With the evolution of the Web and development of web-based search engines, online searching has become a common method for obtaining information. Given this popularity, the question arises as to how much time people save by using search engines for their information needs compared to offline sources, as well as how online searching affects both search experiences and search outcomes. Using a random sample of queries from a major search engine and a sample of reference questions from the Internet Public Library (IPL), we conduct a real-effort experiment to compare online and offline search experiences and outcomes. We find that participants are significantly more likely to find an answer on the Web (100 %), compared to offline searching (between 87 % and 90 %). Restricting our analysis to the set of questions in which participants find answers in both treatments, a Web search takes on average 7 (9) minutes, whereas the corresponding offline search takes 22 (19) minutes for a search-engine (IPL) question. Furthermore, while raters judge library sources to be significantly more trustworthy and authoritative than the corresponding Web sources, they judge Web sources as significantly more relevant. Balancing all factors, we find that the overall source quality is not significantly different between the two treatments for the set of search-engine questions. However, for IPL questions, we find that non-Web sources are judged to have significantly higher overall quality than the corresponding Web sources. In comparison, for factual questions, Web search results are significantly more likely to be correct (66 % vs. 43 %). Lastly, post-search questionnaires reveal that participants find online searching more enjoyable than offline searching.

Although it is well established that gestational diabetes mellitus (GDM) is associated with fetal overgrowth in singleton pregnancies, little is known about its role in twins. We aimed to explore the relationship between GDM and the longitudinal fetal growth in twin pregnancies. This was a retrospective matched cohort study of GDM and non-GDM twin pregnancies delivered ≥36 weeks without other complications. All the women performed ≥3 ultrasounds after 22 weeks. Linear mixed models (LMMs) were used to explore the relationships between longitudinal fetal growth trajectories and GDM. Group-based trajectory modeling (GBTM) and generalized estimating equation (GEE) were applied to identify the latent growth patterns and investigate their relationships with GDM. In total, 215 GDM and 645 non-GDM twins were included, the majority of the patients did not require medication therapy (n = 202, GDMA1). LMM revealed that, compared with non-GDM, GDM was associated with an average increase in fetal weight of 4.36 g (95% CI [1.25, 7.48]) per week. GBTM and GEE further revealed that GDM increased the odds of fetal weight trajectory to nearly 40% of the total fetal weight trajectory, classified into the high-speed group (aOR = 1.39, 95% CI [1.03, 1.88]), associating with a 49.44 g (95% CI [11.41, 87.48]) increase in birth weight. Subgroup analysis revealed that all these differences were only significant among the GDMA1 pregnancies (p < .05). GDM (GDMA1) is significantly associated with an increase in fetal weight during gestation in twin pregnancies. However, this acceleration is mild, and its significance requires further exploration.

Hypertension represents one of the most common pre-existing conditions and comorbidities in Coronavirus disease 2019 (COVID-19) patients. To explore whether hypertension serves as a risk factor for disease severity, a multi-centre, retrospective study was conducted in COVID-19 patients. A total of 498 consecutively hospitalised patients with lab-confirmed COVID-19 in China were enrolled in this cohort. Using logistic regression, we assessed the association between hypertension and the likelihood of severe illness with adjustment for confounders. We observed that more than 16% of the enrolled patients exhibited pre-existing hypertension on admission. More severe COVID-19 cases occurred in individuals with hypertension than those without hypertension (21% vs. 10%, P = 0.007). Hypertension associated with the increased risk of severe illness, which was not modified by other demographic factors, such as age, sex, hospital geological location and blood pressure levels on admission. More attention and treatment should be offered to patients with underlying hypertension, who usually are older, have more comorbidities and more susceptible to cardiac complications.

Sugarcane brown rust, caused by Puccinia melanocephala, is one of the main diseases of sugarcane in China. The identification and discovery of new resistance genes have important theoretical and practical significance for preventing outbreaks of brown rust and ensuring the sustainable production of sugarcane. To screen for polymorphic simple-sequence repeat (SSR) molecular markers for localization of brown rust resistance genes, we used two populations that are suitable for genetic linkage map construction and mapping of new resistance genes to construct resistant and susceptible genetic pools. We then screened 449 pairs of primers to identify polymorphic SSR markers in the parental lines and the resistant/susceptible genetic pools. The results showed that 25 pairs of primers directed amplification of polymorphic DNA fragments between the parents of the cross combination ‘Yuetang 03-393’ × ‘ROC 24’, and 16 pairs of primers amplified polymorphic fragments between the parents of the cross combination ‘Liucheng 03-1137’ × ‘Dezhe 93-88’. Four pairs of primers (SMC236CG, SCESSR0928, SCESSR0636 and SCESSR2551) amplified polymorphic DNA fragments between the parental lines and the resistant/susceptible genetic pools in ‘Yuetang 03-393’ × ‘ROC 24’. The results of this study will establish a solid foundation for the mapping of new brown rust resistance genes, genetic linkage map construction and the development of closely-associated molecular markers in sugarcane.

