A new vaccine supply chain network under COVID-19 conditions considering system dynamic: Artificial intelligence algorithms.

With the discovery of the COVID-19 vaccine, what has always been worrying the decision-makers is related to the distribution management, the vaccination centers' location, and the inventory control of all types of vaccines. As the COVID-19 vaccine is highly demanded, planning for its fair distribution is a must. University is one of the most densely populated areas in a city, so it is critical to vaccinate university students so that the spread of this virus is curbed. As a result, in the present study, a new stochastic multi-objective, multi-period, and multi-commodity simulation-optimization model has been developed for the COVID-19 vaccine's production, distribution, location, allocation, and inventory control decisions. In this study, the proposed supply chain network includes four echelons of manufacturers, hospitals, vaccination centers, and volunteer vaccine students. Vaccine manufacturers send the vaccines to the vaccination centers and hospitals after production. The students with a history of special diseases such as heart disease, corticosteroids, blood clots, etc. are vaccinated in hospitals because of accessing more medical care, and the rest of the students are vaccinated in the vaccination centers. Then, a system dynamic structure of the prevalence of COVID -19 in universities is developed and the vaccine demand is estimated using simulation, in which the demand enters the mathematical model as a given stochastic parameter. Thus, the model pursues some goals, namely, to minimize supply chain costs, maximize student desirability for vaccination, and maximize justice in vaccine distribution. To solve the proposed model, Variable Neighborhood Search (VNS) and Whale Optimization Algorithm (WOA) algorithms are used. In terms of novelties, the most important novelties in the simulation model are considering the virtual education and exerted quarantine effect on estimating the number of the vaccines. In terms of the mathematical model, one of the remarkable contributions is paying attention to social distancing while receiving the injection and the possibility of the injection during working and non-working hours, and regarding the novelties in the solution methodology, a new heuristic method based on a meta-heuristic algorithm called Modified WOA with VNS (MVWOA) is developed. In terms of the performance metrics and the CPU time, the MOWOA is discovered with a superior performance than other given algorithms. Moreover, regarding the data, a case study related to the COVID-19 pandemic period in Tehran/Iran is provided to validate the proposed algorithm. The outcomes indicate that with the demand increase, the costs increase sharply while the vaccination desirability for students decreases with a slight slope.

A stochastic bi-objective simulation-optimization model for plasma supply chain in case of COVID-19 outbreak.

As of March 24, 2020, the Food and Drug Administration (FDA) authorized to bleed the newly recovered from Coronavirus Disease 2019 (COVID-19), i.e., the ones whose lives were at risk, separate Plasma from their blood and inject it to COVID-19 patients. In many cases, as observed the plasma antibodies have cured the disease. Therefore, a four-echelon supply chain has been designed in this study to locate the blood collection centers, to find out how the collection centers are allocated to the temporary or permanent plasma-processing facilities, how the temporary facilities are allocated to the permanent ones, along with determining the allocation of the temporary and permanent facilities to hospitals. A simulation approach has been employed to investigate the structure of COVID-19 outbreak and to simulate the quantity of plasma demand. The proposed bi-objective model has been solved in small and medium scales using ε -constraint method, Strength Pareto Evolutionary Algorithm II (SPEA-II), Non-dominated Sorting Genetic Algorithm II (NSGA-II), Multi-Objective Grey Wolf Optimizer (MOGWO) and Multi Objective Invasive Weed Optimization algorithm (MOIWO) approaches. One of the novelties of this research is to study the system dynamic structure of COVID-19's prevalence so that to estimate the required plasma level by simulation. Besides, this paper has focused on blood substitutability which is becoming increasingly important for timely access to blood. Due to shorter computational time and higher solution quality, MOIWO is selected to solve the proposed model for a large-scale case study in Iran. The achieved results indicated that as the plasma demand increases, the amount of total system costs and flow time rise, too. The proposed simulation model has also been able to calculate the required plasma demand with 95% confidence interval.

Intra- and intermolecular interactions in a series of chlorido-tricarbonyl-diazabutadienerhenium(I) complexes: structural and theoretical studies.

A series of new chlorido-tricarbonylrhenium(I) complexes bearing alkyl-substituted diazabutadiene (DAB) ligands, namely N,N'-bis(2,4-dimethylbenzene)-1,4-diazabutadiene (L1), N,N'-bis(2,4-dimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene (L2), N,N'-bis(2,4,6-trimethylbenzene)-2,3-dimethyl-1,4-diazabutadiene (L3) and N,N'-bis(2,6-diisopropylbenzene)-1,4-diazabutadiene (L4), were synthesized and investigated. The crystal structures have been fully characterized by X-ray diffraction and spectroscopic methods. Density functional theory, natural bond orbital and non-covalent interaction index methods have been used to study the optimized geometry in the gas phase and intra- and intermolecular interactions in the complexes, respectively. The most important studied interactions in these metal carbonyl complexes are n→π*, n→σ* and π→π*. Among complexes 1-4, only 2 shows interesting intermolecular n→π* interactions due to lp(C[triple-bond]O)...π* and lp(Cl)...π* (lp = lone pair) contacts.

