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Previous studies indicated that the omission of the clinical target volume (CTV) in thoracic radiotherapy (TRT) under modern radiotherapy techniques could deliver sufficient dose coverage to subclinical regions and spare organs at risk. This study aims to investigate the feasibility of CTV-omitted TRT in locally advanced esophagus cancer (LAEC). A total of 145 patients with LAEC who received TRT from December 8, 2018, to February 9, 2023 were retrospectively analyzed. There were 86 patients who received TRT with CTV and 59 patients who received TRT without CTV. The possible prognostic factors including gender, age, location, pathology, staging, prescribed dose, neoadjuvant therapy, concurrent therapy, and consolidation therapy were balanced using propensity score matching (PSM). In the arm with CTV, CTV was defined as the primary tumor plus a 3cm expansion superiorly and inferiorly along the esophagus and cardia including the scope of elective nodal regions. Planning target volume (PTV) was generated from an extension of gross target volume (GTV) of 5mm. In the arm without CTV, planning gross target volume (PGTV) was generated from an extension of 3cm of primary tumor superiorly and inferiorly along the esophagus and cardia and 5mm of primary tumor and metastatic lymph nodes. Kaplan-Meier analysis was used to evaluate the overall survival (OS), local-regional relapse free survival (LRFS). Adverse events (AEs) including hematologic toxicities, treatment-related pneumonitis, esophagitis and other AEs were compared between the two arms. After PSM, 85 patients were enrolled in the arm with CTV, 42 patients were enrolled in the arm without CTV. The dose prescription was 95% PTV/PGTV 40-66Gy/20-33fractions/4-7weeks. The incidence of local-regional relapse was 35.7 % in the arm without CTV and 41.9% in the arm with CTV (P = 0.393). The most common site of metastasis was the regional lymph node which accounted for 80% of the arm without CTV and 60% of the arm with CTV (P = 0.005). The median LRFS was 21 months versus 20 months (p = 0.531) and the median OS was 28.0 months versus 39.38 months (p = 0.062) in the arm without CTV and the arm with CTV, respectively. The incidence of grade 3 or higher esophagitis was 21.4% in the arm without CTV, significantly lower than the rate of 32.6 % in the arm with CTV (P = 0.046). The incidence of treatment-related pneumonitis in the arm without CTV group was significantly lower than that in the arm with CTV (7.2% vs 24.4%, p = 0.019). No significant difference was observed in the grade 3 or higher hematologic toxicities between the arm without CTV and the arm with CTV (21.4% vs 18.6%, p = 0.705). It is feasible to omit CTV to reduce treatment-related toxicities without compromising the LRFS and OS for LAEC treated with TRT. However, it should be noted that CTV omission could deliver a higher rate of regional lymph node relapse. More prospective studies are needed to explore the feasibility of CTV omission. [ABSTRACT FROM AUTHOR]

Lung cancer can develop both osteolytic and osteoblastic metastases to bone. However, the difference in the efficacy of radiotherapy in these two types of lesions is unknown. This study aimed to compare the difference between osteolytic vs osteoblastic metastatic lesions on radiotherapy efficacy in lung cancer. A retrospective analysis was conducted for lung cancer patients who received bone radiotherapy from November 2019 to November 2023. The patients were divided into two groups: the osteoblastic group and the osteolytic group. The pain response was obtained 2 weeks after radiotherapy. Similarly, the radiologic response was accessed 3 months after radiotherapy according to the MD-Anderson criteria (Response categories are divided into complete response (CR), partial response (PR), stable disease (SD), progressive disease (PD), PR and CR are considered to be radiologic response). Pain response was defined as a decrease in worst pain NRS score of at least 2 points. And the overall survival (OS) and bone progression-free survival (bPFS) rates were analyzed between the two groups. A total of 94 lung cancer patients including 59 patients with osteolytic metastases and 35 patients with osteoblastic metastases were retrospectively recruited. 84.9% of the patients were diagnosed with adenocarcinoma. The prescribed dose was 20Gy to 60Gy in 4 to 13 fractions. Biological effective dose (BED) ranged from 28Gy to 96Gy. No difference was found between the two groups for BED (P = 0.692). Compared with the osteolytic group, a significantly higher objective pain response rate was observed in the osteoblastic group (64.9% vs 81.3%, P <0.001). Further analysis indicated that there was not any difference between the two groups for the radiologic response (P = 0.128). Moreover, the osteolytic group was observed longer bPFS than the osteoblastic group (P = 0.048). Conversely, there was a trend for longer OS in the osteoblastic group, but the result was not statistically significant (median OS: 46.88 months for the osteolytic group vs 52.4 months for the osteoblastic group, P = 0.130). Pain control of osteoblastic lesions was better than that of osteolytic lesions after radiotherapy for lung cancer. Moreover, patients with osteoblastic lesions may probably have longer OS, but bPFS is inferior to that of patients with osteolytic lesions. More studies are needed to determine the radiosensitivity between osteoblastic lesions and osteolytic lesions. [ABSTRACT FROM AUTHOR]

