Through-Space Charge-Transfer-Based Aggregation-Induced Emission and Thermally Activated Delayed Fluorescence in Fused 2H-Chromene Coumarin Congener Generating ROS for Antiviral (SARS-CoV-2) Approach

Harvesting triplets in metal-free organic frameworks at ambient conditions and finding appropriate applications are a formidable challenge. Herein, we report a donor-acceptor-type system composed of carbazole and fused 2H-chromene coumarin derivative, exhibiting triplet harvesting thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) behavior in solid and aggregated states, respectively. The presence of an sp3 linker and the introduction of a selected cyano/ester group in the acceptor result in twisted D-A architectures, further assisting in the suppression of nonradiative deactivation via through-space charge transfer and H-bonding interactions, fulfilling the stringent requirements for the simultaneous process of TADF and AIE, successively. Experimental and theoretical results revealed that the participation of the singlet/triplet charge transfer (1CT/3CT) and the higher lying hybrid triplet locally excited charge-transfer state (3LE + 3CT) leads to an efficient TADF. Both of the synthesized AIE-TADF congeners actively participated in the generation of reactive oxygen species (ROS) in nanoaggregate forms and were further explored computationally for antiviral prospects as inhibitors of the SARS-CoV-2 spike protein.

Highly efficient color-tunable organic co-crystals unveiling polymorphism, isomerism, delayed fluorescence for optical waveguides and cell-imaging

Photofunctional co-crystal engineering strategies based on donor-acceptor π-conjugated system facilitates expedient molecular packing, consistent morphology, and switchable optical properties, conferring synergic 'structure-property relationship' for optoelectronic and biological functions. In this work, a series of organic co-crystals were formulated using a twisted aromatic hydrocarbon (TAH) donor and three diverse planar acceptors, resulting in color-tunable solid and aggregated state emission via variable packing and through-space charge-transfer interactions. While, adjusting the strength of acceptors, a structural transformation into hybrid stacking modes ultimately results in color-specific polymorphs, a configurational cis-isomer with very high photoluminescence quantum yield. The cis-isomeric co-crystal exhibits triplet-harvesting thermally activated delayed fluorescence (TADF) characteristics, presenting a key discovery in hydrocarbon-based multicomponent systems. Further, 1D-microrod-shaped co-crystal acts as an efficient photon-transducing optical waveguides, and their excellent dispersibility in water endows efficient cellular internalization with bright cell imaging performances. These salient approaches may open more avenues for the design and applications of TAH based co-crystals.

Hot-exciton harvesting via through-space single-molecule based white-light emission and optical waveguides

Through-space donor–alkyl bridge–acceptor (D–σ–A) luminogens are developed as new organic single-molecule white light emitters (OSMWLEs) involving multiple higher lying singlet (S_n) and triplet (T_m) states (hot-excitons). Experimental and theoretical results confirm the origin of white light emission due to the co-existence of prompt fluorescence from locally excited states, thermally activated delayed fluorescence (TADF), and fast/slow dual phosphorescence color mixing simultaneously. Notably, the fast phosphorescence was observed due to trace amounts of isomeric impurities from commercial carbazole, while H-/J-aggregation resulted in slow phosphorescence. Crystal structure-packing-property analysis revealed that the alkyl chain length induced supramolecular self-assembly greatly influenced the solid-state optical properties. Remarkably, the 1D-microrod crystals of OSMWLEs demonstrated the first examples of triplet harvesting waveguides by self-guiding the generated phosphorescence through light propagation along their longitudinal axis. This work thus highlights an uncommon design strategy to achieve multi-functional OSMWLEs with in-depth mechanistic insights and optical waveguiding applications making them a potentially new class of white emissive materials.

Through-space donor–alkyl bridge–acceptor multifunctional organic single molecules that simultaneously displayed white light emission, thermally activated delayed fluorescence, room temperature dual phosphorescence and optical wave-guiding properties.

COVID Associated Mucormycosis: A Study on the Spectrum of Clinical, Biochemical and Radiological Findings in A Series of Ten Patients

BACKGROUND

There is more than twofold rise in prevalence of mucormycosis cases in India during the COVID-19 pandemic which needs to be evaluated.

AIMS

The study aimed to document the spectrum of cases of mucormycosis seen at our Institute during COVID-19 times.

METHODS

The study is a retrospective observational study carried out at our Institute from May 2021 to mid-June 2021. All patients with biopsy-proven mucormycosis were enrolled in the study. The patients were subjected to complete history taking, ophthalmological examination, and imaging studies. The patients were treated with a multidisciplinary approach with antifungal therapy as well as surgical intervention when needed.

