Formation of Group†11 Bismuth Sulfide Nanoparticles Using Bismuth Dithioates under Mild Conditions.

The formation of mixed-metal sulfides with the general structure AgBiS2 and Cu3 BiS2 by a simple two-step process utilizing bismuth dithiocarboxylates as Bi and S precursors is described. A sonochemical reaction of Bi2 O3 with six different aryl dithioic acids: dithiobenzoic acid (BDT-H), 4-methoxydithiobenzoic acid (4-MBDT-H), 3-methyldithiobenzoic acid (3-MBDT-H), 2-mesitylenedithioic acid (2-MDT-H), 4-fluorodithiobenzoic acid (4-FBDT-H), and 2-thiophenedithioic acid (2-TDT-H) resulted in the corresponding complexes: [Bi(BDT)3 ] 1, [Bi(4-MBDT)3 ] 2, [{Bi(3-MBDT)3 }2 ⋅C7 H8 ] (32 ⋅C7 H8 ), [Bi(2-MDT)3 ] 4, [Bi(4-FBDT)3 ] 5 and [Bi(2-TDT)3 ] 6. Microwave irradiation of these bismuth(III)aryldithioate complexes with AgNO3 or CuCl under mild reaction conditions (140 °C) resulted in the respective mixed-metal sulfides. Attempt to synthesize AuBiS2 using similar reaction protocols were unsuccessful, resulting only in the formation of elemental Au0 , S8 and BiOCl.

Self-Enhancement of Efficiency and Self-Attenuation of Hysteretic Behavior of Perovskite Solar Cells with Aging.

Spontaneous enhancement of the photovoltaic performance of perovskite solar cells (PSCs) after aging has been reported, but the underlying reasons for such behavior are still under debate. Herein, we demonstrate that this spontaneous improvement effect accompanied by self-attenuation of hysteresis in the current-voltage characteristics is time- and temperature-dependent. Moreover, it is universal to PSCs based on a range of mixed-ion perovskites and coupled to different hole- and electron-transporting materials. Time-resolved confocal fluorescence microscopy and other characterization techniques suggest that the "self-healing" phenomenon is accompanied by the homogenization and enhancement of the charge extraction efficiency as well as suppressed recombination throughout cm2-scale perovskite layers. These dynamic effects need to be accounted for when assessing the initial and stabilized performance of PSCs.

Flexible Nano-TiO2 Sheets Exhibiting Excellent Photocatalytic and Photovoltaic Properties by Controlled Silane Functionalization-Exploring the New Prospects of Wastewater Treatment and Flexible DSSCs.

TiO2 nanoparticles surface-modified with silane moieties, which can be directly coated on a flexible substrate without the requirement of any binder materials and postsintering processes, are synthesized and characterized using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, time-correlated single-photon counting, and transmission electron microscopy. The viability of the prepared surface-modified TiO2 (M-TiO2) sheets as a catalyst for the photo-induced degradation of a model dye, methylene blue, was checked using UV-visible absorption spectroscopy. The data suggest that, compared to unmodified TiO2, M-TiO2 sheets facilitate better dye-degradation, which leads to a remarkable photocatalytic activity that results in more than 95% degradation of the dye in the first 10 min and more than 99% of the degradation in the first 50 min of the photocatalytic experiments. We also demonstrate that M-TiO2 can be recycled with negligible reduction in photocatalytic activity. Further, the photovoltaic properties of the developed M-TiO2 sheets were assessed using UV-visible absorption spectroscopy, electrochemical impedance spectroscopy (EIS), and photochronoamperometry. Dye-sensitized solar cells (DSSC) fabricated using M-TiO2 as the photoanode exhibited a photoconversion efficiency of 4.1% under direct sunlight. These experiments suggested that M-TiO2 sheets show enhanced photovoltaic properties compared to unmodified TiO2 sheets, and that, when N-719 dye is incorporated, the dye-TiO2 interaction is more favorable for M-TiO2 than bare TiO2. The simple solution processing method demonstrated in this paper rendered a highly flexible photoanode made of M-TiO2 with superior charge-separation efficiency to an electrode made of bare TiO2. We propose that our findings on the photovoltaic properties of M-TiO2 open up arenas of further improvement and a wide scope for the large-scale production of flexible DSSCs on plastic substrates at room temperature in a cost-effective way.

Arteriovenous malformation of ureter presenting without hematuria: An unusual presentation of a rare disease.

Genitourinary tract arteriovenous malformations are extremely rare. Most of the lesions are found either in the kidney or urinary bladder. So far, to the best of our knowledge, only five cases of arteriovenous malformation of the ureter have been reported in the literature. Here, we present, a young male, clinically presented with pain in the left flank with no other significant history. On radiological evaluation found to have left hydroureteronephrosis with stricture of the left distal ureter at the level of iliac vessel crossing. Urine routine, cytology, and cystoscopy were unremarkable. Left retrograde pyelogram showed distal ureteric stricture. Patient underwent excision of left distal ureteric stricture segment and ureteric reimplantation with psoas hitch. Histopathological examination revealed the features of arteriovenous malformation of the left ureter. The patient is asymptomatic and has no recurrence on follow-up until 12 weeks after surgery.

