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1.
Artigo em Inglês | MEDLINE | ID: mdl-32054368

RESUMO

A number of same species of Cerithiidae are morphologically unlike, whereas most of species in the same genus are morphologically similar and just exhibit subtle differences. It is difficult to identify them by morphological methods alone. DNA barcoding is a modern molecular technique that can be used to identify species accurately, and is particularly helpful when distinguishing morphologically similar species. In order to identify species of Cerithiidae using DNA barcoding technology based on mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA (16S rRNA) genes, this study calculated intraspecific and interspecific genetic distance and constructed the phylogenetic trees. A total of 80 COI and 16S rRNA barcode sequences were obtained from 10 species and 3 genera. Some unknown specimens were further identified and a cryptic species may exist in Cerithium traillii, showing that DNA barcoding technology has the potential to discover new species and cryptic species. The phylogenetic trees revealed that all of the cerithiids could converge upon a monophyly with high support values and two genera (Cerithium and Clypeomorus) maybe support the reclassification. It is necessary for traditional morphological methods to combine with the DNA barcoding for classification and identification of Cerithiidae.

2.
Curr Med Sci ; 39(5): 707-718, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31612387

RESUMO

This study aimed to evaluate the effectiveness of tamsulosin monotherapy for the treatment of ureteral stent-related symptoms (SRSs) and compare it with that of solifenacin monotherapy and combined therapy of tamsulosin and silifenacin. Randomized controlled trials (RCTs), which evaluated the effectiveness of tamsulosin for the treatment of SRSs, were searched from the databases PubMed, EMBASE and the Cochrane Library published up to November 2018. Eight RCTs involving 1087 participants were finally included in this meta-analysis. The results showed that tamsulosin monotherapy could significantly decrease the urinary symptoms [mean difference (MD) -7.56, 95% confidence interval (CI) (-11.47, -3.65), P=0.0001] and body pain [MD -5.25, 95% CI (-8.03, -2.46), P=0.0002], and improve the sexual performance [MD -1.06, 95% CI (-1.89, -0.24), P=0.01] compared with the control group. Moreover, there was no significant difference between tamsulosin monotherapy and solifenacin monotherapy in all outcomes except for significantly better sexual performance in solifenacin group [MD 0.29, 95% CI (0.06, 0.51), P=0.01]. In addition, the effectiveness of combined therapy of tamsulosin and solifenacin was not superior to that of tamsulosin monotherapy. Our study demonstrated that tamsulosin monotherapy was effective for the treatment of patients with SRSs; evident superiority could not be found for therapy of tamsulosin and solifenacin combined.

3.
Mol Med Rep ; 15(2): 635-642, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28000867

RESUMO

Dexmedetomidine (DXM) is a selective α2-adrenoceptor (α2­AR) and imidazoline receptor (IR) agonist that has been reported to regulate inflammatory responses mediated by diverse signaling pathways through α2­AR. The majority of the reported receptors or downstream molecules have been demonstrated to locate with caveolin­1, a protein suggested to participate in regulating Toll­like receptor 4 (TLR4)­mediated inflammatory responses and the pathogen endocytosis capability of macrophages. The present study hypothesized that DXM may influence these pathways by regulating the expression of caveolin­1 and mediating the subsequent effects. Using a cecal­ligation and puncture­induced rat sepsis model, it was initially observed that pre­emptive DXM is able to upregulate and stabilize the amount of caveolin­1 expression, which may be partly antagonized by both α2­AR and the IR antagonist atepamezole (APZ). The pathophysiological parameters indicated that DXM is able to inhibit secondary lung injury, in addition to the rise of body temperature and arterial lactate accumulation, however it marginally increased arterial glucose and the murine sepsis score, which can be largely antagonized by APZ. The overall effect was beneficial and improved the 24­h cumulative survival rate of rats with sepsis. In conclusion, preemptive clinical sedative doses of DXM may upregulate the expression of caveolin­1 downregulated by sepsis, which may contribute to the inhibition of inflammatory pathways such as TLR4­mediated pathways. Furthermore, DXM may favor the improvement of short­term outcomes by the regulation of other metabolic pathways.


