Cryo-EM Structure of the Human Cannabinoid Receptor CB2-Gi Signaling Complex.

Drugs selectively targeting CB2 hold promise for treating neurodegenerative disorders, inflammation, and pain while avoiding psychotropic side effects mediated by CB1. The mechanisms underlying CB2 activation and signaling are poorly understood but critical for drug design. Here we report the cryo-EM structure of the human CB2-Gi signaling complex bound to the agonist WIN 55,212-2. The 3D structure reveals the binding mode of WIN 55,212-2 and structural determinants for distinguishing CB2 agonists from antagonists, which are supported by a pair of rationally designed agonist and antagonist. Further structural analyses with computational docking results uncover the differences between CB2 and CB1 in receptor activation, ligand recognition, and Gi coupling. These findings are expected to facilitate rational structure-based discovery of drugs targeting the cannabinoid system.

Detecting heart failure from B-mode ultrasound characterization of arterial pulse waves.

This study investigated the sensitivity and specificity of identifying heart failure with reduced ejection fraction (HFrEF) from measurements of the intensity and timing of arterial pulse waves. Previously validated methods combining ultrafast B-mode ultrasound, plane-wave transmission, singular value decomposition (SVD), and speckle tracking were used to characterize the compression and decompression ("S" and "D") waves occurring in early and late systole, respectively, in the carotid arteries of outpatients with left ventricular ejection fraction (LVEF) < 40%, determined by echocardiography, and signs and symptoms of heart failure, or with LVEF ≥ 50% and no signs or symptoms of heart failure. On average, the HFrEF group had significantly reduced S-wave intensity and energy, a greater interval between the R wave of the ECG and the S wave, a reduced interval between the S and D waves, and an increase in the S-wave shift (SWS), a novel metric that characterizes the shift in timing of the S wave away from the R wave of the ECG and toward the D wave (all P < 0.01). Receiver operating characteristics (ROCs) were used to quantify for the first time how well wave metrics classified individual participants. S-wave intensity and energy gave areas under the ROC of 0.76-0.83, the ECG-S-wave interval gave 0.85-0.88, and the S-wave shift gave 0.88-0.92. Hence the methods, which are simple to use and do not require complex interpretation, provide sensitive and specific identification of HFrEF. If similar results were obtained in primary care, they could form the basis of techniques for heart failure screening.NEW & NOTEWORTHY We show that heart failure with reduced ejection fraction can be detected with excellent sensitivity and specificity in individual patients by using B-mode ultrasound to detect altered pulse wave intensity and timing in the carotid artery.

Improving Molecular Dynamics Simulations for Solid-Liquid Interface with Machine Learning Interatomic Potentials.

Emerging developments in artificial intelligence have opened infinite possibilities for material simulation. Depending on the powerful fitting of machine learning algorithms to first-principles data, machine learning interatomic potentials (MLIPs) can effectively balance the accuracy and efficiency problems in molecular dynamics (MD) simulations, serving as powerful tools in various complex physicochemical systems. Consequently, this brings unprecedented enthusiasm for researchers to apply such novel technology in multiple fields to revisit the major scientific problems that have remained controversial owing to the limitations of previous computational methods. Herein, we introduce the evolution of MLIPs, provide valuable application examples for solid-liquid interfaces, and present current challenges. Driven by solving multitudinous difficulties in terms of the accuracy, efficiency, and versatility of MLIPs, this booming technique, combined with molecular simulation methods, will provide an underlying and valuable understanding of interdisciplinary scientific challenges, including materials, physics, and chemistry.

Relationship between circadian eating behavior (daily eating frequency and nighttime fasting duration) and cardiovascular mortality.

