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Because of its unique mechanical, chemical, and biological properties, 3D-printed polyether ether ketone (PEEK) has great potential as customized bone replacement and other metal alloy implant replacement. PEEK samples were printed using fused deposition modeling (FDM) and evaluated in terms of their dimensional accuracy, crystallinity, and mechanical properties. Crystallinity and mechanical properties increased with elevated chamber temperature and post-printing annealing. Variations of material properties from three printers are evident. Many factors affect the quality of 3D-printed PEEK. Future FDA regulations for 3D-printed products are needed for this highly customizable manufacturing process to ensure safety and effectiveness for biomedical applications.
We assessed inheritance of resistance to sugarcane brown rust (Puccinia melanocephala) in selfing F1 populations of wild sugarcane germplasm Erianthus rockii ‘Yundian 95-19’ and E. rockii ‘Yundian 95-20’. We tested parent and selfing F1 individuals for the brown rust resistance gene, Bru1, that has been shown to confer resistance to brown rust in sugarcane. The Bru1 gene was not detected in E. rockii ‘Yundian 95-19’, E. rockii ‘Yundian 95-20’ or their selfing F1 individuals, and we found there was segregation of resistance in the two selfing F1 populations (segregation ratio: 3:1). The results confirmed resistance in E. rockii ‘Yundian 95-19’ and E. rockii ‘Yundian 95-20’ to sugarcane brown rust is controlled by a novel, single dominant gene.
We report on a high-repetition-rate, high-power continuously pumped Nd:GdVO4 regenerative amplifier. Numerical simulations successfully pinpoint the optimum working point free of bifurcation instability with simultaneous efficient energy extraction. At a repetition rate of 100 kHz, a maximum output power of 23 W was obtained with a pulse duration of 27 ps, corresponding to a pulse energy of
. The system displayed an outstanding stability with a root mean square power noise as low as 0.3%. The geometry of the optical resonator and the pumping scheme enhanced output power in the
mode with a single bulk crystal. Accordingly, nearly diffraction-limited beam quality was produced with
at full pump power.
Concerns over food safety in China not only direct public attention to negative
incidents, but also trigger the government's scrutiny of implicated
firms, particularly MNCs. The question of how to repair legitimacy after media
coverage of negative incidents has become a critical issue for MNCs. Although
the factors for MNCs’ public crises have been identified, how local
contexts and mechanisms shape repair approaches remain unclear. To address this
research gap, we conducted a study of Walmart China's approaches
associated with two negative incidents across two regions. We found that the
negative incidents can be framed differently depending on the local
environment's unfavorability for MNCs. Specifically, the negative
framing gave rise to varying degrees of legitimacy loss and offered different
leeway for MNCs to repair their legitimacy. We also identified the varied
outcomes of different repair approaches. By revealing the linkages among local
context, framing, legitimacy repair, and its outcomes, our study contributes to
research on MNCs’ legitimacy management under institutional
complexity and underscores the China context for legitimacy maintenance. We also
offer insights that advance the institutional approach to legitimacy repair in
this context. Last, we reflect on the techniques for conducting qualitative
research in China.
In this paper, based on a novel multimode stub-loaded resonator, a second-order quad-band bandpass filter (BPF) with mixed electric and magnetic coupling is presented. The electric coupling and magnetic coupling are realized by arranging the parallel coupled lines and the grounded stub, respectively. Eight controllable resonant modes can be simultaneously excited and easily tuned. Eight transmission zeros are created, enhancing the passband selectivity. In addition, the bandwidths can be controlled independently by adjusting the coupling strength. A quad-band BPF centering at 0.67, 1.51, 2.84, 3.58 GHz with respective 3 dB fractional bandwidths of 13.4, 15.6, 9.2, 11.5% is designed, fabricated, and measured. The filter is compact with overall size 0.058λg × 0.13λg. The measured results show a good consistence with the simulated ones.
