To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Soft robots can perform effectively inspecting than rigid robots in some special environments such as nuclear pipelines and high-voltage cables. This article presents a versatile quadruped soft rod-climbing robot (SR-CR) that consists of four bending actuators and a telescopic actuator. The bending actuator is composed of flexible bellows with multiple folding air chambers, elastic telescopic layer (ETL), and strain-limiting layer (SLL). The telescopic actuator provides the energy for the robot to climb forward. The SR-CR is activated by a control strategy that alternates the body deformation and feet pneumatic clenched for stable climbing. The robot can climb rods at 90°, with the maximum speed of up to 2.33 mm/s (0.018 body length/s). At 0.83 HZ, the maximum moving speed of the robot in climbing horizontally parallel rods can reach 18.43 mm/s. In addition, the SR-CR can also achieve multiple impressive functions, including turning around a corner at a rate of 7 mm/s (0.054 body length/s), carrying a payload of 3.7 times its self-weight on horizontal rods at a speed of 9 mm/s (0.069 body length/s).
Effects of dietary supplemental stachyose on caecal skatole concentration, hepatic cytochrome P450 (CYP450, CYP) mRNA expressions and enzymatic activities in broilers were evaluated. Arbor Acre commercial mixed male and female chicks were assigned randomly into six treatments. The positive control (PC) diet was based on maize–soyabean meal, and the negative control (NC) diet was based on maize–non-soyabean meal. The NC diet was then supplemented with 4, 5, 6 and 7 g/kg stachyose to create experimental diets, named S-4, S-5, S-6 and S-7, respectively. Each diet was fed to six replicates of ten birds from days 1 to 49. On day 49, the caecal skatole concentrations in the PC, S-4, S-5, S-6 and S-7 groups were lower than those in the NC group by 42·28, 23·68, 46·09, 15·31 and 45·14 % (P < 0·01), respectively. The lowest pH value was observed in the S-5 group (P < 0·05). The stachyose-fed groups of broilers had higher caecal acetate and propionate levels compared with control groups, and propionate levels in the S-6 and S-7 groups were higher than those in the S-4 and S-5 groups (P < 0·001). The highest CYP3A4 expression was found in the S-7 group (P < 0·05), but this was not different from PC, S-4, S-5 and S-6 treatments. There was no significant difference in CYP450 (1A2, 2D6 and 3A4) enzymatic activities among the groups (P > 0·05). In conclusion, caecal skatole levels can be influenced by dietary stachyose levels, and 5 g/kg of stachyose in the diet was suggested.
This study aimed to evaluate the effect of in ovo feeding (IOF) of vitamin C at embryonic age 11 (E11) on post-hatch performance, immune status and DNA methylation-related gene expression in broiler chickens. A total of 240 Arbor Acres breeder eggs (63 (sem 0·5) g) were randomly divided into two groups: normal saline and vitamin C (VC) groups. After incubation, newly hatched chicks from each group were randomly divided into six replicates with ten chicks per replicate. Hatchability, average daily feed intake (D21–42 and D1–42), and average daily gain and feed conversion ratio (D1–21) were improved by vitamin C treatment (P < 0·05). IOF of vitamin C increased vitamin C content (D1), total antioxidant capacity (D42), IgA (D1), IgM (D1 and D21), stimulation index for T lymphocyte (D35) and lysozyme activity (D21) in plasma (P < 0·05). On D21, vitamin C increased the splenic expression of IL-4 and DNMT1 and decreased IL-1β, Tet2, Tet3 and Gadd45β expression (P < 0·05). On D42, vitamin C increased the splenic expression of IL-4 and DNMT3A and decreased IFN-γ, Tet3, MBD4 and TDG expression (P < 0·05). In conclusion, the vitamin C via in ovo injection can be absorbed by broiler’s embryo and IOF of vitamin C at E11 improves the post-hatch performance and immune status and, to some extent, the antioxidant capacity of broiler chickens. The expression of enzyme-related DNA methylation and demethylation indicates that the level of DNA methylation may increase in spleen in the VC group and whether the fluctuating expression of pro- and anti-inflammatory cytokines is related to DNA methylation change remained to be further investigated.
