Total Rate Research Articles

Effects of climate warming on soil nitrogen cycles and bamboo growth in core giant panda habitat

Climate change can pose a significant threat to terrestrial ecosystems by disrupting the circulation of soil nitrogen. However, experimental analyses on the effect of climate change on soil nitrogen cycles and the implications for the conservation of key wildlife species (i.e., the giant panda, Ailuropoda melanoleuca) remain understudied. We investigated the effects of a 1.5 °C, 3 °C, and 4.5 °C temperature increase on nitrogen distribution in different soil layers of bamboo forest via an in-situ experiment and assessed the implications for the growth and survival of arrow bamboo (Bashania faberi), a critical food resource for giant pandas. Our results showed that warming treatments generally increased soil N content, while effects differed between surface soil and subsurface soil and at different warming treatments. Particularly an increase of 1.5 °C raised the subsurface soil NO3-N content, as well as the content of N in bamboo leaves. We found a significant positive correlation between the subsurface soil NO3-N content and the N content of arrow bamboo. An increase of 3–4.5 °C raised the content of total N and NO3-N in the surface soil and led to a reduction in the total aboveground biomass and survival rate of arrow bamboo. Limited warming (e.g., the increase of 0–1.5 °C) may promote the soil N cycle, raise the N-acetylglucosaminidase (NAG) enzyme activity, increase NO3-N in subsurface soil, increase the N content of bamboo, and boost the biomass of bamboo – all of which could be beneficial to giant panda survival. However, higher warming (e.g., an increase of 3–4.5 °C) resulted in mass death of bamboo and a large reduction in aboveground biomass. Our findings provide a cautiously optimistic scenario for bamboo forest ecosystems under low levels of warming over a short period of time, but risks from higher levels of warming may be serious, especially considering the unpredictability of global climatic change.

Response of a simulated aquatic fungal community to nanoplastics exposure and functional consequence on leaf decomposition

Nanoplastics pose a potential threat to a wide variety of aquatic organisms. Despite the awareness of this existing hazard, the impact of nanoplastics on natural fungal communities remains a research gap. In this study, five dominant fungi species, isolated from a stream ecosystem, were used to explore the effects of different nano-polystyrene (nano-PS) particles concentrations on a simulated fungal community. Specifically, the evaluation was conducted regarding the fungal growth, reproductivity, structural composition, and ecological function in leaf litter decomposition. A 15-day exposure experiment showed that 100 μg/L nano-PS significantly reduced the microcosm pH. The extracellular enzyme activities of β-glucosidase, leucine-aminopeptidase, and peroxidase were significantly promoted by nano-PS exposure for 5 days or 15 days. Total sporulation rate significantly decreased after the 15-day exposure to 1 and 100 μg/L nano-PS and significantly increased under 10 μg/L nano-PS. In contrast, nano-PS concentrations had no effects on fungal biomass. In addition, the reduced relative abundance of Geotrichum candidum lowered its contribution to leaf decomposition, resulting in a decreased litter decomposition rate of a 24.5–27.9 % after exposure. This suggests that 1–100 μg/L nano-PS inhibited leaf decomposition by inhibiting fungal reproduction and reducing the contribution of specific fungal species. In addition, the findings highlight the importance of exploring the potential mechanisms of the interaction between nanoplastics and fungal species.

Understanding the Manufacturing Process of Lipid Nanoparticles for mRNA Delivery Using Machine Learning.

Lipid nanoparticles (LNPs), used for mRNA vaccines against severe acute respiratory syndrome coronavirus 2, protect mRNA and deliver it into cells, making them an essential delivery technology for RNA medicine. The LNPs manufacturing process consists of two steps, the upstream process of preparing LNPs and the downstream process of removing ethyl alcohol (EtOH) and exchanging buffers. Generally, a microfluidic device is used in the upstream process, and a dialysis membrane is used in the downstream process. However, there are many parameters in the upstream and downstream processes, and it is difficult to determine the effects of variations in the manufacturing parameters on the quality of the LNPs and establish a manufacturing process to obtain high-quality LNPs. This study focused on manufacturing mRNA-LNPs using a microfluidic device. Extreme gradient boosting (XGBoost), which is a machine learning technique, identified EtOH concentration (flow rate ratio), buffer pH, and total flow rate as the process parameters that significantly affected the particle size and encapsulation efficiency. Based on these results, we derived the manufacturing conditions for different particle sizes (approximately 80 and 200 nm) of LNPs using Bayesian optimization. In addition, the particle size of the LNPs significantly affected the protein expression level of mRNA in cells. The findings of this study are expected to provide useful information that will enable the rapid and efficient development of mRNA-LNPs manufacturing processes using microfluidic devices.

