2,551 research outputs found

    Data-driven extraction of the substructure of quark and gluon jets in proton-proton and heavy-ion collisions

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    The different modification of quark- and gluon-initiated jets in the quark-gluon plasma produced in heavy-ion collisions is a long-standing question that has not yet received a definitive answer from experiments. In particular, the relative sizes of the modification of quark and gluon jets differ between theoretical models. Therefore a fully data-driven technique is crucial for an unbiased extraction of the quark and gluon jet spectra and substructure. We perform a proof-of-concept study based on proton-proton and heavy-ion collision events from the PYQUEN generator with statistics accessible in Run 4 of the Large Hadron Collider. We use a statistical technique called topic modeling to separate quark and gluon contributions to jet observables. We demonstrate that jet substructure observables, such as the jet shape and jet fragmentation function, can be extracted using this data-driven method. These results suggest the potential for an experimental determination of quark and gluon jet spectra and their substructure

    Feasibility of Combined UASB-MBR System in Treating PTA Wastewater and Polyimide Membrane for Biogas Purification

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

    Investigation of optimum EDM die sinking parameters in micro dimple machining

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    Micro dimple is a standard surface structure that is commonly used in micro-moulds, micro/nano-fluid devices, micromechanical systems, and bionic functional surfaces. These microstructure surfaces can be used for optical communication systems, micro sensors, flat panel display, light emitting diode applications and others. Many researchers have performed investigations on the parameters that help in manufacturing the micro dimple. However, there is still limited research on the certain parameters that will affect the micro dimple using EDM die sinking machine. EDM die sinking process involved a tool and workpiece material which immersed in a dielectric fluid medium and use the electrical spark discharges from electric pulse generation to remove the workpiece material. The actual performance of the surface integrity and form accuracy in micro dimple by EDM die sinking machine remains unclear. Therefore, this research attempts to investigate the effect of the dimple measurement such as diameter, depth and surface roughness (Ra) to the parameters which is surface roughness (Rz), sparking gap and type of electrode. By utilising the parameters, the lab experiment was conducted, and their surface integrity, effects in micro dimple behaviour were investigated. It was discovered that the higher surface roughness (Rz), the higher current produced thus erodes the material and caused the measurement of the dimple (diameter, depth and surface roughness (Ra)) differed from the expected size. Also the findings that the surface integrity was ununiformed due to the tool worn out occurred during the electric spark process causing high material rate removal. Other than that, the material electrode which has the high thermal conductivity and melting point resulted the best form accuracy of micro dimple

    Inhibitory Effects of Ketamine on Lipopolysaccharide-Induced Microglial Activation

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    Microglia activated in response to brain injury release neurotoxic factors including nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Ketamine, an anesthetic induction agent, is generally reserved for use in patients with severe hypotension or respiratory depression. In this study, we found that ketamine (100 and 250 μM) concentration-dependently inhibited lipopolysaccharide (LPS)-induced NO and IL-1β release in primary cultured microglia. However, ketamine (100 and 250 μM) did not significantly inhibit the LPS-induced TNF-α production in microglia, except at the higher concentration (500 μM). Further study of the molecular mechanisms revealed that ketamine markedly inhibited extracellular signal-regulated kinase (ERK1/2) phosphorylation but not c-Jun N-terminal kinase or p38 mitogen-activated protein kinase stimulated by LPS in microglia. These results suggest that microglial inactivation by ketamine is at least partially due to inhibition of ERK1/2 phosphorylation

    Analysing online reviews to investigate customer behaviour in the sharing economy: The case of Airbnb

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    Purpose: The purpose of this paper is to investigate attributes that influence Airbnb customer experience by analysing online reviews from users staying in London. It presents a text mining approach to identify a set of broad themes from the textual reviews. It aims to highlight the customers’ changing perception of good quality of accommodations. Design/methodology/approach: This paper analyses 169,666 reviews posted by Airbnb users who stayed in London from 2011 to 2015. Hierarchical clustering algorithms are used to group similar words into clusters based on their co-occurrence. Longitudinal analysis and seasonal analysis are conducted for a more coherent understanding of the Airbnb customer behaviour. Findings: This paper provides empirical insights about how Airbnb users’ mindset of good quality of accommodations changes over a five-year timespan and in different seasons. While there are common attributes considered important throughout the years, exclusive attributes are discovered in particular years and seasons. Research limitations/implications: This paper is confined to Airbnb experiences in London. Researchers are encouraged to apply the proposed methodology to investigate Airbnb experiences in other cities and detect any change in customer perception of quality stay. Practical implications: This paper offers implications for the prioritisation of customer concerns to design and improve services offerings and for alignment of services with customer expectations in the sharing economy. Originality/value: This paper fulfils an identified need to examine the change in customer expectation across the timespan and seasons in the case of Airbnb. It also contributes by illustrating how big data can be used to uncover key attributes that facilitate the engagement with the sharing economy

