Prevalence and correlates of depression, anxiety, and stress among adolescents in urban and rural areas of Mysuru, South India.

Background: Adolescence, a volatile period of growth between the ages of 10 and 19, is associated with increased vulnerability to mental health problems. Factors such as academic pressure can contribute to these challenges. Objectives: The current study aimed to evaluate the factors and prevalence of depression, anxiety, and stress among adolescents in the urban and rural areas of Mysuru district. Materials and Methods: A cross-sectional study was conducted in private high schools in both urban and rural regions. Prior permission and informed consent were obtained from participants and their legal guardians aged 18 years and older. Results: The gender distribution in urban areas was 60.2% female and 39.8% male, while in rural areas, it was 51% male and 49% female. The prevalence of depression was higher in rural (39.3%) than in urban areas (24.2%), while anxiety was more prevalent in urban (50.6%) than in rural areas (49%). Stress was also more common in rural (16.6%) than urban adolescents (14.6%). Factors significantly associated with mental health outcomes included monthly family income, parenting practices, academic pressures, and self-esteem. Key needs identified were mobile mental health applications, online counseling services, and access to school counselors. Conclusion: This study provides insights into the prevalence and correlates of common mental health issues among adolescents in this region of South India. The findings emphasize the necessity of providing mobile applications and offline counseling services to effectively support and meet the needs of adolescents in these settings.

Synthesis, Structural, Electrochemical, and DFT Studies of Highly Substituted Nonplanar Ni(II) Porphyrins and Their Intensity-Dependent Third-Order Nonlinear Optical Properties.

We designed and successfully synthesized highly substituted electron-deficient nonplanar Ni(II) porphyrins and their derivatives (1-7) in moderate to good yields. These derivatives were comprehensively characterized by various spectroscopic techniques and single-crystal X-ray diffraction (SCXRD) analysis. SCXRD analysis confirmed the structures of compounds 2, 4, and 7, adopting saddle-shape geometry. These nonplanar porphyrins demonstrated significant bathochromic shifts in their absorption spectra compared to parent NiTPP, attributed to the influence of bulky ß-substituents and/or peripheral fusion. π-Extended porphyrins 6 and 7 displayed panchromatic absorption spectra extending into the NIR region. Porphyrins 6 and 7 demonstrated a profound anodic shift (∼400 mV) in their first reduction peak potentials compared to precursor NiTPP(NO2)Br6. The experimental absorption spectral pattern matches the simulated absorption spectra obtained from TD-DFT studies. The femtosecond laser intensity-dependent third-order nonlinear optical studies revealed that NiDFP(VCN)2Br6 (6) and NiDFP(VCN)2(PE)6 (7) displayed giant optical nonlinearities compared to the other porphyrins. Among all, NiDFP(VCN)2Br6 (6) possessed the highest two-photon absorption coefficient (ß) and cross-section (σTPA) values in the range of 22-33 × 10-10 m/W and 3.77-6.95 × 106 GM, respectively. These findings suggest that the investigated nonplanar π-extended porphyrins are promising candidates for future optoelectronic applications.

Mono- and Difluoromethylation of 3(2H)-Pyridazinones.

A method for direct N-monofluoromethylation of pyridazinones with S-monofluoromethyl-S-phenyl-2,3,4,5-tetramethylphenylsulfonium triflate is disclosed. A method for the N- and O-difluoromethylated pyridazinones with TMSCF2Br as the only promising difluorocarbene precursor is also reported. Substrates with various relevant functional groups, including analogues of Lynparza, are tolerated under both methods.

The Psychological Burden of Surgery During a Pandemic: Evaluating Preoperative Anxiety in the COVID-19 Era.

