bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of the integer factorization complexity upper bound to the complexity of the Diffie–Hellman problem
Authors: Cherepnev Mikhail A.
Published: February 2021

We construct a probabilistic polynomial algorithm that solves the integer factorization problem using an oracle solving the Diffie–Hellman problem.
Structuring of hydroxy-terminated polydimethylsiloxane filled by fumed silica
Authors: Peng Zhengwei , Qin Yan , Song Jiuqiang , Zhu Di , Chen Shuisheng , Ren Jingwen , Li ZhuangZhuang , Zou Zhenyue
Published: February 2021

The term “structuring” used in silicone rubber describes a phenomenon of the increase in the viscosity of polydimethylsiloxane filled with silica during storage, which limits the applications of the room temperature vulcanized (RTV) silicone rubber in the field of aerospace and military. In this pursuit, the present study was envisaged to solve the problem of structuring of the RTV. A solvent-free method was used to hydrophobize the hydrophilic silica with hexamethyldisilazane. An RTV composition prepared using eight parts of hydrophobic silica with 2.91% C content exhibited a viscosity of less than 100 Pa s, with no significant change in 21 days. In contrast, eight parts of the hydrophilic fumed silica showed an initial viscosity of RTV to be greater than 2,000 Pa s. Silica samples with different adsorbed water content were used to prepare the RTV compositions. It was found that the viscosity of the RTV prepared using the sufficiently dried silica was 5.6 times lower than that of the wet silica. The “dissolution” model of the silica–silica hydrogen bonds in water was proposed. Furthermore, the change in the viscosity of the RTV compositions at different temperatures in the range of −15°C to 30°C was studied. The viscosity of RTV stored at –15°C for 34 days did not change significantly, whereas that stored at room temperature increased from 100 to 1,710 Pa s within 21 days.
Influence of composite structure design on the ablation performance of ethylene propylene diene monomer composites
Authors: Ren Jingwen , Qin Yan , Peng Zhengwei , Li Zhuangzhuang
Published: February 2021

By introducing functional fillers into the ethylene propylene diene monomer matrix, the anti-ablation, thermal insulation, and adhesive layer were prepared, respectively. We have studied the mechanical properties, ablation properties, thermal insulation properties, and bonding properties of different composite structures after design and analyzed the ceramic mechanism. The results showed that the content of ceramic fillers improved the thermal stability and ablation properties of anti-ablation layer composites. The formation of liquid structure can fill the hole defects and ablation pit. The foaming agent improved thermal insulation properties of the thermal insulation layer, and the strength of the bonding layer has been greatly improved. The design of the composite structure can not only reduce the density but also have an excellent thermal insulation effect. And as the thickness of the heat insulation layer increases, the heat blocking effect becomes more excellent.
Potent antibacterial action of phycosynthesized selenium nanoparticles using Spirulina platensis extract
Authors: ElSaied Basant E.F. , Diab Amany M. , Tayel Ahmed A. , Alghuthaymi Mousa A. , Moussa Shaaban H.
Published: February 2021

Selenium nanoparticles (SeNPs) are reinforced safe forms of the essential micronutrient selenium (Se) which take a lead in countless biotechnological and biomedical applications. The phycosynthesis of SeNPs was successfully investigated using cell-free extract of the microalgae, Spirulina platensis. The phycosynthesized S. platensis-SeNPs (SpSeNPs) were characterized using several characterization techniques such as UV-Visible, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and energy dispersive X-ray. They were effectually achieved using different concentration from sodium selenite (Na2SeO3) (1, 5, and 10 mM) to give size means of 12.64, 8.61, and 5.93 nm, respectively, with spherical shapes and highly negative zeta potentialities. The infrared analyses revealed the involvement of many phycochemials in SpSeNPs production. The antibacterial properties of SpSeNPs were confirmed, qualitatively and quantitatively, against foodborne microorganisms (Staphylococcus aureus and Salmonella typhimurium); the antibacterial activity was correlated and increased with SeNPs’ size diminution. The scanning micrographs of S. typhimurium cells treated with SpSeNPs indicated the severe action of nanoparticles to destroy bacterial cells in time-dependent manners. The innovative facile phycosynthesis of SeNPs using S. platensis is recommended to generate effectual bioactive agents to control hazardous bacterial species.
Anticancer activity of novel Schiff bases and azo dyes derived from 3-amino-4-hydroxy-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione
Authors: Saeed Abdeltawab Mohamed , AlNeyadi Shaikha S. , Abdou Ibrahim M.
Published: February 2021

New Schiff bases and azo dyes derivatives have been synthesized via appropriate conventional methods using pyranoquinolinone as a starting material. The compounds obtained were characterized by spectral analysis and evaluated for anticancer activity in several human tumor cell lines: MCF-7 breast cancer, HepG2 liver cancer and HCT-116 colon carcinoma. 5-fluorouracil was used as a reference drug. The in vitro cytotoxicity screening results revealed that all tested compounds showed promising activity against MCF-7 cells. In particular, compounds 6a, 6b, and 7b showed excellent activity against the three human tumor cell lines. Structure-activity relationship studies indicated that the azo derivative with a trifluoromethoxy group (compound 7b) was the most potent candidate against the three human tumor cell lines (IC50, 1.82-8.06 μg/mL). Our findings highlight pyranoquinolinone analogues as a promising class of compounds for new anticancer therapies.
Design, Synthesis and Biological Evaluation of N-((2-phenyloxazol-4-yl)methyl) Pyrimidine Carboxamide Derivatives as Potential Fungicidal Agents
Authors: Huang Danling , Zheng Shumin , Cheng Yong-Xian
Published: February 2021

