Prolonged Exciton Lifetime Is Achieved in Porphyrin Nanoring by Template Engineering: A Nonadiabatic Tight Binding Approach

Porphyrin nanoring has been attracting immense attention due to its light harvesting capacity and potential applications in optical, catalysis, sensor, and electronic devices. We demonstrate by nonadiabatic quantum dynamics simulations that the photovoltaic efficiency can be enhanced by template engineering. Altering the hexadentate template (T6) with two tridentate templates (2T3) within the porphyrin ring (P6) cavity accelerated the electron transfer twice and suppressed the electron-hole recombination by nearly three times. The atomistic tight-binding simulation rationalized the dynamics by different localizations of charge of the band edge states, changes in nonadiabatic coupling, alteration in quantum coherence, and involvement of diverse electron-phonon vibrational modes. Further 2T3 templates more strongly hold the P6 ring than T6, reducing the structural fluctuation. As a result, the nonadiabatic coupling becomes weaker and suppresses the carrier recombination. Current atomistic simulation presents a template engineering strategy to enhance the exciton lifetime along with ultrafast charge separation, crucial factors for photovoltaic applications.

Stray Dogs (Mongrels) Are Potent Reservoir of Drug-Resistant Pathogens: A Study in Peri-Urban Areas of Kolkata, India

This study depicts the drug-resistance and phylogenomic characteristics of 365 Escherichia coli (EC) and 76 Klebsiella pneumoniae (KP) isolated from stray dogs (293) in and around Kolkata, India. Initial screening found 59 isolates, including 48 E. coli and 11 KP multidrug resistant, which included 33 extended-spectrum β-lactamase, 41 AmpC β-lactamase and 18 metallo-β-lactamase producers carrying blaNDM-1 (11) and blaNDM-5 (7) genes. Majority of them had the resistant genes such as blaCTX-M (33), blaTEM (18), blaSHV (4), blaOXA (17), blaFOX (2), blaDHA (2), blaCITM (15), blaCMY-2 (13), blaGES (2) and blaVEB (2), qnrS (15), qnrB (3), aac-6'-Ib-cr (14), tetA (26), tetB (14), sul-1 (25), armA (2) and rmtB (6), in addition to adherence genes such as csgA (33), fimA (27), fliC (13), sdiA (33), rcsA (38), and rpoS (39). They also carried plasmid of diverse replicon types of which IncFIA and FIB were the most frequent. Phylogrouping categorized most of the MDR E. coli in phylogroup A (20), B1 (14), and B2 (6). Enterobacteriaceae repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) showed genetic diversity of multidrug resistant isolates irrespective of their origin, resistance, and virulence types, differentiating the EC in five clades (A-E) and KP in four clades (A-D). As these stray dogs, which had no history or scope of previous antimicrobial therapy, were found to have contracted potential antimicrobial resistance pathogens, the role of environment in spread of such pathogens and further possibility of human infections cannot be ruled out.

Genomic characterization of Puccinia triticina using molecular marker technology

Abstract Leaf rust, caused by Puccinia triticina, is the most common rust disease of wheat. The fungus is an obligate parasite capable of producing infectious urediniospores. To study the genetic structure of the leaf rust population 20 RAPD primers were evaluated on 15 isolates samples collected in Pakistan. A total of 105 RAPD fragments were amplified with an average of 7 fragments per primer. The number of amplified fragments varied from 1 to 12. GL Decamer L-07 and GL Decamer L-01 amplified the highest number of bands (twelve) and primer GL Decamer A-03 amplified the lowest number of bands i.e one. Results showed that almost all investigated isolates were genetically different that confirms high genetic diversity within the leaf rust population. Rust spores can follow the migration pattern in short and long distances to neighbor areas. Results indicated that the greatest variability was revealed by 74.9% of genetic differentiation within leaf rust populations. These results suggested that each population was not completely identical and high gene flow has occurred among the leaf rust population of different areas. The highest differentiation and genetic distance among the Pakistani leaf rust populations were detected between the leaf rust population in NARC isolate (NARC-4) and AARI-11and the highest similarity was observed between NARC isolates (NARC-4) and (NARC-5). The present study showed the leaf rust population in Pakistan is highly dynamic and variable.

Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates

Understanding the dynamics of photogenerated charge carriers is essential for enhancing the performance of solar and optoelectronic devices. Using atomistic quantum dynamics simulations, we demonstrate that a short π-conjugated optically active template can be used to control hot carrier relaxation, charge carrier separation, and carrier recombination in light-harvesting porphyrin nanorings. Relaxation of hot holes is slowed by 60% with an optically active template compared to that with an analogous optically inactive template. Both systems exhibit subpicosecond electron transfer from the photoactive core to the templates. Notably, charge recombination is suppressed 6-fold by the optically active template. The atomistic time-domain simulations rationalize these effects by the extent of electron and hole localization, modification of the density of states, participation of distinct vibrational motions, and changes in quantum coherence. Extension of the hot carrier lifetime and reduction of charge carrier recombination, without hampering charge separation, demonstrate a strategy for enhancing efficiencies of energy materials with optically active templates.

Promoting psychological well-being in preschool children: study protocol for a randomized controlled trial of a mindfulness- and yoga-based socio-emotional learning intervention

BACKGROUND

Mental health issues in youths have cascading negative effects on school outcomes, professional life, and physical health. Psychological well-being (P-WB) is an important protective factor against mental illness. Preliminary research suggests that mindfulness- and yoga-based socio-emotional learning (SEL) interventions can each have a positive impact on preschoolers P-WB. The objective of this trial is to rigorously evaluate the effect of a 24-week combined mindfulness- and yoga- based SEL intervention in preschool children from a French socio-economically disadvantaged area.

