PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta （PRD）, South China, during winter and summer in 2002. Six water-soluble ions, Na^＋, NH4＋, K^＋, Cl^-, NO3^- and SO4^2- were measu...PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta （PRD）, South China, during winter and summer in 2002. Six water-soluble ions, Na^＋, NH4＋, K^＋, Cl^-, NO3^- and SO4^2- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant species followed by nitrate. Overall, a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter but lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3^-/SO4^2- ratio indicated that mobile sources have considerably contribution to the urban aerosol, and stationary sources should not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.展开更多
Background： Atopic dermatitis （AD） is an inflammatory skin disease characterized by chronic recurrent dermatitis with profound itching. Most patients have personal and/or family history of atopic diseases. Several ...Background： Atopic dermatitis （AD） is an inflammatory skin disease characterized by chronic recurrent dermatitis with profound itching. Most patients have personal and/or family history of atopic diseases. Several criteria have been proposed for the diagnosis of AD. Although the clinical features of childhood AD have been widely studied, there has been less large-scale study on adult/adolescent AD. The aim of this study was to investigate the clinical features of adult/adolescent patients with chronic symmetrical eczemaJAD and to propose Chinese diagnostic criteria for adult/adolescent AD. Methods： A hospital-based study was performed. Forty-two dermatological centers participated in this study. Adult and adolescent patients （12 years and over） with chronic symmetrical eczema or AD were included in this study. Questionnaires were completed by both patients and-investigators. The valid questionnaires were analyzed using EpiData 3.1 and SPSS 17.0 software. Results： A total of 2662 valid questionnaires were collected （1369 male and 1293 female）. Of all 2662 patients, 2062 （77.5%） patients had the disease after 12 years old, while only 600 （22.5%） patients had the disease before 12 years old, suggesting late-onset eczema/AD is common. Two thousand one hundred and thirty-nine （80.4%） patients had the disease for more than 6 months. One thousand one hundred and forty-four （43.0%） patients had a personal and/or family history of atopic diseases. One thousand five hundred and forty-eight （58.2%） patients had an elevated total serum IgE and/or eosinophilia and/or positive allergen-specific IgE. Based on these clinical and laboratory features, we proposed Chinese criteria for adult/adolescent AD. Of all 2662 patients, 60.3% were satisfied with our criteria, while only 48.2% satisfied with Hanifin Rajka criteria and 32.7% satisfied with Williams criteria, suggesting a good sensitivity of our criteria in adult/adolescent AD patients. Conclusion： Late-onset of eczema or AD is common. Th展开更多
Electroacupuncture has been widely used to treat cognitive impairment after cerebral ischemia,but the underlying mechanism has not yet been fully elucidated.Studies have shown that autophagy plays an important role in...Electroacupuncture has been widely used to treat cognitive impairment after cerebral ischemia,but the underlying mechanism has not yet been fully elucidated.Studies have shown that autophagy plays an important role in the formation and development of cognitive impairment,and the phosphoinositide 3-kinase(PI3K)/Akt signaling pathway plays an important role in autophagy regulation.To investigate the role played by the PI3K/Akt signaling pathway in the electroacupuncture treatment of cerebral ischemia/reperfusion rat models,we first established a rat model of cerebral ischemia/reperfusion through the occlusion of the middle cerebral artery using the suture method.Starting at 2 hours after modeling,electroacupuncture was delivered at the Shenting(GV24)and Baihui(GV20)acupoints,with a dilatational wave(1-20 Hz frequency,2 mA intensity,6 V peak voltage),for 30 minutes/day over 8 consecutive days.Our results showed that electroacupuncture reduced the infarct volume in a rat model of cerebral ischemia/reperfusion injury,increased the mRNA expression levels of the PI3K/Akt signaling pathwayrelated factors Beclin-1,mammalian target of rapamycin(mTOR),and PI3K,increased the protein expression levels of phosphorylated Akt,Beclin-1,PI3K,and mTOR in the ischemic cerebral cortex,and simultaneously reduced p53 mRNA and protein expression levels.In the Morris water maze test,the latency to find the hidden platform was significantly shortened among rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation.In the spatial probe test,the number of times that a rat crossed the target quadrant was increased in rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation.Electroacupuncture stimulation applied to the Shenting(GV24)and Baihui(GV20)acupoints activated the PI3K/Akt signaling pathway and improved rat learning and memory impairment.This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Henan Unive展开更多
