Display omitted
•The progress in photoswitches based on spiropyran, oxazine, spirooxazine and chromenes is overviewed.•The photochromic molecules demonstrate excellent metal affinity towards heavy ...metal ions.•The photochromic molecules produce an excellent optical signal in the presence of specific metal ions.•The photosensitive nature of the metal complex allow for the release of metal ion triggered by light.
This review focuses on the recent growth in the photo triggered molecular receptors for heavy metal ions. The photochromic unit in such molecular receptors performs as a trigger unit to allow control over a range of the properties through an external stimulus. This review opens up with the new opportunities for the development of host molecular motifs for heavy metal ion sensing applications. The photochromic switches based on a chemical structure like spiropyran, chromenes and spirooxazines tagged with appropriate chromogenic or fluorogenic unit reported till date have been summarized and categorized by the selectivity of metal ion to achieve the suitable optical response. The review has relevance for designing new photoreversible switches with the interesting optical response for environmentally important heavy metal ions.
•A spirooxazine receptor was synthesized and structure was investigated through single crystal X-ray determination.•The optical response (color, absorbance and fluorescence change) of the ...spirooxazine receptor toward transition metal ions was investigated.•The spirooxazine receptor displayed highly sensitive and selective optical response toward Fe3+ ions.•Detection limit value suggested that the spirooxazine receptor can be used for detection of trace concentration of Fe3+ ions in aqueous solution.
A photochromic spirooxazine derivative was synthesized and evaluated for optical response toward heavy metal ions. The spirooxazine derivative was observed to selectively respond to the presence of Fe3+ ions and produced both chromogenic and fluorogenic response. The spirooxazine derivative produced a ∼100nm shift in the UV–visible spectrum and ∼90 fold enhancement in fluorescence intensity in the presence of one equivalent Fe3+ ions. A large stokes shift (110nm) was also observed on addition of one equivalent Fe3+ ions in methanol or methanol:water (1:1) solvent system.
RAZOR (Randomized Open versus Robotic Cystectomy) trial is a phase 3 randomized control trial comparing robot-assisted laparoscopic radical cystectomy with open radical cystectomy for the treatment ...of bladder cancer published by Parekh et.al. Three-year follow-up analysis of this trial showed that there was no difference in overall survival, progression-free survival, and local or distant recurrence in both the group. The present report will discuss this landmark trial in brief in the context of the advantage and feasibility of robotic radical cystectomy in the developing world.
Penile fracture with an associated urethral injury is a rare urological emergency resulting from trauma to the erect penis during vigorous sexual intercourse. The patient often presents with swelling ...of the penis, discoloration of the penile skin, localized pain, and hematuria with a typical history of sudden detumescence during intercourse. Subcoronal penile degloving incision has been conventionally described and is frequently used by many clinicians for the management of penile fracture-urethral injury. Here, we describe a case of complex penile fracture managed through the vertical penoscrotal incision. The penoscrotal approach confers excellent exposure to both the ruptured corpus cavernosum and urethra. This approach ensures successful outcomes in such an emergency procedure without having disadvantages of the degloving incision.
Abstract
In this article, we highlight the alterations in the photoinduced electron transfer (ET) and hydrogen atom transfer (HAT) pathways between an anti-tumor drug vitamin-K3 (MQ) and a nucleobase ...adenine (ADN) in the presence of gold (Au) and iron (Fe) nanoparticles (NPs). Inside the confined micellar media, with laser flash photolysis corroborated with an external magnetic field (MF), we have detected the transient geminate radicals of MQ and ADN, photo-generated through ET and HAT. We observe that the presence of AuNP on the MQ-ADN complex (
Au
MQ-ADN) assists HAT by limiting the ET channel, on the other hand, FeNP on the MQ-ADN complex (
Fe
MQ-ADN) mostly favors a facile PET. We hypothesize that through selective interactions of the ADN molecules with AuNP and MQ molecules with FeNP, a preferential HAT and PET process is eased. The enhanced HAT and PET have been confirmed by the escape yields of radical intermediates by time-resolved transient absorption spectroscopy in the presence of MF.