Pneumococcal carriage and serotype distribution in children with nephrotic syndrome.

Patients with nephrotic syndrome (NS) are at a higher risk of developing invasive pneumococcal disease (IPD). Pneumococcal carriage studies are helpful tools for detecting potentially infectious serotypes and guiding immunization efforts. Pneumococcal nasopharyngeal colonization is common, and IPD can easily occur in an immunosuppressed state. Limited information is available regarding the frequency of pneumococcal carriage in individuals with NS. The aim of this study was to evaluate pneumococcal carriage and serotype distribution in children with NS. Pneumococcal carriage was detected by real-time PCR assays from nasopharyngeal swab samples from 98 children with NS, and 100 healthy controls. Isolates were serotyped by real-time PCR. The pneumococcal carriage rate was 44.9% in children with NS. Regarding the recommendation about pneumococcal immunization in children with NS, the vaccination rate was low. Also, non-PCV13 serotypes have been detected in at least 25% of PCV13-vaccinated children. There is no statistically significant difference in total pneumococcal carriage rate, PCV13 serotype carriage rate, or non-PCV13 serotype carriage rate between children with NS and healthy controls (p > 0.05 for all). The pneumococcal carriage rate was similar between children with NS and healthy controls. However, because children with NS have an increased risk for IPD, the serotype distribution of children with NS can demonstrate the improved protection offered by new pneumococcal vaccines. Regular monitoring for IPD is crucial for assessing the evolving sero-epidemiology of pneumococcal infections and evaluating the effectiveness of vaccines for children with NS.

HIV, syphilis and sexual-risk behaviours' prevalence among in-and out-of-school adolescent girls and young women in Zambia: A cross-sectional survey study.

In Zambia, 3.8% of young women and men aged 15-24 are HIV positive. However, like in most developing nations, HIV prevalence is higher among young women than young men (5.6% versus 1.8%). Despite the recognition of the rights of young people to sexual reproductive health (SRH) information and services, adolescent and young people (AYP) still face challenges in accessing healthcare in public health institutions including access to comprehensive knowledge on HIV/AIDs, HIV testing and contraceptives. The overall objective of the study was to collect baseline HIV, SRH and gender based violence (GBV) data at district level to inform the design of interventions targeting adolescent girls and young women (AGYW) aged 10-24 years in 20 districts of Zambia. A cross-sectional, mixed-methods study was conducted in 20 districts of Zambia with the highest incidence of HIV. Data was collected between August and October 2022 with a total response rate of 92% (12,813/13960), constituting 5979 (46.7%) in-school and 6834 (53.3%) out-of-school participants. Overall, Mwinilunga, Chinsali, Chisamba and Chembe districts had the highest number of respondents, while Sinazongwe and Mungwi districts contributed the least. The overall age distribution was such that 12.6% (n = 1617) of those interviewed were aged 10 to 14 years, 35.4% (n = 4536) were aged 15-19 years, and 52.0% (n = 6660) were aged 20-24 years. The overall mean age at first sex among AGYW interviewed was 16.6 years which was broken down as follows: 16.2 years for in-school and 16.8 years for out of school. Overall, most of the respondents had first time sex with either their boyfriend (80.4%) or husband (15.6%), with 2.4% of the in-school participants reporting to have had their sexual debut in marriage compared to 21.0% among out-of-school AGYW. Prevalence of HIV was higher in the out-of-school compared to the in-school participants (5.5% vs 2.0%), Similarly, the prevalence of syphilis was higher in the out-of-school than the in-school participants (4.1% vs 1.5%). The study focused on assessing the prevalence and vulnerability of HIV, syphilis, GBV, and SRH services uptake among adolescent girls and young women, and exploring factors affecting girls' stay-in-school and re-engagement. The study found that HIV and syphilis are still significant public health problems among adolescent girls and young women in Zambia, emphasizing the need for increased efforts to prevent and manage these infections.

