Theory of transition from brittle to ductile fracture.

In this paper, two improvements to the theory of transition from brittle to ductile fracture developed by Langer [J. S. Langer, Phys. Rev. E 103, 063004 (2021)2470-004510.1103/PhysRevE.103.063004] are proposed. First, considering the drastic temperature rise near the crack tip, the temperature dependence of the shear modulus is included to better quantify the thermally sensitive dislocation entanglement. Second, the parameters of the improved theory are identified by the large-scale least-squares method. The comparison between the fracture toughness predicted by the theory and the values obtained in Gumbsch's experiments for tungsten at different temperatures [P. Gumbsch et al., Science 282, 1293 (1998)10.1126/science.282.5392.1293] shows good agreement.

RENEB Inter-Laboratory Comparison 2021: The Cytokinesis-Block Micronucleus Assay.

The goal of the RENEB inter-laboratory comparison 2021 exercise was to simulate a large-scale radiation accident involving a network of biodosimetry labs. Labs were required to perform their analyses using different biodosimetric assays in triage mode scoring and to rapidly report estimated radiation doses to the organizing institution. This article reports the results obtained with the cytokinesis-block micronucleus assay. Three test samples were exposed to blinded doses of 0, 1.2 and 3.5 Gy X-ray doses (240 kVp, 13 mA, ∼75 keV, 1 Gy/min). These doses belong to 3 triage categories of clinical relevance: a low dose category, for no exposure or exposures inferior to 1 Gy, requiring no direct treatment of subjects; a medium dose category, with doses ranging from 1 to 2 Gy, and a high dose category, after exposure to doses higher than 2 Gy, with the two latter requiring increasing medical attention. After irradiation the test samples (no. 1, no. 2 and no. 3) were sent by the organizing laboratory to 14 centers participating in the micronucleus assay exercise. Laboratories were asked to setup micronucleus cultures and to perform the micronucleus assay in triage mode, scoring 500 binucleated cells manually, or 1,000 binucleated cells in automated/semi-automated mode. One laboratory received no blood samples, but scored pictures from another lab. Based on their calibration curves, laboratories had to provide estimates of the administered doses. The accuracy of the reported dose estimates was further analyzed by the micronucleus assay lead. The micronucleus assay allowed classification of samples in the corresponding clinical triage categories (low, medium, high dose category) in 88% of cases (manual scoring, 88%; semi-automated scoring, 100%; automated scoring, 73%). Agreement between scoring laboratories, assessed by calculating the Fleiss' kappa, was excellent (100%) for semi-automated scoring, good (83%) for manual scoring and poor (53%) for fully automated scoring. Correct classification into triage scoring dose intervals (reference dose ±0.5 Gy for doses ≤2.5 Gy, or reference dose ±1 Gy for doses >2.5 Gy), recommended for triage biodosimetry, was obtained in 79% of cases (manual scoring, 73%; semi-automated scoring, 100%; automated scoring, 67%). The percentage of dose estimates whose 95% confidence intervals included the reference dose was 58% (manual scoring, 48%; semiautomated scoring, 72%; automated scoring, 60%). For the irradiated samples no. 2 and no. 3, a systematic shift towards higher dose estimations was observed. This was also noticed with the other cytogenetic assays in this intercomparison exercise. Accuracy of the rapid triage modality could be maintained when the number of manually scored cells was scaled down to 200 binucleated cells. In conclusion, the micronucleus assay, preferably performed in a semi-automated or manual scoring mode, is a reliable technique to perform rapid biodosimetry analysis in large-scale radiation emergencies.

Panels of circulating microRNAs as potential diagnostic biomarkers for breast cancer: a systematic review and meta-analysis.

