Flexible Copper Films Modification via Spontaneous Reduction of Aryldiazonium Gold Salts: Unraveling Surface Properties and Energy Profile.

In this study, we report the modification of flexible copper films via the spontaneous reduction of aryldiazonium gold salts [X-4-C6H4N≡N]AuCl4 (X═COOH, NO2). The electroless modification involves dipping of flexible copper films in the aryldiazonium gold solutions for a few seconds, under ambient conditions, followed by a washing step with deionized water to obtain a mechanically robust gold-aryl coating. The chemical composition, morphology, electronic structure, and optical properties of the gold-aryl layer and the flexibility of the modified copper films are supported by the results from X-ray photoelectron spectroscopy (XPS), electrochemistry, contact angle, scanning electron microscopy (SEM), and ultraviolet photoelectron spectroscopy (UPS). XPS surface analysis showed metallic gold in addition to C-C, C-O/C-N, and C═O functional groups from the grafted aryls. Cu 2p showed metallic copper as a major component and a small amount of Cu(II) ions. Wettability studies showed that Au-COOH@Cu increased the contact angle of the bare copper films from 68.0 ± 0.7° to 82.0° ± 0.7°, while Au-NO2@Cu increased the contact angle to 134.0° ± 0.3°. UPS energy profile analysis of [HOOC-4-C6H4N≡N]AuCl4 (valence band maximum = 1.91 eV) exhibited greater reducibility than [O2N-4-C6H4N≡N]AuCl4 (valence band maximum = 2.91 eV). The lower ionization potential of [HOOC-4-C6H4N≡N]AuCl4 (IP = 4.33 eV) enhanced the reactivity upon copper film contact, potentially inducing efficient energy level alignment, compared with [O2N-4-C6H4N≡N]AuCl4 (IP = 5.62 eV). UPS results were further supported by electrochemistry investigation which revealed that [HOOC-4-C6H4N≡N]AuCl4 is easily reducible compared with [O2N-4-C6H4N≡N]AuCl4. The findings presented here hold significant implications for developing flexible copper films and pave the way for future advancements in electronic material modification for industrial applications.

Impact of Graphene Oxide on SERS Enhancement of Arylated Gold Nanospheres: Mechanistic Insight.

The performance of gold nanospheres as substrates for surface-enhanced Raman spectroscopy (SERS) investigation has been compromised by their low adsorption efficiency, high colloidal dispersibility, and diminishing hot spots. However, gold nanosphere substrates modified using aryldiazonium gold(III) chemistry via durable gold-carbon bonds are promising for SERS enhancement due to their controlled organic layer density. In this study, arylated gold nanospheres AuNSs-COOH have shown SERS enhancement when incorporated into graphene oxide (GO) to form nanocomposites (NCs) labeled AuNSs-COOH/GO (AuNCs). Our investigation using X-ray photoelectron spectroscopy (XPS) surface analysis showed that the gold-aryl nanospheres reached their maximum SERS enhancement with an optimal coating. The evaluation included the Au 4f chemical environment and compact graphitic layers for the SERS substrate optimization. The fabricated AuNC substrates demonstrated superior efficiency and reproducibility. A broad linear range of 10-3-10-7 M 4-nitrophenol detection was obtained with exceptional repeatability, as evidenced by the relative standard deviation (RSD) of 9.32%. A detailed investigation of the energy profiles, particularly the valence band maximum (VBM) and band gap values of the substrate and analyte, depicted the electromagnetic (EM) and charge-transfer-induced enhancement and the role of GO inclusion in substrate efficiency in SERS enhancement mechanisms. The finite-difference time domain (FDTD) simulation results revealed that AuNCs incorporated with graphitic nanostructures exhibited the most substantial SERS effect through an EM field enhancement mechanism. This study demonstrated significant SERS enhancement using gold-aryl nanospheres when modified with GO, in contrast to the typical reliance on anisotropic nanostructures.

Comparison of perioperative surgical outcomes following total robotic and total laparoscopic Roux-en Y hepaticojejunostomy for choledochal cyst in paediatric population: a preliminary report from a tertiary referral centre.