BACKGROUND: Knowledge regarding the health impacts of daily eating frequency (DEF) and nighttime fasting duration (NFD) on mortality is very limited. OBJECTIVE: This study aimed to examine whether DEF and NFD are associated with CVD and all-cause mortality. METHODS: This was a prospective cohort study of a nationally representative sample from the United States, including 30,464 adults who participated in the National Health and Nutrition Examination Survey 2003-2014. Using 24-h dietary recall, DEF was assessed by the number of eating episodes, and NFD was calculated by the first and last eating time across a day. Death information was obtained from the National Death Index up to 2019. Weighted Cox proportional hazards regression models were used to assess survival relationships of DEF and NFD with mortality. RESULTS: During 307,686 person-years of follow-up, 4560 deaths occurred, including 1824 CVD cases. After adjustment for confounders, compared to DEF at 4-6 times, participants whose DEF was less than 3 times had greater CVD [hazard-ratio (HR) = 1.33, 95% confidence-interval (CI): 1.06-1.67] and all-cause (HR = 1.16, 95% CI: 1.01-1.33) mortality risks. Furthermore, compared to NFD of 10 to 11 h, participants whose NFD was shorter than 10 h had HRs of 1.30 (95% CI: 1.08-1.55) for CVD mortality and 1.23 (95% CI: 1.08-1.39) for all-cause mortality. NFD longer than 14 h was also related to CVD mortality (HR = 1.37, 95% CI: 1.12-1.67) and all-cause mortality (HR = 1.36, 95% CI: 1.19-1.54). Similar results for the association of NFD and DEF with heart-specific and stroke-specific mortality were observed. CONCLUSION: This study found that DEF less than 3 times and NFD shorter than 10 h or longer than 14 h were independently associated with greater cardiovascular and all-cause mortality.

Spontaneous development of an autoimmune hepatitis - primary biliary cholangitis overlap syndrome in dnTGFßRII Aire-/- mice.

Autoimmune regulator (Aire) and TGF-ß signaling play important roles in central tolerance and peripheral tolerance, respectively, by eliminating or suppressing the activity of autoreactive T cells. We previously demonstrated that dnTGFßRII mice develop a defect in peripheral tolerance and a primary biliary cholangitis (PBC)-like disease. We hypothesized that by introducing the Aire gene to this model, we would observe a more severe PBC phenotype. Interestingly, however, we demonstrated that, while dnTGFßRII Aire-/- mice do manifest key histological and serological features of autoimmune cholangitis, they also develop mild to moderate interface hepatitis and show high levels of alanine transaminase (ALT) and antinuclear antibodies (ANA), characteristics of autoimmune hepatitis (AIH). To further understand this unique phenotype, we performed RNA sequencing (RNA-seq) and flow cytometry to explore the functional pathways and immune cell pathways in the liver of dnTGFßRII Aire-/- mice. Our data revealed enrichments of programmed cell death pathways and predominant CD8+ T cell infiltrates. Depleting CD8+ T cells using an anti-CD8α antibody significantly alleviated hepatic inflammation and prolonged the life span of these mice. Finally, RNA-seq data indicated the clonal expansion of hepatic CD8+ T cells. In conclusion, these mice developed an autoreactive CD8+ T-cell-mediated autoimmune cholangitis with concurrent hepatitis that exhibited key histological and serological features of the AIH-PBC overlap syndrome, representing a novel model for the study of tolerance and autoimmune liver disease. © 2023 The Pathological Society of Great Britain and Ireland.

Publisher Correction: Cryo-EM structure of human rhodopsin bound to an inhibitory G protein.

In the PDF version of this Article, owing to a typesetting error, an incorrect figure was used for Extended Data Fig. 5; the correct figure was used in the HTML version. This has been corrected online.

Cryo-EM structure of human rhodopsin bound to an inhibitory G protein.

