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1.
Nano Lett ; 23(7): 2764-2770, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37010357

RESUMO

Two-dimensional (2D) semiconductors such as monolayer molybdenum disulfide (MoS2) are promising building blocks for ultrascaled field effect transistors (FETs), benefiting from their atomic thickness, dangling-bond-free flat surface, and excellent gate controllability. However, despite great prospects, the fabrication of 2D ultrashort channel FETs with high performance and uniformity remains a challenge. Here, we report a self-encapsulated heterostructure undercut technique for the fabrication of sub-10 nm channel length MoS2 FETs. The fabricated 9 nm channel MoS2 FETs exhibit superior performances compared with sub-15 nm channel length including the competitive on-state current density of 734/433 µA/µm at VDS = 2/1 V, record-low DIBL of ∼50 mV/V, and superior on/off ratio of 3 × 107 and low subthreshold swing of ∼100 mV/dec. Furthermore, the ultrashort channel MoS2 FETs fabricated by this new technique show excellent homogeneity. Thanks to this, we scale the monolayer inverter down to sub-10 nm channel length.

2.
Front Oncol ; 11: 733589, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34540699

RESUMO

Lysosomes have become a hot topic in tumor therapy; targeting the lysosome is therefore a promising strategy in cancer therapy. Based on our previous lysosome-targeted bio-imaging agent, homospermine-benzo[cd]indol-2(1H)-one conjugate (HBC), we further developed three novel series of polyamine- benzo[cd]indol-2(1H)-one conjugates. Among them, compound 15f showed potent inhibitory activity in hepatocellular carcinoma migration both in vitro and in vivo. Our study results showed that compound 15f entered the cancer cells via the polyamine transporter localized in the lysosomes and caused autophagy and apoptosis. The mechanism of action revealed that the crosstalk between autophagy and apoptosis induced by 15f was mutually reinforcing patterns. Besides, 15f also targeted lysosomes and exhibited stronger green fluorescence than HBC, which indicated its potential as an imaging agent. To summarize, compound 15f could be used as a valuable dual-functional lead compound for future development against liver-cancer metastasis and lysosome imaging.

3.
Front Nutr ; 7: 50, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32435650

RESUMO

Objectives: The aim of this study was to evaluate a total fasting regimen assisted by a novel prebiotic, Flexible Abrosia (FA), in more than 7 days of continual dietary deprivation (7D-CDD). Our analysis included basic physical examinations, bioelectrical impedance analysis, and clinical lab and ELISA analysis in normal volunteers. Methods: Seven healthy subjects with normal body weight participated in 7D-CDD with the assistance of a specially designed probiotic. Individuals were assigned to take FA (113.4 KJ/10 g) at each mealtime to avoid possible injuries to intestinal flora and smooth the hunger sensation. During 7D-CDD, the subjects were advised to avoid any food intake, especially carbohydrates, except for drinking plentiful amounts of water. The examination samples were collected before CDD as self-control, at 7 days fasting, and after 7~14 days of refeeding. Three subjects were also tested after 6-m refeeding. Results: The FA-CDD regimen significantly decreased suffering from starvation, with tolerable hunger sensations during the treatment. With the addition of daily mineral electrolytes, the subjects not only passed through the entire 7D-CDD regimen but also succeed in 12~13 days total fasting in two subjects. There was a significant reduction in blood glucose, insulin, and high-density lipoprotein levels during fasting, and the blood concentrations of uric acid (UA), alanine aminotransferase (ALT), and creatine kinase (CK) were increased. However, after more than 2 months of refeeding, the disease markers ALT, GOT, and CK either remained stable or were slightly downregulated compared to their initial D0 control level. Conclusion: Our experiment has supplied the first positive evidence that, with the assistance of a daily nutritional supply of around 100 kcal total calories to their intestinal flora, human subjects were able to tolerate hunger sensations. We have found that, although 7D-CDD induced increases in UA, CK, and transferases during fasting, refeeding led the markers to become either down-regulated or unchanged compared to their initial levels. This phenomenon was further confirmed in longer-term (6 m) recovery. Our results failed to support the hypothesis that fasting induced liver damage, since ALT, GOT, and CK remained low after longer-term refeeding. Our findings indicate that the 7D-CDD regimen might be practical and that it might be valuable to design larger clinical fasting trials for improvement of health strategy-targeting in metabolic disorders.

