Search Results (233)

During the process of oil and gas drilling, due to the existence of pores or micro-cracks, drilling fluid is prone to invade the formation. Under the action of hydration expansion of clay in the formation and liquid pressure, wellbore instability occurs. In order to reduce the wellbore instability caused by drilling fluid intrusion into the formation, this study proposed a method of forming a dynamic hydrogen bond cross-linked network weak gel structure with modified nano-silica and P(AM-AAC). The plugging performance of the drilling fluid and the performance of inhibiting the hydration of shale were evaluated through various experimental methods. The results show that the gel composite system (GCS) effectively optimizes the plugging performance of drilling fluid. The 1% GCS can reduce the linear expansion rate of cuttings to 14.8% and increase the recovery rate of cuttings to 96.7%, and its hydration inhibition effect is better than that of KCl and polyamines. The dynamic cross-linked network structure can significantly increase the viscosity of drilling fluid. Meanwhile, by taking advantage of the liquid-phase viscosity effect and the physical blocking effect, the loss of drilling fluid can be significantly reduced. Mechanism studies conducted using zeta potential measurement, SEM analysis, contact angle measurement and capillary force assessment have shown that modified nano-silica stabilizes the wellbore by physically blocking the nano-pores of shale and changing the wettability of the shale surface from hydrophilic to hydrophobic when the contact angle exceeds 60°, thereby reducing capillary force and surface free energy. Meanwhile, the dynamic cross-linked network can reduce the seepage of free water into the formation, thereby significantly lowering the fluid loss of the drilling fluid. This research provides new insights into improving the stability of the wellbore in drilling fluids. Full article

Spinal muscular atrophy (SMA) is a fatal motor neuron disease characterized by five clinical subtypes, each presenting with different rates of disease progression and varying responses to recently approved therapies. The identification of reliable biomarkers is essential for improving diagnosis and prognosis, monitoring disease progression, enabling personalized treatment strategies, and evaluating therapeutic responses. In this review, we conducted a comprehensive literature search using PubMed and Web of Science with the keywords “spinal muscular atrophy”, “biomarker” and advanced technologies such as “single-cell omics”, “nanopore and long-read sequencing” and “epigenetics” to identify and summarize current advances in SMA biomarker discovery and application. We begin with a brief overview of SMA and its current treatment barriers. We then conclude with well-established and emerging molecular and non-molecular biomarkers, followed by a conclusion of emerging technologies in biomarker discovery. In the meantime, we highlight the application of biomarkers in key areas, including early diagnosis and disease stratification, monitoring of disease progression, and prediction of treatment response. Finally, we summarize biomarker-targeted therapies, addressing current challenges in biomarker research, with the goal of improving clinical outcomes for patients with SMA. Full article

Introduction: In recent years, antimicrobial resistance (AMR) rates have increased significantly in bacterial pathogens, particularly extended beta-lactam resistance. This study aimed to investigate resistome and phylogenomics of Escherichia coli (E. coli) strains isolated from various sources in Jimma, Ethiopia. Methods: Phenotypic antibiotic resistance patterns of E. coli isolates were determined using automated Kirby–Bauer disc diffusion and minimum inhibitory concentration (MIC). Isolates exhibiting phenotypic resistance to beta-lactam antibiotics were further analyzed with a DNA microarray to confirm the presence of resistance-encoding genes. Additionally, multilocus sequence typing (MLST) of seven housekeeping genes was conducted using PCR and Oxford Nanopore-Technology (ONT) to assess the phylogenetic relationships among the E. coli isolates. Results: A total of 611 E. coli isolates from human, animal, and environmental sources were analyzed. Of these, 41.6% (254) showed phenotypic resistance to at least one of the tested beta-lactams, 96.1% (244) thereof were confirmed genotypically. More than half of the isolates (53.3%) had two or more resistance genes present. The most frequent ESBL-encoding gene was CTX-M-15 (74.2%; 181), followed by TEM (59.4%; 145) and CTX-M-9 (4.1%; 10). The predominant carbapenemase gene was NDM-1, detected in 80% (12 out of 15) of carbapenem-resistant isolates. A phylogenetic analysis revealed clonality among the strains obtained from various sources, with international high-risk clones such as ST131, ST648, ST38, ST73, and ST405 identified across various niches. Conclusions: The high prevalence of CTX-M-15 and NDM-1 in multidrug-resistant E. coli isolates indicates the growing threat of AMR in Ethiopia. The discovery of these high-risk clones in various niches shows possible routes of transmission and highlights the necessity of a One Health approach to intervention and surveillance. Strengthening antimicrobial stewardship, infection prevention, and control measures are crucial to mitigate the spread of these resistant strains. Full article

