Impact of Legislation on Brominated Flame Retardant Concentrations in UK Indoor and Outdoor Environments: Evidence for Declining Indoor Emissions of Some Legacy BFRs.

Concentrations of polybrominated diphenyl ethers, hexabromocyclododecane (HBCDD), and novel brominated flame retardants (NBFRs) were measured in indoor dust, indoor air, and outdoor air in Birmingham, UK. Concentrations of ΣBFRs ranged from 490 to 89,000 ng/g, 46-14,000 pg/m3, and 22-11,000 pg/m3, respectively, in UK indoor dust, indoor air, and outdoor air. BDE-209 and decabromodiphenyl ethane (DBDPE) were the main contributors. The maximum concentration of DBDPE (10,000 pg/m3) in outdoor air is the highest reported anywhere to date. In contrast with previous studies of outdoor air in Birmingham, we observed significant correlations between concentrations of tri- to hepta-BDEs and HBCDD and temperature. This may suggest that primary emissions from ongoing use of these BFRs have diminished and that secondary emissions (e.g., evaporation from soil) are now a potentially major source of these BFRs in outdoor air. Conversely, the lack of significant correlations between temperature and concentrations of BDE-209 and DBDPE may indicate that ongoing primary emissions from indoor sources remain important for these BFRs. Further research to clarify the relative importance of primary and secondary sources of BFRs to outdoor air is required. Comparison with earlier studies in Birmingham reveals significant (p < 0.05) declines in concentrations of legacy BFRs, but significant increases for NBFRs over the past decade. While there appear minimal health burdens from BFR exposure for UK adults, dust ingestion of BDE-209 may pose a significant risk for UK toddlers.

What our children lost and gained at the time of school closure during the Covid-19 pandemic: a study on psychological distress, behavioural concerns and protective factors of resilience among preschool children in Kerala, India.

BACKGROUND: The pandemic has put at risk the social and emotional development of children on account of the paucity of arenas for social interaction. This study from Kerala, India was conducted to assess the resilience factors, behavioural concerns, psychological distress symptoms among the children aged 3 to 5 years. We also tried to look into the lost opportunities that could have aided the social and emotional development of children like peer interaction, child care hours. METHODS: The cross-sectional study was conducted among the children aged 3 to 5 years. A total of 535 children attending the immunisation clinics were enrolled by consecutive sampling. Devereux Early Childhood Assessment P2 (DECA P2) questionnaire was used to assess the levels of resilient factors and behavioural concerns in the study population. RESULTS: We observed a high proportion of children in the area of need category of protective factors under DECA P2. The proportion of children falling under area of concern was 64.5%, 49%, 68.4% for attachment/relationship, self-regulation, and initiative respectively. 24.9% study subjects have a behavioural concern score that puts them in the area of need category. The logistic regression model we created identified 'Male Gender,' 'Mothers could spend only less time for child care' and 'electronic devices used as pacifier' as significant predictors for belonging to Area of need Behavioural Concerns T score category. CONCLUSION: A large proportion of children aged between 3 to 5 years with reported behavioural concerns and lack of protective factors for socioemotional development. This can be attributed partly to the ongoing pandemic and its associated restrictions. The increased child care hours invested by parents or grandparents could have sized down the full impact that the pandemic would have had on the socio emotional development of the child. Increased time spent using electronic devices coupled with dwindled opportunities for interaction with peers have been notable challenges.

BAR-based optimum adaptive steered MD for configurational sampling.

