Rectus muscle re-approximation in cesarean section - a surgical dilemma: to close or not to close?

OBJECTIVES: Cesarean section is one of the most common operations worldwide since decades. However, the optimum surgical cesarean section technique is still being discussed. Closure or non-closure of the rectus muscles is also unclear among obstetricians. We aimed to evaluate the effect of rectus muscle re-approximation (RMR) in cesarean section on postoperative pain among singleton primi gravida elective cesarean sections at term. MATERIAL AND METHODS: The current study was planned as a prospective, blinded, randomized controlled trial. A total of 279 elective primi gravida singleton cesarean sections; 142 undergoing RMR and 137 not-undergoing RMR were included in the study. All participants were managed with our clinic's postoperative protocol and obstetric outcomes were also recorded. The patients' pain was assessed face to face 24 hours and 48 hours after operation by using visual analog scale (VAS) score. RESULTS: The elective singleton primi gravida cesarean sections with and without RMR exhibited no significant difference with respect to maternal age, Body Mass Index, delivery week and other obstetric outcomes. The VAS scores at 24th and 48th hours (67 ± 24 versus 69 ± 25, p: 0.635; 47 ± 25 versus 52 ± 26, p: 0,126, respectively) were similar between the RMR and non-RMR group. CONCLUSIONS: RMR has not any negative effect on postoperative pain, operation time, analgesic use and hospital stay in singleton primi gravida elective CS at term. Additionally, RMR did not lead to any adverse postoperative risks such as increased blood loss and sub-rectus hematoma.

Overview: Polycarbonates via Ring-Opening Polymerization, Differences between Six- and Five-Membered Cyclic Carbonates: Inspiration for Green Alternatives.

This review aims to cover the topic of polycarbonate synthesis via ring-opening polymerization (ROP) of cyclic carbonates. We report a wide variety of ROP-initiating systems along with their detailed mechanisms. We focus on the challenges of preparing the polymers; the precise control of the properties of the materials, including molecular weight; the compositions of the copolymers and their structural characteristics. There is no one approach that works for all scales in cyclic carbonates ROP. A green process to produce polycarbonates is a luring challenge in terms of CO2 utilization and the targeted domains for application. The main resolution seems to be the use of controlled incorporation of functional/reactive groups into polymer chains that can tailor the physicochemical and biological properties of the polymer matrices, producing what appears to be an unlimited field of applications. Glycerol carbonate (GC) is prepared from renewable glycerol and considered as a CO2 fixation agent resulting in GC compound. This family of five-membered cyclic carbonates has attracted the attention of researchers as potential monomers for the synthesis of polycarbonates (PCs). This cyclic carbonate group presents a strong alternative to Bisphenol A (BPA), which is used mainly as a monomer for the production of polycarbonate and a precursor of epoxy resins. As of December 2016, BPA is listed as a substance of very high concern (SVHC) under the REACH regulation. In 2006, Mouloungui et al. reported the synthesis and oligomerization of GCs. The importance of GCs goes beyond their carbonate ring and their physical properties (high boiling point, high flash point, low volatility, high electrical conductivity) because they also contain a hydroxyl group. The latter offers the possibility of producing oligo and/or polycarbonate compounds that have hydroxyl groups that can potentially lead to different reaction mechanisms and the production of new classes of polycarbonates with a wide range of applications.

Self-Assembled Light-Harvesting System from Chromophores in Lipid Vesicles.

Lipid vesicles are used as the organizational structure of self-assembled light-harvesting systems. Following analysis of 17 chromophores, six were selected for inclusion in vesicle-based antennas. The complementary absorption features of the chromophores span the near-ultraviolet, visible, and near-infrared region. Although the overall concentration of the pigments is low (~1 µM for quantitative spectroscopic studies) in a cuvette, the lipid-vesicle system affords high concentration (≥10 mM) in the bilayer for efficient energy flow from donor to acceptor. Energy transfer was characterized in 13 representative binary mixtures using static techniques (fluorescence-excitation versus absorptance spectra, quenching of donor fluorescence, modeling emission spectra of a mixture versus components) and time-resolved spectroscopy (fluorescence, ultrafast absorption). Binary donor-acceptor systems that employ a boron-dipyrrin donor (S0 ↔ S1 absorption/emission in the blue-green) and a chlorin or bacteriochlorin acceptor (S0 ↔ S1 absorption/emission in the red or near-infrared) have an average excitation-energy-transfer efficiency (ΦEET) of ~50%. Binary systems with a chlorin donor and a chlorin or bacteriochlorin acceptor have ΦEET ∼ 85%. The differences in ΦEET generally track the donor-fluorescence/acceptor-absorption spectral overlap within a dipole-dipole coupling (Förster) mechanism. Substantial deviation from single-exponential decay of the excited donor (due to the dispersion of donor-acceptor distances) is expected and observed. The time profiles and resulting ΦEET are modeled on the basis of (Förster) energy transfer between chromophores relatively densely packed in a two-dimensional compartment. Initial studies of two ternary and one quaternary combination of chromophores show the enhanced spectral coverage and energy-transfer efficacy expected on the basis of the binary systems. Collectively, this approach may provide one of the simplest designs for self-assembled light-harvesting systems that afford broad solar collection and efficient energy transfer.

