Background: As the global novel coronavirus pneumonia (NCP) remains severe, elderly people are at high risk for NCP and osteoporotic vertebral compression fractures, with high complications and mortality. How to treat...Background: As the global novel coronavirus pneumonia (NCP) remains severe, elderly people are at high risk for NCP and osteoporotic vertebral compression fractures, with high complications and mortality. How to treat patients and protect medical staff from infection, and at the same time strictly prevent the occurrence of clustered transmission events in the hospital, the establishment of perfect pre-hospital emergency measures and infection prevention and control strategy is the first element to ensure success. Objective: To establish the diagnosis and treatment and infection protection strategy for Osteoporotic vertebral compression fractures (OVCF) patients undergoing minimally invasive percutaneous kyphoplasty (PKP) surgery during the prevention and control of COVID-19, so as to ensure the stable, orderly and safe medical treatment. Methods: A total of 583 OVCF patients were admitted to the First Affiliated Hospital of Hebei North University during the epidemic prevention and control period from January 2020 to July 2022. After urgent and outpatient strict standardized screening, 382 patients met the inclusion criteria, including 112 males and 270 females, aged (70.50 ± 5.49) years. The preoperative visual analogue scale (VAS) score was 6.92 ± 1.86. Preoperative Oswestry disability index (ODI) was 74.67 ± 4.84. The satisfaction rate was (45.89 ± 3.67) %. According to the clinical diagnostic criteria and classification, 367 patients were diagnosed as ordinary OVCF, including 156 cases of mild compression and 226 cases of moderate compression. The clinical classification of 15 patients with OVCF diagnosed as COVID-19 was type I, including 10 cases of mild COVID-19 and 5 cases of common COVID-19. All patients were treated with PKP. Results: All patients were followed up at 1 day, 1 month and 3 months after operation, VAS (2.01 ± 0.56, 0.45 ± 0.11, 0 ± 0), ODI (45.41 ± 4.15, 10.22 ± 2.73, 4.03 ± 1.57) and satisfaction (90.12%, 95.57%, 99.23%) were significantly improved compared with those before operation (p < 0.05), and the original medical diseases were not aggravated. In this group, 15 cases of OVCF diagnosed with COVID-19 were given priority to treat COVID-19 under strict three-level protection in the designated isolation ward. PKP was carried out after the condition was stable, and the areas, items and personnel in contact with patients during the perioperative period must be strictly and thoroughly disinfected. The patient had a good prognosis, no complications, no cross-infection in the hospital, and no infection rate among medical staff. Conclusions: The implementation of the diagnosis and treatment and infection protection strategy for OVCF patients undergoing minimally invasive PKP surgery during the prevention and control of COVID-19 has a guiding role in preventing the spread of infection, improving the cure rate, promoting rapid recovery, reducing complications and reducing mortality.展开更多
The present work focused on investigating the corrosion behavior of NiCu low alloy steel in 0.05 M NaHCO_(3) solutions with different Cl−concentrations under the aerobic–anoxic condition.The results showed that NiCu ...The present work focused on investigating the corrosion behavior of NiCu low alloy steel in 0.05 M NaHCO_(3) solutions with different Cl−concentrations under the aerobic–anoxic condition.The results showed that NiCu steel tended to be pseudo-passivated in the solutions of 0.05 M NaHCO_(3) and 0.05 M NaHCO_(3)+0.01 M NaCl exposed to air.The cathodic process transformed from oxygen reduction to the common reduction of oxygen andα-FeOOH,while the anodic process was the iron dissolution.As Cl^(−)increased to 0.1 M,the steel tended to be activity dissolution.Due to the blocking effect of rust layer on the oxygen,the cathodic process transformed to the reduction ofα-FeOOH.After the solutions were deoxidized,the cathodic process was controlled by only rust reduction.Meanwhile,both the cathodic process and anodic process of NiCu steel corrosion were significantly inhibited.During the whole aerobic–anoxic immersion,the corrosion rate of NiCu steel increased with Cl^(−)concentration.It was not only related to the promotion of Cl^(−)on the anodic dissolution of steel,but also related to the cathodic reduction of moreα-FeOOH generated,which could accelerate the cathodic process.展开更多