Assuntos
Caveolina 1/metabolismo , Dexmedetomidina/farmacologia , Hipnóticos e Sedativos/farmacologia , Pulmão/metabolismo , Sepse/patologia , Regulação para Cima/efeitos dos fármacos , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 2/uso terapêutico , Animais , Gasometria , Temperatura Corporal/efeitos dos fármacos , Caveolina 1/genética , Modelos Animais de Doenças , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Pulmão/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Sepse/tratamento farmacológico , Sepse/mortalidade , Receptor 4 Toll-Like/metabolismo
4.
Nanotechnology ; 27(42): 425703, 2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-27622904

RESUMO

The organic semiconductor silver-tetracyanoquinodimethane (Ag-TCNQ) exhibits electrical switching and memory characteristics. Employing a scanning tunnelling microscopy setup inside a transmission electron microscope, the switching behaviour of individual Ag-TCNQ nanowires (NWs) is investigated in detail. For a large number of NWs, the switching between a high (OFF) and a low (ON) resistance state was successfully stimulated by negative bias sweeps. Fitting the experimental I-V curves with a Schottky emission function makes the switching features prominent and thus enables a direct evaluation of the switching process. A memory cycle including writing, reading and erasing features is demonstrated at an individual NW. Moreover, electronic failure mechanisms due to Joule heating are discussed. These findings have a significant impact on our understanding of the switching behaviour of Ag-TCNQ.

5.
Phys Chem Chem Phys ; 17(28): 18278-81, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26123655

RESUMO

We investigate the resistivity switching in individual Ag-TCNQ wires with on/off-ratios of up to 10(3). Raman and soft X-ray absorption microspectroscopy studies disclose reverse charge transfer. Quantifying of the fraction of neutral TCNQ within the switched material yields values up to 22.3%. These findings expedite the understanding of the switching process in Ag-TCNQ nanowires.

6.
Mol Med Rep ; 12(2): 2953-60, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936412

RESUMO

The aim of the present study was to investigate the differences in the expression of hippocampal proteins between normal control aged rats and aged rats with postoperative cognitive dysfunction (POCD). A total of 24 aged rats were randomly divided into a surgery group (n=12) and a control group (n=12). The rats in the surgery group were treated with 2 h isoflurane anesthesia and splenectomy, while the rats in the control group received 40% oxygen for 2 h without surgery. The cognitive functions of the two groups were examined using a Y-maze test. The protein expression profiles of the hippocampus of six aged rats (three rats with POCD and three from the normal control group) were assessed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry. A total of three differential proteins were further confirmed between the POCD rats and normal rats using reverse transcription quantitative polymerase chain reaction (RT-qPCR). The expression levels of 21 proteins in the rats with POCD were significantly different compared with the normal control rats. These proteins were functionally clustered to synaptic plasticity (three proteins), oxidative stress (four proteins), energy production (six proteins), neuroinflammation (three proteins) and glutamate metabolism (two proteins). In addition, three proteins (fatty acid binding protein 7, brain, glutamate dehydrogenase 1 and glutamine synthetase), associated with astrocytic function, were significantly different in the rats with POCD compared with those in the normal control (P<0.05). Similar changes in the mRNA expression levels of the three proteins in the hippocampi of POCD rats were also detected using RT-qPCR. Neuroinflammation, glutamate toxicity and oxidative stress were possibly involved in the pathological mechanism underlying POCD in aged rats. In addition, astrocytes may also be important in POCD in aged rats.


Assuntos
Anestésicos Inalatórios/administração & dosagem , Transtornos Cognitivos/cirurgia , Regulação da Expressão Gênica , Hipocampo/fisiopatologia , Isoflurano/administração & dosagem , Proteoma/análise , Proteômica , Anestésicos Inalatórios/farmacologia , Animais , Cognição/efeitos dos fármacos , Eletroforese em Gel Bidimensional , Hipocampo/metabolismo , Isoflurano/farmacologia , Masculino , Aprendizagem em Labirinto , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Esplenectomia
7.
Nanoscale ; 4(24): 7825-31, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23149481

RESUMO

Individual WS(2) nanotubes (NTs) were bended and released in-situ inside a transmission electron microscope. Kinks appeared in the NTs suddenly during the bending process. Shell distortion, shell breaking and rotation of broken shells were observed in these kinks. Spontaneous self-healing and focused electron beam-assisted healing of the structure were observed after the load was removed. More importantly, the strength and electrical conductivity of the NTs were also restored to their original level when the structure recovered.

