The high speed imaging technique is an attractive tool to elucidate welding phenomena. In this paper, applications of this technique are reviewed in order to understand the power beam welding ...phenomenon. Monochromatic imaging technique, which can take pictures of plasma with any specific spectrum wavelength, is used to analyse state of the laser induced plasma and distribution of some species, such as ions and atoms of gases and metals. During electron beam welding, intermittent melting process and spiking phenomenon can be clearly recorded by a pinhole X-ray streak camera. The in situ X-ray transmission imaging system is useful to observe the dynamic keyhole and fluid flow behaviour, which cannot be directly observed by any other method. High speed observations of the solidification front clearly show the solidification cracking process. In the present paper, methods to analyse the solidification cracking using high speed imaging are also described.
ABSTRACT
Quaternary climatic changes in the Nile Basin and their effects on the evolution of African mammals and vegetation are poorly understood, particularly for the last 1 Ma. Pleistocene (~230 to ...<17 ka) alluvial sediments exposed along the middle stretches of the Atbara River in eastern Sudan are rich in fossil vertebrates and are ideal for paleoenvironmental reconstruction during this time interval. We performed petrographic, mineralogical and geochemical analyses on the middle Atbara paleosols to reconstruct the paleoclimate and paleolandscape. We describe Aridisols/Calcisols characterized by calcretes and containing gypsum and halite, and Vertisols with pedogenic slickensides and a relatively large amount of smectite. The paleosols indicate that the study area transitioned from an arid to semi‐arid climate during Marine Isotope Stage (MIS)7/6, to a more humid climate during MIS5, and then a return to more arid conditions during MIS2. The studied paleosols likely supported a range of grassland and wooded grassland savanna habitats. Our study confirms that the Atbara River Valley provided favorable living conditions for Pleistocene large mammal communities including Homo, potentially facilitating dispersals out of Africa through the Nile corridor.
In this paper, we investigate the sensitivity of the digital coherent receiver both theoretically and experimentally. The receiver sensitivity close to the shot-noise limit is demonstrated in the ...10-Gbit/s binary phase-shift keying system with the help of a low-noise optical preamplifier. We also introduce polarization diversity into our receiver. Maximal-ratio polarization combining in the digital domain makes the receiver sensitivity independent of the state of polarization of the incoming signal without power penalty.
Smad1, Smad5 and Smad9 (also known as Smad8) are activated by phosphorylation by bone morphogenetic protein (BMP)-bound type I receptor kinases. We examined the role of Smad1, Smad5, and Smad9 by ...creating constitutively active forms (Smad(DVD)). Transcriptional activity of Smad9(DVD) was lower than that of Smad1(DVD) or Smad5(DVD), even though all three Smad(DVD)s associated with Smad4 and bound to the target DNA. The linker region of Smad9 was sufficient to reduce transcriptional activity. Smad9 expression was increased by the activation of BMP signaling, similar to that of inhibitory Smads (I-Smads), and Smad9 reduced BMP activity. In contrast to I-Smads, however, Smad9 did not inhibit the type I receptor kinase and suppressed the constitutively active Smad1(DVD). Smad9 formed complexes with Smad1 and bound to DNA but suppressed the transcription of the target gene. Taken together, our findings suggest that Smad9 is a new type of transcriptional regulator in BMP signaling.
Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of cancer and the 5-year survival rate is only 5%. Several studies have suggested that cancer stem cells (CSCs) are thought to ...be involved in recurrence and metastasis and so it is essential to establish an approach targeting CSCs. Here we have demonstrated that cyclic guanosine monophosphate (cGMP) suppressed CD44 expression and the properties of CSCs in PDAC. Microarray analysis suggested that cGMP inhibited Forkhead box O3 (FOXO3), which is known as a tumor suppressor. Surprisingly, our data demonstrated that FOXO3 is essential for CD44 expression and the properties of CSCs. Our data also indicated that patients with high FOXO3 activation signatures had poor prognoses. This evidence suggested that cGMP induction and FOXO3 inhibition could be ideal candidates for pancreatic CSC.
Background
Japan Clinical Oncology Group (JCOG) 0212 (ClinicalTrials.gov NCT00190541) was a non‐inferiority phase III trial of patients with clinical stage II–III rectal cancer without lateral pelvic ...lymph node enlargement. The trial compared mesorectal excision (ME) with ME and lateral lymph node dissection (LLND), with a primary endpoint of recurrence‐free survival (RFS). The planned primary analysis at 5 years failed to confirm the non‐inferiority of ME alone compared with ME and LLND. The present study aimed to compare ME alone and ME with LLND using long‐term follow‐up data from JCOG0212.
Methods
Patients with clinical stage II–III rectal cancer below the peritoneal reflection and no lateral pelvic lymph node enlargement were included in this study. After surgeons confirmed R0 resection by ME, patients were randomized to receive ME alone or ME with LLND. The primary endpoint was RFS.
Results
A total of 701 patients from 33 institutions were assigned to ME with LLND (351) or ME alone (350) between June 2003 and August 2010. The 7‐year RFS rate was 71.1 per cent for ME with LLND and 70·7 per cent for ME alone (hazard ratio (HR) 1·09, 95 per cent c.i. 0·84 to 1·42; non‐inferiority P = 0·064). Subgroup analysis showed improved RFS among patients with clinical stage III disease who underwent ME with LLND compared with ME alone (HR 1·49, 1·02 to 2·17).
Conclusion
Long‐term follow‐up data did not support the non‐inferiority of ME alone compared with ME and LLND. ME with LLND is recommended for patients with clinical stage III disease, whereas LLND could be omitted in those with clinical stage II tumours.
