Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 68
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Chem Phys ; 151(12): 124307, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31575165

RESUMO

Ce atom reactions with ethylene, 2-butene, and isobutene are carried out in a pulsed laser vaporization molecule beam source. Ce-containing species are observed with time-of-flight mass spectrometry, and Ce(C4H6) is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and relativistic quantum chemical calculations. Two structural isomers are identified for Ce(C4H6): one is the tetrahedronlike Ce[C(CH2)3] in C3v symmetry and the other is the five-membered metallocyclic Ce(CH2CHCHCH2) in Cs. The MATI spectrum of the C3v isomer exhibits two vibronic band systems separated by 88 cm-1, while that of the Cs isomer displays three split by 60 and 101 cm-1. The multiple band systems are attributed to spin-orbit splitting and vibronic transitions involving metal-hydrocarbon and hydrocarbon-based vibrations. The splitting in the C3v isomer arises from interactions of two triplet and two singlet states at the lowest energies, while each splitting in the Cs isomer involves two triplets and a singlet. Although the Ce atom has ground electron configuration 4f15d16s2, Ce valence electron configurations in both isomers are 4f16s1 in the neutral ground state and 4f1 in the ion. The remaining Ce 5d electrons in the isolated atom are spin paired in molecular orbitals that are a bonding combination between Ce 5dπ and hydrocarbon π* orbitals.

2.
Sci Total Environ ; 686: 869-877, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31200307

RESUMO

Jarosites are secondary iron-hydroxyl-sulfate minerals and widely occur in bioleaching, acid mine drainage, and acid sulfate soil environments. Anaerobic reductive dissolution of jarosites is yet to be methodically examined. In this study, we explored the bio-dissolution of jarosites by Acidithiobacillus ferrooxidans (At. ferrooxidans) by using hydrogen in batch experiments. After bio-dissolution by At. ferrooxidans for 22 d, ferrous ion concentrations reached 10.07 mM (biologically produced jarosites), 7.68 mM (potassium jarosite), and 1.45 mM (lead jarosite). Strengthening the dissolved jarosites by decreasing the initial pH (pH < 2.0) or by adding citric acid (1, 5, and 10 mM) was inefficient for bio-dissolution owing to restricted cellular activity. The pathways of bio-dissolution should include direct contact bio-dissolution and indirect bio-dissolution and relate to the solubility of jarosites in a bio-dissolution system. The results demonstrate that anaerobic reductive bio-dissolution of jarosites by At. ferrooxidans using hydrogen shows potential. This study also provides opportunities to contribute to the development of the bioleaching field via the aerobic/anaerobic cycle using a single strain to control and reuse jarosites in situ.


Assuntos
Acidithiobacillus/metabolismo , Compostos Férricos/metabolismo , Sulfatos/metabolismo , Elétrons , Compostos Ferrosos , Hidrogênio/metabolismo , Ferro/metabolismo , Minerais/metabolismo , Mineração , Oxirredução
3.
J Chem Phys ; 149(23): 234301, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30579310

RESUMO

Ln (Ln = La and Ce) atom reactions with ammonia are carried out in a pulsed laser vaporization supersonic molecular beam source. Lanthanide-containing species are observed with time-of-flight mass spectrometry, and LnNH molecules are characterized by mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical calculations. The theoretical calculations include density functional theory for both Ln species and a scalar relativity correction, electron correlation, and spin-orbit coupling for the Ce species. The MATI spectrum of LaNH exhibits a single vibronic band system with a strong origin band and two weak vibronic progressions, whereas the spectrum of CeNH displays two band systems separated by 75 cm-1 with each being like the LaNH spectrum. By comparing with the theoretical calculations, both LaNH and CeNH are identified as linear molecules with C∞v symmetry, and the two vibronic progressions are attributed to the excitations of Ln-N stretching and Ln-N-H bending modes in the ions. The additional band system observed for CeNH is due to the spin-orbit splitting from the interactions of triplet and singlet states. The ground valence electron configurations of LaNH and CeNH are La 6s1 and Ce 4f16s1, and the ionization of each species removes the Ln 6s1 electron. The remaining two electrons that are associated with the isolated Ln atoms or ions are in a doubly degenerate molecular orbital that is a bonding combination between Ln 5dπ and N pπ orbitals.

