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Patients receiving brain Intensity-modulated Proton Therapy (IMPT) are treated with 1-3 fields. Typically, beam angles must be selected manually, requiring substantial planner time and experience. The choice of beam angles has a major impact on the treatment plan quality. An AI model was developed to automate this process aiming to improve efficiency and potentially plan quality. AI performance was tested by comparing predicted beam angles to the human ground truth angles and evaluating plans resulting from each set of beam angles. Previously treated IMPT brain patients were divided into a training (n = 40) and validation set (n = 10) for the AI. Beam-angle selection in the AI was cast as a multi-label classification problem, training the convolution neural network with a Circular Earth Mover's Distance based regularization and multi-label circular-smooth label technique. An analytical post-processing algorithm is employed to minimize distance to the target and avoid organs-at-risk. Finalized gantry angle predictions are discretized in steps of 5°. For an independent test set of n = 10 patients beam angles were predicted by the AI and compared to those chosen by human planners. Both sets of angles were used to create treatment plans with an automated knowledge-based planning (KBP) tool for brain IMPT utilizing single-field optimization and robust optimization. Plan differences are therefore solely due to the choice of beam angles as automated KBP removes human optimization variability. Resulting plan quality was compared by standard clinical dosimetric parameters to the CTV, brain, brainstem, cochlea, cord, eye, lens, optic chiasm, optic nerves, pituitary, and temporal lobes. All Human and AI selected beam angles are shown in the table. For cases 1-6, AI and Human selected beam angles were within ±15° and resulting plans showed minimal dosimetric differences. In cases 7-9 AI beam angles reduced max dose while keeping organ-at-risk dose within ±2 Gy. In case 10 the AI chosen beam angles reduced cord Dmax by 9.1 Gy but increased left eye Dmax by 4.9 Gy, other organs-at-risk showed minimal differences. Gantry beam angle selection was automated by a newly developed AI model and tested on 10 brain IMPT patients. The comparison showed that the AI often chooses similar beam angles to the human planners. When there are differences, dosimetric analysis demonstrated that plans created from AI beam angles have at least the same quality as the human ones. Results motivate further research into this approach showing the AI being a promising tool to fill a current gap in the strive for automating proton treatment planning, increasing planning efficiency and potentially quality. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation. Materials and methods: Following surgical induction of MCAO for 90min, agmatine was injected 5min after beginning of reperfusion and again once daily for the next 3 post-operative days. The events during ischemia and reperfusion were investigated by T2-weighted images (T2WI), serial diffusion-weighted images (DWI), calculated apparent diffusion coefficient (ADC) maps and contrast-enhanced T1-weighted images (CE-T1WI) during 3h–72h in a 1.5T Siemens MAGNETON Avanto Scanner. Lesion volumes were analyzed in a blinded and randomized manner. Triphenyltetrazolium chloride (TTC), Nissl, and Evans Blue stainings were performed at the corresponding sections. Results: Increased lesion volumes derived from T2WI, DWI, ADC, CE-T1WI, and TTC all were noted at 3h and peaked at 24h–48h after MCAO injury. TTC-derived infarct volumes were not significantly different from the T2WI, DWI-, and CE-T1WI-derived lesion volumes at the last imaging time (72h) point except for significantly smaller ADC lesions in the MCAO model (P<0.05). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived on T2WI, DWI or CE-T1WI than ADC (P<0.05). At the last imaging time point, a significant increase in Evans Blue extravasation and a significant decrease in Nissl-positive cells numbers were noted in the vehicle-treated MCAO injured animals. The lesion volumes derived from T2WI, DWI, CE-T1WI, and Evans blue extravasation as well as the reduced numbers of Nissl-positive cells were all significantly attenuated in the agmatine-treated rats compared with the control ischemia rats (P<0.05). Conclusion: Our results suggest that agmatine has neuroprotective effects against brain edema on a reperfusion model after transient cerebral ischemia. [Copyright &y& Elsevier]

Abstract: Ca3−x Eu x Co4O9+δ (x=0.00, 0.05 and 0.10) samples were prepared by conventional solid-state synthesis and their properties measured at 25–300K. The x-ray diffraction (XRD) patterns revealed that all the samples are single phase. The thermopower of all the samples was positive, indicating that the predominant carriers are holes over the entire temperature range. The total thermal conductivity values decreased monotonically with increasing Eu3+ content. Ca2.95Eu0.05Co4O9+δ had the highest dimensionless figure of merit of 0.038 at 300K, representing an improvement of about 52% compared to undoped Ca3Co4O9+δ . [Copyright &y& Elsevier]