Optimization of a combined gas turbine and steam Rankine cycle utilizing the chemical looping combustion (CLC) reactor for CO2 capture and Storage: Towards enhanced efficiency and Cost-Effectiveness

In recent years, CO2 released by fossil fuel power plants, through the process of capture and storage, has been tried to be separated from other combustion products and directed to the underground to prevent it from entering the environment. While various methods exist for this purpose, they are typically expensive and consume a significant amount of power. In this research, a proposed solution to study and optimize the capture and storage process involves a combined cycle power plant with two gas turbines and four steam turbines, equipped with a carbon dioxide capture and storage system using the chemical looping combustion (CLC) method. The storage of released CO2 is facilitated by four compressors operating in four stages. To begin, the developed model is validated in terms of energy, exergy, and economic factors. Subsequently, the system is optimized using an NSGA genetic algorithm, with two objective functions: exergy efficiency and total cost rate. Sensitivity analysis is conducted to define the decision variables. The results demonstrate that the optimization process has led to a 4.37 % increase in the system’s power output, from 379.75 MW to 396.37 MW. Moreover, the optimization has improved both the exergy and energy efficiency values, with these parameters rising from 51.97 % and 54.23 % to 54.24 % and 56.61 %, respectively. Furthermore, the total cost rate has slightly decreased from 46,267 to 46,020 $/hr as a result of system optimization.

Machine learning guided prediction of warfarin blood levels for personalized medicine based on clinical longitudinal data from cardiac surgery patients: a prospective observational study.

Warfarin is a common oral anticoagulant, and its effects vary widely among individuals. Numerous dose-prediction algorithms have been reported based on cross-sectional data generated via multiple linear regression or machine learning. This study aimed to construct an information fusion perturbation theory and machine learning prediction model of warfarin blood levels based on clinical longitudinal data from cardiac surgery patients. The data of 246 patients were obtained from electronic medical records. Continuous variables were processed by calculating the distance of the raw data with the moving average (MA ∆vki(sj)), and categorical variables in different attribute groups were processed using Euclidean distance (ED ǁ∆vk(sj)ǁ). Regression and classification analyses were performed on the raw data, MA ∆vki(sj), and ED ǁ∆vk(sj)ǁ. Different machine-learning algorithms were chosen for the STATISTICA and WEKA software. The random forest (RF) algorithm was the best for predicting continuous outputs using the raw data. The correlation coefficients of the RF algorithm were 0.978 and 0.595 for the training and validation sets, respectively, and the mean absolute errors were 0.135 and 0.362 for the training and validation sets, respectively. The proportion of ideal predictions of the RF algorithm was 59.0%. General discriminant analysis (GDA) was the best algorithm for predicting the categorical outputs using the MA ∆vki(sj) data. The GDA algorithm's total true positive rate (TPR) was 95.4% and 95.6% for the training and validation sets, respectively, with MA ∆vki(sj) data. An information fusion perturbation theory and machine learning model for predicting warfarin blood levels was established. A model based on the RF algorithm could be used to predict the target international normalized ratio (INR), and a model based on the GDA algorithm could be used to predict the probability of being within the target INR range under different clinical scenarios.

Effects of centrifugation treatment before electroporation on gene editing in pig embryos.

Genetic mosaicism, characterized by multiple genotypes within an individual, is considered an obstacle to CRISPR/Cas9 genome editing in animal models. Despite the various strategies for minimizing mosaic mutations, no definitive methods exist to eliminate them. This study aimed to enhance gene editing efficiency in porcine zygotes using CRISPR/Cas9, which targets specific genes through centrifugation and zona pellucida removal before electroporation. Centrifugation at 2000 × g did not adversely affect blastocyst formation rates in zygotes electroporated with gRNA targeting the GGTA1 gene; instead, it led to increased total and monoallelic mutation rates compared with control zygotes without centrifugation. However, the groups had no significant differences in biallelic mutation rates. In zygotes electroporated with gRNA targeting the CMAH gene, centrifugation treatments exceeding 1000 × g significantly increased both biallelic mutation rates and mutation efficiency. The combination of centrifugation and zona pellucida removal did not have a detrimental effect on blastocyst formation rates. It led to a higher rate of double biallelic mutations in embryos targeting both GGTA1 and CMAH compared to embryos without centrifugation treatment. In summary, our results demonstrate that pre-electroporation treatments, including centrifugation and zona pellucida removal, positively influenced the reduction of mosaic mutations, with the effectiveness of centrifugation depending on the specific gRNA used.

