Prognostic factors for surgical site infection in patients with spinal metastases and following surgical treatment.

There were few articles reviewed prognostic factors of surgical site infection (SSI) in patients with spinal metastases following surgery. The purpose of the present study was to systematically: (1) investigate the incidence rates of SSI following spinal metastases surgery; (2) identify the factors which were independently associated with postoperative wound infection. One hundred sixty-seven consecutive adult patients with spinal metastases and underwent surgical treatment were retrospectively enrolled from January 2011 to February 2022. Demographic data, disease and operation-related indicators were extracted and analyzed. Univariate and multivariate logistic analysis model were performed respectively to determine independent risk factors of SSI. 17 cases infection were collected in this study. The overall incidence of SSI after surgery of spinal metastases patients was 10.2%. Univariate regression analysis showed that age (P = .028), preoperative ALB level (P = .024), operation time (P = .041), intraoperative blood loss (P = .030), Karnofsky Performance Status score (P = .000), body mass index (P = .013), American Society of Anesthesiologists > 2 (P = .010), Tobacco consumption (P = .035), and number of spinal levels involved in surgical procedure (P = .007) were associated with wound infection. Finally, the multivariate logistic model demonstrated that body mass index (P = .043; OR = 1.038), preoperative ALB level (P = .018; OR = 1.124), and number of spinal levels (P = .003; OR = 1.753) were associated with SSI occurrence. Surgery on multiple vertebral levels for spinal metastases significantly increases the risk of SSI and weight management, nutritional support and palliative surgery have the positive significance in reducing wound complications. Orthopedist should focus on identifying such high-risk patients and decrease the incidence of wound infection by formulating comprehensive and multi-disciplinary care strategy.

A Strategy of In Situ Catalysis and Nucleation of Biocompatible Zinc Salts of Amino Acids towards Poly(l-lactide) with Enhanced Crystallization Rate.

The intrinsic drawback of slow crystallization rate of poly(l-lactide) (PLLA) inevitably deteriorates its final properties of the molded articles. In this work, we proposed a new strategy towards poly(l-lactide) with enhanced crystallization rate by ring opening polymerization (ROP) of l-lactide (l-LA) catalyzed by biocompatible zinc salts of amino acids. For the first time we developed a one-pot facile method of zinc salts of amino acids acting dual roles of catalysis of l-LA polymerization and in situ nucleation of the as-prepared PLLA. Nine zinc salts of different amino acids, including three kinds of amino acids ligands (alanine, phenylalanine, and proline) with l/d-enantiomers and their equimolar racemic mixtures, were first prepared and tested as catalysts of l-LA polymerization. A partial racemization was observed for zinc salts of amino acids whereas no racemization was detected for the reference stannous octoate. The polymerization mechanism study showed that the interaction of zinc salts of amino acids and benzyl alcohol forms the actual initiator for l-LA polymerization. Isothermal crystallization kinetics analysis showed that the residual zinc salts of amino acids exhibited a significant nucleation effect on PLLA, evidenced by the promotion of the crystallization rate, depending on the amino acid ligand and its configuration. Meanwhile, the residual zinc salts of amino acids did not compromise the thermal stability of the pristine PLLA.

Syndioselective Polymerization of Vinylnaphthalene.

Coordination polymerizations of 1-vinylnaphthalene (1VN), 2-vinylnaphthalene (2VN) and 6-methoxy-2-vinylnaphthalene (MVN) are carried out at room temperature by using the half-sandwich scandium precursor FluSiMe3 Sc(CH2 SiMe3 )2 (THF) (1) and the constrained geometry configuration rare-earth metal precursors FluCH2 PyLn(CH2 SiMe3 )2 (THF)n [Flu = C13 H8 , Py = C5 H4 N; Ln = Sc (2a), n = 0; Ln = Lu (2b), Y(2c), n = 1]. Atactic poly(1VN) and perfect syndiotactic poly(2VN) and poly(MVN) are produced by precursors 2a-2c in a controlled way. Treatment of poly(MVN) with boron tribromide at -20 °C provides a syndiotactic poly(6-hydroxy-2-vinylnaphthalene).

Enhancement of intramolecular charge transfer strength in diphenylamine substituted symmetric 1,3,4-oxadiazole derivatives.

The intramolecular charge transfer characteristic of two diphenylamine substituted symmetric 1,3,4-oxadiazole derivatives (DPAOXD and DPAOXDBEN) was studied through a combination of experimental techniques and theoretical calculations. Significant enhancement of intramolecular charge transfer strength has been found in both these compounds through molecular structure modification. The experimental result found only a small red shift in the absorption spectra (∼15 nm) but a very large red shift in the emission spectra (∼114 nm for DPAOXD and ∼140 nm for DPAOXDBEN) with increasing solvent polarity, indicating a large extent charge transfer occurred in their excited state. The increase of molecular dipole moment from the ground state to the charge transfer excited state is calculated to be 22.10 D in DPAOXD and 26.67 D in DPAOXDBEN, respectively. Theoretical calculations present clear evidence that electrons transfer from the terminal diphenylamine to the bi-1,3,4-oxadiazole rings in DPAOXD, and the two 1,3,4-oxadiazole rings and central benzene ring in DPAOXDBEN. As compared to the methoxy group, the substitution by a diphenylamine group could increase both the transferred charge and distance, which could substantially strengthen the charge transfer character. Further introduction of a central benzene ring in DPAOXDBEN could further increase the transferred distance, and then the charge transfer strength. These findings could provide good guidance for the design of molecules with high intramolecular charge transfer characteristics.

