Effect of Topical Silver Nanoparticle Formulation on Wound Bacteria Clearance and Healing in Patients With Infected Wounds Compared to Standard Topical Antibiotic Application: A Randomized Open-Label Parallel Clinical Trial.

BACKGROUND: Infected wounds pose a special challenge for management, with an increased risk of wound chronicity, systemic infection, and the emergence of antibiotic resistance. Silver nanoparticles have multimodal effects on bacteria clearance and wound healing. This study aimed to document the efficacy of a topical silver nanoparticle-based cream on bacteria clearance and wound healing in infected wounds compared to Mupirocin. METHODS: This open-label parallel randomized clinical trial allocated 86 participants with infected wounds (culture-positive) into Kadermin, silver nanoparticle-based cream arm (n=43) and Mupirocin arm (n=43) and documented the swab culture on day 5 and wound healing at day 28, along with periodic wound status using the Bates-Jensen Wound Assessment Tool. Patients received oral/systemic antibiotics and other medications for underlying diseases. The intention-to-treat principle was adopted for data analysis using the chi-square and Student t tests to document the differences between groups according to variable characteristics. RESULTS: All participants completed the follow-up. On day 5, wound bacteria clearance was observed in 86% and 65.1% of the participants in the Kadermin and Mupirocin arms, respectively (p=0.023). At day 28, complete wound healing was observed in 81.4% and 37.2% of the participants in the Kadermin and Mupirocin arms, respectively (p≤0.001). No local or systemic adverse event or local reaction was observed in any of the participants. CONCLUSION: Kadermin, the silver nanoparticle-based cream, has better efficacy in achieving faster wound bacteria clearance and healing in infected wounds compared to Mupirocin. This may have relevance for its use as an antibiotic-sparing agent in wound management.

Lumacaftor as a potential repurposed drug in targeting breast cancer stem cells: insights from in silico study.

CONTEXT: Breast cancer stem cells (BCSCs) are a small subset of cells within breast tumors with characteristics similar to normal stem cells. Despite advancements in chemotherapy and targeted therapy for breast cancer, the prognosis for breast cancer patients has remained poor due to drug resistance, reoccurrence, and metastasis. Growing evidence suggests that deregulation of the self-renewal pathways, like the Wnt signaling pathway mediated by ß-catenin, plays a crucial role in the survival of breast cancer stem cells. Targeting the Wnt signaling pathway in breast cancer stem cells offers a promising avenue for developing effective therapeutic strategies targeting these cells, potentially leading to improved patient outcomes and reduced tumor recurrence. METHODS: For this purpose, we have screened a 1615 FDA-approved drug library against our target protein, ß-catenin, which is involved in the Wnt signaling pathway using molecular docking analysis, molecular dynamics (MD) simulations, and molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations. RESULTS: Molecular docking studies showed that the Lumacaftor- ß-catenin complex had the lowest docking score of - 8.7 kcal/mol towards ß-catenin protein than the reference inhibitor. Molecular dynamic simulations and MM/PBSA calculations were also performed for the Lumacaftor-ß-catenin complex to establish the stability of the interactions involved. Considering its promising attributes and encouraging results, Lumacaftor holds significant potential as a novel therapeutic option to target BCSCs. This study opens avenues for further investigation and may pave the way for developing therapeutic potential in breast cancer treatment. Further confirmation is warranted through in vitro and clinical studies to validate the findings of this study.

An Asymmetric Coumarin-Anthracene Conjugate as Efficient Fullerene-Free Acceptor for Organic Solar Cells.