The increasing demand for sustainable and cost-effective energy storage solutions has driven interest in biomass-derived carbon materials for supercapacitor electrodes. This study explores the valorization of coconut residue (CR), an abundant agricultural waste, as a carbon precursor for nanoporous carbon (NPC) production. NPC was synthesized via hydrothermal carbonization (HTC) of CR, followed by chemical activation using potassium hydroxide (KOH) at varying temperatures (700, 800, and 900 °C). The effects of activation temperature on the structure and electrochemical performance of the NPC were systematically investigated. The activated materials exhibited amorphous, highly porous structures, with surface areas increasing alongside activation temperature—reaching a maximum of 1969 m² g⁻¹ at 900 °C. Electrochemical characterization was conducted using a three-electrode setup through cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) in a 1 M Na₂SO₄ electrolyte. The sample activated at 900 °C with a CR:KOH weight ratio of 1:2.5 achieved the highest specific capacitance of 52 F g⁻¹ at a specific current of 1 A g⁻¹. These findings underscore the potential of CR as a low-cost and sustainable raw material for fabricating efficient electrode materials in energy storage applications. Full article

Background: Antimicrobial resistance (AMR) poses significant risks to human and animal health, while the environment can contribute to its spread. National AMR surveillance programs are pivotal for assessing AMR prevalence, trends, and intervention outcomes; however, integrating advanced surveillance tools can be difficult. This pilot study, conducted by FAO ECTAD Indonesia and DGLAHS, the Indonesian Ministry of Agriculture, evaluated the costs and benefits of integrating the Nanopore MinION, Illumina MiSeq, and Sensititre system into a culture-based slaughterhouse–river surveillance system. Methods: Water samples were collected from six chicken slaughterhouses and adjacent rivers (pre- and post-treatment effluent, upstream, and downstream). Culture-based ESBL and general E. coli concentrations were estimated via the WHO Tricycle Protocol, while isolates (n = 42) were sequenced (MinION, MiSeq) and antimicrobial susceptibility testing conducted (Sensititre). Results: The Tricycle Protocol results provided estimates of effluent and river concentrations of ESBL and general E. coli identifying ESBL-to-general E. coli ratios of 13.8% and 6.2%, respectively. Compared to hybrid sequencing assemblies, MinION had a higher concordance than MiSeq for ARG identification (98%), virulence genes (96%), and locations for both (predominately plasmids). Furthermore, MinION concordance with Sensititre AST was 91%. Conclusions: Cost–benefit comparisons suggest sequencing can complement culture-based methods but is dependent on the value placed on the additional information gained. Full article

