bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing the tropical forest cover change in northern parts of Sonitpur and Udalguri district of Assam, India
Authors: Mahato Ranjit , Nimasow Gibji , Nimasow Oyi Dai , Bushi Dhoni
Published: March 2021

Sonitpur and Udalguri district of Assam possess rich tropical forests with equally important faunal species. The Nameri National Park, Sonai-Rupai Wildlife Sanctuary, and other Reserved Forests are areas of attraction for the tourists and wildlife lovers. However, these protected areas are reportedly facing the problem of encroachment and large-scale deforestation. So, this study attempts to estimate the forest cover change in the area through integrating the remotely sensed data of 1990, 2000, 2010, and 2020 with Geographic Information System. The Maximum Likelihood algorithm based supervised classification shows acceptable agreement between the classified image and the ground truth data with an overall accuracy of about 96% and a Kappa coefficient of 0.95. The results reveal a forest cover loss of 7.47% from 1990 to 2000 and 7.11% from 2000 to 2010. However, there was a slight gain of 2.34% in forest cover from 2010 to 2020. The net change of forest to non-forest was 195.17 km2 in the last forty years. The forest transition map shows a declining trend of forest remains forest till 2010 and a slight increase after that. There was a considerable decline in the forest to non-forest (11.94% to 3.50%) from 2000-2010 to 2010-2020. Further, a perceptible gain was also observed in the non-forest to the forest during the last four decades. The overlay analysis of forest cover maps show an area of 460.76 km2 (28.89%) as forest (unchanged), 764.21 km2 (47.91%) as non-forest (unchanged), 282.67 km2 (17.72%) as deforestation and 87.50 km2 (5.48%) as afforestation. The study found hotspots of deforestation in the closest areas of National Park, Wildlife Sanctuary, and Reserved Forests due to encroachments for human habitation, agriculture, and timber/fuelwood extractions. Therefore, the study suggests an early declaration of these protected areas as Eco-Sensitive Zone to control the increasing trends of deforestation.
Protective effect of Bmscs-derived exosomes on testicular ischemia-reperfusion injury in rats
Authors: Tian Hu , Zhang Wan-song , Yang Cheng , Zhou Jun-hao , Zhou Ran-ran , Guo Wen-bin , Liu Cun-dong
Published: March 2021

Background: Testicular Ischemia reperfusion injury(IRI) is a major pathophysiological process of surgical reduction after testicular torsion, and oxidative stress is the main injury factor. However, the role of BMSCs-derived exosomes in testicular IRI and its mechanism have not been reported. In this study, we investigated the protective effect of bone marrow mesenchymal stem cell-derived exosomes against testicular ischemia-reperfusion injury.Results: BMSCs were successfully isolated and cultured from rat bone marrow, and exosomes secreted by BMSCs were successfully extracted. In vivo experiment: The testicular torsion rat model was established, and various biochemical indexes of oxidative stress and testicular tissue HE was detected in the sham operation group, testicular torsion group and bone marrow mesenchymal stem cell-derived exosome treatment group. In vitro experiment: H2O2 was used to construct TM4 and GC1 oxidative stress models, and various biochemical indexes of oxidative stress and corresponding pathway proteins were detected in the control group, H2O2 group and bone marrow mesenchymal stem cell-derived exosome treatment group.Conclusion: BMSCs-derived exosomes can be absorbed by rat spermatogonia and have antioxidant and anti-inflammatory protective effects against testicular ischemia-reperfusion injury。
Springback and Longitudinal Bow in Chain-Die Forming U and Hat Channels
Authors: Liang Zhenye , Liu Yang , Zou Tianxia , Li Dayong , Ding Shichao , Xiao Hua , Shi Lei , Peng Yinghong
Published: March 2021

Chain-die forming is an emerging sheet metal technique for manufacturing advanced high strength steel (AHSS) products. Springback and longitudinal bow are two of the major shape defects in gradual forming. In this study, the springback and longitudinal bow of AHSS in chain-die forming of hat and U profiles are investigated through experiment and finite element simulation. The disparity of springback along the longitudinal direction and disparate longitudinal bow signifies complex deformation processes of chain-die forming. Finite element simulation of the chain-die forming process gives an insight into the formation of non-uniform springback and longitudinal bow. The gradual forming process by one die block after another causes bending and reverse-bending deformation in the web area and the redundant deformation of the sheet metal, which further leads to non-uniform bending moment and accumulated stresses along the longitudinal direction. At the same time, the redundant deformation will also result in the longitudinal strain on the edge, while the downhill deformation decreases the maximum longitudinal strain at the edge and introduces the longitudinal strain on the web. The different non-uniform longitudinal strain distribution along the transversal direction causes disparate longitudinal bow behaviors for chain-die formed AHSS hat and U profiles, downward bowing and upward bowing respectively. By the established model, the disparate springback and longitudinal bow behavior can be determined, which also contribute to the process design for chain-die formed AHSS products.
The Effects of Three Months of Aerobic Dance on Hippocampal Volume and Cognition in Elderly People with Amnestic Mild Cognitive Impairment: A Randomized Controlled Trial
Authors: Zhu Yi , Gao Yaxin , Qi Ming , Xiao Ming , Wu Han , Ma Jinhui , Zhong Qian , Ding Hongyuan , Zhou Qiumin , Ali Nawab , Zhou Li , Zhang Qin , Wu Ting , Wang Wei , Sun Cuiyun , Thabane Lehana , Zhang Ling , Wang Tong
Published: March 2021

