fertilization

施肥
  • 文章类型: Editorial
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  • 文章类型: Journal Article
    目的:这项研究的重点是prosaposin的精液浓度与环境空气污染物之间的关联,以及该关联是否会影响体外受精(IVF)治疗的正常受精率。
    方法:从1月开始招募323名22-46岁的夫妇参与者2013年6月2018.在入学时,获得居民住址信息,并根据WHO标准评估男性对应的精液参数.我们使用反距离加权插值来估计环境污染物(SO2,O3,CO,周围区域的NO2、PM2.5和PM10)。根据从空气质量监测站收集的数据及其在精液采样前的不同时期(0-9、10-14和0-90天)的家庭住址来估计每个参与者的暴露量。采用广义线性回归模型(GLM)和贝叶斯核机回归(BKMR)分析污染物之间的关联,精液参数,prosaposin,正常受精。此外,研究了prosaposin和精液参数对污染物与正常受精之间联系的中介作用。
    结果:GLM和BKMR显示暴露于环境空气污染物都与精浆prosaposin的浓度有关,其中,O3和CO也与正常受精有关(-0.10,95CI:-0.13,-0.06;-26.43,95CI:-33.79,-19.07)。在精液参数中,只有prosaposin浓度和活动精子总数(TMC)与正常受精相关(0.059,95CI:0.047,0.071;0.016,95CI:0.012,0.020)。中介分析表明,在短期暴露于O3与受精之间的关系中,prosaposin比TMC发挥了更强的中介作用(66.83%,P<0.001对3.05%,P>0.05)。
    结论:精浆比常规精液参数表现出更强的冥想效应,反映了环境空气污染物与正常受精率之间的相关性。这可能是IVF中污染和受精之间的指标之一。
    OBJECTIVE: This study focuses on the association between seminal concentration of prosaposin and ambient air pollutants and whether the association affects the normal fertilization rate in vitro fertilization (IVF) treatment.
    METHODS: The cohort of 323 couple participants aged 22-46 was recruited from Jan. 2013 to Jun. 2018. At enrollment, resident address information was obtained and semen parameters of male counterparts were evaluated according to WHO criteria. We used inverse distance weighting interpolation to estimate the levels of ambient pollutants (SO2, O3, CO, NO2, PM2.5, and PM10) in the surrounding area. The exposure of each participant was estimated based on the data gathered from air quality monitoring stations and their home address over various periods (0-9, 10-14, and 0-90 days) before semen sampling. The generalized linear regression model (GLM) and the Bayesian kernel machine regression (BKMR) were used to analyze the associations between pollutants, semen parameters, prosaposin, and normal fertilization. Additionally, the mediating effect of prosaposin and semen parameters on the link between pollutants and normal fertilization was investigated.
    RESULTS: GLM and BKMR showed exposure to ambient air pollutants was all associated with the concentration of seminal prosaposin, among them, O3 and CO were also associated with normal fertilization (-0.10, 95 %CI: -0.13, -0.06; -26.43, 95 %CI: -33.79, -19.07). Among the semen parameters, only the concentration of prosaposin and total motile sperm count (TMC) was associated with normal fertilization (0.059, 95 %CI: 0.047, 0.071; 0.016, 95 %CI: 0.012, 0.020). Mediation analysis showed that prosaposin played a stronger mediating role than TMC in the relationship between short-term exposure to O3 and fertilization (66.83 %, P<0.001 versus 3.05 %, P>0.05).
    CONCLUSIONS: Seminal plasma prosaposin showed a stronger meditating effect reflect the correlation between ambient air pollutants and normal fertilization rate than conventional semen parameters, which may be used as one of the indicators between pollution and fertilization in IVF.
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  • 文章类型: English Abstract
    女性生育率随着女性年龄的增加而逐渐下降。其根本原因包括卵母细胞数量和质量的下降。卵母细胞老化是卵母细胞质量下降的重要表现,包括排卵前体内卵母细胞老化和排卵后体外卵母细胞老化。目前,很少有研究来检查卵母细胞的衰老,和相关的分子机制尚未完全了解。因此,我们使用斑马鱼作为研究卵母细胞衰老的模型。选择三种不同年龄范围的雌性斑马鱼与最佳繁殖年龄的雄性斑马鱼交配。这样,我们研究了母亲年龄相关的卵母细胞老化对生育能力的影响,并探讨了母亲年龄相关的生育能力下降的潜在分子机制.
