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The aim of this study is to examine a low-power, InAs/Si hetero-gate oxide double-gate Tunnel field effect transistor (H-DM-DG-InAs-TFET) for high frequency application and to determine how trap charges (ITCs) affect the DC characteristics and analog/RF electrical performance metrics of the device. It is unfeasible to disregard the trap charges because the device's performance and reliability are negatively impacted by the buildup of trap charges at the interface between the semiconductor and oxide. Hence, an in-depth analysis of the performance characteristics of the proposed device, a InAs/Si hetero-gate oxide double-gate Tunnel FET (H-DM-DG-InAs-TFET), is conducted in this work to ascertain the impact of interface trap charges (ITCs). Comparison study of proposed device with dual metal gate Si Tunnel Field Effect Transistor (DM-DG-Si-TFET) is conducted. The proposed device is capable of effortlessly carrying enhanced ON current (1.54 × 10–3 A/µm) and exhibits improved current ratio (1.63 × 1011). To ascertain the device's suitability for low-power applications, its threshold voltage is determined by employing a constant current methodology. An improvement in threshold voltage (0.17 V) is noted. According to the study, the efficacy of the proposed device was enhanced due to the dielectric engineering performed on the oxide layer. Further investigation is conducted into the impact of ITCs on linearity parameters, as advanced communication device necessitates linear responses. The comparison with the DM-DG-Si-TFET reveals that the proposed TFET has virtually no distortion and a negligible impact on the linearity metrics. This indicates that the proposed TFET can be utilised in extremely low-power, high-frequency electrical devices. [ABSTRACT FROM AUTHOR]

Objective: The purpose was to investigate the risk factors for delayed upper gastrointestinal transit (DUGT) in small bowel capsule endoscopy (SBCE) and to improve the efficacy of SBCE. Methods: The medical records of patients who underwent SBCE in Renji hospital between January 2015 and January 2023 were retrospectively reviewed. Data collection included patient demographics and potential risk factors for DUGT such as indications for the examination, underlying diseases, hospitalization status, anemia, inflammation. Risk factors were analyzed using univariable and multivariable logistic regression models. DUGT was defined as failure of a capsule to pass through the pylorus within 1 h. Results: A total of 1459 patients who underwent SBCE were included in the study. 306 Cases (21%) experienced DUGT and all received conservative observation, medication treatment, endoscopic intervention, and other measures based on specific circumstances. The overall completion rate (CR) of the examination was 95.5% (1394/1459). Logistic regression analysis showed that hospitalization status (p = 0.030), diarrhea (p = 0.017), diabetes (p = 0.027) and cerebrovascular disease (p = 0.038) were significant risk factors for DUGT. Conclusions: In our study, DUGT of SBCE was associated with hospitalization status, diarrhea, diabetes and cerebrovascular disease. Therefore, for the patients with the above risk factors, we should closely check the capsule status during the examination process, in order to take appropriate intervention measures as soon as possible. [ABSTRACT FROM AUTHOR]

The Sierra Seca aquifer system is located in the northeast (NE) of the province of Granada, in the Prebetic Domain (Betic Cordillera). It is composed of different aquifer units hosted in the Lower Cretaceous and Upper Cretaceous limestones. The two aquifers are separated by a low permeability marl layer, which effectively acts as a barrier between them. To outline the behavior of the hydrogeological system, 407 samples of precipitation and 67 samples of groundwater were obtained from May 2020 to Oct. 2022 and isotopically ( δ 18 O and δ 2 H ) analyzed. For the estimation of the recharge elevation, a new methodology has been applied to estimate the isotopic content of recharge as a function of precipitation. This allowed the evaluation of the vertical gradient of both precipitation ( ∇ Z δ 18 O P = − 2.9   ‰ / k m ) and aquifer recharge ( − 4.4   ‰ / k m ≤ ∇ Z δ 18 O R ≤ − 2.9   ‰ / k m ). Therefore, estimating (1) the recharge zone elevation associated with the aquifer system, which is comprised between 1500 and 1700 m a.s.l., and (2) the transit time of recharge to reach the outflow point of the aquifer system, which varies between 4 and 5 months, is possible. Additionally, three tracer tests were conducted to outline the hydrologic connection between the recharge and discharge zones of the aquifer system. The results show that the Fuente Alta spring drains the limestones of the Lower Cretaceous, while La Natividad spring does the same with the limestones of the Upper Cretaceous. In the case of the Enmedio spring, groundwater discharge is related to infiltration through the streambed of the watercourse fed by the Fuente Alta spring. [ABSTRACT FROM AUTHOR]

Fuel switching is the most mature, reliable, and economical technology for ship operators to comply with regulations of sulfur emission control area (SECA), and will remain so for the next few years. Under SECA regulations, this paper tries to optimize liner shipping operation by integrating ship deployment, schedule design, and speed optimization while considering transit time. Specifically, a mixed integer nonlinear programming model was built to minimize operating costs, and fully guarantee the logic and superiority of the existing liner shipping network. A two-stage algorithm based on ɛ outer approximation estimation and enumeration was designed, and a backtracking algorithm was provided for determining initial port combinations in large-scale instances. After that, a case study on the Orient Overseas Container Line was carried out to verify the operability and flexibility of our method. The optimized strategy refines the existing network by adjusting initial port combinations, enhancing speed, and expanding new ship deployments. To mitigate the impact of rising port demurrage fees, liner companies are reducing transshipment penalty costs. While easing connecting time window (CTW) restrictions offers limited benefits, optimizing speed and loosening CTW can reduce operational costs by approximately 2–5%, helping liner companies navigate the fluctuating fuel market post-Covid. [ABSTRACT FROM AUTHOR]

This paper proposes a new dielectrically modulated (DM) twin cavity nanotube biosensor and its sensitivity evaluation suitability by the transit time (τ) and device efficiency (g m / I ds ). In addition, the vertical structure of the device also helps the uniform spreading of biomolecules within the nanogap cavity region. The inner cavity of the proposed biosensor offers more space for the stabilization of biomolecules and uses the benefits of material solubility. In this paper, the sensing ability of the biosensor is examined in terms of τ and g m / I ds for five neutral biomolecules. Furthermore, the charged biomolecule and deoxyribonucleic acid (DNA) are separately investigated for positive as well as negative charge densities. Also, various optimizations on the device are analyzed for different biomolecules in this paper. [ABSTRACT FROM AUTHOR]

Surgeons request intraoperative parathyroid hormone (PTH) monitoring during parathyroidectomy procedures to confirm identification of abnormal gland tissue. Generally, a 50% decrease in the baseline PTH level indicates the abnormal tissue has been removed. A delay in collecting and processing PTH blood samples can complicate intraoperative decision making and prolong the procedure. The purpose of this quality improvement project was to develop tools to facilitate the specimen management process (eg, requesting, transporting, analyzing) for PTH blood samples and decrease the average total time required for transit and assay. We implemented a two‐pronged initiative that involved improving the laboratory requisition form and creating a parathyroid tote box to contain all the needed information and supplies. The average total time for transit and assay decreased from 31.36 minutes before implementation to 22.06 minutes after implementation. Perioperative nurses expressed satisfaction with the changes and continue to use the revised process. [ABSTRACT FROM AUTHOR]

