Read by QxMD icon Read


Sukrit Ranjan, Dimitar D Sasselov
The UV environment is a key boundary condition to abiogenesis. However, considerable uncertainty exists as to planetary conditions and hence surface UV at abiogenesis. Here, we present two-stream multilayer clear-sky calculations of the UV surface radiance on Earth at 3.9 Ga to constrain the UV surface fluence as a function of albedo, solar zenith angle (SZA), and atmospheric composition. Variation in albedo and latitude (through SZA) can affect maximum photoreaction rates by a factor of >10.4; for the same atmosphere, photoreactions can proceed an order of magnitude faster at the equator of a snowball Earth than at the poles of a warmer world...
March 2017: Astrobiology
Samia Esmat, Rehab A Hegazy, Suzan Shalaby, Stephen Chu-Sung Hu, Cheng-Che E Lan
Vitiligo is a disease characterized by disappearance of melanocytes from the skin. It can negatively influence the physical appearance of affected individuals, and may profoundly affect a person's psychosocial function and quality of life. Therefore, vitiligo should not be considered as merely a condition that affects a patient's appearance, but needs to be actively treated in patients who seek medical help. Phototherapy has been used as the main treatment modality for patients with vitiligo. Different forms of phototherapy for vitiligo include broadband UVB, narrowband UVB, excimer light and excimer laser, and psoralen plus UVA...
April 2017: Dermatologic Clinics
Arturo Espinosa Ferao, Rafaela García
Azine ligands show preference for the antiperiplanar conformation, but their 2:2 ligand-metal complexes can exhibit a central N4M2 core in the most stable chair arrangement, as in the case of the model lithium complex, with the ligand displaying a synclinal conformation that is not stable in the free ligand. According to DFT calculations, complexation of Cu(2+) with bis(1-pyrenyl)azine (1) affords a C2-symmetric [1·Cu(2+)]2 species with a planar central N4Cu2 core exhibiting a weak cuprophilic interaction...
April 2017: Journal of Molecular Modeling
S BinSheikhan, M Al Abadie
No abstract text is available yet for this article.
April 2017: Clinical and Experimental Dermatology
O A Kostin, S V Rebrikov, A I Ovchinnikov, A A Stepanov, Kh P Takhchidi
AIM: to evaluate functional results of reoperation performed according to the CIRCLE technology and using the VisuMax femtosecond laser and MEL-80 excimer laser in cases of regression of the refractive effect after SMILE surgery. MATERIAL AND METHODS: We studied a group of post-SMILE patients. In those, who showed regression of the refractive effect at 1 year, reoperation was performed according to the CIRCLE technology and using the VisuMax femtosecond laser. The corneal flap was separated from the stromal bed and turned aside...
2017: Vestnik Oftalmologii
Luis J A Martins, João M M Ferreira
Laser flash photolysis of 5-nitro-2-furaldehyde (NFA) in solution shows a short-lived transient absorption with λmax = 475 ± 5 nm, which is relatively insensitive to solvent polarity and is assigned to the lowest triplet state of NFA ((3)NFA*). In water, the (3)NFA* absorption decays to a long-lived absorption, the study of which, at different times after the end of the laser pulse, reveals it to be due to a furyloxyl radical (λmax ≈ 375 nm) and to the radical anion NFA˙(-) (λmax ≈ 400 nm). These radicals were produced independently to confirm the assignment...
March 13, 2017: Photochemical & Photobiological Sciences
O A Krasheninina, A A Lomzov, V S Fishman, D S Novopashina, A G Venyaminova
In this paper, we report structure-based rational design and physico-chemical and biological studies of novel pyrene excimer forming dual probes for visualization of intracellular RNAs. Herein, the probes based on 2'-O-methyl RNA with linkers of different structure and length between pyrene moiety and ribose are studied with respect to their hybridization and spectral properties. We found optimal linkers that provide more intense excimer emission (at ∼480nm) of RNA-bound probes; particularly, the length of the linker arm of the 3'-component of dual probes plays a key role in formation of pyrene excimer...