Background The COVID-19 pandemic has introduced unprecedented challenges to global healthcare systems, including heightened psychological stress among patients. This study evaluates the preoperative anxiety levels among patients scheduled for surgery during the COVID-19 pandemic. Methods This cross-sectional observational study was conducted between April 2020 and March 2022. Adult patients aged 18-80 years, scheduled for elective or emergency surgery, were included. Exclusion criteria were mental illness, impaired communication, and hemodynamic instability. A pre-validated questionnaire addressing demographics, prior surgery exposure, surgery-related anxiety, and COVID-19-related fears was administered. Anxiety levels were scored on a 1-5 Likert scale. Data were analyzed using SPSS version 22 (IBM Corp., Armonk, USA). Results A total of 112 patients participated, with a mean age of 42.3±14.2 years. The majority were female (61 patients, 54.5%), married (96 patients, 85.7%), and resided in urban areas (85 patients, 75.9%). Most patients had no prior surgical history (87 patients, 77.7%). Surgery-related fears were prevalent, with 110 patients (98.2%) fearing surgical complications and 111 patients (99.1%) fearing postoperative pain. COVID-19-related fears were also significant, with 108 patients (96.4%) fearing infection during hospital stay and 100 patients (89.3%) fearing infecting family members. Mild fear was the most common anxiety level (70 patients, 62.95%), followed by moderate fear (25 patients, 22.5%). Discussion The study highlights the dual stressors of surgery and the pandemic, contributing to heightened preoperative anxiety. Findings indicate that significant anxiety levels were present, driven by fears related to surgery, anesthesia, and COVID-19. This aligns with other studies that report high preoperative anxiety levels exacerbated by the pandemic. The comprehensive assessment of anxiety factors underscores the need for tailored interventions to mitigate these anxieties. Conclusion The COVID-19 pandemic has significantly increased preoperative anxiety among surgical patients. Addressing both surgical and pandemic-related anxieties is crucial for improving patient outcomes. Healthcare providers should implement psychological support programs to alleviate these anxieties. Understanding the multifaceted nature of preoperative anxiety during the pandemic can enhance patient care.

Hysteretic Piezochromism in a Lead Iodide-Based Two-Dimensional Inorganic-Organic Hybrid Perovskite.

Two-dimensional inorganic-organic hybrid perovskites are in the limelight due to their potential applications in photonics and optoelectronics. They are environmentally stable, and their various chemical compositions offer a wide range of bandgap energies. Alternatively, crystal deformation enables in situ control over their optical properties. Here, we investigate (C6H9C2H4NH3)2PbI4, a hybrid perovskite whose organic linkers are 2-(1-cyclohexenyl)ethylammonium. Pressure-dependent optical absorption and emission spectroscopy reveal a hysteretic piezochromism that was not reported for other lead iodide-based 2D perovskites. We combine our optical studies with high-pressure X-ray diffraction experiments and first-principles calculations to demonstrate that the deformation of the inorganic lead iodide layers is the main reason for the observed changes in the optical bandgap.

End-of-life Care Patient Information Leaflets-A Comparative Evaluation of Artificial Intelligence-generated Content for Readability, Sentiment, Accuracy, Completeness, and Suitability: ChatGPT vs Google Gemini.

Background: End-of-life care (EOLC) is a critical aspect of healthcare, yet accessing reliable information remains challenging, particularly in culturally diverse contexts like India. Objective: This study investigates the potential of artificial intelligence (AI) in addressing the informational gap by analyzing patient information leaflets (PILs) generated by AI chatbots on EOLC. Methodology: Using a comparative research design, PILs generated by ChatGPT and Google Gemini were evaluated for readability, sentiment, accuracy, completeness, and suitability. Readability was assessed using established metrics, sentiment analysis determined emotional tone, accuracy, and completeness were rated by subject experts, and suitability was evaluated using the Patient Education Materials Assessment Tool (PEMAT). Results: Google Gemini PILs exhibited superior readability and actionability compared to ChatGPT PILs. Both conveyed positive sentiments and high levels of accuracy and completeness, with Google Gemini PILs showing slightly lower accuracy scores. Conclusion: The findings highlight the promising role of AI in enhancing patient education in EOLC, with implications for improving care outcomes and promoting informed decision-making in diverse cultural settings. Ongoing refinement and innovation in AI-driven patient education strategies are needed to ensure compassionate and culturally sensitive EOLC. How to cite this article: Gondode PG, Khanna P, Sharma P, Duggal S, Garg N. End-of-life Care Patient Information Leaflets-A Comparative Evaluation of Artificial Intelligence-generated Content for Readability, Sentiment, Accuracy, Completeness, and Suitability: ChatGPT vs Google Gemini. Indian J Crit Care Med 2024;28(6):561-568.

Dynamics of direct hydrocarbon PEM fuel cells.

