Patients with unruptured intracranial aneurysms routinely undergo surveillance imaging to monitor growth. Angiography is the criterion standard for aneurysm diagnosis, but it is invasive. This study ...aimed to evaluate the accuracy and reproducibility of a 3D noncontrast black-blood MR imaging technique for unruptured intracranial aneurysm measurement in comparison with 3D-TOF and contrast-enhanced MRA, using 3D rotational angiography as a reference standard.
Sixty-four patients (57.3 ± 10.9 years of age, 41 women) with 68 saccular unruptured intracranial aneurysms were recruited. Patients underwent 3T MR imaging with 3D-TOF-MRA, 3D black-blood MR imaging, and contrast-enhanced MRA, and they underwent 3D rotational angiography within 2 weeks. The neck, width, and height of the unruptured intracranial aneurysms were measured by 2 radiologists independently on 3D rotational angiography and 3 MR imaging sequences. The accuracy and reproducibility were evaluated by Bland-Altman plots, the coefficient of variance, and the intraclass correlation coefficient.
3D black-blood MR imaging demonstrates the best agreement with DSA, with the smallest limits of agreement and measurement error (coefficients of variance range, 5.87%-7.04%). 3D-TOF-MRA had the largest limits of agreement and measurement error (coefficients of variance range, 12.73%-15.78%). The average coefficient of variance was 6.26% for 3D black-blood MR imaging, 7.03% for contrast-enhanced MRA, and 15.54% for TOF-MRA. No bias was found among 3 MR imaging sequences compared with 3D rotational angiography. All 3 MR imaging sequences had excellent interreader agreement (intraclass correlation coefficient, >0.95). 3D black-blood MR imaging performed the best for patients with intraluminal thrombus (
= 10).
3D black-blood MR imaging achieves better accuracy for aneurysm size measurements compared with 3D-TOF, using 3D rotational angiography as a criterion standard. This noncontrast technique is promising for surveillance of unruptured intracranial aneurysms.
ABSTRACT
Adaptive optics (AO) restore the angular resolution of ground-based telescopes, but at the cost of delivering a time- and space-varying point spread function (PSF) with a complex shape. PSF ...knowledge is crucial for breaking existing limits on the measured accuracy of photometry and astrometry in science observations. In this paper, we concentrate our analyses of the anisoplanatism signature only on to the PSF. For large-field observations (20 arcmin) with single-conjugated AO, PSFs are strongly elongated due to anisoplanatism that manifests itself as three different terms for laser guide star (LGS) systems: angular, focal and tilt anisoplanatism. First, we propose a generalized model that relies on a point-wise decomposition of the phase and encompasses the non-stationarity of LGS systems. We demonstrate that it is more accurate and less computationally demanding than existing models: it agrees with end-to-end physical-optics simulations to within 0.1 per cent of PSF measurables, such as the Strehl ratio, FWHM and the fraction of variance unexplained (FVU). Secondly, we study off-axis PSF modelling with respect to the $C_n^2(h)$ profile (heights and fractional weights). For 10-mclass telescopes, PSF morphology is estimated at the 1 per cent level as long as we model the atmosphere with at least seven layers, whose heights and weights are known with precisions of 200 m and 10 per cent, respectively. As a verification test, we used the Canada’s National Research Council – Herzberg NFIRAOS Optical Simulator (HeNOS) testbed data, featuring four lasers. We highlight the capability of retrieving off-axis PSF characteristics within 10 per cent of the FVU, which complies with the expected range from the sensitivity analysis. Our new off-axis PSF modelling method lays the groundwork for testing on-sky in the near future.
This paper presents a directed self-assembly (DSA) approach for assembling small electronic components, such as semiconductor dies, into sparse 2D arrays using diamagnetic levitation. The dies ...attached to a diamagnetic layer can be levitated at a room temperature over a stage made of magnets arranged in a checkerboard pattern. By selecting a proper die design, levitation height, and vibration pattern of the magnetic stage we assemble the dies into a regular 2D array with a specific lateral and vertical orientation of the dies. The assembled dies are transferred to a receiving substrate using capillary force.
•Self-assembly of semiconductor dies into arrays using diamagnetic levitation.•Control over the die orientation in vertical and lateral dimensions.•Simulation shows good scalability of assembly time with the number of dies.•Suitable for assembly of LED panels, displays and microcell photovoltaics.
Continents are underlain by thick, cold thermal boundary layers. Thermal contraction should render these boundary layers negatively buoyant and unstable; this is why old, cold oceanic lithospheres ...subduct. However, the ancient lithospheric roots of many continents appear to have existed for billions of years. In the common view, this preservation is due to the fact that the thermal boundary layers are compositionally distinct from the ambient mantle in that they are highly melt-depleted and dehydrated; the former provides positive buoyancy and the latter provides strength. Here, we show using mantle xenoliths that the Precambrian South China Block originally was underlain by highly depleted mantle, but has been refertilized via silicate melts generated from the asthenosphere. It is now more fertile than the ambient convecting mantle and is intrinsically denser by more than 1.5%. Achieving sufficient melt generation for refertilization is only possible if the lithosphere is thin enough to provide “headspace” for decompression melting. Thus, continental boundary layers thinner than the maximum depth of melting should experience refertilization, whereas thicker continents would altogether suppress melting and hence the potential for refertilization. We propose that refertilization, once initiated, will destabilize the base of the continent; this in turn will increase the amount of “headspace” and promote further refertilization, resulting in a positive feedback that could culminate in lithospheric destruction. By contrast, continents that are thick enough may not experience significant refertilization. This suggests that initial lithospheric thickness, as well as lithospheric composition, may be important for defining the fate of continents.
