Objective To research paramagnetic contrast media(PCM)dose,injection speed and imaging time etc in low field MRI.Methods 406 patients with lesions spreading all over the body received Gadolinium-DTPA-enhanced scan by bolus injection with the dose of 0.1～0.15 mmol/kg within 60 seconds,and the effects of contrast-enhanced were observed.Results Among 406 patients lesions,337 cases(83%)were enhanced,9 undiscovered lesions displayed enhancement on the precontrast views,5 cases were discovered new lesions in delaying enhancement scan.Conclusion It is safe to apply the above mentioned dose and injection speed in clinic.The side-effects is small,and the development effect is good.It is especially important for lesions involving the structure of the blood brain barrier(BBB).

BACKGROUND: Traditional glass ion sealant has a poor abradability and a low rupture strength. The sealant on the occlusal surfaces easily fell off, and is difficult to replace resin sealant. OBJECTIVE: To observe the effects of traditional resin sealant and atraumatic restorative treatment (ART) glass ionomer-based pit and fissure sealant for the young children. METHODS: Randomized comparison method was used to compare ART glass ionomer-based pit on molars of one side with resin sealant on the opposite side in 89 3-year-old children. RESULTS AND CONCLUSION: The retention rates of ART glass ionomer sealant after 6 and 18 months were significantly lower than those of resin sealant (P < 0.05). The caducous position of ART gliass ionomer sealant was the second deciduous molar of the lower mandible, but the caducous position of resin sealant was the second deciduous molar of the upper mandible. The secondary caries rate of ART glass ionomer sealant was significantly lower than that of resin sealant at 6 months. No significant difference was determined between groups at 18 months. These suggest that ART glass ionomer pit and fissure sealant has lower drop-out rate, simple operation and low cost with excellent caries-preventing effect. Since it is economically superior to resin sealant, the method is worth popularizing in caries-preventing projects.

BACKGROUND: It has been reported that glass ionomer sealants have a poor wear resistance and low rupture strength that are easy to fall off on the occlusal surfaces. OBJECTIVE: To observe the effects of high-strength glass ionomer via the atraumatic restorative treatment (ART) on the pit and fissure of deciduous teeth in the young children. METHODS: A self-controlled method was used to compare ART glass ionomer-based pit and fissure seal on unilateral molars with resin sealant on the contralateral side in 89 children aged 3 years. RESULTS AND CONCLUSION: The retention rates of ART glass ionomer sealant after 6 and 18 months were 94.15% and 77.72%, respectively. At 6 months after treatment, ART gliass ionomer sealant was more caducous in mandibular second deciduous molars > mandibular first deciduous molars > maxillary second deciduous molars > maxillary first deciduous molars; at 18 months after treatment, the rank was mandibular second deciduous molars > maxillary second deciduous molars > mandibular first deciduous molars > maxillary first deciduous molars. The second deciduous molar of the lower mandible, but the caducous position of resin sealant was the second deciduous molar of the upper mandible. The caries prevalence rate of the deciduous teeth treated with ART glass ionomer sealant was significantly lower than that without sealant at 6 and 18 months (P < 0.01). These findings indicate that ART glass ionomer pit and fissure sealant is of a lower drop-out rate, easy to operate and of low cost with excellent caries-preventing effect.

Lipoxygenases (linoleate: oxygen oxidoreductase, EC 1.13.11.12; LOXs) are encoded by a multi-gene family in plants. The LOXs are monomeric non-heme, non-sulfur iron dioxygenases, which catalyze the incorporation of molecular oxygen into polyunsaturated fatty acids containing a cis, cis-1,4-pentadiene moiety. The LOX isoforms are distinguished by differences in optimum pH of the reaction, pI, substrate and product specificity, spatial and temporal expression, and subcellular localization. The function of various LOXs in plants has been suggested. Some of the physiological processes in which lipoxygenases have been implicated include wounding, pathogen attack, seed germination, fruit ripening, plant senescence, and synthesis of Abscisic acid (ABA) and Jasmonic acid (JA). During normal vegetative and reproductive growth, lipoxygenases have also been suggested to act as vegetative storage proteins, participate in transference of lipoid, and response to nutrient stress and source/sink relationships. Significant progress in understanding LOX families will be beneficial to the application of the LOX in crop breeding, research on new-type phytoalexin and food industry.
Gene Expression Regulation, Plant ; Lipoxygenase ; genetics ; metabolism ; Multigene Family ; Plants ; enzymology ; Protein Isoforms ; genetics ; metabolism

A new microfluidic system with four different microchambers (a circle and three equilateral concave polygons) was designed and fabricated using poly(dimethylsiloxane) (PDMS) and the soft lithography method.Using this microfluidic device at six flow rates (5,10,20,30,40,and 50 μL/h),the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated.Escherichia coli HB101 pGLO,which could produce a green fluorescent protein induced by L-arabinose,was utilized as the model bacteria.The results demonstrated that bacterial adhesion was significantly related to culture time,microenvironment geometry,and aqueous flow rates.Adhered bacterial density increased with the culture time.Initially,the adhesion occurred at the microchamber sides,and then the entire chamber was gradually covered with increased culture time.Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone.Also,the adhesion densities in the complex chambers were larger than those in the simple chambers.At low flow rates,the orientation of adhered bacteria was random and disorderly.At high flow rates,bacterial orientation became close to the streamline and oriented toward the flow direction.All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells,as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.

