Increased Signal Intensity Research Articles

Association Between Thenar Musculature and Carpal Tunnel Syndrome.

Background: Dynamic forces acting on the transverse carpal ligament (TCL) may influence the mechanics of the carpal tunnel (CT), thus affecting the occurrence of CT syndrome (CTS). Previous studies demonstrated an association between muscle overlying the CT and the diagnosis of CTS. Understanding the location of insertion/origin of the thenar musculature will allow mechanical analysis of the forces applied to the TCL during performance of individual tasks. Our purpose was to determine the location of muscle overlying the CT on magnetic resonance imaging (MRI) in CTS and controls. Methods: Case-control study of 21 normal adult wrist MRI scans. MRI measurements were performed on an axial cut at the level of the hook-of-hamate. Median nerve cross-sectional area (CSA), median nerve shape and increased signal intensity within the CT were associated with CTS. The amount and length of muscle crossing the midline and the CT on the same cut was measured and the association with the occurrence of CTS was analysed. Results: We found an inverse relationship between the amount of muscle crossing the midline and the size of the CT, and a direct relationship with occurrence of CTS p less than 0.01, but no differences regarding length of muscle crossing the midline. Conclusions: This study supports an association between the thenar musculature location relative to the CT and the predictors of CTS on MRI. Since the location of muscle origin/insertion is variable, their effect may differ accordingly, therefore, further study is needed to describe the exact location of origin/insertion and its differential dynamic or static effect on the pathogenesis of CTS. Level of Evidence: Level IV (Diagnostic).

Improving the Key Enzyme Activity, Conversion Intensity, and Nitrogen Supply Capacity of Soil through Optimization of Long-Term Oilseed Flax Rotation Planting Patterns in Dry Areas of the Loess Plateau of China

Various crop rotation patterns can result in differences in nutrient consumption and the accumulation of toxic substances in the soil, indirectly impacting the soil environment and its nutrient supply capacity. Implementing optimized crop planting practices is beneficial for maintaining the favorable physical and chemical properties of farmland soil in the arid area of northwestern China. This study aimed to establish a crop rotation pattern to improve key enzyme activities and soil nitrogen conversion efficiency, as well as understand the underlying mechanism for enhancing nitrogen supply capacity. A field experiment was conducted to study the effect of four flax planting patterns, which included 13 crop rotation patterns with different crop frequencies: 100% Flax (Cont F), 50% Flax (I) (WFPF, FPFW, PFWF, FWFP), 50% Flax (II) (FWPF, WPFF, PFFW, FFWP), 25% Flax (WPWF, PWFW, WFWP, FWPW), on the key enzyme activities and the rate of soil nitrogen conversion, as well as the nitrogen supply capacity. Here, F, P, and W represent oilseed flax, potato, and wheat, respectively. The results indicated that the wheat stubble significantly increased the intensity of soil ammonification and denitrification before planting. Additionally, the activity levels of soil nitrate reductase and nitrite reductase under wheat stubble were significantly increased by 66.67% to 104.55%, while soil urease activity significantly decreased by 27.27–133.33% under wheat stubble compared to other stubbles. After harvest, the activities of soil nitrate reductase and nitrite reductase under the wheat stubble decreased significantly, and the intensity of soil ammonification, nitrification, and denitrification reduced significantly by 7.83–27.72%. The WFWP and FWFP treatments led to a significant increase in soil nitrogen fixation intensity under various crop rotations after harvest and significantly increased the levels of inorganic nitrogen in the soil before the planting of the next crop. This study suggests that the long-term rotation planting patterns WFWP and FWFP can significantly enhance the key enzyme activities of soil nitrogen conversion and significantly improve soil nitrogen conversion before crop sowing. This may increase the rate of soil nitrogen transfer and raise the available nitrogen content of the soil. These findings are crucial for reducing soil nitrogen loss and improving soil nitrogen nutrient supply capacity in dry areas of the Loess Plateau of China.

Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content.