The equilibrium and nonequilibrium adaptive alchemical free energy simulation methods optimum Bennett's acceptance ratio and optimum crooks' equation (OCE), based on the statistically optimal bidirectional reweighting estimator named Bennett's Acceptance Ratio or Crooks' equation, perform initial sampling in the staging alchemical transformation and then determine the importance rank of different states via the time-derivative of the variance. The method is proven to give speedups compared with the equal time rule. In the current work, we extend the time derivative of variance guided adaptive sampling method to the configurational space, falling in the term of steered MD (SMD). The SMD approach biasing physically meaningful collective variable (CV) such as one dihedral or one distance to pulling the system from one conformational state to another. By minimizing the variance of the free energy differences along the pathway in an optimized way, a new type of adaptive SMD (ASMD) is introduced. As exhibits in the alchemical case, this adaptive sampling method outperforms the traditional equal-time SMD in nonequilibrium stratification. Also, the method gives much more efficient calculation of potential of mean force than the selection criterion-based ASMD scheme, which is proven to be more efficient than traditional SMD. The OCE workflow is periodicity-of-CV dependent while ASMD is not. The performance is demonstrated in a dihedral flipping case and two distance pulling cases, accounting for periodic and nonperiodic CVs, respectively. © 2019 Wiley Periodicals, Inc.

Synthesis and Antitumor Activity of a Series of Novel 1-Oxa-4-azaspiro[4,5]deca-6,9-diene-3,8-dione Derivatives.

A series of novel 1-oxa-4-azaspiro[4.5]deca-6,9-diene-3,8-diones were designed and synthesized by using 4-aminophenol and α-glycolic acid or lactic acid as starting materials in three or four steps. The key step is the metal-catalyzed oxidative cyclization of the amide to 1-oxa-4-azaspiro[4.5]deca-6,9-diene-3,8-diones (10a and 10b), the reaction conditions of which are investigated and optimized. The anticancer activity of 17 1-oxa-4-azaspiro[4.5]deca-6,9-diene-3,8-dione derivatives was evaluated. Preliminary results showed that 15 compounds have moderate to potent activity against human lung cancer A549, human breast cancer MDA-MB-231, and human cervical cancer HeLa cancer cell lines. Among them, compounds 11b and 11h were the most potent against A549 cell line with 0.18 and 0.19 µM of IC50, respectively; compounds 11d, 11h, and 11k showed the most potent cytotoxicity against MDA-MB-231 cell line with 0.08, 0.08, and 0.09 µM of IC50, respectively, while the activities of 11h, 11k, and 12c against HeLa cell line were the most potent with 0.15, 0.14, and 0.14 µM of IC50, respectively. Compound 11h is a promising candidate for further development, which emerged as the most effective compound overall against the three tested cancer cell lines.

Lipid Profile Changes Induced by Chronic Administration of Anabolic Androgenic Steroids and Taurine in Rats.

Background and Objectives: Anabolic androgenic steroids (AAS), used as a therapy in various diseases and abused in sports, are atherogenic in supraphysiological administration, altering the plasma lipid profile. Taurine, a conditionally-essential amino acid often used in dietary supplements, was acknowledged to delay the onset and progression of atherogenesis, and to mitigate hyperlipidemia. The aim of the present study was to verify if taurine could prevent the alterations induced by concomitant chronic administration of high doses of AAS nandrolone decanoate (DECA) in rats. Materials and Methods: Thirty-two male Wistar rats, assigned to 4 equal groups, were treated for 12 weeks either with DECA (A group), taurine (T group), both DECA and taurine (AT group) or vehicle (C group). Plasma triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), hepatic triglycerides (TGh) and liver non-esterified fatty acids (NEFA) were then determined. Results: DECA elevated TG level in A group vs. control (p = 0.01), an increase prevented by taurine association in AT group (p = 0.04). DECA decreased HDL-C in A group vs. control (p = 0.02), while taurine tended to increase it in AT group. DECA decreased TGh (p = 0.02) in A group vs. control. Taurine decreased TGh in T (p = 0.004) and AT (p < 0.001) groups vs. control and tended to lower NEFA (p = 0.08) in AT group vs. A group. Neither DECA, nor taurine influenced TC and LDL-C levels. Conclusions: Taurine partially prevented the occurrence of DECA negative effects on lipid profile, suggesting a therapeutic potential in several conditions associated with chronic high levels of plasma androgens, such as endocrine disorders or AAS-abuse.

Development, safety and efficacy of a novel circular-irrigated deca-channel mapping and ablation catheter for pulmonary vein isolation.