Asymmetric wide-band gap fullerene-free acceptors (FFAs) play a crucial role in organic solar cells (OSCs). Here, we designed and synthesized a simple asymmetric coumarin-anthracene conjugate named CA-CN with optical band gap of 2.1 eV in a single-step condensation reaction. Single crystal X-ray structure analysis confirms various multiple intermolecular non-covalent interactions. The molecular orbital energy levels of CA-CN estimated from cyclic voltammetry were found to be suitable for its use as an acceptor for OSCs. Binary OSCs fabricated using CA-CN as acceptor and PTB7-Th as the donor achieve a power conversion efficiency (PCE) of 11.13 %. We further demonstrate that the insertion of 20 wt % of CA-CN as a third component in ternary OSCs with PTB7-Th : DICTF as the host material achieved an impressive PCE of 14.91 %, an improvement of ~43 % compared to the PTB7-Th : DICTF binary device (10.38 %). Importantly, the ternary blend enhances the absorption coverage from 400 to 800 nm and improves the morphology of the active layer. The findings highlight the efficacy of an asymmetric design approach for FFAs, which paves the way for developing high-efficiency OSCs at low cost.

Post-Operative Outcomes of Laparoscopic Appendectomy in Acute Complicated Appendicitis: A Single Center Study.

BACKGROUND: Acute appendicitis (AA) is a surgical emergency because of inflammation in the appendix leading to swelling, whereas acute complicated appendicitis is characterized by a gangrenous or perforated appendix with or without periappendicular abscess, peritonitis, and an appendicular mass. The laparoscopic approach in complicated acute appendicitis is a viable alternative method but is not practiced in all cases because of technical difficulties and unpredictable complications. Thus, the present study aimed to evaluate the primary and secondary outcome predictors of laparoscopic appendectomy in complicated appendicitis. METHODS: A single-center prospective observational study was carried out after the approval of the Institutional Ethics Committee (IEC). A total of 87 complicated acute appendicitis patients were included in the study. Clinico-demographic features such as age, gender, duration of surgery, post-operative pain, and hospital stay were monitored in different age groups of <20, 20-39, and >40 years, and the primary and secondary outcomes of laparoscopic surgery in acute complicated appendicitis were measured. RESULT: Acute complicated appendicitis cases were observed mostly in people older than 42 years in the total study population. Laparoscopic appendectomy was conducted in all 87 acute complicated appendicitis patients, and the major surgical outcome predictors were monitored, such as mean operating time (87.9 minutes), post-operative pain (3.9 scores), and post-operative stay (6.7 days). Post-operative complications such as drain site infection (1.14%), enterocutaneous fistula (2%), and intra-abdominal abscess (7%) were observed. CONCLUSION: Based on our observations, a laparoscopic appendectomy can be considered a viable alternative with an acceptable complication rate. Operative time varies from 84 to 94 minutes in different age groups and with the extent of the disease.

Assessment of the Diagnostic Reliability of Modified Alvarado Scores and Abdominal Ultrasonography in Acute Appendicitis.

Introduction Acute appendicitis is a common surgical emergency. Clinical assessment plays a major role; however, subtle clinical features in early stages and atypical presentation makes diagnosis challenging. Ultrasonography (USG) of the abdomen is a usual investigation that aids in diagnosis, however, it is operator dependent. A contrast-enhanced computed tomography (CECT) of the abdomen is more accurate; however, it exposes the patient to hazardous radiation. The study aimed to combine clinical assessment and USG abdomen in the reliable diagnosis of acute appendicitis. Objectives The objective of this study was to assess the diagnostic reliability of the Modified Alvarado Score and ultrasonography of the abdomen in acute appendicitis. Material and methods All patients with right iliac fossa pain, clinically suspected of having acute appendicitis, admitted to the department of general surgery, Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar, between January 2019 and July 2020, who gave consent were included. Clinically, Modified Alvarado Score (MAS) was calculated, after which patients were subjected to USG abdomen, where findings were noted and a sonologic score was calculated. The study group was the patients who needed appendicectomy (n=138). Operative findings were noted. Histopathological diagnosis of acute appendicitis was deemed as confirmatory in these cases and was correlated with MAS and USG scores to determine diagnostic accuracy. Results A combined clinicoradiological (MAS + USG) score of seven showed a sensitivity of 81.8% and a specificity of 100%. The specificity of score seven or above was 100%; however, the sensitivity at 81.8%. The diagnostic accuracy of the clinicoradiological was 87.5%. The negative appendicectomy rate was 4.34%, with a diagnosis of acute appendicitis being confirmed for 95.7% of patients upon histopathological examination. Conclusion The MAS and USG of the abdomen, which is an affordable and non-invasive tool, showed increased diagnostic reliability, and hence it can help reduce the use of CECT abdomen, as CECT abdomen is considered as a gold standard for confirmation or exclusion of diagnosis of acute appendicitis. Use of the combined scoring system of MAS and USG abdomen can be used as a cost-effective alternative.

