Photochemistry Of Monochloro Complexes Of Copper(ii) In Methanol Probed By Ultrafast Transient Absorption Spectroscopy

Ultrafast transient absorption spectra in the deep to near UV range (212-384 nm) were measured for the [Cu-II(MeOH)(5)Cl](+) complexes in methanol following 255-nm excitation of the complex into the ligand-to-metal charge-transfer excited state. The electronically excited complex undergoes sub-200 fs radiationless decay, predominantly via back electron transfer, to the hot electronic ground state followed by fast vibrational relaxation on a 0.4-4 Ps time scale. A minor photochemical channel is Cu-Cl bond dissociation, leading to the reduction of copper(H) to copper(I) and the formation of MeOH center dot Cl charge-transfer complexes. The depletion of ground-state [Cu-II(MeOH)(5)Cl](+) perturbs the equilibrium between several forms of copper(II) complexes present in solution. Complete re-equilibration between [Cu-II(MeOH)(5)Cl](+) and [Cu-II(MeOH)(4)Cl-2] is established on a 10-500 ps time scale, slower than methanol diffusion, suggesting that the involved ligand exchange mechanism is dissociative

Photoaffinity Labeling Via Nitrenium Ion Chemistry: Protonation of the Nitrene Derived from 4-Amino-3-Nitrophenyl Azide to Afford Reactive Nitrenium Ion Pairs

Phenyl azides with powerful electron-donating substituents are known to deviate from the usual photochemical behavior of other phenyl azides. They do not undergo ring expansion but form basic nitrenes that protonate to form nitrenium ions. The photochemistry of the widely used photoaffinity labeling system 4-amino-3-nitrophenyl azide, 5, has been studied by transient absorption spectroscopy from femtosecond to microsecond time domains and from a theoretical perspective. The nitrene generation from azide 5 occurs on the S(2) surface, in violation of Kasha\u27s rule. The resulting nitrene is a powerful base and abstracts protons extremely rapidly from a variety of sources to form a nitrenium ion. In methanol, this protonation occurs in about 5 ps, which is the fastest intermolecular protonation observed to date. Suitable proton sources include alcohols, amine salts, and even acidic C-H bonds such as acetonitrile. The resulting nitrenium ion is stabilized by the electron-donating 4-amino group to afford a diiminoquinone-like species that collapses relatively slowly to form the ultimate cross-linked product. In some cases in which the anion is a good hydride donor, cross-linking is replaced by reduction of the nitrenium ion to the corresponding amine

The introduction of anti-VEGF remedy into the anterior chamber with secondary neovascular glaucoma

For the purpose of reduction of newly formed vessels of the iris, reduction of intraocular pressure and preservation of the organ of vision, in the anterior chamber to 3 patients with secondary neovascular glaucoma was introduced 0,025 ml (0,25 mg) bevacizumab. The drug bevacizumab, introduced into the anterior chamber, did not cause any visible complications structures of the eye, leading to rapid disappearance of newly formed blood vessels in the iris and anterior chamber angle. Introduction to the anterior chamber of the eye to patients with neovascular glaucoma refractory promoted regression of neovascularization in the anterior segment of the eye, allowing effectively reduce IOP and preserve the eye