4.
J Chem Phys ; 148(19): 194302, 2018 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-30307187

RESUMO

La atom reaction with isoprene is carried out in a laser-vaporization molecular beam source. The reaction yields an adduct as the major product and C-C cleaved and dehydrogenated species as the minor ones. La(C5H8), La(C2H2), and La(C3H4) are characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of all three species exhibit a strong origin band and several weak vibronic bands corresponding to La-ligand stretch and ligand-based bend excitations. La(C5H8) is a five-membered metallacycle, whereas La(C2H2) and La(C3H4) are three-membered rings. All three metallacycles prefer a doublet ground state with a La 6s1-based valence electron configuration and a singlet ion. The five-membered metallacycle is formed through La addition and isoprene isomerization, whereas the two three-membered rings are produced by La addition and insertion, hydrogen migration, and carbon-carbon bond cleavage.

5.
Alcohol Clin Exp Res ; 42(10): 1863-1873, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30080257

RESUMO

Alcoholic liver disease (ALD), a liver function disorder caused by excessive alcohol intake, is a serious threat to global public health and social development. Toxic metabolites and reactive oxygen species produced during the metabolism of alcohol can alter the epigenetic state including DNA methylation, histone modifications, and expression of microRNAs. Epigenetic alterations can conversely involve various signaling pathways, which could contribute to the initiation and progression of ALD. To elucidate the relationship between epigenetic alterations and alcohol damage not only reinforces our understanding on pathogenesis of ALD, but also provides novel targets for clinical diagnosis, treatment, and drug research of ALD. In this review, we have summarized the research progress of epigenetic alterations and related mechanisms caused by alcohol in the pathogenesis of ALD. Considering the invertibility of epigenetic alterations, treatment of ALD through epigenetic modification with common less harmful compounds is also related.

6.
J Chem Phys ; 149(3): 034303, 2018 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-30037237

RESUMO

La atom reactions with 1-pentene and 2-pentene are carried out in a laser-vaporization molecular beam source. The two reactions yield the same metal-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage of the pentene molecules. The dehydrogenated species La(C5H8) is the major product, whereas the carbon-carbon bond cleaved species La(C2H2) and La(C3H4) are the minor ones. La(C10H18) is also observed and is presumably formed by La(C5H8) addition to a second pentene molecule. La(C5H8) and La(C2H2) are characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of each species from the two reactions exhibit the same transitions. Adiabatic ionization energies and metal-ligand stretching frequencies are determined for the two species, and additional methyl bending and torsional frequencies are measured for the larger one. Five possible isomers are considered for La(C5H8), and a C1 metallacyclopentene (Iso A) is identified as the most possible isomer. La(C2H2) is confirmed to be a C2v metallacyclopropene. The ground electronic state of each species is a doublet with a La 6s1-based electron configuration, and ionization yields a singlet state. The formation of the lanthanacyclopentene includes La addition to the C=C double bond, La insertion into two C(sp3)-H bonds, and concerted dehydrogenation. For the 2-pentene reaction, the formation of the five-membered ring may also involve 2-pentene to 1-pentene isomerization. In addition to the metal addition and insertion, the formation of the three-membered metallacycle from 1-pentene includes C(sp3)-C(sp3) bond breakage and hydrogen migration from La to C(sp3), whereas its formation from 2-pentene may involve the ligand isomerization.

7.
J Colloid Interface Sci ; 527: 132-140, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29787949

RESUMO

Graphene quantum dots (GQDs) have been synthesized reproducibly by chemical oxidation (CO) of carbon nano-onions (nCNOs) and a one-step pulsed laser ablation (LA) of nCNOs in deionized water. The photoluminescence (PL) spectra show that the LA-GQDs have blue shifted emission relative to the CO-GQDs which is attributed to the effects of both particle sizes and surface functional groups. The CO-GQDs have an average diameter of 4.1(8) nm and a thickness corresponding to two or three graphene layers, while the LA-GQDs have an average diameter of 1.8(6) nm and a thickness comparable to a single layer of graphene. The CO-GQDs favor the presence of carboxylic groups and have a higher fraction of sp2 carbons, while the LA-GQDs prefer the presence of hydroxyl groups and have a higher fraction of sp3 carbons. PL lifetime data suggests that surface functional groups are the main source of radiative deactivation and the sp2 carbon domains are mainly responsible for non-radiative decay. PL lifetimes are measured to be 7.9(6) ns for the emission from the carboxylic groups and 3.18(10) ns from the hydroxyl groups. Compared to CO, liquid-phase LA is a faster and cleaner one-step method for producing GQDs with fewer starting chemicals and byproducts.

