Density Functional Theory Investigation on Muon Hyperfine Interaction in Methylated Guanine-Cytosine Double-Strand DNA

The aims of this study were to determine the most likely Mu trapping sites based on total energy consideration as well as identifying the associated muon hyperfine coupling constant of 1, 2, and 3 methylated guanine-cytosine base pair double-strand DNA. The Density Functional Theory method was used at B3LYP/6-31G level of theory to accomplish the objectives of the investigation. The relative energy in the 3 methylated guanine-cytosine base pair double-strand DNA molecule showed that N7 sites in the guanine base have the lowest energy, followed by N3, and C8 sites. It was found that the addition of a methyl group at the C5 atom in the cytosine base does change the stability of the C8 sites in the 3 methylated guanine-cytosine base pair double-strand DNA molecule, but the associated muon hyperfine coupling constant (HFCC) is not affected. The results of this study indicate that there will be no overlaps in the resonance dips due to N7, N3, and all C8 sites of the guanine bases and N3, C5, and C6 sites of the cytosine bases in the Avoided Level Crossing Muon Spin Resonance spectrum

Linear and Nonlinear Electro-optic Response of MHPOCBC

This study investigated the linear and second-order electro-optic responses in chiral smectic liquid crystal 4-(1-methylheptyloxycarbonyl) phenyl 4-octylcarbonyloxybiphenyl-4-carboxylate (MHPOCBC). The result revealed a single Debye-type relaxation in the linear electro-optic frequency dispersion, with a relaxation frequency extending up to one hundred kHz. Conversely, the second-order electro-optic response exhibited intricate temperature-dependence, accurately depicted by a phenomenological Landau theory around the SmA–SmCa* phase transition point. Notably, in the SmCa* phase, critical slowing down of the amplitude mode occurred near the transition to the SmA phase, while at lower temperatures of the SmCa* phase, a distinct low-frequency relaxation mode emerged. Furthermore, the relaxation frequency of the antiferroelectric Goldstone mode in the SmCA* phase remained constant across the entire temperature range. These findings should significantly contribute to the understanding of dynamic behaviors in chiral smectic liquid crystals, shedding light on their complex phase transitions and electro-optic properties

Rapid Synthesis of Graphene Oxide Derived from Biomass with Atmospheric Plasma Technology

In this study, we explored a low-cost, green, and renewable approach utilizing biomass resources, i.e., coconut fronds, palm fronds, and rambutan stems, to rapidly synthesize graphene oxide via atmospheric plasma techniques. The plasma treatment, with argon gas as the plasma source and a power source of 960 W, lasted for 5 minutes. Graphene oxide (GO) was confirmed using SEM and TEM images with a C:O content ratio greater than 80% for all samples and the formation of graphene layers. The presence of a D-band and a G-band in Raman spectroscopy as well as O-H and C-O groups in the FTIR confirmed the existence of GO

Synthesis and Characterization of Bi2S3 Deposited on TiO2 Nanotubes (TiO2NTAs) as Photoanode in the Tandem DSSC-PEC System for Hydrogen Evolution

TiO2NTAs is one of the most frequently used photoanodes. However, TiO2NTAs has a wide bandgap, so it is only active under UV light. Therefore, this study modified TiO2NTAs photoanode film to increase its efficiency. A simple method that successfully assists the Bi2S3 coating process on the surface of TiO2NTAs film is the Successive Ionic Layer Adsorption and Reaction (SILAR) method. In this research, modified Bi2S3 with TiO2NTAs was prepared using the SILAR method with variations of the number of synthesis cycles at 1, 2, 4, and 6. Based on the synthesis results, the number of deposition cycles greatly influences the performance of TiO2NTAs films. The synthesized TiO2NTAs/Bi2S3 results were characterized using SEM, XRD, FTIR, UV-Vis DRS, and photoelectrochemistry. The X-ray diffractogram showed that the composite compound was obtained successfully. The SEM images showed that Bi2S3 was deposited on the surface of the TiO2NTAs without blocking the nanotube holes. The constructed DSSC-PEC system could produce hydrogen with an STH (solar-to-hydrogen) efficiency of 0.02318% in an H-type reactor using anode irradiation for 6 hrs

Environmentally Friendly Graphene Oxide Production using Ultrasonication for Fiber Optic Coating as Humidity Sensor

Graphene oxide (GO) has many applications, such as energy storage, sensors, and polymer composites. This study aimed to produce environmentally friendly GO for use as a humidity sensor. The GO was synthesized using liquid phase exfoliation (LPE) with ultrasonication. The ultraviolet-visible (UV-Vis) test results showed an absorption peak at a wavelength of 227 nm and a shouldering peak at 270 nm. The Fourier transform infrared (FTIR) spectrum showed the presence of oxygen functional groups indicating hydrophilic material characteristics. The X-ray diffraction (XRD) patterns indicated that the GO had an amorphous phase, as evidenced by a broadened peak at 2θ ≅ 12.2°. The scanning electron microscope (SEM) images showed that the synthesized GO was in the form of indentations or sheets of planar hexagonal structures in single or multi-layers. Based on the energy dispersive X-ray (EDX) characterization, the GO consisted of 63.6% carbon (C) and 26.4% oxygen (O). The C/O ratio after sonication showed a reduction in oxygen with a ratio of 2.4. Interestingly, the humidity tests showed that the GO coated on polymer optical fiber (POF) significantly enhanced the gradient values from 0.0567 to 0.4042 compared to the POF without coating, confirming its potential as a humidity sensor.

