Staphylococcus aureus is a serious foodborne pathogen threatening food safety and public health.Especially the emergence of methicillin-resistant Staphylococcus aureus(MRSA)increased the difficulty of S.aureus treatme...Staphylococcus aureus is a serious foodborne pathogen threatening food safety and public health.Especially the emergence of methicillin-resistant Staphylococcus aureus(MRSA)increased the difficulty of S.aureus treatment.Staphyloxanthin is a crucial virulence factor of S.aureus.Blocking staphyloxanthin production could help the host immune system counteract the invading S.aureus cells.In this study,we first screened for staphyloxanthin inhibitors using a virtual screening method.The outcome of the virtual screening method resulted in the identification of eugenol(300μg/mL),which significantly inhibits the staphyloxanthin production in S.aureus ATCC 29213,S.aureus Newman,MRSA ATCC 43300 and MRSA ATCC BAA1717by 84.2%,63.5%,68.1%,and 79.5%,respectively.The outcome of the growth curve assay,field-emission scanning electron,and confocal laser scanning microscopy analyses confirmed that eugenol at the test concentration did not affect the morphology and growth of S.aureus.Moreover,the survival rate of S.aureus ATCC 29213 and MRSA ATCC 43300 under H_(2)O_(2) pressure decreased to 51.9%and 45.5%in the presence of eugenol,respectively.The quantitative RT-PCR and molecular simulation studies revealed that eugenol targets staphyloxanthin biosynthesis by downregulating the transcription of the crtM gene and inhibiting the activity of the CrtM enzyme.Taken together,we first determined that eugenol was a prominent compound for staphyloxanthin inhibitor to combat S.aureus especially MRSA infections.展开更多
Objective： To evaluate the efficacy and safety of icotinib hydrochloride in patients with advanced non-small cell lung cancer （NSCLC）. Methods： A total of 89 patients with stage IIIB or IV NSCLC received icotinib ...Objective： To evaluate the efficacy and safety of icotinib hydrochloride in patients with advanced non-small cell lung cancer （NSCLC）. Methods： A total of 89 patients with stage IIIB or IV NSCLC received icotinib at a dose of 125 mg administered 3 times a day. Icotinib treatment was continued until disease progression or development of unacceptable toxicity. Results： A total of 89 patients were assessable. In patients treated with icotinib, the overall response rate （RR） was 36.0% （32/89）, and the disease control rate （DCR） was 69.7% （62/89）. RR and DCR were significantly improved in patients with adenocarcinoma versus non-adenocarcinoma （P〈0.05）. The symptom improvement rate was 57.3% （51/89）, and the main symptoms improved were cough, pain, chest distress, dyspnea, and Eastern Cooperative Oncology Group performance status. The main toxic effects were rash [30/89 （33.7%）] and diarrhea [15/89 （16.9%）]. The level of toxicity was typically low. Conclusions： The use of icofinib hydrochloride in the treatment of advanced NSCLC is efficacious and safe, and its toxic effects are tolerable.展开更多
The structural, mechanical, electronic, mechanical anisotropy, and thermal properties of boron nitride(BN) polymorphs, such as B_4 N-4-Ⅰ and B4 N4-Ⅱ, are investigated under ambient pressure utilizing first-principle...The structural, mechanical, electronic, mechanical anisotropy, and thermal properties of boron nitride(BN) polymorphs, such as B_4 N-4-Ⅰ and B4 N4-Ⅱ, are investigated under ambient pressure utilizing first-principles generalized gradient approximation calculations using an ultrasoft pseudopotential scheme. The phonon spectra and elastic constants reveal that B_4 N_4-Ⅰ is dynamically and mechanically stable at the pressure of 0 GPa and temperature of 0 K. Anisotropic calculations indicate that both B_4 N_4-Ⅰ and B4 N4-Ⅱ exhibit higher anisotropy of Young's modulus than cubic BN(c-BN). B_4 N_4-Ⅱ and B_4 N_4-Ⅰ present indirect and wide band gaps of 5.32 eV and 4.86 eV, respectively. In addition, B_4 N_4-Ⅰ is more brittle than B_4 N_4-Ⅱ. Moreover, the minimum thermal conductivity,κmin, of B4 N4-Ⅱ at 300 K is 1.92 W/(cm·K), which is slightly higher than those of B_4 N_4-Ⅰ and c-BN(1.84 W/(cm-K) and 1.83 W/(cm-K), respectively. However, κ_(min) of B_4 N_4-Ⅰ is slightly higher than that of c-BN.展开更多
A real time PCR assay for the detection of Vibrio para-haemolyticus in seafood samples was developed using a novel specific target and a competitive internal ampli-fication control(IAC).The specificity of this assay w...A real time PCR assay for the detection of Vibrio para-haemolyticus in seafood samples was developed using a novel specific target and a competitive internal ampli-fication control(IAC).The specificity of this assay was evaluated using 390 bacterial strains including V.parahaemolyticus,and other strains belonging to Vibrio and non-Vibrio species.The real time PCR assay un-ambiguously distinguished V.parahaemolyticus with a detection sensitivity of 4.8 fg per PCR with purified genomic DNA or 1 CFU per reaction by counting V.parahaemolyticus colonies.The assays of avoiding interference demonstrated that,even in the presence of 2.1μg genomic DNA or 107 CFU background bacteria,V.parahaemolyticus could still be accurately detected.In addition,the IAC was used to indicate false-negative results,and lower than 94 copies of IAC per reaction had no influence on the detection limit.Ninety-six sea-food samples were tested,of which 58(60.4%)were positive,including 3 false negative results.Conse-quently,the real time PCR assay is effective for the rapid detection of V.parahaemotyticus contaminants in seafood.展开更多
基金supported by the National Natural Science Foundation of China (31972169 and 32001798)。
文摘Staphylococcus aureus is a serious foodborne pathogen threatening food safety and public health.Especially the emergence of methicillin-resistant Staphylococcus aureus(MRSA)increased the difficulty of S.aureus treatment.Staphyloxanthin is a crucial virulence factor of S.aureus.Blocking staphyloxanthin production could help the host immune system counteract the invading S.aureus cells.In this study,we first screened for staphyloxanthin inhibitors using a virtual screening method.The outcome of the virtual screening method resulted in the identification of eugenol(300μg/mL),which significantly inhibits the staphyloxanthin production in S.aureus ATCC 29213,S.aureus Newman,MRSA ATCC 43300 and MRSA ATCC BAA1717by 84.2%,63.5%,68.1%,and 79.5%,respectively.The outcome of the growth curve assay,field-emission scanning electron,and confocal laser scanning microscopy analyses confirmed that eugenol at the test concentration did not affect the morphology and growth of S.aureus.Moreover,the survival rate of S.aureus ATCC 29213 and MRSA ATCC 43300 under H_(2)O_(2) pressure decreased to 51.9%and 45.5%in the presence of eugenol,respectively.The quantitative RT-PCR and molecular simulation studies revealed that eugenol targets staphyloxanthin biosynthesis by downregulating the transcription of the crtM gene and inhibiting the activity of the CrtM enzyme.Taken together,we first determined that eugenol was a prominent compound for staphyloxanthin inhibitor to combat S.aureus especially MRSA infections.
