Size Restrictions Research Articles

Fast On-Site Speciation and High Spatial Resolution Imaging of Labile Arsenic in Freshwater and Sediment Using the DGT-SERS Sensor.

Diffusive gradients in thin films (DGT) technique is renowned for in situ passive sampling but not for rapid on-site analysis, whereas surface-enhanced Raman spectroscopy (SERS) excels in ultrasensitive on-site detection but is limited by substrate contamination from complex matrices. Here, a hierarchical nanostructure of silver (Ag) mirror-supported large Ag nanoparticles (∼120 nm) was grown in situ in polyacrylamide hydrogel with a restricted pore size (PAM/Ag mirror/AgNPs) to serve as both the DGT binding phase and the SERS substrate. The substrate exhibited a maximum electric field enhancement factor of 9.9 × 108 and a signal relative standard error of 4.8%. Using the DGT-SERS sensor, As(III) and As(V) in freshwater were simultaneously detected at limits of 0.9 and 0.8 μg L-1, respectively, applicable across a wide range of environmental conditions. The DGT-SERS effectively mitigated the interfacial reduction of As(V) caused by humic acid by excluding it from plasmonic hotspots through size exclusion of the diffusive layer. The Raman analysis of a DGT sample in the field requires only 2 s using a portable spectrometer without DGT device disassembly. More importantly, the DGT-SERS captured the first two-dimensional image of As(III) and As(V) in one DGT at the micron scale resolution, revealing their spatially supplementary distribution patterns at the sediment-water interface. This study paves the way for next-generation speciation imaging DGT and the application of SERS in complex environments.

De novo genome of thick-tailed pygmy jerboa Salpingotus crassicauda, Cardiocraniinae, Dipodidae

Pygmy jerboas are one of the smallest taxa of rodents. They exhibit distinctly different morphological and biological characteristics from other subfamilies, such as more restricted distribution, species richness, reproductive ability, and population size. Agricultural expansion and the development of new energy projects in recent years lead to sharp decline of their natural populations. Here, we assembled and annotated the first reference genome for the subfamily Cardiocraniinae using Illunima and Nanopore sequencing from the thick-tailed pygmy jerboa, Salpingotus crassicauda. The final genome is 2.44 Gb in size, with a contig N50 length of 13.71 Mb and a BUSCO completeness of 96.35%. A total of 23,344 protein-coding genes were annotated in the final genome. We also determined the mitochondrial genome of this species and annotated 13 protein-coding genes, 22 tRNAs, and 2 rRNA. These genomic assemblies provide resources in studying phylogeny and adaptive evolution of Dipodidae, as well as implementing conservation management of jerboas.

Permeability Characteristics of Improved Loess and Prediction Method for Permeability Coefficient

Due to its unique geotechnical properties, loess presents itself as a cost-effective and energy-efficient material for engineering construction, aiding in cost reduction and environmental sustainability. However, to meet engineering specifications, loess often requires enhancement. Evaluating its permeability properties holds significant importance for employing improved loess for construction materials in landfills and artificial water bodies. This study investigates the influence of dry densities, grain size characteristics, grain size distribution, and admixture contents and types on the permeability of improved loess, focusing on the Malan and Lishi loess. The falling head permeability test was conducted to analyze how each factor affects the permeability of the improved loess. The findings indicate that the permeability coefficient decreases with increased dry density and admixture content. Conversely, it demonstrates a linear increase with the average grain size (d50), restricted grain size (d60), and the product of the coefficient of uniformity and coefficient of curvature (Cu × Cc). The primary influencing factor is the type of admixture, followed by Cc and d60. Furthermore, this study developed a predictive model for permeability using a support vector machine (SVM), surpassing the predictive accuracy of linear regression and neural network models. The model provides a robust prediction for the permeability of superior loess material.

Therapeutic ketogenic diet as treatment for anorexia nervosa.