For the guarantee of the long-distance transport of the bunches of China Initiative Accelerator Driven System (CIADS), a new scheme is proposed that extra magnetic field is used in the accelerator-target coupling section before the windowless target to minimize the self-modulation (SM) mechanism. Particle-in-cell simulations are carried out to study the influence of the solenoidal magnetic field on the self-modulation mechanism when long proton bunches move in the background plasmas. The long proton bunches used in the simulations are similar to these in the linear accelerator of CIADS. It is found that the presence of the solenoidal magnetic field will significantly inhibit the self-modulation process. For the strong magnetic field, the longitudinal separation and transverse focusing of the long bunches disappear. We attribute these phenomena to the reason that the strong solenoidal magnetic field restricts the transverse movement of plasma electrons. Thus, there are not enough electrons around the bunch to compensate the space charge effect. Moreover, without transverse current, the longitudinal pinched effect disappears, and the long bunch can not be separated into small pulses anymore.
During recent stratigraphical and micropaleontological investigations of the Gulupu section in Tüna, Yadong, of the Eocene Zhepure Formation, numerous holoplanktonic mollusks (pteropods) were recovered. Four species, assignable to two genera of pteropods (including Limacina yadongensis new species) were systematically described and illustrated, and a gastropod-bivalve biofacies was identified. This is the first report of Eocene (Ypresian) pteropods in southern Tibet; the same stratum also yields many other neritic faunas. The data presented in this study suggest that a semi-closed restricted gulf in the Tüna area existed and the occurrence of pteropods in Tüna may indicate transport from more open, deep water by oceanic currents during early Eocene. Based on the analysis of paleogeographical distribution of pteropods, it indicates that a Tethys seaway existed during the early Eocene (Ypresian).
In this research paper we filter and verify miRNAs which may target silent information regulator homolog 2 (SIRT2) gene and then describe the mechanism whereby miRNA-212 might regulate lipogenic genes in mammary epithelial cell lines via targeting SIRT2. Bioinformatics analysis revealed that the bovine SIRT2 gene is regulated by three miRNAs: miR-212, miR-375 and miR-655. The three miRNAs were verified and screened by qRT-PCR, western blot, and luciferase multiplex verification techniques and only miR-212 was shown to have a targeting relationship with SIRT2. The results of co-transfecting miR-212 and silencing RNA (siRNA) showed that by targeting SIRT2, miR-212 can regulate the expression of fatty acid synthetase (FASN) and sterol regulatory element binding factor 1 (SREBP1) but not peroxisome proliferator-activated receptor gamma (PPARγ). Measurement of triglyceride (TAG) content showed that miR-212 increased the fat content of mammary epithelial cell lines. The study indicates that miR-212 could target and inhibit the expression of the SIRT2 gene to promote lipogenesis in mammary epithelial cell lines.
A bidirectional dielectric resonator (DR) antenna array using back-to-back quasi-Yagi antenna configuration is proposed and implemented for the first time. The DR operating at higher-order TE3δ1 mode is used as a magnetic dipole, applying for the driver of quasi-Yagi antenna. Due to the high-order mode employment, the antenna gain can be enhanced. By partially loading the metallic strip on the side wall of the DR, the gain can be further enhanced. In addition, a simple dual Marchand balun is constructed for feeding the two quasi-Yagi antennas directly for bidirectional radiation. To verify the design concept, a prototype operating at the X-band is fabricated and measured. Good agreement between the simulated and measured results can be observed.