    随机选择年龄在158至195d之间的8条雌性斑马鱼作为6月龄(180±12)d组,随机选取年龄在330~395d的雌性斑马鱼8只作为12月龄组(360±22)d,随机选择年龄在502至583d之间的8只雌性斑马鱼作为18月龄组(540±26)d。从年龄在158至195d之间的斑马鱼中随机选择(180±29)d的雄性斑马鱼,并与雌性斑马鱼交配。每个交配实验包括1只雌性斑马鱼和1只雄性斑马鱼。收集并计数通过交配实验产生的斑马鱼胚胎。在显微镜下观察受精后4小时的胚胎,计算胚胎总数和未受精胚胎的数量,并据此计算了受精率。受精后24小时计数畸形胚胎和死亡胚胎的数量,并据此计算胚胎畸形率和死亡率。主要结局指标是胚胎受精率,次要结果指标是每个产卵的胚胎数(斑马鱼开始交配和繁殖后1.5小时内产下的胚胎总数),胚胎死亡率,和胚胎畸形率。比较各组的结局指标。收集各组雌性斑马鱼在最佳繁殖期与雄性斑马鱼交配后出生的囊胚进行转录组学分析。收集各组雌性斑马鱼的新鲜卵母细胞进行转录组学分析,以探讨母亲年龄相关生育力下降的潜在分子机制。
    与6个月组(94.9%±3.6%)相比,12个月组胚胎受精率(92.3%±4.2%)差异无统计学意义,但18个月组(86.8%±5.5%)显着降低(P<0.01)。此外,18个月组受精率明显低于12个月组(P<0.05)。与6个月组相比,12个月组和18个月组雌性斑马鱼的胚胎死亡率明显高于6个月组(P<0.0001,P<0.001)。三组之间每个菌种的胚胎数量或胚胎畸形率没有显着差异。囊胚胚胎的转录组学分析结果表明,包括dusp5,bdnf,ppip5k2,dgkg,aldh3a2a,acsl1a,哈尔,毛,etc,与6个月组的表达水平相比,在12个月组或18个月组中差异表达。根据KEGG富集分析,这些差异表达基因(DEGs)在MAPK信号通路中显著富集,磷脂酰肌醇信号系统,脂肪酸降解和组氨酸代谢途径(P<0.05)。三组间差异表达基因的表达趋势分析(6个月组,12个月组,反过来,18个月组)显示,fancc的基因表达趋势,Fancg,Fancb,和telo2,涉及范可尼贫血途径,有统计学意义(P<0.05)。在卵母细胞转录组学分析的结果中,与6个月组相比,12个月组或18个月组差异表达的基因主要富集在细胞粘附分子和蛋白质消化吸收途径(P<0.05)。三组斑马鱼卵母细胞基因表达变化趋势的结果(6个月组,12个月组,18个月组)显示,随着母亲年龄的增长,生育力下降的三种基因表达趋势具有显着差异(P<0.05)。进一步分析三种显著差异表达趋势,结果显示51个DEGs与线粒体相关,5个DEGs与端粒维持和DNA修复相关,包括tomm40,mpc2,nbn,tti1等.
    随着斑马鱼母亲年龄的增加,胚胎受精率显著下降,胚胎死亡率显著上升。此外,随着斑马鱼母亲年龄的增加,线粒体和端粒相关基因的表达,如tomm40,mpc2,nbn,和tti1,在雌性斑马鱼卵母细胞中逐渐减少。母亲年龄可能是导致卵母细胞受精能力下降和早期胚胎死亡率增加的因素。母亲年龄相关的卵母细胞老化影响后代的生育能力和胚胎发育。
    UNASSIGNED: Female fertility gradually decreases with the increase in women\'s age. The underlying reasons include the decline in the quantity and quality of oocytes. Oocyte aging is an important manifestation of the decline in oocyte quality, including in vivo oocyte aging before ovulation and in vitro oocyte aging after ovulation. Currently, few studies have been done to examine oocyte aging, and the relevant molecular mechanisms are not fully understood. Therefore, we used zebrafish as a model to investigate oocyte aging. Three different age ranges of female zebrafish were selected to mate with male zebrafish of the best breeding age. In this way, we studied the effects of maternal age-related oocyte aging on fertility and investigated the potential molecular mechanisms behind maternal age-related fertility decline.
