Rc Values Research Articles

Association of remnant cholesterol with nonalcoholic fatty liver disease: a general population-based study

BackgroundRemnant cholesterol (RC) mediates the progression of coronary artery disease, diabetic complications, hypertension, and chronic kidney disease. Limited information is available on the association of RC with nonalcoholic fatty liver disease (NAFLD). This study aimed to explore whether RC can be used to independently evaluate the risk of NAFLD in the general population and to analyze the predictive value of RC for NAFLD.MethodsThe study included 14,251 subjects enrolled in a health screening program. NAFLD was diagnosed by ultrasound, and the association of RC with NAFLD was assessed using the receiver operating characteristic (ROC) curve and logistic regression equation.ResultsSubjects with elevated RC had a significantly higher risk of developing NAFLD after fully adjusting for potential confounding factors (OR 1.77 per SD increase, 95% CI 1.64–1.91, P trend< 0.001). There were significant differences in this association among sex, BMI and age stratification. Compared with men, women were facing a higher risk of RC-related NAFLD. Compared with people with normal BMI, overweight and obesity, the risk of RC-related NAFLD was higher in thin people. In different age stratifications, when RC increased, young people had a higher risk of developing NAFLD than other age groups. Additionally, ROC analysis results showed that among all lipid parameters, the AUC of RC was the largest (women: 0.81; men: 0.74), and the best threshold for predicting NAFLD was 0.54 in women and 0.63 in men.ConclusionsThe results obtained from this study indicate that (1) in the general population, RC is independently associated with NAFLD but not with other risk factors. (2) Compared with traditional lipid parameters, RC has a better predictive ability for NAFLD in men.

Evolution of a deeply-buried oil reservoir in the north Shuntuoguole Low Uplift, Tarim Basin, western China: Insights from molecular geochemistry and Re–Os geochronology

The recently discovered Shunbei Oilfield is perceived as a remarkable breakthrough in deep marine carbonate petroleum exploration in the Tarim Basin, western China. Constraining the absolute timing of petroleum system evolution is crucial for further hydrocarbon exploration and development in the area. Here, we integrated molecular geochemical correlation, stable carbon isotopes of bulk oil (bitumen) and Re–Os geochronology to trace the petroleum sources, to constrain the absolute timing of hydrocarbon generation, and to reconstruct the petroleum system evolution of the deeply-buried oil accumulations in carbonate reservoirs. Biomarker parameters derived from isoprenoids, terpanes, steranes and aromatic compounds, as well as stable carbon isotopic compositions, revealed that the Ordovician reservoir oils and bitumens were all originated from the same source rock, deposited under a highly-reduced environment with organic matters being predominantly contributed by algae and bacteria. The calculated equivalent vitrinite reflectance (Rc) values of reservoir bitumen and oil samples indicate that the Shunbei Oilfield has experienced at least two hydrocarbon charges. Geochemical characteristics and thermal maturity suggest that the bitumen within the Ordovician Yijianfang Formation reservoirs in the north Shuntuoguole Low Uplift is not originated from thermal cracking, thermochemical sulfate reduction, biodegradation, nor gas washing. Re–Os isotopic data from six reservoir bitumen samples yield an isochron age of 399 ± 12 Ma with an initial 187Os/188Os ratio (Osi) of 1.26 ± 0.11. This age is interpreted to represent the timing of oil generation when compared with the thermal evolution of possible source rocks and other radiometric dating results in the region. A comparison of 187Os/188Os of the 399 Ma-old bitumen and that of possible source rocks at the time of oil generation suggests that the reservoir oil was possibly originated from the lower Cambrian Yuertusi source rock. This work highlights that Re–Os geochronology combining with the initial 187Os/188Os ratio can be used to effectively constrain the timing of hydrocarbon generation in petroleum systems with complex tectonic history, multiple oil charges and alterations.