Whether dancing could increases the hippocampal volume of seniors with amnestic mild cognitive impairment(aMCI) remains debatable. The aim of the present study was to investigate the influence of aerobic dance on hippocampal volume and cognition after three months' aerobic dance in older adults with aMCI. In this randomized controlled trial, 68 elderly people with aMCI were randomized to either aerobic dance group or the control group using 1:1 allocation ratio. Specially designed aerobic dance routine was performed by the dance group three times a week for three months, while all participants received monthly health care education after inclusion. MRI with a 3.0 T MRI scanner and cognitive assessments were performed before and after intervention. The high-resolution 3D T1-weighted anatomical images were acquired for the analysis of hippocampal volume. A total of 35 participants (mean age: 71.51 ± 6.62 years) were randomized into aerobic dance group and 33(mean age:69.82 ± 7.74 years ) into control group, and all the data was analyzed based on the intention to treat (ITT) method. Patients in the treatment group showed increased volume in the right hippocampus (mean difference [MD] in right hippocampus volume over 3 months 0.13; 95% confidence interval [CI] 0.05, 0.21; p<0.001) and memory enhancement (MD in Memory Scale-Revised Logical Memory change over 3 months 2.12; 95% CI -0.06, 4.13; p = 0.02) compared to the control group. In conclusion, three months of aerobic dance could increase the volume of right hippocampus and improve episodic memory in elderly persons with aMCI. This study was registered on the Chinese Clinical Trial Registry (www.chictr.org.cn). Registration number：ChiCTR-INR-15007420.
Preparation of Hydrothermally Solidified Materials from Waste Cathode Ray Tube Panel Glass for Construction Applications
Authors: Xu Qingbo , Zhang Jing , Li Shunyi
Published: March 2021

Solidification of cathode ray tube (CRT) panel glass was carried out using a hydrothermal processing method. In this way, the glass powder was first compacted in a mold at 20 MPa, and then hydrothermally cured in an autoclave under saturated steam pressure at 200 ℃ for 6 hours. The CRT panel glass was then hydrothermally solidified by the formation of tobermorite (Ca5Si6O16(OH)2·4H2O), which was encouraged by the addition of slaked lime (Ca(OH)2). The final solidified specimen’s strength was heavily depended on the amount of tobermorite formed, with higher concentrations of tobermorite producing commensurately greater mechanical strength. With the addition of slaked lime at 20%-30% by mass, the specimen achieved a flexural strength of approximately 16 MPa, which is sufficiently great for using as a construction material. As such, there is cause to believe that the hydrothermal processing method used here may have substantial potential for the product of high-quality recycled CRT panel glass with properties suitable for utilization as a construction material.
Undetected but widespread: the cryptic invasion of non-native cattail (Typha spp.) in a Pacific Northwest estuary
Authors: Stewart Daniel James , Hood W. Gregory , Martin Tara G.
Published: March 2021

Early detection of invasive species is an important predictor of management success. Non-native narrow-leaved cattail (Typha angustifolia) has been detected in the Fraser River Estuary (FRE) in recent decades, but questions around their degree of establishment, and the potential emergence of hybrid cattail (Typha x glauca), remain unanswered. This study models the current and potential future distribution of non-native cattails in the FRE using a unique combination of spectral imagery analysis and species distribution modelling. Contrary to our expectation, we find that non-native cattails are already widespread, currently occupying approximately 4% of FRE tidal marshes. Though never formally recorded in the FRE, hybrid cattail is the more abundant of the two taxa, suggesting that heterosis may be facilitating this invasion. In our species distribution model, we distinguish between site suitability (ability to establish and persist) and site susceptibility (risk of being colonized when suitable). Our model predicts that 28% of the estuary has > 50% probability of suitability, and 21% has > 50% probability of susceptibility to non-native Typha, indicating the scale of this invasion may increase over time. Restoration projects had proportionally more cattail, susceptible habitat, and suitable habitat than the overall estuary, casting doubt on their effectiveness at mitigating wetland destruction. Due to their resemblance to native Typha latifolia, these cattails qualify as cryptic invaders, which explains how they were able to establish and remain undetected for decades. Regional eradication is unlikely given the extent of invasion, therefore management should prioritize areas of high conservation and cultural values.
Assessment of Potential Heavy Metal Contamination in the Agricultural Soils Based on Various Improved Evaluation Methods in Beijing, China
Authors: Chen Rui , Cai Xuying , Ding Guoyu , Ren Fumin , Wang Qi , Cheng Nuo , Liu Jiaxing , Li Lanxin , Shi Rongguang
Published: March 2021

The evaluation of the soil contaminated by heavy metals can help to judge whether the soil meets the standard and whether the pollution will threaten human health and the ecological environment. In this study, the farmland soil from eight districts in Beijing was used as the research object, and the concentration of heavy metal elements, Pb, As and Cd in the soils and agricultural products were analyzed. The analysis results showed that: (1) The evaluation based on the improved Hakanson method suggested that the crops exhibit a significantly higher ability to absorb Cd than to absorb Pb and As. Pb, As and Cd are all at normal level of ecological risk; among them, Cd is mainly in a moderate ecological risk, without strong ecological risk. (2) Based on the Improved analytic hierarchy process(AHP) of evaluation, 0.2317 is the average value of the integrated index of heavy metal pollution of soil in the study area, which is a mild level of pollution. (3) Through the calculation of various parameters in the Influence index of comprehensive quality(IICQ) of soil and agricultural products, it was found that 0＜IICQS＜1, suggesting that the environmental quality of soil is at a clean level. In summary, the pollution of heavy metals Pb, As and Cd in the farmland soils and crops in the eight districts of Beijing, including Fangshan, Daxing, Shunyi, and Shijingshan is at a low level, and no significant impact has been brought to the surrounding environment.
Lightweight and Anonymous Mutual Authentication Protocol for IoT Devices With Physical Unclonable Functions
Authors: Meng Jin , Zhang Xufeng , Cao Tengfei , Xie Yong
Published: March 2021