Hydrocarbon fuels contain approximately 50 times more energy per unit mass than commercial batteries, thus converting even 10% of the energy contained in hydrocarbon fuels to electrical energy could present a more mass-efficient electrical energy source than batteries. Considering the storability of hydrocarbon fuels compared to hydrogen, the viability of direct hydrocarbon polymer electrolyte membrane fuel cells was examined. With extremely pure (> 99.99%) propane, the cell Open-Circuit Voltage (OCV) was only 0.05 V and produced negligible power. However, with addition of trace quantities of unsaturated hydrocarbons, the cell had an OCV of 0.85 V and produced power, even after the unsaturated hydrocarbon addition was discontinued. At sufficiently high current densities, power output gradually decreased then the cell rapidly "extinguished" but by periodically shutting off the current for short time intervals the average power density could be increased significantly. Chemical analysis revealed that no significant amounts of hydrocarbon intermediates or CO were present in the effluent and that conversion of the hydrocarbon fuel to CO2 and H2O was nearly complete. An analytical model incorporating the relative rates of conversion of active anode catalyst sites to inactive sites and vice versa was developed to interpret this behavior. The model predictions were consistent with the experimental observations; possible physical mechanisms are discussed.

First report of Curvularia spicifera (≡ Bipolaris spicifera) causing spathe blight and leaf spot disease of pearl millet (Cenchrus americanus) in India.

Cenchrus americanus (L.) Morrone (Poaceae), is an important millet crop cultivated mainly in arid and semiarid regions and is a staple food grain for millions of people. During 2021 July surveys in the pearl millet fields in Mysore (12°30'55" N; 76°56'54" E), Karnataka, India, plants showed spathe blight and leaf spot disease with an overall incidence ranging from 5 - 8% in the 15 hectares surveyed. Infected leaves appeared brown, and lesions extended to the sheath. Some spathes were also found infected with similar symptoms. Diseased leaves and spathes were collected (n = 5 each) for pathogen identification. Samples were cut into small pieces (0.5 cm2), sterilized with sodium hypochlorite (2%, v/v), and blotted dried. The associated fungal pathogen was isolated on potato dextrose agar (PDA) medium amended with Streptomycin (40 mg/L) and incubated at 28 ºC for 1 week. Colonies were grey, fluffy, cottony with an irregular margin, undulate and dark brown in the back of the plate. Conidiophores were pale brown, erect, slightly curved, septate, unbranched, verruculose and measured 27.1 - 94 µm in length × 2.3 - 4.5 µm in width (n = 20). Conidiogenous cells were brown, subcylindrical, irregularly shaped, and conidia were straight, mainly elliptical, dark brown smooth, with two to three septa, with measurements of 11.1 - 26.4 µm by 5.7 - 14.3 µm (n = 50). Based on morphological characters, the pathogen was identified as Curvularia sp. Two representative isolates (UOMPM1 & UOMPM2) were molecularly identified. The total genomic DNA was extracted with a CTAB method, and ITS, GAPDH and tef-1α loci were amplified using primers ITS1/ITS4 (White et al., 1990), GPD1/GPD2 (Berbee et al., 1999) and EF1983F/EF-2218R (Schoch et al., 2009) respectively. ITS sequence had 100% similarity (706/706bp) with reference sequence C. spicifera (MH863648; HF934915 & HF934916); tef-1α sequence had 100% (933/933bp) identity with C. spicifera (KM062878, KJ939505), and the GAPDH sequence was 99.8% identical to that of Curvularia sp. (MG979055), and C. spicifera (MH809681). Combined dataset of concatenated sequence (ITS-GAPDH-tef-1α) was used in a phylogenetic analysis and revealed that the isolates were in a common clade with the isolate of Curvularia spicifera (CBS 274.52) thus, confirming the identity of the isolated pathogen as C. spicifera. The sequences obtained in the present study were deposited in the GenBank (ITS: OQ253406, OQ253407; LSU: OQ253429, OQ253430; GAPDH: OQ263372, OQ263373 & TEF: OQ263374, OQ263375). Pathogenicity test was carried out by inoculating (foliar /whole plant spray) 60 healthy pearl millet plants (45-days old), grown in field plot with spore suspension (105 conidia/ml). Control plants (n=20) were treated with sterile water. The experiments were conducted in triplicates and repeated twice. Development of disease symptoms was recorded on 41 plants, and all control plants remained healthy. The identity was confirmed after re-isolation as C. spicifera based on cultural and molecular sequence analysis. To our knowledge, this is the first report of C. spicifera causing a leaf spot and spathe blight disease of pearl millet in India. This disease seriously affects grain production, and effective disease management strategies need to be investigated.

