High-resolution Sequence Research Articles

High-resolution sequence stratigraphy of clastic shelves IX: Methods for recognizing maximum flooding conditions in shallow-marine settings

Maximum flooding conditions in high-frequency sequences are associated with a condensed section, a generally cryptic maximum flooding surface, and with facies contacts marked by grain size changes, shell beds and bioturbation; i.e., the downlap surface and the local flooding surface. Conditions of maximum water depth usually occur above the condensed section, in the early highstand systems tract. Due to its importance in sequence stratigraphic analysis, the identification of the precise position of the maximum flooding surface, which separates the transgressive and highstand systems tracts, is critical. This is particularly true in high-resolution studies based on field and core data, where only facies contacts that are older and younger than the maximum flooding surface are recognizable. An integration of several criteria, including sedimentological (facies analysis), diagenetic, micropaleontological, geophysical and geochemical, represents the best approach to define a relatively thin uncertainty interval within high-frequency sequences, in which the cryptic MFS should lie. Among the available criteria, those sedimentological and diagenetic are the ones best suited to recognize facies contacts, whereas those micropaleontological are the most reliable ones to identify the position of the maximum flooding surface. Future studies on the integration of these methods with those geophysical and geochemical have the potential to improve the ability to identify the maximum flooding surface, and improve the available tools in the high-resolution sequence stratigraphic analysis.

Automated 2-Dimensional Measurement of Vestibular Schwannoma: Validity and Accuracy of an Artificial Intelligence Algorithm.

Validation of automated 2-dimensional (2D) diameter measurements of vestibular schwannomas on magnetic resonance imaging (MRI). Retrospective validation study using 2 data sets containing MRIs of vestibular schwannoma patients. University Hospital in The Netherlands. Two data sets were used, 1 containing 1 scan per patient (n = 134) and the other containing at least 3 consecutive MRIs of 51 patients, all with contrast-enhanced T1 or high-resolution T2 sequences. 2D measurements of the maximal extrameatal diameters in the axial plane were automatically derived from a 3D-convolutional neural network compared to manual measurements by 2 human observers. Intra- and interobserver variabilities were calculated using the intraclass correlation coefficient (ICC), agreement on tumor progression using Cohen's kappa. The human intra- and interobserver variability showed a high correlation (ICC: 0.98-0.99) and limits of agreement of 1.7 to 2.1 mm. Comparing the automated to human measurements resulted in ICC of 0.98 (95% confidence interval [CI]: 0.974; 0.987) and 0.97 (95% CI: 0.968; 0.984), with limits of agreement of 2.2 and 2.1 mm for diameters parallel and perpendicular to the posterior side of the temporal bone, respectively. There was satisfactory agreement on tumor progression between automated measurements and human observers (Cohen's κ = 0.77), better than the agreement between the human observers (Cohen's κ = 0.74). Automated 2D diameter measurements and growth detection of vestibular schwannomas are at least as accurate as human 2D measurements. In clinical practice, measurements of the maximal extrameatal tumor (2D) diameters of vestibular schwannomas provide important complementary information to total tumor volume (3D) measurements. Combining both in an automated measurement algorithm facilitates clinical adoption.

High resolution sequence stratigraphy of the Mishrif Formation (Cenomanian-Early Turonian) at zubair oilfield (al-rafdhiah dome), southern Iraq