Standardizing Heat Pulse Probe measurements for thermal property determination using ice and water

The growing demand for Heat Pulse Probes (HPPs) to estimate thermal properties and surrogate soil processes comes with a need for improved standards for calibration and validation in reference materials. This study proposed air-free ice as a calibration material to determine the apparent rod spacing (rc) for HPPs. The advantage of using air-free ice as a calibration standard over agar-stabilized water stems from the fact that at 0 °C ice provides a reference volumetric heat capacity (Cv = 1.93 MJ m−3 °C−1), less than half that of water (Cv = 4.22 MJ m−3 °C−1), while ice provides a four times larger reference thermal conductivity value (λ = 2.16 W m−1 oC−1) relative to that of water (λ = 0.56 W m−1 °C−1), which leads to a sharper peak temperature rise curve that may improve thermal property estimates in ice compared to the elongated peak obtained in water. We performed rc calibrations with air-free ice in a freezer at −21 °C and agar-stabilized water at 21 °C using both Infinite-Line Source (ILS) and Identical-Cylinders Perfect-Conductors (ICPC) models to fit λ and Cv to temperature rise data and compute thermal diffusivity (κ) from the fitted λ and Cv (i.e., κ = λ/Cv). Results showed that the ICPC model yielded similar rc values in both air-free ice and agar-stabilized water with reduced Total Error (TE) in estimating λ, Cv, and κ compared to results with the conventional ILS model. We suggest air-free ice as another standard for Heat Pulse Probe (HPP) rod spacing calibration and sensor-based thermal property validation.

Magnetocaloric properties of Ni50Mn28Ga22 melt-spun ribbons

ABSTRACT NiMnGa-based Heusler alloys are known for their shape-memory effect. However, in this study, the focus will be on the magneto-thermal (magnetocaloric) properties of rapidly solidified Ni50Mn28Ga22 ribbons melt spun at 1300 and 1600 RPM as well as annealed bulk specimens. The ribbons, both as-spun and annealed, and the annealed bulk specimens were tested in a SQUID to determine the magnetic properties at a field of 50 kOe with a temperature step of 3 K in the temperature range 355–385 K. The magnetic data from the isotherms were used to achieve Arrott plots. Second-order transitions were observed in the materials at the TC temperature. The values of magnetic entropy ΔSm were calculated from the magnetic data and these were further used to calculate the values of refrigeration capacity RC. The highest RC value of 273 J/kg was obtained for 1300NMG5 800 where 1300, 800 and 5, represent the melt spinning rate in RPM, the annealing temperature in Celsius and the duration of annealing in hours, respectively. The values of ΔSm were similar for all the ribbons. To confirm the order of the magnetic transition, universal curves were plotted which led to the conclusion that the transformation at the Curie temperature is a second-order ferromagnetic to paramagnetic transition.

Magnetic properties, martensitic transformations and magnetocaloric performances in Ni44Mn45-xFexSn11 (x = 0–3) Heusler alloys

The structural, magnetic, and magnetocaloric properties of Ni44Mn45-xSn11Fex (x = 0, 1, 2 and 3) Heusler alloys have been studied detailly by means of X-ray diffraction, differential scanning calorimetry, and magnetization measurements. The martensitic transition temperature (TM) and austenite Curie temperature (TAC) increase gradually with increasing Fe content. Large differences in magnetization between the ferromagnetic austenite and weakly magnetic martensite phases and obvious thermal hysteresis have also been observed during the martensite transformation. With the magnetic field change up to 0–7 T, the maximum value of magnetic entropy changes reaches 26.7 and 23 J kg−1K−1 for x = 1 and 2, respectively, which are much larger than the undoped sample (9.8 J kg−1K−1). Whereas, the effective refrigerant capacity RCeff reduced due to Fe doping increased the hysteresis loss. The alloy for x = 1 has highest RC value of 172 (255) J kg−1 for a magnetic field change of 0–5 T (0–7 T), furthermore, a large magnetic entropy change and moderate RCeff has been obtained around room temperature.

