BACKGROUND Antibiotic resistance has become a global threat for human health,calling for rational use of antibiotics.AIM To analyze the distribution and drug resistance of the bacteria,providing the prerequisite for u...BACKGROUND Antibiotic resistance has become a global threat for human health,calling for rational use of antibiotics.AIM To analyze the distribution and drug resistance of the bacteria,providing the prerequisite for use of antibiotics in emergency patients.METHODS A total of 2048 emergency patients from 2013 to 2017 were enrolled.Their clinical examination specimens were collected,followed by isolation of bacteria.The bacterial identification and drug susceptibility testing were carried out.RESULTS A total of 3387 pathogens were isolated.The top six pathogens were Acinetobacter baumannii(660 strains),Staphylococcus aureus(436 strains),Klebsiella pneumoniae(347 strains),Pseudomonas aeruginosa(338 strains),Escherichia coli(237 strains),and Candida albicans(207 strains).The isolation rates of these pathogens decreased year by year except Klebsiella pneumoniae,which increased from 7.1%to 12.1%.Acinetobacter baumannii is a widely-resistant strain,with multiple resistances to imipenem,ciprofloxacin,minocycline and tigecycline.The Staphylococcus aureus had high resistance rates to levofloxacin,penicillin G,and tetracycline.But the susceptibility of it to vancomycin and tigecycline were 100%.Klebsiella pneumoniae had high resistance rates to imipenem,cefoperazone/sulbactam,amikacin,and ciprofloxacin,with the lowest resistance rate to tigecycline.The resistance rates of Pseudomonas aeruginosa to cefoperazone/sulbactam and imipenem were higher,with the resistance rate to amikacin below 10%.Besides,Escherichia coli had high resistance rates to ciprofloxacin and cefoperazone/sulbactam and low resistance rates to imipenem,amikacin,and tigecycline.CONCLUSION The pathogenic bacteria isolated from the emergency patients were mainly Acinetobacter baumannii,Staphylococcus aureus,Klebsiella pneumoniae,Pseudomonas aeruginosa,Escherichia coli,and Candida albicans.The detection rates of drugresistant bacteria were high,with different bacteria having multiple drug resistances to commonly used antimicrobial agents,guiding the rational use of drugs and reducing the production of multidrug-resistant bacteria.展开更多
A kind of erbium doped photosensitive fiber(EDPF) was proposed and fabricated,whose core was made of double layers named photosensitive layer and erbium doped layer.The double-layer core de-sign can overcome difficult...A kind of erbium doped photosensitive fiber(EDPF) was proposed and fabricated,whose core was made of double layers named photosensitive layer and erbium doped layer.The double-layer core de-sign can overcome difficulties in fabrication of EDPF with single core design,i.e.the conflict between the high consistency rare earth doping and high consistency germanium doping.A sample was fabri-cated through the modified chemical vapor deposition method combined with solution doping tech-nique.The peak absorption coefficient was 48.80 dB/m at 1.53 μm,the background loss was lower than 0.1 dB/m,and the reflectivity of the fiber Brag gratings(FBG) written directly on the sample fiber was up to 97.3% by UV-writing technology.Moreover,a C band tunable fiber laser was fabricated using the sample fiber,in which a uniform FBG was written directly on EDPFs as a reflector.A single wavelength lasing with a maximum wavelength tuning range of 1555.2―1558.0 nm was achieved experimentally.Within this tuning range,the full-width at half maximum(FWHM) of the laser output was smaller than 0.015 nm and the side mode suppression ratio(SMSR) was better than 50 dB.展开更多
An optimal refractive index profile of pure silica core optical fiber (PSCF) was de- signed, in combination with the characters of the modified chemical vapor deposi- tion (MCVD) process. Techniques of preform fabrica...An optimal refractive index profile of pure silica core optical fiber (PSCF) was de- signed, in combination with the characters of the modified chemical vapor deposi- tion (MCVD) process. Techniques of preform fabrication by a new furnace round heating MCVD process and fiber drawing process were reviewed. Difficulties in doping fluorine in silica, widening the depressed-index cladding and maintaining the index of fiber core were discussed. Methods used to overcome these difficulties were given at the same time. Additionally, the optimal refractive index profiles of PSCF were presented.展开更多