Atomic electron tomography (AET) has become a powerful tool for atomic-scale structural characterization in three and four dimensions. It provides the ability to correlate structures and properties of materials at the single-atom level. With recent advances in data acquisition methods, iterative three-dimensional (3D) reconstruction algorithms, and post-processing methods, AET can now determine 3D atomic coordinates and chemical species with sub-Angstrom precision, and reveal their atomic-scale time evolution during dynamical processes. Here, we review the recent experimental and algorithmic developments of AET and highlight several groundbreaking experiments, which include pinpointing the 3D atom positions and chemical order/disorder in technologically relevant materials and capturing how atoms rearrange during early nucleation at four-dimensional atomic resolution.
As an emerging infectious disease, COVID-19 has involved many countries and regions. With the further development of the epidemic, the proportion of clusters has increased.
In our study, we collected information on COVID-19 clusters in Qingdao City. The epidemiological characteristics and clinical manifestations were analyzed.
Eleven clusters of COVID-19 were reported in Qingdao City between January 29, and February 23, 2020, involving 44 confirmed cases, which accounted for 73.33% of all confirmed cases. From January 19 to February 2, 2020, the cases mainly concentrated in the district that had many designated hospitals. Patients aged 20-59 y old accounted for the largest proportion (68.18%) of cases; the male-to-female sex ratio was 0.52:1. Three cases were infected from exposure to confirmed cases. The average incubation period was 6.28 d. The median number of cases per cluster was 4, and the median duration time was 6 d. The median cumulative number of exposed persons was 53.
More attention should be paid to the epidemic of clusters in prevention and control of COVID-19. In addition to isolating patients, it is essential to track, screen, and isolate those who have come in close contact with patients. Self-isolation is the key especially for healthy people in the epidemic area.
The aim of this study was to investigate the combined effect of n-3 fatty acids (EPA and DHA, at an EPA:DHA ratio of 150:500) and phytosterol esters (PS) on non-alcoholic fatty liver disease (NAFLD) patients. We conducted a randomised, double-blind, placebo-controlled trial. Ninety-six NAFLD subjects were randomly assigned to the following groups: the PS group (receiving 3·3 g/d PS); the FO group (receiving 450 mg EPA + 1500 mg DHA/d); the PS + FO combination group (receiving 3·3 g/d PS and 450 mg EPA + 1500 mg DHA/d) and the PO group (a placebo group). The baseline clinical characteristics of the four groups were similar. The primary outcome was liver:spleen attenuation ratio (L:S ratio). The percentage increase in liver–spleen attenuation (≤1) in the PS + FO group was 36 % (P = 0·083), higher than those in the other three groups (PS group, 11 %, P = 0·519; FO group, 18 %, P = 0·071; PO group, 15 %, P = 0·436). Compared with baseline, transforming growth factor-β (TGF-β) was significantly decreased in the three study groups at the end of the trial (PS, P = 0·000; FO, P = 0·002; PS + FO, P = 0·001) and TNF-α was significantly decreased in the FO group (P = 0·036), PS + FO group (P = 0·005) and PO group (P = 0·032) at the end of the intervention. Notably, TGF-β was reduced significantly more in the PS + FO group than in the PO group (P = 0·032). The TAG and total cholesterol levels of the PS + FO group were reduced by 11·57 and 9·55 %, respectively. In conclusion, co-supplementation of PS and EPA + DHA could increase the effectiveness of treatment for hepatic steatosis.
Systematic error is one of the major factors that affect positioning accuracy owing to the changeable and complex nature of seawater environments. Based on a Global Navigation Satellite System-acoustic intelligent buoys system, whose acoustic array consists of a series of surface buoys, a single-difference method for underwater dynamic positioning is proposed to eliminate systematic error. Positioning configuration optimisation was addressed using dilution of precision (DOP). A simulation of DOP proved that for the single-difference method, a radiation network with a centre-difference reference point was superior to a regular polygon network. The positioning experiment showed that the novel method could effectively eliminate systematic error, improving vertical positioning accuracy from a metre- to a decimetre scale.
