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[Display omitted] • Recent advances in biosurfactant production strategies and bioreactor scalability. • Genetic engineering and process optimization tools to enhance biosurfactant yield. • Diverse applications of biosurfactants. • Insights into the current commercial biosurfactant producers. • Major challenges and future prospects of biosurfactant production. Biosurfactants are surface-active compounds produced by numerous microorganisms. They have gained significant attention due to their wide applications in food, pharmaceuticals, cosmetics, agriculture, and environmental remediation. The production efficiency and yield of microbial biosurfactants have improved significantly through the development and optimization of different process parameters. This review aims to provide an in-depth analysis of recent trends and developments in microbial biosurfactant production strategies, including submerged, solid-state, and co-culture fermentation. Additionally, review discusses biosurfactants' applications, challenges, and future perspectives. It highlights their advantages over chemical surfactants, emphasizing their biodegradability, low toxicity, and diverse chemical structures. However, the critical challenges in commercializing include high production costs and low yield. Strategies like genetic engineering, process optimization, and downstream processing, have been employed to address these challenges. The review provides insights into current commercial producers and highlights future perspectives such as novel bioprocesses, efficient microbial strains, and exploring their applications in emerging industries. [ABSTRACT FROM AUTHOR]

A theoretical model is purposed which explains propagation of the cosh-Gaussian laser beam in the plasma with exponential density transition. Also the influence of linear absorption on self-focusing of the beam is taken into account and it may be helpful in achieving enhanced self-focusing of laser beam. The nonlinearity arises because of the relativistic motion of electrons, is considered for the penetration of laser in plasma. By considering the expression of dielectric function, we have set up differential equation for the beam width parameter. Further, the effect of decentred parameter is studied which results in stronger self-focusing of cosh-Gaussian laser beam. Stronger self-focusing of laser beam is also noticed on account of the increased plasma frequency. [ABSTRACT FROM AUTHOR]

Abstract This manuscript presents the analysis on exponential plasma density progression based self-focusing of the Gaussian laser beam in cold quantum plasma. It is noticed that beam width parameter gets reduced significantly because of the nonlinear dielectric involvement of the relativistic plasma under exponential density ramp and hence, leads to stronger self-focusing. Also, the major contribution of cold quantum plasma in the embellishment of self-focusing of laser beam has been observed. A comparison has also been attempted by considering exponential versus tangential plasma density ramp and found the former one better than later one. The current analysis may have important uses in the area of laser driven particle accelerators, laser interaction with quantum plasma etc. [ABSTRACT FROM AUTHOR]

Abstract Influence of density ripple on pulse slippage of third harmonic generation has been investigated. When highly intense short range laser pulse incident on plasma, it imparts oscillatory velocity to electrons and exert a ponderomotive force at twice the frequency of incident laser beam. It induces oscillatory velocity at second harmonic frequency 2 ω which further couples with density ripple resulting in density oscillations at 2 ω. Density oscillations at 2 ω , couple with the oscillatory velocity at ω , to produce non-linear current density at 3 ω which drives the third harmonic generation. In order to provide phase matching condition between fundamental and third harmonic pulses, density ripple in plasma is introduced which offers the required momentum to the third harmonic photon to make the process resonant. At resonance, amplitude of the third harmonic pulse is found to be maximum for optimized values of density ripple factor. It is observed that the peak value of third harmonic pulse shifted towards higher value of normalized distance z ' for higher values of normalized time t '. It is also seen that on account of the group velocity mismatch between pump and third harmonic pulses, the third harmonic pulse slips out of the domain of pump pulse. [ABSTRACT FROM AUTHOR]

Stronger self-focusing of chirped pulse laser with exponential plasma density ramp profile in cold quantum magnetoplasma has been presented. Low value of the beam width parameter in the focal region due to nonlinear dielectric role of relativistic plasma with exponential density transition is observed. Further, the significant contribution of the cold quantum magnetoplasma with the optimized value of magnetic field lead to enhanced self-focusing. Here, in this present manuscript we have observed stronger self-focusing with increased value of the chirp parameter ‘ b ’. Also intensity of the laser beam imparts chief role in achieving the stronger self-focusing. The present work may have very valuable applications in the field of laser driven accelerators, laser driven fusion etc. [ABSTRACT FROM AUTHOR]