8.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 41(5): 559-63, 2012 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-23086650

RESUMO

OBJECTIVE: To investigate the effects of hydrogen sulfide preconditioning on myocardial ischemia reperfusion injury in rats. METHODS: Sprague-Dawley male rats were divided into 4 groups with 10 in each group: in S group rats received sham operation; in IR group rats were given with NS (1.0 ml/kg iv) 24 h before ischemia; in H group rats were treated with NaHS (0.05 mg/kg iv) 24 h before ischemia; and in D group, NaHS-treated rats received 5-hydroxydecanoate (5-HD) 15 min before ischemia. Rats in IR group,H group and D group were subjected to ischemia by occlusion of coronary artery for 30 min followed by 2 h of reperfusion. At the end of the reperfusion,myocardial infarct size was measured. SAM-s was measured by Western blotting. Plasma SOD activity and MDA were determined at the end of reperfusion. RESULTS: The infarct size was significantly lesser in H group (25.40 % ± 3.54%) than that in IR group (38.27% ±5.64%,P<0.05). The SAM-s protein expression in myocardium was significantly lower in H group than that in IR group. The plasma MDA content was significantly lower and SOD activity was higher in H group than those in IR group,but there was no difference between IR group and D group. CONCLUSION: The hydrogen sulfide preconditioning attenuates myocardial IR injury possibly through down-regulating SAM-s expression,reducing the production of oxygen free radicals and enhancing anti-oxidize effect in rats.


Assuntos
Sulfeto de Hidrogênio/farmacologia , Precondicionamento Isquêmico Miocárdico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Modelos Animais de Doenças , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Ratos , Ratos Sprague-Dawley
9.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 24(4): 211-4, 2012 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-22464572

RESUMO

OBJECTIVE: To investigate the changes in protein of myocardium after hydrogen sulfide delayed preconditioning by using proteomics technology. METHODS: Sixteen Sprague-Dawley rats were randomly assigned to control (group S) or hydrogen sulfide group (group H), n = 8 for each group. Myocardial ischemia/reperfusion injury model (ischemia 30 minutes followed by reperfusion 120 minutes) was reproduced at 24 hours after preconditioning either with normal saline or hydrogen sulfide for proteomics analysis in group S or group H, and the myocardial tissue was harvested. The total proteins were extracted and separated by two dimensional gel electrophoresis (2-DE), and the differential protein expression spots were analyzed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS: Analysis of 2-DE showed that 929 ± 14 protein spots were found in group S and 906 ± 10 protein spots in group H, and the expression of 15 protein spots was different between two groups. These protein spots were chosen to undergo MALDI-TOF-MS analysis, and 11 proteins were preliminarily identified, including DNA ligase, cystathionine gamma-lyase, transcription initiation factor, NADH dehydrogenase, guanine nucleotide-releasing factor, fructose-bisphosphate aldolase A, glycogen synthase kinase-3, electron transfer flavoprotein subunit beta, glutathione S-transferase, soluble calcium-activated nucleotidase and S-adenosylmethionine synthetase. CONCLUSIONS: Hydrogen sulfide delayed preconditioning of myocardium resulted in the changes in protein expression profiles in the myocardium. The differential proteins might function as anti-oxidants, to improve the energy metabolism of myocardium, confer cytoprotection and protection of respiratory chain, thus conferring cardioprotection.


