Search Results (1,545)

Stainless steel welding plays a critical role in industrial manufacturing due to its superior corrosion resistance and structural reliability. The keyhole tungsten inert gas (K-TIG) welding, renowned for its high efficiency, high precision, and cost-effectiveness, demonstrates particular advantages in medium-to-thick plate joining. In order to synergistically leverage the properties of 2205 duplex stainless steel (DSS) and 316L austenitic stainless steel (ASS), we have implemented K-TIG welding with a single variable under control: a constant current and voltage travelling speeds spanning 280–360 mm/min. Defect-free dissimilar joints were consistently achieved within the 280–320 mm/min speed window. The effects of welding speed on microstructural characteristics, mechanical properties, and corrosion behavior of the weld seams were systematically investigated. The percentage of austenite in the weld zone decreases from 84.7% to 59.9% as the welding speed increases. At a welding speed of 280 mm/min, the microstructural features in the regions near the weld seam and fusion zone were investigated. All obtained joints exhibited excellent tensile properties, with their tensile strengths surpassing those of the 316L base metal. The optimal impact toughness of 142 J was achieved at a welding speed of 320 mm/min. The obtained joints exceeded the hardness of TIG joints by 19%. Notably, the grain refinement in the weld zone not only enhanced the hardness of the welded joint but also improved its corrosion resistance. This study provides valuable process references in dissimilar stainless steel K-TIG welding applications. Full article

This paper presents the novel design of a printed, low-cost, dual-port, and dual-polarized slot antenna for microwave biomedical radars. The butterfly shape of the radiating element, with orthogonally positioned arms, enables simultaneous radiation of both vertically and horizontally polarized waves. The antenna is intended for full-duplex in-band applications using two mutually isolated antenna ports, with the CPW port on the same side of the substrate as the slot antenna and the microstrip port positioned orthogonally on the other side of the substrate. Those two ports can be used as transmit and receive ports in a radar transceiver, with a port isolation of 25 dB. Thanks to the bow-tie shape of the slots and an additional coupling region between the butterfly arms, there is more flexibility in simultaneous optimization of the resonant frequency and input impedance at both ports, avoiding the need for a complicated matching network that introduces the attenuation and increases antenna dimensions. The advantage of this design is demonstrated through the modeling of an eight-element dual-port linear array with an extremely simple feed network for high-gain biosensing applications. To validate the simulation results, prototypes of the proposed antenna were fabricated and tested. The measured operating band of the antennas spans from 2.35 GHz to 2.55 GHz, with reflection coefficients of less than—10 dB, a maximum gain of 8.5 dBi, and a front-to-back gain ratio that is greater than 15 dB, which is comparable with other published single dual-port slot antennas. This is the simplest proposed dual-port, dual-polarization antenna that enables straightforward scaling to other frequency bands. Full article

This paper presents a blind source separation (BSS)-based framework for joint communication and sensing (JCAS) in in-band full-duplex (IBFD) multiple-input multiple-output (MIMO) systems operating under time-varying channel conditions. Conventionally, self-interference (SI) in IBFD systems is a major obstacle to recovering the signal of interest (SOI). Under the JCAS paradigm, however, this high-power SI signal presents an opportunity for efficient sensing. Since each transceiver node has access to the original SI signal, its environmental reflections can be exploited to estimate channel conditions and detect changes, without requiring dedicated radar waveforms. We propose a blind source separation (BSS)-based framework to simultaneously perform self-interference cancellation (SIC) and extract sensing information in IBFD MIMO settings. The approach applies the Fast Independent Component Analysis (FastICA) algorithm in dynamic scenarios to separate the SI and SOI signals while enabling simultaneous signal recovery and channel estimation. Simulation results quantify the trade-off between estimation accuracy and channel dynamics, demonstrating that while FastICA is effective, its performance is fundamentally limited by a frame size optimized for the rate of channel variation. Specifically, in static channels, the signal-to-residual-error ratio (SRER) exceeds 22 dB with 500-symbol frames, whereas for moderately time-varying channels, performance degrades significantly for frames longer than 150 symbols, with SRER dropping below 4 dB. Full article

