Cognitive function enhancement refers to the process of enhancing one or more core component of human brain cognition.Transcranial direct current stimulation(tDCS),as a non-invasive neuromodulation technique,can regulate brain cortical excitability,synaptic plasticity and brain networks functional connection.tDCS can be used to modulate cognitive function components,such as perception,working memory,attention,motor learning and decision-making.This article reviews the neural and physiological mechanism of tDCS over cerebral cortex modulating neural activity and the research progress in human cognitive performance ofsingle tDCS on perception,working memory,attention,motor learning,decision-making and language of healthy individuals in order to provide reference for researchers.

Methanol has become an attractive substrate for the biomanufacturing industry due to its abundant supply and low cost. The biotransformation of methanol to value-added chemicals using microbial cell factories has the advantages of green process, mild conditions and diversified products. These advantages may expand the product chain based on methanol and alleviate the current problem of biomanufacturing, which is competing with people for food. Elucidating the pathways involving methanol oxidation, formaldehyde assimilation and dissimilation in different natural methylotrophs is essential for subsequent genetic engineering modification, and is more conducive to the construction of novel non-natural methylotrophs. This review discusses the current status of research on methanol metabolic pathways in methylotrophs, and presents recent advances and challenges in natural and synthetic methylotrophs and their applications in methanol bioconversion.
Humans ; Methanol/metabolism* ; Metabolic Engineering ; Metabolic Networks and Pathways ; Biotransformation

Nano-metallic materials are playing an important role in the application of medicine, catalysis, antibacterial and anti-toxin due to their obvious advantages, including nanocrystalline strengthening effect, high photo-absorptivity, high surface energy and single magnetic region performance. In recent years, with the increasing consumption of global petrochemical resources and the aggravation of environmental pollution, nanomaterials based on bio-based molecules have aroused great concern. Bio-based molecules refer to small molecules and macromolecules directly or indirectly derived from biomass. They usually have good biocompatibility, low toxicity, degradability, wide source and low price. Besides, most bio-based molecules have unique physical, chemical properties and physiological activity, such as optical activity, acid/alkali amphoteric property, hydrophilic property and easy coordination with metal ions. Thus, the corresponding nano-materials based on bio-based molecules also have unique functions, such as anti-inflammatory, anti-cancer, anti-oxidation, antiviral fall blood sugar and blood fat etc. In this paper, we give a comprehensive overview of the preparation and application of nano-metallic materials based on bio-based molecules in recent years.
Anti-Infective Agents ; Catalysis ; Metals ; Nanostructures

Tetracarbon organic acids are important platform chemicals that are widely used in the food, chemical, medicine, material industries and agriculture. Compared with the traditional petrochemical process, the production of tetracarbon organic acids by microbial fermentation is more promising due to milder reaction conditions, greener process and better environmental compatibility. This review summarizes the biosynthetic pathways and metabolic mechanisms for the production of tetracarbon organic acids, and illustrates recent advances, challenges, and future perspectives in the production of tetracarbon organic acids by naturally selected or purposefully engineered strains.
Acids ; Biosynthetic Pathways ; Fermentation ; Metabolic Engineering ; Organic Chemicals

OBJECTIVE: To assess the efficacy of letrozole in treatment of children with congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency (21-OHD). METHODS: Twenty eight children, including 19 boys and 9 girls aged 4-10y, with CAH due to 21-OHD were enrolled in the study. At the first six months of study, all children received conventional treatment with hydrocortisone or fludrocortisone, then letrozole was added to original regimen. The height velocity (HV), difference between bone age and chronological age (BA-CA), height standard diviation score based on bone age (HtSDS ), predicted adult height (PAH), Tanner phase, sex hormone, and possible adverse reaction were evaluated and compared between those before and after letrozole treatment. RESULTS: After 6 months of letrozole treatment, there was significant deceleration of HV, but it would recover soon. There was significant increase of HtSDS after 12 months of letrozole treatment ( < 0.05 or < 0.01), and significant changes in BA-CA after 18 months of letrozole treatment ( < 0.05). PAH of female children was significantly increased during letrozole treatment ( < 0.05), whereas PAH of male children was significantly increased 18 months after letrozole treatment ( < 0.05). Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were significantly increased, but did not meet the diagnostic criteria of central precocious puberty. Estradiol was significantly decreased ( < 0.01), but no changes in testosterone level was observed. During 24 months letrozole treatment, no hirsutism, severe acne, headache, bone pain, obesity, hypertension, rash and other adverse reactions were observed. CONCLUSIONS Letrozole can delay bone maturation and improve PAH, which can be used with conventional treatment for children with CAH due to 21-OHD, especially for those with high BA and low PAH.
Adrenal Hyperplasia, Congenital ; drug therapy ; Body Height ; Child ; Child, Preschool ; Female ; Humans ; Letrozole ; therapeutic use ; Male ; Puberty, Precocious