Anorexia nervosa (AN) is a severe psychiatric disorder. However, we lack neurobiological models and interventions to explain and treat the core characteristics of food restriction, feeling fat, and body size overestimation. Research has made progress in understanding brain function involved in the pathophysiology of AN, but translating those results into biological therapies has been challenging. Studies have suggested that metabolic factors could contribute to developing and maintaining AN pathophysiology. Here, we describe a neurobiological model for why using a therapeutic ketogenic diet could address key alterations in brain function in AN and prevent the desire for weight loss and associated eating disorder-specific symptoms. This translational model is based on animal studies and human data and integrates behavioral traits, brain neural energy metabolism, and neurotransmitter function. Pilot data indicate that the intervention can dramatically reduce eating and body-related fears, although larger studies across illness stages still need to be conducted.

Optimizing Manufacturing of Zr–Cu–AI–NI Metallic Glasses via Laser Metal Deposition

Recently, it was discovered that the cutting-edge technique known as laser powder bed fusion (LPBF) is the best way to produce Zr-based bulk glasses made of metal (BMGs). While LPBF gives greater versatility, current state-of-the-art production techniques like copper mold casting and arc-melting have limits when it comes to implementing complicated designs. Furthermore, LPBF enables a delicate balance to be struck between producing intricate characteristics and sustaining suitable temperatures all through the whole operation. Because of its exceptional features and practical availability, this research focuses on optimizing the process variables for a specific Zr-based alloy, AMZ4, which is produced by additive manufacturing in order to optimize both its mechanical and thermal characteristics. Belonging to the class of zirconium-based alloys known as bulk metallic glasses (BMG), Zr57Cu15Ni10AI5 (or Vit-106) has an excellent glass-forming ability and shows great promise. By casting, a BMG alloy may be transformed into workpieces that are about one centimeter in size in all three dimensions. Nevertheless, crystallization is induced when the cast size is further increased since it reduces the cooling rate. By building a workpiece from many melt sections with the cooling rate maintained above the critical one, selective laser melt (SLM) is an established technique for overcoming size restrictions for BMGs. Partially crystallized BMG is now an issue with SLM-obtained components. The effect of SLM process variables on partial crystallization is investigated in this paper. You may regulate the size and intensity of the inclusion by altering the speed of the laser scanning. Microhardness and wear resistance may be improved by incorporating submicron crystalline inclusions into the amorphous matrix by SLM.

Memory-bound k-mer selection for large and evolutionarily diverse reference libraries.

Using k-mers to find sequence matches is increasingly used in many bioinformatic applications, including metagenomic sequence classification. The accuracy of these downstream applications relies on the density of the reference databases, which are rapidly growing. Although the increased density provides hope for improvements in accuracy, scalability is a concern. Reference k-mers are kept in the memory during the query time, and saving all k-mers of these ever-expanding databases is fast becoming impractical. Several strategies for subsampling have been proposed, including minimizers and finding taxon-specific k-mers. However, we contend that these strategies are inadequate, especially when reference sets are taxonomically imbalanced, as are most microbial libraries. In this paper, we explore approaches for selecting a fixed-size subset of k-mers present in an ultra-large data set to include in a library such that the classification of reads suffers the least. Our experiments demonstrate the limitations of existing approaches, especially for novel and poorly sampled groups. We propose a library construction algorithm called k-mer RANKer (KRANK) that combines several components, including a hierarchical selection strategy with adaptive size restrictions and an equitable coverage strategy. We implement KRANK in highly optimized code and combine it with the locality-sensitive hashing classifier CONSULT-II to build a taxonomic classification and profiling method. On several benchmarks, KRANK k-mer selection significantly reduces memory consumption with minimal loss in classification accuracy. We show in extensive analyses based on CAMI benchmarks that KRANK outperforms k-mer-based alternatives in terms of taxonomic profiling and comes close to the best marker-based methods in terms of accuracy.

An autoregulatory poison exon in Smndc1 is conserved across kingdoms and influences organism growth.

Many of the most highly conserved elements in the human genome are "poison exons," alternatively spliced exons that contain premature termination codons and permit post-transcriptional regulation of mRNA abundance through induction of nonsense-mediated mRNA decay (NMD). Poison exons are widely assumed to be highly conserved due to their presumed importance for organismal fitness, but this functional importance has never been tested in the context of a whole organism. Here, we report that a poison exon in Smndc1 is conserved across mammals and plants and plays a molecular autoregulatory function in both kingdoms. We generated mouse and A. thaliana models lacking this poison exon to find its loss leads to deregulation of SMNDC1 protein levels, pervasive alterations in mRNA processing, and organismal size restriction. Together, these models demonstrate the importance of poison exons for both molecular and organismal phenotypes that likely explain their extraordinary conservation.

