遗传和环境因素对儿童青少年身体高度及其比例的影响

目前有关儿童青少年坐高、下肢长及其比值的报道多为非双生子人群的研究。为了解遗传和环境因素对儿童青少年坐高、下肢长及坐高与下肢长比值影响的相对大小,我们对796对6～18岁双生子的身高和坐高进行了测量,计算下肢长及坐高与下肢长比值,采用结构方程模型分析其遗传和环境相对效应。结果发现,校正年龄后,男女15～18岁年龄组坐高和下肢长的遗传度(0.63～0.78)均分别高于同性别低年龄段儿童青少年(0.31～0.68);坐高与下肢长比值的遗传度除9～11岁女生(0.84)外,其他年龄组均较低(男0.16～0.46,女0.21～0.57);共同环境因素和特殊环境因素对6～14岁儿童青少年各指标的作用较大。本研究提示,在快速发育时期,坐高、下肢长和坐高与下肢长比值对环境因素更为敏感,遗传度较低;机体越成熟,其遗传效应更强。     

Regulation of intracellular polyamine biosynthesis and transport by NO and cytokines TNF-alpha and IFN-gamma

Nitric oxide (NO)has been described to exert cytostatic effects on cellularproliferation; however the mechanisms responsible for these effectshave yet to be fully resolved. Polyamines, conversely, are requiredcomponents of cellular proliferation. In experimental models ofinflammation, a relationship between these two pathways has beensuggested by the temporal regulation of a common precursor, arginine.This study was undertaken to determine the effects NO and the NOsynthase (NOS)-inducing cytokines, tumor necrosis factor- (TNF-)and interferon- (IFN-), exert on polyamine regulation. Thetransformed kidney proximal tubule cell line, MCT, maintains highconstitutive levels of the first polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). NO donors markedly suppressed ODC activity in MCT and all other cell lines examined. TNF- and IFN- induction of NO generation resulted in suppressed ODC activity, aneffect prevented by the inducible NOS inhibitorL-N⁶-(1-iminoethyl)lysine(L-NIL). Dithiothreitol reversalof NO-mediated ODC suppression supports nitrosylation as the mechanismof inactivation. We also evaluated polyamine uptake, inasmuch asinhibition of ODC can result in a compensatory induction of polyaminetransporters. Administration of NO donors, or TNF- and IFN-,suppressed[³H]putrescine uptake,thereby preventing transport-mediated reestablishment of intracellularpolyamine levels. This study demonstrates the capacity of NO andinflammatory cytokines to regulate both polyamine biosynthesis and transport.     

Macrocylic thioether-esters and thioether-thioesters and their palladium, platinum and silver complexes

Preparations by the high dilution method are reported for seven macrocyclic thioether-esters and thioether-thioesters (L1–;L7). Yields in these reactions between thiodiglycolyl dichloride and appropriate ,ω-diols or dithiols range from 10 to 51%. The compounds are characterized by ¹H and ¹³C NMR, IR and high resolution mass spectroscopy. They react with salts of Pd(II), Pt(II) and Ag(I) to form complexes of which MX₂·L2, (M = Pt, X = Cl; M = Pd, X = Cl, Br, I, SCN), [Pd(L2)₂][CF₃SO₃]₂·H₂O and [Ag(L5)₂][CF₃SO₃]·C₂H₅OH have been isolated and characterized by elemental analysis, IR and NMR spectroscopy. NMR spectra indicate reversible dissociation of the ligand occurs in dimethyl sulfoxide solvent for PdCl₂·L2 but not for the Pt analogue. For PtCl₂·L2, spectra indicate that the ligand is undergoing a conformational ‘wag’ about its pair of equivalent sulfurs. These remain bound to the metal while the unique sulfur moves from the apical position of the coordination sphere to a non-coordinated situation. Simultaneously, inversions at the bound sulfurs are occurring.     

