Longitudinal tracking of perfluorooctanoic acid exposure on mammary epithelial cell spheroids by dynamic optical coherence tomography.

We investigated the morphology and intracellular motility of mammary epithelial cell (MCF10DCIS.com) spheroids cultured in 3D artificial extracellular matrix under perfluorooctanoic acid (PFOA) exposure. Dynamic optical coherence tomography (OCT) was employed for real-time, non-invasive imaging of these spheroids longitudinally over 12 days under PFOA exposures up to 500 µM. Despite no significant changes in volume or asphericity of spheroids, morphological alterations were observed in OCT images of spheroids at 100 µM on Day 12 and from Day 4 at 500 µM. Intracellular motility was assessed by the inverse-power-law exponent of the speckle fluctuation spectrum (α), and an autocorrelation-based motility amplitude (M). Linear regression indicated that both PFOA concentration and culture time are highly significant predictors for both α and M (p < 0.001 for all). Both PFOA concentration and culture time have positive associations with α and negative association with M, where increased α indicates suppression of higher frequency fluctuations (∼> 2 Hz) relative to those at lower frequencies, and decreased M indicates overall suppression of intracellular motility. This study can lead to the future development of biomarkers for per- and polyfluoroalkyl substances (PFAS) exposure using dynamic OCT and its associated toolkit of quantitative metrics.

What is the Difference between Conventional Drinking Water, Potable Reuse Water, and Nonpotable Reuse Water? A Microbiome Perspective.

As water reuse applications expand, there is a need for more comprehensive means to assess water quality. Microbiome analysis could provide the ability to supplement fecal indicators and pathogen profiling toward defining a "healthy" drinking water microbiota while also providing insight into the impact of treatment and distribution. Here, we utilized 16S rRNA gene amplicon sequencing to identify signature features in the composition of microbiota across a wide spectrum of water types (potable conventional, potable reuse, and nonpotable reuse). A clear distinction was found in the composition of microbiota as a function of intended water use (e.g., potable vs nonpotable) across a very broad range of U.S. water systems at both the point of compliance (Betadisper p > 0.01; ANOSIM p < 0.01, r-stat = 0.71) and point of use (Betadisper p > 0.01; ANOSIM p < 0.01, r-stat = 0.41). Core and discriminatory analysis further served in identifying distinct differences between potable and nonpotable water microbiomes. Taxa were identified at both the phylum (Desulfobacterota, Patescibacteria, and Myxococcota) and genus (Aeromonas and NS11.12_marine_group) levels that effectively discriminated between potable and nonpotable waters, with the most discriminatory taxa being core/abundant in nonpotable waters (with few exceptions, such as Ralstonia being abundant in potable conventional waters). The approach and findings open the door to the possibility of microbial community signature profiling as a water quality monitoring approach for assessing efficacy of treatments and suitability of water for intended use/reuse application.

Levosimendan and Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials. / Levosimendana e Fibrilação Atrial: Uma Metanálise de Ensaios Clínicos Randomizados.

BACKGROUND: Atrial fibrillation (AF) is a prevalent complication associated with levosimendan; however, it remains uncertain whether there are any disparities in the effects of levosimendan on non-postoperative and postoperative AF. OBJECTIVES: This study aimed to evaluate the levosimendan effect on non-postoperative and postoperative AF by conducting a meta-analysis of randomized control trials (RCTs). METHODS: PubMed, Embase, Cochrane Library, and other databases were searched. Pairs of reviewers identified RCTs that compared levosimendan and placebo or other therapies, and the results reported AF events data. Random effects models were used (at a significance level of 5%). RESULTS: Twenty-nine eligible trials comprising 6550 participants were included, eleven of which evaluated the non-postoperative AF incidence, and 18 included postoperative AF. The analysis revealed that levosimendan elevated the AF risk significantly in the non-postoperative group (OR, 1.62; 95% CI: 1.19-2.20; p=0.002) and reduced the AF incidence in the postoperative group (OR, 0.65; 95% CI: 0.44-0.96; p=0.03). AF occurrence decreased more significantly in patients who used levosimendan after cardiac surgery (OR, 0.53; 95% CI: 0.32-0.88; p=0.02) than in patients who used levosimendan before cardiac surgery (OR, 0.67; 95% CI: 0.42-1.06; p=0.09). Moreover, The AF risk was significantly elevated by levosimendan large bolus dose (bolus dose≥12 µg/kg) (OR, 1.44; 95% CI: 1.10-1.88; p=0.004) and decreased by small bolus dose of levosimendan (bolus dose<12 µg/kg) (OR, 0.64; 95% CI: 0.34-1.20; p=0.16). CONCLUSION: Levosimendan was linked to an increased non-postoperative AF incidence. The employment of levosimendan was effective in preventing postoperative AF.