Substituent Effect on Intramolecular Charge Transfer of Symmetric Methoxy-Substituted Bi-1,3,4-oxadiazole Derivatives.

Intramolecular charge-transfer characteristics of a series symmetric methoxy -substituted bi-1,3,4-oxadiazole derivatives with various substituted positions and quantities have been studied with a combination of experimental techniques and theoretical calculations to investigate the substituent effect. Different degrees of fluorescence red shift in polar solvents are observed in these compounds. The meta-substituted molecule (BOXD-m-OCH3) exhibits a larger red shift (82 nm) than the other two monosubstituted molecules, BOXD-o-OCH3 (40 nm) and BOXD-p-OCH3 (37 nm); the polysubstituted molecules BOXD-D1 and BOXD-T1 show 80 and 104 nm red shifts, respectively, which are obviously larger than the monosubstituted molecules. The changes of molecular dipole moment between the ground state and charge transfer (CT) excited state are calculated to be on the same order with the degree of red shift (7.56 D in BOXD-o-OCH3, 12.07 D in BOXD-m-OCH3, 7.38 D in BOXD-p-OCH3, 14.79 D in BOXD-D1, and 16.80 D in BOXD-T1). Theoretical calculations at the density functional theory level reveal that the first singlet excited state of all of these compounds shows both π-π* and CT characteristics and the charge has been proven to transfer from the terminal methoxy phenyl group to the central bioxadiazole group. The analysis of charge transfer based on electron density shows that the greater the amount substituent, the more charge would be involved in the intramolecular charge transfer. In addition, the negative barycenter has a tendency to locate close to the methoxy substituent, which would cause the difference in the charge-transferred distance. The transferred charge and CT distance work jointly and finally lead to differences in dipole moment variation. These findings could provide very good guidance for the design of molecules with intramolecular charge-transfer characteristics.

Metabolizable lanthanum-coordination nanoparticles as efficient radiosensitizers for solid tumor therapy.

The clinical potential of radiotherapy cannot be realised as expected due to the inherent radioresistance of tumors. To overcome these problems, radiosensitizers containing heavy metal elements have been used in radiotherapy as efficient radiation dose enhancers. In the present study, we report the design and preparation of novel lanthanum-coordination nanoparticles, and their application as nano-sized radiosensitizers in radiotherapy against solid tumors. Via a simple one-pot hydrothermal route, these nanoparticles were fabricated without any expensive chemical reagents. The polyvinylpyrrolidone molecules used in a typical synthesis could highly enhance the dispersity and bio-compatibility of these nanoparticles. In vitro toxicity studies demonstrated that these nanoparticles had low cytotoxicity, negligible hemolysis, and no effect on blood coagulation. Upon exposure to high energy X-ray radiation, these nanoparticles possessed excellent radiosensitization effects and induced serious cellular death both in vitro and in vivo. In addition, time-dependent bio-distribution and long-term toxicity results for these nanoparticles after intravenous administration indicated their high bio-compatibility. More importantly, these metabolizable nanoparticles could be cleared up after intravenous administration along with time passing. These significant findings promise the prospective use of these nanoparticles as vigorous X-ray radiation-mediated therapeutic agents in coming cancer treatments.

Self-assembly of lambda-DNA networks/Ag nanoparticles: hybrid architecture and active-SERS substrate.

In this article, highly rough and stable surface enhanced Raman scattering (SERS)-active substrates had been fabricated by a facile layer-by-layer technique. Unique lambda-DNA networks and CTAB capped silver nanoparticles (AgNP) were alternatively self-assembled on the charged mica surface until a desirable number of bilayers were reached. The as-prepared hybrid architectures were characterized by UV-vis spectroscopy, tapping mode atomic force microscopy (AFM) and confocal Raman microscopy, respectively. Linear increases of the maximum absorbance of DNA band with the number of bilayers present a common LBL assembly feature. The red-shift of surface plasmon of silver nanoparticles within the hybrid films was mainly due to the aggregation effect. With the increase of number of bilayers, the surface coverage of nanoparticles on the substrate became larger, as well as the rising of total amount of nanoparticles and the surface roughness of hybrid films. These rough metallic hybrid architectures could be utilized as SERS-active substrates. A significant enhanced Raman scattering effect of the adsorbed analytes, e.g., methylene blue (MB), on these hybrid films was easily exploited by the confocal Raman microscopy. The enhancement factor depended on the surface coverage of nanoparticles and number of bilayers of lambda-DNA/AgNP.