Penile hair coil strangulation of the child

AbstractWe report the case of a child with a delayed presentation of penile strangulation with a coil of hair that resulted in a complete transection of the urethra. Hair coil strangulation of the penis is uncommon. It is also known as penile Tourniquet syndrome. It has been reported with circumcised and uncircumcised penises and it can lead to serious complications like the amputation of the penis. Prompt diagnosis and treatment are necessary to prevent complications

Evolution of Linear Absorption and Nonlinear Optical Properties in V-Shaped Ruthenium(II)-Based Chromophores

In this article, we describe a series of complexes with electron-rich cis-{Ru^(II)(NH_3)_4}^(2+) centers coordinated to two pyridyl ligands bearing N-methyl/arylpyridinium electron-acceptor groups. These V-shaped dipolar species are new, extended members of a class of chromophores first reported by us (Coe, B. J. et al. J. Am. Chem. Soc. 2005, 127, 4845−4859). They have been isolated as their PF_6− salts and characterized by using various techniques including ^1H NMR and electronic absorption spectroscopies and cyclic voltammetry. Reversible Ru^(III/II) waves show that the new complexes are potentially redox-switchable chromophores. Single crystal X-ray structures have been obtained for four complex salts; three of these crystallize noncentrosymmetrically, but with the individual molecular dipoles aligned largely antiparallel. Very large molecular first hyperpolarizabilities β have been determined by using hyper-Rayleigh scattering (HRS) with an 800 nm laser and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d → π^* metal-to-ligand charge-transfer (MLCT) and π → π^* intraligand charge-transfer (ILCT) bands. The latter measurements afford total nonresonant β_0 responses as high as ca. 600 × 10^(−30) esu. These pseudo-C_(2v) chromophores show two substantial components of the β tensor, β_(zzz) and β_(zyy), although the relative significance of these varies with the physical method applied. According to HRS, β_(zzz) dominates in all cases, whereas the Stark analyses indicate that β_(zyy) is dominant in the shorter chromophores, but β_(zzz) and β_(zyy) are similar for the extended species. In contrast, finite field calculations predict that β_(zyy) is always the major component. Time-dependent density functional theory calculations predict increasing ILCT character for the nominally MLCT transitions and accompanying blue-shifts of the visible absorptions, as the ligand π-systems are extended. Such unusual behavior has also been observed with related 1D complexes (Coe, B. J. et al. J. Am. Chem. Soc. 2004, 126, 3880−3891)

Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability

In this article, we present a detailed study of structure−activity relationships in diquaternized 2,2′-bipyridyl (diquat) derivatives. Sixteen new chromophores have been synthesized, with variations in the amino electron donor substituents, π-conjugated bridge, and alkyl diquaternizing unit. Our aim is to combine very large, two-dimensional (2D) quadratic nonlinear optical (NLO) responses with reversible redox chemistry. The chromophores have been characterized as their PF_6^− salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Their visible absorption spectra are dominated by intense π → π^* intramolecular charge-transfer (ICT) bands, and all show two reversible diquat-based reductions. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering with an 800 nm laser, and Stark spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and increase with the extent of π-conjugation and electron donor strength. Extending the quaternizing alkyl linkage always increases the ICT energy and decreases the E_(1/2) values for diquat reduction, but a compensating increase in the ICT intensity prevents significant decreases in Stark-based β_0 responses. Nine single-crystal X-ray structures have also been obtained. Time-dependent density functional theory clarifies the molecular electronic/optical properties, and finite field calculations agree with polarized HRS data in that the NLO responses of the disubstituted species are dominated by ‘off-diagonal’ β_(zyy) components. The most significant findings of these studies are: (i) β_0 values as much as 6 times that of the chromophore in the technologically important material (E)-4′-(dimethylamino)-N-methyl-4-stilbazolium tosylate; (ii) reversible electrochemistry that offers potential for redox-switching of optical properties over multiple states; (iii) strongly 2D NLO responses that may be exploited for novel practical applications; (iv) a new polar material, suitable for bulk NLO behavior

Near-lethal heat treatment induced metabolic changes associated with endodormancy release of Superior Seedless grapevine cv. (Vitis vinifera L.) buds

Abstract To assess the efficacy of near lethal heat stress for endodormancy release of Superior Seedless grapevine buds, single-node cuttings were soaked for 1 h in hot water (50°C) and then forced for one month. The effects of hot water treatment (HWT) on budburst, metabolic changes of carbohydrates, proline, free polyamines PAs (putrescine (Put), spermidine (Spd) and spermine (Spm)) and antioxidant enzymes' activity were investigated in bud under forcing conditions. Near-lethal heat stress caused a transient increase in starch hydrolysis, leading to an abrupt accumulation of soluble sugars, especially sucrose concentration during the first 3 days after treatment. This accumulation of soluble sugars coincided with a brief stimulation of the antioxidant system represented by ascorbate peroxidase (APX; EC 1.11.1.11), peroxidase (POD; EC 1.11.1.7) as well as an increase in the concentration of proline and free polyamines, especially putrescine (Put) and spermidine (Spd). These changes, which occurred immediately upon treatment, appear to be related with a process leading to endodormancy release. These results support the argument that a temporary and acute oxidative stress is involved in the mechanism leading to dormancy release and budbreak. Furthermore, it is possible that the stimulation of both peroxidases' activity and proline biosynthesis activated the pentose phosphate pathway (PPP) which helped the bud to overcome endodormancy. After this initial period and towards budbreak initiation, there was a rapid decline in the concentration of soluble sugars, proline and Put, while, Spm and Spd became abundant. Such post stress changes appear to be associated with the reactivation of growth leading to an earlier and more vigorous budbreak. The metabolic response to HWT was compared to those observed after bud chilling or the application of restbreaking agents such as hydrogen cyanamide (HC). The similarity in the response to these various stimuli suggests the presence of common regulatory pathways involved in bud dormancy release and subsequent sprouting