Structural and biochemical mechanism for increased infectivity and immune evasion of Omicron BA.1 and BA.2 variants and their mouse origins

The Omicron BA.2 variant has become a dominant infective strain worldwide. Receptor binding studies reveal that the Omicron BA.2 spike trimer have 11-fold and 2-fold higher potency to human ACE2 than the spike trimer from the wildtype (WT) and Omicron BA.1 strains. The structure of the BA.2 spike trimer complexed with human ACE2 reveals that all three receptor-binding domains (RBDs) in the spike trimer are in open conformation, ready for ACE2 binding, thus providing a basis for the increased infectivity of the BA.2 strain. JMB2002, a therapeutic antibody that was shown to have efficient inhibition of Omicron BA.1, also shows potent neutralization activities against Omicron BA.2. In addition, both BA.1 and BA.2 spike trimers are able to bind to mouse ACE2 with high potency. In contrast, the WT spike trimer binds well to cat ACE2 but not to mouse ACE2. The structures of both BA.1 and BA.2 spike trimer bound to mouse ACE2 reveal the basis for their high affinity interactions. Together, these results suggest a possible evolution pathway for Omicron BA.1 and BA.2 variants from human-cat-mouse-human circle, which could have important implications in establishing an effective strategy in combating viral infection.

Effectiveness and safety of clinical use of stem cells and its implications for regulations / 上海预防医学

ObjectiveTo analyze the effectiveness and safety of clinical use of different types of stem cells to provide evidence for governmental supervision of key issues in clinical utilization of stem cells. MethodsSix literature databases in China and abroad were searched for relevant literature published from January 2010 to July 2020， and a systematic review was conducted. ResultsThe study showed 72 studies concerning the effectiveness and safety of different types of stem cells in clinical utilization. Although clinical utilization of stem cells had some therapeutic effects for certain diseases， their long-term effect and safety need to be further evaluated， especially their potential risk of tumorigenicity. ConclusionTo protect the patients’ interest， physicians should fully weigh the benefits against the risks of clinical utilization of stem cells， and relevant governmental departments should strengthen supervision of ethics of clinical research and therapies involving stem cells as well as supervision of stem cell products.

Structures of the Omicron Spike trimer with ACE2 and an anti-Omicron antibody

The Omicron variant of SARS-CoV-2 has rapidly become the dominant infective strain and the focus efforts against the ongoing COVID-19 pandemic. Here we report an extensive set of structures of the Omicron spike trimer by its own or in complex with ACE2 and an anti-Omicron antibody. These structures reveal that most Omicron mutations are located on the surface of the spike protein, which confer stronger ACE2 binding by nearly 10 folds but become inactive epitopes resistant to many therapeutic antibodies. Importantly, both RBD and the closed conformation of the Omicron spike trimer are thermodynamically unstable, with the melting temperature of the Omicron RBD decreased by as much as 7{degrees}C, making the spiker trimer prone to random open conformations. An unusual RBD-RBD interaction in the ACE2-spike complex unique to Omicron is observed to support the open conformation and ACE2 binding, serving the basis for the higher infectivity of Omicron. A broad-spectrum therapeutic antibody JMB2002, which has completed Phase 1 clinical trial, is found to interact with the same two RBDs to inhibit ACE2 binding, in a mode that is distinguished from all previous antibodies, thus providing the structural basis for the potent inhibition of Omicron by this antibody. Together with biochemical data, our structures provide crucial insights into higher infectivity, antibody evasion and inhibition of Omicron.

Structural basis for repurpose and design of nucleoside drugs for treating COVID-19

SARS-CoV-2 has caused a global pandemic of COVID-19 that urgently needs an effective treatment. Nucleoside analog drugs including favipiravir have been repurposed for COVID-19 despite of unclear mechanism of their inhibition of the viral RNA polymerase (RdRp). Here we report the cryo-EM structures of the viral RdRp in complex with favipiravir and two other nucleoside inhibitor drugs ribavirin and penciclovir. Ribavirin and the ribosylated form of favipiravir share a similar ribose scaffold that is distinct from penciclovir. However, the structures reveal that all three inhibitors are covalently linked to the primer strand in a monophosphate form despite the different chemical scaffolds between favipiravir and penciclovir. Surprisingly, the base moieties of these inhibitors can form mismatched pairs with the template strand. Moreover, in view of the clinical disadvantages of remdesivir mainly associated with its prodrug form, we designed several orally-available remdesivir parent nucleoside derivatives, including VV16 that showed 5-fold more potent than remdesivir in inhibition of viral replication. Together, these results demonstrate an unexpected promiscuity of the viral RNA polymerase and provide a basis for repurpose and design of nucleotide analog drugs for COVID-19. One Sentence SummaryCryo-EM structures of the RNA polymerase of SARS-CoV-2 reveals the basis for repurposing of old nucleotide drugs to treat COVID-19.

