Efficient Control of Electron Localization and Probability Modulation with Synthesized Two-Color Intense Laser Pulses.

A coupled electron-nuclear dynamical study at attosecond time scale is performed on the HD+ and H2+ molecular ions under the influence of synthesized intense two-color electric fields. We have employed ω - 2ω and also, ω - 3ω two-color fields in the infrared/mid-infrared regime to study the different fragmentation processes originating from the interference of n - (n + i) (i = 1, 2) photon absorption pathways. The branching ratios corresponding to different photofragments are controlled by tuning the relative phase as well as intensity of the two-color pulses, while the effect of the initial nuclear wave function is also studied by taking an individual vibrational eigenstate or a coherent superposition of several eigenstates of HD+ and H2+. By comprehensive analysis, the efficacy of the two different types of synthesized two-color pulses (ω - 2ω and ω - 3ω) are analyzed with respect to one-color intense pulses in terms of controlling the probability modulation and electron localization asymmetry and compared with previous theoretical calculations and experimental findings. Through the detailed investigation, we have addressed which one is the major controlling knob to have better electron localization as well as probability modulation.

Coupled 3D (J ≥ 0) Time-Dependent Wave Packet Calculation for the F + H2 Reaction on Accurate Ab Initio Multi-State Diabatic Potential Energy Surfaces.

We had calculated adiabatic potential energy surfaces (PESs), nonadiabatic, and spin-orbit (SO) coupling terms among the lowest three electronic states (12A', 22A', and 12A″) of the F + H2 system using the multireference configuration interaction (MRCI) level of theory, and the adiabatic-to-diabatic transformation equations were solved to formulate the diabatic Hamiltonian matrix [J. Chem. Phys. 2020, 153, 174301] for the entire region of the nuclear configuration space. The accuracy of such diabatic PESs is explored by performing scattering calculations to evaluate integral cross sections (ICSs) and rate constants. The nonadiabatic and SO effects are studied by utilizing coupled 3D time-dependent wave packet formalism with zero and nonzero total angular momentum on multiple adiabatic/diabatic surfaces calculation. We depict the convergence profiles of reaction probabilities for the reactive as well as nonreactive processes on various electronic states at different collision energies with respect to total angular momentum including all helicity quantum numbers. Finally, total ICSs are calculated as functions of collision energies for the initial rovibrational state (v = 0, j = 0) of the H2 molecule along with the temperature-dependent rate coefficient, where those quantities are compared with previous theoretical and experimental results.

Quasi-Classical Trajectory Calculations on a Two-State Potential Energy Surface Including Nonadiabatic Coupling Terms as Friction for D+ + H2 Collisions.

Akin to the traditional quasi-classical trajectory method for investigating the dynamics on a single adiabatic potential energy surface for an elementary chemical reaction, we carry out the dynamics on a 2-state ab initio potential energy surface including nonadiabatic coupling terms as friction terms for D+ + H2 collisions. It is shown that the resulting dynamics correctly accounts for nonreactive charge transfer, reactive non-charge transfer and reactive charge transfer processes. In addition, it leads to the formation of triatomic DH2+ species as well.

Pantoea tagorei sp. nov., a Rhizospheric Bacteria with Plant Growth-Promoting Activities.

A Gram-negative, short-rod, non-motile, facultatively anaerobic, potassium-solubilizing bacterium MR1 (Mine Rhizosphere) was isolated from rhizospheric soil of an open-cast coal mine of Jharia, Jharkhand, India. Isolate MR1 can grow in a broad range of temperature, pH, and NaCl concentrations. The 16S rRNA gene sequence of the strain showed 99.24% similarity with Pantoea septica LMG 5345T. However, maximum-likelihood tree constructed using 16S rRNA gene sequence, multilocus sequence analysis using concatenated sequences of ten housekeeping genes, whole-genome based phylogenetic reconstruction, digital DNA-DNA hybridization, and average nucleotide identity (ANIm and ANIb) values indicated segregation of MR1 from its closest relatives. Fatty acid profile of MR1 also suggested the same, with clear variation in major and minor fatty acid contents, having C13:0 anteiso (10-Methyldodecanoic acid) as the unique one. Thus, considering all polyphasic data, strain MR1T (= MTCC 13265T, where 'T' stands for Type strain) is presented as a novel species of the genus Pantoea, for which the name Pantoea tagorei sp. nov. is proposed. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01147-9.