Despite high altitude was implicated in adverse birth outcomes, there remained a paucity of evidence on low-to-medium altitude effect. This study aimed to explore the association of low-to-medium altitude with birth outcomes. A population-based cross-sectional survey was performed using a stratified multistage random sampling method among women with their infants born during 2010–2013 in Northwestern China. Altitude was determined in meters based on the village or community of the mother’s living areas. Birth outcomes involved birth weight, gestational age, and small for gestational age (SGA). Generalized linear models were fitted to investigate the association of altitude with birth outcomes. Moreover, the dose–response relationship between altitude and birth outcomes was evaluated with a restricted cubic spline function. A total of 27 801 women with their infants were included. After adjusting for potential confounders, every 100-m increase in the altitude was associated with reduced birth weight by 6.4 (95% CI −8.1, −4.6) g, the slight increase of gestational age by 0.015 (95% CI 0.010, 0.020) week, and an increased risk of SGA birth (odds ratio 1.03, 95% CI 1.02, 1.04). Moreover, there was an inversely linear relationship between altitude and birth weight (P for overall < 0.001 and P for nonlinear = 0.312), and a positive linear relationship between altitude and SGA (P for overall < 0.001 and P for nonlinear = 0.194). However, a nonlinear relationship was observed between altitude and gestational age (P for overall < 0.001 and P for nonlinear = 0.010). The present results suggest that low-to-medium altitude is possibly associated with adverse birth outcomes.

Few studies have investigated the association between maternal dietary patterns (DP) during pregnancy, derived from reduced-rank regression (RRR), and fetal growth. This study aims to identify DP during pregnancy associated with macro- and micronutrient intakes, using the RRR method, and to examine their relationship with birth weight (BW). We used data of 7194 women from a large-scale cross-sectional survey in Northwest China. Dietary protein, carbohydrate, haem Fe density and the ratio of PUFA and MUFA:SFA were used as the intermediate variables in the RRR model to extract DP. Generalised estimating equation models were applied to evaluate the associations between DP and BW and related outcomes (including BW z-score, low birth weight (LBW) and small for gestational age (SGA)). Four DP during pregnancy were identified. Socio-demographically disadvantaged pregnant women were more likely to have lower BW and lower adherence to DP1 (high legumes, soyabean products, vegetables and animal-source foods, with relative low wheat and oils). Women with medium and high adherence to DP1 had significantly increased BW (medium 28·6 (95 % CI 7·1, 50·1); high 25·2 (95 % CI 2·7, 47·6)) and BW z-score and had significantly reduced risks of LBW and SGA. The associations were stronger among women with babies <3100 g. There is no association between other DP and outcomes. Higher adherence to the DP that was high in legumes, soyabean products, vegetables and animal-source foods was associated with improved BW in the Chinese pregnant women, particularly among those with disadvantageous socio-demographic conditions.

The effect of tea intake on blood pressure (BP) is controversial. We performed a meta-analysis of randomised controlled trials to determine the changes in systolic and diastolic BP due to the intake of black and green tea. A systematic search was conducted in MEDLINE, EMBASE and the Cochrane Controlled Trials Register up to May 2014. The weighted mean difference was calculated for net changes in systolic and diastolic BP using fixed-effects or random-effects models. Previously defined subgroup analyses were performed to explore the influence of study characteristics. A total of twenty-five eligible studies with 1476 subjects were selected. The acute intake of tea had no effects on systolic and diastolic BP. However, after long-term tea intake, the pooled mean systolic and diastolic BP were lower by − 1·8 (95 % CI − 2·4, − 1·1) and − 1·4 (95 % CI − 2·2, − 0·6) mmHg, respectively. When stratified by type of tea, green tea significantly reduced systolic BP by 2·1 (95 % CI − 2·9, − 1·2) mmHg and decreased diastolic BP by 1·7 (95 % CI − 2·9, − 0·5) mmHg, and black tea showed a reduction in systolic BP of 1·4 (95 % CI − 2·4, − 0·4) mmHg and a decrease in diastolic BP of 1·1 (95 % CI − 1·9, − 0·2) mmHg. The subgroup analyses showed that the BP-lowering effect was apparent in subjects who consumed tea more than 12 weeks (systolic BP − 2·6 (95 % CI − 3·5, − 1·7) mmHg and diastolic BP − 2·2 (95 % CI − 3·0, − 1·3) mmHg, both P< 0·001). The present findings suggest that long-term ( ≥ 12 weeks) ingestion of tea could result in a significant reduction in systolic and diastolic BP.