METHODS

The P-WB promotion intervention is compared to a wait-list control condition in a cluster randomized controlled trial (RCT). Sixty-four pre-Kindergarten classrooms are randomized to the intervention or control group. Primary outcomes measure self-management capacity and core P-WB components: connection, insight, engagement, and positive relationship. Secondary outcomes include measures of mental health, executive functioning, and school performance. Primary and secondary outcomes are assessed through teacher questionnaires, standardized observations of children in school context, and experimental tasks and by collecting results of the national evaluation at first grade. All children-level outcomes are evaluated at pre-intervention, at the end of the intervention, and 1 year later (follow-up analysis), to the exception of school performance which is evaluated at follow-up only. Intention-to-treat analyses, accounting for clustering within classes, will adopt a random effects linear regression model to examine outcomes for the intervention versus control children.

DISCUSSION

This is the first trial to rigorously evaluate a combined mindfulness- and yoga-based P-WB promotion intervention, and the first RCT evaluating a SEL curriculum in French schools. Results may have key implications for P-WB promotion in preschool children.

TRIAL REGISTRATION

https://www.drks.de/ DRKS00028623. Retrospectively registered on 30 May 2022.

Antimicrobial Resistance Pattern, Clustering Mechanisms and Correlation Matrix of Drug-Resistant Escherichia coli in Black Bengal Goats in West Bengal, India

A cross-sectional study covering four agro-climatic zones of West Bengal, India, was carried out to understand the risk-factors, antimicrobial resistance mechanism and clustering of the resistance characteristics of Escherichia coli isolated from healthy (170) and diarrhoeic (74) goats reared under intensive (52) and semi-intensive (192) farming practices. Of the 488 E. coli isolates, the majority, including the extended spectrum (n: 64, 13.11%) and AmpC β-lactamase (ACBL) (n: 86, 17.62%) producers, were resistant to tetracycline (25.2%), followed by enrofloxacin (24.5%), cefotaxime (21.5%) and amikacin (20.5%). Statistical modelling revealed that the isolates from diarrhoeic animals (p < 0.001) are likely to be more ACBL-positive than those from the healthy counterparts. Similarly, cefotaxime (p < 0.05) and enrofloxacin-resistance (p < 0.01) were significantly higher in diarrhoeic goats and in goats reared intensively. The isolates (n = 35) resistant to multiple drugs revealed the presence of β-lactamase [blaCTXM-1-(21), blaSHV-(7), blaTEM-(3), blaCMY-6-(1), blaCITM-(3)]; quinolone [qnrB-(10), qnrS-(7), aac(6’)-Ib-cr-(3)]; tetracycline [tetA-(19), tetB-(4)] and sulphonamide resistance determinants [sul1-(4)]; multiple plasmids, especially those belonging to the IncF and IncI1 replicon types; and active acrAB efflux pumps. Further, two isolates harbored the carbapenem resistance (blaNDM-5) gene and eight were strong biofilm producers. This first ever study conducted to unravel the status of AMR in goat farming reveals that not only the intensive farming practices but also certain clinical ailments such as diarrhoea can increase the shedding of the drug-resistant isolate. The emergence of multi-drug resistant (MDR) E. coli in goats, particularly those that are carbapenem resistant, is a cause for concern that indicates the spread of such pathogens even in the livestock sub-sector generally considered as naive.

Symmetrical Linkage in Porphyrin Nanoring Suppressed the Electron-Hole Recombination Demonstrated by Nonadiabatic Molecular Dynamics

Macromolecular porphyrin nanorings are receiving significant attention because of their excellent optoelectronic properties. However, their efficiencies as potential solar materials are significantly affected by nonradiative charge recombination. To understand the recombination mechanism by alternating structural parameters and using tight-binding nonadiabatic molecular dynamics, we demonstrate that charge recombination depends strongly on the mode of the linker in the porphyrin nanoring. The nanoring having all-butadiyne-linkage (pristine-P8) inhibits carrier relaxation. In contrast, a partially fused nanoring (fused-P8) expedites the rate of quantum transition. An extension of the lifetime by a factor of 4 is due to the larger optical gap in pristine-P8 that reduces the NA coupling by decreasing the overlap between band edge states. Additionally, an intense phonon peak in the low-frequency region and rapid coherence loss within the electronic subsystem favors prolonging the carrier lifetime. This study provides an atomistic realization for the design of macromolecular porphyrin nanorings for the potential use in photovoltaic materials.

Prevalence and molecular characterization of extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolated from dogs suffering from diarrhea in and around Kolkata

BACKGROUND

Dogs are the favorite companion animals among humans. The close interaction between dogs and people increases the risk of antibiotic resistance spreading. Surveillance for antimicrobial resistance and the identification of ESBL-producing Escherichia coli as an indicator bacterium is an important tool for managing antimicrobial drug therapy.

AIMS

The present study targeted to identify and characterize ESBL-producing E. coli among dogs suffering from diarrhea in and around Kolkata.

METHODS

Isolation and identification of E. coli from dogs suffering from diarrhea (n=70) along with screening for the production of both ESBL and AmpC. The isolates were further characterized through antimicrobial resistance profiling, resistance genes (bla _CTX-M, bla _TEM, and bla _SHV) screening, and phylogenetic group study.

