When a charge neutral drop impacts on a flat solid substrate, a small air bubble is always trapped underneath due to the lubrication pressure coming from the viscous stress in the squeezed air film. Herein we find experimentally and numerically that the process of the air entrapment and the initial contact state of the drop with the substrate can be profoundly altered via an external electric field. In an electric field, the induced electric stresses at the bottom of the drop increase drastically right before the drop contacts the substrate, which acts against the lubrication pressure, resulting in reduced initial contact radius and air bubble size. When the external electric field reaches a critical value, the electrical stress accelerates the flow near the bottom of the drop and generates a conical tip quickly instead of a dimple, resulting in a centre contact and eliminating the air bubble entrapment. Based on the dipole mirror charge model, we find the dimensionless strength of critical electric field scales with the square root of capillary number based on the air viscosity. This scaling law of the critical electric field for eliminating the air bubble entrapment is verified experimentally and numerically. This work may offer a new way to mitigate defects caused by air bubble entrapment for inkjet printing and droplet-based additive manufacturing.

The safety and reliability of robots are very important for the inspection in a long-distance pipeline used for the oil and gas transportation. In this paper, the long-distance pipeline pig and robots (LDPPRs) are classified into two categories, which are velocity-uncontrollable type and velocity-controllable type. Among them, the velocity control of velocity-controllable LDPPR has three ways, which are friction resistance, driving force, and self-running. Meanwhile, the mechanical models of the motion of the LDPPRs are classified into the dynamic model of the velocity-uncontrollable LDPPRs, velocity-controllable LDPPRs, and vibration, and the contact mechanics model between the rubber barrel and the pipe wall. In addition, the anti-stuck technologies, the inspection technologies, and the location technologies are investigated and analyzed. Thus, the purpose of this review is to provide a concise reference for the development and research directions, as well as the design of the LDPPRs.

The 4.2 ka event is widely presumed to be a globally widespread aridity event and has been linked to several episodes of societal changes across the globe. Whether this climate event impacted the cultural development in south-central China remains uncertain due to a lack of regional paleorainfall records. We present here stalagmite stable carbon isotope and trace element–based reconstruction of hydroclimatic conditions from south-central China. Our data reveal a sub–millennial scale (~5.6 to 4.3 ka) drying trend in the region followed by a gradual transition to wetter conditions during the 4.2 ka event (4.3–3.9 ka). Together with the existing archaeological evidence, our data suggest that the drier climate before 4.3 ka may have promoted the Shijiahe culture, while the pluvial conditions during the 4.2 ka event may have adversely affected its settlements in low-lying areas. While military conflicts with the Wangwan III culture may have accelerated the collapse of Shijiahe culture, we suggest that the joint effects of climate and the region's topography also played important causal roles in its demise.

Many waterflooding oil fields, injecting water into an oil-bearing reservoir for pressure maintenance, are in their middle to late stages of development. To explore the geological conditions and improve oilfield recovery of the most important well group of the Hu 136 block, located on the border areas of three provinces (Henan, Shandong, and Hebei), Zhongyuan Oilfield, Sinopec, central China, a 14C cross-well tracer monitoring technology was developed and applied in monitoring the development status and recognize the heterogeneity of oil reservoirs. The tracer response in the production well was tracked, and the water drive speed, swept volume of the injection fluid were obtained. Finally, the reservoir heterogeneity characteristics, such as the dilution coefficient, porosity, permeability, and average pore-throat radius, were fitted according to the mathematical model of the heterogeneous multi-layer inter-well theory. The 14C-AMS technique developed in this work is expected to be a potential analytical method for evaluating underground reservoir characteristics and providing crucial scientific guidance for the mid to late oil field recovery process.

For a multi-vectored propeller aerostat with actuator faults, this study presents a fault-tolerant tracking control strategy, which includes fault modeling, observer, force estimation and tracking controller. Fault modeling considers the four types of faults of vectored propellers, namely, thrust offset, thrust efficiency loss, vectored angle offset and vectored angle stuck. Actuator faults can be determined from the fault observer, which identifies the thrust offset from the acceleration difference of the faulty aerostat with the ideal model. For tracking positions, a traditional PID controller is constructed with virtual control, compensated with the estimated fault force. The control allocation scheme is proposed to redistribute the available actuators in case faults occur. Simulation results of position tracking prove the effectiveness of the proposed strategy.