Micellar calcium phosphate (MCP) content of skim milk was modified by pH adjustment followed by dialysis. Turbidity, casein micelle size and partitioning of Ca and caseins between the colloidal and soluble phases of milk were determined. Protein structure was characterised by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H NMR), whereas organic and inorganic phosphorus were studied by phosphorus-31 nuclear magnetic resonance (31P NMR). The sample with the lowest MCP content (MCP7) exhibited the smallest particle size and turbidity, measuring 83 ± 8 nm and 0.08 ± 0.01 cm-1, respectively. Concentrations of soluble caseins increased with decreasing MCP levels. At ~60% MCP removal, FTIR analysis indicated a critical stage of structural rearrangement and 31P NMR analysis showed an increase in signal intensity for Ca-free Ser-P, which further increased as MCP concentration was further reduced. In conclusion, this study highlighted the importance of MCP in maintaining micellar structure and its impact on the integrity of casein micelle.

Spontaneous resolution of spinoglenoid ganglion cyst: a case series

BackgroundSpontaneous resolution of a spinoglenoid notch ganglion cyst (SGC) without surgical treatment has been rarely reported; however, we have encountered this phenomenon occasionally. Therefore, we aimed to describe a case series of consecutive patients with SGC in whom it spontaneously resolved without surgical treatment. MethodsWe retrospectively reviewed 12 patients with magnetic resonance imaging (MRI)-confirmed SGC in whom it resolved without surgical treatment between January 2011 and March 2023. We included patients without abnormally increased signal intensity or muscle atrophy due to denervation from suprascapular neuropathy on MRI. Resolution of the SGC was confirmed via MRI or ultrasound at the follow-up visit, and suprascapular neuropathy was assessed using electromyography and nerve conduction studies when needed. For functional assessments, the visual analog scale (VAS) for pain and active range of motion of the shoulder were used to compare pre- and post-resolution follow-ups. ResultsEleven men and one woman with a median age of 54.0 years (interquartile range [IQR] 37.0–65.3) were included in this study. The SGCs resolved spontaneously at a median of 13.2 months with an IQR of 8.2–23.0 after initial evaluation using MRI. The SGCs were multiloculated cysts with superior labrum anterior and posterior (SLAP) II–IX lesions, with a median diameter of 2.5 cm (IQR 2.0–2.8). The median VAS for pain (pre-resolution 5.0 [IQR 4.0–7.0] vs. post-resolution 1.0 [IQR 0.0–1.0], P = 0.002) and internal rotation at the back (pre-resolution 8.0 [IQR 7.0–10.3] vs. post-resolution 7.5 [IQR 7.0–8.0], P = 0.034) were significantly improved after the resolution. ConclusionsSurgical treatment may not be necessary in all cases of SGC. Nonsurgical treatment may be a viable option in the absence of suprascapular nerve involvement or SLAP-related physical findings.

Enzyme-free sensitive SERS biosensor for the detection of thalassemia-associated microRNA-210 using a cascade dual-signal amplification strategy

Backgroundβ-thalassemia is a blood disorder caused by autosomal mutations. Gene modulation therapy to activate the γ-globin gene to induce fetal hemoglobin (HbF) synthesis has become a new option for the treatment of β-thalassemia. MicroRNA-210 (miR-210) contributes to studying the mechanism regulating γ-globin gene expression and is a potential biomarker for rapid β-thalassemia screening. Traditional miRNA detection methods perform well but necessitate complex and time-consuming miRNA sample processing. Therefore, the development of a sensitive, accurate, and simple miRNA level monitoring method is essential. ResultsWe have developed a non-enzymatic surface-enhanced Raman scattering (SERS) biosensor utilizing a signal cascade amplification of catalytic hairpin assembly reaction (CHA) and proximity hybridization-induced hybridization chain reaction (HCR). Au@Ag NPs were used as the SERS substrate, and methylene blue (MB)- modified DNA hairpins were used as the SERS tags. The SERS assay involved two stages: implementing the CHA-HCR cascade signal amplification strategy and conducting SERS measurements on the resulting product. The HCR was started by the products of target-triggered CHA, which formed lengthy nicked double-stranded DNA (dsDNA) on the Au@Ag NPs surface to which numerous SERS tags were attached, leading to a significant increase in the SERS signal intensity. High specificity and sensitivity for miR-210 detection was achieved by monitoring MB SERS intensity changes. The suggested SERS biosensor has a low detection limit of 5.13 fM and is capable of detecting miR-210 at concentration between 10 fM and 1.0 nM. SignificanceThe biosensor can detect miR-210 levels in the erythrocytes of β-thalassemia patients, enabling rapid screening for β-thalassemia and suggesting a novel approach for investigating the regulation mechanism of miR-210 on γ-globin gene expression. In the meantime, this innovative technique has the potential to detect additional miRNAs and to become an important tool for the early diagnosis of diseases and for biomedical research.