The past few years have seen the topic of Internet of Things (IoT) rush into the forefront of various industries, which is changing people’s conventional production methods and lifestyles. Connected to the Internet, the physical devices could be as fluffy as kids’ teddy bears or as balky as driverless cars. However, the security related to the IoT is faced with some serious challenges simultaneously. Confronted with these issues, we propose a mutual authentication protocol for devices in the IoT system. It is lightweight that just hash functions, XORs as well as PUFs are utilized and there is no need to store plenty of pseudo-identities. Furthermore, not only does it use the reverse fuzzy extractor to acclimatize to the noisy environment, but it also introduces the supplementary sub-protocol to enhance the resistance to the desynchronization attack. Besides, the security analysis based on the improved BAN logic by Mao and Boyd presents the higher security and reliability of the proposed protocol, and the performance analysis shows its more comprehensive functions as well as lower computation and communication overhead.
Analysis of the Impact of Local Government Competition on Green Total Factor Productivity From the Perspective of Factor Market Distortion--Based on the Three-Stage DEA model
Authors: Tang Juan , Qin Fangming
Published: March 2021

From the perspective of factor market distortion, this paper explores the effect and internal mechanism of local government competition on green total factor productivity (GTFP). A three-stage DEA model was applied to measure the GTFP of 30 provinces from 2008 to 2017. Furthermore, the article analyses local government competition and factor market distortions influence on GTFP using the Spatial SDM model and mediation effect model. The statistical results reveal that the spatial correlation of GTFP is significantly present across Chinese different provinces. The growth of GTFP will be significantly inhibited by local government competition. Local government competition can indirectly restrict the improvement of GTFP through factor market distortion. Regional heterogeneity indicates that, in the eastern and central regions, local government competition does not significantly inhibit the growth of GTFP. Moreover, local government competition failed to restrain the improvement of GTFP through factor market distortion. However, in the western region, local government competition not only inhibited the growth of GTFP, but also inhibited the growth of GTFP by causing factor market distortion.
A Hybrid Glowworm Swarm Optimization for Enhancing the Lifespan of Wireless Sensor Networks
Authors: D Deepak raj , K RAJA , A AYYASAMY
Published: March 2021

The special features of smart grid technology includes regular metering communication, renewable power incorporation, allotment computerization and whole scrutinizing and organization of complete power grid. Little micro-electrical automatic schemes that are deployed in collecting and broadcasting data from ambience are Wireless Sensor Networks (WSNs). Providing security and energy consumptions are the most emerging issues in Wireless sensor network communication. To enhance the lifespan of a network, energy efficiency should be increased by decreasing energy consumption of the sensor nodes, thus striking a balance in the power consumption of each node. As the primary source of origin of energy consumption of sensor nodes is long distance transmission of data, good impact on energy consumption can be provided through an efficient routing protocol. So as to enhance the lifespan of a network, a number of protocols have been put forth in the form of optimization algorithms. This study involves Glowworm Swarm Optimization (GSO). In GSO, a probabilistic cost is computed by every glowworm in spite of finding its neighboring glowworm that has the enhanced luciferin intensity than others. Based on this probability cost, a glow worm moves towards the chosen glowworm. To enhance GSO performance, the GSO hybrid optimized with Harmony Search (HS) and Tabu Search (TS) local methods are also proposed. Results prove that proposed method achieves better performance.
Associations between pain, self-efficacy, sleep duration, and symptoms of depression in adolescents: a cross-sectional survey
Authors: Haraldstad Kristin , Stea Tonje Holte
Published: March 2021

Background: Although pain has been identified as an important public health problem among adolescents, few studies have investigated possible protective and risk factors for pain. The main aim of the present study was to investigate associations between prevalence of daily pain, self-efficacy, sleep duration, and symptoms of depression in a representative sample of Norwegian adolescents. Methods: A comprehensive cross-sectional survey was completed by 12 867 junior high school students and high school students (response rate: 90%) aged 14–19 years. Logistic regression models were adjusted for age, gender, and parental educational level. Results: We found a high prevalence of daily pain among adolescents, especially among girls (19%) compared with boys (7%). Short sleep duration was associated with increased odds ratios (ORs) of pain in the shoulders/neck (OR 1.3; 95% CI 1.3–2.0) and stomach (1.7; 1.2–2.4). Symptoms of depression were associated with increased ORs for all measured types of daily pain, including head (3.7; 3.0–4.6), shoulders/neck (3.9; 3.1–4.8), joints/muscles (4.3; 3.3–5.6), and stomach (5.5; 4.1–7.4). By contrast, self-efficacy was not associated with any form of daily pain. Conclusion: Given the burden of pain, high incidence of pain problems, and strong association between pain and depression and, to some degree, short sleep duration, co-occurring symptoms may be an important area for research in the public health field. The results highlight the importance of early identification and prevention. Longitudinal studies are needed to understand better pain problems and their underlying mechanisms with the aim of developing targeted interventions.
Resuscitative Endovascular Balloon Occlusion of the Aorta（REBOA） in A Swine Model of Iliac Artery Hemorrhage under the Guidance of Portable Ultrasound
Authors: Huang Yuqing , Shan Xuexia , Wu Shengzheng , Chen Xianghui , Lin Xingxi , Zhang Liye , Li Zhihui , Lv Faqin
Published: March 2021