Ginsenoside Rg1(Rg1), the major effective component of ginseng, has been shown to have multiple bioactivities, but low oral bioavailability. The aim of this study was to develop a simple, sensitive and rapid high perf...Ginsenoside Rg1(Rg1), the major effective component of ginseng, has been shown to have multiple bioactivities, but low oral bioavailability. The aim of this study was to develop a simple, sensitive and rapid high performance liquid chromatography–tandem mass spectrometry(LC–MS/MS) method, which could be used to validate and quantify the concentrations of Rg1 and its metabolites in Sprague-Dawley rat bile,urine, and feces after oral administration(25 mg/kg). Calibration curves offered satisfactory linearity(r40.995)within the determined ranges. Both intra-day and inter-day variances were less than 15%, and the accuracy was within 80–120%. The excretion recoveries of Rg1, ginsenoside Rh1(Rh1), and protopanaxatriol(Ppt) in bile,urine, and feces combined were all greater than 70%. The fecal excretion recoveries of Rg1, Rh1, and Ppt were40.11%, 22.19%, and 22.88%, respectively, whereas 6.88% of Rg1 and 0.09% of Rh1 were excreted in bile.Urinary excretion accounted for only 0.04% of Rg1. In conclusion, the observed excretion profiles for Rg1 and its metabolites after oral administration are helpful for understanding the poor oral bioavailability of Rg1 and will aid further investigations of Rg1 as a pharmacologically active component.展开更多
The enantiomers separation of ei ght pharmaceutical racemates collected in Chinese Pharmacopoeia 2010(Ch.P2010),including nitrendipine,felodipine,omeprazole,praziquantel,sulpiride,clenbuterol hydrochloride,verapamil h...The enantiomers separation of ei ght pharmaceutical racemates collected in Chinese Pharmacopoeia 2010(Ch.P2010),including nitrendipine,felodipine,omeprazole,praziquantel,sulpiride,clenbuterol hydrochloride,verapamil hydrochloride and chlorphenamine maleate,was performed on chiral stationary phase of amylose ramification by high performance liquid chromatography(HPLC)on Chiralpak AD-H column and Chiralpak AS-H column with the mobile phase consisted of isopropanol and n-hexane.The detection wavelength and the flow rate were set at 254 nm and 0.7 mL/min,respectively.The effects of proportion of organic additives,alcohol displacer and temperature on the separation were investigated.The results indicated that eight chiral drugs were separated on chiral stationary phase of amylase ramification in normal phase chroma tographic system.The chromatographic retention and resolution of enantiomers were adjusted by factors,including the changes of the concentration of alcohol displacer in mobile phase,organic alkaline modifier and column temperature.It was shown that the resolution was improved with reducing concentration of alcohol displacer.When the concentration of organic alkaline modifier was 0.2%,the resolution and the peak shape were fairly good.Most racemates mentioned above had the best resolution at column temperature of 25℃.The best temperature should be kept unchanged in the process of separation so as to obtain stable separation results.展开更多
Edge effects are predicted to significantly impact the properties of low dimensional materials with layered structures. The synthesis of low dimensional materials with copious edges is desired for exploring the effect...Edge effects are predicted to significantly impact the properties of low dimensional materials with layered structures. The synthesis of low dimensional materials with copious edges is desired for exploring the effects of edges on the band structure and properties of these materials. Here we developed an approach for synthesizing MoS2 nanobelts terminated with vertically aligned edges by sulfurizing hydrothermally synthesized MoO3 nanobelts in the gas phase through a kinetically driven process; we then investigated the electrical and magnetic properties of these metastable materials. These edge-terminated MoS2 nanobelts were found to be metallic and ferromagnetic, and thus dramatically different from the semiconducting and nonmagnetic two-dimensional (2D) and three-dimensional (3D) 2H-MoS2 materials. The transitions in electrical and magnetic properties elucidate the fact that edges can tune the properties of low dimensional materials. The unique structure and properties of this one-dimensional (1D) MoS2 material will enable its applications in electronics, spintronics, and catalysis.展开更多