This study explores the impact of sub-mesoscale structures and vertical advection on the connectivity properties of the Baltic Sea using a Lagrangian approach. High-resolution flow fields from the General Estuarine Transport Model (GETM) were employed to compute Lagrangian trajectories, focusing on the influence of fine-scale structures on connectivity estimates. Six river mouths in the Baltic Sea served as initial positions for numerical particles, and trajectories were generated using flow fields with varying horizontal resolutions: 3D trajectories with 250m resolution as well as 2D trajectories with 250m and 1km resolutions. Several Lagrangian indices, such as mean transit time, arrival depths, and probability density functions of transit times, were analyzed to unravel the complex circulation of the Baltic Sea and highlight the substantial impact of submesoscale structures on numerical trajectories. Results indicate that in 2D simulations, particles exhibit faster movement on the eastern side of the Gotland Basin in high-resolution compared to coarse-resolution simulations. This difference is attributed to the stronger coastal current in high-resolution compared to coarse-resolution simulations. Additionally, the study investigates the influence of vertical advection on numerical particle motion within the Baltic Sea, considering the difference between 3D and 2D trajectories. Findings reveal that denser water in the eastern and south-eastern areas significantly affects particle dispersion in 3D simulations, resulting in increased transit times. Conversely, regions in the North-western part of the basin accelerate particle movement in 3D compared to the 2D simulations. Finally, we calculated the average residence time of numerical particles exiting the Baltic Sea through the Danish strait. Results show an average surface layer residence time of approximately 790 days over an eight-year integration period, highlighting the relatively slow water circulation in the semi-enclosed Baltic Sea basin. This prolonged residence time emphasizes the potential for the accumulation of pollutants. Overall, the study underscores the pivotal role of fine-scale structures in shaping the connectivity of the Baltic Sea, with implications for understanding and managing environmental challenges in this unique marine ecosystem. [ABSTRACT FROM AUTHOR]

Water transit time is now a standard measure in catchment hydrological and ecohydrological research. The last comprehensive review of transit time modeling approaches was published 15+ years ago. But since then the field has largely expanded with new data, theory and applications. Here, we review these new developments with focus on water-age-balance approaches and data-based approaches. We discuss and compare methods including StorAge-Selection functions, well/partially mixed compartments, water age tracking through spatially distributed models, direct transit time estimates from controlled experiments, young water fractions, and ensemble hydrograph separation. We unify some of the heterogeneity in the literature that has crept in with these many new approaches, in an attempt to clarify the key differences and similarities among them. Finally, we point to open questions in transit time research, including what we still need from theory, models, field work, and community practice.

Dendritic cell (DC)-based immunotherapy is a promising approach to treat cancer. However, key aspects governing the reproducible manufacturing of high-quality DC remain incompletely defined. Here, we show that the time window between leukapheresis and DC manufacturing is critical. Transcriptomic profiling by RNA-seq was used to unbiasedly characterize cellular states during each step of DC manufacturing process, and functional assays were used to determine the anti-tumor activities of DC. During preclinical development of a DC-based cytotherapy platform, CUD-002 (NCT05270720), we found that DC quality varied among different batches, even though commonly used DC maturation markers CD80, CD83 and CD86 were indistinguishable. Multivariate analysis indicated that DC quality was negatively associated with the shipping time from the leukapheresis site to the manufacturing center. To investigate the potential effect of shipping time, we stored leukapheresis materials from three donors for 0, 1, 2 or 3 days before DC manufacturing. For each step, we carried out RNA-seq analysis to unbiasedly characterize cellular states. Integrated bioinformatic analyses indicated that longer storage time reduced the expression of several transcription factors to attenuate interferon pathways. Consistently, we found that 3-day storage of leukapheresis materials significantly lowered the efficiency to generate DC but also impaired DC responses to inflammatory signals, resulting in inferior antigen-presentation and cytotoxic T-cell activities. Thus, we recommend using leukapheresis materials within 48 h to manufacture therapeutic DCs. [ABSTRACT FROM AUTHOR]

Throughout the world, emerging barriers in river systems block longitudinal connectivity for migrating fish, causing significant impacts by precluding them from carrying out vital life cycle activities. Fishways are still the main mitigation solution implemented, where barrier removal is not feasible. Within the multiple technical fish passage devices, the vertical slot fishway (VSF) is considered the most reliable. Early design guidelines, established for cyprinids, indicate that the volumetric dissipation power (Pv) in the pools should be Pv < 150 Wm−3, while most frequent slope values range from 10 to 12%. In this study, an experimental approach was conducted to question and debate the validity of these recommendations. For this, the Iberian barbel (Luciobarbus bocagei, Steindachner, 1864) passage performance was assessed in a full-scale fishway that exceeded Pv design guidelines, under different configurations. These varied in discharge (Q) and mean pool water depth (hm): VSF1 (Q = 81 Ls−1; hm = 0.55 m); VSF2 (Q = 110 Ls−1; hm = 0.80 m); and the same design was equipped with a deep notch: DN1 (Q = 71 Ls−1; hm = 0.55 m); DN2 (Q = 99 Ls−1; hm = 0.80 m). The slope was set to 15.2% while the head drop per pool was Δh = 0.28 m, which generated a Pv that ranged from 222 in VSF1 to 187 Wm−3 in DN2. Passage behaviour was assessed using PIT telemetry and time-to-event analysis to evaluate the barbel upstream passage using standardized metrics: (i) motivation (ii) ascend success, and (iii) transit time. The hydrodynamic scenarios experienced by fish were characterized through a numerical model using computational fluid dynamics (CFD). The results, contrary to what was expected, showed a higher performance in VSF1 confirmed by the ascent analysis and transit time. Although no differences were found in fish motivation, the results indicate that larger fish displayed lower times to perform the first passage attempt. The CFD results show that, although maximum velocities and turbulence (turbulent kinetic energy (TKE) and Reynolds shear stress (RSS)) do not change significantly between configurations, their distribution in the pools is quite different. Regarding TKE, larger volumes with magnitudes higher than 0.05 m2s−2 were notorious in both DN1 and DN2 configurations compared to VSF1, influencing passage efficiency which is in line with the ascent and transit time metrics results. Overall, the present research undeniably debates the literature design guidelines and reinforces the need to jointly assess species-specific fish passage criteria and fishway hydrodynamics, whereas precaution should be taken when using very general recommendations. [ABSTRACT FROM AUTHOR]

Groundwater transit time distributions (TTDs) describe the spectrum of flow‐weighted apparent ages of groundwater from aquifer recharge to discharge. Regional‐scale TTDs in stream baseflow are often estimated from numerical models with limited calibration from groundwater sampling and suggest much younger groundwater discharge than has been observed by discrete age‐dating techniques. We investigate both local and regional‐scale groundwater TTDs in the Upper Middle Loup watershed (5,440 km2) overlying the High Plains Aquifer in the Nebraska Sand Hills, USA. We determined flow‐weighted apparent ages of groundwater discharging through the streambed at 88 discrete points along a 99 km groundwater‐dominated stream segment using 3H, noble gases, 14C, and groundwater flux measurements at the point‐scale (<7.6 cm diameter). Points were organized in transects across the stream width (3–10 points per transect) and transects were clustered in five sampling areas (10–610 m in stream length) located at increasing distances along the stream. Groundwater apparent ages ranged from 0 to 8,200 years and the mean groundwater transit time along the 99 km stream is >3,000 years. TTDs from upstream sampling areas were best fit by distributions with a narrow range of apparent ages, but when older groundwater from downstream sampling areas is included, the regional TTD is scale dependent and the distribution is better described by a gamma model (α ≈ 0.4) which accommodates large fractions of millennial‐aged groundwater. Observations indicate: (a) TTDs can exhibit spatial variability within a watershed and (b) watersheds can discharge larger fractions of old groundwater (>1,000 years) than commonly assumed. Plain Language Summary: The transit time distribution (TTD) of an aquifer describes the complete spectrum of groundwater transit times from the water table to discharge at an outlet such as a stream. TTDs indicate how susceptible aquifers may be to contamination, drought, or pumping. Despite their importance, TTDs are difficult to quantify and many approaches either overestimate the relative fraction of young groundwater discharge or have been conducted in small systems (areas <1,000 km2 or stream lengths <10 km). We measured the flow‐weighted transit time of groundwater through the streambed at 88 points along a 99 km stream in the Upper Middle Loup watershed (5,440 km2) in Nebraska, USA to estimate TTDs of the underlying High Plains Aquifer at various spatial scales. Transit times ranged from 0 to 8,200 years and the mean transit time is >3,000 years along the entire study stream with substantially older groundwater discharge downstream. Upstream TTDs were well‐fit by distributions with larger fractions of young groundwater (<15 years), but TTDs for the entire study stream were better fit by distributions that accommodate large fractions of millennial‐aged groundwater. Our findings suggest that TTDs can vary within a watershed and ancient groundwater may be a significant component of modern streamflow. Key Points: Groundwater age and flux along a 99 km stream overlying the High Plains Aquifer, USA yield transit time distributions (TTD) and meanGroundwater ages ranged from 0 to 8,200 years with mean age >3,000 years and increasing apparent age of baseflow downstreamTTD evolution with stream distance suggests streams overlying regional systems may intersect large fractions of millennial‐aged groundwater [ABSTRACT FROM AUTHOR]