The Mishrif Formation (Cenomanian -E Turonian) is one of the most important geological formations in the Middle East and Iraq because it contains enormous petroleum accumulations. It is considered to be the first reservoir in the region, and is still being studied because of its economic significance. The carbonate of the Mishrif Formation derives from a variety of depositional settings, including mid-ramp, shoal, lagoon, and intertidal. The five main microfacies discussed in this paper are wackestone, packstone, grainstone, floatstone, and bindstone. The most frequent fossilised components found in the Mishrif Formation are rudists, benthic foraminifera, echinoderms, burrows molluscs, and algae. According to the microfacies and analysed wireline log data, the sequence stratigraphy of the studied formation is composed of two regression cycles. Five parasequences of transgressive–regressive cycles make up the depositional sequence of the Mishrif Formation. The standard depositional environments seem to demonstrate a gradual regression, beginning with a short period of the outer ramp, then a steady period of the mid-ramp, and ending in the intertidal environment. Additionally, the study recorded two regional maximum flooding surfaces: K-135 and K-140. The former is present in the lowermost part of the formation, while the other lies in the middle. This study shows a close relationship between facies (environments) and hydrocarbon accumulation. The increased accumulation focuses on the lower part of the studied formation, and seems to be lower in the upper part of the formation as a result of changes in the environment of deposition.

Skull-base temporal encephalocele: Hidden cause of temporal lobe epilepsy.

In the present study patients with previously diagnosed MRI-negative temporal lobe epilepsy (TLE) on long-term video electroencephalography (VEEG) monitoring were re-evaluated with high resolution 3T MRI brain to look out for a skull base temporal lobe encephalocoele (TE). A total of 234 VEEGs were analyzed. TLE had been diagnosed in 104 patients based on semiology, ictal, interictal EEG data, and brain positron emission tomography (PET) studies. Of these, 99 patients had temporal lobe abnormality (78 had mesial temporal sclerosis, 8 had tumor, 3 had focal cortical dysplasia, and 10 had mixed pathology). Out of the five 1.5T MRI-negative TLE patients, two patients were diagnosed with TE on subsequent 3T MRI brain scans and one patient underwent electrocorticography-guided tailored resection for complete removal of epileptogenic tissue; with Engels class I seizure freedom at one year follow-up. We propose that TE should be carefully searched for, as a cause of refractory TLE, using high-resolution MRI sequences.

Relationship between structural changes in the myocardium of the left atrium and the effectiveness of cryoablation in persistent atrial fibrillation

Introduction. High-resolution contrast-enhanced cardiac magnetic resonance imaging reveals left atrial fibrosis, the severity of which may be related to the effectiveness of catheter ablation.Aim. To study the structural changes of the left atrium myocardium according to magnetic resonance imaging with contrast in patients with persistent atrial fibrillation before balloon cryoablation and compare the results with the effectiveness of the intervention.Materials and methods. The study included 89 patients with persistent form of atrial fibrillation. The patients were randomized into two groups: in the 1st, the pulmonary veins cryoablation was performed (n = 39 (53.4%)); in the 2nd, the pulmonary veins and posterior wall of the left atrium cryoablation was performed (n = 34 (46.6%)). All patients before cryoablation underwent cardiac magnetic resonance imaging with delayed contrast using a high-resolution MR pulse sequence. The clinical efficacy of the intervention was evaluated after 12 months after the cryoablation.Results. The severity of fibrotic myocardial lesion of the left atrium before balloon cryoablation was 0.7% [0; 3,07]. Overall efficiency of the intervention rate was 57.1%. Cryoablation was most effective (59.5%) in patients severity of fibrosis less than 20% and least effective (50%) severity of fibrosis more than 20%. Risk factors for atrial fibrillation recurrence after cryoablation were: early atrial fibrillation recurrence, female sex, the maximum atrial fibrillation duration more than 3 months, stroke/TIA.Conclusion. The severity of left atrial fibrosis more than 20%, early recurrence of atrial fibrillation in the first 3 months after the cryoablation, female sex, the duration of the maximum atrial fibrillation episode more than 3 months, and a history of stroke/transient ischemic attack may be associated with recurrence of AF during the period observation 3–12 months.