The accelerated retreat of glaciers and the reduction of glacier ice reserves caused by climate change can significantly affect regional water resources and hydrological cycles. Changes in glacier thickness are among the key indicators that reflect this process. We analyzed changes observed in the elevation of glacier surfaces in the Gongga Mountains (GGM) using multi-temporal Digital Elevation Models (DEMs) derived from topographic maps, SRTM, ICESat and ZY-3 data. The results showed that the mean rate of change in glacier surface altitude in the GGM was ~−26.7 ± 2.03 m (0.54 ± 0.04 m a−1) between 1966 and 2015. The mean melt rates differed over different time periods, latterly showing an accelerating trend. As a general rule, glaciers appear to be losing more volume at lower than at higher elevations. Further analysis of these results suggests that supraglacial debris coverage in the GGM promotes higher rates of mass loss.
Two wide band gap conjugated polymers, namely PBDT-TT25 and PBDT-TT36, derived from (4,8-bis(4,5-dioctyl-thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)bis(trimethylstannane) with 2,5-dibromothieno[3,2-b]thiophene (TT25) or 3,6-dibromothieno[3,2-b]thiophene (TT36), have been synthesized by simply altering the linker positions of thieno[3,2-b]thiophene unit. The impact of linker positions on the energy levels, aggregation, active layer morphology, and optical and photovoltaic properties was evaluated systemically. We found that the absorption was greatly broadened, and the highest occupied molecular orbital (HOMO) energy level was elevated as the result of the significantly reduced twist angle on the polymer backbone when the linker positions changed from 3,6-isomer to 2,5-isomer. Therefore, the optimal inverted polymer solar cells exhibited a 1.87 times enhancement in power conversion efficiencies (PCE), which was mainly ascribed to the higher short circuit current densities (JSC) and fill factor (FF) of the devices mainly benefited from the widened, stronger absorption, higher hole mobility, and more ordered structure.
Imaging studies have shown that the subcallosal region (SCR) volume was decreased in patients with major depressive disorder (MDD). However, whether the volumetric reductions in the SCR are due to thinning of the cortex or a loss of surface area (SA) remains unclear. In addition, the relationship between cortical measurements of the SCR and age through the adult life span in MDD remains unclear.
We used a cross-sectional design from 114 individuals with MDD and 112 matched healthy control (HC) individuals across the adult life span (range: 18–74 years). The mean cortical volume (CV), SA and cortical thickness (CT) of the SCR were computed using cortical parcellation based on FreeSurfer software. Multivariate analyses of covariance models were performed to compare differences between the MDD and HC groups on cortical measurements of the SCR. Multiple linear regression models were used to test age-by-group interaction effects on these cortical measurements of the SCR.
The MDD had significant reductions in the CV and SA of the left SCR compared with HC individuals after controlling of other variables. The left SCR CV and SA reductions compared with matched controls were observed only in early adulthood patients. We also found a significant age-related CT reduction in the SCR both in the MDD and HC participants.
The SCR volume reduction was mainly driven by SA in MDD. The different trajectories between the CT and SA of the SCR with age may provide valuable information to distinguish pathological processes and normal ageing in MDD.
It has been demonstrated that the introduction of NaCl can significantly improve the quality of monolayer WS2 at the growth temperatures ranging from 700°C to 850°C by atmospheric pressure chemical vapor deposition (APCVD) without the assistant of hydrogen. Here, the influence of NaCl on the nucleation and growth of WS2 has been thoroughly investigated. The morphology and quality of WS2 grown with different temperatures are discussed by optical microscope, Raman and Photoluminescence (PL) spectra. It was found that amount of NaCl can efficiently influence the morphology and quality of WS2 crystals. PL intensity of WS2 crystal increases around three times from the center region to the edge of an individual domain, which may be attributed to the appearance of small triangle hollows formed during the growth at the edge of single crystal WS2.
