Horizontal secondary gas injection in fluidized beds: Solids concentration and velocity in multiphase jets

Secondary gas injection into fluidized beds is used in many industrial applications to control the particle size (1) or to introduce a reactant gas (2). Also in fluidized bed opposed jet mills a highly expanded gas can be used to grind particles into the submicron range. To model and improve processes which use secondary gas injection, a better understanding of the multiphase flow inside the jets is indispensable. A contribution to this is the analysis of the particle velocity via particle image velocimetry (PIV). These experiments were carried out in a semicircle fluidized bed with optical access, so that the morphology, particle acceleration and entrainment behavior can be visualized. These results can be compared to a simple model for the calculation of particle velocities in free jets and give a good agreement. Additionally, the solids concentrations in the particle laden gas jets are investigated with capacitance probes, an invasive measurement technique (3). Thus a solid concentration profile of the jet area can be determined and together with the PIV-data the solid mass flow can be estimated. This information is important for the calculation of the residence time in a reaction zone or the load condition in a jet mill. Parameters for those studies were the particle-size-distributions, the nozzle diameter, secondary gas velocity or the fluidization velocity. The measurements as well as the comparisons with calculations and models have discovered some unexpected insights in the multiphase flow of gas jets into fluidized beds and in the comminution process in fluidized bed opposed jet mills. REFERENCES J. McMillan, C. Briens, F.Berruti, and E.Chan. High velocity attrition nozzles in fluidized beds. Powd. Techn., 175:133-141, 2007. L. Chen, and H. Weinstein. Shape and extent of the void formed by a horizontal jet in a fluidized bed. AIChE. Journ., 39(12):1901-1909, 1993. M. Richtberg, R. Richter, and K.-E. Wirth. Characterization of the flow patterns in a pressurized circulating fluidized bed. Powd. Techn., 155:145-152, 2005

In defence of soil biodiversity: towards an inclusive protection in the European Union

Since soil biodiversity sustains above-ground life, the European Union (EU) has recently announced its new Soil Strategy to better protect soil ecosystems as part of the Biodiversity Strategy for 2030. Also, the EU’s Farm to Fork Strategy and the Zero Pollution Action Plan aim for soil protection. However, the status of soil biodiversity protection has not been comprehensively assessed. Therefore, we explored regulatory, incentive-based and knowledge-based instruments and strategic policy documents at the EU and national levels to determine whether they adequately protect soil biodiversity. Our review of 507 literature references concluded that only eight EU member states explicitly address threats to soil biodiversity in 14 regulatory instruments while 13 countries mainly focus on implicit threats to soil biodiversity, whereas six countries do not consider soil biodiversity. At the EU level, current directives and regulations only tackle individual threats to soil biodiversity. An EU-wide, legally binding protection could ensure a standardised minimum level of soil biodiversity protection while preventing surging costs of not acting. The EU Soil Health Law foreseen for 2023 could couple land management practices beneficial for soil biodiversity with incentive-based instruments. Simultaneously, models should be designed to predict soil biodiversity, considering soil biodiversity’s spatial and temporal heterogeneity.European Commission's Joint Research Centre | Ref. 3553

Anti-Mullerian-Hormone during pregnancy and peripartum using the new Beckman Coulter AMH Gen II Assay

Background: AMH levels determined by the conventional AMH assay declined during pregnancy and postpartum. A new Beckman Coulter AMH Gen II assay removes the potentially assay-interfering complement which is activated in pregnancy. The aim of this study was to evaluate if the decline of AMH levels in the serum of pregnant women during the course of pregnancy and peripartum was assay-dependent and thus artificial. Methods: In this cross-sectional study prepartal blood samples were collected from 62 patients (median age 30.6 years [interquartile range: 25.6 - 34.5]) in the third trimester of pregnancy and again 1–4 days after delivery between 2011 and 2012. In another cohort of 11 patients (median age 34.1 years [interquartile range: 32.6 - 37.8]) blood samples were taken in different trimesters of pregnancy between 1995 and 2001. The conventional and the modified AMH assay were performed in the same patient serum samples. We used the conventional and the modified AMH-Gen-II ELISA (Beckman Coulter, Immunotech, Webster, USA) for the assessment of AMH levels. The Wilcoxon signed rank test was used for determining differences between AMH levels pre- and postpartum. The method of Bland and Altman was applied for analyzing the agreement of both methods for determining AMH levels. Results: AMH values peripartum were lower than those expected in fertile non-pregnant women of comparable age. An overall mean difference of 0.44 ng/ml was observed between the conventional and the modified assay. Measurements with the modified assay showed a significant decline of postpartal levels compared with prepartal levels which is consistent with values obtained using the conventional assay (both p < 0.00001). Compared to the longitudinal measurements of AMH levels determined using the conventional assay, AMH levels obtained using the modified assay suggest a steeper decline of values during the course of pregnancy. Conclusion: By comparing the conventional assay for AMH determination with the modified assay the present study confirmed that AMH levels decline during the course of pregnancy and early after delivery