Research on optical interferometric imaging with flexible control using optical fibers and PIC chip

We propose a prototype called a flexible integrated resolution and efficient light-imaging-expanded synthetic system (FIREFLIES). This paper describes the design, manufacturing, and experimental demonstration of the proposed system. FIREFLIES enables interferometric imaging at approximately 1550 nm using a variable baseline sampling technique, in which the baseline-collected light field forms interference fringes that are captured by an on-chip photodetector. This innovation extends the limited sampling distance imposed by the processing size restrictions of traditional photonic integrated circuit (PIC) links. Furthermore, we introduce a unique method for achieving super-resolution sampling by flexibly controlling the baseline. An experimental platform is constructed to test the FIREFLIES against a one-dimensional grating target. The experimental curves closely align with the theoretical predictions, confirming the efficacy of the system in super-resolution sampling and imaging performance.

Peningkatan Hasil Belajar Siswa melalui Model Kooperatif Tipe TGT dalam Pembelajaran Matematika di Kelas XI

Purpose – Several phenomena have been observed, including a notable lack of active student engagement, which has led to poor learning outcomes. Consequently, this research aims to investigate the enhancement of student learning outcomes through the implementation of the TGT (Teams-Games-Tournaments) cooperative learning model in eleventh-grade mathematics education.Method – The research method employed is Classroom Action Research (CAR), which comprises two cycles, each encompassing four stages: planning, action, observation, and reflection. The research instrument consists of test questions designed in accordance with the learning objectives. The success indicator for this research is that 75% of the students achieve learning mastery.Findings – The integration of the TGT (Teams-Games-Tournaments) cooperative learning model can improve student learning outcomes. Based on the research results and data analysis in cycle 1, the percentage of students achieving learning completeness was 42%. Since this did not meet the success indicators, the research continued into cycle 2, where an increase of 36% was observed. The percentage of students achieving learning completeness in cycle 2 was 78%, thereby meeting the success indicators, and thus, the research concluded at cycle 2. Research Implications – The implications of this research highlight the importance of selecting a learning model that promotes active student participation in the learning process to enhance students' learning outcomes in vector material. However, a limitation of this research is the restricted sample size, as it focuses solely on one school.

Advancements in mobile antenna design: A comprehensive literature review

This study reviews the literature on antenna design in mobile applications, analyzing research, theses, and academic papers to summarize current developments, identify gaps, and suggest future research lines. The review aims to compile the most recent findings on mobile antenna design from respected English-language journals. The study analyzes forty articles discussing both advanced and traditional antenna designs, focusing on efficiency, noise reduction, SAR compliance, size restrictions, polarization, and gain. It emphasizes the importance of innovation and multidisciplinary methods to meet the changing needs of the global communication network. The review uses keywords such as "Antenna," "Antenna Design," "Mobile Antenna," and "Mobile Antenna Design" to find relevant studies across IEEE Xplore, Scopus, Web of Science, and Google Scholar.

Atrial Septal Defect Stent Compression During Resuscitation of an Infant With Hypoplastic Left Heart Syndrome.

A newborn with hypoplastic left heart syndrome underwent a Norwood procedure with a Sano shunt. A month later, he had an atrial septal defect (ASD) stent placed due to ASD size and flow restriction. Three weeks later, he had sudden bradycardia and cardiac arrest in the intensive care unit. He was resuscitated and cannulated for extracorporeal membrane oxygenation (ECMO) through a right neck approach. An attempt to wean him from ECMO a week later failed due to hypoxia. Echocardiography showed ASD flow restriction and a chest x-ray showed flattening of the left atrial side of the ASD stent from chest compression resulting in a restrictive ASD. The patient underwent surgical removal of the ASD stent with ASD enlargement and was successfully weaned from ECMO after surgery.