Second harmonic generation (SHG) of a chirped pulse laser propagating through magnetized-plasma has been examined by taking into consideration the exponential plasma density ramp profile. Highly intense laser beam propagating under the effect of transverse magnetic field through homogeneous plasma is studied and noticed that the transverse current density starts oscillating with a frequency almost double of the laser field. One may observe that the exponential plasma density ramp plays a key role in the enhancement of SHG. It is due to the fact that the exponential plasma density ramp helps in making the self-focusing of pump laser stronger which leads to enhanced SHG in plasma. Also, it is noticed that with the increase in the value of the positive chirp parameter and magnetic field, the enhancement in the conversion efficiency of the harmonic generation of second order remarkably observed. Our results reveal that the conversion efficiency of SHG enhances significantly in the presence of exponential plasma density ramp. [ABSTRACT FROM AUTHOR]

Resonant second harmonic generation of a relativistic self-focused laser beam in plasma under exponential density ramp profile is investigated. It has been found that the self-focusing of Gaussian laser beam becomes stronger in plasma with exponential density ramp profile hence, leads to enhance the resonant second harmonic generation. The periodic variation of the normalized second-harmonic amplitude with normalized distance has been analyzed for different laser and plasma parameters. Therefore, enhanced second harmonic generation on account of relativistic self-focusing of fundamental laser beam in plasma under plasma density transition is observed. One may notice that exponential density ramp plays an important role in making the self-focusing stronger which in turn enhances the second harmonic generation in plasma. [ABSTRACT FROM AUTHOR]

We present the numerical analysis of optimization of wiggler wave number for density transition based second harmonic generation during laser plasma interaction. Wiggler wave number required for phase matching increases with plasma density and the intensity of pump wave. It is due to the fact that wiggler magnetic field offers the additional angular momentum which is necessary to make the second harmonic generation process resonant. A considerable enhancement in the resonant second harmonic generation of an ultra-short pulse laser in plasma with density transition surrounded by a magnetic wiggler is observed. Density transition in plasma plays a key role in self-focusing which further enhances the harmonic generation of second order in plasma. Also we have examined the effect of magnetic wiggler on the harmonic generation of second order in plasma. [ABSTRACT FROM AUTHOR]

The propagation of a high power laser beam, with frequency ω 1 and wave vector k 1 z ˆ , through a semiconductor under chirped pulse effect has been investigated which results in the harmonic generation of second order. When a highly intense beam of laser propagates through a semiconductor under the impact of wiggler magnetic field, the transverse current density starts oscillating with a frequency which is twice of the laser field. Enhancement in the second harmonic generation of chirped pulse laser in semiconductor under the influence of wiggler magnetic field is seen. We have also examined the effect of chirped pulse on power conversion efficiency of the second harmonic generation which increases with the increase of the chirp parameter. [ABSTRACT FROM AUTHOR]

Resonant second harmonic generation of a relativistic self-focusing chirped pulse laser in plasma has been investigated. The second harmonic undergoes periodic focusing in the plasma channel created by the fundamental wave and the strength of focusing increases with the propagation distance. The normalized second-harmonic amplitude varies periodically with distance and attains maximum value in the focal region. A significant enhancement in the intensity of second harmonic on account of relativistic self-focusing of the chirped pulse laser is seen. We have also examined the effect of chirped pulse on the normalized amplitude of the second harmonic generation. A sharp increase in the normalized second harmonic amplitude is seen for positive chirp. [ABSTRACT FROM AUTHOR]

Second harmonic generation of a relativistic self-focusing chirped laser pulse in magnetized-plasma has been investigated. When a highly intense laser beam propagates through homogeneous plasma under the influence of transverse magnetic field, it is found that transverse current density starts oscillating with a frequency twice of the laser field. Further as we increase the value of the positive chirp parameter, efficiency of the second harmonic generation increases significantly. Cyclotron frequency associated with plasma electrons plays a crucial role in the enhancement of the second harmonic generation. The dynamics of oscillating electrons is changed due to Lorentz force which modifies the plasma wave which affects the second harmonic significantly. [ABSTRACT FROM AUTHOR]

