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By combining frequency modulation Chirp Z transform ion mobility spectrometers (IMS) and multi nozzle electrospray array ionization source, a method of NanoESI-Chirp Z transform ion mobility spectrometry-high performance liquid chromatography was developed for the determination of n-alkyl ammonium bromide compounds.The parameters of NanoESI-Chirp Z transform IMS such as electric field intensity, solvent composition, and solution flow rate were investigated and optimized.Subsequently, four kinds of n-alkyl ammonium bromide compounds were respectively detected by this developed Chirp Z transform method and Fourier transform method, and the obtained results were compared.The result indicated that the optimum conditions were electric field intensity of 4.5 kV, and ESI solution flow rate of 8 μL/min.Then a test mixture containing tetrabutylammonium bromide, tetrapentylammoniumbromide, tetrahexylammonium bromide, tetraheptylammonium bromide, tetranoctylammoniumbromideandtetrakis(decyl) ammonium bromide was successfully separated and determined by the HPLC-nanoESI-Chirp Z IMS method.Chirp Z transform method provided higher signal to noise ratio compared to conventional signal averaging method, and was superior to FT method in the determination of drift time.
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BACKGROUND: The study of tissue-engineered cartilage with predetermined shaping and regeneration has provided novel ideas and techniques for repair of laryngeal cartilage erosion; however, due to the special natures of the morphology, location and function of laryngeal cartilage, tissue engineering research has not, to date, exhibited its ful advantages in the reconstruction of laryngeal cartilage. OBJECTIVE:To explore the feasibility of building tissue-engineered larynx-shaped cartilage using poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHH) as a scaffold filed and encapsulated with pedicled myofascial flaps. METHODS:Porous PHBHH was prepared and formed into a holow like larynx-shape, and the cel PHBHH composites were cultured for 1 weekin vitro prior to implantationin vivo. The cel-PHBHH composite was filed and encapsulated with myofascial flaps with the pedicle forin situ implantation in nine rabbits as experimental group. PHBHH scaffold with no chondrocytes was implanted alone in three rabbits as control group. Cartilage regeneration was assessed at 6, 12 and 18 weeks after surgery through morphological observation, histological and immunohistochemical detection. RESULTS AND CONCLUSION: In the experimental group, the shape and porosity (> 90%) of the material were ideal, the cels exhibited good adhesion with the material and the blood supply within the myofascial flap with pedicle was rich for effective filing and encapsulation of the cel PHBHH composite. Tissue-engineered laryngeal cartilage with the holow, semi-trumpet shape was idealy formed at 6 weeks after the surgery. Further maturation of the cartilage was observed at 12 and 18 weeks after the surgery. However, there was no cartilage tissue in the control group. This study shows that PHBHH is a suitable material for the formation of a holow, semi-trumpet shape with good celular compatibility. Myofascial flap filing and encapsulating can be used to build tissue-engineered laryngeal cartilage with a holow, semi-trumpet shape.
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Objective To investigate the relationship between the urinary albumin excretion (UAE) and serum uric acid in general population. Methods The study participants were derived from the epidemiological study on the association of metabolic syndrome and chronic kidney disease (CKD) in Pinggu district, Beijing. A total of 992 participants (463 men and 529 women) aged from 30 to 75 years were enrolled in this study. For each participant, UAE, serum uric acid, serum creatinine, and serum lipids were detected and other potential risk factors for CKD were surveyed. Results ( 1 ) The frequencies of microalbuminuria, macroalbuminuria and hyperuricemia were 12.9% , 1.8% and 4.3% respectively. The persons with hyperuricemia had significantly higher frequency of albuminuria than those without hyperuricemia (37. 2% vs 13. 7% , P ＜0. 01). (2) The participants were divided according to the quartiles (25% , 50% , 75% ) of serum uric acid level, and the frequencies of albuminuria in males were 13. 2% , 13. 9% , 17. 2% and 25.4% , while those in females were 8. 4% , 6. 2% , 9. 6% and 24. 8%. ( 3 ) Multivariate logistic regression analysis showed, hyperuricemia was significantly associated with albuminuria in females (OR =2. 31, 95% CI 1. 15-4. 68; P=0.02), but not in males. If the persons with reduced renal function were excluded, similar result still could be gained. Conclusions The prevalence of albuminuria increases gradually with uric acid elevation. Serum uric acid is an independent risk factor of elevated UAE, especially in females.
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Objective To investigate the discriminator value of Han Chinese first morning urine albumin creatinine ratio (ACR) for determining the microalbuminuria. Methods A total of 1056 participants (494 males and 562 females) were selected from epidemiologic study of the metabolic syndrome and chronic kidney disease in Pinggu district, Beijing. Eight-hour overnight urinary albumin excretion (UAE) was regarded as the gold standard for defining the albuminuria,and the ROC curve analysis was used to determine the ACR discriminator value for microalbuminuria. Results (1)Microalbuminuria was found in 12.5% of participants,macroalbuminuria in 1.7%. (2)The ACR discriminator value for microalbuminuria by ROC curve analysis was 1.95 g/mol (sensitivity 97.6% and specitivity 88.6%) for men, 3.62 g/mol(sensitivity 83.8% and specitivity 89.1%) for women, 2.78 g/mol (sensitivity 88.7% and specitivity 85.9%)for overall. The upper boundary of microalbuminuria by ROC curve analysis was 22.59 g/mol (sensitivity 100.0% and specitivity 98.8%) . (3)The inter-rater agreement of the result in this study showed that sensitivity was 91.3% and specitivity was 88.2%, positive likelihood ratio was 7.56 and negative likelihood ratio was 0.10, positive predictive value was 56.9% and negative predictive value was 98.4%. Conclusions The ACR discriminator value for determining microalbuminuria is obviously higher in women than that in men, and is higher than recommendation of international guidelines. The result by ROC curve analysis has better sensitivity and specitivity.
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I. Under scanning electron microscope, the vascular network of the cutaneous, subcutaneous, and deep fascia in planta can be divided into five layers according totheir vascular morphological characteristics. They are as following: the papillary layer, the subpapillary layer, the deep dermal layer, the subcutaneous layer, and the deep fascia layer. 2. The papillary layer is the most superficial one, it is easy to recognize that there are five types of capillary network: the single loop, the multiple loop, the tower-like type, the finger-like type, and irregular type. 3. The network in the subpapillary layer is polygon-like, parallel to the surface of skin. 4. In the deep dermal layer, there are many vascular balls in the vascular trunks. 5. The subcutaneous layer: The vascular networks are limited by fat lobules. 6. The vascular-trunks run across each other and anastomose each other in deep fascia layer.