8.
J Chem Phys ; 148(4): 044312, 2018 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-29390854

RESUMO

La atom reactions with 1-butene, 2-butene, and isobutene are carried out in a laser-vaporization molecular beam source. The three reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butenes. The dehydrogenated species La(C4H6) is the major product, which is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectrum of La(C4H6) produced from the La+1-butene reaction exhibits two band systems, whereas the MATI spectra produced from the La+2-butene and isobutene reactions display only a single band system. Each of these spectra shows a strong origin band and several vibrational progressions. The two band systems from the spectrum of the 1-butene reaction are assigned to the ionization of two isomers: La[C(CH2)3] (Iso A) and La(CH2CHCHCH2) (Iso B), and the single band system from the spectra of the 2-butene and isobutene reactions is attributed to Iso B and Iso A, respectively. The ground electronic states are 2A1 (C3v) for Iso A and 2A' (Cs) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and leads to the 1A1 ion of Iso A and the 1A' ion of Iso B. The formation of both isomers consists of La addition to the C=C double bond, La insertion into two C(sp3)-H bonds, and H2 elimination. In addition to these steps, the formation of Iso A from the La+1-butene reaction may involve the isomerization of 1-butene to isobutene prior to the C-H bond activation, whereas the formation of Iso B from the La+trans-2-butene reaction may include the trans- to cis-butene isomerization after the C-H bond activation.

9.
J Phys Chem A ; 121(44): 8440-8447, 2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-29061045

RESUMO

Lan(benzene) (n = 1 and 2) are formed in a pulsed laser-ablation molecular beam source and characterized by low-energy photoelectron imaging spectroscopy. The photoelectron spectrum of La2(benzene) displays a strong origin band, a short metal-ligand stretching progression, and a weak ring deformation band. Four isomers are considered for La2(benzene), and the preferred structure is an inverse sandwich with two La atoms residing on the opposite sides of the benzene ring. The ground electronic state of the inverse sandwich is 1A1g (D3d) with (5dxy,x2-y2 + π*)46s2 electron configuration. Ionization removes a La-based 6s electron and yields a 2A1g ion. The spectrum of La(benzene) is similar to the zero-electron kinetic energy spectrum reported previously by our group, although the spectral line width is somewhat broader. The measurement of the photoelectron angular distribution of La(benzene) confirms that the ejected electron has largely a p wave character. The metal-ligand bonding of La2(benzene) is considerably stronger than that of La(benzene) due to the threefold binding of each La atom in the dilanthanum species and the twofold binding in the monolanthanum complex.

10.
Opt Express ; 25(14): 16364-16377, 2017 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-28789141

RESUMO

Lack of efficient routes to modulate the propagation properties of the terahertz (THz) wave is a major barrier for the further development of THz technology. In recent years, two dimensional transition metal dichalcogenides (2D TMDCs) were applied to the design of effective THz modulator by forming heterostructure with Si. Here, we experimentally demonstrate an optical controlled THz modulator consisting of liquid-exfoliated WS2 nanosheets and a silicon substrate (WS2-Si). By innovatively depositing liquid-exfoliated WS2 nanosheets on the Si instead of growing by chemical vapor deposition (CVD) method, both of the size and the thickness of WS2 film is controlled. The WS2-Si sample presents a flat modulation depth from 0.2 THz to 1.6 THz. The modulation depth reaches 56.7% under a 50 mW pumping power, which is over 5 times enhanced compared with that of the Si substrate. With the increase of illumination power, the modulation depth continues to increase, finally reaching up to 94.8% under 470 mW. Besides, the WS2-Si sample also achieves ~80% modulation depth under 450 nm illumination, indicating its ability to operate under either of wavelength in visible spectra. Moreover, we compare the sample to the reported modulators including CVD growth TMDCs-Si ones and find our sample has comparable modulation effects while is much easy to be prepared. Therefore, we believe our work is meaningful to provide an alternative route to achieve effective modulation of THz waves by adopting liquid-exfoliated 2D materials.

11.
J Chem Phys ; 147(6): 064303, 2017 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-28810759

RESUMO

La atom reactions with 1-butyne and 2-butyne are carried out in a laser-vaporization molecular beam source. Both reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butynes. The dehydrogenated species La(C4H4) is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of La(C4H4) produced from the two reactions exhibit two identical transitions, each consisting of a strong origin band and several vibrational intervals. The two transitions are assigned to the ionization of two isomers: La(η4-CH2CCCH2) (Iso A) and La(η4-CH2CHCCH) (Iso B). The ground electronic states are 2A1 (C2v) for Iso A and 2A (C1) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and results in a 1A1 ion of Iso A and a 1A ion of Iso B. The formation of Iso A from 2-butyne and Iso B from 1-butyne involves the addition of La to the C≡C triple bond, the activation of two C(sp3)-H bonds, and concerted elimination of a H2 molecule. The formation of Iso A from 1-butyne and Iso B from 2-butyne involves the isomerization of the two butynes to 1,2-butadiene in addition to the concerted H2 elimination.