Colloidal silica can seep through calcareous sand in the subgrade, forming colloidal-silica-cemented sand with self-sensing ability—that is, it is sensitive to stress changes caused by vehicle loading. Its self-sensing sensitivity is higher than that of traditional Portland-cement-based self-sensing materials. The self-sensing mechanism is attributed to the ionic conductive network formed by seawater. However, a change in tidal water level causes an unsaturated state, and foundation deformation leads to cracking of the roadbed. The effect of unsaturation and cracking on self-sensing remains unclear, and they have not been studied in the previous literature. The aim of this paper is to study the self-sensing ability of subgrades formed via colloidal-silica-cemented sand under unsaturated and cracked states, as well as to explore the underlying mechanisms. Specimens with different degrees of saturation and different levels of joint roughness in precracks were prepared; then, the self-sensing ability was tested using the four-electrode method for each specimen under cyclic stress loading. NMR (nuclear magnetic resonance) and an unsaturated triaxial apparatus were also used to investigate the underlying mechanisms. This paper discovers that (1) either unsaturation or crack alone can increase self-sensing, but their self-sensing sensitivities are on the same order; (2) under the coupled effect of unsaturation and cracking, the self-sensing sensitivity increases by one order of magnitude, which is higher than when only unsaturation or cracking exists; and (3) the joint roughness of precracks does not affect self-sensing in the saturated state, but it affects self-sensing dramatically in the unsaturated state. The NMR test demonstrated the conductive ionic water within nanopores, which forms the conductive network for self-sensing. Unsaturation causes suction-induced shrinkage based on the unsaturated triaxial apparatus, while unsaturation increases self-sensing sensitivity, indicating that shrinkage is accompanied by self-sensing improvement. This paper provides the effects of unsaturation and cracking on the self-sensing capabilities of colloidal-silica-cemented sand, and the findings can contribute to the knowledge of subgrades formed via colloidal-silica-cemented sand for stress-sensing under traffic loading. Full article

Background: Sanger sequencing remains the gold standard for characterizing genetic variants in short DNA fragments (<700 bp). However, the increasing demand for short TATs and high sensitivities in variant detection, particularly in oncohematology, is driving the need for more efficient methods. Next-generation sequencing (NGS) has improved sensitivity and allows for the simultaneous analysis of multiple genes, but it is still costly and time-consuming. Consequently, Sanger sequencing continues to be widely used. In this study, we have compared Sanger sequencing with Oxford Nanopore technology (ONT), which offers enhanced sensitivity and faster sequencing, delivering diagnostic results within 24 h. Methods: This study involves 164 samples (for a total of 174 analyzed regions of interest) previously characterized using either Sanger sequencing or a next-generation sequencing (NGS) panel, categorized by their genetic alterations. Validation was conducted on 15 genes crucial for the diagnosis, prognosis, or identification of drug resistance in myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). The primary objective was to assess whether MinION could identify the same variants previously detected in these patients. Results and Conclusions: With a 99.43% concordance observed in our comparison, our results support the implementation of MinION technology in routine variant detection in MPN, MDS, AML, and CML cases due to its significant advantages over Sanger sequencing. Full article

Brucella intermedia, a gram-negative, non-lactose-fermenting, aerobic, rod-shaped bacterium, is found in environmental sources (e.g., soil and water). In 2020, Ochrobactrum was reclassified as Brucella. We conducted a genomic analysis of B. intermedia from hospital wastewater samples in western Ghana. A hybrid genome assembly was constructed integrating short-read data from DNA Nanoball sequencing with long-read sequences generated by Oxford Nanopore MinION technology. Identification and antimicrobial susceptibility profiles were determined using MicroScan autoSCAN-4 based on Clinical and Laboratory Standard Institute documents. ResFinder and CARD Resistance Gene Identifier (RGI) were used to identify antimicrobial resistance (AMR) genes, and BLAST and VFDB datasets were used to identify virulence factor genes. The complete genome had two chromosomes, no plasmid, and a high average nucleotide identity value (98.05%) with B. intermedia. Resistance to trimethoprim-sulfamethoxazole was revealed, the first report in this species. CARD RGI revealed the presence of AMR genes, including ANT(9)-Ic and adeF. Local BLAST analysis revealed Cgs, a B. melitensis virulence factor. B. intermedia is an opportunistic human pathogen clinically isolated several times, suggesting the importance of accurately identifying multidrug resistance. B. intermedia may possess virulence factors similar to those of B. melitensis. Further study is needed to fully elucidate its pathogenesis. Full article