304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most...304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most important cariogenic bacteria. In this work, MIC behavior of a new 304-Cu SS in presence of S. mutans was studied by the observations using scanning electron microscopy(SEM) and confocal laser scanning microscopy(CLSM) including live/dead staining, extracellular polymeric substance(EPS)staining and pitting corrosion, electrochemical test, and X-ray photoelectron spectroscopy(XPS). Above results showed that 304-Cu SS possessed excellent biofilm inhibition ability and presented lower corrosion current density(icorr), larger polarization resistance(Rp) and charge transfer resistance(Rct) in the presence of S. mutans, indicating that 304-Cu SS had a better MIC resistance against S. mutans. It was further affirmed by XPS results that the presence of Cu-oxide in passive film of 304-Cu SS inhibited the formation of biofilm.展开更多
Frequently, the shooting angles available to photograph an object are limited, and the resultant images contain perspective distortions. These distortions make more difficult to perform subsequent tasks like feature e...Frequently, the shooting angles available to photograph an object are limited, and the resultant images contain perspective distortions. These distortions make more difficult to perform subsequent tasks like feature extraction and information identification. This paper suggested a perspective correction method that extracts automatically distortion features through edge detection. Results showed that this method is powerful in correcting images with perspective distortions. The corrected image has virtually little information missing, clear features and high recovery rate.展开更多
The corrosion behavior of NiCu low alloy steel and Q235 low carbon steel as the candidate materials for geological disposal containers of high-level radioactive waste in the simulated Beishan groundwater was comparati...The corrosion behavior of NiCu low alloy steel and Q235 low carbon steel as the candidate materials for geological disposal containers of high-level radioactive waste in the simulated Beishan groundwater was comparatively studied by weight loss test,electrochemical measurements,scanning electron microscope(SEM),electron probe microanalysis(EPMA),X-ray diffraction(XRD),Raman spectrum and X-ray photoelectron spectroscopy(XPS).The electrochemical results showed that the corrosion potential of NiCu steel and Q235 steel gradually increased with the immersion time.Simultaneously,the cathodic process transited from hydrogen evolution reaction(HER) control to the rust reduction control,while the anodic process was always dominated by the active dissolution of iron.By comparison,both the cathodic resistance and the anodic dissolution resistance of NiCu steel corrosion were apparently higher than that of Q235 steel.The results of rust layer characterization indicated that Ni and Cu elements could be enriched in the inner rust layer of NiCu steel and the rust layer was more compact.As the main corrosion products,the content of α-FeOOH in the rust layer of NiCu steel was obviously increased more than that of Q235 steel.Fe_(6)(OH)_(12)SO_(4)stably existed in the corrosion products of NiCu steel because Ni(Ⅱ) or Cu(Ⅱ)could substitute Fe(Ⅱ) of Fe_(6)(OH)_(12)SO_(4)and increased its oxidation resistance,Moreover,Ni and Cu could also make Fe3O4ionic selective by doping.After the long-term immersion,the corrosion mass loss of NiCu steel was significantly lower than Q235 steel,which further confirmed the benefits of Ni and Cu alloying on improving the steel corrosion resistance.展开更多
The corrosion evolution of steel disposal container largely depends on the evolution of surrounding bentonite environment in the long-term geological disposal of high-level radioactive wastes. This study focused on th...The corrosion evolution of steel disposal container largely depends on the evolution of surrounding bentonite environment in the long-term geological disposal of high-level radioactive wastes. This study focused on the influence of the deteriorated bentonite sediments on the corrosion behavior of NiCu low alloy steel in the top supernatant and bottom slurry formed by Gaomiaozi bentonite and 0.05 M NaHCO_(3) + 0.1 M NaCl + 0.1 M Na_(2)SO_(4) solution. In the top supernatant, the cathodic process of the steel corrosion was transformed from the reduction in oxygen to the reduction in ferric corrosion products with time as same as that in the blank solution. While in the bottom bentonite slurry, the cathodic process always maintained as the hydrogen evolution reaction due to the coverage of more bentonite sediments. Meanwhile, the corrosion rate of NiCu steel was obviously decreased. In addition, the localized corrosion tendency of the steel could also be reduced by the large amount of deteriorated bentonite sediments.展开更多