A matheuristic for the resource-constrained project scheduling problem

This paper presents a matheuristic solution algorithm to solve the well-known resource-constrained project scheduling problem (RCPSP). The problem makes use of a restricted neighbourhood method using an activity selection and a search space restriction module and implements them as two alternative search algorithms. The first algorithm makes use of the best-performing components of the branch-and-bound procedures from the literature, and embeds them into a greedy neighbourhood search. The second matheuristic implements the exact branch-and-bound procedures into a known and well-performing meta-heuristic search algorithm.Computational experiments have been carried out on seven different datasets consisting of 10,000+ project instances. Experiments reveal that the choice of exact algorithm is key in finding high-quality solutions, and illustrate that the trade-off between selecting an activity set size and search space restriction depends on the specific implementation. The computational tests demonstrate that the matheuristic discovered 24 new best known solutions that could not be found by either a meta-heuristic or an exact method individually. Moreover, a new benchmark dataset has been proposed that can be used to develop new matheuristic search procedures to solve the problem consisting of 461 instances from the literature.

Treatment of infections caused by carbapenem-resistant Acinetobacter baumannii.

Patients with severe carbapenem-resistant Acinetobacter baumannii (CRAB) infections currently face significant treatment challenges. When patients display signs of infection and the clinical suspicion of CRAB infections is high, appropriate treatment should be immediately provided. However, current treatment plans and clinical data for CRAB are limited. Inherent and acquired resistance mechanisms, as well as host factors, significantly restrict options for empirical medication. Moreover, inappropriate drug coverage can have detrimental effects on patients. Most existing studies have limitations, such as a restricted sample size, and are predominantly observational or non-randomized, which report significant variability in patient infection severity and comorbidities. Therefore, a gold-standard therapy remains lacking. Current and future treatment options of infections due to CRAB were described in this review. The dose and considerable side effects restrict treatment options for polymyxins, and high doses of ampicillin-sulbactam or tigecycline appear to be the best option at the time of initial treatment. Moreover, new drugs such as durlobactam and cefiderocol have substantial therapeutic capabilities and may be effective salvage treatments. Bacteriophages and antimicrobial peptides may serve as alternative treatment options in the near future. The advantages of a combination antimicrobial regimen appear to predominate those of a single regimen. Despite its significant nephrotoxicity, colistin is considered a primary treatment and is often used in combination with antimicrobials, such as tigecycline, ampicillin-sulbactam, meropenem, or fosfomycin. The Infectious Diseases Society of America (IDSA) has deemed high-dose ampicillin-sulbactam, which is typically combined with high-dose tigecycline, polymyxin, and other antibacterial agents, the best option for treating serious CRAB infections. A rational combination of drug use and the exploration of new therapeutic drugs can alleviate or prevent the effects of CRAB infections, shorten hospital stays, and reduce patient mortality.

Memory-bound k -mer selection for large and evolutionary diverse reference libraries.

Using k -mers to find sequence matches is increasingly used in many bioinformatic applications, including metagenomic sequence classification. The accuracy of these down-stream applications relies on the density of the reference databases, which, luckily, are rapidly growing. While the increased density provides hope for dramatic improvements in accuracy, scalability is a concern. Reference k -mers are kept in the memory during the query time, and saving all k -mers of these ever-expanding databases is fast becoming impractical. Several strategies for subsampling have been proposed, including minimizers and finding taxon-specific k -mers. However, we contend that these strategies are inadequate, especially when reference sets are taxonomically imbalanced, as are most microbial libraries. In this paper, we explore approaches for selecting a fixed-size subset of k -mers present in an ultra-large dataset to include in a library such that the classification of reads suffers the least. Our experiments demonstrate the limitations of existing approaches, especially for novel and poorly sampled groups. We propose a library construction algorithm called KRANK (K-mer RANKer) that combines several components, including a hierarchical selection strategy with adaptive size restrictions and an equitable coverage strategy. We implement KRANK in highly optimized code and combine it with the locality-sensitive-hashing classifier CONSULT-II to build a taxonomic classification and profiling method. On several benchmarks, KRANK k -mer selection dramatically reduces memory consumption with minimal loss in classification accuracy. We show in extensive analyses based on CAMI benchmarks that KRANK outperforms k -mer-based alternatives in terms of taxonomic profiling and comes close to the best marker-based methods in terms of accuracy.

Tuned exchange imaging: Can the filter exchange imaging pulse sequence be adapted for applications with thin slices and restricted diffusion?