    UNASSIGNED: Eight female zebrafish aged between 158 and 195 d were randomly selected for the 6-month age group (180±12) d, 8 female zebrafish aged between 330 and 395 d were randomly selected for the 12-month age group (360±22) d, and 8 female zebrafish aged between 502 and 583 d were randomly selected for the 18-month age group (540±26) d. Male zebrafish of (180±29) d were randomly selected from zebrafish aged between 158 and 195 d and mated with female zebrafish in each group. Each mating experiment included 1 female zebrafish and 1 male zebrafish. Zebrafish embryos produced by the mating experiments were collected and counted. The embryos at 4 hours post-fertilization were observed under the microscope, the total number of embryos and the number of unfertilized embryos were counted, and the fertilization rate was calculated accordingly. The numbers of malformed embryos and dead embryos were counted 24 hours after fertilization, and the rates of embryo malformation and mortality were calculated accordingly. The primary outcome measure was the embryo fertilization rate, and the secondary outcome measures were the number of embryos per spawn (the total number of embryos laid within 1.5 hours after the beginning of mating and reproduction of the zebrafish), embryo mortality, and embryo malformation rate. The outcome measures of each group were compared. The blastocyst embryos of female zebrafish from each group born after mating with male zebrafish in their best breeding period were collected for transcriptomics analysis. Fresh oocytes of female zebrafish in each group were collected for transcriptomics analysis to explore the potential molecular mechanisms of maternal age-related fertility decline.
    UNASSIGNED: Compared with that of the 6-month group (94.9%±3.6%), the embryo fertilization rate of the 12-month group (92.3%±4.2%) showed no significant difference, but that of the 18-month group (86.8%±5.5%) decreased significantly (P<0.01). In addition, the fertilization rate in the 18-month group was significantly lower than that in the 12-month group (P<0.05). Compared with that of the 6-month group, the embryo mortality of the female zebrafish in the 12-month group and that in the 18-month group were significantly higher than that in the 6-month group (P<0.000 1, P<0.001). There was no significant difference in the number of embryos per spawn or in the embryo malformation rate among the three groups. The results of the transcriptomics analysis of blastocyst embryos showed that some genes, including dusp5, bdnf, ppip5k2, dgkg, aldh3a2a, acsl1a, hal, mao, etc, were differentially expressed in the 12-month group or the 18-month group compared with their expression levels in the 6-month group. According to the KEGG enrichment analysis, these differentially expressed genes (DEGs) were significantly enriched in the MAPK signaling pathway, the phosphatidylinositol signaling system, and the fatty acid degradation and histidine metabolism pathway (P<0.05). The analysis of the expression trends of the genes expressed differentially among the three groups (the 6-month group, the 12-month group, and the 18-month group in turn) showed that the gene expression trends of fancc, fancg, fancb, and telo2, which were involved in Fanconi anemia pathway, were statistically significant (P<0.05). In the results of oocyte transcriptomics analysis, the genes that were differentially expressed in the 12-month group or the 18-month group compared with the 6-month group were mainly enriched in cell adhesion molecules and the protein digestion and absorption pathway (P<0.05). The results of the trends of gene expression in the zebrafish oocytes of the three groups (the 6-month group, the 12-month group, and the 18-month group in turn) showed that three kinds of gene expression trends of declining fertility with growing maternal age had significant differences (P<0.05). Further analysis of the three significantly differential expression trends showed 51 DEGs related to mitochondria and 5 DEGs related to telomere maintenance and DNA repair, including tomm40, mpc2, nbn, tti1, etc.
    UNASSIGNED: With the increase in the maternal age of the zebrafish, the embryo fertilization rate decreased significantly and the embryo mortality increased significantly. In addition, with the increase in the maternal age of the zebrafish, the expression of mitochondria and telomere-related genes, such as tomm40, mpc2, nbn, and tti1, in female zebrafish oocytes decreased gradually. Maternal age may be a factor contributing to the decrease in oocyte fertilization ability and the increase in early embryo mortality. Maternal age-related oocyte aging affects the fertility and embryo development of the offspring.