Varicocele is a common, potentially correctable condition associated with impaired male fertility. Despite being frequently encountered in clinical andrology, its pathophysiological mechanisms, diagnostic criteria, and therapeutic approaches remain areas of active investigation and debate. The authors conducted a comprehensive literature search, using the PubMed database, covering clinical studies, systematic reviews, meta-analyses, and current international guidelines from the past ten years. Emphasis was placed on studies investigating novel diagnostic modalities, therapeutic innovations, and prognostic markers. Emerging evidence supports the multifactorial pathophysiology of varicocele, involving oxidative stress, hypoxia, inflammatory pathways, and potential genetic predisposition. Biomarkers, including microRNAs, antisperm antibodies, and sperm DNA fragmentation, offer diagnostic and prognostic utility, though their routine clinical implementation requires further validation. Advances in imaging, such as shear wave elastography, may improve diagnostic accuracy. While microsurgical subinguinal varicocelectomy remains the gold standard, technological refinements and non-surgical alternatives are being explored. Indications for treatment have expanded to include selected cases of non-obstructive azoospermia, hypogonadism, and optimization for assisted reproduction, though high-level evidence is limited. Full article

This paper proposes a novel dual-functional radar-communication (DFRC) framework that integrates unmanned aerial vehicle (UAV) communications into an integrated sensing and communication (ISAC) system, termed the ISAC-UAV architecture. In this system, the UAV’s mobility is leveraged to simultaneously serve multiple single-antenna uplink users (UEs) and perform radar-based sensing tasks. A key challenge stems from the target position uncertainty due to movement, which impairs matched filtering and beamforming, thereby degrading both uplink reception and sensing performance. Moreover, UAV energy consumption associated with mobility must be considered to ensure energy-efficient operation. We aim to jointly maximize radar sensing accuracy and minimize UAV movement energy over multiple time steps, while maintaining reliable uplink communications. To address this multi-objective optimization, we propose a deep reinforcement learning (DRL) framework based on a long short-term memory (LSTM)-enhanced deep deterministic policy gradient (DDPG) network. By leveraging historical target trajectory data, the model improves prediction of target positions, enhancing sensing accuracy. The proposed DRL-based approach enables joint optimization of UAV trajectory and uplink power control over time. Extensive simulations validate that our method significantly improves communication quality and sensing performance, while ensuring energy-efficient UAV operation. Comparative results further confirm the model’s adaptability and robustness in dynamic environments, outperforming existing UAV trajectory planning and resource allocation benchmarks. Full article

Our understanding of foreland basin subsurface structures relies heavily on seismic reflection data. The seismic profile across the eastern Rioni foreland basin in western Georgia is critical for characterizing its deformation structural style. We applied fault-related folding and thrust wedge theories to interpret the seismic profile and construction structural cross-section, which reveals that compressional structures are controlled by multiple detachment levels. Both thin-skinned and thick-skinned structures are identified. The seismic profile and structural cross-section reveal the presence of normal faults, reverse faults, thrust faults, duplexes, triangle zone, and crustal-scale duplexes. The deep-level detachment within the basement is responsible for the development of the crustal-scale duplexes. These structures appear to have formed through the reactivation of pre-existing normal faults during compressive deformation. Based on our interpretation, the imaged duplex system likely represents the western subsurface continuation of the Dzirula Massif. Full article

The use of low-resolution analog-to-digital converters (ADCs) in receivers has emerged as an effective solution for reducing power consumption in millimeter-wave (mmWave) massive multiple-input–multiple-output (MIMO) systems. However, low-resolution ADCs also pose significant challenges for channel estimation. To address this issue, we propose a joint uplink/downlink (UL/DL) channel estimation algorithm that utilizes the spatial reciprocity of frequency division duplex (FDD) to improve the estimation of quantized UL channels. Quantified UL/DL channels are concentrated at the BS for joint estimation. This estimation problem is regarded as a compressed sensing problem with finite bits, which has led to the development of expectation-maximization-based quantitative generalized approximate messaging (EM-QGAMP) algorithms. In the expected step, QGAMP is used for posterior estimation of sparse channel coefficients, and the block maximization minimization (MM) algorithm is introduced in the maximization step to improve the estimation accuracy. Finally, simulation results verified the robustness of the proposed EM-QGAMP algorithm, and the proposed algorithm’s NMSE (normalized mean squared error) outperforms traditional methods by over 90% and recent state-of-the-art techniques by 30%. Full article

