A topological index (TI) is a real number that defines the relationship between a chemical structure and its properties and remains invariant under graph isomorphism. TIs defined for chemical ...structures are capable of predicting physical properties, chemical reactivity and biological activity. Several kinds of TIs have been defined and studied for different molecular structures. Graphene is the thinnest material known to man and is also extremely strong while being a good conductor of heat and electricity. With such unique features, graphene and its derivatives have found commercial uses and have also fascinated theoretical chemists. In this article, the neighbourhood sum degree-based M-polynomial and entropy measures have been computed for graphene, graphyne and graphdiyne structures. The proper analytical expressions for these indices are derived. The obtained results will enable theoretical chemists to study these exciting structures further from a structural perspective.
The use of masks as a personal protective material is the new normal in the post-pandemic. The higher use of masks triggers immediate disposal of synthetic textile fibers leading to environmental ...pollution. This research is aimed to analyse the level of mask-related pollution and its impact on microfiber release. Microfiber emission characteristics of the tri-layer nonwoven mask (Polypropylene-based disposable mask) are analysed in the dry and wet stages. The individual layers of the mask and the entire mask are evaluated by subjecting them to static immersion and mechanical agitation against freshwater and seawater in the wet stage. The results of the study showed a higher microfiber shedding at dry state (14,031.97–177,601.58 fibers/mask) than the wet state (2557.65–22,525.89 fibers/mask). The increased fuzz formation in the dry state than the wet state is noted as the main reason. In the case of wet state, when the freshwater and seawater are compared, both in a static and agitated state, seawater degraded the mask highly (3358.03–27,348.9 fibers/mask) than the freshwater (1757.26–17,702.86 fibers/mask). Higher salinity and density of the seawater were noted as influencing parameters over the freshwater. When the results of naturally weathered masks are compared with the new mask, weathered masks released significantly (p < 0.05) higher amount of fibers at the evaluation stages. Similar to the new masks, the weathered masks also showed a higher amount of shedding in the dry state and presence of seawater. When the individual layers of the disposable masks were evaluated, at dry and wet states, all the layers showed a similar shedding (no significant difference between individual layers) in the case of a new mask. Whereas, after weathering, a significant amount of higher shedding (p < 0.05) is noted in the middle layer of the mask followed by the outer and inner layer. The difference in fiber composition is noted as the main reason for the strength difference of the nonwoven structure. Statistical analysis confirmed the significant impact of the natural weathering process and seawater on the microfiber shedding.
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•Dry abrasion during the handling, usage, and open land disposal cause the release of 14031.97 – 177601.58 fibers/mask.•Seawater exposed samples released more microfibers than the freshwaters exposed samples but lower than the dry state.•The natural weathering process has a significant impact on microfiber release at both dry and wet states.•Improper disposal of masks in open lands and water bodies was reported as a potential source of microfiber pollution.
Microfibers released from textile materials are receiving greater attention due to their severe adverse effects on the environment. Although mitigation strategies have been developed for laundering, ...researchers uphold that it is crucial to start mitigating at the source. In that aspect, this research aims to analyze the cutting and sewing methods of knitted fabrics and their impact on the microfiber release of garments during laundry. The results of the study have confirmed that cutting and sewing methods have a significant impact on the microfiber release of a garment. The analysis of different cutting methods showed that laser and ultrasonic cutting methods reduce the microfiber release up to 20 times compared to the conventional scissor-cut edges. While comparing the different stitch types, the overlock stitch type showed reduced shedding than the other stitch types (flatlock stitch and single needle lockstitch). Our results showed that the use of more needles increases the microfiber emission among different stitch variations of the same stitch type. For instance, a 45.27 % increase in microfiber emission was reported with the 4-thread overlock stitch (2 needles) than with the 3-thread stitch (1 needle). Regarding seam type, the proposed edge finishing seam (EFb) was effective in reducing 93 % of microfiber release as the edges are completely covered. When the effect of stitch density is considered, in the case of single needle lockstitch and flatlock stitch, the microfiber release is reduced with increased stitch density. However, a different trend was noted in overlock, which needed detailed exploration in the future. The results confirmed that a proper selection of stitch, stitch density, and seam type would reduce the microfiber release from a garment by up to 64.6 %.
Synthesized of graphene nano sheets were carried out by using new route and ammonia as well as to produce gram scale graphene. Graphene nano sheets was characterized by using Fourier transform ...infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX). The results of XRD showed that the reemergence of diffraction lines C(002) at 2θ =26.5°, and the distance between the planes is 3.35 Å, which shows the typical structure of graphite and multiple layer of graphene. The results of SEM-EDX showed that the particle size and the graphene nano sheets has a smaller pore size and uniform and randomly arranged aggregates with a thin layer which is closely related to one another. Graphene nano sheets has small size or shape is small and thin also aggregate related with each other.