AIM:To compare the incidence of early portal or splenic vein thrombosis(PSVT) in patients treated with irregular and regular anticoagulantion after splenectomy with gastroesophageal devascularization.METHODS:We retros...AIM:To compare the incidence of early portal or splenic vein thrombosis(PSVT) in patients treated with irregular and regular anticoagulantion after splenectomy with gastroesophageal devascularization.METHODS:We retrospectively analyzed 301 patients who underwent splenectomy with gastroesophageal devascularization for portal hypertension due to cirrhosis between April 2004 and July 2010.Patients were categorized into group A with irregular anticoagulation and group B with regular anticoagulation,respectively.Group A(153 patients) received anticoagulant monotherapy for an undesignated time period or with aspirin or warfarin without low-molecular-weight heparin(LMWH) irregularly.Group B(148 patients) received subcutaneous injection of LMWH routinely within the first 5 d after surgery,followed by oral warfarin and aspirin for one month regularly.The target prothrombin time/international normalized ratio(PT/INR) was 1.25-1.50.Platelet and PT/INR were monitored.Color Doppler imaging was performed to monitor PSVT as well as the effectiveness of thrombolytic therapy.RESULTS:The patients' data were collected and analyzed retrospectively.Among the patients,94 developed early postoperative mural PSVT,including 63 patients in group A(63/153,41.17%) and 31 patients in group B(31/148,20.94%).There were 50(32.67%) patients in group A and 27(18.24%) in group B with mural PSVT in the main trunk of portal vein.After the administration of thrombolytic,anticoagulant and antiaggregation therapy,complete or partial thrombus dissolution achieved in 50(79.37%) in group A and 26(83.87%) in group B.CONCLUSION:Regular anticoagulation therapy can reduce the incidence of PSVT in patients who undergo splenectomy with gastroesophageal devascularization,and regular anticoagulant therapy is safer and more effective than irregular anticoagulant therapy.Early and timely thrombolytic therapy is imperative and feasible for the prevention of PSVT.展开更多
Background The severity of respiratory distress was associated with neonatal prognosis. This study aimed to explore the clinical characteristics, therapeutic interventions and short-term outcomes of late preterm or te...Background The severity of respiratory distress was associated with neonatal prognosis. This study aimed to explore the clinical characteristics, therapeutic interventions and short-term outcomes of late preterm or term infants who required respiratory support, and compare the usage of different illness severity assessment tools.Methods Seven neonatal intensive care units in tertiary hospitals were recruited. From November 2008 to October 2009, neonates born at ≥34 weeks＇ gestational age, admitted at 〈72 hours of age, requiring continuous positive airway pressure （CPAP） or mechanical ventilation for respiratory support were enrolled. Clinical data including demographic variables, underlying disease, complications, therapeutic interventions and short-term outcomes were collected. All infants were divided into three groups by Acute care of at-risk newborns （ACoRN） Respiratory Score 〈5, 5-8, and 〉8.Results During the study period, 503 newborn late preterm or term infants required respiratory support. The mean gestational age was （36.8±2.2） weeks, mean birth weight was （2734.5±603.5） g. The majority of the neonates were male （69.4%）, late preterm （63.3%）, delivered by cesarean section （74.8%）, admitted in the first day of life （89.3%） and outborn （born at other hospitals, 76.9%）. Of the cesarean section, 51.1% were performed electively. Infants in the severe group were more mature, had the highest rate of elective cesarean section, Apgar score 〈7 at 5 minutes and resuscitated with intubation, the in-hospital mortality increased significantly. In total, 58.1% of the patients were supported with mechanical ventilation and 17.3% received high frequency oscillation. Adjunctive therapies were commonly needed.Higher rate of infants in severe group needed mechanical ventilation or high frequency oscillation, volume expansion,bicarbonate infusion or vasopressors therapy （P 〈0.05）. The incidence of complications was also increased significantly in severe group （P 〈0.展开更多
Objective Chinese allergic subjects have high levels of sensitization to house dust mite （HDM） and other indoor allergens. This study quantifies common indoor allergen levels in Chinese households. Methods Dust samp...Objective Chinese allergic subjects have high levels of sensitization to house dust mite （HDM） and other indoor allergens. This study quantifies common indoor allergen levels in Chinese households. Methods Dust samples were collected from nine cities. Major allergens Der p 1 and Der f I from Dermatophagoides pteronyssinus and D. farinae, and specific antigens of Blomia tropicalis, Tyrophagus putrescentiae, Acarus siro, and cockroach species Blattella germanica and Periplaneta americana were measured by ELISA.Results HDM allergens were found in dust samples from bedding in 95% of the Chinese households. The