RESULTS

Ten patients (n=10) were seen, with a mean age of 50.3 years. The major risk factors included recent use of steroids, uncontrolled diabetes, and CKD. The most common presentation was swelling of unilateral eye and ptosis, followed by loss of vision. Inflammatory marker (CRP) and d-dimer were raised at presentation in all cases. Imaging showed the spread of infection from paranasal sinus to orbit and brain via cavernous sinus, which was a poor prognostic factor. Intravenous Amphotericin-B was given to all patients for at least 4 weeks. Two patients were discharged after completion of treatment and mortality was seen in three patients.

CONCLUSION

We present an array of COVID-associated-mucormycosis (CAM) cases from Eastern India. CAM is presenting with rhino-orbito-cerebral involvement. There is poor outcome with cerebral involvement and high incidence of adverse effects with deoxycholate formulation of amphotericin-B. The causal association of COVID-19 with mucormycosis needs to be unearthed but possible preventive role of anticoagulation should be evaluated.

Stimuli-Responsive Trimorphs and Charge-Transfer Complexes of a Twisted Molecular Donor

Supramolecular self-assemblies and co-assemblies possess multiple noncovalent interactions, highly ordered structures, and multifunctional properties. Yet, the fundamental understanding of their "structure-property relationship" remains very challenging. Herein, two kinetically controlled supramolecular charge transfer (CT) complexes were conceptualized from a trimorphic molecular donor denoted as "twisted aromatic hydrocarbon" (TAH), with p-fluoranil (TFQ) and p-chloranil (TCQ) in water, organic solvent, and solvent-free methods. Elucidating their co-assembling mechanism revealed that segmentation of the TAH with molecules having planar deficient cores spontaneously formed a distinct "H-type mixed stack" and "J-type segregated stack", regulated by blue/red-shifted charge-transfer and π-π stacking including weak C-H···F and C-H···O noncovalent interactions. By utilizing the structural transformational ability of the self-assembled TAH, the mechanistic aspects for the rapid nanoscopic co-assembly formation were precisely demonstrated experimentally and theoretically. The trimorphs and co-crystals of TAH could be disassembled resulting in turn-on emission by applying various external stimuli and being repeatedly reconfigured, thus providing a unique structure-property relationship and new TAH-based materials. This unique concept offers color-specific polymorphism and CT-complex formation strategy involving a simple class of functional materials having cooperative network forming ability using the twisted molecular donor.

Assessment of Prescribing Pattern and Safety Profile of Drugs Used in Intranasal Route in Paediatric Age Group of Patients in a Tertiary Care Hospital

Background Recently there has been an increased preference for intranasal delivery of drugs due to highly vascular nasal mucosa, bypassing first pass metabolism and the blood brain barrier (BBB) lead in quick drug absorption to the systemic circulation and direct access to brain from olfactory region. For pediatric patients this route offers significant benefits over injections or oral routes, like increased compliance, easy administration, and minimal side effects. Objective Assessment of prescription pattern of drugs and safety profile of drugs used by intranasal route in paediatric age group. Method Our study was a prospective observational study paediatric age group of patients conducted in the departments of Pharmacology, Paediatrics and Otorhinolaryngology of Burdwan Medical College and Hospital, Burdwan. Data were collected in CRF and frequency distribution of collected data done. Microsoft Excel 2010 was used for analysis. Result Common age group was infants. Males were more in number. Most common indication was epistaxis. Intranasal drugs per prescription were 1.05. Most commonly prescribed intranasal drug was nasal saline. Nasal decongestant was the most common prescribed medication. Nasal drops were the most common dose formulation. Conclusion Intranasal drug prescribing in our study was mainly aimed for treating local problems, very few being for systemic action. Some prescribing indicators like prescribing by generic name and prescribing from national essential drug lists were acceptable with scope for improvement. Average number of drugs per prescription and antibiotic use was high. Adverse events after intranasal drug use were primarily local and nose related.

A conformational tweak for enhanced cellular internalization, photobleaching resistance and prolonged imaging efficacy

A strategy of conformational tweaking regulates the condensed state behavior of naphthalimide skeletal isomers (NSIs) and enhances their photophysical properties, cellular uptake and prolonged imaging capability. This salient approach results in a large Stokes shift (>120 nm), rapid cellular internalization, photobleaching resistance, and efficient bioimaging of the ribbon-like nano-assembly superior to that of its electronically similar micro-flower isomer.

