1.A new biosynthesis route for production of 5-aminovalanoic acid, a biobased plastic monomer.
Yaqi KANG ; Ruoshi LUO ; Fanzhen LIN ; Jie CHENG ; Zhen ZHOU ; Dan WANG
Chinese Journal of Biotechnology 2023;39(5):2070-2080
5-aminovalanoic acid (5AVA) can be used as the precursor of new plastics nylon 5 and nylon 56, and is a promising platform compound for the synthesis of polyimides. At present, the biosynthesis of 5-aminovalanoic acid generally is of low yield, complex synthesis process and high cost, which hampers large-scale industrial production. In order to achieve efficient biosynthesis of 5AVA, we developed a new pathway mediated by 2-keto-6-aminohexanoate. By combinatory expression of L-lysine α-oxidase from Scomber japonicus, α-ketoacid decarcarboxylase from Lactococcus lactis and aldehyde dehydrogenase from Escherichia coli, the synthesis of 5AVA from L-lysine in Escherichia coli was achieved. Under the initial conditions of glucose concentration of 55 g/L and lysine hydrochloride of 40 g/L, the final consumption of 158 g/L glucose and 144 g/L lysine hydrochloride, feeding batch fermentation to produce 57.52 g/L of 5AVA, and the molar yield is 0.62 mol/mol. The new 5AVA biosynthetic pathway does not require ethanol and H2O2, and achieved a higher production efficiency as compared to the previously reported Bio-Chem hybrid pathway mediated by 2-keto-6-aminohexanoate.
Nylons
;
Lysine/metabolism*
;
Hydrogen Peroxide/metabolism*
;
Metabolic Engineering
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Plastics/metabolism*
;
Fermentation
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Escherichia coli/metabolism*
;
Aminocaproates/metabolism*
2.Proteomics-based screening of differentially expressed proteins in skin of Chinese merino fine sheep (JunKen type) of different gender.
Yiyuan ZHANG ; Yanhua GUO ; Hong TANG ; Xinhua WANG ; Limin WANG ; Ping ZHOU
Chinese Journal of Biotechnology 2022;38(10):3925-3939
The purpose of this study was to understand the effect of gender on the traits of wool. One-year-old male and female Chinese merino sheep (JunKen type) were used to screen differentially expressed proteins in skin tissues by quantitative proteomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and data independent acquisition (DIA) strategy. This was followed by GO function annotation, KEGG metabolic pathway and protein network interaction analysis on the differential proteins obtained. The result showed that there were 674 differentially expressed proteins between male and female groups, whereas 280 proteins were up-regulated and 394 proteins were down-regulated in the male group. Through further comparison and analysis, there were 43 differentially expressed proteins related to skin hair follicle development and wool phenotype, 30 up-regulated and 13 down-regulated. The GO annotation analysis of differentially expressed proteins were mainly enriched in 37 processes of molecular function such as oxygen binding, chondroitin sulfate binding, heme binding, glutathione peroxidase activity and glutathione transferase activity; 120 biological processes such as cellular oxidant detoxification, regulation of muscle contraction, notch signaling pathway, calcium ion transmembrane transport and glutathione metabolism; and 31 processes related to cellular components such as mast cell granule, nucleus, sarcoplasmic reticulum and endoplasmic reticulum lumen. KEGG analysis showed that the differentially expressed proteins were involved sixteen signaling pathways, among which MAPK and p53 signaling pathways were closely related to wool growth and development. The protein network interaction analysis discovered that COL1A1 was closely related to MMP2, SPARC, THBS1 and other differentially expressed proteins, which might play a key role in wool growth and development. Thus, this study obtained basic data for revealing the molecular mechanism of sheep wool traits of different gender.
Animals
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Male
;
Female
;
Proteomics
;
Chromatography, Liquid/methods*
;
Tandem Mass Spectrometry/methods*
;
Wool
;
China
4.Research progress on the biomimetic remineralization of hard tooth tissues based on polyamide-amine dendrimer.
Ke-Zhen XIANG ; Liang CHEN ; De-Qin YANG
West China Journal of Stomatology 2020;38(6):692-696
Polyamide-amine (PAMAM) dendrimer, a new hyperbranched macromolecular polymer, is considered an "artificial protein" by many scholars on account of its excellent chemical and biological characteristics. PAMAM has internal cavities and a large number of reactive terminal groups. These structures allow the polymer to be used as a bionic macromoleculethat could simulate the biomimetic mineralization of the natural organic matrix on the surface of tooth tissue. Specifically, PAMAM can beused as an organic template to regulate mineral nucleation and crystal growth; thus, the polymerisa more ideal dental restoration material than traditional allogenic materials. This article reviews research progress on thePAMAM-induced biomimetic mineralization of hard tooth tissues.
Amines
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Biomimetics
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Dendrimers
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Humans
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Nylons
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Tooth Remineralization
5.Isolation of Penicillium expansum WH-3 for the production of L(+)-tartaric acid.