Pathomorphological changes in the optic nerve in hypertencive disease

Гіпертонічна хвороба - це хронічне захворювання, клінічними ознаками якого є стійке підвищення артеріального тиску. Ускладнення якого призводять до часткової або повної втрати зору. Метою роботи було вивчення морфогенезу та гістотопографії патологічних змін зорового нерва у хворих на гіпертонічну хворобу. Досліджували матеріал гістологічних препаратів відділів зорового нерва здорових людей ( померлих в наслідок автотравми) та хворих на гіпертонічну хворобу ( померлих в наслідок ускладнень. Проведення морфологічних досліджень свідчить, що при гострому перебігу гіпертонічної хвороби спостерігаються зміни у вигляді мукоїдного, фібриноїдного набухання переважно в септальних артеріолах. При хронічному перебігу гіпертонічної хвороби поряд із мозаїчними деструктивними процесами в артеріях та артеріолах відбуваються компенсаторні процеси у вигляді міоеластозу, міогіпереластозу, що супроводжується збільшенням індексу Керногана; Гипертоническая болезнь - это хроническое заболевание, клиническими признаками которого являются стойкое повышение артериального давления, осложнения которого приводят к частичной или полной потере зрения. Целью работы было изучение морфогенеза и гистотопографии патологических изменений зрительного нерва у больных гипертонической болезнью. Исследовали материал гистологических препаратов отделов зрительного нерва здоровых людей (умерших вследствие автотравмы) и больных гипертонической болезнью (умерших вследствие осложнений). Проведенные морфологические исследования свидетельствует, что при остром течении гипертонической болезни наблюдаются изменения в виде мукоидного, фибриноидного набухания преимущественно в септальных артериолах. При хроническом течении гипертонической болезни наряду с мозаичными деструктивными процессами в артериях и артериолах происходят компенсаторные процессы в виде миоеластоза, миогипереластоза, что сопровождается увеличение индекса Керногана; Hypertensive disease is a chronic disease which clinical signs are sustained increase of blood pressure. The main pathogenetic mechanism of arterial hypertension is change in the relationship between the volume of circulating blood and general arterial resistance. Hypertensive disease clinically has benign and malignant course. . With benign hypertension there is a gradual development of episodes of short-term increase in blood pressure, then its steady increase, characterized by morphological changes in the vessels during the first and second stages of the disease. And in the third stage there are secondary changes in various organs in connection with the development in arterioles and arteries of sclerotic processes. It should be noted that during the benign course of hypertension in each of its stages there may be episodes of exacerbation with a sharp increase in blood pressure, which characterizes the malignant nature of the disease. The last are morphologically characterized by destructive lesions of arterioles in the form of plasmoragiosis and mucoid swelling of the vascular wall. Consequently, destructive changes in arterioles have a mosaic character. In this case, in some arteries simultaneously compensatory changes are determined, due to which the adaptation of vessels and surrounding tissues to the elevated blood pressure occurs. That is why the morphological changes of small arteries and arterioles with hypertension are manifested in two forms: hyalinism and hyperplastic arteriosclerosis. It should be noted that if morphological changes in the arterioles of the retina, as clinically and morphologically, are sufficiently described in the literature, then the morphological changes in the vessels accompanying the optic nerve are insufficiently described. The purpose of the work was to study morphogenesis and histopography of pathological changes in the optic nerve in patients with hypertension. The histological preparation material of the optic nerve was taking from healthy people (died as a result of autotrauma) and patients with hypertonic disease (died as a result of complications) was studied. Conclusions. The development of destructive processes in the optic nerve is associated with both plasmorrhagia and the gyalinosis of septal arterioles. At the same time, in these vessels, the formation of the wall or flat microtubes are noted. It is due to the presence of blood clots that develop ischemia in adjacent arterioles in the areas of the optic nerve. At the same time, on the transverse section of the optic nerve in areas of ischemic damage to the nerve fibers, granular cells are constantly found in the form of layers. The second pathogenetic factor of local circulatory disorders in the microcirculatory channel of the optic nerve is associated with increased vascular permeability, due to the presence of proteolytic enzymes in the cytoplasm of the endothelial cells. Precisely because of the presence of the latter increases the permeability of arterioles and capillaries. This is accompanied by diapedeous hemorrhages in the optic nerve tissue, which are caused by minor changes in the arterioles and capillaries

Comparative characteristics crystallographic changes tears in patients with diabetic retinopathy using different preparations of artificial tears