Recent Developments on Multi-Functional Metal-Free Mechanochromic Luminescence and Thermally Activated Delayed Fluorescence Organic Materials

Metal-free organic compounds with highly ordered π-conjugated twisted skeletons are capable of generating brilliant multi-colored light. Additionally, the co-existence of numerous other multi-functional properties have endowed them with the potential to be a promising class of materials for several electronic and photonic applications and next-generation advanced luminescent material-based devices. This review highlights the recent developments made in this fascinating class of multi-property encompassing materials, involving a highly twisted donor-acceptor based single molecular platform with synchronized photophysical behavior such as thermally activated delayed fluorescence (TADF), mechanoresponsive (MR), room-temperature phosphorescence (RTP), and aggregation induced emission (AIE) with associated unique and inherently manifested structure-property relationship investigations. Furthermore, a brief summary of the optoelectronic behavior of TADF materials are also presented by correlating their performances in the organic light-emitting diodes (OLEDs) and corresponding EL devices. In addition to mechanochromic luminescence (MCL) with TADF behavior, new types of emitters are also being developed, with tunable color changes such as blue-green, yellow-orange, yellow-red, etc., with some emitters crossing the entire visible span to produce white OLEDs. These developments have enriched the library of fascinating organic materials in addition to providing new directions of multifunctional material design for solutions processed OLED and several other advanced devices.

White light emitting diode based on purely organic fluorescent to modern thermally activated delayed fluorescence (TADF) and perovskite materials

White organic/polymer light emitting diode (WOLED/WPLED) processed from solution has attracted significant research interest in recent years due to their low device production cost, device flexibility, easy fabrication over large area including roll to roll and ability to print in various designs and shapes providing enormous design possibilities. Although WOLEDs fabricated using solution process lack their thermally evaporated counterparts in terms of device efficiency, remarkable progress has been made in this regard in recent years by utilizing new materials and device structures. In the present review, we have summarized and extrapolated an excellent association of old and modern concept of cost-effective materials and device structure for realization of white light. In particular, this article demonstrated and focused on design, and development of novel synthesis strategy, mechanistic insights and device engineering for solution process low cost WOLEDs device. Herein, an overview of the prevailing routes towards white light emitting devices (WLEDs) and corresponding materials used, including polymer based WLED, small molecules emitters based thermally activated delayed fluorescence (TADF), perovskite light-emitting diodes (PeLEDs) and hybrid materials based LEDs, color down-converting coatings with corresponding best efficiencies ever realized. We presume that this exhaustive review on WLEDs will offer a broad overview of the latest developments on white SSL and stonework the approach en route for innovations in the immediate future.

Land use and land cover dynamics with special emphasis on shifting cultivation in Eastern Ghats Highlands of India using remote sensing data and GIS

Continual, historical, and accurate information about the land use/land cover (LULC) changes of the earth's surface is extremely important for sustainable management of natural resources. In this study, historical topographic sheets, IRS P6 LISS-III, and LANDSAT TM images were used to provide recent and historical LULC conditions of the Eastern Ghats Highlands of east India. The supervised classification results were further improved by employing image enhancement and visual interpretation. Ratio Vegetation Index with fuzzy-based possibilistic c-means classification approach has improved the classification accuracy of the shifting cultivated area. Post-classification comparisons of the classified images indicated that the major change consisted of barren land and forestland changing into agricultural land and scrubland. Between 1931 and 2008, forest cover was decreased from 52.7% to 29.6% of total area. There was an increase in the scrub area from 874 (10.4%) to 1269 km² (15.2%), and agricultural land from 978 (11.7%) to 2864 km² (34.2%) during the same period. The rate of deforestation was found to be 0.65 km² per year for reserve forest and 24.50 km² per year for mixed forest. The shifting cultivated area in the district was 308.7 km² during 2004, and that has been reduced since then and now is stabilized to 186.4 km² area. Among this 186.4 km² area, nearly half is covered by abandoned shifting cultivation. The decadal rate of decrease of shifting cultivated area is 0.15% per year. The shifting cultivated areas were mainly distributed at elevations 580-810 and 810-907 m and slopes 20-30 and 30-40%. Southeast and south facing slopes were preferred for shifting cultivation. Based on the identified causes of the change in shifting cultivation, policy recommendations for their better management were made.

Epidemiology of gynecological cancers in Kamrup Urban District cancer registry

BACKGROUND

Cancers of the female reproductive system - namely cancer of the cervix, corpus uteri, ovarian, vulvar, vaginal, fallopian tube cancers and choriocarcinoma are an important cause of cancer morbidity and mortality among women worldwide. It is estimated to be the third most common group of malignancies in women. The comprehensive global cancer statistics from the International Agency for Research on Cancer indicate that gynaecological cancers accounted for 20% of the 14.1 million estimated new cancer cases and 8.2 million cancer deaths among women in the world in 2012. The estimation of cancer burden is necessary to set up priorities for disease control. Gynaecological cancers have increased in India and are estimated to be around 182,602 by the year 2020 constituting about 30% of the total cancers among women in India. Among these, cancer of the uterine cervix followed by ovary and corpus uteri are the major contributors.

METHODS AND MATERIALS

Cancer is not notifiable in India, so method of collecting information on cancer was active with voluntary participation of different sources including major hospitals, diagnostic centers, state referral board and birth and death registration centers within registry area.

RESULTS

A total of 3767 (44%) cases were registered in women out of the total number of 8561 cancer cases during the period from 2010-2014. In case of gynaecological cancers a total of 661 cases of cervical, ovarian and corpus uterine cancers were registered out of the total 3767 female cancer cases (17.5%) for the year 2010-2014.The annual average crude rate in women for all sites of cancer was 117.4 per 100000 population. The corresponding AARs was 166.6.

CONCLUSIONS

Women's health issues have attained high concern in recent decades. Utmost efforts should be made to educate women in early cancer detection by creating awareness on risk factors and symptoms.

Detection of multidrug-resistant tuberculosis using MGIT™(TM) and MAS-PCR in Tripura, India

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) poses a global threat that is further compounded by the human immunodeficiency virus (HIV) epidemic.

OBJECTIVE

To detect MDR-TB among pulmonary TB (PTB) patients with or without HIV coinfection by isolating and identifying Mycobacterium tuberculosis from clinical samples and performing drug susceptibility testing (DST).

METHODS

Sputum was collected from presumed PTB cases. Microscopic examination was performed following Ziehl-Neelsen (ZN) staining and cultured in Löwenstein-Jensen (LJ) medium. First-line anti-tuberculosis DST of the isolates was performed using MGIT™ (Mycobacterial Growth Indicator Tube) and multiplex allele-specific polymerase chain reaction (MAS-PCR).

RESULTS

Of 172 study subjects, 59.3% (102/172) were smear-positive and 40.7% (70/172) were smear-negative. In the smear-positive and -negative groups, respectively 62.7% (64/102) and 8.6% (6/70) were culture-positive. DST on MGIT showed a cumulative resistance of 7.1% (5/70) to isoniazid (INH) and rifampicin. More ethambutol (EMB) and combined INH+EMB resistance was detected using MAS-PCR.

CONCLUSION

MDR-TB is a problem in Tripura, and culture and phenotypic DST are required for diagnosis. MAS-PCR may provide an alternative rapid screening tool.

Biophysical and socioeconomic characterization of a water-stressed area and simulating agri-production estimates and land use planning under normal and extreme climatic events: a case study

This study aims in linking the biophysical and socioeconomic data base layers with the technical coefficients or simulation models for agri-production estimates and land use planning under normal and extreme climatic events, and exploring the resource and inputs management options in village Shikohpur, Gurgaon district located in the northwest part of India. The socioeconomic profile of Shikohpur is highly skewed with mostly small and marginal farmers. Though the areas under wheat in Shikohpur are increasing, the productivity is declining or remaining stagnant over the years. Most of the area during kharif season (June-September) remains fallow. Pearl millet based cropping systems (pearl millet-mustard and pearl millet-wheat) are predominant. Soils are mostly loamy sand to sandy loam with average of 70-80% sand content. Organic C content in soil is less than 0.3%, due to high prevailing temperature with little rainfall and also intensive agriculture followed in this region. Though the annual average seasonal rainfall in Gurgaon did not have much variation over the years, occurrence of extreme climate events has increased in the last two decades. The crop intensity is low and the water table is declining. Water and nitrogen production functions were developed for the important crops of the region, for their subsequent use in scheduling of the inputs. InfoCrop, WTGROWS and technical coefficients were used for crop planning and resource management under climate change and its variability, extreme events, limited resource availability and crop intensification. These will help in disseminating necessary agro-advisories to the farmers so that they will be able to manipulate the inputs and agronomic management practices for sustained agricultural production under normal as well as extreme climatic conditions.