PURPOSE: There is a paucity of data regarding the comparison of robotic and laparoscopic hepaticojejunostomy (HJ) for the treatment of paediatric choledochal cysts. Thus, our primary objective was a comparison of early complications namely post-operative bleeding, anastomotic leak, intestinal obstruction and the need for reoperation in both techniques. Our secondary objectives included a comparison of the mean time for surgery and HJ, conversion of procedure to open, intraoperative blood loss, late complications like cholangitis, stricture and post-operative outcomes like time to start oral feeds and length of post-operative stay. METHODS: A retrospective data analysis of all children who underwent laparoscopic and robotic choledochal cyst excision with Roux-en-Y HJ from 2008 to 2021 was performed. RESULTS: Ninety patients were classified into Group R (robotic HJ), n = 20 and Group L (laparoscopic HJ), n = 70. Post-operative complications were comparable amongst groups R and L (2 vs 6; p = 1 and 1 vs 2, p = 0.53, respectively). Intraoperative blood loss was significantly less in group R (54.8 ± 13.5 ml vs 64.1 ± 17.3 ml; p = 0.0280). The mean time to complete HJ was significantly less in group R (58 ± 12 min vs 71 ± 11 min; p < 0.001) while the mean time to complete surgery was significantly more in Group R (284 ± 14 min vs 195 ± 18 min; p < 0.001). CONCLUSION: Our preliminary research report suggests overall comparable early complications in both groups.

Seaweed Sargassum wightii mediated preparation of zirconia (ZrO2) nanoparticles and their antibacterial activity against gram positive and gram negative bacteria.

In the present study, a facile and green combustion method has been optimized for the synthesis of zirconia (ZrO2) nanoparticles using marine brown alga (seaweed), Sargassum wightii (S. wightii). Structural, optical and photoluminescence properties of the prepared ZrO2 nanoparticles were studied using XRD, FTIR, HR-TEM, UV-vis and PL spectroscopy. The average grain size of the nanoparticles calculated from the XRD pattern was around 4.8 nm which exhibits tetragonal structure. TEM results showed that the synthesized nanoparticles were uniformly monodispersed without aggregation. Formation of zirconia nanoparticles were confirmed by FTIR studies. The PL spectra exhibit broad emission peaks at the interface of UV and visible regions which can be assigned to the ionized oxygen vacancy in the material. Antibacterial activity of the synthesized zirconia nanoparticles was studied against gram positive and gram negative bacterial strains using agar well diffusion method. The prepared zirconia nanoparticles show significant antibacterial effect against Bacillus subtilis, Escherichia coli and Salmonella typhi due to their large surface area by their nanosize.

Laparoscopic central pancreatectomy: Our technique and long-term results in 14 patients.

INTRODUCTION: Conventional pancreatic resections may be unnecessary for benign tumours or for tumours of low malignant potential located in the neck and body of pancreas. Such extensive resections can place the patient at increased risk of developing postoperative exocrine and endocrine insufficiency. Central pancreatectomy is a plausible surgical option for the management of tumours located in these locations. Laparoscopic approach seems appropriate for such small tumours situated deep in the retroperitoneum. AIMS: To assess the technical feasibility, safety and long-term results of laparoscopic central pancreatectomy in patients with benign and low malignant potential tumours involving the neck and body of pancreas. SETTINGS AND DESIGN: This study was an observational study which reports a single-centre experience with laparoscopic central pancreatectomy over a 9-year period. MATERIALS AND METHODS: 14 patients underwent laparoscopic central pancreatectomy from October 2004 to September 2013. These included patients with tumours located in the neck and body of pancreas that were radiologically benign-looking tumours of less than 3 cm in size. STATISTICAL ANALYSIS USED: The statistical analysis was done using GraphPad Prism software. RESULTS: The mean age of patients was 48.93 years. The mean operative time was 239.7 min. Mean blood loss was 153.2 ml. Mean postoperative ICU stay was 1.2 days and overall mean hospital stay was 8.07 days. There were no mortalities and no major postoperative complications. Margins were negative in all cases and with a median follow-up of 44 months, there was no recurrence. CONCLUSIONS: Laparoscopic central pancreatectomy is a feasible procedure with acceptable morbidity. In the long term, there were no recurrences and pancreatic function was well preserved.

A Curious Case of Methemoglobinemia Complicating a Pediatric Live Donor Liver Transplantation Surgery.

