Objective: To evaluate the effects of various degrees of hyperventilation on balance of cerebral oxygensupply and consumption during intravenous general anesthesia with jugular venous oxygen saturation monitoringMetbo...Objective: To evaluate the effects of various degrees of hyperventilation on balance of cerebral oxygensupply and consumption during intravenous general anesthesia with jugular venous oxygen saturation monitoringMetbods: Sixty-six patients with supratentorial tumor undergoing intravenous general anesthesia for brain surgerywere randomly divided into three groups. In group Ⅰ, Ⅱ and Ⅲ, end-tidal pressure of Co2(PETCO2) were maintained at 3. 5, 4. 0 and 4. 5 kPa respectively. Radial arterial blood samples and jugular bulb blood samples weretaken synchronously at 60 min after hyperventilation to measure jugular venous oxygen saturation (SjvO2), cerebral extraction of oxygen (CEO2) and cerebral arteriovenous oxygen content difference (AVDO2) were calculatedResults: In group Ⅰ after hyperventilation, SjvO, and jugular venous oxygen content (CjvO2) were decreasedmarkedly while CEO2 was increased significantly, which was different significantly compared with the baseline andcorresponding value in group Ⅱ and Ⅲ (P<0. 05). After hyperventilation in group, and, SjvO2 CjvO2, CEO2and AVDO, remained unchanged. Conclusion: This study shows that sustained excessive hyperventilation (PETCO23.5 kPa) may account for the less favorable cerebral oxygen supply and consumption balance and maintained PETCO, at 4. 0~4. 5 kPa was optimal hyperventilation for brain surgery anesthesia.展开更多
Terpenoids are a class of high value-added natural products with a variety of biological functions.Genetically engineered microorganisms,such as those of Escherichia coli and Saccharomyces cerevisiae,have merits in pr...Terpenoids are a class of high value-added natural products with a variety of biological functions.Genetically engineered microorganisms,such as those of Escherichia coli and Saccharomyces cerevisiae,have merits in producing plant or fungus-derived terpenoids,due to their mature genetic manipulation,simple nutrient demand and fast growth.Oxygen,as a key environmental factor,is particularly important to microbial metabolism and growth,and suitable oxygen supply is viewed as a prerequisite for realizing highly efficient production of terpenoids by engineered microorganisms.In this article,the role of oxygen in regulating terpenoid bioproduction is overviewed from the viewpoints of cellular carbon metabolism,energy metabolism and terpenoid anabolism.Strategies on adjusting oxygen availability to microorganisms,including genetic modification of cellular metabolism related with oxygen utilization,are summarized and discussed,to provide helpful information for further improvement of terpenoid biosynthesis by microbes.展开更多
In order to fulfill the needs of life-support oxygen supply during the development of plateau mineral resources,four oxygen supply patterns suitable for the plateau mine in specific environment were developed:tunnel f...In order to fulfill the needs of life-support oxygen supply during the development of plateau mineral resources,four oxygen supply patterns suitable for the plateau mine in specific environment were developed:tunnel face diffusive oxygen supply,tunnel oxygen-bar car,carried oxygen cylinder and portable oxygen generator. Through the study of safety oxygen supply experiments in low- pressure plateau areas,the mathematical relationship between maximum integration of secure oxygen volume and altitude has been achieved. Oxygen supply safety control should follow this relationship in plateau mines during the time of executing tunnel face or in room air diffusive oxygen supply. The application results of life-support oxygen supplement technologies in the development of mineral resources in high altitude areas show that the oxygen supply for tunneling miners in plateau mines can not only effectively enhance the oxygen saturation,reduce the pulse rate and the breath rate per minute,but also improve various symptoms caused by altitude hypoxia and high-intensity physical labor.展开更多
Chemical oxygen generators(COGs)have been used worldwide in confined spaces as an emergency oxygen supply technology,mainly because they are independent and have a long shelf life.However,a number of challenges relate...Chemical oxygen generators(COGs)have been used worldwide in confined spaces as an emergency oxygen supply technology,mainly because they are independent and have a long shelf life.However,a number of challenges related to COGs remain unsolved,and a literature review of the current state of the technology is needed.First,the present article summarizes the basic information and applications of COGs,including their oxygen production mechanism,components,forming technology,and ignition system.Four current challenges encountered in applying COGs are discussed,along with the strategies adopted thus far to solve these problems,as found in the published literature.The literature survey reveals that,although much effort has been devoted to controlling the oxygen production rate and the heat output of COGs,the mechanism of producing toxic gases remains unclear and a reliable and safe ignition system has not been fully developed.Finally,future opportunities in the development of COGs are briefly listed.展开更多
Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics ...Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics and the severe lack of new drugs necessitates the development of novel agents for biofilm eradication.Photodynamic therapy(PDT)is a promising non-antibiotic method for treating bacterial infections.However,its application in biofilm eradication is hampered by the hypoxic microenvironment of biofilms and the physical protection of extracellular polymeric substances.In this study,we develop a composite nanoplatform with oxygen(O_(2))self-supplying and heat-sensitizing capabilities to improve the PDT efficacy against biofilms.CaO_(2)/ICG@PDA nanoparticles(CIP NPs)are fabricated by combining calcium peroxide(CaO_(2))with the photosensitizer indocyanine green(ICG)via electrostatic interactions,followed by coating with polydopamine(PDA).The CIP NPs can gradually generate O_(2)in response to the acidic microenvironment of the biofilm,thereby alleviating its hypoxic state.Under near-infrared(NIR)irradiation,the nanoplatform converts O_(2)into a significant amount of singlet oxygen(^(1)O_(2))and heat to eradicate biofilm.The generated heat enhances the release of O_(2),accelerates the generation of^(1)O_(2)in PDT,increases cell membrane permeability,and increases bacterial sensitivity to^(1)O_(2).This nanoplatform significantly improves the efficacy of PDT in eradicating biofilm-dwelling bacteria without fostering drug resistance.Experiments on biofilm eradication demonstrate that this nanoplatform can eradicate over 99.9999%of methicillin-resistant Staphylococcus aureus(MRSA)biofilms under 5-min NIR irradiation.Notably,these integrated advantages enable the system to promote the healing of MRSA biofilm-infected wounds with negligible toxicity in vivo,indicating great promise for overcoming the obstacles associated with bacterial biofilm eradication.展开更多
文摘Objective: To evaluate the effects of various degrees of hyperventilation on balance of cerebral oxygensupply and consumption during intravenous general anesthesia with jugular venous oxygen saturation monitoringMetbods: Sixty-six patients with supratentorial tumor undergoing intravenous general anesthesia for brain surgerywere randomly divided into three groups. In group Ⅰ, Ⅱ and Ⅲ, end-tidal pressure of Co2(PETCO2) were maintained at 3. 5, 4. 0 and 4. 5 kPa respectively. Radial arterial blood samples and jugular bulb blood samples weretaken synchronously at 60 min after hyperventilation to measure jugular venous oxygen saturation (SjvO2), cerebral extraction of oxygen (CEO2) and cerebral arteriovenous oxygen content difference (AVDO2) were calculatedResults: In group Ⅰ after hyperventilation, SjvO, and jugular venous oxygen content (CjvO2) were decreasedmarkedly while CEO2 was increased significantly, which was different significantly compared with the baseline andcorresponding value in group Ⅱ and Ⅲ (P<0. 05). After hyperventilation in group, and, SjvO2 CjvO2, CEO2and AVDO, remained unchanged. Conclusion: This study shows that sustained excessive hyperventilation (PETCO23.5 kPa) may account for the less favorable cerebral oxygen supply and consumption balance and maintained PETCO, at 4. 0~4. 5 kPa was optimal hyperventilation for brain surgery anesthesia.
基金This work was supported by the National Key R&D Program of China(Nos.2019YFA0904800 and 2018YFA0901900)the National Natural Science Foundation of China(No.31770037)。
文摘Terpenoids are a class of high value-added natural products with a variety of biological functions.Genetically engineered microorganisms,such as those of Escherichia coli and Saccharomyces cerevisiae,have merits in producing plant or fungus-derived terpenoids,due to their mature genetic manipulation,simple nutrient demand and fast growth.Oxygen,as a key environmental factor,is particularly important to microbial metabolism and growth,and suitable oxygen supply is viewed as a prerequisite for realizing highly efficient production of terpenoids by engineered microorganisms.In this article,the role of oxygen in regulating terpenoid bioproduction is overviewed from the viewpoints of cellular carbon metabolism,energy metabolism and terpenoid anabolism.Strategies on adjusting oxygen availability to microorganisms,including genetic modification of cellular metabolism related with oxygen utilization,are summarized and discussed,to provide helpful information for further improvement of terpenoid biosynthesis by microbes.