Під нашим спостереженням було 138 очей у яких діагностовані різні форми діабетичної ре¬тинопатії. Всі пацієнти були поділені на 3 групи в залежності від складу сльозозамінника. При непроліфе- ративній формі ДРП ефективнішими у відновленні балансу між центральною і аморфною зоною внаслідок ущільнення кристалів проміжної зони виявилися розчини гіалуронової кислоти з або без трегалози в порів¬нянні з розчином гіпромелози. При проліферативній формі ДРП застосування розчину гіалуронової кислоти чи гіпромелози протягом 6 тижнів виявилося недостатнім для нормалізації якісного складу слізної рідини, а застосування розчину гіалуронової кислоти з трегалозою сприяло відновленню папоротеподібної структури кристалів в центральній зоні; Под нашим наблюдением было 138 глаз в которых диагностированы различные формы диабе-тической ретинопатии. Все пациенты были разделены на 3 группы в зависимости от состава сльозозамени- теля. При непролиферативной форме ДРП эффективными в восстановлении баланса между центральной и аморфной зоной вследствие уплотнения кристаллов промежуточной зоны оказались растворы гиалу- роновой кислоты с или без трегалозы по сравнению с раствором гипромеллозы. При пролиферативной форме ДРП применения раствора гиалуроновой кислоты или гипромеллозы в течение 6 недель оказалось недостаточным для нормализации качественного состава слезной жидкости, а применение раствора гиа- луроновой кислоты с трегалозой способствовало обновлению папоротникообразной структуры кристаллов в центральной зоне; Under our supervision, based ophthalmology department POKL them N.V Sklifosovsky was 138 eyes in which according to the classification and Kohner E. Porta M. 1992 diagnosed with various forms of diabetic retinopathy. The average age of patients studied was 53 ± 2,3 years. Depending on the active ingredient drops of artificial tears used to correct deviations crystallographic characteristics tears, patients were divided into 3 groups. Thus, using a solution of hypromellose was rebalancing between central and amorphous zone by sealing the crystal intermediate zones, these signs are sufficient for normal crystallogram and indicate the balance of biochemical elements tears with nonproliferative stage diabetic retinopathy, and no abnormal crystal formation in the amorphous area dominated crystals at large preproliferatyvniy form diabetic retinopathy showed improvement of the quality of the tears, but remained dybalans components. When using hyaluronic acid solution was rebalancing between central and amorphous zone by sealing the crystal intermediate zones, these signs are sufficient for normal crystallogram and indicate the balance of biochemical elements and tears in the nonproliferative stage preproliferatyvniy diabetic retinopathy. In the case of these solutions in the form of diabetic retinopathy proliferative changes in crystallograms were not significant at week 4 and 6 of native crystallography, indicating the imbalance components tears. When using a solution of hyaluronic acid and trehalose correction features crystallogram occurred not only in nonproliferative and preproliferatyvniy form diabetic retinopathy. Thus, in the proliferative form diabetic retinopathy in the central zone recovery was fern structure arrangement of crystals, indicating improving the quality of the tear fluid. However, the lack of basic branching trunk 3rd order indicative of the lack of rebalancing tears during this time of use. In nonproliferative form diabetic retinopathy on 25% effective in restoring a balance between central and amorphous zone due to consolidation crystals were intermediate zone solutions of hyaluronic acid with or without trehalose in comparison with hypromellose solution. In preproliferatyvniy form diabetic retinopathy solution using hypromellose contributed compacted crystals intermediate zone facies tears in 47%. In proliferative form diabetic retinopathy application solution hypromellose or hyaluronic acid for 6 weeks was insufficient to normalize the quality of the tear fluid. In proliferative diabetic retinopathy application form hyaluronic acid solution with trehalose contributed restored fern crystal structure in the central area with the presence of branching 1st, 2nd, 3rd order of 29%. Use of drugs for treatment were well tolerated by all patients. Manifestations of side effects were found. Within two weeks of using the drug, all patients noted a decrease of discomfort, indicating improving the quality of the tears

Light-activated chemical probing of nucleobase solvent accessibility inside cells

This corrects the article DOI: 10.1038/nchembio.2548

Copper-Catalyzed Oxyazidation of Unactivated Alkenes: A Facile Synthesis of Isoxazolines Featuring an Azido Substituent

A novel and efficient Cu(OAc)2-catalyzed oxyazidation of unactivated alkenes was developed. The reactions are easy to conduct, occur under mild conditions, and form azido-substituted isoxazolines in good yields