RESULTS

Among the 70 isolates, 21 (30%) were confirmed ESBL producers. An antibiogram typing of ESBL-producing E. coli revealed that the majority of them were resistant to norfloxacin (85.7%) followed by tetracycline (61.90%), doxycycline (57.14%), piperacillin/tazobactam (52.38%), cotrimoxazole (47.62%), gentamicin (42.62%), amikacin (23.81%), and chloramphenicol (19.05%). Major resistance genes included bla _CTX-M (100%), bla _TEM (28.57%), and bla _SHV (9.50%). The predominant phylogenetic groups were phylogroup A (76%) followed by phylogroup D (24%).

CONCLUSION

The current investigation reported a high prevalence of both ESBL and AmpC β-lactamase (AmpC) producing E. coli, co-resistance to a distinct group of antibiotics, and co-existence of different ESBL genes in dogs. Our findings highlight the importance of diagnostic antimicrobial susceptibility testing for proper antimicrobial therapy and to prevent antimicrobial resistance from spreading to humans from dogs in Kolkata and the surrounding area.

Elucidating the resistance repertoire, biofilm production, and phylogenetic characteristics of multidrug-resistant Escherichia coli isolated from community ponds: A study from West Bengal, India

This study details about the phenotypic and molecular characteristics of multidrug-resistant (MDR) Escherichia coli in the fresh community pond water (n = 257) collected from three districts of West Bengal, India. In total, 57 isolates were MDR of which 38 emerged as extended spectrum and 7 as AmpC-type β-lactamase producers in phenotypic assay. Among β-lactamase genes, blaCTXM-1was predominant (87.71%) followed by blaAmpC (77.2%) and blaTEM-1 (22.8%). Six MDR strains carried metallo-β-lactamase (MBL, blaNDM-1) gene. Tissue culture plate assay confirmed strong biofilm (SP) production in four MDR and one non-MDR isolates. In PCR-based replicon typing (PBRT), multiple plasmids of diverse replicon types (Frep, FIB, I1, FIA, K/B, HI1, and Y) were identified. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR)-based phylogenetic analysis revealed a high degree of genetic divergence among the MDR isolates. Multiplex PCR-based phylogrouping categorized 11 isolates as virulent (B2/D/F), which carried blaCTXM-1 gene and three had blaNDM-1 gene. Relative transcriptional activity of AcrAB efflux pump was significantly elevated among the SP and MBL producers. The presence of MDR E. coli isolates, particularly those resistant to carbapenem, in pond water used for daily domestic and household work, is a cause of concern as these pathogens may sneak into human food chain causing life-threatening infections. PRACTITIONER POINTS: Multidrug-resistant biofilm producing E. coli isolated from community pond water. A few of them were carbapenem-resistant and belonged to virulent (B2/D) types. Expression of AcrAB efflux pumps was found significantly elevated among biofilm producers and carbapenem-resistant population.

Enhancing sweat rate using a novel device for the treatment of congestion in heart failure

Background

Current treatment of fluid retention in heart failure (HF) relies primarily on diuretics. However, adequate decongestion is not achieved in many patients.

Purpose

To study the feasibility and short-term performance of a novel approach to remove fluids and sodium directly from the interstitial compartment by enhancing sweat rate.

Methods

We used a device designed to enhance fluid and salt loss via the eccrine sweat glands. Skin temperature in the lower body was increased to 35–38°, where the slope of the relationship between temperature and sweat production is linear. With this wearable device, the sweat evaporates instantaneously, thus avoiding the awareness of perspiration. The primary efficacy endpoint was the ability to increase skin temperature to the desired range without elevating the core temperature above normal range. A secondary efficacy endpoint was a clinically meaningful hourly sweat output, defined as ≥150 mL/h. The primary safety endpoint was any procedure-related adverse events.

Results

We studied 6 normal subjects and 10 HF patients with clinical evidence of congestion and median NT-proBNP of 602 pg/mL [interquartile range 427 to 1719 pg/mL]. Participants underwent 3 treatment sessions of up to 4h. Skin temperature increased to a median of 37.5°C (interquartile range 37.1–37.9°C) with the core temperature remaining unchanged. The median total weight loss during treatment was 219±67 g/h (Figure) with a range of 100–338 g/h. In 77% of cases, the average sweat rate was ≥150 mL/h. Systolic (P=0.25) and diastolic (P=0.48) blood pressure and heart rate (P=0.11) remained unchanged during the procedure. There were no significant changes in renal function and no procedure-related adverse events.

Conclusion

Enhancing sweat rate was safe and resulted in a clinically meaningful fluid removal and weight loss. Further evaluation of this concept is warranted.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): AquaPass Inc Weight loss due to sweat

Clinicopathological spectrum of Diffuse Large B Cell lymphoma: a study targeting population yet unexplored in Pakistan

Objective

Diffuse Large B Cell Lymphoma (DLBCL) is the most common type of Non-Hodgkin Lymphoma (NHL). The aim of this study was to assess the clinico pathological characteristics of DLBCL specifically, among the affected individuals residing in Northern areas of Pakistan who had not been previously included in major lymphoma studies due to their remote location.

Results

Mean age of the patients was 49.7 years. Male: female ratio was 1.5:1. Primary site was lymph node in 99 (71.74%) patients, out of which, 36 (26.09%) patients had B symptoms and 19 (13.77%) patients had stage IV disease. 39 (28.26%) patients had primary extra nodal involvement, 4 (2.90%) patients had B symptoms and 3 (2.17%) had stage IV disease. Extra nodal sites involved in primary extra nodal DLBCL were gastrointestinal tract (GIT) 19 (48.72%), tonsils 6 (15.38%), spine 4 (10.26%), soft tissue swelling 3 (7.69%), parotid gland 2 (5.13%), thyroid 2 (5.13%) central nervous system (CNS) 1 (2.56), breast 1 (2.56%) and bone marrow 1 (2.56%). Our study revealed increased percentage of patients with nodal DLBCL in stage IV and with B symptoms. Few patients with primary extra nodal DLBCL had B symptoms and stage IV disease at presentation. GIT was the most common site of involvement in primary extra nodal DLBCL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05768-5.

