to digital converter controls bistable transfer competence development of a widespread bacterial integrative and conjugative element
Authors: Carraro Nicolas , Richard Xavier , Sulser Sandra , Delavat François , Mazza Christian , van der Meer Jan Roelof
Published: July 2020

Conjugative transfer of the integrative and conjugative element ICEclcinPseudomonasrequires development of a transfer competence state in stationary phase, which arises only in 3–5% of individual cells. The mechanisms controlling this bistable switch between non-active and transfer competent cells have long remained enigmatic. Using a variety of genetic tools and epistasis experiments inP. putida, we uncovered an ‘upstream’ cascade of three consecutive transcription factor-nodes, which controls transfer competence initiation. One of the uncovered transcription factors (named BisR) is representative for a new regulator family. Initiation activates a feedback loop, controlled by a second hitherto unrecognized heteromeric transcription factor named BisDC. Stochastic modelling and experimental data demonstrated the feedback loop to act as a scalable converter of unimodal (population-wide or ‘analog’) input to bistable (subpopulation-specific or ‘digital’) output. The feedback loop further enables prolonged production of BisDC, which ensures expression of the ‘downstream’ functions mediating ICE transfer competence in activated cells. Phylogenetic analyses showed that the ICEclcregulatory constellation with BisR and BisDC is widespread amongGamma-andBeta-proteobacteria, including various pathogenic strains, highlighting its evolutionary conservation and prime importance to control the behaviour of this wide family of conjugative elements.
48-Hour Hospice Home Immersion Encourages Osteopathic Medical Students to Broaden Their Views on Dying and Death
Authors: Gugliucci Marilyn R. , Padmanabhan Divya L. , Silberstein Emily B.
Published: July 2020

To augment learning about interprofessional palliative and end-of-life care, the University of New England College of Osteopathic Medicine immersed 2 second-year osteopathic medical students in an 18-bed acute care hospice home in Scarborough, Maine, for 48 hours. The students worked with an interprofessional staff and independently to provide patient care, family support, and postmortem care. For data collection, students wrote in journals before the immersion experience (prefieldwork), while living in the hospice home (fieldwork), and for 10 days following the immersion experience (postfieldwork). The students recorded their subjective and objective reporting of observations, experiences, feelings, and patient/family encounters. Data analyses included a review of the journals, identifying thematic categorizations, and coding through content analysis. Three themes identified in the students’ journals reflected shared experiences: (1) shifting perspectives, (2) path to family acceptance, and (3) emotional journey. The students learned how to converse with patients and families about end-of-life care while ensuring attainment of patients’ goals. They also learned about the importance of helping patients enjoy life's simple pleasures like taking them outside to enjoy the sunshine, and they learned to trust themselves when handling emotional and difficult situations. Each student gained confidence in her ability to help guide patients through this stage of life.
Report on 7 Years’ Experience Implementing an Undergraduate Medical Curriculum for Osteopathic Medical Students Using Entrustable Professional Activities
Authors: Reynolds Tristan S. , Frothingham Christopher , Carreiro Jane E. , Branda Angela , Schuenke Mark D. , Tucker Kerry L. , Daly Frank , Willard Frank H.
Published: July 2020

Calls for changes in undergraduate medical education and the advent of the single graduate medical education accreditation system have challenged the osteopathic medical profession to maintain its identity and distinctiveness while adapting to innovations. For the osteopathic medical profession to thrive, its colleges must provide students with an educational framework that solidifies their osteopathic identity. The authors developed an integrated anatomy-clinical skills course at the University of New England College of Osteopathic Medicine, Osteopathic Clinical Skills, that used the performance benchmarks of the Entrustable Professional Activities and the Osteopathic Core Competencies for Medical Students from the American Association of Colleges of Osteopathic Medicine. A primary tenet of osteopathic medicine is the relationship of structure and function; Osteopathic Clinical Skills fuses anatomical sciences with clinical skills and underscores this tenet in clinical diagnosis and treatment. This article describes the development and implementation of an educational framework that integrates anatomy, physical examination, history taking, and other clinical skills with osteopathic medicine principles and practice and osteopathic manipulative treatment.
Deep learning based Sequential model for malware analysis using Windows exe API Calls
Authors: Catak Ferhat Ozgur , Yazı Ahmet Faruk , Elezaj Ogerta , Ahmed Javed
Published: July 2020

