Search Results (15)

Recent work has identified biomphalysin (BM) protein from the snail Biomphalaria glabrata as a cytolytic toxin against the Schistosoma mansoni parasite. Ex vivo interactome studies further evidenced BM’s ability to bind bacterial outer membrane proteins, but its specific antibacterial mechanisms and selectivity remain unclear. Accordingly, this study aims to elucidate the interaction between BM and two model bacteria with distinct cell surface architectures: Escherichia coli (Gram−) and Micrococcus luteus (Gram+). Employing a multiscale approach, we used in vivo single-molecule force spectroscopy (SMFS) to probe molecular interactions at the single cell level. Combined with cell aggregation assays, immunoblotting and Atomic Force Microscopy (AFM) imaging, SMFS results evidenced a selective interaction of BM from snail plasma with M. luteus but not E. coli. Exposure of M. luteus to BM compromised cell surface integrity and induced cell aggregation. These effects correlated with a patch-like distribution of BM on M. luteus reminiscent of pore-forming toxins, as revealed by the anti-BM antibody-functionalized AFM tip. Overall, this work highlights the utility of SMFS in dissecting host–pathogen molecular dialogs. It reveals BM’s selective action against M. luteus, potentially via surface clustering, and it shows spatially heterogeneous responses to the toxin within and between individual cells. Full article

Background: The role of brain metastases (BM) surgery is of paramount importance for patients’ progression-free and overall survival. “En-bloc” and “piecemeal” resection represent the main surgical techniques. Although en-bloc resection remains the best surgical option, it is not widely adopted or feasible as the first choice. We describe our point of view about the en-bloc surgical technique with an illustrative case and discuss its indications with pros and cons through a comprehensive literature review. Materials and methods: A Medline search up to December 2023 in the Embase and PubMed online electronic databases was made and PRISMA statement was followed. An illustrative case of “en-bloc” resection from our surgical series was also added as a technical note. Results: We describe tips and tricks of our surgical technique and added a surgical video from our series. The literature review disclosed 19 studies. Resulting data suggested that “en-bloc” resection, when feasible, provides lesser risk of leptomeningeal dissemination, local recurrence rates, intraoperative bleeding occurrence and perioperative complications; in addition, it preserves the normal anatomy. Conclusions: En-bloc resection is the gold standard technique for surgical treatment of brain metastases especially for patients with superficial lesions that are small in size and far from eloquent areas. Full article

A sensitive, miniaturized, ultrawideband probe is proposed for near-field measurements. The proposed probe is based on a new V-shaped tip design and a slope structure resulting in better field distribution and impedance matching with a span bandwidth from 10 kHz up to 52 GHz, which is compatible with ultrawideband applications. The proposed E-probe fabrication process utilizes a four-layer printed circuit board (PCB) using Rogers RO4003 (tm) and RO4450 high-performance dielectrics, with εr = 3.55 and 3.3, respectively. The probe length is 40 mm with a minimum width of 4 mm, which is suitable for narrow, complex, and integrated PCBs. The passive E-probe sensitivity is −106.29 dBm and −87.48 dBm at 2 GHz and 40 GHz, respectively. It has a very small spatial resolution of 0.5 mm at 20, 25, 30, and 35 GHz. The probe is small and cheap and can diagnose electromagnetic interference (EMI) in electronic systems such as telemetry, UAVs, and avionics. Full article