Filter exchange imaging (FEXI) is a double diffusion-encoding (DDE) sequence that is specifically sensitive to exchange between sites with different apparent diffusivities. FEXI uses a diffusion-encoding filtering block followed by a detection block at varying mixing times to map the exchange rate. Long mixing times enhance the sensitivity to exchange, but they pose challenges for imaging applications that require a stimulated echo sequence with crusher gradients. Thin imaging slices require strong crushers, which can introduce significant diffusion weighting and bias exchange rate estimates. Here, we treat the crushers as an additional encoding block and consider FEXI as a triple diffusion-encoding sequence. This allows the bias to be corrected in the case of multi-Gaussian diffusion, but not easily in the presence of restricted diffusion. Our approach addresses challenges in the presence of restricted diffusion and relies on the ability to independently gauge sensitivities to exchange and restricted diffusion for arbitrary gradient waveforms. It follows two principles: (i) the effects of crushers are included in the forward model using signal cumulant expansion; and (ii) timing parameters of diffusion gradients in filter and detection blocks are adjusted to maintain the same level of restriction encoding regardless of the mixing time. This results in the tuned exchange imaging (TEXI) protocol. The accuracy of exchange mapping with TEXI was assessed through Monte Carlo simulations in spheres of identical sizes and gamma-distributed sizes, and in parallel hexagonally packed cylinders. The simulations demonstrate that TEXI provides consistent exchange rates regardless of slice thickness and restriction size, even with strong crushers. However, the accuracy depends on b-values, mixing times, and restriction geometry. The constraints and limitations of TEXI are discussed, including suggestions for protocol adaptations. Further studies are needed to optimize the precision of TEXI and assess the approach experimentally in realistic, heterogeneous substrates.

P-630 Assessing Bologna and POSEIDON criteria as predictors of PGT-A in Poor Ovarian Response: A comparative analysis

Abstract Study question Do Bologna or POSEIDON criteria more accurately predict PGT-A outcomes in poor ovarian response, considering aneuploidy rates and clinical outcomes? Summary answer Comparing Bologna and POSEIDON criteria highlights higher aneuploidy rates in Bologna patients, with no significant differences in mosaicism rate or clinical outcomes in either group. What is known already Ovarian reserve stands out as the primary factor influencing reproductive senescence. Approximately 9-24% of individuals undergoing ovarian stimulation are categorized as ‘low-responders’. Key indicators of Poor Ovarian Response (POR) include age, antral follicle count (AFC), Anti-Müllerian Hormone (AMH), and response to controlled ovarian stimulation. While some studies link ovarian reserve to embryo quality, others dispute any correlation with embryo abnormalities. The Bologna criteria classify patients meeting at least two of the following: advanced maternal age, low AFC, and AMH. The more precise POSEIDON criteria combine these factors, forming four distinct groups for classification. Study design, size, duration We conducted a retrospective case-control study, examining PGT-A results of 2740 embryos derived from 797 IVF cycles conducted in our clinic between 2021 and 2022. Trophoectoderm biopsies, taken at D + 5/6, underwent Next-Generation Sequencing. Embryos were vitrified and transferred after analysis. Regarding the interpretation of the results, embryos with ≤25% cells aneuploids were considered euploid, between 25% and 50% were classified as mosaic and those with >50% cells were considered aneuploid. Participants/materials, setting, methods All patients used their own oocytes. Bologna and POSEIDON criteria were used for the classification of POR and non-POR patients. Univariate analysis was performed using Pearson’s chi-square statistical test for categorical variables and binary logistic regression to compare the rates of aneuploidy and embryonic mosaicism, pregnancy rate miscarriage, ongoing pregnancy rate and implantation rate with the above variables taking into account possible confounding factors. Main results and the role of chance Patient ages ranged from 22 to 47 years, with a mean of 38.9 years. In Bologna groups, mean ages were 41.15 years for Bologna and 38.43 years for the control. For POSEIDON: 32.47 group I, 39.85y group II, 32.11y group III, 40.41y group IV and 38.24y control group of the classified by POSEIDON criteria. The mean AFC was 10.95 and the AMH value was 13.15pmol/L. Among 797 cycles, 59.16% (449/797) met POR criteria by POSEIDON, distributed across groups: 1.19% (9/797) in group I, 1.32% (10/797) in group II, 22.66% (172/797) in group III and 33.99% (258/797) in group IV. Using Bologna criteria, 17.74% (486/797) were classified as POR. Our findings reveal that individuals identified with POR by Bologna criteria exhibit a significantly elevated incidence of embryo aneuploidy (78.8% POR patients vs. 59.9% control patients; p = 0.004). However, no such distinction was observed when employing the POSEIDON criteria for classification. In terms of embryo mosaicism, no notable differences were detected between POR and non-POR patients under both Bologna and POSEIDON criteria. Furthermore, no significant variations in clinical data were observed between the two groups, even after correcting for maternal age. Limitations, reasons for caution The study is constrained by the inherent limitations of a retrospective design and a restricted sample size. Moreover, the complexity and heterogeneity involved in classifying patients with POR contribute to additional challenges in the interpretation of results. Wider implications of the findings The study indicates that diminished ovarian reserve does not significantly augment the probability of embryo aneuploidies. Particularly noteworthy is the observation that young women with low ovarian reserve do not exhibit an increased susceptibility to aneuploidies. This finding holds implications for understanding reproductive outcomes among ovarian reserve variations. Trial registration number No aplicable