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  • 文章类型: Journal Article
    pH稳态对精子发生至关重要,精子成熟,精子生理功能,哺乳动物的受精。HCO3-和H是调节男性生殖系统pH稳态的最重要因素。多个pH调节转运蛋白和离子通道位于睾丸中,附睾,精子,如HCO3-转运蛋白(溶质载体家族4和溶质载体家族26转运蛋白),碳酸酐酶,和H+转运通道和酶(例如,Na+-H+交换器,单羧酸盐转运蛋白,H+-ATP酶,和电压门控质子通道)。激素介导的信号对某些HCO3-或H+转运蛋白的产生有影响,如NBCe1、SLC4A2、MCT4等。此外,离子通道,包括精子特异性阳离子通道Ca2+(CatSper)和K+(SLO3)直接或间接受pH调节,对精子施加特定作用。微碱性的睾丸酸碱度有利于精子发生,而附睾的低HCO3-浓度和酸性管腔有利于精子成熟和储存。精子与精液融合后,pH值大大增加,以增强运动性。在女性生殖道,精子在子宫和输卵管中的HCO3-浓度增加,导致精子的细胞内pH(pHi)升高,导致精子质膜超极化,获能,过度激活,顶体反应,最终受精。由SLC26A3,SLC26A8,NHA1,sNHE,而位于精子中的CFTR被证明与男性生育能力有关。本文旨在介绍睾丸中pHi调控的关键因素和特点,输出管,附睾,精液,和女性生殖道,以及精子受精过程中的相关机制,提出对优秀学科和未来研究趋势的见解。
    pH homeostasis is crucial for spermatogenesis, sperm maturation, sperm physiological function, and fertilization in mammals. HCO3- and H+ are the most significant factors involved in regulating pH homeostasis in the male reproductive system. Multiple pH-regulating transporters and ion channels localize in the testis, epididymis, and spermatozoa, such as HCO3- transporters (solute carrier family 4 and solute carrier family 26 transporters), carbonic anhydrases, and H+-transport channels and enzymes (e.g., Na+-H+ exchangers, monocarboxylate transporters, H+-ATPases, and voltage-gated proton channels). Hormone-mediated signals impose an influence on the production of some HCO3- or H+ transporters, such as NBCe1, SLC4A2, MCT4, etc. Additionally, ion channels including sperm-specific cationic channels for Ca2+ (CatSper) and K+ (SLO3) are directly or indirectly regulated by pH, exerting specific actions on spermatozoa. The slightly alkaline testicular pH is conducive to spermatogenesis, whereas the epididymis\'s low HCO3- concentration and acidic lumen are favorable for sperm maturation and storage. Spermatozoa pH increases substantially after being fused with seminal fluid to enhance motility. In the female reproductive tract, sperm are subjected to increasing concentrations of HCO3- in the uterine and fallopian tube, causing a rise in the intracellular pH (pHi) of spermatozoa, leading to hyperpolarization of sperm plasma membranes, capacitation, hyperactivation, acrosome reaction, and ultimately fertilization. The physiological regulation initiated by SLC26A3, SLC26A8, NHA1, sNHE, and CFTR localized in sperm is proven for certain to be involved in male fertility. This review intends to present the key factors and characteristics of pHi regulation in the testes, efferent duct, epididymis, seminal fluid, and female reproductive tract, as well as the associated mechanisms during the sperm journey to fertilization, proposing insights into outstanding subjects and future research trends.