median levels varied from 〈0.006 to 9.2 μg/g of dust, depending on the city. The percentages of households having HDM allergen levels associated with the risk of developing allergy sensitization and asthma were 65% and 25%, respectively. Specific antigens of the storage mite and cockroach were only found in samples from the southern and tropical regions of China. Levels of mite allergens were generally higher in samples from bedding compared to samples from the living room, even for storage mites, whereas levels of cockroach antigens were higher in the living room samples.Conclusion HDM allergens are present in bedding dust samples from most Chinese households. Cities in southern and central China have relatively high levels of HDM major allergens compared to cities in northern and western China. Antigens of storage mites and cockroaches are not as common as HDM allergens.展开更多
Background Tp15, Tp17, Tp45, and Tp47 are outer-membrane proteins found in Treponema pallidum, the etiologic agent of syphilis. These proteins are potent antigens and are potential markers for the serological detectio...Background Tp15, Tp17, Tp45, and Tp47 are outer-membrane proteins found in Treponema pallidum, the etiologic agent of syphilis. These proteins are potent antigens and are potential markers for the serological detection of syphilis. The present study analyzed antibodies to these protein antigens （TP-IgM and TP-IgG） in human serum and investigated the expression of these antibodies during different stages of syphilis. Methods Serum samples were collected from 69 subjects （male 45, female 24） diagnosed with syphilis and analyzed by Western blotting for the expression of IgM and IgG against the four protein antigens. Expression levels of the target antibodies were compared during the same stage of syphilis as well as between different stages of this disease. Results In subjects with primary syphilis, the positive rate of Tp45 IgM was higher than that of other TP-IgM. Tp15 IgM was detected only in subjects with tertiary syphilis. Similarly, the seroprevalence of Tp45 IgG in primary syphilis was higher than for other TP-IgG. No target TP-IgM was detected in subjects with latent syphilis. In subjects with secondary syphilis, the expression level of Tp15 IgG （138.73±20.16） was higher than for other target TP-IgG. In subjects with tertiary syphilis, all target TP-IgG were detected. In subjects with tertiary or latent syphilis, the expression levels of Tp45 IgG （121.33±11.04 and 110.10±40.19, respectively） were higher than those of other target TP-IgG. The expression levels of all Tp-lgM were similar before or after anti-syphilis treatment. In comparison, the expression levels of all TP-IgG decreased compared with the pre-treatment levels, and this decrease was statistically significant （both P 〈0.05） for Tp17 IgG and Tp47 IgG. Conclusions After Treponema pallidum infection, Tp45 IgM appeared first and Tp15 IgM occurred during later stages. The positive rates of all TP-IgG increased with the duration of this disease. Anti-syphilis treatment reduced the expression levels of Tp17 IgG and Tp47 IgG. La展开更多
Biomimetic design employs the principles of nature to solve engineering problems. Such designs which are hoped to be quick, efficient, robust, and versatile, have taken advantage of optimization via natural selection....Biomimetic design employs the principles of nature to solve engineering problems. Such designs which are hoped to be quick, efficient, robust, and versatile, have taken advantage of optimization via natural selection. In the present research, an environment-friendly propulsion system mimicking undulating fins of stingray was built. A non-conventional method was considered to model the flexibility of the fins of stingray. A two-degree-of-freedom mechanism comprised of several linkages was designed and constructed to mimic the actual flexible fin, The driving linkages were used to form a mechanical fin consisting of several fin segments, which are able tO produce undulations, similar to those produced by the actual fins. Owing to the modularity of the design of the mechanical fin, various undulating patterns can be realized. Some qualitative observations, obtained by experiments, predicted that the thrusts produced by the mechanical fin are different among various undulating patterns. To fully understand this experimental phenomenon is very important for better performance and energy saving for our biorobotic underwater propulsion system. Here, four basic undulating patterns of the mechanical fin were performed using two-dimensional unsteady computational fluid dynamics （CFD） method. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive re-meshing was used to compute the unsteady flow around the fin through twenty complete cycles. The pressure distribution on fin surface was computed and integrated to provide fin forces which were decomposed into rift and thrust. The pressure force and friction force were also computed throughout the swimming cycle. Finally, vortex contour maps of these four basic fin undulating patterns were displayed and compared.展开更多