BACKGROUND: Pediatric live donor liver transplantation (LDLT) surgery is by itself a complicated surgery. Added to the difficulty in the operative technique are the complex preoperative work-up, optimization, and postoperative treatment. Intraoperative events and immediate postoperative recovery are important in graft function and the patient's overall recovery. Intraoperative greenish-blue urine and hypoxia are seldom seen during this period in the case of LDLT. Knowing the differential diagnosis and treatment are of predominant importance. METHODS: A case of decompensated chronic liver disease due to Wilson's disease underwent routine LDLT. Here we describe an uncommon complication, methemoglobinemia, which complicated this patient's recovery. The case is presented for the condition's rarity and the confusing clinical picture it produced. RESULTS: Observations of greenish-blue urine, ascites, serum, gastric aspirate, bile, maroon or brown-colored blood, and hypoxia with normal PaO2 were made in this case. Timely diagnosis of suspected drug-induced methemoglobinemia and treatment, which led to the uneventful recovery of the patient, are explained. CONCLUSION: Even though methemoglobinemia does not have a direct graft effect, it can affect the graft oxygen perfusion and the overall oxygenation of the postoperative patient, causing adverse impacts if not detected and treated promptly. No such association of methemoglobinemia with Wilson's disease or during transplantation has been reported in the literature so far.

Liver Transplant Society of India Guidelines for Liver Transplant During COVID-19 times.

Coronavirus disease-2019 (COVID-19) pandemic has affected liver transplantation in many ways. There is risk of infection to the transplant recipients; and COVID-19 is associated with significant risk of mortality in patients on wait list. The Liver Transplant Society of India (LTSI) has prepared guidelines regarding selection of adult and pediatric patients for liver transplantation, transplant for acute liver failure, use of deceased donor organs, transplant techniques and minimally invasive donor hepatectomy, pre- and postsurgery testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related coronavirus disease 2019 in donors and recipients, role of COVID-19 antibody testing, shifting of recipients from COVID-19 to non-COVID-19 areas after recovery, isolation policy of team members exposed to COVID-19 patients, drug therapy of proven or suspected COVID-19 infection early posttransplant, care of SARS-CoV-2 positive donors and recipients and a separate COVID-19 consent for surgery.

Green synthesis of copper oxide nanoparticles and mosquito larvicidal activity against dengue, zika and chikungunya causing vector Aedes aegypti.

In the present study, high purity copper oxide nanoparticles (NPs) were synthesised using Tridax procumbens leaf extract. Green syntheses of nano-mosquitocides rely on plant compounds as reducing and stabilising agents. Copper oxide NPs were characterised using X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR), Field-emission scanning electron microscopy with energy dispersive spectroscopy, Ultraviolet-visible spectrophotometry and fluorescence spectroscopy. XRD studies of the NPs indicate crystalline nature which was perfectly matching with a monoclinic structure of bulk CuO with an average crystallite size of 16 nm. Formation of copper oxide NPs was confirmed by FT-IR studies and photoluminescence spectra with emission peaks at 331, 411 and 433 nm were assigned to a near-band-edge emission band of CuO in the UV, violet and blue region. Gas chromatography-mass spectrometry studies inferred the phytochemical constituents of the leaf extract. Larvicidal activity of synthesised NPs using T. procumbens leaf extract was tested against Aedes aegypti species (dengue, chikungunya, zika and yellow fever transmit vector).

Laparoscopic Major Hepatectomy-Technique and Outcomes.

BACKGROUND: With technological innovations especially newer parenchymal transection devices, improved understanding of hepatic anatomy facilitated by better imaging, and reconstructions along with experiences gained from advanced minimal invasive procedures, laparoscopic liver surgery is gaining momentum with more than 5300 reported cases worldwide. Most of the published literature comprises nonanatomical and segmental resections with only few case series having major hepatic resections performed by minimally invasive approach. Aim of this article is to share our technique and experience of total laparoscopic major hepatectomy. METHODS: It is a retrospective analysis of prospectively maintained database of 56 patients, who underwent laparoscopic major hepatectomy for various indications during 2001 to 2013. RESULTS: Of 56 patients operated, 37 had malignant disease and 19 had benign lesions with mean size of 6.0 ± 2.8 cm. Thirty-four patients underwent right hepatectomy and 22 left with mean age of 54.8 ± 15.3 years. Mean operating time was 227.4 ± 51.8 min with mean blood loss 265.5 ± 143.4 ml and transfusion needed in 10.7 %. Pringle's maneuver was used in 19.6 % with mean occlusion time of 34.0 ± 11.4 min. Liver-specific complications were observed in 12.5 % and overall complications in 19.6 %. Mean resection margin length in malignant lesions was 2.1 ± 0.9 cm, with <1 cm margin noted in 5.4 %. Median hospital stay was 8 days (6-29) with readmission rate of 8.9 %, re-intervention rate of 5.3 % and 90 days mortality of 1.7 %. CONCLUSION: Laparoscopic major liver resection is a formidable task. It requires considerable expertise in both, advanced laparoscopy, and liver surgery. It can be feasible, safe, and oncologically adequate in well-selected cases in experience hands.