Does high-latitude ionospheric electrodynamics exhibit hemispheric mirror symmetry?

Abstract. Ionospheric electrodynamics is a problem of mechanical stress balance mediated by electromagnetic forces. Joule heating (the total rate of frictional heating of thermospheric gases and ionospheric plasma) and ionospheric Hall and Pedersen conductances comprise three of the most basic descriptors of this problem. More than half a century after identification of their central role in ionospheric electrodynamics, several important questions about these quantities, including the degree to which they exhibit hemispheric symmetry under reversal of the sign of dipole tilt and the sign of the y component of the interplanetary magnetic field (so-called “mirror symmetry”), remain unanswered. While global estimates of these key parameters can be obtained by combining existing empirical models, one often encounters some frustrating sources of uncertainty: the measurements from which such models are derived, usually magnetic field and electric field or ion drift measurements, are typically measured separately and do not necessarily align. The models to be combined moreover often use different input parameters, different assumptions about hemispheric symmetry, and/or different coordinate systems. We eliminate these sources of uncertainty in model predictions of electromagnetic work J⋅E (in general not equal to Joule heating ηJ2) and ionospheric conductances by combining two new empirical models of the high-latitude ionospheric electric potential and ionospheric currents that are derived in a mutually consistent fashion: these models do not assume any form of symmetry between the two hemispheres; are based on Apex magnetic coordinates (denoted Apex), spherical harmonics, and the same model input parameters; and are derived exclusively from convection and magnetic field measurements made by the Swarm and CHAMP satellites. The model source code is open source and publicly available. Comparison of high-latitude distributions of electromagnetic work in each hemisphere as functions of dipole tilt and interplanetary magnetic field clock angle indicates that the typical assumption of mirror symmetry is largely justified. Model predictions of ionospheric Hall and Pedersen conductances exhibit a degree of symmetry, but clearly asymmetric responses to dipole tilt and solar wind driving conditions are also identified. The distinction between electromagnetic work and Joule heating allows us to identify where and under what conditions the assumption that the neutral wind corotates with the Earth is not likely to be physically consistent with predicted Hall and Pedersen conductances.

Surface thermal-curing phosphorus-containing coated rigid polyurethane foam with highly-efficient flame retardancy and reinforced mechanical property

A phosphorous-containing HEMAP–co–GMA (HPG) prepolymer was successfully prepared by the ring-opening reaction of glycidyl methacrylate (GMA) and 2–hydroxyethyl methacrylate phosphate (HEMAP) as monomers, and flame retardant HEMAP–GMA copolymer (HPG) coating on the surface of rigid polyurethane foam (RPUF) was further fabricated by free-radical thermal-curing. The HPG coating endowed RPUF excellent flame retardancy and fire hazardous safety. The HPG coated on RPUF (HPG/RPUF) reached UL94 V–0 rating, and the limited oxygen index value of the HPG-2/RPUF improved from 19.0 % of RPUF to 27.8 %. The cone calorimetric test results showed that the total heat release and mean peak heat release rate values of the HPG-2/RPUF reduced by 79.6 % and 54.6 % compared to those of RPUF, respectively. The flame–retardant mechanism of HPG/RPUG was speculated the synergistic flame retardant effect between the barrier of the dense char layer and the inhibition of phosphorus–containing free–radicals. The three–dimensional crosslinked HPG coating not only provided HPG/RPUF excellent water resistance, but also enhanced compressive properties and heat–insulation. The highly efficient flame–retardant HPG coating has great potential in fire protection of the heat insulation foams.

