Frailty indices predict mortality, complications and functional improvements in supratentorial meningioma patients over 80 years of age.

PURPOSE: To assess whether the Modified 5 (mFI-5) and 11 (mFI-11) Factor Frailty Indices associate with postoperative mortality, complications, and functional benefit in supratentorial meningioma patients aged over 80 years. METHODS: Baseline characteristics were collected from eight centers. Based on the patients' preoperative status and comorbidities, frailty was assessed by the mFI-5 and mFI-11. The collected scores were categorized as "robust (mFI=0)", "pre-frail (mFI=1)", "frail (mFI=2)", and "significantly frail (mFI≥3)". Outcome was assessed by the Karnofsky Performance Scale (KPS); functional benefit was defined as improved KPS score. Additionally, we evaluated the patients' functional independence (KPS≥70) after surgery. RESULTS: The study population consisted of 262 patients (median age 83 years) with a median preoperative KPS of 70 (range 20 to 100). The 90-day and 1-year mortality were 9.0% and 13.2%; we recorded surgery-associated complications in 111 (42.4%) patients. At last follow-up within the postoperative first year, 101 (38.5%) patients showed an improved KPS, and 183 (69.8%) either gained or maintained functional independence. "Severely frail" patients were at an increased risk of death at 90 days (OR 16.3 (CI95% 1.7-158.7)) and one year (OR 11.7 (CI95% 1.9-71.7)); nine (42.9%) of severely frail patients died within the first year after surgery. The "severely frail" cohort had increased odds of suffering from surgery-associated complications (OR 3.9 (CI 95%) 1.3-11.3)), but also had a high chance for postoperative functional improvements by KPS≥20 (OR 6.6 (CI95% 1.2-36.2)). CONCLUSION: The mFI-5 and mFI-11 associate with postoperative mortality, complications, and functional benefit. Even though "severely frail" patients had the highest risk morbidity and mortality, they had the highest chance for functional improvement.

A randomized phase 2b trial examined the effects of the glucagon-like peptide-1 and glucagon receptor agonist cotadutide on kidney outcomes in patients with diabetic kidney disease.

Cotadutide is a glucagon-like peptide-1 (GLP-1) and glucagon receptor agonist that may improve kidney function in patients with type 2 diabetes (T2D) and chronic kidney disease (CKD). In this phase 2b study, patients with T2D and CKD ,estimated glomerular filtration rate [eGFR] of 20 or more and under 90 mL/min per 1.73 m2 and urinary albumin-to-creatinine ratio [UACR] over 50 mg/g) were randomized 1:1:1:1:1 to 26 weeks treatment with standard of care plus subcutaneous cotadutide up-titrated to100, 300, or 600 µg, or placebo daily (double-blind), or the GLP-1 agonist semaglutide 1 mg once-weekly (open-label).The co-primary endpoints were absolute and percentage change versus placebo in UACR from baseline to the end of week 14. Among 248 randomized patients, mean age 67.1 years, 19% were female, mean eGFR was 55.3 mL/min per 1.73 m2, geometric mean was UACR 205.5 mg/g (coefficient of variation 270.0), and 46.8% were receiving concomitant sodium-glucose co-transporter 2 inhibitors. Cotadutide dose-dependently reduced UACR from baseline to the end of week 14, reaching significance at 300 µg (-43.9% [95%confidence interval -54.7 to -30.6]) and 600 µg (-49.9% [-59.3 to -38.4]) versus placebo; with effects sustained at week 26. Serious adverse events were balanced across arms. Safety and tolerability of cotadutide 600 µg were comparable to semaglutide. Thus, our study shows that in patients with T2Dand CKD, cotadutide significantly reduced UACR on top of standard of care with an acceptable tolerability profile, suggesting kidney protective benefits that need confirmation in a larger study.

Reduced Density Matrix Formulation of Quantum Linear Response.