Harnessing the Structure-Performance Relationships in Designing Non-Fused Ring Acceptors for Organic Solar Cells.

The prerequisite for commercially viable organic solar cells (OSC) is to reduce the efficiency-stability-cost gap. Therefore, the cost of organic materials should be reduced by minimizing the synthetic steps, yet maintaining the molecular planarity and efficiencies achieved by the fused ring acceptors (FRA). In this respect, developing non-fused ring acceptors (NFRA) with suitable functionalization to favor conformational planarity and effective molecular packing is beneficial and cost-effective. Presently, the power conversion efficiency (PCE) for NFRAs is around 16 %, yet lower than the 19 % achieved for FRAs. Despite their potential, a thorough understanding of the effective structural design of NFRAs is necessary for developing efficient OSCs. This article pays special attention to the molecular design concept for NFRAs developed in the last years and analyzed the approach toward materials design and efficiency improvement, an important step toward technological application.

A comprehensive overview on Micro RNA signature in type 2 diabetes Mellitus and its complications.

MicroRNAs (miRNAs) are small endogenous, non-coding RNA molecules that can modulate the expression of their target genes. Since its discovery, an enormous breakthrough has been established regarding its biogenesis and pathophysiological action, which has revolutionized the field of molecular biology. In addition, recent studies have identified the existence of stable extracellular/circulating miRNAs tissues and in biological fluids like blood where they are safeguarded from endogenous ribonuclease activity. Type 2 diabetes mellitus (T2DM) has emerged as a prime health issue worldwide. Incidence has increased considerably over the past decade. There are various tests that have been employed to diagnose T2DM. But for early detection and development, the establishment of biomarkers are of paramount importance. Contemporary evidence also validates the signature of a set of this epigenetic factor miRNA in the development of various diseases, including T2DM. This article reviews the contemporary corroboration associating miRNAs and T2DM and emphasizes the potential role of miRNA as a circulatory biomarker that could alert the growing prevalence of T2DM. Also, it acknowledges the valuable compendium of information regarding biogenesis and functional role of circulating miRNA in insulin resistance which is intimately linked to T2DM. Supplementary Information: The online version contains supplementary material available at 10.1007/s12291-022-01069-1.

Targeting notch signaling pathway in breast cancer stem cells through drug repurposing approach.

Breast cancer is recognized globally as one of the leading causes of malignant morbidity. It is a heterogeneous disease that accounts for 30 percent of all women diagnosed with cancer. To bring an anti-cancer drug from the bench to the bedside is an expensive and time-consuming process. The drug repurposing approach targets new enemies (new diseases) with old weapons (known drugs). The present study identified an FDA-approved drug targeting the γ-secretase complex involved in the Notch signaling pathway in breast cancer stem cells (BCSCs). A literature survey and in-silico study identified Venetoclax as a γ-secretase inhibitor (GSI) from 1615 FDA-approved drug compounds. In-silico docking potential of Venetoclax was better than the standard γ-secretase inhibitor RO4929097. Also, the molecular dynamics simulations of 200 ns confirmed the stability of the Venetoclax-γ-secretase complex. These findings suggest that the use of Venetoclax represents a potential γ-secretase inhibitor in breast cancer stem cells. Eventually, the in vitro and clinical evaluation will be needed to confirm the potential chemopreventive and treatment effects of Venetoclax against breast cancer and breast cancer stem cells. Venetoclax appeared as the most promising drug of the 1615 FDA-approved drugs. Our in-silico findings suggest that Venetoclax may act as a γ-secretase inhibitor against the Notch signaling pathway in breast cancer stem cells.

Natural compounds as a potential modifier of stem cells renewal: Comparative analysis.