Abstract A new microfluidic system with four different microchambers （a circle and three equilateral concave polygons） was designed and fabricated using poly（dimethylsiloxane） （PDMS） and the soft lithography method. Using this microfluidic device at six flow rates （5, 10, 20, 30, 40, and 50 μL/h）, the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated. Escherichia coli HB101 pGLO, which could produce a green fluorescent protein induced by L-arabinose, was utilized as the model bacteria. The results demonstrated that bacterial adhesion was significantly related to culture time, microenvironment geometry, and aqueous flow rates. Adhered bacterial density increased with the culture time. Initially, the adhesion occurred at the microchamber sides, and then the entire chamber was gradually covered with increased culture time. Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone. Also, the adhesion densities in the complex chambers were larger than those in the simple chambers. At low flow rates, the orientation of adhered bacteria was random and disorderly. At high flow rates, bacterial orientation became close to the streamline and oriented toward the flow direction; All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells, as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.

Biocompatibility has always been the focal point in the study of biomaterials applied to medical apparatus. But at present, the standard system hasn't formed completely to evaluate the biomaterials. In recent years scientists tend to use general standard of evaluation. In this article, based on the recalcification time, the adhesion of platelets as well as the total quantity of plasma protein and some other evidences, combining with the Analytic hierarchy process (AHP), the method of general evaluation on the biocompatibility of anticoagulant biomaterials was discussed.
Anticoagulants ; analysis ; Biocompatible Materials ; standards ; Blood Proteins ; analysis ; Humans ; Materials Testing ; methods ; standards ; Platelet Adhesiveness ; drug effects

Objective:To evaluate the diagnostic value of 99Tc m-pyrophosphate (PYP) in transthyretin cardiac amyloidosis. Methods:From December 2018 to July 2019, 17 patients (9 males, 8 females, age: (53.4±13.0) years) with suspected cardiac amyloidosis underwent 99Tc m-PYP imaging in Peking Union Medical College Hospital were prospectively included. Visual score and semi-quantitative values (heart to contralateral ratio, H/CL) of 99Tc m-PYP uptake were used to diagnose transthyretin amyloidosis (ATTR). Biopsies and genetic measurements were also developed to evaluate the diagnostic value of the imaging. Results:Five of the 17 patients were diagnosed as ATTR with a visual score of 2-3, H/CL≥1.5, and confirmed with the biopsy or gene test. Four patients were diagnosed as ATTR with positive genetic results but no cardiac symptoms, and their visual scores were between 0 and 1 with H/CL<1.5. Considering the young age of the patients, amyloid deposition might have not yet caused visceral damage. Visual score of other 8 patients with negative 99Tc m-PYP imaging were also between 0 and 1 with H/CL<1.5, 2 of 8 were confirmed with light chain amyloidosis (AL) by biopsy, 3 were clinically diagnosed as AL and 3 were ATTR excluded. The accuracy of 99Tc m-PYP imaging for diagnosing ATTR was 11/11. Conclusion:99Tc m-PYP imaging is helpful for non-invasive diagnosis of transthyretin cardiac amyloidosis.

Objective:To investigate the application of different imaging methods of 99Tc m-pyrophosphate (PYP) in the diagnosis and pathological classification of cardiac amyloidosis (CA). Methods:A total of 31 patients (22 males, 9 females, age 21-81(57.2±13.4) years) with suspected CA who underwent 99Tc m-PYP dual-phase scintigraphy (early-phase: 1 h, delay-phase: 2-3 h) and SPECT/CT (1 h) between December 2018 and December 2019 in Peking Union Medical College Hospital were retrospectively included. Taking clinical diagnosis as the standard, the results of visual score (≥2, positive) and semi-quantitative values (heart to contralateral lung (H/CL)≥1.5, positive) of 99Tc m-PYP uptake in dual-phase scintigraphy and SPECT/CT imaging were analyzed. One-way analysis of variance and Bonferroni test were used to analyze the data. Results:Among 31 patients with suspected CA, 15 were clinically diagnosed as CA (5 patients with transthyretin-related CA (ATTR-CA) and 10 patients with light chain CA (AL-CA)) and 16 were diagnosed as non-CA. All 5 patients with ATTR-CA had positive dual-phase scintigraphy and SPECT/CT imaging results. Three out of 10 patients with AL-CA had positive early-phase scintigraphy whereas negative delay-phase scintigraphy and SPECT/CT imaging results. Sixteen patients who were clinically diagnosed as non-CA had negative dual-phase scintigraphy and SPECT/CT imaging results. The sensitivity (5/5), specificity (10/10), positive predictive value (5/5), negative predictive value (10/10) and accuracy (15/15) of delay-phase scintigraphy and SPECT/CT imaging were the same. Among 31 patients, 16 patients carried transthyretin-related (TTR) gene mutation, and 4 of them who clinically diagnosed as variant ATTR (ATTRv) had positive image findings while 12 of them who not clinically diagnosed as CA had negative image findings. There were significant differences in H/CL between ATTR-CA group and AL-CA group in early-phase (2.11±0.24 vs 1.31±0.07) and delay-phase (2.02±0.19 vs 1.30±0.05; F values: 75.41 and 87.15, Bonferroni test, both P<0.01). Conclusions:99Tc m-PYP delay-phase scintigraphy and SPECT/CT have high diagnostic efficiencies in ATTR-CA, helping to determine the pathological classification of CA; while early-phase scintigraphy has false positive results. Moreover, 99Tc m-PYP imaging is helpful to detect CA in patients with TTR gene mutation.