A novel magnetically recoverable copper catalyst was successfully fabricated through the immobilization of Cu(OAc)2 on the surface of silica-coated magnetic Fe3O4 nanoparticles (Fe3O4@SiO2) functionalized with amine and thiol groups as ligand. The as-fabricated Fe3O4@SiO2-Imine/Thio-Cu(II) nanocomposite was fully characterized by FT-IR spectroscopy, SEM, EDX, TEM, XRD, VSM, ASS and ICP-OES techniques. The Fe3O4@SiO2-Imine/Thio-Cu(II) nanocomposite exhibited high catalytic activity in the synthesis of biologically active diaryl sulfones. According to our research on the literature, this is the first report in the use of magnetic copper nanocatalyst for the synthesis of diaryl sulfones via sulfonylative Suzuki–Miyaura cross-coupling reactions. This method gives notable advantages such as easy separation of the catalyst by external magnetic field; excellent yields, short reaction times, nontoxic metal catalyst, and simplicity of operation make this method a facile tool for the synthesis of diaryl sulfones.
Cryptosporidium is a coccidian protozoan parasite infecting alimentary system and epithelial respiratory tract of humans and a wide range of vertebrates such as mammals, birds, reptiles, and fish. This study was carried out in Al-Kut city, Iraq, in two major hospitals: Al-Kut Hospital for Gynecology, Obstetric and Pediatric and Al-Karama Teaching Hospital, which included collection of stool samples from diarrheal patients. 96 stool samples taken from patients with different ages and both genders were examined by multiplex PCR technique. The results showed that the percentage of Cryptosporidium spp. infection was 39.6% and 4.2% for C. parvum and C. hominis, respectively. There are no statistically significant associates between gender and Cryptosporidium infection. The higher infection for C. parvum (41.2%) appeared in females, while the higher infection for C. hominis was found in male (4.8%). The study showed that the percentage of C. parvum infection in the rural areas is more than the urban, where the percentage in rural areas (52.9%) showed a significant difference at p = 0.004, while the infection rate for C. hominis was 6.7% in urban area. Regarding the water source, higher cryptosporidiosis rate was found in participants who used bottled water than in those who used tap water, and there is statistical significant between C. parvum infection and water source (p = 0.03), while the high infection in individuals who used bottled water were 58%. The present study aimed to determine the common Cryptosporidium species in diarrhea samples.
This article critically studies coronavirus (COVID-19) pandemic news in the press. The article attempts to study the way the news of COVID-19 is used for political and ideological purposes. In order to achieve the aim, two newspapers namely, The New York Times from the United States of America and Global Times from China are selected. Van Dijk’s news schemata framework is used for the analysis of the reports selected from the two newspapers. Van Dijk’s news schemata is crucial for the analysis of any news story (report) whether such a news story is taken from a news channel or a newspaper and whether broadcasted or printed. Based on data analysis, the article found out that the news of COVID-19 has been politicized and used for ideological interests. The article recommends that pandemics should not be politicized, instead we should work together to save our lives and live peacefully.
Undoubtedly and unfortunately, COVID-19 pandemic has been politicized in media see Abbas (Int J Semiot Law, 2020), Rui Zhang (Media Asia 48:89–107, 2021). Although vaccines play a crucial role in eliminating the pandemic, they have been politicized by media. This article aims to show how COVID-19 vaccines are politicized in the press. The article collects some selected reports on vaccines taken from American and Chinese media. The reports are analyzed according to an analytical framework suggested by the researcher. The framework and data collection and description are clearly presented in the method section. Based on data analysis, the article shows that COVID-19 vaccines have been politicized. The study recommends that diseases and vaccines should not be politicized. In other words, we should respect and trust science and our scientists for no other purpose than to reach herd immunity and overcome a dangerous pandemic that has taken and is still taking thousands of innocent lives.