Non-ST Elevation Myocardial Infarction in Patients With Hypertensive Emergency.

Background Hypertensive emergencies represent high-cardiovascular-risk situations defined by severe increases in blood pressure. The prevalence of hypertension in non-ST elevation myocardial infarction (NSTEMI) is higher compared to STEMI and there is a lack of studies on NSTEMI patients with hypertensive emergencies. Patients with diabetes exhibited a higher rate of hypertensive emergencies. This study's primary aim was to investigate the coronary artery disease profile in hypertensive emergency patients with NSTEMI, and the secondary aim was to determine the impact of diabetes on the development of hypertensive emergencies. Methodology A total of 100 patients with NSTEMI and hypertensive emergency presenting to the hospital were enrolled in the study. The duration of the study was 24 months. The patients were also sub-grouped into diabetic and nondiabetic. Baseline characteristics were noted, and coronary angiogram and renal angiogram were also done. Based on variables, the chi-square test and t-test were employed to assess the significance. P-value < 0.05 was considered statistically significant. Results The mean age at presentation for patients with NSTEMI and hypertensive emergency was 58 years. Patients consuming alcohol were slightly higher (28, 28%) than those who smoked (23, 23%). Among all, 48 (48%) patients had diabetes. When considering the number of vessels, diabetic patients had more single-vessel diseases (18, 37.5%) and nondiabetic patients had more double-vessel diseases (15, 28.8%). The mean ejection fraction of the diabetic group was 56.1% ± 6.8% and the nondiabetic group was 54.2% ± 7.7%. Among all the patients, 52 (62.6%) used combination drugs, while 39 (46.9%) were on defaulter drugs. Conclusions Several risk factors like age, smoking, alcohol, and nonadherence to drugs were found to have an association with the occurrence of hypertensive emergency. Diabetes was found to be significantly associated with unfavorable coronary anatomy among the population.

In vitro impact of ethanolic extract of Bryonia laciniosa seed on Gir bull spermatozoa: a comprehensive evaluation through transcriptome profiling.

Aim/objectives: This study examines the in vitro impact of an ethanolic extract derived from Bryonia laciniosa seeds on the Gir bull (Bos indicus) spermatozoa. The objective is to thoroughly assess the effects of the seed extract on the physiological parameters of bull spermatozoa, followed by evaluating its effects on X and Y-bearing spermatozoa and its impact on gene expression through transcriptome profiling. Material method: For this study, one Gir bull was selected, and 12 ejaculates were collected at one-week time intervals. Sperm cells were isolated from each ejaculate and incubated with varying concentrations of the ethanolic extract. The physiological parameters of the spermatozoa were assessed using Computer Assisted Semen Analysis (CASA) and compared with control groups to evaluate the extract's effects on sperm quality and motility. Results and discussion: At a concentration of 18 mg/mL B. laciniosa extract, we noticed a statistically significant 16.4% increase in sperm motility (p = 0.0065). In order to understand the specific effect on X and Y-bearing spermatozoa, motile and non-motile sperm separated by glass wool column method and further evaluated for quantification of X and Y-bearing sperm in all samples by ddPCR. To understand the effect of B. laciniosa extract on spermatozoa at the molecular level, whole transcriptome profiling was carried out using Illumina MiSeq. Transcriptome profiling revealed 81 genes that were expressed differently between the group treated with the extract and the control group. The current investigation revealed an increase in the expression of TLX1, CRYGB, KLF13, and ZAR1 transcripts, which play a role in embryonic development. In addition, several genes have been identified that are involved in sperm motility, such GSK3B, LAPRS, MAPK1, CAMK2B, and AQP7. The findings exhibited the therapeutic effectiveness of B. laciniosa seeds in augmenting fertility through a synergistic blend of activities, including enhanced sperm motility and positive influence on embryogenesis.

Azidodifluoromethanide (N3CF2-): In Situ Generation and Nucleophilic Addition to Aldehydes.