Mobile fronthaul solution based on visible light fiber communication and zero-padding 8-D CAP modulation

With the deployment of the fifth-generation (5 G) emerging technologies, such as massive multiple-input multiple-output (mMIMO), conventional mobile fronthaul (FH) schemes based on Common Public Radio Interface (CPRI) are limited in their abilities to support ultra-high data rate, large bandwidth and massive connectivity. This has led to a growing demand for alternative solutions that can better fulfill these requirements. Visible light communication (VLC) has recently gained increasing research interest as a potential complementary technology for beyond-5 G communication, offering advantages such as unlicensed and abundant spectrum, high bandwidth and cost-efficiency. In this paper, we propose a novel mobile fronthaul solution based on visible light fiber communication (VLFC), incorporating innovative zero-padding N-D (N>2) carrierless amplitude and phase (CAP) modulation. To avoid strong low-frequency noise (LFN) in the practical VLFC system, we innovatively propose zero-padding N-D CAP based on the actual distribution of LFN for the first time. In contrast to frequency division multiplexing (FDM), N-D CAP eliminates guard bands and ensures similar performance among multiple channels. To prove the concept, we demonstrate the transmission of PAM8 symbols at three typical visible light wavelengths (R/G/B) over 100 m multi-mode fiber (MMF) using zero-padding 8-D CAP modulation. The experiment verifies that zero-padding significantly enhances communication performance, with all 8 channels achieving similar BER. Communication performance improves as wavelengths are longer due to attenuation and dispersion caused by MMF. Finally, we have achieved a total data rate of 10.8Gbps at 635 nm (red), 9.0Gbps at 520 nm (green), and 7.5Gbps at 488 nm (blue) under the 7% HD-FEC threshold.

Intrinsic flame-retardant epoxy resin based on phosphorus-containing liquid imidazole compound: Simultaneously improving fire safety, mechanical property and heat resistance

In this work, two phosphorus-containing liquid imidazole compounds with different phosphorus oxidation states (1,1′-(phenylphosphanediyl)bis(1H-imidazole) (DCPPI) with + 1 valence phosphorus, and imidazole-phenylphosphate (PPOAI) with + 3 valence phosphorus) were designed and synthesized. Both of DCPPI and PPOAI were used as curing agents to obtain intrinsic flame-retardant epoxy resin (EP-DCPPI and EP-PPOAI), in which the imidazole group was used as the curing group of EP, and the phosphorus-containing group was directly connected to the EP crosslinking network. On the one hand, the efficient flame-retardant groups containing + 1 or + 3 valence phosphorus were incorporated into the EP system to obtain excellent flame-retardant properties; on the other hand, the introduction of phenylphosphine or phenoxyphosphine groups in the molecular chain of EP greatly enhanced the interaction between molecular chains, adjusted crosslinking density and endowed EP with excellent tensile strength and toughness. Compared with imidazole cured EP (EP-MZ), the peak heat release rate (PHRR) of EP-15DCPPI and EP-15PPOAI decreased by 70 % and 68 %, and the total heat release rate (THR) decreased by 37 % and 36 %, respectively. Meanwhile, EP-15DCPPI passed UL-94 V-0 rating, and the limiting oxygen index (LOI) reached 36.1 %. EP-15PPOAI passed UL-94 V-1 rating and the LOI reached 29.1 %. The flame-retardant mechanism was analyzed and discussed. Compared with EP-MZ, the dynamic and static mechanical properties of EP-15DCPPI and EP-15PPOAI were enhanced simultaneously, and the glass transition temperature (Tg) was obviously increased.