Malware development has seen diversity in terms of architecture and features. This advancement in the competencies of malware poses a severe threat and opens new research dimensions in malware detection. This study is focused on metamorphic malware, which is the most advanced member of the malware family. It is quite impossible for anti-virus applications using traditional signature-based methods to detect metamorphic malware, which makes it difficult to classify this type of malware accordingly. Recent research literature about malware detection and classification discusses this issue related to malware behavior. The main goal of this paper is to develop a classification method according to malware types by taking into consideration the behavior of malware. We started this research by developing a new dataset containing API calls made on the windows operating system, which represents the behavior of malicious software. The types of malicious malware included in the dataset are Adware, Backdoor, Downloader, Dropper, spyware, Trojan, Virus, and Worm. The classification method used in this study is LSTM (Long Short-Term Memory), which is a widely used classification method in sequential data. The results obtained by the classifier demonstrate accuracy up to 95% with 0.83 $F_1$-score, which is quite satisfactory. We also run our experiments with binary and multi-class malware datasets to show the classification performance of the LSTM model. Another significant contribution of this research paper is the development of a new dataset for Windows operating systems based on API calls. To the best of our knowledge, there is no such dataset available before our research. The availability of our dataset on GitHub facilitates the research community in the domain of malware detection to benefit and make a further contribution to this domain.
Identification of predictive factors of the degree of adherence to the Mediterranean diet through machine-learning techniques
Authors: Arceo-Vilas Alba , Fernandez-Lozano Carlos , Pita Salvador , Pértega-Díaz Sonia , Pazos Alejandro
Published: July 2020

Food consumption patterns have undergone changes that in recent years have resulted in serious health problems. Studies based on the evaluation of the nutritional status have determined that the adoption of a food pattern-based primarily on a Mediterranean diet (MD) has a preventive role, as well as the ability to mitigate the negative effects of certain pathologies. A group of more than 500 adults aged over 40 years from our cohort in Northwestern Spain was surveyed. Under our experimental design, 10 experiments were run with four different machine-learning algorithms and the predictive factors most relevant to the adherence of a MD were identified. A feature selection approach was explored and under a null hypothesis test, it was concluded that only 16 measures were of relevance, suggesting the strength of this observational study. Our findings indicate that the following factors have the highest predictive value in terms of the degree of adherence to the MD: basal metabolic rate, mini nutritional assessment questionnaire total score, weight, height, bone density, waist-hip ratio, smoking habits, age, EDI-OD, circumference of the arm, activity metabolism, subscapular skinfold, subscapular circumference in cm, circumference of the waist, circumference of the calf and brachial area.
Epitope-based chimeric peptide vaccine design against S, M and E proteins of SARS-CoV-2 etiologic agent of global pandemic COVID-19: an in silico approach
Authors: Rahman M. Shaminur , Hoque M. Nazmul , Islam M. Rafiul , Akter Salma , Rubayet-Ul-Alam ASM , Siddique Mohammad Anwar , Saha Otun , Rahaman Md. Mizanur , Sultana Munawar , Crandall Keith A. , Hossain M. Anwar
Published: July 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of the ongoing pandemic of coronavirus disease 2019 (COVID-19), a public health emergency of international concerns declared by the World Health Organization (WHO). An immuno-informatics approach along with comparative genomics was applied to design a multi-epitope-based peptide vaccine against SARS-CoV-2 combining the antigenic epitopes of the S, M, and E proteins. The tertiary structure was predicted, refined and validated using advanced bioinformatics tools. The candidate vaccine showed an average of ≥90.0% world population coverage for different ethnic groups. Molecular docking and dynamics simulation of the chimeric vaccine with the immune receptors (TLR3 and TLR4) predicted efficient binding. Immune simulation predicted significant primary immune response with increased IgM and secondary immune response with high levels of both IgG1 and IgG2. It also increased the proliferation of T-helper cells and cytotoxic T-cells along with the increased IFN-γ and IL-2 cytokines. The codon optimization and mRNA secondary structure prediction revealed that the chimera is suitable for high-level expression and cloning. Overall, the constructed recombinant chimeric vaccine candidate demonstrated significant potential and can be considered for clinical validation to fight against this global threat, COVID-19.
An analysis of the perceived causes leading to task-failure in resistance-exercises
Authors: Emanuel Aviv , Rozen Smukas Isaac Isur , Halperin Israel
Published: July 2020

Background

While reaching task-failure in resistance-exercises is a topic that attracts scientific and applied interest, the underlying perceived reasons leading to task-failure remain underexplored. Here, we examined the reasons subjects attribute to task-failure as they performed resistance-exercises using different loads.

Methods

Twenty-two resistance-trained subjects (11-females) completed one Repetition-Maximum (RM) tests in the barbell squat and bench-press. Then, in the next two counterbalanced sessions, subjects performed two sets to task-failure in both exercises, using either 70% or 83% of 1RM. Approximately 30 seconds after set-completion, subjects verbally reported the reasons they perceived to have caused them to reach task-failure. Their answers were recorded, transcribed, and thematically analyzed. The differences between the frequencies of the identified categories were then tested using a mixed logistic regression model.

Results

The most commonly reported reason was muscle fatigue (54%, p < 0.001), mostly of the target muscles involved in each exercise. However, remote muscles involved to a lesser extent in each exercise were also reported. Approximately half of the remaining reasons included general fatigue (26%), pain (12%), cardiovascular strain (11%), and negative affect (10%), with the latter three reported more often in the squat (p = 0.022).