BACKGROUND: Pulmonary vein isolation (PVI), a cornerstone for catheter ablation of atrial fibrillation (AF), remains a complex and time-consuming procedure. Present study introduces a novel, circular-irrigated, deca-channel mapping and ablation catheter (CIDMA), describes the in vitro test results on feasibility, safety, and acute efficacy of the CIDMA catheter. METHODS: An assembled CIDMA catheter was subjected to a number of in vitro tests. With this catheter, ablation procedures were first performed in a pig's myocardial strips in vitro to determine the effects in unipolar or bipolar configuration. RESULTS: Three catheters were assembled. The adjustable circular diameter was changed from initial state of 32.41 ± 0.61 mm into controlled state of 28.61 ± 0.47 mm (P = 0.013). In the plastic model, the push-ability, torque-ability, and kink resistance of CIDMA catheter were shown to be satisfactory. In vitro, our findings showed that ablation could produce obvious ablation lesions, and unipolar ablation (at length, width and depth of 5.0 ± 1.3, 4.6 ± 0.7, and 4.2 ± 0.6 mm, respectively) was more effective than bipolar (at length, width and depth of 2.8 ± 0.2, 4.2 ± 0.5, and 2.3 ± 0.4 mm, respectively) (P < 0.01). CONCLUSIONS: In vitro, our preliminary data suggest that the CIDMA catheter produced optimal ablation lesions, especially in the unipolar ablation mode. Future in vivo animal and clinical studies are warranted to test the efficacy of this catheter in real-world scenario.

Polybrominated diphenyl ethers in plastic products, indoor dust, sediment and fish from informal e-waste recycling sites in Vietnam: a comprehensive assessment of contamination, accumulation pattern, emissions, and human exposure.

Residue concentrations of polybrominated diphenyl ethers (PBDEs) in different kinds of samples including consumer products, indoor dust, sediment and fish collected from two e-waste recycling sites, and some industrial, urban and suburban areas in Vietnam were determined to provide a comprehensive assessment of the contamination levels, accumulation pattern, emission potential and human exposure through dust ingestion and fish consumption. There was a large variation of PBDE levels in plastic parts of obsolete electronic equipment (from 1730 to 97,300 ng/g), which is a common result observed in consumer plastic products reported elsewhere. PBDE levels in indoor dust samples collected from e-waste recycling sites ranged from 250 to 8740 ng/g, which were markedly higher than those in industrial areas and household offices. Emission rate of PBDEs from plastic parts of disposed electronic equipment to dust was estimated to be in a range from 3.4 × 10-7 to 1.2 × 10-5 (year-1) for total PBDEs and from 2.9 × 10-7 to 7.2 × 10-6 (year-1) for BDE-209. Some fish species collected from ponds in e-waste recycling villages contained elevated levels of PBDEs, especially BDE-209, which were markedly higher than those in fish previously reported. Overall, levels and patterns of PBDE accumulation in different kinds of samples suggest significant emission from e-waste sites and that these areas are potential sources of PBDE contamination. Intakes of PBDEs via fish consumption were generally higher than those estimated through dust ingestion. Intake of BDE-99 and BDE-209 through dust ingestion contributes a large proportion due to higher concentrations in dust and fish. Body weight normalized daily intake through dust ingestion estimated for the e-waste recycling sites (0.10-3.46 ng/day/kg body wt.) were in a high range as compared to those reported in other countries. Our results highlight the potential releases of PBDEs from informal recycling activities and the high degree of human exposure and suggest the need for continuous investigations on environmental pollution and toxic impacts of e-waste-related hazardous chemicals.

Crystal structure of 2,9-diphenyl-17λ(6)-thia-tetra-cyclo-[8.7.0.0(3,8).0(11,16)]hepta-deca-1(10),2,4,6,8,11(16),12,14-octa-ene-17,17-dione.