Cancer stem cells (CSCs) are indispensable for development, progression, drug resistance, and tumor metastasis. Current cancer-directed interventions target targeting rapidly dividing cancer cells and slow dividing CSCs, which are the root cause of cancer origin and recurrence. The most promising targets include several self-renewal pathways involved in the maintenance and renewal of CSCs, such as the Wnt/ß-Catenin, Sonic Hedgehog, Notch, Hippo, Autophagy, and Ferroptosis. In view of safety, natural compounds are coming to the front line of treatment modalities for modifying various signaling pathways simultaneously involved in maintaining CSCs. Therefore, targeting CSCs with natural compounds is a promising approach to treating various types of cancers. In view of this, here we provide a comprehensive update on the current status of natural compounds that effectively tune key self-renewal pathways of CSCs. In addition, we highlighted surface expression markers in several types of cancer. We also emphasize how natural compounds target these self-renewal pathways to reduce therapy resistance and cancer recurrence properties of CSCs, hence providing valuable cancer therapeutic strategies. The inclusion of nutraceuticals is believed to enhance the therapeutic efficacy of current cancer-directed interventions significantly.

A Clinical Significance of Fungal Infections in Diabetic Foot Ulcers.

BACKGROUND: Diabetic foot ulcers (DFUs) are the most common and serious complications in uncontrolled diabetes. Infections are predominantly polymicrobial, with aerobic Gram-positive, anerobic, and fungal infections. Early detection of fungal infection and initiation of appropriate treatment in DFUs may lead to better healing and avoid amputations. The primary objective was to find out the prevalence of DFUs getting infected with fungus and the secondary objective was to identify the appropriate methodology for the detection of the fungus in DFUs. MATERIALS AND METHODS:  This was a cross-sectional observational study carried out in a tertiary care hospital with a sample size of 60 DFUs. Microbiological analysis was done by swab culture and deep tissue culture. Observational data were collected and the significance level was statistically analyzed. RESULTS:  In the present study, the prevalence of fungal infections in DFUs was 31.7%. Only fungal tissue was positive in 15%, the fungal swab was positive in 8.33%, and both tissue and swab were positive in 8.33%. All these patients were treated with antifungal treatment as per the culture report in addition to appropriate antimicrobial therapy. CONCLUSION:  A fungal culture should be done in all patients with non-healing DFUs. Both fungal swab and tissue culture testing should be advocated in patients with DFUs for better mycological evaluation. The addition of antifungal medications may provide better outcomes in selected cases.

Conformational Selectivity of Merocyanine on Nanostructured Silver Films: Surface Enhanced Resonance Raman Scattering (SERRS) and Density Functional Theoretical (DFT) Study.

In this study, detailed structural and vibrational analysis of merocyanine has been investigated using Raman, surface enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS). The Raman, SERS and SERRS studies aided by density functional theoretical (DFT) calculations clearly established the prevalence of the trans- and cis-conformers of the protonated form of merocyanine (MCH+) in solid and acetonitrile solution. The binding characteristics of merocyanine adsorbed on nanostructured silver-coated films (SCFs) were investigated using excitation-dependent SERS, concentration-dependent SERRS and DFT studies. The conformers of merocyanine involved in the surface adsorption processes were recognized. The prominent marker bands observed at 1538 (ethylenic C=C stretch) and 1133 cm-1 (pyridinium C-N stretch) in the Raman spectrum of merocyanine in acetonitrile shifted to 1540 and 1126 cm-1, respectively on the nanostructured SCFs. The shift in the marker bands is associated with either the preferential binding of selective conformer or change in resonance equilibrium between the benzenoid and quinoid forms. The excitation wavelength dependent SERS spectrum infers that in addition to the major contribution from the electromagnetic enhancement, chemical (resonance) effect leads to the amplification of the 1540 cm-1 band. The concentration-dependent SERRS study showed maximum enhancement for the nanostructured SCFs functionalized with 1 µM concentration of merocyanine, indicative of monolayer coverage. For lower concentrations of merocyanine, the SERRS signal intensity reduced without any alteration in the peak positions. The SERRS study thus, revealed sub-nanomolar (0.1 nM) sensing of merocyanine using nanostructured SCFs with the analytical enhancement factor (AEF) of ∼ 1010 for the 1126 cm-1 and 1540 cm-1 Raman bands for MC concentration of 0.1 nM. In this study, combination of SERRS and DFT have clearly established the predominance of trans-MCH+ on the nanostructured silver surface with minor contribution from cis-MCH+, which remain exclusively bound to the surface via the phenoxyl ring O atom. This conformational surface selectivity of geometrical isomers of merocyanine using nanostructured surfaces can be further explored for energy efficient and economical separation of geometrical isomers.

