140La/140Ba ratio dating of a nuclear release

In May 2010, air sampling stations in South Korea, Japan and the Russian Federation detected different unstable xenon isotopes and their progenies attached to aerosol particles. The origin of these fission products remains unclear. Previous studies have suggested that a possible reason for these observations is a nuclear test performed in North Korea in May 2010. In the present paper, preliminary spectra recorded at 2 h intervals at the particulate sampling station in Okinawa, Japan are analysed with rigorous mathematical methods. Based on the activity ratios of the ¹⁴⁰Xe progenies ¹⁴⁰Ba and ¹⁴⁰La in a sudden release scenario, the analysis provides an estimate of 12 May 16:00 (UTC) for the release date of the nuclear debris in the form of ¹⁴⁰Xe. The 95 % uncertainty limits for the release date are 11 May 9:00–13 May 13:00 (UTC). The result is very sensitive to the coincidence correction factor of the measurement setup and a larger uncertainty interval cannot be excluded. A continuous release scenario could also explain the data, possibly referring to a leak in a running nuclear reactor either on shore or in a vessel. No studies were made on the attribution of the observations to a release site. However, our conclusion is that fresh nuclear debris has been detected in East Asia, and further studies are required in an international forum to reanalyse the data. Of particular importance for the time-zero analysis is the a posteriori calibration of the Okinawa station with a ¹⁴⁰Ba sample to resolve the uncertainty related to the coincidence correction and other factors.     

Bestimmung von140Ba in Uranspaltungsproduktgemischen

Zusammenfassung Nach Überprüfung der in der Literatur beschriebenen Abtrennverfahren für¹⁴⁰Ba auf ihre Wirksamkeit hin wurde eine Schnellmethode zur Bestimmung von¹⁴⁰Ba in Uranspaltungsproduktgemischen ausgearbeitet. Anschließend an eine kombinierte Al(OH)₃–La(OH)₃-Fällung wird BaCl₂·2 H₂O gefällt, umkristallisiert und zusätzlich durch einen Zr₃(PO₄)₄-Scavengerschritt gereinigt. So gelingt es,¹⁴⁰Ba aus Spaltungsproduktlösungen frei von anderen -Strahlen emittierenden Nukliden abzuscheiden. Der Dekontaminationsfaktor für⁹⁰Sr wurde mit 10³ bestimmt.Mit 4 AbbildungenHerrn Prof. Dr.Erich Hayek mit besten Wünschen zum 60. Geburtstag gewidmet.     

Collagen-Derived Biomaterials in Bone and Cartilage Repair

Summary: We have analyzed a number of collagen-derived biomaterials for the matrix- induced and assisted bone and cartilage tissue regeneration. These include the Small intestine submuosa (SIS) Restor ™, ACI-Maix collagen membrane, Chondro- Gide collagen membrane, Permacol collagen Ossix and lycoll collagen membrane and five types of collagen-based marine sponge skeletons. Certain characteristics of different scaffold materials with comparable chemical composition may vary significantly. This variation may have a relevant impact on the suitability of the scaffolds for bone and cartilage regeneration. It suggests that the ACI-Maix® membrane is the best available collagen-derived material for an MACI®/MACT® application. In addition, the study of marine sponge indicates that the collagenous fibre skeleton of marine sponges provides a suitable bioscaffold for bone regeneration, as it supports the adhesion, migration and proliferation of osteoblasts in vitro.     

Separation of140Ba−140La by reversed phase chromatography using high molecular weight amine

A method has been described for the isolation of radiochemically pure¹⁴⁰La from¹⁴⁰Ba. The tracer¹⁴⁰Ba−¹⁴⁰La is mixed with 6M LiNO₃ solution to make an anionic complex. The solution is then fed into a column (1 cm×0.4 cm) of Kieselguhr impregnated with Aliquat-336.¹⁴⁰La is adsorbed in the column while¹⁴⁰Ba is eluted with 6M LiNO₃. After complete removal of¹⁴⁰Ba,¹⁴⁰La is eluted with 0.002M HNO₃ solution. The purity of¹⁴⁰La is established by both its half-life and γ-spectrum.     

Eine Methode zur Bestimmung von 140Ba und 140La in einem Gemisch beider Radioisotope

Ohne Zusammenfassung     

Controlled‐Potential Electromechanical Reshaping of Cartilage

An alternative to conventional “cut‐and‐sew” cartilage surgery, electromechanical reshaping (EMR) is a molecular‐based modality in which an array of needle electrodes is inserted into cartilage held under mechanical deformation by a jig. Brief (ca. 2 min) application of an electrochemical potential at the water‐oxidation limit results in permanent reshaping of the specimen. Highly sulfated glycosaminoglycans within the cartilage matrix provide structural rigidity to the tissue through extensive ionic‐bonding networks; this matrix is highly permselective for cations. Our studies indicate that EMR results from electrochemical generation of localized, low‐pH gradients within the tissue: fixed negative charges in the proteoglycan matrix are protonated, resulting in chemically induced stress relaxation of the tissue. Re‐equilibration to physiological pH restores the fixed negative charges, and yields remodeled cartilage that retains a new shape approximated by the geometry of the reshaping jig.     