The prediction of spectral properties via linear response (LR) theory is an important tool in quantum chemistry for understanding photoinduced processes in molecular systems. With the advances of quantum computing, we recently adapted this method for near-term quantum hardware using a truncated active space approximation with orbital rotation, named quantum linear response (qLR). In an effort to reduce the classic cost of this hybrid approach, we here derive and implement a reduced density matrix (RDM) driven approach of qLR. This allows for the calculation of spectral properties of moderately sized molecules with much larger basis sets than so far possible. We report qLR results for benzene and R-methyloxirane with a cc-pVTZ basis set and study the effect of shot noise on the valence and oxygen K-edge absorption spectra of H2O in the cc-pVTZ basis.

A belly full of jelly? DNA metabarcoding shows evidence for gelatinous zooplankton predation by several fish species in Greenland waters.

The waters of Greenland harbour a high species richness and biomass of gelatinous zooplankton (GZP); however, their role in the diet of the many fish species, including commercially exploited species, has not yet been verified. Traditionally, GZP was considered to be a trophic dead end, i.e. with a limited contribution as prey for higher trophic levels. We applied DNA metabarcoding of two gene fragments (COI, 18S V1-V2) to the stomach contents of seven pelagic and demersal fish species in Greenland waters, to identify their prey composition as well as the occurrence of GZP predation. We detected GZP DNA reads in the stomachs of all investigated fish species, with frequency of occurrences ranging from 12.5% (for Melanogrammus aeglefinus) to 50% (for Argentina silus). GZP predation had not yet been reported for several of these species. GZP were found to majorly contribute to the diet of A. silus and Anarhichas denticulatus, particularly, the siphonophore Nanomia cara and the scyphozoan Atolla were of a high importance as prey, respectively. The use of multiple genetic markers enabled us to detect a total of 59 GZP taxa in the fish stomachs with several GZP species being detected only by one of the markers.

Resection of meningiomas located in motor eloquent areas - comparative analysis of navigated transcranial magnetic stimulation and conventional neuronavigation.

BACKGROUND: Navigated transcranial magnetic stimulation (nTMS) has been established as a preoperative diagnostic procedure in glioma surgery, increasing the extent of resection and preserving functional outcome. nTMS motor mapping for the resection of motor eloquent meningiomas has not been evaluated in a comparative analysis, yet. METHODS: We conducted a retrospective matched-pair analysis for tumor location and size in meningioma patients with tumors located over or close to the primary motor cortex. Half of the study population received nTMS motor mapping preoperatively (nTMS-group). The primary endpoint were permanent surgery-related motor deficits. Additional factors associated with new motor deficits were evaluated apart from nTMS. RESULTS: 62 patients (mean age 62 ± 15.8 years) were evaluated. 31 patients received preoperative nTMS motor mapping. In this group, motor thresholds (rMT) corresponded with tumor location and preoperative motor status, but could not predict motor outcome. No patient with preoperative intact motor function had a surgery-related permanent deficit in the nTMS group whereas four patients in the non-TMS group with preoperative intact motor status harbored from permanent deficits. 13 patients (21.3%) had a permanent motor deficit postoperatively with no difference between the nTMS and the non-TMS-group. Worsening in motor function was associated with higher patient age (p = 0.01) and contact to the superior sagittal sinus (p = 0.027). CONCLUSION: nTMSmotor mapping did not lead to postoperative preservation in motorfunction. nTMS data corresponded well with the preoperative motorstatus and were associated with postoperative permanent deficits if tumors were located over the motor hotspot according to nTMS.

Tumor-Specific Alterations in Motor Cortex Excitability and Tractography of the Corticospinal Tract-A Navigated Transcranial Magnetic Stimulation Study.