Diagnostic Necropsy and Selected Tissue and Sample Collection in Rats and Mice

There are multiple sample types that may be collected from a euthanized animal in order to help diagnose or discover infectious agents in an animal colony. Proper collection of tissues for further histological processing can impact the quality of testing results. This article describes the conduct of a basic gross examination including identification of heart, liver, lungs, kidneys, and spleen, as well as how to collect those organs. Additionally four of the more difficult tissue/sample collection techniques are demonstrated. Lung collection and perfusion can be particularly challenging as the tissue needs to be properly inflated with a fixative in order for inside of the tissue to fix properly and to enable thorough histologic evaluation. This article demonstrates the step by step technique to remove the lung and inflate it with fixative in order to achieve optimal fixation of the tissue within 24 hours. Brain collection can be similarly challenging as the tissue is soft and easily damaged. This article demonstrates the step by step technique to expose and remove the brain from the skull with minimal damage to the tissue. The mesenteric lymph node is a good sample type in which to detect many common infectious agents as enteric viruses persist longer in the lymph node than they are shed in feces. This article demonstrates the step by step procedure for locating and aseptically removing the mesenteric lymph node. Finally, identification of infectious agents of the respiratory tract may be performed by bacterial culture or PCR testing of nasal and/or bronchial fluid aspirates taken at necropsy. This procedure describes obtaining and preparing the respiratory aspirate sample for bacterial culture and PCR testing.Download video file.^{(56M, mov)}     

Cadmium and copper change root growth and morphology of Pinus pinea and Pinus pinaster seedlings

Heavy metal loads in forest soils have been increasing over time due to atmospheric inputs. Accumulation in the upper soil layers could affect establishment of seedlings and forest regeneration. Mediterranean species show a high initial root development, allowing seedlings to reach the moisture of deeper soil layers. In the present work seedlings of stone pine ( Pinus pinea L.) and maritime pine ( Pinus pinaster Ait.), were grown in culture solution supplied with 0.0, 0.1, 1 or 5 μ M CdSO₄ or with 1 μ M CdSO₄ and 1 μ M CuSO₄ combined. In both species tap-root elongation was drastically reduced in the 5 μ M Cd²⁺ and in the (Cd²⁺+ Cu²⁺) treatments. A supply of 0.1 or 1 μ M Cd²⁺, however, enhanced root elongation in Pinus pinea without significantly influencing root elongation in Pinus pinaster . In both species the root density (weight per unit length) and the width of the cortex increased in response to Cd²⁺ exposure. In Pinus pinaster the mitotic index decreased at the higher Cd²⁺ concentrations and when Cd²⁺ and Cu²⁺ were combined. The data suggest that cell elongation is more sensitive to Cd²⁺ than cell division. The number and length of the lateral roots were also affected by Cd²⁺ treatment to a higher degree in Pinus pinaster than in Pinus pinea, reflecting the different Cd- tolerance of the two species.     

Denitrification and nitrate-reducing bacterial populations in abandoned and reclaimed minesoils

Abstract Microbial populations, nitrogen mineralization potentials, and denitrification enzyme activities were examined in two abandoned carbolithic minesoils. Numbers and activities of bacteria and fungi were lower in nonamended than in lime and/or fly ash amended sites. Rates of aerobic NO₃⁻ production (3 to 38 μg-N kg⁻¹ h⁻¹) and anaerobic NO₃⁻ reduction to N₂O (5 to 68 μg-N kg⁻¹ h⁻¹) were measured. Organisms capable of N₂O production under anaerobic soil conditions were present in low numbers, and their activity was restricted in part by low soil pH. Nondenitrifying nitrate-reducing bacteria were more diverse and in greater numbers than respiratory denitrifiers and may have been responsible for N₂O production in assays measuring denitrification enzyme activity.     

