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Background Statistical data on the burden and relevant risk factors of lung cancer are valuable for policy‐making. This study aimed to compare the mortality of lung cancer attributable to smoking stratified by sex and age among adults in China and the United States (US). Methods We extracted age‐standardized mortality rates of lung cancer during 1990‐2017 using the comparative risk assessment framework of the 2017 Global Burden of Disease study. We performed an age‐period‐cohort analysis to estimate time trend of lung cancer mortality attributable to smoking. Results During 1990‐2017, the age‐standardized mortality rate of lung cancer was increasing in China but decreasing in the US for both sexes. The mortality attributable to smoking in China showed a generally increasing trend, while a continuous decrease was observed in the US. The age‐period‐cohort analysis showed a similar trend of age effect among adults between China and the US: the mortality substantially increased from the 30‐34 to 80‐84 age group and subsequently decreased in the 90‐94 age group. However, the period effect rapidly increased in Chinese adults during 1990‐2017, while it tended to be stable in the US although it was still slightly increasing in women. The cohort effect generally peaked in the earlier cohort born in 1902‐1906 in the two countries. Conclusions During 1990‐2017, the lung cancer mortality attributable to smoking and the period effect are generally increasing in Chinese adults; the mortality attributable to smoking is decreasing in the US adults, but the period effect tends to be stable. The rapid aging and prevalence of smoking may intensify the increasing mortality of lung cancer in China.

Background Statistical data on burden of kidney cancer and the relavant risk factors are valuable for policy-making. This study aims to estimate kidney cancer deaths and high body-mass index (BMI) attributable to the deaths by gender and age group in China adults, compared with U.S. Methods We extracted kidney cancer data (1990–2017) about the age-standardized rates using the comparative risk assessment framework of the 2017 Global Burden of Disease study. We performed an age-period-cohort (APC) analysis to estimate trends of kidney cancer mortality attributable to high BMI. Results During 1990–2017, age-standardized mortality rate of kidney cancer was increasing in China but decreasing in U.S. The mortality attributable to high BMI in China showed a general increasing trend, while that in U.S. men was increasing and tended to be stable in women since 1995. APC analysis showed a similar pattern of age effect between China and U.S. adults, which substantially increased from 20 to 24 to 90–94 age group. Differently, the period effect rapidly increased in China than U.S. adults during 1990–2017. The cohort effect peaked in the earlier cohort born in 1902–1906 in China, and it declined consistently in U.S. with exception of 1902–1906 and 1907–1911 birth cohort. Conclusions The kidney cancer deaths attributable to high BMI, and period effect have been generally increasing in China adults, compared with U.S. adults in which the trend tends to be stable in recent years. The rapid aging may also intensify the increasing trend of kidney cancer death in China. Effective measures should be conducted on body weight control and care for kidney cancer prevention.

Graphene has unique electronic properties 1 , 2 , and graphene nanoribbons are of particular interest because they exhibit a conduction bandgap that arises due to size confinement and edge effects 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . Theoretical studies have suggested that graphene nanoribbons could have interesting magneto-electronic properties, with a very large predicted magnetoresistance 4 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 . Here, we report the experimental observation of a significant enhancement in the conductance of a graphene nanoribbon field-effect transistor by a perpendicular magnetic field. A negative magnetoresistance of nearly 100% was observed at low temperatures, with over 50% magnetoresistance remaining at room temperature. This magnetoresistance can be tuned by varying the gate or source–drain bias. We also find that the charge transport in the nanoribbons is not significantly modified by an in-plane magnetic field. The large observed values of magnetoresistance may be attributed to the reduction of quantum confinement through the formation of cyclotron orbits and the delocalization effect under the perpendicular magnetic field 15 , 16 , 17 , 18 , 19 , 20 . A significant enhancement in the conductance of a graphene nanoribbon field-effect transistor is observed when a perpendicular magnetic field is applied.

The previous studies estimated the association between PM 2.5 (particulate matter with aerodynamic diameter less than or equal to 2.5 μm) exposure during pregnancy and preterm birth, only considered and highlighted the hazard effects of high levels of air pollutant exposure, and underestimated that low levels of pollutant exposure might also affect pregnancy outcome. We conducted a meta-analysis of 11 cohort studies, a total of more than 1,500,000 subjects. The results of these studies were pooled by exposure levels and study periods. PM 2.5 exposure during pregnancy was positively associated with preterm birth (OR = 1.15, 95% CI = 1.07–1.23), and during the first trimester of pregnancy, low levels of PM 2.5 exposure were also positively associated with preterm birth (OR = 1.17, 95% CI = 1.04–1.30). It is important to protect pregnant women from PM 2.5 exposures, especially during their first trimester of pregnancy even when the ambient PM 2.5 concentration is relatively low. More relevant health policy should be carried out to prevent hazard effect of air pollutants.