Complex Featuring Two Double Dative Bonds Between Carbon(0) and Uranium

Complex Featuring Two Double Dative Bonds Between Carbon(0) and Uranium

One-Step Synthesis of NbSe2/Nb-Doped-WSe2 Metal/Doped-Semiconductor van der Waals Heterostructures for Doping Controlled Ohmic Contact.

van der Waals heterostructures (vdWHs) of metallic (m-) and semiconducting (s-) transition-metal dichalcogenides (TMDs) exhibit an ideal metal/semiconductor (M/S) contact in a field-effect transistor. However, in the current two-step chemical vapor deposition process, the synthesis of m-TMD on pregrown s-TMD contaminates the van der Waals (vdW) interface and hinders the doping of s-TMD. Here, NbSe2/Nb-doped-WSe2 metal-doped-semiconductor (M/d-S) vdWHs are created via a one-step synthesis approach using a niobium molar ratio-controlled solution-phase precursor. The one-step growth approach synthesizes Nb-doped WSe2 with a controllable doping concentration and metal/doped-semiconductor vdWHs. The hole carrier concentration can be precisely controlled by controlling the Nb/(W + Nb) molar ratio in the precursor solution from ∼3 × 1011/cm2 at Nb-0% to ∼1.38 × 1012/cm2 at Nb-60%; correspondingly, the contact resistance RC value decreases from 10 888.78 at Nb-0% to 70.60 kΩ.μm at Nb-60%. The Schottky barrier height measurement in the Arrhenius plots of ln(Isat/T2) versus q/KBT demonstrated an ohmic contact in the NbSe2/WxNb1-xSe2 vdWHs. Combining p-doping in WSe2 and M/d-S vdWHs, the mobility (27.24 cm2 V-1 s-1) and on/off ratio (2.2 × 107) are increased 1238 and 4400 times, respectively, compared to that using the Cr/pure-WSe2 contact (0.022 cm2 V-1 s-1 and 5 × 103, respectively). Together, the RC value using the NbSe2 contact shows 2.46 kΩ.μm, which is ∼29 times lower than that of using a metal contact. This method is expected to guide the synthesis of various M/d-S vdWHs and applications in future high-performance integrated circuits.

Loading rate effect on mixed mode I/II brittle fracture behavior of PMMA using inclined cracked SBB specimen

This paper investigates the effect of loading rate on the mixed-mode I/II fracture behavior of PolymethylMethacrylate (PMMA). Experimental studies are performed using a novel fracture test specimen which has recently been developed, called short bend beam (SBB), in different loading rates of 1 mm/min, 20 mm/min, and 200 mm/min. Fracture test data are presented for pure mode I, pure mode II, and mixed-mode I/II conditions, thanks to the geometrical configuration offered by the specimen covering a full spectrum of mode mixities. Two fracture criteria including maximum tangential stress (MTS), and generalized maximum tangential stress (GMTS) are employed to predict the onset of fracture and the fracture initiation angle in different loading rates. The MTS criterion only considers the singular crack tip terms associated with the stress intensity factors (SIFs) in the solution while the GMTS includes the T-stress effect as well as the SIF-related terms. While enhanced predictions provided by the GMTS criterion, as compared to MTS results, reveals the significance of including the T-stress term in the theoretical calculations, the critical distance (rc) is also found as another major parameter playing an important role in the fracture behavior. It is shown that the size of rc decreases by increasing the loading rate. Therefore, for the first time, a variable and loading rate dependent rc value is utilized for employment of the GMTS criterion and it is demonstrated that considering variable critical distance can provide acceptable theoretical predictions for different loading rates.