Twelve N-((2-phenyloxazol-4-yl)methyl) pyrimidine carboxamide derivatives were designed, synthesized, and characterized by 1H NMR, 13C NMR, and HRMS. The fungicidal activities of these new compounds against Sclerotinia sclerotiorum, Botrytis cinereal, and Colletotrichum fragariae were evaluated. The results indicated that compounds 5b, 5f, and 5g displayed potential fungicidal activities against tested fungi, especially 5f exhibited IC50 value of 28.9 mg/L against S. sclerotiorum. Moreover, the compounds 5f and 5g showed IC50 values of 54.8 mg/L and 62.2 mg/L against C. fragariae respectively, which shows that they were more active than the commercial fungicide hymexazol. The superficial structure-activity relationships were discussed, which may be of benefit for the development of fungicides and discovery of novel fungicides.
Dynamic recrystallisation and modelling of microstructural evolution of high-titanium-content 6061 aluminium alloy
Authors: Chen Wei , Gu Yanfei , Guan Yingping , Dong Chunfa
Published: February 2021

The dynamic recrystallisation behaviour of high-titaniumcontent 6061 aluminium alloy was investigated by hot compression tests within the temperature range of 623- 783 K and at strain rates of 0.01 -10 s-1. The characteristics of the true stress-strain curves acquired in the hot compression tests were investigated, and it was observed that the dynamic recrystallisation of high-titanium-content 6061 aluminium alloy occurs within the range of deformation temperatures of 623 -783 K, with strain rates of 0.001 - 0.1 s-1as evinced by a physically-based constitutive analysis. The kinetic model of dynamic recrystallisation was deduced to describe the dynamic recrystallisation behaviour of high-titanium-content 6061 aluminium alloy, and the dynamic recrystallisation grain size model was also constructed.
High-strength wire + arc additive manufactured steel
Authors: Guo Chun , Liu Maoxue , Hu Ruizhang , Yang Tuoyu , Wei Baoli , Chen Feng , Zhang Liyong
Published: February 2021

High-strength 690-MPa steel was prepared using a wire + arc additive manufacturing (WAAM) technology. The phase composition, microstructure, and crystal structure of highstrength 690-MPa steel samples were analysed, and the results show that a sample prepared using WAAM technology achieves a good formation quality. The metallographic structure was mainly acicular ferrite, massive ferrite, and granular bainite. The microhardness distribution of the vertical and horizontal sections of the samples is uniform. Excellent mechanical properties of the specimen were shown, including a horizontal yield strength of 536 MPa, a tensile strength of 760 MPa, an elongation of 23.5%, a Charpy impact value of 70 J at -508C, a vertical yield strength of 486 MPa, a tensile strength of 758 MPa, an elongation of 21.5%, and a Charpy impact value of 51 J at -508C.
Investigation of time-dependent corrosion behavior of Sr-modified AlSi12 alloy
Authors: Hapçı Aǧaoǧlu Gökçe , Kaan Duygun İnal , Orhan Gökhan
Published: February 2021

The effect of Sr addition on the microstructure and time-dependent corrosion properties of the AlSi12 eutectic alloy was investigated. The modified alloy contained 90 ± 3 ppm Sr. The microstructural differences in the eutectic structure of AlSi12 alloys were assessed in terms of the Si particle size and a-Al volume fraction. The unmodified and Sr-modified alloys were immersed for 1, 24, 72 and 120 h in 3.5 wt.% NaCl. Electrochemical impedance spectroscopy and potentiodynamic polarization techniques were performed to analyze the corrosion characteristics of the alloys. Sr addition led to a decrease in the Si particle size, and the formation of long dendritic a-Al. It was found that the presence of Sr resulted in more stable corrosion behavior up to 24 h. The deterioration of the corrosion behavior of Sr-modified alloy was observed with the further increase of immersion time.
Synthesis of LiCoO2 particles with tunable sizes by a urea-based-homogeneous-precipitation method
Authors: Motoyama Munekazu , Iwasaki Hiroki , Sakakura Miyuki , Yamamoto Takayuki , Iriyama Yasutoshi
Published: February 2021

This paper reports the synthesis of monodisperse spherical LiCoO2 particles in a wide range of average diameter using a urea-based-uniform-precipitation method. The average diameter of LiCoO2 particles can be varied from 2 to 14 lm with a uniform size distribution. The effective approach to maintain the size uniformity while changing the average size of LiCoO2 particles is to keep the ratio of [CO(NH2)2] to [CoSO4] at 8 even when the CoSO4 and urea concentrations are changed.
Direct Effects under Differential Misclassification in Outcomes, Exposures, and Mediators
Authors: Li Yige , VanderWeele Tyler J.
Published: February 2021

Direct effects in mediation analysis quantify the effect of an exposure on an outcome not mediated by a certain intermediate. When estimating direct effects through measured data, misclassification may occur in the outcomes, exposures, and mediators. In mediation analysis, any such misclassification may lead to biased estimates in the direct effects. Basing on the conditional dependence between the mismeasured variable and other variables given the true variable, misclassification mechanisms can be divided into non-differential misclassification and differential misclassification. In this article, several scenarios of differential misclassification will be discussed and sensitivity analysis results on direct effects will be derived for those eligible scenarios. According to our findings, the estimated direct effects are not necessarily biased in intuitively predictable directions when the misclassification is differential. The bounds of the true effects are functions of measured effects and sensitivity parameters. An example from the 2018 NCHS data will illustrate how to conduct sensitivity analyses with our results on misclassified outcomes, gestational hypertension and eclampsia, when the exposure is Hispanic women versus non-Hispanic White women and the mediator is weights gain during pregnancy.
Sensitivity of the neutron multiplication factor to water ingress into a spent fuel cask
Authors: Leotlela M. J. , Petr I. , Mathye A.
Published: February 2021

