[Clinical Outcomes and Prognostic Factors of Allogeneic Hematopoietic Stem Cell Transplantation in the Treatment of Refractory/Relapsed Acute Myeloid Leukemia].

OBJECTIVE: To investigate the clinical outcomes and prognostic factors of refractory/relapsed acute myeloid leukemia (AML) patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of 80 refractory/relapsed AML patients who received allo-HSCT from December 2013 to June 2020 were retrospectively analyzed, including the overall survival (OS) rate, disease-free survival (DFS) rate, relapse rate, incidence of transplant-related mortality (TRM), and the related risk factors were explored. RESULTS: Hematopoietic reconstitution was obtained in all 80 patients after transplantation, the 3-year OS and DFS rates were (48.8±6.3)% and (40.8±6.7)%, respectively. The 3-year cumulative incidence of relapse and TRM were 33.8% (95%CI: 0.254-0.449) and 15.0%(95%CI: 0.114-0.198), respectively. Univariate analysis showed that non-remission (NR) status before transplantation, DNMT3A R882 mutations and grade II-IV acute graft-versus-host disease (aGVHD) had negative effects on OS and DFS. Multivariate analysis indicated that the DNMT3A R882 mutations and grade II-IV aGVHD were independent risk factors for OS (HR=0.253, 95%CI: 0.092-0.695, P=0.008; HR=5.681, 95%CI: 2.101-15.361, P=0.001) and DFS (HR=0.200, 95%CI: 0.071-0.569, P=0.003; HR=7.117, 95%CI: 2.556-19.818, P<0.001). The 3-year cumulative incidence of relapse was 71.4%(95%CI: 0.610-0.836) in genetic high-risk group, which was higher than 23.3%(95%CI: 0.147-0.370) in intermediate-risk group and 23.5%(95%CI: 0.127-0.437) in favorable-risk group (P=0.006). CONCLUSION: Allo-HSCT is an effective and safe choice for refractory/relapsed AML patients. DNMT3A R882 mutations and grade II-IV aGVHD are negative prognostic factors of allo-HSCT for refractory/relapsed AML patients.

Adsorption of nitrosamines by mesoporous zeolite.

On the basis of a study of the adsorption of zeolite and mesoporous silica, we attempted to create a hierarchical structure in the new nitrosamines trapper. Thus, mesoporous HZSM-5 zeolite was fabricated through impregnating a structure-directing agent into the as-synthesized MCM-41 followed by dry-gel conversion to transform amorphous silica to zeolite crystal. The texture of mesoporous ZSM-5 was tailored by adjusting the Si/Al ratio in the MCM-41 source and the thermal treatment time. The resulting samples were characterized by N(2) adsorption to evaluate their textural properties. One volatile nitrosamine, N-nitrosopyrrolidine (NPYR), was used as probe molecule in instantaneous adsorption to survey the function of the resulting composites. Adsorptions of N'-nitrosonornicotine (NNN) in dichloromethane solution and tobacco-specific nitrosamines (TSNA) in tobacco-extract solution were also utilized for the same purpose. As expected, mesoporous zeolite exhibits a good adsorption capacity in laboratory tests, superior to either microporous zeolite or mesoporous silica, providing a valuable candidate for controlling nitrosamines in the environment.

Capturing nitrosamines in tobacco-extract solution by hydrophobic mesoporous silica.

Adsorption of tobacco-specific nitrosamines (TSNA) by the functionalized MCM-48 mesoporous silica in tobacco-extract solution was studied using batch experiments, in order to explore the new strategy enhancing the efficiency of molecular sieve in the solution with complex composition. The techniques of XRD, N(2) adsorption-desorption at 77K, (29)Si MAS NMR, (27)Al MAS NMR and TG-DSC together with FTIR were used to inspect the mesoporous adsorbents. The hydrophobic character of adsorbent is crucial for the adsorption of TSNA in aqueous solution, and the organic 3-chloropropyltriethoxysilane (CPTES) was employed to functionalize the ordered porous silica through direct co-condensation and post-synthesis grafting methods. Besides, aluminum is also incorporated into the framework of MCM-48 to enhance the adsorption capability of nitrosamines. As the result, about 70% of TSNA can be removed by the chloropropyl-modified Al-containing mesoporous silica, obviously exceeded that by activated carbon, offering the new efficient adsorbents for environment protection.