Soils store large quantities of carbon in the subsoil (below 0.2 m depth) that is generally old and believed to be stabilized over centuries to millennia, which suggests that subsoil carbon sequestration (CS) can be used as a strategy for climate change mitigation. In this article, we review the main biophysical processes that contribute to carbon storage in subsoil and the main mathematical models used to represent these processes. Our guiding objective is to review whether a process understanding of soil carbon movement in the vertical profile can help us to assess carbon storage and persistence at timescales relevant for climate change mitigation. Bioturbation, liquid phase transport, belowground carbon inputs, mineral association, and microbial activity are the main processes contributing to the formation of soil carbon profiles, and these processes are represented in models using the diffusion–advection–reaction paradigm. Based on simulation examples and measurements from carbon and radiocarbon profiles across biomes, we found that advective and diffusive transport may only play a secondary role in the formation of soil carbon profiles. The difference between vertical root inputs and decomposition seems to play a primary role in determining the shape of carbon change with depth. Using the transit time of carbon to assess the timescales of carbon storage of new inputs, we show that only small quantities of new carbon inputs travel through the profile and can be stabilized for time horizons longer than 50 years, implying that activities that promote CS in the subsoil must take into consideration the very small quantities that can be stabilized in the long term. [ABSTRACT FROM AUTHOR]

Purpose: Pelvi-ureteric junction obstruction (PUJO) is the leading cause for hydronephrosis in children. Diuretic renography used in the pre- and post-operative evaluation of pyeloplasty may not be reliable in predicting the outcome. Methods: A prospective study was conducted from October 2018 to November 2020, including all children with unilateral PUJO undergoing Pyeloplasty. Renal diuretic renography scans done in the pre and post operative periods were assessed for transit time. The time taken for the isotope to reach the renal pelvis was noted by a single observer as the transit time, from the dynamic frames of the diuretic renogram. Results: Of the 65 children, 74% were boys. The transit time (median) in the preoperative renography was 10 min, whereas the same was 4 min 45 s in the postoperative period, the decrease was statistically significant. On evaluation of transit time with ROC (receiver operating characteristics) curve, a cut-off of 4 min and 25 s was arrived at, which could identify the delayed drainage reliably. Conclusion: Improvement in transit time is a reliable predictor of renal function improvement after pyeloplasty, comparing favorably in relation to split renal function. [ABSTRACT FROM AUTHOR]

This study explores the impact of sub-mesoscale structures and vertical advection on the connectivity properties of the Baltic Sea using a Lagrangian approach. High-resolution flow fields from the General Estuarine Transport Model (GETM) were employed to compute Lagrangian trajectories, focusing on the influence of fine-scale structures on connectivity estimates. Six river mouths in the Baltic Sea served as initial positions for numerical particles, and trajectories were generated using flow fields with varying horizontal resolutions: 3D trajectories with 250m resolution as well as 2D trajectories with 250m and 1km resolutions. Several Lagrangian indices, such as mean transit time, arrival depths, and probability density functions of transit times, were analyzed to unravel the complex circulation of the Baltic Sea and highlight the substantial impact of sub-mesoscale structures on numerical trajectories. Results indicate that in 2D simulations, particles exhibit faster movement on the eastern side of the Gotland Basin in high-resolution compared to coarse-resolution simulations. This difference is attributed to the stronger coastal current in high-resolution compared to coarse-resolution simulations. Additionally, the study investigates the influence of vertical advection on numerical particle motion within the Baltic Sea, considering the difference between 3D and 2D trajectories. Findings reveal that denser water in the eastern and south-eastern areas significantly affects particle dispersion in 3D simulations, resulting in increased transit times. Conversely, regions in the North-western part of the basin accelerate particle movement in 3D compared to the 2D simulations. Finally, we calculated the average residence time of numerical particles exiting the Baltic Sea through the Danish strait. Results show an average surface layer residence time of approximately 790 days over an eight-year integration period, highlighting the relatively slow water circulation in the semi-enclosed Baltic Sea basin. This prolonged residence time emphasizes the potential for the accumulation of pollutants. Overall, the study underscores the pivotal role of fine-scale structures in shaping the connectivity of the Baltic Sea, with implications for understanding and managing environmental challenges in this unique marine ecosystem.

In order to avoid the congestion in front of the entrance gate units, it is necessary to analyse and optimise the queuing situation at the planning and design stage. The security inspection area and the ticket-checking area were jointly considered, and a queuing congestion analysis method was proposed. Firstly, the research problem was stated. Then, the problem of calculating the number of passengers in each subarea at any time was transformed into the problem of calculating the transit time of each passenger in each subarea. The transit time was divided into basic transit time and additional transit time. Based on the velocity-density relationship, a quantisation method for basic transit time was proposed related to passenger arrival time. The additional transit time was determined by the moment when the passengers left the subarea according to the sequence of arrival of passengers, the number of queuing passengers in the subarea and the congestion of the subarea to be entered. Finally, the queuing situation of passengers in each subarea at any moment was obtained through passenger flow recursion. Examples showed that the proposed method can deal with multiple working conditions and avoid the tedious and time-consuming scene construction process of the microsimulation software.

Managed grasslands have the potential to store carbon (C) and partially mitigate climate change. However, it remains difficult to predict potential C storage under a given soil or management practice. To study C storage dynamics due to long-term (1952-2009) phosphorus (P) fertilizer and irrigation treatments in New Zealand grasslands, we measured radiocarbon (14C) in archived soil along with observed changes in C stocks to constrain a compartmental soil model. Productivity increases from P application and irrigation in these trials resulted in very similar C accumulation rates between 1959 and 2009. The ∆14C changes over the same time period were similar in plots that were both irrigated and fertilized, and only differed in a non-irrigated fertilized plot. Model results indicated that decomposition rates of fast cycling C (0.1 to 0.2 year-1) increased to nearly offset increases in inputs. With increasing P fertilization, decomposition rates also increased in the slow pool (0.005 to 0.008 year-1). Our findings show sustained, significant (i.e. greater than 4 per mille) increases in C stocks regardless of treatment or inputs. As the majority of fresh inputs remain in the soil for less than 10 years, these long term increases reflect dynamics of the slow pool. Additionally, frequent irrigation was associated with reduced stocks and increased decomposition of fresh plant material. Rates of C gain and decay highlight trade-offs between productivity, nutrient availability, and soil C sequestration as a climate change mitigation strategy.Supplementary informationThe online version contains supplementary material available at 10.1007/s10533-021-00838-z.

Abstract Background The increasing elderly population and wide use of magnetic capsule endoscopy (MCE) have led to more attention to elderly patients. Aim The aim of this study was to assess the performance (including transit time, cleanliness score, positive findings and safety) of MCE in aging patients (≥ 60 years), especially patients over 80 years old. Methods Consecutive patients of ≥ 60 years undergoing MCE at our center from August 2017 to August 2022 were classified into the oldest (≥ 80 years) and the older (60–79 years) groups. Esophageal transit time (ETT), gastric examination time (GET), small bowel transit time (SITT), and the quality of gastric preparation were compared. Information on examination indications, subjective discomforts, adverse events, and MCE outcomes were compared. Results Of 293 enrolled patients, 128 patients were in the oldest group and 165 patients were in the older group. ETT and GET were longer in the oldest group, whereas SITT was slightly longer in the oldest patients. Visualization scores were significantly lower in the body and antrum in the oldest patients. The total visualization score was lower in the older group compared with the oldest group; however, the difference was not significant. Cleanliness scores at the fundus and antrum and total cleanliness scores were lower in the oldest patients compared with the older patients. Positive findings and ulcers and erosions in the small intestine were more common in the oldest group. One patient had nausea during the gastric examination. Capsule retention in the cecum occurred in one case. Conclusion MCE was feasible and safe for aging patients. ETT and GET were markedly longer and gastric cleanliness and visualization were worse, while overall small intestine-positive findings were higher in the oldest patients compared with the older patients.

OBJECTIVE To compare the effect of volume and solution on transit time and fluorescence intensity (FI) using near-infrared fluorescence imaging (NIRF) in a simulated tumor model in cats. Secondarily, to describe SLN mapping with indocyanine green (ICG) NIRF and report any adverse effects of intradermally injected ICG in cats. ANIMALS 7 healthy purpose-bred domestic shorthaired male cats. METHODS Cats were randomly divided into 2 groups (ICG or ICG + methylene blue [MB]). Transit time and FI were determined for 1 or 2 mL solutions injected intradermally in 4 quadrants around a simulated tumor. Following massage, fluorescence intensity was quantified by calculating the corrected total ROI fluorescence using ImageJ software. Cats were monitored for adverse effects up to 4 weeks post-injection. RESULTS A larger solution volume had decreased transit times to the SLN (P = .001). There was no significant difference in transit times between ICG and ICG-MB. ICG demonstrated a greater FI (P = .001) in the SLN compared to ICG-MB. Methylene blue did not percutaneously fluoresce under NIRF. The volume of the solution did not significantly affect FI. No adverse reactions were reported. CLINICAL RELEVANCE Increased volume of ICG may aid in rapid percutaneous lymphatic tracking from tumor to SLN. Indocyanine green alone may be preferred over ICG-MB for greater visualization of the SLN. Intradermal injections of ICG and ICG-MB were well-tolerated in healthy cats with no significant complications. Clinical evaluation of this technique in an impaired lymphatic system, as seen in cancer patients, should be assessed in future research. [ABSTRACT FROM AUTHOR]

Open conjectures state that, for every $x\in [0,1]$ , the orbit $(x_n)_{n=1}^\infty $ of the mean-median recursion $$ \begin{align*}x_{n+1}=(n+1)\cdot\operatorname{\mathrm{median}}(x_1,\ldots,x_{n})-(x_1+\cdots+x_n),\quad n\geqslant 3,\end{align*} $$ with initial data $(x_1,x_2,x_3)=(0,x,1)$ , is eventually constant, and that its transit time and limit functions (of x) are unbounded and continuous, respectively. In this paper, we prove that for the slightly modified recursion $$ \begin{align*}x_{n+1}=n\cdot\operatorname{\mathrm{median}}(x_1,\ldots,x_{n})-(x_1+\cdots+x_n),\quad n\geqslant 3,\end{align*} $$ first suggested by Akiyama, the transit time function is unbounded but the limit function is discontinuous. [ABSTRACT FROM AUTHOR]

Low-frequency electrical noise is a sensitive measure of defects in semiconductor devices because the noise has an impact, directly or indirectly, on the performance and reliability of the device. Its measurement is particularly important to characterize noise in semiconductor devices. [ABSTRACT FROM AUTHOR]

Background: Ingestible capsule (IC) systems can assess gastrointestinal (GI) transit times as a surrogate for gut motility for extended periods of time within a minimally invasive, radiation-free and ambulatory setting. Methods: A literature review of IC systems and a systematic review of studies utilizing IC systems to measure GI transit times in healthy volunteers was performed. Screening for eligible studies, data extraction and bias assessments was performed by two reviewers. A narrative synthesis of the results was performed. Results: The literature review identified 23 different IC systems. The systematic review found 6892 records, of which 22 studies were eligible. GI transit time data were available from a total of 1885 healthy volunteers. Overall, seventeen included studies reported gastric emptying time (GET) and small intestinal transit time (SITT). Colonic transit time (CTT) was reported in nine studies and whole gut transit time (WGTT) was reported in eleven studies. GI transit times in the included studies ranged between 0.4 and 15.3 h for GET, 3.3–7 h for SITT, 15.9–28.9 h for CTT and 23.0–37.4 h for WGTT. GI transit times, notably GET, were influenced by the study protocol. Conclusions: This review provides an up-to-date overview of IC systems and reference ranges for GI transit times. It also highlights the need to standardise protocols to differentiate between normal and pathological function. [ABSTRACT FROM AUTHOR]

Background: The increasing elderly population and wide use of magnetic capsule endoscopy (MCE) have led to more attention to elderly patients. Aim: The aim of this study was to assess the performance (including transit time, cleanliness score, positive findings and safety) of MCE in aging patients (≥ 60 years), especially patients over 80 years old. Methods: Consecutive patients of ≥ 60 years undergoing MCE at our center from August 2017 to August 2022 were classified into the oldest (≥ 80 years) and the older (60–79 years) groups. Esophageal transit time (ETT), gastric examination time (GET), small bowel transit time (SITT), and the quality of gastric preparation were compared. Information on examination indications, subjective discomforts, adverse events, and MCE outcomes were compared. Results: Of 293 enrolled patients, 128 patients were in the oldest group and 165 patients were in the older group. ETT and GET were longer in the oldest group, whereas SITT was slightly longer in the oldest patients. Visualization scores were significantly lower in the body and antrum in the oldest patients. The total visualization score was lower in the older group compared with the oldest group; however, the difference was not significant. Cleanliness scores at the fundus and antrum and total cleanliness scores were lower in the oldest patients compared with the older patients. Positive findings and ulcers and erosions in the small intestine were more common in the oldest group. One patient had nausea during the gastric examination. Capsule retention in the cecum occurred in one case. Conclusion: MCE was feasible and safe for aging patients. ETT and GET were markedly longer and gastric cleanliness and visualization were worse, while overall small intestine-positive findings were higher in the oldest patients compared with the older patients. [ABSTRACT FROM AUTHOR]

An isotope-enabled module of Hydrus-1D was applied to a potted olive tree to trace water parcels originating from 26 irrigation events in a glasshouse experiment. The soil hydraulic parameters were optimized via inverse modelling by minimizing the discrepancies between observed and simulated soil water content and soil water isotope (18O) values at three soil depths. The model's performance was validated with observed sap flow z-scores and xylem water 18O. We quantified the source and transit time of irrigation water by analysing the mass breakthrough curves derived from a virtual tracer injection experiment. On average, 26% of irrigation water was removed by plant transpiration with a mean transit time of 94 hours. Our proof of concept work suggests that transit time may represent a functional indicator for the uptake of irrigation water in agricultural ecosystems. [ABSTRACT FROM AUTHOR]

Summary: The effects of dietary fibre on gut microbiota and the colonic markers of health have been well investigated, along with the kinetics of fibre fermentation. Most of the evidence available is based on faecal analysis or static in vitro models of colonic fermentation of constant amounts of fibres incubated individually with faecal inoculum. These results offer a limited understanding of the effects of different fibres on different bacterial species, and changes that occur along the GI tract, when dietary patterns involving different mixed sources of fibre consumed in a single day are considered. The normal gut transit time is 40–60 h. With three meals in a day, fibres and undigested nutrients tend to accumulate in the colon as they traverse from the proximal to the distal colon. There is an evolving need for a paradigm shift in nutritional research to investigate the metabolomic and physiological effects of fibres in combination, as they are consumed in a normal dietary pattern of daily three meals. We propose a research framework to harness the health‐beneficial effects of fermentation metabolites of fibre by manipulating the site of colonic fermentation resulting from the interplay between fibre fermentation and transit rates in the colon. Based on this framework, a hypothesis is developed to reduce the side effect of excessive gas production from the colonic fermentation of indigestible oligosaccharides in legumes such as chickpeas and soybean. [ABSTRACT FROM AUTHOR]

Stream solute tracers are commonly injected to assess transport and transformation in study reaches, but results are biased toward the shortest and fastest storage locations. While this bias has been understood for decades, the impact of an experimental constraint on our understanding has yet to be considered. Here, we ask how different our understanding of reach‐ and segment‐scale transport would be if our empirical limits were extended. We demonstrate a novel approach to manipulate experimental conditions and observe mass that is stored at timescales beyond the traditional reach‐scale window of detection. We are able to explain the fate of an average of 26% of solute tracer mass that would have been considered as "lost" in a traditional study design across our 14 replicates, extending our detection limits to characterize flowpaths that would have been previously unmeasured. We demonstrate how this formerly lost mass leads to predicting lower magnitudes of gross gains and losses in individual reaches, and ultimately show that the network turnover we infer from solute tracers represents an upper limit on actual, expected behavior. Finally, we review the evolution of tracer studies and their interpretation including this approach and provide a proposed future direction to extend empirical studies to not‐before‐seen timescales. Key Points: With careful design, solute tracer studies can be used to assess the fate of solute mass along flowpaths that would not normally be detectedExtended mass recovery allows us to understand the formerly unknown fate of more than 26% of all lost tracer massAccounting for mass recovery beyond the typical window of detection reduced inferred channel water turnover, changing interpreted spatial sources of gains [ABSTRACT FROM AUTHOR]

Background: Neisseria gonorrhoeae (Gonococcus-GC) is a fastidious, autolytic Gram-negative diplococcus with stringent growth requirements, and cannot be cultivated in a routine microbiology laboratory, without well-equipped incubators, reagents, and special media. Hence, many clinics and laboratories prefer to ship the specimens or isolates to a dedicated referral laboratory for confirmation of isolates and antimicrobial susceptibility testing. Thus, transportation conditions for gonococcal isolates, become crucial for its recovery and successful isolation in the laboratory. This retrospective study was conducted at a national referral laboratory for gonococcus, in India, over 3 years. Aim: In this study, an attempt was made to determine the factors affecting the revival of isolates of gonococci, that were despatched, from across India, to the referral laboratory for confirmation of species and antimicrobial susceptibility patterns. Method: Over 3 years, the culture plates, test tubes, or vials used for transporting gonococcal isolates, and their modes of transport to the referral laboratory, were studied in detail. The isolates were revived (whenever possible), subcultured, and identified by standard methods in the referral laboratory. Results: A total of 77 samples were processed for revival and 83.12% of isolates were recovered, with failure of recovery in 16.88% of specimens. Conclusion: Several factors play a role in the successful revival of N. gonorrhoeae from culture isolates transported across the Indian subcontinent. These include purity of growth, culture media used for transport, sending of isolates in duplicates, temperature, time, distance, and season of transport. All these factors must be kept in mind when transporting gonococcal isolates, for successful revival. Finally, the skills of the laboratory technician are of immense importance too. [ABSTRACT FROM AUTHOR]

This work represents a complete sensitivity evaluation of label-free biosensors based on double-gate tunnel FET (DB) and vertical tunnel FET (VB) through the TCAD simulator. The nanogap cavity is present at both biosensors' left side of the fixed dielectric (HfO2). The sensitivities of VB and DB have been compared using neutral and charged biomolecules with varying dielectric constants. VB's drain current and electric field sensitivities are higher than that of DB because the conduction of current in VB is in both lateral and vertical directions. We have evaluated the sensitivity of neutral biomolecules in the cavity as a function of the cavity thickness. The transit time of the biosensors is calculated to study the sensing speed. The biosensors with less transit time have better sensing speed. VB has a better sensing speed than DB as its transit time is less. The impacts of steric hindrance and non-uniform probe/receptor position are also investigated to understand the biosensors' non-ideal performance. The simulated results of partially filled nanogaps – concave, convex, decreasing, and increasing patterns - are used to calculate the sensitivity. Finally, a summary of the work shows that the VB can perform excellently as a low-power biosensor with increased sensitivity. [ABSTRACT FROM AUTHOR]

Parkinson’s disease (PD) is neurodegenerative disease, which is accompanied by degeneration of dopaminergic neurons in subtantia nigra. Non-motor symptoms, in particular, disorders of the gastrointestinal (GI) tract are observed in 20-80% of patients some 15-20 years before clinically diagnosed PD and are not a least important feature of PD pathogenesis. The transient receptor potential (TRP) channels are expressed throughout the GI tract, where they play an important role in taste, thermoregulation, pain, mucosal function and homeostasis, control of interstitial motility etc. The aim of this study was to investigate the contribution of TRPV4 and TRPM8 channels in the GI motor function in the colon of rats with PD, incduced by injection of the 12 μg 6-hydroxydopamine (6-OHDA). The studies were performed on the 4th week and the 7th month after PD induction The rats were randomly divided into: I group – the sham-lesioned rats, 4 μl 0.9% NaCl, autopsy 4 weeks after injection (n = 5); II group – the 6-OHDA-PD rats, 4 μl 12 μg of 6-OHDA, autopsy 4 weeks after injection (n = 5); III group – the sham-lesioned rats, 4 μl 0.9% NaCl, autopsy 7 months after injection (n = 4); IV group – the 6-OHDA-PD rats, 4 μl 12 μg of 6-OHDA, autopsy 7 months after injection (n = 5). We evaluated the body weight of rats, GI transit time, the cecum weight index and immunohistochemical identification of tyrosine hydroxylase (TH) -positive cells, and TRPV4, TRPM8 expression in rat’s colon. We showed that on the 7th month of the experiment, the GI transit time doubles over time; the cecum weight index of 6-OHDA rats increased by 57%; the number of TH-positive cells in colon rats decreased 2-fold, while TRPM8 ion channels were downregulated in PD rats and TRPV4 ion channels were upregulated in the colon of rats with 6-OHDA-PD. It was concluded that TRPV4 and TRPM8 ion channels may be considered pharmacological targets in the progression of PD pathology.