Conclusions

In contrast to our expectations, task-failure was perceived to be caused by a range of limiting factors other than fatigue of the target muscles. It now remains to be establishedwhether different perceived limiting factors of resistance-exercises lead to different adaptations, such as muscular strength and hypertrophy.
How “dirty” is the Dark Triad? Dark character profiles, swearing, and sociosexuality
Authors: Garcia Danilo
Published: July 2020

Malevolent character traits (i.e., the Dark Triad: Machiavellianism, narcissism, and psychopathy) are associated to emotional frigidity, antagonism, immoral strategic thinking, betrayal, exploitation, and sexual promiscuity. Despite the fact that character is a complex adaptive system, almost every study has solely investigated the linear association between malevolent character and attitudes towards both swearing and sociosexual orientation (i.e., behavior, attitude, and desire regarding promiscuous sexual behavior). In contrast, the aim in this set of studies was to evaluate these associations in relation to specific profiles of malevolent character (i.e., the Dark Cube). In two studies participants responded to the Dark Triad Dirty Dozen, the Taboo Words’ Offensiveness and Usage Inventories (i.e., attitudes towards 30 swear words’ level of offensiveness and usage) (Study 1:N1= 1,000) and the Sociosexual Orientation Inventory Revised (Study 2:N2= 309). Participants were clustered according to all eight possible combinations based on their dark trait scores (M/m = high/low Machiavellianism; N/n = high/low narcissism; P/p = high/low psychopathy). The results of this nonlinear approach suggested that the frequent usage, not level of offensiveness, of swear words was associated to Machiavellianism and narcissism. In other words, individuals with high levels in these traits might swear and are verbally offensive often, because they do not see swearing as offensive (cf. with the attitude-behavior-cognition-hypothesis of taboo words; Rosenberg, Sikström & Garcia, 2017). Moreover, promiscuous sociosexual attitude and desire were related to each dark traitonlywhen the other two were low. Additionally, promiscuous sociosexual behavior was not associated to these malevolent character traits. That is, individuals high in the dark traits are willing to and have the desire to engage in sexual relations without closeness, commitment, and other indicators of emotional bonding. However, they do not report high levels of previous sexual experience, relationships, and infidelity. Hence, they approve and desire for it, but they are not actually doing it. The use of person-centered and non-linear methods, such as the Dark Character Cube, seem helpful in the advancement of a coherent theory of a biopsychosocial model of dark character.
Ocular Morbidity Pattern and Presentation among Residence of a Semi-Urban Community in Rivers State, Nigeria
Authors: Chinawa N. E. , Odogu V. K. , Ezeh E. I. , Anyiam F. E.
Published: July 2020

Background: Ocular diseases vary in different parts of the world and are influenced by racial, geographic, socioeconomic and cultural factors. The common ocular diseases worldwide are cataract, glaucoma, conjunctivitis, corneal ulcers, uveitis, refractive errors, pterygium.

Methods: This was a community-based cross-sectional descriptive study carried out in Rumuokwuta community in Rivers state. Socio-demographic and clinical presentation information was obtained from an interviewer-administered questionnaire. Distant visual acuity was assessed at 6 m with the Snellen’s chart while near vision assessment was at 33 cm with a Sussex vision R near vision chart. External eye examination was with pen touch while fundoscopy was with direct Ophthalmoscope. Data were analyzed with the Statistical Package for Social Sciences (SPSS) v20. Using descriptive statistics, categorical variables were presented in the form of frequencies and percentages (%) and summary statistics in means and standard deviations (SD). Using inferential statistics, the Chi-Square (X2) test of significance was used to associate categorical variables and a p-value ≤ 0.05 was considered statistically significant.

Results: A total of 114 subjects were examined.The mean age was 41.41± 15.49 years. The male to female ratio was 2:3. About 70.5% and 76.2% respectively in Right Eye and Left Eye had normal vision better than 6/18, while 27.1% and 21.9% respectively in Right Eye and Left Eye had a low vision (VA between 6/18 and 6/60). About 2.6% in either eye were blind. The three most common ocular conditions were Glaucoma (13.95%), Refractive error (13.02%) and Presbyopia (12.56%).

Conclusion: The commonest cause of Ocular morbidity in this study are glaucoma, refractive error and presbyopia. The age distribution of a study area was a significantly associated factor in the frequency of visual impairment and blindness.
Immediate Effects of Altered Auditory Feedback on Associated Motor Behaviors of People Who Stutter
Authors: Kyriakou Kyriaki , Seal Brenda
Published: July 2020

Aims: This investigation explored the immediate effects of an altered auditory feedback device on motor behaviors associated with stuttering in monologue and conversation with and without the device and it also investigated the effects of an AAF device on stuttering frequency.

Methods: Fifteen adults with a diagnosis of stuttering and exhibited associated motor behaviors participated in this study. The author analyzed associated motor behaviors by type and frequency and statistically compared associated motor behaviors per frequency of stuttering events during monologue and conversation with and without an altered auditory feedback device.