Low urinary iodine concentration (UIC) is associated with dyslipidaemia in adults but is not well characterised in adolescents. Because dyslipidaemia is a cardiovascular risk factor, identifying such an association in adolescents would allow for the prescription of appropriate measures to maintain cardiovascular health. The present study addresses this question using data in the 2001–2012 National Health and Nutrition Examination Survey for 1692 adolescents aged 12–19 years. Primary outcomes were UIC, cardiometabolic risk factors and dyslipidaemia. Data for subjects categorised by low and normal UIC and by sex were analysed by univariate and multivariate logistic regression. Treating UIC as the independent variable, physical activity level, apoB and lipid profiles differed significantly between subjects with low and normal UIC. Subjects with low UIC had a significantly greater risk of elevated total cholesterol (TC) (95 % CI 1·37, 2·81), elevated non-HDL (95 % CI 1·33, 2·76) and elevated LDL (95 % CI 1·83, 4·19) compared with those with normal UIC. Treating UIC as a dependent variable, the risk of low UIC was significantly greater in those with higher apoB (95 % CI 1·52, 19·08), elevated TC (≥4·4mmol/l) (95 % CI 1·37, 2·81) and elevated non-HDL (≥3·11mmol/l) (95 % CI 1·33, 2·76) than in those with normal UIC. These results show that male and female adolescents with low UIC tend to be at greater risk of dyslipidaemia and abnormal cardiometabolic biomarkers, though the specific abnormal parameters differed between sexes. These results may help to identify youth who would benefit from interventions to improve their cardiometabolic risk.
Highly dense zirconia dental ceramic coatings were fabricated by aqueous electrophoretic deposition (EPD) and subsequently sintered between 1250 and 1450 °C. Microstructural examination revealed that aqueous EPDZrO2 coatings possessed a tetragonal phase structure and the grain size increased with increasing sintering temperature. Nanoindentation study proved that the aqueous EPDZrO2 coating also had excellent mechanical properties. The effect of different applied loads on hardness and elastic modulus of the 1350 °C-sintered sample at room temperature was investigated by the method of progressive multicycle measurement nanoindentation. The simulative experiment proved that hardness of aqueous EPDZrO2 exhibited reverse indentation size effect (ISE) behavior and then displayed the normal ISE response. The analysis indicates that the reverse ISE is attributed to the relaxation of surface stresses resulting from indentation cracks at small loads and normal ISE is caused by geometrically necessary dislocations. The tetragonal–monoclinic stress-induced phase transformation during nanoindentation is the primary cause of dental zirconia failures.
Living Caprini are dominant bovids in the pan-Tibetan area that are strongly adapted to dry steppe and high-mountain meadow habitats. Some taxa with Holarctic distributions, e.g., Ovis Linnaeus, 1758, were thought to originate on the Tibetan Plateau and subsequently dispersed elsewhere, which was depicted as an ‘out of Tibet’ story. However, except for some information on a stem caprine assemblage from the Qaidam Basin, the early evolution of Caprini around the Tibetan Plateau is poorly known. Here, we report new material of Olonbulukia tsaidamensis Bohlin, 1937, which was a member of this stem caprine assemblage, from the Wuzhong region, northern China, confirming the similarity of the Wuzhong Fauna and ‘Qaidam Fauna.’ Based on a biometric study of horncores from the ‘Qaidam’ and Wuzhong faunas, we recognize six taxa from this stem caprine assemblage: O. tsaidamensis, O. sp., Qurliqnoria cheni Bohlin, 1937, Tossunnoria pseudibex Bohlin, 1937, ?Protoryx cf. P. enanus Köhler, 1987, and cf. Pachytragus sp. Among these taxa, Q. cheni and T. pseudibex are probably related to some extant Tibetan endemic species, e.g., the Tibetan antelope, Pantholops hodgsonii (Abel, 1826), and the Himalayan tahr, Hemitragus jemlahicus (Smith, 1826). Others might be ancestral to the Turolian caprine assemblages and even possibly gave rise to the extant Caprina. This work reveals an early radiation of stem caprines along the northern side of the rising Tibetan Plateau and indicates a mixed pattern of pan-Tibetan stem caprine evolution prior to their dispersal out of the Tibetan Plateau.