Precision hill-drop direct seeding using mechanical drilling is a unique direct seeding technique employed in south China that offers advantages such as excellent grain yield and high lodging resistance. Improving yield and lodging-related traits is essential for efforts to improve mechanically direct-seeded rice (MDSR) production. Seeding rates (SR) and nitrogen (N) fertilization rate are two of the main factors affecting grain yield and lodging resistance under MDSR production. However, little information about double-season MDSR production in south China is available. Here, we evaluated yield and lodging risk for two rice cultivars Huanghuazhan, HHZ, lodging-resistant; Xiangyaxiangzhan, XYXZ, lodging-susceptible across two consecutive growing seasons under two under two seeding rates (LSR, 30 cm × 18 cm; HSR, 30 cm × 12 cm) and three N fertilization rates (N1 = 100 kg ha⁻¹, reduced N; N2 = 150 kg ha⁻¹, normal N; and N3 = 200 kg ha⁻¹, enhanced N). We found that increased SR and N fertilization rate improved grain yield and increased lodging risk. SR and N were consistently and positively related to plant height (PH), gravity center height (GCH), the length from the broken basal internode to the panicle tip (SL), the fresh plant weight of the plant part above the broken point (FW), and the length of the two basal internodes. SR and N decreased breaking force (F) and breaking strength (BM), driving increased lodging risk as reflected by increases in lodging index (LI) values. Culm diameter (CD) and culm wall thickness (CWT) did not respond consistently to SR and N treatments. Correlation analysis revealed that PH, GCH, the length of first and second basal internodes, FW, and bending moment for the whole plant (WP) were positively correlated with LI, while F and BM were negatively associated with LI. These findings suggest that the increased lodging risk resulting from high SR could be mitigated by applying appropriate rates of N; that is, this work suggests that grain yield can be maximized and lodging risk minimized by increasing SR while decreasing N fertilization rate. Seasonal differences in the effects of SR and N fertilization should be considered to achieve a high grain yield and maintain high lodging resistance. Our study suggests that increasing SR and decreasing N fertilization can enhance rice grain yield while improving lodging resistance for both varieties. Optimizing grain yield by increasing SR while reducing lodging risk by lowering N application rates may maintain lodging resistance and improve grain yield. Full article

Crack size and undermatching effects on fracture behavior of undermatched welded joints are presented and analyzed. Experimental and numerical analysis of the fracture behavior of high-strength low-alloyed (HSLA) steel welded joints with so-called small and large crack in undermatched weld metal and the base metal was performed, as a part of more extensive research previously conducted. J integral was determined by direct measurement using special instrumentation including strain gauges and a CMOD measuring device. Numerical analysis was performed by 3D finite element method (FEM) with different tensile properties in BM and WM. Results of J-CMOD curves evaluation for SUMITEN SM 80P HSLA steel and its weld metal (WM) are presented and analyzed for small and large cracks in tensile panels. This paper is focused on some new numerical results and observations on crack tip fields and constraint effects of undermatching and crack size keeping in mind previously performed experiments on the full-scale prototype. In this way, a unique combined approach of experimental investigation on the full-scale proto-type and tensile panels, as well as numerical investigation on mismatching and crack size effects, is achieved. Full article

Climate change is leading to combined drought and high temperature stress in many areas, drastically reducing crop production, especially for high-water-consuming crops such as maize. This study aimed to determine how the co-inoculation of an arbuscular mycorrhizal (AM) fungus (Rhizophagus irregularis) and the PGPR Bacillus megaterium (Bm) alters the radial water movement and physiology in maize plants in order to cope with combined drought and high temperature stress. Thus, maize plants were kept uninoculated or inoculated with R. irregularis (AM), with B. megaterium (Bm) or with both microorganisms (AM + Bm) and subjected or not to combined drought and high temperature stress (D + T). We measured plant physiological responses, root hydraulic parameters, aquaporin gene expression and protein abundances and sap hormonal content. The results showed that dual AM + Bm inoculation was more effective against combined D + T stress than single inoculation. This was related to a synergistic enhancement of efficiency of the phytosystem II, stomatal conductance and photosynthetic activity. Moreover, dually inoculated plants maintained higher root hydraulic conductivity, which was related to regulation of the aquaporins ZmPIP1;3, ZmTIP1.1, ZmPIP2;2 and GintAQPF1 and levels of plant sap hormones. This study demonstrates the usefulness of combining beneficial soil microorganisms to improve crop productivity under the current climate-change scenario. Full article