四会市140名婴儿服食真珠钙效果观察

对四会市１４０名婴儿服食真珠钙的效果进行了调查，结果表明，补钙后０￣６个月和０￣１２个月的婴儿的体重与身高均明显高于对照组，两者有明显差异，Ｐ〈０．０１。     

Fit-for-Purpose Synthesis of CDK2 Inhibitor GNE-140

A six-step, stereoselective synthesis of cyclin-dependent kinase 2 (CDK2) inhibitor GNE-140 was developed. The key bonds were assembled through palladium-catalyzed Negishi cross-coupling and Buchwald–Hartwig C−N coupling steps. The stereodiad was established through a single-step, CuH-catalyzed enone reduction proceeding in >99 : 1 er and 89 : 11 dr. GNE-140 was obtained in 25 % overall yield with 98.6 A% HPLC purity.     

Advances in Mechanical Properties of Hydrogels for Cartilage Tissue Defect Repair

Numerous factors, such as degeneration and accidents, frequently cause cartilage deterioration. Owing to the absence of blood vessels and nerves in cartilage tissue, the ability of cartilage tissue to heal itself after an injury is relatively low. Hydrogels are beneficial for cartilage tissue engineering owing to their cartilage-like structure and advantageous properties. Due to the disruption of its mechanical structure, the bearing capacity and shock absorption of cartilage are diminished. The tissue should possess excellent mechanical properties to ensure the efficacy of cartilage tissue repair. This paper discusses the application of hydrogels in the fields of cartilage repair, the mechanical properties of hydrogels used for cartilage repair, and the materials used for hydrogels in cartilage tissue engineering. In addition, the challenges faced by hydrogels and future research directions are discussed.     

Electron-photon polarisation correlations in 140 eV electron impact excitation of helium

Electron-polarised photon coincidence techniques are used to determine linear and circular polarisation correlations from the differential electron impact excitation of the 2¹ P state of helium at an incident electron energy of 140 eV. At 30° and 45° electron scattering angles, all the Stokes parameters are determined, whereas at 52.5° onlyP ₂ is measured. Comparisons are made with the distorted wave (DW) calculations of Madison [11] and the first order many-body theory (FOMBT) of Cartwright and Csanak [4].     

Development and In Vivo Assessment of an Injectable Cross-Linked Cartilage Acellular Matrix-PEG Hydrogel Scaffold Derived from Porcine Cartilage for Tissue Engineering

The cartilage acellular matrix (CAM) derived from porcine cartilage, which does not induce significant inflammation and provides an environment conducive for cell growth and differentiation, is a promising biomaterial candidate for scaffold fabrication. However, the CAM has a short period in vivo, and the in vivo maintenance is not controlled. Therefore, this study is aimed at developing an injectable hydrogel scaffold using a CAM. The CAM is cross-linked with a biocompatible polyethylene glycol (PEG) cross-linker to replace typically used glutaraldehyde (GA) cross-linker. The cross-linking degree of cross-linked CAM by PEG cross-linker (Cx-CAM-PEG) according to the ratios of the CAM and PEG cross-linker is confirmed by contact angle and heat capacities measured by differential scanning calorimetry. The injectable Cx-CAM-PEG suspension exhibits controllable rheological properties and injectability. Additionally, injectable Cx-CAM-PEG suspensions with no free aldehyde group are formed in the in vivo hydrogel scaffold almost simultaneously with injection. In vivo maintenance of Cx-CAM-PEG is realized by the cross-linking ratio. The in vivo formed Cx-CAM-PEG hydrogel scaffold exhibits certain host–cell infiltration and negligible inflammation within and near the transplanted Cx-CAM-PEG hydrogel scaffold. These results suggest that injectable Cx-CAM-PEG suspensions, which are safe and biocompatible in vivo, represent potential candidates for (pre-)clinical scaffolds.     

鲨鱼软骨质量的聚类分析法

用电感耦合等离子体原子发射光谱法（ＩＣＰ－ＡＥＳ）测定了１８个鲨鱼软骨真品中１３个元素含量，对测定结果进行分析和变量聚类分析，抽提５个特征指标，并以谱系数聚类建立了鉴别鲨鱼软骨真伪的数学模式，用３个假冒产品和一个鲨鱼软骨胶囊对其进行检验，结果表明，用无机元素所建立的数学模式不仅能鉴别鲨鱼软骨的真伪，还能区分鲨鱼软骨的部分及不同部位的混合物。