Abstract: We describe a method of ultrashort-pulse and ultrafast-pulse-train generation through optical parametric amplification of a laser beat wave. Numerical simulation shows that 250-fs laser pulses at 1.55μm are generated from a beat-wave seeded optical parametric amplifier pumped by a 30-ps laser at 1064nm. The pulse compression is attributable to sideband generation and parametric amplification under group velocity mismatch. Our experimental result confirms efficient generation of comb-like sidebands for the mixing waves from such an optical parametric amplifier. [Copyright &y& Elsevier]

Abstract: With approximately 0.7mol% Ni doping, the formation of hexagonal phase in BaTiO3 after sintering at a temperature above 1385°C in air has been observed. The shape of the h-BaTiO3 grains is plate-like, and the length of these h-BaTiO3 plates can be longer than 15mm. As the amount of Ni doping increases above or decreases below 0.7mol%, the hexagonal phase disappears and the resulting microstructure is dominated by small BaTiO3 grains. This critical amount of Ni (i.e. 0.7mol%) corresponds to the solubility of Ni in BaTiO3. The exaggerated growth of the plate-like grains in BaTiO3 relates strongly to the formation of oxygen vacancies due to the presence of Ni acceptors. [Copyright &y& Elsevier]

Abstract: Through the tight-binding model, the effect of electric field on electronic and optical properties of a zigzag (an armchair) H-terminated nanographite ribbon is studied. The effective electric field shifts the Fermi level (E F), modifies the energy dispersions, alters the subband spacing, produces the new edge state, changes the band gap, and causes the semiconductor–metal transitions. First, in the metallic zigzag ribbon, the degeneracy of flat bands at E F is lifted by the electric field. Meanwhile, an energy band gap E g, depending on the ribbon width and the field strength, is induced. And while the field strength increases, the semiconductor–metal transition occurs in both the semiconducting armchair and the zigzag ribbons. Then, the effect of electric field on band structures is completely reflected in the features of density of states—the shift of peak position, the change of peak height and the alternation of band gap. Most importantly, the effective electric field has great influence on the low-energy absorption spectra. It can change frequency of the first peak, alter the peak height, and even produce the new peaks. [Copyright &y& Elsevier]

A mathematical expression of the quantitative causal principle is given, using the expression this letter shows the unified expressions of D’Alembert–Lagrange, virtual work, Jourdian, Gauss and general D’Alembert–Lagrange principles of differential style, first finds the intrinsic relations among these variational principles, the conservation quantities of the above principles are first found, finally the Noether conservation charges of the all differential variational principles in the systems with the symmetry of Lie group Dm are first obtained. [Copyright &y& Elsevier]

Chitosan (CTS) microspheres were prepared by a spray drying method using type-A gelatin and ethylene oxide–propylene oxide block copolymer as modifiers. Surface morphological characteristics and surface charges of prepared microspheres were investigated by using scanning electron microscopy (SEM) and microelectrophoresis. The particle shape, size and surface morphology of microspheres were significantly affected by the concentration of gelatin. Betamethasone disodium phosphate (BTM)-loaded microspheres demonstrated good drug stability (less 1% hydrolysis product), high entrapped efficiency (95%) and positive surface charge (37.5 mV). The in vitro drug release from the microspheres was related to gelatin content. Microspheres containing gelatin/CTS 0.4∼0.6(w/w) had a prolong release pattern for 12 h. These formulation factors were correlated to particulate characteristics for optimizing BTM microspheres in pulmonary delivery. [Copyright &y& Elsevier]

General Weitzenbo¨ck theory of crystals with different dislocation distributions is proposed, the new results of Vα(t)=Mα(t) and Vm(t)=M(t) are deduced. In terms of Einstein equivalence principle, we overcome the nonperfect properties of the Volterra process, the reference, idealized and deformation states of the crystals in general case are unifiedly represented by general manifolds, we gain the new general expression of Burgers vector in practical available Euclidean space, the wrong expressions (up to now viewed as correct in all articles and books) of the strain tensor are corrected, the exact strain tensor formulas in exact condensed theory are given, the new relative volume expansion value and their new relation δ=gijEij=Eaa are given, the hard difficulty giving the really serious one-to-one correspondences between the two theories of dislocations in Euclidean space and Weitzenbo¨ck material manifolds is overcome. [Copyright &y& Elsevier]