Prospective cohort studies linking organ meat consumption and nonalcoholic fatty liver disease (NAFLD) are limited, especially in Asian populations. This study aimed to prospectively investigate the association between organ meat consumption and risk of NAFLD in a general Chinese adult population. This prospective cohort study included a total of 15,568 adults who were free of liver disease, cardiovascular disease, and cancer at baseline. Dietary information was collected at baseline using a validated food frequency questionnaire. NAFLD was diagnosed by abdominal ultrasound after excluding other causes related to chronic liver disease. Cox proportional regression models were used to assess the association between organ meat consumption and risk of NAFLD. During a median of 4.2 years of follow-up, we identified 3,604 incident NAFLD cases. After adjusting for demographic characteristics, lifestyle factors, vegetable, fruit, soft drink, seafood, and red meat consumption, the multivariable hazard ratios (95% confidence intervals) for incident NAFLD across consumption of organ meat were 1.00 (reference) for almost never, 1.04 (0.94, 1.15) for tertile 1, 1.08 (0.99, 1.19) for tertile 2, and 1.11 (1.01, 1.22) for tertile 3, respectively (P for trend <0.05). Such association did not differ substantially in the sensitivity analysis. Our study indicates that organ meat consumption was related to a modestly higher risk of NAFLD among Chinese adults. Further investigations are needed to confirm this finding.

Athetis lepigone Möschler (Lepidoptera, Noctuidae) is a common maize pest in Europe and Asia. However, there is no long-term effective management strategy is available yet to suppress its population. Adults rely heavily on olfactory cues to locate their optimal host plants and oviposition sites. Pheromone-binding proteins (PBPs) are believed to be responsible for recognizing and transporting different odorant molecules to interact with receptor membrane proteins. In this study, the ligand-binding specificities of two AlepPBPs (AlepPBP2 and AlepPBP3) for sex pheromone components and host plant (maize) volatiles were measured by fluorescence ligand-binding assay. The results demonstrated that AlepPBP2 had a high affinity with two pheromones [(Z)-7-dodecenyl acetate, Ki = 1.11 ± 0.1 μM, (Z)-9-tetradecenyl acetate, Ki = 1.32 ± 0.15 μM] and ten plant volatiles, including (-)-limonene, α-pinene, myrcene, linalool, benzaldehyde, nonanal, 2-hexanone, 3-hexanone, 2-heptanone and 6-methyl-5-hepten-2-one. In contrast, we found that none of these chemicals could bind to AlepPBP3. Our results clearly show no significant differences in the functional characterization of the binding properties between AlepPBP2 and AlepPBP3 to sex pheromones and host plant volatiles. Furthermore, molecular docking was employed for further detail on some crucial amino acid residues involved in the ligand-binding of AlepPBP2. These findings will provide valuable information about the potential protein binding sites necessary for protein-ligand interactions which appear as attractive targets for the development of novel technologies and management strategies for insect pests.

This paper presents a geometrical alternative to estimate the accuracy of a deployable mechanism equipped on the Synthetic Aperture Radar (SAR) space satellite. The deployable mechanism is simplified into a planar mechanism, and the error space of the outer panel in its deployed state is modeled concerning multiple revolute joint clearances and link length tolerances. Compared with the existing methods, the advance of the proposed geometrical approach lies in that it gives expressions of the complete error mobility that the outer panel may have. After deducing the expressions, the final error space is visualized and evaluated numerically with discrete sampling points. Finally, based on the error space and the computed maximum errors, effects of tolerances on accuracy are studied and the optimal accuracy design of tolerances is obtained. The result reveals that, for the deployable mechanism discussed in this paper, effects of tolerances on the final accuracy can be eliminated without increasing the manufacturing cost.

The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6, was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6. These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6. These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.

Mars exploration motivates the search for extraterrestrial life, the development of space technologies, and the design of human missions and habitations. Here, we seek new insights and pose unresolved questions relating to the natural history of Mars, habitability, robotic and human exploration, planetary protection, and the impacts on human society. Key observations and findings include:

1. – high escape rates of early Mars' atmosphere, including loss of water, impact present-day habitability;

2. – putative fossils on Mars will likely be ambiguous biomarkers for life;

3. – microbial contamination resulting from human habitation is unavoidable; and

4. – based on Mars' current planetary protection category, robotic payload(s) should characterize the local martian environment for any life-forms prior to human habitation.