To assess the effect of famine exposure during early life on dietary patterns, chronic diseases, and the interaction effect between famine exposure and dietary patterns on chronic diseases in adulthood.
Cross-sectional study. Dietary patterns were derived by factor analysis. Multivariate quantile regression and log-binomial regression were used to evaluate the impact of famine exposure on dietary patterns, chronic diseases and the interaction effect between famine exposure and dietary patterns on chronic diseases, respectively.
Adults aged 45–60 years (n 939).
‘Healthy’, ‘high-fat and high-salt’, ‘Western’ and ‘traditional Chinese’ dietary patterns were identified. Early-childhood and mid-childhood famine exposure were remarkably correlated with high intake of the traditional Chinese dietary pattern. Compared with the non-exposed group (prevalence ratio (PR); 95 % CI), early-childhood (3·13; 1·43, 6·84) and mid-childhood (2·37; 1·05, 5·36) exposed groups showed an increased PR for diabetes, and the early-childhood (2·07; 1·01, 4·25) exposed group showed an increased PR for hypercholesterolaemia. Additionally, relative to the combination of non-exposed group and low-dichotomous high-fat and high-salt dietary pattern, the combination of famine exposure in early life and high-dichotomous high-fat and high-salt dietary pattern in adulthood had higher PR for diabetes (4·95; 1·66, 9·05) and hypercholesterolaemia (3·71; 1·73, 7·60), and significant additive interactions were observed.
Having suffered the Chinese famine in childhood might affect an individual’s dietary habits and health status, and the joint effect between famine and harmful dietary pattern could have serious consequences on later-life health outcomes.
A multi-speaker acoustic study on citation tones in Kaifeng Mandarin, referred to as LH, HL, H and L, shows that L is realized as three different subtypes by different speakers, i.e. dipping, falling and falling with lengthening, while generally being longer than the other three tones and frequently spoken with creaky voice in part of the vowel. This inter-speaker variation is reflected in the different transcriptions of Kaifeng L that have been given in the literature. We argue that a L-tone is intrinsically less salient than a H-tone, due to a lack of phonetic space in the low pitch range as well as to a potential ambiguity between contextual low pitch around f0 peaks and low pitch due to L-tones, and thus more likely to be enhanced.
be a residually finite Dedekind domain and let
be a nonzero ideal of
. We consider counting problems for the ideal chains in
. By using the Cauchy–Frobenius–Burnside lemma, we also obtain some further extensions of Menon’s identity.
be a positive integer. We obtain new Menon’s identities by using the actions of some subgroups of
on the set
. In particular, let
be an odd prime and let
be a positive integer. If
is a subgroup of
Since the late 1990s, hand, foot and mouth disease (HFMD) has become a common health problem that mostly affects children and infants in Southeast and East Asia. Global climate change is considered to be one of the major risk factors for HFMD. This study aimed to assess the correlation between meteorological factors and HFMD in the Asia-Pacific region. PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data and Weipu Database were searched to identify relevant articles published before May 2018. Data were collected and analysed using R software. We searched 2397 articles and identified 51 eligible papers in this study. The present study included eight meteorological factors; mean temperature, mean highest temperature, mean lowest temperature, rainfall, relative humidity and hours of sunshine were positively correlated with HFMD, with correlation coefficients (CORs) of 0.52 (95% confidence interval (CI) 0.42–0.60), 0.43 (95% CI 0.23–0.59), 0.43 (95% CI 0.23–0.60), 0.27 (95% CI 0.19–0.35), 0.19 (95% CI 0.02–0.35) and 0.19 (95% CI 0.11–0.27), respectively. There were sufficient data to support a negative correlation between mean pressure and HFMD (COR = −0.51, 95% CI −0.63 to −0.36). There was no notable correlation with wind speed (COR = 0.10, 95% CI −0.03 to 0.23). Our findings suggest that meteorological factors affect the incidence of HFMD to a certain extent.