In the present manuscript, an analysis has been done on strong self-focusing of a chirped pulse laser in thermal quantum plasma under exponential plasma density transition. It is observed that the beam width parameter reduces up to great extent which in turns enhances the process of self-focusing. It is observed that in the embellishment of self-focusing of laser beam, thermal quantum plasma contributes significantly. Further, it is seen that with change in different parameters like intensity of the laser beam, chirped parameter value and plasma frequency, self-focusing is sensitive and becomes stronger at higher values of these parameters. The present work may have important applications in field of laser interaction with the quantum plasma, laser driven particle accelerators etc. [ABSTRACT FROM AUTHOR]

Effect of linear absorption, intensity of fundamental laser pulse and plasma frequency on beam width parameter is investigated to study the self-focusing of Hermite-Gaussian(HG) laser beam in plasma under relativistic and ponderomotive regime. Intense short pulse laser propagates through plasma imparts oscillatory velocity to electrons and non linearity arises. Using the paraxial approach we have derived the second order differential equation for beam width parameter and the equation for normalized radius of incident beam is also obtained using the critical condition. The outcome of our study reveals that light absorption and intensity of radiation enhance the self focusing of Hermite-Gaussiam laser beam. It is observed that the beam width parameter shows significant decrease for higher values of linear absorption coefficient and plasma frequency. We also observe that radius of the incident beam decreases sharply with increasing intensity of incident pulse for higher values of plasma frequency. [ABSTRACT FROM AUTHOR]

In the present study, we analyze the self-focusing / defocusing of an intense laser beam in the plasma under combined effect of density ramp and higher order axial electron temperature. The differential equation for beam width parameter is obtained and then solved numerically under paraxial ray approximation. The behavior of beam width parameter with propagation distance is extensively investigated for different values of optimized parameters and is strongly influenced by the higher order axial electron temperature, T p 4 . The results indicate that the electron temperature component T p 4 is not of little significance than T p 0 and T p 2 . Under the influence of plasma density ramp and higher order axial electron temperature T p 4 the defocusing is reduced and self-focusing becomes stronger, especially for large propagation distance. Furthermore, increase in the density ramp results more reduction in the laser beam spot size and hence, increase in the intensity of the laser which may be useful for various applications including laser-driven fusion. [ABSTRACT FROM AUTHOR]

The AIFM1 gene encodes a mitochondrial protein that acts as a flavin adenine dinucleotide-dependent nicotinamide adenine dinucleotide oxidase and apoptosis regulator. Monoallelic pathogenic AIFM1 variants result in a spectrum of X-linked neurological disorders, including Cowchock syndrome. Common features in Cowchock syndrome include a slowly progressive movement disorder, cerebellar ataxia, progressive sensorineural hearing loss, and sensory neuropathy. We identified a novel maternally inherited hemizygous missense AIFM1 variant, c.1369C>T p.(His457Tyr), in two brothers with clinical features consistent with Cowchock syndrome using next-generation sequencing. Both individuals had a progressive complex movement disorder phenotype, including disabling tremor poorly responsive to medications. Deep brain stimulation (DBS) of the ventral intermediate thalamic nucleus ameliorated contralateral tremor and improved their quality of life; this suggests the beneficial role for DBS in treatment-resistant tremor within AIFM1 -related disorders. [ABSTRACT FROM AUTHOR]

Ab-initio calculations are performed to investigate the effect of defects on structural, electronic and optical properties of Ag 8-x Cu x I 8 (0 ≤x ≤ 8). Initially AgI geometrically optimized and Ag atoms are replaced successively by Cu atoms. AgI is thermodynamically most stable, it exhibits low defect formation energy and fast ion conduction. The forbidden energy gap successively decreases with x. There is higher Ag+ ions formation than Cu+ ions. In the optical study, by increasing x, peaks of imaginary and real dielectric functions are shifted towards lower frequency regions, with Ag/Cu defects, there is slight shifting towards higher energy region, gradual increase in refractive index, and the reflectivity peaks are shifted towards higher energy. [ABSTRACT FROM AUTHOR]