Synthesis of Quinolines and Pyrido[3,2- g or 2,3- g]quinolines Catalyzed by Heterogeneous Propylphosphonium Tetrachloroindate Ionic Liquid.

This report explains an efficient method for synthesis of an array of quinolines via the reaction of 2-aminoaryl ketones with terminal and internal alkynes in the presence of propylphosphonium tetrachloroindate ionic liquid supported on nanosilica (PPInCl-nSiO2) as a heterogeneous and reusable catalyst under solvent-free conditions. Inspired by this catalytic system, the first easy one-step synthesis of symmetric and unsymmetric pyrido[3,2- g or 2,3- g]quinolines was investigated through the reaction of diaroylphenylenediamines with one alkyne or two different alkynes.

First heterobimetallic AgI-CoIII coordination compound with both bridging and terminal -NO2 coordination modes: synthesis, characterization, structural and computational studies of (PPh3)2AgI-(µ-κ2O,O':κN-NO2)-CoIII(DMGH)2(κN-NO2).

An unusual heterobimetallic bis(triphenylphosphane)(NO2)AgI-CoIII(dimethylglyoximate)(NO2) coordination compound with both bridging and terminal -NO2 (nitro) coordination modes has been isolated and characterized from the reaction of [CoCl(DMGH)2(PPh3)] (DMGH2 is dimethylglyoxime or N,N'-dihydroxybutane-2,3-diimine) with excess AgNO2. In the title compound, namely bis(dimethylglyoximato-1κ2O,O')(µ-nitro-1κN:2κ2O,O')(nitro-1κN)bis(triphenylphosphane-2κP)cobalt(III)silver(I), [AgCo(C4H7N2O2)2(NO2)2(C18H15P)2], one of the ambidentate -NO2 ligands, in a bridging mode, chelates the AgI atom in an isobidentate κ2O,O'-manner and its N atom is coordinated to the CoIII atom. The other -NO2 ligand is terminally κN-coordinated to the CoIII atom. The structure has been fully characterized by X-ray crystallography and spectroscopic methods. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been used to study the ground-state electronic structure and elucidate the origin of the electronic transitions, respectively.

Stimuli-responsive emissive behavior of 1- and 1,3-connectivities in azulene-based imine ligands: cycloplatination and Pt-Tl dative bond formation.

The preparation of two new azulene-based imine ligands N-(2,6-diisopropylphenyl)-6-tBu-1-azulenylmethaneimine, 3, and N-(2,6-diisopropylphenyl)-6-tBu-3-(2,6-diisopropylphenyliminomethyl)-1-azulenylmethaneimine, 4, is described. These imine ligands display stimuli responsive emissive behavior and their fluorescence can be switched on and off by protonation and neutralization with trifluoroacetic acid and trimethylamine, respectively. The cyclometalation of the monoimine ligand by platinum gave the cyclometalated complex [PtMe(SMe2)(3')], 5, (where the prime denotes the cyclometalated ligand 3). The reaction of 5 with TlPF6 yields the trinuclear bent Pt2Tl complex {[PtMe(SMe2)(3')]2(µ-Tl)}PF6, 6, via Pt-Tl dative bonds. The compounds 3-6 were characterized using NMR spectroscopy and the solid-state structures of 5 and 6 were further determined by X-ray crystallography. The electronic absorption spectra of the species 3-H+, 4-H+, 5 and 6 were obtained and compared with those observed for the parent species 3 and 4. DFT and TD-DFT calculations are used to elucidate the origin of the electronic transitions in monoimine ligand 3 and its protonated form 3-H+.

Cyclometalated platinum(ii) complexes of 2,2'-bipyridine N-oxide containing a 1,1'-bis(diphenylphosphino)ferrocene ligand: structural, computational and electrochemical studies.

The preparation and characterization of new heteronuclear-platinum(ii) complexes containing a 1,1'-bis(diphenylphosphino)ferrocene (dppf) ligand are described. The reaction of the known starting complex [PtMe(κ2N,C-bipyO-H)(SMe2)], A, in which bipyO-H is a cyclometalated rollover 2,2'-bipyridine N-oxide, with the dppf ligand in a 2 : 1 ratio or an equimolar ratio led to the formation of the corresponding binuclear complex [Pt2Me2(κ2N,C-bipyO-H)2(µ-dppf)], 1, or the mononuclear complex [PtMe(κ1C-bipyO-H)(dppf)], 2, respectively. According to the reaction conditions, the dppf ligand in 1 and 2 behaves as either a bridging or chelating ligand. All complexes were characterized by NMR spectroscopy. The solid-state structure of 2 was determined by the single-crystal X-ray diffraction method and it was shown that the chelating dppf ligand in this complex was arranged in a "synclinal-staggered" conformation. Also, the occurrence of intermolecular C-HCpObipyO-H interactions in the solid-state gave rise to an extended 1-D network. The electronic absorption spectra and the electrochemical behavior of these complexes are discussed. Density functional theory (DFT) was used for geometry optimization of the singlet states in solution and for electronic structure calculations. The analysis of the molecular orbital (MO) compositions in terms of occupied and unoccupied fragment orbitals in 2 was performed.