Assuntos
Sulfeto de Hidrogênio/farmacologia , Precondicionamento Isquêmico Miocárdico , Miocárdio/metabolismo , Proteômica/métodos , Animais , Ratos , Ratos Sprague-Dawley
10.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 37(1): 89-93, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22349392

RESUMO

OBJECTIVE: To determine the effect of Gingkgo biloba leaf extract (EGb761) induced delayed preconditioning on cytochrome c oxidase (CcO) expression during myocardial ischemia-reperfusion in rats. METHODS: Four groups (10 in each) of Sprague-Dawley male rats were studied. In the sham group, the rats received no treatment. Rats in the ischemia-reperfusion (IR) group were treated with NS (1.0 mL/kg intravenously) 24 h before ischemia. Rats in the M group were treated with EGb761 (100 mg/kg intravenously) 24 h before the ischemia. In the D group , EGb761-treated rats that received the 5-hydroxydecanoate (5-HD), an inhibitor of mitochondrial KATP channels 15 min before the ischemia. The IR, M, and D groups were subjected to ischemia by 30 min of coronary artery occlusion before 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size was measured. CcO was measured by Western blot. The myocardial ultrastructure was observed under the electron microscope. RESULTS: The infarct size was significantly smaller in the M group [(23.78 ± 4.82)%] than in the I/R group [(37.87 ± 5.92)%] (P<0.05). The CcO protein expression in the myocardium was significantly higher in the M group than in the I/R group(P<0.05). Microscopic examination showed less myocardial damage in the M group than that in the I/R group. The infarct size, CcO protein expression, and myocardial damage had no significant difference between the D group and the I/R group (P>0.05). CONCLUSION: EGb761 induced delayed preconditioning attenuates myocardial ischemia-reperfusion injury possibly through up-regulating CcO expression in rats.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Ginkgo biloba/química , Precondicionamento Isquêmico Miocárdico/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Medicamentos de Ervas Chinesas/uso terapêutico , Pós-Condicionamento Isquêmico/métodos , Masculino , Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Fitoterapia , Folhas de Planta/química , Ratos , Ratos Sprague-Dawley
11.
Ultramicroscopy ; 119: 72-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22244495

RESUMO

We demonstrate the potential of electrons for single molecule diffraction and imaging using C60 molecules confined inside single-walled carbon nanotubes (C60s@SWCNT or peapod) as a model system. A 25 nm diameter electron beam from a field emission gun source is used to record diffraction patterns from individual peapods using imaging plates. The electron beam illuminates about 25 C60 molecules. Experimentally, we found that the molecules diffract inside ∼15% of the host nanotubes. With the help of simulations, we explore the limits of electron molecular diffraction and its sensitivity to the molecular configurations. We show that the combination of electron diffraction and electron direct imaging provides the best approach to single molecule imaging.

12.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 36(10): 999-1002, 2011 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-22086014

RESUMO

OBJECTIVE: To investigate the changes of myocardial protein expression profiles in 2-chloro-N6-cyclopentyladenosine (CCPA), an adenosine A1 receptor agonist-induced delayed myocardial protection in New Zealand rabbits . METHODS: A total of 8 rabbits were randomly divided into a CCPA group (CCPA group) and a normal saline group (NS group). CCPA and NS were infused into rabbits in the CCPA group and the NS group respectively. Twenty-four hours later, the rabbits were subjected to 30 min left anterior descending coronary artery occlusion and were reperfused for 2 hours, then the ischemic zone tissues of left ventricle were sampled for proteomic analysis.A total of 12 other New Zeland rabbits were divided into a sham group (Sham group), a normal saline group (NS group) and a CCPA group (CCPA group). The expression of αB-crystalline, one of the differential proteins, was confirmed by Western blot. RESULTS: Analysis of two dimensional gel electrophoresis showed that the expression of 55 protein spots were different between the two groups, 17 protein spots were preliminarily identified with the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and Mascot and Expasy bioinformatics software. These proteins included stress proteins, metabolism-associated proteins, signal transduction pathway-related proteins, ionophorous proteins, immunity-associated proteins, and so on. Western blot showed that the expression of αB-crystalline was significantly up-regulated in the CCPA group. CONCLUSION: The myocardial protein expression profiles are changed markedly in the preconditioning late phase of CCPA .The differential proteins might be involved in the delayed cardioprotection induced by CCPA.