G-protein-coupled receptors comprise the largest family of mammalian transmembrane receptors. They mediate numerous cellular pathways by coupling with downstream signalling transducers, including the hetrotrimeric G proteins Gs (stimulatory) and Gi (inhibitory) and several arrestin proteins. The structural mechanisms that define how G-protein-coupled receptors selectively couple to a specific type of G protein or arrestin remain unknown. Here, using cryo-electron microscopy, we show that the major interactions between activated rhodopsin and Gi are mediated by the C-terminal helix of the Gi α-subunit, which is wedged into the cytoplasmic cavity of the transmembrane helix bundle and directly contacts the amino terminus of helix 8 of rhodopsin. Structural comparisons of inactive, Gi-bound and arrestin-bound forms of rhodopsin with inactive and Gs-bound forms of the ß2-adrenergic receptor provide a foundation to understand the unique structural signatures that are associated with the recognition of Gs, Gi and arrestin by activated G-protein-coupled receptors.

[Clinical experience of Tianxiong Granules in treatment of hypertension based on treatment principle of supressing Yang and promoting blood circulation].

Hypertension is the most common chronic disease in clinics and has become the most common risk factor for cardiovascular diseases. Because of its high incidence rate, disability rate, and mortality, it has attracted worldwide attention. Despite continuous progress in modern medicine in the treatment of hypertension with new antihypertensive drugs such as Zilebesiran, a nucleic acid drug that acts on microRNA, direct renin inhibitors, and renal sympathetic blockade, the control rate is still not ideal. How to effectively prevent and control hypertension has become one of the urgent clinical challenges to be solved. Traditional Chinese medicine(TCM) has a long record of treating hypertension and has accumulated rich experience, including theoretical understanding, effective single medicine, compound medicine, traditional Chinese patent medicines, and classic famous prescriptions. In TCM, hypertension belongs to the categories of diseases such as dizziness and headache. Previous literature and clinical studies have found that hypertension has key pathogenesis such as fire syndrome, fluid syndrome, deficiency syndrome, and blood stasis syndrome. Among them, the hyperactivity of liver Yang is closely related to blood pressure fluctuations, blood pressure variability, inflammation, and sympathetic activity stimulation. Internal obstruction by blood stasis is closely related to the damage of target organs such as the heart, brain, and kidneys in hypertension. Therefore, the two key pathogenesis of liver yang hyperactivity and internal obstruction by blood stasis run through the entire process of hypertension. Previous studies have found that the effective empirical formula Tianxiong Granules, based on the principles of suppressing Yang and promoting blood circulation, originated from the classic formula Xiongqiong Tianma Pills in Yu Yao Yuan Fang. It is composed of Gastrodiae Rhizoma, Chuanxiong Rhizoma, Puerariae Lobatae Radix, Achyranthis Bidentatae Radix, and Cyathulae Radix and has significant therapeutic effects in the treatment of hypertension. The clinical indications include headache, dizziness, bloating, strong neck, and weak waist and legs. At the same time, it may be accompanied by poor speech, thirst, normal or loose stools, soreness in the waist and legs, lower limb pain, muscle and pulse spasm, menstrual and abdominal pain, dark red tongue, strong pulse strings, or straight and long pulse strings that pass through the mouth of an inch. In the combination rule, it can be used according to the different pathogenesis stages of hypertension patients. In the fire syndrome stage, it is often combined with Tianma Gouteng Decoction and Chaihu Jia Longgu Muli Decoction. In the fluid syndrome stage, it is often combined with Banxia Baizhu Tianma Decoction. In the deficiency syndrome stage, it is often combined with Liuwei Dihuang Pills and Shenqi Pills. In terms of dosage, it is important to focus on the main symptoms and adjust the dosage of key drugs based on blood pressure values. Some drugs can be used in sufficient quantities. By analyzing the compatibility of Tianxiong Granules, clinical application indications, combined formula experience, and dosage application experience, we provide effective treatment methods and more options for TCM to treat hypertension with Yang hyperactivity and blood stasis syndrome.

Capillary-Scale Hydrogel Microchannel Networks by Wire Templating.