The potential of electromyography, diagnostic transcranial magnetic stimulation, and multiparametric magnetic resonance imaging in the combinatory assessment of facial nerve disorders: a literature review and clinical case series

Facial neuropathy (FN) is a complex multicausal problem that, with a seemingly obvious clinical picture, might be challenging to diagnose. Up to 5% of FN cases could be caused by neoplastic or otogenic processes, necessitating an interdisciplinary approach to its treatment by various specialties and in some cases a surgical intervention. In addition, in the early stages of FN, it is difficult to predict its outcomes. Therefore, beyond usual neurological exam and widely used electromyography (EMG), other additional diagnostic tools are used to ensure extended diagnosis, including cancer awareness.
 In this paper we have analyzed the principles, role and value of computed tomography, magnetic resonance imaging (MRI), diagnostic transcranial magnetic stimulation combined with EMG, and ultrasound assessment with a high-frequency linear transducer in acute FN. We present our own clinical cases of pediatric patients with FN, who were assessed with EMG and multiparametric MRI including diffusion tensor imaging. These cases illustrate both the abnormalities found in the typical course of Bell's palsy, as well as the abnormalities in neoplasm-associated FN that clinically fully mimic the Bell's palsy. Based on the world experience in multiparametric MRI, including the use of extended protocols in the Pediatric Research and Clinical Center for Infectious Diseases, in case of suspected FN, the most important are high-resolution structural submillimeter sequences based on the gradient echo (SSFP) and diffusion tensor imaging (DTI). Measurement and assessment of fractional anisotropy at the motor nuclei of the facial nerves in the pons look promising for further research. The paper is the first to describe a modified combination diagnostic approach to Bell's palsy with the use of diagnostic transcranial magnetic stimulation with round coil, supramaximal stimulation with identification of the motor evoked response threshold (minimal inducer power to register a reproducible evoked motor response of 50-100 mV in amplitude) in the occipito-parietal area of the ipsilateral muscle.

Intracranial Arachnoiditis and Hydrocephalus

A 62-year-old man presented a diffuse and predominantly cisternal acute nonaneurysmal subarachnoid hemorrhage associated with hydrocephalus. An external ventricular drain was placed, followed by clinical deterioration after its removal. At this point, a heavily T2-weighted high-resolution sequence of a brain magnetic resonance imaging showed acute hydrocephalus recrudescence and multiple arachnoid adhesions in the supravermian and interpeduncular cisterns, creating a loculated/cystic appearance. The diagnosis of intracranial arachnoiditis was made. Intracranial arachnoiditis results from meningeal inflammation. Fibrosis and adhesions at the subarachnoid spaces may follow, restricting cerebrospinal fluid circulation, particularly at the cranial base. Hydrocephalus probably resulted from the combination of subarachnoid hemorrhage and extensive scaring at the basal cisterns, precluding transdural and transvenous cerebrospinal fluid efflux. Heavily T2-weighted high-resolution magnetic resonance imaging sequences allow an exquisite depiction of arachnoiditis, displaying obstructive cisternal membranes, and contribute to better etiologic assessment and management of hydrocephalus.

Astronomically forced cycles in Lower Carboniferous Luzhai Formation shales, Guizhong Depression, South China

Early Carboniferous Luzhai Formation developed continuous and thick shales, which is a critical succession for hydrocarbon exploration and production in southern China. However, no high-resolution stratigraphic sequence framework or cyclostratigraphic studies on early Carboniferous (Tournaisian Stage) are available for this organic-rich shale formation. In this research, Milankovitch cycle evidence has been reported in two boreholes of Luzhai Formation in Guizhong Depression. Natural gamma-ray logging data allowed the establishment of a ∼5.9-Myr floating astronomical timescale (FATS) based on stable long eccentricity (405-kyr) cycles in Luzhai Formation. We anchored FATS to Devonian and Carboniferous boundary age (359.3 ± 0.4 Ma), and an absolute timescale for intervals of 359.3 to 353.4 Ma was developed. Correlation coefficient (COCO), evolutionary COCO, and evolutionary TimeOpt method (eTimeOpt) were employed for quantitatively fit observed stratigraphic cycles to astronomical cycles for providing possible range of sedimentation rates. Sedimentary noise model was adopted for detecting orbital forcing-controlled high-resolution sea-level changes which were correlated to ∼1.2-Myr obliquity amplitude modulation (AM) cycles. Sedimentary noise models (autocorrelation coefficient analysis, ρ1, and dynamic noise after orbital tuning analysis, DYNOT) revealed a correlation between obliquity AM cycle (∼1.2-Myr) and sea level changes in early Carboniferous Luzhai Formation. The ∼1.2-Myr obliquity AM was the main driver of third-order sequence development, the 3rd-order sequence boundaries were related to maximum values of DYNOT median curve and minima values of ∼1.2-Myr amplitude modulation (AM) curve.