5-ALA localises to the autophagy compartment and increases its fluorescence upon autophagy enhancement through caloric restriction and spermidine treatment in human glioblastoma

Glioblastoma Multiforme (GBM) is the most invasive and prevalent Central Nervous System (CNS) malignancy. It is characterised by diffuse infiltrative growth and metabolic dysregulation that impairs the extent of surgical resection (EoR), contributing to its poor prognosis. 5-Aminolevulinic acid (5-ALA) fluorescence-guided surgical resection (FGR) takes advantage of the preferential generation of 5-ALA-derived fluorescence signal in glioma cells, thereby improving visualisation and enhancing the EoR. However, despite 5-ALA FGR is a widely used technique in the surgical management of malignant gliomas, the infiltrative tumour margins usually show only vague or no visible fluorescence and thus a significant amount of residual tumour tissue may hence remain in the resection cavity, subsequently driving tumour recurrence. To investigate the molecular mechanisms that govern the preferential accumulation of 5-ALA in glioma cells, we investigated the precise subcellular localisation of 5-ALA signal using Correlative Light and Electron Microscopy (CLEM) and colocalisation analyses in U118MG glioma cells. Our results revealed strong 5-ALA signal localisation in the autophagy compartment – specifically autolysosomes and lysosomes. Flow cytometry was employed to investigate whether autophagy enhancement through spermidine treatment (SPD) or nutrient deprivation/caloric restriction (CR) would enhance 5-ALA fluorescence signal generation. Indeed, SPD, CR and a combination of SPD/CR treatment significantly increased 5-ALA signal intensity, with a most robust increase in signal intensity observed in the combination treatment of SPD/CR. When using 3-D glioma spheroids to assess the effect of 5-ALA on cellular ultrastructure, we demonstrate that 5-ALA exposure leads to cytoplasmic disruption, vacuolarisation and large-scale mitophagy induction. These findings not only suggest a critical role for the autophagy compartment in 5-ALA engagement and signal generation but also point towards a novel and practically feasible approach to enhance 5-ALA fluorescence signal intensity. The findings may highlight that indeed autophagy control may serve as a promising avenue to promote an improved resection and GBM prognosis.

The Comparison of the Effect of Prolonged Sitting on Lumbar Repositioning Error in Asymptomatic and Chronic Low Back Pain Participants with Seated Sedentary Behavior