BACKGROUND: Non-invasive brain mapping using navigated transcranial magnetic stimulation (nTMS) is a valuable tool prior to resection of malignant brain tumors. With nTMS motor mapping, it is additionally possible to analyze the function of the motor system and to evaluate tumor-induced neuroplasticity. Distinct changes in motor cortex excitability induced by certain malignant brain tumors are a focal point of research. METHODS: A retrospective single-center study was conducted involving patients with malignant brain tumors. Clinical data, resting motor threshold (rMT), and nTMS-based tractography were evaluated. The interhemispheric rMT-ratio (rMTTumor/rMTControl) was calculated for each extremity and considered pathological if it was >110% or <90%. Distances between the corticospinal tract and the tumor (lesion-to-tract-distance - LTD) were measured. RESULTS: 49 patients were evaluated. 16 patients (32.7%) had a preoperative motor deficit. The cohort comprised 22 glioblastomas (44.9%), 5 gliomas of Classification of Tumors of the Central Nervous System (CNS WHO) grade 3 (10.2%), 6 gliomas of CNS WHO grade 2 (12.2%) and 16 cerebral metastases (32.7%). 26 (53.1%) had a pathological rMT-ratio for the upper extremity and 35 (71.4%) for the lower extremity. All patients with tumor-induced motor deficits had pathological interhemispheric rMT-ratios, and presence of tumor-induced motor deficits was associated with infiltration of the tumor to the nTMS-positive cortex (p = 0.04) and shorter LTDs (all p < 0.021). Pathological interhemispheric rMT-ratio for the upper extremity was associated with cerebral metastases, but not with gliomas (p = 0.002). CONCLUSIONS: Our study underlines the diagnostic potential of nTMS motor mapping to go beyond surgical risk stratification. Pathological alterations in motor cortex excitability can be measured with nTMS mapping. Pathological cortical excitability was more frequent in cerebral metastases than in gliomas.

Electric Field Gradient Calculations for Ice VIII and IX Using Polarizable Embedding: A Comparative Study on Classical Computers and Quantum Simulators.

We test the performance of the polarizable embedding variational quantum eigensolver self-consistent field (PE-VQE-SCF) model for computing electric field gradients with comparisons to conventional complete active space self-consistent-field (CASSCF) calculations and experimental results. We compute quadrupole coupling constants for ice VIII and ice IX. We find close agreement of the quantum-computing PE-VQE-SCF results with the results from the classical PE-CASSCF calculations and with experiment. Furthermore, we observe that the inclusion of the environment is crucial for obtaining results that match the experimental data. The calculations for ice VIII are within the experimental uncertainty for both CASSCF and VQE-SCF for oxygen and lie close to the experimental value for ice IX as well. With the VQE-SCF, which is based on an adaptive derivative-assembled problem-tailored (ADAPT) ansatz, we find that the inclusion of the environment and the size of the different basis sets do not directly affect the gate counts. However, by including an explicit environment, the wavefunction and therefore the optimization problem become more complicated, which usually results in the need to include more operators from the operator pool, thereby increasing the depth of the circuit.

Manifestation of site energy landscapes for ion transport in borate glasses.

The potential energy landscape of lithium borate glass of composition Li3B7O12 has been investigated by the charge attachment induced transport (CAIT) technique. Here, native lithium ions have been replaced by foreign alkali ions, M+ = K+, Rb+, Cs+. All experiments exhibit a pronounced decrease of native ion diffusion coefficients over more than 4 orders of magnitude with decreasing local population of Li+. The energy landscape is modelled by a site energy distribution (SED) with a concentration dependent Fermi energy of the native Li+ ions. The width of the populated part of the SED is found to be 250 meV (FWHM). The conclusion is made possible by a combination of a macroscopic ion replacement experiment with a Nernst-Planck-Poisson modelling of concentration depth profiles measured by secondary ion mass spectrometry (SIMS). Possible generalizations of macroscopic transport theory to match an Onsager ansatz are discussed.

Subspace Methods for the Simulation of Molecular Response Properties on a Quantum Computer.