Background/Objectives: The gene pool of the Apennine wolf is affected by admixture with domestic variants due to anthropogenic hybridisation with dogs. Genetic monitoring at the population level involves assessing the extent of admixture in single individuals, ranging from pure wolves to recent hybrids or wolf backcrosses, through the analysis of nuclear and mitochondrial DNA (mtDNA) markers. Although individually non-diagnostic, mtDNA is nevertheless essential for completing the final diagnosis of genetic admixture. Typically, the identification of wolf mtDNA haplotypes is carried out via sequencing of coding genes and non-coding DNA stretches. Our objective was to develop a fast real-time PCR assay to detect the mtDNA haplotypes that occur exclusively in the Apennine wolf population, as a valuable alternative to the demanding sequence-based typing. Methods: We validated a qualitative duplex real-time PCR that exploits the combined presence of diagnostic point mutations in two mtDNA segments, the NDH-4 gene and the control region, and is performed in a single-tube step through TaqMan-MGB chemistry. The aim was to detect mtDNA multi-fragment haplotypes that are exclusive to the Apennine wolf, bypassing sequencing. Results: Basic validation of 149 field samples, consisting of pure Apennine wolves, dogs, wolf × dog hybrids, and Dinaric wolves, showed that the assay is highly specific and sensitive, with genomic DNA amounts as low as 10⁻⁵ ng still producing positive results. It also proved high repeatability and reproducibility, thereby enabling reliable high-throughput testing. Conclusions: The results indicate that the assay presented here provides a valuable alternative method to the time- and cost-consuming sequencing procedure to reliably diagnose the maternal lineage of the still-threatened Apennine wolf, and it covers a wide range of applications, from scientific research to conservation, diagnostics, and forensics. Full article

SMoV and SVBV are two major viruses that pose significant threats to the global strawberry industry. Both are latent viruses, making early detection difficult due to their uneven distribution and low concentration in host tissues. Traditional RT-PCR techniques are insufficient for precise and quantitative detection. In this study, TaqMan RT-qPCR detection systems for SMoV and SVBV were established for application in practical production settings, enabling accurate, rapid, and efficient detection of strawberry viruses. When viral accumulation in plants is low, the highly sensitive TaqMan RT-qPCR technique allows for accurate quantification, facilitating the early identification of infected plants and preventing large-scale outbreaks in cultivation areas. The development of a duplex TaqMan RT-qPCR assay enables simultaneous quantification of SMoV and SVBV in a single reaction, improving detection efficiency and providing technical support for risk assessment and effective control of strawberry viral diseases. Full article

Background: Salmonella enterica and Escherichia coli are common foodborne pathogens of global concern, particularly due to their antimicrobial resistance, notably to cephalosporins. Objective: This study aimed to evaluate a polymerase chain reaction-based lateral flow strip (PCR-LFS) assay for the detection of Salmonella spp. and E. coli harboring the bla_CTX-M gene, which confers resistance to third-generation cephalosporins. Methods: Two duplex PCRs (dPCR) were established to detect E. coli-harboring bla_CTX-M (set 1) and Salmonella-harboring bla_CTX-M (set 2). 600 bacterial isolates and raw pork mince spiked with bla_CTX-M-harboring E. coli and Salmonella were used to evaluated. Results: Both dPCR assays successfully detected bla_CTX-M-positive E. coli or Salmonella strains, while strains lacking the gene showed no amplification. Non-E. coli and non-Salmonella strains were PCR-negative unless they carried bla_CTX-M. The dPCR-LFS showed 100% validity including accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for both E. coli or Salmonella spp. harboring or lacking bla_CTX-M. The assay accurately detected target strains without cross-reactivity with other bacteria or antimicrobial resistance genes. Cohen’s Kappa coefficient indicated perfect agreement (κ = 1), reflecting the high reliability of the dPCR-LFS. The assay could detect as low as 25 CFU/mL for bla_CTX-M-positive E. coli and 40 CFU/mL for bla_CTX-M-positive Salmonella in spiked raw pork mince. Conclusions: This assay is rapid, easy to interpret, and suitable for large-scale screening in surveillance programs. Full article