Synthesis of Cu (II) and Zn (II) Complexes of a Quinoline Based Flexible Amide Receptor as Fluorescent Probe for Dihydrogen Phosphate and Hydrogen Sulphate and Their Antibacterial Activity.

A novel 8-hydroxy quinoline-derived amide receptor, in conjunction with its Cu (II) and Zn (II) complexes, has been strategically developed to function as remarkably efficient fluorescent receptors with a distinct capability for anion sensing. The comprehensive characterization of the synthesized compounds were achieved through UV-Vis, IR, NMR, and HRMS spectroscopic techniques. Among the Cu (II) and Zn (II) complexes, the latter exhibits superior selectivity for anions, specifically dihydrogen phosphate and hydrogen sulfate, as their tetrabutylammonium salts in a 9:1 acetonitrile-water (v/v) mixture. The Cu (II) complex demonstrates enhanced anion binding compared to the amide ligand, albeit with reduced selectivity. Furthermore, the affinity was evaluated using the Benesi-Hildebrand plot. The binding constants and Limit of Detection (LOD) for both complexes were precisely quantified. The Job plot illustrates a clear 1:1 binding interaction between the metal complexes and the guest anions. Significantly, both metal-complex receptors display a broad spectrum of antibacterial activity, against both gram-positive and gram-negative bacteria. It is worth highlighting that the Zn (II) complexed receptor outperforms the Cu (II) complexed receptor, as evidenced by its considerably lower Minimum Inhibitory Concentration (MIC) value against both bacterial strains.

Strong Laser Field-Driven Coupled Electron-Nuclear Dynamics: Quantum vs Classical Description.

We have performed a coupled electron-nuclear dynamics study of H2+ molecular ions under the influence of an intense few-cycle 4.5 fs laser pulse with an intensity of 4 × 1014 W/cm2 and a central wavelength of 750 nm. Both quantum and classical dynamical methods are employed in the exact similar initial conditions with the aim of head-to-head comparison of two methodologies. A competition between ionization and dissociation channel is explained under the framework of quantum and classical dynamics. The origin of the electron localization phenomena is elucidated by observing the molecular and electronic wave packet evolution pattern. By probing with different carrier envelope phase (CEP) values of the ultrashort pulse, the possibility of electron localization on either of the two nuclei is investigated. The effects of initial vibrational states on final dissociation and ionization probabilities for several CEP values are studied in detail. Finally, asymmetries in the dissociation probabilities are calculated and mutually compared for both quantum and classical dynamical methodologies, whereas Franck-Condon averaging over the initial vibrational states is carried out in order to mimic the existing experimental conditions.

Recent advances in the design of intracellular pH sensing nanoprobes based on organic and inorganic materials.