The title compound, C28H18O2S, is composed of a naphthalene ring system fused with a benzo-thio-phene ring and attached to two phenyl rings. The phenyl rings make dihedral angles of 70.92 (8) and 79.23 (8)° with the essentially planar naphthalene ring system (r.m.s. deviation = 0.031 Å). There is an intra-molecular C-H⋯π inter-action present. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds which generate C(7) zigzag chains running parallel to [10-1]. The chains are linked via further C-H⋯π inter-actions, forming a three-dimensional structure.

Crystal structure of 1,6-di-thia-cyclo-deca-cis-3,cis-8-diene (DTCDD).

The title compound, C8H12S2 (trivial name DTCDD), was obtained as a side product of the reaction between cis-1,4-di-chloro-but-2-ene and sodium sulfide. The asymmetric unit consists of one-quarter of the mol-ecule (S site symmetry 2) and the complete mol-ecule has 2/m (C 2h ) point symmetry with the C=C bond in an E conformation. The geometry of the title compound is compared to those of a chloro derivative and a mercury complex.

Monetizing shipping emission reduction: Environmental benefit analysis of domestic emission control areas policy 2.0 in China.

Shipping is a major contributor to anthropogenic emissions, exerting complex effects on both the environment and climate. To improve the air quality of coastal areas, China adopted an upgraded policy on domestic emission control areas (DECA 2.0) for shipping in December 2018, which expanded the geographical scope of ECAs from three designated heavy-traffic coastal regions to the entire 12 nautical mile-territorial seas and also introduced more stringent ship emission requirements. Based on data from the Automatic Identification System, this study first evaluates the environmental effects of ship emissions' reduction brought by DECA policy 2.0. Results reveal that implementation of DECA policy 2.0 has resulted in a cumulative reduction (2019-2021) of 8.43 × 105 tons, 1.3 × 105 tons, and 1.49 × 105 tons of sulfur dioxide (SO2), particulate matter <2.5 µm diameter (PM2.5) and PM <10 µm (PM10) emissions, respectively. Based on the external cost method, we further monetize the environmental benefits arising from reduction of air pollution emissions, averaging $3.6 billion USD per year. This number equates to ca. 4 % of the total output value of China's marine transportation industry over the three-year period. Finally, we calculate the fuel replacement cost arising from the implementation of DECA policy 2.0, which is on average $1.23 billion USD. This indicates that the net environmental benefits of DECA policy 2.0 equate nearly double the associated costs.

MAGIX, a new software for the analysis of complex gamma spectra.

The MAGIX code (a French acronym standing for Automatic Gamma and X-ray Measurement) is a software developed to analyze γ/X spectra on the topic of severe accident diagnosis. Indeed, the gamma spectra obtained after a severe reactor core accident are complex because they are composed of hundreds of lines of short-lived fission products and Fukushima accident demonstrated a lack in robustness of data interpretation during a crisis. MAGIX allows a complete and entirely automatic analysis of the spectra, with identification of radionuclides and calculation of activities. It can analyze spectra measured by detectors with excellent resolution such as HPGe detectors as well as detectors with medium resolution (e.g. CZT and LaBr3). For most detectors, the analysis of the spectra can be done without a detection efficiency curve because its process can include the calculation of a relative detection efficiency. MAGIX accepts spectra corresponding to any experimental setup (energy slope, energy range, resolution, absorber, etc.). However, these experimental conditions can have an impact on the quality of the results. Results on spectra simulated in different configurations showed that the analysis of the HPGe spectrum with the user defined efficiency and with the MAGIX detection efficiency were close. Furthermore, they also showed that the accuracy of activities was similar with increasing energy slopes but decreased with resolution degradation, with fewer correctly identified radionuclides in this case.

Deca-BDE emissions, validation, and environmental fate in China.

