In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrob...In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrobial activity screening and evaluating methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cy- tofluorometric and bioluminescent methods are not widely used because they require specified equip- ment and further evaluation for reproducibility and standardization, even if they can provide rapid re- sults of the antimicrobial agent＇s effects and a better understanding of their impact on the viability and cell damage inflicted to the tested microorganism. In this review article, an exhaustive list of in vitro antimicrobial susceptibility testing methods and detailed information on their advantages and limita- tions are reported.展开更多
Background Some studies suggested that human papillomavirus （HPV） infection could reduce the clinical pregnancy rate and double the spontaneous abortion rate compared with non-infected women after in-vitro fertiliza...Background Some studies suggested that human papillomavirus （HPV） infection could reduce the clinical pregnancy rate and double the spontaneous abortion rate compared with non-infected women after in-vitro fertilization and embryo transfer （IVF-ET）. But some other studies showed there was no difference between HPV infected and non-infected groups of ART outcomes. The role of HPV infection in infertile women undergoing IVF treatments has been a controversial issue which this article attempts to investigate. Methods This is a retrospective analysis of 3880 infertile women undergoing IVF treatment at Peking University Third hospital reproductive medical center in 2008. Patients with abnormal thin-layer preparation cytologic test （TCT） results who underwent fresh cycle embryo transfer were divided into an HPV positive group （n=56） and an HPV negative group （n=56）. The clinical parameters were compared （using Student＇s t-test and chi-squared test）. Univariate and multivariate analyses were taken to see if HPV infection affects the clinical pregnancy rate. Results Of the 3880 cases 157 had TCT abnormality （4.0%）. Of the 149 patients who had HPV test results, 112 women （81.2%） received a fresh cycle embryo transfer. Each group had 56 cases. The patients were of similar age and BMI, basic hormone levels, and infertile factors were similar. The gonadotropin use, oocyte retrieval number, clinical pregnancy rate, abortion rate and newborn condition were all similar between groups. Analyses showed neither HPV infection nor HPV hybrid capture （HC） II results affected clinical pregnancy rate after IVF treatments, but the FSH level did. Conclusion HPV positivity did not appear to impact assisted reproductive technology （ART） success. ＂Extensive treatment＂ for HPV before IVF was not recommended because treatment time will increase age and reduce ovarian function, which will lead to inferior IVF outcomes.展开更多
The combination patterns and depositional characteristics of the carbonate banks are investigated based on outcrop sections, thin sections, and carbon isotopes of Ordovician in the western Tarim Basin, China. Four car...The combination patterns and depositional characteristics of the carbonate banks are investigated based on outcrop sections, thin sections, and carbon isotopes of Ordovician in the western Tarim Basin, China. Four carbonate bank combination patterns are deposited in the Ordovician, western Tarim Basin, including： Reef-Bank Complex （RBC）, Algae-Reef-Bank Interbed （ARBI）, Thick-Layer Cake Aggradation Bank （TLCAB）, and Thin-Layer Cake Retrogradation Bank （TLCRB）. All combination patterns show clear periods vertically. The RBC is mainly composed of reefs and bioclastic banks, and the dimension of the RBC depends on the scale of the reefs. Bioclastic banks deposits surround the reefs. The range of the ARBI is determined by the scale of algae-reefs, algae peloid dolomite microfacies and algal dolomite microfacies deposit alternating vertically. TLCAB and TLCRB are deposited as layer-cakes stacking in cycles and extending widely with cross bedding developed. The grains of TLCAB and TLCRB are diverse and multi-source. With the impacting of relative sea level change, biological development and geomorphology, the ARBI, TLCAB or TLCRB, RBC are successively developed from the Lower Ordovician Penglaiba Formation to the Middle Ordovician Yijianfang Formation. The depositional environment analysis of Ordovician indicates that the RBC and ARBI can form effective oil and gas reservoirs, and the TLCAB and TLCRB have the potential to form the huge scale oil and gas reservoirs and to be the crucial targets of exploration for the Ordovician carbonate banks in the future.展开更多