We explore Davidson methods for obtaining excitation energies and other linear response properties within the recently developed quantum self-consistent linear response (q-sc-LR) method. Davidson-type methods allow for obtaining only a few selected excitation energies without explicitly constructing the electronic Hessian since they only require the ability to perform Hessian-vector multiplications. We apply the Davidson method to calculate the excitation energies of hydrogen chains (up to H10) and analyze aspects of statistical noise for computing excitation energies on quantum simulators. Additionally, we apply Davidson methods for computing linear response properties such as static polarizabilities for H2, LiH, H2O, OH-, and NH3, and show that unitary coupled cluster outperforms classical projected coupled cluster for molecular systems with strong correlation. Finally, we formulate the Davidson method for damped (complex) linear response, with application to the nitrogen K-edge X-ray absorption of ammonia, and the C6 coefficients of H2, LiH, H2O, OH-, and NH3.

Quantum Equation of Motion with Orbital Optimization for Computing Molecular Properties in Near-Term Quantum Computing.

Determining the properties of molecules and materials is one of the premier applications of quantum computing. A major question in the field is how to use imperfect near-term quantum computers to solve problems of practical value. Inspired by the recently developed variants of the quantum counterpart of the equation-of-motion (qEOM) approach and the orbital-optimized variational quantum eigensolver (oo-VQE), we present a quantum algorithm (oo-VQE-qEOM) for the calculation of molecular properties by computing expectation values on a quantum computer. We perform noise-free quantum simulations of BeH2 in the series of STO-3G/6-31G/6-31G* basis sets and of H4 and H2O in 6-31G using an active space of four electrons and four spatial orbitals (8 qubits) to evaluate excitation energies, electronic absorption, and, for twisted H4, circular dichroism spectra. We demonstrate that the proposed algorithm can reproduce the results of conventional classical CASSCF calculations for these molecular systems.

Ion molecule reactions in the HBr+ + CH4 system: a combined experimental and theoretical study.

Reactions in the system HBr+ + CH4 have been investigated inside a guided ion-beam apparatus under single-collision conditions. The HBr+ is vibrational and rotational state selected in the electronic X2Π1/2 state created by (2+1)-REMPI. Due to the exitation scheme employed different rotational states of the HBr+ are accessible. Four reaction channels have been observed. The cross section, σ, for the exothermic proton transfer channel (PT) decreases with increasing collision energy, steeper than predicted by the Langevin model. The cross section also decreases with increasing rotational energy in the HBr+, with the effect of the rotational energy being stronger than that of translational energy. The cross section for the endothermic charge transfer (CT) increased with increasing collision energy. The energy dependence is well reproduced by a simple line of center (loc) model. Although the bromine transfer (BT) is exothermic the observed cross section increased with increasing collision energy due to an activation barrier on the potential energy surface (PES). Analysis by a modified loc model suggest the relevance of an angle dependence of σ. The cross section for the endothermic hydrogen atom abstraction (HA) exhibits a maximum at 2 eV Ecm. The measured cross sections are rationalized by means of reaction dynamics simulations which show good agreement with the experimental cross sections. The dynamics simulations are carried out with a machine learning potential that is developed and benchmarked with ab initio molecular dynamics simulation. The absolute cross sections predicted by reaction dynamics simulations are well within the same order of magnitude while reproducing the trends over three different collision energies for all four reaction channels. Furthermore, the simulations demonstrate various reaction mechanisms for these reaction channels, including a very interesting HBr+ orientation selectivity for the BT reaction channel.

Acute-to-chronic subdural hematoma: radiographic and clinical progression from acute subdural hematoma.