Rare case of gangrene of penis in a patient with chronic kidney disease on dialysis.

Gangrene of the penis in patients with chronic kidney disease undergoing haemodialysis is a rare occurrence. Such patients often have associated comorbidities such as type II diabetes mellitus and systemic hypertension, along with secondary hyperparathyroidism leading to dystrophic calcification. These conditions accelerate the process of atherosclerosis, which, along with calcium deposition, causes partial or complete obstruction of the blood vessel lumen, leading to ischaemic necrosis at the tip of the penis. This adds to the pre-existing morbidity and mortality in such patients. In most cases, appropriate medical management is advocated to prevent the deposition of calcium in the lumen.

Incorporation of γ-butyrolactone (GBL) dramatically lowers the phase transition temperature of formamidinium-based metal halide perovskites.

We demonstrate that the δ to α phase transition temperature of formamidinium-based perovskites is reduced by ∼50 °C through the incorporation of ∼2 wt% γ-butyrolactone (GBL) into the crystal lattice. The intercalation of GBL is found to expand the unit cell of the δ-phase, reducing the energy barrier for thermal conversion.

Multiple Roles of Cobalt Pyrazol-Pyridine Complexes in High-Performing Perovskite Solar Cells.

Chemical doping is a ubiquitously applied strategy to improve the charge-transfer and conductivity characteristics of spiro-OMeTAD, a hole-transporting material (HTM) used widely in solution-processed perovskite solar cells (PSCs). Cobalt(III) complexes are commonly employed HTM dopants, whose major role is to oxidize spiro-OMeTAD to provide p-doping for improved conductivity. The present work discloses additional, previously unknown important functions of cobalt complexes in the HTM films that influence the photovoltaic performance. Specifically, it is demonstrated that commercial p-dopant FK269 (bis(2,6-di(1H-pyrazol-1-yl)pyridine) cobalt(III) tris(bis(trifluoromethylsulfonyl)imide)) reduces the interfacial recombination and alleviates the decomposition of the perovskite layer under the action of tert-butylpyridine and lithium bis(trifluoromethanesulfonyl)imide. These effects are demonstrated for 1 cm2 perovskite solar cells that achieve a stabilized power conversion efficiency of 19% under 1 sun irradiation.

Molecular Engineering of Zinc-Porphyrin Sensitisers for p-Type Dye-Sensitised Solar Cells.

Design of novel efficient light-harvesters for p-type dye-sensitised solar cells (DSSCs) is indispensable for further advances in this photovoltaic technology. Herein, a novel D-π-A (D=donor, π=π-conjugated linker, A=acceptor) sensitiser, ZnP1, featuring an electron acceptor, perylenemonoimide (PMI), connected to an electron donor, di(p-carboxyphenyl)amine (DCPA), through fluorene and a zinc(II) porphyrin with alkyl chains as a π-conjugated bridge is introduced. Spectroscopic and electrochemical characterisation of this dye along with a newly synthesised PMI-free reference dye ZnP0 has been undertaken to demonstrate strong electron coupling between the DCPA donor and PMI acceptor subunits through the porphyrin ring in ZnP1, which redshifts the light absorption onset to the near-IR region. When integrated into p-DSSCs based on a mesoporous nickel(II) oxide semiconductor electrode and a tris(acetylacetonato) iron(III/II) redox mediator, ZnP1 exhibits an onset of the incident photon-to-current conversion efficiency at 800 nm and a power conversion efficiency of up to 0.92 % under simulated 100 mW cm-2 AM 1.5 G irradiation. This is the highest efficiency of the porphyrin-based p-DSSCs hitherto reported.

Molecular Engineering of Zinc-Porphyrin Sensitisers for p-Type Dye-Sensitised Solar Cells.

Invited for this month's cover are the groups of Prof. Dr. Udo Bach, Prof. Dr. Yi-Bing Cheng, and Prof. Dr. Leone Spiccia (Monash University, Australia), and Dr. Mingkui Wang (Huazhong University of Science and Technology, China). The cover picture shows the charge-transfer processes between a novel porphyrin dye adsorbed on nickel oxide and tris(acetylacetonato) iron(III/II) redox mediator after excitation by sunlight. Read the full text of the article at 10.1002/cplu.201800104.

An Unusual Presentation of a Breast Lump.

Trichilemmal cyst also known as pilar cyst is a rare cyst arising from the external root sheath of the hair follicle. These cysts are observed on the scalp most commonly in females. The occurrence of trichilemmal cysts in areas other than the scalp is extremely rare. We report a case of an 80-year-old female with trichilemmal cyst of the breast which was first misdiagnosed as a sebaceous cyst because of the unusual disease site and our unfamiliarity with the disease. The patient underwent excision of cyst along with the cyst wall and histopathological diagnosis was trichilemmal cyst of the breast. A review of literature shows that trichilemmal cyst of the breast is an extremely rare condition which accounts for 0.1 % of the skin biopies reported till to date. We report a case of trichilemmal cyst of the breast with relevant discussion on trichilemmal cysts.