In the biological system, the intracellular pH (pHi) plays an important role in regulating diverse physiological activities, including enzymatic action, ion transport, cell proliferation, metabolism, and programmed cell death. The monitoring of pH inside living cells is also crucial for studying cellular events such as phagocytosis, endocytosis, and receptor-ligand internalization. Furthermore, some organelles, viz., endosomes and lysosomes, have intracompartmental pH, which is critical for maintaining the stability of protein structure and function. The dysfunction and abnormal pH regulation can result in terminal diseases such as cancer, Alzheimer, and so forth. Therefore, the accuracy of intracellular pH measurement is always the top priority and demands cutting-edge research and analysis. Such techniques, such as Raman spectroscopy and fluorescence imaging, preferably use nanotechnology due to their remarkable advantages, such as a non-invasive approach and providing accuracy, repeatability, and reproducibility. In the past decades, there have been numerous attempts to design and construct non-invasive organic and inorganic materials-based nanoprobes for pHi sensing. For Raman-based techniques, metal nanostructures such as Au/Ag/Cu nanoparticles are utilized to enhance the signal intensity. As for the fluorescence-based studies, the organic-based small molecules, such as dyes, show higher sensitivity toward pH. However, they possess several drawbacks, including high photobleaching rate, and autofluorescence background signals. To this end, there are alternative nanomaterials proposed, including semiconductor quantum dots (QDs), carbon QDs, upconversion nanoparticles, and so forth. Moreover, the fluorescence technique allows for ratiometric measurement of pHi, which as a result, offers a reliable calibration curve. This timely review will critically examine the current progression in the existing nanoprobes. In addition, based on our knowledge and available research findings, we provide a brief future outlook that may advance the state-of-the-art methodologies for pHi sensing.

Coupled three-dimensional quantum mechanical wave packet study of proton transfer in H2+ + He collisions on accurate ab initio two-state diabatic potential energy surfaces.

We have carried out fully close-coupled three dimensional quantum mechanical wave packet dynamical calculations for the reaction He+H2+→HeH++H on the ground electronic adiabatic potential energy surface and on the lowest two electronic states of newly constructed ab initio calculated diabatic potential energy surfaces for the system [Naskar et al., J. Phys. Chem. A 127, 3832 (2023)]. With the reactant diatom (H2+) in its roto-vibrational ground state (v = 0, j = 0), the calculations have been carried out in hyperspherical coordinates to obtain the reaction attributes. Convergence profiles of the reaction probability with respect to the total angular momentum quantum number at different collision energies are presented for the title reaction. State-to-state as well as initial state selected integral reaction cross sections are calculated from the fully converged reaction probabilities over a range of collision energies. The integral cross section values computed using the two-state diabatic potential energy surfaces are significantly lower than those obtained using the ground electronic state adiabatic potential energy surface and are in much better agreement with the available experimental results than the latter for total energy greater than 1.1 eV. Therefore, it becomes clear that it is important to include the nonadiabatic coupling terms for a quantitative prediction of the dynamical observables.

Efficacy and Tolerability of Tenofovir/Lamivudine/Dolutegravir among Antiretroviral Therapy Naive Human Immunodeficiency Virus Infected Patients of a Tertiary Care Center in Eastern India.

BACKGROUND: Although many drug regimens have been used in the treatment of human immunodeficiency virus (HIV) infection, the National AIDS Control Organization (NACO) of India recommends the use of a fixed-dose combination of tenofovir/lamivudine/dolutegravir (TLD) as a first-line regimen since 2020. In spite of much global data on the use of this combination, experience in the Indian population is still limited. We aim to find out the efficacy and tolerability of this novel regimen, in a tertiary care center of Eastern India. MATERIALS AND METHODS: A descriptive observational study, longitudinal in design performed in the antiretroviral therapy (ART) center of a tertiary care hospital in Kolkata, West Bengal, India. All patients who attended the ART center from April 2021 to October 2022 were enrolled in the study following inclusion and exclusion criteria. A detailed history, clinical examination, necessary biochemical tests, and CD4 count of all patients were done at baseline. Subsequently, they were followed up for 6 months with monthly visits when they were enquired about any adverse effects requiring therapy interruptions. At the end of 6 months, CD4 count and viral load were measured. RESULTS: Out of a total sample of 249 patients, the TLD regimen was efficacious in 99.2% (n = 247) in whom viral load was suppressed to <1,000 copies/mL after 6 months of treatment. The regimen had to be temporarily discontinued in 6% of patients (n = 15). The most common cause of treatment interruption was hepatic dysfunction (3.2%) followed by cutaneous manifestation (2.4%). In 14 out of 15 patients, the regimen could be reintroduced and was safely tolerated afterward. Only one patient had to be shifted to an alternative regimen due to tenofovir-induced nephrotoxicity. Thus TLD was tolerated in 99.6% (n = 248) patients. CONCLUSION: The fixed-dose combination of TLD is a highly efficacious and well-tolerated first-line regimen for ART naïve patients with HIV infection having >95% adherence. How to cite this article: Sengupta D, Ghosh S, Pain S, et al. Efficacy and Tolerability of Tenofovir/Lamivudine/Dolutegravir among Antiretroviral Therapy Naive Human Immunodeficiency Virus Infected Patients of a Tertiary Care Center in Eastern India. J Assoc Physicians India 2023;71(9):72-74.