Microvascular networks are essential for the efficient transport of nutrients, waste products, and drugs throughout the body. Wire-templating is an accessible method for generating laboratory models of these blood vessel networks, but it has difficulty fabricating microchannels with diameters of ten microns and narrower, a requirement for modeling human capillaries. This study describes a suite of surface modification techniques to  selectively control the interactions amongst wires, hydrogels, and world-to-chip interfaces. This wire templating method enables the fabrication of perfusable hydrogel-based rounded cross-section capillary-scale networks whose diameters controllably narrow at bifurcations down to 6.1 ± 0.3 microns in diameter. Due to its low cost, accessibility, and compatibility with a wide range of common hydrogels of tunable stiffnesses such as collagen, this technique may increase the fidelity of experimental models of capillary networks for the study of human health and disease.

Amide Proton Transfer-Weighted Imaging Combined With Intravoxel Incoherent Motion for Evaluating Microsatellite Instability in Endometrial Cancer.

BACKGROUND: Microsatellite instability (MSI), caused by mismatch repair (MMR) protein defects that lead to uncorrectable mismatch bases, results in the accumulation of gene mutations and ultimately to tumors. Preoperative prediction of MSI can provide a basis for personalized and precise treatment of endometrial cancer (EC) patients. PURPOSE: To investigate amide proton transfer weighting (APTw) imaging combined with intravoxel incoherent motion (IVIM) in the assessment of MSI in EC. STUDY TYPE: Retrospective. POPULATION: A total of 71 patients with EC (12 classified as the MSI group and 22 as the microsatellite stabilization [MSS] group after entering and leaving the group standard). FIELD STRENGTH/SEQUENCE: A 3.0 T/IVIM, diffusion-weighted imaging (DWI) and APTw. ASSESSMENT: Amide proton transfer (APT) value, apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo diffusion coefficient (D*), and perfusion fraction (f) were calculated and compared between MSI and MSS groups. STATISTICAL TESTS: The Kendall's W test; Mann-Whitney U-test; Chi-square test or Fisher's exact test; logistic regression analysis; Area under the receiver operating characteristic (ROC) curve (AUC); The Delong test; Pearson or Spearman correlation coefficients. The significance threshold was set at P < 0.05. RESULTS: APT and D* values of the MSI group were significantly higher than those of the MSS group. While ADC, D, and f values in the MSI group were significantly lower than those in the MSS group. The multivariate analysis revealed that only APT and D* values were independent predictors to evaluate the MSI status. And the ROC curves indicated that the combination of APT and D* values could distinguish the MSI status of EC with the highest diagnostic efficacy (AUC = 0.973), even without significant difference to those by APT (AUC = 0.894) or D* (AUC = 0.920) value separately (P = 0.149 and 0.078, respectively). CONCLUSION: Combination of APTw and IVIM imaging may serve as an effective noninvasive method for clinical assessment of MSI in EC. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Predictive Impact of Prognostic Nutritional Index in Patients with Cancer Treated with Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis.

A few previous studies have investigated the prognostic value of the prognostic nutritional index (PNI) in patients treated with immune checkpoint inhibitors (ICIs); however, the results are inconsistent. Therefore, this study aimed to clarify the prognostic significance of PNI. The PubMed, Embase, and Cochrane Library databases were searched. A meta-analysis of the impact of PNI on overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and rate of adverse events (AEs) in patients treated with ICIs was performed. Twenty-three studies involving 2,386 patients were included. Low PNI was associated with significantly poor OS (hazard ratio [HR] = 2.26, 95% confidence interval [CI]: 1.81-2.82, P < .001) and short PFS (HR = 1.75, 95% CI: 1.54-1.99, P < .001). Patients with low PNI tended to have a low ORR (odds ratio [OR] = 0.47, 95% CI: 0.34-0.65, P < .001) and DCR (OR = 0.43, 95% CI: 0.34-0.56, P < .001). However, the subgroup analysis demonstrated no significant association between PNI and survival time in patients receiving a programmed death ligand-1 inhibitor. PNI was significantly associated with survival time and treatment efficacy in patients treated with ICIs.

Construction of Zr-Metal-Organic Frameworks-Based Composite Materials toward Anhydrous Proton Conduction and Photocatalytic CO2 Reduction.