Residue level and health risk assessment of organophosphorus pesticides in eggplant and cauliflower collected from Dhaka city, Bangladesh

Residue levels of seven organophosphorus pesticides in two vegetables (eggplant and cauliflower) collected from major markets of Dhaka city, Bangladesh were analysed. The collected samples were analysed using a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction technique by Gas Chromatography coupled with Flame Thermionic Detector (GC-FTD). Among the 50 analysed samples of the eggplant 12% samples contained residues of chlorpyrifos (0.384~0.980 mg/kg), 6% samples contained residue of dimethoate (0.052~0.132 mg/kg) and 2% samples contained residue of diazinon (0.01 mg/kg). Whereas, among the 50 samples of cauliflower, 12% samples contained residues of chlorpyrifos (0.056~0.540 mg/kg), 8% samples contained residues of diazinon (0.033~0.42 mg/kg) and 2% samples contained residues of quinalphos (0.06 mg/kg). The chlorpyrifos was found as the most frequently detected organophosphorus pesticide. Among the 21 contaminated samples, 20 were above EU-MRL. Short and long-term health risk assessment based on ARfD and ADI indicates that the intake risks of eggplant and cauliflower were in the acceptable range. Nevertheless, establishing strong monitoring and traceability system together with controlling pre-harvest interval needed to ensure food safety, consumer confidence and promote vegetable export from Bangladesh.

Common Defects Accelerate Charge Separation and Reduce Recombination in CNT/Molecule Composites: Atomistic Quantum Dynamics

Carbon nanotubes (CNTs) are appealing candidates for solar and optoelectronic applications. Traditionally used as electron sinks, CNTs can also perform as electron donors, as exemplified by coupling with perylenediimide (PDI). To achieve high efficiencies, electron transfer (ET) should be fast, while subsequent charge recombination should be slow. Typically, defects are considered detrimental to material performance because they accelerate charge and energy losses. We demonstrate that, surprisingly, common CNT defects improve rather than deteriorate the performance. CNTs and other low dimensional materials accommodate moderate defects without creating deep traps. At the same time, charge redistribution caused by CNT defects creates an additional electrostatic potential that increases the CNT work function and lowers CNT energy levels relative to those of the acceptor species. Hence, the energy gap for the ET is decreased, while the gap for the charge recombination is increased. The effect is particularly important because charge acceptors tend to bind near defects due to enhanced chemical interactions. The time-domain simulation of the excited-state dynamics provides an atomistic picture of the observed phenomenon and characterizes in detail the electronic states, vibrational motions, inelastic and elastic electron-phonon interactions, and time scales of the charge separation and recombination processes. The findings should apply generally to low-dimensional materials, because they dissipate defect strain better than bulk semiconductors. Our calculations reveal that CNT performance is robust to common defects and that moderate defects are essential rather than detrimental for CNT application in energy, electronics, and related fields.

16 Re-Do of Laparoscopic CBD Exploration Through Cystic Duct Remnant Following Laparoscopic Cholecystectomy; A Case Series

Introduction

Common bile duct (CBD) stones are detected in approximately 10-15% of patients with gallstone disease. They can be formed in the absence of gallbladder stones or in patients who underwent previous cholecystectomy. Laparoscopic common bile duct exploration has been documented since 1999, with increasing evidence illustrating the effectiveness of the transcystic approach. There is no review of re-exploration of the CBD, due to retained stones, following laparoscopic cholecystectomy (LC) via this approach. Four cases are presented detailing need for initial intervention, and intra-operative findings.

Method

Review of four cases in 2020 in Aberdeen Royal Infirmary. Each underwent re-do laparoscopic transcystic common bile duct exploration for retained stone, following previous laparoscopic cholecystectomy.

Results

Each case had successful stone clearance and resolution of symptoms.

Conclusions

With increasing laparoscopic technology and surgical skill, re-exploration of the CBD following previous LC due to emergency surgical presentations should be performed. This is feasible and safe. We recommend the transcystic approach due to reduced morbidity and high success rates of stone extraction.

Characterization of Multidrug-Resistant Biofilm-Producing Escherichia coli and Klebsiella pneumoniae in Healthy Cattle and Cattle with Diarrhea

This study describes comparative occurrence and characterization of multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae (KP) in healthy cattle (HC) and cattle with diarrhea (DC) in India. During 2018-2020, 72 MDR isolates, including 35 E. coli (DC: 27; HC 8) and 37 K. pneumoniae (DC: 34; HC: 3), from 251 rectal swabs (DC: 219; HC: 32) were investigated for extended-spectrum beta-lactamase (ESBL), AmpC type β-lactamase and carbapenemase production, antimicrobial susceptibility profile, biofilm production, and efflux pump activity. Fifty-five MDR isolates were ESBL producers (ESBLPs) (DC: 50; HC: 5) and ESBLPs from DC were coresistant to multiple antibiotics. The blaCTX-M gene (50) was the most frequently detected β-lactamases followed by blaAmpC (22), blaTEM1 (13), blaCMY-6 (6), blaOXA1 (5), blaPER (2), blaDHA, and blaFOX and blaSHV12 (1 each). Plasmid-mediated quinolone resistance determinants qnrB, qnrS, qnrA, and qepA were detected in 18, 16, 2, and 3 isolates, respectively. Twenty three isolates revealed mutation in gyrA and parC genes. Tetracycline-resistance markers tetA, tetB, tetC, and tetE were detected in 33, 10, 3, and 2 isolates, respectively. Only one of the 41 imipenem-resistant isolates harbored blaNDM-5 and two were colistin-resistant. Altogether, 20 MDR isolates were strong biofilm producers and 19 harbored different virulence factors. This is the first ever report from India on the presence of MDR Enterobacteriaceae with resistance to even last-resort antimicrobials in the bovine diarrhea.