Summary Background Fetal alcohol spectrum disorder (FASD) is related to many comorbidities because of the permanent effects of prenatal alcohol exposure on the fetus. We aimed to identify the ...comorbid conditions that co-occur in individuals with FASD and estimate the pooled prevalence of comorbid conditions occurring in individuals with fetal alcohol syndrome (FAS). Methods We did a systematic literature search of studies reporting on the comorbidity and cause of death in individuals with FASD using multiple electronic bibliographic databases, searching for studies published up to July, 2012. We included original research published in a peer-reviewed journal in the English language. We used the following criteria for determining study quality: use of an established FASD diagnostic guideline, study setting, method of data collection, and sample size. All comorbid disease conditions were coded according to the International Classification of Diseases, tenth revision (ICD-10). To estimate the pooled prevalence of comorbid conditions found to co-occur in individuals with FAS, we did meta-analyses assuming a random-effects model. Findings Of 5068 studies found, 127 met eligibility criteria for data extraction. From those studies, we identified 428 comorbid conditions co-occurring in individuals with FASD, spanning across 18 of 22 chapters of the ICD-10. The most prevalent disease conditions were within the sections of congenital malformations, deformities, and chromosomal abnormalities, and mental and behavioural disorders. 33 studies reported data for frequency in a total of 1728 participants with FAS. The five comorbid conditions with the highest pooled prevalence (between 50% and 91%) included abnormal results of function studies of peripheral nervous system and special senses, conduct disorder, receptive language disorder, chronic serous otitis media, and expressive language disorder. Interpretation The high prevalence of comorbid conditions in individuals with FASD highlights the importance of assessing prenatal alcohol exposure as a substantial clinical risk factor for comorbidity. The harmful effects of alcohol on a developing fetus represent many cases of preventable disability, and thus, alcohol use during pregnancy should be recognised as a public health problem globally. Funding Public Health Agency of Canada.
At present, the fault diagnosis of pumping units in major oil fields in China is time-consuming and inefficient, and there is no universal problem for high requirements of hardware resources. In this ...study, a fault fusion diagnosis method of pumping unit based on improved Fourier descriptor (IDF) and rapid density clustering RBF (RDC-RBF) neural network is proposed. Firstly, the minimum inertia axis of the center of gravity of the indicator diagram is obtained. The farthest point of the intersection of the inertial axis and the contour is determined as the starting point. Then Fourier transform is performed on the contour boundary of the graph to obtain the feature vector. Then, combining with the idea of fast density clustering algorithm, the number of hidden layer neurons of RBF is determined by finding the point with the highest density and using it as the hidden layer neuron. At the same time, the characteristics of Gaussian function are introduced to ensure the activity of hidden layer neurons. Finally, through dynamic adaptive cuckoo search (DACS), the step size is automatically adjusted according to the convergence speed of the objective function of RBF, and the efficiency and accuracy of RBF in different search stages are balanced. The optimal parameters such as the width and weight of RBF are determined, and the optimal RDC-RBF fault diagnosis model is established. The model is applied to the diagnosis of different fault types of pumping units, and compared with the current mainstream models. The average detection accuracy of the fusion RDC-RBF fault diagnosis method proposed in this paper reaches 96.3%. The measured results have high accuracy and short time. At the same time, this method is currently applied to oil production sites such as Shengli Oilfield in China, which greatly reduces the human resources required for fault diagnosis of pumping units in the past.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sleep is an essential process that supports learning and memory by acting on synapses through poorly understood molecular mechanisms. Using biochemistry, proteomics, and imaging in mice, we find that ...during sleep, synapses undergo widespread alterations in composition and signaling, including weakening of synapses through removal and dephosphorylation of synaptic AMPA-type glutamate receptors. These changes are driven by the immediate early gene Homer1a and signaling from group I metabotropic glutamate receptors mGluR1/5. Homer1a serves as a molecular integrator of arousal and sleep need via the wake- and sleep-promoting neuromodulators, noradrenaline and adenosine, respectively. Our data suggest that homeostatic scaling-down, a global form of synaptic plasticity, is active during sleep to remodel synapses and participates in the consolidation of contextual memory.