Case of Botryoid Rhabdomyosarcoma Mimicking Biliary Hydatid Disease.

Hepatobiliary rhabdomyosarcoma (RMS) is a soft tissue malignant musculoskeletal tumor of the biliary tract. It is rare tumor, mostly seen in children and mimics common benign biliary condition. Here, we present a case of 1 year 9 months child of biliary RMS who presented with obstructive jaundice and diagnosed after biopsy. This case highlights the unusual childhood malignancy of bile duct RMS in obstructive jaundice with atypical imaging findings.

Intraoperative Findings of Elective Laparoscopic Cholecystectomy in Diabetics Versus Nondiabetics: A Comparative Study.

Objectives Diabetes mellitus predisposes to the formation of gallstones. Surgery for gallstone disease (GSD) in diabetic patients also carries more risk compared with nondiabetic patients. The objective of the present study was to evaluate the intraoperative findings of elective laparoscopic cholecystectomy in diabetics and nondiabetics. Methods This study was carried out for two years in the department of general surgery as a prospective observational study. Two groups of patients with uncomplicated gallstone disease were recruited: one group included 75 diabetics and the other one included 75 nondiabetics. The two study groups were matched by age and gender. Detailed history and intraoperative findings and their outcomes were recorded. Patients with emergencylaparoscopiccholecystectomy for acute cholecystitis and its complications and cholecystectomy associated with common bile duct (CBD) stones were excluded from the study. Results The results of elective laparoscopic cholecystectomy in the groups were compared. No demographic differences were found between the groups. Adverse intraoperative findings such as thick-walled gallbladder (GB), pericholecystic collections, and adhesions to the surrounding structures, surgical difficulties, modification to subtotal cholecystectomy, and open conversion were more frequent in diabetic patients than in nondiabetic patients. Conclusion Laparoscopic cholecystectomy in diabetic patients had more adverse intraoperative findings in comparison to nondiabetic patients. However, in elective laparoscopic cholecystectomy, good preoperative preparation and meticulous surgical technique are mandatory to achieve similar outcomes between the groups.

Efficacy and Cost-Effectiveness of Laparoscopic Transversus Abdominis Plane (TAP) Block in Laparoscopic Cholecystectomy: A Comparison With the Non-TAP Group.

BACKGROUND: Postoperative pain caused by laparoscopic cholecystectomy can be controlled by different methods. The study aimed to observe the efficacy of laparoscopic transversus abdominis plane (TAP) block in laparoscopic cholecystectomy and to analyze the cost-effectiveness of the procedure in comparison to the non-TAP method. METHODS:  In this double-blinded randomized clinical trial, the subjects who had come for cholecystectomy were randomly divided into two groups (n = 43 in each group). Group A received laparoscopy-guided subcostal TAP block bilaterally (0.25% bupivacaine, 20 ml each) along with parenteral analgesics (100 mg tramadol injection in 100 ml normal saline IV) SOS as rescue analgesia, and group B received parenteral analgesics (injection paracetamol 1 gm IV) eight hourly and injection tramadol 100 mg in 100 ml normal saline IV SOS as rescue analgesia. RESULT:  A bulge was visualized by the surgeon through a laparoscope as a signature view for confirming the placement of local anesthetic in TAP. Based on the Visual Analog Scale (VAS) for assessment of postoperative pain and the Numeric Rating Scale (NRS) for assessment of pain at 30 minutes, four hours, eight hours, 12 hours, and 24 hours postoperatively, patients of both groups were assessed. According to the VAS, the pain assessment was better in the TAP block group at 30 minutes post-surgery than in the non-TAP group. As a primary outcome, 37% of TAP block group cases were recovered without any rescue analgesia. VAS score revealed a significant difference in postoperative nausea and vomiting (PONV) among the TAP block and non-TAP groups. PONV at four hours, eight hours, and 12 hours showed significantly lesser incidences in the TAP group as compared to the non-TAP group (p-value: 0.015, 0.028, and 0.055, respectively). CONCLUSION:  The cost-effectiveness of the TAP block method is 20 times lesser than the non-TAP method. Thus, a laparoscopic-guided TAP block could offer better postoperative analgesia at a low cost with a similar advantage to a USG-guided TAP block.