Transitions in photosynthetic parameters of midvein and interveinal regions of leaves and their importance during leaf growth and development

Abstract: The areal development of photosynthetic efficiency and growth patterns in expanding leaves of two different dicotyledonous species - Coccoloba uvifera and Sanchezia nobilis - was investigated by imaging both processes repeatedly over 32 days. Measurements were performed using combined imaging systems for chlorophyll fluorescence and growth, with the same spatial resolution. Significant differences in potential quantum yield of photosynthesis (F_v/F_m), a parameter indicating the functional status of photosystem II, were found between midvein and interveinal tissue. Although base-tip gradients and spatial patchiness were observed in the distribution of relative growth rate, neither midvein nor interveinal tissue showed such patterns in F_v/F_m. In young leaves, F_v/F_m of the midvein was higher than F_v/F_m of interveinal tissue. This difference declined gradually with time, and upon cessation of growth, F_v/F_m of interveinal regions exceeded those of midvein tissue. Images of chlorophyll fluorescence quenching showed that ΔF/F_m' in the different tissues correlated with F_v/F_m, indicating that, in these uniformly illuminated leaves, transitions in photosynthetic electron transport activity follow those of predawn quantum efficiency. We explore the implications of these observations during leaf development, discuss effects of sucrose delivery from veins to interveinal areas on relative rates of photosynthetic development in these tissues, and propose that the initially higher photosynthetic activity in the midvein compared to the intervein tissues may supply carbohydrates and energy for leaf growth processes.     

Effects of Cl- on and Malate Fluxes and CO2 Fixation in Carrot and Barley Root Cells

Cl^– and ions interact apparently competitively during influx across the plasmalemma of carrot root cells. Cl^–,however, reduces influx much less than predicted from the effect of on Cl^– influx.Cl^– and plasmalemma influxes both increase with time after excision of carrot tissue. Cl^–and may therefore be transported by a common mechanism. The effect of pH changes on the influx of malate across theplasmalemma in barley roots shows that malate crosses the plasmalemmaas the singly charged anion. Stimulations of influx by bothK₂SO₄ and KCl suggest that the malate anion crosses in associationwith. K⁺. If malate entry is passive, P_mal- is about 2?10^–8cm s^–1, but it is thought that malate entry is partlyan active process. A slight, apparently competitive inhibition by Cl^– ofmalate flux into the vacuole of barley root cells suggests thatthe two anions may be transported by a common process at thetonoplast, but this is not thought to be physiologically significant. The accumulation of ¹⁴C from 1 mM is drastically reduced by 10 mM Cl^–. A quantitative analysis of the kineticsof ¹⁴C exchange shows that Cl^– directly inhibits the formationof malate from . The decreased influx of endogenously produced malate to the vacuole in the presenceof Cl^– is probably a secondary consequence of the fallin the cytoplasmic concentration. The nature of the Cl^–inhibition of malate formation is discussed. In KCl-loaded tissue the influx of external malate and the accumulationof ¹⁴C from external are reduced. The location of these effects is not certain, but the effects suggest thatregulation of malate synthesis and accumulation may be relatedto the negative-feedback regulation of Cl^– and transport.     

Conductance and relaxations of gelatin films in glassy and rubbery states

The dielectric constant, ′, and the dielectric loss, ″, for gelatin films were measured in the glassy and rubbery states over a frequency range from 20 Hz to 10 MHz; ′ and ″ were transformed into M* formalism (M*=1/(′−i″)=M′+iM″; i, the imaginary unit). The peak of ″ was masked probably due to dc conduction, but the peak of M″, e.g. the conductivity relaxation, for the gelatin used was observed. By fitting the M″ data to the Havriliak–Negami type equation, the relaxation time, τ_HN, was evaluated. The value of the activation energy, E_τ, evaluated from an Arrhenius plot of 1/τ_HN, agreed well with that of E_σ evaluated from the DC conductivity σ₀ both in the glassy and rubbery states, indicating that the conductivity relaxation observed for the gelatin films was ascribed to ionic conduction. The value of the activation energy in the glassy state was larger than that in the rubbery state.     

