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Formamidinium lead iodide perovskites are promising light-harvesting materials, yet stabilizing them under operating conditions without compromising optimal optoelectronic properties remains challenging. We report a multimodal host–guest complexation strategy to overcome this challenge using a crown ether, dibenzo-21-crown-7, which acts as a vehicle that assembles at the interface and delivers Cs + ions into the interior while modulating the material. This provides a local gradient of doping at the nanoscale that assists in photoinduced charge separation while passivating surface and bulk defects, stabilizing the perovskite phase through a synergistic effect of the host, guest, and host–guest complex. The resulting solar cells show power conversion efficiencies exceeding 24% and enhanced operational stability, maintaining over 95% of their performance without encapsulation for 500 h under continuous operation. Moreover, the host contributes to binding lead ions, reducing their environmental impact. This supramolecular strategy illustrates the broad implications of host–guest chemistry in photovoltaics. It remains a challenge to achieve a balance between performance and stability, as well as addressing the environmental impact of perovskite solar cells. Here, the authors propose a multimodal host-guest complexation strategy enabling these shortcomings to be addressed simultaneously.

Cost management and toxic waste generation are two key issues that must be addressed before the commercialization of perovskite optoelectronic devices. We report a groundbreaking strategy for eco-friendly and cost-effective fabrication of highly efficient perovskite solar cells. This strategy involves the usage of a high volatility co-solvent, which dilutes perovskite precursors to a lower concentration (<0.5 M) while retaining similar film quality and device performance as a high concentration (>1.4 M) solution. More than 70% of toxic waste and material cost can be reduced. Mechanistic insights reveal ultra-rapid evaporation of the co-solvent together with beneficial alteration of the precursor colloidal chemistry upon dilution with co-solvent, which in-situ studies and theoretical simulations confirm. The co-solvent tuned precursor colloidal properties also contribute to the enhancement of the stability of precursor solution, which extends its processing window thus minimizing the waste. This strategy is universally successful across different perovskite compositions, and scales from small devices to large-scale modules using industrial spin-coating, potentially easing the lab-to-fab translation of perovskite technologies. A universal strategy is reported for formation of very low concentration of perovskite precursor inks that yields high-efficiency photovoltaics while substantially reducing toxic waste generation, fabrication cost and process complexity, thus taking a step closer towards commercialization.

The presence of defects at the interface between the perovskite film and the carrier transport layer poses significant challenges to the performance and stability of perovskite solar cells (PSCs). Addressing this issue, we introduce a dual host-guest (DHG) complexation strategy to modulate both the bulk and interfacial properties of FAPbI 3 -rich PSCs. Through NMR spectroscopy, a synergistic effect of the dual treatment is observed. Additionally, electro-optical characterizations demonstrate that the DHG strategy not only passivates defects but also enhances carrier extraction and transport. Remarkably, employing the DHG strategy yields PSCs with power conversion efficiencies (PCE) of 25.89% (certified at 25.53%). Furthermore, these DHG-modified PSCs exhibit enhanced operational stability, retaining over 96.6% of their initial PCE of 25.55% after 1050 hours of continuous operation under one-sun illumination, which was the highest initial value in the recently reported articles. This work establishes a promising pathway for stabilizing high-efficiency perovskite photovoltaics through supramolecular engineering, marking a significant advancement in the field. The defects at the perovskite/carrier transport layer interface pose significant challenges to the performance of perovskite solar cells. Here, the authors introduce a dual host-guest complexation strategy with Cs-crown-ether and ammonium salt, achieving a high PCE of 25.9% with superior stability.

