Search Results (156)

This paper proposes relaxed Simultaneous Signal and Noise Matching (SSNM) conditions to address limitations in selecting source degeneration inductors for multistage LNA design, achieved by introducing controlled mismatches at the external ports. Additionally, a novel frequency-bounded mismatch envelope is introduced to guide load termination selection based on desired IM-OM (input mismatch-output mismatch) characteristics across the operating band. Building on these concepts, a systematic, easy-to-follow strategy is presented for implementing wideband multistage low-noise amplifiers (LNAs), significantly reducing reliance on blind CAD-based optimisation. This approach is validated through a three-stage MMIC LNA prototype, fabricated using a 0.15 μm GaAs process and operating from 28 to 34 GHz. The measured results closely match the simulation, demonstrating a stable gain of 23 ± 1 dB and a noise figure of 2–2.5 dB, confirming the practical effectiveness of the proposed design approach for wideband amplifiers. Full article

Pathological complete response (pCR) following neoadjuvant therapy for IBC has shown a strong correlation with event-free survival and overall survival. Over the past three decades, the five-year net survival rate for breast cancer has generally increased; however, several Eastern European countries exhibit lower survival rates. Data from Romania, specifically regarding Her2-positive breast cancer response to therapy, are notably limited. Background/Objectives: The aim of our study was to evaluate the response to NAT using chemotherapy and Her2-targeted therapy in a cohort of 167 patients diagnosed with invasive breast cancer in our institution. Methods: We retrospectively analyzed 167 consecutive cases diagnosed with IBC in our institution between January 2020 and September 2024 with Stages II and III Her2-positive IBC. The overall pCR rates and several factors cited in the literature as predictors of pCR were analyzed. Results: Overall, the pCR rate was 50.29%, with higher values in 3+ cases (62.28%) compared to 2+ cases/ISH amplified (24.53%). Higher pCR rates were observed in hormone-negative cases, Stage II cases, estrogen receptor-negative cases, and high Ki-67 values. Patient age, ISH group, Her2 copy number, Her2:CEP17 ratio, and clinical lymph node involvement did not seem to influence pCR rates in our study. Conclusions: The data presented in our study represent, to the best of our knowledge, the largest cohort of patients diagnosed with Her2-positive IBC from Romania. The presented results and the pCR predictive factors were comparable to those cited in other studies on Her2-positive IBC cases. Full article

The study examined the relations and Granger causality among environmental pollution, air quality, life expectancy, religious tourism, petroleum consumption and economic growth in three countries, Italy, Saudi Arabia and Türkiye, three countries with a prominent role of religious tourism, given the high shares of religious tourism revenues in their economies and due to pilgrimage-type religious tourism activities in total tourism activities. The study employed a yearly sample of 1975–2019 and novel Fourier-augmented vector autoregressive and Fourier Granger causality tests, under the structural breaks in the data. The findings indicate negative effects on environmental pollution and air quality from tourism in addition to such effects on life expectancy in all countries analyzed, and in this relation, fossil fuel consumption in these nations and its acceleration with tourism play crucial roles. These effects are amplified by economic growth coupled with tourism revenues that go in hand with high fossil fuel consumption, which further worsen the impacts on the environment. In the causality testing stage, the results determined unidirectional causality from tourism, fossil fuel energy consumption, and economic growth to both carbon dioxide emissions and to particulate matter 2.5. These effects are also reinforced by feedback effects between air pollution and life expectancy, which enhance the effects on both environment and air quality. These findings are used to suggest important policy recommendations, among which, the reduction in high dependency on fossil fuel in the energy mix is most central. Equally, policies are suggested to encourage sustainable tourism to reverse the adverse effects on health, environmental degradation and worsened air quality in these nations. Full article

In recent years, ultrafast bursts with high power have been applied in many significant fields. However, the peak power of the pulse train generated by fiber lasers is limited by fiber characteristics from nonlinear effects, which can only be at the level of milliwatt. In this research, the pulse frequency is reduced by an AOM pulse picker-integrated modulator. With M2 and pulse width guaranteed, the frequency of the reduced pulse train is amplified by a solid-state three-stage Nd:YVO₄ amplifier system. Finally, the peak power of the pulse train is increased. The final output pulse repetition rate of the experiment is 1 MHz with a pulse width of 8.09 picoseconds and a peak power of up to 3.7 MW. Full article