Lumbar Repositioning Error (LRPE) refers to an individual’s capacity to perceive and control the precise position of their lumbar spine. An adequate lumbar repositioning is crucial for sustaining spinal stability and an optimal function during sitting activities. When lumbar repositioning is inaccurate, it can lead to ineffective movement patterns that might contribute to the development of low back pain (LBP). However, the impact of prolonged sitting on LRPE in asymptomatic individuals and those with chronic low back pain (CLBP) remains unexplored. To assess the effects of continuous 30 min sitting on LRPE and pain in asymptomatic and CLBP participants with sedentary behavior, 50 participants (25 asymptomatic and 25 CLBP) were recruited. Their LRPE and pain were measured before and after a 30 min sitting condition. Both groups experienced a significant increase in pain intensity after the 30 min sitting period (p = 0.001 for asymptomatic, p = 0.006 for CLBP). The LRPE remained unchanged in the asymptomatic group (p = 0.066), but it was significantly increased in the CLBP group (p = 0.001). Furthermore, the CLBP group exhibited significantly higher levels of LRPE and pain compared to the asymptomatic group after sitting (p = 0.041 and p = 0.001, respectively). Prolonged sitting posture is a risk of LBP, particularly in sedentary individuals. To prevent the exacerbation of LRPE and LBP, individuals with CLBP, especially those with sedentary lifestyles, should avoid sitting continuously for 30 min. These findings highlight the importance of physical therapists providing such guidance in practice. HIGHLIGHTS Prolonged sitting for 30 min appears to impact back pain CLBP participants experienced a significant increase in lumbar repositioning error (LRPE) after the 30 min sitting condition Physical therapists should advise people with sedentary lifestyles with low back pain to refrain from sitting for 30 min GRAPHICAL ABSTRACT

Climate Extremes and Sustainability Issues: A Case of Proposed Hydropower Projects in Lahaul Valley, Himachal Pradesh

Water and energy are the key to development; however, a great deal of contestation is at the very core of hydropower and sustainability debate in the context climate change and risk of disasters. A vast potential for renewable energy in the Himalayas has led to planning for hydropower projects since 1990s. However, social, economic and environmental issues linked to such development has also led to a fear among local communities in light of climate change. This study analysed the relation between climate extremes, disaster risk and hydropower development in Lahaul Valley of Himachal Pradesh. The study examined long-term climate data for precipitation and temperature trends while daily rainfall gridded data was used for the analysis of climate extremes. The results show statistically significant increase in precipitation intensity and rise of winter and post winter temperature. Also, heavy and very heavy rainfall days, daily rainfall intensity shows increasing trends that may have serious repercussions on local economy, livelihood and hydropower development. The field observations reveal discontentment of local population to proposed development. It is important that this debate must be reviewed logically to ensure safe future of the area with sound understanding of disasters and climate change risk.

Effects of 1-hour computer use on ulnar and median nerve conduction velocity and muscle activity in office workers.

To compare the effects of 1-hour computer use on ulnar and median nerve conduction velocity and muscle activity in office workers with symptomatic neck pain and asymptomatic office workers. A total of 40 participants, both male and female office workers, with symptomatic neck pain (n = 20) and asymptomatic (n = 20), were recruited. Pain intensity, ulnar nerve conduction velocity, median nerve conduction velocity, and muscle activity were determined before and after 1 hour of computer use. There was a significant increase in pain intensity in the neck area in both groups (P < .001). The symptomatic neck pain group revealed a significant decrease in the sensory nerve conduction velocity of the ulnar nerve (P = .008), whereas there was no difference in the median nerve conduction velocity (P > .05). Comparing before and after computer use, the symptomatic neck pain group had less activity of the semispinalis muscles and higher activity of the anterior scalene muscle than the asymptomatic group (P < .05). The trapezius and wrist extensor muscles showed no significant differences in either group (P > .05). This study found signs of neuromuscular deficit of the ulnar nerve, semispinalis muscle, and anterior scalene muscle after 1hour of computer use among office workers with symptomatic neck pain, which may indicate the risk of neuromuscular impairment of the upper extremities. The recommendation of resting, and encouraging function and flexibility of the neuromuscular system after 1hour of computer use should be considered.

