Short-wavelength infrared photodetector on Si employing strain-induced growth of very tall InAs nanowire arrays

One-dimensional crystal growth enables the epitaxial integration of III-V compound semiconductors onto a silicon (Si) substrate despite significant lattice mismatch. Here, we report a short-wavelength infrared (SWIR, 1.4-3 mu m) photodetector that employs InAs nanowires (NWs) grown on Si. The wafer-scale epitaxial InAs NWs form on the Si substrate without a metal catalyst or pattern assistance; thus, the growth is free of metal-atom-induced contaminations, and is also cost-effective. InAs NW arrays with an average height of 50 mu m provide excellent anti-reflective and light trapping properties over a wide wavelength range. The photodetector exhibits a peak detectivity of 1.9 x 10(8) cm.Hz(1/2)/W for the SWIR band at 77 K and operates at temperatures as high as 220 K. The SWIR photodetector on the Si platform demonstrated in this study is promising for future low-cost optical sensors and Si photonicsopen0

Validation of tissue microarray technology in squamous cell carcinoma of the esophagus

Tissue microarray (TMA) technology has been developed to facilitate high-throughput immunohistochemical and in situ hybridization analysis of tissues by inserting small tissue biopsy cores into a single paraffin block. Several studies have revealed novel prognostic biomarkers in esophageal squamous cell carcinoma (ESCC) by means of TMA technology, although this technique has not yet been validated for these tumors. Because representativeness of the donor tissue cores may be a disadvantage compared to full sections, the aim of this study was to assess if TMA technology provides representative immunohistochemical results in ESCC. A TMA was constructed containing triplicate cores of 108 formalin-fixed, paraffin-embedded squamous cell carcinomas of the esophagus. The agreement in the differentiation grade and immunohistochemical staining scores of CK5/6, CK14, E-cadherin, Ki-67, and p53 between TMA cores and a subset of 64 randomly selected donor paraffin blocks was determined using kappa statistics. The concurrence between TMA cores and donor blocks was moderate for Ki-67 (κ = 0.42) and E-cadherin (κ = 0.47), substantial for differentiation grade (κ = 0.65) and CK14 (κ = 0.71), and almost perfect for p53 (κ = 0.86) and CK5/6 (κ = 0.93). TMA technology appears to be a valid method for immunohistochemical analysis of molecular markers in ESCC provided that the staining pattern in the tumor is homogeneous

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Estudo comparativo dos meios de contraste baritado e iodado-iônico e não-iônico no trato respiratório de ratos Comparative study of barium and iodine agents - ionic and nonionic on the respiratory tract of the rats

OBJETIVO: Durante estudos radiológicos pode ocorrer a passagem do meio de contraste para a árvore traqueo-brônquica, determinando reações adversas e até fatais. O objetivo deste estudo é conhecer as alterações desencadeadas no trato respiratório pela presença do meio de contraste. MÉTODOS: Utilizaram-se 91 ratos divididos, aleatoriamente, em 4 grupos. Um grupo de controle não manipulado com 7 animais e os demais grupos com 21 ratos. O grupo controle manipulado recebeu solução fisiológica e os grupos de experimento: bário, iodo ônico e iodo não iônico conforme o grupo a que pertenciam. Sob anestesia e visibilização direta da traquéia, injetou-se 0,75 ml/kg (0,25 ml) do meio de contraste de acordo com o grupo ao qual pertencesse o animal. Realizaram-se as aferições com 1 hora, 1 dia e 1 semana. Os ratos foram sorteados para a autanásia nos três tempos estudados. Fez-se documentação radiográfica seguida da ressecção dos pulmões e exame histo-patológico. RESULTADOS: Na primeira hora, no grupo que recebeu bário, os campos médios e o superior direito ficaram acometidos. Nos grupos que receberam iodo iônico e iodo não iônico, todo o pulmão direito mostrava-se opacificado. Nas avaliações de uma dia e 1 semana os grupos que receberam iodo estavam normais enquanto que o grupo que recebeu bário mostrava comprometimento dos campos médios. No estudo histo-patológico observou-se, no grupo que recebeu bário, na avaliação de uma semana, grande quantidade de macrófagos intra-alveolares, perivasculares e peribrônquicos. CONCLUSÃO: Os contrastes iodados iônico e não iônico levam a alterações passageiras enquanto que o bário promove reação inflamatória crônica com manutenção da tradução radiográfica, no rato.<br>PURPOSE: During roadiologic studies, passage of the contrast medium to the tracheobronchial tree may occur, causibng adverse or even fatal reactions. The objective of the present study was to determine the changes in the respiratory tract triggered by the presence of contrast medium. METHODS: Ninety-one rats were divided at random into 5 groups, i.e., an intact control group of 7 animals and 4 groups of 21 rats each. The manipulated control group received physiological saline and the experimental groups respectively received barium, ionic iodine and non-ionic iodine. Under anesthesia and direct visualization of the trachea, 0.75 ml/kg (0.25 ml) of the contrast medium was injected into the animals of each group. The effects of the procedure were determined after 1 hour, 1 day and 1 week, with the animals being sacrificed at each time point by drawing lots. Radiographic documentation was obtained, followed by resection and histopathologic examination of the lungs. RESULTS: After 1 hour, the middle fields and the right upper field were involved in the group injected with barium. In the groups injected with ionic iodine and non-ionic iodine, the entire right lung was found to be opacified. After 1 day and 1 week, the groups injected with iodine were normal, whereas the group injected with barium showed involvement of the middle fields. After 1 week, histopathologic examination revealed that the group injected with barium exhibited large amounts of intra-alveolar, perivascular and peribronchial macrophages CONCLUSION: The ionic and non-ionic iodine contrast media led to temporary changes, whereas barium promoted a chronic inflammatory reaction with maintenance of radiographic translation