Some of the outstanding questions are:

1. – which interpretation of the hemispheric dichotomy of the planet is correct;

2. – to what degree did deep-penetrating faults transport subsurface liquids to Mars' surface;

3. – in what abundance are carbonates formed by atmospheric processes;

4. – what properties of martian meteorites could be used to constrain their source locations;

5. – the origin(s) of organic macromolecules;

6. – was/is Mars inhabited;

7. – how can missions designed to uncover microbial activity in the subsurface eliminate potential false positives caused by microbial contaminants from Earth;

8. – how can we ensure that humans and microbes form a stable and benign biosphere; and

9. – should humans relate to putative extraterrestrial life from a biocentric viewpoint (preservation of all biology), or anthropocentric viewpoint of expanding habitation of space?

Studies of Mars' evolution can shed light on the habitability of extrasolar planets. In addition, Mars exploration can drive future policy developments and confirm (or put into question) the feasibility and/or extent of human habitability of space.

Laser–plasma accelerators (LPAs) have great potential to realize a compact X-ray free-electron laser (FEL), which is limited by the beam properties currently. Two-color high-intensity X-ray FEL provides a powerful tool for probing ultrafast dynamic systems. In this paper, we present a simple and feasible method to generate a two-color X-ray FEL pulse based on an LPA beam. In this scheme, time-dependent mismatch along the bunch is generated and manipulated by the designed lattice system, enabling FEL lasing at different wavelength within two undulator sections. The time separation between the two pulses can be precisely adjusted by varying the time-delay chicane. Numerical simulations show that two-color soft X-ray FELs with gigawatt-level peak power and femtosecond duration can be generated, which confirm the validity and feasibility of the scheme.

The present study investigated the effect of black soldier fly (Hermetia illucens) larvae meal (BSF) on haemolymph biochemical indicators, muscle metabolites as well as the lipid and glucose metabolism of Pacific white shrimp Litopenaeus vannamei. Four diets were formulated in which the control diet contained 25 % of fishmeal (FM) and 10 % (BSF10), 20 % (BSF20), and 30 % (BSF30) of FM protein were replaced with BSF. Four hundred and eighty shrimp (0·88 ± 0·00 g) were distributed to four groups of three replicates and fed for 7 weeks. Results showed that growth performance of shrimp fed BSF30 significantly decreased compared with those fed FM, but there was no significant difference in survival among groups. The whole shrimp crude lipid content, haemolymph TAG and total cholesterol were decreased with the increasing BSF inclusion. The results of metabolomics showed that the metabolite patterns of shrimp fed different diets were altered, with significant changes in metabolites related to lipid metabolism, glucose metabolism as well as TCA cycle. The mRNA expressions of hk, pfk, pk, pepck, ampk, mcd, cpt-1 and scd1 in hepatopancreas were downregulated in shrimp fed BSF30, but mRNA expression of acc1 was upregulated. Unlike BSF30, the mRNA expressions of fas, cpt-1, fbp and 6pgd in hepatopancreas were upregulated in shrimp fed BSF20. This study indicates that BSF20 diet promoted lipid synthesis and lipolysis, while BSF30 diet weakened β-oxidation and glycolysis as well as affected the unsaturated fatty acids synthesis, which may affect the growth performance and body composition of shrimp.

Chronic inflammation exerts pleiotropic effects in the aetiology and progression of chronic obstructive pulmonary disease (COPD). Glucosamine is widely used in many countries and may have anti-inflammatory properties. We aimed to prospectively evaluate the association of regular glucosamine use with incident COPD risk and explore whether such association could be modified by smoking in the UK Biobank cohort, which recruited more than half a million participants aged 40–69 years from across the UK between 2006 and 2010. Cox proportional hazards models with adjustment for potential confounding factors were used to calculate hazard ratios (HR) as well as 95 % CI for the risk of incident COPD. During a median follow-up of 8·96 years (interquartile range 8·29–9·53 years), 9016 new-onset events of COPD were documented. We found that the regular use of glucosamine was associated with a significantly lower risk of incident COPD with multivariable adjusted HR of 0·80 (95 % CI, 0·75, 0·85; P < 0·001). When subgroup analyses were performed by smoking status, the adjusted HR for the association of regular glucosamine use with incident COPD were 0·84 (0·73, 0·96), 0·84 (0·77, 0·92) and 0·71 (0·62, 0·80) among never smokers, former smokers and current smokers, respectively. No significant interaction was observed between glucosamine use and smoking status (Pfor interaction = 0·078). Incident COPD could be reduced by 14 % to 84 % through a combination of regular glucosamine use and smoking cessation.

