Publications by authors named "Van Thai Pham"

Background: Afatinib is indicated for advanced-stage non-small-cell lung cancer (NSCLC) with Epidermal Growth Factor Receptor (EGFR) and uncommon mutations. However, real-world studies on this topic are limited. This study aimed to evaluate afatinib as first-line therapy for locally advanced and metastatic NSCLC with uncommon EGFR mutations.

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Background: This study aimed to evaluate the efficacy and side effects of first-line afatinib treatment in a real-world setting in Vietnam.

Methods: This retrospective study was conducted across nine hospitals in Vietnam. Advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients who received afatinib as first-line therapy between April 2018 and June 2022 were included, and patient medical records were reviewed.

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Time-resolved x-ray diffraction has been used to measure the low-temperature thermal transport properties of a Pt/GdFeO//GdGaO metal/oxide heterostructure relevant to applications in spin caloritronics. A pulsed femtosecond optical signal produces a rapid temperature rise in the Pt layer, followed by heat transport into the GdFeO (GdIG) thin film and the GdGaO (GGG) substrate. The time dependence of x-ray diffraction from the GdIG layer was tracked using an accelerator-based femtosecond x-ray source.

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Protein dynamics contribute to protein function on different time scales. Ultrafast X-ray diffraction snapshots can visualize the location and amplitude of atom displacements after perturbation. Since amplitudes of ultrafast motions are small, high-quality X-ray diffraction data is necessary for detection.

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Time-resolved optical pump/X-ray probe experiments are often used to study structural dynamics. To ensure high temporal resolution, it is necessary to monitor the timing between the X-ray pulses and the laser pulses. The transition from a crystalline solid material to a disordered state in a non-thermal melting process can be used as a reliable timing monitor.

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This study shows that initial atomic velocities as given by thermodynamics play an important role in the dynamics of phase transitions. We tracked the atomic motion during nonthermal laser-induced melting of InSb at different initial temperatures. The ultrafast atomic motion following bond breaking can in general be governed by two mechanisms: the random velocity of each atom at the time of bond breaking (inertial model), and the forces acting on the atoms after bond breaking.

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The photochemical reaction pathways of CHBr in solution were unveiled using two complementary X-ray techniques, time-resolved X-ray solution scattering (TRXSS) and X-ray transient absorption spectroscopy, in a wide temporal range from 100 ps to tens of microseconds. By performing comparative measurements in protic (methanol) and aprotic (methylcyclohexane) solvents, we found that the reaction pathways depend significantly on the solvent properties. In methanol, the major photoproducts are CHOCHBr and HBr generated by rapid solvolysis of CHBr-Br, an isomer of CHBr.

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The foundations of nuclear medicine in Vietnam were established from 1970. Until now, after 48 years of development, in Vietnam, we have some basic equipment including 31 SPECT, 4 SPECT/CT machines, 11 PET/CT scanners, five cyclotrons, and one nuclear reactor. Many nuclear medicine techniques in diagnosis and treatment have been routinely performed at provincial and central level health facilities such as tumor scintigraphy, thyroid scintigraphy, bone scintigraphy, kidney scintigraphy, cardiac scintigraphy, and radio-isotope therapy with I-131 and P-32.

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The FemtoMAX beamline facilitates studies of the structural dynamics of materials. Such studies are of fundamental importance for key scientific problems related to programming materials using light, enabling new storage media and new manufacturing techniques, obtaining sustainable energy by mimicking photosynthesis, and gleaning insights into chemical and biological functional dynamics. The FemtoMAX beamline utilizes the MAX IV linear accelerator as an electron source.

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Background/aim: We developed a scoring system to predict 1-year survival after radiosurgery for 1-3 brain metastases. This study aimed to validate this system.

Patients And Methods: Seventy-six new patients were included in this validation study.

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Article Synopsis
  • * The key process involves multiple rounds of charge separation to gather enough redox equivalents for chemical reactions, requiring long-lived charge-separated states to monitor these events.
  • * The study presents a novel experiment that reveals a surprisingly long-lived two-electron charge accumulation (200 microseconds) in a specific molecular arrangement involving naphthalene diimide and a ruthenium chromophore.
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Radiosurgery is frequently used for patients with few cerebral metastases. Decisions regarding personalized treatment should include the patient's survival prognosis. Prognostic tools should be available for estimating the remaining lifetime for each primary tumor and treatment.

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Aim: Two dose groups of patients treated with stereotactic radiosurgery (SRS) alone for 1-3 brain metastases from non-small cell lung cancer (NSCLC) were compared for outcomes.