The microbiota–gut–brain axis, especially the microbial tryptophan (Trp) biosynthesis and metabolism pathway (MiTBamp), may play a critical role in the pathogenesis of major depressive disorder (MDD). However, studies on the MiTBamp in MDD are lacking. The aim of the present study was to analyze the gut microbiota composition and the MiTBamp in MDD patients.
We performed shotgun metagenomic sequencing of stool samples from 26 MDD patients and 29 healthy controls (HCs). In addition to the microbiota community and the MiTBamp analyses, we also built a classification based on the Random Forests (RF) and Boruta algorithm to identify the gut microbiota as biomarkers for MDD.
The Bacteroidetes abundance was strongly reduced whereas that of Actinobacteria was significantly increased in the MDD patients compared with the abundance in the HCs. Most noteworthy, the MDD patients had increased levels of Bifidobacterium, which is commonly used as a probiotic. Four Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologies (KOs) (K01817, K11358, K01626, K01667) abundances in the MiTBamp were significantly lower in the MDD group. Furthermore, we found a negative correlation between the K01626 abundance and the HAMD scores in the MDD group. Finally, RF classification at the genus level can achieve an area under the receiver operating characteristic curve of 0.890.
The present findings enabled a better understanding of the changes in gut microbiota and the related Trp pathway in MDD. Alterations of the gut microbiota may have the potential as biomarkers for distinguishing MDD patients form HCs.
Polyhedral YVO4: Ln3+ (Ln = Eu, Sm, Yb/Er, Yb/Tm) microcrystals were fabricated via a facile sol–gel auto-combustion method using NH4VO3 as vanadium source in the presence of glycine. The X-ray diffraction patterns were well matched with pure YVO4, and the doped lanthanide ions did not change the host structure. The YVO4 microcrystals annealed from 500 to 1000 °C for 3 h were polyhedral and ranged in particle size from 0.1 to 2 μm. The luminescence properties of YVO4: Ln3+ (Ln = Eu, Sm, Yb/Er, Yb/Tm) samples indicated that all of the YVO4: Ln3+ samples exhibited typical emission spectra of Ln3+ cations, suggesting that the Ln3+ cations were well doped in YVO4 and could be excited efficiently through matrix absorption. In addition, the corresponding mechanisms of emission and energy transfer in the YVO4: Ln3+ are proposed.
This study aimed to evaluate the effectiveness of hypertension management and analyse the factors associated with blood pressure reduction within China’s primary healthcare system.
Hypertension is one of the leading risk factors for global disease burden and is strongly associated with cardiovascular diseases. In China, hypertension is a serious public health problem, but few studies have evaluated the effectiveness of hypertension management in China’s primary healthcare system.
The study sites were 24 primary healthcare institutions, selected using multistage stratified random sampling method. In each institution, hypertension patients aged at least 35 years who agreed to participate and had no disabilities or mental health problems were enrolled for hypertension management. Participants received comprehensive interventions in the primary healthcare system via a team. After a one-year intervention, data from 6575 hypertension patients were analysed to check the effectiveness of hypertension management and examined factors associated with hypertension control.
There was an overall mean reduction of 4.5 mmHg in systolic blood pressure (SBP) and 1.9 mmHg in diastolic blood pressure (DBP). The blood pressure reduction after one year was greater in rural patients than in urban patients, 6.6 mmHg versus 3.4 mmHg for SBP and 2.6 mmHg versus 1.6 mmHg for DBP, respectively. The hypertension control rate also increased more in rural areas (22.1%) than in urban areas (10.6%) after the one-year intervention. Age, body mass index, region and being in an urban area had a significant negative association with the reduction of SBP (P < 0.05). Education level and baseline SBP showed a significant positive association (P < 0.05).
Community-based hypertension management by general practitioners was feasible and effective. The effectiveness of hypertension management in rural areas was greater than in urban areas. Intervention strategies should pay more attention to patients in rural areas and western China.