AIM: To study hepatic virus C (HCV) RNA and HCV proteinexpression in peripheral blood mononuclear cells (PBMCs)of patients with HCV infection, and explore the relationshipbetween the HCV RNA in the PBMCs and response ...AIM: To study hepatic virus C (HCV) RNA and HCV proteinexpression in peripheral blood mononuclear cells (PBMCs)of patients with HCV infection, and explore the relationshipbetween the HCV RNA in the PBMCs and response tointerferon (IFN) therapy.METHODS: Type-specific primers were designed and RT-nested PCR was used to detect the plus- and minus- strandsof HCV RNA in PBMCs of 54 patients with HCV infection;Indirect immunofluorescence assay was applied to identifyHCVNS5 protein expression in PBMCs; 6 month-, 3 MU-IFNregiment was administrated to observe the responses toIFN in 35 chronic hepatitis C patients with different HCVRNA status in PBMCs.RESULTS: HCV plus strand RNA was found in 10 of 19(52.6 %) acute hepatitis C patients and 22 of 35 (62.9 %)chronic hepatitis C patients. HCV minus strand RNA wasdetected in 14 of 35 (40.0 %) chronic hepatitis C patients,but only one patient (5.3 %) with acute HCV infection wasfound to be minus HCV RNA positive. Though no HCV NS5protein expression was found in the examined 10 cases ofacute HCV infection, it was positive in 17 of 20 (85.0 %)chronic hepatitis C patients by indirect immunofluoresenceassay. There are significant differences of positive rate of theminus-strand and HCVNS5 protein between acute and chronichepatitis C groups(u=2.07, P＜0.05and u=4.43, P＜0.01respectively). The patients with minus-strand HCV RNAshowed a significantly lower 6-month sustained response (SR-6) to IFN compared to those without minus-strand HCVRNAin PBMCs (biologically 14.3 % vs 42.8 %, X2=4.12, P＜0.05and virologically 7.1% vs23.9 %, X2=4.24, P＜0.05).CONCLUSION: HCV is capable of infecting and replicatingin PBMCs, and HCVNS5 protein was expressed in PBMCs.The patients with minus strand HCV RNA in PBMCs showeda significantly lower 6-month sustained response to IFN,suggesting that minus-strand HCV RNA in PBMCs may beone of the factors influencing response to IFN therapy.展开更多
基金Project supported by the National Natural Science Founding of China(No.20347003,40121303)the Research Grants Council of Hong Kong(No.PolyU5038/01E,PolyU5145/03E)the Area of Strategic Development on Atmospheric and Urban Air Pollution of The Hong Kong Polytechnic University(No.A516,A510).
文摘PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta （PRD）, South China, during winter and summer in 2002. Six water-soluble ions, Na^＋, NH4＋, K^＋, Cl^-, NO3^- and SO4^2- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant species followed by nitrate. Overall, a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter but lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3^-/SO4^2- ratio indicated that mobile sources have considerably contribution to the urban aerosol, and stationary sources should not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.
文摘Background： Atopic dermatitis （AD） is an inflammatory skin disease characterized by chronic recurrent dermatitis with profound itching. Most patients have personal and/or family history of atopic diseases. Several criteria have been proposed for the diagnosis of AD. Although the clinical features of childhood AD have been widely studied, there has been less large-scale study on adult/adolescent AD. The aim of this study was to investigate the clinical features of adult/adolescent patients with chronic symmetrical eczemaJAD and to propose Chinese diagnostic criteria for adult/adolescent AD. Methods： A hospital-based study was performed. Forty-two dermatological centers participated in this study. Adult and adolescent patients （12 years and over） with chronic symmetrical eczema or AD were included in this study. Questionnaires were completed by both patients and-investigators. The valid questionnaires were analyzed using EpiData 3.1 and SPSS 17.0 software. Results： A total of 2662 valid questionnaires were collected （1369 male and 1293 female）. Of all 2662 patients, 2062 （77.5%） patients had the disease after 12 years old, while only 600 （22.5%） patients had the disease before 12 years old, suggesting late-onset eczema/AD is common. Two thousand one hundred and thirty-nine （80.4%） patients had the disease for more than 6 months. One thousand one hundred and forty-four （43.0%） patients had a personal and/or family history of atopic diseases. One thousand five hundred and forty-eight （58.2%） patients had an elevated total serum IgE and/or eosinophilia and/or positive allergen-specific IgE. Based on these clinical and laboratory features, we proposed Chinese criteria for adult/adolescent AD. Of all 2662 patients, 60.3% were satisfied with our criteria, while only 48.2% satisfied with Hanifin Rajka criteria and 32.7% satisfied with Williams criteria, suggesting a good sensitivity of our criteria in adult/adolescent AD patients. Conclusion： Late-onset of eczema or AD is common. Th
基金supported by the National Natural Science Foundation of China,No.81574042the Traditional Chinese Medicine Special Research Projects of Henan Province of China,No.2018JDZX011(both to XDF).