Wen-Na BAO ; Yi CHEN ; Hong-Xiu LIAO ; Hang CHEN ; Shi-Wang LIU ; Yong LIU
Journal of Zhejiang University. Science. B 2020;21(10):835-840
The L(+)-form of tartaric acid (L(+)-TA) exists extensively in nature, and is widely used in the food, chemical, textile, building, and pharmaceutical industries (Su et al., 2001). The main method for L(+)-TA production is microbial transformation by cis-epoxysuccinate hydrolase (CESH), which can catalyze the asymmetric hydrolysis of cis-epoxysuccinic acid or its salts to TA or tartrate (Bao et al., 2019). Seventeen species containing CESH have been isolated so far. However, most species for L(+)-TA production have been reported from bacteria (Xuan and Feng, 2019). The only fungus isolated from soil by our lab recently, that could be used as catalyst for the process under acidic condition, is Aspergillus niger WH-2 (Bao et al., 2020). In order to find strains with new characteristics, this study attempted to isolate a new CESH source from fungi and investigate its application value.
Aspergillus niger/metabolism*
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Biomass
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Catalysis
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Fermentation
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Hydrogen-Ion Concentration
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Hydrolases/chemistry*
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Hydrolysis
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Industrial Microbiology
;
Magnetic Resonance Spectroscopy
;
Penicillium/metabolism*
;
Phylogeny
;
Soil
;
Species Specificity
;
Stereoisomerism
;
Tartrates/chemistry*
;
Temperature
;
Textiles
6.Device and method for evaluating the performance of dry electrode for fabric surface bioelectricity.
Sha LI ; Mingyuan JIANG ; Jun XIE ; Yao HU ; Hao LIU
Journal of Biomedical Engineering 2019;36(3):460-467
In order to quantitatively evaluate the performance of dry electrode for fabric surface bioelectricity, a set of active measuring devices that can simulate electrocardiosignal has been developed on the basis of passive system by our group. Five Ag/AgCl fabric dry electrodes were selected to test and evaluate the devices. The results show that the deviation ratios of peak time interval of the five electrodes are all less than 1%. The maximum voltage amplitude decay rate is 7.2%, and the noise amplitudes are lower than 0.004 mV. The variable coefficient of peak time offset is less than 8%. The variable coefficient of voltage amplitude is less than 2%. The variable coefficient of noise amplitude is less than 10%. Research shows the devices has good repeatability and stability in measuring the simulated electrocardiosignal. The active measuring devices proposed in this paper can provide a new method for performance evaluation and standard formulation of surface bioelectricity dry electrode.
Electrodes
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Textiles
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Wearable Electronic Devices
7.Physical properties and color stability of injection-molded thermoplastic denture base resins
So Yeon SONG ; Kyoung Soo KIM ; Jeong Yol LEE ; Sang Wan SHIN
The Journal of Advanced Prosthodontics 2019;11(1):32-40
PURPOSE: The purpose of this study was to compare mechanical and physical properties of injection-molded thermoplastic denture base resins. MATERIALS AND METHODS: In this study, six commercially available products (VA; Valplast, LC; Lucitone, ST; Smiltone, ES; Estheshot-Bright, AC; Acrytone, WE; Weldenz) were selected from four types of thermoplastic denture base materials (Polyamide, Polyester, Acrylic resin and Polypropylene). The flexural properties and shore D hardness have been investigated and water sorption and solubility, and color stability have evaluated. RESULTS: For the flexural modulus value, ES showed the highest value and WE showed significantly lower value than all other groups (P < .05). Most of experimental groups showed weak color stability beyond the clinically acceptable range. CONCLUSION: Within the limits of this study, thermoplastic denture base resin did not show sufficient modulus to function as a denture base. In addition, all resins showed discoloration with clinical significance, and especially polyamides showed the lowest color stability.
Denture Bases
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Dentures
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Hardness
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Nylons
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Polyesters
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Solubility
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Water
8.Association Between Organic Dust Exposure and Adult-Asthma: A Systematic Review and Meta-Analysis of Case-Control Studies
Yan ZHANG ; Bing YE ; Hongling ZHENG ; Wei ZHANG ; Lin HAN ; Peng YUAN ; Chao ZHANG
Allergy, Asthma & Immunology Research 2019;11(6):818-829
BACKGROUND: Exposure to organic dust has been widely investigated as a potential risk factor for asthma with different results. To clarify a potential relationship, we performed the present meta-analysis to integrate the results of studies examining the association of organic dust exposure with asthma. METHODS: A comprehensive literature search in the electronic databases including EMBASE, PubMed and Cochrane Library databases (up to August 2018) was conducted. The adjusted odds ratios (ORs) with corresponding 95% confidence interval (CI) for organic dust exposure and asthma were retrieved and pooled to generate summary effect estimates in Revman 5.2. RESULTS: Database searches retrieved 1,016 records. A total of 17 studies containing 3,619 cases and 6,585 controls were finally included in our meta-analysis. The summary estimates suggested that organic dust exposure was positively associated with asthma (OR, 1.48; 95% CI, 1.26–1.75; P < 0.00001), whether among population-based case-control studies (OR, 1.24; 95% CI, 1.13–1.35; P < 0.00001) or hospital-based case-control studies (OR, 2.79; 95% CI, 1.27–6.12; P = 0.01). Subgroup analysis showed that paper/wood (OR, 1.62; 95% CI, 1.38–1.90; P < 0.00001), flour/grain (OR, 1.48; 95% CI, 1.11–1.97; P = 0.008), and textile dust (OR, 1.50; 95% CI, 1.08–2.09; P = 0.02) exposure were significantly associated with asthma. CONCLUSIONS: Based on the studies evaluated, our meta-analysis results prompt that organic dust exposure is a risk factor inducing asthma, although precise analysis focus on specific organic dust materials is still warranted.