An updated review on the role of the CXCL8-CXCR1/2 axis in the progression and metastasis of breast cancer.

Chronic inflammation is a major factor in tumor growth and progression. Cancer cells secrete C-X-C chemokine ligand 8 (CXCL8) along with its receptor C-X-C chemokine receptor 1 (CXCR1) and chemokine receptor 2 (CXCR2). It plays a significant role in the activation and trafficking of inflammatory mediators, tumor proliferation and interferes in breast cancer development by controlling cell adhesion, proliferation, migration, and metastasis. This axis also plays a significant role in driving different cancers and melanomas, including breast cancer progression, by controlling stem cell masses. Few small-molecule CXCR1/2 inhibitors and CXCL8 releasing inhibitors have been identified in the past two decades that bind these receptors in their inactive forms and blocks their signaling as well as the biological activities associated with inflammation. Inhibitors of certain inflammatory molecules are projected to be more efficient in different inflammatory diseases. Preclinical trials indicate that patients may be benefitted from combined treatment with targeted drugs, chemotherapies, and immunotherapies. Thus, targeting the CXCL8-CXCR1/2 signaling axis in breast cancer could be a promising approach for its therapeutics. This review examines the roles of the CXCL8-CXCR1/2 signaling axis and how it is implicated in the tumor microenvironment in breast cancer. In addition, we also discuss the potential role of the CXCL8-CXCR1/2 axis in targeted therapeutics for breast cancer.

Rifampicin and Letermovir as potential repurposed drug candidate for COVID-19 treatment: insights from an in-silico study.

INTRODUCTION: Drug repurposing is the need of the hour considering the medical emergency caused by the COVID-19 pandemic. Recently, cytokine storm by the host immune system has been linked with high viral load, loss of lung function, acute respiratory distress syndrome (ARDS), multiple organ failure, and subsequent fatal outcome. OBJECTIVE: This study aimed to identify potential FDA approved drugs that can be repurposed for COVID-19 treatment using an in-silico analysis. METHODS: In this study, virtual screening of selected FDA approved drugs was performed by targeting the main protease (Mpro) of SARS-CoV-2 and the key molecules involved in the 'Cytokine storm' in COVID-19 patients. Based on our preliminary screening supported by extensive literature search, we selected FDA approved drugs to target the SARS-CoV-2 main protease (Mpro) and the key players of cytokine storm, TNF-α, IL-6, and IL-1ß. These compounds were examined based on systematic docking studies and further validated using a combination of molecular dynamics simulations and molecular mechanic/generalized/Born/Poisson-Boltzmann surface area (MM/G/P/BSA) free energy calculations. RESULTS: Based on the findings, Rifampicin and Letermovir appeared as the most promising drug showing a very good binding affinity with the main protease of SARS-CoV-2 and TNF-α, IL-6, and IL-1ß. However, it is pertinent to mention here that our findings need further validation by in vitro analysis and clinical trials. CONCLUSION: This study provides an insight into the drug repurposing approach in which several FDA approved drugs were examined to inhibit COVID-19 infection by targeting the main protease of SARS-COV-2 and the cytokine storm.

Ovarian Inguinal Hernia in Premenopausal Women: A Case Report.