Bioreactive thin-layer capping（BTC）with biozeolite provides a potential remediation design that can sustainably treat N contamination from sediment and overlying water in eutrophic water bodies.Nitrogen（N）reductio...Bioreactive thin-layer capping（BTC）with biozeolite provides a potential remediation design that can sustainably treat N contamination from sediment and overlying water in eutrophic water bodies.Nitrogen（N）reduction using BTC with biozeolite was examined in a field incubation experiment in a eutrophic river in Yangzhou,Jiangsu Province,China.The biozeolite was zeolite with attached bacteria,including two isolated heterotrophic nitrifiers（Bacillus spp.）and two isolated aerobic denitrifiers（Acinetobacter spp.）.The results showed that the total nitrogen（TN）reduction efficiency of the overlying water by BTC with biozeolite（with thickness of about 2 mm）reached a maximum（56.69%）at day 34,and simultaneous heterotrophic nitrification and aerobic denitrification occurred in the BTC system until day 34.There was a significant difference in the TN concentrations of the overlying water between biozeolite capping and control（t-test;p〈0.05）.The biozeolite had very strong in situ bioregeneration ability.Carbon was the main source of nitrifier growth.However,both dissolved oxygen（DO）and carbon concentrations affected denitrifier growth.In particular,DO concentrations greater than 3 mg/L inhibited denitrifier growth.Therefore,BTC with biozeolite was found to be a feasible technique to reduce N in a eutrophic river.However,it is necessary to further strengthen the adaptability of aerobic denitrifiers through changing domestication methods or conditions.展开更多
Objective： This study examined the antimicrobial activity of Cannabis sativa, Thuja orientalis and Psidium guajava against methicillin-resistant Staphylococcus aureus （MRSA） and used a standardized purification pro...Objective： This study examined the antimicrobial activity of Cannabis sativa, Thuja orientalis and Psidium guajava against methicillin-resistant Staphylococcus aureus （MRSA） and used a standardized purification protocol to determine the presence and abundance of bioactive compounds in the leaf extracts. Methods： In vitro antimicrobial activities of the ethanolic extracts of C sativa, T. orientalis and P. guajava were tested against MRSA. The presence of bioactive molecules in these three leaves was evaluated using biochemical assays and high-performance thin-layer chromatography （HPTLC）. Results： Resistance to methicillin, penicillin, oxacillin and cefoxitin was observed in each of the clinical and nonclinical MRSA isolates. However, they were still vulnerable to vancomydn. Used individually, the 50% extract of each plant leaf inhibited MRSA growth. A profound synergism was observed when C sativa was used in combination with T. orientalis （1：1 ） and when P. guajava was used in combination with T. orientalis （1：1 ）. This was shown by larger zones of inhibition. This synergism was probably due to the combined inhibitory effect of phenolics present in the leaf extracts （i.e., quercetin and gallic acid） and catechin, as detected by HPTLC. Conclusion： The leaf extracts of C sativa, T. orientalis and P. guajava had potential for the control of both hospital- and community-acquired MRSA. Moreover, the inhibitory effect was enhanced when extracts were used in combination.展开更多
A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.Afte...A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.After shell is dried,organics from shrimp shell are extracted with anhydrous ethanol.The alcohol extrative of the shrimp shell is mixed with the ammonium sulfate to extract astaxanthin by aqueous two-phase extraction.The crude astaxanthin is collected,which is distributed in the middle layer of the aqueous two-phase layer.After distilled water is added to the crude astaxanthin,the aqueous solution is centrifuged,and the previous step is repeated for several times.The precipitation in centrifuge tube is collected and dried.The crude astaxanthin dried is dissolved with acetone,and the sample solution is separated by TLC.Every pigment on the TLC plate is collected and dissolved with acetone.The pigments are determined by high performance liquid chromatograph.The results show that aqueous two-phase system,3 mL alcohol extractive of astaxanthin and 4.5 mL 20%ammonium sulfate,can be used to acquire crude astaxanthin.The wavelength of the maximum peak of astaxanthin in ethanol solution is 472 nm.A variety of pigments can be separated from the crude astaxanthin by thin-layer chromatography,including free astaxanthin,astaxanthin monoester,astaxanthin diester,echinenone and other substances.It can be seen from high performance liquid chromatography that the appearance time of free astaxanthin is from 4 min to 5.5 min,and the appearance time of astaxanthin monoester is from 10.5 min to 27.8 min.The method is simple about the sample pretreatment and feasible about the determination of astaxanthin and astaxanthin esters in shrimp shell.展开更多
文摘In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrobial activity screening and evaluating methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cy- tofluorometric and bioluminescent methods are not widely used because they require specified equip- ment and further evaluation for reproducibility and standardization, even if they can provide rapid re- sults of the antimicrobial agent＇s effects and a better understanding of their impact on the viability and cell damage inflicted to the tested microorganism. In this review article, an exhaustive list of in vitro antimicrobial susceptibility testing methods and detailed information on their advantages and limita- tions are reported.
