Advances in AI and robotics have the potential to enhance the dexterity of human surgeons.
View Article and Find Full Text PDFModeling the behavior of a prototype cantilevered X-ray adaptive mirror (held from one end) demonstrates its potential for use on high-performance X-ray beamlines. Similar adaptive mirrors are used on X-ray beamlines to compensate optical aberrations, control wavefronts and tune mirror focal distances at will. Controlled by 1D arrays of piezoceramic actuators, these glancing-incidence mirrors can provide nanometre-scale surface shape adjustment capabilities.
View Article and Find Full Text PDFTo evaluate bifunctional ligand reactivity involving NH acidic sites in the secondary coordination sphere, complexes where the proton has been substituted with a methyl group (NMe) are often investigated. An alternative strategy involves substitution of the NH group for an O. This contribution considers and compares the merits of these approaches; the synthesis and characterization of cationic square-planar Rh carbonyl complexes bearing diprotic bispyrazole pyridine ligand L1, and the bis-methylated pyrazole pyridine ligand L1Me are described.
View Article and Find Full Text PDFThe use of molecular oxygen as an oxidant in chemical synthesis has significant environmental and economic benefits, and it is widely used as such in large-scale industrial processes. However, its adoption in highly selective homogeneous catalytic transformations, particularly to produce oxygenated organics, has been hindered by our limited understanding of the mechanisms by which O reacts with transition metals. Of particular relevance are the mechanisms of the reactions of oxygen with late transition metal hydrides as these metal centers are better poised to release oxygenated products.
View Article and Find Full Text PDFMultiparametric MRI-the most accurate imaging technique for detection of prostate cancer-has transformed the landscape of prostate cancer diagnosis by enabling targeted biopsies. In a targeted biopsy, tissue samples are obtained from suspicious regions identified at prebiopsy diagnostic MRI. The authors briefly compare the different strategies available for targeting an MRI-visible suspicious lesion, followed by a step-by-step description of the direct MRI-guided in-bore approach and an illustrated review of its application in challenging clinical scenarios.
View Article and Find Full Text PDFCancer drug development remained robust in 2023. Highlights of U.S.
View Article and Find Full Text PDFThe upgrading of ethanol to -butanol was performed using a molecular catalyst integrated into a carbon nitride support, one of the first examples of a supported molecular catalyst performing the Guerbet process. Initial studies using crystalline poly(triazine)imide (PTI) with lithium or transition-metal cations imbedded in the support together with a base as the catalyst system did not produce any significant amounts of -butanol. However, when using the catalyst material formed by treatment of PTI-LiCl with [(Cp*)IrCl] (Cp* = pentamethylcyclopentadienyl) along with sodium hydroxide, a 59% selectivity for butanol (13% yield) was obtained at 145 °C.
View Article and Find Full Text PDFA new generation of adaptive x-ray optics (AXO) is being installed on high-coherent-flux x-ray beamlines worldwide to correct and control the optical wavefront with sub-nm precision. These ultra-smooth mirrors achieve high reflectivities at glancing angles of incidence and can be hundreds of mm long. One type of adaptive x-ray mirror relies on piezoelectric ceramic strips which are segmented into channels and actuated to induce local, longitudinal bending, generating one-dimensional shape changes in the mirror substrate.
View Article and Find Full Text PDFA neural-network machine learning model is developed to control a bimorph adaptive mirror to achieve and preserve aberration-free coherent X-ray wavefronts at synchrotron radiation and free electron laser beamlines. The controller is trained on a mirror actuator response directly measured at a beamline with a real-time single-shot wavefront sensor, which uses a coded mask and wavelet-transform analysis. The system has been successfully tested on a bimorph deformable mirror at the 28-ID IDEA beamline of the Advanced Photon Source at Argonne National Laboratory.
View Article and Find Full Text PDFA series of dinuclear molecular copper complexes were prepared and used to model the binding and Lewis acid stabilization of CO in heterogeneous copper CO reduction electrocatalysts. Experimental studies (including measurement of rate and equilibrium constants) and electronic structure calculations suggest that the key kinetic barrier for CO binding may be a σ-interaction between Cu and the incoming CO ligand. The rate of CO coordination can be increased upon the addition of Lewis acids or electron-withdrawing substituents on the ligand backbone.
View Article and Find Full Text PDFThe FDA Oncology Center of Excellence recently launched a crowdsourcing pilot to request ideas from the scientific community for research questions that FDA could address with pooled analyses of clinical trial data submitted to the agency for regulatory purposes. This effort builds on FDA's track record of publishing pooled analyses to explore scientific questions that cannot be addressed in a single trial due to limited sample size. The research crowdsourcing pilot tested a new approach for obtaining external input on regulatory science activities, because FDA is generally unable to share patient-level data outside of the agency due to federal disclosure laws and regulations protecting different types of data submitted in regulatory applications.