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  • 文章类型: Journal Article
    未受精的鸭蛋在孵化前会很快变质,有污染正常受精卵的风险。因此,尽早检测养殖鸭蛋的受精状况是一项有意义且具有挑战性的任务。大多数现有的工作通常集中在中期孵化期间鸡蛋的特性上。然而,在孵化之前很少注意检测鸭蛋。在本文中,我们提出了一种新的混合深度学习检测框架,用于预孵化鸭蛋的受精状态,称为CVAE-DF,基于可见/近红外(VIS/NIR)透射光谱。该框架包括卷积变分自动编码器(CVAE)的编码器和改进的深度森林(DF)模型。更具体地说,我们首先收集了255个鸭蛋孵化前的透射光谱数据(400-1000nm)。然后使用乘法散射校正(MSC)方法来消除原始光谱数据的噪声和无关信息。采用了两种有效的数据增强方法来提供足够的数据。之后,CVAE用于提取代表性特征并降低检测任务的特征维数。最后,采用改进的DF模型在增强特征集上建立分类模型。CVAE-DF模型在测试数据集上实现了95.94%的总体准确度。根据四个指标的这些实验结果表明,我们的CVAE-DF方法明显优于传统方法。此外,结果还表明,CVAE作为一种新颖的特征提取方法,有望用于其他农产品的VIS/NIR光谱分析。这对实际工程是非常有益的。
    Unfertilized duck eggs not removed prior to incubation will deteriorate quickly, posing a risk of contaminating the normally fertilized duck eggs. Thus, detecting the fertilization status of breeding duck eggs as early as possible is a meaningful and challenging task. Most existing work usually focus on the characteristics of chicken eggs during mid-term hatching. However, little attention has been paid to the detection for duck eggs prior to incubation. In this paper, we present a novel hybrid deep learning detection framework for the fertilization status of pre-incubation duck eggs, termed CVAE-DF, based on visible/near-infrared (VIS/NIR) transmittance spectroscopy. The framework comprises the encoder of a convolutional variational autoencoder (CVAE) and an improved deep forest (DF) model. More specifically, we first collected transmittance spectral data (400-1000 nm) of 255 duck eggs before hatching. The multiplicative scatter correction (MSC) method was then used to eliminate noise and extraneous information of the raw spectral data. Two efficient data augmentation methods were adopted to provide sufficient data. After that, CVAE was applied to extract representative features and reduce the feature dimension for the detection task. Finally, an improved DF model was employed to build the classification model on the enhanced feature set. The CVAE-DF model achieved an overall accuracy of 95.94 % on the test dataset. These experimental results in terms of four metrics demonstrate that our CVAE-DF method outperforms the traditional methods by a significant margin. Furthermore, the results also indicate that CVAE holds great promise as a novel feature extraction method for the VIS/NIR spectral analysis of other agricultural products. It is extremely beneficial to practical engineering.
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  • 文章类型: Journal Article
    有机施肥是增强农田土壤抗生素抗性的主要驱动因素。然而,目前尚不清楚细菌抗生素抗性如何在施肥土壤中演变,甚至传播到农作物。与没有肥料和商业肥料处理相比,有机肥料显着增加了土壤抗生素抗性基因(ARGs)的丰度,但抗性基因从土壤到作物的转移相对较弱。有机肥料的引入使土壤富含养分,推动土著微生物走向K战略。pH值,EC,和营养素作为关键驱动因素影响了ARGs的丰度。中性(pH7.2),低盐(TDS1.4%)和中营养(碳含量3.54g/L)的生境与有机肥料调节的土壤环境相似。这些环境条件明显延长了抗性质粒的持久性,并促进它们传播到大量的结合剂土壤微生物组,而不是植物内生菌。这表明有机肥料抑制了ARGs向农作物的传播。此外,在这些条件下,缀合物的组成显示了内生菌对抗性质粒的差异选择。这项研究揭示了农田中抗生素耐药性的演变和传播,并有助于制定农业中的抗生素耐药性控制策略。
    Organic fertilization is a major driver potentiating soil antibiotic resistance in farmland. However, it remains unclear how bacterial antibiotic resistance evolves in fertilized soils and even spreads to crops. Compared with no fertilizer and commercial fertilizer treatments, organic fertilizers markedly increased the abundance of soil antibiotic resistance genes (ARGs) but the relatively weaker transfer of resistance genes from soil to crops. The introduction of organic fertilizers enriches the soil with nutrients, driving indigenous microorganisms towards a K-strategy. The pH, EC, and nutrients as key drivers influenced the ARGs abundance. The neutral (pH 7.2), low salt (TDS 1.4 %) and mesotrophic (carbon content 3.54 g/L) habitats similar to the soil environment conditioned by organic fertilizers. These environmental conditions clearly prolonged the persistence of resistant plasmids, and facilitated their dissemination to massive conjugators soil microbiome but not to plant endophytes. This suggested that organic fertilizers inhibited the spread of ARGs to crops. Moreover, the composition of conjugators showed differential selection of resistant plasmids by endophytes under these conditions. This study sheds light on the evolution and dissemination of antibiotic resistance in farmlands and can aid in the development of antimicrobial resistance control strategies in agriculture.