An essential component of safety analyses is the investigation of accident scenarios. In this paper water ingress scenarios of spent fuel containers, as they may occur during transport or storage, are examined. In the main body of this paper, a number of paths are studied through which water can gain access to the spent fuel cask and eventually reach the fuel pellet, potentially resulting in an increase in reactivity as a result of over-moderation. The primary objective of this project was to perform an assessment of what, in the unlikely event of a Fukushima- type accident, the impact would be on the reactivity of the cask by analyzing a gradual increase in water level in the spent fuel casks. In addition, the way the keff of the system responds to such an increase is discussed. The paper also provides the results of an assessment of the reactivity effect of water ingress via various pathways/channels.
Static and dynamic analyses of auxetic hybrid FRC/CNTRC laminated plates
Authors: Huang Xu-Hao , Yang Jian , Azim Iftikhar , Ren Xin , Wang Xing-er
Published: February 2021

In this work, a hybrid laminated plate is developed by changing ply orientations and stacking sequences. The hybrid laminated plate is composed of carbon nanotube reinforced composite and fiber reinforced composite layers. Negative Poisson’s ratio (NPR) is obtained for the case of [22F/(22C/−22C)3T/−22F] laminate. A theoretical laminated model considering geometric nonlinearity and shear deformation is presented. Based on a two-step perturbation method, the solutions of the motion equations are obtained to capture the nonlinear frequencies and load–deflection curves. On this basis, the fourth-order Runge–Kutta method is used to obtain the dynamic response of hybrid laminated plates. The presented model is verified by comparing the results obtained analytically and numerically. Several factors such as loading and distribution of carbon nanotubes (CNTs), and foundation type are considered in parametric study. Numerical results indicate that the thermal-mechanical behavior of hybrid laminated plates significantly improved by properly adjusting the CNT distribution. In addition, the results reveal that changes in temperature and foundation stiffness have pronounced influence on the nonlinear vibration characteristics of hybrid laminate plates with NPR as compared to those with positive Poisson’s ratio.
Pure-silk fibroin hydrogel with stable aligned micropattern toward peripheral nerve regeneration
Authors: Gu Xinyi , Chen Xiaoli , Tang Xiaoxuan , Zhou Zhihao , Huang Tingting , Yang Yumin , Ling Jue
Published: February 2021

Successful repair of long-distance peripheral nerve injuries remains a challenge in the clinic. Rapid axon growth is a key to accelerate nerve regeneration. Herein, a pure silk fibroin (SF) hydrogel with a combination of high-strength and aligned microgrooved topographic structure is reported. The hydrogels exhibit excellent mechanical properties with high strength. Good biocompatibility also allows the hydrogels to support cell survival. Significantly, the hydrogel with aligned microgrooved structures enables the aligned growth of Schwann cells. Moreover, the hydrogel holds a strong capacity for promoting axon growth and guiding neurite sprouting. Thus, this micropatterned SF hydrogel would have great potential for peripheral nerve regeneration.
Can Wittgenstein’s Philosophy account for Uncertainty in Introspection?
Authors: Hubacher Haerle Pablo
Published: February 2021

What happens when we are uncertain about what we want, feel or whish for? How should we understand uncertainty in introspection? This paper reconstructs and critically assess two answers to this question frequently found in the secondary literature on Wittgenstein: indecision and self-deception (Hacker 1990, 2012; Glock 1995, 1996). Such approaches seek to explain uncertainty in introspection in a way which is completely distinct from uncertainty about the ‘outer world’. I argue that in doing so these readings fail to account for the substantial role the intellect seems to play in the process of resolving such uncertainties. I then attempt to show that Wittgenstein’s remarks connecting psychological vocabulary, behaviour and public criteria (e. g. PI 2009: 580) provide alternative ways for thinking about uncertainty in introspection which allow for a substantial role of the intellect.
Retrograde Suppression of Post-Tetanic Potentiation at the Mossy Fiber-CA3 Pyramidal Cell Synapse
Authors: Makani Sachin , Lutzu Stefano , Lituma Pablo J. , Hunt David L. , Castillo Pablo E.
Published: February 2021

In the hippocampus, the excitatory synapse between dentate granule cell (GC) axons, or mossy fibers (MFs), and CA3 pyramidal cells (MF-CA3) expresses robust forms of short-term plasticity, such as frequency facilitation and post-tetanic potentiation (PTP). These forms of plasticity are due to increases in presynaptic neurotransmitter release, and can be engaged when dentate GCs fire in bursts (e.g., during exploratory behaviors) and bring CA3 pyramidal neurons above threshold. While frequency facilitation at this synapse is limited by endogenous activation of presynaptic metabotropic glutamate receptors (mGluRs), whether MF-PTP can be regulated in an activity-dependent manner is unknown. Here, using physiologically relevant patterns of MF stimulation in acute mouse hippocampal slices, we found that disrupting postsynaptic Ca2+dynamics increases MF-PTP, strongly suggesting a form of Ca2+-dependent retrograde suppression of this form of plasticity. PTP suppression requires a few seconds of MF bursting activity and Ca2+release from internal stores. Our findings raise the possibility that the powerful MF-CA3 synapse can negatively regulate its own strength not only during PTP-inducing activity typical of normal exploratory behaviors, but also during epileptic activity.
Effects of Optogenetic Stimulation of Primary Somatosensory Cortex and Its Projections to Striatum on Vibrotactile Perception in Freely Moving Rats
Authors: Sun Zongpeng , Schneider Artur , Alyahyay Mansour , Karvat Golan , Diester Ilka
Published: February 2021