A Novel Method to Reduce Specific Contact Resistivity of TiSix/n+-Si Contacts by Employing an In-Situ Steam Generation Oxidation Prior to Ti Silicidation

Due to extremely tight Contacted Poly Pitch (CPP) in sub-10 nm nodes, specific contact resistivity ( ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ) has become the main concern for further improvement of transistor performance. Both the reduction of Schottky barrier heights (SBHs) and the enhancement of surface dopant concentration (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> ) are considered as the most effective approaches to reduce ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> . In this work, a novel in-situ steam generation (ISSG) oxidation process prior to Ti silicidation is proposed to achieve an enhanced N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> value, thanks to the segregation of P at the surface of n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -Si. Refined Transmission Line Model (RTLM) structures were fabricated to extract the ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> accurately and reliably. The dopant redistribution of P was characterized by both secondary ion mass spectrometry (SIMS) and spreading resistance probe (SRP). Compared to control samples, the ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> value for samples with 4 nm ISSG SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> is reduced from 2.91×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup> to 1.90×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup> Ω-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and this is attributed to the enhancement of N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> value.

A robot system for the autodetection and classification of apple internal quality attributes

Soluble solids content (SSC) is an important index of apple internal quality. To invent a more flexible and efficient method of apple internal quality detection and classification, a robot system for the autodetection and classification of apple internal quality attributes was developed. Visible and near infrared (Vis/NIR) spectroscopy is a promising technology for the nondestructive detection of the internal quality attributes of apples. The end effector of the robot system mainly carried the Vis/NIR spectra collection module and gripping mechanism. The Vis/NIR spectrum was collected when the end effector gripped the apple. Single shot multibox detector (SSD) target detection algorithm was applied to process the images and calculate the position of the apple, which greatly reduced the low accuracy of apple identification caused by light intensity and complex backgrounds, and the speed was approximately 0.055 s per frame. In comparing different modeling results, the normalized spectral ratio (NSR) pretreatment combined with the competitive adaptive reweighted sampling algorithm (CARS) obtained the best modeling result, with Rc and Rcv values of 0.979 and 0.969 and RMSEC and RMSECV values of 0.335 % and 0.385 %, respectively. The classification accuracy of independent validation was 90.0 % with Rp and RMSEP values of 0.952 and 0.393 %. The robot system required approximately 5.200 s to complete a classification for each sample. The results showed feasibility of the robot system to detect the internal quality attributes of apples.

Advanced method for electrical characterization of carrier-selective passivating contacts using transfer-length-method measurements under variable illumination

Carrier-selective passivating contacts have been demonstrated to be crucial to reach the practical efficiency limit of single junction, crystalline silicon (c-Si) based solar cells. Yet, the electrical transport losses affecting the collection of photogenerated carriers remain to be addressed. To this aim, different methodologies and characterization techniques are currently used. In this contribution, we propose the concept of shell as a new terminology to describe carrier-selective passivating contacts. Then, we present a novel characterization methodology using transfer length method (TLM) measurement under variable illumination to investigate the charge-carrier transport in amorphous/crystalline silicon heterojunction (SHJ) n-type contact stacks. We use technology computer-aided design simulation to model a TLM structure and to identify the physical phenomena and the key parameters affecting the contact resistivity (ρc) and the charge carrier accumulation of such contact stacks. Then, the simulation results are compared with experimental data by performing variable-illumination TLM measurements of actual SHJ n-type contact stacks. Specifically, we demonstrate that illumination has a strong impact on the measured ρc value, highlighting the importance of measuring ρc under maximum power point conditions for a relevant characterization of solar cell transport losses. In addition, we investigate the dependence of ρc to a change in the injected carrier density within the c-Si bulk to compare the illumination responses of different SHJ n-type contact stacks. In the quest for maximal efficiency, this method may insightfully complete other characterization techniques to further understand and study the electrical transport in solar cells.

Comfort Distance—A Single-Number Quantity Describing Spatial Attenuation in Open-Plan Offices

ISO 3382-3 is globally used to determine the room acoustic conditions of open-plan offices using in situ measurements. The key outcomes of the standard are three single-number quantities: distraction distance, rD, A-weighted sound pressure level of speech, Lp,A,S,4m, and spatial decay rate of speech, D2,S. Quantities Lp,A,S,4m and D2,S describe the attenuation properties of the office due to room and furniture absorption and geometry. Our purpose is to introduce a new single-number quantity, comfort distance rC, which integrates the quantities Lp,A,S,4m and D2,S. It describes the distance from an omnidirectional loudspeaker where the A-weighted sound pressure level of normal speech falls below 45 dB. The study explains why the comfort criterion level is set to 45 dB, explores the comfort distances in 185 offices reported in previous studies. Based on published data, the rC values lie typically within 3 m (strong attenuation) and 30 m (weak attenuation). Based on this data, a classification scheme was proposed. The new quantity could benefit the revised version of ISO 3382-3.