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  • 文章类型: Journal Article
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  • 文章类型: Journal Article
    基因的时空表达模式对于维持动物的正常生理功能至关重要。使用环化重组酶(Cre)/P1交叉基因座(Cre/LoxP)策略的条件基因敲除已广泛用于特定组织或发育阶段的功能测定。这种方法有助于揭示表型和基因调控之间的关联,同时最大程度地减少不同组织之间的干扰。各种Cre工程小鼠模型已用于雄性生殖系统,包括原始生殖细胞的Dppa3-MERCre,Ddx4-Cre和Stra8-Cre用于精原细胞,Prm1-Cre和Acrv1-iCre用于单倍体精子细胞,Leydig细胞的Cyp17a1-iCre,Sox9-Cre用于支持细胞,和Lcn5/8/9-Cre用于附睾的分化节段。值得注意的是,Cre重组酶的特异性和功能阶段各不相同,Cre驱动的重组效率取决于具有不同序列的内源启动子以及构建的Cre载体,即使受相同启动子控制。通过传统重组或CRISPR/Cas9产生的Cre小鼠模型也表现出不同的敲除特性。本文综述了应用于雄性生殖系统的Cre工程小鼠模型,包括Cre目标策略,小鼠模型筛选,和遇到的实际挑战,特别是在过去十年中的新型小鼠品系。旨在为男性生殖系统的研究提供有价值的参考。
    The spatiotemporal expression patterns of genes are crucial for maintaining normal physiological functions in animals. Conditional gene knockout using the cyclization recombination enzyme (Cre)/locus of crossover of P1 (Cre/LoxP) strategy has been extensively employed for functional assays at specific tissue or developmental stages. This approach aids in uncovering the associations between phenotypes and gene regulation while minimizing interference among distinct tissues. Various Cre-engineered mouse models have been utilized in the male reproductive system, including Dppa3-MERCre for primordial germ cells, Ddx4-Cre and Stra8-Cre for spermatogonia, Prm1-Cre and Acrv1-iCre for haploid spermatids, Cyp17a1-iCre for the Leydig cell, Sox9-Cre for the Sertoli cell, and Lcn5/8/9-Cre for differentiated segments of the epididymis. Notably, the specificity and functioning stage of Cre recombinases vary, and the efficiency of recombination driven by Cre depends on endogenous promoters with different sequences as well as the constructed Cre vectors, even when controlled by an identical promoter. Cre mouse models generated via traditional recombination or CRISPR/Cas9 also exhibit distinct knockout properties. This review focuses on Cre-engineered mouse models applied to the male reproductive system, including Cre-targeting strategies, mouse model screening, and practical challenges encountered, particularly with novel mouse strains over the past decade. It aims to provide valuable references for studies conducted on the male reproductive system.
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  • 文章类型: Journal Article
    全球范围内,森林土壤被认为是温室气体(GHGs)的重要来源和汇。然而,大多数关于森林土壤温室气体通量的研究仅限于表土(土壤深度超过20厘米),关于底土(土壤深度低于20厘米)中这些通量的信息非常有限,特别是在管理森林中。这限制了对不同土壤深度对GHG通量和全球变暖潜力(GWP)的相对贡献的更深入理解。这里,我们使用基于浓度梯度的方法来全面研究稀释强度的影响(15%与35%)和营养添加(无肥料与NPK肥料)在杉木(Cunninghamialanceolata)人工林中以10cm的深度间隔从0-40cm的土壤层中获得土壤温室气体通量。结果表明,森林土壤是CO2和N2O的来源,而是CH4的水槽。土壤温室气体通量随着土壤深度的增加而降低,0-20厘米的土壤层被确定为CO2和N2O的主要生产者和CH4的消费者。稀疏强度对土壤GHG通量没有显着影响。然而,施肥显着增加了0-20厘米土壤层的CO2和N2O排放以及CH4吸收,但在20-40厘米的土壤层减少了它们。这是因为施肥减轻了表层土壤中微生物氮的限制和减少的充满水的孔隙空间(WFPS)。虽然它增加了底土的WFPS,最终表明土壤WFPS和氮素有效性(尤其是NH4-N)是沿土壤剖面温室气体通量的主要调节剂。一般来说,间伐和施肥对土壤温室气体通量有积极的交互效应。此外,在所有处理中,不施肥的35%间伐强度的GWP最低。总的来说,我们的结果表明,施肥可能不仅会对土壤剖面内的温室气体通量产生深度依赖性影响,但也阻碍了通过促进有管理的森林种植园的温室气体排放来缓解气候变化的努力。
    Globally, forest soils are considered as important sources and sinks of greenhouse gases (GHGs). However, most studies on forest soil GHG fluxes are confined to the topsoils (above 20 cm soil depths), with only very limited information being available regarding these fluxes in the subsoils (below 20 cm soil depths), especially in managed forests. This limits deeper understanding of the relative contributions of different soil depths to GHG fluxes and global warming potential (GWP). Here, we used a concentration gradient-based method to comprehensively