View Article and Find Full Text PDFOn October 15, 2021, the FDA approved atezolizumab as adjuvant therapy in patients with stage II to IIIA non-small cell lung cancer (NSCLC) whose tumors have programmed cell death ligand 1 (PD-L1) expression on ≥1% of tumor cells (TC), as detected by an FDA-approved test. The approval was based on results from the IMpower010 trial, in which 1,005 patients with NSCLC who had completed tumor resection and cisplatin-based adjuvant chemotherapy were randomly assigned 1:1 to receive atezolizumab for 16 cycles or best supportive care. The primary endpoint of disease-free survival (DFS) as assessed by investigator was tested hierarchically in the following analysis populations: stage II-IIIA NSCLC with PD-L1 expression on ≥1% of TCs (PD-L1 ≥ 1% TC); all randomly assigned patients with stage II-IIIA NSCLC; and the intent-to-treat population comprising all randomly assigned patients.
View Article and Find Full Text PDFIntroduction: Researchers have become increasingly concerned with the stigmatizing impact that regulations and policies aimed to curve down cigarette smoking may have on smokers. Given the lack of psychometrically validated tools available to assess smoking stigma, we developed and evaluated the Smoker Self-Stigma Questionnaire (SSSQ).
Aims And Methods: A total of 592 smokers recruited through Amazon's Mechanical Turk (MTurk) completed an online, Qualtrics survey that included 45 items developed and vetted by tobacco-research experts.
J Synchrotron Radiat
May 2023
Mirror-centered, closed-form expressions for hyperbolic surfaces used in X-ray beamlines have been derived. Hyperbolic mirrors create a virtual focus or source point and can be used to lengthen or shorten the effective focal distance of a compound optical system. The derivations here express off-axis segments of a hyperbolic surface in terms of the real and virtual focal distances and the incident glancing angle at the center of the mirror.
View Article and Find Full Text PDFJ Synchrotron Radiat
January 2023
Adaptive X-ray mirrors are being adopted on high-coherent-flux synchrotron and X-ray free-electron laser beamlines where dynamic phase control and aberration compensation are necessary to preserve wavefront quality from source to sample, yet challenging to achieve. Additional difficulties arise from the inability to continuously probe the wavefront in this context, which demands methods of control that require little to no feedback. In this work, a data-driven approach to the control of adaptive X-ray optics with piezo-bimorph actuators is demonstrated.
View Article and Find Full Text PDFIn 2022, cancer drug development continued to progress rapidly despite the lingering COVID-19 pandemic. Highlights of U.S.
View Article and Find Full Text PDFMultiple myeloma (MM) causes approximately 20% of deaths from blood cancers. Notwithstanding significant therapeutic progress, such as with proteasome inhibitors (PIs), MM remains incurable due to the development of resistance. mTORC1 is a key metabolic regulator, which frequently becomes dysregulated in cancer.
View Article and Find Full Text PDFScience Robotics welcomes papers demonstrating technical and scientific advances, with potential for influence beyond robotics.
View Article and Find Full Text PDFProc IEEE Inst Electr Electron Eng
July 2022
Thermolysis of [(BPI)Pt(CH)][OTf] (BPI = 1,3-bis(2-(4--butyl)pyridylimino)isoindole) to release methane and form (BPI)Pt(OTf) is reported. Kinetic, mechanistic, and computational studies point to an unusual anion-assisted pathway that obviates the need for a higher oxidation state intermediate to couple the metal-bound methyl group with the ligand-bound hydrogen. Leveraging this insight, a triflimide derivative of the (BPI)Pt complex was shown to activate benzene, highlighting the role of the counteranion in controlling the activity of these complexes.
View Article and Find Full Text PDFSyntheses of Vaska-type complexes [IrPX(CO)] (P = phosphine, X = halide) with all four common halides (fluoride, chloride, bromide, and iodide) was attempted using a protic and hemilabile imidazolyl di--butyl phosphine ligand. In the solid-state, all four complexes were found to be ionic with the halides in the outer-sphere, and the fourth coordination site of the square plane occupied by the imidazole arm of the ligand. In solution, however, the chloride complex was found to be in equilibrium with an octahedral Ir-H species at room temperature.
View Article and Find Full Text PDFJ Synchrotron Radiat
July 2022
Ellipsoidal and plane-elliptical surfaces are widely used as reflective, point-to-point focusing elements in many optical systems, including X-ray optics. Here the classical optical path function approach of Fermat is applied to derive a closed-form expression for these surfaces that are uniquely described by the object and image distances and the angle of incidence at a point on a mirror surface. A compact description facilitates design, modeling, fabrication, and testing to arbitrary accuracy.
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