Solving a mathematical model integrating unequal-area facilities layout and part scheduling in a cellular manufacturing system by a genetic algorithm.

In this article, a novel integrated mixed-integer nonlinear programming model is presented for designing a cellular manufacturing system (CMS) considering machine layout and part scheduling problems simultaneously as interrelated decisions. The integrated CMS model is formulated to incorporate several design features including part due date, material handling time, operation sequence, processing time, an intra-cell layout of unequal-area facilities, and part scheduling. The objective function is to minimize makespan, tardiness penalties, and material handling costs of inter-cell and intra-cell movements. Two numerical examples are solved by the Lingo software to illustrate the results obtained by the incorporated features. In order to assess the effects and importance of integration of machine layout and part scheduling in designing a CMS, two approaches, sequentially and concurrent are investigated and the improvement resulted from a concurrent approach is revealed. Also, due to the NP-hardness of the integrated model, an efficient genetic algorithm is designed. As a consequence, computational results of this study indicate that the best solutions found by GA are better than the solutions found by B&B in much less time for both sequential and concurrent approaches. Moreover, the comparisons between the objective function values (OFVs) obtained by sequential and concurrent approaches demonstrate that the OFV improvement is averagely around 17 % by GA and 14 % by B&B.

Ultrafast dynamical study of pyrene-N,N-dimethylaniline (PyDMA) as an organic molecular diode in solid state.

Femtosecond optical pump-probe spectroscopy has been employed for studying the directly linked electron donor-acceptor system pyrene-N,N-dimethylaniline (PyDMA) in solid state. This DMA-pyrene derivative discussed is being applied as a molecular diode system switching on an ultrafast time scale. Our ultrafast solid-state studies reveal a complex photochemistry of this molecular crystal system. Strong couplings of the optically induced charge-transfer state with the radical ion pair state allow a femtosecond transition of the latter. One could see on the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) description that a pure optical transition switches the system from a conducting to a blocked system because the molecular orbitals (MOs) of DMA moiety lie in a node plane of the LUMO. Within 800 fs the system relaxes back to the ground state and/or forms a radical ion pair, which is the surprising result of our study; when the system was probed further, the system underwent vibrational cooling and enhanced population inversion of the radical ion pair.

N,N-Dimethyl-4-(pyren-1-yl)aniline.

In the title compound, C24H19N, the di-methyl-amino group is inclined to the benzene ring by 2.81 (9)°. Their mean plane makes a dihedral angle of 64.12 (2)° with the mean plane of the pyrene ring system [r.m.s. deviation = 0.031 (1) Å]. In the crystal, mol-ecules are linked via C-H⋯π inter-actions, which connect neighbouring mol-ecules into columns along the c axis.

New pyridinium-based ionic liquid as an excellent solvent-catalyst system for the one-pot three-component synthesis of 2,3-disubstituted quinolines.

The synthesis of a variety of 2,3-disubstituted quinolines has been achieved successfully via a one-pot three-component reaction of arylamines, arylaldehydes and aliphatic aldehydes in the presence of butylpyridinium tetrachloroindate(III), [bpy][InCl4], ionic liquid as a green catalyst and solvent. Mild conditions with excellent conversions, and simple product isolation procedure are noteworthy advantages of this method. The recyclability of the ionic liquid makes this protocol environmentally benign.

[Hexane-2,5-dione bis-(thio-semi-carba-zon-ato)]nickel(II).

In the title compound, [Ni(C8H14N6S2)], the Ni(II) ion is coordinated by N2S2 donor atoms of the tetradentate thio-semicarbazone ligand, and has a slightly distorted square-planar geometry. In the crystal, inversion-related mol-ecules are linked via pairs of N-H⋯N and N-H⋯S hydrogen bonds, forming R 2 (2)(8) ring motifs. Mol-ecules are further linked by slightly weaker N-H⋯N, N-H⋯S and C-H⋯S hydrogen bonds, forming two-dimensional networks which lie parallel to the bc plane.