A 34-year-old woman presented to the hospital emergency department complaining of abdominal pain for four days, more so in the left iliac fossa, and six episodes of vomiting for one day. Physical and sonographic examinations revealed an inguinal hernia containing a twisted gangrenous ovary with fallopian tube and partially developed uterus. The patient underwent an emergency hernia exploration with left oophorectomy, repositioning of the uterus with a fallopian tube, and herniorrhaphy without complications. A preoperative diagnosis based on history, physical examination, and ultrasonography allows for accurate surgical planning and corrective surgery without complications.

Natural compounds as potential inhibitors of SARS-CoV-2 main protease: An in-silico study

Objective:To explore natural compounds as potential inhibitors against main protease (Mpro) of SARS-CoV-2. Methods:In the current study, systematic molecular docking analysis was conducted using AutoDock 4.2 to determine the binding affinities and interactions between natural compounds and Mpro. Selected natural compounds were further validated using a combination of molecular dynamic (MD) simulations and molecular mechanic Poisson-Boltzmann surface area (MM/PBSA) free energy calculations. Results:Out of twenty natural compounds, four natural metabolites namely, amentoflavone, guggulsterone, puerarin, and piperine were found to have strong interaction with Mpro of SARS-CoV-2 based on docking analysis. During MD simulations, all four natural compounds bound to Mpro at 50 ns and MM/G/P/BSA free energy calculations showed that all four shortlisted ligands had stable and favorable energies with strong binding to Mpro protein. Conclusions:Guggulsterone is a potential inhibitor of COVID-19 main protease Mpro. Further in vitro and pre-clinical studies are needed.

Efficient Fullerene-Free Organic Solar Cells Using a Coumarin-Based Wide-Band-Gap Donor Material.

In recent years, tremendous growth has been seen for solution-processed bulk heterojunction solar cells (BHJSCs) using fullerene-free molecular acceptors. Herein, we report the synthesis, characterization of a coumarin-based organic semiconducting molecule C1, and its use in BHJSCs as an electron donor. The compound exhibited an absorption band at 472 nm in chloroform solution with an optical energy gap of 2.33 eV. The HOMO/LUMO energy levels of C1 were found to be ideal for use in BHJSCs. Using PC71BM and a fullerene-free acceptor IT-4F, the device generated power conversion efficiencies (PCEs) of 6.17 and 8.31%, respectively. The success of the device based on a fullerene-free acceptor is a result of complementary absorption and well-matched energy levels, resulting in an improved photocurrent and photovoltage in the device. Moreover, ternary solar cells fabricated by employing C1 (20 wt%) as a secondary donor, i.e., an active layer of C1:PM6:IT-4F (0.2:0.8:1.5), generated an enhanced PCE of 11.56% with a high short-circuit current density (JSC) of 16.42 mA cm-2, an open-circuit voltage (VOC) of 1.02 V, and a fill factor of 0.69 under 1 sun spectral illumination, which is ∼8% higher than that for the PM6:IT-4F-based binary device (PCE = 10.70%). The increased PCE for the ternary organic solar cell may be related to the efficient exciton generation and its dissociation via Forster resonance energy transfer, which guarantees enough time for an exciton to diffuse toward the D/A interfaces.

Donor-Acceptor-Type S,N-Heteroacene-Based Hole-Transporting Materials for Efficient Perovskite Solar Cells.

Two new donor-acceptor (D-A)-substituted S,N-heteroacene-based molecules were developed and investigated as hole-transporting material (HTM) for perovskite solar cells (PSCs). Optical and electrochemical characterization brought out that the energy levels of both HTMs are suitable for their use in PSCs. Consequently, a power-conversion efficiency of 17.7% and 16.1% was achieved from PSCs involving the HTM-1 and HTM-2, respectively. The optoelectronic properties in terms of series resistance, conductivity, and charge carrier recombination were further examined to unfold the potential of these new HTMs. Time-resolved photoluminescence spectroscopy brought out that the hole injection from the valence band of perovskite into HTMs follows the trend, which is in accordance with the position of the highest occupied molecular orbital. Overall, our findings underline the potential of S,N-heteroacene co-oligomers as promising HTM candidates for PSCs.