文摘Background Some studies suggested that human papillomavirus （HPV） infection could reduce the clinical pregnancy rate and double the spontaneous abortion rate compared with non-infected women after in-vitro fertilization and embryo transfer （IVF-ET）. But some other studies showed there was no difference between HPV infected and non-infected groups of ART outcomes. The role of HPV infection in infertile women undergoing IVF treatments has been a controversial issue which this article attempts to investigate. Methods This is a retrospective analysis of 3880 infertile women undergoing IVF treatment at Peking University Third hospital reproductive medical center in 2008. Patients with abnormal thin-layer preparation cytologic test （TCT） results who underwent fresh cycle embryo transfer were divided into an HPV positive group （n=56） and an HPV negative group （n=56）. The clinical parameters were compared （using Student＇s t-test and chi-squared test）. Univariate and multivariate analyses were taken to see if HPV infection affects the clinical pregnancy rate. Results Of the 3880 cases 157 had TCT abnormality （4.0%）. Of the 149 patients who had HPV test results, 112 women （81.2%） received a fresh cycle embryo transfer. Each group had 56 cases. The patients were of similar age and BMI, basic hormone levels, and infertile factors were similar. The gonadotropin use, oocyte retrieval number, clinical pregnancy rate, abortion rate and newborn condition were all similar between groups. Analyses showed neither HPV infection nor HPV hybrid capture （HC） II results affected clinical pregnancy rate after IVF treatments, but the FSH level did. Conclusion HPV positivity did not appear to impact assisted reproductive technology （ART） success. ＂Extensive treatment＂ for HPV before IVF was not recommended because treatment time will increase age and reduce ovarian function, which will lead to inferior IVF outcomes.
基金financially supported by the National Natural Science Foundation of China grant(41102087)the Key Project of the National Science & Technology grant(2011ZX05005-002-010HZ,2011ZX05009-002)+1 种基金National Basic Research Program of China grant (2012CB214802)the Special Foundation for Doctoral Subjects in China University of Geosciences(Beijing) grant(2011PY0199)
文摘The combination patterns and depositional characteristics of the carbonate banks are investigated based on outcrop sections, thin sections, and carbon isotopes of Ordovician in the western Tarim Basin, China. Four carbonate bank combination patterns are deposited in the Ordovician, western Tarim Basin, including： Reef-Bank Complex （RBC）, Algae-Reef-Bank Interbed （ARBI）, Thick-Layer Cake Aggradation Bank （TLCAB）, and Thin-Layer Cake Retrogradation Bank （TLCRB）. All combination patterns show clear periods vertically. The RBC is mainly composed of reefs and bioclastic banks, and the dimension of the RBC depends on the scale of the reefs. Bioclastic banks deposits surround the reefs. The range of the ARBI is determined by the scale of algae-reefs, algae peloid dolomite microfacies and algal dolomite microfacies deposit alternating vertically. TLCAB and TLCRB are deposited as layer-cakes stacking in cycles and extending widely with cross bedding developed. The grains of TLCAB and TLCRB are diverse and multi-source. With the impacting of relative sea level change, biological development and geomorphology, the ARBI, TLCAB or TLCRB, RBC are successively developed from the Lower Ordovician Penglaiba Formation to the Middle Ordovician Yijianfang Formation. The depositional environment analysis of Ordovician indicates that the RBC and ARBI can form effective oil and gas reservoirs, and the TLCAB and TLCRB have the potential to form the huge scale oil and gas reservoirs and to be the crucial targets of exploration for the Ordovician carbonate banks in the future.