Sleep apnea (SA) is a common respiratory disorder, especially among obese people. It is caused by either the relaxation of the upper respiratory tract muscles or the failure of the neural signal to reach the muscles responsible for breathing, both of which interrupt the patient’s sleep–wake cycles. The traditional method for diagnosing this disorder, based on polysomnography, is complicated, vexing, expensive, time-consuming, and requires both sleep centers and specialized staff capable of connecting electrodes to the patient’s body. This paper proposes an SA prediction system based on merging five soft computing algorithms, specifically, combining the multi-verse optimizer (MVO) with an artificial neural network (ANN) to leverage measurements from heart rate, SpO2, and chest movement sensors. The most substantial novelty of this research is the hybridization of MVO and ANN (MVO-ANN), which improves the ANN performance by selecting the best learning rate and number of neurons in hidden ANN layers. This enables highly accurate prediction of sleep apnea events. This work’s experimental results reveal that the MVO-ANN performs better than other algorithms, with mean absolute errors of 0.042, 0.202, and 0.166 for training, testing, and validation of the ANN. In addition, the SA prediction system achieved an accuracy of 98.67%, a sensitivity of 96.71%, and a specificity of 99.24%. These results provide good evidence that the proposed method can reliably predict respiratory events in people suffering from SA.
During environmental testing, scientists face the problem of developing and designing a new type of sensor electrode with distinguished stability, high activity, and cost-effectiveness to detect acetaminophen (ACE). Density functional theory (DFT) calculations were used to investigate the interaction and electrical response of Zn-doped and pristine boron nitride nanocones (BNNCs) with and to ACE with the disclination angle of 240°. The adsorption energy for ACE in the Zn-doped was − 56.94 kJ.mol−1. This value for BNNCs was approximately − 26.11 kJ.mol−1. Furthermore, after the adsorption of ACE, the value of band gap (Eg) for Zn-doped BNNCs decreased significantly (from 4.01 to 3.10 eV), thereby increasing the electrical conductivity. However, Eg value of the pristine BNNCs decreased marginally after the adsorption of ACE. Compared with the pristine BNNCs, the Zn-doped BNNCs could be considered promising materials for the detection of ACE and could be employed in electronic sensors. In the Zn-doped BNNCs, the molecular and electrostatic interactions and the creation of Zn–O bond played key roles in the adsorption of ACE. The Zn-doped BNNCs had other merits such as slight recovery time which was approximately 7.09 ms for the desorption of ACE at ambient temperature.
In this study, blend nanofibrous scaffolds were electrospun from polycaprolactone/gelatin (PCL/Gel) blend solutions reinforced by bone morphogenetic protein (BMP)-modified graphene oxide (GO). SEM results showed that uniform and bead-less nanofibers with 270 nm average diameter were obtained from electrospun of PCL/Gel blend solutions. Tensile strength test and contact angle measurement demonstrated that addition of PCL led to higher mechanical and physical properties of the resulting nanofibers. The addition of PCL as well as GO in the blend supports the suitable mechanical strength in the body media. The loading of BMP-modified graphene in the Gel/PCL structure caused the formation of nanofibrous substrate with great resemblance to bone tissue. Gel/PCL-G hybrid nanofibers revealed good biocompatibility in the presence of human osteosarcoma cells, and no trace of cellular toxicity was observed. The cells grown on the scaffolds exhibited a spindle-like and broad morphology and almost uniformly covered the entire nanofiber scaffold. Graphical abstract Gel/PCL nanofibers reinforced by graphene oxide-immobilized bone morphogenetic protein was prepared as a promising safe and biocompatible nanofiber with high antibacterial activity for bone tissue engineering.