Evaluation of quantitative buffy coat (QBC) assay and polymerase chain reaction (PCR) for diagnosis of malaria

A prospective study was undertaken to compare the Polymerase Chain Reaction (PCR) and Quantitative Buffy Coat (QBC) assay with conventional Giemsa technique for diagnosis of malaria. A total of 104 samples were taken for the purpose. They comprised of fever cases suggestive of malaria (n=74) and control group, fever cases other than malaria (n=30). Peripheral blood smears were prepared by Giemsa staining and QBC assay was performed as per standard protocol. From the stored blood samples, parasite DNA was extracted and PCR was performed using P. falciparum and P. vivax specific sets of primers. The QBC assay was 100% in agreement with the Giemsa stain. Specificity of the PCR detection of P. falciparum parasites was 100%. However, sensitivity for detection of P. falciparum and P. vivax by PCR was 64.28% and 82.35% respectively. In mixed cases of malaria (n=2), PCR results were in 100% agreement with that of Giemsa. The lower sensitivity of PCR for P. falciparum could probably be due to inaccessibility of target DNA, presence of PCR inhibitors in samples and parasite strain variations.

Paraganglioma of external auditory canal

In the ear, paragangliomas are commonly found in the tympanic cavity or in juglar bulb. We, here, present a case of paraganglioma originating from the external auditory canal as it has not been reported in the world literature. The clinico-pathologic features of such a case has been described.

Latissimus dorsi muscle blood flow during synchronized contraction: implications for cardiomyoplasty

BACKGROUND

Damage in latissimus dorsi muscle flaps has been reported after clinical and experimental cardiomyoplasty, and an ischemic origin has been suggested.

METHOD

In situ, preconditioned latissimus dorsi muscles in 5 sheep were stimulated in either 1:1 (muscle: heart) or 1:2 synchrony with the systolic phase of the cardiac cycle, using a burst duration of either 21% or 35% of the cycle. Thoracodorsal artery blood flow and thoracodorsal venous lactate concentrations were measured before and immediately after a 3-minute period of stimulation.

RESULTS

The exercise-induced augmentation of thoracodorsal artery blood flow was significantly (p < 0.05) less with a 1:2 regimen than a 1:1 regimen, for both a 21% (88%; 95% confidence interval [CI], 55.6% to 127.3% versus 138.9%; CI, 97.6% to 188.8%) and 35% burst duration (123.2%; CI, 84.7% to 169.9% versus 167.0; CI, 120.8% to 222.6%). After cessation of stimulation, reactive hyperaemia was observed in 3 of 5 animals with 1:1 21% burst stimulation, and in 5 of 5 animals with a 35% burst duration, but was not seen after 1:2 regimens. A significant (p < 0.01) increase in thoracodorsal venous lactate levels was present after 1:1 35% burst stimulation (34.9%; CI, 9.9% to 65.6%), but lactate levels tended to fall when a 1:2 ratio was used (15.9%; CI, -3.2% to 31.5%; p < 0.1).

CONCLUSIONS

One-to-one stimulation regimens may be detrimental to latissimus dorsi blood flow, and an adaptive, rather than fixed, burst duration may be preferable. These findings have important implications for the cardiomyoplasty procedure.

Factors affecting the integrity of latissimus dorsi muscle grafts: implications for cardiac assistance from skeletal muscle

BACKGROUND

Severe latissimus dorsi muscle damage may compromise cardiomyoplasty performance. We analyzed factors underlying the damage produced in 20 sheep latissimus dorsi muscles by isolating the influences of electrical stimulation, mobilization (with some loss of vascular supply), loss of normal resting tension, or a combination of these.

METHODS

In group I (n = 3), the muscle was mobilized except for its neurovascular pedicle and reattached at normal resting length. In group II (n = 3), the muscle was mobilized and reattached at about 80% of resting length. Groups III (n = 6) and IV (n = 4) were as groups I and II except that continuous indirect stimulation at 2 Hz was added after 2 weeks. In group V (n = 4), the undisturbed muscle received stimulation alone. After 10 to 12 weeks, muscle samples were taken for morphometric analysis.

RESULTS

Loss of resting muscle tension appeared to be the single most damaging intervention, though mobilization and stimulation had further deleterious effects. The worst damage was seen when all three factors were combined, when 60% of the muscle cross section was occupied by connective tissue and fat. The changes were significantly more severe in the distal than in the proximal part of the muscle, implicating ischemia as a contributory factor.

CONCLUSIONS

Fiber damage reduces the effectiveness of muscle grafts used for cardiac assistance and merits further systematic investigation.

Anaesthesia for cardiomyoplasty

Cardiomyoplasty is a new surgical procedure for the treatment of severe heart failure, but early mortality has been high in the preliminary experience of many centres. This report describes the anaesthetic techniques used for the first two successful cases to be performed in the UK.