Research describing the tapping mode dynamics of atomic force microscopy is presented. In particular power and harmonic balance techniques are investigated for identifying tip-sample interaction.

The problem of distributed-program reliability in various types of distributed computing systems was examined. This problem is computationally difficult for arbitrary distributed computing systems, even when it is limited to the class of star distributed computing systems. One solvable case for star distributed computing systems is presented, in which data files are distributed with respect to a consecutive property and a polynomial-time algorithm was developed for this case.

An alternative approach to fully automatic speckle-displacement measurement is described. Two speckle patterns of a specimen, one before and one after deformation, are captured by a CCD camera and registered by a frame grabber. Two series of small subimages are obtained by segmenting the two speckle patterns. The corresponding subimage pairs extracted from both series are analyzed pointwise. The interrogation of each subimage pair involves a two-step fast-Fourier transform. While the first-step fast-Fourier transform achieves a complex spectrum characterized by the local displacement information, the second-step one generates a signal peak in the second spectral domain that resolves the local displacement vector. A rough estimate of the displacement vector is achieved by detecting the maximum pixel of the discrete spectrum. A more accurate determination is attained by a subpixel-maximum determination through a biparabolic fitting near the signal peak. The u- and v-displacement fields are deduced by analyzing all subimage pairs. A large rigid-body displacement can be overcome by introducing an artificial rigid shift of the two speckle patterns toward each other before the numerical process. The technique retains all the advantages of optical speckle photography and provides an extended range of measurement. Dynamic incremental deformations can be inspected by registering more speckle patterns at many consecutive deformation stages by using a high-speed CCD camera. The system was applied successfully to the study of crack-tip deformation fields.

A fully automatic speckle metrology technique is developed. Two speckle patterns of a specimen, one before and one after the specimen deformation, are captured by a video camera. An equivalent double-exposure speckle pattern is obtained by superimposing the two digital images. The superimposed speckle pattern is then segmented into a series of small subimages. For each subimage a fast-Fourier transform is applied and a computer-generated Young's fringe pattern is obtained. The fringe pattern, which characterizes the local displacement vector, is analyzed by a second fast-Fourier transform. The local displacement vector is determined by a cardinal interpolation and a crest searching around a signal peak in the second spectral domain. An artificial rigid shift between the two images is introduced in the cases of extremely large or small displacements. From analysis of all subimage pairs of the whole superimposed speckle pattern a complete two-dimensional displacement field is deduced. Experimental results using laser as well as white-light speckle patterns are demonstrated.

Spin splitting of the two-dimentional electron gas (2DEG) in modulation-doped Al[sub 0.22]Ga[sub 0.78]N/GaN heterostructures has been studied by means of magnetotransport measurements at low temperatures and high magnetic fields. The spin splitting is observed in Shubnikov–de Haas oscillations at a magnetic field higher than 5.4 T and a temperature of 1.4 K. The effective g factor g[sup *] is enhanced due to the exchange interaction of the 2DEG at high densities. The ratio of the transverse effective g factor g[sub ⊥][sup *] and the longitudinal effective g factor g[sub ∥][sup *] is g[sub ⊥][sup *]/g[sub ∥][sup *]=2.6 indicating the large difference between g[sub ∥][sup *] and g[sub ⊥][sup *]. It is demonstrated that the anisotropy of the g[sup *] is due to the strong polarization-induced electric field at the heterointerface. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Large-area Au/Pt/n-[In.sub.0.2][Ga.sub.0.8]N Schottky contacts are prepared for photovoltaic devices and their current transport mechanisms with different background carrier concentrations are examined. The thermionic emission is a dominating current transport mechanism at the Pt/n-InGaN interface and Schottky diode fabricated using the low background carrier concentration sample has provided much better Schottky barrier characteristics.