4.
Zhongguo Zhong Yao Za Zhi ; 39(23): 4642-6, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25911816

RESUMO

OBJECTIVE: To establish an HPLC-DAD/ESI-MS method for quickly identifying chemical constituents in diterpene lactone effective fraction of Andrographis panniculata and to study its pharmacodynamics. METHOD: The separation was performed on an Agilent SB-C18 column (2.1 mm x 150 mm, 5 µm) with a mobile phase of acetonitrile (A) and water (B). The flow rate was maintained at 0.4 mL x min(-1) and detection wavelength was set at 205 nm. The samples were analyzed in positive ion mode, and mass scan range was m/z 50-1 000. Using two kinds of tumor cell lines made living animal models, and studied preliminary pharmacodynamics on anti-tumor aspect. RESULT: Five diterpene lactones in the diterpene lactone effective fraction of A. panniculata could be separated in one run. Pharmacodynamic experiments showed that the effectve fraction had an inhibitory effect on the growth of tumor. CONCLUSION: A rapid and efficient HPLC-ESI-MS method to determine the chemical constituents in diterpene lactone effective fraction of A. panniculata has been established, and the preliminary pharmacodynamics research has been done, which could be used for the quality control and further studies of diterpene lactone effective fraction of A. panniculata in vivo.


Assuntos
Andrographis/química , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/química , Neoplasias Pulmonares/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Neoplasias Pulmonares/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Espectrometria de Massas por Ionização por Electrospray
5.
Protein Pept Lett ; 20(6): 715-23, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22973850

RESUMO

Porcine ß defensin 2(pBD2)is a cationic 37-amino acid antimicrobial peptide with disulfide bonds. Synthetic pBD2 had broad antimicrobial activity against pathogenic bacteria, and thus pBD2 could be a good candidate as a bactericidal agent for pigs. This study reported the successful recombinant expression of pBD2 in Escherichia coli and analysis of its antimicrobial activity, its hemolytic activity, salt-tolerance and thermal stability as well. The pBD2 gene, obtained by RT-PCR using the tongue total RNA as a template and cloned into pET30a expression vector, was transformed into E. coli BL21 (DE3) plysS. The recombinant pBD2 was expressed after induction by IPTG and purified by His tag affinity column with 95% purity. The recombinant pBD2 exhibited antimicrobial activity against both Gram-positive S. aureus and Gram-negative E. coli including the multi-resistant E. coli. The minimum inhibitory concentration (MIC) of recombinant pBD2 against tested bacteria was 10 µg/mL, and the recombinant pBD2 could kill 50% E. coli at 14.39 µg/mL and S. aureus at 21.1 µg/mL. In addition, pBD2 showed low hemolytic activity, salt-tolerance and thermal stability, the properties would be important for its application in practice.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologia , beta-Defensinas/química , beta-Defensinas/farmacologia , Análise de Variância , Animais , Antibacterianos/metabolismo , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Hemólise/efeitos dos fármacos , Cinética , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Estabilidade Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Cloreto de Sódio , Staphylococcus aureus/efeitos dos fármacos , Suínos , Temperatura , beta-Defensinas/genética , beta-Defensinas/metabolismo
6.
Protein Expr Purif ; 88(1): 47-53, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23220638

RESUMO

Porcine ß defensin 1 (pBD1) is a cationic antimicrobial peptide with three pairs of disulfide bonds. When expressed in insect cells, two polypeptides of different length (pBD1(38) and pBD1(42)) accumulated, which differed by N-terminal truncation. However, only pBD1(42) was found in pigs. pBD1(42) had stronger antimicrobial activity than pBD1(38), and thus could be a good candidate as a bactericidal agent for pigs. In this study, pBD1(42) gene, obtained by RT-PCR using the tongue total RNA as a template, was cloned into pET30a expression vector and transformed into Escherichia coli BL21 (DE3) plysS. The recombinant pBD1(42) was expressed after induction by IPTG and purified by His tag affinity column with 90% purity. The recombinant pBD1(42) exhibited antimicrobial activity against both Gram-positive Staphylococcus aureus and Gram-negative E. coli including the multi-resistant E. coli. The minimum inhibitory concentrations (MICs) of recombinant pBD1(42) against tested bacteria were 100 µg/mL for E. coli and 80 µg/mL for S. aureus. In addition, pBD1(42) showed low hemolytic activity and high thermal stability. These properties are relevant for the biotechnological applications of the peptide.


Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , beta-Defensinas/genética , beta-Defensinas/isolamento & purificação , Animais , Anti-Infecciosos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/biossíntese , Clonagem Molecular , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Escherichia coli/efeitos dos fármacos , Expressão Gênica , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Suínos , beta-Defensinas/biossíntese , beta-Defensinas/farmacologia
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