Islanding detection remains a critical challenge for grid-connected distributed generation systems, as passive techniques suffer from inherent non-detection zones (NDZ), and active methods often degrade power quality. This paper introduces a hybrid detection strategy based on monitoring inherent grid harmonics via a Digital Lock-In Amplifier. By comparing real-time 5th and 7th harmonic amplitudes against their three-cycle-delayed values, the passive stage adaptively identifies potential islanding without fixed thresholds. Upon detecting significant relative variation, a brief injection of a non-characteristic 10th harmonic (limited to under 3% distortion for three line cycles) serves as active verification, ensuring robust discrimination between islanding and normal disturbances. Case studies demonstrate detection within 140 ms—faster than typical reclosing delays and well below the 2 s limit of IEEE std. 1547—while preserving current zero-crossings and enabling grid impedance estimation. The method’s resilience to grid disturbances and stiffness is validated through PSIM simulations and laboratory experiments, meeting IEEE 1547 and UL 1741 requirements. Comparative analysis shows superior accuracy and minimal power-quality impact relative to existing passive, active, and intelligent approaches. Full article

The increasing concentration of greenhouse gases is amplifying the global risk of drought on crop productivity. This study sought to investigate the effects of drought on the growth of maize (Zea mays L.) seedlings. A total of 78 maize hybrids were employed in this study to replicate drought conditions through the potting method. The maize seedlings were subjected to a 10-day period of water breakage following a standard watering cycle until they reached the third leaf collar (V3) stage. Parameters including plant height, stem diameter, chlorophyll content, and root number were assessed. The eight phenotypic traits include the fresh and dry weights of both the aboveground and underground parts. Three machine learning methods—random forest (RF), K-nearest neighbor (KNN), and extreme gradient boosting (XGBoost)—were employed to systematically analyze the relevant traits of maize seedlings’ drought tolerance and to assess their predictive performance in this regard. The findings indicated that plant height, aboveground weight, and chlorophyll content constituted the primary indices for phenotyping maize seedlings under drought conditions. The XGBoost model demonstrated optimal performance in the classification (AUC = 0.993) and regression (R² = 0.863) tasks, establishing itself as the most effective prediction model. This study provides a foundation for the feasibility and reliability of screening drought-tolerant maize varieties and refining precision breeding strategies. Full article

Under China’s dual-carbon strategy, the construction sector still lacks a systematic quantitative view of what drives its shift to a circular economy. This study couples the Decision-Making Trial and Evaluation Laboratory (DEMATEL) with Total Adversarial Interpretive Structural Modeling (TAISM) to build a weighted, multi-layer model of the policy–market–organization–technology chain. DEMATEL measures causal strengths, and TAISM arranges the variables into five levels without subjective thresholds, revealing a five-stage activation pathway. Fiscal incentives and regulations start the cascade; market demand amplifies their effect into a “resonant resilience” mechanism that improves cost performance. Robustness tests show 87% hierarchy stability and causal variation within ±0.6%. Sensitivity checks indicate that policy support must supply at least 30% of total network weight, because market capital alone cannot meet circular-construction costs. A three-tier intervention—policy incentives, financial amplification, and digital decomposition via green finance, BIM, and material passports—is therefore recommended. Full article

The mechanisms underlying formation energy depletion after initial fracturing and post-refracturing production decline in shale oil horizontal wells remain poorly understood. This study proposes a novel numerical simulation framework for refracturing processes based on a three-dimensional fully coupled hydromechanical model. By dynamically reconfiguring the in situ stress field through integration of production data from initial fracturing stages, our approach enables precise control over fracture propagation trajectories and intensities, thereby enhancing reservoir stimulation volume (RSV) and residual oil recovery. The implementation of fully coupled hydromechanical simulation reveals two critical findings: (1) the 70 m fracture half-length generated during initial fracturing fails to access residual oil-rich zones due to insufficient fracture network complexity; (2) a 3–5° stress reorientation combined with reservoir repressurization before refracturing significantly improves fracture network interconnectivity. Field validation demonstrates that refracturing extends fracture half-lengths to 97–154 m (38–120% increase) and amplifies RSV by 125% compared to initial operations. The developed seepage–stress coupling methodology establishes a theoretical foundation for optimizing repeated fracturing designs in unconventional reservoirs, providing critical insights into residual oil mobilization through engineered stress field manipulation. Full article