FUNDAMENTO: A fibrilação atrial (FA) é uma complicação prevalente associada à levosimendana; no entanto, permanece incerto se existem disparidades nos efeitos da levosimendana na FA não pós-operatória e pós-operatória. OBJETIVOS: Este estudo teve como objetivo avaliar o efeito da levosimendana na FA não pós-operatória e pós-operatória conduzindo uma metanálise de ensaios clínicos randomizados (ECR). MÉTODOS: PubMed, Embase, Biblioteca Cochrane e outras bases de dados foram pesquisadas. Pares de revisores identificaram ECRs que compararam levosimendana e placebo ou outras terapias, e os resultados relataram dados de eventos de FA. Foram utilizados modelos de efeitos aleatórios (com nível de significância de 5%). RESULTADOS: Foram incluídos 29 ensaios elegíveis compreendendo 6.550 participantes, onze dos quais avaliaram a incidência de FA não pós-operatória e 18 incluíram FA pós-operatória. A análise revelou que a levosimendana elevou significativamente o risco de FA no grupo não pós-operatório (OR, 1,62; IC 95%: 1,19-2,20; p=0,002) e reduziu a incidência de FA no grupo pós-operatório (OR, 0,65; IC 95%: 0,44-0,96; p=0,03). A ocorrência de FA diminuiu mais significativamente em pacientes que usaram levosimendana após cirurgia cardíaca (OR, 0,53; IC 95%: 0,32-0,88; p=0,02) do que em pacientes que usaram levosimendana antes da cirurgia cardíaca (OR, 0,67; IC 95%: 0,42-1,06; p=0,09). O risco de FA foi significativamente elevado pela grande dose em bolus de levosimendana (dose em bolus ≥12 µg/kg) (OR, 1,44; IC 95%: 1,10-1,88; p=0,004) e diminuído pela pequena dose em bolus de levosimendana (dose em bolus <12 µg/kg) (OR, 0,64; IC 95%: 0,34-1,20; p=0,16). CONCLUSÃO: A levosimendana foi associada a um aumento da incidência de FA não pós-operatória. O emprego da levosimendana foi eficaz na prevenção da FA pós-operatória.

Compressed intracellular motility via non-uniform temporal sampling in dynamic optical coherence tomography.

Significance: Optical coherence tomography has great utility for capturing dynamic processes, but such applications are particularly data-intensive. Samples such as biological tissues exhibit temporal features at varying time scales, which makes data reduction challenging. Aim: We propose a method for capturing short- and long-term correlations of a sample in a compressed way using non-uniform temporal sampling to reduce scan time and memory overhead. Approach: The proposed method separates the relative contributions of white noise, fluctuating features, and stationary features. The method is demonstrated on mammary epithelial cell spheroids in three-dimensional culture for capturing intracellular motility without loss of signal integrity. Results: Results show that the spatial patterns of motility are preserved and that hypothesis tests of spheroids treated with blebbistatin, a motor protein inhibitor, are unchanged with up to eightfold compression. Conclusions: The ability to measure short- and long-term correlations compressively will enable new applications in (3+1)D imaging and high-throughput screening.

Levosimendana e Fibrilação Atrial: Uma Metanálise de Ensaios Clínicos Randomizados / Levosimendan and Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials

Resumo Fundamento A fibrilação atrial (FA) é uma complicação prevalente associada à levosimendana; no entanto, permanece incerto se existem disparidades nos efeitos da levosimendana na FA não pós-operatória e pós-operatória. Objetivos Este estudo teve como objetivo avaliar o efeito da levosimendana na FA não pós-operatória e pós-operatória conduzindo uma metanálise de ensaios clínicos randomizados (ECR). Métodos PubMed, Embase, Biblioteca Cochrane e outras bases de dados foram pesquisadas. Pares de revisores identificaram ECRs que compararam levosimendana e placebo ou outras terapias, e os resultados relataram dados de eventos de FA. Foram utilizados modelos de efeitos aleatórios (com nível de significância de 5%). Resultados Foram incluídos 29 ensaios elegíveis compreendendo 6.550 participantes, onze dos quais avaliaram a incidência de FA não pós-operatória e 18 incluíram FA pós-operatória. A análise revelou que a levosimendana elevou significativamente o risco de FA no grupo não pós-operatório (OR, 1,62; IC 95%: 1,19-2,20; p=0,002) e reduziu a incidência de FA no grupo pós-operatório (OR, 0,65; IC 95%: 0,44-0,96; p=0,03). A ocorrência de FA diminuiu mais significativamente em pacientes que usaram levosimendana após cirurgia cardíaca (OR, 0,53; IC 95%: 0,32-0,88; p=0,02) do que em pacientes que usaram levosimendana antes da cirurgia cardíaca (OR, 0,67; IC 95%: 0,42-1,06; p=0,09). O risco de FA foi significativamente elevado pela grande dose em bolus de levosimendana (dose em bolus ≥12 μg/kg) (OR, 1,44; IC 95%: 1,10-1,88; p=0,004) e diminuído pela pequena dose em bolus de levosimendana (dose em bolus <12 μg/kg) (OR, 0,64; IC 95%: 0,34-1,20; p=0,16). Conclusão A levosimendana foi associada a um aumento da incidência de FA não pós-operatória. O emprego da levosimendana foi eficaz na prevenção da FA pós-operatória.

Abstract Background Atrial fibrillation (AF) is a prevalent complication associated with levosimendan; however, it remains uncertain whether there are any disparities in the effects of levosimendan on non-postoperative and postoperative AF. Objectives This study aimed to evaluate the levosimendan effect on non-postoperative and postoperative AF by conducting a meta-analysis of randomized control trials (RCTs). Methods PubMed, Embase, Cochrane Library, and other databases were searched. Pairs of reviewers identified RCTs that compared levosimendan and placebo or other therapies, and the results reported AF events data. Random effects models were used (at a significance level of 5%). Results Twenty-nine eligible trials comprising 6550 participants were included, eleven of which evaluated the non-postoperative AF incidence, and 18 included postoperative AF. The analysis revealed that levosimendan elevated the AF risk significantly in the non-postoperative group (OR, 1.62; 95% CI: 1.19-2.20; p=0.002) and reduced the AF incidence in the postoperative group (OR, 0.65; 95% CI: 0.44-0.96; p=0.03). AF occurrence decreased more significantly in patients who used levosimendan after cardiac surgery (OR, 0.53; 95% CI: 0.32-0.88; p=0.02) than in patients who used levosimendan before cardiac surgery (OR, 0.67; 95% CI: 0.42-1.06; p=0.09). Moreover, The AF risk was significantly elevated by levosimendan large bolus dose (bolus dose≥12 μg/kg) (OR, 1.44; 95% CI: 1.10-1.88; p=0.004) and decreased by small bolus dose of levosimendan (bolus dose<12 μg/kg) (OR, 0.64; 95% CI: 0.34-1.20; p=0.16). Conclusion Levosimendan was linked to an increased non-postoperative AF incidence. The employment of levosimendan was effective in preventing postoperative AF.

4f/5d Hybridization Induced Single-Electron Delocalization in an Azide-Bridged Dicerium Complex.

Dilanthanide complexes with one-electron delocalization are important targets for understanding the specific 4f/5d-bonding feature in lanthanide chemistry. Here, we report an isolable azide-bridged dicerium complex 3 [{(TrapenTMS)Ce}2(µ-N3)]• [Trapen = tris (2-aminobenzyl)amine; TMS = SiMe3], which is synthesized by the reaction of tripodal ligand-supported (TrapenTMS)CeIVCl complex 2 with NaN3. The structure and bonding nature of 3 are fully characterized by X-ray crystal diffraction analysis, electron paramagnetic resonance (EPR), magnetic measurement, cyclic voltammetry, X-ray absorption spectroscopy, and quantum-theoretical studies. Complex 3 presents a trans-bent central Ce-N3-Ce unit with a single electron of two mixed-valent Ce atoms. The unique low-temperature (2 K) anisotropic EPR signals [g = 1.135, 2.003, and 3.034] of 3 indicate that its spin density is distributed on the central Ce-N3-Ce unit with marked electron delocalization. Quantum chemical analyses show strong 4f/5d orbital mixing in the singly occupied molecular orbital of 3, which allows for the unpaired electron to extend throughout the cerium-azide-cerium unit via a multicentered one-electron (Ce-N3-Ce) interaction. This work extends the family of mixed-valent dilanthanide complexes and provides a paradigm for understanding the bonding motif of ligand-bridged dilanthanide complexes.

