Asymmetric formal sp2-hydrocarbonations of dienes and alkynes via palladium hydride catalysis.

Transition metal-catalyzed asymmetric hydrofunctionalizations of unsaturated bonds via π-ƞ3 substitution have emerged as a reliable method to construct stereogenic centers, and mainly rely on the use of heteroatom-based or carbon nucleophiles bearing acidic C-H bonds. In comparison, sp2 carbon nucleophiles are generally not under consideration because of enormous challenges in cleaving corresponding inert sp2 C-H bonds. Here, we report a protocol to achieve asymmetric formal sp2 hydrocarbonations, including hydroalkenylation, hydroallenylation and hydroketenimination of both 1,3-dienes and alkynes via hydroalkylation and Wittig reaction cascade. A series of unachievable motifs via hydrofunctionalizations, such as di-, tri- and tetra-substituted alkenes, di-, tri- and tetra-substituted allenes, and tri-substituted ketenimines in allyl skeletons are all facilely constructed in high regio-, diastereo- and enantioselectivities with this cascade design. Stereodivergent synthesis of all four stereoisomers of 1,4-diene bearing a stereocenter and Z/E-controllable olefin unit highlights the power of present protocol. An interesting mechanistic feature is revealed that alkyne actually undergoes hydrocarbonation via the formation of conjugated diene intermediate, different from conventional viewpoint that the hydrofunctionalization of alkynes only involves allene species.

Output feedback full-order sliding mode control for a three-tank system.

A robust output feedback nonlinear control method is proposed for output tracking of an uncertain three-tank system by using only the level sensor of the target tank. By using a coordinate transformation, we first transform the system model into a canonical form with uncertainties. The canonical system's state variables are estimated by a higher-order sliding mode differentiator based on the measurement of the target tank's liquid level. Then based on the estimated state variables, a continuous full-order sliding mode controller is constructed which can eliminate the effects of both the additive and multiplicative uncertainties. Rigorous analysis is carried out to clarify the control performance. And the effectiveness of the proposed method is verified by experimental studies on the Inteco Multi-tank system.

Multicenter epidemiological characteristics of Mycoplasma pneumoniae infection in children in Hainan Province, 2012-2020 / 中国热带医学

@#Abstract: Objective　To analyze the epidemiological characteristics (season, age, gender, mixed infection and clinical manifestations, etc.) of Mycoplasma pneumoniae (MP) infection in children in Hainan Province, so as to provide epidemiological evidence-based medical basis for the prevention and control of MP infection in children in Hainan Province. Methods　The serum IgM antibodies of MP, Legionella pneumophila, Chlamydia pneumoniae, adenovirus, respiratory syncytial virus (RSV), Q fever Rickettsia, parainfluenza virus, influenza A virus and influenza B virus in children with respiratory tract infections (RTIs) who were hospitalized in pediatrics of many hospitals in Hainan Province from March 2012 to February 2020 were detected by indirect immunofluorescence method. The positive serum MP-IgM antibody was defined as MP infection. The epidemiological and clinical data of MP infected cases were analyzed retrospectively. Results　From March, 2012 to February, 2020, a total of 35 731 qualified pediatric inpatients with RTIs in many hospitals in Hainan Province were tested for serum MP-IgM with the total positive rate of 39.12% (13 978/35 731). The yearly positive rates of MP-IgM from 2012 to 2020 were 48.39%, 56.23%, 56.62%, 47.04%, 29.71%, 24.14%, 47.55%, 36.84% and 24.46% respectively. The positive rates of MP-IgM in 2013 and 2014 were significantly higher than those in other years (P<0.05). The positive rate of MP-IgM in summer in Hainan Province was the highest (41.34%) and the lowest in winter (35.77%) (P<0.05). MP infection occurred in all age groups, the positive rate of MP-IgM in children of preschool (51.80%) was significantly higher than that in other age groups (P<0.01), and the positive rate of MP IgM in children of infancy (15.36%) was lower than that in other age groups (P<0.01). The positive rate of MP-IgM in female was 44.77%, which was significantly higher than that in male (35.83%) (P<0.05). MP infection combined with positive IgM of another pathogen accounted for 32.63% (4 561 cases), positive IgM of another two pathogens accounted for 1.26% (176 cases). MP infection was mostly found in pneumonia (68.73%), and the main clinical symptoms were cough (84.72%), fever (51.01%) and wheezing (3.16%). Conclusions　MP is an important pathogen of respiratory tract infection in children in Hainan Province, and infection is more common in children in early school age and early childhood. Mp-specific tests should be performed to identify the pathogen in children suspected of MP infection. In the high incidence season, health education should be strengthened in kindergartens, schools and other places to prevent respiratory tract infection.