Microwave photonic technologies, which upshift the carrier into the optical domain, have facilitated the generation and processing of ultra-wideband electronic signals at vastly reduced fractional ...bandwidths. For microwave photonic applications such as radars, optical communications and low-noise microwave generation, optical frequency combs are useful building blocks. By virtue of soliton microcombs, frequency combs can now be built using CMOS-compatible photonic integrated circuits. Yet, currently developed integrated soliton microcombs all operate with repetition rates significantly beyond those that conventional electronics can detect, preventing their use in microwave photonics. Access to this regime is challenging due to the required ultra-low waveguide loss and large dimensions of the nanophotonic resonators. Here, we demonstrate soliton microcombs operating in two widely employed microwave bands, the X-band (~10 GHz, for radar) and the K-band (~20 GHz, for 5G). Driven by a low-noise fibre laser, these devices produce more than 300 frequency lines within the 3 dB bandwidth, and generate microwave signals featuring phase noise levels comparable to modern electronic microwave oscillators. Our results establish integrated microcombs as viable low-noise microwave generators. Furthermore, the low soliton repetition rates are critical for future dense wavelength-division multiplexing channel generation schemes and could significantly reduce the system complexity of soliton-based integrated frequency synthesizers and atomic clocks.Nanophotonic microwave synthesizers in the X-band (10 GHz, for radar) and K-band (20 GHz, for 5G), based on integrated soliton microcombs driven by a low-noise fibre laser, link the fields of microwave photonics and integrated microcombs.
Low-loss photonic integrated circuits and microresonators have enabled a wide range of applications, such as narrow-linewidth lasers and chip-scale frequency combs. To translate these into a ...widespread technology, attaining ultralow optical losses with established foundry manufacturing is critical. Recent advances in integrated Si
N
photonics have shown that ultralow-loss, dispersion-engineered microresonators with quality factors Q > 10 × 10
can be attained at die-level throughput. Yet, current fabrication techniques do not have sufficiently high yield and performance for existing and emerging applications, such as integrated travelling-wave parametric amplifiers that require meter-long photonic circuits. Here we demonstrate a fabrication technology that meets all requirements on wafer-level yield, performance and length scale. Photonic microresonators with a mean Q factor exceeding 30 × 10
, corresponding to 1.0 dB m
optical loss, are obtained over full 4-inch wafers, as determined from a statistical analysis of tens of thousands of optical resonances, and confirmed via cavity ringdown with 19 ns photon storage time. The process operates over large areas with high yield, enabling 1-meter-long spiral waveguides with 2.4 dB m
loss in dies of only 5 × 5 mm
size. Using a response measurement self-calibrated via the Kerr nonlinearity, we reveal that the intrinsic absorption-limited Q factor of our Si
N
microresonators can exceed 2 × 10
. This absorption loss is sufficiently low such that the Kerr nonlinearity dominates the microresonator's response even in the audio frequency band. Transferring this Si
N
technology to commercial foundries can significantly improve the performance and capabilities of integrated photonics.
The indiscriminate use of antimicrobials in aquaculture results in antibiotic selection pressure and proliferation of antimicrobial resistant (AMR) bacteria. Frequent assessment of antimicrobial ...resistance in aquaculture environment is inevitable so as to reduce the passage of clinically important AMR from aquatic to other environment. The present study analysed the antimicrobial resistance of pathogens associated with diseased koi carp and goldfish from an ornamental fish farm. Phenotypic and genotypic characterization of the recovered isolates from both fishes revealed significant pathogens in aquaculture such as Aeromonas, Edwardsiella tarda, Acinetobacter, Lactococcus, Citrobacter, Enterobacter and Comamonas. Shannon–Wiener diversity of koi isolates (2·359) was found to be higher than that of goldfish (1·864). Antibiotic susceptibility testing using disc diffusion with 47 antibiotics revealed significant resistance pattern of Acinetobacter, Comamonas, Klebsiella and Enterobacter from goldfish and Edwardsiella, Aeromonas, Lactococcus, Enterobacter and Acinetobacter from koi with higher multiple antibiotic resistance indexes (>0·3). The minimum inhibitory concentration of antibiotics for the major resistant isolates was found to be very high with >256 μg. All the isolates were susceptible to amoxicillin, kanamycin, cefepime, cefexime, cefotaxime, ceftazidime, doripenem, ciprofloxacin and norfloxacin, recommending their successful application in the farm.
Significance and Impact of the Study
Antimicrobial resistance is a major threat faced in aquaculture industry. The current study provides baseline information regarding the antibiotic resistance patterns of diverse pathogens recovered from ornamental koi carp and goldfish. The higher MAR index of pathogens and greater MIC of antibiotics for the resistant isolates highlighted the intense use of antibiotics in aquaculture farm. The potential of the pathogens to exhibit resistance even towards the new generation antibiotics remind the need of prudent use of antibiotics and continuous monitoring and surveillance programmes.
Significance and Impact of the Study: Antimicrobial resistance is a major threat faced in aquaculture industry. The current study provides baseline information regarding the antibiotic resistance patterns of diverse pathogens recovered from ornamental koi carp and goldfish. The higher MAR index of pathogens and greater MIC of antibiotics for the resistant isolates highlighted the intense use of antibiotics in aquaculture farm. The potential of the pathogens to exhibit resistance even towards the new generation antibiotics remind the need of prudent use of antibiotics and continuous monitoring and surveillance programmes.
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