INTRODUCTION: The pathogenesis of chronic subdural hematoma (CSDH) has not been completely understood. However, different mechanisms can result in space-occupying subdural fluid collections, one pathway can be the transformation of an original trauma-induced acute subdural hematoma (ASDH) into a CSDH. MATERIALS AND METHODS: All patients with unilateral CSDH, requiring burr hole trephination between 2018 and 2023 were included. The population was distributed into an acute-to-chronic group (group A, n = 41) and into a conventional group (group B, n = 282). Clinical and radiographic parameters were analyzed. In analysis A, changes of parameters after trauma within group A are compared. In analysis B, parameters between the two groups before surgery were correlated. RESULTS: In group A, volume and midline shift increased significantly during the progression from acute-to-chronic (p < 0.001, resp.). Clinical performance (modified Rankin scale, Glasgow Coma Scale) dropped significantly (p = 0.035, p < 0.001, resp.). Median time between trauma with ASDH and surgery for CSDH was 12 days. Patients treated up to the 12th day presented with larger volume of ASDH (p = 0.012). Before burr hole trephination, patients in group A presented with disturbance of consciousness (DOC) more often (p = 0.002), however less commonly with a new motor deficit (p = 0.014). Despite similar midline shift between the groups (p = 0.8), the maximal hematoma width was greater in group B (p < 0.001). CONCLUSION: If ASDH transforms to CSDH, treatment may become mandatory early due to increase in volume and midline shift. Close monitoring of these patients is crucial since DOC and rapid deterioration is common in this type of SDH.

Which Options Exist for NISQ-Friendly Linear Response Formulations?

Linear response (LR) theory is a powerful tool in classic quantum chemistry crucial to understanding photoinduced processes in chemistry and biology. However, performing simulations for large systems and in the case of strong electron correlation remains challenging. Quantum computers are poised to facilitate the simulation of such systems, and recently, a quantum linear response formulation (qLR) was introduced [Kumar et al., J. Chem. Theory Comput. 2023, 19, 9136-9150]. To apply qLR to near-term quantum computers beyond a minimal basis set, we here introduce a resource-efficient qLR theory, using a truncated active-space version of the multiconfigurational self-consistent field LR ansatz. Therein, we investigate eight different near-term qLR formalisms that utilize novel operator transformations that allow the qLR equations to be performed on near-term hardware. Simulating excited state potential energy curves and absorption spectra for various test cases, we identify two promising candidates, dubbed "proj LRSD" and "all-proj LRSD".

Significance of navigated transcranial magnetic stimulation and tractography to preserve motor function in patients undergoing surgery for motor eloquent gliomas.

Resection of gliomas in or close to motor areas is at high risk for morbidity and development of surgery-related deficits. Navigated transcranial magnetic stimulation (nTMS) including nTMS-based tractography is suitable for presurgical planning and risk assessment. The aim of this study was to investigate the association of postoperative motor status and the spatial relation to motor eloquent brain tissue in order to increase the understanding of postoperative motor deficits. Patient data, nTMS examinations and imaging studies were retrospectively reviewed, corticospinal tracts (CST) were reconstructed with two different approaches of nTMS-based seeding. Postoperative imaging and nTMS-augmented preoperative imaging were merged to identify the relation between motor positive cortical and subcortical areas and the resection cavity. 38 tumor surgeries were performed in 36 glioma patients (28.9% female) aged 55.1 ± 13.8 years. Mean distance between the CST and the lesion was 6.9 ± 5.1 mm at 75% of the patient-individual fractional anisotropy threshold and median tumor volume reduction was 97.7 ± 11.6%. The positive predictive value for permanent deficits after resection of nTMS positive areas was 66.7% and the corresponding negative predictive value was 90.6%. Distances between the resection cavity and the CST were higher in patients with postoperative stable motor function. Extent of resection and distance between resection cavity and CST correlated well. The present study strongly supports preoperative nTMS as an important surgical tool for preserving motor function in glioma patients at risk.

Fluorescein-stained confocal laser endomicroscopy versus conventional frozen section for intraoperative histopathological assessment of intracranial tumors.