Decabromodiphenyl ether (Deca-BDE) was officially listed in Annex A of the Stockholm Convention for persistent organic pollutants (POPs). It is necessary to establish its emission inventory to help reduce Deca-BDE contamination in the environment. We established a comprehensive Deca-BDE emission inventory in China. The results reveal that, from 2015 to 2017, the Deca-BDE emissions in its production source (source I) were less altered but increased annually in flame retarded plastics processing (source II), Deca-BDE-containing products usage (source III), and electronic waste (e-waste) treatment (source IV). We show that Deca-BDE emissions declined significantly in sources I and II but grew in source III and source IV from 2017 to 2018. We set up the provincial emission inventory to a gridded map on a spatial resolution of 0.25°× 0.25° latitude/longitude. The gridded inventory was incorporated into ChnMETOP model to simulate Deca-BDE concentrations in air and soil, and the modeled concentrations were compared to field-sampling data. The results show that the Deca-BDE emission inventory developed in this study agreed well with observed data, demonstrating that the Deca-BDE inventory in China developed in the present study is reliable. The inventory provides a support for quantifying human exposure risk to Deca-BDE and developing effective mitigation measures to mitigate Deca-BDE emissions.

Structures of rac-2,4:3,5-di-methyl-ene xylitol -derivatives.

The structures of three racemic (tetra-hydro-[1,3]dioxino[5,4-d][1,3]dioxin-4-yl)methanol derivatives are reported, namely, 4-[(methyl-sulfon-yloxy)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-d][1,3]dioxine, C8H14O7S, 1, 4-[(benz-yloxy)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H18O5, 2, and 4-[(anilinocarbon-yl)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H17NO6, 3. Mesylate ester 1 at 173 K has triclinic P symmetry and both benzyl ether 2 at 173 K and phenyl urethane 3 have monoclinic P21/c symmetry. These structures are of inter-est because of the conformation of the cis-fused tetra-oxadeca-lin ring system. This cis-bi-cyclo-[4.4.0]decane ring system, i.e. cis-deca-lin, can undergo conformational equilibration. In the two most stable conformers, both six-membered rings adopt a chair conformation. However, there are significant consequences in these two stable conformers, with heteroatom substitution at the 1,3,5,7-ring positions as described. Only one conformation, denoted as 'concave' or 'inside', is found in these crystal structures. This is consistent with previously reported structures of the 1,1-geminal dihy-droxy aldehyde and tosyl-ate analogs.

Virtual screening and invitro evaluation of cyclooxygenase inhibitors from Tinospora cordifolia using the machine learning tool.

Tinospora cordifolia has a variety of compounds, and some of these compounds may have anti-inflammatory and antioxidant properties. In the present study, we identified the compounds in the leaf extract of T. cordifolia through Gas Chromatography-Mass Spectrometry (GC-MS) analysis and found the various metabolites. The compounds are screened virtually using a machine learning model, followed by molecular docking and simulation study to identify top-hit compounds as cyclooxygenase (COX) inhibitors. The molecular docking revealed that the compound 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-2,8-dione (CID:545303) exhibited the lowest binding energies of -7.1 and -6.8 kcal/mol against COX 1 and COX 2 respectively. The interactions are favored by hydrogen bonding and hydrophobic interaction inside the binding pocket. The 100 ns MD simulation study for these compounds was performed to know the stability and found the RMSD around 2 Å and around 1.0 Å with minimal fluctuations indicating a stable complex throughout the simulation of 100 ns. Based on these findings, we proposed 7,9-Di-tertbutyl- 1-oxaspiro (4,5) deca-6,9-diene-2,8-dione could be used as a dual inhibitor of COX enzymes and a drug-like molecule for treating inflammation after evaluation of their biological properties. The methanolic extract of T. cordifolia was subjected to in vitro DPPH, ABTS, nitric oxide, anti-microbial, COX, and LOX inhibition activity. The results exhibited possible positive effects against the above activities.Communicated by Ramaswamy H. Sarma.

Quantification and stability assessment of 7,9-di­tert­butyl­1-oxaspiro(4,5)deca-6,9-diene-2,8­dione leaching from cross-linked polyethylene pipes using gas and liquid chromatography.