Structural basis for repurposing a 100-years-old drug suramin for treating COVID-19

The COVID-19 pandemic by non-stop infections of SARS-CoV-2 has continued to ravage many countries worldwide. Here we report the discovery of suramin, a 100-year-old drug, as a potent inhibitor of the SARS-CoV-2 RNA dependent RNA polymerase (RdRp) through blocking the binding of RNA to the enzyme. In biochemical assays, suramin and its derivatives are at least 20-fold more potent than remdesivir, the currently approved nucleotide drug for COVID-19. The 2.6 [A] cryo-EM structure of the viral RdRp bound to suramin reveals two binding sites of suramin, with one site directly blocking the binding of the RNA template strand and the other site clash with the RNA primer strand near the RdRp catalytic active site, therefore inhibiting the viral RNA replication. Furthermore, suramin potently inhibits SARS-CoV-2 duplication in Vero E6 cells. These results provide a structural mechanism for the first non-nucleotide inhibitor of the SARS-CoV-2 RdRp and a rationale for repurposing suramin for treating COVID-19. One Sentence SummaryDiscovery and mechanism of suramin as potent SARS-CoV-2 RNA polymerase inhibitor and its repurposing for treating COVID-19.

Structural Basis for the Inhibition of the RNA-Dependent RNA Polymerase from SARS-CoV-2 by Remdesivir

The pandemic of Corona Virus Disease 2019 (COVID-19) caused by SARS-CoV-2 has become a global crisis. The replication of SARS-CoV-2 requires the viral RNA-dependent RNA polymerase (RdRp), a direct target of the antiviral drug, Remdesivir. Here we report the structure of the SARS-CoV-2 RdRp either in the apo form or in complex with a 50-base template-primer RNA and Remdesivir at a resolution range of 2.5-2.8 [A]. The complex structure reveals that the partial double-stranded RNA template is inserted into the central channel of the RdRp where Remdesivir is incorporated into the first replicated base pair and terminates the chain elongation. Our structures provide critical insights into the working mechanism of viral RNA replication and a rational template for drug design to combat the viral infection.

Eye-tracking study on circumscribed interest in preschool-aged children with autism spectrum disorder / 中华行为医学与脑科学杂志

Objective:To explore the characteristics of eye tracking movement on circumscribed interests in preschool children with autism spectrum disorder (ASD), providing some reference for behavior correction and rehabilitation training.Methods:Fifty ASD children and fifty-two age-matched typically developing children(TDC) were investigated by the childhood autism rating scale(CARS), the autism diagnostic observation schedule(ADOS), the autism diagnostic interview-revised (ADI-R) and Gesell Developmental Schedule, (GDS). Eye movement during the visual search task was captured by the Tobii Pro X3-120 eye tracker.All data were analyzed by the IBM SPSS Statistics 20.0.Eye movement patterns were compared between TDC and ASD children using the independent-sample t test, and the correlations were then analyzed between abnormal eye movement characteristics and their core syndrome. Results:The total scores of CARS, ADOS and ADI-R in ASD group were 34.13±4.59, 14.44±2.59 and 39.91±12.11 respectively.During passive viewing of complex non-social picture arrays, ASD and TDC group explored total number of images were 9.28±2.72 and 12.67±2.45.The fixation time per image explored in ASD and TDC group were (0.67±0.37)ms and (0.54±0.15)ms.Moreover, the number of discrete fixations per image explored in ASD and TDC group was 2.80±1.00 and 2.48±0.48.Compared with the TDC group, ASD children demonstrated circumscribed attention ( t=6.610, P<0.01) with more perseveration ( t=-2.363, P=0.021) and detail-orientation ( t=-2.360, P=0.021). Exploration was negatively correlated with the total score of ADOS ( r=-0.480, P<0.01), CARS ( r=-0.487, P<0.01), communication score of ADOS( r=-0.290, P=0.041), social score of ADOS( r=-0.491, P<0.01), game score of ADOS( r=-0.397, P=0.004)and communication score of ADI-R( r=-0.331, P=0.025)in the ASD group. Conclusion:Compared with TDC, the eye movement pattern shows the circumscribed interests of ASD children, who not only explore fewer objects but also demonstrate circumscribed attention with more perseveration and detail-orientation.Moreover, the more severe the symptoms of ASD children, the fewer objects the children explore and the more stereotyped the circumscribed interest.