The tandem metal inert gas (MIG) process uses two wires that are continuously fed through a special welding torch and disbursed to form a single molten pool. Within the contact tip of the modern approach, the wires are electrically insulated from one another. This study identified the effect of welding electrode spacing on the distortion of AA5052 aluminum plates and different mechanical properties including hardness and thermal cycle using grey relational analysis. Plate distortion was subsequently predicted using the grey prediction model GM (1, 6). This research used a pair of 400 mm × 75 mm × 5 mm of AA5052 plates and electrode distances of 18, 27, and 36 mm. The welding current, voltage, welding speed, and argon flow rate were 130 A, 23 V, 7 mm/s, and 17 L/min, respectively. The temperature was measured using a type-K thermocouple at 10, 20, 30, and 40 mm from the center of the weld bead. The smallest distortion at an electrode distance of 27 mm was 1.4 mm. At an electrode distance of 27 mm, the plate may reach a proper peak temperature where the amount of heat input and dissipation rate are similar to those for electrode distances of 18 mm and 36 mm. The highest relative VHN of 57 was found in the BM, while the lowest, 46, was found in the WM, showing good agreement with their respective grain sizes. Six parameters were designed using grey relational analysis (GRA) and subsequently employed in the grey prediction model GM (1, 6). Process evaluation results show that predictions for welding distortions are consistent with actual results, thus, the GM (1, 6) model can be used as a predictive model for welding distortions of 5052 aluminum plates. Full article

Objectives: Thermography is an imaging technique based on the acquisition and analysis of thermal data. The present study evaluates the use of tongue infrared thermography (IRT) as a tool for the diagnosis of burning mouth syndrome (BMS). Material and methods: An IRT study was carried out in patients diagnosed with BMS according to the criteria of the International Association for the Study of Pain (n = 32) and in healthy controls (n = 35). Burning sensations, dry mouth and taste disturbances were assessed, and three temperature values were recorded for each tongue surface (dorsal, right lateral, left lateral and tip), along with body temperature and environmental temperature. Results: A statistically significant difference was recorded in the temperature of the dorsal surface of the tongue between the BMS group and the controls (p = 0.01). The area under the curve (AUC) was 0.731 (95% CI: 0.402–0.657; p = 0.003). The sensitivity and specificity obtained was 62% and 77%, respectively. Conclusions: Infrared thermography appears to be useful as a complementary tool for the diagnosis of BMS, though further studies are needed in this field. Full article

Aiming at the base metal (BM) zone, heat affected zone (HAZ) and fusion zone (FZ) of the weld, the tip plastic zone and initiation behavior of microscopic short cracks (MSCs) in the toe of cross-welded joints are studied. Based on the theory of crack tip plastic zone and the fatigue index parameter (FIP), the shape and boundary size of the plastic zone at the tip of MSCs as well as the initiation life were calculated. The results show that the plastic zone was bone-like under plane stress and butterfly-like under plane stress; when the crack length increased from 2 μm to 30 μm, the boundary size of the plastic zone at the MSC tip increased by 15 μm and 2 μm under the action of plane stress and plane strain in the X-axis direction, respectively. As the grain gradient decreased from 0.5 to 0.1, the boundary size of the plastic zone at the tip of the MSC increased about 50%. MSC initiation occurs first in the BM zone, and life of initiation was about several hundred thousand cycles, which was consistent with the experimental result. The MSC expansion rate in BM zone was the fastest, with the average expansion rate about 2.5 × 10⁻³ μm/cycle; the MSC expansion rate in the FZ and HAZ was about 3.1 × 10⁻⁴ μm/cycle. Full article