Ethyl 4-(5-bromo-2-hy-droxy-phen-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

In the title compound, C21H24BrNO4, the dihedral angle between the heterocyclic ring and the pendant aromatic ring is 80.20 (13)°. The hexahydroquinone [i.e. the one with the C=O group] ring adopts a sofa conformation. An intra-molecular O-H⋯O hydrogen bond generates an S(6) ring motif. The ethyl group is disordered over two sets of sites with a refined site occupancy ratio of 0.633 (10):0.366 (10). In the crystal, mol-ecules are linked by N-H⋯O inter-actions, forming chains parallel to [101]. There are no significant C-H⋯π or π-π inter-actions in the crystal structure.

1,1'-Bis(tert-butyl-dimethyl-sil-yl)ferrocene.

The asymmetric unit of the title compound, [Fe(C11H19Si)2], consists of one half of a ferrocene derivative. The Fe(II) atom lies on a twofold rotation axis, giving an eclipsed conformation for the cyclo-penta-dienyl ligands. No significant inter-molecular inter-actions are observed in the crystal structure.

{4,4'-Dimeth-oxy-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}copper(II) monohydrate.

The asymmetric unit of the title compound, [Cu(C(21)H(24)N(2)O(4))]·H(2)O, comprises half of a Schiff base complex and a water mol-ecule. The Cu(II) atom, water mol-ecule and one C atom of the central propyl-ene segment are located on a twofold rotation axis. The geometry around the Cu(II) atom is distorted square-planar, supported by the N(2)O(2) donor atoms of the coordinating ligand. The dihedral angle between the symmetry-related benzene rings is 42.56 (19)°. In the crystal, O-H⋯O hydrogen bonds involving the water mol-ecule make an R(2) (1)(6) ring motif. Complex mol-ecules are linked into a chain along the c axis via C-H⋯O inter-actions.

{4,4'-Dimethyl-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}copper(II) monohydrate.

The asymmetric unit of the title compound, [Cu(C(21)H(24)N(2)O(2))]·H(2)O, comprises half of a Schiff base complex and half of a water mol-ecule. The whole compound is generated by crystallographic twofold rotation symmetry. The geometry around the Cu(II) atom, located on a twofold axis, is distorted square-planar, which is supported by the N(2)O(2) donor atoms of the coordinating Schiff base ligand. The dihedral angle between the symmetry-related benzene rings is 47.5 (4)°. In the crystal, the water mol-ecule that is hydrogen bonded to the coordinated O atoms links the mol-ecules via O-H⋯O inter-actions into chains parallel to [001]. The crystal structure is further stabilized by C-H⋯π inter-actions, and by π-π inter-actions involving inversion-related chelate rings [centroid-centroid distance = 3.480 (4) Å].

An ortho-rhom-bic polymorph of 2-(1,3-benzothia-zol-2-yl)-6-eth-oxy-phenol.

In the title mol-ecule, C(15)H(13)NO(2)S, an intra-molecular O-H⋯N hydrogen bond forms an S(6) ring motif. The benzothia-zole ring system and the benzene ring form a dihedral angle of 8.9 (3) Å. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming chains along the b axis. In addition, π-π inter-actions [centroid-centroid distances = 3.772 (4) and 3.879 (4) Å] are observed.

4-Bromo-2-[(E)-(2-{2-[(2-{[(E)-5-bromo-2-hy-droxy-benzyl-idene]amino}-phen-yl)sulfan-yl]ethyl-sulfan-yl}phen-yl)imino-meth-yl]phenol.

The asymmetric unit of the title compound, C(28)H(22)Br(2)N(2)O(2)S(2), comprises half of a Schiff base ligand, the whole mol-ecule being generated by a crystallographic inversion center located at the mid-point of the C-C bond of the central methyl-ene segment. Intra-molecular O-H⋯N and O-H⋯S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant inter-molecular inter-actions.

{4,4',6,6'-Tetra-iodo-2,2'-[propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato-κ(4)O,N,N',O'}nickel(II).

The asymmetric unit of the title compound, [Ni(C(17)H(12)I(4)N(2)O(2))], comprises half of a Schiff base complex. The Ni(II) and central C atom of the propyl chain are located on a twofold rotation axis. The geometry around the Ni(II) atom is square planar, supported by the N(2)O(2) donor atoms of the coordinated ligand. In the crystal, there are no significant inter-molecular inter-actions present. The crystal studied was a non-merohedral twin with a refined twin component ratio of 0.944 (1):0.056 (1).

{4,4'-Dichloro-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}copper(II).

In the title Schiff base complex, [Cu(C(19)H(18)Cl(2)N(2)O(2))], the Cu(II) ion is coordinated in a distorted square-planar environment by two N atoms and two O atoms of the tetra-dentate ligand. The dihedral angle between the benzene rings is 36.86 (14)°. In the crystal, mol-ecules are linked into inversion dimers by pairs of weak C-H⋯O hydrogen bonds. In addition, π-π [centroid-centroid distance = 3.7279 (16) Å] and weak C-H⋯π inter-actions are observed.