The Late Paleozoic Ice Age in western equatorial Pangea: Context for complex interactions among aeolian, alluvial, and shoreface sedimentary environments during the Late Pennsylvanian – early Permian

The evolution of depositional environments in the Late Pennsylvanian-early Permian of the Paradox Basin in Utah, USA, is investigated through detailed sedimentological and high-resolution sequence stratigraphic analyses, in order to define a model of landscape evolution, to discuss the stratigraphic model, and to evaluate the significance of the cyclicity in the paleoclimatic context. Forty high-resolution cycles integrated in 15 minor and two major cycles are observed for the first time throughout the Late Pennsylvanian-early Permian units. A-three steps landscape evolution is recognized. First, the lower Cutler beds, mainly corresponded to a marine environment, with longshore bar, subtidal, tidal, mouth-bar, and with locally fluvial deposits. The upper part of the lower Cutler beds also contains an aeolian dune. Second, the Cedar Mesa Sandstone, corresponded to broad erg deposits which are present across the entire study area, whereas longshore bar, subtidal, mouth-bar, and some fluvial deposits are mainly preserved in the northern part of the studied area. Third, the Organ Rock Formation records decreasing aeolian dune field preservation. To the south, the aeolian environments are interbedded with shoreface deposits, whereas to the north, fluvial deposits with some mouth-bars are more developed. Semi-arid climatic conditions persisted, as indicated by the presence of calcretes. Everywhere in these three steps, root traces within sandstone bars indicate that a soil was once present above the sand dunes. This new model of landscape evolution documents complex interactions between aeolian, fluvial and marine environments within the entire Permian succession of the Paradox Basin. High-resolution stratigraphic analyses allow to discuss the significance of the cyclicity in a scenario that take into consideration sea-level variation in the Late Paleozoic Ice Age paleoclimatic context. This Late Pennsylvanian to early Permian succession reflects both relative sea-level fluctuations and the variability of sediment supply.

The effect of prenatal stress on offspring depression susceptibility in relation to the gut microbiome and metabolome

Prenatal stress (PS) increases offspring susceptibility to depression, but the underlying mechanism remains unclear. Our previous results showed that PS can affect depression-like behavior in offspring through neurotransmitters and neuroinflammatory substances in the hippocampus and frontal cortex. In recent years there has been increasing evidence for a role of the gut microbiome in depression. The brain-gut axis theory suggests there is a need to further explore the mechanism involving the gut microbiome in the susceptibility of offspring to depression caused by PS. In the present study we used a stress model relevant to depression in which pregnant female rats undergo prenatal restraint stress and the offspring show susceptibility to depression. High-resolution gene sequencing for 16S ribosomal RNA markers and non-targeted metabolomic analysis were used to evaluate the fecal microbiome and the availability of metabolites, respectively. PS was found to induce depressive-like behavior in susceptible offspring (PS-S), as detected by the sucrose preference and forced swimming tests, as well as altering Alpha and Beta diversity. The different microbiota between the PS-S and control groups were mainly involved in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair pathways. In total, 237 and 136 important differential metabolites with significant influence on modeling analysis were obtained under positive and negative modes, respectively. The main canonical pathways found to be altered were glycerophospholipid metabolism and glycerolipid metabolism. These results suggest that gut microbiota might contribute to the onset of PS-induced depression-like behavior by affecting the glycerophospholipid and glycerolipid metabolic pathways.