A wireless sensor network node fault diagnosis model based on belief rule base with power set.

Wireless sensor network (WSN) is inevitably subject to node failures due to their harsh operating environments and extra-long working hours. In order to ensure reliable and correct data collection, WSN node fault diagnosis is necessary. Fault diagnosis of sensor nodes usually requires the extraction of data features from the original collected data. However, the data features of different types of faults sometimes have similarities, making it difficult to distinguish and represent the types of faults in the diagnosis results, these indistinguishable types of faults are called ambiguous information. Therefore, a belief rule base with power set (PBRB) fault diagnosis method is proposed. In this method, the power set identification framework is used to represent the fuzzy information, the evidential reasoning (ER) method is used as the reasoning process, and the projection covariance matrix adaptive evolution strategy (P-CMA-ES) is used as the parameter optimization algorithm. The results of the case study show that PBRB method has higher accuracy and better stability compared to other commonly used fault diagnosis methods. According to the research results, PBRB can not only represent the fault types that are difficult to distinguish, but also has the advantage of small sample training. This makes the model obtain high fault diagnosis accuracy and stability.

PanaxGDB: A Comprehensive Platform for Panax.

The genus Panax is a valuable natural medicinal source used worldwide that contains high levels of triterpenoid saponins with extensive pharmacological activities. In past decades, molecular biotechnology and breeding techniques have been respectively used to generate omics data and information on cultivars primarily from Panax ginseng (ginseng), Panax quinquefolium (American ginseng), and Panax notoginseng (Sanqi) to biosynthesize valuable saponins, improve product quality, and conduct cost-controlled cultivation. Although much data have been produced, there are concerns that redundant data might be generated and that relatively scattered data might be overlooked. Therefore, many scientists desire a reliable, comprehensive omics database of the Panax genus that could save time and promote integrated analysis. Therefore, to provide all-inclusive, reliable, and valuable information on the Panax genus, PanaxGDB, an open comprehensive database that integrates data on omics and information on varieties, was established. The database contains information on nearly 600 compounds from 12 Panax species, draft genomic sequences with annotations and gene expression levels, single nucleotide polymorphisms, genome-wide association analysis based on agronomic traits, globally collected germplasm information, summaries, omics data of the Panax genus, and online versatile analytic tools. The Panax genus database will be updated when new data are released to continue serving as a central portal to boost research on the biology and functions of Panax. PanaxGDB is available at: http://panaxGDB.ynau.edu.cn.

Cadmium-induced injury and the ameliorative effects of selenium on chicken splenic lymphocytes: mechanisms of oxidative stress and apoptosis.

Cadmium (Cd) is an important environmental pollutant present in soil, water, air, and food. Selenium (Se) can antagonize some metal element toxicity including Cd. To investigate the cytotoxicity of Cd and the protective effects of Se on bird immunocytes in vitro, chicken splenic lymphocytes with CdCl2 (10(-6) mol/L), Na2SeO3 (10(-7) mol/L), and the mixture (10(-7) mol/L Na2SeO3 and 10(-6) mol/L CdCI2) were incubated for 12, 24, 36, and 48 h, respectively. A high level of malondialdehyde (MDA) and reactive oxygen species (ROS) productions were observed in Cd treatment group; the activities of catalase (CAT), glutathione peroxidise (GSH-Px), superoxide dismutase (SOD), and the mitochondrial inner transmembrane potential (ΔΨm) were significantly lower in Cd treatment group than those in controls (P < 0.05 or P < 0.01). In contrast, Se significantly improved the activities of antioxidant enzymes and reduced MDA and ROS levels compared to Cd treatment alone group, although not restored to the levels of control group. The population of apoptosis cells demonstrated that Cd induces the apoptosis of chicken splenic lymphocytes; in addition, increased mRNA level of Bak, p53, caspase-3, caspase-9, and cytochrome c (Cyt c) and decreased Bcl-2, Bcl-xl, and CaM were observed in Cd treatment group. Se ameliorated ΔΨm and [Ca(2+)]i for mitochondria function restoring, and Se was able to modulate the expression of relative genes. In conclusion, concurrent treatment with Se reduced the Cd-induced morphological changes and oxidative stress, ion disorder, and apoptosis, suggesting that the toxic effects of Cd on the chicken splenic lymphocytes were partly meliorated by Se.

Prediction of selenoprotein T structure and its response to selenium deficiency in chicken immune organs.