Primary Neuroendocrine Carcinoma of Breast.

Neuroendocrine differentiation can be identified in a subset of human breast carcinomas, either as scattered cells or as a predominant neuroendocrine component. Clinically, there are no notable or specific differences in presentation from other type of breast tumors. The diagnosis of neuroendocrine breast carcinoma relies mainly on histopathological examination and immunohistochemistry marker study. Treatment modalities are not different from those for the other conventional types. We report a case of primary neuroendocrine carcinoma of breast with relevant discussion on neuroendocrine tumor.

Clinical Presentation, Management and Outcome in Diverticular Colovesical Fistulas - Our Experience.

Colovesical fistula (CVF) is an abnormal communication between the urinary bladder and the large intestine, usually sigmoid colon. Diverticulitis is the most common cause of CVF in most of the western studies, accounting for approximately 70% of cases. Diverticular CVF is uncommon in Asia. This case series shares the experience of six cases of diverticular CVF in Indian population. METHODSMedical records of six patients with diverticular colovesical fistulas during the period January 2016 - August 2019 were reviewed with regard to symptoms, diagnostic investigations, and management. Various aspects of the disease were analysed to determine the common features of colovesical fistula in our population. RESULTSAll patients with diverticular colovesical fistula were presented with urinary symptoms and none were aware about their existing colonic diverticulosis. Five out of the six cases presented with pneumaturia. Contrast enhanced computed tomography (CECT) abdomen detected sigmoid diverticulosis with vesical fistula in all cases. The most common site of fistula found on cystoscopy was on the left superolateral wall of bladder. All cases were operated as a single stage procedure including fistula repair, colonic resection, omental interposition with no temporary colostomy which provided an excellent surgical cure. CONCLUSIONSColovesical fistula secondary to diverticular disease has shown a rising incidence and can be effectively managed by a multidisciplinary team. It requires prompt diagnosis, adequate preoperative evaluation, perioperative care including bowel preparation, nutritional supplementation, appropriate antibiotics, and meticulous surgical skills allowing an elective one-stage approach.

A Study of Comparison between DJ Stenting and Silodosin after Ureteroscopic Lithotripsy for Mid and Lower Ureteric Calculus.

Ureteric calculi are known to affect approximately 10 – 15% of the overall population. We wanted to determine as to whether silodosin can be used instead of DJ stenting in patients with uncomplicated ureteroscopic lithotripsy.METHODSWe selected 60 patients who underwent ureteroscopic lithotripsy (URSL) in the study group. They were divided into ‘stented group’ and ‘non-stented group on silodosin’. Patients with stone of 5 to 18 mm size with no intraoperative mucosal injury and no stricture were included in the study. All patients underwent surgery using an 8/9.8 Fr rigid ureteroscope, without ureteral dilation, with lithotripsy using an electro-hydraulic lithotripter, without extraction. A 4.5 Fr Double J stent was placed in the first group for three to four weeks. The patients underwent urine routine examination, plain x-ray KUB, and ultrasound abdomen before and after lithotripsy. Lower urinary tract symptoms and pain scores were recorded on 3, 7 and 15 days postoperatively. We compared mean operative time, emergency visits, rehospitalisation rates, and residual fragments between each group.RESULTSOut of 60 patients, 53.3% of patients had lower ureteric calculus, 30% had mid ureteric, and 16.7% had calculus at vesicoureteric junction. The mean calculus size on the left side was 10.23 mm, and on the right side was 10.33 mm. The mean intraoperative time was 33.23 minutes in stented and 29.9 minutes in the silodosin group (p< 0.003). Patients underwent assessment for flank pain, fever, and LUTS on postoperative days (POD) 3, 7 and 15. There was no statistically significant difference between the two groups though patients with DJ stent had more symptoms on inquiry. A total of 5 patients in the treatment groups were re-hospitalised, two patients (6.7%) in the stented group, and three patients (10%) in the silodosin group, out of which three patients (5%) required a secondary procedure which was not statistically significant. Three subjects treated with silodosin and 12 with the DJ stent in situ had residual fragments on POD 21 which was statistically significant (p 0.27).CONCLUSIONSPatients with uncomplicated URSL have similar recovery of renal function when treated with silodosin as compared to the placement of DJ stent. Treatment without stent with silodosin also has less irritative LUTS. We conclude that silodosin can be an alternative to DJ stent after uncomplicated ureteroscopic electrohydraulic lithotripsy, thereby reducing operative time and patient morbidity.

Fournier’s gangrene following retrograde urethrography: a rare complication

Retrograde urethrography (RGU) is a useful investigation to look for urethral injuries. It can result in various complications like anaphylaxis due to contrast material, urinary tract infection and intravasation or extravasation of contrast. In this case report, a rare complication of RGU was seen in the form of Fournier’s gangrene. This complication was probably due to extravasation of contrast material during the procedure which lead to reactionary changes of the penile skin and scrotum. Patient was managed aggressively and had a good recovery and is on regular follow up.