68 research outputs found
Characteristics of multipleâyear nitrous oxide emissions from conventional vegetable fields in southeastern China
The annual and interannual characteristics of nitrous oxide (N2O) emissions from conventional vegetable fields are poorly understood. We carried out 4 year measurements of N2O fluxes from a conventional vegetable cultivation area in the Yangtze River delta. Under fertilized conditions subject to farming practices, approximately 86% of the annual total N2O release occurred following fertilization events. The direct emission factors (EFd) of the 12 individual vegetable seasons investigated ranged from 0.06 to 14.20%, with a mean of 3.09% and a coefficient of variation (CV) of 142%. The annual EFd varied from 0.59 to 4.98%, with a mean of 2.88% and an interannual CV of 74%. The mean value is much larger than the latest default value (1.00%) of the Intergovernmental Panel on Climate Change. Occasional application of lagoonâstored manure slurry coupled with other nitrogen fertilizers, or basal nitrogen addition immediately followed by heavy rainfall, accounted for a substantial portion of the large EFds observed in warm seasons. The large CVs suggest that the emission factors obtained from shortâterm observations that poorly represent seasonality and/or interannual variability will inevitably yield large uncertainties in inventory estimation. The results of this study indicate that conventional vegetable fields associated with intensive nitrogen addition, as well as occasional applications of manure slurry, may substantially account for regional N2O emissions. However, this conclusion needs to be further confirmed through studies at multiple field sites. Moreover, further experimental studies are needed to test the mitigation options suggested by this study for N2O emissions from open vegetable fields
Association between behavioral patterns and depression symptoms: dyadic interaction between couples
BackgroundBehavioral patterns are sometimes associated with depression symptoms; however, few studies have considered the intra-couple effects. This study examined the effect of a spousesâ behavioral patterns on depression symptoms within themself and in their spouse.MethodsA total of 61,118 childbearing age participants (30,559 husband-wife dyads) were surveyed. The depression symptoms were assessed using the nine-item Patient Health Questionnaire (PHQ-9). The behavioral patterns were identified by the latent class analysis. The effects of behavioral patterns on the coupleâs own depression symptoms (actor effect) and their partnerâs depression symptoms (partner effect) were analyzed using the Actor-Partner Interdependence Model (APIM).ResultsThree behavioral patterns were identified: low-risk group, moderate-risk group, and high-risk group. The high risk of these behavior patterns would be associated with a higher score on the PHQ-9; for both husbands and wives, their behavioral patterns were positively associated with PHQ-9 scores (ÎČhusband = 0.53, P < 0.01; ÎČwife = 0.58, P < 0.01). Wivesâ behavioral patterns were also positively associated with their husbandsâ PHQ-9 scores (ÎČ = 0.14, P < 0.01), but husbandsâ behavioral patterns were not associated with their wivesâ PHQ-9 scores.ConclusionsWivesâ depression symptoms were affected only by their own behavioral patterns, whereas husbandsâ depression symptoms were influenced by both their own and their spousesâ behavioral patterns
Association between pelvic floor muscle strength and sexual function based on PISQ-12âan analysis of data from a multicenter cross-sectional study on 735 nulliparae during pregnancy
BackgroundPelvic floor muscle strength is well-known to be associated with female sexual function. However, there were a few studies that reported on the relationship between pelvic floor muscle strength and female sexual function in pregnant women, and the presented results were inconsistent. Nulliparae represent a specific cohort with simplicity to exclude confounding factors that are caused by parity. The present study aimed to explore the association of pelvic floor muscle strength and sexual function based on the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) of nulliparae during pregnancy.MethodsThis is the second analysis of the baseline data from a randomized controlled trial (RCT), which aimed to study the protective efficacy of pelvic floor muscle training on stress urinary incontinence at 6th week postpartum (registration number: ChiCTR2000029618). Nulliparae aged 20â40 years with singleton pregnancy before 16 weeks of gestation were enrolled in this study, and data, including participants' demographic information, the Modified Oxford Scale (MOS), and PISQ-12, were collected. Eligible nulliparae were divided into two groups: Group MOS > 3 and Group MOS †3. Demographic information of the two groups was compared. Sexual function based on the PISQ-12 scores of the two groups was compared. A comparison of the PISQ-12 scores between the two groups was calculated by the MannâWhitney U-test using SPSS version 23.0.ResultsA total of 735 eligible nulliparae were enrolled in this study. Along with MOS grading up, PISQ-12 scores tended to get lower. Of the 735 nulliparae, there were 378 and 357 participants included in Group MOS > 3 and Group MOS †3, respectively. The PISQ-12 scores of Group MOS > 3 were significantly lower than those of Group MOS †3 (11 vs. 12, p < 0.001). The scores of the frequency of feeling sexual desire, orgasm achievement, sexual excitement, sexual activity satisfaction, sexual intercourse pain, fear of urinary incontinence, and negative emotion reactions with the sexual intercourse of Group MOS > 3 were lower than those of Group MOS †3 (p < 0.05).ConclusionPelvic floor muscle strength was positively associated with sexual function based on the questionnaire of young nulliparae during their first trimester. Up to half of the nulliparae during the first trimester were suffering from weak pelvic floor muscle strength and nearly a quarter of the nulliparae were facing this weakness combined with sexual dysfunction.Trial registrationThis study has been registered at http://www.chictr.org.cn (registration number: ChiCTR2000029618)