Capturing 1,3-butadiene by the highly ordered Al-containing SBA-15.

This investigation examined the instantaneous adsorption of 1,3-butadiene by aluminum-modified mesoporous silica SBA-15 at ambient temperature. To efficiently trap the 1,3-butadiene pollutant in environment, alumina was incorporated in SBA-15 through various pathways such as one-pot synthesis, solid state grinding and impregnation, and the property-function relation of resulting composites were characterized with XRD, N(2) adsorption-desorption, FTIR and NH(3)-TPD techniques. Adsorption of N-nitrosopyrrolidine (NPYR) was employed for the first time to reveal the difference between the mesoporous silica with the same Al-content but prepared with different methods, providing a potential method for the delicate characterization. Modification with alumina significantly increased the capability of SBA-15 to adsorb 1,3-butadiene, and the one-pot synthesized sample exhibited a higher activity than the post-modified samples, resulting from the formation of Brønsted acidic sites and reservation of silianol groups on SBA-15 host.

Functional mesoporous material derived from 3D net-linked SBA-15.

A novel, versatile functional mesoporous material with the structure of SBA-15 but a specific 3D net-linked morphology has been prepared by using a facile method. This material has been assessed for its ability to reduce the level of nitrosamines in tobacco smoke so that the actual effect of this material in the reduction of carcinogenic environmental pollutants in a complex chemical system can be verified. By adjusting the force field during the hydrolysis and condensation processes of tetramethyl orthosilicate (TMOS) in an aqueous reaction system, the SBA-15 silica, which has a special morphology in that it is long and fiberlike from a microscopic view but large and block-like from a macroscopic angle, has been successfully synthesized. Moreover, the synthetic product is no longer a powder but a block because of its specific 3D net-linked morphology, which enables the material not only to trap particles in smoke but also to potentially be applied as a device. To strengthen the adsorptive capability of this porous material, a dry-impregnation procedure was applied in which zirconia was coated on the silica wall without changing the morphology. As expected, this functional material shows a high activity in the adsorption of N'-nitrosonornicotine (NNN), a bulky tobacco-specific nitrosamine, in solution and of N-nitrosopyrrolidine (NPYR), a volatile nitrosamine, in the gas stream. Furthermore, this 3D net-linked SBA-15 material can efficiently decrease the amount of nitrosamines and total number of particles in mainstream smoke when it is tested as an additive in the filter of a cigarette, thus providing powerful protection for the environment and public health.

New attempt at directly generating superbasicity on mesoporous silica SBA-15.

Direct generation of superbasicity on mesoporous silica SBA-15 was realized by tailoring the host-guest interaction, and calcium species were selected as the guest in modifying SBA-15. The results show that calcium species could be homogeneously distributed on the surface of SBA-15. Because of the host-guest interaction, the decomposition of the supported calcium nitrate was apparently easier than the bulk one. Surprisingly, the calcium nitrates modified SBA-15 (CaNS) samples exhibited superbasicity with good preservation of the mesostructure after activation, differing from the potassium nitrate loaded SBA-15 samples that displayed weak basicity with collapsed mesostructure. The present superbasic CaNS materials also possess good water resistance and high surface areas, up to 429 m(2) g(-1), which is promising for their potential applications in adsorption and catalysis. Further investigation concerning the roles played by the guest in basicity formation on SBA-15 was conducted. The samples modified by Group 2 metal nitrates showed strong basicity with base strength (H-) of 22.5-27.0 and good preservation of mesostructure. In contrast, loading Group 1 metal nitrates on SBA-15 produced samples with weak basicity ( H-=9.3-15.0) and collapsed mesostructure after activation. Such differences can be related to the interaction between the resulting metal oxide and the silica support, as well as the mobility of the cations in the metal oxide.