文摘Electroacupuncture has been widely used to treat cognitive impairment after cerebral ischemia,but the underlying mechanism has not yet been fully elucidated.Studies have shown that autophagy plays an important role in the formation and development of cognitive impairment,and the phosphoinositide 3-kinase(PI3K)/Akt signaling pathway plays an important role in autophagy regulation.To investigate the role played by the PI3K/Akt signaling pathway in the electroacupuncture treatment of cerebral ischemia/reperfusion rat models,we first established a rat model of cerebral ischemia/reperfusion through the occlusion of the middle cerebral artery using the suture method.Starting at 2 hours after modeling,electroacupuncture was delivered at the Shenting(GV24)and Baihui(GV20)acupoints,with a dilatational wave(1-20 Hz frequency,2 mA intensity,6 V peak voltage),for 30 minutes/day over 8 consecutive days.Our results showed that electroacupuncture reduced the infarct volume in a rat model of cerebral ischemia/reperfusion injury,increased the mRNA expression levels of the PI3K/Akt signaling pathwayrelated factors Beclin-1,mammalian target of rapamycin(mTOR),and PI3K,increased the protein expression levels of phosphorylated Akt,Beclin-1,PI3K,and mTOR in the ischemic cerebral cortex,and simultaneously reduced p53 mRNA and protein expression levels.In the Morris water maze test,the latency to find the hidden platform was significantly shortened among rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation.In the spatial probe test,the number of times that a rat crossed the target quadrant was increased in rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation.Electroacupuncture stimulation applied to the Shenting(GV24)and Baihui(GV20)acupoints activated the PI3K/Akt signaling pathway and improved rat learning and memory impairment.This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Henan Unive
基金Supported by Grants from Beijing Municipal Health Bureau,No.2011-2-18
文摘AIM:To compare the incidence of early portal or splenic vein thrombosis(PSVT) in patients treated with irregular and regular anticoagulantion after splenectomy with gastroesophageal devascularization.METHODS:We retrospectively analyzed 301 patients who underwent splenectomy with gastroesophageal devascularization for portal hypertension due to cirrhosis between April 2004 and July 2010.Patients were categorized into group A with irregular anticoagulation and group B with regular anticoagulation,respectively.Group A(153 patients) received anticoagulant monotherapy for an undesignated time period or with aspirin or warfarin without low-molecular-weight heparin(LMWH) irregularly.Group B(148 patients) received subcutaneous injection of LMWH routinely within the first 5 d after surgery,followed by oral warfarin and aspirin for one month regularly.The target prothrombin time/international normalized ratio(PT/INR) was 1.25-1.50.Platelet and PT/INR were monitored.Color Doppler imaging was performed to monitor PSVT as well as the effectiveness of thrombolytic therapy.RESULTS:The patients' data were collected and analyzed retrospectively.Among the patients,94 developed early postoperative mural PSVT,including 63 patients in group A(63/153,41.17%) and 31 patients in group B(31/148,20.94%).There were 50(32.67%) patients in group A and 27(18.24%) in group B with mural PSVT in the main trunk of portal vein.After the administration of thrombolytic,anticoagulant and antiaggregation therapy,complete or partial thrombus dissolution achieved in 50(79.37%) in group A and 26(83.87%) in group B.CONCLUSION:Regular anticoagulation therapy can reduce the incidence of PSVT in patients who undergo splenectomy with gastroesophageal devascularization,and regular anticoagulant therapy is safer and more effective than irregular anticoagulant therapy.Early and timely thrombolytic therapy is imperative and feasible for the prevention of PSVT.