•Refertilization drives destabilization of continental mantle.•Lithospheric initial thickness is important to the fate of continents.•South China mantle xenoliths have a slightly high density.
We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. ...Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.
Aim: To investigate the efficacy and tolerability of vildagliptin as add‐on therapy to metformin in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin.
...Methods: This was a 24‐week, randomized, double‐blind, placebo‐controlled study. Patients with T2DM (N = 438) with haemoglobin A1c (HbA1c) of 7.0–10.0% and fasting plasma glucose (FPG) <15 mmol/l (<270 mg/dl) were randomized (1 : 1 : 1) to vildagliptin 50 mg bid, vildagliptin 50 mg qd or placebo in addition to metformin.
Results: The treatment groups were well balanced at baseline mean HbA1c, 8.0%, FPG, 8.8 mmol/l (158 mg/dl); body mass index, 25.5 kg/m2. The adjusted mean change (AMΔ) in HbA1c at endpoint was −1.05 ± 0.08%, −0.92 ± 0.08% and −0.54 ± 0.08% in patients receiving vildagliptin 50 mg bid, 50 mg qd and placebo, respectively. The between‐treatment difference (vildagliptin 50 mg bid–placebo) was −0.51 ± 0.11%, p < 0.001. A greater proportion of vildagliptin‐treated patients met at least one responder criterion (82.1 and 70.7%) compared to placebo‐treated patients (60.4%). The AMΔ at endpoint for FPG with vildagliptin 50 mg bid, −0.95 mmol/l (−17.1 mg/dl); 50 mg qd, −0.84 mmol/l (−15.1 mg/dl) was significantly different compared with the placebo −0.26 mmol/l (−4.68 mg/dl) (p ≤ 0.001). Adverse events (AEs) were reported as 34.2, 36.5 and 37.5% for patients receiving vildagliptin 50 mg bid, 50 mg qd or placebo, respectively. Two patients in the vildagliptin 50 mg qd and one in the placebo group reported serious AEs, which were not considered to be related to the study drug; one incidence of hypoglycaemic event was reported in the vildagliptin 50 mg bid group.
Conclusion: Vildagliptin as add‐on therapy to metformin improved glycaemic control and was well tolerated in Chinese patients who were inadequately controlled by metformin only.
Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry ...has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems.
To screen the risk factors for death in patients with nasopharyngeal carcinoma (NPC) using artificial intelligence (AI) technology and establish a risk prediction model.
The clinical data of NPC ...patients obtained from SEER database (1973-2015). The patients were randomly divided into model building and verification group at a 7∶3 ratio. Based on the data in the model building group, R software was used to identify the risk factors for death in NPC patients using 4 AI algorithms, namely eXtreme Gradient Boosting (XGBoost), Decision Tree (DT), Least absolute shrinkage and selection operator (LASSO) and random forest (RF), and a risk prediction model was constructed based on the risk factor identified. The C-Index, decision curve analysis (DCA), receiver operating characteristic (ROC) curve and calibration curve (CC) were used for internal validation of the model; the data in the validation group and clinical data of 96 NPC patients (collected from First Affiliated Hospital of Bengbu Medical College) were used f
Understanding cellular coordination remains a challenge despite knowledge of individual pathways. The RNA exosome, targeting a wide range of RNA substrates, is often downregulated in cellular ...senescence. Utilizing an auxin-inducible system, we observed that RNA exosome depletion in embryonic stem cells significantly affects the transcriptome and proteome, causing pluripotency loss and pre-senescence onset. Mechanistically, exosome depletion triggers acute nuclear RNA aggregation, disrupting nuclear RNA-protein equilibrium. This disturbance limits nuclear protein availability and hinders polymerase initiation and engagement, reducing gene transcription. Concurrently, it promptly disrupts nucleolar transcription, ribosomal processes, and nuclear exporting, resulting in a translational shutdown. Prolonged exosome depletion induces nuclear structural changes resembling senescent cells, including aberrant chromatin compaction, chromocenter disassembly, and intensified heterochromatic foci. These effects suggest that the dynamic turnover of nuclear RNA orchestrates crosstalk between essential processes to optimize cellular function. Disruptions in nuclear RNA homeostasis result in systemic functional decline, altering the cell state and promoting senescence.
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•The RNA exosome governs nuclear ribosomal, messenger, and noncoding RNA homeostasis•Dynamic RNA turnover orchestrates nuclear organization and processes•RNA exosome depletion induces nuclear RNA aggregation, impeding transcription•Prolonged depletion disrupts chromatin state and translation, eliciting pre-senescence
Han et al. report that the RNA exosome complex regulates nuclear RNA homeostasis, synchronizing rRNA and mRNA transcription with translation and facilitating chromatin organization. This RNA-mediated systematic coordination is vital for cellular identity and fitness, with a critical impact on preventing senescence.
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