High Threshold Research Articles

Measuring Integrin Force Loading Rates Using a Two-Step DNA Tension Sensor.

Cells apply forces to extracellular matrix (ECM) ligands through transmembrane integrin receptors: an interaction which is intimately involved in cell motility, wound healing, cancer invasion and metastasis. These small (piconewton) integrin-ECM forces have been studied by molecular tension fluorescence microscopy (MTFM), which utilizes a force-induced conformational change of a probe to detect mechanical events. MTFM has revealed the force magnitude for integrin receptors in a variety of cell models including primary cells. However, force dynamics and specifically the force loading rate (LR) have important implications in receptor signaling and adhesion formation and remain poorly characterized. Here, we develop an LR probe composed of an engineered DNA structure that undergoes two mechanical transitions at distinct force thresholds: a low force threshold at 4.7 pN (hairpin unfolding) and a high force threshold at 47 pN (duplex shearing). These transitions yield distinct fluorescence signatures observed through single-molecule fluorescence microscopy in live cells. Automated analysis of tens of thousands of events from eight cells showed that the bond lifetime of integrins that engage their ligands and transmit a force >4.7 pN decays exponentially with a τ of 45.6 s. A subset of these events mature in magnitude to >47 pN with a median loading rate of 1.1 pN s-1 and primarily localize at the periphery of the cell-substrate junction. The LR probe design is modular and can be adapted to measure force ramp rates for a broad range of mechanoreceptors and cell models, thus aiding in the study of molecular mechanotransduction in living systems.

The cost-utility analysis of adding ocrelizumab to the treatment plan for primary progressive multiple sclerosis in Iran

ABSTRACT Background This study evaluates the cost-effectiveness of adding ocrelizumab to supportive care for primary progressive multiple sclerosis (PPMS) in Iran. Research design and methods Using a lifetime horizon from the payer’s perspective, we developed a decision analytic model with Expanded Disability Status Scales (EDSS) as Markov health states while taking transition probabilities and treatment effects into account. Data were sourced from clinical trials and other literature. The target population was PPMS patients receiving either supportive care or ocrelizumab. We assessed cost- effectiveness through total costs, quality-adjusted life-years (QALYs), and the incremental cost- effectiveness ratio (ICER). Sensitivity analyses addressed uncertainties. Results The addition of ocrelizumab to supportive care provided an incremental gain of 0.89 QALYs and an additional cost of US$76,771.34, resulting in an ICER of US$86,220.35 compared to supportive care, which is 5.2 times Iran’s GDP per capita (US$16,557). Thus, ocrelizumab is not cost-effective at the threshold of one time GDP per capita. However, the probability of cost-effectiveness increases at higher thresholds. Sensitivity analyses confirmed the robustness of the results. Conclusion While ocrelizumab is not cost-effective at the threshold of one-time GDP per capita, its clinical benefits are significant. Formulating healthcare policies for high-cost medications with low alternatives like ocrelizumab is essential.

Long-Term Outcomes in Patients With Relatively High His-Bundle Capture Threshold After Permanent His-Bundle Pacing - A Multicenter Clinical Study.

Outcomes in patients with relatively high His-bundle (HB) capture thresholds at implantation are unknown. This study aimed to compare changes in the HB capture threshold and prognosis between patients with a relatively high threshold and those with a low threshold. Forty-nine patients who underwent permanent HB pacing (HBP) were divided into two groups: low (<1.25 V at 1.0 ms; n=35) and high (1.25-2.49 V; n=14) baseline HB capture threshold groups. The HB capture threshold was evaluated at implantation, and after 1 week, 1, 3, and 6 months, and every 6 months thereafter. HB capture threshold rise was defined as threshold rise ≥1.0 V at 1.0 ms compared with implantation measures. We compared outcomes between the groups. During a mean follow-up period of 34.6 months, the high-threshold group showed a trend toward a higher incidence of HB capture threshold of ≥2.5 V (50% vs. 14%; P=0.023), HBP abandonment (29% vs. 8.6%; P=0.091), lead revision (21% vs. 2.9%; P=0.065), and clinical events (all-cause death, heart failure hospitalization, and new-onset or progression of atrial fibrillation; 50% vs. 23%; P=0.089) than the low-threshold group. A baseline HB capture threshold of ≥1.25V was an independent predictor of clinical events. A relatively high HB capture threshold is associated with increased risk of HBP abandonment, lead revision, and poor clinical outcomes.