Tactile sensation is one of our primary means to collect information about the nearby environment and thus crucial for daily activities and survival. Therefore, it is of high importance to restore sensory feedback after sensory loss. Optogenetic manipulation allows local or pathway-specific write-in of information. However, it remains elusive whether optogenetic stimulation can be interpreted as tactile sensation to guide operant behavior and how it is integrated with tactile stimuli. To address these questions, we employed a vibrotactile detection task combined with optogenetic neuromodulation in freely moving rats. By bidirectionally manipulating the activity of neurons in primary somatosensory cortex (S1), we demonstrated that optical activation as well as inhibition of S1 reduced the detection rate for vibrotactile stimuli. Interestingly, activation of corticostriatal terminals improved the detection of tactile stimuli, while inhibition of corticostriatal terminals did not affect the performance. To manipulate the corticostriatal pathway more specifically, we employed a dual viral system. Activation of corticostriatal cell bodies disturbed the tactile perception while activation of corticostriatal terminals slightly facilitated the detection of vibrotactile stimuli. In the absence of tactile stimuli, both corticostriatal cell bodies as well as terminals caused a reaction. Taken together, our data confirmed the possibility to restore sensation using optogenetics and demonstrated that S1 and its descending projections to striatum play differential roles in the neural processing underlying vibrotactile detection.
Diversity of Receptive Fields and Sideband Inhibition with Complex Thalamocortical and Intracortical Origin in L2/3 of Mouse Primary Auditory Cortex
Authors: Liu Ji , Kanold Patrick O.
Published: February 2021

Receptive fields of primary auditory cortex (A1) neurons show excitatory neuronal frequency preference and diverse inhibitory sidebands. While the frequency preferences of excitatory neurons in local A1 areas can be heterogeneous, those of inhibitory neurons are more homogeneous. To date, the diversity and the origin of inhibitory sidebands in local neuronal populations and the relation between local cellular frequency preference and inhibitory sidebands are unknown. To reveal both excitatory and inhibitory subfields, we presented two-tone and pure tone stimuli while imaging excitatory neurons (Thy1) and two types of inhibitory neurons (parvalbumin and somatostatin) in L2/3 of mice A1. We classified neurons into six classes based on frequency response area (FRA) shapes and sideband inhibition depended both on FRA shapes and cell types. Sideband inhibition showed higher local heterogeneity than frequency tuning, suggesting that sideband inhibition originates from diverse sources of local and distant neurons. Two-tone interactions depended on neuron subclasses with excitatory neurons showing the most nonlinearity. Onset and offset neurons showed dissimilar spectral integration, suggesting differing circuits processing sound onset and offset. These results suggest that excitatory neurons integrate complex and nonuniform inhibitory input. Thalamocortical terminals also exhibited sideband inhibition, but with different properties from those of cortical neurons. Thus, some components of sideband inhibition are inherited from thalamocortical inputs and are further modified by converging intracortical circuits. The combined heterogeneity of frequency tuning and diverse sideband inhibition facilitates complex spectral shape encoding and allows for rapid and extensive plasticity.

SIGNIFICANCE STATEMENTSensory systems recognize and differentiate between different stimuli through selectivity for different features. Sideband inhibition serves as an important mechanism to sharpen stimulus selectivity, but its cortical mechanisms are not entirely resolved. We imaged pyramidal neurons and two common classes of interneurons suggested to mediate sideband inhibition (parvalbumin and somatostatin positive) in the auditory cortex and inferred their inhibitory sidebands. We observed a higher degree of variability in the inhibitory sideband than in the local frequency tuning, which cannot be predicted from the relative high homogeneity of responses by inhibitory interneurons. This suggests that cortical sideband inhibition is nonuniform and likely results from a complex interplay between existing functional inhibition in the feedforward input and cortical refinement.
Network Asynchrony Underlying Increased Broadband Gamma Power
Authors: Guyon Nicolas , Zacharias Leonardo Rakauskas , Fermino de Oliveira Eliezyer , Kim Hoseok , Leite João Pereira , Lopes-Aguiar Cleiton , Carlén Marie
Published: February 2021

Synchronous activity of cortical inhibitory interneurons expressing parvalbumin (PV) underlies expression of cortical γ rhythms. Paradoxically, deficient PV inhibition is associated with increased broadband γ power in the local field potential. Increased baseline broadband γ is also a prominent characteristic in schizophrenia and a hallmark of network alterations induced by NMDAR antagonists, such as ketamine. Whether enhanced broadband γ is a true rhythm, and if so, whether rhythmic PV inhibition is involved or not, is debated. Asynchronous and increased firing activities are thought to contribute to broadband power increases spanning the γ band. Using male and female mice lacking NMDAR activity specifically in PV neurons to model deficient PV inhibition, we here show that neuronal activity with decreased synchronicity is associated with increased prefrontal broadband γ power. Specifically, reduced spike time precision and spectral leakage of spiking activity because of higher firing rates (spike “contamination”) affect the broadband γ band. Desynchronization was evident at multiple time scales, with reduced spike entrainment to the local field potential, reduced cross-frequency coupling, and fragmentation of brain states. Local application of S(+)-ketamine in (control) mice with intact NMDAR activity in PV neurons triggered network desynchronization and enhanced broadband γ power. However, our investigations suggest that disparate mechanisms underlie increased broadband γ power caused by genetic alteration of PV interneurons and ketamine-induced power increases in broadband γ. Our study confirms that enhanced broadband γ power can arise from asynchronous activities and demonstrates that long-term deficiency of PV inhibition can be a contributor.