文摘Background: As the global novel coronavirus pneumonia (NCP) remains severe, elderly people are at high risk for NCP and osteoporotic vertebral compression fractures, with high complications and mortality. How to treat patients and protect medical staff from infection, and at the same time strictly prevent the occurrence of clustered transmission events in the hospital, the establishment of perfect pre-hospital emergency measures and infection prevention and control strategy is the first element to ensure success. Objective: To establish the diagnosis and treatment and infection protection strategy for Osteoporotic vertebral compression fractures (OVCF) patients undergoing minimally invasive percutaneous kyphoplasty (PKP) surgery during the prevention and control of COVID-19, so as to ensure the stable, orderly and safe medical treatment. Methods: A total of 583 OVCF patients were admitted to the First Affiliated Hospital of Hebei North University during the epidemic prevention and control period from January 2020 to July 2022. After urgent and outpatient strict standardized screening, 382 patients met the inclusion criteria, including 112 males and 270 females, aged (70.50 ± 5.49) years. The preoperative visual analogue scale (VAS) score was 6.92 ± 1.86. Preoperative Oswestry disability index (ODI) was 74.67 ± 4.84. The satisfaction rate was (45.89 ± 3.67) %. According to the clinical diagnostic criteria and classification, 367 patients were diagnosed as ordinary OVCF, including 156 cases of mild compression and 226 cases of moderate compression. The clinical classification of 15 patients with OVCF diagnosed as COVID-19 was type I, including 10 cases of mild COVID-19 and 5 cases of common COVID-19. All patients were treated with PKP. Results: All patients were followed up at 1 day, 1 month and 3 months after operation, VAS (2.01 ± 0.56, 0.45 ± 0.11, 0 ± 0), ODI (45.41 ± 4.15, 10.22 ± 2.73, 4.03 ± 1.57) and satisfaction (90.12%, 95.57%, 99.23%) were significantly improved compared with those before operation (p < 0.05), and the original medical diseases were not aggravated. In this group, 15 cases of OVCF diagnosed with COVID-19 were given priority to treat COVID-19 under strict three-level protection in the designated isolation ward. PKP was carried out after the condition was stable, and the areas, items and personnel in contact with patients during the perioperative period must be strictly and thoroughly disinfected. The patient had a good prognosis, no complications, no cross-infection in the hospital, and no infection rate among medical staff. Conclusions: The implementation of the diagnosis and treatment and infection protection strategy for OVCF patients undergoing minimally invasive PKP surgery during the prevention and control of COVID-19 has a guiding role in preventing the spread of infection, improving the cure rate, promoting rapid recovery, reducing complications and reducing mortality.
基金supported by the National Natural Science Foundation of China(Nos.U1867216,52173304 and 51701222).
文摘The present work focused on investigating the corrosion behavior of NiCu low alloy steel in 0.05 M NaHCO_(3) solutions with different Cl−concentrations under the aerobic–anoxic condition.The results showed that NiCu steel tended to be pseudo-passivated in the solutions of 0.05 M NaHCO_(3) and 0.05 M NaHCO_(3)+0.01 M NaCl exposed to air.The cathodic process transformed from oxygen reduction to the common reduction of oxygen andα-FeOOH,while the anodic process was the iron dissolution.As Cl^(−)increased to 0.1 M,the steel tended to be activity dissolution.Due to the blocking effect of rust layer on the oxygen,the cathodic process transformed to the reduction ofα-FeOOH.After the solutions were deoxidized,the cathodic process was controlled by only rust reduction.Meanwhile,both the cathodic process and anodic process of NiCu steel corrosion were significantly inhibited.During the whole aerobic–anoxic immersion,the corrosion rate of NiCu steel increased with Cl^(−)concentration.It was not only related to the promotion of Cl^(−)on the anodic dissolution of steel,but also related to the cathodic reduction of moreα-FeOOH generated,which could accelerate the cathodic process.