Magnetic resonance-enhanced high-resolution three-dimensional water-selective cartilage sequence visualization of hip vessels in children.

Hip vessel examination provides key information on many hip-related pediatric diseases, and it has an important role in the evaluation of femoral head (FH) blood supply and diagnosis of avascular necrosis (AVN). The aim of this study was to investigate the feasibility of MR-enhanced high-resolution three-dimensional water-selective cartilage (3D-WATSc) sequence in visualizing the vessels of the hip joint in children. Children with hip disease were randomly enrolled prospectively at our hospital from January 2021 to August 2022. We performed our institution's hip MRI protocol and enhanced high-resolution 3D-WATSc sequence. The 3D-WATSc images were reconstructed and analyzed, and images of the normal hip were categorized into grades 0-3. The abnormal hip images were compared with those of the normal side using the χ2 test. Twenty-four patients with unilateral hip abnormalities were included in this study. The cartilaginous vascular canal and ossification centre vessels of normal FHs were observed in 18 patients (75%) and met the grade 3 standard. An abnormal cartilaginous canal was observed in 16 patients (67%); meanwhile, 18 patients (75%) had abnormal extrachondral vessels. Comparison of high-resolution 3D-WATSc images with those of the normal side provided effective abnormal vascular information in 95.8% of patients. Enhanced high-resolution 3D-WATSc can visualize the blood vessels of the hip in children. This may provide a new method for the vascular study of various pediatric hip diseases.

Selection for immune evasion in SARS-CoV-2 revealed by high-resolution epitope mapping and sequence analysis

Here, we exploit a deep serological profiling strategy coupled with an integrated, computational framework for the analysis of SARS-CoV-2 humoral immune responses. Applying a high-density peptide array (HDPA) spanning the entire proteomes of SARS-CoV-2 and endemic human coronaviruses allowed identification of B cell epitopes and relate them to their evolutionary and structural properties. We identify hotspots of pre-existing immunity and identify cross-reactive epitopes that contribute to increasing the overall humoral immune response to SARS-CoV-2. Using a public dataset of over 38,000 viral genomes from the early phase of the pandemic, capturing both inter- and within-host genetic viral diversity, we determined the evolutionary profile of epitopes and the differences across proteins, waves, and SARS-CoV-2 variants. Lastly, we show that mutations in spike and nucleocapsid epitopes are under stronger selection between than within patients, suggesting that most of the selective pressure for immune evasion occurs upon transmission between hosts.

High-Resolution Genotyping of Expressed Equine MHC Reveals a Highly Complex MHC Structure.

The Major Histocompatibility Complex (MHC) genes play a key role in a number of biological processes, most notably in immunological responses. The MHCI and MHCII genes incorporate a complex set of highly polymorphic and polygenic series of genes, which, due to the technical limitations of previously available technologies, have only been partially characterized in non-model but economically important species such as the horse. The advent of high-throughput sequencing platforms has provided new opportunities to develop methods to generate high-resolution sequencing data on a large scale and apply them to the analysis of complex gene sets such as the MHC. In this study, we developed and applied a MiSeq-based approach for the combined analysis of the expressed MHCI and MHCII repertoires in cohorts of Thoroughbred, Icelandic, and Norwegian Fjord Horses. The approach enabled us to generate comprehensive MHCI/II data for all of the individuals (n = 168) included in the study, identifying 152 and 117 novel MHCI and MHCII sequences, respectively. There was limited overlap in MHCI and MHCII haplotypes between the Thoroughbred and the Icelandic/Norwegian Fjord horses, showcasing the variation in MHC repertoire between genetically divergent breeds, and it can be inferred that there is much more MHC diversity in the global horse population. This study provided novel insights into the structure of the expressed equine MHC repertoire and highlighted unique features of the MHC in horses.