Background: The major challenge of applying Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in the pre-hospital setting is to accurately place the balloon in. To evaluate the effects of applying portable ultrasound to guide REBOA for iliac artery hemostasis.Methods: We first established a swine model of hemorrhage by percutaneously puncture the right iliac artery under the guidance of portable ultrasound. Then we randomly divided the swine into two groups. We recorded systolic pressure (SP), diastolic pressure (DP), heart rate (HR), and the maximum depth of the ascites at baseline (T1), free bleeding for the 30s (T2), bleeding for 10min (T3), and bleeding for 30min (T4). Immediately after T2, we performed REBOA under the guidance of portable ultrasound in the intervention group and manual extracorporeal compression by dry gauze in the control group. We collected total blood loss at T4.Results: There were 11 swine included in the analysis (intervention group=6, control group=5). The characteristics of the two groups were similar at T1. After punctured the right iliac artery, hemorrhagic shock appeared in both groups at T2 - BP and DP fell, HR elevated, and the maximum depth of the ascites increased. After performing REBOA, SP(in mmHg) in the intervention group significantly increased to 97.17±11.92 at T3 and remained stable throughout T4; while SP in the control group kept decreasing and reached 62.40±3.44 at T4. A similar trend was found in DP. HR(in bpm) in the intervention group increased from 101.50±5.39 in T2 to 111.83±7.39 in T3 and stabilized at 113.83±5.49 in T4; in the control group, it kept increasing from 103.20±3.70 in T2 to 132.40±3.98 in T4. The maximum depth of the ascites increased between T2 and T4 in both groups, but significantly slower in the intervention group (at T4 3.50±0.36cm vs 5.14±0.35cm, P<0.05). The total blood loss was significantly less in the intervention group (1245.23±190.07g) than in the control group (2605.63±291.67g).Conclusions: Performing REBOA under the guidance of portable ultrasound can improve the effectiveness of iliac artery hemostasis and have great potential to save lives in pre-hospital settings.
hucMSC Exosome Ameliorates Pressure Ulcers Through Inhibition of HMGB1.
Authors: Yan Fei , Gong Meihua , Li Furong , Yu Li
Published: March 2021

Background: Pressure ulcers (PU) are a chronic wound for elderly populations. Previous works have shown that exosomes from stem cells contain cytokines and growth factors that play a role in tissue repair and can represent a therapeutic strategy for wound healing. Thus, as a new cell-free treatment model, fully understanding the extraction of exosomes and its mechanism of action can help promote the management of clinically chronic refractory wound healing. Material and Methods: In this study, we initially isolated exosomes from human umbilical cord mesenchymal stem cells (hucMSC-Exo) and examined their roles in wound healing. Different time points were evaluated for 15 mice which were randomly divided into three groups to serve three I-R circles and took different dose of hucMSC-Exo. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to analyze collagen mRNA levels in tissue samples. HMGB1 content was explored by western blot and immunohistochemistry. Comparing α-SAM, CD34, HMGB1 were used to investigate the potential mechanisms.Results: We found that hucMSC-Exo could be taken up by fibroblasts and significantly regulate and improve fibroblast fibrotic status and in-vivo PU wound healing. Further, we observed that hucMSC-Exo treatment of PU wound was able to downregulate the expression of HMGB1 previously shown to have a deleterious role in the wound healing process. Conclusion: Our study indicates that hucMSC-Exo regulates the repair of pressure ulcer wounds in part by inhibiting HMGB1. Exosome treatment has opened up a new perspective in regenerative medicine and trauma management.
Evaluation of Immunization Status in Patients with Cerebral Palsy: Multicenter CP-VACC Study
Authors: YILMAZ Sema BOZKAYA , ONCEL Eda KARADAG , DUNDAR Nihal OLGAC , GENCPINAR Pinar , SARIOGLU Berrak , ARICAN Pinar , ERSEN Atilla , CIFTDOGAN Dilek YILMAZ , YUKSEL Merve Feyza , BEKTAS Omer , TEBER Serap , KILIC Betul , CALIK Mustafa , KARACA Meryem , CANPOLAT Mehmet , KUMANDAS Sefer , PER Huseyin , GUMUS Hakan , OZTURK Selcan , OKUYAZ Cetin , KOMUR Mustafa , IPEK Rojan , OZBUDAK Pinar , ARHAN Ebru , INCE Hulya , GURBUZ Gurkan , MERT Gulen GUL , OZCAN Neslihan , TURKER Akgun OLMEZ , TEKIN Hande GAZETECI , KIRIK Serkan , GUNBEY Ceren , CARMAN Kursat Bora , YARAR Coskun , CAVUSOGLU Dilek
Published: March 2021