基金supported by the National Natural Science Foundation of China(Nos.81173578 and 81573493)Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD study(No.Z141102004414062)+2 种基金National 863 Program of China(No.2014AA020803)the PUMC Youth Fund and Fundamental Research Funds for the Central Universities(No.3332015136)the Fundamental Research Funds for Central Public Institutes(No.2015CX12)
文摘Ginsenoside Rg1(Rg1), the major effective component of ginseng, has been shown to have multiple bioactivities, but low oral bioavailability. The aim of this study was to develop a simple, sensitive and rapid high performance liquid chromatography–tandem mass spectrometry(LC–MS/MS) method, which could be used to validate and quantify the concentrations of Rg1 and its metabolites in Sprague-Dawley rat bile,urine, and feces after oral administration(25 mg/kg). Calibration curves offered satisfactory linearity(r40.995)within the determined ranges. Both intra-day and inter-day variances were less than 15%, and the accuracy was within 80–120%. The excretion recoveries of Rg1, ginsenoside Rh1(Rh1), and protopanaxatriol(Ppt) in bile,urine, and feces combined were all greater than 70%. The fecal excretion recoveries of Rg1, Rh1, and Ppt were40.11%, 22.19%, and 22.88%, respectively, whereas 6.88% of Rg1 and 0.09% of Rh1 were excreted in bile.Urinary excretion accounted for only 0.04% of Rg1. In conclusion, the observed excretion profiles for Rg1 and its metabolites after oral administration are helpful for understanding the poor oral bioavailability of Rg1 and will aid further investigations of Rg1 as a pharmacologically active component.
文摘The enantiomers separation of ei ght pharmaceutical racemates collected in Chinese Pharmacopoeia 2010(Ch.P2010),including nitrendipine,felodipine,omeprazole,praziquantel,sulpiride,clenbuterol hydrochloride,verapamil hydrochloride and chlorphenamine maleate,was performed on chiral stationary phase of amylose ramification by high performance liquid chromatography(HPLC)on Chiralpak AD-H column and Chiralpak AS-H column with the mobile phase consisted of isopropanol and n-hexane.The detection wavelength and the flow rate were set at 254 nm and 0.7 mL/min,respectively.The effects of proportion of organic additives,alcohol displacer and temperature on the separation were investigated.The results indicated that eight chiral drugs were separated on chiral stationary phase of amylase ramification in normal phase chroma tographic system.The chromatographic retention and resolution of enantiomers were adjusted by factors,including the changes of the concentration of alcohol displacer in mobile phase,organic alkaline modifier and column temperature.It was shown that the resolution was improved with reducing concentration of alcohol displacer.When the concentration of organic alkaline modifier was 0.2%,the resolution and the peak shape were fairly good.Most racemates mentioned above had the best resolution at column temperature of 25℃.The best temperature should be kept unchanged in the process of separation so as to obtain stable separation results.
文摘Edge effects are predicted to significantly impact the properties of low dimensional materials with layered structures. The synthesis of low dimensional materials with copious edges is desired for exploring the effects of edges on the band structure and properties of these materials. Here we developed an approach for synthesizing MoS2 nanobelts terminated with vertically aligned edges by sulfurizing hydrothermally synthesized MoO3 nanobelts in the gas phase through a kinetically driven process; we then investigated the electrical and magnetic properties of these metastable materials. These edge-terminated MoS2 nanobelts were found to be metallic and ferromagnetic, and thus dramatically different from the semiconducting and nonmagnetic two-dimensional (2D) and three-dimensional (3D) 2H-MoS2 materials. The transitions in electrical and magnetic properties elucidate the fact that edges can tune the properties of low dimensional materials. The unique structure and properties of this one-dimensional (1D) MoS2 material will enable its applications in electronics, spintronics, and catalysis.