Characteristics of the labor market in Croatia and contemporary external migration

The paper analyzes the characteristics of the labor market in Croatia, the changes in the demographic potential of the working-age population, and the structural determinants of the labor system. The movement of the number of able-bodied, active and inactive population from 2013 until today, points to a trend of decreasing the able-bodied contingent, economic activity and unemployment of the population, and an increase in employment. The analysis showed that the structural problems on the labor market in Croatia are an insufficiency of educational staff, structural unemployment, youth unemployment, and the mismatch between the supply and demand of jobs. Such characteristics of the work system influenced the movement of the determinants of external migration in Croatia, especially after 2013. Simultaneously with the strengthening of emigration, the number of immigrated persons also increases, so that from 2013 to 2022, their number amounted to about 195 thousand of mostly foreign citizens. We can establish that we are talking about free economic migrations and an increased inflow of labor, mostly unskilled workers, which makes up for the lack of domicile workforce.Structural-selective unemployment in Croatia can be analyzed on a general level according to age groups and according to education, and on a specific level, through indicators of the skills mismatch on the labor market. The total unemployment rate in Croatia has experienced a significant decline since 2013, and current unemployment is the lowest in the youngest working age, and the highest in the age over 40. Compared to 2013, the share of unemployed persons with primary and lower secondary education in Croatia is continuously decreasing, the share of unemployed persons with upper secondary and post-secondary non-tertiary education levels is slightly falling (with frequent oscillations), while the share of unemployed persons with tertiary education is increasing. Problems on the labor market in Croatia have been noticeable after the global economic crisis of 2008 and its high unemployment, and in the last ten years also in the areas with a low level of economic activity of the population and a lack of domestic labor for the functionality of certain sectors of activity.On the other hand, the structure of the emigrant contingent, in which the young and able-bodied population predominates, points to the outflow of labor force of medium and high qualification levels. The review of research on recent emigration confirms the complex conditionality of leaving Croatia, and among the main factors a group of economic ones arising from the macroeconomic situation and structural deficiencies in the labor market stands out. In addition to economic factors, other types of factors are strengthening, which is why the continuation of the emigration of the Croatian population and the immigration of the foreign population are likely to be expected. The isolated and presented indicators and trends point to the complexity of the relationship between economic and labor factors, contemporary migration patterns and demographic characteristics of the resident population, in accordance with previous theoretical and empirical knowledge.

Machine learning-based optimization and 4E analysis of renewable-based polygeneration system by integration of GT-SRC-ORC-SOFC-PEME-MED-RO using multi-objective grey wolf optimization algorithm and neural networks

This study introduces a new solar-methane-driven setup that recovers waste heat from flue gases to produce electricity, hydrogen, oxygen, fresh water (FW), and domestic hot water (DHW) while reducing the environmental impact of gas turbines. This integration includes the Brayton cycle and solid oxide fuel cell as motive cycles, the steam and organic Rankine cycle, a parabolic trough solar collector (PTC), a proton exchange membrane electrolyzer, multi-effect distillation, and reverse osmosis. Using Engineering Equation Solver software, analyses in energy, exergy, exergoeconomic, and exergoenvironment (4E) are conducted to identify critical system evaluation parameters in thermodynamics, economics, and the environment. Additionally, the proposed system is optimized using an artificial neural network and the multi-objective grey wolf optimizer algorithm, utilizing decision variables identified through sensitivity analysis to enhance system performance. The results of six-objective optimization show energy and exergy efficiencies at 49.48 % and 47.21 %, with a net power production of 133 MW and a total cost rate of $7903/h. Among all the components, the combustion chamber and PTC have the maximum exergy destruction, with values of 58.87 MW and 17.29 MW, respectively. Also, hydrogen, FW, and DHW production rates are 201.6 kg/h, 43.88 kg/s, and 40.98 kg/s, respectively. Moreover, the costs of hydrogen, FW, and DHW are $953.64/h, $57.35/h, and $82.48/h, respectively. Finally, Bloemfontein, Las Vegas, and Tunis are the most favorable regions economically, with a low levelized cost of electricity of $0.05931, $0.06006, and $0.05932 per kWh, along with payback periods of 0.6144, 0.5524, and 1.069 years, respectively.

