Impact of COVID-19 lockdown in Tamil Nadu: Benefits and challenges on environment perspective

Prior to COVID-19 lockdown in our country, the air around us was highly polluted due to emission of greenhouse gases for over centuries. Melting of glaciers and rising of the sea levels were evidenced as the alarming signs of Global warming. Environmental degradation was observed rapidly due to depletion and exploitation of natural resources like soil, water and air. But there are few changes observed in the environment after the country’s lockdown due to coronavirus pandemic. The effects of lockdown are also entwined with human and political effects such as uncontrollable public mobility, poor access to health care due to lack of sufficient medical facilities, unemployment, migrants’ crisis, starvation and prevailing poverty. However, apart from sufferings of entire country especially the people by social, economic and psychologic effects in day-to-day life, this lockdown has given to the nature the most optimistic scenarios in environment especially with enhanced air quality, cleaner water and undisturbed pristine forest. The present review brings out the actual picture of the eco-processes that reduced man-made pollution in air and water as well as disposal of domestic or biological waste along with societal implications after imposing lockdown in the state of Tamil Nadu

1-(2-Naphth­yl)-3-phenyl-3-(4,5,6,7-tetra­hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C25H22N2OSe, the fused six-membered cyclo­hexene ring of the 4,5,6,7-tetra­hydro-1,2,3-benzoselenadiazole group adopts a near half-chair conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.004 Å). There are weak inter­molecular C—H⋯O and C—H⋯π inter­actions in the crystal structure. Inter­molecular π–π stacking is also observed between the naphthyl units, with a centroid–centroid distance of 3.529 (15) Å

Impact of COVID-19 lockdown in Tamil Nadu: Benefits and challenges on environment perspective

370-381Prior to COVID-19 lockdown in our country, the air around us was highly polluted due to emission of greenhouse gases for over centuries. Melting of glaciers and rising of the sea levels were evidenced as the alarming signs of Global warming. Environmental degradation was observed rapidly due to depletion and exploitation of natural resources like soil, water and air. But there are few changes observed in the environment after the country’s lockdown due to coronavirus pandemic. The effects of lockdown are also entwined with human and political effects such as uncontrollable public mobility, poor access to health care due to lack of sufficient medical facilities, unemployment, migrants’ crisis, starvation and prevailing poverty. However, apart from sufferings of entire country especially the people by social, economic and psychologic effects in day-to-day life, this lockdown has given to the nature the most optimistic scenarios in environment especially with enhanced air quality, cleaner water and undisturbed pristine forest. The present review brings out the actual picture of the eco-processes that reduced man-made pollution in air and water as well as disposal of domestic or biological waste along with societal implications after imposing lockdown in the state of Tamil Nadu

Multi-level scoring approach to discover multi-targeting potency of medicinal plant phytochemicals against protein targets in SARS-CoV-2 and human ACE-2 receptor

SARS-CoV-2 pandemic has become a major threat to human healthcare and world economy. Due to the rapid spreading and deadly nature of infection, we are in a situation to develop quick therapeutics to combat SARS-CoV-2. In this study, we have adopted a multi-level scoring approach to identify multi-targeting potency of bioactive compounds in selected medicinal plants and compared its efficacy with two reference drugs, Nafamostat and Acalabrutinib which are under clinical trials to treat SARS-CoV-2. In particular, we employ molecular docking and implicit solvent free energy calculations (as implemented in the Molecular Mechanics -Generalized Born Surface Area approach) and QM fragmentation approach for validating the potency of bioactive compounds from the selected medicinal plants against four different viral targets and one human receptor (Angiotensin-converting enzyme 2 -ACE-2) which facilitates the SARS-CoV-2entry into the cell. The protein targets considered for the study are viral 3CL main protease (3CLpro), papain-like protease (PLpro), RNA dependent RNA polymerase (RdRp), and viral spike protein-human hACE-2 complex (Spike:hACE2)including human protein target (hACE-2). Herein, thereliable multi-level scoring approach was used to validate the mechanism behind the multi-targeting potency of selected phytochemicals from medicinal plants. The present study evidenced that the phytochemicals Chebulagic acid, Stigmosterol, Repandusinic acid and Geranin exhibited efficient inhibitory activity against PLpro while Chebulagic acid was highly active against 3CLpro. Chebulagic acid andGeranin also showed excellent target specific activity against RdRp.Luteolin, Quercetin, Chrysoeriol and Repandusinic acid inhibited the interaction of viral spike protein with human ACE-2 receptor. Moreover Piperlonguminine and Piperine displayed significant inhibitory activity against human ACE-2 receptor. Therefore, the identified compounds namely Chebulagic acid, Geranin and Repandusinic acid can serve as potent multi-targeting phytomedicine for treating COVID-1