This study assesses the formation and stability of the water contaminant 7,9-di­tert­butyl­1-oxaspiro(4,5)deca-6,9-diene-2,8­dione ([1]) which repeatedly occurs in the migration waters of cross-linked polyethylene (PE-X) pipes. In aqueous solution [1] is partially transformed to 3-(3,5-di­tert­butyl­1­hydroxy-4-oxo-2,5-cyclohexadien-1-yl)propionic acid ([2]). For a better understanding of the formation of [1] and its transformation into [2] an analytical method was established to allow the analysis of both species separately. Because of thermal instability [2] cannot be detected with GC-MS. Therefore, two methods were validated for a reliable and reproducible quantification: GC-MS for [1] and HPLC-MS/MS for both [1] and [2]. Comparative measurements of migration waters from PE-X pipes using GC-MS and HPLC-MS/MS methods showed that the concentrations of [1] detected with GC-MS corresponds to the sum of [1] and [2] measured with HPLC-MS/MS. In the migration waters [1] was detected in higher concentrations than [2]. The highest concentrations of [1], detected with GC-MS, were > 300 µg/L. The longer the materials are stored without contact with water, the more [1] is measured in the migration waters. Most of the previous values reported in the literature for [1] were based on semi-quantification. Hence, we compared results of the semi-quantitative determination according to EN 15768 with those of a quantitative method with a standard. The results gained with the semi-quantitative method represent less than 50% of the quantified values for the amount leaching from the pipes, which means that the semi-quantification method according to EN 15768 leads to a significant underestimation of [1]. Finally, stability assessment showed that [1] developed an equilibrium with [2] under acidic conditions, whereas it will completely be transferred to [2] at pH 10. At pH 7, it takes more than 50 days for [1] to reach an equilibrium with [2]. However, at increasing the temperature to 60 °C, [1] will be rapidly transformed into [2]. Besides [1] and [2], other currently unknown degradation products are formed. As there is no comprehensive toxicological assessment for both substances available today, our findings underline the need for regulatory consequences.

Bis{[amino-(iminium-yl)meth-yl]urea} tetra-kis-{2-[(di-methyl-amino)(iminium-yl)meth-yl]guanidine} di-µ6-oxido-tetra-µ3-oxido-tetra-deca-µ2-oxido-octa-oxidodeca-vanadium(V) tetra-hydrate.

The title compound, (C4H12N5)4(C2H7N4O)2[V10O28]·4H2O, is a by-product obtained by reacting ammonium metavanadate(V), metformin hydro-chloride and acetic acid in the presence of sodium hypochlorite, at pH = 5. The crystal structure comprises a deca-vanadate(V) anion (V10O28)6- lying on an inversion centre in space group P , while cations and solvent water mol-ecules are placed in general positions, surrounding the anion, and forming numerous N-H⋯O and O-H⋯O hydrogen bonds. Metforminium (C4H12N5)+ and guanylurea (C2H7N4O)+ cations display the expected shape. Inter-estingly, in physiology the latter cation is known to be the main metabolite of the former one. The reported structure thus supports the role of sodium hypochlorite as an oxidizing reagent being able to degrade metformin hydro-chloride to form guanylurea.

Crystal structure of bis-(ammonium) bis-[penta-aqua-(di-methyl-formamide)-zinc(II)] deca-vanadate tetra-hydrate.

The crystalline product (NH4)2[Zn(C3H7NO)(H2O)5]2[V10O28]·4H2O was success-fully isolated from an H2O/DMF solvent combination by evaporation at ambient temperature. The salt crystallizes in the P21/n space group. Imidazole, initially used in the synthesis but not present in the product, and DMF solvent appear to affect the synthesis and crystallization as structural-directing agents. In the title compound, the complex cation [Zn(H2O)5(DMF)]2+ acts as a counter-ion without being directly coordinated to the deca-vanadate anion. An extensive framework of hydrogen bonds integrates the whole architecture as evidenced by X-ray crystallography. The polyoxometalate [V10O28]6- lies on a center of symmetry while the complex cation [Zn(H2O)5(DMF)]2+ links three adjacent anions through a set of 2 + 2 + 3 hydrogen bonds.

Development and Evaluation of the POPBL (Patient-Oriented Problem-Based Learning) Module in Pathology: A Comparative Analysis of Performance and Perception Among Second-Year Pathology Students.