BACKGROUND: The aim of this clinical trial was to compare Fluorescein-stained intraoperative confocal laser endomicroscopy (CLE) of intracranial lesions and evaluation by a neuropathologist with routine intraoperative frozen section (FS) assessment by neuropathology. METHODS: In this phase II noninferiority, prospective, multicenter, nonrandomized, off-label clinical trial (EudraCT: 2019-004512-58), patients above the age of 18 years with any intracranial lesion scheduled for elective resection were included. The diagnostic accuracies of both CLE and FS referenced with the final histopathological diagnosis were statistically compared in a noninferiority analysis, representing the primary endpoint. Secondary endpoints included the safety of the technique and time expedited for CLE and FS. RESULTS: A total of 210 patients were included by 3 participating sites between November 2020 and June 2022. Most common entities were high-grade gliomas (37.9%), metastases (24.1%), and meningiomas (22.7%). A total of 6 serious adverse events in 4 (2%) patients were recorded. For the primary endpoint, the diagnostic accuracy for CLE was inferior with 0.87 versus 0.91 for FS, resulting in a difference of 0.04 (95% confidence interval -0.10; 0.02; P = .367). The median time expedited until intraoperative diagnosis was 3 minutes for CLE and 27 minutes for FS, with a mean difference of 27.5 minutes (standard deviation 14.5; P < .001). CONCLUSIONS: CLE allowed for a safe and time-effective intraoperative histological diagnosis with a diagnostic accuracy of 87% across all intracranial entities included. The technique achieved histological assessments in real time with a 10-fold reduction of processing time compared to FS, which may invariably impact surgical strategy on the fly.

Development of a bleeding scale and hemostasis algorithm in cranial neurosurgery.

Effective hemostasis is crucial in neurosurgery as anatomical and functional considerations reduce tolerance for any bleeding. The classification of bleeding severities is a necessary step to enable neurosurgeons to counteract bleeding during surgery. Even though bleeding scales are used for a variety of surgical specialties, they cannot be transferred to cranial neurosurgery without adaption, and no consensus on the nature of such a classification exists to date. Moreover, there is plethora of topical hemostasis products with diverse mechanisms of action and application available. Clinical studies investigating those products used in neurosurgery did not define standardized procedures. This article demonstrates the systematic establishment of both a bleeding scale and a hemostasis algorithm to close this gap in the assessment of intracranial bleeding. The expert panel consisting of 7 members from different neurosurgical centers developed a qualitative bleeding scale with the peculiarities of neurosurgical procedures, based on the experience of each member in daily practice. The hemostasis algorithm is a recommendation for neurosurgeons to aid in the decision-making process to control any sort of bleeding, taking into account the rational use of available hemostatics, depending on type and location of bleeding, as well as the mechanism of action of such agents. Effectiveness of hemostasis, surgery times and economic costs can be optimized by applying the algorithm in daily practice.

Influence of clinical and tumor-specific factors on the resting motor threshold in navigated transcranial magnetic stimulation.

OBJECTIVE: Preoperative non-invasive mapping of motor function with navigated transcranial magnetic stimulation (nTMS) has become a widely used diagnostic procedure. Determination of the patient-individual resting motor threshold (rMT) is of great importance to achieve reliable results when conducting nTMS motor mapping. Factors which contribute to differences in rMT of brain tumor patients have not been fully investigated. METHODS: We included adult patients with all types of de novo and recurrent intracranial lesions, suspicious for intra-axial brain tumors. The outcome measure was the rMT of the upper extremity, defined as the stimulation intensity eliciting motor evoked potentials with amplitudes greater than 50µV in 50 % of applied stimulations. RESULTS: Eighty nTMS examinations in 75 patients (37.5 % female) aged 57.9 ± 14.9 years were evaluated. In non-parametric testing, rMT values were higher in patients with upper extremity paresis (p = 0.024) and lower in patients with high grade gliomas (HGG) (p = 0.001). rMT inversely correlated with patient age (rs=-0.28, p = 0.013) and edema volume (rs=-0.28, p = 0.012) In regression analysis, infiltration of the precentral gyrus (p<0.001) increased rMT values. Values of rMT were reduced in high grade gliomas (p<0.001), in patients taking Levetiracetam (p = 0.019) and if perilesional edema infiltrated motor eloquent brain (p<0.001). Subgroup analyses of glioma patients revealed similar results. Values of rMT did not differ between hand and forearm muscles. CONCLUSION: Most factors confounding rMT in our study were specific to the lesion. These factors contributed to the variability in cortical excitability and must be considered in clinical work with nTMS to achieve reliable results with nTMS motor mapping.