SIGNIFICANCE STATEMENTBrain oscillations are fundamental to the coordination of neuronal activity across neurons and structures. γ oscillations (30-80 Hz) have received particular attention through their association with perceptual and cognitive processes. Synchronous activity of inhibitory parvalbumin (PV) interneurons generates cortical γ oscillation, but, paradoxically, PV neuron deficiency is associated with increases in γ oscillations. We here reconcile this conundrum and show how deficient PV inhibition can lead to increased and asynchronous excitatory firing, contaminating the local field potential and manifesting as increased γ power. Thus, increased γ power does not always reflect a genuine rhythm. Further, we show that ketamine-induced γ increases are caused by separate network mechanisms.
ZEYTİNYAĞINDA MİNİMAL RAFİNASYON UYGULAMASININ İŞLEM PERFORMANSI VE KALİTE KRİTERLERİ AÇISINDAN DEĞERLENDİRİLMESİ
Authors: YAZILIKAYA PARASIZ Merve , ÖZDİKİCİERLER Onur , YEMİŞÇİOĞLU Fahri
Published: February 2021

Bu çalışmada rafinajlık zeytinyağı, sodyum hidroksit (NaOH), magnezyum oksit (MgO) ve kalsiyum hidroksit (Ca(OH)2) olacak şekilde farklı kuvvetteki alkaliler ile asitlik giderme işlemine, natürel ve asitle aktifleştirilmiş değişken oranlardaki (%0.1-%0.5-%0.9) ağartma toprakları ile renk açma işlemine tabi tutulmuştur. NaOH ve MgO ile SYA miktarının etkin biçimde azaldığı ve rafinasyon kaybının Ca(OH)2’ye göre düşük olduğu tespit edilmiştir. Başlangıç TOTOX değeri 152.02 olan rafinajlık yağlarda bu değerin NaOH ve MgO ile gerçekleştirilen asitlik giderme işlemleri sonrasında sırasıyla 47.82 ve 56.9’a düştüğü ancak Ca(OH)2 ile 123.53 düzeyinde kaldığı görülmektedir. Asitliği giderilen örnekler arasında en yüksek fenolik bileşen içeriği 175.3 mg/kg ile NaOH örneğinde tespit edilmiştir. Natürel ağartma topraklarının kullanılmasının biyoaktif bileşenler açısından önemli bir koruma sağlamadığı ancak artan oranlarda kullanıldığında işlem etkinliği açısından asitle aktifleştirilmiş topraklara göre daha etkin sonuçlar verdiği tespit edilmiştir.
Progesterone induces porcine sperm release from oviduct glycans in a proteasome-dependent manner
Authors: Sharif Momal , Kerns Karl , Sutovsky Peter , Bovin Nicolai , Miller David J
Published: February 2021

In mammals, the oviduct retains sperm, forming a reservoir from which they are released in synchrony with ovulation. However, the mechanisms underlying sperm release are unclear. Herein, we first examined in greater detail the release of sperm from the oviduct reservoir by sex steroids, and secondly, if the ubiquitin–proteasome system (UPS) mediates this release in vitro. Sperm were allowed to bind to oviductal cells or immobilized oviduct glycans, either bi-SiaLN or a suLeX, and channeled with steroids in the presence or absence of proteasome inhibitors. Previously, we have demonstrated progesterone-induced sperm release from oviduct cells and immobilized glycans in a steroid-specific manner. Herein, we found that the release of sperm from an immobilized oviduct glycan, a six-sialylated branched structure, and from immobilized fibronectin was inhibited by the CatSper blocker NNC 055-0396, akin to the previously reported ability of NNC 055-0396 to inhibit sperm release from another oviduct glycan, sulfated Lewis-X trisaccharide. Thus, CatSper may be required for release of sperm from a variety of adhesion systems. One possible mechanism for sperm release is that glycan receptors on sperm are degraded by proteasomes or shed from the sperm surface by proteasomal degradation. Accordingly, the inhibition of proteasomal degradation blocked sperm release from oviduct cell aggregates both immobilized oviduct glycans as well as fibronectin. In summary, progesterone-induced sperm release requires both active CatSper channels and proteasomal degradation, suggesting that hyperactivation and proteolysis are vital parts of the mechanism by which sperm move from the oviduct reservoir to the site of fertilization.
MOLECULAR MODELLING DESIGN AND OPIOID BINDING AFFINITY EVALUATION OF NEW 4-CHROMANONE DERIVATIVES
Authors: Ezzat Mohammed , Abd Razik Basma
Published: February 2021

The pharmacotherapy treatment of pain is an active and motivated area of investigation for treatment with free side effects. This paper presents the docking ability of twenty-five analogues of 4-Chromanone derivatives inside the crystal structure of μ opioid receptor to estimate the binding affinity of each derivative. Molecular modelling design approach applied to identify the effective substation position with generation of 989 novel 4-Chromanone derivatives. The final result of the most active twenty novel 4-Chromanone derivatives with docking affinity range (-9.89 to -9.34) kcal/mol were selected as promising hit ligand drugs comparing with morphine docking affinity at (-6.02) kcal/mol.
UTILIZATION OF MICROWAVE ASSISTED BLACK CUMIN SEED EXTRACT AS HYPOCHOLESTEROLEMIC AGENT IN ALBINO RATS
Authors: Khalil Anees Ahmed , Khalid Ahood , Khalid Hira , Aslam Ayesha , Shahid Quratul Ain , Hlebová Miroslava , Rebezov Maksim , Derkho Marina , Shariati Mohammad Ali
Published: February 2021