PURPOSE: Circulating microRNAs (miRNAs) are potential diagnostic biomarkers for breast cancer (BC). The application of miRNA panels could improve the performance of screening tests. Here, we integrated bioinformatic tools and meta-analyses to select circulating miRNAs with high diagnostic accuracy and combined these markers to develop diagnostic panels for BC. METHODS: Analyses across databases were performed to identify potential BC-related circulating miRNAs. Next, a comprehensive meta-analysis was conducted for each miRNA following the PRISMA guidelines. An electronic and manual search for relevant literature was carried out by two reviewers through PubMed, ScienceDirect, Biomed Central, and Google Scholar. The quality of the included studies was assessed using the QUADAS-2, and the statistical analyses were performed using R software 4.1.1. Finally, the accurate biomarkers confirmed through meta-analyses were combined into diagnostic models for BC. RESULTS: Twenty-seven circulating miRNAs were identified as BC-related by bioinformatic tools. After screening, only 10 miRNAs presented in 45 studies were eligible for meta-analyses. By assessing pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio, 8 miRNAs (miR-21, miR-30b, miR-125b, miR-145, miR221 miR-222, and miR-335) were revealed as promising BC diagnostic biomarkers. Two panels constructed from these miRNAs showed excellent diagnostic accuracy for BC, with areas under the SROC curve of 0.917 and 0.944. CONCLUSION: We identified 8 potential circulating miRNAs and 2 diagnostic models that are useful for diagnosing BC. However, the established miRNA panels have not been tested in any experimental studies and thus should be validated in large case-control studies for clinical use.

The course of primary progressive aphasia diagnosis: a cross-sectional study.

BACKGROUND: The primary progressive aphasia (PPA) diagnosis trajectory is debated, as several changes in diagnosis occur during PPA course, due to phenotype evolution from isolated language alterations to global cognitive impairment. The goal of the present study, based on a French cohort, was to describe the demographics and the evolution of subjects with (PPA) in comparison with Alzheimer's disease (AD) on a period of 7 years. METHODS: We conducted a repeated cross-sectional study. The study population comprised individuals with PPA and AD diagnosis (N=167,191) from 2010 to 2016 in the French National data Bank (BNA). Demographic variables, MMSE scores, diagnosis status at each visit and prescribed treatments were considered. RESULTS: From 2010 to 2016, 5186 patients were initially diagnosed with PPA, 162,005 with AD. Compared to AD subjects, significant differences were found concerning age (younger at first diagnosis for PPA), gender (more balanced in PPA), education level (higher in PPA) and MMSE score (higher of 1 point in PPA). Percentage of pending diagnosis, delay between first consultation and first diagnosis and the number of different diagnoses before the diagnosis of interest were significantly higher in PPA group compared to AD group. Pharmacological and non-pharmacological treatments were significatively more recommended following PPA than AD diagnosis. CONCLUSION: This study improves the knowledge of PPA epidemiology and has the potential to help adopting appropriate public health service policies. It supports the hypothesis that PPA is diagnosed later than AD. The PPA diagnosis increases the prescription of non-pharmacological treatments, especially speech and language therapy (SLT) that is the main treatment available and most effective when at the initial stage. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03687112.

The utility of anthopometric indicators to identify cardiovascular risk factors in Vietnamese children.

BMI, waist circumference (WC) and waist-to-height ratio (WHtR) can be used for discriminating children and adolescents at risk of CVD. However, consensus on how to use these anthropometric indicators is lacking for children and adolescents in Asia. Discrete criteria are promoted internationally, but continuous variables could be used. Data from a survey of 10 949 Vietnamese school-aged children (6-18 years) were used to evaluate the performance of anthropometric indicators to identify elevated blood pressure (BP), dyslipidaemia or at least three cardiovascular risk factors (CVRF). Weight, height, WC and BP were measured using standardised protocols; 1009 participants who had blood lipids were analysed. AUC was used to assess the performance, and the Youden index to identify optimal cut-offs. The prevalence of elevated BP, dyslipidaemia and CVRF was 26·5, 49·3 and 12·2 %, respectively. BMI, WC and WHtR had low capacity to identify elevated BP and dyslipidaemia (AUC range 0·61-0·66) but moderate capacity to identify CVRF (0·72-0·74). Optimal BMIZ cut-offs to identify elevated BP, dyslipidaemia and CVRF were 0·40, 1·01 and 1·1 sd; for WC z-score, they were 0·06, 0·49 and 0·62 sd; for WHtR, optimal cut-offs were close to 0·5. A BMIZ cut-off of 1·0 sd and a WHtR cut-off of 0·5 would, therefore, be useful criteria to identify Vietnamese children who are likely to have CVRF. However, further validation of these criteria in other studies of Asian children and adolescents is needed.

Thermodynamic dislocation theory: Bauschinger effect.