Antecedentes
El JCOG0212 (ClinicalTrials.gov: NCT00190541) fue un ensayo fase III de no inferioridad en pacientes con cáncer de recto en estadio clínico II/III sin ganglios linfáticos aumentados de tamaño en la pared pélvica lateral. El ensayo comparó la escisión del mesorrecto (mesorectal excision, ME) con la ME con disección de los ganglios linfáticos laterales (lateral lymph node dissection, LLND), siendo el criterio de valoración principal la supervivencia libre de recidiva (recurrence free survival, RFS). El análisis primario planificado a los 5 años de seguimiento no pudo confirmar la no inferioridad de la ME frente a la ME con LLND. Este estudio tuvo como objetivo comparar la ME como procedimiento único y la ME con LLND utilizando datos de seguimiento a largo plazo del ensayo JCOG0212.
Métodos
En este estudio se incluyeron pacientes con cáncer de recto en estadio clínico II/III por debajo de la reflexión peritoneal sin ganglios linfáticos aumentados de tamaño en la pared pélvica lateral. Después de que los cirujanos confirmaran la resección R0 mediante la ME, los pacientes fueron asignados al azar al brazo de ME sola o al brazo de ME con LLND. El criterio de valoración principal fue la supervivencia libre de recidiva (RFS).
Resultados
Un total de 701 pacientes de 33 instituciones fueron asignados al azar para ser tratados mediante una ME con LLND (n = 351) o EM sola (n = 350) entre junio de 2003 y agosto de 2010. Las tasas de RFS a 7 años fueron del 71,1% para ME con LLND y 70,7 % para ME sola (cociente de riesgos instantáneos, hazard ratio, HR: 1,09 (i.c. del 95% 0,84‐1,42), no inferioridad P = 0,064)). El análisis de subgrupos mostró una mejor RFS entre los pacientes en estadio clínico III que se sometieron a ME con LLND en comparación con ME sola (HR: 1,49 (i.c. del 95%: 1,02‐2,17)).
Conclusión
Los datos de seguimiento a largo plazo no justificaron la no inferioridad de la ME en comparación con la ME con LLND. Se recomienda la ME con LLND para pacientes en estadio clínico III, mientras que LLND podría omitirse para pacientes en estadio clínico II.
Long‐term follow‐up data did not support the non‐inferiority of mesorectal excision (ME) alone compared with ME and lateral lymph node dissection (LLND). ME with LLND is recommended for clinical stage III disease, whereas LLND could be omitted for patients with clinical stage II tumours.
Selective lateral lymph node dissection supported
Background
Pelvic exenteration for locally recurrent rectal cancer (LRRC) is associated with variable outcomes, with the majority of data from single‐centre series. This study analysed data from an ...international collaboration to determine robust parameters that could inform clinical decision‐making.
Methods
Anonymized data on patients who had pelvic exenteration for LRRC between 2004 and 2014 were accrued from 27 specialist centres. The primary endpoint was survival. The impact of resection margin, bone resection, node status and use of neoadjuvant therapy (before exenteration) was assessed.
Results
Of 1184 patients, 614 (51·9 per cent) had neoadjuvant therapy. A clear resection margin (R0 resection) was achieved in 55·4 per cent of operations. Twenty‐one patients (1·8 per cent) died within 30 days and 380 (32·1 per cent) experienced a major complication. Median overall survival was 36 months following R0 resection, 27 months after R1 resection and 16 months following R2 resection (P < 0·001). Patients who received neoadjuvant therapy had more postoperative complications (unadjusted odds ratio (OR) 1·53), readmissions (unadjusted OR 2·33) and radiological reinterventions (unadjusted OR 2·12). Three‐year survival rates were 48·1 per cent, 33·9 per cent and 15 per cent respectively. Bone resection (when required) was associated with a longer median survival (36 versus 29 months; P < 0·001). Node‐positive patients had a shorter median overall survival than those with node‐negative disease (22 versus 29 months respectively). Multivariable analysis identified margin status and bone resection as significant determinants of long‐term survival.
Conclusion
Negative margins and bone resection (where needed) were identified as the most important factors influencing overall survival. Neoadjuvant therapy before pelvic exenteration did not affect survival, but was associated with higher rates of readmission, complications and radiological reintervention.
Complete resection is key
The mechanism of type IV failure has been investigated by using a conventional 9Cr ferritic heat-resistant steel Gr.92. In order to clarify the main cause of type IV failure, different heat ...treatments were performed on the base metal in order to change the prior austenite grain (PAG) size and precipitate distribution after applying the heat-affected zone (HAZ) simulated thermal cycle at the peak temperature of around
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(
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HAZ thermal cycle) and postweld heat treatment (PWHT). The microstructural evolution during the
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HAZ thermal cycle and PWHT was investigated by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), electron probe microanalysis (EPMA), and transmission electron microscope (TEM). It was found that M
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carbides were scarcely precipitated at the newly formed fine PAG, block, and lath boundaries in
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HAZ-simulated Gr.92, because the carbide forming elements such as Cr and C were segregated at the former PAG and block boundaries of the base metal. On the other hand, if all the boundaries were covered by sufficient M
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carbides by homogenization of the alloying elements prior to applying the HAZ thermal cycle, the creep strength was much improved even if the fine PAG was formed. From these results, it is concluded that fine-grained microstructure cannot account for the occurrence of type IV failure, and it only has a small effect during long-term creep. The most important factor is the precipitate formation behavior at various boundaries. Without sufficient boundary strengthening by precipitates, the microstructure of
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HAZ undergoes severe changes even during PWHT and causes premature failure during creep.
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