Lowering platelet-count threshold for transfusion in preterm neonates decreases the number of transfusions without increasing severe hemorrhage events

Thrombocytopenia is common in preterm neonates and can be associated with hemorrhage. Most platelet transfusions are prophylactic. Previously, higher platelet-count thresholds were recommended for neonates, but this recommendation has been questioned in recent studies. In the PlaNeT2 trial, mortality and serious bleeding were more frequent in neonates with the highest platelet-count threshold than in others. Following this trial, we changed our platelet transfusion practice by lowering the platelet-count threshold for prophylactic transfusion from 50,000 to 25,000/mm3. We conducted a before–after retrospective cohort study to quantify the frequency of platelet transfusions and assess the new protocol by analyzing death and serious hemorrhage events. This retrospective monocentric study included neonates born before 37 weeks of gestation with platelet count < 150,000/mm3 during the 2 years preceding the new platelet transfusion protocol (high prophylactic transfusion threshold, 50,000/mm3) and during the 2 years after the new platelet transfusion protocol (low prophylactic transfusion threshold, 25,000/mm3). The primary outcome was the proportion of neonates receiving at least one platelet transfusion in both groups. We also compared the proportion of deaths and severe hemorrhage events. A total of 707 neonates with thrombocytopenia were identified. In the high-threshold group, 99/360 (27.5%) received at least one platelet transfusion as compared with 56/347 (16.1%) in the low-threshold group (p < 0.001). The groups did not differ in proportion of deaths or severe hemorrhage events.Conclusions: A reduced platelet-count threshold for transfusion allowed for a significant reduction in the number of platelet transfusions without increasing severe hemorrhage events.What is Known:• A recent randomized trial suggested that restrictive platelet-count thresholds for platelet transfusion could be beneficial for preterm neonates.What is New:• On lowering the platelet-count threshold for transfusion from 50,000 to 25,000/mm3, the number of transfusions significantly decreased without increasing severe hemorrhage events in a neonatal intensive care unit.

Machine Learning Based Algorithm for the Early Prediction of Postoperative Hypocalcemia Risk After Thyroidectomy.

We used machine learning to develop and validate a multivariable algorithm allowing the accurate and early prediction of postoperative hypocalcemia risk. Post-operative hypocalcemia is frequent after total thyroidectomy. An early and accurate individualized prediction of the risk of hypocalcemia could guide the selective prescription of calcium supplementation only to patients most likely to present with hypocalcemia after total thyroidectomy. This retrospective study enrolled all patients undergoing total thyroidectomy in a single referral center between November 2019 and march 2022 (derivation cohort) and april 2022 and September 2022 (validation cohort) . The primary study outcome was post-operative hypocalcemia (serum calcium under 80mg/L). Exposures were multiple clinical and biological variables prospectively collected and analyzed with various machine learning methods, to develop and validate a multi variable prediction algorithm. Among 610 / 118 participants in the derivation / validation cohorts, 100 (16.4%) / 26 (22%) presented post-operative hypocalcemia. The most accurate prediction algorithm was obtained with random forest, and combined intraoperative parathyroid hormone measurements with three clinical variables (age, sex and body mass index), to calculate a postoperative hypocalcemia risk for each patient. After multiple cross validation, the area under the receiver operative characteristic curve was 0.902 (0.829-0.970) in the derivation cohort, and 0.928 (95% CI : 0.86; 0.97) in the validation cohort. Postoperative hypocalcemia risk values of 7% (low threshold) and 20% ( high threshold) had respectively a sensitivity of 92% and a negative likelihood ratio of 0.11, and a specificity of 90% and a positive of 7.6 for the prediction of postoperative hypocalcemia. Using machine learning, we developed and validated a simple multivariable model which allowed the accurate prediction of postoperative hypocalcemia. The resulting algorithm could be used at the point of care to guide clinical management after total thyroidectomy.

