Graphite oxide (GO) and its derivatives have been studied using 13C and 1H NMR. NMR spectra of GO derivatives confirm the assignment of the 70 ppm line to C−OH groups and allow us to propose a new structural model for GO. Thus we assign the 60 ppm line to epoxide groups (1,2-ethers) and not to 1,3-ethers, as suggested earlier, and the 130 ppm line to aromatic entities and conjugated double bonds. GO contains two kinds of regions:  aromatic regions with unoxidized benzene rings and regions with aliphatic six-membered rings. The relative size of the two regions depends on the degree of oxidation. The carbon grid is nearly flat; only the carbons attached to OH groups have a slightly distorted tetrahedral configuration, resulting in some wrinkling of the layers. The formation of phenol (or aromatic diol) groups during deoxygenation indicates that the epoxide and the C−OH groups are very close to one another. The distribution of functional groups in every oxidized aromatic ring need not be identical, and both ...

Structure of Graphite Oxide Revisited

Stereochemical Control in Organic-Synthesis Using Silicon-Containing Compounds

A review is presented of the recent developments in the metabolism andfunction of polyamines in plants. Polyamines appear to be involved in a widerange of plant processes so their exact role is not completely understood. Inthis review, the metabolic pathways involved in polyamine biosynthesis anddegradation are explained, along with the transport and conjugation of thesecompounds. The methodologies involved in the analysis of polyamine functionusing metabolic inhibitors and genetic and molecular approaches are described.The occurrence and distribution of polyamine-derived alkaloids are also dealtwith. The direction of future research in the study of plant polyamines isindicated.

Metabolism and function of polyamines in plants: recent development (new approaches)

We thank the Spanish Ministerio de Ciencia e Innovacion (Grant Nos. CTQ2007-65218 and Consolider Ingenio 2010-CSD-2007-00006 and CTQ2011-24165), the Generalitat Valenciana (Grant No. PROMETEO/2009/039 and FEDER), and the University of Alicante for generous and continuous financial support.

/pdf/diastereoselective-allylation-of-carbonyl-compounds-and-2yzd9tlqi5.pdf

Diastereoselective allylation of carbonyl compounds and imines: application to the synthesis of natural products.

Matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry in lipid and phospholipid research

Spektroskopische Methoden im Uberblick 3-9 Einfuhrung in die Schwingungsspektroskopie (IR) 10-19 Mechanismen der Schwingungsanregung 20-23 Prinzip der Raman-Spektroskopie 24-30 Schwingungsfrequenz 31-39 Grundschwingungen und Schwingungen hoherer Ordnung 40-44 Spektreninterpretation 45-62 Molekulsymmetrie und Schwingungsaktivitat 63-81

/pdf/spektroskopische-methoden-in-der-organischen-chemie-otmyh14hf0.pdf

Spektroskopische Methoden in der organischen Chemie

OBJECTIVES
To analyze the evidence regarding the efficacy of lateral bone augmentation procedures in terms of defect resolution in cases of horizontal ridge deficiencies after implant placement.
MATERIALS AND METHODS
Included studies met the following inclusion criteria: randomized controlled trials (RCTs) or controlled clinical trials (CCT's), re-entry procedure to assess defect resolution, minimum of 10 patients (5 per group). Meta-analyses were performed whenever possible, including subgroup analysis based on membranes and grafting materials.
RESULTS
Twenty-eight publications (20 short-term, 8 follow-up studies) were included. The most often used type of intervention was a xenogeneic particulated grafting material (XE) and a resorbable collagen membrane (CM). The mean defect height at baseline amounted to 5.1 mm (range 2.4 - 7.8) and decreased to a mean of 0.9 mm (range 0.2 - 2.2) at re-entry, and the mean defect resolution was 81.3% (range 56.4% - 97.1%). Defect height reduction was not significantly different using CM +XE as control treatment compared to the combined data of the respective test groups [n=11; weighted mean difference (WMD) = -0.006mm; 95% CI, -0.61, 0.60; p=0.985]. The absence of any lateral bone augmentation was less favorable than the conjunction of a membrane and a bone grafting material (n=1; MD = -1.96mm; 95% CI, -3.48, -0.44; p=0.011). The lack of a grafting material was less favorable than the conjunction of grafting material and membrane (n=1; MD = -2.44mm; 95% CI, -4.53, -0.35; p=0.022) and the addition of a membrane compared to a grafting material alone was more favorable (n=3; WMD = 0.97mm; 95% CI, 0.31, 1.64; p=0.004).
CONCLUSIONS
Lateral bone augmentation is a successful treatment modality. For optimal defect height reduction, a barrier membrane and a grafting material should be combined. This article is protected by copyright. All rights reserved.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/jcpe.13050

Efficacy of lateral bone augmentation performed simultaneously with dental implant placement: A systematic review and meta-analysis

Objectives
To evaluate the volumetric changes and peri-implant health at implant sites with and without previous soft tissue grafting over a 5-year observation period.