A comparative study is done on Si, 4H-SiC, Wz-GaN and InP based impact avalanche transit time (IMPATT) diodes operating at 94 GHz. A double-iterative simulation procedure is utilized to investigate the DC and small-signal features of the diodes from which corresponding avalanche response times and transit times are obtained. The studies exhibit that SiC and GaN diodes are potential sources for radiating high power at 94 GHz. It is also observed that SiC and GaN diodes are highly appropriate for mm-wave frequency bands due to shorter values of their avalanche response time. The power output for SiC IMPATT source is noticed as 47.61Wand for GaN IMPATT, the same is seen as 1.96 W; corresponding avalanche response times are found to be 2.42×10-15 and 3.45×10-16 s respectively. [ABSTRACT FROM AUTHOR]

Transit-time flow meters need to compensate for cross-sensitivity to temperature. We show that Lamb wave-based setups are less affected by temperature. An optimality criterion is derived that allows to tune the meter into a zero local sensitivity to temperature. For this end, the flow-induced change in ultrasonic transit time is revisited first. While wetted piston transducer meters are directly sensitive to the change in propagation speed, the change in time of flight of Lamb wave-based systems is due to the beam displacement. Second, the effect of temperature is incorporated analytically. It is found that the temperature-dependent radiation angle of Lamb waves is able to compensate for changes in the speed of sound, leading to an (almost) unaffected overall time of flight. This effect is achievable with any fluid and in a wide temperature range. As an example, we discuss a water meter in the range from 0°C to 100°C. The model is validated against temperature and flow rate-dependent measurements obtained on a prototype. The measured data fits well to the developed model and confirms the reduced cross-sensitivity to temperature. Although an in-line meter is considered here, the results extend to clamp-on devices. [ABSTRACT FROM AUTHOR]

The passage of a bubble and the required energy for its motion through a confining pore can potentially be affected by the surface roughness and geometry of the pore. The motion of an isolated bubble passing through four different pore geometries (three circular pores, a smooth pore and 2 with different roughness, and a sharp triangular pore) is investigated. The shape of the deformed bubble passing these geometries was evaluated to determine the pressure drop across the bubble and hence the driving force to cause motion. The results of investigating the motion of the bubbles and the change in the pressure and velocity of the bubbles showed that the pore shape and surface roughness have a significant effect on the passage of the isolated phase. The motion of the bubble entering the entrance of the circular pores was similar for all circular cases. On exiting, however, a clear difference between the cases due to the presence of the peaks of the roughness was observed. These results indicate that, in addition to the critical pressure at the entrance of the pore, extra resistance will be introduced due to bubble phase pinning at the exit caused by roughness of the pore. [ABSTRACT FROM AUTHOR]

Soil carbon (C) is comprised of a continuum of organic compounds with distinct ages (i.e., the time a C atom has experienced in soil since the C atom entered soil). The contribution of different age groups to soil C efflux is critical for understanding soil C stability and persistence, but is poorly understood due to the complexity of soil C pool age structure and potential distinct turnover behaviors of age groups. Here, we build upon the quantification of soil C transit times to infer the age of C atoms in soil C efflux (aefflux) from seven sequential soil layer depths down to 2 m at a global scale, and compare this age with radiocarbon‐inferred ages of C retained in corresponding soil layers (asoil). In the whole 0–2 m soil profile, the mean aefflux is 194211021 (mean with 5%–95% quantiles) year and is just about one‐eighth of asoil (14767172547 year), demonstrating that younger C dominates soil C efflux. With increasing soil depth, both aefflux and asoil are increased, but their disparities are markedly narrowed. That is, the proportional contribution of relatively younger soil C to efflux is decreased in deeper layers, demonstrating that C inputs (new and young) stay longer in deeper layers. Across the globe, we find large spatial variability of the contribution of soil C age groups to C efflux. Especially, in deep soil layers of cold regions (e.g., boreal forests and tundra), aefflux may be older than asoil, suggesting that older C dominates C efflux only under a limited range of conditions. These results imply that most C inputs may not contribute to long‐term soil C storage, particularly in upper layers that hold the majority of new C inputs. [ABSTRACT FROM AUTHOR]

Using Cerenkov photons to improve detector timing resolution in time-of-flight positron emission tomography scanners is promising since they constitute most of the signal rising edge. The main challenge in using Cerenkov light is its low yield per photoelectric interaction, which requires optimizing their complex optical transport in the detector. Monte Carlo simulations unlock information unavailable through benchtop measurements and help better understand the Cerenkov photon behavior. Although the first Cerenkov photons are emitted forward, part of the early triggering signal is lost due to poor light extraction at the crystal-photodetector interface. In addition, the electron path in the crystal, that determines the Cerenkov photon direction, is tortuous due to multiple scattering, causing the Cerenkov photons emitted after a few scatters to no longer be forward-directed. In this context, the transit time spread in the crystal, highly dependent on the detector geometry, plays a crucial role in the photon detection time. In this work, we performed optical simulations in bismuth germanium oxide using 511 keV gamma with GATE to investigate the optical photons extraction when modifying the index of refraction at the crystal-photodetector interface and the crystal aspect ratio. The mean detection time of the first, second, and third detected optical and Cerenkov photon separately was studied as a function of the total number of Cerenkov detected per event. For each configuration, we calculated the expected mean detection time using the probability of detection. Thinner crystals led to lower expected detection times due to the reduced transit time in the crystal. Reducing the refractive index discontinuity at the crystal-photodetector interface decreased all configurations expected mean detection time values. We showed that it not only improves the optical photons (scintillation and Cerenkov) detection efficiency at the photodetector face but directly ameliorates the probability of detecting the fastest one, reducing the effect of thicker materials and of losing the first detected photon information, both crucial to reduce the detector timing resolution. Thanks to their prompt emission and directionality at emission, Cerenkov photons represent the first detected optical photon in most configurations but increasing their detection efficiency is crucial to detect the fastest one.

Local pulse wave velocity (PWV), a metric of the target artery’s stiffness, has been emerging in its clinical value and adoption. State-of-the-art ultrasound technologies used to evaluate local PWV based on pulse waves’ features are sophisticated, non-real-time, and are not amenable for field and resource-constrained settings. In this work, we present an image-free ultrasound system to measure local PWV in real-time by employing a pair of ultrasound transducer elements. An in vitro study was performed on the arterial phantom to: 1) characterize the design aspects of the system and 2) validate its accuracy against beat-by-beat (invasive) local PWV measured by a reference dual-element catheter. Furthermore, a repeatability and reproducibility study on 33 subjects (21–52 years) investigated the in vivo measurement feasibility from the carotid artery. With the experimentally deduced optimal design (frame-rate $=500$ Hz, RF sampling rate $=125$ MHz, LPF cutoff $=14$ Hz, and order $=4$), the system yielded repeatable beat-to-beat measurements (variability $=1.9$ % and over 15 cycles) and achieved a high accuracy (root-mean-square-error $=0.19$ m/s and absolute-percentage-error $=2.4$ %) over a wide range of PWVs (2.7–11.4 m/s) from the phantom. Subsequently, on human subjects, the intra- and inter-operator PWV measurements were highly repeatable (intraclass correlation coefficient $>0.92$). The system does not impose a demand for special processors with high-computational power while offering real-time feedback on acquisition and measurement quality and provides local PWV online. Future large population and animal studies are required to establish the device’s clinical usability. [ABSTRACT FROM AUTHOR]

The traditional elevator system design practice is to calculate the round trip time (RTT) and associated parameters of pure incoming traffic during up-peak, followed by real-time computer simulation. Recent studies indicated that the normal traffic is much more complicated, consisting of a mixture of incoming, outgoing and interfloor patterns. A major breakthrough to analytically calculate the Universal RTT, under such complicated traffic patterns, emerged 6 years ago based on an appropriate origin-destination matrix describing the passenger transit probability. That genesis model played safe by assuming that the total number of passengers demanding service within one round trip is limited elevator contract capacity, which is in line with the traditional up-peak incoming RTT formulae. In this article, such assumption is removed and the study is based on Monte Carlo simulation. It is found that there is room for enhancing the handling capacity, up to two times the contract capacity, by not sacrificing the RTT and average passenger transit time by too much. This phenomenon, that is, total passenger demand beyond contract capacity, is only valid under the existence of multiple entrance floors and/or mixed traffic conditions. This approach may prevent oversizing the design which could be more realistic. Practical applications : Elevator system designers, according to ISO 8100:32:2020 and CIBSE Guide D: 2020, are recommended to carry out calculation of the RTT and related parameters before any real-time computer simulation. This practice has been adopted by the elevator industry for decades. However, conventional RTT evaluation is mainly on pure incoming traffic during up-peak. The Universal RTT calculation method developed in 2014–15 extended RTT evaluation to cover dominant and complicated traffic patterns of modern buildings, but the assumed number of passengers to be handled within one round trip was limited to the contract capacity of the elevator. This article further removes this limitation to evaluate the limit of handling capacity with reasonable RTT and average passenger transit time. Then, the Universal RTT method could be more realistic and rolled out, and prevent oversizing the system design. [ABSTRACT FROM AUTHOR]