A 3D-Var assimilation scheme for vertical velocity with CMA-MESO v5.0

Abstract. Certain vertical motions associated with meso-microscale systems are favorable for convection development and maintenance. Correct initialization of updraft motions is thus significant in convective precipitation forecasts. A three-dimensional variational-based vertical velocity (w) assimilation scheme has been developed within the high-resolution (3 km) CMA-MESO (the Mesoscale Weather Numerical Forecast System of the China Meteorological Administration) model. This scheme utilizes the adiabatic Richardson equation as the observation operator for w, enabling the update of horizontal winds and mass fields of the model's background. The tangent linear and adjoint operators are subsequently developed and undergo an accuracy check. A single-point w observation assimilation experiment reveals that the observational information is effectively spread both horizontally and vertically. Specifically, the assimilation of w contributes to the generation of horizontal wind convergence at lower model levels and divergence at higher model levels, thereby adjusting the locations of convection occurrence. The impact of assimilating w on the forecast is then examined through a series of continuous 10 d runs. Further assimilation of w, in addition to the assimilation of conventional and radial wind data, significantly improves the forecast accuracy of precipitation, resulting in higher FSS (fractions skill score) values and higher ETS (equitable threat score) skills at higher thresholds (5 and 20 mm h−1). However, it should be noted that further assimilation of w can potentially lead to some false precipitation, resulting in slightly lower ETS values at lower thresholds (1 mm h−1) and a neutral impact on BIAS (bias score) skills. An individual case study conducted within the batch experiments reveals that assimilating w has a beneficial impact on the enhancement of vertical motion across different layers of the model, facilitating the transport of moisture from lower to middle–high model levels, thereby leading to an improvement in forecast skills.

Unlocking superior performance of broadband powerful mid-IR optical parametric amplifiers with a BaGa2GeS6 crystal pumped at 1.24 µm.

We report on the development of a tunable (1.5-6.5 µm) femtosecond optical parametric amplifier (OPA) based on a novel, to the best of our knowledge, BaGa2GeS6 (BGGS) crystal with a Cr:Forsterite pumping laser. Total conversion efficiency as high as 28% is achieved in a robust two-stage setup resulting in the generation of a 340-µJ 1.67-µm signal and 100-µJ 4.65-µm idler pulses. A 5-optical-cycles 94-fs 6-µm idler pulses are demonstrated with a propriate dispersion compensation by Ge and GaAs plates. An experimental estimate is given for the effective nonlinearity of a BGGS material, which for our nonlinear process reaches 19.5 pm/V for Type II phase matching. The crystal is additionally tested as a final amplifier in a high-energy OPA, where total output reaches 1.2 mJ with more than 40% conversion efficiency. The demonstrated high nonlinearity, high damage threshold, and chemical stability of the polished surface make BGGS crystal an ideal candidate for the development of high-energy OPAs with multi-millijoule pumping lasers.

The Biology, Epidemiology, Host Variability and Management of Sorghum Smut Diseases in Nigeria: A Review

Sorghum Smut diseases in Nigeria are widely circulated and are economically important in most of the regions of the country growing Sorghum. Perhaps, all the four types of smut can co-exist on the same field and are co-extensive with sorghum cultivation. The four smut diseases are incited by four species belonging to two genera of the order ustilaginales, namely; Sporisorium or Sphacelotheca and Tolyposporium. The distribution of the four smut diseases depend on several interacting factors of epidemiology and pathogenesis. It has been reported that all the four species that causes smuts in sorghum have narrow host range. As a consequence therefore, they do not vary remarkably in their biology and pathogenesis. However, their severity, distribution and prevalence depend on the environmental conditions, seasons and variety of sorghum. Several control as well as management strategies have been suggested by workers for the prevention and control of sorghum smuts including the pre-sowing seed treatment using fungicides, the use of resistant plant variety and modification of cultural and handling practices. However, only few of these measures have been found suitable and promising. Moreover, there is scarce of scientific information on the incidence of sorghum smuts probably because they were thought to have been eradicated or that they are economically less important in most sorghum growing areas in Nigeria. But with the current climatic changes coupled with the negligence from the poor resource sorghum farmers, sorghum smut diseases are re-emerging with high threshold as such they are becoming very important in Nigeria’s sorghum growing regions. This paper reviews the epidemiology, biology and variability of smut pathogens and their possible control strategies.

Encoded-Fusion-Based Quantum Computation for High Thresholds with Linear Optics.