Dissociative ionization of the H2 molecule under a strong elliptically polarized laser field: carrier-envelope phase and orientation effect.

A coupled electron-nuclear dynamical study is performed to investigate the sub-cycle dissociation and ionization of the H2 molecule in a strong 750 nm 4.5 fs elliptically polarized laser pulse. A quasi-classical method is employed in which additional momentum-dependent potentials are added to the molecular Hamiltonian to account for the non-classical effects. The effect of molecular orientation with respect to the laser polarization plane on the probabilities of different dynamical channels and proton energy spectra has been examined. We demonstrate the 2D-control of proton anisotropy by manipulating the carrier-envelope phase of the pulse. We demonstrate that the quasi-classical method can capture the carrier-envelope phase effects in the dissociative ionization of the H2 molecule. Our results indicate that the classical models provide an efficient approach to study the mechanistic insights of strong-field molecular dynamics.

Accurate Calculation of Rate Constant and Isotope Effect for the F + H2 Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface.

We employ coupled three-dimensional (3D) time dependent wave packet formalism in hyperspherical coordinates for reactive scattering problem on the newly constructed ab initio calculated ground adiabatic potential energy surface for the F + H2/D2 reaction. The convergence profiles for various reactive channels are depicted at low collision energy regimes with respect to the total angular momentum (J) quantum numbers. For two different reactant diatomic molecules (H2 and D2) initially at their respective ground roto-vibrational state (v = 0, j = 0), calculated state-to-state as well as total integral cross sections as a function of collision energy, temperature dependent rate constants, and the kinetic isotope effect for various reactivity profiles of F + H2 and F + D2 reactions are presented along with previous theoretical and experimental results.

A UK nationwide study of people with type 1 diabetes admitted to hospital with COVID-19 infection.

AIMS/HYPOTHESIS: The aim of this work was to describe the clinical characteristics of adults with type 1 diabetes admitted to hospital and the risk factors associated with severe coronavirus disease-2019 (COVID-19) in the UK. METHODS: A retrospective cohort study was performed using data collected through a nationwide audit of people admitted to hospital with diabetes and COVID-19, conducted by the Association of British Clinical Diabetologists from March to October 2020. Prespecified demographic, clinical, medication and laboratory data were collected from the electronic and paper medical record systems of the participating hospitals by local clinicians. The primary outcome of the study, severe COVID-19, was defined as death in hospital and/or admission to the adult intensive care unit (AICU). Logistic regression models were used to generate age-adjusted ORs. RESULTS: Forty UK centres submitted data. The final dataset included 196 adults who were admitted to hospital and had both type 1 diabetes and COVID-19 on admission (male sex 55%, white 70%, with mean [SD] age 62 [19] years, BMI 28.3 [7.3] kg/m2 and last recorded HbA1c 76 [31] mmol/mol [9.1 (5.0)%]). The prevalence of pre-existing microvascular disease and macrovascular disease was 56% and 39%, respectively. The prevalence of diabetic ketoacidosis on admission was 29%. A total of 68 patients (35%) died or were admitted to AICU. The proportions of people that died were 7%, 38% and 38% of those aged <55, 55-74 and ≥75 years, respectively. BMI, serum creatinine levels and having one or more microvascular complications were positively associated with the primary outcome after adjusting for age. CONCLUSIONS/INTERPRETATION: In people with type 1 diabetes and COVID-19 who were admitted to hospital in the UK, higher BMI, poorer renal function and presence of microvascular complications were associated with greater risk of death and/or admission to AICU. Risk of severe COVID-19 is reassuringly very low in people with type 1 diabetes who are under 55 years of age without microvascular or macrovascular disease. IN PEOPLE WITH TYPE 1 DIABETES AND COVID-19 ADMITTED TO HOSPITAL IN THE UK, BMI AND ONE OR MORE MICROVASCULAR COMPLICATIONS HAD A POSITIVE ASSOCIATION AND LOW SERUM CREATINE LEVELS HAD A NEGATIVE ASSOCIATION WITH DEATH/ADMISSION TO INTENSIVE CARE UNIT AFTER ADJUSTING FOR AGE.