Metal-organic frameworks constructed from Zr usually possess excellent chemical and physical stability. Therefore, they have become attractive platforms in various fields. In this work, two families of hybrid materials based on ZrSQU have been designed and synthesized, named Im@ZrSQU and Cu@ZrSQU, respectively. Im@ZrSQU was prepared through the impregnation method and employed for proton conduction. Im@ZrSQU exhibited terrific proton conduction performance in an anhydrous environment, with the highest proton conduction value of 3.6 × 10-2 S cm-1 at 110 °C. In addition, Cu@ZrSQU was synthesized via the photoinduction method for the photoreduction of CO2, which successfully promoted the conversion of CO2 into CO and achieved the CO generation rate of up to 12.4 µmol g-1 h-1. The photocatalytic performance of Cu@ZrSQU is derived from the synergistic effect of Cu NPs and ZrSQU. Based on an in-depth study and discussion toward ZrSQU, we provide a versatile platform with applications in the field of proton conduction and photocatalysis, which will guide researchers in their further studies.

A general strategy to stabilize 1T-MoS2 using MXene heterostructures and unlock its hydrogen evolution reaction capabilities.

The two-dimensional (2D) metallic phase of MoS2, 1T-MoS2, has extraordinary electrical conductivity in contrast to the common 2D semiconducting phase, 2H-MoS2. However, the thermodynamic instabilities of 1T-MoS2 hinder its application. In this work, we investigate the possibilities of stabilizing 1T-MoS2 through heterostructure design using first-principles calculations. We found that MXene-based heterostructures could hamper phase transitions from 1T-MoS2 to 2H-MoS2 enabled by a larger phase transition kinetic energy barrier. Based on this finding, we propose a general and effective strategy for stabilizing 1T-MoS2, that is, building heterostructures using 1T-MoS2 and oxygen-functionalized MXenes. Besides, we have also observed that due to the occurrence of electron transfer in the heterostructure, 1T-MoS2 in the heterostructure exhibits improved hydrogen adsorption free energy and more active sites compared to the monolayer 1T-MoS2. These findings provide guidance for promoting and developing 1T-MoS2 for practical applications. In addition, the proposed heterostructure design strategy could inspire the study of phase transition behaviors and electrochemical properties of materials using interfaces.

Hepatic adenoma in a 7-year-old girl: a case report and literature review.

BACKGROUND: Hepatocellular adenomas (HCAs) are rare benign tumors of the liver that occur predominantly in women taking oral contraceptives. In children, HCAs comprise < 5% of hepatic tumors. We report a case of HCAs in a 7-year-old girl with estrogen and glucose imbalance. CASE PRESENTATION: A 7-year-old girl was presented to our hospital with bilateral breast enlargement for 2 months, polydipsia, polyuria, polyphagia, hyperglycemia, and significant weight gain. Computed tomography (CT) showed a 7.2 cm×6.9 cm×5.3 cm round-shaped mass in the left inner lobe of the liver, ovarian ultrasound showed multiple follicles in the ovaries bilaterally, and cranial magnetic resonance imaging (MRI) showed an enlarged superior pituitary. Hematological and biochemical results were as follows: fasting glucose was 19.7 mmol/L, estradiol was 122.9 pmol/L, follicle-stimulating hormone 10.81 IU/L, luteinizing hormone 10.99 IU/L, insulin-like growth factor 1,513 ng/mL, glutamine aminotransferase 86 U/L, and alkaline phosphatase 362 U/L. Thyroid functions, methemoglobin, fetal protein, carcinoembryonic antigen, and chorionic gonadotropin were normal. The patient had a complete surgical resection of the liver tumor, and the postoperative histopathological diagnosis was HCAs. After the surgery, insulin was injected and the glucose levels were stable. During the 36-month follow-up period, neither tumor recurrence nor significant abnormalities were detected using color Doppler ultrasound of the liver. The child's precocious puberty is currently under control. CONCLUSIONS: HCAs are particularly rare in children with liver tumors, and risk factors for the development of HCAs in children include sex hormone imbalance, obesity, Fanconi anemia (FA), glycogen storage diseases (GSDs) type I, III, and IV, galactosemia, immunodeficiency, congenital portosystemic shunts (CPSS), cardiac hepatopathy status-post Fontan procedure, Hurler syndrome, familial adenomatous polyposis, germline HNF1A mutations, and maturity-onset diabetes of the young type 3. Most HCAs are detected during a physical examination without clinical symptoms, and some patients may present with symptoms such as abdominal pain, abdominal distension, and abdominal masse. Serum liver function tests can show increased alkaline phosphatase (ALP) and γ- glutamyl transferase (GT), whereas α-Fetoprofein (AFP) levels are normal. The definitive diagnosis relies mainly on histopathological examination. Because HCAs can rupture and bleed and become malignant. Early surgical treatment is recommended after detection.