Morphological Rule-Constrained Object Detection of Key Structures in Infant Fundus Image.

The detection of optic disc and macula is an essential step for ROP (Retinopathy of prematurity) zone segmentation and disease diagnosis. This paper aims to enhance deep learning-based object detection with domain-specific morphological rules. Based on the fundus morphology, we define five morphological rules, i.e., number restriction (maximum number of optic disc and macula is one), size restriction (e.g., optic disc width: 1.05 +/- 0.13 mm), distance restriction (distance between the optic disc and macula/fovea: 4.4 +/- 0.4 mm), angle/slope restriction (optic disc and macula should roughly be positioned in the same horizontal line), position restriction (In OD, the macula is on the left side of the optic disc; vice versa for OS). A case study on 2953 infant fundus images (with 2935 optic disc instances and 2892 macula instances) proves the effectiveness of the proposed method. Without the morphological rules, naïve object detection accuracies of optic disc and macula are 0.955 and 0.719, respectively. With the proposed method, false-positive ROIs (region of interest) are further ruled out, and the accuracy of the macula is raised to 0.811. The IoU (intersection over union) and RCE (relative center error) metrics are also improved .

Preliminary results of intracranial aneurysm treatment with derivo2heal embolization device

IntroductionThe Derivo 2 Heal Embolization Device (D2HED) is a novel flow diverter (FD) providing a fibrin-/heparin-based surface coating aiming at lower thrombogenicity. We evaluate periprocedural aspects and preliminary aneurysm occlusion efficacy for intracranial aneurysm treatment.MethodsThirty-four D2HEDs deployments (34 aneurysms, 32 patients) between 04/2021 and 10/2023 were analyzed. All patients were under dual antiplatelet therapy (dAPT). Periprocedural details, adverse events, and follow-up (FU) imaging were reviewed by consultant-level neuroradiologists. Complication rates and aneurysm occlusion efficacy are compared with performance data of other FDs based on literature research.ResultsEach intervention succeeded in the deployment of one D2HED. Significant and/or increased intraaneurysmal contrast stagnation immediately after D2HED deployment was seen in 73.5% of cases according to O’Kelly-Marotta (OKM) grading scale. Clinically relevant early adverse events occurred in three patients: Among them two cases with fusiform aneurysms in the posterior circulation (ischemic events, early in-stent-thrombosis) and one patient (ischemic event) out of the majority of 31 treated internal carotid artery aneurysms (3,2%). Regarding mid-term FU (> 165 days), one aneurysm did not show progressive occlusion presumably caused by a prominent A1 segment arising from the terminal ICA aneurysm itself. Apart from that, mid-term complete / partial occlusion rates of 80% / 20% could be demonstrated.ConclusionOur case series - although suffering from restricted sample size - suggests a potential effectiveness of D2HED in managing intracranial aneurysms. Further studies with larger samples are warranted to quantify long-term occlusion efficacy and the impact of antithrombogenic surface coating on the necessary (d)APT.