Sodium-glucose co-transporter-2 inhibitors and susceptibility to COVID-19: A population-based retrospective cohort study.

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are widely prescribed in people with type 2 diabetes. We aimed to investigate whether SGLT2 inhibitor prescription is associated with COVID-19, when compared with an active comparator. We performed a propensity-score-matched cohort study with active comparators and a negative control outcome in a large UK-based primary care dataset. Participants prescribed SGLT2 inhibitors (n = 9948) and a comparator group prescribed dipeptidyl peptidase-4 (DPP-4) inhibitors (n = 14 917) were followed up from January 30 to July 27, 2020. The primary outcome was confirmed or clinically suspected COVID-19. The incidence rate of COVID-19 was 19.7/1000 person-years among users of SGLT2 inhibitors and 24.7/1000 person-years among propensity-score-matched users of DPP-4 inhibitors. The adjusted hazard ratio was 0.92 (95% confidence interval 0.66 to 1.29), and there was no evidence of residual confounding in the negative control analysis. We did not observe an increased risk of COVID-19 in primary care amongst those prescribed SGLT2 inhibitors compared to DPP-4 inhibitors, suggesting that clinicians may safely use these agents in the everyday care of people with type 2 diabetes during the COVID-19 pandemic.

The detection of fipronil residue in egg on layered gold nanorod-graphene oxide-based 3D SERS substrate.

Fipronil and its metabolite fipronil sulfone, when found in some food products, such as eggs, have caused major public health concerns. In this study, we used gold nanorods (AuNRs) and graphene oxide (GO) nanocomposites to fabricate a layer-by-layer assembled three dimensional (3D) substrate for toxin detection by surface enhanced Raman scattering (SERS). The 4-layers of GO-AuNR 3D SERS substrate were optimized using rhodamine 6G. The optimized SERS substrate was used to detect fipronil and fipronil sulfone in spiked eggs. The obtained limit of detection was 10-8 M (∼4.4 ppb), which is below the maximum residue limit in Taiwan of 10 ppb. Egg samples spiked with fipronil (10-7 and 10-3 M) and fipronil sulfone (10-8 and 10-4 M) were measured and the maximum departure of the measured SERS intensity from the calibrated SERS intensity was ∼14%. Thus, a facile screening method for the detection of fipronil/fipronil sulfone in food-grade eggs by SERS is demonstrated.

Dynamical calculations of O(3P) + OH(2Π) reaction on the CHIPR potential energy surface using the fully coupled time-dependent wave-packet approach in hyperspherical coordinates.