Main aim of this study was to evaluate hypocholesterolemic potential of microwave-assisted black cumin (Nigella sativa) extracts (MABCEs) in a rat bioassay. Efficacy trial in this study comprised of 25 male albino rats which were divided into 5 groups having 5 rats each. Out of these 25 rats, 20 were hypercholesterolemic and 5 were normal rats. Hypercholesterolemia was induced by providing high cholesterol diet for 15 days, and after the onset of hypercholesterolemia these rats were administered with different concentrations of the MABCE i.e. 150, 300 & 450 mg/kg B.W. for a period of 28 days. The administration of extract displayed significant lowering in the lipid profile of the experimental rats. The 300mg/kg B.W. dose of black cumin MAE provided the optimum results giving cholesterol, triglyceride and LDL-c content lowered by 14.9%, 11.32% and 12% and value of HDL-c elevated by 12.88% compared to the hypercholesterolemic control. Similarly, there was a percent elevation in levels of SOD and CAT by 19.83% and 13.97%. The current study concluded that MABCEs have hypocholesterolemic effect thus can be used for its therapeutic property.
DEVELOPMENT OF NANOEMULSION AND ITS CHARACTERIZATION FOR ANTI BIOFILM AND LARVICIDAL ACTIVITY
Authors: Subramani Ponnarmadha , Saminathan Chornaraj , Gowda Dinesh Narayana , Basha Niyas Sathik , Chandrasekar Vaidheki , Thangavel Santhosh kumar , Rajarathinam Ravikumar
Published: February 2021

Dengue is a mosquito borne viral disease and the main root cause vector is Aedes aegypti. Hence in this work a rapid measure was taken to eradicate the vector using nanoemulsion. Plant essential oil based nanoemulsions was formulated by ultrasonic emulsification method.  In the current study, nanoemulsion (O/W) was developed using oil extracted from the leaves of a Tulsi, Neem and Nochi. The emulsions were prepared in different ratios of oil and surfactant (Tween 80) and evaluated for their mechanical and thermal stability. After the confirmation of stable nanoemulsion formation, it was evaluated for its antibiofilm activity. Results revealed that the formulated mixed oil nanoemulsion exhibited enhanced antibiofilm activity against isolated microorganisms from contaminated wall samples. Further the biofilm forming capability of bacterial culture was indirectly assessed by staining with 1% crystal violet and measured absorbance using ethanol as a destaining solution. The mean biofilm production of S3 bacterial isolates significantly greater than that observed for S1 & S2. In addition, antibiofilm activity of the emulsion NE3 was higher against bacterial culture S3. Different concentration of mixed oil nanoemulsiom (NE3) treated group was subjected to evaluate the larvicidal activity against Aedes aegypti between 1 to 12 hours respectively. It was observed that an increase in the nanoemulsion concentration (NE3) to 25 ppm and 50 ppm resulted in complete loss of larval viability in 5 hr and 6 hr respectively. There is no significant difference in larval viability after 6 hr and 12 hr in all the treatment groups. Hence the above findings suggest the applicative potential of mixed nanoemulsion formulation for various applications including mosquito larval control and antibiofilm activity.
CAMPYLOBACTER AS A MAJOR FOODBORNE PATHOGEN: A REVIEW OF ITS CHARACTERISTICS, PATHOGENESIS, ANTIMICROBIAL RESISTANCE AND CONTROL
Authors: Ammar Ahmed M. , El-Naenaeey El-Sayed Y. , Abd El-Hamid Marwa I. , El-Gedawy Attia A. , Elmalt Rania M. S.
Published: February 2021

Campylobacter, mainly Campylobacter jejuni is viewed as one of the most well-known reasons of foodborne bacterial diarrheal sickness in people around the globe. The genus Campylobacter contains 39 species (spp.) and 16 sub spp. Campylobacter is microaerophilic, Gram negative, spiral-shaped rod with characteristic cork screw motility. It is colonizing the digestive system of numerous wild and household animals and birds, particularly chickens. Intestinal colonization brings about transporter/carrier healthy animals. Consequently, the utilization of contaminated meat, especially chicken meat is the primary source of campylobacteriosis in humans and chickens are responsible for an expected 80% of human campylobacter infection. Interestingly, in contrast with the most recent published reviews that cover specific aspects of campylobacter/campylobacteriosis, this review targets the taxonomy, biological characteristics, identification and habitat of Campylobacter spp. Moreover, it discusses the pathogenesis, resistance to antimicrobial agents and public health significance of Campylobacter spp. Finally, it focuses on the phytochemicals as intervention strategies used to reduce Campylobacter spp.in poultry production.
CONVERSION OF WHEAT STRAW INTO FERMENTABLE SUGARS USING CARBOXYMETHYL CELLULASE FROM TRICHODERMA VIRIDE THROUGH BOX-BEHNKEN DESIGN AND ARTIFICIAL NEURAL NETWORK
Authors: Nelofer Rubina , Nadeem Muhammad , Irfan Muhammad , Syed Quratulain , Nawaz Sara , Tahir Arifa
Published: February 2021

In this study, carboxymethyl cellulase was produced in submerged fermentation characterized and saccharification was optimized through Box-Behnken design. The optima pH and temperature of enzyme produced by Trichoderma viride were 5 and 50 oC, respectively. The crude enzyme had Km and Vmax values of 1.5143 µM and 0.9253µM/min, respectively, using carboxymethyl cellulose as substrate respectively. Three variables including pH (X1), incubation temperature (X2) and substrate concentration (X3) with three levels were used to optimize saccharification of wheat straw having 83% cellulose content using Box Behnken design and Artificial Neural Network (ANN). Results reveal that the proposed model was significant and quadratic effect of these parameters significantly affects the sugar production. Maximum sugar production (28.87 mg/ml) was predicted at RSM predicted levels of pH (6.6), incubation temperature (50 ºC) and (6.2%) substrate concentration, while the levels predicted for pH, temperature and substrate concentration were 5, 50 oC and 3.5 %, respectively, by ANN. The predicted sugar concentration at these levels was 30.72 mg/mL. The observed values at the predicted levels of RSM and ANN were 25.52 and 29.95 mg/mL respectively.
ISOLATION AND CHARACTERIZATION OF BIOACTIVE COMPOUNDS IN MEDICINAL PLANT Centella asiatica AND STUDY THE EFFECTS ON FUNGAL ACTIVITIES
Authors: BHUYAR PRAKASH , Ab. rahim Mohd Hasbi , Maniam Gaanty Pragas , Govindan Natanamurugaraj
Published: February 2021

