Development of Lightweight and Flexible Perovskite Solar Cells on Ultrathin Colorless Polyimide Foils.

The development of Perovskite Solar Cells (PSCs) on flexible substrates marks a significant advancement in thin-film photovoltaic technology. However, current state-of-the-art research predominantly utilizes Poly(ethylene terephthalate) (PET) substrate, which limits the deployment to less challenging environments. To address this limitation, we explore the fabrication of inverted PSCs on colorless polyimide (CPI) substrates that can withstand harsh environmental conditions. We employed a sequential sputtering technique to deposit indium tin oxide (bottom electrode) and nickel oxide (hole transport layer) as a base stack for the perovskite. This base layer was further enhanced by incorporating MeO-2PACz into the hole transport bilayer, significantly improving the NiOx interface, and thereby enhancing the efficiency of the devices. The PSCs fabricated on CPI demonstrated a power conversion efficiency (PCE) of 15.52% and a remarkable power-to-weight ratio (PWR) of 4.39 W/g, which is five times higher than that of devices on PET (0.87 W/g). Moreover, the active stack developed in this study can be used on any transparent substrate, showing its broader application potential.

Light-Stable Methylammonium-Free Inverted Flexible Perovskite Solar Modules on PET Exceeding 10.5% on a 15.7 cm2 Active Area.

Perovskite solar modules (PSMs) have been attracting the photovoltaic market, owing to low manufacturing costs and process versatility. The employment of flexible substrates gives the chance to explore new applications and further increase the fabrication throughput. However, the present state-of-the-art of flexible perovskite solar modules (FPSMs) does not show any data on light-soaking stability, revealing that the scientific community is still far from the potential marketing of the product. During this work, we demonstrate, for the first time, an outstanding light stability of FPSMs over 1000 h considering the recovering time (T80 = 730 h), exhibiting a power conversion efficiency (PCE) of 10.51% over a 15.7 cm2 active area obtained with scalable processes by exploiting blade deposition of a transporting layer and a stable double-cation perovskite (cesium and formamidinium, CsFA) absorber.

Venoatrial shunt-assisted cavopulmonary anastomosis.

The bidirectional Glenn shunt operation is conventionally performed under cardiopulmonary bypass. Between June 2007 and September 2009, 218 consecutive patients underwent off-pump bidirectional Glenn shunt institution for single ventricle with pulmonary stenosis complex. Their mean age was 4.72 ± 1.80 years (range, 4 months to 6 years) and median weight was 10.12 kg (range, 4.1-19 kg). A temporary shunt was created between the innominate vein and the right atrium, with a 3-way connector for de-airing. Fifty-five patients had bilateral cavae. The mean internal jugular venous pressure on clamping the superior vena cava was 24.69 ± 1.81 mm Hg. Continuous end-tidal CO2 and O2 saturation were monitored. Adequate oxygen saturation and blood pressure were maintained by optimizing inotropics, volume, and inspired oxygen. The mean duration of ventilation was 10.17 ± 8.96 h (range, 1-73 h). There were no gross neurological complications. Postoperative pleural effusion developed in 6 (2.75%) patients, and 4 (1.83%) had nodal rhythm. Four (1.83%) patients died in the immediate postoperative period due to low cardiac output syndrome. Venoatrial shunt-assisted bidirectional Glenn shunt surgery can be performed safely by optimizing intraoperative management strategies. It is economical and avoids the deleterious effects cardiopulmonary bypass.

Veno-venous shunt-assisted cavopulmonary anastomosis.

OBJECTIVE: The bidirectional Glenn shunt is commonly performed under cardiopulmonary bypass for conditions that lead to a single ventricle repair. We report our experience of bidirectional Glenn shunt done without cardiopulmonary bypass. METHODS: Between June 2007 and May 2009, 186 consecutive patients underwent off-pump bidirectional Glenn shunt for a variety of complex cyanotic congenital heart defects. Age ranged from four months to six years and the median weight was 11.17 kg (range 4.3 - 18). After systemic heparinization, the procedure was done by creating a temporary shunt between the innominate vein and the right atrium connected across a three way connector for de-airing. Fifty one patients had bilateral cavae. All cases underwent complete clinical neurological examination. RESULTS: No case required conversion onto cardiopulmonary bypass. Four patients (2.14%) died in the immediate postoperative period. The mean internal jugular venous pressure on clamping the decompressed superior vena cava was 24.69 +/- 1.81 mm Hg. There was no intra-operative hemodynamic instability and oxygen saturation was maintained at more than 70% throughout. Post Glenn shunt, the saturations improved to mid 80s. Seventy four cases had documented forward flow across the pulmonary valve. The mean duration of ventilation was 10.17 +/- 8.96 hours and there were no neurological complications. Six patients (3.22%) developed pleural effusions, 4 patients (2.15%) had nodal rhythm and 9 patients (4.83%) had superficial sternal wound infection. CONCLUSIONS: Our results show that off-pump bidirectional Glenn shunt can be done safely in patients not requiring associated intra-cardiac correction. It avoids cardiopulmonary bypass and its related complications, is economical and associated with excellent results. In our opinion, this is the largest series of off-pump bidirectional Glenn shunt in the literature.

Sternotomy approach for modified Blalock-Taussig shunt: is it a safe option?