Children with chronic neurological diseases,including cerebral palsy(CP)are especially susceptible to vaccine-preventable infections and face an increased risk of severe respiratory infections and decompensation of their disease.This study aims to examine age-appropriate immunization status and related factors in the CP population of our country. This cross-sectional prospective multicentered survey study included 18 pediatric neurology clinics around Turkey,wherein outpatients children with CP were included in the study.Data on patient and CP characteristics,concomitant disorders as well as vaccination status included in the National Immunization Program(NIP),administration and recommendation of influenza vaccine were collected at a single visit. A total of 1194 patients were enrolled.Regarding immunization records,the most frequently administrated and schedule completed vaccines were BCG(90.8%),hepatitis B(88.9%)and oral poliovirus vaccine (88.5%).MMR was administered to 77.3% and DTaP-IPV-HiB was administered to 60.5% of patients.For the pneumococcal vaccines,54.1% of children had received PCV in the scope of the NIP, and 15.2% of children were not fully vaccinated for their age.The influenza vaccine, was administered only to 3.4% of the patients at any time and had never been recommended to 1122 parents(93.9%).In the patients with severe(grade 4 and 5)motor dysfunction,the frequency of incomplete/none vaccination of hepatitis B,BCG, DTaP-IPV-HiB,OPV,MMR were statistically more common than mild to moderate(grade 1–3)motor dysfunction(p = 0.003, p < 0.001, p < 0.001, p < 0.00, and p < 0.001, respectively).Influenza vaccine recommendation by physicians was higher in the severe motor dysfunction group and the difference was statistically significant(p = 0.029). Children with CP had lower immunization rates and incomplete immunization programs.Clinicians must ensure children with CP receive the same preventative health measures as healthy children,including vaccines.
Toxicological evaluation of engineered layered double hydroxide nanomaterials to Biomphalaria alexandrina snails: a study on the mechanism of action
Authors: Abdo Heba , Ibrahim Amina Mohamed , Hussein Taghreed , Mohamed Fatma
Published: March 2021

Layered double hydroxide (LDH) nanomaterials have recently become immense research area as it is used widely in industries. So, it's chance of their release into natural environment and risk assessment to non-target aquatic invertebrate increasing. So, the present study aimed to synthesize and confirme the crystalline formation of Co-Cd-Fe LDHs and Co-Cd-Fe /PbI2 (LDH), and then to investigate the toxic impact of the two LDH on the adult freshwater snails (Biomphalaia alexandrina). Results showed that Co-Cd-Fe /PbI2 LDH has more toxic effect to adult Biomphalaria than Co-Cd-Fe LDHs (LC50 was 56.4 mg/l, 72 h of exposure). The effect of LC25 (117.1 mg/l) of Co-Cd-Fe LDHs exposure on the embryo; showed suppression of embryonic development and induced embryo malformation. Also, it showed alterations in the tegmental architectures of the mantle-foot region of B. alexandrina snails as declared in scanning electron micrograph. Also, exposure to this sub lethal concentration caused abnormalities in hemocyte shapes and up-regulated IL-2 level in soft tissue. In addition, it decreased levels of non-enzymatic reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), caspase-3 activity and total protein content in significant manner. While, glutathione S-transferase (GST) activity was not affected by LDH exposure. It caused histopathological damages in both the hermaphrodite and digestive glands. Also, it has a genotoxic effect that was confirmed by alkaline comet assay. The results from the present study indicated that LDH has risk assessment on aquatic B. alexandrina snails and that it can be used as a biological indicator of water pollution with LDH
Intratumoral Cellular Heterogeneity Critically Determines Extracellular Vesicle Uptake in Colorectal Cancer
Authors: Kelemen Andrea , Carmi Idan , Oszvald Ádám , Lőrincz Péter , Petővári Gábor , Tölgyes Tamás , Dede Kristóf , Bursics Attila , Buzás Edit I. , Wiener Zoltán
Published: March 2021

The majority of colorectal cancer (CRC) patients carry mutations in the APC gene, which leads to an unregulated activation of the Wnt pathway. Extracellular vesicles (EV) are considered as potential therapeutic tools. Although CRC is a genetically heterogenous disease, the significance of the inter- and intra-tumor heterogeneity in EV uptake of CRC cells is not yet known. By using mouse and patient-derived organoids, the currently available best model of capturing cellular heterogeneity, we found that Apc mutation induces the expression of interferon-induced transmembrane protein 1 (Ifitm1), a membrane protein that plays a major role in cellular antiviral responses. Importantly, organoids derived from IFITM1high CRC cells contained more proliferating cells. Whereas we found no difference in the uptake of liposomes between IFITM1high and IFITM1low/− cells, IFITM1high cells had a markedly reduced uptake of fibroblast EVs as compared to IFITM1low/− cells. In contrast, there was no difference in the intensity of EV release between CRC subpopulations with high and low IFITM1 level. Importantly, the difference in cell proliferation between these two subpopulations disappeared in the presence of fibroblast-derived EVs, proving the functional relevance of the enhanced EV uptake by IFITM1low CRC cells. Collectively, we identified CRC cell subpopulations with functional difference in their EV, but not liposome uptake ability that must be taken into consideration when using EVs as therapeutic tools for targeting cancer cells.
The assisting-approach of horseradish peroxidase immobilized onto amine-functionalized superparamagnetic iron oxide nanoparticles as a biocatalyst
Authors: Keshta Basem E. , Gemeay Ali H. , Khamis Abeer A.
Published: March 2021