12.
J Chem Phys ; 146(7): 074305, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-28228024

RESUMO

La(C3H4) and La(C3H6) are observed from the reaction of laser-vaporized La atoms with propene by photoionization time-of-flight mass spectrometry and characterized by mass-analyzed threshold ionization spectroscopy. Two isomers of La(C3H4) are identified as methyl-lanthanacyclopropene [La(CHCCH3)] (Cs) and lanthanacyclobutene [La(CHCHCH2)] (C1); La(C3H6) is determined to be H-La(η3-allyl) (Cs), a C-H bond inserted species. All three metal-hydrocarbon radicals prefer a doublet ground state with a La 6s-based electron configuration. Ionization of the neutral doublet state of each of these radicals produces a singlet ion state by removing the La-based 6s electron. The threshold ionization allows accurate measurements of the adiabatic ionization energy of the neutral doublet state and metal-ligand and ligand-based vibrational frequencies of the neutral and ionic states. The formation of the three radicals is investigated by density functional theory computations. The inserted species is formed by La inserting into an allylic C-H bond and lanthanacyclopropene by concerted vinylic H2 elimination, whereas lanthanacyclobutene involves both allylic and vinylic dehydrogenations. The inserted species is identified as an intermediate for the formation of lanthanacyclobutene.

13.
J Phys Chem A ; 121(6): 1233-1239, 2017 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-28124565

RESUMO

The reaction between La atoms and 1,3-butadiene is carried out in a laser-vaporization molecular beam source. Metal-hydrocarbon species with formulas La(CnHn) (n = 2, 4, and 6) and La(CmHm+2) (m = 4 and 6) are observed with time-of-flight mass spectrometry and characterized with mass-analyzed threshold ionization spectroscopy. A lanthanum-benzene complex [La(C6H6)] is formed by 1,3-butadiene addition to lanthanacyclopropene [La(C2H2)] followed by molecular hydrogen elimination. Lanthanacyclopropene is an intermediate generated by the primary reaction between La and 1,3-butadiene. Two other intermediates produced by the La + 1,3-butadiene reaction are La[η4-(1-buten-3-yne)] [La(C4H4)] and 1-lanthanacyclopent-3-ene [La(C4H6)]. The La(benzene) complex exhibits distinctive metal-ligand bonding from that of the three intermediates as shown by the adiabatic ionization energies and ground electron configurations.

14.
Shanghai Kou Qiang Yi Xue ; 25(3): 322-6, 2016 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-27609387

RESUMO

PURPOSE: To investigate the expression and significance of discoidin domain receptor 1 (DDR1) in salivary gland mucoepidermoid carcinoma (MEC). METHODS: Immunohistochemical and Western blot method were used to detect the expression of DDR1 in MEC M3SP2 and MC3 cell lines. Immunohistochemical method was used to detect the expression of DDR1 in 58 MEC and 20 normal salivary gland tissues. SPSS 13.0 software package was used for statistical analysis. RESULTS: The positive expression rate of DDR1 in salivary gland MEC tissues was 79.3%, significantly higher than 10.0% in normal salivary gland tissues (P<0.01). High expression of DDR1 was not related to clinicopathological parameters of MEC(P>0.05). The expression of DDR1 was positive in MEC M3SP2 and MC3 cell lines. CONCLUSIONS: DDR1 may play an important role in carcinogenesis and progress of salivary gland MEC.