Material and methods
In 18 partially edentulous patients, dental implants were placed in the esthetic zone (15–25) with simultaneous guided bone regeneration, followed by submerged healing. During the healing phase, eight patients (test) received a subepithelial connective tissue graft, whereas 10 patients (control) did not receive any soft tissue augmentation. Subsequently, abutment connection was performed and final reconstructions were inserted. Impressions were taken 1 week after crown insertion and at 5 years. Obtained casts were scanned and superimposed for volumetric and linear measurements. The mean distance (MD) in the mid-buccal area between the two surfaces and the differences in buccal marginal mucosal level (bMMLchange) and in ridge width (RWchange) were evaluated. Peri-implant health was assessed using probing pocket depth (PPD) values, plaque index (PlI) and bleeding on probing (BOP).

Results
At a median follow-up time of 60.5 months a median MD of −0.38 mm (Min: −0.94; Max: −0.03) (test) and of −0.51 mm (Min: −0.76; Max: 0.05) (control) was calculated. The level of the margo mucosae (bMMLchange) demonstrated a median loss of −0.42 mm (Min: −1.1; Max: −0.01) (test) and of −0.33 mm (Min: −1.02; Max: 0.00) (control). The median RWchange ranged between −0.44 mm and −0.73 mm (test) and between −0.49 mm and −0.54 mm (control). Mean PPD values slightly increased, whereas PlI and BOP remained stable over time in both groups. None of the comparisons between the groups revealed statistically significant differences (P > 0.35). A small sample size must be considered, however.

Conclusions
Limited by a retrospective case–control study design, implant sites with and without soft tissue grafting on the buccal side revealed only minimal volumetric and linear changes and stability of peri-implant parameters over 5 years.

/pdf/volumetric-changes-and-peri-implant-health-at-implant-sites-2zxx1s6b46.pdf

Volumetric changes and peri-implant health at implant sites with or without soft tissue grafting in the esthetic zone, a retrospective case-control study with a 5-year follow-up.

Publisher Summary This chapter discusses the chemistry, biological, and pharmacological aspects of putrescine, spermidine, spermine, and related polyamine alkaloids. Aliphatic di- and polyamines are widespread in microorganisms, plants, and animals, as conjugates to a number of different biological structures, and also in free form. They are known since; Lewenhoeck examined a linear tetra-amine derivative obtained from sperm, spermine phosphate. In addition to the almost ubiquitous spermine, and the two equally abundant compounds putrescine and spermidine, a great number of other biogenic di-, tri-, and tetra-amine compounds are known. Among these, sym -nor-spermidine, homospermidine, sym-homospennidine, and sym-homospermine are of particular relevance for this treatise because they occur together with putrescine, spermidine, and spermine as fundamental building blocks in polyamine alkaloids. For pharmacological studies, two biological properties of the polyamines and their derivatives are of significance. The first concerns the influence of polyamines on cell proliferation, which makes the polyamines and their derivatives interesting compounds for investigations in the field of neoplastic diseases. The second concerns the interactions of polyamines with ion channels and related receptors, which is interesting with regard to diseases of the central nervous system. With respect to cancer research, the biosynthetic enzymes of polyamines were considered as promising targets for chemotherapy. In particular, spermidine/spermine N 1 -acetyltransferase, the highly regulated key enzyme of polyamine degradation, represents a new target for novel antineoplastic agents. Many synthetic analogs of the natural polyamines have been tested as agents against different cancers, and in some cases the results are rather promising. The interaction of polyamines with ion channels is of central importance for neurotransmittance.

Putrescine, spermidine, spermine, and related polyamine alkaloids

The first asymmetric total synthesis of the unnatural enantiomer of (-)-A9(12)-capnellene has been achieved in 141 % overall yield The synthesis is based on the chiral nonracemic bicyclic lactam 15 derived from inexpensive (S)-valinol and levulinic acid The goal of the synthesis, which was accomplished, was to reach the intermediate 13, originally reported in racemic form, and carry out the last step to the title compound

Stefan Bienz

Papers

Spektroskopische Methoden in der organischen Chemie

Efficacy of lateral bone augmentation performed simultaneously with dental implant placement: A systematic review and meta-analysis

Volumetric changes and peri-implant health at implant sites with or without soft tissue grafting in the esthetic zone, a retrospective case-control study with a 5-year follow-up.

Putrescine, spermidine, spermine, and related polyamine alkaloids

Asymmetric total synthesis of (+)-.DELTA.9(12)-capnellene