    Experimental and Clinical Pharmacology of Andrographis paniculata

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    Andrographis paniculata (Burm. F) Nees, generally known as “king of bitters,” is an herbaceous plant in the family Acanthaceae. In China, India, Thailand, and Malaysia, this plant has been widely used for treating sore throat, flu, and upper respiratory tract infections. Andrographolide, a major bioactive chemical constituent of the plant, has shown anticancer potential in various investigations. Andrographolide and its derivatives have anti-inflammatory effects in experimental models asthma, stroke, and arthritis. In recent years, pharmaceutical chemists have synthesized numerous andrographolide derivatives, which exhibit essential pharmacological activities such as those that are anti-inflammatory, antibacterial, antitumor, antidiabetic, anti-HIV, antifeedant, and antiviral. However, what is noteworthy about this paper is summarizing the effects of andrographolide against cardiovascular disease, platelet activation, infertility, and NF-κB activation. Therefore, this paper is intended to provide evidence reported in relevant literature on qualitative research to assist scientists in isolating and characterizing bioactive compounds

    SERPINE2, an inhibitor of plasminogen activators, is highly expressed in the human endometrium during the secretory phase

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    <p>Abstract</p> <p>Background</p> <p>SERPINE2, also known as protease nexin-1, belongs to the serine protease inhibitor (SERPIN) superfamily. It is one of the potent SERPINs that modulates the activity of plasminogen activators (PAs). PAs and their SERPIN inhibitors, such as SERPINB2 and SERPINE1, were expressed in the human endometrium and were implicated in implantation. However, expression data about SERPINE2 in the human endometrium is still unknown. Thus, we conducted an investigation to reveal the spatiotemporal and cellular expression of SERPINE2 in the human uterus during the menstrual cycle.</p> <p>Methods</p> <p>Seven patients who underwent a hysterectomy and samples of 120 archived patients' endometrial curettage or parts of the uterus that were formalin-fixed and embedded in paraffin. Western blotting was performed to evaluate the specificity and sensitivity of the antibody. Immunohistochemistry was conducted to localize the SERPINE2 expression site. Quantitative analysis was conducted to evaluate expression levels of SERPINE2 in various sub-phases of the menstrual cycle.</p> <p>Results</p> <p>The SERPINE2 protein was primarily detected in the uterine fluid during the mid- and late-secretory phases of the menstrual cycle. It was predominantly expressed in the luminal and glandular epithelium, less in the myometrium, and only dispersedly in certain stromal cells throughout the menstrual cycle. A quantitative analysis of expression levels of SERPINE2 in the glandular epithelium revealed that it was highly expressed in the endometrium during the secretory phase compared to the proliferative phase.</p> <p>Conclusions</p> <p>The SERPINE2 protein is highly expressed in the endometrium during the secretory phase, indicating that it may participate in tissue remodeling involved in implantation.</p

    The land snail fauna of Batu Kudik, isolated limestone outcrop near Simunjan, Sarawak, Malaysian Borneo (Mollusca, Gastropoda)

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    The present study provides a checklist of land snails collected from Batu Kudik, a small and isolated limestone outcrop in Simunjan, Sarawak. A total of 24 species of land snails, representing 18 genera and 14 families were recorded, including one newly-described subspecies. The most species-rich of the families in Batu Kudik are Diplommatinidae (17%) and Chronidae (17%) with four recorded species from each of the families. Based on our analysis, Plectostoma wallacei kudikense subsp. nov., Opisthostoma javanica and Georissa pyrrhoderma were identified as the most abundant land snails at this isolated outcrop, whereas Diplommatina onyx and Everettia minuta were recorded as the least abundant. All of the land snails at Batu Kudik were exclusively found sheltered between limestone boulders, underscoring the critical role of this outcrop as their refuge for survival. Consequently, conserving this biodiversity-rich limestone area becomes paramount to prevent the local extinction of these land snail species and possibly other organisms that depend on the unique attributes of the limestone for their survival. We also provide detailed descriptions of Plectostoma wallacei kudikense, a new subspecies of the genus Plectostoma which is endemic to Batu Kudik.A description of a new subspecies Plectostoma wallacei kudikense subsp. nov
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