Assessment of ovarian reserve: Anti-Mullerian hormone versus follicle stimulating hormone

Background: This study aimed to evaluate the strength of anti-Mullerian hormone (AMH) and follicle stimulating hormone (FSH) in reflecting the antral follicle count (AFC) in infertile females.Materials and methods: This cross-sectional study was conducted on 160 females, visiting infertility clinic for assisted reproduction. Serum samples collected on the 3rd day of the cycle were assayed for FSH, luteinizing hormone, and AMH while AFC was assessed via transvaginal ultrasound. The study cohort was segregated into three groups based on AFC.Results: Chronological age and FSH was significantly high in females with very low AFC (P \u3c 0.01 and 0.009, respectively), yet they failed to discriminate patients with normal and higher follicle count (P = 0.65 and 0.84). Conversely, AMH reported highly significant difference between very low AFC and with those having either normal AFC (P = 0.002) or higher AFC (P = 0.001). Moreover, a significant difference in AMH was observed between normal and higher AFC group (P = 0.04).Conclusion: Compared to female\u27s age and FSH, AMH is superior in clustering study cohort on the bases of antral follicular pool, especially in setups with nonavailability of technological expertise to assess AFC. Incorporation of AMH along with other biomarkers improves estimation of baseline ovarian reserve, required to standardize dose for optimum response; avoiding the risk of failure to retrieve oocyte or inappropriate stimulation leading to ovarian hyperstimulation syndrome. Further prospective studies are required to ascertain its role in predicting the outcomes of ART in such patients

Ecosystem type drives soil eukaryotic diversity and composition in Europe

Soil eukaryotes play a crucial role in maintaining ecosystem functions and services, yet the factors driving their diversity and distribution remain poorly understood. While many studies focus on some eukaryotic groups (mostly fungi), they are limited in their spatial scale. Here, we analyzed an unprecedented amount of observational data of soil eukaryomes at continental scale (787 sites across Europe) to gain further insights into the impact of a wide range of environmental conditions (climatic and edaphic) on their community composition and structure. We found that the diversity of fungi, protists, rotifers, tardigrades, nematodes, arthropods, and annelids was predominantly shaped by ecosystem type (annual and permanent croplands, managed and unmanaged grasslands, coniferous and broadleaved woodlands), and higher diversity of fungi, protists, nematodes, arthropods, and annelids was observed in croplands than in less intensively managed systems, such as coniferous and broadleaved woodlands. Also in croplands, we found more specialized eukaryotes, while the composition between croplands was more homogeneous compared to the composition of other ecosystems. The observed high proportion of overlapping taxa between ecosystems also indicates that DNA has accumulated from previous land uses, hence mimicking the land transformations occurring in Europe in the last decades. This strong ecosystem-type influence was linked to soil properties, and particularly, soil pH was driving the richness of fungi, rotifers, and annelids, while plant-available phosphorus drove the richness of protists, tardigrades, and nematodes. Furthermore, the soil organic carbon to total nitrogen ratio crucially explained the richness of fungi, protists, nematodes, and arthropods, possibly linked to decades of agricultural inputs. Our results highlighted the importance of long-term environmental variables rather than variables measured at the time of the sampling in shaping soil eukaryotic communities, which reinforces the need to include those variables in addition to ecosystem type in future monitoring programs and conservation efforts.Collaborative Doctoral Partnership JRC and Universidade de Vigo | Ref. n. 35533Universidade de Vigo/CISUG | Ref. acceso abiert

Prevention of Cesarean Scar Defects: What Is Possible?

Defect healing of the uterotomy at ceasarean section (CS) results in a morphological und probably functional disruption of the anterior uterine wall. Clinical sequelae concern subsequent pregnancies with a broad range of complications before and during pregnancy as well as at birth. In the following chapter, we provide an overview about the definition, diagnosis, symptoms and pathogenetical mechanisms of CS scar defects. Keeping in mind the pathogenesis allows to introduce preventative approaches

Human inflammatory bowel disease does not associate with Lawsonia intracellularis infection