Central aorta-pulmonary artery shunts have fallen into disfavor because of shunt thrombosis and congestive heart failure, and a modified Blalock-Taussig shunt via thoracotomy can lead to pulmonary artery hypoplasia and distortion. We reviewed the outcomes of a modified Blalock-Taussig shunt by a sternotomy approach in 20 infants from July 2007 to October 2009. Their mean age was 5.79 months, and median weight was 5.4 kg. A 4-mm graft was placed in 11 patients, a 5-mm graft in 8, and a 3.5-mm graft in 1. There was no incidence of sepsis, seroma, or phrenic nerve palsy. There was one hospital death. The mean hospital stay was 10.4 +/- 4.3 days (range, 8-15 days). The mean oxygen saturation at discharge was 89% (range, 81%-93%). The sternotomy approach is technically easier to perform, cosmetically preferable, and probably hemodynamically superior. Correction of branch pulmonary stenosis is easily incorporated into this procedure. The theoretical disadvantage of this method is a potential technical difficulty with sternal reentry for subsequent procedures.

Primary leiomyosarcoma of the breast: A case report and review of literature.

Leiomyosarcomas of the breast are rare tumours. Only 18 such cases have been reported in the literature so far. We describe herein a case of primary leiomyosarcoma of the breast in a 54-year-old woman whose preoperative clinical and cytological findings indicated a benign breast tumour. However, a core needle biopsy of the lesion showed malignant spindle cells without any ductal elements. Histopathological examination of the mastectomy specimen suggested a diagnosis of leiomyosarcoma, which was subsequently confirmed by immunohistochemical analysis. Primary leiomyosarcoma of the breast is very rare and is difficult to diagnose preoperatively as it needs immuno-histochemical staining. It is necessary to excise the tumour with sufficient margins to prevent local recurrence. The role of postoperative adjuvant chemotherapy is not well documented.

Experiences with carotid endarterectomy at Sree Chitra Tirunal Institute.

BACKGROUND: Atherosclerotic carotid artery disease poses a grave threat to cerebral circulation, leading to a stroke with its devastating sequelae, if left untreated. Carotid endarterectomy has a proven track record with compelling evidence in stroke prevention. OBJECTIVES: a) To confirm that carotid endarterectomy (CEA) is safe and effective in preventing stroke at both short and long term. b) to demonstrate long term patency of internal carotid artery when arteriotomy repair is performed using autologous saphenous vein patch. MATERIALS AND METHODS: During ten years, from September 1997 to February 2008, thirty nine patients who underwent consecutive carotid endarterectomy at our institute, form the basis of this report. Their age ranged from thirty to seventy eight years, with a mean age of 56. There were four women in this cohort. Thirty seven patients were symptomatic with >70% stenosis and two were asymptomatic with >80% stenosis, incidentally detected. Imaging included Duplex scan and MRA for carotid territory and brain, and non-invasive cardiac assessment. Co-morbidities included smoking, hypertension, diabetes, and coronary artery disease. Carotid Endarterectomy was performed under general anaesthesia, using carotid shunt and vein patch arteriotomy repair. RESULTS: All the patients made satisfactory recovery, without major adverse cerebral events in this series. Morbidities included Transient Ischemic Attack (TIA) in two, needing only medications in one, and carotid stenting in the other. Minor morbidities included neck hematoma in two and transient hypoglossal paresis in three patients. Yearly follow-up included duplex scan assessment for all the patients. Two patients died of contralateral stroke, two of myocardial events and two were lost to follow up. Thirty three patients are well and free of the disease during the follow up of three to 120 months. CONCLUSION: Carotid endarterectomy provided near total freedom from adverse cerebral events and its catastrophic sequelae, leading to excellent outcome, both short as well as long term.

Role of eradication of Cag A Helicobacter pylori in non ulcer dyspepsia.

The role of Helicobacter pylori (H.pylori) in patients with non ulcer dyspepsia (NUD), the relationship of the virulence of the organism to the occurrence and severity of NUD and the need for eradication of H. pylori in alleviating symptoms of NUD remain controversial. This study was carried out for the purpose of determining the interaction between virulent H.pylori and symptoms of NUD and to clarify whether H. pylori eradication is beneficial in-patients with NUD. Sixty consecutive patients who fulfilled standard criteria for the diagnosis of NUD and who were positive H. pylori status by the urease test were studied. NUD was classified into ulcer-like and dysmotility-like as per standard criteria. All patients were treated with a triple drug regimen for H. pylori for 10 days, which consisted of Clarithromycin, Amoxicillin and Omeprazole. Blood was drawn for IgG antibodies against Cag A strains and H. pylori by ELISA. All patients were evaluated at 6 months for symptomatic improvement, which was, correlated with Cag A H. pylori positive status. No significant difference was seen in the H. pylori Cag A prevalence between ulcer-like and dysmotility-like dyspepsia. While there was a trend towards a better symptomatic improvement with H.pylori eradication in patients with ulcer-like NUD as opposed to dysmotility-like NUD, this did not reach significance (73% vs. 57%, p= 0.18). However "there was a statistically significant benefit of eradication of H. pylori in-patients with ulcer-like NUD who were positive for Cag A H.pylori status (p=0.02). No such benefit was seen in-patients with dysmotility-like NUD. H. pylori eradication seems to confer significant benefit as regards symptomatic relief inpatients with ulcer like NUD who are positive for Cag A strain for H. pylori.