GO-Ti3C2 two-dimensional heterojunction nanomaterial for anticorrosion enhancement of epoxy zinc-rich coatings

MXenes are a unique family of two-dimensional (2D) transition metal carbides and/or nitrides, which have been proven useful for energy storage, water purification, and biomedical applications. Herein, a kind of heterojunction structure was designed by grafting highly conductive MXene (Ti3C2) on the graphene oxide (GO) nanosheets， which was confirmed by Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectronic spectroscopy (XPS) and Raman results. Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and salt spray measurements corroborated that inclusion of 0.5 wt% Ti3C2 or GO-Ti3C2 into epoxy zinc-rich coating (ZRC) effectively enhance the cathodic protection capability. Additionally, superior corrosion resistance was achieved by incorporation of GO-Ti3C2 into ZRC since GO-Ti3C2 in the coating improved the utilization rate of zinc particles and GO provided barrier protection for inhibiting the diffusion of corrosive agents. At the end of immersion, Rc value of ZRC/GO-Ti3C2 coating was 3.047 × 104 Ω·cm2, which was one order of magnitude higher than that of ZRC coating. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) measurements demonstrated that ZRC/GO-Ti3C2 coating exhibited lower speed of zinc particles oxidation and intact steel substrate. Hence, ZRC/GO-Ti3C2 coating exhibited the optimal corrosion resistance among the four kinds of coatings.

Maritime Cloud and Drizzle Microphysical Properties Retrieved From Ship‐Based Observations During MAGIC

AbstractThe Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign provided a wealth of information looking at the stratocumulus to cumulus transition (SCT) over the Eastern‐North Pacific (ENP), however, the lack of cloud in situ measurements gave limited information. Using the observations of Marine W‐band ARM cloud radar, ceilometer, and three‐channel microwave radiometer onboard the ship, we retrieve the single‐layer, low‐level cloud‐droplet effective radius and drizzle median radius (rc and rm,d), number concentration (Nc and Nd), and liquid water content (LWCc and LWCd) using the methods in Wu et al. (2020, https://doi.org/10.1029/2019JD032205). Based on the results during MAGIC, we found that both cloud base and top heights increase approximately 0.75 km from Los Angeles (LA) until cloud breakup (CB) before leveling off. Low cloud fractions (CFs) ranged from ∼85% halfway between LA and CB to ∼20% near Hawaii. Retrieved rc values decreased approximately 2 μm from peak CF to Hawaii while rm,d increased more than 20 μm over the same path. Mean values of rc, rm,d, Nc, Nd, LWCc, and LWCd during MAGIC are 12.1 μm, 55.8 μm, 97.9 cm−3, 0.09 cm−3, 0.40 g m−3, and 0.05 g m−3, respectively. Compared to the mean values over the Azores in Wu et al. (2020, https://doi.org/10.1029/2019JD032205), the mean cloud and drizzle microphysical properties during MAGIC, except LWCd which is roughly equal, are greater due to higher liquid water path and warmer sea surface temperature. This information allows for a better understanding of the SCT over the ENP and can be used to better improve model simulations.

Generic Approach for Contacting Thermoelectric Solid Solutions: Case Study in n- and p-Type Mg2Si0.3Sn0.7.