Assuntos
Carcinoma Mucoepidermoide/metabolismo , Receptor com Domínio Discoidina 1/metabolismo , Neoplasias das Glândulas Salivares/metabolismo , Carcinoma Mucoepidermoide/diagnóstico , Carcinoma de Células Escamosas , Domínio Discoidina , Neoplasias de Cabeça e Pescoço , Humanos , Neoplasias das Glândulas Salivares/diagnóstico , Glândulas Salivares , Carcinoma de Células Escamosas de Cabeça e Pescoço
15.
J Phys Chem A ; 120(35): 6963-9, 2016 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-27548080

RESUMO

A Ce atom reaction with ethylene was carried out in a laser-vaporization metal cluster beam source. Ce(C2H2) formed by hydrogen elimination from ethylene was investigated by mass-analyzed threshold ionization (MATI) spectroscopy, isotopic substitutions, and relativistic quantum chemical computations. The theoretical calculations include a scalar relativistic correction, dynamic electron correlation, and spin-orbit coupling. The MATI spectrum exhibits two nearly identical band systems separated by 128 cm(-1). The separation is not affected by deuteration. The two-band systems are attributed to spin-orbit splitting and the vibrational bands to the symmetric metal-ligand stretching and in-plane carbon-hydrogen bending excitations. The spin-orbit splitting arises from interactions of a pair of nearly degenerate triplets and a pair of nearly degenerate singlets. The organolanthanide complex is a metallacyclopropene in C2v symmetry. The low-energy valence electron configurations of the neutral and ion species are Ce 4f(1)6s(1) and Ce 4f(1), respectively. The remaining two electrons that are associated with the isolated Ce atom or ion are spin paired in a molecular orbital that is a bonding combination between a 5d Ce orbital and a π* antibonding orbital of acetylene.

16.
J Phys Chem A ; 120(26): 4482-9, 2016 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-27322131

RESUMO

La(C2H2) and La(C4H6) are observed from the reaction of laser-vaporized La atoms with ethylene molecules by photoionization time-of-flight mass spectrometry and characterized by mass-analyzed threshold ionization spectroscopy. La(C2H2) is identified as a metallacyclopropene and La(C4H6) as a metallacyclopentene. The three-membered ring is formed by concerted H2 elimination and the five-membered cycle by dehydrogenation and C-C bond coupling. Both metallacycles prefer a doublet ground state with a La 6s-based unpaired electron. Ionization of the neutral doublet state of either complex produces a singlet ion state by removing the La-based electron. The ionization allows accurate measurements of the adiabatic ionization energy of the neutral doublet state and metal-ligand and ligand-based vibrational frequencies of the neutral and ionic states. Although the La atom is in a formal oxidation state of +2, the ionization energies of these metal-hydrocarbon cycles are lower than that of the neutral La atom. Deuteration has a small effect on the ionization energies of the two cyclic radicals but distinctive effects on their vibrational frequencies.

17.
Shanghai Kou Qiang Yi Xue ; 25(2): 199-203, 2016 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-27329885

RESUMO

PURPOSE: To discuss the clinical and pathological characteristics and management of parotid gland cyst. METHODS: Forty-five resected samples of parotid gland tumors were selected from Shengjing Hospital of China Medical University from January 2000 to June 2014 whose postoperative pathological diagnosis were parotid gland cysts. The clinico-pathological characteristics in different types of parotid gland cysts were analyzed. RESULTS: Of 45 cases of parotid gland cyst, 25 were males, 20 were females. The median age was 51 years old. 21 cases were located on the left side of parotid gland, while 24 on the right side. The main clinical symptom was painless swelling in parotid gland region. The sizes varied from 0.8 cm×0.6 cm×0.5 cm to 10 cm×2.8 cm×0.6 cm. Nine cases were accompanied with pain, and 36 without. 4 cases were seen with lymph node enlargement, and 41 without pain. The main treatment modality was simple resection of cyst without any injury of facial nerve. No recurrence was seen after following up for 1-10 years. Of the 45 postoperative histopathological results, 29 cases (64.4%) were simple cysts, 9 cases (20.0%) were polycystic disease cysts, and 7 cases (15.6%) were lymphoepithelial cysts. Besides the above-stated pathological manifestations, some non-specific microscopic changes were accompanied with parotid gland cysts, including tumor-like hyperplasia of fibrous tissue, inflammations, calcifications, synovial cyst-like changes, foreign-body giant cell reactions and granulomatous changes. CONCLUSIONS: The main symptom of parotid gland cyst is progressive enlargement, and simple resection of cyst is the first-line treatment without facial nerve injury or reoccurrence. The main pathological classifications are simple cysts,lymphoepithelial cysts and polycystic disease cysts.