Conversion therapy in patients with colorectal liver metastases

BACKGROUND

The occurrence of colorectal liver metastases (CRLM) impairs prognosis, yet long-term survival can be achieved by enabling liver resection. This study aims to describe factors associated with conversion therapy leading to liver surgery and treatment outcome.

METHODS

A retrospective cohort study was conducted including all patients with CRLM discussed at multidisciplinary team conference at Karolinska University Hospital, Stockholm, Sweden, from 2013 to 2018. Factors associated with conversion therapy and outcome following conversion therapy were analysed with logistic regression and survival analyses.

RESULTS

Out of 1023 patients with CRLM, 100 patients (10%) received conversion chemotherapy, out of whom 31 patients (31%) subsequently underwent liver resection. Patients in whom conversion chemotherapy resulted in liver resection were younger (median age 61 vs. 66 years, p = .024), less likely to have a KRAS/NRAS-mutated primary tumours (25% vs. 53%, p = .039) and more likely to have received anti-EGFR agents (32% vs. 4%, p = .001) than patients progressing during conversion chemotherapy. The median OS for patients treated with conversion chemotherapy leading to liver resection was 24 months, compared to 14 months for patients progressing during conversion chemotherapy, p < .001. The OS for patients progressing during conversion chemotherapy was similar to patients given palliative chemotherapy, approximately 13 months.

CONCLUSION

Conversion therapy offers a survival benefit in selected patients. Despite treatment advances, the majority of patients undergoing conversion chemotherapy never become eligible for curative treatment.

Health risk assessment of pesticide residues in vegetables collected from northern part of Bangladesh

The use of synthetic pesticides for agricultural production in developing countries like Bangladesh is unavoidable. Therefore, there is also a concern for the residual effects in public health. The present study aimed to assess the health hazards associated with the residual effect of pesticides in two common vegetables (cauliflower and tomato) collected from five different markets of a northern city of Bangladesh. A total 80 samples (i.e. 40 of each vegetable) were collected for the analysis of seven major organophosphorus insecticides namely acephate, chlorpyrifos, diazinon, dimethoate, fenitrothion, malathion and quinalphos used in that region. Modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction technique and GC-FTD (Gas Chromatography coupled with Flame Thermionic Detector) used for the analysis of the samples. Results indicate that 11 (6 cauliflower, 5 tomato) analyzed samples contained residues which are about 14% of the total number of samples. Most of the samples contaminated diazinon at a level above EU-MRLs. However, health risk assessment based on ADI, the contaminated samples were safe. Continuous monitoring together with a sample traceability system is suggested to protect consumers’ health from the cumulative effects of other contaminated dietary products.

Structural rigidity accelerates quantum decoherence and extends carrier lifetime in porphyrin nanoballs: a time domain atomistic simulation

Nonradiative electron-hole (e-h) recombination is the primary source of energy loss in photovoltaic cells and inevitably, it competes with the charge transfer process, leading to poor device performance. Therefore, much attention has to be paid for delaying such processes; increasing the excitonic lifetime may be a solution for this. Using the real-time, density functional tight-binding theory (DFTB) combined with nonadiabatic molecular dynamics (NAMD) simulations, we demonstrate the exciton relaxation phenomena of different metal-centered porphyrin nanoballs, which are supposed to be very important for the light-harvesting process. It has been revealed that the carrier recombination rate gradually decreases with the increase in the molecular stiffness by introducing metal-coordinating templating agents into the nanoball. Our simulation demonstrates that the lower atomic fluctuations lead to poorer electron-phonon nonadiabatic coupling in association with weak phonon modes and these as a whole are responsible for shorter quantum coherence and hence delayed recombination events. Our analysis is in good agreement with the recent experimental observation. By replacing the Zn metal center with a heavier Cd atom, a similar trend is observed; however, the rate slows down abruptly. The present simulation study provides the fundamental mechanism in detail behind the undesired energy loss during exciton recombination and suggests a rational design of impressive nanosystems for future device fabrication.

Unambiguous hydrogenation of CO2 by coinage-metal hydride anions: an intuitive idea based on in silico experiments

Coinage metal hydride anions, especially AgH⁻, can effectively and deterministically hydrogenate CO₂ to HCO₂⁻.

Highly-Sensitive Refractive Index Sensing by Near-infrared Metatronic Nanocircuits

In this work, we present a highly-sensitive refractive index sensor based on metatronic nanocircuits operating at near-infrared spectral range. The structure is designed based on simple nanorod geometry and fabricated by nanopatterning of transparent conducting oxides. The functionality of these polarization dependent metatronic nanocircuits is enhanced by applying tunable response. This feature is investigated by depositing NH₂ (Amine) groups via plasma polymerization technique on top of indium-tin-oxide nanorods. The dielectric constant of Amine groups is a function of their thickness, which can be controlled by the RF power and the time duration of the applied plasma polymerization process. The resonance wavelengths of nanocircuits shift to higher wavelength, as the dielectric constant of the deposited material increases. An excellent agreement between the design and experimental results are obtained. Our metatronic based nanosensor offers a high-sensitive performance of 1587 nm/RIU with a satisfactory figure of merit for this class of sensors.

Ultrafast, asymmetric charge transfer and slow charge recombination in porphyrin/CNT composites demonstrated by time-domain atomistic simulation

The versatile photochemical properties of porphyrin molecules make them excellent candidates for solar energy applications. Carbon nanotubes (CNTs) exhibit superior charge conductivity and have been combined with porphyrins to achieve efficient and ultrafast charge separation. Experiments show that the charge separated state lives less than 10 ps, which is too short for applications. Using real-time time-dependent tight binding density functional theory (DFTB) combined with non-adiabatic molecular dynamics (NAMD), we model photo-induced charge separation and recombination in two porphyrin/CNT composites. Having achieved excellent agreement with the experiment for the electron transfer from the porphyrins to the CNT, we demonstrate that hole transfer can be achieved upon CNT excitation, although in a less efficient way. By exciting the CNT one can extend light harvesting into lower energies of the solar spectrum and increase solar light conversion efficiency. We also show that the charge separated state can live over 1 ns. The two orders of magnitude difference from the experimental lifetime could arise due to the presence of defects or metallic tubes in the samples. The charge separated state is long-lived because the non-adiabatic electron-phonon coupling is very small, less than 1 meV, and the quantum coherence is short, 15-20 fs. The excited states in the isolated porphyrins and CNT live around 100 ps, in agreement with experiments as well. The porphyrin/CNT interaction occurs through the π-electron systems of the two species. The non-radiative relaxation is promoted by both high and low frequency phonons, with higher frequency phonons playing more important roles in electron relaxation than in hole relaxation. Low frequency phonons contribute significantly to the decay of the charge separated state, because they modulate the relative positions of the porphyrins and the CNT. The time-domain atomistic simulations provide a detailed understanding of the charge separation and recombination mechanisms, and generate valuable guidelines for the optimization of photovoltaic efficiency in modern nanoscale materials.

Rapid detection of infectious bursal disease by loop-mediated isothermal amplification for field analysis

Infectious bursal disease (IBD) is an immunosuppressive, acute and highly contagious illness of growing-poultry stock infected with infectious bursal disease virus (IBDV). It is common in Pakistan, causing potential economic losses throughout the year. The objective of the study is to propose a rapid, sensitive and specific diagnostic tool, and compare it with existing commonly used reverse transcriptase polymerase chain reaction (RT-PCR) method for IBDV. Different primers were used for RT-PCR and reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) to target the IBD virus. RT-LAMP primers showed prodigious specificity without cross reaction to the other animal pathogens. Moreover, RT-LAMP was found to have 10 times higher selectivity for IBDV identification as compared to RT-PCR. RT-LAMP detected 9.2% more field samples than RT-PCR. Sequences of PCR products were determined and phylogenetic analysis of research isolates revealed its maximum similarity with indigenous and Indian IBDV isolates. RT-LAMP was found to be simple, specific, less laborious and a better technique as compared to RT-PCR for quick analysis. In general, RT-LAMP was declared positive on observing turbidity or adding fluorescence staining reagent such as SYBR Green I. The options of direct use of field sample homogenate and viewing directly the peaks in the graph shown on a monitor/laptop have made it much more convenient and time saving than gel based RT-PCR.

Fowl adenovirus: history, emergence, biology and development of a vaccine against hydropericardium syndrome

The poultry industry has emerged as one of the largest and fastest growing public sectors in the developed and developing countries. Unfortunately, this industry is under a major threat from diseases that are viral (Newcastle disease, infectious bursal disease, influenza, hydropericardium syndrome), bacterial (colibacillosis, pasteurellosis, salmonellosis, mycoplasmosis), parasitic (coccidiosis, histoplasmosis) or nutritional (dyschondroplasia, osteoporosis). Among these diseases, hydropericardium syndrome (HPS) is one of the important emerging diseases occurring in the specific areas of the world where broilers (chickens) are reared under intensive conditions. HPS was first observed in 1987 at Angara Goth, an area near Karachi, Pakistan, where broilers are raised. Since then, HPS has been reported in many countries of the world. From these reported cases, an adenovirus that was either isolated from or visualized electron microscopically in the liver of affected broilers has been implicated in the syndrome. The syndrome has been reproduced by inoculation of isolated fowl adenovirus (FAdV) strains, and hence, the syndrome is also called infectious hydropericardium syndrome. To our knowledge, HPS has not been observed in humans, so it is not considered a zoonotic disease, but it is of economic importance and causes huge losses to the poultry industry. Efforts have been made to develop conventional vaccines against this disease, which were formulated from infected liver homogenate. Formalin-inactivated liver organ vaccines have failed to protect the poultry industry. Hence, there is a dire need to develop a suitable vaccine to combat this disease. Currently, recombinant vaccine candidates are being developed by using molecular biology and biotechnological approaches for the prevention and control of infectious diseases, including HPS. Therefore, it is suggested that the immunogenicity of these recombinant proteins should be evaluated for their use as subunit vaccines.

Efficacy of 0.2 μg/day fluocinolone acetonide implant (ILUVIEN) in eyes with diabetic macular edema and prior vitrectomy

Purpose

Limited data are available on the efficacy of the 0.2 μg/day fluocinolone acetonide (FAc) implant in eyes with prior vitrectomy. Here, we present a collection of 26 vitrectomized eyes treated with the 0.2 μg/day FAc implant.

Methods

Retrospective study involving six centers from four European countries analyzing the safety and efficacy data from patients (26 eyes from 25 patients) with DME and a prior vitrectomy that had been treated with one 0.2 μg/day FAc implant.

Results

Prior intravitreal therapies included anti-VEGF (mean, 3.8 injections) and steroids (mean, 1.9 injections). Pars plana vitrectomy (PPV) was performed in these eyes primarily for abnormalities of vitreoretinal interface, followed by proliferative diabetic retinopathy and vitreous hemorrhage. The 0.2 μg/day FAc implant was injected 24.2 months, on average, after PPV and the mean duration of follow-up after injection was 255 days (range, 90 to 759 days). The mean change in BCVA was +11.7 ETDRS letters (range, −19 to +40 letters; P<0.0004) and the mean change in central foveal thickness (CFT) was −233.5 μm (range, −678 to 274 μm; P<0.0001). The mean change in IOP from baseline at the last visit was +1.4 mm Hg (range, −9 to +8 mm Hg; P=0.0090). Eight eyes initiated or continued IOP lowering medications.

Conclusions

These data suggest the 0.2 μg/day FAc implant is effective in vitrectomized patients with an acceptable safety profile. Further studies are still required to confirm the current findings and to assess the effect of the 0.2 μg/day FAc implant over a longer period of follow-up.

Physician preferences for bone metastasis drug therapy in Canada

BACKGROUND

Currently in Canada, several bone-targeted agents (btas) with varying characteristics are available for the prevention of skeletal-related events (sres) in patients with bone metastasis secondary to solid tumours. In the present study, we evaluated the preferences of physicians in Canada for the various attributes of the available btas.

METHODS

Physicians treating patients with bone metastasis from solid tumours were invited to complete an online discrete-choice experiment. Respondents were asked to choose between pairs of hypothetical medications for virtual patients. Each hypothetical medication was described based on predefined key attributes: time until first sre, time until worsening of pain, medication-related annual risk of osteonecrosis of the jaw (onj), medication-related annual risk of renal impairment, and mode of administration. A random-parameters logit model was used to analyze the choices between hypothetical medications and thus infer physician preferences for medication attributes.

RESULTS

Responses from the 200 physicians who completed the discrete-choice experiment suggested that months until first sre, risk of renal impairment, and months until worsening of pain were considered the most important attributes affecting choice of bta. The annual risk of onj was considered the least important attribute.

CONCLUSIONS

When making treatment decisions about the choice of bta for patients with bone metastasis from solid tumours, delaying sres and worsening of pain, and reducing the risk of renal impairment are primary considerations for physicians in Canada.

Molecular cloning, expression and characterization of 100K gene of fowl adenovirus-4 for prevention and control of hydropericardium syndrome

Fowl adenovirus-4 is an infectious agent causing Hydropericardium syndrome in chickens. Adenovirus are non-enveloped virions having linear, double stranded DNA. Viral genome codes for few structural and non structural proteins. 100K is an important non-structural viral protein. Open reading frame for coding sequence of 100K protein was cloned with oligo histidine tag and expressed in Escherichia coli as a fusion protein. Nucleotide sequence of the gene revealed that 100K gene of FAdV-4 has high homology (98%) with the respective gene of FAdV-10. Recombinant 100K protein was expressed in E. coli and purified by nickel affinity chromatography. Immunization of chickens with recombinant 100K protein elicited significant serum antibody titers. However challenge protection test revealed that 100K protein conferred little protection (40%) to the immunized chicken against pathogenic viral challenge. So it was concluded that 100K gene has 2397 bp length and recombinant 100K protein has molecular weight of 95 kDa. It was also found that the recombinant protein has little capacity to affect the immune response because in-spite of having an important role in intracellular transport & folding of viral capsid proteins during viral replication, it is not exposed on the surface of the virus at any stage.

Digital Subtraction Angiography is Superior to Magnetic Resonance Angiography in Diagnosis of Cerebral Arteriovenous Malformation

This study was carried out to compare MRA and DSA in diagnosis of cerebral AVM. It was a retrospective observational study conducted in the Department of Neurology Dhaka Medical College Hospital (DMCH), Dhaka during the period of January 2010 to December 2010. Thirty patients with haemorrhagic stroke age ranging from 13 to 65 years were selected on the basis of inclusion and exclusion criteria as the study sample. MRA and DSA were done in all the selected patients. The mean age of the patients of haemorrhagic stroke was 30.3 ± 14.3 years and male female ratio was 2.7:1. Regarding the venous drainage of AVM 13 and 12 were superficial and deep respectively, and evaluated 100% by MRA. In the diagnosis of cerebral AVM nidus size S1: <3 and S2: 3-6 cm sensitivity was 100% but accuracy was 100% and 73.3% respectively. DSA was 100% sensitive in the diagnosis of superficial and deep venous drainage AVM. Regarding the eloquence of brain area 15 had no eloquence by both MRA and DSA and identification of eloquence of brain area sensitivity was 73.3% and accuracy was 86.7%. The main feeding vessels was found (22, 73.3%) in both DSA and MRA findings. Distal vessels was seen (8, 26.7%) in DSA but not seen in MRA findings. Intranidal aneurysm and Angiopathic AVM were seen in 3(10.0%) and 4(13.3%) respectively in DSA. This study was carried out to diagnose the patients presented with cerebral AVM by MRA and DSA. MRA could not be evaluated flow status of AVM, distal feeding arteries, intranidal aneurysm and angiopathic AVM which could be detected by DSA. So, DSA is superior to MRA in diagnosis of cerebral AVM.

Anconeus pedicle olecranon flip osteotomy: an approach for the fixation of complex intra-articular distal humeral fractures

In order to achieve satisfactory reduction of complex distal humeral fractures, adequate exposure of the fracture fragments and the joint surface is required. Several surgical exposures have been described for distal humeral fractures. We report our experience using the anconeus pedicle olecranon flip osteotomy approach. This involves detachment of the triceps along with a sliver of olecranon, which retains the anconeus pedicle. We report the use of this approach in ten patients (six male, four female) with a mean age of 38.4 years (28 to 51). The mean follow-up was 15 months (12 to 18) with no loss to follow-up. Elbow function was graded using the Mayo Score. The results were excellent in four patients, good in five and fair in one patient. The mean time to both fracture and osteotomy union was 10.6 weeks (8 to 12) and 7.1 weeks (6 to 8), respectively. We found this approach gave reliably good exposure for these difficult fractures enabling anatomical reduction and bicondylar plating without complications.

Stroke in Bangladeshi patients and risk factor

To evaluate comprehensively the distribution of established risk factors of stroke among Bangladeshi patients. This is an observational study. It involved 8400 stroke patients from different hospitals in Bangladesh over a period of sixteen years. Common established risk factors of stroke e.g. age, sex, family history, hypertension, diabetes, ischemic heart disease, smoking, obesity, dyslipidaemia, alcoholism, use of oral contraceptive pill, lack of fresh fruit consumption etc. were evaluated in these patients through a preformed questionnaire and data were analyzed. Majority of the stroke events occurred after the age of forty (82.3%) and the ischemic stroke (72%) is the most common. Apart from non modifiable risk factors (advancing age, sex, Family history of stroke) hypertension was the most common modifiable risk factor found in stroke patients (57.6%) followed by smoking (44.6%), tobacco use (24.3%), OCP use in female (40% of female stroke), diabetes (23%), ischemic heart disease (17.1%), obesity (10.6%) and dyslipidaemia (5.3%). Lack of fresh fruit consumption and alcoholism were found in some of the patients. Stroke is common after the age of forty. Ischemic events are commonest type of stroke. Hypertension, smoking, tobacco use, diabetes and ischemic heart disease were five most common risk factors of stroke. Outlining the common stroke risk factors in our settings, may help the physicians and care givers in managing this disabling disease properly.

Diubiquitin (Ubd) is a susceptibility gene for virus-triggered autoimmune diabetes in rats

Genetic studies of type 1 diabetes (T1D) have been advanced by comparative analysis of multiple susceptible and resistant rat strains with a permissive class II MHC haplotype, RT1(u). LEW.1WR1 (but not resistant LEW.1W or WF) rats are susceptible to T1D induced by a TLR3 agonist polyinosinic:polycytidylic acid followed by infection with parvovirus. We have mapped genetic loci for virus-induced T1D susceptibility, identifying a major susceptibility locus (Iddm37) near the MHC. The Iddm37 homologs on mouse and human chromosomes are also diabetes linked. We report that a major effect gene within Iddm37 is diubiquitin (Ubd). Gene expression profiling of pancreatic lymph nodes in susceptible and resistant rats during disease induction showed differences in Ubd transcript abundance. The LEW.1WR1 Ubd promoter allele leads to higher inducible levels of UBD than that of LEW.1W or WF. Using zinc-finger nucleases , we deleted a segment of the LEW.1WR1 Ubd gene and eliminated its expression. UBD-deficient rats show substantially reduced diabetes after viral infection. Complementary studies show that there may be another diabetes gene in addition to Ubd in the Iddm37 interval. These data prove that Ubd is a diabetes susceptibility gene, providing insight into the interplay of multiple genes and environmental factors in T1D susceptibility.

Risk of epithelial ovarian cancer in asymptomatic women with ultrasound-detected ovarian masses: a prospective cohort study within the UK collaborative trial of ovarian cancer screening (UKCTOCS)

OBJECTIVE

To estimate the risk of primary epithelial ovarian cancer (EOC) and slow growing borderline or Type I and aggressive Type II EOC in postmenopausal women with adnexal abnormalities on ultrasound.

METHODS

This was a prospective cohort study in the ultrasound group of the UK Collaborative Trial of Ovarian Cancer Screening of postmenopausal women with ultrasound-detected abnormal adnexal (unilocular, multilocular, unilocular solid and multilocular solid, solid) morphology on their first scan. Women were followed up through the national cancer registries and by postal questionnaires. Absolute risks of EOC and borderline, Type I and Type II EOC within 3 years of initial scan were calculated.

RESULTS

Of 48 053 women who underwent ultrasound examination and had complete scan data, 4367 (9.1% (95% CI, 8.8-9.3%)) had abnormal adnexal morphology. Median follow-up was 7.09 (25(th) -75(th) centiles, 6.03-7.92) years. Forty-seven (32 borderline or Type I, 15 Type II) were diagnosed with EOC. The overall absolute risk of EOC associated with abnormal adnexal morphology was 1.08% (95% CI, 0.79-1.43%); for borderline and Type I it was 0.73% (95% CI, 0.5-1.03%); and for Type II it was 0.34% (95% CI, 0.33-0.79%). In the subgroup (n = 741) with solid elements (unilocular solid, multilocular solid and solid) overall absolute risk was 4.45% (95% CI, 3.08-6.20%), for borderline and Type I it was 3.1% (95% CI, 1.9-4.6%) and for Type II it was 1.3% (95% CI, 0.6-2.4%). 11 982 women had both ovaries visualized and normal annual scans throughout the 3-year follow-up period. In this group, no borderline or Type I and eight Type II cancers were diagnosed.

CONCLUSION

Asymptomatic postmenopausal women with ultrasound-detected adnexal abnormalities with solid elements have a 1 in 22 risk for EOC. Despite the higher prevalence of Type II EOC, the risk of borderline or Type I cancer in women with ultrasound abnormalities seems to be higher than does the risk of Type II cancer. This has important immediate implications for patients with incidental adnexal findings as well as for any future ultrasound-based screening.