Metallization (known as contacting) of thermoelectric (TE) legs is vital to the long-term performance of a TE device. It is often observed that the compositional changes in a TE solid solution may render a given contact material unsuitable due to a mismatch in the thermal expansion coefficient values. Finding suitable contact materials for TE solid solutions (which often are the best TE materials) remains a challenge. In this work, we propose a multilayer single-step approach in which the same combination of contact materials can be used for a wide compositional range in a solid solution. The outer layer is a metal foil, which helps in creating an Ohmic contact with the interconnects. The intermediate layer is a mixture of the TE material and a metal powder, which results in the formation of the diffusion barrier. The innermost layer is the TE material, which is the active component of the device. The strategy was applied on n- and p-doped Mg2Si0.3Sn0.7 with elemental Cu and Ni providing the desired interface functionalities. Single-step compaction was carried out using the monoblock sintering technique. Microscopic investigation reveals the formation of a well-bonded crack-free interface. Various intermetallic phases were identified at the interface, and the formation of the MgNi2Sn phase was found to be critical to prevent any interdiffusion of elements. Electrical contact resistance (rc) measurements were conducted, and low values of 3 and 19 μΩ cm2 were measured in n- and p-type legs, respectively. The contacted TE legs were further annealed at 400 °C for 7 days to check their stability. Microstructural and electrical resistance measurements reveal minimal changes in the interface layer and rc values, indicating the workability of the multilayer technique.

Production costs and business benefits hydroponics spinach

Analysis of the cost structure of spinach farming with a hydroponic system needs to be done to determine the costs incurred in this business and how to allocate costs for each activity. Increasing production and income can be done if the costs incurred are known with certainty. The objectives of the research are to analyze costs, revenues, income, R/C ratio, B/C ratio and BEP for spinach farming using hydroponic systems in Bandar Lampung. The analytical methods used were descriptive analysis and quantitative analysis. Methods of data analysis using calculating costs, profit R/C ratio, B/C ratio and BEP. The results showed that the total costs incurred for the production of hydroponic spinach with a land area of 108 m2 is IDR 4,000,000. The profit obtained from spinach hydroponic farming is IDR 817,839 per growing season with a BEP value of IDR 3,978 and a selling price of IDR 5,000. Based on the value of R/C and B/C ratio, it can be concluded that spinach hydroponic farming is profitable. This is because the value of RC&gt; 1 is 1.26 and the value of BC&gt; 0 is 0.26

Studing the Effect of Etching Process on the Ohmic Specific Contact Resistance of AlGaN/GaN HEMT

In electronic devices, ranging from integrated circuits to solar cells, the Ohmic specific contact resistance between metal and semiconductor is a measure of device performance. In this paper, the effect of Induction Coupled Plasma etching (ICP) on creating specific contact resistance between metals and semiconductors was investigated by linear transmission method (LTLM). The obtained results show that selecting etching depth and etch process conditions by ICP method before metal coating is a decisive step in the manufacture of low resistance Ohmic contact. The value of formed Ohmic specific contact resistance is the lowest when the etching depth ensures the metal layers to cover the doped AlGaN region at a distance of about 8nm above the AlGaN/GaN interface. With an ion power source (RIE) of 30W and a plasma power source (ICP) of 250W, the etching rate of AlGaN material is approximately 27.21 nm / minute. The Ohmic specific contact resistance of metal layers Ti (20nm) / Al (200nm) / Pd (60nm) / Au (100nm) with AlGaN semiconductor has an optimal value of ρc = 1.08 x 10-7 cm2, despite the sample was annealing at a relatively low temperature of 650oC, in a nitrogen atmosphere at 650oC.

Trends in socioeconomic inequalities in the incidence of ovarian cancer among women in Canada: 1992–2010

ABSTRACT Ovarian cancer is the seventh most common cancer among women worldwide. We assessed the effect of socioeconomic status on ovarian cancer incidence in Canada between 1992 and 2010. We linked data from the Canadian Cancer Registry (CCR), Canadian Census of Population (CCP), and National Household Survey (NHS) to measure socioeconomic inequalities in the incidence of ovarian cancer among Canadian women over the study period. The age-standardized relative and absolute concentration index (RC and AC, respectively) were calculated to quantify income- and education-related inequalities in the incidence of ovarian cancer in Canadian women during this period. Despite a slight increase in the crude incidence of ovarian cancer in Ontario, Quebec, New Brunswick, Newfoundland and Labrador & Prince Edward Island, and Canada as a whole, the incidence of ovarian cancer in Canada has mostly remained stable, between 13 and 15 new cases per 100,000 per year between 1992 and 2010. The estimated age-standardized RC and AC values for the study period did not indicate any statistically significant relationship between income or education status, and the incidence of ovarian cancer in Canada. Future work should be directed at seeking related risk factors other than socioeconomic status that may contribute to the incidence of this disease.