This paper investigated the fretting failure of axial thrust steel bearings as per ASTM 4170 in the presence of anti-fretting pastes used in process industries. The pastes were differentiated based on the content of additives in them. The results indicated that the paste containing the additive package of copper, molybdenum disulfide, and graphite exhibited excellent anti-fretting properties (75–80% less bearing race mass loss) as compared with other lubricating pastes that contained only graphite/molybdenum disulfide and nickel as primary additives. There was less surface damage to the bearing races in the lubricating paste containing copper, graphite, and molybdenum disulfide. The machine vision images of the false brinelling indicated that the average area of false brinelling on the bearing races with the paste containing copper, molybdenum disulfide, and graphite was 2.537 ± 0.623 mm2, while that of the other pastes containing graphite/molybdenum disulfide and nickel as primary additives were 4.504 ± 0.566 mm2 and 4.914 ± 0.621 mm2, respectively, indicating 50% less false brinelling area in the paste containing copper, molybdenum disulfide, and graphite as compared with the paste containing graphite/molybdenum disulfide and nickel. An asymmetric wear pattern was also observed in the thrust bearings used during the tribo test. Surface characterizations indicated the formation of wear debris, plastic deformations, and surface cracks during the tribo tests. The physico-chemical properties of the lubricating pastes such as the viscosity and work penetration properties played an important role in controlling the failure of the bearings due to fretting.

Background The incidence of inguinal hernia in the pediatric population is 0.8–4.4% with a male to female ratio of 5:1.The reported incidence of sliding hernia containing an ovary in female infants and children is 15–20%.The complete androgen insensitivity syndrome occurs in 1–2% of girls with an inguinal hernia. Thus, the incidence of CAIS in females with hernias and palpable gonads is 4/1,000,000. Results This is a retrospective analysis of 694 children that had undergone inguinal hernia repair in last 11 years. Out of these, 123 were females, 36 cases had palpable gonads at the time of presentation. FISH analysis was done in 29 cases (80%). None of the cases showed the presence of the Y chromosome. An abnormal chromosomal pattern was seen in one case on complete karyotyping. Conclusion The reported incidence of CAIS in girls with inguinal hernia is low, thus subjecting every girl child with inguinal hernia to undergo karyotyping is distressing for the parents. FISH analysis is an effective screening modality to rule out CAIS in girls with an inguinal hernia. Thus, it is recommended to screen only high-risk cases with palpable gonads at presentation.

Background Congenital perineal hernia is an extremely rare entity with only 10 cases having been reported in literature. We report a newborn with exposed bowel loops coming out through a defect in the perineum to the right of the median raphe and propose the term perineoschisis for this abnormality. The exposed bowel loops were a sequestered segment of colon. The baby also had extreme perineal hypospadias and left undescended testis. Case presentation A term neonate, born of caesarean section, was noted at birth to have exposed bowel loops visible in the perineum. The bowel loops were not covered by any membrane. To avoid injury to the exposed bowel loops and setting in of infection, the baby was taken up for emergency surgery. At laparotomy, the bowel loops were traced from duodeno–jejunal junction to ileocecal junction and sigmoid colon and rectum. No loops were seen herniating outside from the abdomen through the perineum opening. The extruded bowel loops were sequestered and ending blindly close to the rectum. The sequestered bowel loops were excised completely and perineum reconstruction was done. Conclusion The extruded bowel loops would appear to be a form of colonic duplication with the duplicated colonic loops herniating outside through an opening in the perineum. Since the bowel loops were lying to the right of median raphe and were not covered by hernia sac or any other membrane we propose the term perineoschisis for this abnormality. The baby also had extreme hypospadias with a perineal meatus, bifid scrotum and penoscrotal transposition. This association of herniated duplicated colon with extreme hypospadias is hitherto unreported to the best of our knowledge.

We report a rare case of a 3-year-old male child with scapular bronchogenic cyst. The cyst was excised because of associated pain and discharge from the swelling. Till date, 64 cases of cutaneous bronchogenic cyst have been reported in the literature. Only 12 of these patients had lesion located in periscapular area. The treatment is surgical as it can undergo malignant transformation.

Paraesophageal hiatus hernia (PEHH) is an uncommon type of diaphragmatic hernia in the pediatric age group. Two patients aged 5-months and 8-months presented with respiratory symptoms and underwent a laparoscopic repair. Preoperative assessment included chest x-ray and CT scan. We suggest that laparoscopic repair of PEHH in infants is safe and preferred mode of the treatment.

We report a rare case of a 3-year-old male child with scapular bronchogenic cyst. The cyst was excised because of associated pain and discharge from the swelling. Till date, 64 cases of cutaneous bronchogenic cyst have been reported in the literature. Only 12 of these patients had lesion located in periscapular area. The treatment is surgical as it can undergo malignant transformation.