Background/Objectives: Pancreatic cancer (PC) is among the most aggressive malignancies, often diagnosed at late stages. MicroRNAs (miRNAs) and proteins released from the tumor microenvironment into body fluids represent promising non-invasive biomarkers for early cancer detection. In this study, we took advantage of an innovative ultrasound (US)-based instrument (SonoWell^®, Inno-Sol srl, Rome, Italy) to treat PC cells in order to promote and amplify the release of molecules, with the aim of identifying novel putative diagnostic PC biomarkers. Methods: Three human pancreatic adenocarcinoma cell lines (T3M-4, Panc02.03, and PaCa-44) and a non-cancerous pancreatic epithelial line (HPanEPic) were subjected to US using the SonoWell instrument. MiRNAs released in the supernatants were profiled by TaqMan-based qRT-PCR microfluidic cards, while proteins were analyzed by antibody arrays. Publicly available datasets of circulating miRNAs in PC patients were also reviewed. Results: Expression levels of 22 miRNAs in T3M-4 cells, 11 in Panc02.03, and 22 in PaCa-44, none of which were identified in the non-cancerous cell line profiling, were increased in the supernatant of US-treated as opposed to control cells. Among the statistically significant miRNAs or miRNAs common to at least two tumor cell lines, the expression levels of miR-155-5p, miR-320a, miR-32-5p, and miR-93-5p were also found to be significantly upregulated in sera from PC patients compared to the results for healthy controls. With regard to proteins released after sonication, several molecules were identified as candidate biomarkers in cancer US supernatants (Beta-2 microglobulin, CA125, CA19-9, CEA, CRP, Galectin-3, TIMP-1, uPA, and VEGF-A). Conclusions: We demonstrated that US-mediated sonoporation can promote and amplify the release of small molecules, miRNAs, and proteins into cell culture supernatants for consideration as putative biomarkers, thus encouraging further studies aimed at directly validating their expression levels in sera/plasma from PC patients and at deepening their role in the treatment of PC. Full article

This paper presents a 2-stage GaN Doherty power amplifier module (DPAM) on a compact $7\times 7$ quad flat no-lead (QFN) package, designed for the needs of 5G massive MIMO base transceiver systems. The interstage and input matching networks employ high-quality factor integrated passive devices (IPDs) to achieve a small form factor. This multi-chip module consists of three GaN-HEMT bare dies used for the driver stage, carrier amplifier, and peaking amplifier. Additionally, two IPD dies are included for the interstage and input matching networks. The external load network is developed using a printed circuit board (PCB). Utilizing a 5G NR signal of 100 MHz bandwidth and a 9.3 dB PAPR within the 3.4–3.8 GHz band, the developed DPAM demonstrated a power gain exceeding 26.8 dB and a power-added efficiency (PAE) greater than 37.8% at a 39 dBm average output power. Full article

This work presents a novel three-stage low-noise amplifier (LNA) design methodology. The first two stages consist of common-source stages with inductive source degeneration, while the third stage consists of an RC network attached before the common-source FET transistor. The input matching network is designed to meet the optimum noise measurement termination, which results in a noise Figure of less than 1.6 dB. The highest gain level of 25 dB was measured, and the input and output reflection coefficients are better than 10 dB for the operating bandwidth, i.e., 13–15 GHz. The LNA’s large signal performance and robustness against continuous high input power and pulse waves are reported. This LNA can handle up to 15 dBm input pulse of 50 nS width and 10% duty cycle, and 18 dBm continuous wave without noticing an increment in the forward gate current. Full article