The impact toughness of a high-strength metastable β titanium alloy (Ti-5Cr-4Al-4Zr-3Mo-2W-0.8Fe) with two typical microstructures is studied by Charpy impact tests. The bimodal microstructure (BM) and the lamellar microstructure (LM) are obtained by the solution and aging treatments and the β annealing, slow cooling and aging treatments, respectively. In the impact crack initiation process, the deformation capacities of the primary α (α_p) phase, secondary α (α_s) phase and transformed β (β_t) matrix in the BM are very different, and the stress gradient at the interface of the three causes the crack initiation. The lamellar α (α_l) phase and β_t in the LM satisfy the BOR relationship, and the effective slip transfer between α and β phases slows down the crack initiation. Meanwhile, the appearance of deformation twins in the LM improves the crack initiation energy. In the crack propagation process, the lack of coordinated deformation between the α and β phases in the BM leads to rapid crack propagation. In the LM, the deformation of α_l and β_t is relatively more coordinated, so the severe plastic deformation is only concentrated near the crack and at the interface. The secondary crack initiation and the crack propagation along the twin boundary reduce the stress concentration at the crack tip. The deformation twins and zigzag propagation path can improve the crack propagation energy. To summarize, the alloy with LM exhibits better impact toughness than the alloy with BM. Full article

Tip60, a key histone acetyltransferase of the MYST family and member of the nuclear multimeric protein complex (NuA4), regulates the activity and stability of proteins involved in the cell cycle, DNA damage responses, autophagy, etc. However, the function and regulatory mechanism of Tip60 homolog in Bombyx mori are not elucidated. In the present study, Bombyx Tip60 (BmTip60) was functionally identified. Developmental profiles showed that the protein levels and nuclear localization of BmTip60 peaked in fat body during the larval–pupal metamorphosis when autophagy was intensive; simultaneously, the BmTip60 protein migrated to form an upper band as detected by Western blot. Interestingly, the upper band of BmTip60 was reduced by λ-phosphatase treatment, indicating that it was a phosphorylated form of BmTip60. Results showed that BmTip60 was promoted by starvation but not 20-hydroxyecdysone treatment. Transcription factor AMP-activated protein kinase (AMPK) affected by starvation was pivotal for BmTip60 protein migration. In addition, one mammalian phosphorylation site was identified in BmTip60 at Ser99, the constitutive-activation mutation of Ser99 to Asp99 but not its inactive mutation to Ala99 significantly upregulated autophagy, showing the critical role of phosphorylation at Ser99 for BmTip60-mediated autophagy. In conclusion, the starvation-AMPK axis promotes BmTip60 in B. mori, which was requisite for autophagy induction. These results reveal a regulatory mechanism of histone acetyltransferase Tip60 homologs by phosphorylation in insects, and sheds light on further related studies of acetylation regulation. Full article

Cucumber is a major vegetable crop grown in facilities, and its seedlings are sensitive to salinity. Thus, it is important for cucumber cultivation to research the effects of Ca(NO₃)₂. In this study, we investigated salt-sensitive Chunqiu (CQ) and salt-tolerant BoMei 49 (BM) seedlings, the changes to the enzymes involved in the mitochondria antioxidant system in the seedlings, and the changes in the MPTP (Mitochondrial Permeability Transition Pore) opening, mitochondrial membrane fluidity, mitochondrial membrane potential depolarization, mitochondrial electron transfer chain, and NO metabolism in response to Ca(NO₃)₂. Ca(NO₃)₂ stresses inhibited the growth of the cucumber seedlings, which showed a reduced root length, a decreased surface area and a decreased number of root tips, but a significantly increased root diameter. The mitochondrial malondialdehyde (MDA) content, H₂O₂ content, and O₂⁻ producing rate of the two cucumber roots were gradually increased in the Ca(NO₃)₂ treatment. The activity of superoxide dismutase (SOD) and peroxidation enzyme (POD) gradually increased, and catalase (CAT) activity gradually decreased. The electron transport chain activity of “BM” was higher than “CQ” under Ca(NO₃)₂ stress. Ca(NO₃)₂ stress destroyed the membrane structure of the mitochondria, so that the mitochondrial body tended to bend, causing double-membrane digestion and a hollow interior. Under the stress of Ca(NO₃)₂, the NO₃⁻ content of the seedlings increased significantly. The contents of NH₄⁺ and NO, as well as the activities of nitrate reductase (NR), nitrite reductase (NIR), and nitric oxide synthase (NOS) decreased significantly. These findings provide physiological insights into root damage in response to salt stress for salt tolerance in cucumber. Full article