Simulation of Ultra-Short Laser Pulses Propagation and Ionization in Dual-Gas-Cells to Enhance the Quasi-Phase Matching of Harmonics Generation in Plasmas

A numerical model was designed and implemented to investigate the influence of plasma defocusing on laser characteristics. The effects of plasma defocusing were investigated by studying beam divergence, intensity reduction, and blue shifting. The diffusion of the ultra-intense laser beam in gas cells was within a Rayleigh range. Moreover, using dual-gas-cells, the impact of quasi-phase matching (QPM) on the creation of harmonic pulses in argon and hydrogen plasmas was studied. The alternating structure of argon and hydrogen gas cells showed a perfect build-up of the generated ultra-short harmonics pulses. The impact of electron density on laser diffusion and the creation of harmonic pulses were also investigated in this work. In the simulation, argon plasma with different plasma densities was used in an alternating structure to create dual-gas-cells and quasi-phase-matching. Noticeable conversion of the fundamental laser pulses to harmonics pulses was accomplished in the model by using the QPM concept

Sedimentary Facies, Palynology, and Organic Geochemistry of Eocene Kalumpang Formation in Lariang and Karama Areas, West Sulawesi, Indonesia

The Kalumpang Formation was deposited in a delta plain setting. A Middle to Late Eocene age (Proxapertites operculatus zone) was inferred from palynological analysis, with a paleoenvironment in a coastal plain setting with a strong terrestrial influence. Samples from the Kalumpang Formation indicate a marginal to early mature stage for hydrocarbon generation. It is mostly composed of gas-prone to oil and gas-prone Type III kerogen facies. The biomarker character of both the rock and oil samples suggests a terrestrial origin, with a significant contribution of estuarine or bay organic material. The oil derives from a non-carbonate lithology, while the rock samples are from carbonate/calcareous shale origin. The abundance of oleanane compound and C30 resins suggests higher plant angiosperm input of Late Cretaceous or younger age for both the rock and the oil samples. The oil seep contains more abundant oleananes compared to the carbonaceous mudstone of the Kalumpang Formation. This suggests that the oil originated from more marine facies than the rock samples, which were deposited in a delta plain setting. This study demonstrated the agreement of depositional environment interpretation and age assessment between lithofacies, palynological, and organic geochemistry analysis

Implementation of Non-Uniform F-K and Strict F-K Filter Normalization in Seismic Downhole Processing

In fundamental geophysics, we can understand that if we hit the surface, the body and surface waves propagate into and on the soil or rock. The body waves consist of pressure waves, which are the fastest, and shear waves, which are slower. This phenomenon can be measured using the seismic downhole method to determine the velocity of P and S waves of soil layers by generating source energy at the surface and calculating the arrival time at a tri-axial sensor inside a borehole. Determining the arrival time of S waves is often tricky because the recorded S wave arrival is on the coda of the P waves and is also distracted by measurement noise. A common method to separate P and S waves is direct F-K filtering from the F-K image of the measurement data. This study modified this method by adjusting the actual source-receiver distance by implementing a non-uniform F-K transform to produce the correct velocity response. Another improvement was strict filter normalization to regain continuity, thus preventing a shadow response in the F-K image. Synthetic and real measurement data showed that our modification performed better than direct FK-filtering

Hydrolysis Optimization and In Vitro Anti-aging Effect of Cihateup Duck Eggshell Membrane

An altered skin morphology and physiology are the most evident signs of increasing age in humans. These changes may affect pivotal skin functions. Eggshell membrane (ESM) is an egg byproduct that is regarded as waste. Nonetheless, studies have shown its beneficial effect in preventing dermal aging. Currently, only chicken ESM has been extensively studied and is commercially available. Our study explored the potential of duck ESM, which has been overlooked. We examined the use of Cihateup duck (Anas platyrhynchos Javanica) eggshell membrane hydrolysate (ESMH) in anti-aging skincare products. Enzymatic hydrolysate of ESM was obtained by varying the papain and sodium sulfite concentrations. The optimum concentrations were used for further analysis, i.e., hyaluronic acid content, amino acid composition, antioxidant activity, and collagenase inhibition activity. The result showed that 60 U/mg of papain and 30 mM of sodium sulfite yielded a total protein of 80.18±1.47 mg/g for duck ESMH and 71.41±2.13 mg/g for chicken ESMH. In addition, duck ESMH showed higher hyaluronic acid content and different amino acid composition than chicken. Duck ESMH also showed the highest collagenase inhibition activity. In conclusion, our findings suggest that duck ESMH holds great promise for anti-aging skincare, offering better activity than chicken ESMH

Bioinformatic Analysis Strategy in Restriction Enzyme Selection for Indonesian Panulirus homarus Identification by PCR-RFLP

The spiny lobster (Panulirus homarus) is a valuable fishery commodity in Indonesia, particularly in its juvenile life form. However, identifying the early life forms of the spiny lobster can be challenging, as it exhibits similar morphological features compared to the juveniles of other Panilurid lobsters. Molecular-based identification, specifically DNA sequencing, is the best method for species identification, but it requires advanced instruments and is costly. An alternative method is proposed here, using the PCR-RFLP technique, which is low-cost, rapid, and has standard instrumentation requirements. The challenge with this method is selecting the appropriate restriction enzyme to determine the targeted species’ identity. This study proposes using the REfind (https://github.com/indriatmoko07/REfind), R package to select the best restriction enzyme for identifying P. homarus, applicable to other species. The bioinformatics workflow used in this study successfully identified BseSI or BmgI as the most suitable restriction enzymes among 739 restriction enzymes to differentiate P. homarus from other Panilurid species. This result was validated by employing a wet lab test using the BseSI enzyme and successfully validated the bioinformatics result. These findings may be useful for biologists in conducting various studies that require rapid, low-cost, and identification of specific species in the future