In order to improve the erosion resistance of steel PDC (Polycrystalline Diamond Compact) bit under high-speed fluid flow conditions underground, it is necessary to develop a high-performance erosion-resistant coating. In this paper, laser cladding was used to prepare the new coating by modifying tungsten carbide with graphene. And the effects of tungsten carbide content and graphene content on the coating performance have been thoroughly studied and analyzed to obtain the optimal covering layer. The research results indicate that, for new coatings, 60% tungsten carbide and 0.3% graphene are the optimal ratios. After adding tungsten carbide, the hardness has significantly improved. However, when the tungsten carbide content further increases more than 30%, the increase in hardness is limited. In addition, when the content of graphene is more than 0.3%, the branched structure becomes thicker. In detail, this is a phenomenon where the segregation of Cr, Si, and W becomes very obvious again, and the segregation of Fe occurs at the Ni enrichment site. The research results contribute to the development and optimization of high-quality erosion-resistant coatings under the high-speed flow conditions in wellbore. These are of great significance for improving the efficiency of oil and gas exploration and development.

This study investigated the hypothesis that the chromosomal genotoxicity of inorganic mercury results from interaction(s) with cytoskeletal proteins. Effects of Hg2+ salts on functional activities of tubulin and kinesin were investigated by determining tubulin assembly and kinesin-driven motility in cell-free systems. Hg2+ inhibits microtubule assembly at concentrations above 1 microM, and inhibition is complete at about 10 microM. In this range, the tubulin assembly is fully (up to 6 microM) or partially (~6-10 microM) reversible. The inhibition of tubulin assembly by mercury is independent of the anion, chloride or nitrate. The no-observed-effect-concentration for inhibition of microtubule assembly in vitro was 1 microM Hg2+, the IC50 5.8 microM. Mercury(II) salts at the IC50 concentrations partly inhibiting tubulin assembly did not cause the formation of aberrant microtubule structures. Effects of mercury salts on the functionality of the microtubule motility apparatus were studied with the motor protein kinesin. By using a \"gliding assay\" mimicking intracellular movement and transport processes in vitro, HgCl2 affected the gliding velocity of paclitaxel-stabilised microtubules in a clear dose-dependent manner. An apparent effect is detected at a concentration of 0.1 microM and a complete inhibition is reached at 1 microM. Cytotoxicity of mercury chloride was studied in V79 cells using neutral red uptake, showing an influence above 17 microM HgCl2. Between 15 and 20 microM HgCl2 there was a steep increase in cell toxicity. Both mercury chloride and mercury nitrate induced micronuclei concentration-dependently, starting at concentrations above 0.01 microM. CREST analyses on micronuclei formation in V79 cells demonstrated both clastogenic (CREST-negative) and aneugenic effects of Hg2+, with some preponderance of aneugenicity. A morphological effect of high Hg2+ concentrations (100 microM HgCl2) on the microtubule cytoskeleton was verified in V79 cells by immuno-fluorescence staining. The overall data are consistent with the concept that the chromosomal genotoxicity could be due to interaction of Hg2+ with the motor protein kinesin mediating cellular transport processes. Interactions of Hg2+ with the tubulin shown by in vitro investigations could also partly influence intracellular microtubule functions leading, together with the effects on the kinesin, to an impaired chromosome distribution as shown by the micronucleus test.