The thermodynamic dislocation theory developed for nonuniform plastic deformations is used here to simulate the stress-strain curves for crystals subjected to antiplane shear-controlled load reversal. We show that the presence of the positive back stress during the load reversal reduces the magnitude of shear stress required to pull excess dislocations back to the center of the specimen. There, the excess dislocations of opposite signs meet and annihilate each other leading to the Bauschinger effect.

[Dynamics of Egg Excretion of Schistosoma haematobium in a Longitudinal Cohort Under Treatment with Praziquantel over a Five-Year Period in Kalifabougou, Mali]. / Dynamique de l'excrétion ovulaire de Schistosoma haematobium dans une cohorte de Kalifabougou (Mali) sous traitement par le praziquantel (PZQ) durant cinq ans.

This study aim was to evaluate the dynamics of Schistosoma haematobium eggs excretion after the scaling up of "Mass Drug Administration" (MDA) with praziquantel (PZQ) from 2011 to 2016 in a cohort of volunteers living in the village of Kalifabougou, Mali. We conducted a cross-sectional study on 676 volunteers in May 2011 niched in cohort study from 696 volunteers aged three months to 25 years. The eggs of Schistosoma haematobium (Sh) were tested by urine filtration technique, Soil-transmitted helminth and Schistosoma mansoni by the Kato-Katz technique. Maximal MDA/ PZQ population coverage was 83% in 2015 and no MDA/PZQ n 2014. A total of 676 volunteers was included in this prospective cohort. The prevalence rate of Sh showed a significate decreasing from 2011, 2013 to 2014 with respectively 10.2% [95% CI=10.04-10,18], 5.32% [95% CI=5.30-5.33], and 5.25% [95% CI=524.-5.31], followed by an increase to 10.6% [95% CI = 10.47-10.63] in 2015 and a significative decrease in 2016 to 5.4% [95% CI=3.5-7,3]. Children aged from six to 10 years and mostly boys were more infected with Sh, then could serve of parasite reservoir. MDA with PZQ remains an effective strategy for schistosomiasis control against Sh in Kalifabougou. Additional studies on MDA/PZQ average treatment covering human-water contact behaviors and population migration are necessary to understand the persistence of the 5% annual prevalence rate of egg shedding in the cohort of volunteers periodically treated with PQZ. Testing eggs shed viability will be also an added value.

L'objectif de cette étude était d'évaluer la dynamique de l'excrétion ovulaire de Schistosoma haematobium (Sh) après la mise à échelle du « traitement de masse ¼ (TDM) avec le praziquantel (PZQ) de 2011 à 2016 dans une cohorte de volontaires vivant dans le village de Kalifabougou au Mali. Nous avons conduit une étude transversale sur 676 volontaires au mois de mai 2011 nichée dans une étude de cohorte de 695 volontaires, âgés de 3 mois à 25 ans et suivis de 2011 à 2016. Les œufs de Sh ont été recherchés par la technique de filtration d'urines et ceux des géo helminthes et de Schistosoma mansoni avec le Kato-Katz. Le taux de couverture maximum de la population cible de Kalifabougou en TDM/PZQ était de 83 % en 2015 et il n'a pas eu de TDM/PZQ en 2014. Le taux de prévalence de Sh montrait une réduction significative entre 2011, 2013 et 2014 avec respectivement 10,20 % [95 % CI = 10,04-10,18]- 5,32 % [95 % CI = 5,30- 5,33], et 5,25 % [95 % CI = 5,24-5,31], suivi d'une augmentation à 10,60 % [95 % CI = 10,47-10,63] en 2015 et d'une baisse significative en 2016 à 5,40 % [95 % CI = 3,5-7,3]. Les enfants âgés de six à dix ans, et majoritairement les garçons, seraient plus infectés par Sh, et pourraient servir de réservoir de parasites. Le TDM avec le PZQ reste une stratégie efficace pour le contrôle de la schistosomose à Sh à Kalifabougou. Des études complémentaires sur la couverture moyenne en TDM-PZQ, les comportements de contact homme-eau et les mouvements de population sont nécessaires pour comprendre la persistance du taux de prévalence annuel de 5 % de l'excrétion ovulaire dans la cohorte de volontaires traités périodiquement par le PQZ. Un test de viabilité des œufs excrétés serait aussi une valeur ajoutée.