Assuntos
Cistos/diagnóstico , Recidiva Local de Neoplasia , Glândula Parótida/patologia , China , Cistos/patologia , Nervo Facial , Traumatismos do Nervo Facial , Feminino , Humanos , Hiperplasia , Hipertrofia , Doenças Linfáticas , Masculino , Neoplasias Parotídeas , Período Pós-Operatório
18.
Xenobiotica ; 46(10): 896-900, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26928207

RESUMO

1. The primary objective of this study was to evaluate the effects of quercetin on the pharmacokinetics of cefprozil. The secondary objective was to evaluate the safety of the combined use of cefprozil and quercetin. 2. An open-label, two-period, crossover phase I trial among 24 Han Chinese male subjects was conducted. Participants were given 500 mg of quercetin orally once daily for 15 d followed by single dose of cefprozil (500 mg) on day 15. Serum concentrations of cefprozil were then measured in all participants on day 15. A 15-d washout period was then assigned after which a 500 mg dose of cefprozil was administered and measured in the serum on day 36. 3. All subjects completed the trial, and no serious adverse events were reported. We measured mean serum concentrations of cefprozil in the presence and absence of quercetin in all participants. The maximum serum concentration of cefprozil in the presence of quercetin was 8.18 ug/ml (95% CI: 7.55-8.81) versus a maximum cefprozil concentration of 8.35 ug/ml (95% CI: 7.51-9.19) in the absence of quercetin. We conclude that the concurrent use of quercetin has no substantial effect on serum concentrations of orally administered cefprozil. 4. Co-administration of quercetin showed no statistically significant effects on the pharmacokinetics of cefprozil in healthy Chinese subjects.


Assuntos
Antibacterianos/farmacocinética , Antioxidantes/farmacologia , Cefalosporinas/farmacocinética , Quercetina/farmacologia , Adulto , Antibacterianos/sangue , Cefalosporinas/sangue , Estudos Cross-Over , Humanos , Masculino , Voluntários
19.
J Am Chem Soc ; 138(8): 2468-71, 2016 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-26875834

RESUMO

We report the first example of metal-mediated acetylene bicyclopentamerization to form naphthalene in the gas phase. The bicyclic aromatic compound was observed in a complex with La. The La(naphthalene) complex was formed by the reaction of laser-ablated La atoms with acetylene molecules in a molecular beam source and was characterized by mass-analyzed threshold ionization spectroscopy. The bicyclo-oligomerization reaction occurs through sequential acetylene additions coupled with dehydrogenation. Three intermediates in the reaction have been identified: lanthanacyclopropene [La(C2H2)], La(cyclobut-1-en-3-yne) [La(C4H2)], and La(benzyne) [(La(C6H4)]. The metal-ligand bonding in the three intermediates is considerably different from that in the La(naphthalene) complex, as suggested by accurately measured adiabatic ionization energies.

20.
Tumour Biol ; 37(3): 3757-64, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26468018

RESUMO

The objective of this study is to determine the effects of Rho-associated coiled-coil containing protein kinase (ROCK) inhibitor Y-27632 on the growth, invasion, and migration of Tca8113 and CAL-27 cells in tongue squamous cell carcinoma (TSCC). The methods of the study are as follows: After being routinely cultured for 24 h, Tca8113 and CAL-27 cells were treated with Y-27632 solution. The morphological change of Y-27632-treated cells was observed under an optical microscope and an inverted microscope; MTT assay was performed to measure the optical density (OD) of cells and calculate cell growth inhibition rate; the change of apoptosis was detected by AnnexinV-FITC/PI assay; cell invasion and migration were measured by Transwell assay. The results were as follows: (1) With increasing concentration of Y-27632, cell morphology changed and cell apoptosis appeared; (2) MTT assay showed that inhibition effect of Y-27632 on Tca8113 and CAL-27 cells was enhanced with increasing concentrations and time (all P < 0.01); (3) Apoptosis showed that, compared with controls, the number of apoptosis cells in experimental groups was significantly increased (all P < 0.01). Apoptosis rate was elevated with increasing concentrations of Y-27632; (4) Transwell assay showed, after a treatment with Y-27632, the number of migrated and invaded Tca8113 and CAL-27 cells in each group was statistically different (all P < 0.01); compared with controls, the number of migrated cell in groups treated with Y-27632 was decreased and less Tca8113 and CAL-27 cells in experimental groups passed through polycarbonate membrane (all P < 0.05). The study concludes that Y-27632 can inhibit the growth, invasion, and migration of Tca8113 and CAL-27 cells, suggesting that Y-27632 may be therapeutically useful in TSCC.


Assuntos
Amidas/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Piridinas/farmacologia , Quinases Associadas a rho/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Humanos , Invasividade Neoplásica , Fatores de Tempo , Neoplasias da Língua/patologia , Quinases Associadas a rho/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA