Search Results (1,929)

Liquid biopsy, the analysis of tumor-derived material in blood, saliva, and other body fluids, is increasingly explored for the diagnosis, surveillance, and molecular characterization of head and neck squamous cell carcinoma (HNSCC). Its performance, however, is not uniform across the disease, and the reason is fundamentally molecular. human papillomavirus (HPV)-positive oropharyngeal cancers carry viral oncogenes that are absent from the host genome and therefore provide a near ideal, tumor specific circulating marker, whereas HPV-negative tumors are driven by a heterogeneous somatic landscape that offers no single universal target. In this narrative review, we adopt a molecular perspective. We first examine the biological origin of circulating tumor DNA and of the other analytes that liquid biopsy can interrogate including circulating tumor HPV DNA, viral transcripts, microRNAs, extracellular vesicles, and methylation signatures. We then consider how analytical platforms, from droplet digital PCR to next generation and ultrasensitive whole-genome sequencing, translate these molecules into measurements. Only afterward do we discuss the clinical questions, organized by clinical objective rather than by individual study: diagnosis and early detection, prognosis and risk stratification, treatment response monitoring, minimal residual disease and surveillance, and biomarker guided de-escalation in HPV-positive disease. Twelve registered clinical trials, involving approximately 1183 patients, are presented as illustrations of these questions. We close on the biological and technical gaps that still separate promising signals from clinical practice, and on the multi analyte and dynamic strategies most likely to bridge them. At present, liquid biopsy should be regarded as a complementary tool rather than as a replacement for established clinicopathological assessment. Full article

Background: Intraoperative hypotension during major abdominal surgery is common and can result from changes in preload, afterload, or myocardial contractility. Recognising the underlying cause is essential for targeted haemodynamic management. Arterial dP/dt_max has been proposed as a surrogate marker for ventricular systolic function, but its behaviour during fluid and vasopressor administration under general anaesthesia remains not fully understood. This study evaluated changes in radial arterial dP/dt_max following protocol-guided fluid administration and norepinephrine boluses during intraoperative hypotension. Methods: This prospective observational study involved 88 adult patients undergoing elective major abdominal surgery with continuous radial arterial waveform monitoring. Hypotensive episodes were defined as a mean arterial pressure <65 mmHg persisting for at least 60 s and were managed according to a predefined algorithm based on stroke volume variation and dynamic arterial elastance. The primary outcome was the change in arterial dP/dt_max from baseline to 5 min after fluid administration. Linear mixed-effects models were used to account for repeated intervention episodes within patients. Results: A total of 502 protocol-guided intervention episodes contributed by 76 patients were included in the primary analysis: 228 fluid-treated episodes and 274 norepinephrine-treated episodes. Estimated mean arterial dP/dt_max increased from 517 mmHg·s⁻¹ (95% CI 477–557) at baseline to 631 mmHg·s⁻¹ (95% CI 591–671) at 5 min during fluid-treated episodes and from 575 mmHg·s⁻¹ (95% CI 536–615) to 647 mmHg·s⁻¹ (95% CI 608–686) during norepinephrine-treated episodes (both p < 0.001). A significant intervention-condition-by-time interaction was observed (F = 5.55, p = 0.019), indicating that temporal evolution of arterial dP/dt_max differed between the two algorithm-defined haemodynamic conditions. Conclusions: Radial arterial dP/dt_max increased after both fluid administration and norepinephrine, confirming its sensitivity to haemodynamic loading conditions. It should therefore be interpreted as an integrated haemodynamic variable influenced by ventricular performance, preload, and arterial properties rather than as a direct measure of intrinsic myocardial contractility. Full article

Background: Sleep-dependent glymphatic clearance has emerged as a potential mechanism linking sleep disruption with Alzheimer’s Disease (AD) pathology. However, the relationship between objectively measured sleep and glymphatic function across the AD continuum remains unclear. Methods: Four databases (PubMed, Embase, Cochrane Library, and PsycINFO) were systematically searched for studies assessing objective sleep metrics and glymphatic-related biomarkers or clearance measures in humans across the AD continuum. Following peer review of the search strategy, supplementary searches of PubMed and Embase using expanded glymphatic and sleep electrophysiology terminology were undertaken to maximize sensitivity. The final database searches identified 416 records. After removal of 72 duplicates, 344 records were screened, 64 reports underwent full-text assessment, and four studies met the inclusion criteria. Results: Four studies involving participants across the AD continuum were included. Objective sleep assessment was performed using polysomnography or electroencephalography, while brain clearance was evaluated using direct or surrogate imaging measures including diffusion tensor image analysis along the perivascular space (DTI-ALPS), perivascular space burden, blood oxygen level-dependent–cerebrospinal fluid (BOLD-CSF) coupling, or direct tracer-based clearance imaging. Across studies, better preserved slow-wave sleep, slow-wave activity, and sleep oscillatory coupling were generally associated with more favorable glymphatic function or glymphatic-related biomarkers. Conversely, disrupted sleep architecture, reduced sleep efficiency, and altered sleep oscillatory coupling were associated with impaired glymphatic clearance or glymphatic dysfunction. Conclusions: Current evidence suggests that objectively measured sleep architecture, particularly slow-wave sleep and sleep oscillatory dynamics, may be associated with biomarkers of brain clearance across the AD continuum. However, the available evidence remains preliminary, is predominantly cross-sectional, and relies largely on indirect measures of brain clearance. Larger longitudinal studies incorporating standardized sleep assessment and validated measures of cerebral clearance are required to clarify temporal relationships, establish causality, and determine whether sleep-targeted interventions influence brain clearance or disease progression. Summary of findings: Preliminary evidence suggests that preserved slow-wave sleep and sleep oscillatory activity are associated with more favorable biomarkers of brain clearance, whereas disrupted sleep architecture is associated with less favorable clearance-related measures. Full article

Tight reservoirs commonly exhibit low permeability and pronounced lithological heterogeneity, resulting in complex interactions among far-field stress, local structural weakness, and fluid-driven fracture propagation. In this study, four non-replicated 2 m × 2 m × 1 m physical-model specimens representing tight glutenite, tight sandstone, and No. 3 coal rock from the Huabei Oilfield were investigated using an ultra-large true-triaxial hydraulic-fracturing system. Surface-fracture observations, microseismic monitoring, and high-frequency wellhead-pressure measurements were integrated to compare fracture responses under lithology-specific combinations of injection rate, fluid viscosity, perforation configuration, and stress state. The tested glutenite cases exhibited branched or localized fracture patterns depending on the combined treatment configuration; the sandstone case was dominated by a throughgoing main fracture approximately aligned with the principal-stress direction; and the coal-rock case showed extensive participation of bedding and cleat systems. These morphological differences were accompanied by distinct pressure and microseismic signatures, indicating different pathways of hydraulic-energy redistribution and fracture activation. For the two glutenite cases, the combined change from a single-perforation configuration at 0.5 m³/min to three helical perforations at 120° and 0.7 m³/min was associated with a 42.2% larger microseismic-derived stimulated reservoir volume (SRV). Taken together, these responses indicate a shift from stronger far-field-stress-controlled localization in the comparatively uniform sandstone to progressively greater local structural control by heterogeneous interfaces in glutenite and by bedding/cleat discontinuities in coal rock. Because each configuration was represented by a single specimen and several experimental variables changed simultaneously among cases, the observed differences are interpreted as case-specific mechanistic trends rather than statistically established universal relationships. The results show the value of combining fracture morphology, microseismic spatial evolution, and pressure dynamics for interpreting lithology-dependent fracture propagation in ultra-large physical models and for developing qualitative, lithology-adapted hydraulic-fracturing concepts. Full article

To reveal how meniscus dynamics affect wet film uniformity during slot-die coating for perovskite solar cell manufacturing, a 2D numerical model employing the VOF method is established for perovskite precursor fluids. A photoresist is used as a qualitative substitute liquid for auxiliary experimental validation, and dry film thickness is measured to characterize the relative uniformity of wet coating. The results show that the capillary number governs the upstream meniscus shape. Inlet velocity, slot gap, and coating gap influence film thickness by altering the downstream meniscus climbing height. Optimal film thickness uniformity is achieved when the pre-coating liquid volume accounts for about 31% of the total coating volume; this empirical optimal ratio is only valid within the tested inlet flow rate range under the fixed experimental conditions adopted in this work, and further multi-parameter verification under diverse process windows will be carried out in follow-up research. Full article

A computational fluid dynamics and conjugate heat transfer (CFD+CHT) methodology is developed for the thermal simulation of a commercial prismatic ${\mathrm{LiFePO}}_4$ cell under charging and discharging operating conditions. The approach couples a three-dimensional representation of the battery, including a simplified description of its internal layered structure, with an electrochemical–thermal heat-generation model implemented as a temperature- and time-dependent volumetric source term. The heat source is applied within the active layers of the cell and updated during the transient simulation according to the local thermal state and to the evolution of the state of charge. The methodology is applied to 1C and 2C cycles under natural convection and forced-air cooling at free-stream velocities of $10\mathrm{m}{\mathrm{s}}^{-1}$ and $20\mathrm{m}{\mathrm{s}}^{-1}$. A dedicated wind-tunnel campaign is carried out on the same cell, instrumented with type-K thermocouples distributed over its external surfaces, to provide experimental data for model validation. The results show that the proposed framework accurately reproduces the main wall-temperature trends observed experimentally. Under natural convection, the temperature distribution remains nearly uniform, whereas forced convection produces more pronounced vertical and in-plane gradients. For the charge cycles, the comparison between CFD predictions and end-of-cycle measurements yields a mean absolute error (MAE) of ${0.66}^{\circ }\mathrm{C}$ and a root-mean-square error (RMSE) of ${0.82}^{\circ }\mathrm{C}$ over 168 measurement locations. The discharge cycles yield a comparable level of agreement (MAE ${0.65}^{\circ }\mathrm{C}$, RMSE ${0.81}^{\circ }\mathrm{C}$ over 168 probe points), confirming the predictive capability of the methodology for both operating modes. Full article

This paper presents an experimental investigation into the flow characteristics and volumetric efficiency (η_vol) of a fixed-displacement external gear pump (GHD 17R) operating under coupled hydraulic parameters using an eco-friendly synthetic ester-based hydraulic fluid (48 mm²·s⁻¹ at 40 °C). Measurements were performed on a laboratory single-circuit hydraulic test rig across a rotational speed range of 500–2500 min⁻¹, operating pressure range of 2–10 MPa, and fluid temperature range of 30–60 °C. To eliminate flow fluctuations caused by structural vibrations at 1250 and 1750 min⁻¹, a 15% trimmed mean statistical filter was successfully implemented. A comparative sensitivity analysis—evaluating absolute, normalized, and relative significance—was developed and compared against a three-way analysis of variance (ANOVA) effect size model (η² and partial η²). The relative sensitivity approach identified rotational speed as the dominant parameter for direct hydraulic flow, accounting for 95.80% of total variation. Conversely, when evaluating volumetric efficiency, the proportional impact of speed was removed, revealing a balanced distribution of internal losses: rotational speed contributed 54.73%, fluid temperature 26.08%, and pressure 19.19%. The three-way ANOVA confirmed that all primary parameters and their cross-interactions had a statistically significant effect (p < 0.05). The findings scientifically demonstrate that temperature-induced viscosity collapse exhibits a stronger relative dynamic sensitivity on volumetric losses than pressure fluctuations within standard operating envelopes. The constructed multi-dimensional flow and efficiency maps provide practical input for advanced diagnostic tools, real-time thermal condition monitoring, predictive maintenance, and energy-optimized control schemes in modern fluid power systems using eco-friendly lubricants. Full article

This study explores the multifunctional properties of Ni nanoparticles obtained by laser ablation in liquid, with emphasis on the potential use of these nanoparticles in different applications such as cooling fluids or photoelectrochemical ones. The Ni nanoparticles were synthesized by the laser ablation in liquid technique using an Nd-YAG laser and ultrapure water as liquid. The structural, dimensional, morphologic, and stoichiometric characterizations of the nanoparticles were performed using different techniques such as transmission electron microscopy (TEM), energy dispersive X-ray (EDS) and dynamic light scattering spectroscopy (DLS). Nickel nanoparticles with sizes ranging from 5 to 15 nm in diameter were obtained. The experimental measurements were performed to determine the thermal conductivity and viscosity of the obtained nanofluids, essential parameters in the evaluation of the cooling fluid performances. Loading TiO₂ thin films with Ni nanoparticles led to the enhancement of the photoelectrochemical water splitting properties of TiO₂ thin films, the Ni nanoparticles acting on the collecting, transferring and separating the photogenerated charges and ultimately improving the overall anodic and cathodic efficiencies. The results obtained can contribute to the development of innovative, multifunctional solutions based on non-precious metals for cooling and water splitting systems used in industrial, electronics and other applications. Full article

The advancement of catalytic substrates through Additive Manufacturing (AM) offers notable benefits over conventional techniques, particularly for producing intricate three-dimensional forms that enable precise control over pore dimensions and surface characteristics. These attributes play a vital role in improving catalytic efficiency, which is evaluated by measuring pressure drop and mass transfer. This research focuses on the design and manufacture of a monolithic ceramic filter for catalytic cracking. The monoliths under study have a Triply Periodic Minimal Surface (TPMS) lattice. A macroporosity of about 65% is the criterion used to model the structures, and the TPMS unit cell length is the design parameter to achieve that porosity. Adapting a conventional Fused Filament Fabrication (FFF) desktop to use alumina filament, we produced samples based on three TPMS types: Schwar-Primitive (SP), Schoen Gyroid (SG), and Schwarz-Diamond (SD), which, after a plastic debinding process and subsequent sintering, resulted in meso-scale porous structures. The samples showed relative dimensional errors below 5% and a real total porosity of around 70%, with a maximum difference of 4% among the TPMS types. Because the printed SP lattices have the lowest unit cell length and real porosity, their pressure drop measurements were higher than those of the SG and SD. The opposite occurred with the estimated permeability. Although yielding similar pressure drop results, printed SG lattices had greater permeability than SD; therefore, in terms of monolith fluid dynamics, the SG lattice is the preferred geometry. Full article

Greenhouses in subtropical and tropical regions must be designed as agricultural engineering systems adapted to local climates, rather than simply replicating the “insulation” models of temperate areas. Under extreme climatic conditions such as persistent high temperatures, intense solar radiation, high humidity, heavy rainfall, and frequent extreme winds, greenhouses transform from enclosed insulation layers into selective climate filters, mitigating crop stress while maintaining close contact with the outdoor environment. This paper summarizes how these climate drivers are reshaping the use, structure, and control concepts of greenhouses, emphasizing that the performance of warm-zone greenhouses depends primarily on heat dissipation, humidity management, and biohazard control, rather than heating and insulation. In this review, we analyze the climatic boundary conditions that define warm-climate conservation cultivation, including long-term overheating risk, high UV radiation, vapor pressure deficit, and suppressed condensation tendency, as well as storm-induced uplift and dynamic loads. These constraints necessitate unique structural forms: tall, lightweight, well-ventilated building types with large roof and side openings, roof geometries that facilitate rainwater runoff, sophisticated drainage systems, and corrosion-resistant materials suitable for humid and coastal environments. Because insect netting significantly reduces ventilation, pest control and temperature regulation become co-design issues, requiring oversized vents, optimized airflow paths, and hybrid roof–mesh structures. Ventilation is considered the primary climate-control mechanism, supplemented by passive cooling measures such as shading and radiation/optical management (e.g., diffuse films and near-infrared-selective films). Active evaporative cooling is considered a conditional measure due to humidity limitations and disease risks. This paper also integrates the impacts on specific crops (fruits and vegetables, leafy greens, and orchids). It highlights emerging trends: typhoon-resistant and adaptive geometries, computational fluid dynamics (CFD)-based design, and sensor-rich IoT/digital twin control frameworks. These principles collectively establish a coherent design framework for achieving resilient, resource-efficient greenhouse production in warm climates. Full article