Assuntos
Agonistas do Receptor A1 de Adenosina/uso terapêutico , Pós-Condicionamento Isquêmico/métodos , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Proteômica/métodos , Adenosina/análogos & derivados , Adenosina/uso terapêutico , Animais , Feminino , Masculino , Miocárdio/metabolismo , Proteoma/análise , Coelhos
13.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 40(5): 535-9, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-21984157

RESUMO

OBJECTIVE: To investigate the effect of hydrogen sulfide-induced delayed preconditioning on glutathione S-transferase (GST) expression during myocardial ischemia-reperfusion in rats. METHODS: Sprague-Dawley male rats were randomly divided into 4 groups (n= 10 in each): Group S (sham operation group), Group IR (ischemia/reperfusion group), Group H (IR+ NaHS 0.05 mg/kg iv, 24 h before ischemia) and Groups D receiving IR+NaHS 24 h before ischemia and 5-hydroxydecanoate (5-HD)15 min before ischemia. Animals in groups IR, H and D were subjected to ischemia by 30 min of coronary artery occlusion followed by 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size (IS) was examined. Glutathione S-transferase (GST) was measured by Western blotting. The myocardial ultrastructures were observed under the electron microscopy. RESULTS: The IS was significantly smaller in Group H than that in Group IR [(25.40 ± 3.54)% compared with (38.27 ± 5.64)%, P<0.05]. The GST expression in myocardium was significantly higher in Group H than that in Group IR. Microscopic examination showed less myocardial damage in Group H than in Group IR. The protective effects of delayed preconditioning by hydrogen sulfide was prevented by 5-HD pre-treatment. CONCLUSION: The hydrogen sulfide-induced delayed preconditioning attenuates myocardial IR injury possibly through up-regulating glutathione S-transferase expression in rats.


Assuntos
Glutationa Transferase/metabolismo , Sulfeto de Hidrogênio/administração & dosagem , Precondicionamento Isquêmico Miocárdico , Traumatismo por Reperfusão Miocárdica/enzimologia , Animais , Modelos Animais de Doenças , Sulfeto de Hidrogênio/uso terapêutico , Masculino , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/terapia , Miocárdio/enzimologia , Miocárdio/ultraestrutura , Ratos , Ratos Sprague-Dawley
14.
Anesth Analg ; 113(2): 224-32, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21659557

RESUMO

BACKGROUND: Delayed myocardial preconditioning by volatile anesthetics involves changes in DNA transcription and translation. Mitochondria play a central role in myocardial ischemia/reperfusion (I/R) injury and in ischemic or pharmacologic preconditioning. In this study, we investigated whether there are alterations in myocardial mitochondrial protein expression after volatile anesthetic preconditioning (APC) to examine the underlying mechanisms of delayed cardioprotection. METHODS: Thirty-six Sprague-Dawley rats were randomly assigned to 1 of 3 groups (n = 12 for each group). Rats in the delayed APC group were exposed to sevoflurane (2.5% for 60 minutes) 24 hours before myocardial ischemia was induced. Myocardial ischemia in the I/R and APC groups was induced by left coronary artery occlusion for 30 minutes, followed by 120 minutes of reperfusion. The control group received no treatment. The mitochondria fractions were prepared by differential centrifugation with density gradient isolation for proteomic analysis. Two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry was used to identify differences in the protein expression from mitochondria of the rat hearts. RESULTS: Fifteen differentially expressed mitochondrial proteins between the APC group and I/R group were identified and the expression patterns of 2 of the proteins were confirmed by Western blot analysis. These proteins were associated with mitochondrial substrate metabolism, respiration, and adenosine triphosphate (ATP)/adenosine diphosphate transport. The modifications of the mitochondrial proteome suggest an enhanced capacity of mitochondria to maintain myocardial ATP levels after I/R injury. CONCLUSION: Delayed sevoflurane myocardial preconditioning induces mitochondrial proteome remodeling, which mainly involves proteins that are related to ATP generation and transport. Therefore, proteomic changes related to bioenergetic balance may be the mechanistic basis of delayed anesthetic myocardial preconditioning.


