高氟铝暨铝引起性发育前人和动物高钙及高骨矿性骨软化

对铝氟联合中毒27例2－11岁儿童和100日龄雄鸡实验3个月进行了动态观察。结果表明，骨软化伴 骨硬化的病人有22例，占81％；随着年龄增长，骨硬化渐渐突出；患儿全血钙、磷升高，血清Ca^2 正常范围偏高，血清P^5 下降。铝氟联合作用实验鸡性发育前、后全血钙一直较高，全血磷与血清Ca^2 、P^5 及其相关关系出现由高到低到高的交错变化；单独铝作用全血钙一直较高，碱到性成熟期下降，血清Ca^2 、P^5 一直较低。在性发育完成阶段，高铝可使类骨质矿化过度延迟，小幅度减少骨钙、磷含量，但骨部矿物元素和骨矿含量及骨密度不一定降低，甚至可小幅度升高，又有同软化；铝氟联合作用时类骨质矿化延迟时间仍过长，骨矿沉积率已高于对照，存在明显分离。氟可提高矿物元素含量，使骨矿化与骨硬化在骨组织不同层面茯结合成年病人的情况，认为铝氟联合 作用骨损害的表现与骨代谢速度及细胞生物化学和物理化学骨形成方式偏转的变化密切相关。     

铝和铝氟病鸡模型全血骨元素和血清生化骨矿含量骨形态学的相关研究

复制了铝危害和铝氟病鸡模型。将100日龄84只雄性种鸡随机分为7个组,毒物加进配合饲料自由摄食,实验3个月。结果表明,高铝、高氟、高氟铝组在实验3周内全血多种元素和7周内的血清生化物质含量及其相关性便发生显著变化,实验13周性成熟后出现逆转并接近正常。均引骨骼元素含量、骨细胞、骨胶元、骨组织形态、骨矿代谢、骨塑形和骨骼力学机能的病理变化。性成熟后饲料加氟与未加氟各3个组的全血铁、磷、血清钙、GRT才出现分异,并与骨矿代谢动态参数的分异相吻合。表晨本实验性成熟前诸多病变主要是铝危害引起。铝可较长期使全血锌和和骨锌含量下降。全血元素含量和相关性的变化是受机体内环境影响较大的动态变化过程。骨代谢联系着广泛的生物无机化学基础。性成熟后高氟、高氟铝、高铝的危害尚有各自的特点。     

铝氟联合中毒大鼠骨、脑、血、尿中多元素含量动态检测

同批断乳两周的Wistar雄性大鼠59只,随机分为3个组,用同一病家的高岭土拌煤烘干与柴烘玉米加入配合饲料喂养.饲料含氟、铝3.9×10-6,12.4×10-6;107×10-6,40.4×10-6;212,66.8×10-6.实验11、20周分两批股动脉放血处死.检测了大鼠骨、脑、血、尿中多种元素.结果表明,血清钙一直较高,磷降低.实验11周,Ⅱ、Ⅲ组骨氟分别增高6、10倍,尿氟增高4、6倍;骨、脑、全血铝均随摄氟、铝量的增多而递减,尿铝递增.尿中其它元素多一直减少.骨中金属元素随骨铝的递减而递减.Ⅱ组全血锌显著下降.实验20周,Ⅱ、Ⅲ组骨氟是Ⅰ组的3.5和8.2倍,为实验11周时的58.1%和80.7%;尿氟是1.4和3倍.骨、脑铝随氟、铝摄入量的递增而递增,骨中金属元素含量也随之递增,骨磷降低.全血磷递增,锌均升高.本实验多元素含量由低向高变化的逆反过程与骨软化向硬化的病理转换相吻合;铝和氟彼此可影响对方的体内过程和在骨骼中的蓄积并引起多元素含量和相关性的显著变化.提示消化道内源性无机盐排泄过多;低龄动物的骨、脑对铝有排斥反应,但有铝危害表现.     

高氟铝和铝引起低龄鸡骨发育不全

进行了高氟铝和铝对低龄鸡骨损害的实验。５７日龄鸡９６只随机分为８组,毒物加进饲料,实验期３个月。结果表明,各高氟、高氟铝组骨氟均数倍于对照组,低铝组骨氟显著升高;单饲ＮａＦ组骨铝增高近３倍,高氟铝组骨氟比ＮａＦ组和病区玉米组低１／３以上,骨铝低约５０％;单饲铝达对照４～２１倍的骨铝与对照组接近。饲氟与骨氟ｒ＝０．７７,与骨铝ｒ＝０．６５;饲铝与骨铝ｒ＝－０．４６,与骨氟ｒ＝－０．５３;骨氟与骨铝ｒ     

不同发育阶段大鼠NaF与血清生化和元素含量慢性反应的研究

不同日龄３批雄性大鼠饲氟浓度５３．２＊１０＾－６,实验３个月。结果表明,与同日龄正常对照组相比,杆、肾铝显著升高的断乳２周大鼠的血清钙,ＲＢＣ、Ｈｂ含量、红细胞平均血红蛋白量、全血锌,全血铁,骨钙,骨磷含量均出现显著变化。２８０日龄且的体重和全血磷受影响较为显著。     