BAW filters have been widely used in RF circuits, and their combination with integrated passive inductors is one of the most common forms of BAW filters. However, the large size of passive inductors increases the area of the filter, making it unable to meet packaging requirements. At the same time, their low quality factor (Q) severely degrades the performance of the BAW filter. This paper presents a miniaturized wide band BAW filter with small-size high-Q active inductor. The active inductor is implemented by a circuit topology with three common-source amplifiers constructed with N-type transistors. The three-stage topology uses a small-size transistor in the middle stage to reduce the parasitic capacitance at the input node, achieving a large inductive bandwidth. The simulation results show that the active inductor has variable inductance from 1 nH to 10 nH, and a quality factor of up to 4 K from 2 to 7 GHz. The 30 × 30 μm² active inductor is embedded in a 4.55–5.05 GHz BAW filter ladder so as to substantially decrease filter size. Simulation results indicate that the BAW filter based on the active inductor achieves a low insertion loss of −1.1 dB, out-of-band rejection of −35 dB on the left side, and out-of-band rejection of −53 dB on the right side. Compared to the traditional passive inductor, this active inductor significantly improves the performance of the BAW filter while occupying a much smaller chip size of 0.83 × 0.75 mm². Full article

This manuscript provides insight into optimally noise-matched three-stage Low-Noise Amplifiers (LNAs) by proposing a novel chart that illustrates the relationship between the gain of a three-stage LNA and inter-stage mismatch levels. Under certain conditions, the chart also indicates the required feedback inductor values for all transistors. It is demonstrated that, under the specific assumption of optimal noise and signal matching, the LNA gain depends on the levels of two inter-stage mismatches. Contrary to common belief, the results show that the LNA gain increases as the inter-stage mismatch levels rise. This finding is supported through the discussion of two LNA designs, one with lower and one with higher inter-stage mismatch levels, achieving gains of 24 dB and 26 dB, respectively, with a Noise Figure of 1.7 dB at the center design frequency of 28 GHz. Subsequently, one LNA topology is validated in a Monolithic Microwave Integrated Circuit (MMIC) implementation using WIN Foundry’s PIH1-10 GaAs E-mode technology. The MMIC characterization aligns with the simulated behavior, accounting for the unavoidable losses in the matching networks. Full article

Accurately detecting rice panicles in complex field environments remains challenging due to their small size, dense distribution, diverse growth directions, and easy confusion with the background. To accurately detect rice panicles, this study proposes OE-YOLO, an enhanced framework derived from YOLOv11, incorporating three synergistic innovations. First, oriented bounding boxes (OBB) replace horizontal bounding boxes (HBB) to precisely capture features of rice panicles across different heights and growth stages. Second, the backbone network is redesigned with EfficientNetV2, leveraging its compound scaling strategy to balance multi-scale feature extraction and computational efficiency. Third, a C3k2_DConv module improved by dynamic convolution is introduced, enabling input-adaptive kernel fusion to amplify discriminative features while suppressing background interference. Extensive experiments on rice Unmanned Aerial Vehicle (UAV) imagery demonstrate OE-YOLO’s superiority, achieving 86.9% mAP50 and surpassing YOLOv8-obb and YOLOv11 by 2.8% and 8.3%, respectively, with only 2.45 M parameters and 4.8 GFLOPs. The model has also been validated at flight heights of 3 m and 10 m and during the heading and filling stages, achieving mAP50 improvements of 8.3%, 6.9%, 6.7%, and 16.6% compared to YOLOv11, respectively, demonstrating the generalization capability of the model. These advancements demonstrated OE-YOLO as a computationally frugal yet highly accurate solution for real-time crop monitoring, addressing critical needs in precision agriculture for robust, oriented detection under resource constraints. Full article

A novel over-constrained XYθ_z nano-positioning stage with a high load-bearing capacity is proposed. This serially connected displacement stage adopts an embedded structural design that integrates a translation stage with a rotation stage in series. The Z-axis amplification mechanism employs out-of-plane actuation, realising a compact solution for three-axis independent motion. The hybrid amplification mechanism designed in the translation stage ensures enhanced output displacement and structural stiffness. The hybrid-parallel amplification mechanism comprises a lever-type displacement amplifier and a Scott–Russell displacement amplifier connected in series, which is then connected in parallel with a bridge-type displacement amplifier. An over-constrained mechanism is introduced to impose redundant constraints along the Z-axis, effectively suppressing parasitic displacement in the Z-direction while enhancing resistance to out-of-plane deformation. A quasi-static model of the XYθ_z motion stage was established to comprehensively characterise the deformation behaviour of the stage, which was verified by finite element simulations and experiments on the prototype. The experimental results indicate that the XYθ_z stage achieves a large motion range (up to 152.22 μm × 151.3 μm × 2.885 mrad) while maintaining excellent anti-deformation capability 200 nm at 4 kg loading. Full article