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91.
Nina V. Vlasenko Yuri N. Kochkin German M. Telbiz Oleksiy V. Shvets Peter E. Strizhak 《RSC advances》2019,9(62):35957
The nature of active acid sites of zeolite H-BEA with different Si/Al ratios (15–407) in liquid phase etherification of isobutylene with ethanol in a continuous flow reactor in the temperature range 80–180 °C has been explored. We describe and discuss data concerning the strength and concentration of acid sites of H-BEA obtained by techniques of stepwise (quasi-equilibrium) thermal desorption of ammonia, X-ray diffraction, low-temperature adsorption of nitrogen, FTIR spectroscopy of adsorbed pyridine and solid-state 27Al MAS NMR. The average values of the adsorption energy of NH3 on H-BEA were experimentally determined as 63.7; 91.3 and 121.9 mmol g−1 (weak, medium, and strong, respectively). In agreement with this, a correlation between the rate of ethyl-tert-butyl ether synthesis and the concentration of weak acid sites (ENH3 = 61.6–68.9 kJ mol−1) has been observed. It was concluded that the active sites of H-BEA for this reaction are Brønsted hydroxyls representing internal silanol groups associated with octahedrally coordinated aluminum in the second coordination sphere.The active sites of H-BEA zeolites for ETBE synthesis are the weak Brønsted acid sites representing internal silanol groups. 相似文献
92.
Tomoro Hishiki Hiroshi Horie Yasuyuki Higashimoto Katsumi Yotsumoto Shugo Komatsu Yuri Okimoto Harumi Kakuda Yuichi Taneyama Takeshi Saito Keita Terui Tetsuya Mitsunaga Mitsuyuki Nakata Hidemasa Ochiai Moeko Hino Kumiko Ando Hideo Yoshida Jun Iwai 《Pediatric surgery international》2014,30(9):919-926
Purpose
In the recent years in Japan, an increasing number of patients with neuroblastoma (NB) are being treated by the “delayed local treatment (DL)” policy, undergoing surgery after the completion of high-dose chemotherapy with hematopoietic stem cell rescue (HDC). We reviewed the histopathological findings of second-look operations, including those of patients treated with DL.Patients
From 1998 to 2013, 26 patients with high-risk NB underwent radical operation following chemotherapy. Surgery was performed after induction chemotherapy in 17 cases (standard; STD), whereas 9 cases completed induction chemotherapy and HDC before undergoing tumor resection (DL). The amount of necrosis and the degree of differentiation within the post-treatment tumor were assessed.Results
Eighty-eight percent of the tumors showed necrosis in more than 1/3 of the specimen. Two DL cases showed complete disappearance of viable tumor cells. Amount of necrosis did not affect the prognosis of the patient. Tumors with immature, poorly differentiated phenotypes showed an extremely aggressive thereafter. Though not statistically proven, 123I-MIBG (metaiodobenzylguanidine) uptake may be correlated with the amount of viable cells remaining within the tumor, but not with the degree of differentiation.Conclusions
Our results support the previous reports advocating that tumors that sustain unfavorable histology after chemotherapy behave aggressively thereafter. 相似文献93.
Rabea Alhosh Yuri Genyk Sophoclis Alexopoulos Daniel Thomas Shengmei Zhou George Yanni Nanda Kerkar 《Pediatric transplantation》2014,18(5):E157-E160
HPS is a significant complication of portal hypertension in children with chronic liver disease and is an established indication for LT. It is characterized clinically by the triad of pulmonary vascular dilatation causing hypoxemia in the setting of advanced liver disease. NRH, a cause of non‐cirrhotic portal hypertension, is characterized by diffuse benign transformation of the hepatic parenchyma into small regenerative nodules with minimal or no fibrosis. Development of NRH and HPS in pediatric LT recipients has not been reported, although occasional cases have been reported in adult LT recipients. In this report, we discuss a case of a three‐yr‐old male who developed HPS, two yr after LT. Pulmonary and cardiac causes for hypoxemia were ruled out by appropriate investigations including a chest X ray, echocardiogram, cardiac catheterization, and a CT angiographic study. The diagnosis of HPS was confirmed via bubble echocardiogram that demonstrated intrapulmonary shunting. Open liver biopsy revealed marked NRH. The patient underwent liver retransplantation that resulted in complete reversal of his pulmonary symptoms and normal oxygen saturations within three months after LT. 相似文献
94.
95.