The present study investigated whether a recloning procedure would affect the reproductive performance or the germline transmission capacity of recloned transgenic pigs. This study has also laid the foundation for the development of elite transgenic swine breeds in the future. Recloned transgenic pigs were developed from ear tissue fibroblasts of primary transgenic cloned pigs using a recloning procedure, and their reproductive performance and exogenous gene transmission were analyzed. Two transgenic cell lines with different genetic backgrounds (derived from a female miniature pig and a male Landrace pig) with stable expression of green fluorescent protein (GFP) were established successfully. Furthermore, recloned transgenic embryos were developed to full term successfully. One female Chinese experimental miniature piglet (CEMP) (GFP+) and three male Landrace piglets (GFP+) were delivered naturally. Furthermore, the index values for the reproductive characteristics of the recloned transgenic pigs, such as puberty, gestation period, sperm volume and sperm concentration, were not significantly different from those of conventionally bred pigs. In addition, 53% of the F1 offspring of the recloned transgenic pigs were GFP positive. These results demonstrate that ear tissue fibroblasts from primary transgenic cloned pigs efficiently support the full-term development of recloned transgenic embryos. Furthermore, recloned transgenic pigs maintain normal reproductive performance and stable germline (genetic) transmission capacities.

The Fe64B22.8Nd6.6Y3.9Nb2.7 nanocomposite permanent magnets in the form of rods of 2 mm in diameter and 25 mm in length have been prepared by annealing the amorphous precursors. The phase evolution, microstructure, and magnetic properties of Fe64B22.8Nd6.6Y3.9Nb2.7 nanocomposite permanent magnets have been investigated by x-ray diffractometry, transmission electron microscopy, and magnetometry techniques. The exchange coupling between the magnetically soft and hard magnetic phase is evidenced by the δM curves. The hard magnetic properties of the nanocomposites were found to be sensitive to the annealing process. The microstructure of the annealed nanocomposite consists of magnetically soft α-Fe (15–25 nm) and Fe3B (25–35 nm) grains and hard magnetic Nd2Fe14B (45–55 nm) grains. The optimum hard magnetic properties, such as jHc = 961.6 kA/m (12.0 kOe), Br = 0.65 T (6.5 kG), and BHmax = 65.17 kJ/m3 (8.19 MGOe), were obtained by annealing the alloy at 700 °C for 15 min and are related to the more refined nanostructure leading to strong exchange coupling between the soft and hard magnetic grains. Annealing above 700 °C induces a decoupling effect due to the coarsening of soft and hard magnetic phases.

A 〈110〉 oriented Tb0.3Dy0.7Fe1.95 alloy rod was annealed at 500 °C under a magnetic field of 0.3 T, which was applied 35° away from the rod axis. X-ray diffraction characterization and optical microscopy observation showed that both the crystal orientation and morphologies were retained after magnetic annealing. Magnetic force microscopy images exhibited obvious change of the magnetic domain configurations. The magnetostrictive performance was changed drastically. Saturation axial magnetostriction λ‖s increased from 1023 to 1650 ppm by the ratio of 61.3%, but saturation perpendicular magnetostriction λ⊥s decreased from −802 to −624 ppm. Maximum magnetostrictive strain coefficients d33 and d31 were found to be enhanced by 29.3% and 32.6%, respectively. In addition, the fields for obtaining both optimum d33 and d31 decreased, which indicates that better magnetostrictive performance can be achieved at lower external fields after magnetic annealing.

Compressive stress–strain behaviors in a 〈110〉-oriented crystal Tb0.3Dy0.7Fe1.95 after magnetic annealing have been investigated under a series of quasi-static magnetic fields, attempting to add more insight into the corresponding domain-switching process. The magnetically annealed crystal outputs larger final strains than the untreated one, although it exhibits similar stress–strain behaviors. An obvious improvement also occurs in the initial Young's modulus E0 after magnetic annealing. The corresponding domain switching processes under compressive stress have been discussed. Non-180° domain processes are favored because of the specific initial domain states, which can be reflected by the shortening of the flat stage in magnetostriction–magnetic induction (λ–B) curve and the increase of the critical field where maximum forced magnetostriction constant d33 locates.

Primordial germ cells (PGCs) were isolated from the genital ridges of chicken (Gallus domesticus) embryos at the 19th stage and purified by Ficoll density-gradient centrifugation. PGCs were co-cultured with somatic cells in preliminary culture and subcultured. Identification of PGCs was carried out by histochemical methods, including alkaline phosphatase (AKP) and periodic acid–Schiff (PAS). The proliferating activity of PGCs in subculture was demonstrated by immunocytochemistry of proliferating cell nuclear antigen (PCNA). Meanwhile, proliferating PGCs were compared under different culture conditions of 5–20% fetal cattle serum (FCS), insulin–transferrin–selenite (ITS) medium, conditioned medium (CM), 15% FCS+ITS, 15% FCS+40% CM. The results showed that the cultured PGCs were positive for AKP and PAS staining and displayed intensive proliferating activity by PCNA. The PGCs without centrifugation grew better than those with centrifugation. The PGCs formed larger colonies in media with 5% FCS or ITS than other media, indicating that 5% FCS or ITS supplemented media could be an ideal culture system for PGC proliferation in the PGC-somatic cell co-culture, in addition to the embryonic fibroblast feeder layer.