铝氟联合中毒病人全血尿元素含量及相互关系的分析

取某病区明显骨软化畸形、年龄４～１９岁的病人晨尿、空腹全血,湿法消化,原子吸收法检测。结果表明,病人有小细胞贫血,脑电图未见有意义的异常波。血清磷、尿磷低于对照,全血磷显著升高,出现分离。全血钙并不低。全血和尿铝、氟显著高于对照。全血和尿锌显著或明显低于对照。病人与对照之间的全血铝与磷,镁、锌与铁相关性有显著差异。铝氟联合中毒康复者全血７种元素含量与对照接近,相关性也趋于一致。病人全血、尿元素含量     

鸡铝氟联合作用--铁与骨矿化和矿物元素的关系

为探讨铝氟联合作用时铁与矿物代谢的关系,在鸡铝氟病及铝危害模型基础上对全血铁和骨铁用 AAS法进行了检测.结果表明,性成熟前各实验组全血铁均升高,但以加氟组更为明显;性成熟后饲料加入氟化物的 3个组全血铁仍高于对照,未加的另3个组则低于或接近对照组.骨铁含量均有所下降.饲氟、骨氟、骨铝与全血铁有明显正相关(P＜0.2)或显著正相关(P＜0.05),与骨铁有明显负相关,差异均有显著或非常明显(P＜0.1) 意义.全血铁与全血钙、镁、磷,骨灰化率、骨矿含量、平均骨壁厚度、骨矿沉积率均呈显著正相关.骨铁与骨钙、镁呈显著或明显负相关,与成骨细胞指数、破骨细胞指数、类骨质体积呈明显或非常显著(P＜0.01)负相关,与骨单位吸收周期呈明显正相关.全血铁与骨铁呈明显负相关.提示,全血与骨骼铁代谢是能分离又相对应的体系,可能有相互平衡、调节和补偿作用.铁不仅是血红蛋白的必需成分,还与骨矿化和骨细胞及矿物元素有密切关系.     

煤烘玉米和饮水为介质地氟病区骨畸形病人全血尿多元素含量的分析

采集了贵族个煤烘玉米为主要介质和河北２个饮水为介质氟病区内骨畸形病人的全血、尿、检测了其中８种元素含量,结果表明,贵州各氟病区少儿骨软化与成年骨硬化畸形病人的全血铝、钙、磷、铁和尿氟、铝均显著高于同龄对照组,尿磷均低于同龄对照组。少儿骨软化病人全血锌均下降,尿锌多下降。某水型氟病区骨软化经产妇尿氟、全血铜升高;骨软化少年全血铝显著升高,锌、铁下降,尿氟升高,尿锌,磷下降。海边的典型氟骨症病人全血、     

高铝引起性发育成熟前人和动物的排斥性损害和主动调节保护及自身平衡稳定反应

在铝氟联合中毒的系列研究中 ,发现性发育成熟前头发和血尿高铝的骨软化畸形病人 ,肝、肾铝显著升高的大鼠和鸡的骨铝、脑铝含量在接近或明显甚至显著低于正常对照组时 ,出现了铝骨病和铝危害的其它表现 ;AlCl3 ·6H2 O对童鸡非蓄积危害阈值范围指数 >5 (2 1 40 41 9) ,较低浓度比较高浓度饲铝组病变更为显著 ,铝在一定浓度或剂量范围与反应强度可呈非正相关关系 ;一定浓度以上 ,摄铝与高氟促成铝吸收和蓄积的数倍到 1 0数倍浓度差别的病情差异并不明显。表明人和动物在地壳高铝环境中的长期进化与适应 ,于生长发育旺盛的性成熟前形成并完善了对自然条件下进入内环境高铝的排斥和主动调节保护及自身平衡稳定反应的机制 ,以避免铝危害和减轻铝的危害程度     

基于铝氟配位反应的动力学-电位法对铝的测定

以氟离子选择性电极作指示电极,用动力学电位法对铝的测定进行了研究.在低pH条件下,铝氟反应E～t曲线的斜率△E/△t与铝的浓度cAl成正比.实验步骤为:第一步,根据铝的校正溶液与氟反应的△E/△t,作出△E/△t～cAl工作曲线;第二步,根据铝试液与氟反应的△E/△t,求出铝的浓度.合适的实验条件是:pH范围1～2;温度范围288～303 K;铝的浓度范围1×10-3～5×10-2mol/L;加入的氟的浓度范围5×10-4～5×10-2mol/L.此外,对动力学电位法测定铝的计算式进行了理论推导,对该法存在的问题、可以采取的措施及误差的分布进行了讨论.     

Organogermyl,Organostannyl, and Organoplumbyl Phosphines,Arsines, Stibines,and Bismuthines

The preparation, properties, and reactions of the compounds named in the title are described, with particular reference to the possible participation of (p→d)_π components in the bonding between the group IVB and the group VB elements.     