Objective:To establish a rat model of volume-controlled hemorrhage and observe the pathophysiological changes that ensued.Methods:Sprague Dawley (SD) rats were subjected to femoral arterial cannulation and hemorrhage for 40% or 50% of total volume. The hemodynamics data and arterial blood gas were collected, and survival after hemorrhage was monitored for 24 hours ( n=8/group). Then lung, liver, intestine and kidney were collected for HE staining after 40% hemorrhage at 4, 8 and 12 hours ( n=6/group). Results:Mean arterial pressure of 40% and 50% blood loss group decreased significantly from (90±5)mmHg and (93±4)mmHg to (40±4)mmHg and (34±4)mmHg ( P<0.05). Heart rate of 40% and 50% blood loss group increased significantly from (330±35) bpm and (336±32) bpm to (478±36) bpm and (490±21) bpm ( P<0.05). Hemoglobin and pH decreased significantly following hemorrhage, while lactate increased. The survival rate of 50% blood loss group was just 12.5% and 40% blood loss group was 100% ( P<0.05). Compared with sham group, the most significant injury was observed in lung and small intestine after 4 hours, in liver after 8 hours and in kidney after 12 hours following hemorrhage. Conclusion:This study established a stable and repeatable volume-controlled hemorrhagic shock model in rat.

Consolidated bioprocessing (CBP) is a multi-step process in a bioreactor, which completes hydrolase production, enzymatic hydrolysis, and microbial fermentation. It is considered to be the most promising process for the production of second-generation biofuels because of its simple steps and low cost. Due to the complexity of lignocellulose degradation and the butanol synthesis pathway, few wild microorganisms can directly utilize lignocellulose to synthesize butanol. With the development of synthetic biology, single-bacterium directly synthesizes butanol using lignocellulose by introducing a butanol synthesis pathway in the cellulolytic Clostridium. However, there are still some problems such as heavy metabolic load of single bacterium and low butanol yield. Co-culture can relieve the metabolic burden of single bacterium through the division of labor in different strains and can further improve the efficiency of butanol synthesis. This review analyzes the recent research progress in the synthesis of biobutanol using lignocellulose by consolidated bioprocessing from both the single-bacterium strategy and co-culture strategy, to provide a reference for the research of butanol and other biofuels.
1-Butanol ; Biofuels ; Butanols ; Fermentation ; Lignin/metabolism*

3-Deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) is the key enzyme to synthesize eight-carbon sugar in plant and gram-negative bacterial cell wall. To analyze the polymerization and characterization in plant KDO8PS, the candidate gene was cloned from fresh Phyllostachys edulis seedling by RT-PCR. The open reading frame of PeKDO8PS is 876 bp deduced into 291 amino acid residues. The target protein was overexpressed in Escherichia coli induced by IPTG and then lager amount of fusion protein was purified through two-step methods with affinity chromatography and size-exclusion chromatography (SEC). SEC analysis shows that PeKDO8PS protein existed mainly in the form of dime in solution. Glutaraldehyde cross-linking experiments confirmed that the enzyme could form dimers. Further we identified that KDO8PS at high concentration two dimers could form tetramer in aqueous solution by analytical ultracentrifuge (AUC) analysis. The pH of the catalytic reaction was between 4.0 and 9.0, the optimum pH value was 8, the thermal stability range was between 25 and 65 ℃, and the optimum temperature was about 55 ℃. The enzyme activity was inhibited by some metal ions at lower concentrations, especially in the presence of Fe3+metal ion and activated by metal protease inhibitor EDTA at low concentration.