Position-Sensing Graph Neural Networks: Proactively Learning Nodes Relative Positions.

Most existing graph neural networks (GNNs) learn node embeddings using the framework of message passing and aggregation. Such GNNs are incapable of learning relative positions between graph nodes within a graph. To empower GNNs with the awareness of node positions, some nodes are set as anchors. Then, using the distances from a node to the anchors, GNNs can infer relative positions between nodes. However, position-aware GNNs (P-GNNs) arbitrarily select anchors, leading to compromising position awareness and feature extraction. To eliminate this compromise, we demonstrate that selecting evenly distributed and asymmetric anchors is essential. On the other hand, we show that choosing anchors that can aggregate embeddings of all the nodes within a graph is NP-complete. Therefore, devising efficient optimal algorithms in a deterministic approach is practically not feasible. To ensure position awareness and bypass NP-completeness, we propose position-sensing GNNs (PSGNNs), learning how to choose anchors in a backpropagatable fashion. Experiments verify the effectiveness of PSGNNs against state-of-the-art GNNs, substantially improving performance on various synthetic and real-world graph datasets while enjoying stable scalability. Specifically, PSGNNs on average boost area under the curve (AUC) more than 14% for pairwise node classification and 18% for link prediction over the existing state-of-the-art position-aware methods. Our source code is publicly available at: https://github.com/ZhenyueQin/PSGNN.

Association between gout and the risk of osteoporosis and fractures: a meta-analysis.

OBJECTIVE: The relationship between gout and osteoporosis is poorly clarified, and the association between gout and fractures incidence remains controversial. Hence, in the present study, we aimed to comprehensively evaluate the available literature to elucidate whether gout is associated with an increased risk of both osteoporosis and fractures. MATERIALS AND METHODS: We conducted an exhaustive search of pertinent literature published until 20 March 2023, in well-recognized databases, namely Medline, Embase and Cochrane Library, focusing on examining the association between gout and the risk of osteoporosis or fracture. Meta-analysis was performed to aggregate the relative risks (RR) using random- or fixed-effects models. Sensitivity analyses were conducted iteratively, whereby each study was removed sequentially to gauge its impact on the overall outcome. Publication bias was assessed using Egger's and Begg's tests. This study was registered with PROSPERO (registry number: CRD42022376822). RESULTS: Herein, we included 10 observational studies comprising a total of 1,606,095 participants. An independent population sample of four studies validated the significant association between gout and osteoporosis (RR = 1.25, 95% confidence interval [CI] 1.05-1.48), with the results demonstrating robustness. However, our analysis did not detect any association between gout and fracture risk when compared with the control group (RR = 1.09, 95%CI 0.99-1.19), along with high heterogeneity (p for heterogeneity = 0.000; I2 = 79.7%). Further subgroup analysis revealed that gout is positively associated with fracture risk in the Chinese population (RR = 1.17, 95%CI 1.14-1.21), with no evidence of heterogeneity (p for heterogeneity = 0.420; I2 = 0.00%). CONCLUSION: Our meticulous evaluation of the available literature indicates that gout has no discernible impact on fracture incidence, although it is positively associated with an enhanced risk of osteoporosis. Therefore, it is imperative to prioritize preventive measures to prevent osteoporotic complications in individuals diagnosed with gout.

Th6-Based Multicomponent Heterometallic Metal-Organic Frameworks Featuring 6,12-Connected Topology for Iodine Adsorption.

Its high coordination number and tendency to cluster make Th4+ suitable for constructing metal-organic frameworks (MOFs) with novel topologies. In this work, two novel thorium-based heterometallic MOF isomers (IHEP-17 and IHEP-18) were assembled from a Th6 cluster, a multifunctional organic ligand [4-(1H-pyrazol-4-yl)benzoic acid (HPyba)], and Cu2+/Ni2+ cations via the one-pot solvothermal synthesis strategy. The framework features a 6,12-connected new topology net and contains two kinds of supramolecular cage structures, Th36M4 and Th24M2, suitable for guest exchange. Both MOF materials can efficiently adsorb I2. X-ray photoelectron spectroscopy, Raman spectroscopy, and single-crystal X-ray diffraction indicate that the adsorbed iodine is uniformly distributed within the Th36M4 cage but not the Th24M2 cage in the form of I3-.

Association of hyperhomocysteinemia and chronic kidney disease in the general population: a systematic review and meta-analysis.