Epidemiological analysis of new pneumoconiosis among workers in coal industry in Chongqing / 中华劳动卫生职业病杂志

Objective@#To analyze the incidence of pneumoconiosis among workers in the coal industry in the past 13 years in Chongqing, understand the different epidemiological characteristics of new pneumoconiosis among workers in the coal industry in the city, provide basic evidence for the prevention and treatment of pneumoconiosis.@*Methods@#Collecting new cases of pneumoconiosis diagnosed in the coal industry in Chongqing in January 2006-May 2018, and analyze its epidemiological characteristics.@*Results@#In January 2006-May 2018, 25329 cases of pneumoconiosis were added to workers in the coal industry in Chongqing, and 23, 328 cases were present, all male. Among the existing cases: coal workers' pneumoconiosis accounted for 89.30%, silicosis accounted for 10.70%; age distribution was 50-59 years old. The main, accounting for 45.19%, the average age of onset was 52.21±7.45 years; the actual dusting age was mainly 10-19 years, the average actual working age was 17.52±8.47 years; the distribution of the work was mainly by the main coal mining (53.20%) ; There are more new cases in enterprises, accounting for 88.86%; distributed in 36 districts and counties.@*Conclusion@#There was a large number of new pneumoconiosis diseases in the coal industry in Chongqing. Different measures should be taken according to the characteristics of different enterprises, and relevant enterprises should be urged to take the initiative to carry out occupational health surveillance, effectively protect the health of workers, improve the coordination mechanism, improve medical security, and gradually realize government assistance and Social care is combined.

Analysis on social security of pneumoconiosis patients in two areas of Chongqing from 2006 to 2018 / 中华劳动卫生职业病杂志

Objective@#To investigate the current status of social security among pneumoconiosis patients from two areas of Chongqing, China with different economic levels from 2006 to 2018, and to provide a reference for the development of security policy for pneumoconiosis patients.@*Methods@#The current status of social security was analyzed for pneumoconiosis patients from A and B counties of Chongqing who were diagnosed from 2006 to 2018, and a comparative analysis was performed.@*Results@#From 2006 to 2017, there was a significant increase in the number of newly diagnosed pneumoconiosis patients in A county, while the number of newly diagnosed pneumoconiosis patients remained relatively stable in B county. As of May 2018, there were 5738 pneumoconiosis patients in A county and 4155 pneumoconiosis patients in B county. Among the 5738 pneumoconiosis patients in A county, 5335 (93%) had employers, and among these patients, 2729 (47.6%) received one-time compensation from occupational injury insurance, and currently 1884 (32.8%) were covered by the insurance. Among the 4155 pneumoconiosis patients in B county, 2482 (59.7%) received one-time compensation from occupational injury insurance, and currently 3062 (73.7%) were covered by the insurance. The social security rate of pneumoconiosis patients was 71.0% in A county and 81.4% in B county, and there was a significant difference in the distribution of social security among pneumoconiosis patients between the two counties (χ2=4704.9, P<0.01) .@*Conclusion@#Strict implementation of social security policies for pneumoconiosis patients by local governments is the key to solving social assistance for pneumoconiosis patients and improving their quality of life and social security level.

The analysis of prevalence of pneumoconiosis and civil aid and medical care among xiangyang-chongqing railway construction workers in Chongqing from 2011 to 2018 / 中华劳动卫生职业病杂志