We propose a fault-tolerant quantum computation scheme in a measurement-based manner with finite-sized entangled resource states and encoded-fusion scheme with linear optics. The encoded fusion is an entangled measurement devised to enhance the fusion success probability in the presence of losses and errors based on a quantum error-correcting code. We apply an encoded-fusion scheme, which can be performed with linear optics and active feedforwards to implement the generalized Shor code, to construct a fault-tolerant network configuration in a three-dimensional Raussendorf-Harrington-Goyal lattice based on the surface code. Numerical simulations show that our scheme allows us to achieve up to 10 times higher loss thresholds than nonencoded fusion approaches with limited numbers of photons used in fusion. Our scheme paves an efficient route toward fault-tolerant quantum computing with finite-sized entangled resource states and linear optics.

A preliminary study exploring the effects of transcutaneous spinal cord stimulation on spinal excitability and phantom limb pain in people with a transtibial amputation

Objective. Phantom limb pain (PLP) is debilitating and affects over 70% of people with lower-limb amputation. Other neuropathic pain conditions correspond with increased spinal excitability, which can be measured using reflexes andF-waves. Spinal cord neuromodulation can be used to reduce neuropathic pain in a variety of conditions and may affect spinal excitability, but has not been extensively used for treating PLP. Here, we propose using a non-invasive neuromodulation method, transcutaneous spinal cord stimulation (tSCS), to reduce PLP and modulate spinal excitability after transtibial amputation.Approach. We recruited three participants, two males (5- and 9-years post-amputation, traumatic and alcohol-induced neuropathy) and one female (3 months post-amputation, diabetic neuropathy) for this 5 d study. We measured pain using the McGill Pain Questionnaire (MPQ), visual analog scale (VAS), and pain pressure threshold (PPT) test. We measured spinal reflex and motoneuron excitability using posterior root-muscle (PRM) reflexes andF-waves, respectively. We delivered tSCS for 30 min d-1for 5 d.Main Results. After 5 d of tSCS, MPQ scores decreased by clinically-meaningful amounts for all participants from 34.0 ± 7.0-18.3 ± 6.8; however, there were no clinically-significant decreases in VAS scores. Two participants had increased PPTs across the residual limb (Day 1: 5.4 ± 1.6 lbf; Day 5: 11.4 ± 1.0 lbf).F-waves had normal latencies but small amplitudes. PRM reflexes had high thresholds (59.5 ± 6.1μC) and low amplitudes, suggesting that in PLP, the spinal cord is hypoexcitable. After 5 d of tSCS, reflex thresholds decreased significantly (38.6 ± 12.2μC;p< 0.001).Significance. These preliminary results in this non-placebo-controlled study suggest that, overall, limb amputation and PLP may be associated with reduced spinal excitability and tSCS can increase spinal excitability and reduce PLP.

Spatio-temporal action detector with cross-stream knowledge transfer

Abstract Relying on human labor for uninterrupted monitoring through surveillance systems is highly inefficient and prone to oversight, making intelligent surveillance have great application prospects and value. To implement this technology, spatio-temporal action detectors are typically used, which are neural networks capable of locating action instances simultaneously in both time and space dimensions. To address the issue of high computational demand commonly associated with 3D backbone architectures, we propose a Dynamic Cross-Stream MovingCenter Detector (DCMOC) based on a 2D backbone network, an improved version of the MOC detector. In the DCMOC detector, the movement branch and the bounding box branch correspond to the motion and appearance features of action instances, respectively. Through a designed cross-stream knowledge transfer module, feature knowledge is transferred between the two branches to enhance feature representation. To compare with existing spatio-temporal action detectors, experiments were conducted on two datasets, JHMDB and UCF101-24. The experiments demonstrate that the DCMOC detector achieves competitive performance with significantly lower computational requirements than existing 3D architecture models and achieves optimal performance on the video-map metric at high thresholds.