Medicinal plants are sources of important therapeutic aids for alleviating human ailments. The present research investigation was carried out to study anti-fungal activity of C. asiatica were tested against C. albicans, Aspergillus niger, and Penicillium sp. using two methods, disc diffusion method and broth dilution method. C. asiatica crude methanol extract was found to be the most effective against fungal activity. Compared to disc diffusion, broth dilution was a more appropriate method to quantitatively determine the anti-Candida activity of plant extract, whereby the MIC values of the crude extracts was determined. The result from disc diffusion assay demonstrates that plant extracts have an inhibitory effect. However, the broth dilution method result reveal that C. asiatica crude methanol extract has lower MIC values, meaning it has more prove that C. asiatica has an anti-fungal effect. Bioactive analysis results reveled that bioactive compounds present in the leaf, stems, roots, and the whole plant extract from Centella asiatica are the major chemical constituents are n-Hexadecanoic acid (99%), cis-Vaccenic acid (91%), 5-Hydroxymethylfurfural (88%), Tetradecanoic acid (86%). Further study is required to find out the specific phytochemical which is responsible for its medicinal value.
DEVELOPMENT OF DIRECT EXPANDED HIGH PROTEIN SNACK PRODUCTS FORTIFIED WITH SACHA INCHI SEED MEAL
Authors: Jiapong Sutharut , Ruttarattanamongkol Khanitta
Published: February 2021

Direct expanded or ready-to-eat (RTE) snacks fortified with Sacha inchi (Plukenetia volubilis L.) seed meal, a by-product of oil extraction process, were developed using a co-rotating twin-screw extruder. The composite blends of various amounts of Sacha inchi seed meal (20-60%), rice flour (40-80%) were prepared for extrusion cooking at 10-15% in-barrel moisture, 10.88-15.14 kg/h of feeder speed and 400 rpm of screw speed. The final products were characterized in terms of physical properties (color, texture, density, expansion ratio, water absorption index (WAI), water soluble index (WSI), proximate compositions, sensory, in-vitro digestibility and antioxidant activities, respectively. The results indicate that level of Sacha inchi seed meal significantly affected the physical characteristics by increasing hardness and density of the snack products. Expansion ratio and WAI of the snack products were decreased by increasing the level of Sacha inchi seed meal. The sensory evaluation result shows that all snack formulations were generally accepted by consumers. The snack fortified with 40% Sacha inchi seed meal was the most acceptable product based on the overall characteristics. It contained highest protein content (24.94±0.07%) with approximately 1.79±0.16% fiber, 2.09±0.00% fat, 3.42±0.02% ash, 5.61±0.14% moisture, and 62.27±0.11% carbohydrate, respectively. Total digestibility of the snack was 41.11% in which 12.36% and 28.75% were digested in stomach and small intestine, respectively. The total phenolic content (TPC) was 205.46±11.66 mg GAE/g dry weight snack and the Trolox equivalent antioxidant capacity (TEAC) was 135.40±1.10 µmol TE/g dry weight snack. The extruded product developed from Sacha inchi seed meal is protein-rich and suitable for health-conscious consumers.
BIOCHEMICAL CHARACTERIZATION OF VEGETABLES WASTES AND DEVELOPMENT OF FUNCTIONAL BREAD
Authors: Hashmi Muhammad Saad , Akhtar Saeed , Ismail Tariq
Published: February 2021

The present study aimed at evaluating nutritional potential and antioxidant activity of the extracts derived from vegetable wastes such as carrot pomace, onion upper bulbs, and peels from garlic, tomato & potato. Proximate composition, minerals profiling and antioxidants activity as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and trolox equivalent antioxidant capacity (TEAC) were estimated, and phenolics characterization was performed using high performance liquid chromatography (HPLC). Our results suggest that vegetable wastes such as peel and pomace, may be exploited as carriers of proteins, fiber, calcium, potassium, iron and zinc. Phenolics screening demonstrated presence of total hydroxybenzoic, hydroxylcinammic acids and catechin albeit anthocyanins and total flavonols were inadequately present in tomato pomace. Maximum total phenolics contents and DPPH activity were observed in HCl/MeOH extracts of tomato and garlic peels, respectively. Product development data suggest incorporating onion peel’s extracts in wheat flour to not elicit a significant change in bread composition.  Likewise, supplementation of onion peel powder (OPP) and extracts @ 6% and 1.5%, respectively improved color and textural properties of supplemented bread. Contextualizing the challenges of food insecurity and food industry waste management, our results confirmed that vegetable wastes, with improved nutritional profile and increased antioxidant potential, may be used for the preparation of value-added food products.
VIRAL PANDEMICS OF TWENTY-FIRST CENTURY
Authors: Roychoudhury Shubhadeep , Das Anandan , Sengupta Pallav , Dutta Sulagna , Roychoudhury Shatabhisha , Kolesarova Adriana , Hleba Lukas , Massanyi Peter , Slama Petr
Published: February 2021