The microstructural changes due to the aging process in steel pipeline weldments as a function of the thermoelectric power (TEP) were studied. In general, the thermoelectric methods are based on the well-known Seebeck effect. The thermoelectric methods monitor the TEP via an electron flux induced by a temperature gradient in metallic materials, which is affected by the different types of defects that are present in the atomic lattice, such as atoms in the solid solution, precipitates and dislocations. In this present study, the relationship among the TEP data, hardness and the microstructure of steel pipeline weldments was investigated. In addition, the coarse and dendritic grain structure of the welding material is extremely and unpredictably anisotropic. Such microstructures are no longer direction-independent to the electron flux. Therefore, it has an opposite negative effect on the TEP and overlaps the precipitation effect due to the aging process. TEP and hardness measurements were obtained in each zone of the weldments. For each section of the weldment, the weld bead (WB), heat affected zone (HAZ) and base metal (BM) were found to correspond to particular values of TEP. The relationship between the TEP and the microstructure of a weldment of X60 and X65 micro-alloyed steel that was artificially aged was obtained using the conventional contact TEP technique (hot-tip) and scanning electron microscopy (SEM). It was found that thermoelectric power is very sensitive to the aging process in the two-studied steel pipeline weldments. Full article

In this paper, the fatigue crack growth behavior of the base metal (BM), the weld metal (WM) and the heat-affected zone (HAZ) in the metal-inert gas (MIG) welded joints of the 06Cr19Ni10 stainless steel are analyzed and studied. Results of the fatigue crack propagation tests show that a new fatigue crack initiates at the crack tip of a pre-existing crack, then propagates perpendicular to the direction of cyclic fatigue loads. This observation indicates that the original mixed-mode crack transforms into the mode I crack. The WM specimen has the largest fatigue crack growth rate, followed by the HAZ specimen and the BM specimen. To illustrate the differences in fatigue crack growth behavior of the three different types of specimens, metallographic structure, fracture morphology and residual stresses of the BM, HAZ and WM are investigated and discussed. The metallographic observations indicate that the mean grain size of the HAZ is relatively larger than that of the BM. The fractographic analysis shows that the WM has the largest fatigue striation width, followed by the HAZ and the BM. It is also found that the depth of dimple in the WM is relatively shallower than the one in the HAZ and BM, implying the poor plasticity behavior of the material. Analysis results of the residual stress analysis demonstrate a high level of tensile residual stress appearance in the WM and HAZ. Full article

Objective. To delineate technical aspects of vascular models with intracranial aneurysm in vitro production, suitable for angiographic imaging.
Material and methods. Wax (K2 exact, S-U-CERAMO-CAPS-WAX), Girtl’s mass, gelatin, and silicone (Silicone 10015 Den Braven, Elastosil 7683/25, Elite Double 32 Shore-A, Rema-Sil) were used for model production. Construction of models was based on T-shaped plastic tube connections and lost core techniques. Images of rotational angiography, glass tubes with aneurysm, and casts obtained in human specimen were used as samples of cerebral arteries.
Results. Technical aspects of vascular models production were delineated in experience of eight silicone models produced. M1 was hand made with basilar tip aneurysm; M2 was obtained according to angiography images with internal carotid artery supraclinoid part bifurcation to anterior and middle cerebral artery aneurysm. BM1 and BM2 casts were made using glass tubes with lateral aneurysm, M3 – from T-shaped plastic tubes with lateral aneurysms. M4, M5, and M6 were formed using casts obtained in human specimen with basilar tip aneurysm.
Conclusions. Silicone of two components is practical for casts of cerebral arteries in human specimen production. Gelatinous solution 50°C diluted 1:1 with water can be used for copies of arterial casts production. Wax materials are unsuitable for making casts in a human specimen. Full article