The ACI 544-2R introduced a qualitative test to compare the impact resistance of fibrous concretes under repeated falling-mass impact loads, which is considered to be a low-cost, quick solution for material-scale impact tests owing to the simplified apparatus, test setup and procedure, where none of the usual sophisticated sensors and data acquisition systems are required. However, previous studies showed that the test results are highly scattered with noticeably unacceptable variations, which encouraged researchers to try to use statistical tools to analyze the scattering of results and suggest modifications to reduce this unfavorable disadvantage. The current article introduces a state-of-the-art literature review on the previous and recent research on repeated impact testing of different types of fibrous concrete using the ACI 544-2R test, while focusing on the scattering of results and highlighting the adopted statistical distributions to analyze this scattering. The influence of different mixture parameters on the variation of the cracking and failure impact results is also investigated based on data from the literature. Finally, the article highlights and discusses the literature suggestions to modify the test specimen, apparatus and procedure to reduce the scattering of results in the ACI 544-2R repeated impact test. The conducted analyses showed that material parameters such as binder, aggregate and water contents in addition to the maximum size of aggregate have no effect on the variation of test results, while increasing the fiber content was found to have some positive influence on decreasing this variation. The survey conducted in this study also showed that the test can be modified to lower the unfavorable variations of impact and failure results.
Background: Iraq's health care system has gradually declined after several decades of wars, terrorism, and UN economic sanctions. The Oncology Unit at Children's Welfare Teaching Hospital (CWTH) in Baghdad was lacking basic facilities and support. To address this shortcoming, a humanitarian and educational partnership was established between CWTH and Sapienza University of Rome (SUR). Methods: We investigated the outcomes of 80 online and 16 onsite educational sessions and 142 teleconsultation sessions from 2006 to 2014. We also determined the outcomes of pathology reviews by SUR of 1216 tissue specimens submitted by CWTH from 2007 until 2019 for second opinions. The primary outcomes were discordance, concordance, and changes among clinical diagnoses and pathology review findings. The measures included the frequency of teleconsultation and tele-education sessions, the topics discussed in these sessions, and the number of pathology samples requiring second opinions. Findings: A total of 500 cases were discussed via teleconsultations during the study period. The median patient age was 7 years (range, 24 days to 16·4 years), and the cases comprised 79 benign tumors, 299 leukemias, 120 lymphomas, and 97 solid tumors. The teleconsultation sessions yielded 27 diagnostic changes, 123 confirmed diagnoses, and 13 equivocal impacts. The pathology reviews by SUR were concordant for 996 (81·9%) cases, discordant for 186 (15·3%), and inconclusive for 34 (2·8%). The major cause of discordance was inadequate immunohistochemical staining. The percentage of discordance markedly decreased over time (from 40% to 10%). The cause of the improvement is multifactorial: training of two CWTH pathologists at SUR, better immunohistochemical staining, and the ongoing clinical and pathologic telemedicine activities. The partnership yielded 12 publications, six posters, and three oral presentations by CWTH investigators. Interpretation: The exchange of knowledge and expertise across continental boundaries meaningfully improved the diagnoses and management of pediatric cancer at CWTH.
The adsorption process of 5-Fluorouracil (5FU) drugs on Aluminum nitride nanotubes surface (AlNNTs) have been evaluated through density functional theory (DFT). The DFT results show that the interaction of AlNNTs with the F atoms of 5FU drugs is strong due to the fact that the amount of adsorption energy was about −29.65 kcal.mol⁻¹. Conversely, the interaction of the 5FU through O atoms with the AlNNTs was weaker due to the lower value of adsorption energy. Also, based on the values of Gibbs free energy, the 5FU adsorption on the surfaces of AlNNTs was spontaneous. In addition, based on natural bond orbital (NBO) analysis, the direction of charge transfer was from fluorine’s σ orbitals of the drug to nitrogen’s and aluminum’s n* orbitals of AlNNTs with a considerable amount of transferred energy. Based on the obtained results, 5FU drug’s tendency toward interaction with AlNNTs is favorable. During the adsorption of 5FU drug onto the AlNNTs, a significant changed in the electrical band gap (Eg) were seen, resulting in increased electrical conductance. The current research is devoted to investigating the potentials of AlNNTs for 5FU anticancer drugs delivery in a bio-based environment.
