Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals.
Acetic Acid ; pharmacology ; Genomics ; Industrial Microbiology ; Saccharomyces cerevisiae ; drug effects ; genetics

Objective To investigate the influence of pullulan molecular weight and spacer length on the properties of modified pullulan carriers including morphologies,sizes and in vitro release behaviours of drug-loading carriers.Methods Using cholesterol as hydrophobic ligand,succinic anhydride and 1,6-hexyldiisocyanate as spacers,hydrophobic modified pullulans with different molecular weights were prepared.Self-assembled nanoparticles were then formed in the aqueous solution,and drug-loaded nanoparticles were prepared by dialysis method.The influence of pullulan molecular weight and spacer length on the loading-content,morphologies and in vitro release behaviours of drug-loading nanoparticles were then investigated in detail.Results Self-assembled nanoparticles could be formed by the cholesterol-modified pullulan,and doxorubicin and mitoxantrone could be loaded into cholesterol-modified pullulan to form nanoparticles.Pullulan molecular weight and spacer length show influences on sizes,morphologies and stabilities of pullulan nanoparticles and drug-loaded nanocarriers.Conclusions Before drug loading,nanoparticles with larger moleculare weight and shorter spacer length are more stable in solution,while after drug loading,the influences of these two factors on the nanoparticles are drug-type depended.

Objective:To analyze the use status of antibiotics and the resistance of clinic isolate bacteria against the commonly used antibiotics before and after the intervention. Methods:Using the information retrieval systems, the consumption of antibiotics in the inpatients during the 1st quarter of 2012(before the intervention) and the same period of 2013(after the intervention) was com-pared. According to the defined daily dose ( DDDs) , the antibiotics were ranked, and the resistance rate against the commonly used antibiotics was analyzed. Results:Compared with the top ten before the intervention, the top ten after the intervention was changed sig-nificantly, however, cephalosporins was still the main species. After the intervention, the overall decline in DDDs was significant, the separation rate and distribution of bacteria remained stable. ESBLs enzyme production rate of Enterobacteriaceae Escherichia coli was re-duced by 7. 61%, and that of Klebsiella pneumoniae was reduced by 1. 34%, and the resistance rate against the commonly used antibi-otics was in an overall downward trend. The resistance rate of Gram-positive staphylococci against the commonly used antibiotics was de-creased, while that of Gram-positive enterococci showed notable difference. Conclusion:The DDDs of antibiotics and bacterial resist-ance rate are in an overall downward trend in our hospital after the intervention;however, there is still exception. Therefore, the clini-cal antimicrobial susceptibility tests should be performed as soon as possible to help the choice of antibiotics.

Objective:To analyze the drug resistance of Pseudomonas aeruginosa( PA) isolated from clinical specimen to provide the guidance for the clinical treatment. Methods:The infection status of PA from January 2012 to December 2012 was reviewed retro-spectively, and the results of susceptibility test for 448 PA strains were analyzed. Results:The antibiotic susceptibility of the PA strains to cefoperazone sodium and sulbac, ampicillin aodium and aulbacta,aiprofloxacin,cefepime,piperacillin/ sulbactam,amikacin, ceftazi-dime,meropenem, imipenem, minocycline, selectrin and aefuroxime was 100%, 76%, 72. 8%, 69. 4%, 66. 3%, 65. 6%, 64. 8%, 59. 9%,28. 9%,2. 4% and 0%,respectively. Conclusion:PA is one of the main pathogenic bacteria for nosocomial infection. It is necessary to strengthen the drug resistance test and standardize the application of antibiotics in order to provide the reference for clinical rational use of antibacterial drugs.

We constructed a recombinant strain BL21 (DE3) (pETST3LTBalphabeta) including ST1-LT(B)-alpha-beta fusion gene via molecular technology. The SDS-PAGE and Western blotting indicated that the ST1-LT(B)-alpha-beta fusion protein was highly expressed in Escherichia coli and the molecular weight of the fusion protein was about 110 kD. The recombinant strain was induced in different concentrations of lactose and different aeration rate. The optimal culture conditions in 20 L fermentor were 1% inoculation (V/V), initial aeration 5 L/min, 0.03 mol/L lactose addition 3 hours after inoculation, and increased the aeration to 12.5 L/min for the following 6 hours. The fusion protein was about 38.53% of total cellular protein. It was nontoxic, immunogenic and protective against enterotoxigenic E. coli and Clostridium perfringens infection. The constructed recombinant strain BL21 (DE3) (pETST3LTBalphabeta) could serve as a candidate vaccine strain against diarrhea of piglet.
Animals ; Bacterial Toxins ; biosynthesis ; genetics ; Calcium-Binding Proteins ; biosynthesis ; genetics ; Clostridium perfringens ; genetics ; Dysentery ; prevention & control ; veterinary ; Enterotoxins ; biosynthesis ; genetics ; Escherichia coli ; genetics ; immunology ; Escherichia coli Proteins ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Swine ; Transformation, Bacterial ; genetics ; Type C Phospholipases ; biosynthesis ; genetics ; Vaccines, Synthetic ; immunology