Objective@#To analyze the prevalence of pneumoconiosis and civil aid and medical care among Xiangyang-Chongqing railway construction workers in Chongqing from 2011 to 2018, so as to provide scientific basis for prevention and control of pneumoconiosis.@*Methods@#The Chongqing database of Xiangyang-Chongqing railway construction workers cases from 2011 to 2018 were subjected to systematic collected. SPSS 18.0 was adopted for statistical description and analysis.@*Results@#From 2011 to 2018, a total of 7031 silicosis cases were diagnosed, and 5827 cases were existed, including 4056 cases of stage I, 1491 cases of stage II, and 280 cases of stage III. The cases were concentrated in the area along the southwest to northeast of Chongqing. The diagnosis age of silicosis patients was mainly 60~64 years old (69.73%) . Most silicosis cases were the drill workers and the stone workers. The exposure time of silicosis patients was short and concentrated in 3 years. The 5827 cases of pneumoconiosis in the Xiangyang-Chongqing railway were all treated with special civil aid and medical care for pneumoconiosis in the Xiangyang-Chongqing railway.@*Conclusion@#The prevalence of silicosis among workers who participated in Xiangyang-Chongqing railway construction remained serious. Civil aid and medical care covers all silicosis patients. Occupational health surveillance for silicosis and assistance should be carried out in these workers.

The analysis of prevalence of pneumoconiosis and assistance guarantee of the migrant workers of the district in Chongqing from 2006 to 2017 / 中华劳动卫生职业病杂志

Objective@#To analyze the prevalence of pneumoconiosis and assistance guarantee of the migrant workers of the district in Chongqing from 2006 to 2017, so as to provide scientific basis for prevention and control of pneumoconiosis of the migrant workers.@*Methods@#The database of new pneumoconiosis cases of the migrant workers and assistance guarantee of the district in Chongqing from 2006 to 2017 were subjected to systematic arrangement. SPSS 18.0 was adopted for statistical description and analysis.@*Results@#From 2006 to 2017 a total of 2188 new cases of pneumoconiosis were diagnosed, including I (917, 41.91%) , II (1003, 45.84%) , III (268, 12.25%) . Most of new cases of pneumoconiosis were silicosis. The median length of seniority was 6 years. The mean diagnostic age was 44.25. Significant difference was found in diagnosis age between different stages (F=3.161, P=0.043) . 98.77% of migrant workers had no units. There were 5.07% of migrant workers who took out industrial injury insurance, 14.58% receiving civil aid, 31.12% receiving aid from poverty alleviation, and 93.46% participating medical insurance.@*Conclusion@#The prevalence of pneumoconiosis of the migrant workers of the district in Chongqing was serious. The prevention and control of pneumoconiosis should be enhanced to reduce the harm of pneumoconiosis of the migrant workers in Chongqing.

Investigation and analysis of social security in patients with lung diseases in Kaizhou district of Chongqing / 中华劳动卫生职业病杂志

Objective@#To analyze the social insurance guarantee of pneumoconiosis patients in Kaizhou from 2006 to 2018, and to provide basis for the prevention and treatment of pneumoconiosis in the future.@*Methods@#The social security situation of pneumoconiosis patients in Kai Zhou District in 2006-2018 years was analyzed.@*Results@#There were 3357 cases of pneumoconiosis in Kaizhou District, with a social security rate of 99%; 79.4% of the coal mine pneumoconiosis patients, 87.5% of whom enjoy industrial injury insurance; the majority of the Xiangyu Railway pneumoconiosis patients were over 60 years old, accounting for 3.4%, all enjoy special treatment of Xiangyu Railway; the former township enterprises restructure pneumoconiosis patients, mainly under 60 years old, accounting for 3.4%. Among them, 79% enjoy work-related injury insurance, and 15.2% were rural poverty victims.@*Conclusion@#Kaizhou district provides better social security for pneumoconiosis patients in this area, which can provide basis for formulating social security policies for pneumoconiosis patients in other areas.

The analysis of the epidemiological characteristics of pneumoconiosis notified in Chongqing from 2011 to 2015 / 中华劳动卫生职业病杂志