Asthma
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Case-Control Studies
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Dust
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Odds Ratio
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Risk Factors
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Textiles
9.Fluid Dynamics of Small Diameter Tubes Used in Membrane-tube Type Glaucoma Shunt Devices
Jong Chul HAN ; Young Hoon HWANG ; Byung Heon AHN
Korean Journal of Ophthalmology 2019;33(4):371-378
PURPOSE: To investigate the outflow characteristics of silicone tubes with intraluminal stents used in membrane-tube (MT) type glaucoma shunt devices. METHODS: The silicone tubes used in MicroMT (internal diameter of 100 µm with a 7-0 nylon intraluminal stent) and Finetube MT (internal diameter of 200 µm with a 5-0 nylon intraluminal stent) were connected to a syringe-pump that delivered a continuous flow of distilled water at flow rates of 2, 5, 10, and 25 µL/min. The pressures and resistances of tubes were measured at a steady flow rate with full-length, half-length, and absence of intraluminal stents. RESULTS: The mean outflow resistance of the two types of tubes ranged from 3.0 ± 1.9 to 3.8 ± 1.7 mmHg/µL/min with a full-length intraluminal stent, 1.8 ± 1.1 to 2.2 ± 1.1 mmHg/µL/min with a half-length intraluminal stent, and 0.1 ± 0.0 to 0.2 ± 0.0 mmHg/µL/min without an intraluminal stent. Theoretically, for a physiologic state with a flow rate of 2 µL/min and episcleral venous pressure of 6 mmHg, the mean pressures of tubes were expected to be 13.2 ± 3.0, 10.5 ± 2.4, and 6.4 ± 0.2 mmHg in MicroMT with full-length, half-length, and absence of intraluminal stents, respectively, and 12.5 ± 3.9, 9.6 ± 2.4, and 6.2 ± 0.2 mmHg in Finetube MT with full-length, half-length, and absence of intraluminal stents, respectively. The pressure variance also decreased with intraluminal stent retraction (p < 0.01). CONCLUSIONS: The small diameter tubes of 100 and 200 µm internal diameters, with 7-0 and 5-0 nylon intraluminal stents, respectively, used in the MT-type glaucoma shunt device showed safe and effective outflow characteristics.
Glaucoma
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Hydrodynamics
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Intraocular Pressure
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Nylons
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Silicon
;
Silicones
;
Stents
;
Venous Pressure
;
Water
10.Transperitoneal para-aortic lymphadenectomy by robot assisted laparoscopy in 10 steps
Mellie HEINEMANN ; Isabelle MASQUIN ; Guillaume BLACHE ; Laura SABIANI ; Camille JAUFFRET ; Gilles HOUVENAEGHEL ; Eric LAMBAUDIE
Journal of Gynecologic Oncology 2019;30(5):e74-
OBJECTIVE: Para-aortic lymphadenectomy was the cornerstone of gynecologic oncology surgery. In endometrial cancer, the quality of para-aortic lymphadenectomy had direct impact on survival of patient. The launch of robot assisted laparoscopy started in 2005 in France, and in 2008 a transperitoneal para-aortic lymphadenectomy was described [1]. With the increase of robots, the robot assisted laparoscopy became more and more popular, hence the need of video tutorial to help less experienced surgeon in this surgical procedure [2]. METHODS: We proposed a description in 10 key steps, of a transperitoneal para-aortic lymphadenectomy by robot assisted laparoscopy (Da Vinci® Si or Xi Robot Surgical System; Intuitive Surgical Inc., Sunnyvale, CA, USA), without other surgical procedure. RESULTS: The 10 steps are: Step 1: port placement and Da Vinci robot positioning Step 2: identification of the right ureter Step 3: identification of the left renal vein Step 4: latero-caval and aorto-caval lymph nodes dissection Step 5: identification of the left ureter Step 6: creation of peritoneal tent Step 7: identification of the inferior mesenteric artery Step 8: latero-aortal lymph nodes dissection Step 9: pre-sacral lymph nodes dissection Step 10: extraction of bags with specimen and surgical textile CONCLUSION: A standardization of transperitoneal para-aortic lymphadenectomy by robot-assisted laparoscopy is the basis of teaching and learning process. Also it increases the quality of surgery, and consequently decreases the risk of complications.
Endometrial Neoplasms
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Female
;
France
;
Humans
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Laparoscopy
;
Learning
;
Lymph Node Excision
;
Lymph Nodes
;
Mesenteric Artery, Inferior
;
Renal Veins
;
Textiles
;
Ureter

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