A merocyanine dye as a p-toluenesulfonate salt was synthesized. The structure of the dye was characterized using IR, NMR, HR-MS and single crystal X-ray crystallography. The X-ray crystallographic ...studies revealed the formation of a stacked aggregated structure of the merocyanine dye. The stacking interactions were investigated using the Crystal Explorer program, which estimated the strength of the interactions between different molecular pairs. The merocyanine dye was screened for affinity towards heavy metal ions, which revealed a color change from pink to colorless in the presence of mercuric ions, while other metal ions did not produce a similar change in color. In addition, the fluorescence spectroscopy indicated a change in the fluorescence intensity upon addition of mercuric ions. Both techniques displayed a good limit of detection value towards mercuric ions. In addition, the pixel intensity-based detection technique was also employed for the determination of limit of detection value with the help of a smartphone. The dynamic light scattering (DLS) studies indicated that the optical change occurred in the spectra of the receptor is due to the disaggregation of the receptor induced by mercuric ions. In addition, 1H-NMR studies were also used for investigating the mechanism of interaction between the receptor and the mercuric ions. The density functional theory (DFT) studies were used to investigate the formation of the complex at the molecular level, while time dependent density functional theory (TD-DFT) studies were used to understand the observed absorption spectra through the calculation of electronic excitation parameters, which indicated an increase in the energy difference between ground and the excited state.
In this paper, an angular symmetric, common radiator coplanar waveguide (CPW) fed four-port multiple-input-multiple-output (MIMO) antenna is designed on a <inline-formula> <tex-math ...notation="LaTeX">0.129\lambda _{\mathrm{ L}}^{2} </tex-math></inline-formula> RT Duroid (<inline-formula> <tex-math notation="LaTeX">\varepsilon _{\mathrm{ r}} =3.0 </tex-math></inline-formula>, tan<inline-formula> <tex-math notation="LaTeX">\delta =0.001 </tex-math></inline-formula>) substrate where <inline-formula> <tex-math notation="LaTeX">\lambda _{\mathrm{ L}} </tex-math></inline-formula> is the free space wavelength at the lowest operating frequency (<inline-formula> <tex-math notation="LaTeX">{f} _{\mathrm{ L}} </tex-math></inline-formula>) of 0.6 GHz. The antenna has a −6 dB impedance bandwidth from 0.6-1.09 GHz, 2.6-3.4 GHz and 4.2-7.0 GHz to cover the emerging wireless communication bands. At the same time, it also has a −10 dB impedance bandwidth extending from 0.7-1.01 GHz, 2.6-3.18 GHz, 5.3-6.06 GHz, and 6.7-6.94 GHz. Design steps to enhance the operating bandwidth and the isolation in the sub-1GHz bands are presented. The antenna has a reasonable realized gain at the simulated and measured frequencies. It exhibits the pattern diversity which is useful for the MIMO implementation. The envelope correlation coefficient (ECC), Mean effective gain (MEG), and the channel capacity of the antenna have been computed from the measured results. In spite of the small circuit size at <inline-formula> <tex-math notation="LaTeX">{f} _{\mathrm{ L}} </tex-math></inline-formula>, the ECC ≤ 0.50 over the entire band is observed. In addition to the existing communication applications, this antenna can find newer applications in the emerging 0.6-1.09 GHz band, sub-6GHz 5G near radio (NR), and Wi-Fi 6 communications.
Urogenital sinus (UGS) and cloacal malformations are the spectra of disease affecting mainly females, resulting in an unusual confluence of the genital and urinary tract with or without the ...involvement of the gastrointestinal tract. Successful reconstruction of these anomalies depends on the accurate preoperative delineation of abnormal anatomy with the help of cross-sectional and other contrast studies like genitourogram along with cystourethroscopy wherever indicated. We hereby report a case of a 14-year-old female who presented with irregular cyclical hematuria and was diagnosed with persistent UGS with urethral duplication. After a thorough evaluation, the patient was successfully managed with surgical reconstruction, described in this study. Persistent UGS is a complex developmental anomaly. Complete characterization of anomaly requires a thorough evaluation such as hormonal assessment, endoscopy, cross-sectional, and radiological contrast study. Surgical reconstruction needs individualization and may need clitoroplasty, labioplasty, and urethral and vaginal mobilization. Morphological and functional outcome is satisfactory in a well-planned surgical reconstruction.
PDF