基金This study was supported by the grants from National Natural Science Foundation of China （No. 30711120575 and No. 30672265）. We thank Dr. Nalini Singhal （University of Calgary, Alberta, Canada） and Dr. Khalid Aziz （University of Alberta, Alberta, Canada） for careful reading and correction of the manuscript and constructive discussion.
文摘Background The severity of respiratory distress was associated with neonatal prognosis. This study aimed to explore the clinical characteristics, therapeutic interventions and short-term outcomes of late preterm or term infants who required respiratory support, and compare the usage of different illness severity assessment tools.Methods Seven neonatal intensive care units in tertiary hospitals were recruited. From November 2008 to October 2009, neonates born at ≥34 weeks＇ gestational age, admitted at 〈72 hours of age, requiring continuous positive airway pressure （CPAP） or mechanical ventilation for respiratory support were enrolled. Clinical data including demographic variables, underlying disease, complications, therapeutic interventions and short-term outcomes were collected. All infants were divided into three groups by Acute care of at-risk newborns （ACoRN） Respiratory Score 〈5, 5-8, and 〉8.Results During the study period, 503 newborn late preterm or term infants required respiratory support. The mean gestational age was （36.8±2.2） weeks, mean birth weight was （2734.5±603.5） g. The majority of the neonates were male （69.4%）, late preterm （63.3%）, delivered by cesarean section （74.8%）, admitted in the first day of life （89.3%） and outborn （born at other hospitals, 76.9%）. Of the cesarean section, 51.1% were performed electively. Infants in the severe group were more mature, had the highest rate of elective cesarean section, Apgar score 〈7 at 5 minutes and resuscitated with intubation, the in-hospital mortality increased significantly. In total, 58.1% of the patients were supported with mechanical ventilation and 17.3% received high frequency oscillation. Adjunctive therapies were commonly needed.Higher rate of infants in severe group needed mechanical ventilation or high frequency oscillation, volume expansion,bicarbonate infusion or vasopressors therapy （P 〈0.05）. The incidence of complications was also increased significantly in severe group （P 〈0.
文摘Objective Chinese allergic subjects have high levels of sensitization to house dust mite （HDM） and other indoor allergens. This study quantifies common indoor allergen levels in Chinese households. Methods Dust samples were collected from nine cities. Major allergens Der p 1 and Der f I from Dermatophagoides pteronyssinus and D. farinae, and specific antigens of Blomia tropicalis, Tyrophagus putrescentiae, Acarus siro, and cockroach species Blattella germanica and Periplaneta americana were measured by ELISA.Results HDM allergens were found in dust samples from bedding in 95% of the Chinese households. The median levels varied from 〈0.006 to 9.2 μg/g of dust, depending on the city. The percentages of households having HDM allergen levels associated with the risk of developing allergy sensitization and asthma were 65% and 25%, respectively. Specific antigens of the storage mite and cockroach were only found in samples from the southern and tropical regions of China. Levels of mite allergens were generally higher in samples from bedding compared to samples from the living room, even for storage mites, whereas levels of cockroach antigens were higher in the living room samples.Conclusion HDM allergens are present in bedding dust samples from most Chinese households. Cities in southern and central China have relatively high levels of HDM major allergens compared to cities in northern and western China. Antigens of storage mites and cockroaches are not as common as HDM allergens.
基金This study was supported by a grant from the Natural Science Foundation of Beijing （No. 7102079）.