基金"973"National Key Basic Research and Development Program(No.2012CB518202)Project of Qinghai Development of Science and Technology(No.2011-N-150)
文摘In order to fulfill the needs of life-support oxygen supply during the development of plateau mineral resources,four oxygen supply patterns suitable for the plateau mine in specific environment were developed:tunnel face diffusive oxygen supply,tunnel oxygen-bar car,carried oxygen cylinder and portable oxygen generator. Through the study of safety oxygen supply experiments in low- pressure plateau areas,the mathematical relationship between maximum integration of secure oxygen volume and altitude has been achieved. Oxygen supply safety control should follow this relationship in plateau mines during the time of executing tunnel face or in room air diffusive oxygen supply. The application results of life-support oxygen supplement technologies in the development of mineral resources in high altitude areas show that the oxygen supply for tunneling miners in plateau mines can not only effectively enhance the oxygen saturation,reduce the pulse rate and the breath rate per minute,but also improve various symptoms caused by altitude hypoxia and high-intensity physical labor.
基金financially supported by the National Key Research and Development Program of China (No.2017YFC0805204)the National Natural Science Foundation of China (Nos.51504017 and 51874015)
文摘Chemical oxygen generators(COGs)have been used worldwide in confined spaces as an emergency oxygen supply technology,mainly because they are independent and have a long shelf life.However,a number of challenges related to COGs remain unsolved,and a literature review of the current state of the technology is needed.First,the present article summarizes the basic information and applications of COGs,including their oxygen production mechanism,components,forming technology,and ignition system.Four current challenges encountered in applying COGs are discussed,along with the strategies adopted thus far to solve these problems,as found in the published literature.The literature survey reveals that,although much effort has been devoted to controlling the oxygen production rate and the heat output of COGs,the mechanism of producing toxic gases remains unclear and a reliable and safe ignition system has not been fully developed.Finally,future opportunities in the development of COGs are briefly listed.
基金supported by the National Natural Science Foundation of China(No.22175125)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.21KJA150008)the Key Laboratory of Polymeric Materials De-sign and Synthesis for Biomedical Function,Soochow University,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics and the severe lack of new drugs necessitates the development of novel agents for biofilm eradication.Photodynamic therapy(PDT)is a promising non-antibiotic method for treating bacterial infections.However,its application in biofilm eradication is hampered by the hypoxic microenvironment of biofilms and the physical protection of extracellular polymeric substances.In this study,we develop a composite nanoplatform with oxygen(O_(2))self-supplying and heat-sensitizing capabilities to improve the PDT efficacy against biofilms.CaO_(2)/ICG@PDA nanoparticles(CIP NPs)are fabricated by combining calcium peroxide(CaO_(2))with the photosensitizer indocyanine green(ICG)via electrostatic interactions,followed by coating with polydopamine(PDA).The CIP NPs can gradually generate O_(2)in response to the acidic microenvironment of the biofilm,thereby alleviating its hypoxic state.Under near-infrared(NIR)irradiation,the nanoplatform converts O_(2)into a significant amount of singlet oxygen(^(1)O_(2))and heat to eradicate biofilm.The generated heat enhances the release of O_(2),accelerates the generation of^(1)O_(2)in PDT,increases cell membrane permeability,and increases bacterial sensitivity to^(1)O_(2).This nanoplatform significantly improves the efficacy of PDT in eradicating biofilm-dwelling bacteria without fostering drug resistance.Experiments on biofilm eradication demonstrate that this nanoplatform can eradicate over 99.9999%of methicillin-resistant Staphylococcus aureus(MRSA)biofilms under 5-min NIR irradiation.Notably,these integrated advantages enable the system to promote the healing of MRSA biofilm-infected wounds with negligible toxicity in vivo,indicating great promise for overcoming the obstacles associated with bacterial biofilm eradication.