BACKGROUND: Increasing evidence shows that an elevated homocysteine(Hcy) level is associated with an increased risk of chronic kidney disease (CKD). This study systematically evaluated the correlation between homocysteine level and the incidence of CKD reported in cohort and cross-sectional studies. METHODS: We searched electronic databases and reference lists for relevant articles. 4 cohort studies and 7 cross-sectional studies including 79,416 patients were analyzed in a meta-analysis. Hyperhomocysteinemia was defined as a Hcy level > 15 µmol/L, which was the criterium used in previous studies. Meta-analyses were conducted of literature searches from online databases such as PubMed, Embase, Cochrane and Scopus. Computed pooled adjusted odds ratios with corresponding 95% confidence intervals (95% CI) were used to estimate the risk of new-onset CKD according to Hcy levels in the general population. RESULTS: People with high Hcy levels were more likely to suffer from CKD than people with normal Hcy levels (pooled OR, 2.09; 95% CI, 1.72-2.55). This positive relationship persisted across different study types such as cohort studies (summary OR, 2.2; 95% CI, 1.55-3.13) and cross-sectional studies (summary OR, 2.07; 95% CI, 1.63-2.63). CONCLUSIONS: People with hyperhomocysteinemia have a higher incidence of CKD, Hyperhomocysteinemia may also be an independent risk factor for CKD in the general population.

Colossal negative thermal expansion in a cucurbit[8]uril-enabled uranyl-organic polythreading framework via thermally induced relaxation.

It is an ongoing goal to achieve the effective regulation of the thermal expansion properties of materials. In this work, we propose a method for incorporating host-guest complexation into a framework structure and construct a flexible cucurbit[8]uril uranyl-organic polythreading framework, U3(bcbpy)3(CB8). U3(bcbpy)3(CB8) can undergo huge negative thermal expansion (NTE) and has a large volumetric coefficient of -962.9 × 10-6 K-1 within the temperature range of 260 K to 300 K. Crystallographic snapshots of the polythreading framework at various temperatures reveal that, different from the intrinsic transverse vibrations of the subunits of metal-organic frameworks (MOFs) that experience NTE via a well-known hinging model, the remarkable NTE effect observed here is the result of a newly-proposed thermally induced relaxation process. During this process, an extreme spring-like contraction of the flexible CB8-based pseudorotaxane units, with an onset temperature of ∼260 K, follows a period of cumulative expansion. More interestingly, compared with MOFs that commonly have relatively strong coordination bonds, due to the difference in the structural flexibility and adaptivity of the weakly bonded U3(bcbpy)3(CB8) polythreading framework, U3(bcbpy)3(CB8) shows unique time-dependent structural dynamics related to the relaxation process, the first time this has been reported in NTE materials. This work provides a feasible pathway for exploring new NTE mechanisms by using tailored supramolecular host-guest complexes with high structural flexibility and has promise for the design of new kinds of functional metal-organic materials with controllable thermal responsive behaviour.

Unveiling Structural Diversity of Uranyl Compounds of Aprotic 4,4'-Bipyridine N,N'-Dioxide Bearing O-Donors.

As an aprotic O-donor ligand, 4,4'-bipyridine N,N'-dioxide (DPO) shows good potential for the preparation of uranyl coordination compounds. In this work, by regulating reactant compositions and synthesis conditions, diverse coordination assembly between uranyl and DPO under different reaction conditions was achieved in the presence of other coexisting O-donors. A total of ten uranyl-DPO compounds, U-DPO-1 to U-DPO-10, have been synthesized by evaporation or hydro/solvothermal treatment, and the possible competition and cooperation of DPO with other O-donors for the formation of these uranyl-DPO compounds are discussed. Starting with an aqueous solution of uranyl nitrate, it is found that an anionic nitrate or hydroxyl group is involved in the coordination sphere of uranyl in U-DPO-1 ((UO2)(NO3)2(H2O)2·(DPO)), U-DPO-2 ((UO2)(NO3)2(DPO)), and U-DPO-3 ((UO2)(DPO)(µ2-OH)2), where DPO takes three different kinds of coordination modes, i.e. uncoordinated, monodentate, and biconnected. The utilization of UO2(CF3SO3)2 in acetonitrile, instead of an aqueous solution of uranyl nitrate, precludes the participation of nitrate and hydroxyl, and ensures the engagement of DPO ligands (4-5 DPO ligands for each uranyl) in a uranyl coordination sphere of U-DPO-4 ([(UO2)(CF3SO3)(DPO)2](CF3SO3)), U-DPO-5 ([UO2(H2O)(DPO)2](CF3SO3)2) and U-DPO-6 ([(UO2)(DPO)2.5](CF3SO3)2). Moreover, when combined with anionic carboxylate ligands, terephthalic acid (H2TPA), isophthalic acid (H2IPA), and succinic acid (H2SA), DPO works well with them to produce four mixed-ligand uranyl compounds with similar structures of two-dimensional (2D) networks or three-dimensional (3D) frameworks, U-DPO-7 ((UO2)(TPA)(DPO)), U-DPO-8 ((UO2)2(DPO)(IPA)2·0.5H2O), U-DPO-9 ((UO2)(SA)(DPO)·H2O), and U-DPO-10 ((UO2)2(µ2-OH)(SA)1.5(DPO)). Density functional theory (DFT) calculations conducted to probe the bonding features between uranyl ions and different O-donor ligands show that the bonding ability of DPO is better than that of anionic CF3SO3 -, nitrate, and a neutral H2O molecule and comparable to that of an anionic carboxylate group. Characterization of physicochemical properties of U-DPO-7 and U-DPO-10 with high phase purity including infrared (IR) spectroscopy, thermogravimetric analysis (TGA), and luminescence properties is also provided.