Purpose: Develop and evaluate a deep learning approach to estimate cerebral blood flow (CBF) and arterial transit time (ATT) from multiple post‐labeling delay (PLD) ASL MRI. Methods: ASL MRI were acquired with 6 PLDs on a 1.5T or 3T GE system in adults with and without cognitive impairment (N = 99). Voxel‐level CBF and ATT maps were quantified by training models with distinct convolutional neural network architectures: (1) convolutional neural network (CNN) and (2) U‐Net. Models were trained and compared via 5‐fold cross validation. Performance was evaluated using mean absolute error (MAE). Model outputs were trained on and compared against a reference ASL model fitting after data cleaning. Minimally processed ASL data served as another benchmark. Model output uncertainty was estimated using Monte Carlo dropout. The better‐performing neural network was subsequently re‐trained on inputs with missing PLDs to investigate generalizability to different PLD schedules. Results: Relative to the CNN, the U‐Net yielded lower MAE on training data. On test data, the U‐Net MAE was 8.4 ± 1.4 mL/100 g/min for CBF and 0.22 ± 0.09 s for ATT. A significant association was observed between MAE and Monte Carlo dropout‐based uncertainty estimates. Neural network performance remained stable despite systematically reducing the number of input images (i.e., up to 3 missing PLD images). Mean processing time was 10.77 s for the U‐Net neural network compared to 10 min 41 s for the reference pipeline. Conclusion: It is feasible to generate CBF and ATT maps from 1.5T and 3T multi‐PLD ASL MRI with a fast deep learning image‐generation approach. [ABSTRACT FROM AUTHOR]

Quantifying the transfer of organic carbon from the terrestrial to the riverine ecosystems is of crucial importance to fully appreciate the carbon cycle at the catchment, regional and global scales. In this study, we propose a framework for modeling the flux of dissolved organic carbon (DOC) from hillslopes to stream and river networks which couples a transport model based on travel time distributions with the reactivity continuum (RC) approach to model DOC degradation. We test the model by applying it to the Plynlimon catchments (UK) exploiting both weekly and high‐frequency (7‐hr interval) time‐series. We use information about chloride to get an independent estimate of water travel times using the framework of StorAge Selection functions. Following the RC model, the composition and the degradation of DOC along the flowpaths, and its consequent concentration in the streamflow, is described assuming that DOC is composed by a mixture of compounds that follows a continuous spectrum of reactivity. For the high‐frequency data set, the model is able to reproduce DOC streamflow concentrations and to capture the complex hysteretic relation between DOC concentration and discharge. Weekly data are instead not frequent enough to properly describe DOC dynamics in this catchment. The distribution of the age of the water comprised in the streamflow proves thus a key variable to predict the quantity and the reactivity of the DOC exported from soils, and the effect of hydrologic variability on this process. Plain Language Summary: Streams and rivers are able to drain, transport, process and mineralize the carbon stored in the terrestrial ecosystems. This set of processes controls stream water quality, the metabolic functioning of riverine ecosystems, and eventually the carbon balance and the CO2 emissions at the global scale. We focus on the flux of dissolved organic carbon (DOC) originating from the decomposition of soil organic matter and exported from hillslopes to the streamflow by rainfall‐runoff processes. Our goal is to contribute to the understanding of this process and to disentangle the complex relation between DOC concentration and discharge. We estimate the quantity of DOC that survives the pathways from the soil to the stream using two key variables: the time that the water transporting DOC spends along the pathway and the DOC reactivity, which controls its degradation. The model is able to capture the complex behavior of stream DOC concentration in two headwater catchments, suggesting that the mixture of water with different ages that characterizes the streamflow controls the time available for degradation and thus the flux of DOC exported. Key Points: Quantity and reactivity of dissolved organic carbon (DOC) exported from a hillslope are modeled coupling water age and reactivity continuumThe age structure of water in the catchment controls DOC degradation within soilsDOC concentration‐discharge relations are explained by water travel time distribution [ABSTRACT FROM AUTHOR]

• TiO 2 /CuInSe 2 and HF-TiO 2 /CuInSe 2 heterojunctions are recognized as p-n junction. • Built-in-potential and Mobility-transit time product improved after light soaking. • Device performance was improved by improving the absorption of TiO 2 after HF treatment. Searching of electronic system with functionality is the epitome of the material research and in this context; nanomaterials CuInSe 2 and TiO 2 are the promising stars whose possible applications in electronic devices are just endless. However, the fabrication of junction based device using these two materials is most tantalizing prospect in material science is still at its rudimentary stage. In this letter, we report our recognition of current rectification behavior of CuInSe 2 /TiO 2 heterojunction, identical to the I-V characteristics of p-n junction diode and the impact of white light on it. The HOMO-LUMO band positions of hydrothermally derived CuInSe 2 and TiO 2 nanomaterials indicate that in thermal equilibrium a built-in-potential must arise across the junction. The current-rectification ratio of the configuration Al/CuInSe 2 /TiO 2 /ITO is improved from 560 to 627 at voltage ±2 V on white light illumination and this kind of behavior is certainly offering us an unprecedented way to realize the CuInSe 2 /TiO 2 hetero-junction as photo-sensing p-n diode. The device performance is improved further by replacing TiO 2 with HF treated TiO 2. [ABSTRACT FROM AUTHOR]

Single-particle ICP-mass spectrometry (SP-ICP-MS) is a powerful method for micro/nano-particle (MNP) sizing. Despite the outstanding evolution of the technique in the last decade, most studies still rely on traditional approaches based on (1) the use of integrated intensity as the analytical signal and (2) the calculation of the transport efficiency (TE). However, the increasing availability of MNP standards and advancements in hardware and software have unveiled new venues for MNP sizing, including TE-independent and time-based approaches. This work systematically examines these different methodologies to identify and summarize their strengths and weaknesses, thus helping to determine their preferred application areas. Different SP-ICP-MS methods for MNP sizing were assessed using AuNPs (20–70 nm) and SiO 2 MNPs (100–1000 nm). Among TE-dependent approaches, the particle frequency method was characterized by larger uncertainties than the particle size method. The results of the latter were dependent on the appropriate selection of the reference MNP, making the use of multiple reference MNPs recommended. TE-independent methods were based on external (linear and polynomial) calibrations and a relative approach. These methods exhibited the lowest uncertainties of all the strategies evaluated. External calibrations benefited from simpler calculations, but their application could be hindered by a lack of reference MNPs within the desired size range or by the need for interpolations outside the calibration range. Finally, transit time signals are directly proportional to the MNP size rather than its mass. The time-based method demonstrated adequate performance for sizing AuNPs but failed when sizing the largest SiO 2 MNPs (1000 nm). This work provides further insights into the application of different SP-ICP-MS methodologies for MNP sizing. Both TE-independent approaches and the monitoring of the transit time as the analytical signal are underused strategies; in this context, a Python script was developed for accurate transit time measurement. After 20 years of development, a quantitative comparison of the different methodologies, including the most novel approaches, is deemed necessary for further growth on solid theoretical ground. [Display omitted] • Critical comparison of different SP-ICP-MS methodologies for MNP sizing. • Analytical signals based on both integrated intensities and transit times evaluated. • The particle frequency method provided larger uncertainties than the particle size. • TE-independent approaches displayed better precision than TE-dependent ones. • The time-based method is suitable for sizing AuNPS but not the largest SiO 2 MNPs. [ABSTRACT FROM AUTHOR]