Thermodynamic dislocation theory of high-temperature deformation in aluminum and steel.

The statistical-thermodynamic dislocation theory developed in previous papers is used here in an analysis of high-temperature deformation of aluminum and steel. Using physics-based parameters that we expect theoretically to be independent of strain rate and temperature, we are able to fit experimental stress-strain curves for three different strain rates and three different temperatures for each of these two materials. Our theoretical curves include yielding transitions at zero strain in agreement with experiment. We find that thermal softening effects are important even at the lowest temperatures and smallest strain rates.

Collisional damping rates for electron plasma waves reassessed.

Collisional damping of electron plasma waves, the primary damping for high phase velocity waves, is proportional to the electron-ion collision rate, ν_{ei,th}. Here, it is shown that the damping rate normalized to ν_{ei,th} depends on the charge state, Z, on the magnitude of ν_{ei,th} and the wave number k in contrast with the commonly used damping rate in plasma wave research. Only for weak collision rates in low-Z plasmas for which the electron self-collision rate is comparable to the electron-ion collision rate is the damping rate given by the commonly accepted value. The result presented here corrects the result presented in textbooks at least as early as 1973. The complete linear theory requires the inclusion of both electron-ion pitch-angle and electron-electron scattering, which itself contains contributions to both pitch-angle scattering and thermalization.

Electrical lysis of cells for detergent-free droplet assays.

Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assays by measuring the catalysis of ß-glucosidase, an important cellulase used in the conversion of biomass to biofuel. Our method enables assays in microfluidic droplets that are incompatible with detergents.

Collection of Oral Fluids Using Cotton Ropes as a Sampling Method to Detect Foot-and-Mouth Disease Virus Infection in Pigs.

In high-density farming practices, it is important to constantly monitor for infectious diseases, especially diseases that have the potential to spread rapidly between holdings. Pigs are known to amplify foot-and-mouth disease (FMD) by excreting large amounts of virus, and it is therefore important to detect the virus quickly and accurately to minimize the spread of disease. Ropes were used to collect oral fluid samples from pigs, and each sample was compared to saliva samples collected from individual animals by detecting FMD virus RNA using real-time PCR. Two different experiments are described where groups of pigs were infected with different serotypes of FMD virus, either with or without vaccination, and unvaccinated pigs were kept in aerosol contact. The sensitivity of the rope sampling varied between 0.67 and 0.92, and the statistical agreement between this method and individual sampling ranged from substantial to moderate for the two different serotypes. The ease of collecting oral fluids using ropes together with the high sensitivity of subsequent FMD detection through PCR indicates that this could be a useful method to monitor pig populations for FMD virus infection. With further validation of the sensitivity of detection of FMD virus RNA, this can be a cost-effective, non-invasive diagnostic tool.

Nanosecond pulses in a THz gyrotron oscillator operating in a mode-locked self-consistent Q-switch regime.

An experimental study of a nanosecond pulsed regime in a THz gyrotron oscillator operating in a self-consistent Q-switch regime has been carried out. The gyrotron is operated in the TE(7,2) transverse mode radiating at a frequency of 260.5 GHz. The 5 W nanosecond pulses are obtained in a self-consistent Q-switch regime in which the cavity diffraction quality factor dynamically varies by nearly 2 orders of magnitude on a subnanosecond time scale via the nonlinear interaction of different mode-locked frequency-equidistant sidebands. The experimental results are in good agreement with numerical simulations performed with the TWANG code based on a slow time scale formulation of the self-consistent time-dependent nonlinear wave particle interaction equations.

B cell epitope mapping and characterization of naturally acquired antibodies to the Plasmodium vivax merozoite surface protein-3α (PvMSP-3α) in malaria exposed individuals from Brazilian Amazon.

The Plasmodium vivax Merozoite Surface Protein-3α (PvMSP-3α) is considered as a potential vaccine candidate. However, the detailed investigations of the type of immune responses induced in naturally exposed populations are necessary. Therefore, we aim to characterize the naturally induced antibody to PvMSP-3α in 282 individuals with different levels of exposure to malaria infections residents in Brazilian Amazon. PvMSP3 specific antibodies (IgA, IgG and IgG subclass) to five recombinant proteins and the epitope mapping by Spot-synthesis technique to full-protein sequence of amino acids (15aa sequence with overlapping sequence of 9aa) were performed. Our results indicates that PvMSP3 is highly immunogenic in naturally exposed populations, where 78% of studied individuals present IgG immune response against the full-length recombinant protein (PVMSP3-FL) and IgG subclass profile was similar to all five recombinant proteins studied with a high predominance of IgG1 and IgG3. We also observe that IgG and subclass levels against PvMSP3 are associated with malaria exposure. The PvMSP3 epitope mapping by Spot-synthesis shows a natural recognition of at least 15 antigenic determinants, located mainly in the two blocks of repeats, confirming the high immunogenicity of this region. In conclusion, PvMSP-3α is immunogenic in naturally exposed individuals to malaria infections and that antibodies to PvMSP3 are induced to several B cell epitopes. The presence of PvMSP3 cytophilic antibodies (IgG1 and IgG3), suggests that this mechanism could also occur in P. vivax.

Comparison of extent of sensory block following posterior and subcostal approaches to ultrasound-guided transversus abdominis plane block.

Transversus abdominis plane block provides postoperative analgesia following abdominal surgery by targeting thoracolumbar nerves between the internal oblique and transversus abdominis muscles. Posterior and subcostal approaches using ultrasound guidance have been described. However there have been inconsistent results in relation to the extent of the sensory block. This observational study evaluated the distributions of sensory block following either a posterior or subcostal approach and the quality of analgesia achieved. Following ethics committee approval, 50 patients undergoing minimally invasive and major abdominal surgery were recruited. A total of 81 transversus abdominis plane blocks were performed preoperatively under real-time ultrasound guidance. Postoperatively, patients received multimodal analgesia including morphine via patient-controlled pumps. Ninety-eight percent of patients had some degree of demonstrable sensory block and the dermatomal spread differed between posterior and subcostal approaches (P < 0.001). The posterior approach produced a median sensory block of three dermatomal segments (interquartile range 2 to 4), the most cephalad being T10 (interquartile range T9 to T10), while the subcostal approach blocked a median of four segments (interquartile range 3 to 5), the most cephalad being T8 (interquartile range T7 to T9, P < 0.001). Maximum dermatomal block distribution was observed at 30 minutes and usually regressed by 24 hours. Median cumulative morphine consumption was 40.8 mg (interquartile range 17 to 50 mg) at 24 hours. Median pain scores at rest and with coughing were 20 (interquartile range 10 to 35) and 50 (interquartile range 29 to 67) respectively at 24 hours. The posterior approach appears to be more appropriate for lower abdominal surgery and the subcostal approach better suited to upper abdominal surgery. Whichever approach is used, transversus abdominis plane block is only one component of a multimodal analgesic technique.

Factors associated with adolescent overweight/obesity in Ho Chi Minh city.

OBJECTIVE: To identify factors associated with overweight/obesity among adolescents in Ho Chi Minh City, Vietnam. METHODS: In 2004, a cross-sectional survey was conducted using multi-stage cluster sampling. Weight and height of 2 678 students from 31 junior high schools in Ho Chi Minh City were measured. Dietary intake and physical activity were assessed using a validated food frequency questionnaire and a physical activity questionnaire. Parental, household and neighbourhood characteristics were also collected. Factors associated with overweight/obesity in adolescents were modelled using hierarchical, multivariate logistic regression. "Survey commands" in STATA were used to account for the multi-stage cluster sampling design. RESULTS: After adjusting for other study factors, the odds of overweight/obesity was significantly higher for male gender (OR=3.1, 95% CI: 1.8, 3.8), younger age (OR=3.4, 95% CI: 2.1, 5.3), schools located in wealthy districts (OR=2.5, 95% CI: 1.8, 3.4), higher family economic status (OR=1.9, 95% CI: 1.1, 4.9), higher parental education (OR=2.0, 95% CI: 1.4, 2.9), overweight or obese parents (OR=3.5, 95% CI: 1.7, 7.0), more time spent watching TV (OR=4.3, 95% CI: 1.3, 14.7), frequent consumption of soft drinks (OR=3.0, 95% CI: 1.6, 5.3) and more time studying after class (OR=2.9, 95% CI: 1.7, 4.9). The odds of overweight/obesity was lower with the availability of fruit at home (OR=0.5, 95% CI: 0.3, 0.7), frequent consumption of fruit/vegetables (OR=0.3, 95% CI: 0.2, 0.4) and being physically active (OR=0.5, 95% CI: 0.4, 0.8). CONCLUSIONS: Family/parental factors as well as children's lifestyle should be taken into account when planning interventions to prevent adolescent obesity.