Results: An analysis of associated motor behaviors during monologue and conversation with and without altered auditory feedback showed a predominance of associated motor behaviors involving the eyes, head, lips and hands. Altered auditory feedback significantly reduced the overall frequency of these four behaviors in monologue and conversation. Altered auditory feedback also decreased the frequency of associated motor behaviors per stuttering event in both monologue and conversation. An analysis of effect sizes associated with the statistical results revealed a larger magnitude of effect on reducing the frequency of associated motor behaviors than on reducing associated motor behaviors per stuttering event in the altered auditory feedback condition. Additionally, the Pearson correlation test designated the following positive correlations between the percentage of syllables stuttered and AMBs (r=.76 and r=.74) and percentage of syllables stuttered and AMBs per stuttering event (r=.56 and r=.41 in monologue and conversation respectively).

Conclusions: People who exhibit motor behaviors associated with their stuttering may more confidently and frequently use an altered auditory feedback device to decrease the associated motor behaviors of their stuttering in order to more easily communicate and socialize and consequently improve the quality of their life.
Serum Levels of Adenosine Deaminase and Insulin in Type 2 Diabetes Mellitus
Authors: Singh Yengkhom Upen , Noarem Sangeeta , Devi Potsangbam Jenny , Kshetrimayum Victoria , Marbaniang Racheal Sweet , Debbarma Uma , Singh Ksh. Birendra , Singh Maisnam Amuba
Published: July 2020

Aim: To estimate the levels of serum adenosine deaminase and insulin in patients with type 2 diabetes mellitus and healthy subjects and to find the correlation between serum adenosine deaminase and serum insulin in type 2 diabetes mellitus.

Study Design: Case-control study.

Place and Duration of the Study: Department of Biochemistry and Department of Medicine, Regional Institute of Medical Sciences (RIMS), Imphal, Manipur between October 2017 to September 2019.

Methodology: 40 cases of type 2 diabetes mellitus were recruited from the Medicine Outpatient Department, RIMS and 40 healthy controls of age and sex-matched were recruited from those who came for a routine health check-up. Serum adenosine deaminase was measured by the calorimetry method and serum insulin was measured by ELISA method. The data were analyzed using statistical tools like Chi-square test, Independent sample t-test, Pearson’s Correlation through SPSS 21.0.

Results: Mean serum adenosine deaminase was (38.97±8.853)U/L in cases and (20.05±5.309)U/L in controls and it was statistically significant (P<0.001). Mean serum insulin in cases was found to be (18.09±5.554) μIU whereas in controls, it was (9.06±2.509) μIU which is statistically significant (p<0.001). Serum adenosine deaminase and insulin were found to be positively correlated to each other (r= 0.956, p<0.001).

Conclusion: Serum adenosine deaminase and serum insulin were significantly increased in type 2 diabetes mellitus and positively correlated to each other. Serum adenosine deaminase may be used as a prognostic marker for the pathogenesis of type 2 diabetes mellitus.
Chronic Periaortitis – Review and Presentations
Authors: Taribagil Savita , Bhattacharya Sabrina , Taribagil Priyal , Saravanan Vadivelu , Bhattacharya Vish
Published: July 2020

Chronic periaortitis is a rare inflammatory condition predominantly affecting the abdominal segment of the aorta. This can present as IgG4 related inflammatory disease, idiopathic retroperitoneal fibrosis, perianeurysmal retroperitoneal fibrosis and inflammatory abdominal aortic aneurysm (IAAA). Aortitis can also be a manifestation of a number of rheumatological large vessel vasculitides such as Takayasu arteritis and giant cell arteritis (GCA). We present three interesting cases of chronic periaortitis and a literature review. The first case shows a classic picture of IgG4 periaortitis. The second case illustrates periaortitis with retroperitoneal fibrosis, ureteric involvement and hydronephrosis, following abdominal aortic aneurysmal stenting. The final case presents as widespread periaortitis due to Takayasu's disease involving the entire aorta including the arch and root of the subclavian artery.
A Novel Green Synthesis Method of Poly (3-Glycidoxypropyltrimethoxysilane) Catalyzed by Treated Bentonite
Authors: Embarek Nadia , Sahli Nabahat
Published: July 2020

The present work focuses on the preparation and characterization of poly(3-Glycidoxypropyltrimethoxysilane) (PGPTMS) under mild conditions. Ring-opening polymerization of the 3-Glycidoxypropyltrimethoxysilane (GPTMS) is initiated with the bentonite of Maghnite-H+ (Mag-H+), an ecologic and low-cost catalyst. The evolution of epoxy ring-opening was studied in bulk and in solution using CH2Cl2 as solvent, as well as the influences of several factors such as the amount of Mag-H+, polymerization time and temperature on the yield of polymer were investigated. The best polymer yield (30 %) was obtained in bulk polymerization at room temperature (20 °C) for a reaction time 8 h, and it’s increases with time and reaches 68 % for 7 days. The structures of the obtained polymers (PGPTMS) were confirmed respectively by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). The thermal properties of the prepared polymers were given by Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA), the Tg of PGPTMS is recorded at -31.27 °C, and it is thermally stable with a degradation start temperature greater than 300 °C, all  decomposition stopped at 600 °C. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
One-Pot Access to Diverse Functionalized Pyran Annulated Heterocyclic Systems Using SCMNPs@BPy-SO3H as a Novel Magnetic Nanocatalyst
Authors: Chen Ke , He Guangzu , Tang Qiong , Yousif Qahtan A.
Published: July 2020