Breeding of robust industrial Saccharomyces cerevisiae strains with high ethanol tolerance is of great significance for efficient fuel ethanol production. Zinc finger proteins play important roles in gene transcription and translation, and exerting control on the regulation of multiple genes. The sequence and localization of the zinc finger motif can be designed and engineered, and the artificial zinc finger protein can be used to regulate celluar metabolism. Stress tolerance of microbial strains is related to multiple genes. Therefore, it is possible to use artificially-designed zinc finger proteins to breed stress tolerant strains. In this study, a library containing artificial zinc finger protein encoding genes was transformed into the model yeast strain S288c. A recombinant strain named M01 with improved ethanol tolerance was obtained. The plasmid in M01 was isolated, and then transformed into the industrial yeast strain Sc4126. Ethanol tolerance of the recombinant strain of Sc4126 were significantly improved. When high gravity ethanol fermentation using 250 g/L glucose was performed, comparing with the wild-type strain, fermentation time of the recombinant strain was decreased by 24 h and the final ethanol concentration was enhanced by 6.3%. The results of this study demonstrate that artificial zinc finger proteins are able to exert control on stress tolerance of yeast strains, and these results provide basis to construct robust industrial yeast strains for efficient ethanol fermentation.
Adaptation, Physiological ; drug effects ; Drug Resistance, Fungal ; genetics ; Ethanol ; pharmacology ; Fungal Proteins ; genetics ; metabolism ; Industrial Microbiology ; Mutation ; genetics ; Peptide Library ; Saccharomyces cerevisiae ; genetics ; growth & development ; Zinc Fingers

Objective: To analyze effects of pulse contour cardiac output (PiCCO) monitoring technology in amelioration of myocardial damage in fluid resuscitation of patients with large area burn in the early stage. Methods: From November 2015 to November 2017, medical data of 52 patients with large area burn hospitalized in our unit, meeting the inclusion criteria, were analyzed retrospectively. Twenty-seven patients (18 males and 9 females) with age of (43±10)years in tradition group hospitalized from November 2015 to November 2016 were monitored by traditional monitoring methods for fluid resuscitation, and 25 patients (18 males and 7 females) with age of (44±10)years in PiCCO group hospitalized from December 2016 to November 2017 were monitored by traditional monitoring methods and PiCCO monitoring equipment for fluid resuscitation. Fluid infusion coefficients and total fluid replacement volume of patients in both groups at the first and second post burn hour (PBH) 24, as well as the levels of N terminal pro B type natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), and creatine kinase MB (CK-MB) immediately on admission and post burn day (PBD) 1, 2, 3, 4, 5, 6, and 7 were recorded. Data were processed with analysis of variance for repeated measurement, chi-square test, t test and Bonferroni correction, and Mann-Whitney U test and Bonferroni correction. Results: (1) The fluid infusion coefficients of patients in tradition group at the first and second PBH 24 were respectively (1.42±0.10) and (0.94±0.14)mL·kg^-1·% total body surface area (TBSA)^-1, and those in PiCCO group were respectively (1.76±0.14) and (0.85±0.08) mL·kg^-1·%TBSA^-1. Fluid infusion coefficient and total fluid replacement volume at the first PBH 24 of patients in PiCCO group were significantly higher than those in tradition group (t=-9.775, -4.769, P<0.01). Fluid infusion coefficient at the second PBH 24 of patients in PiCCO group was significantly lower than that in tradition group (t=2.682, P<0.05). There was no statistically significant difference in total fluid replacement volume at the second PBH 24 in patients between the two groups (t=1.167, P>0.05). (2) Immediately on admission and PBD 1, 2, 3, 4, 5, 6, and 7, the levels of NT-proBNP of patients in tradition group were respectively 518 (320, 763), 236 (98, 250), 139 (62, 231), 172 (104, 185), 296 (225, 341), 727 (642, 921), 1 840 (1 357, 2 081), 1 005 (671, 1 297) pg/mL, and those in PiCCO group were respectively 444 (206, 601), 66 (29, 73), 54(28, 75), 139(101, 175), 199 (106, 279), 576 (333, 837), 833 (466, 1 080), 485 (225, 710) pg/mL. The levels of NT-proBNP of patients in PiCCO group on PBD 1, 2, 6, and 7 were significantly lower than those in tradition group (Z=-5.004, -3.967, -5.285, -4.626, P<0.01). The levels of NT-proBNP immediately on admission and PBD 3, 4, and 5 in patients between the two groups were close (Z=-0.834, -0.806, -2.665, -2.153, P>0.05). (3) Immediately on admission and PBD 1, 2, 3, 4, 5, 6, and 7, the levels of cTnT of patients in tradition group were respectively (42±15), (21±12), (17±7), (11±4), (12±4), (94±32), (88±23), (42±23) pg/L, and those in PiCCO group were respectively (37±15), (9±3), (10±3), (13±3), (12±5), (85±30), (60±26), (22±14) pg/L. The levels of cTnT of patients in PiCCO group on PBD 1, 2, 6, and 7 were significantly lower than those in tradition group (t=5.227, 4.751, 4.239, 3.845, P<0.01). The levels of cTnT immediately on admission and PBD 3, 4, and 5 of patients between the two groups were close (t=1.098, -1.562, -0.117, 1.107, P>0.05). (4) The levels of CK-MB of patients in PiCCO group on PBD 3, 6, and 7 were significantly lower than those in tradition group (t=3.123, 4.103, 3.178, P<0.05 or P<0.01). The levels of CK-MB immediately on admission and PBD 1, 2, 4, and 5 in patients between the two groups were close (t=0.351, 1.868, 1.100, 0.798, 2.094, P>0.05). Conclusions PiCCO monitoring technology can monitor and guide fluid resuscitation of patients with large area burn in the early stage more scientifically and reasonably, and the effect of reducing myocardial damage is better than traditional monitoring methods.