Radiotherapy-activated NBTXR3 nanoparticles promote ferroptosis through induction of lysosomal membrane permeabilization

PurposeRadiotherapy-activated NBTXR3 (NBTXR3 + RT) has demonstrated superior efficacy in cancer cell destruction and tumor growth control, compared to radiotherapy (RT), in preclinical and clinical settings. Previous studies highlighted the immunomodulatory properties of NBTXR3 + RT, such as modification of tumor cell immunogenicity/adjuvanticity, producing an effective local tumor control and abscopal effect, related to an enhanced antitumor immune response. Furthermore, NBTXR3 + RT has shown potential in restoring anti-PD1 efficacy in a refractory tumor model. However, the early events leading to these results, such as NBTXR3 endocytosis, intracellular trafficking and primary biological responses induced by NBTXR3 + RT remain poorly understood.MethodsWe analyzed by transmission electron microscopy endocytosis and intracellular localization of NBTXR3 nanoparticles after endocytosis in various cell lines, in vitro and in vivo. A kinetic of NBTXR3 endocytosis and its impact on lysosomes was conducted using LysoTracker staining, and a RNAseq analysis was performed. We investigated the ability of NBTXR3 + RT to induce lysosomal membrane permeabilization (LMP) and ferroptosis by analyzing lipid peroxidation. Additionally, we evaluated the recapture by cancer cells of NBTXR3 released from dead cells.ResultsNBTXR3 nanoparticles were rapidly internalized by cells mainly through macropinocytosis and in a less extend by clathrin-dependent endocytosis. NBTXR3-containing endosomes were then fused with lysosomes. The day following NBTXR3 addition, we measured a significant increase in LysoTracker lysosome labeling intensity, in vitro as in vivo. Following RT, a significant lysosomal membrane permeabilization (LMP) was measured exclusively in cells treated with NBTXR3 + RT, while RT had no effect. The day post-irradiation, a significant increase in lipid peroxidation, a biomarker of ferroptosis, was measured with NBTXR3 + RT compared to RT. Moreover, we demonstrated that NBTXR3 nanoparticles released from dead cells can be recaptured by cancer cells.ConclusionsOur findings provide novel insights into the early and specific biological effects induced by NBTXR3 + RT, especially LMP, not induced by RT in our models. The subsequent significant increase in lipid peroxidation partially explains the enhanced cancer cell killing capacity of NBTXR3 + RT compared to RT, potentially by promoting ferroptosis. This study improves our understanding of the cellular mechanisms underlying NBTXR3 + RT and highlights its potential as an agnostic therapeutic strategy for solid cancers treatment.Graphical

БЛОК-СОПОЛИМЕРЫ, ПОЛУЧЕННЫЕ С ИСПОЛЬЗОВАНИЕМ МАКРОИНИЦИАТОРА, 2,4-ТОЛУИЛЕНДИИЗОЦИАНАТА И ОРГАНОЗАМЕЩЁННЫХ КРЕМНЕЗМОВ

Using tetraethoxysilane, polyoxyethylene glycol, and copper chloride (CuCl2), self-condensation-resistant silicas with polyoxyethylene branches (ASiP-Cu) were synthesized. Features of the supramolecular organization of transparent block copolymers (OBCs) determine the chemical structure of the internal cavity of micro-sized voids and significant changes in the shape of the spectrum of the sorbed dye. The use of ASiP-Cu modifiers leads to a noticeable increase in the sorption capacity of OBS, which depends on the method of preparing ASiP-Cu and its amount in the OBC composition. The most significant increase in intensity in the maximum region of the electronic spectrum of immobilized organic dye R6G is observed when using ASiP-Cu-0.1 and ASiP-Cu-0.5 which were obtained using 0.1 and 0.5 wt.% CuCl2, respectively. An increase in the intensity of R6G sorption on OBC with an increase in the content of modifiers in their composition is accompanied by a decrease in the contact angle of the polymers. Modification of block copolymers using ASiP-Cu leads to an increase in their water absorption, reflecting an increase in the free volume of the polymers. Using OBC modified with 0.5 wt.% of the ASiP-Cu-0.5, a test system was obtained by immobilizing the analytical reagent PAN onto the polymer. It was found that PAN molecules quickly fill the free space of the polymer. Before carrying out the analytical reaction to determine CuCl2, the polymer with (1-(2-pyridylazo)-2-naphthol) (PAN) immobilized on it was preliminarily kept in water for 24 hours. This procedure is necessary to prevent the processes of desorption of the analytical reagent and its capture of ions of the metal being determined directly in the solution. The surface morphology of the samples was studied using atomic force microscopy (AFM). Indentations are fixed on the surface of the samples. AFM images indicate the porous structure of OBC. Modification of OBC using ASiP-Cu leads to noticeable changes in the morphology of modified OBC, which depends on the structure of ASiP-Cu. The use of the ASiP-K modifier leads to a reduction in the number and size of depressions on the surface of the OBC sample.