Objective@#To analyze the epidemiological characteristics and the harmfulness situation of pneumoconiosis notified in Chongqing from 2011 to 2015, so as to provide scientific basis for prevention and control of pneumoconiosis.@*Methods@#The Chongqing database of new cases of pneumoconiosis reported from 2011 to 2015 was subjected to systematic arrangement. SPSS 18.0 was adopted for statistical description and trend test.@*Results@#From 2011 to 2015 a total of 24903 new cases of pneumoconiosis were diagnosed, including I (16 294 cases, 65.43%), II (6 520 cases, 26.18%), III (2 089 cases, 8.39%). Of all patients, 98.93% were cases of coal-workers' pneumoconiosis and silicosis. 13 383 (53.74%) were coal-workers' pneumoconiosis cases, and 11 253 (45.19%) were silicosis cases. The pneumoconiosis cases were distributed mainly in Fengjie County (3 329 cases, 13.37%), Yongchuan District (2 849 cases, 11.44%), and Chengkou County (2 584 cases, 10.38%). Most cases were centered in mining industry (17 575 cases, 70.57%) and construction industry (6 613 cases, 26.56%). The median lengths of service at the onsets of new cases of pneumoconiosis, silicosis, coal-workers' pneumoconiosis were 7.0, 3.0, and 16.0 years, respectively. The median age at the onset of pneumoconiosis was shortened from 2011 to 2015. The median ages at the onsets of new cases of pneumoconiosis, silicosis, coal-workers' pneumoconiosis were 53.0, 62.0, and 49.0 years, respectively.@*Conclusion@#The research results showed obvious diseases, regions and industries distribution. The median length of service at the onset of pneumoconiosis was on the low side, and a shortening trend showed in age at the onset of pneumoconiosis. Based on the epidemiological characteristics of pneumoconiosis, the prevention and control of pneumoconiosis should be enhanced in key industries such as mining industry and construction industry.

Improvement role of clotrimazole suppositories and fluconazole combined therapy in sex life of patients with candidal vaginitis / 中国生化药物杂志

Objective To investigate the improvement role of clotrimazole suppositories and fluconazole combined therapy in sex life of patients with candidal vaginitis.MethodsThe clinical data of 80 cases of patients with candidal vaginitis in our hospital from January 2015 to January 2017 were retrospectively analyzed, these patients were divided into clotrimazole suppositories and fluconazole combined therapy group (combined treatment group, n=40) and fluconazole single therapy group (single treatment group, n=40) according to the treatment methods, the clinical effects, main clinical symptoms and signs improvement time, quality of life of the two groups were statistically analyzed.ResultsThe total treatment efficiency of the combined treatment group 100.0% (40/40) was significantly higher than the single treatment group 87.5% (35/40) (P<0.05), the vaginal itching, pain, burning sensation, abnormal leucorrhea, abnormal discharge improvement time were significantly shorter than the single treatment group (P<0.05), the sexual desire, sexual arousal, lubrication, orgasm and sexual satisfaction scores were significantly higher than the single treatment group (P<0.05), the pain score was significantly lower than the single treatment group (P<0.05).ConclusionClotrimazole suppositories and fluconazole combined therapy can more effectively improve the sex life of patients with candidal vaginitis than fluconazole single therapy.

The random and comparative study on therapeutic effect and safety between Levetiracetam and Phenobarbitaladministration for neonatal seizures / 中华实用儿科临床杂志

Objective To randomly compare the therapeutic effect and safety between Levetiracetam (LEV) and Phenobarbital (PB) in the treatment of neonatal seizures.Methods A total of 61 infants with acute convulsion were randomly divided into 2 groups:LEV group (n =30) and PB group (n =31) during January 2013 to December 2014 in Urumqi Children's Hospital.All neonates received routine management including etiology treatment and adverse drug reaction monitoring.In the LEV group,subjects received oral formulation of LEV with initial loading dose 30 mg/kg,followed by 15 mg/kg twice a day.If the seizures were not controlled completely,PB treatment was added until seizures were completed controlled.If seizures were controlled quickly,the dose of PB was gradually reduced and LEV was used as monotherapy.The subjects in PB group received intramuscular or intravenous injection of PB with 10 mg/kg as the first dose,then 5 mg/(kg · d) oral PB was administered,if seizures were not controlled,LEV treatment was added,then dose of PB was gradually reduced until seizures were controlled completely,and then patients were switched to LEV monotherapy gradually.The drug adverse reactions were observed.Results (1) After LEV or PB monotherapy,66.7％ (20/30 cases) and 54.8％ (17/31 cases) of the subjects obtained sustainable seizure free respectively.Although,there was a higher control ratio in LEV group,but no significant difference was observed between the 2 groups (P ＞0.05).(2) LEV group (16/30 cases,53.33％) had higher rapid seizure control ratio with seizure controlled within 24 h after first dosage administration than that of PB group (8/31 cases,25.80％),and there was significant difference (x2 =4.841,P =0.028).Further more,if adding the cases who had to change to use another comparative one (LEV or PB) due to their seizures failure control with the first one treated,LEV group (21/44 cases,47.72％) still had higher rapid seizure control ratio in total patients than that of PB group(10/41 cases,24.39％),and there was significant difference (x2 =4.988,P =0.026).(3) Eight cases who changed to LEV after PB as the first treatment drug failed obtained sustainable seizure free.(4) One case in PB group with transient urinary retention was observed but the symptom disappeared 36 h after PB withdrawal,and no significant drug adverse reaction was observed in LEV group.Conclusion LEV is more rapid and safe for seizure control of neonates than PB.