Objective To investigate the prenatal diagnosis and genetic counseling of fetal nuchal fold (NF) thickening.Methods This study retrospectively analyzed 17 fetuses with increased NF detected by prenatal ultrasound examination in Peking Union Medical College Hospital,Peking Union Medical College & Chinese Academy of Medical Sciences from December 1,2016 to December 1,2017.All cases were divided into isolated (isolated group) or non-isolated increased NF group (non-isolated group) according to whether the fetus had concomitant ultrasonographic abnormalities or not.Karyotype and chromosomal microarray analysis (CMA) were performed on all cases.Clinical data,prenatal genetic testing results and pregnancy outcomes were analyzed.Results Of those twelve cases in the isolated group,two were terminated due to the identification of chromosomal abnormalities and pathogenic copy number variations (CNVs) and the fetal autopsy results were consistent with the prenatal diagnosis.The rest 10 pregnancies were all continued including one fetus carrying a variant of unknown significance,which was proved to be a paternal heredity by CMA,and nine without genetic abnormalities and all-these infants were healthy during follow-up.Among the five non-isolated cases,one was diagnosed as trisomy 21 by karyotyping and CMA,and the other four were found to have structural abnormalities under ultrasound scan,but without genetic abnormalities in karyotyping and CMA.And all the five pregnancies were terminated after genetic counseling and three of them chose whole exome sequencing (WES) for further test.One homozygous mutation in CHRNA 1 gene and one de novo mutation in SETD2 gene were found in two cases,respectively,while no abnormality was identified in the other one case.Conclusions Once increased NF were indicated by ultrasound examination,prenatal genetic testing should be offered to the patients,including CMA,regardless of other ultrasonographic abnormalities,and WES should also be offered when necessary.Considering a thickened NF is associated with increased risks of structural defects,a close follow-up with fetal echocardiography and ultrasound is required even the prenatal tests are normal.

With the increasing global burden of various cancer, an abundance of papers emerged every year in the research hotspots of oncology, covering a wide range of research types and topics. In order to facilitate interested readers to quickly grasp the frontier and hotspots of cancer research, it would be helpful to sort out and summarize the research topic in a timely manner. According to the classification of disciplines, we screened the Essential Science Indicators (ESI) hot papers released in 2019 for the ones in the oncology field, utilized methods such as bibliometrics, statistical description, hierarchical induction, analysis and interpretation to further reveal the context and characteristics of research in the field of oncology, summarized the latest progresses and future directions in the field, and provided information and hints for the trajectory of future research. A total of 549 papers were included, which were mainly from the field of clinical medicine; the country with the most publications was the United States, while China ranked the fourth in terms of contribution; the research institution with the highest number of published papers was University of Texas system;
Bibliometrics ; Biomedical Research ; China ; Humans ; Neoplasms ; Publications ; United States

Oral diseases concern almost every individual and are a serious health risk to the popula-tion.The restorative treatment of tooth and jaw defects is an important means to achieve oral function and support the appearance of the contour.Based on the principle of"learning from the nature",Deng Xu-liang's group of Peking University School and Hospital of Stomatology has proposed a new concept of"microstructural biomimetic design and tissue adaptation of tooth/jaw materials"to address the worldwide problems of difficulty in treating dentine hypersensitivity,poor prognosis of restoration of tooth defects,and vertical bone augmentation of alveolar bone after tooth loss.The group has broken through the bottle-neck of multi-stage biomimetic technology from the design of microscopic features to the enhancement of macroscopic effects,and invented key technologies such as crystalline/amorphous multi-level assembly,ion-transportation blocking,and multi-physical properties of the micro-environment reconstruction,etc.The group also pioneered the cationic-hydrogel desensitizer,digital stump and core integrated restora-tions,and developed new crown and bridge restorative materials,gradient functionalisation guided tissue regeneration membrane,and electrically responsive alveolar bone augmentation restorative membranes,etc.These products have established new clinical strategies for tooth/jaw defect repair and achieved inno-vative results.In conclusion,the research results of our group have strongly supported the theoretical im-provement of stomatology,developed the technical system of oral hard tissue restoration,innovated the clinical treatment strategy,and led the progress of the stomatology industry.