ИСПОЛЬЗОВАНИЕ РАДИАЦИОННЫХ ТЕХНОЛОГИЙ В ЖИВОТНОВОДСТВЕ

Experiments were carried out on the boulders of fine-wooled sheep of the Prekos breed in the conditions of the sheep farm. Lambs of the first three experimental groups aged, respectively, 1, 2 and 3 months were subjected to a single external gamma radiation at a dose of 0,4 Gy at the Gamma installation «Puma». Animals of the fourth group served as control and were not subjected to radiation. The data obtained indicate that a single radiation of lambs at a dose of 0,4 Gy led to a significant increase in intensity of their growth, meat, wool productivity, survival, natural length of wool fibers, increased resistance to cod of the facial layer of the skin and the strength of the skin tissue of manufactured and ennobled sheepskin semi-finished products compared to control analogues.

Improvement in the sensitivity of LA-ICP-MS bioimaging by addition of nitrogen to the argon carrier gas.

Elemental bioimaging of low abundant elements via laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) is hampered by a lack of sensitivity. Novel solutions for specific applications have been developed, however there is a need for more universal approaches. Here we investigated the addition of N2 to the ICP carrier gas to increase sensitivity, defined as signal-to-background, for the majority of biologically relevant elements. A gelatine standard that contained 38 elements across the mass range was ablated with increasing amounts of N2 added to the carrier gas post-ablation. The results show that while all elements examined had an increase in signal intensity, some elements did not have a resultant increase in signal-to-background. Sc, V, Mn, Fe, and Se all exhibited a reduction in signal-to-background ratios across all N2 flow rates examined, with the remaining elements experiencing signal-to-background increases from 1.2-7.8x, depending on the N2 flow rate and element. A compromised optimum N2 flow rate was determined for the analysis all elements and used to image endogenous elements in a mouse brain, and antibody-conjugated elements in a quadriceps muscle section. These images confirmed that the addition of N2 to the carrier gas increased the signal-to-background of the analysis, improving image resolution for endogenous elements and low abundant analytes used for immuno-mass spectrometry imaging of biomarkers. These findings offer a promising avenue for advancing the capabilities of LA-ICP-MS in bio-imaging applications.

Targeted fluorescence imaging using bevacizumab‐800CW within neovascular age‐related macular degeneration (AMD) patients to evaluate the upregulation of vascular endothelial growth factor (VEGF‐A) (preliminary results)

Aims/Purpose: With this phase 1 study, we aim to gain insight into the feasibility of using bevacizumab‐800CW to visualize the upregulation of VEGF‐A in AMD patients for treatment optimization.Methods: First, six wet AMD patients who are currently undergoing treatment with anti‐VEGF agents were included to evaluate the optimal tracer dose and received either 4.5 or 15 mg bevacizumab‐800CW. For the ongoing analysis of targeted tracer accumulation, three additional on‐therapy and three naïve patients will be included with the optimal dose of 15 mg. Fluorescence images (Heidelberg Spectralis) were taken before, up to 60 min and 3–4 days after intravenous injection of bevacizumab‐800CW. The target‐to‐background ratios (TBR) were calculated and compared between dose groups to evaluate the optimal dose. To investigate targeted tracer uptake, images of different time points are normalized and aligned, and a fluorescence intensity line is plotted over the active lesion to locate interesting areas for further quantification.Results: The preliminary results showed a clear inflow of the tracer into the eye vasculature after administration of 15 mg bevacizumab‐800CW. The fluorescence remains visible up to 1 h after tracer administration. Visual image comparison and TBR calculation in the first six patients showed that 15 mg bevacizumab‐800CW was the optimal tracer dose. In patients who received 15 mg bevacizumab‐800CW, accumulation of fluorescence signal in a smaller area within the active lesion was seen after 3–4 days.Conclusions: For the first time, we show that bevacizumab‐800CW (4.5 mg/15 mg) can be imaged in AMD patients using a commercially available system. An increase in signal intensity 3–4 days after bevacizumab‐800CW injection predicts tracer accumulation in the diseased area indicating ongoing active disease. VEGF‐A imaging can act as a proof of concept and pave the way for a broad application to track the performance of drugs by fluorescence molecular imaging.