A facile one-pot approach for the azidodifluoromethylation of aldehydes via in situ-generated azidodifluoromethenide (N3CF2-) utilizing commercially available TMSCF2Br and NaN3 is disclosed. The formed O-silyl ether products are obtained in yields of up to 91% in short reaction times at ambient temperature. Examples of both inter- and intramolecular [3 + 2] azide-alkyne cycloaddition reactions of the installed azidodifluoromethyl handles are also presented, demonstrating the prospective synthetic and biochemical functionality and utility.

Role of artificial intelligence, machine learning and deep learning models in corneal disorders - A narrative review.

In the last decade, artificial intelligence (AI) has significantly impacted ophthalmology, particularly in managing corneal diseases, a major reversible cause of blindness. This review explores AI's transformative role in the corneal subspecialty, which has adopted advanced technology for superior clinical judgment, early diagnosis, and personalized therapy. While AI's role in anterior segment diseases is less documented compared to glaucoma and retinal pathologies, this review highlights its integration into corneal diagnostics through imaging techniques like slit-lamp biomicroscopy, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal biomicroscopy. AI has been pivotal in refining decision-making and prognosis for conditions such as keratoconus, infectious keratitis, and dystrophies. Multi-disease deep learning neural networks (MDDNs) have shown diagnostic ability in classifying corneal diseases using AS-OCT images, achieving notable metrics like an AUC of 0.910. AI's progress over two decades has significantly improved the accuracy of diagnosing conditions like keratoconus and microbial keratitis. For instance, AI has achieved a 90.7% accuracy rate in classifying bacterial and fungal keratitis and an AUC of 0.910 in differentiating various corneal diseases. Convolutional neural networks (CNNs) have enhanced the analysis of color-coded corneal maps, yielding up to 99.3% diagnostic accuracy for keratoconus. Deep learning algorithms have also shown robust performance in detecting fungal hyphae on in vivo confocal microscopy, with precise quantification of hyphal density. AI models combining tomography scans and visual acuity have demonstrated up to 97% accuracy in keratoconus staging according to the Amsler-Krumeich classification. However, the review acknowledges the limitations of current AI models, including their reliance on binary classification, which may not capture the complexity of real-world clinical presentations with multiple coexisting disorders. Challenges also include dependency on data quality, diverse imaging protocols, and integrating multimodal images for a generalized AI diagnosis. The need for interpretability in AI models is emphasized to foster trust and applicability in clinical settings. Looking ahead, AI has the potential to unravel the intricate mechanisms behind corneal pathologies, reduce healthcare's carbon footprint, and revolutionize diagnostic and management paradigms. Ethical and regulatory considerations will accompany AI's clinical adoption, marking an era where AI not only assists but augments ophthalmic care.

PPARγ and AKt gene modulation following pregabalin and duloxetine combination for painful diabetic polyneuropathy.

Aim: Diabetic peripheral neuropathy (DPN) induces chronic neuropathic pain in diabetic patients. Current treatments like pregabalin and duloxetine offer limited efficacy. This study evaluates combining pregabalin and duloxetine versus pregabalin alone for DPN pain relief, and explores gene modulation (PPARγ and Akt) to understand neuropathic pain's molecular basis.Materials & methods: Diabetic patients with DPN were randomized into groups receiving combination therapy or pregabalin alone for 4 weeks. Pain intensity, gene expression and quality of life were assessed.Results: Combination therapy significantly reduced pain, improved quality of life and upregulated PPARγ and Akt genes compared with monotherapy.Conclusion: Pregabalin and duloxetine combination therapy in DPN led to PPARγ mRNA upregulation and negative correlation of Akt gene expression with pain scores. This combination therapy effectively reduced pain and improved quality of life.Clinical Trial Registration: CTRI/2021/02/031068.

Combining medicines to reduce nerve pain in diabetic patientsWhat is this article about? People with diabetes often have nerve pain called diabetic peripheral neuropathy (DPN). Some medicines like pregabalin and duloxetine help, but are not enough. This study tested if using both medicines together works better than using just pregabalin. The study also looked at how these medicines affect certain genes.What were the results? Patients with DPN took either both medicines or just pregabalin for 4 weeks. The combined treatment reduced pain, improved life quality and affected certain genes.What do the results of the study mean? Using pregabalin and duloxetine together can reduce DPN pain more effectively. This offers hope for better treatment options.