(1) Background: To compare tube resistance among glaucoma drainage devices (GDDs) with different tube geometries under various intraluminal polypropylene (PP) thread conditions and assess agreement between measured and formula-derived pressure–flow profiles. (2) Methods: Four GDDs were evaluated: Ahmed ClearPath Small Tube (ACP-ST), Paul Glaucoma Implant (PGI), Ahmed ClearPath (ACP), and Virna Glaucoma Implant (VGI) (n = 4/device). ACP-ST and PGI were tested under no-thread, 6-0 PP Corza, and 6-0 PP Ethicon conditions, whereas ACP and VGI were tested under no-thread, 4-0 PP Corza, and 3-0 PP Ethicon conditions. Saline was infused at 1.0–5.0 µL/min, and pressure was recorded using a transducer system. Tube and thread dimensions were measured using ImageJ and used to calculate formula-derived pressure from fluid dynamic equations. Comparisons used linear mixed-effects regression. (3) Results: In ACP-ST and PGI, both 6-0 PP threads significantly increased pressure compared with the no-thread condition, with no significant thread manufacturer-related differences. In ACP and VGI, all threaded conditions significantly increased pressure, and the 3-0 PP Ethicon condition produced higher pressure than the 4-0 PP Corza condition. Under threaded conditions, measured and formula-derived pressure values did not differ significantly in ACP-ST but differed significantly in PGI, ACP, and VGI. (4) Conclusions: Intraluminal PP threads increased GDD tube resistance. Manufacturer-related differences had a limited influence on resistance in small-lumen devices. Agreement between measured and formula-derived pressure varied among devices, highlighting the importance of experimental validation. These findings may help guide intraluminal thread selection and flow-restriction strategies during GDD implantation. Full article

Background: Although numerous magnetic resonance imaging (MRI) findings have been described in idiopathic intracranial hypertension (IIH), the potential contribution of craniocervical junction morphology to disease pathophysiology and diagnosis remains largely unexplored. This study aimed to evaluate foramen magnum morphology and cerebrospinal fluid (CSF) spaces at the craniocervical junction in patients with IIH and to investigate their associations with disease severity and diagnostic performance. Methods: In this retrospective case–control study, 70 patients diagnosed with IIH according to the modified Dandy criteria and 70 age- and sex-matched controls were included. Brain MRI examinations were retrospectively reviewed. Optic nerve sheath diameter, optic nerve tortuosity angle, foramen magnum anteroposterior and transverse diameters, foramen magnum area, foramen magnum index, and anterior and posterior subarachnoid CSF spaces were measured. Correlation analyses with lumbar puncture opening pressure and papilledema grade were performed. Independent imaging predictors of IIH were identified using multivariable logistic regression analysis, and diagnostic performance was assessed using receiver operating characteristic (ROC) analysis. Results: Compared with controls, patients with IIH demonstrated significant alterations in craniocervical junction morphology, including smaller foramen magnum anteroposterior diameter, foramen magnum area, foramen magnum index, and anterior subarachnoid CSF space, together with increased optic nerve sheath diameter and reduced optic nerve tortuosity angle (all p < 0.001). Foramen magnum morphometric parameters and anterior subarachnoid CSF space were significantly associated with both lumbar puncture opening pressure and papilledema grade. Multivariable logistic regression identified optic nerve sheath diameter (OR = 2.143, p = 0.002), optic nerve tortuosity angle (OR = 0.925, p < 0.001), and foramen magnum index (OR = 0.526 per 0.1-unit increase, p = 0.001) as independent imaging predictors of IIH. The combined prediction model demonstrated excellent diagnostic performance (AUC = 0.901), with 81.4% sensitivity and 87.1% specificity. Conclusions: Craniocervical junction morphometric features and subarachnoid CSF spaces at the foramen magnum differed between patients with IIH and controls and may provide complementary imaging information. These cross-sectional associations do not establish whether the observed differences are pre-existing anatomical characteristics or secondary changes related to chronically elevated intracranial pressure. Prospective multicenter studies incorporating dynamic CSF-flow imaging are warranted to validate these findings and clarify the temporal relationship between these morphometric features and disease development. Full article