We used nicorandil, a K-ATP channel opener, to study the role of these channels in the amelioration of renal ischemia/reperfusion (I/R)-induced pancreatic injury, and the possible involvement of PI3K/Akt/mTOR signaling pathway. Forty-two male Wistar rats were included in this study, six were sacrificed for extraction of bone marrow mesenchymal stem cells (BM-MSCs) and conducting the in-vitro work, the others were included in vivo study and equally divided into six groups. Group 1 (sham control), but groups 2–6 were subjected to bilateral renal I/R: Group 2 (I/R); Group 3 (I/R-NC), treated with nicorandil; Group 4 (I/R-MSCs), treated with BM-MSCs; Group 5 (I/R-MSCC), treated with nicorandil-preconditioned BM-MSCs; Group 6 (I/R-NC-MSCC), treated with both systemic nicorandil and preconditioned BM-MSCC. Renal injury and subsequent pancreatic damage were detected in the I/R group by a significant increase in serum urea, creatinine, fasting glucose, and pancreatic enzymes. The pancreatic tissues showed a reduction in cellularity and a significant decrease in the expression of the cell survival pathway, PI3K/Akt/mTOR, in the I/R group compared to the control. Preconditioning MSCs with nicorandil significantly enhanced the proliferation assay and decreased their apoptotic markers. Indeed, combined systemic nicorandil and nicorandil-preconditioning maintained survival of MSC in the pancreatic tissue and amelioration of apoptotic markers and pancreatic TNF-α production. Histologically, all treated groups revealed better pancreatic architecture, and increased area % of anti-insulin antibody and CD31, which were all best observed in the NC-MSCC group. Thus, using K-ATP channel opener was efficient to enhance PI3K/Akt/mTOR expression levels (in vivo and in vitro).
Preplaced aggregate fibrous concrete (PAFC) is a revolutionary kind of concrete composite that is gaining popularity and attracting the interest of academics from across the world. PAFC is a uniquely designed concrete prepared by stacking and packing premixed fibers and coarse aggregate in a steel mold. The gaps between the fibers and aggregates are subsequently filled by injecting a cement grout with high flowability. This study investigates the impact performance of three different sizes of PAFC beams. Steel and polypropylene fibers were used in a 3% dosage to make three different beam sizes, measuring 550 × 150 × 150 mm, 400 × 100 × 100 mm, and 250 × 50 × 50 mm. According to ACI Committee 544, all beams were subjected to a drop weight flexural impact test. Compressive strength, impact energies at initial crack and failure, ductility index, and failure mode were evaluated. Additionally, analytical modeling was used to compute the failure impact energy for the fibrous beams. The results showed that the addition of fibers increased the capacity of the tested beams to absorb greater flexural impact energy. Compared to polypropylene fibers, steel fibers had better crack propagation and opening resistance because of their higher tensile strength and crimped and hooked end configuration. For all large-size beams, the analysis of the percentage increase in impact energy at the failure stages was found to be 5.3 to 14.6 times higher than the impact energy at cracking.
Computational Thinking (CT) is very useful in the process of solving everyday problems for undergraduates. In terms of content, computational thinking involves solving problems, studying data patterns, deconstructing problems using algorithms and procedures, doing simulations, computer modeling, and reasoning about abstract things. However, there is a lack of studies dealing with it and its skills that can be developed and utilized in the field of information and technology used in learning and teaching. The descriptive research method was used, and a test research tool was prepared to measure the level of (CT) consisting of (24) items of the type of multiple-choice to measure the level of "CT". The research study group consists of (100) third-year students studying at the University of Baghdad in Computer Science within the scope of (2020-2021). The results are detailed.