Calcium ion sensors are essential in clinical diagnosis, particularly in the management of chronic kidney disease. Multiple approaches have been developed to measure calcium ions, including flame photometry and ion chromatography. However, these devices are bulky and require specialized staff for operation and evaluation. The integration of all-solid-state ion-selective determination allows the design of miniaturized and low-cost sensing that can be used for the continuous monitoring of electrolytes. However, clinical use has been limited due to the low electrochemical stability and selectivity and high noise rate. This manuscript reports for the first time a novel miniaturized Ca²⁺ ion-selective sensor, developed by using a two-layer nanocomposite thin film (5 µm thick). The device consists of functionalized silica nanoparticles embedded in a poly(vinyl chloride) (PVC) film, which was deposited onto a nanoporous zirconium silicate nanoparticle layer that served as the sensing surface. Systematic evaluation revealed that perfluoroalkane-functionalized silica nanoparticles enhanced Ca²⁺ selectivity by minimizing K⁺ diffusion, confirmed by both potentiometric measurements and quartz microbalance studies. The final sensor demonstrated a super-Nernstian sensitivity of 37 mV/Log[Ca²⁺], a low signal drift of 28 µV/s, a limit of detection of 1 µM, and exceptional selectivity against Na⁺, K⁺, and Mg²⁺ ions. Long-term testing showed stable performance over three months of continuous operation. Clinical testing was conducted on patients with chronic kidney disease. An accurate real-time monitoring of electrolyte dynamics in dialysate samples was observed, where final concentrations matched those observed in physiological conditions. Full article

Silica aerogels exhibit exceptionally low thermal conductivity and a low apparent density, as they are unique porous nanomaterials. They are extensively used in thermal insulation in terms of aerospace and building construction, adsorption processes for environmental applications, concentrating solar power systems, and so on. However, the degradation of the silica aerogel’s nanoporous structure at high temperatures seriously restricts their practical applications. Through a comprehensive review of the high-temperature structural evolution and sintering mechanisms of silica aerogels, this paper introduces two strategies to enhance their thermal stability, including heteroatom doping and surface heterogeneous structure construction. In particular, atomic layer deposition (ALD) of ultra-thin coatings on silica aerogel holds significant potential for enhancing thermal stability, while preserving its ultra-low thermal conductivity. Full article

Based on a review of the existing literature on the use of diatomite and the functioning of phase-change heat accumulators, in this study, we conducted empirical research on the creation of a phase-change composite based on Carpathian diatomite. As part of our mineralogical research, we determined the phase composition of the Carpathian diatomites in this work. Their internal nanostructure was identified. Nanopores create regular systems that, depending on the variety of diatoms, may have sieve, tubular, or “honeycomb” shapes. Diatomites’ internal structure benefits the absorption capacity of phase-change materials (PCM). The obtained calorimetric thermograms of the organic phase-change material and the diatomite compound highlighted an extension of the temperature range in which phase transformation occurs from 4–5 °C (for pure PCM RT28HC) to 15–17 °C for the composites tested with weight proportions of 1:1 and 4:6. In the case of water-rich varieties, the presence of mixed-package minerals, i.e., montmorillonite, with its small size and specific 2:1 package structure, can hinder the penetration and accumulation of PCM. The ability to bind and accumulate heat will be influenced by the size of the diatomite particles or the relative size of the PCM and pores, i.e., structural and textural features. Full article