Electrostatic spraying improves droplet deposition on the undersides of leaves and within canopy-obscured regions. However, existing studies mainly rely on two-dimensional trajectory analyses or simplified computational fluid dynamics (CFD) models, limiting the mechanistic understanding of the three-dimensional transport behaviour of charged droplets. To address this limitation, an integrated analytical framework combining theoretical droplet dynamics, CFD–DPM simulations, high-speed imaging, and wind-tunnel experiments was developed. Within this framework, a three-dimensional trajectory-tracking method was established to quantitatively characterise the electrostatic envelopment effect using measurable transport parameters, including droplet trajectories and effective electrostatic envelopment distance. Numerical simulations and experimental evaluations were combined to analyse the relationships among three-dimensional droplet transport, electrostatic envelopment, and leaf deposition performance. Results showed that deposition efficiency reached 15.92% at an induction voltage of 12 kV, representing an increase of 13.94 percentage points compared with uncharged spraying. Crosswind speed was the dominant factor affecting deposition, followed by induction voltage and spray pressure. The effective electrostatic envelopment distance was approximately 2.1 cm. The proposed framework enables quantitative characterisation of electrostatic envelopment and provides a mechanistic basis for analysing the relationship between three-dimensional droplet transport and deposition performance, offering a framework for electrostatic spraying evaluation and operating parameter optimisation. Full article

Approximately 2.3 billion people still cook over open fires or on basic stoves using polluting fuels, generating indoor air pollution responsible for 3.7 million premature deaths annually. Progress toward real-world health impact has been constrained by a persistent disconnect between computational fluid dynamics (CFD) modeling, standardized experimental evaluation, and sociocultural adoption research. This scoping review maps the current state of evidence across these three domains, analyzing 143 peer-reviewed studies published between 2007 and 2025 using predefined inclusion criteria and bibliometric analysis with VOSviewer v.1.6.20. Thirteen cookstove technologies were characterized by compiling heterogeneous evidence from Water Boiling Tests (WBTs), CFD simulations with k-ε turbulence closure, and CO and PM_2.5 emission protocols. Direct combustion stoves achieve thermal efficiencies of 10–21% under real-world conditions, while TLUD gasifiers and forced-draft systems with densified fuels reach 30–47%. Bibliometric analysis reveals that engineering, epidemiology, and social sciences operate as isolated research communities. None of the technology reviewed simultaneously integrated computational validation, field emissions assessment, and clinical impact evaluation; this a gap remains the central barrier to translating laboratory performance into measurable public health outcomes. These findings point toward integrated research designs connecting fluid dynamic optimization with exposure modeling, clinical follow-up, and the sociocultural needs of communities. Full article

To accurately predict the sustained annular pressure and annular gas–liquid interface depth during the production of high-pressure and high-temperature (HPHT) gas wells and address the issues of natural gas leakage and annular fluid loss caused by leaks in the tubing string, a prediction model for the sustained annular pressure and annular gas–liquid interface depth in HPHT gas wells is established. The model considers the expansion and compression of annular fluid, as well as the variation in annular volume under the effects of temperature and pressure. Taking the HPHT Well H21 in western China as an example, the model is verified using field-measured data, and the variation laws of sustained annular pressure and annular gas–liquid interface depth under different leak parameters and production parameters are investigated. The results show that the predicted sustained annular pressure first rises rapidly, then decreases slowly, and finally tends to stabilize. The expansion, compression, and leakage of annular fluid influence the depth of the annular gas–liquid interface, which changes dynamically in the early stage and stabilizes in the later stage. The maximum error between the measured and predicted sustained annular pressure is 2.65%, the stable sustained annular pressure is 13.97 MPa, and the minimum gas–liquid interface depth is 144.00 m. It is recommended to increase the density of the annular protection fluid, maintain an initial sustained annular pressure, and replenish it regularly, so as to ensure the safe control of HPHT gas wells under sustained annular pressure. Full article