Structure of Mycobacterium smegmatis single-stranded DNA-binding protein and a comparative study involving homologus SSBs: biological implications of structural plasticity and variability in quaternary association

The structure of Mycobacterium smegmatis single-stranded DNA-binding protein (SSB) has been determined using three data sets collected from related crystals. The structure is similar to that of its homologue from Mycobacterium tuberculosis, indicating that the clamp arrangement that stabilizes the dimer and the ellipsoidal shape of the tetramer are characteristic features of mycobacterial SSBs. The central OB fold is conserved in mycobacterial SSBs as well as those from Escherichia coli, Deinococcus radiodurans and human mitochondria. However, the quaternary structure exhibits considerable variability. The observed plasticity of the subunit is related to this variability. The crystal structures and modelling provide a rationale for the variability. The strand involved in the clamp mechanism, which leads to higher stability of the tetramer, appears to occur in all high-G+C Gram-positive bacteria. The higher stability is perhaps required by these organisms. The mode of DNA binding of mycobacterial SSBs is different from that of E. coli SSB partly on account of the difference in the shape of the tetramers. Another difference between the two modes is that the former contains additional ionic interactions and is more susceptible to salt concentration

4-{(4-Chloro­phen­yl)[4-(4-methyl­phen­yl)-1,2,3-selenadiazol-5-yl]meth­yl}-4,5,6,7-tetra­hydro-1,2,3-benzoselenadiazole

In the title compound, C22H19ClN4Se2, the mean plane of the non-fused selenadiazole ring forms dihedral angles of 54.20 (16)° and 70.48 (11)°, respectively, with the essentially planar [maximum deviations of 0.025 (5) and 0.009 (2) Å, respectively] methyl­phenyl and chloro­phenyl substituents. The tetra­hydro-1,2,3-benzoselenadiazole group is disordered over two sets of sites with a refined occupancy ratio of 0.802 (5):0.198 (5). In the crystal, weak inter­molecular C—H⋯N inter­actions are observed

3-(4-Methyl­phen­yl)-1-phenyl-3-(4,5,6,7-tetra­hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C22H22N2OSe, the fused six-membered ring of the 4,5,6,7-tetra­hydro­benzo[d][1,2,3] selenadiazole group adopts a near to envelope (E form) conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.0059 Å). In the crystal, adjacent mol­ecules are inter­linked through weak inter­molecular C—H⋯π inter­actions

Understanding and mitigating project delays in donor funded road projects in Sri Lanka

Delays in donor funded road projects have become inevitable, and an endemic problem in Sri Lanka hindering effective use of foreign aid granted for such projects. The aim of this research is to identify the factors causing project delays that are significant and to present the strategies identified and recommendations developed to mitigate the project delays in donor funded projects in Sri Lanka. The research was approached by setting a frame work on the project management processes. A road map was then developed to identify the major value adding activities in this context. A comprehensive literature survey and semi-structured interviews were carried out with professionals involved in the donor funded projects to identify the causes of delay. Further, 24 projects have been examined for quantitative data on time delays. The study identified general factors causing delays in donor funded road projects in Sri Lanka contributing to various stages of the projects namely initiation, planning, execution, and monitoring and control. The study revealed an alarming result that, during the execution process, increase in quantities had significant effect on the project time and accounted for about 56% of the delays on the projects examined. The results also indicated that errors and omissions in detail design, changes in specifications and scope, were the most prevalent sources of quantity increase. Further, during the planning process, the procurement of works activities was delayed by 23% mainly due to shortcomings in contract documents and approvals from relevant agencies. In this context, the developed process model for action to direct the implementation of donor funded road projects recommends, to incorporate design constructability review as the major value adding activity in order to minimize the project delays. A rigorous approach by the executing agency is essential to make the aid more effective, accountable and transparent. Finally, areas for further research were identified

Crystal and Molecular Structure of an Acridinedione

The title compound, 10-(4-hydroxybenzoylamino)-3,4,6,7,9,10-hexahydro-1,8-(2H,5H)-acridinedione monohydrate, C_20H_2_2N_2O_4.H_2O, consists of partially hydrogenated acridine moiety with one benzoylamino substituent on the central ring. The compound crystallizes in monoclinic system with P21/c space group and the unit cell constants are: a = 11.142(4), b = 12.266(2), c = 13.320(2) $A^o$; \beta = 91.76(2)° and V = 1819.6(8) $A^3$. The central ring (B) adopts boat and the outer rings (A and C) adopt sofa conformations. The water molecule takes part in OW-H...O and N-H...OW hydrogen bond formation with acridinedione and benzoylamino group. The oxygen atom O1 interacts through O-H...O bond with the hydroxyl group and in a head-to-tail link up of molecules that results in the formation of an infinite supra molecular chain