基金supported financially by the National Natural Science Foundation of China (Nos. 51501199, 51631009 and U1906226)the National Key Research and Development Program of China (No. 2016YFB0300205)。
文摘304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most important cariogenic bacteria. In this work, MIC behavior of a new 304-Cu SS in presence of S. mutans was studied by the observations using scanning electron microscopy(SEM) and confocal laser scanning microscopy(CLSM) including live/dead staining, extracellular polymeric substance(EPS)staining and pitting corrosion, electrochemical test, and X-ray photoelectron spectroscopy(XPS). Above results showed that 304-Cu SS possessed excellent biofilm inhibition ability and presented lower corrosion current density(icorr), larger polarization resistance(Rp) and charge transfer resistance(Rct) in the presence of S. mutans, indicating that 304-Cu SS had a better MIC resistance against S. mutans. It was further affirmed by XPS results that the presence of Cu-oxide in passive film of 304-Cu SS inhibited the formation of biofilm.
基金the National Natural Science Foundation of China (NSFC)(Grant No. 61501150).
文摘Frequently, the shooting angles available to photograph an object are limited, and the resultant images contain perspective distortions. These distortions make more difficult to perform subsequent tasks like feature extraction and information identification. This paper suggested a perspective correction method that extracts automatically distortion features through edge detection. Results showed that this method is powerful in correcting images with perspective distortions. The corrected image has virtually little information missing, clear features and high recovery rate.
基金supported by the National Natural Science Foundation of China (Nos.U1867216,52173304 and 51701222)。
文摘The corrosion behavior of NiCu low alloy steel and Q235 low carbon steel as the candidate materials for geological disposal containers of high-level radioactive waste in the simulated Beishan groundwater was comparatively studied by weight loss test,electrochemical measurements,scanning electron microscope(SEM),electron probe microanalysis(EPMA),X-ray diffraction(XRD),Raman spectrum and X-ray photoelectron spectroscopy(XPS).The electrochemical results showed that the corrosion potential of NiCu steel and Q235 steel gradually increased with the immersion time.Simultaneously,the cathodic process transited from hydrogen evolution reaction(HER) control to the rust reduction control,while the anodic process was always dominated by the active dissolution of iron.By comparison,both the cathodic resistance and the anodic dissolution resistance of NiCu steel corrosion were apparently higher than that of Q235 steel.The results of rust layer characterization indicated that Ni and Cu elements could be enriched in the inner rust layer of NiCu steel and the rust layer was more compact.As the main corrosion products,the content of α-FeOOH in the rust layer of NiCu steel was obviously increased more than that of Q235 steel.Fe_(6)(OH)_(12)SO_(4)stably existed in the corrosion products of NiCu steel because Ni(Ⅱ) or Cu(Ⅱ)could substitute Fe(Ⅱ) of Fe_(6)(OH)_(12)SO_(4)and increased its oxidation resistance,Moreover,Ni and Cu could also make Fe3O4ionic selective by doping.After the long-term immersion,the corrosion mass loss of NiCu steel was significantly lower than Q235 steel,which further confirmed the benefits of Ni and Cu alloying on improving the steel corrosion resistance.
基金financially supported by the National Natural Science Foundation of China(Nos.U1867216,51701222 and 51471175)。
文摘The corrosion evolution of steel disposal container largely depends on the evolution of surrounding bentonite environment in the long-term geological disposal of high-level radioactive wastes. This study focused on the influence of the deteriorated bentonite sediments on the corrosion behavior of NiCu low alloy steel in the top supernatant and bottom slurry formed by Gaomiaozi bentonite and 0.05 M NaHCO_(3) + 0.1 M NaCl + 0.1 M Na_(2)SO_(4) solution. In the top supernatant, the cathodic process of the steel corrosion was transformed from the reduction in oxygen to the reduction in ferric corrosion products with time as same as that in the blank solution. While in the bottom bentonite slurry, the cathodic process always maintained as the hydrogen evolution reaction due to the coverage of more bentonite sediments. Meanwhile, the corrosion rate of NiCu steel was obviously decreased. In addition, the localized corrosion tendency of the steel could also be reduced by the large amount of deteriorated bentonite sediments.