Modified oligonucleotides (oligos) are widely used as convenient tools in many scientific fields, including biomedical applications and therapies. In particular, oligos with lipophilic groups attached to the backbone ensure penetration of the cell membrane without the need for transfection. This study examines the interaction between amphiphilic DNA duplexes, in which one of the chains contains a lipophilic substituent, and several DNA repair proteins, particularly DNA-damage-dependent PARPs, using various biochemical approaches. DNA with a lipophilic substituent (LS-DNA) demonstrates more efficient binding with DNA damage activated poly(AD-ribose) polymerases 1-3 (PARP1, PARP2, PARP3) and DNA polymerase β. Chemically reactive LS-DNA derivatives containing a photoactivatable nucleotide (photo-LS-DNAs) or a 5′ deoxyribose phosphate (dRP) group in the vicinity of double-strand breaks (DSBs) are used for the affinity labelling of PARPs and other proteins in several whole-cell extracts of human cells. In particular, photo-LS-DNAs are used to track the level of Ku antigen in the extracts of neuron-like differentiated SH-SY5Y, undifferentiated SH-SY5Y, and olfactory epithelial cells. In vitro, PARP1–PARP3 are shown to be able to slowly excise the 5′ dRP group at DSBs. LS-DNAs can activate PARP1 and PARP2 for autoPARylation, albeit less effectively than regular DNA duplexes. Full article

Objectives: The mechanisms linking vitamin D deficiency to carotid artery stenosis (CAS) remain unclear. Data on cardiovascular outcomes in CAS patients with vitamin D deficiency are limited. We investigated the association of vitamin D deficiency with carotid plaque morphology and patient outcomes in high-grade CAS. Methods: A total of 332 patients undergoing carotid endarterectomy for symptomatic (n = 113, 34%) or asymptomatic (n = 219, 66%) CAS were included. Preoperative vitamin D levels were measured, and duplex sonography was used to assess luminal narrowing. Associations of vitamin D with clinical presentation were analyzed using univariate and multivariate linear regression. For vitamin D deficiency and the prediction of major adverse cardiovascular events (MACE) and all-cause mortality, the Cox proportional hazard regression model was used. Results: The median age was 69 years (interquartile range (IQR) 64–74), and 94 (29.3%) patients were female. Vitamin D deficiency was present in 84 (25%) patients. Symptomatic patients had significantly lower vitamin D levels (41.2 nmol/L, IQR 25.1–63.5) than asymptomatic patients (51.6 nmol/L, IQR 30.5–74.3, p = 0.011). Patients with echolucent (44.9 nmol/L, IQR 27.4–73.7) or mixed plaques (39.2 nmol/L, IQR 22.9–63.5) had lower vitamin D levels than those with echogenic plaques (52.3 nmol/L, IQR 34.1–75.7). Vitamin D deficiency predicted MACE and all-cause mortality with an adjusted HR of 1.6, 95% CI of 1.1–2.6, and p = 0.030 and an HR of 2.2, 95% CI of 1.3–3.6, and p = 0.002, respectively, in a multivariable Cox proportional hazard regression model. Conclusions: A deficiency in vitamin D was correlated with unstable plaque characteristics and symptomatic CAS. Furthermore, vitamin D deficiency was associated with long-term adverse cardiovascular outcomes and mortality, suggesting its potential as a modifiable risk factor for improved risk stratification in patients undergoing carotid endarterectomy. Full article