文摘Background Tp15, Tp17, Tp45, and Tp47 are outer-membrane proteins found in Treponema pallidum, the etiologic agent of syphilis. These proteins are potent antigens and are potential markers for the serological detection of syphilis. The present study analyzed antibodies to these protein antigens （TP-IgM and TP-IgG） in human serum and investigated the expression of these antibodies during different stages of syphilis. Methods Serum samples were collected from 69 subjects （male 45, female 24） diagnosed with syphilis and analyzed by Western blotting for the expression of IgM and IgG against the four protein antigens. Expression levels of the target antibodies were compared during the same stage of syphilis as well as between different stages of this disease. Results In subjects with primary syphilis, the positive rate of Tp45 IgM was higher than that of other TP-IgM. Tp15 IgM was detected only in subjects with tertiary syphilis. Similarly, the seroprevalence of Tp45 IgG in primary syphilis was higher than for other TP-IgG. No target TP-IgM was detected in subjects with latent syphilis. In subjects with secondary syphilis, the expression level of Tp15 IgG （138.73±20.16） was higher than for other target TP-IgG. In subjects with tertiary syphilis, all target TP-IgG were detected. In subjects with tertiary or latent syphilis, the expression levels of Tp45 IgG （121.33±11.04 and 110.10±40.19, respectively） were higher than those of other target TP-IgG. The expression levels of all Tp-lgM were similar before or after anti-syphilis treatment. In comparison, the expression levels of all TP-IgG decreased compared with the pre-treatment levels, and this decrease was statistically significant （both P 〈0.05） for Tp17 IgG and Tp47 IgG. Conclusions After Treponema pallidum infection, Tp45 IgM appeared first and Tp15 IgM occurred during later stages. The positive rates of all TP-IgG increased with the duration of this disease. Anti-syphilis treatment reduced the expression levels of Tp17 IgG and Tp47 IgG. La
文摘Biomimetic design employs the principles of nature to solve engineering problems. Such designs which are hoped to be quick, efficient, robust, and versatile, have taken advantage of optimization via natural selection. In the present research, an environment-friendly propulsion system mimicking undulating fins of stingray was built. A non-conventional method was considered to model the flexibility of the fins of stingray. A two-degree-of-freedom mechanism comprised of several linkages was designed and constructed to mimic the actual flexible fin, The driving linkages were used to form a mechanical fin consisting of several fin segments, which are able tO produce undulations, similar to those produced by the actual fins. Owing to the modularity of the design of the mechanical fin, various undulating patterns can be realized. Some qualitative observations, obtained by experiments, predicted that the thrusts produced by the mechanical fin are different among various undulating patterns. To fully understand this experimental phenomenon is very important for better performance and energy saving for our biorobotic underwater propulsion system. Here, four basic undulating patterns of the mechanical fin were performed using two-dimensional unsteady computational fluid dynamics （CFD） method. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive re-meshing was used to compute the unsteady flow around the fin through twenty complete cycles. The pressure distribution on fin surface was computed and integrated to provide fin forces which were decomposed into rift and thrust. The pressure force and friction force were also computed throughout the swimming cycle. Finally, vortex contour maps of these four basic fin undulating patterns were displayed and compared.
基金National Natural Science Foundation of China,No. 3967067
文摘AIM: To study hepatic virus C (HCV) RNA and HCV proteinexpression in peripheral blood mononuclear cells (PBMCs)of patients with HCV infection, and explore the relationshipbetween the HCV RNA in the PBMCs and response tointerferon (IFN) therapy.METHODS: Type-specific primers were designed and RT-nested PCR was used to detect the plus- and minus- strandsof HCV RNA in PBMCs of 54 patients with HCV infection;Indirect immunofluorescence assay was applied to identifyHCVNS5 protein expression in PBMCs; 6 month-, 3 MU-IFNregiment was administrated to observe the responses toIFN in 35 chronic hepatitis C patients with different HCVRNA status in PBMCs.RESULTS: HCV plus strand RNA was found in 10 of 19(52.6 %) acute hepatitis C patients and 22 of 35 (62.9 %)chronic hepatitis C patients. HCV minus strand RNA wasdetected in 14 of 35 (40.0 %) chronic hepatitis C patients,but only one patient (5.3 %) with acute HCV infection wasfound to be minus HCV RNA positive. Though no HCV NS5protein expression was found in the examined 10 cases ofacute HCV infection, it was positive in 17 of 20 (85.0 %)chronic hepatitis C patients by indirect immunofluoresenceassay. There are significant differences of positive rate of theminus-strand and HCVNS5 protein between acute and chronichepatitis C groups(u=2.07, P＜0.05and u=4.43, P＜0.01respectively). The patients with minus-strand HCV RNAshowed a significantly lower 6-month sustained response (SR-6) to IFN compared to those without minus-strand HCVRNAin PBMCs (biologically 14.3 % vs 42.8 %, X2=4.12, P＜0.05and virologically 7.1% vs23.9 %, X2=4.24, P＜0.05).CONCLUSION: HCV is capable of infecting and replicatingin PBMCs, and HCVNS5 protein was expressed in PBMCs.The patients with minus strand HCV RNA in PBMCs showeda significantly lower 6-month sustained response to IFN,suggesting that minus-strand HCV RNA in PBMCs may beone of the factors influencing response to IFN therapy.