Relationship of VKORC1 and CYP2C9 gene polymorphism and warfarin in patients with non-valvular atrial fibrillation / 实用医学杂志

Objective To evaluate the guidance value of VKORC1 and CYP2C9 gene polymorphism on clinical application of warfarin in patients with non-valvular atrial fibrillation (NVAF). Methods A total of 290 cases of patients with NVAF were identified and their baseline data , initial dose of warfarin and base INR measurement results were recorded, then the follow-up was conducted. The initial administration of warfarin to INR standard time for the first time, total amount of warfarin and the average daily amount were recorded. All participants′ venous blood was extracted for VKORC1 and CYP2C9 gene polymorphism test. Results VKORC1 AG/GG genotype patients had longer INR standard time and higer amount of warfarin than patients with AA (103.38 ± 65.29)g vs. (53.26 ± 24.02)g, P < 0.05. Patients with type CYP2C9 gene mutation had shortest INR standard time(9.10 ± 2.01)d vs. (13.07 ± 4.28)d, P < 0.05. and lowest administration amount of warfarin (28.80 ± 17.35)g vs. (55.45 ± 23.67)g, P < 0.05. Conclusion There exist significant differences of first adminstration amount of warfarin in patients with NVAF to INR standards. Warfarin dose for VKORC1 AA genotype patients is lower than that for GG/AG type; there is short INR standard time and less adminstration amount of warfarin for CYP2C9 genotypes AC/CC patients.

Study of correlation of serum IL-6 levels and cognitive dysfunction among patients with obstructive sleep apnoea syndrome / 中国医师杂志

Objective To investigate the relationship of serum IL-6 levels with cognitive dysfunction among patients with obstructive sleep apnoea syndrome (OSAS).Methods Patients diagnosed with OSAS by polysomnography (PSG) received assessment of cognitive function with Montreal Congnitive Assessment (MoCA).According to the result of MoCA assessment,patients were divided into two groups,without cognitive dysfunction group (n =47) and with cognitive dysfunction group (n =55);30 health volunteers were used as control.Serum IL-6 levels were detected by enzyme-linked immunosorbent assay (ELISA) in three groups;according to the apnea hypopnea index (AHI),OSAS patients with cognitive dysfunction were divided into three groups,light group (n =15),moderate group (n =16),and severe group (n =24),and differences in MoCA scores and serum IL-6 levels were analyzed among three groups.The correlation of serum IL-6 levels and MoCA scores were analyzed in OSAS patients with cognitive dysfunction.Results Serum levels of IL-6 in OSAS patients with cognitive dysfunction [(197.3 ± 72.58) pg/ ml] were significantly increased than those without cognitive dysfunction [(155 ± 39.3)pg/ml] as well as health control [(87.39 ±33.44)pg/ml] (P ＜0.01).For OSAS patients with cognitive dysfunction,MoCA scores were decreased and the level of serum IL-6 was increased among patients with poor AHI grade,with statistically significant difference.Pearson correlation analysis showed serum IL-6 levels were significantly negatively correlated with MoCA scores among OSAS patients with cognitive dysfunction (r =-0.65,P ＜ 0.01).Conclusions Serum levels of IL-6 in OSAS patients with cognitive dysfunction were significandy increased and correlated with the cognitive dysfunction.OSAS patients with cognitive dysfunction experiencing sever AHI grade have more serious cognitive dysfunction and the higher serum levels of IL-6.