Extending the short and long wavelength limits of bacteriochlorin near-infrared absorption via dioxo- and bisimide-functionalization.

Six new bacteriochlorins expanding the range of the strong near-infrared (NIR) absorption (Qy band) to both shorter and longer wavelengths (∼690 to ∼900 nm) have been synthesized and characterized. The architectures include bacteriochlorin-bisimides that have six-membered imide rings spanning the 3,5- and 13,15-macrocycle positions or five-membered imide rings spanning the ß-pyrrolic 2,3- and 12,13-positions. Both bisimide types absorb at significantly longer wavelength than the bacteriochlorin precursors (no fused rings), whereas oxo-groups at the 7- or 7,17-positions shift the Qy band to a new short wavelength limit. Surprisingly, bacteriochlorin-bisimides with five-membered ß-pyrrolic-centered imide rings have a Qy band closer to that of six-membered bacteriochlorin-monoimides. However, the five-membered bisimides (versus the six-membered bacteriochlorin-monoimides) have significantly enhanced absorption intensity that is paralleled by an ∼2-fold higher fluorescence yield (∼0.16 vs ∼0.07) and longer singlet excited-state lifetime (∼4 ns vs ∼2 ns). The photophysical enhancements derive in part from mixing of the lowest unoccupied frontier molecular orbitals of the five-membered imide ring with those of the bacteriochlorin framework. In general, all of the new bacteriochlorins have excited-state lifetimes (1-4 ns) that are sufficiently long for use in molecular-based systems for photochemical applications.

Diblock copolymer micelles and supported films with noncovalently incorporated chromophores: a modular platform for efficient energy transfer.

We report generation of modular, artificial light-harvesting assemblies where an amphiphilic diblock copolymer, poly(ethylene oxide)-block-poly(butadiene), serves as the framework for noncovalent organization of BODIPY-based energy donor and bacteriochlorin-based energy acceptor chromophores. The assemblies are adaptive and form well-defined micelles in aqueous solution and high-quality monolayer and bilayer films on solid supports, with the latter showing greater than 90% energy transfer efficiency. This study lays the groundwork for further development of modular, polymer-based materials for light harvesting and other photonic applications.

Enhanced light-harvesting capacity by micellar assembly of free accessory chromophores and LH1-like antennas.

Biohybrid light-harvesting antennas are an emerging platform technology with versatile tailorability for solar-energy conversion. These systems combine the proven peptide scaffold unit utilized for light harvesting by purple photosynthetic bacteria with attached synthetic chromophores to extend solar coverage beyond that of the natural systems. Herein, synthetic unattached chromophores are employed that partition into the organized milieu (e.g. detergent micelles) that house the LH1-like biohybrid architectures. The synthetic chromophores include a hydrophobic boron-dipyrrin dye (A1) and an amphiphilic bacteriochlorin (A2), which transfer energy with reasonable efficiency to the bacteriochlorophyll acceptor array (B875) of the LH1-like cyclic oligomers. The energy-transfer efficiencies are markedly increased upon covalent attachment of a bacteriochlorin (B1 or B2) to the peptide scaffold, where the latter likely acts as an energy-transfer relay site for the (potentially diffusing) free chromophores. The efficiencies are consistent with a Förster (through-space) mechanism for energy transfer. The overall energy-transfer efficiency from the free chromophores via the relay to the target site can approach those obtained previously by relay-assisted energy transfer from chromophores attached at distant sites on the peptides. Thus, the use of free accessory chromophores affords a simple design to enhance the overall light-harvesting capacity of biohybrid LH1-like architectures.

Hydrophilic tetracarboxy bacteriochlorins for photonics applications.

