Computational Fluid Dynamics Analysis of Upper Airway Changes after Protraction Headgear and Rapid Maxillary Expansion Treatment

Clinically, it is common for Class III patients with maxillary skeletal deficiency, which may result in a variety of adverse consequences. Protraction headgear and rapid maxillary expansion (PE) is an effective treatment, but its effect on upper airway hydrodynamics has not been reported. The main purpose of this study was to evaluate the changes of the flow in the upper airway after PE by computational fluid dynamics (CFD). The sample includes fifteen patients (6 males, 9 females, age 11.00 ± 1.00) and the paired T-test was used to analyze the differences between the measured data before and after treatment. The maximum flow velocity decreased from 8.42 ± 0.16 m/s to 6.98 ± 0.36 m/s (p < 0.05), and the maximum shear force decreased from 3.72 ± 1.48 Pa to 2.13 ± 0.18 Pa. The maximum negative pressure decreased from −101.78 ± 33.60 Pa to 58.15 ± 9.16 Pa, only the changes of velopharynx and glossopharynx were statistically significant; while the maximum resistance decreased from 140.88 ± 68.68 Pa/mL/s to 45.95 ± 22.96 Pa/mL/s. PE can effectively reduce the airflow resistance of the upper airway and the probability of airway collapse, thus improving the patient’s ventilation function.     

Sub-Cellular Distribution of Zinc in Different Vegetative Organs and Their Contribution to Grains Zinc Accumulation in Rice Under Different Nitrogen and Zinc Supply

Journal of Plant Growth Regulation - Zinc is an important micronutrient for the growth and development of human body and plants. Proper use of nitrogen fertilizer and foliar application of Zn have...     

Extracellular volume estimation from ratios of bromide to chloride in urine or saliva.

Use of either urine or saliva samples to estimate extracellular water volume was investigated in 10 men using nonradioactive bromide (Br) and in seven newborn piglets using radioactive Br (82Br) and chloride (36Cl). The relation to Br to Cl concentrations in urine enabled an estimation of Br dilution volume from human urine (267 +/- 42 ml/kg, mean +/- SD) that was not significantly different (P = 1.0) from the Br dilution volume calculated from plasma Br concentration (268 +/- 20 ml/kg). Although the Br dilution volume estimated from saliva was not different from that of plasma, the error in the estimates of Br dilution volume from saliva was too large (mean difference, -36 +/- 64 ml/kg) to make its use practical. The data from piglets showed good agreement between 82Br and 36Cl dilution volumes calculated from 4-hr plasma samples (356 +/- 14 ml/kg and 347 +2- 12 ml/kg; P greater than 0.1) and between 82Br dilution volumes calculated from urine 82Br:36Cl and plasma 82Br (360 +/- 31 ml/kg and 356 +/- 14 ml/kg; P greater than 0.1). Extracellular water volume can be estimated in both adult and young animals using the Br dilution volume calculated from urine samples. It requires (i) two urine collections: one before and one 4 to 8 hr after administration of Br; (ii) a measurement or estimate of plasma Cl concentration; and (iii) a correction factor that describes the relationship of the ratio of Br to Cl in urine to that ratio in plasma.     

Effect of exogenous gibberellin A4/7 on tracheid production, longitudinal growth and the levels of indole‐3‐acetic acid and gibberellins A4, A7 and A9 in the terminal shoot of Pinus sylvestris seedlings

Synchronously dividing cultures of the unicellular green alga Scenedesmus obtusiusculus were cultivated for 24 or 70 h in medium high (1000 μM) or low (60 μM) in phosphorus. Aliquots of AlCl₃ (0, 37, 74, 111, 148, 185, or 222 μmol) were added daily to 1 l cell suspension at the end of the cell division phase. Algae were also grown in media with different pH, adjusted with HCl, in the absence of AlCl₃.
Effects of Al on cell metabolism vary with the intracellular Al concentration and with the concentration of Al available per cell. When the concentration of phosphorus is low, internal concentrations of Al are high and the chlorophyll content and the net dry matter production per cell increase, whereas the photosynthesis and the cell division are increased. Presence of Al in a low P medium decreases the pH of the medium down to 4.5. There are only small effects of Al in the presence of P, due to precipitation of most of the Al with P in the medium.
Despite the Al-induced decrease of the pH of the culture medium, effects caused by Al cannot be explained as a pH effect. Instead, the Al effect may, at least to some extent, be related to a decrease in availability of P in the metabolism, due to formation of aluminium phosphate inside the cell.     