Assuntos
Anestésicos Inalatórios/farmacologia , Precondicionamento Isquêmico Miocárdico , Éteres Metílicos/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/genética , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão/genética , Trifosfato de Adenosina/metabolismo , Animais , Western Blotting , Eletroforese em Gel Bidimensional , Masculino , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/metabolismo , Proteoma/efeitos dos fármacos , Proteômica , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/fisiopatologia , Sevoflurano , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Troponina I/biossíntese , Troponina I/genética
15.
ACS Nano ; 5(4): 3367-72, 2011 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-21428451

RESUMO

Electron microscopy with advances in aberration correction has the power to resolve atoms in single molecules. However, its application is limited by electron irradiation induced molecular motions. A better understanding of damage mechanisms is required to achieve the full potential of electron imaging. Here, we report a direct observation of molecular motions stimulated by an electron beam, which allows us to study the breakdown and formation of molecular bonds using C(60)'s encapsulated inside single-walled carbon nanotubes as a model system. An activation energy of 100 s meV is estimated for the observed molecular motions based on van der Waals interactions. We demonstrate that the molecular confinement can significantly increase the electron energy threshold for breaking the vdW bonds.

16.
Ultramicroscopy ; 111(7): 817-23, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21159441

RESUMO

Information from imaging and diffraction planes, or real and reciprocal spaces, of transmission electron microscopes (TEM) can be combined using iterative transformation algorithms to reconstruct the complex wave function, to improve image resolution and to remove residual aberrations in the case of aberration corrected TEM. Here, we describe the experimental and computation techniques needed for combining real and reciprocal space information. We demonstrate these techniques by reconstructing the complex wave function of quantum dots and carbon nanotubes beyond the microscope's resolution limit.


Assuntos
Elétrons , Difração de Raios X/métodos , Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Microscopia Eletrônica de Transmissão/métodos , Modelos Moleculares , Nanotubos de Carbono/química , Pontos Quânticos
17.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 35(4): 346-50, 2010 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-20448357

RESUMO

OBJECTIVE: To investigate the effect of isoflurane delayed preconditioning on the activation of caspase-3 and the expression of Bcl-2 in rabbit myocardium during ischemia reperfusion and the possible mechanism. METHODS: Forty New Zealand male white rabbits were randomly divided into 4 groups: a sham group (Group C), an I/R group, an isoflurane group (Group S), and an isoflurane + opioid recepters inhibitor group (Group N). Group S was exposed to 2.0% isoflurane for 2 h. Group N was given naloxone (6.0 mg/kg) before exposing to 2.0% isoflurane. Group C and Group I/R were exposed for 2 h to 100% oxygen, serving as untreated controls. Twenty-four hours later, Group S and Group N underwent 40 min of coronary occlusion followed by 2 h of reperfusion. At the end of the reperfusion, infarct size(IS) and area at risk(AAR) were defined by Evans and TTC staining. The myocardial ultrastructure was observed by electron microscopy. The levels of the myocardial Bcl-2 and caspase-3 expression were determined by Western blot. RESULTS: The caspase-3 activity of Group S was significantly lower than that of Group I/R(P<0.05). The IS was significantly reduced in Group S(19.7%+/-2.8%) as compared with Group I/R(37.8%+/-1.7%) (P<0.05). Microscopic examination showed less myocardial damage in Group S than in Group I/R. CONCLUSION: Isoflurane delayed preconditioning can inhibit the apoptosis of myocardium by up-regulating the expression of Bcl-2 and down-regulating the activation of caspase-3, which may be part of the molecular mechanism of isoflurane delayed preconditioning on myocardial preservation.


Assuntos
Caspase 3/metabolismo , Precondicionamento Isquêmico Miocárdico/métodos , Isoflurano/uso terapêutico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Apoptose/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Isoflurano/farmacologia , Masculino , Isquemia Miocárdica/tratamento farmacológico , Isquemia Miocárdica/patologia , Miocárdio/metabolismo , Miocárdio/ultraestrutura , Coelhos , Distribuição Aleatória
18.
Microsc Microanal ; 16(2): 183-93, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20187990

RESUMO

We evaluate the probe forming capability of a JEOL 2200FS transmission electron microscope equipped with a spherical aberration (Cs) probe corrector. The achievement of a real space sub-Angstrom (0.1 nm) probe for scanning transmission electron microscopy (STEM) imaging is demonstrated by acquisition and modeling of high-angle annular dark-field STEM images. We show that by optimizing the illumination system, large probe currents and large collection angles for electron energy loss spectroscopy (EELS) can be combined to yield EELS fine structure data spatially resolved to the atomic scale. We demonstrate the probe forming flexibility provided by the additional lenses in the probe corrector in several ways, including the formation of nanometer-sized parallel beams for nanoarea electron diffraction, and the formation of focused probes for convergent beam electron diffraction with a range of convergence angles. The different probes that can be formed using the probe corrected STEM opens up new applications for electron microscopy and diffraction.