Selenoprotein T (SelT) is associated with the regulation of calcium homeostasis and neuroendocrine secretion. SelT can also change cell adhesion and is involved in redox regulation and cell fixation. However, the structure and function of chicken SelT and its response to selenium (Se) remains unclear. In the present study, 150 1-day-old chickens were randomly divided into a low Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a diet containing sodium selenite at 0.2 mg/kg Se). The immune organs (spleen, thymus, and bursa of Fabricius) were collected at 15, 25, 35, 45, and 55 days of age. We performed a sequence analysis and predicted the structure and function of SelT. We also investigated the effects of Se deficiency on the expression of SelT, selenophosphate synthetase-1 (SPS1), and selenocysteine synthase (SecS) using RT-PCR and the oxidative stress in the chicken immune organs. The data showed that the coding sequence (CDS) and deduced amino acid sequence of SelT were highly similar to those of 17 other animals. Se deficiency induced lower (P < 0.05) levels of SelT, SPS1, and SecS, reduced the catalase (CAT) activity, and increased the levels of hydrogen peroxide (H2O2) and hydroxyl radical (-OH) in immune organs. In conclusion, the CDS and deduced amino acid sequence of chicken SelT are highly homologous to those of various mammals. The redox function and response to the Se deficiency of chicken SelT may be conserved. A Se-deficient diet led to a decrease in SelT, SecS, and SPS1 and induced oxidative stress in the chicken immune organs. To our knowledge, this is the first report of predictions of chicken SelT structure and function. The present study demonstrated the relationship between the selenoprotein synthases (SPS1, SecS) and SelT expression in the chicken immune organs and further confirmed oxidative stress caused by Se deficiency. Thus, the information presented in this study is helpful to understand chicken SelT structure and function. Meanwhile, the present research also confirmed the negative effects of Se deficiency on chicken immune organs.

[Treatment of septic shock in children with low dose pituitrin: report of 24 cases].

OBJECTIVE: To explore the clinical effect of low dose pituitrin in children with septic shock. METHODS: A total of 48 pediatric cases with septic shock, in whom 6 hours, conventional treatment could not reverse shock from January 2008 to December 2010, were selected for this study. The patients were divided into two groups randomly (completely random design) (control group 24, remedial group 24). The conventional treatment included antibiotics/fluid resuscitation/correcting acid-base imbalance, glucocorticoid, organ (heart/lung) support, dopamine 1 - 15 µg/(kg·min) and norepinephrine 0.5 - 2 µg/(kg·min) pumped in continuously in the control group. In initial 6 hours the same treatment was given to the remedial group, while low dose pituitrin (0.01 - 0.03 U/min) was pumped additionally during the rest of time. The therapeutic effect on correcting shock was evaluated in both groups. RESULTS: The total effective rate was 76.2% in the remedial group and 40.0% in the control group; the mortality was 33.3% and 60% respectively. The difference between both groups was significant (P = 0.025). CONCLUSION: Low dose pituitrin could improve the clinical effect significantly in children with septic shock in whom 6 hours conventional treatment failed to correct shock, shorten the total periods of treatment, and decrease mortality.

Development of ELISA kits for antibodies against avian reovirus using the sigmaC and sigmaB proteins expressed in the methyltropic yeast Pichia pastoris.

Both the sigmaC and sigmaB proteins of avian reovirus (ARV) can induce type- and group-specific neutralizing antibodies, respectively. In this study, the full-length of S1133 sigmaC, 1071-1 sigmaC, S1133 sigmaB, and S1133 sigmaC-sigmaB fusion genes of ARV were cloned into a secreted vector pPICZalphaA and then integrated into the chromosome of Pichia pastoris for induced expression. Western blot assay showed that ARV sigmaC, sigmaB, and sigmaC-sigmaB fusion proteins were expressed and secreted into the medium. Two types of ELISA kits using equal mixtures of 1071-1sigmaC and S1133 sigmaB and S1133 sigmaC-sigmaB fusion proteins as antigens were developed. After a checker board titration for optimal conditions, the cut-off values of positive results for the 1071-1sigmaC/S1133 sigmaB and S1133 sigmaC-sigmaB ELISA kits were 0.24 and 0.12, respectively. Forty-four serum neutralization test-positive and twenty-eight serum neutralization-negative samples from vaccinated and commercial farm chickens were tested by the new ELISA kits and by the conventional ELISA. The new ELISA kits have higher positive rates than the conventional ELISA. The results revealed that the correlation rates for the serum neutralization titer and the absorbance values with the new ELISA kits and the conventional ELISA were 100% and 95.8%, respectively.