Objective To investigate the predicting value of intermedin (IMD) for the prognosis of elderly sepsis patients.Methods A retrospective analysis was conducted. Forty-one patients with sepsis, aged ≥65 years, and admitted to geriatrics intensive care unit of Aerospace Center Hospital from April 2015 to December 2016 were enrolled. Thirty healthy patients were studied as control during the same time. The expression of C-reactive protein (CRP), procalcitonin (PCT) and IMD were tested within 24 hours during hospitalization, and the acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ) score and prognosis was evaluated. According to APACHE Ⅱ score, patients were divided into 3 groups, 10-20 score, 21-30 score, and > 30 score group. And based on the prognosis, the patients were divided into death group and survival group. The differences of expression levels of CRP, PCT and IMD in each group were assessed. The relationship of IMD and infection index was analyzed by Pearson correlation. Receiver operating characteristic curve (ROC) was used to evaluate the prognostic value of CRP, PCT and IMD in patients with sepsis.Results Compared with the control group, the levels of CRP, PCT and IMD were significantly higher in the sepsis patients [CRP (mg/L): 114.71±40.08 vs. 4.03±2.68, PCT (μg/L): 1.338±0.812 vs. 0.007±0.001, IMD (ng/L):43.03±9.67 vs. 16.77±2.06, allP < 0.01]. With the increase of APACHE Ⅱ score, the levels of PCT and IMD were gradually increased. In APACHE Ⅱ 10-20 score, 21-30 score, > 30 score groups, PCT (μg/L) were 0.397±0.129, 1.164±0.326, and 1.999±0.888, respectively (F = 19.392,P = 0.000); IMD (ng/L) were 29.12±5.60, 40.48±4.40,52.75±4.73, respectively (F = 33.310,P = 0.000). There was no significant difference in CRP among APACHE Ⅱ score groups (F = 2.137,P = 0.132). The level of IMD was positively correlated with CRP and PCT (r1 = 0.351,P1 = 0.024;r2 = 0.617,P2 = 0.000), and there was no correlation with temperature and white blood cell count (r1 = 0.063,P1 = 0.697;r2 = 0.064,P2 = 0.692). The expression of PCT and IMD in the death groups were significantly higher than the survival group [PCT (μg/L): 1.547±0.883 vs. 1.043±0.608, IMD (ng/L): 47.44±8.23 vs. 36.80±8.13, bothP < 0.05], while CRP was not significantly different. The area under the ROC curve [AUC (95% confidence interval, 95%CI)] of IMD was larger than that of PCT and CRP [0.809 (0.675-0.943) vs. 0.680 (0.511-0.849), 0.664 (0.490-0.838)]; when cut-off value of IMD was 41.58 ng/L, the sensitivity was 75.0% and the specificity was 82.4%.Conclusions The levels of CRP, PCT and IMD were increased in elderly sepsis patients, and IMD and PCT can better reflect the severity of sepsis. IMD is more valuable in predicting the prognosis of sepsis patients.

Objective To evaluate the difference and correlation between ultrasonic cardiac output monitor (USCOM) and pulse indicated continuous cardiac output (PiCCO) monitor on determination of hemodynamic parameters in critical patients.Methods A prospective observation self-control study was conducted.The critical patients who need hemodynamics monitoring,and admitted to Department of Critical Care Medicine of Peking University People's Hospital from March 2013 to December 2015 were enrolled.Cardiac output (CO),cardiac index (CI),stroke volume (SV),and stroke index (SI) were determined by PiCCO using thermodilution method at immediately (0 hour) and 24 hours after successful location of PiCCO catheter for 3 times then the above indexes were measured with USCOM,and the average values were chosen for statistical analysis.The differences in above parameters between the two methods,and the correlation of the parameters monitored by two methods were evaluated by Pearson linear correlation method,the consistency test was conducted by Bland-Altman method.Results In 31 critical patients enrolled,there were 18 males and 13 females,aging 29-89 years old with the mean of (48.1 ± 36.3) years,body mass of (68.7 ± 17.5) kg,and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score of 21.2 ± 3.1.CO,CI,SV,and SI detected by USCOM were significantly higher than those detected by PiCCO [CO (L/min):6.32 ± 1.98 vs.5.86 ± 1.72,t =4.887,P =0.000;CI (mL· s-1· m-2):61.68 ± 20.17 vs.56.84± 17.34,t =5.189,P =0.000;SV (mL):61.9 ± 19.7 vs.57.0± 16.9,t =3.977,P =0.000;SI (mL/m2):36.84 ± 12.67 vs.33.33 ± 10.79,t =4.278,P =0.000].It was shown by correlation analysis that CO,CI,SV,and SI monitored by USCOM and PiCCO was positively correlated (R2 value was 0.795,0.798,0.837,and 0.827,respectively,all P =0.000).It was shown by Bland-Altman analysis that the mean CO change (ΔCO) from 0 hour to 24 hours was 0.1 L/min,and the 95％ confidence interval was-0.62 to 0.80.Conclusion There was significant difference in the comparison of hemodynamics parameters monitored by USCOM and PiCCO respectively in critical patients,the overall values monitored by USCOM were higher than those monitored by PiCCO monitoring,but the correlations were good.