The SCMNPs@BPy-SO3H catalyst was prepared and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Vibrating Sample Magnetometry (VSM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Afterwards, its capability was efficiently used to promote the one-pot, three-component synthesis of pyrano[2,3-c]pyrazole and 2-amino-3-cyano-pyrano[3,2-c]chromen-5(4H)-one derivatives. The strategy resulted in the desired products with excellent yields and short reaction times. The SCMNPs@BPy-SO3H catalyst was readily recovered using a permanent magnetic field and it was reused in six runs with a slight decrease in catalytic activity. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Dehydrogenation of Cyclohexanol to Cyclohexanone Over Nitrogen-doped Graphene supported Cu catalyst
Authors: Mageed Alyaa. K. , Radiah Dayang A. B. , Salmiaton A. , Izhar Shamsul , Razak Musab Abdul , Ayodele Bamidele Victor
Published: July 2020

In this study, the dehydrogenation of cyclohexanol to cyclohexanone over nitrogen-doped reduced graphene oxide (N-rGO) Cu catalyst has been reported. The N-rGO support was synthesized by chemical reduction of graphite oxide (GO). The synthesized N-rGO was used as a support to prepare the Cu/N-rGO catalyst via an incipient wet impregnation method. The as-prepared support and the Cu/N-rGO catalyst were characterized by FESEM, EDX, XRD, TEM, TGA, and Raman spectroscopy. The various characterization analysis revealed the suitability of the Cu/N-rGO as a heterogeneous catalyst that can be employed for the dehydrogenation of cyclohexanol to cyclohexanone. The catalytic activity of the Cu/N-rGO catalyst was tested in non-oxidative dehydrogenation of cyclohexanol to cyclohexanone using a stainless-steel fixed bed reactor. The effects of temperature, reactant flow rate, and time-on-stream on the activity of the Cu/N-rGO catalyst were examined. The Cu/N-rGO nanosheets show excellent catalytic activity and selectivity to cyclohexanone. The formation of stable Cu nanoparticles on N-rGO support interaction and segregation of Cu were crucial factors for the catalytic activity. The highest cyclohexanol conversion and selectivity of 93.3% and 82.7%, respectively, were obtained at a reaction temperature of 270 °C and cyclohexanol feed rate of 0.1 ml/min. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Synergistic Effect of Microwave Calcination and Sonophotocatalytic Activity of TiO2-Montmorillonite on The Degradation of Direct Yellow 106 and Disperse Violet 1
Authors: Labib Issma , Boutoumi Hocine , Khalaf Hussein
Published: July 2020

The TiO2-pillared montmorillonite nanoparticles (TiO2-Mt) were prepared by the sol-gel method, then applied for the elimination of dyes in solution: CI Direct Yellow 106 (DY106) (azo dye) and CI Disperse Violet 1 (DV1) (anthraquinone dye) by the sonocatalytic, photocatalytic and sonophotocatalytic processes, in order to test the efficiency of photocatalysts, while photolysis, sonolysis, and sonophotolysis tests have been done previously. The photocatalysts (TiO2-Mt) were characterized by X-ray Diffraction (XRD), X-ray Fluorescence analysis (XRF), Brunauer-Emmet-Teller (BET), Scanning Electron Microscopy (SEM) methods, thermal and thermogravimetric analysis (TG/DTA) and the zero load point (pHpzc). Aqueous solutions of dye of an initial concentration (50 mg/L), in the presence of 1 g/L of photocatalyst, were irradiated using a mercury lamp (Hg) of 40 Mw/cm2 and put in contact with an ultrasonic probe with a frequency of 20 kHz and a power of 750 W, providing the ultrasound. The results obtained indicate that a weak, good and better dye degradation rate has been observed successively by the application of the sonocatalytic, photocatalytic and sonophotocatalytic processes, where the latter has shown a synergistic effect, while the photocatalyst TiO2-Mt/MW showed significant efficiency during the degradation, due to the beneficial effect of the microwave calcination mode. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Sulfonated Hydrothermal Carbon-Based Catalyzed Esterification under Microwave Irradiation: Optimization and Kinetic Study
Authors: Tumkot Laddawan , Quitain Armando T. , Kida Tetsuya , Laosiripojana Navadol , Shotipruk Artiwan , Boonnoun Panatpong
Published: July 2020