Influence of cover crops on soil aggregate stability, size distribution and related factors in a no-till field

Soil aggregation plays an essential role in maintaining soil structure. A three-year field experiment was undertaken to explore the effects of cover crops on soil aggregate stability indices (mean weight diameter, water-stable aggregates greater than 0.25 mm, and soil erodibility factor), size distribution and their correlations with nine soil physical and chemical properties (soil bulk density, pH, organic carbon, total nitrogen, C/N, calcium, phosphorus, potassium, and cation exchange capacity) at 0–5 and 5–10 cm depths in a Marietta silt loam soil in a no-till field, Northeastern Mississippi. The cover crop treatments included elbon rye (Secale cereale L.), daikon radish (Raphanus sativus ssp. acanthiformis), Austrian winter field peas (Lathyrus hirsutus), and their mixture. The samples were wet-sieved to five size classes of aggregates (> 2, 2–1, 1–0.5, 0.5–0.25, and < 0.25 mm). Results showed that the < 0.25 mm aggregates dominated (50.95–78.02 %) soil aggregate size distribution at 0–5 and 5–10 cm depths. The rye plot soil displayed the greatest values for mean weight diameter (0.58 mm) in the two soil depths. Soil water-stable aggregates greater than 0.25 mm value under peas was significantly higher by 68.61 % compared to the no cover crop treatment at 0–5 cm depth, while soil erodibility factor did not change significantly. Mean weight diameter, water-stable aggregates greater than 0.25 mm, soil erodibility factor, 1–0.5 mm aggregates, and < 0.25 mm aggregates were significantly correlated with soil organic carbon, pH, bulk density, phosphorus, and potassium. The dominant factors driving changes in three aggregate stability indices and size fractions (excluding 2–1 mm aggregates) were bulk density and pH. Furthermore, high pH restricted soil aggregate stability and size distribution. This study demonstrated the positive impact of cover crops, specifically peas and rye, on soil aggregate stability and size distribution. This study will provide valuable information for future research on soil stabilization in crop production management systems.

Increased stable integration efficiency in CHO cells through enhanced nuclear localization of Bxb1 serine integrase

BackgroundMammalian display is an appealing technology for therapeutic antibody development. Despite the advantages of mammalian display, such as full-length IgG display with mammalian glycosylation and its inherent ability to select antibodies with good biophysical properties, the restricted library size and large culture volumes remain challenges. Bxb1 serine integrase is commonly used for the stable genomic integration of antibody genes into mammalian cells, but presently lacks the efficiency required for the display of large mammalian display libraries. To increase the Bxb1 integrase-mediated stable integration efficiency, our study investigates factors that potentially affect the nuclear localization of Bxb1 integrase.MethodsIn an attempt to enhance Bxb1 serine integrase-mediated integration efficiency, we fused various nuclear localization signals (NLS) to the N- and C-termini of the integrase. Concurrently, we co-expressed multiple proteins associated with nuclear transport to assess their impact on the stable integration efficiency of green fluorescent protein (GFP)-encoding DNA and an antibody display cassette into the genome of Chinese hamster ovary (CHO) cells containing a landing pad for Bxb1 integrase-mediated integration.ResultsThe nucleoplasmin NLS from Xenopus laevis, when fused to the C-terminus of Bxb1 integrase, demonstrated the highest enhancement in stable integration efficiency among the tested NLS fusions, exhibiting over a 6-fold improvement compared to Bxb1 integrase lacking an NLS fusion. Subsequent additions of extra NLS fusions to the Bxb1 integrase revealed an additional 131% enhancement in stable integration efficiency with the inclusion of two copies of C-terminal nucleoplasmin NLS fusions. Further improvement was achieved by co-expressing the Ran GTPase-activating protein (RanGAP). Finally, to validate the applicability of these findings to more complex proteins, the DNA encoding the membrane-bound clinical antibody abrilumab was stably integrated into the genome of CHO cells using Bxb1 integrase with two copies of C-terminal nucleoplasmin NLS fusions and co-expression of RanGAP. This approach demonstrated over 14-fold increase in integration efficiency compared to Bxb1 integrase lacking an NLS fusion.ConclusionsThis study demonstrates that optimizing the NLS sequence fusion for Bxb1 integrase significantly enhances the stable genomic integration efficiency. These findings provide a practical approach for constructing larger libraries in mammalian cells through the stable integration of genes into a genomic landing pad.