We have carried out quantum dynamics calculations for the O + OH → H + O2 reaction on the CHIPR [A. J. C. Varandas, J. Chem. Phys., 2013, 138, 134117] potential energy surface (PES) for ground state HO2 using the fully coupled 3D time-dependent wavepacket formalism [S. Adhikari and A. J. C. Varandas, Comput. Phys. Commun., 2013, 184, 270] in hyperspherical coordinates. Reaction probabilities for J > 0 are calculated for different initial rotational states of the OH radical (v = 0; j = 0, 1). State-to-state as well as total integral cross sections and rate-coefficients are evaluated and compared with previous theoretical calculations and available experimental studies. Using the rate constant for the forward (hereinafter considered to be H + O2 → O + OH) and backward (O + OH → H + O2) reactions of this reactive system, the equilibrium constant of the reversible process [H + O2 ⇌ O + OH] is calculated as a function of temperature and compared with previous experimental measurements.

Charge Transfer Processes for H + H2+ Reaction Employing Coupled 3D Wavepacket Approach on Beyond Born-Oppenheimer Based Ab Initio Constructed Diabatic Potential Energy Surfaces.

The dynamics of the H + H2+ reaction has been analyzed from the electronically first excited state of diabatic potential energy surfaces constructed by employing the Beyond Born-Oppenheimer theory [J. Chem. Phys. 2014, 141, 204306]. We have employed the coupled 3D time-dependent wavepacket formalism in hyperspherical coordinates for multisurface reactive scattering problems. To be specific, the charge transfer processes have been investigated extensively by calculating state-to-state as well as total reaction probabilities and integral cross sections, when the reaction process is initiated from the first excited electronic state (21A'). We have depicted the convergence profiles of reaction probabilities for the competing charge transfer processes, namely, reactive charge transfer (RCT) and nonreactive charge transfer (NRCT) processes for different total energies with respect to total angular momentum, J. Total and state-to-state integral cross sections are calculated as a function of total energy for the initial rovibrational state, namely, v = 0, j = 0 level of H2+ (2Σg+) molecule and are compared with previous theoretical calculations. Finally, we have calculated temperature-dependent rate constants using our presently evaluated cross sections and compared their average with the experimentally measured one.

Near-Direct Bandgap WSe2/ReS2 Type-II pn Heterojunction for Enhanced Ultrafast Photodetection and High-Performance Photovoltaics.

Pn heterojunctions comprising layered van der Waals (vdW) semiconductors have been used to demonstrate current-rectifiers, photodetectors, and photovoltaic devices. However, a direct or near-direct heterointerface bandgap for enhanced photogeneration in high light-absorbing few-layer vdW materials remains unexplored. In this work, for the first time, density functional theory calculations show that the heterointerface of few-layer group-6 transition metal dichalcogenide (TMD) WSe2 with group-7 ReS2 results in a sizable (0.7 eV) near-direct type-II bandgap. The interlayer IR bandgap is confirmed through IR photodetection, and microphotoluminescence measurements demonstrate type-II alignment. Few-layer flakes exhibit ultrafast response time (5 µs), high responsivity (3 A/W), and large photocurrent-generation and responsivity-enhancement at the hetero-overlap region (10-100×). Large open-circuit voltage of 0.64 V and short-circuit current of 2.6 µA enable high output electrical power. Finally, long-term air-stability and facile single contact metal fabrication process make the multifunctional few-layer WSe2/ReS2 heterostructure diode technologically promising for next-generation optoelectronics.

The role of electron-nuclear coupling on multi-state photoelectron spectra, scattering processes and phase transitions.

We present first principle based beyond Born-Oppenheimer (BBO) theory and its applications on various models as well as realistic spectroscopic and scattering processes, where the Jahn-Teller (JT) theory is brought in conjunction with the BBO approach on the phase transition of lanthanide complexes. Over one and half decades, our development of BBO theory is demonstrated with ab initio calculations on representative molecules of spectroscopic interest (NO2 radical, Na3 and K3 clusters, NO3 radical, C6H6+ and 1,3,5-C6H3F3+ radical cations) as well as triatomic reactive scattering processes (H+ + H2 and F + H2). Such an approach exhibits the effect of JT, Renner-Teller (RT) and pseudo Jahn-Teller (PJT) type of interactions. While implementing the BBO theory, we generate highly accurate diabatic potential energy surfaces (PESs) to carry out quantum dynamics calculation and find excellent agreement with experimental photoelectron spectra of spectroscopic systems and cross-sections/rate constants of scattering processes. On the other hand, such electron-nuclear couplings incorporated through JT theory play a crucial role in dictating higher energy satellite transitions in the dielectric function spectra of the LaMnO3 complex. Overall, this article thoroughly sketches the current perspective of the BBO approach and its connection with JT theory with various applications on physical and chemical processes.