Liver injury associated with the severity of COVID-19: A meta-analysis.

Background: The current 2019 novel coronavirus disease (COVID-19) pandemic is a major threat to global health. It is currently uncertain whether and how liver injury affects the severity of COVID-19. Therefore, we conducted a meta-analysis to determine the association between liver injury and the severity of COVID-19. Methods: A systematic search of the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2022, was performed to analyse the reported liver chemistry data for patients diagnosed with COVID-19. The pooled odds ratio (OR), weighted mean difference (WMD) and 95% confidence interval (95% CI) were assessed using a random-effects model. Furthermore, publication bias and sensitivity were analyzed. Results: Forty-six studies with 28,663 patients were included. The pooled WMDs of alanine aminotransferase (WMD = 12.87 U/L, 95% CI: 10.52-15.23, I 2 = 99.2%), aspartate aminotransferase (WMD = 13.98 U/L, 95% CI: 12.13-15.83, I 2 = 98.2%), gamma-glutamyl transpeptidase (WMD = 20.67 U/L, 95% CI: 14.24-27.10, I 2 = 98.8%), total bilirubin (WMD = 2.98 µmol/L, 95% CI: 1.98-3.99, I 2 = 99.4%), and prothrombin time (WMD = 0.84 s, 95% CI: 0.46-1.23, I 2 = 99.4%) were significantly higher and that of albumin was lower (WMD = -4.52 g/L, 95% CI: -6.28 to -2.75, I 2 = 99.9%) in severe cases. Moreover, the pooled OR of mortality was higher in patients with liver injury (OR = 2.72, 95% CI: 1.18-6.27, I 2 = 71.6%). Conclusions: Hepatocellular injury, liver metabolic, and synthetic function abnormality were observed in severe COVID-19. From a clinical perspective, liver injury has potential as a prognostic biomarker for screening severely affected patients at early disease stages. Systematic review registration: https://www.crd.york.ac.uk/prospero/, Identifier: CRD42022325206.

Disentangling Noise from Images: A Flow-Based Image Denoising Neural Network.

The prevalent convolutional neural network (CNN)-based image denoising methods extract features of images to restore the clean ground truth, achieving high denoising accuracy. However, these methods may ignore the underlying distribution of clean images, inducing distortions or artifacts in denoising results. This paper proposes a new perspective to treat image denoising as a distribution learning and disentangling task. Since the noisy image distribution can be viewed as a joint distribution of clean images and noise, the denoised images can be obtained via manipulating the latent representations to the clean counterpart. This paper also provides a distribution-learning-based denoising framework. Following this framework, we present an invertible denoising network, FDN, without any assumptions on either clean or noise distributions, as well as a distribution disentanglement method. FDN learns the distribution of noisy images, which is different from the previous CNN-based discriminative mapping. Experimental results demonstrate FDN's capacity to remove synthetic additive white Gaussian noise (AWGN) on both category-specific and remote sensing images. Furthermore, the performance of FDN surpasses that of previously published methods in real image denoising with fewer parameters and faster speed.

Synthesis of Trapen Ligand-Based U(IV) and Th(IV) 2-Phosphaethynolate Complexes and Comparison of Covalency with Corresponding Ti(IV) Analogues.