Featured Application: Feasibility of personalized medical care for patients with sickle cell anemia using a lab-on-chip microfluidic platform to mimic and unravel components of vaso-occlusive crisis. Sickle cell disorder (SCD) is a multisystem disease with heterogeneous phenotypes. Although all patients have the mutated hemoglobin (Hb) in the SS phenotype, the severity and frequency of complications are variable. When exposed to low oxygen tension, the Hb molecule becomes dense and forms tactoids, which lead to the peculiar sickled shapes of the affected red blood cells, giving the disorder its name. This sickle cell morphology is responsible for the profound and widespread pathologies associated with this disorder, such as vaso-occlusive crisis (VOC). How much of the clinical manifestation is due to sickled erythrocytes and what is due to the relative contributions of other elements in the blood, especially in the microcapillary circulation, is usually not visualized and quantified for each patient during clinical management. Here, we used a microfluidic microcirculation mimetic (MMM), which has 187 capillary-like constrictions, to impose deformations on erythrocytes of 25 SCD patients, visualizing and characterizing the morpho-rheological properties of the cells in normoxic, hypoxic (using sodium meta-bisulfite) and treatment conditions (using hydroxyurea). The MMM enabled a patient-specific quantification of shape descriptors (circularity and roundness) and transit time through the capillary constrictions, which are readouts for morpho-rheological properties implicated in VOC. Transit times varied significantly (p < 0.001) between patients. Our results demonstrate the feasibility of microfluidics-based monitoring of individual patients for personalized care in the context of SCD complications such as VOC, even in resource-constrained settings. [ABSTRACT FROM AUTHOR]

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Water age and flow pathways should be related; however, it is still generally unclear how integrated catchment runoff generation mechanisms result in streamflow age distributions at the outlet. Here, we combine field observations of runoff generation at the Dry Creek catchment with StorAge Selection (SAS) age models to explore the relationship between stream water age and runoff pathways. Dry Creek is a 3.5 km2 catchment in the Northern California Coast Ranges with a Mediterranean climate, and, despite an average rainfall of ≈1,800 mm/yr, is an oak savannah due to the limited hillslope water storage capacity. Runoff lag to peak—after initial seasonal wet‐up—is rapid (∼1–2 hr), and total annual streamflow consists predominantly of saturation overland flow, based on field mapping of saturated extents and an inferred runoff threshold for the expansion of saturation extent beyond the geomorphic channel. SAS modeling based on daily isotope sampling reveals that streamflow is typically older than 1 day. Since streamflow primarily consists of overland flow, a significant portion of overland flow must not be event‐rain but instead derive from older, nonevent groundwater returning to the surface, consistent with field observations of exfiltrating head gradients, return flow through macropores, and extensive saturation days after storm events. We conclude that even in a watershed fed primarily by overland flow, runoff is primarily not composed of event water. Our findings have implications for the interpretation of stream chemistry and the assumptions built into widely used hydrograph separation inferences, namely, the assumption that overland flow consists of new (event) water. Plain Language Summary: Streams that respond most rapidly to rainfall tend to be fed by a process called overland flow. This study uses high‐frequency water tracking measurements to show that even in a watershed fed by overland flow, the water entering the stream during storm events tends to be older than the storm event causing the stream response. Hydrologic observations made during storm events reveal that water travels through the subsurface before reemerging as surface flow. The interaction between storm event water and subsurface soils and weathered bedrock likely lead to mixing such that the water entering the stream contains a substantial fraction of water from previous storm events. Key Points: Field observations of surface runoff, groundwater levels, and saturated extents indicate that saturation overland flow dominates streamflowStable isotope tracers show that stream water age decreases as streamflow increasesStreamflow is nevertheless mainly water greater than 1 day old, meaning that even overland flow is mostly not event water [ABSTRACT FROM AUTHOR]

Radiocarbon (14C) is commonly used as a tracer of the carbon cycle to determine how fast carbon moves between different reservoirs such as plants, soils, rivers, or oceans. However such studies mostly emphasize the mean value (as Δ14C) of an unknown probability distribution. We introduce a novel algorithm to compute Δ14C distributions from knowledge of the age distribution of carbon in linear compartmental systems at steady‐state. Our results demonstrate that the shape of the distributions might differ according to the speed of cycling of ecosystem compartments and their connectivity within the system, and might contain multiple peaks and long tails. The distributions are also sensitive to the variations of Δ14C in the atmosphere over time, as influenced by the counteracting anthropogenic effects of fossil‐fuel emissions (14C‐free) and nuclear weapons testing (excess 14C). Lastly, we discuss insights that such distributions can offer for sampling and design of experiments aiming to capture the precise variance of Δ14C values present in the multi‐compartmental ecosystems. Plain Language Summary: Radiocarbon (14C) is a radioactive isotope of carbon prominent in environmental sciences for tracing the dynamics of ecosystems, especially as recent changes in atmospheric radiocarbon allow tracking excess 14C created by nuclear weapons testing in the atmosphere on timescales shorter than what can be determined using radioactive decay. For climate change mitigation, a crucial uncertainty is the time carbon captured through photosynthesis spends in ecosystems before being released. For this purpose, radiocarbon can be valuable as a biological tracer; however, it is necessary to accurately link the real age of carbon and its radiocarbon age, as they usually differ. Forests and soils are open systems, connecting components with intrinsically different cycling timescales, so that the mean age comes from an age distribution that is usually unknown. Here, we developed an algorithm to compute the 14C contents for models consisting of multiple interconnected carbon pools. Our approach offers more accurate estimations of the mean 14C content of the system and computations of the distribution of 14C within the system at different points in time. Results obtained from this method can provide additional insights on the dynamics of the carbon cycle in multiple compartments, and can help to better interpret observations. Key Points: Probability distributions of radiocarbon in ecosystem compartments can be derived from carbon age distributionsThe shape of these distributions vary according to the speed of carbon cycling and the year of observationProbability distributions of radiocarbon provide insights to study carbon dynamics and to interpret radiocarbon data [ABSTRACT FROM AUTHOR]

Spatially integrated water transport dynamics at the hillslope scale have rarely been observed directly, and underlying physical mechanisms of those dynamics are poorly understood. We present time‐variable transit time distributions and StorAge Selection (SAS) functions for a 28 days tracer experiment conducted at the Landscape Evolution Observatory, Biosphere 2, the University of Arizona, AZ, USA. The observed form of the SAS functions is concave, meaning that older water in the hillslope was preferentially discharged than younger water. The concavity is, in part, explained by the relative importance of advective and diffusive water dynamics and by the geomorphologic structure of the hillslopes. A simple numerical examination illustrates that, for straight plan‐shaped hillslopes, the saturated zone SAS function is concave when the hillslope Péclet (Pe) number is large (and thus when the advective water dynamics are more pronounced). We also investigated the effect of hillslope planform geometry on the saturated zone SAS function using a model and found that the more convergent the plan shape is, the more concave the SAS function is. A numerical examination indicates that the unsaturated zone SAS function is concave for straight and convergent hillslopes when the soil thickness is uniform. The concavity of those subcomponent SAS functions signifies that the hillslope scale SAS function is concave for straight or convergent plan shape hillslopes when the hillslope Pe number is high. Key Points: We present the StorAge Selection (SAS) functions observed in hillslope scale experimental systemsThe observed SAS functions are concave, meaning that water leaving the systems is mainly older stored waterPredominance of advective water dynamics and the geomorphologic structure of the hillslopes explain the concavity of the SAS functions [ABSTRACT FROM AUTHOR]