To enhance the removal of dye, horseradish peroxidase (HRP) was immobilized onto amine-functionalized superparamagnetic iron oxide and used as a biocatalyst for the oxidative degradation of Acid black-HC dye. The anchored enzyme was characterized by sets of techniques such as vibrating sample magnetometer, Fourier transform infrared, X-ray diffraction, thermogravimetric, scanning electron microscopy, BET and BJH methods, nitrogen adsorption-desorption measurements , Zeta potential, energy dispersive X-ray (EDX), and transmission electron microscopy. The Michaelis constant (K m ) values of free peroxidase and immobilized horseradish peroxidase were determined that equal 4.5 and 5 mM for hydrogen peroxide; 12.5 and 10 mM for guaiacol, respectively. Besides, the free peroxidase is thermally stable at 40°C however, the immobilized enzyme was up to 60°C. In the catalytic experiment, the immobilized HRP showed superior catalytic activity compared with free HRP for the oxidative decolorization and removal of Acid black-HC dye. The impacts of experimental parameters for instance catalyst dosage, pH, H 2 O 2 concentration, and temperature, were investigated. The reaction followed second-order kinetics and the thermodynamic activation parameters were determined.
Quantification of trace transformation products of rocket fuel unsymmetrical dimethylhydrazine in sand using vacuum-assisted headspace solid-phase microextraction
Authors: Zhakupbekova Aray , Baimatova Nassiba , Psillakis Elefteria , Kenessov Bulat
Published: March 2021

Quantification of unsymmetrical dimethylhydrazine (UDMH) transformation products (TPs) in solid samples is an important stage in monitoring of environmental pollution caused by heavy rockets launches. The new method for simultaneous quantification of UDMH TPs in sand samples using vacuum-assisted headspace solid-phase microextraction (Vac-HSSPME) followed by gas chromatography-mass spectrometry (GC-MS) is proposed. Compared to regular HSSPME, Vac-HSSPME yielded 1.3–4.8 times higher responses for NDMA, MTA and PAl. Increasing air-evacuation time from 20 to 120 s at 23 ºC resulted in decreased responses of analytes by 25–46%. Freezing of samples (-30 ºC) had negligible effect on responses of analytes at air-evacuation time 20 s. The best combination of responses of analytes and their RSDs was achieved after air-evacuation of a sample (m = 1.00 g) for 20 s at 23 ºC, incubation for 30 min and 30-min extraction at 40°C by Car/PDMS fiber. Vac-HSSPME provided linear calibration plots in studied ranges of concentrations with coefficients of determination ranging from 0.9912 to 0.9938. The limits of detection for spiked sand samples varied from 0.035 to 3.6 ng g− 1. Spike recoveries of target analytes from sand samples were 84–97% with RSDs 1–11%. The developed method was successfully tested in the experiment on studying losses of analytes from open vials with model sand spiked with UDMH TPs. The developed method can be recommended for analysis of trace concentrations of UDMH TPs when studying their transformation, migration and distribution in contaminated sand.
HHLA2 and NEBL as novel prognostic biomarkers based on Rayleigh survival model in colorectal cancer
Authors: Khan Altaf , Aziz Mohammed Azhar , Alatar Ghada T , AlGhamdi Amal , Hussein Mohammed A , Khatlani Tanveer S
Published: March 2021

Background The primary focus for this study was investigation of prognostic biomarkers in colorectal cancer (CRC), since biomarkers are instrumental in clinical decision making and patient management as well as playing pivotal roles in precision medicine.Methods We analyzed indigenous dataset from colorectal cancer patients. Exon microarray dataset was used and 135 genes were identiﬁed as novel candidate biomarkers. 135 genes were further split into two groups: low and high gene expression values via ’maxstat’ algorithm, they were analyzed using Kaplan-Meier (K-M) analysis and univariate Cox model, and a set of 33 genes were identiﬁed as statistically signiﬁcant (p¡0.05). Furthermore, using the ’VARCLUS’ algorithms (a SAS software procedure) which is a useful tool for variable reduction, based on the divisive clustering techniques, a small subset of 5 genes were selected out of 33 signiﬁcant genes as potential candidates to build survival models. Both parametric and semi-parametric survival models were utilized to assess whether these 5 genes could be used as prognostic biomarkers.Results HHLA2 (p < 0.01) and NEBL (p < 0.01) genes emerged as potential biomarkers, based on the para- and semi-parametric models such as: Rayleigh, Exponential probability distributions, and Cox models and were also validated on independent datasets, apart from validation with qPCR test as well as with the cell lines patients data in the laboratory. A rigorous statistical evaluation for model’s performance were done via Harrell’s index, Brier score, Shoenfeld residual plots as well as with comparing several predictive model plots. We also made the comparison of Akaike and Bayesian Information(AIC and BIC) criteria as well as log-likelihood estimates. The Tukey-Anscome plot and Quantile-Quantile plot as diagnostic tools were applied to validate the parametric survival models. Conclusion Based on predictive models HHLA2 and NEBL novel biomarkers were found as statically signiﬁcant.
Isolation and functional characterization of exopolysaccharide from Lactobacillus plantarum S123 isolated from traditional Chinese cheese
Authors: Saleem Muhammad , Malik Samiullah , Mehwish Hafiza Mahreen , Ali Muhammad Waqas , Hussain Nazim , Khurshid Mohsin , Rajoka Muhammad Shahid Riaz , Chen Yougen
Published: March 2021