In this study, the esterification reaction of oleic acid (OA) with methanol was investigated in the presence of a sulfonated hydrothermal carbon-based catalyst under microwave irradiation. The reaction conditions were optimized using response surface methodology based on a central composite design. Three following variables were studied: methanol to OA molar ratios (2.5:1–7.5:1), reaction time (50–70 min) and catalyst loading (2–5 wt.%) to provide a statistical model with the coefficient of regression (R2) of 0.9407. Based on the model, the optimum OA conversion of 95.6% was predicted at 5.8:1 methanol to OA molar ratio, 60 min and 3.05 wt.% catalyst loading. The experimental validation indicated that the model gave a good prediction of OA conversion (2.8% error). Furthermore, the reaction was found to be reasonably described by the pseudo-first order kinetics. The dependency of the reaction rate constant on temperatures gave a value of the activation energy of 64 kJ/mol. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Mesoporous Ce-doped Ti:Ash Photocatalyst Investigation in Visible Light Photocatalytic Water Pretreatment Process
Authors: Suliman Abdulkarim Abdulrahman Mohamed , Isha Ruzinah , Seman Mazrul Nizam Abu , Ahmad Abdul Latif , Roslan Jamil
Published: July 2020

The treatment of organic pollutants in water including semiconductor photocatalysis is a promising approach to disinfect water. The objective of this study is to investigate the effect of Ce loaded on mesoporous Ti:Ash catalyst for water pretreatment process. The mesoporous Ti:Ash catalyst that doped with Ce was synthesized through wet impregnation method with 5%, 10%, and 15% weight percentage of Ce doped on 40:60 Ti:Ash. The photocatalytic properties were characterized through X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2 adsorption-desorption studies and diffuse reflectance UV–vis absorption spectroscopy. It is found that the Ti:Ash nanocomposites doped with Ce shifted the light absorption band-edge position to the visible region. Moreover, the Ce doped Ti:Ash has large surface area and pore diameter. The Ce doping could significantly improve the absorption edge of visible light and adjust the cut-off absorption wavelength from 404 nm to 451, 477 and 496 nm for 5%, 10% and 15% Ce-doped mesoporous Ti:Ash catalysts, respectively. As the Ce doping ratio increased, the band gaps decreased from 3.06 eV to 2.53 eV. The most contaminant reduction up to 45% was achieved when Ti:Ash:Ce 40:55:5 was used. Higher Ce loading on the photocatalyst may reduce the photocatalyst performance because supernumerary metal loading on TiO2 can block TiO2 defect sites which are necessary for the adsorption and photoactivation. The OPFA also acts as an adsorbent for some pollutants besides, reducing the water salinity. It can be deduced that the hybrid TiO2 photocatalyst that synthesized with OPFA and doped with Ce has huge potential to treat seawater prior to commercial seawater desalination process. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Graphitization of Coconut Shell Charcoal for Sulfonated Mesoporous Carbon Catalyst Preparation and Its Catalytic Behavior in Esterification Reaction
Authors: Fahmi Fahmi , Widiyastuti Widiyastuti , Setyawan Heru
Published: July 2020

Here, we reported the utilization of coconut shell charcoal used for solid acid catalysts and its performance in the esterification reaction of acetic acid and methanol. The graphitization of coconut shell charcoal was carried out by the calcination and KOH activation at the temperature of 400 °C for an hour and continued at the temperature of 800 °C for an hour under nitrogen flow resulted in graphitic carbon. The effect of the addition of KOH activation was observed by varied the weight ratio of coconut shell charcoal as raw material (RM) and KOH. The selected weight ratio of RM:KOH was 1:1, 1:2, and 1:4. The resulted graphitic carbon was sulfonated by heating with the sulfuric acid to obtain a solid acid catalyst. The sulfonic time was evaluated for 5 and 10 hours. The generated particles were characterized to examine the morphology, the crystallinity, the specific surface area, the chemical bonding, and the ionic capacity using Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD), nitrogen gas absorption-desorption, Fourier Transform Infrared Spectroscopy (FTIR), and titration method, respectively. The best condition for graphitization of raw material is the use of RM:KOH = 1:4, resulting in the highest surface area reaching 1259.67 m2/g and the most dominant of the sulfonic group of −SO3 bond. Furthermore, increasing the sulfonating time from 5 to 10 hours led to the increase of the yield of esterification reaction from 85% to 96.57% for graphite synthesized using RM:KOH = 1:4. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Kinetics of Starch Degradation during Extrusion Cooking of Steady State Flow Konjac (Amorphophallus oncophyllus) Tuber Flour in a Single Screw Extruder
Authors: Kumoro Andri Cahyo , Retnowati Diah Susetyo , Ratnawati Ratnawati
Published: July 2020