Variations and interrelationships of foliar hydraulic and photosynthetic traits for Larix gmelinii

Aims Variations and potential trade-offs of leaf hydraulic and photosynthetic traits are essential for assessing and predicting the effect of climate change on tree survival, growth and distribution. Our aims were to examine variations and interrelationships of leaf hydraulic and photosynthetic traits in response to changes in site conditions for Dahurian larch (Larix gmelinii)—a dominant tree species in Chinese boreal forests.Methods This study was conducted at the Maoershan Forest Ecosystem Research Station. A transect of 27 year-old Dahurian larch plantation was established that consisted of five plots extending from the valley to the ridge of a slope. The predawn leaf water potential (Ψ_pre), area- and mass-based leaf hydraulic conductance (K_area and K_mass, respectively), resistance to embolism capacity (P₅₀), leaf mass per area (LMA), net photosynthetic rate (A), and leaf nitrogen content (N) were measured in August 2016.Important findings The Ψ_pre, K_area, K_mass, P₅₀, A, LMA, and N all varied significantly among the plots (p < 0.05), indicating significant intra-specific variations in these traits in response to the changes in site conditions. The P₅₀ was significantly (p < 0.05) correlated with Ψ_pre, K_area or K_mass, suggesting that a trade-off between hydraulic efficiency and safety exist within the species to some degree. There were significant (p < 0.05) pairwise correlations between A, LMA, and N. Nevertheless, there was no significant (p < 0.05) correlation between the measured photosynthetic traits and hydraulic traits. We concluded that the intra-specific variations and multiple interrelationships of the leaf hydraulic and photosynthetic traits for the larch reflect the plasticity of its leaf traits and strategies of its survival and growth as a result of its acclimation to diverse site conditions.     

盐及干旱胁迫对油菜抗氧化系统和RbohC、RbohF基因表达的影响

以白菜型油菜‘陇油6号’和‘天油2号’为试验材料,经MAPK抑制剂U0126、H_2O_2清除剂DMTU、NADPH氧化酶抑制剂DPI和IMD预处理后再分别进行盐胁迫、PEG-6000模拟干旱胁迫,研究其对两种油菜幼苗活性氧、抗氧化酶活性和RbohC、RbohF基因表达的影响.结果表明:盐胁迫和PEG-6000模拟干旱胁迫下,两种白菜型油菜中H_2O_2积累量上升,O_2^-·积累量下降,抗氧化酶(超氧化物歧化酶SOD、过氧化氢酶CAT、抗坏血酸过氧化物酶APX和谷胱甘肽还原酶GR)活性和RbohC、RbohF基因表达均升高.与单独胁迫处理相比,两种油菜O_2^-·积累、抗氧化酶活性和RbohC、RbohF基因的表达量均明显降低,经DMTU、DPI和IMD预处理后再分别进行盐和干旱胁迫,H_2O_2积累量下降,但U0126预处理后再进行胁迫处理,H_2O_2积累量上升.说明NADPH氧化酶、MAP激酶级联途径、H_2O_2参与了盐、干旱胁迫下活性氧产生、抗氧化酶活性变化和RbohC、RbohF基因表达的调控.     

不同水肥一体化方式对苹果氮素吸收利用特性及产量和品质的影响

以‘嘎啦/八棱海棠’为试材,借助¹⁵N同位素示踪技术,研究了撒施(T₁)、滴灌施氮(T₂)和渗灌施氮(T₃)对嘎啦苹果氮素吸收利用、分配特性和产量品质的影响,以期进一步完善苹果园水肥一体化技术,挖掘提高氮素利用率的途径。结果表明: T₃处理苹果叶片的叶面积、叶绿素和氮含量显著高于T₁和T₂处理。各时期土壤矿化氮(N_min)含量在20~40 cm土层表现为T₃＞T₂＞T₁处理,在0~20 cm土层表现为T₂＞T₃＞T₁处理。同一器官的Ndff值(树体各器官从肥料中吸收到的¹⁵N占该器官全氮量的比例)在各时期均以T₃处理最高,T₂其次,T₁处理最低。果实成熟期的树体¹⁵N利用率表现为T₃＞T₂＞T₁处理,其中T₃处理的树体¹⁵N利用率为24.2%,分别是T₂和T₁处理的1.19和1.65倍。果实成熟期T₁处理的¹⁵N分配率在营养器官最高,T₂处理在贮藏器官最高,T₃处理在生殖器官最高。各处理的单果重、产量、可溶性固形物、硬度、可溶性糖及糖酸比均以T₃处理最高,T₂其次,T₁处理最低。渗灌施氮处理显著促进了嘎啦苹果树体叶片生长和氮素利用,并提高了果实产量和品质。     