Full-spectrum HIV drug resistance mutation detection by high-resolution complete pol gene sequencing.

Drug resistance mutation testing is a key element for HIV clinical management, informing effective treatment regimens. However, resistance screening in current clinical practice is limited in reporting linked cross-class resistance mutations and minority variants, both of which may increase the risk of virological failure. To address these limitations, we obtained 358 full-length pol gene sequences from 52 specimens of 20 HIV infected individuals by combining microdroplet amplification, unique molecular identifier (UMI) labeling, and long-read high-throughput sequencing. We conducted a rigorous assessment of the accuracy of our pipeline for precision drug resistance mutation detection, verifying that a sequencing depth of 35 high-throughput reads achieved complete, error-free pol gene sequencing. We detected 26 distinct drug resistance mutations to Protease Inhibitors (PIs), Nucleoside Reverse Transcriptase Inhibitors (NRTIs), Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs), and Integrase Strand Transfer Inhibitors (INSTIs). We detected linked cross-class drug resistance mutations (PI+NRTI, PI+NNRTI, and NRTI+NNRTI) that confer cross-resistance to multiple drugs in different classes. Fourteen different types of minority mutations were also detected with frequencies ranging from 3.2% to 19%, and the presence of these mutations was verified by Sanger reference sequencing. We detected a putative transmitted drug resistance mutation (TDRM) in one individual that persisted for over seven months from the first sample collected at the acute stage of infection prior to seroconversion. Our comprehensive drug resistance mutation profiling can advance clinical practice by reporting mutation linkage and minority variants to better guide antiretroviral therapy options.

3'UTR heterogeneity and cancer progression.

The majority of human mRNAs generate alternative 3' untranslated regions (UTRs) through various processes, including RNA modifications such as RNA editing, m6A methylation, and alternative polyadenylation (APA), with 3'UTR splicing as an emerging mechanism. Multiple factors, ranging from the genome to transcriptome level, regulate these processes and contribute to 3'UTR heterogeneity. Genomic variants in 3'UTR regions as well as aberrant 3'UTR processing alter the transcriptomic landscape and are associated with cancer. Increasing evidence, aided by high-resolution sequencing technologies and large-scale computational analyses, points towards potential crosstalk between these processes, whose deregulation may further contribute to cancer pathogenesis. In-depth characterization of these events will increase our appreciation of their significance and help to drive therapeutic development in this field.

Large case-control study indicates no association of KIR genotype and risk of developing acute myeloid leukemia.

Immunogenetic association studies may give rise to new hypotheses on the immune surveillance of cancer. We hypothesized that certain combinations of killer immunoglobulin-like receptor (KIR) and HLA genotypes may enhance natural killer (NK) cell immunity against nascent acute myeloid leukemia (AML) and, thereby, lead to a skewed genotype distribution among patients. For this purpose, we analyzed KIR and HLA genotypes of 1767 German patients with AML and compared the results with that of the data of 51 890 German volunteers who had registered with German bone marrow donor file (DKMS). Patient samples were retrieved from the Collaborative Biobank and the biorepository of the Study Alliance Leukemia. All samples were genotyped with high-resolution amplicon-based next-generation sequencing. Because of the large number of controls, this study was very sensitive to detect the impact of KIR genotype. Knowledge on KIRs and their cognate HLA ligands allowed for testing of several hypotheses of NK cell-mediated endogenous leukemia surveillance. We did not find significant differences between the 2 cohorts in regard to the presence or absence of single KIR genes. When grouped based on telomeric or centromeric gene content, the major haplotypes A/A, A/B, and B/B were equally distributed among patients and control subjects. Using information on KIRs and their HLA ligands, we further tested receptor-ligand models and summation models without revealing markedly significant differences between patients and controls, albeit we observed a trend pointing at a minor protective effect of a low number of inhibitory KIR/KIR-ligand pairs. The results suggest that the KIR/KIR-ligand genotype has no effect on the susceptibility for the development of de novo AML.