Biofilms from poly-vinyl alcohol/palmyra root sprout with Boswellia serrata, carbon dots and anthocyanin for sensing the freshness of sardine fish.

One of the main issues that customers worldwide have is food adulteration. In commercial packages, freshness cannot always be determined visually. Here, we propose sensitive films for use in food packaging that could alter colour to indicate a change in freshness. Hybrid, multifunctional, and eco-friendly films were prepared from polyvinyl alcohol/palmyra root sprout (PVA/PRS), fused with soy protein isolate carbon dot (CD), Boswellia serrata (BS), and Clitoriaternatea anthocyanin (CTE). The films showed pH sensitivity, antioxidant, and UV barrier properties. By creating hydrogen bonds between PRS and the other fillers, adding these substances makes PVA less crystallized. These interactions were verified by infrared Fourier-transform analysis. When compared to PVA, PRS films had significantly lower moisture content and swelling ratios. The UV-blocking capabilities of the films were greatly improved by the addition of CD, BS, and CTE without compromising their mechanical, thermal, or water vapor barrier properties. The composite film PVA/PRS/CD/BS/CTE exhibited a maximum tensile strength value of 69.47 ± 1.49 MPa. The CT extract provides the film with superior antioxidant properties. The colorimetric films PVA/PRS/CTE and PVA/PRS/CD/BS/CTE showed distinct pH-responsive colour-change properties as well as good colour stability. The colorimetric films were used to test the freshness of sardine fish, and they revealed unique colour changes that indicated whether the fish sample was spoiled or not.

Involvement of ObRb receptor, nitric oxide, and BKCa channel signaling pathways in leptin-induced relaxation of pregnant mouse uterus.

The purpose of this study was to determine the receptor subtype and the underlying mechanisms involved in the relaxant effect to leptin in mid- and late-pregnant mouse uterus. We determined the relative mRNA expression of receptor subtypes, eNOS, and BKCa channel by quantitative PCR and also the overall receptor expression by immunohistochemistry. Isometric tension studies were conducted to evaluate the effects of leptin and to delineate its mechanisms. A selective siRNA for the ObRb receptor was used to determine the participation of the receptor subtype in biochemical and molecular effects of leptin. The relaxant response to leptin was greater in mid-pregnancy compared to late pregnancy and was mediated by the activation of BKCa channels by eNOS-derived nitric oxide in an ObRb receptor-dependent manner. In comparison to mid-pregnancy, expression of short forms (mainly ObRa receptor) of the receptor was significantly increased in late pregnancy, whereas ObRb receptor expression was similar in both phases. The results of the study suggest that ObRb receptor mediates leptin-induced increase in eNOS expression and NO synthesis. Leptin-induced eNOS expression and activation cause cGMP-independent stimulation of BKCa channels causing uterine relaxation. Increased short forms of the receptors and reduced BKCa channels exert a negative effect on uterine relaxation in late pregnancy. Leptin may have a physiological role in maintaining uterine quiescence in mid-pregnancy and its reduced relaxant response in late gestation may facilitate labor. Further, ObRb receptor agonists may be useful in the management of preterm labor.

Structurally influenced optical nonlinearities and ultrafast dynamics in ß-acroleyl- and ß-dicyanobutadienyl-appended cobalt corroles.

The strong two-photon induced nonlinear absorption and self-focusing type positive nonlinear refraction are pronounced by the structural engineering in ß-functionalized cobalt corroles.

Addition of Imidazolium-Based Ionic Liquid to Improve Methanol Production in Polyamine-Assisted CO2 Capture and Conversion Systems Using Pincer Catalysts.

Ionic liquids have been studied as CO2 capture agents. However, they are rarely used in combined CO2 capture and conversion processes. Utilizing imidazolium-based ionic liquids, the conversion of CO2 to methanol was greatly improved in polyamine assisted systems catalyzed by homogeneous pincer catalysts with Ru and Mn metal centers. Among the ionic liquids tested, [BMIM]OAc was found to perform the best under the given reaction conditions. Among the polyamine tested, pentaethylenehexamine (PEHA) led to the highest conversion rates. Ru-Macho and Ru-Macho-BH were the most active catalysts. Direct air capture utilizing PEHA as the capture material was also demonstrated and produced an 86 % conversion of the captured CO2 to methanol in the presence of [BMIM]OAc.