Background and objective Employing the POPBL (Patient-Oriented Problem-Based Learning) method to teach students offers a fresh take on the classroom experience. It helps to enhance the motivation of the students, improves knowledge, self-learning behavior, and clinical reasoning, and also helps to promote long-lasting memory. In our medical college, we adopted a newer technology-oriented method with the use of case history, laboratory findings, a gross specimen of the same case, microscopic live sessions via Deca and Penta head microscopes, television, and microscopic camera. In light of this, in this study, we aimed to develop a patient- and technology-oriented new Problem-Based Learning (PBL) method and compare its effectiveness with the traditional tutorial method. Materials and methods A total of 149 second-year MBBS students were enrolled in the study. Consent was taken from all students. A total of eight systems of systemic pathology from the second-year MBBS curriculum were selected. Of the eight systems, four were covered under POPBL with gross and microscopic features associated with the help of newer-generation audiovisual aids, and the other four systems were covered under the traditional tutorial/lecture method. The evaluation was performed using prevalidated objective types of questions after exposure of about one week. The objective was to evaluate and compare the outcomes and students' performance between these two sets of pathology systems. Results Students gave excellent responses. Performance (87.92% of students had scores >75%) and attendance (94.14%) parameters with respect to POPBL gross and microscopic features associated with the help of newer-generation audiovisual aids like Deca and Penta head microscopes were superior compared to the traditional tutorial/lecture method, where 53.02% of students scored more than 75% and the attendance was 76.12%. The difference in attendance was also statistically significant (p=0.05). Conclusion Using POPBL instead of standard tutorial/lecture methods leads to better outcomes. Students also found POPBL more appealing than standard lectures. It is a student-centered method that provides a significant level of motivation and encourages active participation among students. The efficacy of this new way of teaching and demonstrating will attract more students to this method.

Tetra-ammonium bis-(metforminium) di-µ6-oxido-tetra-µ3-oxido-tetra-deca-µ2-oxido-octa-oxidodeca-vanadium(V) hexa-hydrate.

The title compound, (NH4)4(C4H12N5)2[V10O28]·6H2O, crystallizes with the deca-vanadate anion placed on an inversion centre in space group P . This anion is surrounded by a first shell of ammonium cations and water mol-ecules, forming efficient N-H⋯O and O-H⋯O hydrogen bonds. A second shell includes metforminium monocations with a twisted geometry, also forming numerous inter-molecular hydrogen bonds. The complex three-dimensional network of non-covalent inter-actions affords a crystal structure in which the cations and anions are densely packed.

Crystal structure of [3,10-bis-(4-fluoro-pheneth-yl)-1,3,5,8,10,12-hexa-aza-cyclo-tetra-deca-ne]nickel(II) diperchlorate.

The square-planar nickel(II) title complex, [Ni(C24H36F2N6)](ClO4)2 or [NiL](ClO4)2 (L = 3,10-bis-(4-fluoro-pheneth-yl)-1,3,5,8,10,12-hexa-aza-cyclo-tetra-deca-ne) was synthesized by a one-pot reaction of template condensation and its X-ray crystal structure was determined. The nickel(II) ion lies close by a twofold axis and the complex displays whole-mol-ecule disorder. Ligand L, a hexa-aza-cyclo-tetra-decane ring having 4-fluoro-phenethyl side chains attached to uncoordinated nitro-gen atoms, adopts a trans III (R,R,S,S) configuration. The average Ni-N bond distance is 1.934 (9) Å, which is quite similar to those of other nickel(II) complexes with similar ligands. The nickel(II) ion is located 0.051 (7) Šabove the least-squares plane through the four coordinated N atoms. The average C-N bond distance and C-N-C angle involving uncoordinated nitro-gen atoms are 1.425 (12) Šand 118.0 (9)°, respectively, indicating a significant contribution of sp 2 hybridization for these N atoms. The inter-molecular N-H⋯O, C-H⋯O/F hydrogen bonds of the complex form a network structure, which looks like a seamless floral lace pattern.