February 27, 2017: Bioorganic & Medicinal Chemistry
Essam-Elden Mohamed Mohamed, Abdel-Khalek Younes, Ahmed Osman, Refaat Mohamed, Mahmoud Makki, Marwa Younis
OBJECTIVE: To compare the efficacy of follicular hair transplantation and mini punch graft in the treatment of stable vitiligo. METHODS: Thirty two patients with stable vitiligo were included in this comparative study. A single patch from each patient was divided into two halves; one half was treated by punch graft while the other half was treated by follicular hair transplantation followed by excimer light twice weekly and the outcome were assessed at 0, 1, 3and 6 months post operatively by photography and quartile scale...
March 8, 2017: Journal of Cosmetic and Laser Therapy: Official Publication of the European Society for Laser Dermatology
Yadong Qiao, Zhiyi Yao, Wenqi Ge, Li Zhang, Hai-Chen Wu
We have developed a ratiometric sensor based on polyelectrolyte-induced pyrene excimers for the rapid and visual detection of heparin in aqueous media. This sensor has a simple preparation method, fast response, low cost, and high sensitivity and selectivity. As a complementary strategy for the detection of heparin based on the formation of pyrene excimers, this approach could identify heparin specifically over chondroitin sulphate, which is the major interferent in most sensing systems for the detection of heparin...
March 7, 2017: Organic & Biomolecular Chemistry
Jesús Jara-Cortés, José Manuel Guevara-Vela, Ángel Martín Pendás, Jesús Hernández-Trujillo
This work provides a novel interpretation of elementary processes of photophysical relevance from the standpoint of the electron density using simple model reactions. These include excited states of H2 taken as a prototype for a covalent bond, excimer formation of He2 to analyze non-covalent interactions, charge transfer by an avoided crossing of electronic states in LiF and conical interesections involved in the intramolecular scrambling in C2 H4 . The changes of the atomic and interaction energy components along the potential energy profiles are described by the interacting quantum atoms approach and the quantum theory of atoms in molecules...
March 7, 2017: Journal of Computational Chemistry
M Töteberg-Harms, J Wachtl, C Schweier, J Funk, C Kniestedt
Background Combined cataract and glaucoma procedures, and minimally-invasive glaucoma surgery in particular, have gained increasing interest over the past few years. The aim of this study was to compare the long-term efficacy of combined phaco-trabeculectomy (Phaco-Trab) and combined phacoemulsification plus excimer laser trabeculotomy (Phaco-ELT). Patients and Methods Retrospective, non-randomised, comparative, interventional case series of consecutive patients after Phaco-Trab and Phaco-ELT at the University Hospital of Zurich and the Talacker Eye Center Zurich in Switzerland...
March 6, 2017: Klinische Monatsblätter Für Augenheilkunde
Steven E Wilson, Gustavo K Marino, Carla S Medeiros, Marcony R Santhiago
PURPOSE: To describe, with videos, the principles of excimer laser phototherapeutic keratectomy (PTK) for the treatment of corneal scars, corneal surface irregularity, and recurrent corneal erosions. METHODS: Depending on the pathology in a treated cornea, the epithelium is removed either by transepithelial PTK ablation with the excimer laser or thorough scraping with a scalpel blade. Stromal PTK can be performed with or without photorefractive keratectomy (PRK), depending on the refractive status of both eyes...
March 1, 2017: Journal of Refractive Surgery
Sabine Kling, Bogdan Spiru, Farhad Hafezi, Walter Sekundo
PURPOSE: To determine the corneal weakening induced by different re-treatment options after small incision lenticule extraction (SMILE) and investigate the potential of corneal cross-linking (CXL) to reestablish the original corneal stress resistance. METHODS: A total of 96 freshly enucleated porcine corneas were used. The initial refractive correction was defined to be -11.00 diopters (D) and the required enhancement to be -3.00 D. Three different re-treatment options were analyzed: -3D Re-SMILE, -3D photorefractive keratectomy (PRK) on top of the SMILE cap, and cap-to-flap conversion and -3D excimer ablation on the stromal bed (LASIK)...
March 1, 2017: Journal of Refractive Surgery
Dan Z Reinstein, Kishore R Pradhan, Glenn I Carp, Timothy J Archer, Marine Gobbe, Walter Sekundo, Raynan Khan, Kim Citron, Purushottam Dhungana
PURPOSE: To evaluate optical zone centration of hyperopic small incision lenticule extraction (SMILE). METHODS: This prospective study of 60 consecutive hyperopic SMILE procedures used the VisuMax femtosecond laser and matched LASIK procedures with the VisuMax and MEL 80 excimer lasers (Carl Zeiss Meditec AG, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and astigmatism up to 6.00 D. For SMILE, the optical zone was between 6...