We propose a DNA nucleobase sequencing device composed of zigzag graphene nanoribbon electrodes connected with a porphyrin molecule via carbon chains (GEPM). The connecting geometry between the nanoribbons with an even width number and the carbon chains is laterally symmetric to filter out electrons of specific modes. Various properties of the GEPM and of the GEPM + nucleobase systems, such as interaction energies, charge density differences, spin-differential electronic densities, and electric currents, are investigated using the density functional theory (DFT) combined with the non-equilibrium Green’s function (NEGF) method. The results show that the GEPM device holds promise for DNA sequencing with the measurement of the electric signals through it. The four nucleobases—adenine (A), cytosine (C), guanine (G), and thymine (T)—can be efficiently distinguished based on the conductance and current sensitivity when they are located on the porphyrin molecule of the GEPM device. The symmetry of the connecting geometry between the carbon chains and the nanoribbons selects Bloch states with specific symmetry to pass through the device and results in broad transmission valleys or gaps. In addition, the edge magnetism of graphene nanoribbons can further manipulate the transmission and then the sequencing effects. The device exhibits extremely high conductance sensitivity in the parallel magnetic configuration. This study explores the possible advantage of this technology compared with conventional nanopore sequencing devices and potentially expands the variety of available sequencing structures. Full article

Recent findings have demonstrated that the desalination and purification of contaminated water and the separation of ions and gases, besides solutions to other related issues, may all be achieved with the use of membranes based on artificial nanoporous materials. Before the expensive stages of production and experimental testing, the optimum size and form of membrane nanopores could be determined using computer-aided modeling. The notion that rectangular nanopores created in a multilayered hexagonal boron nitride (h-BN) membrane in a way that results in different inner lining atoms would exhibit unique properties in terms of the water penetration rate is put forth and examined in the current study. Nanopores in boron nitride sheets can be generated with the inner lining of boron atoms (B-edged), nitrogen atoms (N-edged), or both boron and nitrogen atoms (BN-edged). In this study, we compared the three different inner-lined nanopores of boron nitride nanosheets to a comparable-sized graphene nanopore and evaluated the water conduction. Full article

Acetone is a well-known biogas involved in lipid metabolism and is considered a potential biomarker for diabetes. However, the conventional detection methods for acetone face the limitations of large size, complex usage, and cross-sensitivity. In this study, we developed a portable device comprising a porous colorimetric acetone analytical chip composed of 2-nitrophenyl hydrazine and porous glass. The analytical chip was highly sensitive and selective for acetone because it was based on the chemical reaction between acetone and hydrazine in a nanoporous material, which provides a large surface area. The device consisted of a 450 nm laser light source and a photodiode detector with a volume of less than 40 mL. Acetone gas was measured in the atmosphere for 10 min using the developed flow–stop method. The measurable acetone concentration ranged from 0 to 6.0 ppm with a detection limit of 0.22 ppm. We successfully conducted a feasibility study using human exhaled breath and analyzed the relationship between exercise and the acetone concentration in the breath. An upward trend in exhaled acetone levels was seen post-exercise for each individual. Full article

Recently, there has been an increasing emphasis on improving the performance of metal components across various industries, such as automotive, aerospace, electronics, medical devices, and military applications. However, the challenges related to efficient heat generation and transfer in equipment and devices are becoming increasingly critical. A solution to these issues involves the adoption of a metal–composite hybrid structure, designed to efficiently manage heat, while substituting conventional metal components with polymer–carbon composites. In this study, nanopores were formed on the metal surface using an anodization process, serving as the basis for creating 3D-printed polymer/metal hybrid constructions. Various surface treatments, including plasma treatment, mixed electrolyte anodization, and etching, were applied to the metal surface to enhance the bonding strength between the 3D-printed polymer and the aluminum alloy. These processes were essential for developing lightweight polymer/metal hybrid structures utilizing a range of 3D-printed polymer filaments, such as polylactic acid, thermoplastic polyurethane, acrylonitrile butadiene styrene, polypropylene, thermoplastic polyester elastomer, and composite materials composed of polymer and carbon. In particular, the hybrid structures employing polymer–carbon composite materials demonstrated excellent heat dissipation characteristics, attributed to the remarkable conductive properties of carbon fibers. These technologies have the potential to effectively address the device heat problem by facilitating the development of lightweight hybrid structures applicable across various fields, including automotive, mobile electronics, medical devices, and military applications. Full article