BACKGROUND: There is increasing evidence that bacterial infection of the intestinal mucosa may contribute to the pathogenesis of inflammatory bowel diseases (IBD). In pigs, an obligate intracellular bacterium, Lawsonia intracellularis (LI), was shown to cause proliferative enteropathy (PE) of which some forms display histological and clinical similarities to human IBD. Since LI-similar Desulfovibrio spp. may infect human cells, we hypothesized that LI might be associated with the development of human IBD. RESULTS: In human intestinal tissue samples, PCR using LLG, 50SL27, LSA and strictly LI-specific 16SII primers, yielded either no amplicons or products with weak homology to human genomic sequences. Sequencing of these amplicons revealed no specificity for LI. However, amplification of DNA with less specific 16SI primers resulted in products bearing homology to certain Streptococcus species. These 16SI-amplified products were present in healthy and diseased specimens, without obvious prevalence. CONCLUSION: LI is not associated with the pathogenesis of UC or CD. Whether an immunologic response to commensal bacteria such as streptococci may contribute to the chronic inflammatory condition in IBD, remained to be determined

Prevalence of genital Mycoplasma in pregnancies with shortened cervix

Objective To determine whether colonisation with genital Mycoplasma species (spp.) in patients presenting with a shortened cervix before 34th week of pregnancy is associated with preterm birth. Methods The collection of this retrospective study consisted of 100 pregnant women who presented to a German Tertiary Perinatal Center between 2017 and 2020 due to a shortened cervix defined as a cervical length of 25 mm or shorter measured by transvaginal ultrasound before 34 weeks of gestation. At the time of admission, gestational age ranged from 18 + 4 to 33 + 3 weeks (+ days) of pregnancy. All patients underwent urine polymerase chain reaction (PCR) for genital Mycoplasma [Ureaplasma (U.) urealyticum, U. parvum, M. hominis or M. genitalium]. Patients who were tested positive underwent a therapy with macrolides (azithromycin or clarithromycin). Results 37% of the patients were positive for Ureaplasma spp., whereas 5% (5 patients) were Mycoplasma spp.-positive. All the latter were simultaneously colonised with Ureaplasma spp. Ureaplasma-positive patients were significantly younger than those who were tested negative. Median maternal age at examination was 30 years (a) versus 31a (p = 0.04). There was no difference between Ureaplasma-positive and -negative patients regarding median maternal body mass index (BMI) (kg/m2) (23.4 versus 22.3, p = 0.41), cervical length at admission (mm) (15 versus 17, p = 0.17), gestational age at examination (days, d) (198 versus 197, p = 0.97) or gestational age at birth (d) (250 versus 257, p = 0.33), respectively. Comparing U. parvum-positive and U. urealyticum-positive patients, there was some weak indication that U. parvum-positive patients may get a shortening of the cervix earlier in pregnancy, as the median gestational age at examination was 196d versus 215d (p = 0.06). Regarding Mycoplasma-positive and -negative patients, there was no difference in all examined parameters. Conclusions Overall, one-third of all women in our study with a shortened cervix before 34th week of pregnancy were colonised with genital Mycoplasma spp. We were able to show that pregnant women, who were treated with antibiotics when tested positive for genital Mycoplasma, gave birth at the same gestational age as patients with a shortened cervix without detected Mycoplasma. This raises the question of whether routine testing and early antibiotic treatment should be established in prenatal care

Identification of altered miRNAs and their targets in placenta accreta

Placenta accreta spectrum (PAS) is one of the major causes of maternal morbidity and mortality worldwide with increasing incidence. PAS refers to a group of pathological conditions ranging from the abnormal attachment of the placenta to the uterus wall to its perforation and, in extreme cases, invasion into surrounding organs. Among them, placenta accreta is characterized by a direct adhesion of the villi to the myometrium without invasion and remains the most common diagnosis of PAS. Here, we identify the potential regulatory miRNA and target networks contributing to placenta accreta development. Using small RNA-Seq followed by RT-PCR confirmation, altered miRNA expression, including that of members of placenta-specific miRNA clusters (e.g., C19MC and C14MC), was identified in placenta accreta samples compared to normal placental tissues. In situ hybridization (ISH) revealed expression of altered miRNAs mostly in trophoblast but also in endothelial cells and this profile was similar among all evaluated degrees of PAS. Kyoto encyclopedia of genes and genomes (KEGG) analyses showed enriched pathways dysregulated in PAS associated with cell cycle regulation, inflammation, and invasion. mRNAs of genes associated with cell cycle and inflammation were downregulated in PAS. At the protein level, NF-κB was upregulated while PTEN was downregulated in placenta accreta tissue. The identified miRNAs and their targets are associated with signaling pathways relevant to controlling trophoblast function. Therefore, this study provides miRNA:mRNA associations that could be useful for understanding PAS onset and progression