Theoretical studies on the kinetics and mechanism of hydroxyl radical reaction with quinclorac and quinmerac herbicides in aqueous media

AbstractThe kinetic and mechanistic studies for the reaction of hydroxyl radical with two quinoline based herbicides, namely, quinclorac and quinmerac has been performed using various computational methods in aqueous media. Geometry optimizations were performed using Density Functional Theory (DFT) methods including water as the solvent. Local reactivity parameters of these herbicides towards the •OH radical are predicted using condensed Fukui function. Single point energies of various species were calculated using double hybrid method, namely, B2PLYP–D for better accuracy. The pKa values for these acid based herbicides allow them to exist in deprotonated form in aqueous condition. Hence, the calculations are also performed for the deprotonated or the anionic form apart from the neutral species. Individual rate coefficients for •OH radical addition reaction with each carbon atoms were evaluated using conventional transition state theory using one–dimensional tunneling corrections. The solvent effect on reaction is implemented through Collins–Kimball formulations. Both the approaches, namely, the Fukui index and individual rate constant determination confirms that the most reactive site for the •OH radical addition in these two herbicide is the carbon atom attached to the COOH group. The total rate constant for the •OH radical reaction with both neutral and anionic forms of these two herbicides are relatively high and equal to its diffusion‐limit value. Evaluation of the ecotoxicities of the parent herbicides and their OH adducts is estimated using the structure–activity relationship concept.

Total blastocyst usable rate is a predictor of cumulative live birth rate in IVF cycles

PurposeDespite advances in IVF techniques, determining the prognostic factors influencing cumulative live birth rate (CLBR) remains crucial for optimizing outcomes. Among the various key performance indicators in the lab, blastulation rate, and more specifically Total Blastocyst Usable Rate (TBUR), has gained particular interest. In this study we aimed at determining if TBUR was significantly associated with CLBR. Basic proceduresThis monocentric retrospective case-control study was conducted in 317 consecutive IVF/ICSI cycles in 2014–2020 and leading to the formation of 3 usable blastocysts, including freeze all cycles. TBUR (usable blastocysts / 2PNs) was calculated and CLBR after 2-year follow up was recorded, including both fresh and frozen embyro transfers. CLBR was then compared between 2 groups according to TBUR (group 1: TBUR ≥50 % vs group 2: TBUR ≤30 %). Main findingsCLBR was significantly higher in group 1 than in group 2 (57 vs. 41 %, p = 0.02). Adjusted logistic regression showed a statistically significant relationship between CLBR and TBUR, with a significantly lower chance of achieving a live birth in group 2 than in group 1 (OR = 0.408 [0.17–0.96]; p = 0.04). Principal conclusionsAlthough the monocentric design and the arbitrary choice of thresholds for TBUR and number of blastocysts call for caution when generalizing the findings and advocates for external validation, our results illustrate that TBUR is a valuable prognostic factor of CLBR in IVF cycles which might serve as a tool for lab monitoring, cycle analysis by medical staff and patients’ counselling. These results fit well within the P4 medicine concept (Predictive, Preventive, Personalized, and Participatory), and advocate for further research in order to improve embryo culture conditions.

A novel liquid biopsy assay with an 88% detection rate of genomic alterations across CNS tumors.

2077 Background: Diagnosis and treatment decisions for CNS tumors rely upon imaging with subsequent histological and genomic analyses of tissue to identify appropriate courses of therapy. Genomic profiling of tumor tissue for informative alterations is used to guide treatment, however contemporaneous tissue can sometimes be unavailable, inconclusive or overlook possible actionable alterations given the high amount of spatial heterogeneity in certain tumor types such as glioblastomas GBMs. Liquid biopsies may pose a possible solution, as they are readily accessible and provide a holistic snapshot of the tumoral genomic landscape. However, detection of ctDNAs from CNS tumors is impeded by its inherently low shedding biology and poor permeability across the BBB resulting in low plasma variant allele fractions (VAFs), with alteration detection rates ranging 27-55%. Thus, current assays do not yet have the sensitivity to be clinically useful in aiding decision making for CNS tumors. Methods: 62 cases of primary CNS tumors were submitted commercially for assessment with Northstar Select, a tumor-naive, plasma-based ctDNA liquid biopsy assay. Cases were obtained from a single clinic dating from January-December 2023. Results: See table. Conclusions: There remains an unmet clinical need for a highly sensitive liquid biopsy assay for use in determining the genomic landscape of CNS tumors to aid in clinical decision making. Current assays do not have a low enough limit of detection (LoD) to accurately detect ctDNAs at low VAFs. Herein, we demonstrate that Northstar Select has a detection rate of 88.7% in all cases and 91.4% in GBMs, nearly doubling current rates. This is due to the assay’s uniquely low LoD of 0.13-0.16% VAF, which is below the 0.17% median VAF demonstrated across CNS tumors in this study, allowing for more low-abundance alterations to be detected. Given the increased total variant detection rate, nearly 50% of which were actionable when alterations were detected, these data support the clinical utility of Northstar Select to inform clinical decisions either as a complement to imaging and tissue analyses or independently when tissue biopsies are infeasible. These data further suggest that the clinical utility of Northstar Select may be expanded into metastatic brain disease and other low ctDNA shedding tumors. [Table: see text]