Bacteriochlorins absorb strongly in the near-infrared (NIR, 700-900 nm) region and hence are well suited for photophysical studies and photomedical applications, yet such endeavors heretofore have been largely limited by the intrinsic lipophilicity of the bacteriochlorin macrocycle. Here, a new molecular design is investigated wherein 3,5-dicarboxyphenyl units are appended to the ß-pyrrolic positions of the bacteriochlorin. Use of the 3,5-aryl substitution motif places the carboxylic acid groups, which are anionic at neutral pH, above and below the plane of the bacteriochlorin macrocycle. A de novo synthesis has been employed to create five such bacteriochlorins, which uses as intermediates two new 2,12-dibromobacteriochlorin building blocks and a known 3,13-dibromobacteriochlorin. The aryl groups with protected carboxylate moieties were introduced by Suzuki coupling; subsequent deprotection afforded the hydrophilic bacteriochlorins. The latter were characterized by absorption and fluorescence spectroscopy in DMF and in aqueous phosphate buffer (pH 7). In most cases, comparable sharp emission (FWHM of ∼25 nm) and modest fluorescence yields (0.060-0.11) were observed in aqueous phosphate buffer medium and in DMF. Aqueous solubility was examined by absorption spectral interrogation of samples over a 1000-fold concentration range with reciprocal change in pathlength (∼0.5, 5, 50, and 500 µM; 10, 1, 0.1, and 0.01 cm pathlength cuvettes). One hydrophilic bacteriochlorin was prepared that contains a single maleimido-terminated tether for bioconjugation; the tether was installed by the sequence of 15-bromination of the bacteriochlorin, Suzuki coupling, and DCC-mediated amide formation. The maleimido-bacteriochlorin was conjugated to a 48-residue cysteine-containing peptide analogue of a constituent from a bacterial photosynthetic light-harvesting complex. Taken together, the results show a new molecular design and facile de novo synthetic route for obtaining hydrophilic bacteriochlorins including a bioconjugatable group if desired.

The gingival crevicular fluid ciprofloxacin level in subjects with gingivitis and periodontitis, and its effects on clinical parameters.

OBJECTIVES: The purpose of this study, conducted on patients with gingivitis and periodontitis, was twofold: to find out the serum and gingival crevicular fluid concentration of ciprofloxacin, which is a common drug used effectively against Actinobacillus actinomycetemcomitans and to determine the effects of ciprofloxacin administration on clinical parameters. METHOD: A total of 32 adult patients, consisting of 16 subjects with gingivitis and 16 subjects with untreated chronic periodontitis, were included in the study. The subjects were divided into four groups: group I included eight subjects with chronic gingivitis who had not previously received any ciprofloxacin; group II included eight subjects with chronic gingivitis to whom three doses of ciprofloxacin were administered (Siprosan 500 mg) to establish adequate gingival crevicular fluid and serum concentrations of the agent; group III consisted of eight subjects with chronic periodontitis who had not received any ciprofloxacin; group IV included eight subjects with chronic periodontitis to whom three doses of ciprofloxacin were administered to establish adequate gingival crevicular fluid and serum concentrations of the agent. All patients were systemically healthy, free of pain and reported no current medication usage. Each patient was treated with scaling and/or root planing using specific hand instruments under local anesthesia. Gingival index, plaque index and clinical attachment levels of the teeth were used to determine the clinical condition of the subjects and findings were recorded at the beginning, seventh day, 21st day and third month of the study. Serum ciprofloxacin level was measured in venous blood. Approximately 5 ml of venous blood was drawn from subjects in groups II and IV using a standard venipuncture technique. Gingival crevicular fluid samples were sampled from six interproximal sites with six paper strips in the posterior region of upper jaw (excluding third molar) and all gingival crevicular fluid and serum samples were evaluated by high-performance liquid chromatography. RESULTS: The serum concentrations of ciprofloxacin at the first and 72nd hour were not significantly different in subjects with periodontitis compared to subjects with gingivitis. But the gingival crevicular fluid concentrations of ciprofloxacin at the same hours were significantly high in subjects with periodontitis compared to subjects with gingivitis. Both subjects with gingivitis and periodontitis had significantly higher ciprofloxacin levels in the gingival crevicular fluid than in serum. The application of ciprofloxacin did not have any positive or statistically significant effect upon the clinical parameters of the subjects with gingivitis. On the other hand, a significant decrease in the clinical attachment level scores of the subjects with periodontitis (group IV) was observed compared to group III in the 21st day and third month. CONCLUSION: According to these results, the use of ciprofloxacin as an alternative drug in subjects with periodontitis but not gingivitis can be recommended. However, long-term studies are also needed to assess the effects of ciprofloxacin on clinical parameters.