investigate the effects of thinning intensity (15% vs. 35%) and nutrient addition (no fertilizer vs. NPK fertilizers) on soil GHG fluxes from the 0-40 cm soil layers at 10 cm depth intervals in a Chinese fir (Cunninghamia lanceolata) plantation. Results showed that forest soils were the sources of CO2 and N2O, but the sinks of CH4. Soil GHG fluxes decreased with increasing soil depth, with the 0-20 cm soil layers identified as the dominant producers of CO2 and N2O and consumers of CH4. Thinning intensity did not significantly affect soil GHG fluxes. However, fertilization significantly increased CO2 and N2O emissions and CH4 uptake at 0-20 cm soil layers, but decreased them at 20-40 cm soil layers. This is because fertilization alleviated microbial N limitation and decreased water filled pore space (WFPS) in topsoils, while it increased WFPS in subsoils, ultimately suggesting that soil WFPS and N availability (especially NH4+-N) were the predominant regulators of GHG fluxes along soil profiles. Generally, there were positive interactive effects of thinning and fertilization on soil GHG fluxes. Moreover, the 35% thinning intensity without fertilization had the lowest GWP among all treatments. Overall, our results suggest that fertilization may not only cause depth-dependent effects on GHG fluxes within soil profiles, but also impede efforts to mitigate climate change by promoting GHG emissions in managed forest plantations.
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  • 文章类型: Journal Article
    背景:这项研究的目的是研究静脉麻醉药物对接受辅助生殖技术(ART)取卵的受试者的受精率的影响。
    方法:设计了一项回顾性队列研究。收集接受卵母细胞提取程序的受试者的临床信息。根据所使用的麻醉类型将受试者分为两组:非麻醉组和静脉麻醉组。进行倾向评分匹配(PSM)并进行多元线性回归分析。比较两组PSM前后的受精率。
    结果:共有765名受试者分为两组:非麻醉组(n=482)和静脉麻醉组(n=283)。根据倾向得分,258对受试者匹配良好,两组基线资料比较差异无统计学意义(P>0.05)。静脉麻醉组受精率为77%,无麻醉组76%,组间差异无统计学意义(P=0.685)。匹配之前,Poisson回归分析显示静脉麻醉药物对受精率无影响(RR=0.859,95CI:0.59~1.25,P=0.422)。匹配后,也没有发现差异(RR=0.935,95CI:0.67至1.29,P=0.618)。
    结论:静脉麻醉药物可能对接受ART的受精率没有影响。
    BACKGROUND: The purpose of this study was to investigate the effects of intravenous anesthetic drugs on fertilization rate in subjects receiving oocyte retrieval by assisted reproduction technology (ART).
    METHODS: A retrospective cohort study was designed. The clinical information of subjects who received oocyte retrieval procedure was collected. The subjects were divided into two groups based on the type of anesthesia used: the no-anesthesia group and the intravenous anesthesia group. Propensity score matching (PSM) was performed and multiple linear regression analyses were conducted. Fertilization rate was compared between the two groups before and after PSM.
    RESULTS: A total of 765 subjects were divided into two groups: the no-anesthesia group (n = 482) and the intravenous anesthesia group (n = 283). According to propensity scores, 258 pairs of subjects were well matched, and the baseline data between the two groups were not significantly different (P > 0.05). Fertilization rate was 77% in the intravenous anesthesia group, and 76% in the no-anesthesia group, without significant between-group difference (P = 0.685). Before matching, Poisson regression analysis showed no effect of intravenous anesthetic drugs on fertilization rate (RR = 0.859, 95%CI: 0.59 to 1.25, P = 0.422). After matching, no difference was found either (RR = 0.935, 95%CI: 0.67 to 1.29, P = 0.618).
    CONCLUSIONS: Intravenous anesthetic drugs may exert no effects on fertilization rate in subjects receiving ART.
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