文摘Objective： To evaluate the efficacy and safety of icotinib hydrochloride in patients with advanced non-small cell lung cancer （NSCLC）. Methods： A total of 89 patients with stage IIIB or IV NSCLC received icotinib at a dose of 125 mg administered 3 times a day. Icotinib treatment was continued until disease progression or development of unacceptable toxicity. Results： A total of 89 patients were assessable. In patients treated with icotinib, the overall response rate （RR） was 36.0% （32/89）, and the disease control rate （DCR） was 69.7% （62/89）. RR and DCR were significantly improved in patients with adenocarcinoma versus non-adenocarcinoma （P〈0.05）. The symptom improvement rate was 57.3% （51/89）, and the main symptoms improved were cough, pain, chest distress, dyspnea, and Eastern Cooperative Oncology Group performance status. The main toxic effects were rash [30/89 （33.7%）] and diarrhea [15/89 （16.9%）]. The level of toxicity was typically low. Conclusions： The use of icofinib hydrochloride in the treatment of advanced NSCLC is efficacious and safe, and its toxic effects are tolerable.
基金supported by the National Natural Science Foundation of China(Grant No.61601468)the Fundamental Research Funds for the Central Universities,China(Grant No.3122014C024)the Fund for Scholars of Civil Aviation of the University of China(Grant No.2013QD06X)
文摘The structural, mechanical, electronic, mechanical anisotropy, and thermal properties of boron nitride(BN) polymorphs, such as B_4 N-4-Ⅰ and B4 N4-Ⅱ, are investigated under ambient pressure utilizing first-principles generalized gradient approximation calculations using an ultrasoft pseudopotential scheme. The phonon spectra and elastic constants reveal that B_4 N_4-Ⅰ is dynamically and mechanically stable at the pressure of 0 GPa and temperature of 0 K. Anisotropic calculations indicate that both B_4 N_4-Ⅰ and B4 N4-Ⅱ exhibit higher anisotropy of Young's modulus than cubic BN(c-BN). B_4 N_4-Ⅱ and B_4 N_4-Ⅰ present indirect and wide band gaps of 5.32 eV and 4.86 eV, respectively. In addition, B_4 N_4-Ⅰ is more brittle than B_4 N_4-Ⅱ. Moreover, the minimum thermal conductivity,κmin, of B4 N4-Ⅱ at 300 K is 1.92 W/(cm·K), which is slightly higher than those of B_4 N_4-Ⅰ and c-BN(1.84 W/(cm-K) and 1.83 W/(cm-K), respectively. However, κ_(min) of B_4 N_4-Ⅰ is slightly higher than that of c-BN.
基金supported by grants from the Ministry of Sci-ence and Technology of China(Nos.2012AA101601 and 2011DFA31220)the National Natural Science Foundation of China(Grant Nos.31171690,30972485,31000779 and U1031003)the Science and Technology Commission of Shanghai Municipality(Nos.10DZ0503500 and 10142201300).
文摘A real time PCR assay for the detection of Vibrio para-haemolyticus in seafood samples was developed using a novel specific target and a competitive internal ampli-fication control(IAC).The specificity of this assay was evaluated using 390 bacterial strains including V.parahaemolyticus,and other strains belonging to Vibrio and non-Vibrio species.The real time PCR assay un-ambiguously distinguished V.parahaemolyticus with a detection sensitivity of 4.8 fg per PCR with purified genomic DNA or 1 CFU per reaction by counting V.parahaemolyticus colonies.The assays of avoiding interference demonstrated that,even in the presence of 2.1μg genomic DNA or 107 CFU background bacteria,V.parahaemolyticus could still be accurately detected.In addition,the IAC was used to indicate false-negative results,and lower than 94 copies of IAC per reaction had no influence on the detection limit.Ninety-six sea-food samples were tested,of which 58(60.4%)were positive,including 3 false negative results.Conse-quently,the real time PCR assay is effective for the rapid detection of V.parahaemotyticus contaminants in seafood.
