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The linewidth of the resonances in the single-electron tunneling spectra has been investigated for PbSe semiconductor nanocrystals (NCs) with scanning tunneling spectroscopy at low temperature. The linewidth of the resonances corresponding to tunneling through the first conduction and valence levels is found to increase with decreasing size of the NCs. Based on theoretical calculations, this broadening is mainly induced by the coupling between the tunneling electrons and the longitudinal optical phonon mode of the NC, and by the splitting of the degenerate electronic levels between the different L-valleys in the Brillouin zone. For the smallest sizes, it is shown that the intervalley splitting is the major source of broadening. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the inter-session, inter-tester and inter-site reproducibility of trunk muscle strength scores in flexion, extension, lateral flexion and rotation. Ten healthy students were tested on four apparatus with a 7-10 day break between sessions. The first two sessions were identical while the other two differed either by the tester or by the site. Furthermore, 10 patients with chronic low back dysfunction (CLBD) were assessed with the four apparatus, once only. For all tests, CV ranged from 3.4% to 7.6% and from 3.9% to 8.1% in the inter-session and inter-tester studies, respectively (p>0.05 except for inter-session reproducibility of trunk flexor strength). Peak torque (PT) was more variable from site to site with a CV ranging from 4.2% to 12.7%, particularly in extension and left lateral flexion (p< 0.05). No statistically significant difference in the strength ratios (flexion/extension, right/left lateral-flexion and right/left rotation) were found between sessions or testers (4.9% < CV < 9.7%. The inter-site reproducibility of ratios was lower. Comparison between the CLBD patients and the healthy subjects with regard to PT normalized to body weight indicated significantly decreased performance for the former except for flexion and rotation scores in males. We conclude that in the case of healthy subjects, inter-session and inter-tester trunk strength measurements derived from these devices are reproducible. The low inter-site reproducibility suggests that caution should be exercised when interpreting findings originating from different sites. The lower extension strength scores in CLBD patients test lends some validity to the system. However, further studies focusing on reproducibility and validity of this system in CLBD patients are critical before any conclusion regarding their clinical viability may be drawn. [ABSTRACT FROM AUTHOR]

Ga[sub 1-x]Mn[sub x]As layers with Mn composition of up to 6.2% are investigated by cross-sectional scanning tunneling microscopy and spectroscopy. We identify in the tunneling spectra contributions from Mn[sup -, sub Ga] acceptor states, compensating As[sup 2+, sub Ga] donor states, and additional compensating donor states, which we suggest to be Mn[sup 2+, sub i] interstitials. On basis of the observed Fermi level shift and a charge carrier compensation analysis, we deduce the concentration of Mn[sup 2+, sub i] interstitials. Furthermore, scanning tunneling microscopy images suggest an inhomogeneous distribution of Mn dopant atoms. [ABSTRACT FROM AUTHOR]

Semiconductor PbSe/CdSe core-shell nanocrystals (NCs) in a double barrier tunnel junction have been investigated by means of scanning tunneling spectroscopy at low temperature. From the analysis of the differential conductance peak position as a function of the potential distribution in both potential barriers, we demonstrate a unipolar transport regime for a large amount of NCs. The same charge carriers are injected on both sides of the zero-conductance gap, and the peaks observed at higher energy arise from the charging of the NCs. Similar results are obtained for CdSe/CdS dot-in-rod NCs, indicating that the addition of a shell favors transitions between different charge states rather than single particle excited states. Further characterization of the PbSe/CdSe core-shell NCs by x-ray photoemission spectroscopy reveals that the variations in the transport properties from NC to NC are explained by the occurrence of unprotected PbSe facets that have different orientations in the junction. [ABSTRACT FROM AUTHOR]

Background: In lung transplant patients, direct oral anticoagulants are often taken in combination with immunosuppressive drugs such as tacrolimus. Since tacrolimus is a substrate and inhibitor of the efflux protein ABCB1, also transporting direct oral anticoagulants, a possible drug-drug interaction mediated by competition for this transporter needs to be investigated., Objectives: To determine the in vitro effect of tacrolimus on ABCB1-mediated rivaroxaban transport in order to support clinician practice., Methods: Recombinant cell line models, based on human embryonic kidney 293 cells, were generated by a stable transfection process to overexpress ABCB1 or not (control cells). The impact of tacrolimus on ABCB1-mediated rivaroxaban transport was assessed by accumulation experiments., Results: ABCB1 expression decreased the cellular accumulation of rivaroxaban and tacrolimus at their respective clinically relevant concentrations when compared with control cells. This confirms the involvement of ABCB1 in the active transport of tacrolimus and rivaroxaban. However, tacrolimus had no significant influence on rivaroxaban disposition at those clinically relevant concentrations., Conclusion: Our study does not provide evidence for a possible interaction between tacrolimus and rivaroxaban when used together in practice., (© 2024 The Authors.)

Bictegravir, a key second-generation integrase strand transfer inhibitor in the treatment of HIV, is subject to active efflux transport mediated by ABCB1 (P-glycoprotein). Several coding variants of ABCB1 have been described and associated with variable effects on substrate drugs pharmacokinetics. Here, we investigated the effect of the four most common coding ABCB1 single nucleotide polymorphisms (i.e., c.1199G > A, c.1236C > T, c.2677G > T and c.3435C > T) on the intracellular accumulation of bictegravir. Using a previously validated HEK293 recombinant cell line model, we found decreased bictegravir intracellular concentrations in cell lines overexpressing ABCB1 as compared to control cell lines, in line with the known role of ABCB1 in bictegravir transport. However, we were unable to demonstrate any significant difference in bictegravir intracellular accumulation when comparing HEK293 cells overexpressing the wild type (1236C-2677G-3435C, 1199G) or the variant (1236C-2677G-3435T, 1236T-2677T-3435T or 1199A) proteins. These findings suggest that the ABCB1 c.1199G > A and c.1236C > T-c.2677G > T-c.3435C > T variants have no or at least limited impact on the active transport of bictegravir by ABCB1., (© 2024. The Author(s).)

Objective: To analyze whether significant differences exist between free-hand three-dimensional (3D) planning-guided cortical bone trajectory (CBT) screw placement and 3D-printed template-guided CBT screw positioning in terms of accuracy, size of screws, and potential complications., Methods: In this retrospective study, data of adult patients in whom CBT screws were placed for lumbar degenerative pathologies were extracted from a prospectively collected database and analyzed. Patients in whom screws were placed using free-hand 3D planning-guided technique were compared with patients in whom screws were positioned using customized 3D-printed templates. Size of the screws, accuracy, clinical outcomes, and complications were analyzed., Results: The study evaluated 251 patients (1004 screws). The free-hand 3D planning-guided group included 158 patients (632 screws), and the 3D-printed template-guided group included 93 patients (372 screws). The 3D-printed template-guided group involved screws of larger size from L3 to S1. Differences between the 2 groups in terms of accuracy parameters reached statistical significance (P ≤ 0.05)., Conclusions: With the use of 3D patient-matched template guides, mean diameter and length of CBT screws could be safely increased due to improved accuracy of screw placement. Based on previous evidence regarding CBT biomechanical properties, these advantages could allow increased fixation strength over traditional convergent pedicle screw trajectories. Further biomechanics studies are needed., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Among the many questionnaires available to evaluate low back pain (LBP) patients, the Core Outcome Measures Index (COMI) has the unique advantage to investigate five dimensions using seven short questions. The aim of this study was to explore additional properties of the questionnaire in a French-speaking non-surgical population., Methods: This study was conducted on 168 patients suffering from subacute or chronic LBP and followed up for 6 months in three French-speaking countries. In addition to basic psychometric properties (e.g., construct validity, floor and ceiling effect, reproducibility), internal validity was analyzed by a factor analysis using Cronbach's alpha. Responsiveness and sensitivity to change were assessed through minimal detectable change (MDC), effect size, and Minimal Clinically Important Improvement (MCII). We used an anchor-based method with receiver operating characteristic (ROC) curve analysis to assess MCII and the Patient Acceptable Symptom State., Results: Construct validity, reliability (Cronbach's alpha = 0.87), reproducibility and the absence of floor and ceiling effects were confirmed. Factor analysis indicated a one-dimensional construct that validates the use of a sum score. The MDC (2.1) was inferior to the MCII (2.3). The limit below which the patient claims to be in a fair condition (Patient Acceptable Symptom State) was set at 3., Conclusions: The COMI is a self-report questionnaire with the capacity to easily and quickly explore several dimensions in patients with LBP that can be then summarized in a meaningful sum score. Additional knowledge provided by our study should encourage the widespread use of the COMI among the spine community.

Arcuate line hernia is considered a surgical rarity. This type of hernia is characterized by protrusion of intraperitoneal structures in a concave parietal fold in the abdominal wall. In this report, we aim to describe the diagnostic images of 2 cases of arcuate line hernia. Laparoscopic repair using a polypropylene mesh with a preattached inflatable balloon has been illustrated as well.

Study Design: Observational prospective study., Objective: Our objective was to assess the reliability and validity of the French version of the Keele STarT Back Screening Tool (SBST)., Summary of Background Data: The SBST is a recently validated tool developed to identify subgroups of patients with low back pain (LBP) to guide early secondary prevention in primary care., Methods: Outpatients 18 years or older with LBP, attending a rehabilitation center, a back school, a private physiotherapy unit, or a fitness center were included. Patients were assessed through the SBST, Roland-Morris Disability Questionnaire, Örebro Musculoskeletal Pain Screening Questionnaire, Medical Outcomes Survey Short Form-36 questionnaire, and a pain visual analogue scale. Test-retest reliability was assessed with Kappa score or the intraclass correlation coefficient, internal consistency of the Psychological subscale with the Cronbach α coefficient, construct validity with the Spearman correlation coefficient, and floor and ceiling effects by percentage frequency of lowest or highest possible score achieved by respondents., Results: One hundred eight patients with LBP were included. The test-retest reliability of the SBST total score was excellent with an intraclass correlation coefficient of 0.90 (0.81-0.95). The Cronbach α coefficient was 0.73 showing a good internal consistency for the Psychological subscale. High Spearman correlation coefficients of 0.74 between SBST and Roland-Morris Disability Questionnaire, and 0.74 between the SBST and Örebro Musculoskeletal Pain Screening Questionnaire were observed. As expected, low-to-moderate correlations were observed between the SBST total score and some dissimilar measures of the Short-Form 36. The lowest possible SBST score was observed for 8 patients (7.4%), whereas only 3 patients (2.8%) had the highest possible SBST score., Conclusion: The French version of the SBST is a reliable and valid questionnaire consistent with the original English version. Therefore, this new version may help French-speaking clinicians and scientists to stratify patients with LBP., Level of Evidence: 2.

The chemisorption of specific optically active compounds on metal surfaces can create catalytically active chirality transfer sites. However, the mechanism through which these sites bias the stereoselectivity of reactions (typically hydrogenations) is generally assumed to be so complex that continued progress in the area is uncertain. We show that the investigation of heterogeneous asymmetric induction with single-site resolution sufficient to distinguish stereochemical conformations at the submolecular level is finally accessible. A combination of scanning tunneling microscopy and density functional theory calculations reveals the stereodirecting forces governing preorganization into precise chiral modifier-substrate bimolecular surface complexes. The study shows that the chiral modifier induces prochiral switching on the surface and that different prochiral ratios prevail at different submolecular binding sites on the modifier at the reaction temperature.

Determination of the Coulomb energy of single point defects is essential because changing their charge state critically affects the properties of materials. Based on a novel approach that allows us to simultaneously identify a point defect and to monitor the occupation probability of its electronic state, we unambiguously measure the charging energy of a single Si dangling bond with tunneling spectroscopy. Comparing the experimental result with tight-binding calculations highlights the importance of the particular surrounding of the localized state on the effective charging energy.

Chordoma is a rare slow-growing, locally invasive primary malignant bone tumour arising from notochord remnants. It is characterised by a high local recurrence rate. Most chordomas (60%) are found in the sacrococcygeal region: only 15% originate in the mobile spine. CT-scan and MRI can help evaluate the tumour extension. En bloc resection of the tumour mass is the standard treatment. The main prognostic factor is tumour-negative surgical margins. Due to the location of spinal chordomas, adjacent to vital neural and vascular structures, this can be difficult to achieve. Therefore radiotherapy has been used when adequate excision is not possible and in case of local recurrence. We report the case of a 72-year-old female with a recurrent chordoma of the L2 vertebra, previously treated with resection and radiotherapy. The recurrent chordoma was resected using a right-sided thoraco-phreno-laparotomy as the tumour could not be resected using the left anterior approach or posterior approach due to extensive fibrosis following surgery and radiotherapy.

We report a very rare case of a congenital cervical spine anomaly. The low occurrence rate of this anatomic variant combined with the high frequency of cervical injuries in sports medicine made this case a diagnostic challenge on both emergency and orthopaedic departments. After reading, it should give the clinician a more consistent view in differentiating the traumatic or congenital origin of the disorder seen on radiographs, as well as what can be expected in the future when diagnosis is set.

Trifluoroacetophenone (TFAP) forms C O...H-C bonded dimers and trimers at room temperature on Pt(111). It is proposed that these systems mimic the prochiral carbonyl-chiral modifier interaction in the enantioselective hydrogenation of TFAP on cinchona-modified Pt catalysts. That is, the activation of TFAP in homomolecular assemblies at racemic sites is expected to be roughly the same as in the diastereomeric complex formed at chiral sites. This interpretation suggests a reason why alpha-phenyl ketones do not display a strong measured rate enhancement effect in the Orito reaction.

The purpose of this prospective study was to compare three different ways of conservative management of isolated fractures of the ulnar shaft: immediate mobilisation, below-elbow plaster cast and above-elbow plaster cast immobilisation. Over a 24-month period, 102 minimally displaced isolated fractures of the distal two-thirds of the ulnar shaft were treated on an outpatient basis. Thirty-two fractures were immobilised with an above-elbow plaster cast for 3 weeks and a below-elbow plaster cast for an additional 3 weeks. Thirty-six fractures were immobilised with a below-elbow plaster cast for 6 weeks. The remaining 34 fractures were managed with immediate mobilisation. Radiological healing, range of motion of the wrist, and pain were assessed. Results were good and were comparable in terms of healing, time to healing, pain and range of motion of the wrist.

Pre-clinical drug discovery relies increasingly on huge volumes of inter-related multivariate data. To make sense of these data and enable quality decision-making based on this plethora of information they must be presented in an interpretable form. Reducing the dimensionality of the data often leaves a data set that is too complex to interpret readily, so intuitive visualization methods are needed. Bioinformatics has provided much of the impetus for visualizing complex data, the cheminformatics community has been aggressive with the data-reduction problem. The increasing appreciation of the inter-related multifactorial nature of pre-clinical drug discovery makes visualization a burgeoning and active field that spans biosciences, mathematics and visual psychology.

We investigate the energy and symmetry of Zn and Be dopant-induced acceptor states in GaAs using cross-sectional scanning tunnelling microscopy (STM) and spectroscopy at low temperatures. The ground and first excited states are found to have a nonspherical symmetry. In particular, the first excited acceptor state has a T(d) symmetry. Its major contribution to the STM empty-state images allows us to explain the puzzling triangular shaped contrast observed in the empty-state STM images of acceptor impurities in III-V semiconductors.

We prospectively studied the value of systematic rectal swabs performed for the detection of colonization and the prediction of infections by Acinetobacter baumanii in 751 consecutive patients admitted to five intensive-care units (ICUs) over an 8-month period. Gastrointestinal tract colonization was found in 8.7% of ICU admissions. The positive and negative predictive values of rectal swabs for the detection of subsequent infection were 17% and 99%, respectively. Sensitivity and specificity were 55% and 93%, respectively. We also determined the comparative values of rectal or nasal swabs and skin cultures for the detection of A baumanii colonization in 25 patients already colonized or infected with A baumanii. The combination of rectal and nasal swabs was positive in 20 (80%) of 25. The results of the present study suggest that detection of gastrointestinal tract A baumanii colonization is not an accurate predictor of subsequent A baumanii infection and that combined rectal and nasal swabs might be used for the detection of A baumanii colonization in ICU patients.