Determination of Four Aflatoxins by Pressurized Capillary Electrochromatography-Laser Induced Fluorescence Detection / 分析化学

A rapid, reliable and sensitive pressurized capillary electrochromatography-Laser induced fluorescence ( pCEC/LIF ) method with trifluoroacetic acid ( TFA ) pre-column derivation for simultaneous determination of four aflatoxin ( AFB1 , AFB2 , AFG1 , AFG2 ) was developed. This method included separation on a capillary column packed with 1. 8μm C18 particles using 0. 05% FA aqueous solution/methanol (55:45, V/V) as mobile phase at a pump flow rate of 0. 05 mL/min when the split ratio was 1:300. Under the optimum conditions including running voltage of 15 kV, excitation wavelength of 375 nm and emission wavelength of 450 nm, the baseline separation of four aflatoxins was achieved within 10 minutes. The limits of detection (LODs) were 0. 02, 0. 016, 0. 008 and 0. 01 μg/L for AFG1, AFB1, AFG2, AFB2(S/N=3), respectively. The linear detection ranges of AFG1 , AFB1 , AFG2 , AFB2 were 0. 1-10, 0. 1-10, 0. 1-3 and 0. 1-3 μg/L with correlation coefficients (R2) of 0. 9999, 1. 0000, 0. 9995 and 0. 9997, respectively. The established method was applied to analyze the peanut butter, and the recoveries of standard addition experiment were between 90 . 0% and 112 . 0% for all analytes ( RSDs=0 . 5%-1 . 9%) .

The Moderating and Mediating Roles of Psychological Capital in the Associations of Effort-reward Imbalance and Overcommitment with Job Burnout among Iron-steel Workers / 中国医科大学学报

Objective To explore the moderating and mediating roles of psychological capital in the associations of effort?reward imbalance and overcommitment with job burnout among iron?steel workers. Methods Totally 1 700 male iron?steel workers from an iron and steel company were enrolled for the study. A set of questionnaires that included demographic and working factors,the Maslach Burnout Inventory?General Survey,the Ef?fort?reward Imbalance Scale and the Psychological Capital Questionnaire,as well as perceived work environment was distributed to the subjects. A to?tal of 1 254 effective respondents(73.76%)were collected. Hierarchical linear regression analysis was performed to explore moderating role,and as?ymptotic and resampling strategies were used to detect mediating role. Results There was no moderating role of psychological capital on the associa?tion between effort?reward imbalance and job burnout. Psychological capital had significant and positive moderating roles on the associations of over?commitment with emotional exhaustion and cynicism. Psychological capital showed significant mediating role in the associations of effort?reward im?balance with emotional exhaustion and cynicism,and the proportion of mediating role was 5.84%and 18.75%,respectively. Conclusion In work?ers with high level of psychological capital,emotional exhaustion and cynicism would be significantly increased with overcommitment,and there is a weak increasing trend of emotional exhaustion and cynicism in workers with low level of psychological capital. Effort?reward imbalance could lead to emotional exhaustion and cynicism through the reduction of psychological capital of iron?steel workers.

Levetiracetam treatment for neonatal intractable seizure / 中华实用儿科临床杂志

Objective To investigate the efficacy and safety of Levertiracetam (LEV) in treating the neonates with intractable seizure, those who had under gone failed Phenobarbital (PB) treatment previously switched to or added LEV treatment currently.Methods Totally 14 neonates,designed as intractable seizure by clinical data and video electroencephalography(VEEG) and failed to PB treatment were enrolled in the study, and all neonates were switched to LEV or LEV + PB treatment.The initial loading dose of LEV was 30 mg/kg, followed by 15 mg/kg twice a day if symptoms were controlled 8-12 h,if not, followed by 30 mg/kg once.All neonates were switched to LEV monotherapy after the symptoms were controlled 48-72 h,if the symptoms could not be controlled by combined therapy of PB and LEV after 72 h, other therapies were administered.Electrocardiogram breath synchronous monitoring was performed during the first 72 h treatment.VEEG was performed during 1-3 months follow-up.Results (1) The symptoms of 8 (57.14％) out of 14 cases were completely controlled,2 neonates(14.29％) reduced seizure more than 50％ ,4 neonates(28.57％) failed to LEV or LEV + PB treatment,as a result,all of those neonates were switched to other treatments.(2) No drug adverse effect was observed.(3) One neonate died of hypoxic-ischemic encephalopathy combined with multiple organ failure during follow-up period, 7 cases were seizure-free with normal VEEG, 5 cases were switched to or added other antiepileptic drugs because of uncontrolled symptoms, and one neonate discontinued the follow-ups.Conclusions The high efficiency and safety of LEV for the treatment of the newborn seizures were proved by small samples of patients.And currently there is no evidence to prove PB might increase neuronal excessive apoptosis of the brain and the cognitive impairment, and more clinical researches are needed to promote LEV as a gleam of rescue medications of neonatal seizure as soon as possible.