The presence of glucomannan in Konjac (Amorphophallus oncophyllus) tuber flour has promoted its various applications, especially in the food, drink, drug delivery and cosmetics. Starch is the main impurity of Konjac tuber flour. Although the common wet refining method may result in a high purity Konjac tuber flour, it is very tedious, time consuming and costly. This research aimed to study the kinetics of starch degradation in the extrusion cooking process of dry refining method to produce high quality Konjac tuber flour. In this research, Konjac tuber flour with 20% (w/w) moisture was extruded in a single screw extruder by varying screw speeds (50, 75, 100, 125, 150 and 175 rpm) and barrel temperatures (353, 373, 393, 413 and 433 K). The results showed that the starch extrusion cooking obeys the first reaction order. The reaction rate constant could be satisfactorily fitted by Arrhenius correlation with total activation energy of 6191 J.mol−1 and pre-exponential factor of 2.8728×10−1 s−1. Accordingly, thermal degradation was found to be the primary cause of starch degradation, which shared more than 99% of the energy used for starch degradation. Based on mass Biot number and Thiele modulus evaluations, chemical reaction was the controlling mechanism of the process. The results of this research offer potential application in Konjac tuber flour refining process to obtain high quality flour product. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Frontmatter (Front Cover, Editorial Team, Indexing, and Table of Contents)
Authors: Istadi Istadi
Published: July 2020

Frontmatter (Front Cover, Editorial Team, Indexing, and Table of Contents)
Transition‐Metal‐Catalyzed Alkyne Hydroarylation with Arylmetals and Aryl Halides
Authors: Yamamoto Yoshihiko
Published: July 2020

The aryl alkene is one of the most ubiquitous molecular scaffolds found in diverse natural products, materials, and pharmaceuticals. Aryl alkenes are also essential synthetic intermediates in both industrial and academic laboratories. Nevertheless, traditional preparative methods have fundamental disadvantages, such as the necessity of lengthy synthetic operations and difficulty in the site‐ and stereoselective construction of multiply substituted derivatives. The development of a more straightforward and site‐ and stereoselective method to prepare aryl alkenes has therefore been an important objective in organic chemistry. A particularly attractive method to synthesize aryl alkenes is transition‐metal‐catalyzed alkyne hydroarylation using aryl donor reagents, which proceeds through the formal addition of Ar–H across the carbon–carbon triple bond of an alkyne. This chapter provides an overview of alkyne hydroarylations catalyzed by homogeneous metal catalysts. The mechanism, selectivity, scope and limitations, and experimental conditions of transition‐metal‐catalyzed alkyne hydroarylations are surveyed according to the aryl donor reagent and its role in the reaction; namely, (1) alkyne hydroarylations using arylmetal reagents (alkyne carbometallation/protonation), and (2) alkyne hydroarylations using aryl halides (reductive Heck reaction).
[3 + 2] Cycloadditions of Azomethine Imines
Authors: Grošelj Uroš , Svete Jurij
Published: July 2020

In spite of their late discovery in the middle of 20
th
century, the importance of azomethine imines and their [3+2] cycloaddition reactions has grown constantly throughout the decades. Today, [3+2] cycloadditions of azomethine imines have become indispensable in the preparation of pyrazole derivatives with all degrees of saturation. The structural diversity of azomethine imines is wide and comprises acyclic,
C
,
N
‐cyclic,
N
,
N
‐cyclic, and
C
,
N
,
N
‐cyclic 1,3‐dipoles. Although electron‐deficient dipolarophiles are preferred, electron‐rich dipolarophiles, such as enol ethers and enamines, are also commonly used in these reactions. Compared to cyclocondensation methods and [3+2] cycloadditions with diazoalkanes and nitrile imines, [3+2] cycloadditions with azomethine imines provide access to a greater diversity of pyrazole derivatives with all degrees of saturation. As with other 1,3‐dipolar cycloadditions, a concerted and nearly synchronous mechanism has been proposed for most [3+2] cycloadditions of azomethine imines, although a stepwise mechanism may be viable in some cases. Several examples of asymmetric [3+2] cycloadditions of azomethine imines that afford non‐racemic cycloadducts with high enantioselectivity have been reported. These asymmetric cycloadditions are performed with various types of transition metal catalysts and organocatalysts, and indicate their potential for the asymmetric synthesis of saturated pyrazole derivatives. Finally, many examples of copper‐catalyzed and thermal, strain‐promoted [3+2] cycloadditions of azomethine imines (in particular sydnones) clearly indicate wide applicability of these reactions in bioconjugation, fluorescent labelling, materials functionalization, and other applications outside the realm of pure organic synthesis.
Ionotronics Based on Horizontally Aligned Carbon Nanotubes
Authors: Peng Ran , Pan Yueyue , Li Zhi , Zhang Shuailong , Wheeler Aaron R. , Tang Xiaowu (Shirley) , Liu Xinyu
Published: July 2020