EFFECTS OF HELPER PROTEINS ENCODED BY p19 AND orf1-orf2 GENES ON Cyt1Aa PROTEIN EXPRESSION IN ACRYSTALLIFEROUS STRAIN OF BACILLUS THURINGIENSIS

A series of plasmids were constructed to examine the effects of p19 and orf1‐orf2 genes from Bacillus thuringiensis on Cyt1Aa synthesis and inclusion formation. The plasmids expressed the cyt1Aa gene along with either p19 or orf1‐orf2, or each of them coordinatively with p20 in the acrystalliferous strain of B. thuringiensis subsp. israelensis 4Q7. No effect on the expression of Cyt1Aa protein was found when P19 or Orf1‐Orf2 co‐expressed with Cyt1Aa. However, when including p20 gene, the constructs with p19 or orf1‐orf2 gene produced lower yield of Cyt1Aa proteins than without p19 or orf1‐orf2 gene. Electron microscopy observation and bioassay showed that P19 and Orf1‐Orf2 have no influence on the crystal size and toxicity of Cyt1Aa protein. It is presumed that P19 and Orf1‐Orf2 might have negative effects on Cyt1Aa synthesis in B. thuringiensis.     

Poplar (Populus nigra L.) plants transformed with aBacillus thuringiensis toxin gene: insecticidal activity and genomic analysis

Insect-resistant poplar (Populus nigra L.) plants have been produced by infecting leaves withAgrobacterium tumefaciens strains carrying a binary vector containing different truncated forms of aBacillus thuringiensis (B.t.) toxin gene under a duplicated CaMV 35S promoter. Putative transgenic plants were propagated by cuttings at two experimental farms (in Beijing and Xinjiang, China). At 2–3 years after transformation, 17 of them were selected on the bases of insect-tolerance and good silvicultural traits, and evaluated for insect resistance, for the presence of theB.t. toxin DNA fragment (Southern blots and PCR) and for the expression of the transgene (western and northern blots). Somaclonal variation, as suggested by the appearance of permanent changes in the shape of the leaves, was also investigated with molecular tools (RFLP (restriction fragment length polymorphism), RAPD (random amplified polymorphic DNA) and microsatellite DNA).Bioassays withApochemia cineraius andLymantria dispar on the leaves of the selected clones showed different and, in some cases, high levels of insecticidal activity. The molecular analysis demonstrated integration and expression of the foreign gene. Somatic changes were correlated to extensive genomic changes and were quantified in dendrograms, in terms of genomic similarity. The analysis of control plants suggested that genomic changes were correlated to thein vitro culture step necessary forA. tumefaciens-mediated gene transfer, rather than to the integration of the foreign genes.Three transgenic clones (12, 153 and 192), selected for insect resistance, reduced morphological changes and promising silvicultural traits, are now under large-scale field evaluation in six different provinces in China.     

国家自然科学基金评审程序剖析──1993年和1994年植物学科面上基金项目分析

国家自然科学基金评审程序剖析──１９９３年和１９９４年植物学科面上基金项目分析陈峰,朱大保（中国科学院武汉植物研究所武汉４３００７４）（国家自然科学基金委员会生命科学部北京１０００８３）关键词基金,评审,科研立项,学科ＡＮＡＬＹＳＬＳＦＯＲＪＵＤＧＥ...     

Morphometric Analysis of Hepatocellular carcinoma

Ｍｏｒｐｈｏｍｅｔｒｉｃ　Ａｎａｌｙｓｉｓ　ｏｆ　Ｈｅｐａｔｏｃｅｌｌｕｌａｒ　ｃａｒｃｉｎｏｍａＬａｉＭａｏ－ｄｅ（来茂德）;ＣｈｅｎＰｅｉ－ｈｕｉ（陈培辉）ａｎｄＺｈｏｕＳｈｕｉ－ｙｕｎ（周水云）（ＤｅｐａｒｔｍｅｎｔｏｆＰａｔｈｏｌｏｇｙ,Ｚｈ...     

EB病毒胸苷激酶基因的扩增

ＥＢ病毒胸苷激酶基因的扩增陈尚武,陈瑞君,黄迪,朱振宇,马涧泉（中山医科大学生化教研室,广州５１００８９）（中山医科大学肿瘤研究所,广州５１００６０）关键词Ｅｐｓｔｅｉｎ－Ｂａｒｒ病毒,胸苷激酶,基因,聚合酶链反应鼻咽癌（ｎａｓｏｐｈａｒｙｎｇｅａｌ...     

Biology and life cycle ofAtelocauda koae,an unusual demicyclic rust

Atelocauda koae, a rust of the native HawaiianAcacia koa, is considered as a demicyclic species, having spermogonial, aecial, and telial states, but is unusual in production of aeciospores simultaneously with teliospores rather than consecutively. Host inoculation with spores of each state separately confirmed that the life cycle was perpetuated by the telial state, but the aeciospores, while capable of germination and stomal penetration, did not produce detectable infection. This rust therefore behaves as a microcyclic species, and appears to be in evolutionary transition toward this reduced state. Teliospores produced vestigial, permanently attached basidiosopores which germinated to produce infective hyphae. The hyphae entered the host either through stomata or penetrated the epidermis directly, with the latter method being more common. Unusual nuclear associated with teliospore germination, in which meiosis occurs in more than one diploid nucleus was observed, in confirmation of an earlier study.