19.
Nan Fang Yi Ke Da Xue Xue Bao ; 30(2): 298-300, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20159705

RESUMO

OBJECTIVE: To investigate the role of p38MAPK pathway in the protective effect of glycyrrhiznatis against myocardial ischemia-reperfusion in rabbits. METHODS: Thirty rabbits were randomly divided into control group, I/R group, and glycyrrhiznatis group. In the latter two groups, the left anterior descending branch of the coronary artery was ligated for 40 min followed by 120 min of reperfusion, and in glycyrrhiznatis group, glycyrrhiznatis was given intravenously at 2.5 mg/kg before the occlusion. Blood samples were taken to measure the plasma levels of TNF-alpha, IL-6, and IL-8 at 20 min before (T(0)) and 20 min (T(1)) and 40 min (T(2)) after the occlusion, and at 1 h (T(3)) and 2 h (T(4)) after the reperfusion. At the end of the reperfusion, the infarct size and the area at risk were defined by Evams and TTC staining. The heart was harvested and the levels of the p38 MAPK measured by Western blotting. The ultrastructures of the cardiac myocytes were observed under electron microscope. RESULTS: The p38MAPK activity and the plasma levels of the inflammatory factors were significantly lower in gtycyrrhiznatis group than in I/R group (P<0.05). Glycgrrhiznatis significantly reduced the infarct size as compared with that in I/R group. CONCLUSIONS: lycyrrhiznatis can reduce myocardial ischemia-reperfusion injury by inhibiting p38MAPK activity and modulating the cytokine expression.


Assuntos
Ácido Glicirrízico/uso terapêutico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Citocinas/metabolismo , Feminino , Masculino , Miocárdio/metabolismo , Coelhos , Distribuição Aleatória
20.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 38(5): 521-4, 2009 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-19830867

RESUMO

OBJECTIVE: To investigate the protective effects of morphine postconditioning on myocardial ischemia-reperfusion (I/R)injury and the potential mechanisms in rabbits. METHODS: Thirty-two New Zealand male white rabbits were randomly assigned into 4 groups: Group 1 (Sham), Group 2 (I/R), Group 3 (ischemic postconditioning), Group 4 (ischemia and morphine postconditioning). Group 1 was perfused for 160 min; Group 2 underwent 40 min ischemia and 120 min reperfusion; Group 3 underwent three cycles of 30 s reperfusion and 30 s left anterior descending coronary artery re-occlusion immediately after 40 min ischemia and before 120 min reperfusion; Group 4 was given morphine 1.0 mg/kg immediately after 40 min ischemia in 1 min and before 120 min reperfusion. Blood samples were taken from arterial line at 20 min before occlusion, 20 min after occlusion, 40 min after occlusion, 1 h after reperfusion and 2 h after reperfusion for determination of the plasma levels of cardiac troponin I (cTnI). At the end of the reperfusion, infarct size (IS) and area at risk were defined by Evans and TTC staining. Plasma SOD activity and MDA were determined at the end of reperfusion. RESULT: The levels of cTnI were significantly lower during reperfusion in the two postconditioning groups than those in I/R group. The plasma MDA content was significantly lower and SOD activity was significantly higher in the two postconditioning groups than those in I/R group, but there was no difference between two postconditioning groups. Morphine significantly reduced infarct size of the left ventricular area at risk as compared with I/R group (P<0.05). CONCLUSION: Morphine postconditioning is as effective as ischemic postconditioning in the protection of myocardium against I/R injury in rabbits. Decrease in oxygen free radicals and increased antioxidant activity might be involved in its mechanism.


Assuntos
Doença da Artéria Coronariana/tratamento farmacológico , Precondicionamento Isquêmico Miocárdico , Morfina/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Animais , Masculino , Malondialdeído/sangue , Coelhos , Distribuição Aleatória , Superóxido Dismutase/sangue
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