A Carbon Nano‐Onion–Ferrocene Donor–Acceptor System: Synthesis,Characterization and Properties

Don't cry! The attachment of ferrocene moieties on the surface of carbon nano‐onions influences the electrochemical properties of these moieties and the photophysical properties of the carbon nano‐onions (see figure). Quantum chemical calculations confirm that the spectral properties of carbon nano‐onions depend on their size and the degree of functionalisation.

     

Photoluminescence and Optical Absorption of Cs2NaScF6:Cr3+

The main objective of this paper is the characterization of the spectroscopic properties of new materials that are prospective laser media. This approach allows for the comparison of the properties of the Cr³⁺ in different environments. Here, we have studied the photoluminescence and optical absorption of Cs₂NaScF₆:Cr³⁺ single crystals. On the basis of near-infrared luminescence measurements at 2, 77, and 300 K the observed lines originated from the Cr³⁺-centres were associated with the transition and the lifetimes were obtained. In spite of the quenching observed as a function of temperature at least 10% of the 2 K emission intensity for Cs₂NaScF₆ doped with 1% of Cr³⁺ remains at room temperature. Besides, the 2 K emission broad band could be well described in terms of normal modes of the octahedral complex [CrF₆]³⁻, and the Racah and crystal-field parameters calculated.     

Nuclear-like effects in proton–proton collisions at high energy

We show that several effects considered nuclear effects are not nuclear in the sense that they do not only occur in nucleus–nucleus and hadron–nucleus collisions but, as well, they are present in hadron–hadron (proton–proton) collisions. The matter creation mechanism in hh, hA and AA collision is always the same. The p _T suppression of particles produced in large multiplicity events compared to low multiplicity events, the elliptic flow and the Cronin effect are predicted to occur in pp collisions at LHC energies as a consequence of the high density partonic medium obtained.     

Thermal behaviour of bambus[6]uril and its chloride caviplex

Journal of Thermal Analysis and Calorimetry - The present paper presents the thermal behaviour of methyl-bambus[6]uril in its anion-free and chlorine-included form. Our study was based on...     

Effects of Photobiomodulation on Functionality in Wistar Rats with Sciatic Nerve Injury

A peripheral nerve injury (PNI) can result in motor or sensory disorders. Low‐level laser therapy (LLLT) has demonstrated positive results as a treatment option for PNI. Wistar rats were divided into five groups: Control, Injury, Injury + LLLTn (nerve), Injury + LLLTm (muscle) and Injury + LLLTn + m (nerve and muscle irradiation). The groups were analyzed after one, two, three and four weeks. PNI was achieved by crushing the sciatic nerve. Laser treatment (780 nm, 3.2 J) was realized over the nerve and/or tibialis anterior muscle. In gait analyses, the groups irradiated over the nerve demonstrated an improvement after two weeks. In the analysis of mechanical sensitivity, the Injury + LLLTn demonstrated a reduction after one week in comparison with Injury group; the Injury + LLLTn + m and Injury + LLLTm demonstrated an increase after two weeks in comparison with Injury group; and the irradiated groups demonstrated a reduction in nociception after four weeks in comparison with Injury group. In the analysis of muscle atrophy, the Injury + LLLTn demonstrated more muscle mass after two weeks. LLLT improves functional aspects related to gait, mechanical sensitivity and muscle mass, with better results regarding motor aspects and muscle mass when administered over the injured nerve and better results regarding sensory aspects when administered over the muscle.     

Conjugates of Cryptophycin and RGD or isoDGR Peptidomimetics for Targeted Drug Delivery

RGD-cryptophycin and isoDGR-cryptophycin conjugates were synthetized by combining peptidomimetic integrin ligands and cryptophycin, a highly potent tubulin-binding antimitotic agent across lysosomally cleavable Val-Ala or uncleavable linkers. The conjugates were able to effectively inhibit binding of biotinylated vitronectin to integrin α_vβ₃, showing a binding affinity in the same range as that of the free ligands. The antiproliferative activity of the novel conjugates was evaluated on human melanoma cells M21 and M21-L with different expression levels of integrin α_vβ₃, showing nanomolar potency of all four compounds against both cell lines. Conjugates containing uncleavable linker show reduced activity compared to the corresponding cleavable conjugates, indicating efficient intracellular drug release in the case of cryptophycin-based SMDCs. However, no significant correlation between the in vitro biological activity of the conjugates and the integrin α_vβ₃ expression level was observed, which is presumably due to a non-integrin-mediated uptake. This reveals the complexity of effective and selective α_vβ₃ integrin-mediated drug delivery.     