Learning to Super-resolve Dynamic Scenes for Neuromorphic Spike Camera

Spike camera is a kind of neuromorphic sensor that uses a novel ``integrate-and-fire'' mechanism to generate a continuous spike stream to record the dynamic light intensity at extremely high temporal resolution. However, as a trade-off for high temporal resolution, its spatial resolution is limited, resulting in inferior reconstruction details. To address this issue, this paper develops a network (SpikeSR-Net) to super-resolve a high-resolution image sequence from the low-resolution binary spike streams. SpikeSR-Net is designed based on the observation model of spike camera and exploits both the merits of model-based and learning-based methods. To deal with the limited representation capacity of binary data, a pixel-adaptive spike encoder is proposed to convert spikes to latent representation to infer clues on intensity and motion. Then, a motion-aligned super resolver is employed to exploit long-term correlation, so that the dense sampling in temporal domain can be exploited to enhance the spatial resolution without introducing motion blur. Experimental results show that SpikeSR-Net is promising in super-resolving higher-quality images for spike camera.

Depositional and diagenetic controls on reservoir properties along the shallow-marine carbonates of the Sarvak Formation, Zagros Basin: Petrographic, petrophysical, and geochemical evidence

As the second important oil reservoir of Iran, shallow-marine carbonates of the Sarvak Formation were deposited in a tectonically active setting, under a warm and humid paleoclimatic condition. This study focuses on sedimentological, geochemical, and petrophysical analysis of this formation in the Abadan Plain, Zagros Basin. Petrographic studies have resulted in the recognition of five microfacies deposited in lagoon, patch-reefs and their taluses, shoal, and open marine environments. They represent a ramp-like depositional model for the Sarvak Formation. Two third-order depositional sequences are differentiated and dated as Cenomanian–Turonian, according to the results of biostratigraphic analysis. Effects of intensive meteoric diagenesis are recorded beneath the two paleoexposure surfaces (Cenomanian–Turonian boundary, and middle Turonian). They include pervasive dissolution (karstification), collapsed brecciation, silicification, recrystallization, and development of paleosols. Additionally, decreased values of δ18Ocarb and δ13Ccarb and a sharp inverted-J pattern in the δ18Ocarb vs. δ13Ccarb cross plot indicate major meteoric phases. The most decreased values of δ18Ocarb (−7 ‰) and δ13Ccarb (−8.6 ‰) are measured from the meteoric cements and paleosols. Reservoir quality evaluation revealed that the best reservoir zones of the Sarvak Formation are developed within the rudist-dominated facies with intensive meteoric dissolution. They are concentrated within the regressive systems tract of the Cenomanian sequence. Fractured and dolomitized mud-dominated facies provided the speed/baffle zones in transgressive systems tracts, and highly compacted/cemented facies formed the barrier units. It could be concluded that the facies characteristics and meteoric diagenetic processes had major controls on reservoir quality of the Sarvak Formation, in the Abadan Plain. These controlling factors are predictable in a high-resolution sequence stratigraphic framework.

Imaging in children with hearing loss.

Since the introduction of hearing screening in Germany in 2009, pediatric hearing disorders are detected at an early stage. Early therapy is essential for language development. Imaging plays a central role in diagnosis and therapy planning. Imaging findings of the most relevant causes of pediatric hearing disorders are presented. Specific attention is given to the method used in each case - CT or MRI. While CT is the method of choice for conductive hearing loss, a combination of CT and MRI with high-resolution T2-3D sequences has been established as the best diagnostic method for sensorineural hearing loss. The most common causes of conductive hearing loss in childhood are chronic inflammation and cholesteatoma. Congenital malformations of the outer or middle ear are less frequent. In the case of sensorineural hearing loss, the cause is located in the inner ear and/or the cochlear nerve or the cerebrum. In these cases, congenital malformations are the most common cause. · CT and MRI are necessary to identify morphological causes of hearing disorders and to clarify the possibility of hearing-improving ear surgery or cochlear implantation.. · Contraindications for surgical procedures must be excluded.. · Anatomical variants that may be risk factors for surgery must be described.. · Sorge I, Hirsch F, Fuchs M et al. Imaging diagnostics for childhood hearing loss. Fortschr Röntgenstr 2023; 195: 896 - 904.