Advancing carbohydrate quantification in MALDI mass spectrometry by the rapidly freeze-drying droplet (RFDD) method.

Quantitative carbohydrate analysis faces challenges in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), including insufficient sensitivity and inconsistent spatial distribution of ion intensity. This study introduces an innovative sample preparation approach, the Rapidly Freeze-Drying Droplet (RFDD) method, aimed at overcoming these challenges by enhancing the homogeneity of the sample morphology and signal intensity in MALDI. Compared to conventional preparation methods, the RFDD method reduces the laser energy threshold and demonstrates a remarkable increase in signal intensity for carbohydrates, facilitating the detection of high-molecular-weight polysaccharides (>10 kDa). The RFDD-prepared samples exhibit a uniformly distributed signal intensity that overcomes the 'sweet spot' issue in MALDI. The enhanced signal intensity and reproducibility lead to reliable quantitative analysis of carbohydrates, eliminating the need for expensive isotopic standards in each sample. A straightforward and accessible approach is presented for general laboratories, revolutionizing carbohydrate analysis in MALDI-MS.

I2BODIPY as a new photoswitchable spin label for light-induced pulsed EPR dipolar spectroscopy exploiting magnetophotoselection.

Electron paramagnetic resonance (EPR) pulsed dipolar spectroscopy (PDS) using triplet states of organic molecules is a growing area of research due to the favourable properties that these transient states may afford over stable spin centers, such as switchability, increased signal intensity when the triplet is formed in a non-Boltzmann distribution and the triplet signal is used for detection, and high orientation selection, when the triplet signal is probed by microwave pulses. This arises due to the large spectral width at low fields, a result of the large zero field splitting, and limited bandwidth of microwave pulses used. Here we propose the triplet state of a substituted BODIPY moiety as a spin label in light induced PDS, coupled to a nitroxide, in a model peptide with a rigid structure. Orientation selection allows information on the relative position of the centres of the two labels to be obtained with respect to the nitroxide reference frame. Additionally, magnetophotoselection effects are employed to introduce optical selection and additional constraints for the determination of the relative orientation of the spin labels considering the reference frame of the triplet state.

Characterization and antitumor effect of doxorubicin-loaded Fe3O4-Au nanocomposite synthesized by electron beam evaporation for magnetic nanotheranostics.