Singlet oxygen generation proportion from triplet state of porphyrin in water

The proportion of singlet oxygen (R) produced from the triplet state of porphyrin in aqueous solutions was investigated by substituting porphyrin molecules with the metalloporphyrin Platinum(II) meso-tetraphenylporphyrin (Pt-TPP). The feasibility of using platinum porphyrin as a substitute for porphyrin to study the photophysical properties in photodynamic therapy (PDT) was confirmed. The model of first-order decay in a water-methanol mixed solution encompasses potential deactivation processes of the excited triplet states and was built, which was confirmed by monitoring the change in the total transition rate of the T1 state (A0) value at different water contents under anoxic environments, obtained through measuring the phosphorescence lifetime (τp) of Pt-TPP. Combined with A0 and the quenching rate constant of T1 by O2 (kq), the formula for R in relation to changes in oxygen can be deduced in pure water.

Potential and characteristics of rare-earth metals acid bioleaching from the rare-earth-rich tailings with the enriched functional bacterial consortium: Comparison between one-step and two-step processes

The irreplaceable roles of rare-earth metals (REMs) in modern technologies have renewed interest in the grand challenges of mineral processing and metallurgical engineering—the efficient extraction of REMs. However, traditional methods for extracting REMs are inefficient, costly and harmful to health and the environment. In this study, a method of biological extraction (bioleaching), which has been proved to be effective in the field of mineral processing for extraction of the metals, was employed for REMs bioleaching from Bayan Obo rare-earth-rich tailings (RERT) using the acid functional bacterial consortium, and the optimal culture and leaching conditions were optimized. Under the optimal conditions for 18 days, the total bioleaching rate of the five main REMs of La, Ce, Pr, Nd and Sm was obtained at 82.78 % for one-step process and 83.51 % for two-step process, which has a significant improvement comparing to previous studies. The results demonstrated that REMs could be efficiently bioleached by acid bioleaching functional bacterial consortium, and the difference in leaching efficiency between the one-step and two-step bioleaching process was not significant. In addition, by analyzing the mineral composition of the RERT and leaching residue, the extensively bioleach of REMs in bastnaesite are observed. To sum up, the rare-earth resources of Bayan Obo RERT could be effectively leached by acid bioleaching method.

Experimental investigation of the effect of slenderness ratio and retention time on the separation performance of a two-phase horizontal separator

This study investigates the effect of the slenderness ratio (L/D) on the performance of a three-phase separator for constant retention times in the oil phase. The research combines experimental measurements with statistical analysis. To determine the controlling parameters of separation efficiency. The experiments varied 4 independent variables: slenderness ratios (2:1, 4:1, and 5:1); total mass flow rates (2, 3, 4, 5, and 6 GPM); oil layer thickness (9 18 27 and 36 mm) and composition. In addition, the oil flow rate, as part of the total flow, was varied to allow the oil retention time to be held constant. Taguchi and full factorial statistical analysis methods were used to analyse the results. The performance was seen to increase with increasing slenderness ratio for constant retention time. This implies that the slenderness ratio has a positive effect on separation. However, this is not a simple relationship. The main independent variables that affect separation were identified as total flow and aspect ratio, but the interaction of flow rate and slenderness ratio can cancel each other out. The interaction of the oil layer and slenderness ratio is normally insignificant but becomes controlling when the aspect ratio and flow effect cancel each other out. The performance decreases as the oil layer thickness increases and the aspect ratio decreases. This indicates that separators with shorter and wider configurations are less efficient than those with longer and slimmer designs.