Genome shuffling improves pigment and other bioactive compound production in Monascus purpureus.

Monascus purpureus, a pigment-producing ascomycetous fungus, has been traditionally used for red rice preparation using solid-state fermentation. The objective of this study was to develop an improved pigment-producing strain of M. purpureus MTCC 1090 through genome shuffling followed by detailed analytical estimations of pigments and other bioactive compounds produced by the fusant. Protoplast formation was optimum with 12 h-old mycelia incubated at 30 °C with cellulase, lyticase, and chitinase (40:1:1) for 5 h. Four UV-induced mutants that produced 13.1-39.5% higher amount of yellow, orange, and red pigments in fermented low-grade (cheap) broken rice were used as parents for genome shuffling. After the first round of fusion, four fusants with 35.9-60.52% higher pigment production capabilities were fused again, and finally the fusant F2-19 with distinct culture characteristic was selected under multi-selection pressure. It consistently produced 67%, 70%, and 76% higher content of yellow, orange, and red pigments respectively as compared to the wild-type. High-performance liquid chromatography (HPLC) analysis also reveals clear variation in pigment productions between wild-type and the fusant. Furthermore, HPLC analysis of F2-19 fermented rice extract confirms the production of 186 ± 8.71 and 3810 ± 29.81 mg/kg mevinolin and gamma-aminobutyric acid respectively. Citrinin was not detected. F2-19 fermented rice also has high antioxidant activity (7.92 ± 0.32 mg/g trolox equivalent), with good amount of phenolics (18.0 ± 0.95 mg/g gallic acid equivalent) and flavonoids (2.7 ± 0.26 mg/g quercetin equivalent). Thus, genome shuffling was successfully implemented on M. purpureus for the first time to develop a citrinin-free, better-performing fusant that holds future biotechnological potential. KEY POINTS: • Genome shuffling was performed by recursive protoplast fusion in Monascus purpureus. • The selected fusant, F2-19, was used in solid-state fermentation using low-grade rice. • It produced 67-76% higher content of yellow, orange, and red pigments than the wild-type. • HPLC detected 186 mg/kg mevinolin and 3810 mg/kg γ-aminobutyric acid, but no citrinin. • F2-19 shows high antioxidant activity with good amount of phenolics and flavonoids. Graphical abstract.

Growth, structural and optical characterization of wurtzite GaP nanowires.

Bulk gallium phosphide (GaP) crystallizes in the zinc-blende (ZB) structure and has an indirect bandgap. However, GaP nanowires (NWs) can be synthesized in the wurtzite (WZ) phase as well. The contradictory theoretical predictions and experimental reports on the band structure of WZ GaP suggest a direct or a pseudo-direct bandgap. There are only a few reports of the growth and luminescence from WZ and ZB GaP NWs. We first present a comprehensive study of the gold-catalyzed growth of GaP NWs via metalorganic vapor phase epitaxy on various crystalline and amorphous substrates. We optimized the growth parameters like temperature, pressure and reactant flow rates to grow WZ GaP NWs with minimal taper. These wires were characterized using electron microscopy, x-ray diffraction, Raman scattering and photoluminescence spectroscopy. The luminescence studies of bare GaP NWs and GaP/AlGaP core-shell heterostructures with WZ- and ZB-phase GaP cores suggest that the WZ-phase GaP has a pseudo-direct bandgap with weak near-band-edge luminescence intensity.