Magnetic nanocomposites (MNC) are promising theranostic platforms with tunable physicochemical properties allowing for remote drug delivery and multimodal imaging. Here, we developed doxorubicin-loaded Fe3O4-Au MNC (DOX-MNC) using electron beam physical vapor deposition (EB-PVD) in combination with magneto-mechanochemical synthesis to assess their antitumor effect on Walker-256 carcinosarcoma under the influence of a constant magnetic (CMF) and electromagnetic field (EMF) by comparing tumor growth kinetics, magnetic resonance imaging (MRI) scans and electron spin resonance (ESR) spectra. Transmission (TEM) and scanning electron microscopy (SEM) confirmed the formation of spherical magnetite nanoparticles with a discontinuous gold coating that did not significantly affect the ferromagnetic properties of MNC, as measured by vibrating-sample magnetometry (VSM). Tumor-bearing animals were divided into the control (no treatment), conventional doxorubicin (DOX), DOX-MNC and DOX-MNC + CMF + EMF groups. DOX-MNC + CMF + EMF resulted in 14% and 16% inhibition of tumor growth kinetics as compared with DOX and DOX-MNC, respectively. MRI visualization showed more substantial tumor necrotic changes after the combined treatment. Quantitative analysis of T2-weighted (T2W) images revealed the lowest value of skewness and a significant increase in tumor intensity in response to DOX-MNC + CMF + EMF as compared with the control (1.4 times), DOX (1.6 times) and DOX-MNC (1.8 times) groups. In addition, the lowest level of nitric oxide determined by ESR was found in DOX-MNC + CMF + EMF tumors, which was close to that of the muscle tissue in the contralateral limb. We propose that the reason for the relationship between the observed changes in MRI and ESR is the hyperfine interaction of nuclear and electron spins in mitochondria, as a source of free radical production. Therefore, these results point to the use of EB-PVD and magneto-mechanochemically synthesized Fe3O4-Au MNC loaded with DOX as a potential candidate for cancer magnetic nanotheranostic applications.

The Explosive Crack Propagation Mechanism of Layered Rock Mass

Layered joints significantly affect the propagation and attenuation of engineering blasting stress waves and have a significant influence on rock breakage. In this study, the explosion crack propagation mechanism of a stratified rock mass with weak or no cementation is analyzed. Multilayer plexiglass plates are employed to simulate a layered rock mass, establishing an experimental model to investigate the vertical interaction between explosive charges and layered rock masses. The extent of ruptures and damage within the charging and sealing sections of the rock mass is analyzed. The explosion cracks at the bottom of the hole are relatively dense, whereas those at the hole opening are relatively sparse. The range of the crushing and fracture zones around the gun hole in the charging section is larger than that in the blocking section. Moreover, as the blocking section approaches the free plane, the crushing zone size decreases. A notable area of rapid damage escalation is identified between the blocking and charging sections, leading to a significant increase in damage intensity. The numerical analysis results indicate that the cumulative explosive energy within the charging section surpasses that of the blocking section, and the rate of energy accumulation is notably higher in the charging region.

Identification of fish irradiation by EPR spectrometry: Signal intensity and stability

In this work, the application of electron paramagnetic resonance spectroscopy for assessing the irradiation of fish is described. Pink salmon was chosen as the research object and irradiated at 3 and 6 kGy doses. A linear correlation was observed between the increase in EPR signal intensity and the radiation dose. It was demonstrated that the fish used in this study had previously been irradiated by the supplier for microbiological sterilization. To assess the signal decay kinetics, repeat spectroscopy of samples was conducted over the course of a year after irradiation. A decrease in EPR signal intensity is observed initially after irradiation, attributed to the decay of short-lived radicals. The results indicate that EPR spectroscopy is an accurate and sensitive way to determine whether fish has been irradiated.

Electronic and Structural Analysis of TMD/BP Heterostructures: Insights from Raman Spectroscopy, SEM, and Correlative Probe Electron Microscopy

The current study was designed in order to study the electrical and structural properties of heterostructures of TMD and BP through Raman spectrum mapping technique, Scanning electron microscopy (SEM) and Correlative Probe electron microscopy (CPEM). Single and few layer heterostructures were prepared by mechanical exfoliation and transferred onto a silicon substrate by poly(methyl methacrylate) (PMMA) transfer method. Optical and CPD mapping manifested increased signal intensity at the edges of the flake, and Raman spectroscopy indicated definite electron density near the fringes of the flake. In this system, scanning electron microscopy (SEM) studies performed employing a range of accelerating voltages have supported the presence of electronic domains within the heterostructures especially at their borderlines. The CPEM analysis showed a significant correlation between the topographical and electronic contrast, where the former was attributed to an intense accumulation of electrons at the edge of the flake and not due to structural flaws. These results highlight the fact that TMD/BP heterostructures possess relatively unique electrical properties and may be suitable for future optoelectronic applications.