Syntheses, structural, photophysical and theoretical studies of heteroleptic cycloplatinated guanidinate(1-) complexes bearing acetylacetonate and picolinate ancillary ligands.

Cycloplatination of symmetrical N,N',N''-triarylguanidines, (ArNH)2C[double bond, length as m-dash]NAr with cis-[Pt(TFA)2(S(O)Me2)2] in toluene afforded cis-[Pt(TAG)(TFA)(S(O)Me2)] (TAG = triarylguanidinate(1-)-κC,κN; TFA = OC(O)CF3; 6-9) in 75-82% yields. The reactions of 6-9 and the previously known cis-[Pt(TAG)X(S(O)Me2)] (X = Cl (1) and TFA (2-5)) with acetylacetone (acacH) or 2-picolinic acid (picH) in the presence of a base afforded [Pt(TAG)(acac)] (acac = acetylacetonate-κ2O,O'; 10-18) and [Pt(TAG)(pic)] (pic = 2-picolinate-κN,κO; 19) in high yields. The new complexes were characterised by analytical, IR and multinuclear NMR spectroscopies. Further, molecular structures of 11, 12, 13·0.5 toluene and 14-19 were determined by single crystal X-ray diffraction. Absorption spectra of 10-19 in solution and their emission spectra in crystalline form were measured. Platinacycles 10-19 are bluish green light emitter in the crystalline form, and emit in the λPL = 488-529 nm range (11 and 13-19) while 12 emits at λPL = 570 nm. Unlike other platinacycles, the emission band of 12 is broad, red shifted, and this pattern is ascribed to the presence of an intermolecular N-H⋯Pt interaction involving the endocyclic amino unit of the six-membered [Pt(TAG)] ring and the Pt(ii) atom in the adjacent molecule in an asymmetric unit of the crystal lattice. Lifetime measurements were carried out for all platinacycles in crystalline form, which revealed lifetime in the order of nanoseconds. The origin of absorption and emission properties of 11, 15, 18 and 19 were studied by TD-DFT calculations.

Spectrally resolved nonlinearities within a laser pulse in a single-scan and spectrometer-based nonlinear optical probing.

The intricate spectrally resolved optical nonlinearities resulting from a spectrally broad femtosecond Gaussian laser pulse have been unraveled using a single-scan and spectrometer-based nonlinear optical probing technique. The interaction of the broad femtosecond laser pulse with a strongly absorbing organic dye has unveiled a remarkably distinct nonlinear absorption behavior across the broad spectral window. The nonlinear absorption behavior unveils an unusual transition from the reverse saturation absorption (RSA) to the saturation absorption (SA) as we sweep the wavelength on both sides of the central wavelength of the excitation laser pulse. A competition between the band-filling and excited-state absorption results in such a dramatic switch-over from the RSA to the SA due to the variation of the intensity distribution across the Gaussian pulse spectrum. On the other hand, the nonlinear refraction studies dictate more over the constant Kerr-type positive nonlinear refractive indices across the entire laser pulse, with a pronounced contribution from the nonlinear absorption phase dominating at the center of the pulse. The presented technique establishes a robust and simple spectrometer-based technique that offers new, to the best of our knowledge, avenues for estimating optical nonlinearities for rapid nonlinear optical measurements.

Interplay of mitochondria-associated membrane proteins and autophagy: Implications in neurodegeneration.

Since the discovery of membrane contact sites between ER and mitochondria called mitochondria-associated membranes (MAMs), several pieces of evidence identified their role in the regulation of different cellular processes such as Ca2+ signalling, mitochondrial transport, and dynamics, ER stress, inflammation, glucose homeostasis, and autophagy. The integrity of these membranes was found to be essential for the maintenance of these cellular functions. Accumulating pieces of evidence suggest that MAMs serve as a platform for autophagosome formation. However, the alteration within MAMs structure is associated with the progression of neurodegenerative diseases. Dysregulated autophagy is a hallmark of neurodegeneration. Here, in this review, we highlight the present knowledge on MAMs, their structural composition, and their roles in different cellular functions. We also discuss the association of MAMs proteins with impaired autophagy and their involvement in the progression of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.