文摘BACKGROUND Antibiotic resistance has become a global threat for human health,calling for rational use of antibiotics.AIM To analyze the distribution and drug resistance of the bacteria,providing the prerequisite for use of antibiotics in emergency patients.METHODS A total of 2048 emergency patients from 2013 to 2017 were enrolled.Their clinical examination specimens were collected,followed by isolation of bacteria.The bacterial identification and drug susceptibility testing were carried out.RESULTS A total of 3387 pathogens were isolated.The top six pathogens were Acinetobacter baumannii(660 strains),Staphylococcus aureus(436 strains),Klebsiella pneumoniae(347 strains),Pseudomonas aeruginosa(338 strains),Escherichia coli(237 strains),and Candida albicans(207 strains).The isolation rates of these pathogens decreased year by year except Klebsiella pneumoniae,which increased from 7.1%to 12.1%.Acinetobacter baumannii is a widely-resistant strain,with multiple resistances to imipenem,ciprofloxacin,minocycline and tigecycline.The Staphylococcus aureus had high resistance rates to levofloxacin,penicillin G,and tetracycline.But the susceptibility of it to vancomycin and tigecycline were 100%.Klebsiella pneumoniae had high resistance rates to imipenem,cefoperazone/sulbactam,amikacin,and ciprofloxacin,with the lowest resistance rate to tigecycline.The resistance rates of Pseudomonas aeruginosa to cefoperazone/sulbactam and imipenem were higher,with the resistance rate to amikacin below 10%.Besides,Escherichia coli had high resistance rates to ciprofloxacin and cefoperazone/sulbactam and low resistance rates to imipenem,amikacin,and tigecycline.CONCLUSION The pathogenic bacteria isolated from the emergency patients were mainly Acinetobacter baumannii,Staphylococcus aureus,Klebsiella pneumoniae,Pseudomonas aeruginosa,Escherichia coli,and Candida albicans.The detection rates of drugresistant bacteria were high,with different bacteria having multiple drug resistances to commonly used antimicrobial agents,guiding the rational use of drugs and reducing the production of multidrug-resistant bacteria.
基金Supported by the National High Technology Research and Development Program of China (863 Project) (Grant No. 2007AA01Z258)the National Natural Science Foundation of China (Grant No. 60771008)+2 种基金Program for New Century Excellent Talents in University (Grant No. NCET-06-0076)Beijing Natural Science Founda-tion (Grant No. 4052023)the Beijing Jiaotong University Foundation (Grant No. 2006XM003)
文摘A kind of erbium doped photosensitive fiber(EDPF) was proposed and fabricated,whose core was made of double layers named photosensitive layer and erbium doped layer.The double-layer core de-sign can overcome difficulties in fabrication of EDPF with single core design,i.e.the conflict between the high consistency rare earth doping and high consistency germanium doping.A sample was fabri-cated through the modified chemical vapor deposition method combined with solution doping tech-nique.The peak absorption coefficient was 48.80 dB/m at 1.53 μm,the background loss was lower than 0.1 dB/m,and the reflectivity of the fiber Brag gratings(FBG) written directly on the sample fiber was up to 97.3% by UV-writing technology.Moreover,a C band tunable fiber laser was fabricated using the sample fiber,in which a uniform FBG was written directly on EDPFs as a reflector.A single wavelength lasing with a maximum wavelength tuning range of 1555.2―1558.0 nm was achieved experimentally.Within this tuning range,the full-width at half maximum(FWHM) of the laser output was smaller than 0.015 nm and the side mode suppression ratio(SMSR) was better than 50 dB.
基金the Hi-Tech Research and Development Program of China (Grant No. 2002AA312190)National Natural Science Foundation of China (Grant No. 60477017)+2 种基金Program for the New Century Excellent Talents in University (Grant No. NCET-06-0076)Beijing Natural Science Foun-dation (Grant No. 4052023)the Beijing Jiaotong University Foundation (Grant No. 2006XM003)
文摘An optimal refractive index profile of pure silica core optical fiber (PSCF) was de- signed, in combination with the characters of the modified chemical vapor deposi- tion (MCVD) process. Techniques of preform fabrication by a new furnace round heating MCVD process and fiber drawing process were reviewed. Difficulties in doping fluorine in silica, widening the depressed-index cladding and maintaining the index of fiber core were discussed. Methods used to overcome these difficulties were given at the same time. Additionally, the optimal refractive index profiles of PSCF were presented.