The present study aimed to explore the association between dietary patterns in abdominal obesity obtained by reduced-rank regression (RRR) with visceral fat index (VFI) as a dependent variable and dyslipidemia in rural adults in Henan, China. A total of 29538 people aged 18–79 were selected from the Henan Rural Cohort Study. RRR analysis was used to identify dietary patterns; logistic regression analysis and restricted cubic spline regression models were applied to analyze the association between dietary patterns in abdominal obesity and dyslipidemia. VFI was used as a mediator to estimate the mediation effect. The dietary pattern in abdominal obesity was characterized by high carbohydrate and red meat intake and low consumption of fresh fruits, vegetables, milk, etc. After full adjustment, the highest quartile of dietary pattern scores was significantly associated with an increased risk of dyslipidemia (OR: 1·33, 95 % CI 1·23–1·44, Ptrend < 0·001), there was a non-linear dose–response relationship between them (Poverall-association < 0·001, Pnon-lin-association = 0·022). The result was similar in dose-response between the dietary pattern scores and VFI. The indirect effect partially mediated by VFI was significant (OR: 1·07, 95 % CI 1·06–1·08). VIF explained approximately 53·3 % of odds of dyslipidemia related to the dietary pattern. Abdominal obesity dietary pattern scores positively affected VFI and dyslipidemia; there was a dose-response in both relationships. Dyslipidemia progression increased with higher abdominal obesity dietary pattern scores. In addition, VFI played a partial mediating role in relationship between abdominal obesity dietary pattern and dyslipidemia.

To explore the characteristics of the mitochondrial genome (mitogenome) of the squeaking silkmoths Rhodinia, a genus of wild silkmoths in the family Saturniidae of Lepidoptera, and reveal phylogenetic relationships, the mitogenome of Rhodinia fugax Butler was determined. This wild silkmoth spins a green cocoon that has potential significance in sericulture, and exhibits a unique feature that its larvae can squeak loudly when touched. The mitogenome of R. fugax is a circular molecule of 15,334 bp long and comprises 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and an A + T-rich region, consistent with previous observations of Saturniidae species. The 370-bp A + T-rich region of R. fugax contains no tandem repeat elements and harbors several features common to the Bombycidea insects, but microsatellite AT repeat sequence preceded by the ATTTA motif is not present. Mitogenome-based phylogenetic analysis shows that R. fugax belongs to Attacini, instead of Saturniini. This study presents the first mitogenome for Rhodinia genus.

New detrital U–Pb zircon ages from the Sanandaj–Sirjan metamorphic zone in the Zagros orogenic belt allow discussion of models of the late Neoproterozoic to early Palaeozoic plate tectonic evolution and position of the Iranian microcontinent within a global framework. A total of 194 valid age values from 362 zircon grains were obtained from three garnet-micaschist samples. The most abundant detrital zircon population included Ediacaran ages, with the main age peak at 0.60 Ga. Other significant age peaks are at c. 0.64–0.78 Ga, 0.80–0.91 Ga, 0.94–1.1 Ga, 1.8–2.0 Ga and 2.1–2.5 Ga. The various Palaeozoic zircon age peaks could be explained by sediment supply from sources within the Iranian microcontinent. However, Precambrian ages were found, implying a non-Iranian provenance or recycling of upper Ediacaran–Palaeozoic clastic rocks. Trace-element geochemical fingerprints show that most detrital zircons were sourced from continental magmatic settings. In this study, the late Grenvillian age population at c. 0.94–1.1 Ga is used to unravel the palaeogeographic origin of the Sanandaj–Sirjan metamorphic zone. This Grenvillian detrital age population relates to the ‘Gondwana superfan’ sediments, as found in many Gondwana-derived terranes within the European Variscides and Turkish terranes, but also to units further east, e.g. in the South China block. Biogeographic evidence proves that the Iranian microcontinent developed on the same North Gondwana margin extending from the South China block via Iran further to the west.