Yuri Geinisman Leyla Detoledo-Morrell Frank Morrell Inna S. Persina Michael A. Beatty 《The Journal of comparative neurology》1996,368(3):413-423
Synapses in the middle molecular layer of the rat dentate gyrus were analyzed by electron microscopy during the maintenance phase of long-term potentiation (LTP). LTP was induced by high-frequency stimulation of the medial perforant path carried out on each of 4 consecutive days. The dentate gyrus was examined electron microscopically 13 days following the fourth stimulation. At this time point, synaptic responses were still significantly enhanced relative to baseline, although the extent of their potentiation was lower than 1 hour after the last high-frequency stimulation. Stimulated, but not potentiated, rats served as controls. Using the stereological double disector method, estimates of the number of different morphological types of synapses per postsynaptic neuron were obtained. The number of asymmetrical axodendritic synapses increased (by 28%) during LTP maintenance, whereas the number of other synaptic types was not significantly altered. Our previous work demonstrated that the induction of LTP is followed by a selective increase in the number of axospinous perforated synapses with multiple, completely partitioned, transmission zones. Thus, the induction and maintenance phases of LTP are characterized by different structural synaptic alterations. These alterations may be related to each other as indicated by another finding of the present study regarding the existence of perforated synapses that appear to be transitional between axospinous and axodendritic junctions. This suggests a model of structural synaptic plasticity associated with LTP in which some axospinous perforated synapses increase in numbers shortly after the induction of LTP and are then converted into axodendritic ones during LTP maintenance. © 1996 Wiley-Liss, Inc. 相似文献
96.
Elina Bondareva Yuri Dekhtyar Vladislavs Gorosko Hermanis Sorokins Alexander Rapoport 《Materials》2022,15(1)
The ability of cells to adhere to substrates is an important factor for the effectiveness of biotechnologies and bioimplants. This research demonstrates that the statistical distribution of the sizes of the cells (Saccharomyces cerevisiae) attached to the substrate surface correlates with the statistical distribution of electrical potential on the substrate’s surface. Hypothetically, this behavior should be taken into consideration during the processing of surfaces when cell adhesion based on cell size is required. 相似文献
97.
Patrizia Lamberti Monica La Mura Vincenzo Tucci Erick Nkyalu Ali Khan Marina Yakovleva Nadzeya Valynets Alesia Paddubskaya Aleksandr Saushin Viatcheslav Vanyukov Marian Baah Andrzej Urbanowicz Yuri Svirko Polina Kuzhir 《Materials》2022,15(3)
We report the performance of a graphene-enhanced THz grating fabricated by depositing a gold layer on the femtosecond micromachined SiO2 substrate. The morphology of the gold plated patterned substrate was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while the quality of the chemical vapor deposition (CVD) graphene was evaluated by Raman spectroscopy. The electromagnetic (EM) response of the metasurface comprising the graphene sheet and the gold plated substrate was studied by THz time domain spectroscopy in the 100 GHz–1 THz frequency range. We employed the finite elements method (FEM) to model the metasurface EM response by adjusting the ac conductivity of the gold layer covering the patterned SiO2 substrate to reproduce the measured transmission/reflection spectra. The results of the numerical simulation reveal the impact of the imperfectness of the gold layer on the performance of the THz metasurface. The experimental results are well described in terms of the Drude–Smith model of metal conductivity that takes into account the anisotropic scattering of the carriers in thin metal films. 相似文献
98.
This study suggests an intensive green roof as part of a sustainable and hazard-resistant conceptual design for the retrofitting of old buildings in Israel. The roof is suggested to be built with waste-based materials. A five-story reinforced concrete residential building was retrofitted with: Case 1: concrete wall strengthening (CWS)-conventional concrete + conventional green roof; Case 2: CWS-waste-included concrete + waste-based green roof; Case 3: seismic isolation columns (SIC)-conventional concrete + conventional green roof; and Case 4: SIC-waste-included concrete + waste-based green roof. Palekastro, Nuweiba, Tabas, and Erzincan ground motions were used for a structural dynamic time-history analysis of the retrofitted buildings. Life cycle assessments of cases 1–4 were performed using ReCiPe 2016 midpoint and endpoint evaluations. A two-stage analysis of variance (ANOVA) was used to analyze the ReCiPe endpoint results. According to the seismic results, Case 3 and Case 4 were much more preferable to Case 1 and Case 2, whereas according to the environmental evaluations, Case 4 was the most preferable to the other cases. 相似文献
99.
100.
Falzone Yuri Matteo Domi Teuta Agosta Federica Pozzi Laura Schito Paride Fazio Raffaella Del Carro Ubaldo Barbieri Alessandra Comola Mauro Leocani Letizia Comi Giancarlo Carrera Paola Filippi Massimo Quattrini Angelo Riva Nilo 《Journal of neurology》2020,267(8):2272-2280
Journal of Neurology - To investigate the prognostic role and the major determinants of serum phosphorylated neurofilament heavy -chain (pNfH) concentration across a large cohort of motor neuron... 相似文献