Promiscuous T-cell epitopes of Plasmodium merozoite surface protein 9 (PvMSP9) induces IFN-gamma and IL-4 responses in individuals naturally exposed to malaria in the Brazilian Amazon.

Plasmodium vivax merozoite surface protein (PvMSP9) stimulates both cellular and humoral immune responses in individuals who are naturally infected by this parasite species. To identify immunodominant human T-cell epitopes in PvMSP9, we used the MHC class II binding peptide prediction algorithm ProPred. Eleven synthetic peptides representing predicted putative promiscuous T-cell epitopes were tested in IFN-gamma and IL-4 ELISPOT assays using peripheral blood mononuclear cells (PBMC) derived from 142 individuals from Rondonia State, Brazil who had been naturally exposed to P. vivax infections. To determine whether the predicted epitopes are preferentially recognized in the context of multiple alleles, MHC Class II typing of the cohort was also performed. Five synthetic peptides elicited robust cellular responses, and the overall frequencies of IFN-gamma and IL-4 responders to at least one of the promiscuous peptides were 62% and 46%, respectively. The frequencies of IFN-gamma and IL-4 responders to each peptide were not associated with a particular HLA-DRB1 allelic group since most of the peptides induced a response in individuals of 12 out of 13 studied allelic groups. The prediction of promiscuous epitopes using ProPred led to the identification of immunodominant epitopes recognized by PBMC from a significant proportion of a genetically heterogeneous population exposed to malaria infections. The combination of several such T-cell epitopes in a vaccine construct may increase the frequency of responders and the overall efficacy of subunit vaccines in genetically distinct populations.

Role of plasma elongation on turbulent transport in magnetically confined plasmas.

The theoretical study of plasma turbulence is of central importance to fusion research. Experimental evidence indicates that the confinement time results mainly from the turbulent transport of energy, the magnitude of which depends on the turbulent state resulting from nonlinear saturation mechanisms, in particular, the self-generation of coherent macroscopic structures and large scale flows. Plasma geometry has a strong impact on the structure and magnitude of these flows and also modifies the mode linear growth rates. Nonlinear global gyrokinetic simulations in realistic tokamak magnetohydrodynamic equilibria show how plasma shape can control the turbulent transport. Results are best described in terms of an effective temperature gradient. With increasing plasma elongation, the nonlinear critical effective gradient is not modified while the stiffness of transport is decreasing.

Determination of spread of injectate after ultrasound-guided transversus abdominis plane block: a cadaveric study.

BACKGROUND: The transversus abdominis plane (TAP) block is a new regional anaesthesia technique that provides analgesia after abdominal surgery. It involves injection of local anaesthetic into the plane between the transversus abdominis and the internal oblique muscles. The TAP block can be performed using a landmark technique through the lumbar triangle or with ultrasound guidance. The goal of this anatomical study with dye injection into the TAP and subsequent cadaver dissections was to establish the likely spread of local anaesthesia in vivo and the segmental nerve involvement resulting from ultrasound-guided TAP block. METHODS: An ultrasound-guided injection of aniline dye into the TAP was performed for each hemi-abdominal wall of 10 unembalmed human cadavers and this was followed by dissection to determine the extent of dye spread and nerve involvement in the dye injection. RESULTS: After excluding one pilot specimen and one with advanced tissue decomposition, 16 hemi-abdominal walls were successfully injected and dissected. The lower thoracic nerves (T10-T12) and first lumbar nerve (L1) were found emerging from posterior to anterior between the costal margin and the iliac crest. Segmental nerves T10, T11, T12, and L1 were involved in the dye in 50%, 100%, 100%, and 93% of cases, respectively. CONCLUSIONS: This anatomical study shows that an ultrasound-guided TAP injection cephalad to the iliac crest is likely to involve the T10-L1 nerve roots, and implies that the technique may be limited to use in lower abdominal surgery.