March 1, 2017: Journal of Refractive Surgery
S Guilloto Caballero, J L García Madrona, E Colmenero Reina
OBJECTIVES: The objective of this study was to determine the clinical benefits of pulsed light therapy for the treatment of Dry Eye Syndrome (DES) due to the decrease in aqueous tear production (aqueous deficient DES) and/or excessive tear evaporation (evaporative DES) due to Meibomian Gland Dysfunction (MGD). METHODS: A study was conducted on 72 eyes corresponding to 36 patients with DES. Out of these 72 eyes, 60 underwent refractive surgery (48 with femtosecond laser, 6 were operated with a mechanical microkeratome, and 6 with refractive photo-keratectomy[RPK], 6 treated with phacoemulsification, and 6 with no previous surgical treatment...
February 28, 2017: Archivos de la Sociedad Española de Oftalmología
Pawan Kumar, Pawan K Sharma, Poul Nielsen
A new pyrene-modified nucleotide monomer is introduced, wherein pyrene is attached to the 2'-position of arabino-uridine through a triazolemethyl linker. When the monomer is introduced into oligonucleotides, very stable DNA duplexes and three way junctions are obtained. An oligonucleotide featuring two modifications in the center shows four-fold increase in the intensity of the pyrene excimer signal on hybridization with an RNA target but not with a DNA target. The new nucleotide monomer has potential in DNA invader probes as well as in RNA targeting and detection...
February 9, 2017: Bioorganic & Medicinal Chemistry
Manuela Buonanno, Brian Ponnaiya, David Welch, Milda Stanislauskas, Gerhard Randers-Pehrson, Lubomir Smilenov, Franklin D Lowy, David M Owens, David J Brenner
We have previously shown that 207-nm ultraviolet (UV) light has similar antimicrobial properties as typical germicidal UV light (254 nm), but without inducing mammalian skin damage. The biophysical rationale is based on the limited penetration distance of 207-nm light in biological samples (e.g. stratum corneum) compared with that of 254-nm light. Here we extended our previous studies to 222-nm light and tested the hypothesis that there exists a narrow wavelength window in the far-UVC region, from around 200-222 nm, which is significantly harmful to bacteria, but without damaging cells in tissues...
February 22, 2017: Radiation Research
Andreas Y Andreou, Theodoros Kyriakou, Chrysostomos Mavroudis
No abstract text is available yet for this article.
February 17, 2017: Hellenic Journal of Cardiology: HJC, Hellēnikē Kardiologikē Epitheōrēsē
Maria Ejlersen, Niels Langkjær, Jesper Wengel
Efficient synthesis of a new 3'-O-amino-UNA monomer was developed as a scaffold for further functionalization and incorporation into oligonucleotides (ONs). Pyrene-functionalized 3'-O-amino-UNA was incorporated one, two or three times into 21-mer DNA and 2'-O-Me-RNA ONs. Duplex melting temperatures, circular dichroism (CD) spectra, steady-state fluorescence emission spectra, UV/Vis absorption spectra and triplex melting temperatures were measured for the modified duplexes. The presence of the pyrene-modified UNA monomer lead to a surprising and unprecedented thermal stabilization of especially DNA:DNA duplexes when compared to the corresponding unmodified DNA:DNA duplexes...
February 17, 2017: Organic & Biomolecular Chemistry
Xiaodi Feng, Liya Pi, Sriniwas Sriram, Gregory S Schultz, Daniel J Gibson
We sought to determine if connective tissue growth factor (CTGF) is necessary for the formation of corneal haze after corneal injury. Mice with post-natal, tamoxifen-induced, knockout of CTGF were subjected to excimer laser phototherapeutic keratectomy (PTK) and the corneas were allowed to heal. The extent of scaring was observed in non-induced mice, heterozygotes, and full homozygous knockout mice and quantified by macrophotography. The eyes from these mice were collected after euthanization for re-genotyping to control for possible Cre-mosaicism...
2017: PloS One
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"