A missense variant in DGKG as a recessive functional variant for hepatic fibrinogen storage disease in Wagyu cattle.

Hepatic fibrinogen storage disease (HFSD) was diagnosed in a 5-month-old Wagyu calf with a history of recurrent respiratory disease. It was characterized by lethargy, dehydration, acidemia, and increased liver enzyme activities. Histologically, disseminated hepatocytes were swollen and showed a single, sharply demarcated, faintly eosinophilic cytoplasmic inclusion with a ground-glass appearance, with the nucleus in an eccentric position. Cytoplasmic inclusions did not stain with the periodic acid-Schiff (PAS) reaction. Using a rabbit polyclonal antibody against fibrinogen, the cytoplasmic vacuoles in the hepatocytes stained intensely. Electron microscopy disclosed hepatocytes with membrane-bound cytoplasmic inclusions filled with fine granular material interspersed with a few coarse-grained electron-dense granules. A trio whole-genome sequencing approach identified a deleterious homozygous missense variant in DGKG (p.Thr721Ile). The allele frequency in 209 genotyped Wagyu was 7.2%. This is a report of a DGKG-related recessive inherited disorder in cattle and adds DGKG to the list of candidate genes for HFSD in other species.

Micro-Twinning in IN738LC Manufactured with Laser Powder Bed Fusion.

Components manufactured with Metal Laser Powder Bed Fusion (PBF-LB/M) are built in a layerwise fashion. The PBF-LB/M build orientation affects grain morphology and orientation. Depending on the build orientation, microstructures from equiaxed to textured grains can develop. In the case of a textured microstructure, a clear anisotropy of the mechanical properties affecting short- and long-term mechanical properties can be observed, which must be considered in the component design. Within the scope of this study, the IN738LC tensile and creep properties of PBF-LB/M samples manufactured in 0° (perpendicular to build direction), 45° and 90° (parallel to build direction) build orientations were investigated. While the hot tensile results (at 850 °C) are as expected, where the tensile properties of the 45° build orientation lay between those of 0° and 90°, the creep results (performed at 850 °C and 200 MPa) of the 45° build orientation show the least time to rupture. This study discusses the microstructural reasoning behind the peculiar creep behavior of 45° oriented IN738LC samples and correlates the results to heat-treated microstructures and the solidification conditions of the PBF-LB/M process itself.

Brain metastasis resection: the impact of fluorescence guidance (MetResect study).

OBJECTIVE: Maximal resection of brain metastases (BMs) improves both progression-free survival and overall survival (OS). Fluorescein sodium (FL) in combination with the YELLOW 560-nm filter is a safe and feasible method for visualizing residual tumor tissue during BM resection. The authors of this study aimed to show that use of FL would positively influence the volumetric extent of resection (EOR) and thus the survival outcome in patients undergoing BM resection. METHODS: Analyzing their institution's prospective brain tumor registry, the authors identified 539 consecutive patients with BMs (247 women, mean age 62.8 years) by using preoperative high-quality MR images for volumetric analysis. BMs were resected under white light (WL) in 293 patients (54.4%; WL group) and under FL guidance in 246 patients (45.6%; FL group). Sex, age, presurgical Karnofsky Performance Status (KPS), recursive partitioning analysis class, and adjuvant treatment modalities were well balanced between the two groups. Volumetric analysis was performed in a blinded fashion by quantifying pre- and postoperative tumor volume based on gadolinium-enhanced T1-weighted sequences. RESULTS: In the FL group, the postoperative tumor volume was significantly smaller (p = 0.01), and hence the quantitative EOR was significantly larger (p = 0.024) and OS was significantly longer (p = 0.0001) (log-rank testing). Multivariate Cox regression modeling showed that age, presurgical KPS, metastasis status, and FL-guided resection are independent prognostic factors for survival. CONCLUSIONS: Compared with WL resection, FL-guided BM resection increased resection quality, significantly improved EOR, and prolonged OS.