Simultaneous Construct Surface Microstructural and Internal Network-Like Conductive Pathways of Poly(l-lactic acid)/Carbon Nanomaterials Composite Foams

The poly(l -lactic acid) (PLLA)/carbon nanomaterials composite foams with hierarchical surface microstructural and internal conductive pathways are successfully prepared by a simple crystallization-assisted rapid phase separation (CARPS). The dimension and morphology of carbon nanomaterials can induce different crystallization forms to construct the hierarchical surface microstructure, and they are distributed on the phase interface of solvent and non-solvent to form conductive pathways. It is found that the heterogeneous nucleation of nanomaterials promotes a significant increase in crystallinity, and a stacked granular structure formed on the surface promotes the increase of the water contact angle to 148.7°. Foams with interconnecting pore structures contribute to the formation of 85.3% porosity and 12.33 g g⁻¹ oil absorption. Carbon nanomaterials are distributed on the pore walls of the porous foam, which converts the foam from an insulating material to a conducting polymer. Furthermore, the uniform distribution of nanomaterials significantly affects the thermal stability of the PLLA. In belief, the multifunctional biodegradable foam, prepared by a CARPS method, makes it promising for industrial production and has potential applications in electrical conductivity, oil-water separation, and many other fields.     

Effects of [3H]-BIDN,a novel bicyclic dinitrile radioligand for GABA-gated chloride channels of insects and vertebrates

1. The radiolabelled bicyclic dinitrile, [³H]-3,3-bis-trifluoromethyl-bicyclo[2.2.1]heptane-2,2-dicarbonitrile ([³H]-BIDN), exhibited, specific binding of high affinity to membranes of the southern corn rootworm (Diabrotica undecimpunctata howardi) and other insects. A variety of γ-aminobutyric acid (GABA) receptor convulsants, including the insecticides heptachlor (IC₅₀, 35±3 nM) and dieldrin (IC₅₀, 93±7 nM), displaced [³H]-BIDN from rootworm membranes. When tested at 100 μM, 1-(4-ethynylphenyl)-4-n-propyl-2,6,7-trioxabicyclo[2.2.2]octane(EBOB), 4-t-butyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-thione (TBPS), 1-phenyl-4-t-butyl-2,6,7-trioxabicyclo[2.2.2]octane (TBOB) and picrotoxin failed to displace 50% of [³H]-BIDN binding to rootworm membranes indicating that the bicyclic dinitrile radioligand probes a site distinct from those identified by other convulsant radioligands.
2. Dissociation studies showed that dieldrin, ketoendrin, toxaphene, heptachlor epoxide and α and β endosulphan displace bound [³H]-BIDN from rootworm membranes by a competitive mechanism.
3. Rat brain membranes were also shown to possess a population of saturable, specific [³H]-BIDN binding sites, though of lower affinity than in rootworm and with a different pharmacological profile. Of the insecticidal GABAergic convulsants that displaced [³H]-BIDN from rootworm, cockroach (Periplaneta americana) and rat brain membranes, many were more effective in rootworm.
4. Functional GABA-gated chloride channels of rootworm nervous system and of cockroach nerve and muscle were blocked by BIDN, whereas cockroach neuronal GABA_B receptors were unaffected.
5. Expression in Xenopus oocytes of either rat brain mRNA, or cDNA-derived RNA encoding a GABA receptor subunit (Rdl) that is expressed widely in the nervous system of Drosophila melanogaster resulted in functional, homo-oligomeric GABA receptors that were blocked by BIDN. Thus, BIDN probes a novel site on GABA-gated Cl⁻ channels to which a number of insecticidally-active molecules bind.

     

抗病毒红藻多糖的提取与测定

从我国沿海红灌中撮的粗多糖,经ＤＥＡＥ－纤维素柱层析得到红藻多糖ＲＰ１实验证实有明显抗病毒作用。通过气相色谱、红外光谱、Ｙａｐｈｅ测定方法,证明红藻多糖ＲＰ１含硫酸基是一种硫酸酯化多糖,其单糖组成为半乳糖和３,６－内醚半乳糖,定量分析含量分别为半乳糖７０．０４％、３,６－内醚半乳糖９．５６％１硫酸基１７．３０％。     

No association between an intronic presenilin-1 gene polymorphism and schizophrenia in a Chinese population

We investigated the association between schizophrenic psychosis and an intronic polymorphism of the presenilin-1 (PS1) gene in a Chinese population. Schizophrenic and control groups had similar PS1 genotype distributions and allele frequencies, indicating that this polymorphism may not be involved in the development of schizophrenia.     

Post-parotitis myocarditis: case report

In November, 1993,M.G., a 6 year and 11 month-old girl, was admitted at Hospital Infantil Joana de Gusm?o--Florianópolis, SC, Brazil--with post-parotitis myocarditis and congestive heart failure. Three days after admission it was evidenced, on an echocardiogram, a thrombus in the left ventricle apex which, despite of correct treatment, embolized to iliac and small mesenteric arteries. Epidemic parotitis (mumps) is very common, being endemic around the world. Complications are rare and myocarditis, one of them, is more common than diagnosed because of its poor and benign manifestations, generally transient abnormalities of cardiac rhythm and conduction. This case was astonishing because of its rare subsequent event, that is, the formation of a ventricular mural thrombus during an acute myocarditis.     

New eudesmane sesquiterpene and other constituents from Artemisia mongolica

The aerial parts of Artemisia mongolica afforded the eudesmane derivative ludovicin B, two coumarins, umbelliferone and esculetin, two methoxylated flavones, eupatilin and pectolinarigenin, as well as a new eudesmane sesquiterpene, 6alpha,8alpha-dihydroxyisocostic acid methyl ester. Structures were elucidated by highfield 1D and 2D NMR techniques.     

国产长效皮下埋植剂和Norplant的药物体外释放比较

本文研究了国产18-甲基炔诺酮硅橡胶长效皮下埋植剂的药物体外释放,并与进口Norplant进行了比较。释放试验采用水平振荡法,实验条件符合“漏槽”状态的要求。用紫外分光光度法在240 nm波长处测定18-甲基炔诺酮每天的体外释放量。二年多体外释放试验的实验结果表明:国产埋植剂的药物体外释放无爆破效应,释药速度稳定,为零级速度。平均每天释放量为85μg。体外释放的重现性好。进口Norplant则有明显的爆破效应,经10天释放,才趋于稳定,平均每天释药量为68μg。     

玻璃体切除术治疗严重眼外伤34例观察

目的:观察玻璃体切除术治疗严重眼外伤的临床效果。方法:应用玻璃体切除术治疗严重眼外伤34例(35眼)。结果:本组34例(35眼)中,术后视力提高者29例(30眼,86%),在0.05以上者18例(18眼,51%),4例复发视网膜脱离,3例再手术成功。结论:玻璃体切除术是目前治疗严重眼外伤较为理想的方法,对恢复视功能起到一定作用。