Patients And Methods: Based on the SRS dose administered to the margins of the brain lesions, 46 patients were assigned to groups treated with 15-18 Gy (n=13) or with 20 Gy (n=33). Seven additional factors were investigated: age (≤ 58 vs.

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We present a new methodology involving the simultaneous refinement of both x-ray absorption and x-ray diffraction spectra (x-ray absorption∕diffraction structural refinement, XADSR) to study the hydration and ion pair structure of CaCl(2) and RbBr salts in concentrated aqueous solutions. The XADSR method combines the x-ray absorption fine structure (XAFS) spectral analysis of both the cation and anion as a probe of their short-range structure with an x-ray diffraction (XRD) spectral analysis as a probe of the global structural. Together they deliver a comprehensive picture of the cation and anion hydration, the contact ion pair (CIP) structure, and the solvent-separated ion pair (SSIP) structure.

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An X-ray absorption fine-structure spectroscopy (XAFS) cell that is suitable for solution-phase studies of the light elements in the series from Na(+) and Ca(2+) is described. This cell has an ultra-short pathlength that can be remotely adjusted using a miniature stepper-motor drive and thereby readily provides transmission pathlengths in the range from submicrometer to several hundred micrometers. The flexibility to vary the pathlength enables acquisition of high-quality XAFS spectra and also allows one to check for potential distortions in the spectra from thickness effects.

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We review our recent studies of excited state structures and dynamics of chemical and biological systems with pico- and femtosecond X-ray absorption spectroscopy in the liquid phase.

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Picosecond and femtosecond X-ray absorption spectroscopy is used to probe the changes of the solvent shell structure upon electron abstraction of aqueous iodide using an ultrashort laser pulse. The transient L(1,3) edge EXAFS at 50 ps time delay points to the formation of an expanded water cavity around the iodine atom, in good agreement with classical and quantum mechanical/molecular mechanics (QM/MM) molecular dynamics (MD) simulations. These also show that while the hydrogen atoms pointed toward iodide, they predominantly point toward the bulk solvent in the case of iodine, suggesting a hydrophobic behavior.

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We present the extension of time-resolved optical pump/x-ray absorption spectroscopy (XAS) probe experiments towards data collection at MHz repetition rates. The use of a high-power picosecond laser operating at an integer fraction of the repetition rate of the storage ring allows exploitation of up to two orders of magnitude more x-ray photons than in previous schemes based on the use of kHz lasers. Consequently, we demonstrate an order of magnitude increase in the signal-to-noise of time-resolved XAS of molecular systems in solution.

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Ultrafast X-ray absorption spectroscopy is a powerful tool to observe electronic and geometric structures of short-lived reaction intermediates. The ab initio FEFF9 code is applied to simulate the Pt L(3)-edge XANES spectrum of the photocatalytic diplatinum molecule [Pt(2)(P(2)O(5)H(2))(4)](4-) and the photo-induced changes that occur therein. The spectra are interpreted within a XAFS-like scattering theoretical framework (bound-continuum transitions) or in terms of a final-state local l-projected density of states (LDOS) (bound-bound transitions).

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Metallica: A large contraction of the Pt-Pt bond in the triplet excited state of the photoreactive [Pt(2)(P(2)O(5)H(2))(4)](4-) ion is determined by time-resolved X-ray absorption spectroscopy (see picture). The strengthening of the Pt-Pt interaction is accompanied by a weakening of the ligand coordination bonds, resulting in an elongation of the platinum-ligand bond that is determined for the first time.

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The ultrafast relaxation of aqueous iron(II)-tris(bipyridine) upon excitation into the singlet metal-to-ligand charge-transfer band (1MLCT) has been characterized by femtosecond fluorescence up-conversion and transient absorption (TA) studies. The fluorescence experiment shows a very short-lived broad 1MLCT emission band at approximately 600 nm, which decays in < or =20 fs, and a weak emission at approximately 660 nm, which we attribute to the 3MLCT, populated by intersystem crossing (ISC) from the 1MLCT state. The TA studies show a short-lived (<150 fs) excited-state absorption (ESA) below 400 nm, and a longer-lived one above 550 nm, along with the ground-state bleach (GSB).

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Structural changes of the iron(II)-tris-bipyridine ([Fe(II)(bpy)(3)](2+)) complex induced by ultrashort pulse excitation and population of its short-lived (< or =0.6 ns) quintet high spin state have been detected by picosecond x-ray absorption spectroscopy. The structural relaxation from the high spin to the low spin state was followed over the entire lifetime of the excited state.

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