As deep oil and gas resources and Carbon Capture and Storage (CCS) are developed, enhancing drilling efficiency in hard rock formations has emerged as a critical technology in oil and gas extraction. The advancement of ultrasonic, high-frequency vibration rock-breaking technology significantly facilitates efficient rock crushing. When subjected to ultrasonic high-frequency vibrations, the rock’s response is a crucial issue in implementing ultrasonic vibration rock crushing technology. This study employed numerical simulation and theoretical deduction methods, utilizing a multi-physics approach that couples solid mechanics with pressure acoustics. It integrated information on common influencing parameters of ultrasonic generators and reservoir rock properties to establish model parameters, analyze simulation results, and perform theoretical deductions. The research investigated the response patterns of different-sized rock samples under high-frequency ultrasound vibration excitation across various frequencies, amplitudes, and confining pressure conditions. Through the development of a three-dimensional model and the application of principles from solid mechanics and elastoplasticity, the study derived equations that describe the resonance frequencies of rock blocks under confining pressure as functions of relevant rock parameters. The findings indicate that ultrasonic vibrations can effectively induce rock displacement. Under excitation frequency sources, the rock exhibits a natural frequency correlated with the rock sample size. When the excitation frequency approximates the natural frequency, the rock resonates. At this point, the rock’s surface displacement is maximal. The rock undergoes tensile stress, leading to stress concentration that facilitates rock damage and fragmentation. Increasing the excitation amplitude enhances rock crushing, as it amplifies the maximum surface displacement under the same frequency excitation. Confining pressure exerts an inhibitory effect on the rock’s vibration response, but it does not alter the resonance frequency of the rock sample, a fact verified by both numerical simulation and theoretical results. Based on the research findings in this paper, it can help to optimize the parameters of ultrasonic vibration rock breaking in field application to achieve the best rock-breaking effect.

The application of ultra-high-pressure (UHP) water jets for rock slotting in the bottom hole has been recognized as a highly effective approach to enhance rock-breaking efficiency. However, the current downhole intensifiers are confronted with various limitations, including the short duration of UHP pulse water jet output and challenges in attaining both controllable and adjustable output frequencies, consequently leading to compromised slotting efficiency. In this study, a novel intensifier controlled by an electromagnetic valve was designed, and a visual test platform was constructed to investigate the output pressure characteristics and their influencing factors. The output characteristics of the intensifier consist of a mixed pulse jet composed of high-pressure and low-pressure jets, resulting in a square wave-like output waveform with an adjustable frequency. The output pressure characteristics of the intensifier are primarily influenced by the input pressure and the switching time of the electromagnetic valve, assuming that the structural parameters are constant. Increasing the input pressure raises the peak pressure, thereby enhancing the slotting capability of the jet stream. Aligning the switching time of the electromagnetic valve with the rotation period of the drill bit improves the slotting efficiency. In the lab tests, the output pressure of the intensifier was successfully increased to 118.2 MPa, with a sustained duration of a high-pressure jet segment for 2.1 s. These research findings offer a new method for enhancing drilling efficiency in deep hard rock formations.

The purpose of this study was to analyze the existing studies and to investigate the relationship between children’s full-scale intelligence quotient (FIQ), verbal IQ (VIQ), and performance IQ (PIQ) and their blood lead (Pb) and zinc (Zn) levels. All documents in Chinese and English were collected from the PubMed, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) databases from inception date to December 30, 2016. RevMan software (version 5.2) was used for the meta-analysis and Stata software (version 12.0) for the meta-regression and sensitivity analyses. A total of 32 eligible literatures was included in the study. Seven prevalence studies showed that the blood Pb level was negatively correlated with children’s IQ. The results of the meta-analysis from 22 case-control studies indicate a significant difference between FIQ and PIQ with blood Pb levels, detailed as the FIQ score with a weighted mean difference (WMD) = −6.60 (95% CI: −9.01, −4.20), P < 0.001; PIQ WMD = −8.85 (95% CI: −12.651, −5.05), P < 0.001; but VIQ WMD = −3.32 (95% CI: −6.98, 0.33), P > 0.05. Three studies on the blood Zn concentrations were with a FIQ WMD = 7.88 (95% CI: −0.07, 15.83), VIQ WMD = 7.73 (95% CI: −7.40, 22.86), and PIQ WMD = 6.69 (95% CI: −7.13, 20.51), all P > 0.05. The results indicate that Pb is harmful to children’s intelligence development, especially in PIQ. Zn is beneficial to intelligence, although more studies are needed.

Motivated by the rising of the carbon electronics and the potential applications of bilayer graphene nanoribbons in both electronics and optics, this thesis focuses on the fundamental transport properties of bilayer graphene nanoribbons. Two types of devices were fabricated from mechanically exfoliated bilayer graphene films, by using nanowires masks and the oxygen plasma etching process. In the back-gated devices, transport gaps and Coulomb blockade effect indicate that the disorder-induced potential landscape creates quantum dots along the nanoribbons and governs the transport property. In the dual-gated devices, the effects of the perpendicular electric field leads to the evolution of the transport gap size and the oscillation strength. The interaction between the potential landscape and the field-induced gap is proposed to explain the observed transport behavior. Our study reveals the dominant factors in the bilayer graphene nanoribbon transport under different conditions. The physical understanding presented here points out the possible routes towards future applications.