Association between ambient air pollutants and lipid profile: A systematic review and meta-analysis.

BACKGROUND: Studies of the effects of atmospheric pollutants on lipid profiles remain inconsistent and controversial. AIM: The study was aimed to investigate the relationship between the exposure to ambient air pollutants and variations in the blood lipid profiles in the population. METHODS: A comprehensive search of three different databases (PubMed, Web of Science, and the Cochrane Library) until December 17, 2022, yielded 17 origional studies fulfilling the inclusion criteria for a meta-analysis. Aggregate effect measures and 95% confidence intervals (95% CI) for the relevant ambient air pollutants were deduced employing random effects models. RESULTS: The collective meta-analysis indicated that long-term exposure to PM1, PM2.5, PM10 and CO showed a substantial correlation with TC (PM1: ß = 2.04, 95%CI = 0.15-3.94; PM2.5: ß = 1.11, 95%CI = 0.39-1.84; PM10: ß = 1.70, 95%CI = 0.67-2.73; CO: ß = 0.08, 95%CI = 0.06-0.10), PM10 exhibited a significant association with TG (ß = 0. 537,95% CI = 0.09-0.97), whereas HDL-C demonstrated notable relationships with PM1, PM10, SO2 and CO (PM1: ß = -2.38, 95%CI = -4.00 to -2.76; PM10: ß = -0.77, 95%CI = -1.33 to -0.21; SO2: ß = -0.91, 95%CI = -1.73 to -0.10; CO: ß = -0.03, 95%CI = -0.05 to 0.00). PM2.5, PM10 also showed significant associations with LDL-C (PM2.5: ß = 1.44 95%CI = 0.48-2.40; PM10: ß = 1.62 95%CI = 0.90-2.34). Subgroup analysis revealed significant or stronger correlations predominantly in cohort study designs, with higher male comparisons, and in regions exhibiting elevated contaminant levels. CONCLUSION: In summary, the analysis substantiates that ambient air pollutants can be recognized as potent contributors to alterations in lipid profiles, particularly particulate pollutants which exert more obvious effects on lipid profiles.

Unraveling the Oxidation Behaviors of MXenes in Aqueous Systems by Active-Learning-Potential Molecular-Dynamics Simulation.

MXenes are 2D materials with great potential in various applications. However, the degradation of MXenes in humid environments has become a main obstacle in their practical use. Here we combine deep neural networks and an active learning scheme to develop a neural network potential (NNP) for aqueous MXene systems with ab initio precision but low cost. The oxidation behaviors of super large aqueous MXene systems are investigated systematically at nanosecond timescales for the first time. The oxidation process of MXenes is clearly displayed at the atomic level. Free protons and oxides greatly inhibit subsequent oxidation reactions, leading to the degree of oxidation of MXenes to exponentially decay with time, which is consistent with the oxidation rate of MXenes measured experimentally. Importantly, this computational study represents the first exploration of the kinetic process of oxidation of super-sized aqueous MXene systems. It opens a promising avenue for the future development of effective protection strategies aimed at controlling the stability of MXenes.

