Experimental analysis for the effect of dynamic capillarity on stress transformation in porous silicon

The evolution of real-time stress in porous silicon(PS) during drying is investigated using micro-Raman spectroscopy. The results show that the PS sample underwent non-negligible stress when immersed in liquid and suffered a stress impulsion during drying. Such nonlinear transformation and nonhomogeneneous distribution of stress are regarded as the coupling effects of several physical phenomena attributable to the intricate topological structure of PS. The effect of dynamic capillarity can induce microcracks and even collapse in PSstructures during manufacture and storage.This work is funded by the National Natural Science Foundation of China Contract Nos. 10732080 and 10502014

Strain Sensor of Carbon Nanotubes in Microscale: From Model to Metrology

A strain sensor composed of carbon nanotubes with Raman spectroscopy can achieve measurement of the three in-plane strain components in microscale. Based on previous work on the mathematic model of carbon nanotube strain sensors, this paper presents a detailed study on the optimization, diversification, and standardization of a CNT strain sensor from the viewpoint of metrology. A new miniaccessory for polarization control is designed, and two different preparing methods for CNT films as sensing media are introduced to provide diversified choices for applications. Then, the standard procedure of creating CNT strain sensors is proposed. Application experiments confirmed the effectiveness of the above improvement, which is helpful in developing this method for convenient metrology

An Analytical Model for Adsorption and Diffusion of Atoms/Ions on Graphene Surface

Theoretical investigations are made on adsorption and diffusion of atoms/ions on graphene surface based on an analytical continuous model. An atom/ion interacts with every carbon atom of graphene through a pairwise potential which can be approximated by the Lennard-Jones (L-J) potential. Using the Fourier expansion of the interaction potential, the total interaction energy between the adsorption atom/ion and a monolayer graphene is derived. The energy-distance relationships in the normal and lateral directions for varied atoms/ions, including gold atom (Au), platinum atom (Pt), manganese ion (Mn 2+ ), sodium ion (Na 1+ ), and lithium-ion (Li 1+ ), on monolayer graphene surface are analyzed. The equilibrium position and binding energy of the atoms/ions at three particular adsorption sites (hollow, bridge, and top) are calculated, and the adsorption stability is discussed. The results show that H-site is the most stable adsorption site, which is in agreement with the results of other literatures. What is more, the periodic interaction energy and interaction forces of lithium-ion diffusing along specific paths on graphene surface are also obtained and analyzed. The minimum energy barrier for diffusion is calculated. The possible applications of present study include drug delivery system (DDS), atomic scale friction, rechargeable lithium-ion graphene battery, and energy storage in carbon materials

Searching for dark-matter induced neutrino signals in dwarf spheroidal galaxies using 10 years of IceCube public data

This study searches for neutrino signals from 18 dwarf spheroidal galaxies (dSphs) using 10 years of publicly available muon-track data of the IceCube neutrino observatory. We apply an unbinned likelihood analysis on each of these dSphs to derive the significance the putative neutrino emission. To further enhance our sensitivity, we also stack all dSphs together to perform a joint analysis. However, no significant neutrino emission signal was detected in either the single-source or stacking analysis. Based on these null results, we derive constraints on the annihilation cross section of dark matter particles. Compared to the existing literature, our constraints via the channel $\chi\chi\rightarrow\mu^+\mu^-$ are comparable to the ones from the VERITAS observations of dSphs

Hierarchical chirality transfer in the growth of towel gourd tendrils

Chirality plays a significant role in the physical properties and biological functions of many biological materials, e.g., climbing tendrils and twisted leaves, which exhibit chiral growth. However, the mechanisms underlying the chiral growth of biologic

Skp2 expression unfavorably impacts survival in resectable esophageal squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>The correlation of S-phase kinase–associated protein 2 (Skp2) with metastasis and prognosis in esophageal squamous cell carcinoma (ESCC) is controversial. The purpose of this study was to explore whether there was a correlation between the expression of Skp2 evaluated by immunohistochemistry and the clinical outcome of patients with operable ESCC, and to further determine the possible mechanism of the impact of Skp2 on survival.</p> <p>Methods</p> <p>Tissue microarrays that included 157 surgically resected ESCC specimens was successfully generated for immunohistochemical evaluation. The clinical/prognostic significance of Skp2 expression was analyzed. Kaplan-Meier analysis was used to compare the postoperative survival between groups. The prognostic impact of clinicopathologic variables and Skp2 expression was evaluated using a Cox proportional hazards model. A cell proliferation assay and a colony formation assay were performed in ESCC cell lines to determine the function of Skp2 on the progression of ESCC <it>in vitro</it>.</p> <p>Results</p> <p>Skp2 expression correlated closely with the T category (<it>p</it> = 0.035) and the pathological tumor-node-metastasis (TNM) stage (<it>p</it> = 0.027). High expression of Skp2 was associated with poor overall survival in resectable ESCC (<it>p</it> = 0.01). The multivariate Cox regression analysis demonstrated that pathological T category, pathological N category, cell differentiation, and negative Skp2 expression were independent factors for better overall survival. <it>In vitro</it> assays of ESCC cell lines demonstrated that Skp2 promoted the proliferative and colony-forming capacity of ESCCs.</p> <p>Conclusions</p> <p>Negative Skp2 expression in primary resected ESCC is an independent factor for better survival. Skp2 may play a pro-proliferative role in ESCC cells.</p