微囊藻和栅列藻的垂直迁移及生态学意义

本研究在自制沉降柱中,检测铜绿微囊藻(Microcystis aeroginosa)和斜生栅列藻(Scenedesmus obliquus)不同生长时期的细胞群体在不同光照条件下的垂直迁移。本文首次提出藻密度衰减系数(K)的概念、拟合方法和生态学意义,并根据等细胞密度沉降面的沉降速率来计算细胞沉降速率(Vc),以这两个参数来衡量细胞的沉降特性,对细胞垂直迁移研究的方法进行了的探索。结果表明,两种藻细胞群体在三个生长时期和四种光照条件的沉降特性表现已定的差异。栅列藻细胞密度的衰减系数(K)最小值为-0.0021cm^-1(上浮),最大值为0.0065cm^-1(下沉);微囊藻的K最小值为-0.0029cm^-1(上浮),最大值为0.0036cm^-1(下沉)。两种藻沉降曲线的指数拟合的R²大多在0.6以上,说明K值是一个较好的衡量细胞群体沉降特性的参数,细胞密度与深度的关系较好地服从指数规律。细胞沉降速度V的最大值(4.681cm·h^-1,下沉)出现在栅列藻的指数期,最大上浮速率-1.790cm·h^-1,出现在微囊藻的稳定期。本文得到的活体藻细胞群体的垂直迁移特性差异的实验数据,说明该实验方法的适用性和两种藻沉降特性差异的可检测性。本文讨论了水华优势种形成与藻细胞群体迁移特性之间的关系。     

Dioxo-molybdenum(VI) and -tungsten(VI) BINOL and alkoxide complexes: Synthesis and catalysis in sulfoxidation, olefin epoxidation and hydrosilylation of carbonyl groups

The reaction of MoO₂(mes)₂ with S-H₂BINOL (mes = 2,4,6-Me₃C₆H₂; H₂BINOL = 1,1′-bi-2-naphthol) and (CF₃)₂MeCOH in THF yielded the novel dioxo-molybdenum(VI) complexes MoO₂(S-BINOL)(THF)₂ and MoO₂[OCMe(CF₃)₂]₂(THF), respectively. Similar tungsten derivatives WO₂(S-BINOL)(THF) and WO₂[OCMe(CF₃)₂]₂(THF) have been prepared by the reaction of WO₂Cl₂(DME) with the corresponding lithium salts of BINOL and 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, respectively. Catalytic experiments have shown that MoO₂(S-BINOL)(THF)₂ is an active catalyst in the sulfoxidation of methyl phenyl sulfide and in the epoxidation of cis-cyclooctene with tert-butylhydroperoxide, under mild conditions. The BINOL complex was, however, not found to be enantioselective. In addition, the catalytic activity of the molybdenum species MoO₂(S-BINOL)(THF)₂ and MoO₂[OCMe(CF₃)₂]₂(THF) in the hydrosilylation of carbonyl groups has been explored.     

Effects of sulfate and nitrate on K+ uptake and growth of wheat and cucumber

The uptake of K⁺ ion was studied in the roots of wheat ( Triuicum aestivum L. cv. GK Szeged) and cucumber ( Cucumis sativus L. cv. Budai csemege) seedlings grown in nutrient solution under nitrogen and sulfate stress conditions. Seedlings pretreated with 1 or 10 m M NaNO₃, absorbed more K⁺ than those treated with 0.1 m M NaNO₃. However, the posteffect of NaNO₃ was considerably influenced by the Na₂SO₄, treatment. The results suggest that, at least partly, a feed-back regulation of K⁺ uptake may occur. However, due to the high Na⁺ contents of the roots, a Na⁺ effect in this process cannot be excluded. The growth and dry matter yields of the roots and shoots were strongly influenced by the SO²⁻/₄ and NO⁻/₃ supply of the plants. Appreciable differences were experienced between wheat and cucumber seedlings. The optimum SO²⁻/₄ concentration of the growth solution for maximal growth varied considerably between the species, and was also different for the roots and the shoots in a given species.     