Recently, advanced composite materials have been widely used in numerous applications due to their superior properties. However, their sensitivities to damages during impact loading event limits their usage. In this regards, the influence of yarn hybridisation on the mechanical and thermal performance of composite laminates have been studied using low velocity impact, compression after impact (CAI), flexural and thermal conductivity tests. Two types of composite laminates were manufactured using hybrid yarns (S-glass and polypropylene [PP]) and S-glass yarns through the combination of commingling and core-wrapping methods and converted to non-crimp cross-ply preforms for both laminates. C-scan tests and cross-section microscopy examinations were adopted to identify the damaged areas of impacted laminates and explain the damage failures, which occurred during impact loadings. Results revealed that the hybrid laminates displayed higher damage area reduction compared to glass composites. Although the hybrid composite laminates illustrated considerably lower compressive strength, their residual compressive strength (damage tolerance) was significantly higher than glass composites. Fractography analysis has illustrated that the new damage failure modes such as intra-yarn cracks have been observed in the hybrid yarns laminates. These damage modes have contributed for higher energy absorpsion leading to an enhancement of the damage tolerance of the hybrid laminates. Furthermore, the incorporation of PP fibres resulted in a reduction of thermal conductivity of hybrid laminates compared to pure glass laminates.
Background The sudden and quick propagation of coronavirus-19 disease (COVID-19) has disrupted face-to-face lectures and practical sessions at Iraqi universities. E-learning has surfaced in most countries as an alternative way to continue educational programs. This study aimed to determine the degree of satisfaction and perceived barriers among college students with E-learning. Methods Students of two Iraqi universities studying through an online platform participated in this cross-sectional study. An online survey questionnaire was used to assess student perceptions of the level of satisfaction with and barriers to E-learning. Participants' non-identifying demographics were also collected. Results The majority of students (70.9%) were females, and more than half (57.9%) were from the Faculty of Science. About 64.8% of the students were not satisfied with the E-learning experience. Only 35.5% of the students attended synchronous electronic classes while the rest used asynchronous learning activities. Students’ level of satisfaction was poor, as only 6.4% of students strongly believed that tutoring was informative and that technology and educational technology were adequate. On the contrary, 69% of students strongly agreed that E-learning saved them time and money. Barriers that were perceived by the student were slow internet speed, power interruption, and the lack of face-to-face interaction. Conclusions E-learning has significant barriers that require investment in infrastructures and teaching skills development to make students learning satisfactory.
A new family of two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides that were discovered and developed at Drexel University in 2011, which is called MXene and is applicable for several critical applications. These so-called MXene structures possess excellent properties e.g., rich surface chemistry, electronic structures, high electrical conductivity, hydrophilicity, thermal and mechanical stability, and large specific surface area, which have attracted tremendous attention. This review article will focus on some most recent progress and review comprehensively their fabrication methods and compositing with polymers and metals. A major part has been associated with the electrochemical applications, medical, flame retardance effect in a polymer matrix, and electromagnetic shielding properties. In addition, briefly, we will delve into a brief discussion on the current limitations, and future research needs, along with the various corresponding challenges in order to provide a better understanding of these new 2D materials.
A hybrid auxetic structure named a re‐entrant chiral auxetic structure (RCA) was recently developed based on topological features of both re‐entrant and chiral auxetic honeycombs. In this study, the in‐plane quasi‐static and dynamic performances of the (RCA) are compared. Experimental specimens for both the quasi‐static and dynamic tests were designed to have identical dimensions and fabricated from polyamide12 (PA12) using an additive manufacturing process, Multi Jet Fusion (MJF). Compressive tests were conducted at constant velocities of 0.066 mm/s on a Zwick Roell machine and of 5 m/s on an Instron VHS 8800 high speed machine for quasi‐static and dynamic compressions, respectively. Numerical models were developed using ABAQUS/Explicit and verified by experiments. Results evidenced that performances of the RCA were sensitive to the crushing velocity. Moreover, the base material (PA12) displayed poor ductility under impact loads, therefore, fracture of the structural members dominates the deformation of the structure when it was dynamically crushed. Energy absorption of specimens that were quasi‐statically crushed outperformed those under dynamic compression. Furthermore, discrepancy in Poison’s ratio curves was observed under quasi‐static and dynamic tests due to the change in the deformation modes. This article is protected by copyright. All rights reserved.
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