Trend Analysis of Research Articles Published in the Korean Journal of Women Health Nursing from 2013 to 2017

PURPOSE: To analyze articles published in the Korean Journal of Women Health Nursing from 2013 to 2017 to determine the latest research trends and understand how 2013 Korea Women&apos;s Health Statistics were reflected in journal articles. METHODS: A total of 130 studies were analyzed. Research design, types of research, research framework, research subjects, characteristics of quantitative research, characteristics of qualitative research, and keywords were analyzed using a structured analysis format. RESULTS: Quantitative and qualitative research accounted for 83.8% and 13% of these 130 studies analyzed, respectively. Non-experimental and experimental research accounted for 70.7% and 13.1% of these studies, respectively. The most frequent study subjects were childbearing women (62.8%), including college students, mothers, and adults. A total of 69.1% of non-experimental research and 88.2% of experimental research used convenience sampling. Questionnaires were most frequently used for data collection. The most frequent keyword domain involved health-related concepts (41%) among nine domains and the most frequently used keyword was “women.” CONCLUSION: This study suggest that further experimental research should be conducted in the future. Also, adolescent and the elderly women should be focused on as subjects in future studies based on results of 2013 Korean Women&apos;s Health Statistics

The global mismatch between equitable carbon dioxide removal liability and capacity

Limiting climate change to 1.5°C and achieving net-zero emissions would entail substantial carbon dioxide removal (CDR) from the atmosphere by mid-century, but how much CDR is needed at country level over time is unclear. The purpose of this paper is to provide a detailed description of when and how much CDR is required at country level to take in order to achieve 1.5°C and how much CDR countries can carry out domestically. We allocate global CDR pathways among 170 countries according to six equity principles and assess these allocations with respect to countries' biophysical and geophysical capacity to deploy CDR. Allocating global CDR to countries based on these principles suggests that CDR will, on average, represent ∼4% of nations' total emissions in 2030, rising to ∼17% in 2040. Moreover, equitable allocations of CDR, in many cases, exceed implied land and carbon storage capacities. We estimate ∼15% of countries (25) would have insufficient land to contribute an equitable share of global CDR, and ∼40% of countries (71) would have insufficient geological storage capacity. Unless more diverse CDR technologies are developed, the mismatch between CDR liabilities and land-based CDR capacities will lead to global demand for 6 GtCO2 carbon credits from 2020 to 2050. This demonstrates an imperative demand for international carbon trading of CDR

Fysisk prestation och matchkrav inom elitfotboll - Samband mellan smålagsspel och de mest intensiva perioder inom fotboll

De fysiska kraven hos elitfotbollsspelare är stora och såväl aerob som anaerob förmåga är viktiga för prestationen. Individuella skillnader i fysisk kapacitet spelare emellan är välkänt men individuell träningsplanering med lämplig belastning för att optimera spelares enskilda behov är inte lika väl studerat. Syftet med denna studie är att undersöka sambandet mellan spelares matchkrav i fotboll i form av högintensiva perioder (peakperioder) och träningsrespons på smålagsspel. Vi har studerat individuella spelares högintensiva perioder i match, olika typer av smålagsspel (4v4, 6v6 och 8v8) och andra fysiska tester. Studien har en kvantitativ experimentell design där GPS-data i fotboll är analyserad. 17 elitfotbollsspelare (Ålder 23.7 ± 4.8 år, vikt 76.4 ± 4.8 kg, längd 181.1 ± 5.2 cm) från allsvenskan och superettan i svensk herrfotboll deltog i studien. Resultaten visar att olika typer av smålagsspel belastar spelarna på olika sätt, där vissa fysiska variabler har ett medel (>0.30) till stark korrelation (>0.70), medan andra variabler visar en svag (>0.10) till ingen korrelation (<0.10). Sambandet mellan fysiska tester och matchkrav i form av peakperioder visar att endast Repeated Sprint Ability (RSA) kan ha en relevant användning för att förutse prestation i peakperioder. Information om vilken typ av smålagsspel som har vilken effekt och hur de belastar spelaren samt matchkrav på individ- och gruppnivå kan underlätta för tränaren vid utformning av träningsplanering. Slutligen krävs mer forskning inom området för att säkerhetsställa att tillämpningen av smålagsspel samt de fysiska testerna, gentemot matchkraven i form av peakperioder, blir så matchlik och optimal som möjligt