Deciding The Provisional Measures Regarding the Suspension of Criminal Procedure by International Centre for Settlement of Investment Disputes (ICSID)

The Convention on the Settlement of Investment Disputes Between States and Nationals of Other States (hereafter referred to as the Convention), as well as the International Centre for Settlement of Investment Disputes (ICSID) was established within the framework of the Convention, aims to resolve disputes encountered in international investments in a prompt and facilitated manner under an independent credible judicial mechanism. ICSID tribunals can order provisional measures in a dispute presented before them to protect the parties’ mutual rights as mentioned in Article 47 of the Convention. The raison d’être for these measures is to ensure the integrity of the proceedings and exclusivity of the ICSID arbitration by preserving the status quo and preventing aggravation of the dispute. However, no explicit statement occurs in the Convention which suggests that the possibility of rendering a decision regarding provisional measures against a national criminal proceeding. Criminal proceedings are perhaps the most indisputable component of state sovereignty. Hence, the tribunals acknowledge a high threshold shall be required to justify an intervention in national criminal proceedings. Therefore, any intervention related to criminal proceedings that conflict with the sovereignty of a state authority should be evaluated case by case and kept at a minimum. In this context, the current paper will address the provisional measures that are orderable by ICSID tribunals, the impact these measures have on pending criminal proceedings in domestic law. ICSID’s authority to impose sanctions on state parties if they do not comply with the measures in relation to the criminal proceedings. In addition, the article will evaluate requests for provisional measures to comprehend whether or not they intervene in the sovereign authority of a state party. We should also point out that, arbitration is a multidisciplinary subject, it has connections with International law, Constitution and other legal disciplines. However, the issue will only be handled within the scope of ICSID and criminal procedure.

Dopamine biases decisions by limiting temporal integration.

Motivations bias our responses to stimuli, producing behavioural outcomes that match our needs and goals. Here we describe a mechanism behind this phenomenon: adjusting the time over which stimulus-derived information is permitted to accumulate towards a decision. As a Drosophila copulation progresses, the male becomes less likely to continue mating through challenges1-3. We show that a set of copulation decision neurons (CDNs) flexibly integrates information about competing drives to mediate this decision. Early in mating, dopamine signalling restricts CDN integration time by potentiating Ca2+/calmodulin-dependent protein kinase II (CaMKII) activation in response to stimulatory inputs, imposing a high threshold for changing behaviours. Later into mating, the timescale over which the CDNs integrate termination-promoting information expands, increasing the likelihood of switching behaviours. We suggest scalable windows of temporal integration at dedicated circuit nodes as a key but underappreciated variable in state-based decision-making.

Natural history in Malan syndrome: survey of 28 adults and literature review

BackgroundMalan syndrome (MALNS), previously referred to as “Sotos syndrome 2” due to its resemblance to Sotos syndrome (SS), is an ultra-rare neurodevelopmental disorder characterized by overgrowth, typical craniofacial features, intellectual disability (ID), and a range of psychobehavioral, musculoskeletal, vision and neurological signs. As MALNS and SS partly overlap, it is essential to more accurately profile their clinical presentations and highlight their differences in order to improve syndrome specific management. An increasing number of individuals with MALNS reach adult-age though the natural history of the disorder is poorly characterized due to the small number of adult individuals described so far. As a consequence, current guidelines are limited to the pediatric population. Further delineation of MALNS is essential to optimize care in adulthood.ResultsA mixed approach based on cross-sectional data collection with a survey disseminated to caregivers of adults with molecularly confirmed MALNS and literature review was conducted. Twenty-eight caregivers completed the survey. Clinical presentation in adulthood is multisystemic and defined by psychobehavioral comorbidities (96%), musculoskeletal involvement (96%), vision impairment (96%) and neurological complications (86%). The most common signs were anxiety (79%), hypotonia (75%), movement difficulty (75%), scoliosis (64%), problems with coordination (61%), strabismus (57%), constipation (54%), breastbone abnormalities (54%) and advanced bone age during childhood (54%). Impaired vision was complicated by vision decline (36%) and optic atrophy (32%). We report some previously unidentified features, including high pain threshold (46%), incontinence (25%), tremors (21%), muscle hypoplasia (18%) and tics (18%).ConclusionsThis survey in the adult population has allowed a more complete description of the natural history of MALNS. Our findings will contribute to the development and improvement of standards of care for adults with MALNS to assure optimal health monitoring and treatment of evolutive complications. We propose additional recommendations to the previous dataset of clinical evaluations specifically applied to adults. The comparison of MALNS and SS adult presentation highlights significant differences in terms of prevalence and severity of ID, behavioral issues, and vision problems, confirming that a proper differential diagnosis between the two conditions is indispensable to guide physicians and mental health professionals to syndrome specific management.