Presently, exopolysaccharide (EPS), due to its exceptional biological features is used as an efficient biopolymer. Therefore, the present study aimed is the EPS production by Lactobacillus Plantarum S123, its biopotential investigation and technological functional characterization. The results of microscopic examination suggested that the S123 EPS has a major portion of amorphous spongy like structure with partial crystalline nature. The FTIR and NMR results suggested that the S123 EPS consists on carbonyl and hydroxyl group respectively. Furthermore, the results of biopotential investigation suggested that the S123 EPS exhibited excellent antimicrobial activity against Gram’s positive (7.2mm) and Gram’s negative bacteria (11.5mm), DPPH radical scavenging activity (> 65%), water holding capacity (326.6 ± 0.5%), oil holding capacity (995.3 ± 0.2%), flocculation (89.5 ± 0.6%), and emulsifying (80.1 ± 1.1%) activities. Overall, the present results suggested that due to highly porous structure, efficient biotechnological potential the S123 EPS from Lactobacillus plantarum S123 can be used in the functional food product.
Study of Dieless Radial Spinning for Thick-Walled Cylindrical Parts With External Grooves
Authors: Liu Famei , Jin Junsong , Rao Wei , Wang Ying , Gao Chang , Tang Xuefeng , Wang Xinyun
Published: March 2021

Thick-walled cylindrical parts with external grooves are common components in the automobile and aviation fields. Such components can be produced by pressing the outer surface of a spinning thick-walled aluminum alloy tube by the dieless radial spinning process. The forming characteristics in the spinning process and the effects of various process parameters on forming were studied by using orthogonal tests and finite element simulations. During the forming process, bulge and thickness reductions occur because of material flow. The results of an investigation of process parameter effects show that the stress yield ratio (ξ) had no significant effect on forming. However, the feed thickness ratio (η) and initial wall thickness of the tube (t0) crucially affected the forming quality (e.g., the heights of bulges and thickness reduction in the groove area). Thick-walled tubes presented different phenomena compared to the thin-walled.
An Energy-Efficient Spectrum Sensing in Cognitive Radio Network Using Fractional Optimization Model
Authors: Hipparge Praveen , Jawaligi Shivkumar S.
Published: March 2021

The authors have requested that this preprint be removed from Research Square.
Opto-Electronic Properties of Epoxy/Silicone Blend Based Thin Films
Authors: Ziat Younes , Belkhanchi Hamza , Hammi Maryama , Laghlimi Charaf , Moutcine A
Published: March 2021

Recently, the rise of two dimensional amorphous nanostructured thin films have ignited a big interest because of their intriguingly isotropic structural and physical properties leading to potential applications in the nano-optoelectronics. However, according to literature, most of optoelectronic properties are investigated on chalcogenides related heterostructures. This has motivated the present work aiming to provide a new platform for the fabrication, examination of the properties and the applications of 2D nanostructured thin films based on epoxy/silicone blend. Thin films of Epoxy/Silicone loaded with nitrogen doped carbon nanotubes (N-CNTs) were prepared by sol-gel method and deposited on Indium Tin Oxide (ITO) glass substrates at room temperature. Further examination of optical properties aimed the investigation of optical pseudo-gap and Urbach energy and enabled the determination of processed films thickness based on Manifacier and Swanepol method. The results indicated that the unloaded thin films have a direct optical transition with a value of 3.61 eV followed by noticeable shift towards narrowing gaps depending on the loading rate. Urbach's energy is 0.19 eV for the unloaded thin films, and varies from 0.43 to 1.33 eV for the loaded thin films with increasing the rate of N-CNTs. It is inversely variable with the optical pseudo-gap. Finally, Epoxy/Silicone loaded with N-CNTs nanocomposites films can be developed as active layers with specific optical characteristics, giving the possibility to be used in electro-optical applications.
Aleurodiscus Bicornis and A. Formosanus Spp. Nov. (Basidiomycota) With Smooth Basidiospores, and Description of A. Parvisporus From NE China
Authors: Wu Sheng-Hua , Wei Chia-Ling , Chang Chiung-Chih
Published: March 2021

Three species of Aleurodiscus s.l. characterized in having effused basidiomata, clamped generative hyphae and quasi-binding hyphae, sulphuric positive reaction of gloeocystidia, hyphidia, acanthophyses and smooth basidiospores, are described. They are A. bicornis sp. nov., A. formosanus sp. nov. and A. parvisporus. Aleurodiscus bicornis was found from high mountains of NW Yunnan Province of SW China, grew on branch of Picea sp. Aleurodiscus formosanus was found from high mountains of central Taiwan, grew on branch of gymnosperm. Aleurodiscus parvisporus was previously reported only once from Japan and Sichuan Province of China respectively, and is reported in this study from Jilin Province of China. Phylogenetic relationships of these three species were inferred from analyses of a combined dataset consisting of three genetic markers, viz. 28S, nuc rDNA ITS1-5.8S-ITS2 (ITS), and a portion of the translation elongation factor 1-alpha gene, TEF1. The studied three species are phylogenetically closely related with significant support, corresponds with resemblance of their morphological features.
WITHDRAWN: Measurement of Micro Burr and Slot Widths through Image Processing: Comparison of Manual and Automated Measurements
Authors: AKKOYUN FATIH , Ercetin Ali , Aslantas Kubilay
Published: March 2021