Association Analysis of IL-17A and IL-17F Polymorphisms in Chinese Han Women with Breast Cancer
Background: Research into the etiology of breast cancer has recently focused on the role of the immunity and inflammation. The proinflammatory cytokines IL-17A and IL-17F can mediate inflammation and cancer. To evaluate the influences of IL-17A and IL-17F gene polymorphisms on the risk of sporadic breast cancer, a case-control study was conducted in Chinese Han women. Methodology and Principal Findings: We genotyped three single-nucleotide polymorphisms (SNPs) in IL-17A (rs2275913, rs3819025 and rs3748067) and five SNPs in IL-17F (rs7771511, rs9382084, rs12203582, rs1266828 and rs763780) to determine the haplotypes in 491 women with breast cancer and 502 healthy individuals. The genotypes were determined using the SNaPshot technique. The differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed with the Chi-square test for trends. For rs2275913 in IL-17A, the frequency of the AA genotype was higher in patients than controls (P = 0.0016). The clinical features analysis demonstrated significant associations between IL-17 SNPs and tumor protein 53 (P53), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her-2) and triple-negative (ER-/PR-/Her-2-) status. In addition, the haplotype analysis indicated that the frequency of the haplotype A rs2275913G rs3819025G rs3748067, located in the IL-17A linkage disequilibrium (LD) block, was higher in patients than in controls (P = 0.0471 after correction for multiple testing)
Optimization of filler distribution for organic phase change material composites: Numerical investigation and entropy analysis
Organic phase change materials have been attracting great attentions for their promising potential in thermal energy storage applications. Due to their poor thermal conductivity and thermal diffusivity, thermally conductive fillers are often added to form composites to enhance the thermal performance. To achieve the optimized performance without sacrificing the thermal capacity, a novel numerical methodology has been developed to model the thermal behavior of phase change material composites, which has been validated by the experimental results for pure n-octadecane and n-octadecane/expanded graphite composites. Effects of different filler concentration distributions have been analyzed and compared. It is found that the phase change time is significantly affected by the filler distribution. An optimal polynomial filler distribution can reduce the phase change time by more than 50% with the same filling content, compared with the uniform distribution. Entropy analysis indicates that a shorter phase change time is correlated with a lower entropy generation rate. © 2014 Elsevier Ltd
Analytical Model for Heat Transfer in a Finite Region of Organic Phase Change Materials
The concept of low carbon, energy saving and sustainable design has been widely accepted all over the world. As a matter of fact, large amount energy is consumed to control the indoor environment to maintain a comfortable ambience for living and working. To increase the energy utilization efficiency, phase change material (PCM), which can store and release heat through phase change, has been recognized as an excellent candidate for green building. Analytical model is of great importance to describe and predict heat transfer with phase change. The classic Stefan problem solution is quite suitable for crystalline materials, which requires the input of certain phase change temperature. However, many PCMs widely used, like paraffin, are semi-crystalline materials, which have a much larger phase changing temperature range compared with small molecule crystalline materials. It is important to appropriately model the phase change of semi-crystalline polymers for the application of PCM. Furthermore, in large spatial scale prediction, widely used semi-infinite plane model is usually quite suitable to explain initial heat transfer. Unfortunately, semi-infinite plane is not the same as real situation. In this paper, by using the temperature at the end of the phase change as the equivalent melting temperature, a heat transfer model for semi-crystalline organic PCM is constructed. Meanwhile, this model concerns the phase change in a limited region. This model can serve as a fast tool to predict the one-dimensional heat transfer with phase change in an explicit form. The model is validated by the results of simulations and experiments reported in the literature. © 2013 Materials Research Society
Influence of Cutting Angle of Blade Trailing Edge on Unsteady Flow in a Centrifugal Pump Under Off-Design Conditions
The parameters of blade trailing edge have an important influence on the performance of centrifugal pump and internal unstable flow. In this study, the influences of cutting angles of blade trailing edge on unstable pressure pulsation and unstable flow structure are investigated using a centrifugal pump under off-design conditions through large eddy simulation. Three typical blade trailing edges, namely, original trailing edge (OTE), 15° cutting angle of blade trailing edge (OBS15) and 30° cutting angle of blade trailing edge (OBS30), are analysed. Results show that the cutting angle of blade trailing edge has a certain effect on the performance of the centrifugal pump. Under part-load conditions, the OBS30 impeller evidently contributes to the reduction in pressure pulsation intensity. By contrast, the OBS15 impeller has opposite effect because of the increase in wake vortex intensity. The OBS30 impeller can effectively improve the unstable vortex structure caused by backflow at the centrifugal pump tongue using a new Ω method. Consequently, reduction in the unstable flow structure mainly contributes to the reduction in pressure pulsation used by the proper cutting angle of blade trailing edge
PEG-coated gold nanoparticles attenuate β-adrenergic receptor-mediated cardiac hypertrophy
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