The involvement of the 2-phosphaethynolate anion species with ambident nucleophilic properties serves as an essential protocol for synthesizing oxygen-bound or phosphorus-bound complexes. This work mainly describes the synthesis and characterization of U, Th, and Ti phosphaethynolate complexes featuring a preferential O-coordination fashion. Among these complexes, the first examples of a Ti(IV)-OCP complex 3A, Th(IV)-OCP complex 3B, and U(IV)-OCP complex 3C were assembled by a salt metathesis reaction between M(TrapenTMS)(Cl) (M = Ti, Th, U) and NaOCP(dioxane)2.5 and were all crystallographically characterized. The structural similarity of this series of phosphaethynolate complexes allows us to compare the bonding properties of d- and f-block elements in the corresponding compounds. The well-established density functional theory (DFT) computational method was employed to explore the electronic structures and covalency in M-O bonding, and the results showed a consistent pattern. The calculation result showed that 2-phosphaethynolate complexes exhibited the covalency trend of U-O > Th-O > Ti-O due to the involvement of 5f orbitals.

Fusing Higher-Order Features in Graph Neural Networks for Skeleton-Based Action Recognition.

Skeleton sequences are lightweight and compact and thus are ideal candidates for action recognition on edge devices. Recent skeleton-based action recognition methods extract features from 3-D joint coordinates as spatial-temporal cues, using these representations in a graph neural network for feature fusion to boost recognition performance. The use of first-and second-order features, that is, joint and bone representations, has led to high accuracy. Nonetheless, many models are still confused by actions that have similar motion trajectories. To address these issues, we propose fusing higher-order features in the form of angular encoding (AGE) into modern architectures to robustly capture the relationships between joints and body parts. This simple fusion with popular spatial-temporal graph neural networks achieves new state-of-the-art accuracy in two large benchmarks, including NTU60 and NTU120, while employing fewer parameters and reduced run time. Our source code is publicly available at: https://github.com/ZhenyueQin/Angular-Skeleton-Encoding.

Modular Assembly of Isostructural Mixed-Ligand Uranyl Coordination Polymers Based on a Patterning Strategy.

Controlling the orderly assembly of molecular building blocks for the formation of the desired architectural, chemical, and physical properties of the resulting solid-state materials remains a long-term goal and deserves to be examined. In this work, we propose a patterning strategy for modular assembly and structural regulation of mixed-ligand uranyl coordination polymers (CPs) through the combination of couples of organic ligands with complementary molecular geometry and well-matched coordination modes. By using a 5-(p-tolyldiazenyl)isophthalic acid ligand (H2ptdi) with different rigid linear bicarboxylic acid linkers to construct a well-defined ladder-like pattern, five novel isostructural uranyl coordination polymers, [(UO)2(ptdi)(bdc)0.5](dma) (1), [(UO)2(ptdi)(bpdc)0.5](dma) (2), [(UO)2(ptdi)(tpdc)0.5](dma) (3), [(UO)2(ptdi)(ndc)0.5](dma) (4), and [(UO)2(ptdi) (pdc)0.5](dma) (5) {H2bdc, 1,4-dicarboxybenzene; H2bpdc, 4,4'-biphenyldicarboxylic acid; H2tpdc, terphenyl-4,4″-dicarboxylic acid; H2ndc, 2,6-naphthalenedicarboxylic acid; H2pdc, 1,6-pyrenedicarboxylic acid; [dma]+, [(CH3)2NH2]+}, were successfully synthesized. Structural analysis reveals that 1-5 have similar ladder-like units but different sizes of one-dimensional nanochannels and interlayer spacing due to the different lengths and widths of the linkers. Because of the changes in interlayer spacing of these isostructural cationic frameworks, differences in the performance of Eu3+ ion exchange with [dma]+ are observed. Moreover, those compounds with high phase purity have been further characterized by thermogravimetric analysis, infrared spectroscopy, and luminescence spectroscopy, element analysis, PXRD and UV spectroscopy. Among them, compound 3 with strong fluorescence can selectively detect Fe3+ over several competing metal cations in aqueous solution. This work not only provides a feasible patterning method for effectively regulating the modular synthesis of functional coordination polymers but also enriches the library of uranyl-based coordination polymers with intriguing structures and functionality.

Melatonin alleviates the heat stress-induced impairment of Sertoli cells by reprogramming glucose metabolism.