Introduction: Renal artery stenosis can significantly impact long-term graft survival rates following kidney transplant. Early recognition and management can improve the longevity of the kidney allograft. We aimed to evaluate the clinical role of duplex ultrasound in the diagnosis of renal artery stenosis (RAS). We also wanted to evaluate the current incidence of renal artery stenosis at our institute. Methods: A retrospective, consecutive series of 367 patients who underwent renal transplantation between 1 January 2020 and 30 December 2024 was conducted. We collected data regarding the recipients’ age, body mass index, and comorbidities. All patients diagnosed with renal artery stenosis were identified. The incidence of kidney transplant artery stenosis and presentation were recorded. All general physical parameters and laboratory data were collected and analyzed. Results: A total of 28 patients had initial suspicion of renal artery stenosis, documented via initial dedicated duplex ultrasound of the transplanted kidney. The initial mean systolic BP at initial US was 151 (99–213) mmHg, and mean creatinine was 2.43 (1.28–6.38) mg/dL. However, on repeat duplex ultrasound, three patients showed no features of renal artery stenosis and had no physical parameters consistent with RAS. A total of 25 patients diagnosed with RAS on initial duplex ultrasound underwent angiography. Twenty-four patients were confirmed with RAS on angiography, while one patient had a normal angiogram. Among patients diagnosed with TRAS, the mean resistive index was 0.71 ± 0.17 at the upper pole, 0.73 ± 0.19 at the mid pole, and 0.71 ± 0.21 at the lower pole. The mean peak systolic velocity was 462.57 ± 166.28 cm/s. Conclusions: Duplex ultrasound is an important initial tool for diagnosing transplant renal artery stenosis. An increase in peak systolic velocity was observed in our cohort; however, resistive indices were largely within acceptable limits. Management should be guided by clinical parameters (e.g., elevated systolic BP and rising creatinine) alongside imaging findings. Full article

Writing from a Reformed perspective, I intend to develop a concept of the duplex iustitia. I will argue that it is possible to affirm that infused righteousness is the sole formal cause of justification, while holding that imputation is its material cause. My goal in doing so will be to enumerate another possible area of agreement so that areas of disagreement can be stated in sharper dynamic clarity and therefore more precisely addressed. First, I will articulate what precisely is at issue in the disagreement between Roman Catholics and the Reformed on the matter of justification’s cause. Here I will discuss the role union with Christ plays in both Roman Catholic and Reformed concepts of justification. From these foundations, I will then argue that a Reformed perspective on justification coheres with the Tridentine affirmation that the sole formal cause is the “righteousness of God by which he makes us just”, while retaining the affirmation that its proper material cause is the imputed righteousness of Christ. In this section, I will defend a version of the duplex iustitia. Third, I will conclude by analyzing how this proposal might move beyond some of the agreements reached in the Joint Declaration on the Doctrine of Justification (JDDF henceforth) of 1999 and the International Catholic-Reformed dialogue document “Justification and Sacramentality” of 2015, while also stating the limitations of my proposal. Finally, I will answer some anticipated objections. Full article

Background/Objectives: Early graft loss within the first year is a rare complication of renal transplantations. In some cases, venous congestion may cause renal dysfunction, but, so far, this syndrome has been assessed by the presence of the triad of an unexplained decrease in renal function together with severe volume overload, relevant heart disease, and a typical histopathological pattern of tubular injury. This study aimed to determine the proportion of patients with early allograft loss due to venous congestion within the first year after transplantation. Additionally, we characterized typical renal vein flow profiles to identify patients at risk of early graft loss due to postrenal venous congestion and prerenal perfusion deficit. Methods: In this retrospective, single-center study, patients who underwent kidney transplantations between 2010 and 2020 and experienced early graft loss within the first year after transplantation were included. Clinical data and renal vein blood flow profiles were collected retrospectively. Results: A total of 579 patients received kidney transplants between 2010 and 2020. Of these, 43 patients (7.4%) lost their grafts within the first year of transplantation. Nine of these 43 patients (20.9% with early graft loss) lost their graft due to a suspected cardiorenal syndrome. Besides graft loss, cardiorenal patients had a significantly higher risk of death than other patients. All cardiorenal patients could be identified using a distinct renal vein blood flow profile (100%). Conclusions: We characterized the typical renal vein blood flow profiles in patients at risk of premature graft loss due to venous congestion. The early identification of such patients is crucial in improving outcomes after renal transplantation. Full article