Optical properties of hafnium-dioxide derived from reflection electron energy loss spectroscopy spectra

The optical properties of HfO2 have practical applications. As an important gate dielectric material with high-k dielectric, HfO2 is beneficial to reduce the leakage current of the complementary metal-oxide-semiconductor (CMOS) gate and improves the gate structure. HfO2 also plays a key role in optical coating materials field for its high transmittance in the ultraviolet to near-infrared band, and high laser damage threshold. Therefore, it is of practical significance for the accurate knowledge of optical properties of HfO2. Here we present the optical constants and dielectric function of HfO2 based on the energy loss function (ELF) in the energy loss range of 0–200 eV for nanocrystalline film. Our new data are derived from the analysis of the reflected electron energy loss spectra by using the latest version of our reverse Monte Carlo modelling. Sum rules are used to check the reliability of the new data. We have found that up to 30 eV there are three main peaks, and the first-principles calculation also confirms the three peak structures. A comparison with previous results indicates that the ELF peak positions of HfO2 with different crystal structures are similar, but the peak intensity and shape are different. The heterogenicity of the crystal structure of HfO2 leads to different measurement results for different samples.

‘Low’ LRs obtained from DNA mixtures: On calibration and discrimination performance of probabilistic genotyping software

The validity of a probabilistic genotyping (PG) system is typically demonstrated by following international guidelines for the developmental and internal validation of PG software. These guidelines mainly focus on discriminatory power. Very few studies have reported with metrics that depend on calibration of likelihood ratio (LR) systems. In this study, discriminatory power as well as various calibration metrics, such as Empirical Cross-Entropy (ECE) plots, pool adjacent violator (PAV) plots, log likelihood ratio cost (Cllr and Cllrcal), fiducial calibration discrepancy plots, and Turing’ expectation were examined using the publicly-available PROVEDIt dataset. The aim was to gain deeper insight into the performance of a variety of PG software in the ‘lower’ LR ranges (∼LR 1–10,000), with focus on DNAStatistX and EuroForMix which use maximum likelihood estimation (MLE). This may be a driving force for the end users to reconsider current LR thresholds for reporting. In previous studies, overstated ‘low’ LRs were observed for these PG software. However, applying (arbitrarily) high LR thresholds for reporting wastes relevant evidential value. This study demonstrates, based on calibration performance, that previously reported LR thresholds can be lowered or even discarded. Considering LRs >1, there was no evidence for miscalibration performance above LR ∼1000 when using Fst 0.01. Below this LR value, miscalibration was observed. Calibration performance generally improved with the use of Fst 0.03, but the extent of this was dependent on the dataset: results ranged from miscalibration up to LR ∼100 to no evidence of miscalibration alike PG software using different methods to model peak height, HMC and STRmix. This study demonstrates that practitioners using MLE-based models should be careful when low LR ranges are reported, though applying arbitrarily high LR thresholds is discouraged. This study also highlights various calibration metrics that are useful in understanding the performance of a PG system.

Cellulose nanocrystals built multiscale hydrogel electrolyte for highly reversible all-flexible zinc ion batteries

Hydrogel electrolytes are promising for flexible and stable zinc ion batteries (ZIBs), but they lack fatigue resistance and still face challenges in terms of mechanical stability and durability. Herein, inspired by the hierarchical structure of biological networks, multiscale anti-fatigue hydrogel electrolytes with high toughness, high strength, and rapid recovery are constructed by introducing nanoscale cellulose nanocrystals (CNCs) as building blocks into dual-network cross-linking hydroxypropyl chitosan (HPCS) modified polyacrylamide (PAM) hydrogel (denoted as PHC-gel). As a result, the PHC-gel achieves a high fatigue threshold up to 356 J m−2 and with a superior strength and stretchability up to 180 kPa and 3178 %, respectively. In addition, the assembled Zn//Zn cell exhibits long-term cycling stability of 1800 h at 1 mA cm−2/1 mAh cm−2 with a high Coulombic efficiency of 99.4 %. More importantly, the Zn//PHC-gel//MnO2 flexible cell shows remarkable flexibility and capacity retention under different stretching and deformation conditions. This work demonstrates a promising gel chemistry that improves anti-fatigue properties and controls zinc behavior, offering great potential for high-performance flexible and wearable ZIBs and beyond.