Activity and stability of native and modified alanine aminotransferase in cosolvent systems and denaturants

Alanine aminotransferase (ALT) is used in clinical diagnostics, amino acid synthesis and in biosensors. Here we describe the stabilization of soluble porcine ALT by chemical modification with mono- and bis-imidates. The apparent transition temperatures (‘T_m’, the temperature where 50% of initial activity was lost in 10 min) for native and DMS-modified ALT were 46 and 56 °C respectively. The effects of water-miscible organic solvents (methanol, dimethylformamide, dimethylsulphoxide and 1,4-dioxane) on the activity/stability of native and modified forms were determined. In all systems studied, an abrupt decrease in ALT catalytic activity was observed on reaching a certain threshold concentration of the organic solvent. The modified derivatives were more organotolerant than native enzyme. Comparison of the apparent V_max and K_m for 2-oxoglutarate as substrate, determined in 10% (v/v) organic solvent, with the results of thermal inactivation studies showed that the solvents have different effects on ALT's catalytic parameters and on its conformational stability. At 35 °C with no organic solvent the dimethylsuberimidate (DMS)-modified derivative's half-life was 16 times greater than that for native enzyme; in 30% (v/v) solvent at 35 °C, the DMS-modified ALT's half-life was up to 4.6 times greater than native enzyme's. DMS-modified ALT was also more stable in urea and guanidine HCl, and its refolding was more noticeable, than that of native enzyme.     

Lamb and milk production of Awassi and East-Friesian sheep and their crosses under Mediterranean environment

Data on lambs born per ewe put to the ram (LB/EP), lambs born per ewe lambing (LB/EL), milk production through lactation and lactation length up to six lambings of 603 Awassi (A), East-Friesian (EF), A × EF (F1), F1 × F1 (F2), EF × F1 (1/4A), 1/4A × F1 (3/8A¹) and 3/8A¹ × 3/8A¹ (3/8A²) ewes bred in the same flock in the years 1956–1971 were analysed. The data were obtained from 2293 ewe-years, 1993 lambings and 1698 lactations. Genotype, age at lambing and sire within genotype had an (P < 0.05) effect on each trait. Effect of year of birth, genotype by age at lambing interaction and genotype by year of birth interaction were significant (P < 0.05) for milk production but not for lamb production. The effects of litter size on milk yield and lactation length were not significant. Least squares means (LSM) of LB/EP were highest in 3/8A² (1.48) and lowest in Awassi (0.98). LSMs of LB/EL were highest in EF (1.60), and lowest in Awassi (1.11). The LSMs of milk yield of A, F1, F2 and 3/8A² were similar, ranging from 223 to 248.1. The milk yield of EF was the lowest: only 161 1. The LSMs for lactation length were similar in all genotypes, about 198 days except for 1/4A and EF which had shorter (P < 0.05) lactations. The Awassi-transmitted effects were positive (P < 0.001) for lactation length and milk yield, and negative (P < 0.001) for LB/EL. Heterosis (P < 0.001) was found for LB/EL, milk yield and lactation length. Recombination effect was not significant for any trait.     

Ionic iridium-gold and rhodium-gold perfluorobenzenethiolato binuclear complexes: syntheses and solution behavior

By reacting [(C₅Me₅)M(SR_F)₂] (forM = Ir, Rf = C₆F₅ (1a) or C₆F₄H-p (1b); for M = Rh, Rf = C₆F₅ (2a) or C₆F₄H-p (2a)) in toluene with Na[AuCl₄], ionic binuclear compounds with the general formula [(C₅Me₅)M(μ-SR_F)₂AuCl₂]Cl for M = Ir, R = C₆F₅ (3a) or C₆F₄H-p (3a); for M = Rh, R_F = C₆F₅ (4a) or C₆F₄H-p (4b) can be obtained, together with small amounts of [(C₅Me₅)₂Rh₂(μ-SR_F)(μ-Cl)₂]Cl (R_F = C₆F₅ (5a) or C₆F₄H-p (5b)) as by-products when 2a and 2b were used.