Growth and characterization of REBa2Cu3O7−δ superconductor single crystals obtained from xenotime mineral

Single crystals of REBa₂Cu₃O_7−δ (RE=natural mixture of Y and heavy lanthanides in the single crystals) superconductor were successfully grown using rare-earth oxides extracted from xenotime mineral, allowing an alternative and simple route for superconductor single-crystal production. The methodology to extract the rare-earth mixed oxides from the xenotime mineral has three main steps: alkaline fusion, acid lixiviation and oxalic precipitation. Large single crystals with a typical 5×5×0.03 mm³ size were obtained by using a CuO-BaO self-flux and were characterized by scanning electron microscopy (SEM), energy-dispersive electron spectroscopy, X-ray diffraction, magnetic measurements and nanoindentation. The composition of the rare-earth elements of the crystal was different from the starting mixture, possibly due to the different solubilities of the elements in the melt. The final crystal stoichiometry was RE:Ba:Cu=1:2:3. X-ray diffraction analysis showed highly oriented c-axis (c=11.716±0.002 Å). The critical temperature was determined to be around T_C≅88-89 K after the crystals have been submitted to oxygen annealing. Hardness and elastic modulus for ab- and b(a)c-planes were 8.5±0.5 and 160±20 GPa, respectively.     

Degradation Mechanisms of Biodegradable Poly(DL-lactide-co-glycolide)1000 Diacrylate Network as Studied by Proton Solid-State Flow NMR Relaxometry

Summary: Degradation mechanisms of biodegradable photo-polymerised poly(DL-lactide-co-glycolide)1000 diacrylate {[(DL-LA/GA)DA]} matrices or films were studied by proton solid-state NMR relaxometry. A flow NMR unit cell was developed for this purpose. The (DL-LA/GA)DA-network was degraded in PBS buffer solution of pH = 7.4. A real-time proton NMR method provided information about the staged break down of the network during continuous circulation of the buffer solution through the NMR tube. The current study shows that degradation of the network proceeds in three stages: 1 - extraction of a sol fraction that causes substantial immobilization of the material, 2 - scissions of network chains producing network defects without formation of extractable products, and 3 – finally, chain scissions that cause formation of a sol fraction and complete degradation of the material. It was shown that the [(DL-LA/GA)DA-network was composed of rigid and viscoelastic domains on all stages of degradation. This heterogeneity could be due to heterogeneous spatial distribution of network junctions in the initial network and/or nano-scale phase separation of polyacrylate chains that form multifunctional network junctions and poly(lactide-co-glicolide) network chains. A combination of bulk and surface erosion both on nano- and macroscopic scales could explain the observed degradation mechanisms. It is shown that knowledge of weight loss upon hydrolytic degradation is not sufficient for understanding degradation mechanisms in the relation to functional properties of this type of hydrogels.     

Macroscopic and microscopic aspects of the temporomandibular joint related to its clinical implication

In order to obtain a precise diagnosis and treatment for temporomandibular dysfunctions, it is necessary to have morphological and functional knowledge of the temporomandibular joint. Anatomic components are important to the understanding of the complexity of temporomandibular joint. Nonetheless, just as important are the anatomic relationships that this joint has with the neighboring structures. Thus, the aim of this study was to present the anatomic relationships of the temporomandibular joint in its various surfaces: external or lateral, anterior, posterior, medial, superior, and posterosuperior, considering the morphological and histological aspects. Nine human heads, fixed in formalin (10%) underwent sagittal medial section and were subsequently dissected, evidencing the anatomic components of all surfaces to be analyzed. Components of the external surface were: skin, subcutaneous tissue, lymphatic ganglia, parotid gland, superficial temporal artery, transverse facial artery, zygomatic-orbital artery, superficial temporal vein, facial and auriculotemporal nerves, masseter muscle, and pre-auricular lymphonodus. The anterior surface comprised the masseter and lateral pterygoid muscles (upper and inferior heads), pterygoid venous plexus, mandibular notch, posterior deep temporal artery, masseteric nerve, and deep posterior temporal branches. Medial surface components were: internal maxillary artery, of which middle meningeal artery was one of the closest branches to the TMJ, anterior tympanic artery, inferior alveolar, lingual, auriculotemporal, and chorda tympani nerves, which belonged to the surface posterior to the anterior wall of the auditory duct; auricolotemporal nerve, parotid gland; and petrotympanic fissure. The cerebral fossa (meninges and encephalon) belonged to the superior surface and the ear belonged to the posterosuperior surface. Histologically, the temporomandibular joint is composed by different tissues that compound the mandibular head, mandibular fossa, and articular eminence of the temporomandibular joint. It was concluded that the temporomandibular joint is a complex structure and the clinician must have the ability to formulate the diagnosis based on the understanding of morphological aspects of the structures that compose the stomatognatic system.     

Correlation Between Autofluorescence Intensity and Tumor Area in Mice Bearing Renal Cell Carcinoma

Protoporphyrin IX (PpIX) is a porphyrin derivative that is accumulated in cancerous tissue in consequence of the tumor-specific metabolic alterations. The aim of this study was to evaluate the accumulation of PpIX in mice bearing renal cell carcinoma by spectroscopy analysis. A total of 24 male Balb/c mice, 6 weeks old, were divided into six groups: Normal (without inoculation of tumor cells) and 4, 8, 13, 16, and 20 days after inoculation of tumor cells. The orthotopic tumor model of renal cancer was used. Murine renal cell carcinoma (Renca cells) were inoculated into the subcapsular space of the kidney. Normal and tumor-bearing kidneys in different progression stages were removed and analyzed by ex-vivo spectroscopy and by microscopy, for tumor histometric analysis. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and tumor-bearing kidneys in autofluorescence shape occurred in the 600–700 nm spectral region. A good correlation was found between emission band intensity at 635 nm and the tumor area.