Petroleum charge history of deeply buried carbonate reservoirs in the Shuntuoguole Low Uplift, Tarim Basin, west China

The newly discovered Shunbei Oilfield marks a major breakthrough in deep marine carbonate oil and gas exploration in the Tarim Basin. Understanding the petroleum charge history of the deep reservoirs will greatly benefit further petroleum exploration and development in this area. In this paper, we reconstruct the petroleum charge history of the reservoirs by integrating molecular geochemical correlations of reservoir oils and oil components (free oils and quasi-inclusion oils) from reservoir rocks, fluid inclusion analysis and basin modelling results. Molecular parameters derived from steranes, terpanes and aromatic compounds indicate that the reservoir oils, free oils and quasi-inclusion oils were all derived from the same source rock, deposited in a highly reduced marine environment with organic matters being mainly contributed by algae and bacteria. Utilizing the correlation between methylated aromatic compounds and vitrinite reflectance, the calculated vitrinite reflectance (Rc) values for the reservoir oils, free oils and quasi-inclusion oils fall into two distinct maturity ranges, with one spanning from 0.80%Rc to 0.96%Rc, and the other ranging from 1.15%Rc to 1.24%Rc, respectively. The timing of oil charge in the Shunbei Oilfield is constrained by combining fluid inclusion homogenization temperature (Th) with burial history modelling. Two oil charge events occurred in the reservoirs with the first marked by the relatively “low-maturity” oil, occurring in the latest Silurian around 426 Ma; whereas the second represented by the relatively “high-maturity” oil, occurring during the early Carboniferous around 330 Ma. This study highlights the significance of stable tectonic setting and excellent sealing capability of cap rocks for reservoir preservation. The finding unravels the petroleum charge and accumulation history of the Shunbei oil reservoirs and provides new insights for future exploration.

Critical Frequency and Critical Stretching Rate for Reorientation of Cells on a Cyclically Stretched Polymer in a Microfluidic Chip.

The ability of cells to sense and respond to mechanical signals from their surrounding microenvironments is one of the key issues in tissue engineering and regeneration, yet a fundamental study of cells with both cell observation and mechanical stimulus is challenging and should be based upon an appropriate microdevice. Herein we designed and fabricated a two-layer microfluidic chip to enable simultaneous observation of live cells and cyclic stretching of an elastic polymer, polydimethylsiloxane (PDMS), with a modified surface for enhanced cell adhesion. Human mesenchymal stem cells (hMSCs) were examined with a series of frequencies from 0.00003 to 2 Hz and varied amplitudes of 2%, 5%, or 10%. The cells with an initial random orientation were confirmed to be reoriented perpendicular to the stretching direction at frequencies greater than a threshold value, which we term critical frequency (fc); additionally, the critical frequency fc was amplitude-dependent. We further introduced the concept of critical stretching rate (Rc) and found that this quantity can unify both frequency and amplitude dependences. The reciprocal value of Rc in this study reads 8.3 min, which is consistent with the turnover time of actin filaments reported in the literature, suggesting that the supramolecular relaxation in the cytoskeleton within a cell might be responsible for the underlying cell mechanotransduction. The theoretical calculation of cell reorientation based on a two-dimensional tensegrity model under uniaxial cyclic stretching is well consistent with our experiments. The above findings provide new insight into the crucial role of critical frequency and critical stretching rate in regulating cells on biomaterials under biomechanical stimuli.