基金supported by the National Science and Technology Pillar Program(No.2012BAC04B02)the National Natural Science Fund of China(No.51408243)+3 种基金the Natural Science Foundation of Fujian Province of China(No.2015J01213)the Fundamental Research Funds for Central Universities(No.11QZR07)the Science and Technology Plan Fund of Quanzhou City(No.2014Z218)the Research Funds of Huaqiao University(No.14BS216)
文摘Bioreactive thin-layer capping（BTC）with biozeolite provides a potential remediation design that can sustainably treat N contamination from sediment and overlying water in eutrophic water bodies.Nitrogen（N）reduction using BTC with biozeolite was examined in a field incubation experiment in a eutrophic river in Yangzhou,Jiangsu Province,China.The biozeolite was zeolite with attached bacteria,including two isolated heterotrophic nitrifiers（Bacillus spp.）and two isolated aerobic denitrifiers（Acinetobacter spp.）.The results showed that the total nitrogen（TN）reduction efficiency of the overlying water by BTC with biozeolite（with thickness of about 2 mm）reached a maximum（56.69%）at day 34,and simultaneous heterotrophic nitrification and aerobic denitrification occurred in the BTC system until day 34.There was a significant difference in the TN concentrations of the overlying water between biozeolite capping and control（t-test;p〈0.05）.The biozeolite had very strong in situ bioregeneration ability.Carbon was the main source of nitrifier growth.However,both dissolved oxygen（DO）and carbon concentrations affected denitrifier growth.In particular,DO concentrations greater than 3 mg/L inhibited denitrifier growth.Therefore,BTC with biozeolite was found to be a feasible technique to reduce N in a eutrophic river.However,it is necessary to further strengthen the adaptability of aerobic denitrifiers through changing domestication methods or conditions.
基金Saaii Educational Foundation, Kanpur-209203,India,for their financial assistance
文摘Objective： This study examined the antimicrobial activity of Cannabis sativa, Thuja orientalis and Psidium guajava against methicillin-resistant Staphylococcus aureus （MRSA） and used a standardized purification protocol to determine the presence and abundance of bioactive compounds in the leaf extracts. Methods： In vitro antimicrobial activities of the ethanolic extracts of C sativa, T. orientalis and P. guajava were tested against MRSA. The presence of bioactive molecules in these three leaves was evaluated using biochemical assays and high-performance thin-layer chromatography （HPTLC）. Results： Resistance to methicillin, penicillin, oxacillin and cefoxitin was observed in each of the clinical and nonclinical MRSA isolates. However, they were still vulnerable to vancomydn. Used individually, the 50% extract of each plant leaf inhibited MRSA growth. A profound synergism was observed when C sativa was used in combination with T. orientalis （1：1 ） and when P. guajava was used in combination with T. orientalis （1：1 ）. This was shown by larger zones of inhibition. This synergism was probably due to the combined inhibitory effect of phenolics present in the leaf extracts （i.e., quercetin and gallic acid） and catechin, as detected by HPTLC. Conclusion： The leaf extracts of C sativa, T. orientalis and P. guajava had potential for the control of both hospital- and community-acquired MRSA. Moreover, the inhibitory effect was enhanced when extracts were used in combination.
基金supported by Liao Ning Revitalization Talents Program No. XLYC1807161Dalian High-level Talents Innovation Support Plan No. 2017RQ063+4 种基金Dalian Ocean University Zhanlan scholar ProgramThe National Natural Science Foundation of China under contract Nos. 41206013, 41430963the Public Science and Technology Research Funds Projects of Ocean under contract No. 201205018the National Science and Technology Support Program under contract No. 2014BAB12B02Projects of Institute of Marine Industry Technology of Liaoning Universities
文摘A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.After shell is dried,organics from shrimp shell are extracted with anhydrous ethanol.The alcohol extrative of the shrimp shell is mixed with the ammonium sulfate to extract astaxanthin by aqueous two-phase extraction.The crude astaxanthin is collected,which is distributed in the middle layer of the aqueous two-phase layer.After distilled water is added to the crude astaxanthin,the aqueous solution is centrifuged,and the previous step is repeated for several times.The precipitation in centrifuge tube is collected and dried.The crude astaxanthin dried is dissolved with acetone,and the sample solution is separated by TLC.Every pigment on the TLC plate is collected and dissolved with acetone.The pigments are determined by high performance liquid chromatograph.The results show that aqueous two-phase system,3 mL alcohol extractive of astaxanthin and 4.5 mL 20%ammonium sulfate,can be used to acquire crude astaxanthin.The wavelength of the maximum peak of astaxanthin in ethanol solution is 472 nm.A variety of pigments can be separated from the crude astaxanthin by thin-layer chromatography,including free astaxanthin,astaxanthin monoester,astaxanthin diester,echinenone and other substances.It can be seen from high performance liquid chromatography that the appearance time of free astaxanthin is from 4 min to 5.5 min,and the appearance time of astaxanthin monoester is from 10.5 min to 27.8 min.The method is simple about the sample pretreatment and feasible about the determination of astaxanthin and astaxanthin esters in shrimp shell.