Pyrenes,Peropyrenes, and Teropyrenes: Synthesis,Structures, and Photophysical Properties

The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.     

Structural, magnetic, and spectroscopic studies of YAgSn, TmAgSn, and LuAgSn

The rare earth-silver-stannides YAgSn, TmAgSn, and LuAgSn were synthesized from the elements by arc-melting and subsequent annealing. The three stannides were investigated by X-ray powder and single-crystal diffraction: NdPtSb type, P6₃mc, Z=2, a=468.3(1), pm, wR₂=0.0343, 353 F² values, 12 variables for YAgSn, and ZrNiAl type, P6¯2 m, a=726.4(2), , wR₂=0.0399, 659 F² values, 15 variables for TmAgSn, and a=723.8(2), , wR₂=0.0674, 364 F² values, 15 variables for LuAgSn. Besides conventional laboratory X-ray data with monochromatized Mo radiation, the structures were also refined on the basis of synchrotron data with , in order to clarify the silver-tin ordering more precisely. YAgSn has puckered, two-dimensional [AgSn] networks with Ag-Sn distances of 278 pm, while the [AgSn] networks of TmAgSn and LuAgSn are three-dimensional with Ag-Sn distances of 279 and 284 pm for LuAgSn. Susceptibility measurements indicate Pauli paramagnetism for YAgSn and LuAgSn. TmAgSn is a Curie-Weiss paramagnet with an experimental magnetic moment of 7.2 μ_B/Tm. No magnetic ordering is evident down to 2 K. The local environments of the tin sites in these compounds were characterized by ¹¹⁹Sn Mössbauer spectroscopy and solid-state NMR (in YAgSn and LuAgSn), confirming the tin site multiplicities proposed from the structure solutions and the absence of Sn/Ag site disordering. Mössbauer quadrupolar splittings were found in good agreement with calculated electric field gradients predicted quantum chemically by the WIEN2k code. Furthermore, an excellent correlation was found between experimental ¹¹⁹Sn nuclear magnetic shielding anisotropies (determined via MAS-NMR) and calculated electric field gradients. Electronic structure calculations predict metallic properties with strong Ag-Sn bonds and also significant Ag-Ag bonding in LuAgSn.     

Pyrenes,Peropyrenes, and Teropyrenes: Synthesis,Structures, and Photophysical Properties

The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.     

Pi bonding and negative hyperconjugation in mono-, di-, and triaminoborane, -alane, -gallane, and -indane

A systematic quantum chemical investigation of mono-, di-, and triaminoborane, -alane, -gallane, and -indane is carried out to determine quantitatively the effects of pi bonding and negative hyperconjugation on structures, energetics, and rotational barriers in these systems. Pi bonding plays a significant role in the aminoborane compounds, but becomes rapidly less significant in the aminoalanes, -gallanes, and -indanes. For each main-group metal X investigated, X-N rotational barriers are found to be essentially equal depending only on the number of remaining in-plane amino groups. The contribution of negative hyperconjugation to reducing rotational barriers, as assessed from natural bond orbital (NBO) delocalization energies, is independent of the pyramidalization of the out-of-plane amino group, and is also dependent only on the number of rotated groups. Optimized tris[bis(trimethylsilyl)amino]-substituted structures of boron, aluminum, gallium, and indium are found to compare quite well with available experimental structural data, and exhibit X-N torsion angles that are independent of the central metal atom.     

Borinium, borenium, and boronium ions: synthesis, reactivity, and applications

Boron cations are elusive and highly electrophilic species that play a key role in the chemistry of boron. Despite early interest in the chemistry of boron cations, until recently they have largely remained chemical curiosities. However, hints at harnessing their potential as potent electrophiles have begun to appear and developments in weakly coordinating anion technology suggest that this is an area of research that is ripe for exploration. It has been nearly 20 years since the last major review on boron cations; herein we summarize the progress in the area since that time.     

Transition-metal-free O-, S-, and N-arylation of alcohols, thiols, amides, amines, and related heterocycles

A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxamides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.     

Synthesis of yttrium,lanthanum, neodymium,praseodymium, and lutetium alkoxides and acetylacetonates

A convenient and practical method is proposed for the synthesis of lanthanide and yttrium alkoxides. The method involves dissolving the metals or their hydrides in a solution of dry HCl in the corresponding alcohol, with subsequent dehalogenation of the LnCl₃ solution by an equivalent amount of alkali metal (Na, Li), The rareearth alkoxides are easily converted into acetylacetonates Ln(acac)₃ by the action of acetylacetone.A. N. Nesmeyanov Institute of Elementoorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2490–2493, November, 1992.     

Metal-Directed Formation of Tetra-, Hexa-, Octa-, and Nonanuclear Complexes of Magnesium,Calcium, Manganese,Copper, and Cadmium

Efficacious metal control of self-assembly of dialkylketipinate dianions leads to completely different supramolecular assemblies. The structures of grid 1 , double-decker 2 , triple-decker 3 , and metalla-spherand 4 were characterized by X-ray crystallographic analyses or by NMR spectroscopy.