Controlled ion transport through ion channels of cell membranes regulates signal transduction processes in biological systems and has also inspired the thriving development of ionic electronics (ionotronics or iontronics) and biocomputing. However, for constructing highly integrated ionic electronic circuits, the integration of natural membrane‐spanning ion channel proteins or artificial nanomembrane‐based ionic diodes into planar chips is still challenging due to the vertically arranged architecture of conventional nanomembrane‐based artificial ionic diodes. Here, a new design of ionic diode is reported, which allows chip‐scale integration of ionotronics, based on horizontally aligned nanochannels made from multiwalled carbon nanotubes (MWCNTs). The rectification of ion transport through the MWCNT nanochannels is enabled by decoration of oppositely charged polyelectrolytes on the channel entrances. Advanced ionic electronic circuits including ionic logic gates, ionic current rectifiers, and ionic bipolar junction transistors (IBJT) are demonstrated on planar nanofluidic chips by stacking a series of ionic diodes fabricated from the same bundles of MWCNTs. The horizontal arrangement and facile chip‐scale fabrication of the MWCNT ionic diodes may enable new designs of complex but monolithic ionotronic systems. The MWCNT ionic diode may also prove to be an excellent platform for investigation of electrokinetic ion transport in 1D carbon materials.
Metal–Organic‐Framework‐Derived Co2P Nanoparticle/Multi‐Doped Porous Carbon as a Trifunctional Electrocatalyst
Authors: Liu Haitao , Guan Jingyu , Yang Shaoxuan , Yu Yihuan , Shao Rong , Zhang Zhengping , Dou Meiling , Wang Feng , Xu Qiang
Published: July 2020

Developing efficient and low‐cost replacements for precious metals as electrocatalysts active in electrochemical reactions—the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR)—is a top priority in renewable energy technology. In this work a highly active and very stable trifunctional electrocatalyst composed of Co2P embedded in Co, N, and P multi‐doped carbon has been synthesized using zeolitic imidazolate frameworks as precursors. The synergistic effects between Co2P and the multi‐heteroatom‐doped carbon substrates afford materials having electrocatalytic activities for HER, OER, and ORR, which are comparable—or even superior to—those of commercial RuO2 or Pt/C catalysts. Density functional theory calculations show that Co2P has a higher density of states at the Fermi level than ConP (0 < n < 2), which promotes electron transfer and intermediates adsorption in the catalytic process. Zinc–air batteries and water splitting devices assembled using the materials as electrode electrocatalysts show good performance and outstanding stability. This work represents a breakthrough in improving the catalytic performance of non‐precious metal electrocatalysts for OER, HER, and ORR, and opens new avenues for clean energy generation.
Graphoepitaxy of Large Scale, Highly Ordered CsPbBr3 Nanowire Array on Muscovite Mica (001) Driven by Surface Reconstructed Grooves
Authors: Li Chun , Zhao Liyun , Fan Hua , Shang Qiuyu , Du Wenna , Shi Jianwei , Zhao Yue , Liu Xinfeng , Zhang Qing
Published: July 2020

Muscovite mica is a widely used van der Waals epitaxial substrate for growing high‐quality low‐dimensional crystals owing to its nondangling surface. However, there is a recent debate on the surface atomic arrangement, especially the lattice symmetry, of the cleaved muscovite (001), which is not only crucial for the crystal heteroepitaxy dynamics on the substrate, but also fundamental to optoelectronic devices based on few‐layered muscovite. Herein, the surface reconstruction of the cleaved muscovite (001) is investigated by using high‐resolution atomic force microscopy, which reveals that the removal of interlayer potassium induces a distortion to aluminosilicate tetrahedra by depressing the connecting oxygen, breaking the intrinsic quasi‐hexagonal symmetry and resulting in bunched grooves along the [100] direction. These grooves enable vapor‐phase graphoepitaxy of millimeter‐scale, unidirectional single‐crystalline CsPbBr3 nanowire arrays without inducing unfavorable structural defects. Optical spectroscopy studies demonstrate their high optical quality and potential for anisotropic optoelectronic applications. These results further the understanding of epitaxial dynamics of muscovite (001), promote muscovite a powerful graphoepitaxy platform for anisotropic nanostructures, and provide insights into the development of few‐layered muscovite optoelectronic/proton devices.
Graphitic Carbon Nitride Polymer as a Recyclable Photoredox Catalyst for Decarboxylative Alkynylation of Carboxylic Acids
Authors: Guo Jiaqi , Wang Yating , Li Yuhang , Lu Kailin , Liu Shihui , Wang Wei , Zhang Yongqiang
Published: July 2020

Visible‐light‐induced heterogeneous photocatalysis for decarboxylative alkynylation has been performed. The using of cheap, metal‐free and recyclable graphitic carbon nitride (g‐C3N4) as the photoredox catalyst in the process enables the facile transformation of a variety of carboxylic acids into structurally diverse alkyne‐containing molecular architectures under mild and environmentally‐benign conditions. Notably, the heterogeneous nature of the reaction system allows for the recovery and reuse of the catalyst in multiple runs without loss of reactivity. The photocatalytic reactions could also be performed in a continuous flow fashion and scaled up to gram‐scale. Furthermore, the preparative power of this strategy is further highlighted by its application in the 1, 2‐amido alkynylation of unactivated alkenes.

magnified image