Pandemics are regarded as large-scale outbreaks of infectious disease that has the potential to significantly increase morbidity and mortality over a wide geographical area, which is accompanied by economic, social and political disruption. The likelihood of pandemic, especially caused by viral infectious diseases has increased over the past few years. The 21st century is just two decades old but it has already witnessed some of the deadliest viral pandemics having far-reaching consequences. These include Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) (2002), Influenza A virus subtype H1N1 (H1N1) (2009), Middle East Respiratory Syndrome Coronavirus (MERS-CoV) (2012) and Ebola virus (2013) and the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) (2019-present). The viruses may adopt various mechanisms to invade and hijack the cellular machinery of the host cell, followed by infection-mediated immunomodulation and progressive inflammation, which in turn, may affect the functioning of different organ systems of the body. Although effective commercial vaccines are unavailable for most of these viruses, those against SARS-CoV-2 are being developed at an unprecedented speed with few of the vaccines already being approved for commercial distribution. Significant policy attention is required to limit the outbreak of such pandemics and to expand and sustain investment to build preparedness and health capacity.
Calidad de vida laboral en Cartagena, Barranquilla y Santa Marta.
Authors: Galvis Aponte Luis Armando , Rodriguez Puello Gabriel , Ovallos Bencardino Sara
Published: February 2021

Recientemente, las principales ciudades del Caribe colombiano han alcanzado las menores cifras de desempleo en el país. Sin embargo, presentan altas tasas de informalidad. Así, este artículo tiene como objetivo analizar la situación de la informalidad y la calidad del empleo, en las tres principales ciudades de esta región colombiana. En 2007-2018, la informalidad decreció y las condiciones de vida laboral, analizadas a través del índice multidimensional de calidad del empleo (IMCE), son poco atractivas, en particular, para los ocupados con bajo nivel educativo, empleados domésticos, por cuenta propia y los trabajadores de empresaspequeñas.
The anesthesiologic management of bar removal after the Nuss procedure for repair of pectus excavatum
Authors:   Danylo Halytsky Lviv National Medical University, Ukraine, Myhal I.I.
Published: February 2021

Introduction. The anesthesiologic management of bar removal after the Nuss procedure for repair of pectus excavatum is not clearly discussed in literature. The aim of the study: analysing the anesthetic technique of bar removal after the Nuss procedure for repair of pectus excavatum. Materials and methods. The prospective randomized study included 24 adolescents undergone the bar removal after the Nuss procedure for repair of pectus excavatum under general anesthesia with tracheal intubation and artificial lung ventilation. The patients were randomized into two groups according to the analgesia technique: in group PVA (n=14) bilateral paravertebral anaesthesia was used and in group G (n=10) fentanyl was used intraoperatively and ketoprophen – postoperatively. Intravenous induction: propofol 2–3 mg/kg, fentanyl 3–4 mcg/kg, atracurium 0.6 mg/kg. The maintenance of anesthesia: propofol 6–10 mg/kg/h, fentanyl 2 mcg/kg as needed. The following parameters were analyzed: blood pressure systolic (BPs), diastolic (BPd), mean (BPm), pulse rate (PR) and pain intensity using visual analogue scale (VAS). Results: The changes in hemodynamic parameters during surgery and anesthesia were statistically significant (p<0.05), but the hemodynamics was clinically stable. BP and PR were more decreased during anesthesia in group PVA than in group G. Anesthesia was adequate in both groups. There was no need in additional fentanyl bolus after the induction dose in PVA group. Patients in G group needed additional 200 mcg fentanyl during surgery. After surgery the pain intensity was significantly higher in group G than in group PVA: at recovery from anesthesia and extubation of trachea in group PVA – 0 (0–1), in group G – 3 (2–4) (U=1.5; р=0.000002); in the evening of the day of surgery in group PVA – 1 (0–1); in group G – 3 (2–3) (U=6.0; р=0.000031); in the next morning after surgery in group PVA – 0 (0-0); in group G – 1.5 (1–2) (U=12.0; р=0.00027) cm according to VAS. There was no patient with pain intensity higher than 3 cm, so all patients had adequate analgesia. Conclusion. Bilateral paravertebral anesthesia provides more adequate analgesia than systemic administration of analgesics perioperatively for bar removal after the Nuss procedure for pectus excavatum correction. The study was conducted in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the institution. Informed consent of parents and children was obtained for the study. The author declares no conflict of interest. Key words: anesthesia, paravertebral block, pectus excavatum, Nuss procedure, bar removal.
Review of the theories of gastroschisis pathogenesis
Authors:   Danylo Halytsky Lviv National Medical University, Ukraine, Pereyaslov A.A.
Published: February 2021

Gastroschisis and omphalocele are the most common congenital malformations of the abdominal wall that required surgical correction. Despite of the long history of the gastroschisis’ study, there is no generally accepted theory of the pathogenesis of this malformation. There are numerous theories of the pathogenesis of gastroschisis discussed in the modern literature: disorders of differentiation of embrionic mesenchyme as the result of teratogenic influence on the early stages of the embryonic development; rupture of amniotic membrane at the base of the umbilical cord; vascular disorders during of the embryonic development; disorders of the yolk-sac escape. Each of existing theories has its supporters and opponents. It is no generally accepted theory of the pathogenesis of gastroschisis. Most likely is the rupture of physiological hernia along the umbilical cord in its pars flaccid, with the subsequent elongation of the midgut out of the abdominal cavity with the vascular compression, especially of venous and lymphatic vessels. Narrow mesenteric root and narrow-sized defect may contribute to various complications that jeopardize the ultimate prognosis. Further studies are needed to finalize the pathogenesis of gastroschisis. No conflict of interest was declared by the author. Key words: gastroschisis, pathogenesis, vascular disorders, embryonic disorders.