Bridgman growth and characterizations of nonlinear optical crystal La3Ga5.5Nb0.5O14

La3Ga5.5Nb0.5O14 (LGN) crystal is a promising material for optical parametric chirped-pulse amplification (OPCPA) with high laser damage threshold and wide transmission range which is able to achieve high peak power laser. LGN with a diameter of 25 mm was successfully grown by the vertical Bridgman method for the first time and a series of characterizations were performed. The 1.7 µm absorption peak in transmittance spectra of LGN crystal which was caused by the Czochralski technique can be effectively eliminated by the vertical Bridgman method. LGN crystal possesses a high transmittance of 81.3 % in the range of 0.294 ∼ 7.500 μm. The experimental optical band gap of LGN is 4.16 eV which is positively correlated with laser damage threshold. The experimental laser damage threshold of LGN was determined to 1.416 GW/cm2 by Nd:YAG. The outstanding thermal properties of LGN indicate that it possesses thermal stability in high energy laser field. This work demonstrates that LGN crystal holds great potential for OPCPA applications and the vertical Bridgman method is proved to be a effective and excellent technique to grow high quality LGN crystal.

Linearity and noise evaluation based analysis of extended source heterojunction double gate tunnel FET

This research work evaluates a performance analysis of heterostructure (SiGe/Si) double gate extended source Tunnel FET (Hetero-ES-TFET) to enhance the analog performance, linearity and noise performance. At the source-channel junction, a Hetero-ES-TFET's source is extended into the channel to increase point and line tunneling in the device. The Hetero-ES-TFET exhibits a high ION/IOFF of 3.57 × 1012 and a maximum cut off frequency fT of 54.19 GHz for optimization of device structural parameters. This analysis is conducted using a calibrated SILVACO, technology computer-aided design (TCAD) simulator. The proposed structure includes evaluation of linearity and noise performance characteristics. Furthermore, a linearity analysis as a figure of merit was conducted for the proposed device under study, including different parameters such as 3rd order intermodulation distortion point (IMD3), 3rd order intermodulation intercept point (IIP3), 2nd and 3rd order voltage intercept point (VIP2 and VIP3). The proposed Hetero-ES-TFET has achieved an incredibly high ON current and low threshold voltage. The effect of increasing source width has been examined in this work while sub-threshold swing (SS) remains unchanged during the analysis. There is an improvement in threshold voltage and ION/IOFF value by using silicon-germanium (SiGe) as a source material.

Heavy Metal Accumulation in Fish, Sediment and Water from Three Riverine Ecosystems in the South-western Bangladesh and Nexus to Human Health.

This study investigated heavy metal accumulations in fish, water and sediment from three rivers around a major urban area in Bangladesh, namely the Rupsha, the Atai, and the Bhairab with a view to assessing the ecological and human health risks. Samples were collected from 10 stations over two seasons (summer and winter) and concentrations of 11 metals (As, Se, Pb, Be, Cd, Co, Cr, Cu, Mn, Ni, V) were measured using ICP-MS. Heavy metals in water of these rivers were above the WHO higher thresholds. The Rupsha River, which runs close to industrially dense areas and the downstream part of the three-river network, demonstrated the highest As, Cu, and V concentrations during both seasons. On the other hand, As, Mn and Cr were highest in the Bhairab which is the upstream to the Rupsha and connected to several industrial setups which differ from Bhairab. The less anthropogenically connected Atai River only showed elevated concentrations of Cu and Se. Ecological risk indices indicated low pollution in the rivers during both seasons. In all three rivers and in nearly all fish species, the contamination was higher in winter than summer. Benthic and carnivorous fish species such as, Cynoglossus lingua, Glossogobius giuris, Pseudapocryptes elongatus showed higher metal accumulation compared to other species. Health risk indices like the target hazard quotient (THQ) and carcinogenic risk (CR) suggested low risks but pointed potential risks to human health. The outcomes of this research reports insights into metal contamination pattern in interconnected river systems.