Sertoli cells (SCs) provide structural and nutritional support for developing germ cells. Normal glucose metabolism of SCs is necessary for spermatogenesis. Melatonin could alleviate the effects of heat stress on spermatogenesis. However, the influences of heat stress on glucose metabolism in SCs remain unclear, and the potential protective mechanisms of melatonin on SCs need more exploration. In this study, boar SCs were treated at 43°C for 30 min, and different concentrations of melatonin were added to protect SCs from heat stress-induced impairment. These results showed that heat stress-induced oxidative stress caused cell apoptosis, inhibited the pentose phosphate pathway, and decreased the ATP content. Furthermore, heat stress increased the expressions of glucose intake- and glycolytic-related enzymes, which enhanced the glycolysis activity to compensate for the energy deficit. Melatonin relieved heat stress-induced oxidative stress and apoptosis by activating the Kelch-like ECH-associated protein 1 (KEAP1)/NF-E2-related factor 2 signaling pathway to increase the capacity of antioxidants. In addition, melatonin enhanced heat-shock protein 90 (HSP90) expression through melatonin receptor 1B (MTNR1B), thereby stabilizing hypoxia-inducible factor-1α (HIF-1α). Activation of the HIF-1α signaling pathway enhanced glycolysis, promoted the pentose phosphate pathway, and increased cell viability. Our results suggest that melatonin reprograms glucose metabolism in SCs through the MTNR1B-HSP90-HIF-1α axis and provides a theoretical basis for preventing heat stress injury.

Hydrocortisone for Preventing Adverse Drug Reactions to Snake Antivenom: A Meta-Analysis.

Objective: Pretreatment with hydrocortisone (prehydrocortisone) has been used to protect against adverse drug reactions (ADRs) following antivenom administration after snakebite. However, controversial results have been reported in studies evaluating its efficacy. Herein, we conducted a meta-analysis to evaluate the effect of prehydrocortisone on the risk of ADRs. Methods: We conducted a systematic search of PubMed, Embase, and Cochrane for relevant studies on the literature published up to December 6, 2020, with no language restrictions. Premedications, including hydrocortisone with or without other drugs, were compared with placebo or no premedication. Our primary end point was the risk of ADRs, which was reported as the number of patients who developed ADRs divided by the total number of snakebite patients administered with antivenom separately for the prehydrocortisone and control groups for each study. We evaluated pooled data using of a random-effects model. Results: Among 831 identified studies, 4 were eligible and included in our analysis (N = 1348 participants). Upon combining all eight comparisons from the four selected studies, the overall pooled odds ratio (OR) for ADRs was 0.47 (95% CI 0.19, 1.17; p=0.11; I 2 = 68%). When the analysis was restricted to only articles using hydrocortisone with other drugs, the pooled OR was 0.19 (95% CI 0.05, 0.75; p=0.02; I 2 = 55%). The result was not statistically significant when the analysis was restricted to studies using prehydrocortisone alone, or randomized controlled designs, or cohorts. Our study was limited by heterogeneity, quality, and a paucity of data. Conclusions: The findings in this study revealed that prehydrocortisone alone was ineffective. However, the substantial beneficial effect of prehydrocortisone combinations with premedications (injectable antihistamines or adrenaline) used against ADRs cannot be excluded. Therefore, the use of prehydrocortisone combinations with premedications (injectable antihistamines or adrenaline) as a prophylaxis may reduce the ADRs to antivenom.

Controllable photomechanical bending of metal-organic rotaxane crystals facilitated by regioselective confined-space photodimerization.

Molecular machines based on mechanically-interlocked molecules (MIMs) such as (pseudo) rotaxanes or catenates are known for their molecular-level dynamics, but promoting macro-mechanical response of these molecular machines or related materials is still challenging. Herein, by employing macrocyclic cucurbit[8]uril (CB[8])-based pseudorotaxane with a pair of styrene-derived photoactive guest molecules as linking structs of uranyl node, we describe a metal-organic rotaxane compound, U-CB[8]-MPyVB, that is capable of delivering controllable macroscopic mechanical responses. Under light irradiation, the ladder-shape structural unit of metal-organic rotaxane chain in U-CB[8]-MPyVB undergoes a regioselective solid-state [2 + 2] photodimerization, and facilitates a photo-triggered single-crystal-to-single-crystal (SCSC) transformation, which even induces macroscopic photomechanical bending of individual rod-like bulk crystals. The fabrication of rotaxane-based crystalline materials with both photoresponsive microscopic and macroscopic dynamic behaviors in solid state can be promising photoactuator devices, and will have implications in emerging fields such as optomechanical microdevices and smart microrobotics.