O-076 Update on the International Registry of Mosaic Embryo Transfers

Abstract Study question Which are the results obtained by the International Registry of Mosaic Embryo Transfers? Summary answer An update of clinical outcomes and post-natal results of mosaic embryos with low and high-level of mosaicism is provided. What is known already Chromosomal mosaic embryos are characterized by the presence of chromosomally different cell lines within the same embryo. While the transfer of these embryos is now offered as an option for women who undergo in vitro fertilization (IVF), several concerns remain. For instance, the limited data on pregnancy outcome and the possibility that intra-biopsy mosaicism in the TE is a poor predictor of the ploidy status of the ICM. Therefore, some argue that mosaicism should be not reported until a clear classification of such embryos in relation to their reproductive potential has been defined. Study design, size, duration We collected the clinical outcomes of 2045 mosaic embryos transferred in women who undergoing IVF between May 2019-May 2022. All embryos were cultured to blastocyst stage; trophectoderm (TE) biopsy was performed on Day-5 of development or Day6/7 for slow-growing embryos. The clinical outcomes obtained after the transfer of mosaic embryos with the different chromosomal constitutions were compared. Prenatal and post-natal outcome was collected for available cases. Participants/materials, setting, methods Preimplantation genetic testing for aneuploidies (PGT-A) was performed using high-resolution next-generation sequencing (NGS) methodology. TE biopsies were classified as mosaic if they had 20%-80% abnormal cells. For statistical analysis, mosaic embryos were divided into groups based on mosaic levels and chromosomal constitution detected in TE: single mosaic aneuploidy (monosomy/trisomy; SM), double mosaic chromosomes (monosomy/trisomy or combination, DM), complex mosaic aneuploidy (>2 different aneuploidies; CM) and mosaic segmental aneuploidy (single and double deletion/insertion >5Mb, MS). Main results and the role of chance Embryos classified as ‘low-mosaic’ by NGS-based PGT-A have a higher likelihood of achieving implantation compared to ‘high-mosaic’ embryos (48% vs. 39.%; p < 0.05 ), as well as ongoing pregnancy/live birth (40% vs. 29%; p < 0.05). Chromosomal composition of mosaicism abnormalities dictates the success rate of mosaic embryo transfers, with low and high segmental mosaics being preferable over low- and high-mosaics involving whole chromosomes. For 550/670 pregnancies, parental tests and post-natal data were available. The majority (99.75%) of the babies were largely healthy by routine physical inspection by neonatologists (no gross abnormalities in babies from mosaic embryos, n = 495). Prenatal testing performed on pregnancies from mosaic embryo transfers were generally normal. The mosaicism detected at the embryonic stage by PGT-A was reflected in prenatal testing in only 5 out of 550 pregnancies (0.9%) in which the mosaicism identified with PGT-A at the blastocyst stage was reflected in gestation by prenatal chromosomal testing as true fetal mosaicism. Limitations, reasons for caution Additional clinical data must be obtained to evaluate the contribution of each different chromosome before this approach can be evaluated as an additional tool to choose mosaic embryos for transfer. Wider implications of the findings The International Registry of Mosaic Embryo transfers continues to grow in sample size, in turn increasing the power of analysis. The findings of the mosaic embryo transfer registry can help educate the management and selection of embryos in the clinic. Trial registration number Not applicable