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Microstructured reactors offer fast chemical engineering transfer and precise microfluidic control, enabling the determination of reactions' kinetic parameters. This review examines recent advancements in measuring microreaction kinetics. It explores kinetic modeling, reaction mechanisms, and intrinsic kinetic equations pertaining to two types of microreaction: esterification and transesterification reactions involving acids, bases, or biocatalysts. The utilization of a micro packed-bed reactor successfully achieves a harmonious combination of the micro-dispersion state and the reaction kinetic characteristics. Additionally, this review presents micro-process simulation software and explores the advanced integration of microreactors with spectroscopic analyses for reaction monitoring and data acquisition. Furthermore, it elaborates on the control principles of the micro platform. The superiority of online measurement, automation, and the digitalization of the microreaction process for kinetic measurements is highlighted, showcasing the vast prospects of artificial intelligence applications.
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The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30-150â nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.
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In the title compound, C(14)H(12)ClNO, the planes of the two aromatic rings form a dihedral angle of 4.16â (1)°. The mol-ecule is essentially planar with an r.m.s. deviation for all non-H atoms of 0.0372â Å.
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The title compound, C(8)H(6)N(2)O(2)·2H(2)O, crystallized as a zwitterion with the carboxyl group deprotonated and the imidazole group protonated. The dihedral angle between the benzimidazole ring and the pendant -CO(2) group is 0.62â (2)°. In the crystal, mol-ecules are linked into a three-dimensional network by N-Hâ¯O and O-Hâ¯O hydrogen bonds.
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In the title compound, [Ni(C(9)H(4)O(6))(H(2)O)(3)](n), the Ni(II) ion has a distorted NiO(5) square-pyramidal geometry, the maximum deviation from the least-squares plane formed by the basal atoms being 0.9351â (13)â Å. The basal plane is formed by two O atoms from carboxyl-ate residues of the 5-carb-oxy-benzene-1,3-dicarboxyl-ate ligand and by two O atoms from water mol-ecules. The O atom of the third water mol-ecule is axially positioned, 1.7890â (19)â Å perpendicular to the basal plane. The 5-carb-oxy-benzene-1,3-dicarboxyl-ate ligand bridges the metal atoms, forming a polymeric chain along the b axis. O-Hâ¯O hydrogen bonds between the water mol-ecules and carboxyl-ate groups stabilize the crystal structure.
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Removing Co(II) from wastewater is urgent due to the threat to the environment and human health. In the work, the nanocomposite of graphene oxide-modified palygorskite (mPal-GO) is synthesized by cross-linking one-dimensional palygorskite (Pal) with two-dimensional material graphene oxide (GO), and used to remove Co(II) from wastewater. Its structure is characterized by Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area measurement. The parameters, such as mass ratio (GO:mPal), temperature, pH, and contact time, are carefully investigated. The results indicate that pseudo-second-order equation and Langmuir isotherm model are the best fitting one in the adsorption process of Co(II) onto mPal-GO. The maximum adsorption capacity achieves 16.9 mg/g at pH = 6.0 and T = 298 K according to the Langmuir model analysis. Furthermore, mPal-GO can be reused more than 5 times with a slight decrease according to the adsorption-desorption cycle experiments. Finally, mPal-GO with the low-cost and easy separation is a promising candidate for removing of Co(II) from wastewater.
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Grafite , Nanocompostos , Poluentes Químicos da Água , Adsorção , Humanos , Cinética , Compostos de Magnésio , Compostos de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
A novel kinetic spectrophotometric method is described for the determination of rutin. The method is based on the inhibitory effect of rutin on the oxidation reaction of amaranth by potassium periodate in acidic media at 100 degrees C. The linear range for the determination of rutin is 0.02 - 0.50 microg/ml, and the detection limit is 0.014 microg/ml. The method has been successfully applied to the determination of rutin in medicine of rutin tablet and traditional Chinese medicine.
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Corante Amaranto/química , Ácido Periódico/química , Compostos de Potássio/química , Rutina/análise , Cinética , Oxirredução , Padrões de Referência , Espectrofotometria Atômica , Espectrofotometria Ultravioleta , Ácidos Sulfúricos/químicaRESUMO
OBJECTIVE: To investigate miR-20a expression in human glioma and normal brain tissues and its effect on the proliferation of glioma cells in vitro. METHODS: The expression of miR-20a was detected in human normal brain tissues and glioma tissues by real-time RT-PCR. miR-20a mimics were synthesized and transfected into U251 cells via liposome, and the cell proliferation were detected using MTT assay and flow cytometry. RESULTS: The glioma tissues showed significantly up-regulated expression of miR-20a compared with normal brain tissues (P=0.035). The expression level of miR-20a was higher in high-grade than in low-grade gliomas. miR-20a mimics significantly enhanced the proliferation of U251 cells and the percentage of S-phase cells. CONCLUSION: miR-20a shows potent effect in promoting the growth of glioma cells, suggesting its important role in the pathogenesis of human glioma.
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Neoplasias Encefálicas/metabolismo , Proliferação de Células , Glioma/metabolismo , MicroRNAs/metabolismo , Adulto , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Feminino , Glioma/genética , Glioma/patologia , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Adulto JovemRESUMO
PURPOSE: High-mobility group box 1 (HMGB1) has been implicated in a variety of biologically important processes, including transcription, DNA repair, V(D)J recombination, differentiation, development, and extracellular signaling. The increased expression of HMGB1 has been described in colorectal cancer (CRC). However, there is no report about the correlation of HMGB1 with clinicopathologic features, including the survival of patients with CRC. METHODS: In present study, we investigated HMGB1 expression and its prognostic significance in CRC by performing immunohistochemical analysis, using a total of 192 paraffin-embedded archival CRC samples. Moreover, disruption of endogenous HMGB1 protein through a siRNA knockdown technique was performed to investigate the possible role of HMGB1 in the process of tumor invasion and metastasis. RESULTS: Overexpression of HMGB1 was shown in 55.7% cases. Statistical analysis showed that HMGB1 expression was positively correlated with tumor invasion (P = 0.048), lymph node metastasis (P = 0.011), distant metastasis (P = 0.031), and Duke's stage (P = 0.029) of CRC patients. Patients with higher HMGB1 expression had shorter overall survival time, whereas patients with lower level of HMGB1 had better survival. Multivariate analysis suggested that HMGB1 expression might be an independent prognostic indicator for the survival of patients with CRC. Disruption of endogenous HMGB1 protein through a siRNA knockdown technique was shown to suppress substantially the invasion ability of SW620 cells. CONCLUSIONS: Our results suggest that HMGB1 protein is a valuable marker for progression of CRC patients. High HMGB1 expression is associated with poor overall survival in patients with CRC.