In this study, the burr and slot widths formed after micro-milling process are investigated using a rapid and accurate image processing method. The measurements are obtained by processing the images and results were compared with a manual measurement method. In the cutting experiment stage, Inconel 718 alloy was chosen as the workpiece and cutting tools with various specific properties were used. The images of the burr and slots were captured using scanning electron microscope (SEM). Different tool geometries and cutting parameters were considered for choosing the SEM images. Captured images were processed with a computer vision software which was written in C + + programming language and open-sourced computer library (Open CV). The demonstrated approach was successfully measured the slot and burr widths in plain and complex conditions where slot and burr are nested. According to the close findings of manual and automated measurements, it was observed that burr widths increased especially at the down milling sides and slot widths decreased due to the increased cutting length. Specific tool properties such as number of cutting edge, helix angle and cutting length affected the slot and burr widths. It was determined that there is a good correlation between automated and manual measurements of slot and burr widths. The accuracy of the proposed method is above 91%, 98%, and 99% for up milling, down milling, and slot measurements, respectively.
Human Gingiva-derived Mesenchymal Stem Cells Promote Osteogenic Differentiation via Suppressing T Cell Biological Activity
Authors: Zhao Jing , Liu Rui , Zhu Jing , Chen Shulan , Xu Ling
Published: March 2021

Background: Accumulating evidence has revealed that human gingiva-derived mesenchymal stem cells (GMSCs) are emerging as a new line of mesenchymal stem cells and have a robust immune regulatory function and regenerative ability. However, the relationship between immune regulatory function and regenerative ability is unclear, whether GMSCs promoted osteoblastic differentiation by regulating immune cells. Methods: In this study, we investigated the effect of GMSCs regulating T-cell biological activity on osteoblasts in a direct contact co-culture system. GMSCs and T-cell were co-cultured, the co-culture supernatant was collected and acted on MC3T3-E1 cells, then the alkaline phosphatase (ALP) staining, Alizarin Red staining, Immunofluorescence staining, and real-time quantitative PCR (RT-qPCR) analysis of osteogenic genes were detected to evaluated the osteogenesis differentiation of MC3T3-E1 cells. Results: Our results demonstrated that GMSCs could suppress the activated T-cell function by downregulation pro-inflammatory cytokines (Interleukin-1β [IL-1β] and Tumor necrosis factor-α [TNF-α]) and the upregulation of anti-inflammatory cytokines (IL-10). Meanwhile, the co-culture supernatant significantly increased osteogenic differentiation of ME3T3-E1.Conclusion: GMSCs could promote the osteogenic differentiation of MC3T3-E1 cells by inhibiting the biological activity of activated T-cell.
Assessing Sex Differential in COVID-19 Mortality Rate by Age and Polymerase Chain Reaction Test Results; An Iranian Multi-Center Study
Authors: Looha Mehdi Azizmohammad , Rezaei-Tavirani Mostafa , Rostami-Nejad Mohammad , Janbazi Shahriar , Zarean Elaheh , Amini Payam , Masaebi Fatemeh , Kazemi Maryam , Vahedian-Azimi Amir , Mirmomeni Golshan , Pourhoseingholi Mohamad Amin
Published: March 2021

Background: Males are more likely to die from COVID-19 than females. In addition, the mortality rate among positive and suspected COVID-19 patients were reported in many literatures. The aim of this study is to evaluate the sex differential effect in the COVID-19 mortality by different age groups and polymerase chain reaction (PCR) test results. Methods: in a multicenter cross-sectional study from 55 hospitals in Tehran, Iran, patients were categorized as the positive, negative and suspected cases. Age group, sex and hospital wards were also assessed in analysis. Results: A total of 25481 cases (14791 males) were included in the study with the mortality rate of 12.0%. The mortality rate in positive, negative and suspected cases were 20.55%, 9.97% and 7.31%, respectively. Although the mortality in negative test group was considerable, sex was not associated with the death rate in this group. Using Cox regression model, sex had a significant effect on the hazard of death due to COVID-19 in adults and senior patients having positive and suspected PCR test results. However, sex was not found as significant factor for mortality in patients with negative PCR test occurring to different age groups. Conclusion: Regardless of other risk factors, we found that sex differential effect in COVID-19 mortality varies significantly in different age groups; therefore, appropriate strategies should be designed to protect adult and senior men from this deadly infectious disease. Furthermore, owing to the considerable death rate of COVID-19 patients with negative test results, new policies should be launched increase the accuracy of diagnosis tests.
How Creative Destruction Functions in Corporate Entrepreneurial Process: An Empirical Investigation of Schumpeterian Concept in Engineering Firms Setting in Pakistan
Authors: Alam Muhammad Zubair , Kousar Shazia , Ullah Muhammad Rizwan , Pervaiz Amber
Published: March 2021

Schumpeter's idea of creative destruction (CD) explains innovation functions in organisations. This paper investigates the CD concept in engineering firms by explaining how technical opportunity (TO) transforms into corporate entrepreneurship (CE) actions once opportunities have a market orientation (MO). A survey conducted using a structured questionnaire with 132 managers in engineering firms in Pakistan. Structural Equation Modeling (SEM) using Partial Least Square (PLS) approach has been used to analyse the data. Results reveal that MO and TO exerts a positive influence on CE. MO is the reason for the emergence of TO, which is exploited by CE's in engineering firms. CD intensifies the impact of MO on TO significantly. Opportunity recognition in engineering firms is distinguished and bounded by MO and technical viability. Engineering firms need to identify gaps in the market through naturally occurring obsolescence of products and services (CD) to create TO with appropriate MO. This study has revived a classical debate over opportunity recognition by proposing a CE model by incorporating external factors. The Schumpeterian opportunity recognition process and CD have been explained for engineering firms that are distinguished from other types of firms. Kirznerian opportunity recognition view has also been debated to dialect Schumpeterian view.