Ag Nanoparticle-Modified Polyoxometalate-Based Metal-Organic Framework for Enhanced CO2 Photoreduction.

The photoreduction deposition method is employed to fabricate a family of silver nanoparticle (Ag NP)-modified polyoxometalate-based metal-organic framework (NENU-5) photocatalysts, named Ag/NENU-5. The title photocatalysts, Ag/NENU-5, can be used for the photocatalytic reduction of CO2 and are observed to efficiently reduce CO2 into CO, in which the highest reduction rate is 22.28 µmol g-1 h-1, 3 times greater than that of NENU-5. Photocatalytic reduction performances of CO2 have been extremely improved after the incorporation of Ag NPs as the cocatalyst. The enhancement of the photocatalytic reduction of CO2 has been attributed to the synergistic effects of Ag NPs and NENU-5, inhibiting the charge recombination during the photocatalytic process and increasing the reaction active sites. Furthermore, the influence of Ag NPs on the photocatalytic activity has also been investigated. The experimental results clearly reveal that the size of Ag NPs could exert a main effect on the photocatalytic activity, and the reasonable size of Ag NPs is able to enhance the photocatalytic reduction activity toward CO2 significantly.

Super-Resolution Ultrasound Localization Microscopy of Microvascular Structure and Flow for Distinguishing Metastatic Lymph Nodes - An Initial Human Study.

PURPOSE: Detecting and distinguishing metastatic lymph nodes (LNs) from those with benign lymphadenopathy are crucial for cancer diagnosis and prognosis but remain a clinical challenge. A recent advance in super-resolution ultrasound (SRUS) through localizing individual microbubbles has broken the diffraction limit and tracking enabled in vivo noninvasive imaging of vascular morphology and flow dynamics at a microscopic level. In this study we hypothesize that SRUS enables quantitative markers to distinguish metastatic LNs from benign ones in patients with lymphadenopathy. MATERIALS AND METHODS: Clinical contrast-enhanced ultrasound image sequences of LNs from 6 patients with lymph node metastasis and 4 with benign lymphadenopathy were acquired and motion-corrected. These were then used to generate super-resolution microvascular images and super-resolved velocity maps. From these SRUS images, morphological and functional measures were obtained including micro-vessel density, fractal dimension, mean flow speed, and Local Flow Direction Irregularity (LFDI) measuring the variance in local flow direction. These measures were compared between pathologically proven reactive and metastasis LNs. RESULTS: Our initial results indicate that the difference in the indicator of flow irregularity (LFDI) derived from the SRUS images is statistically significant between the two groups. The LFDI is 60% higher in metastatic LNs compared with reactive nodes. CONCLUSION: This pilot study demonstrates the feasibility of super-resolution ultrasound for clinical imaging of lymph nodes and the potential of using the irregularity of local blood flow directions afforded by SRUS for the characterization of LNs.

Discovery of Dipyridamole Analogues with Enhanced Metabolic Stability for the Treatment of Idiopathic Pulmonary Fibrosis.

Dipyridamole, apart from its well-known antiplatelet and phosphodiesterase inhibitory activities, is a promising old drug for the treatment of pulmonary fibrosis. However, dipyridamole shows poor pharmacokinetic properties with a half-life (T1/2) of 7 min in rat liver microsomes (RLM). To improve the metabolic stability of dipyridamole, a series of pyrimidopyrimidine derivatives have been designed with the assistance of molecular docking. Among all the twenty-four synthesized compounds, compound (S)-4h showed outstanding metabolic stability (T1/2 = 67 min) in RLM, with an IC50 of 332 nM against PDE5. Furthermore, some interesting structure-activity relationships (SAR) were explained with the assistance of molecular docking.

Chlorophyll-Based Organic Heterojunction on Ti3 C2 Tx MXene Nanosheets for Efficient Hydrogen Production.

The Z-scheme process is a photoinduced electron-transfer pathway in natural oxygenic photosynthesis involving electron transport from photosystem II (PSII) to photosystem I (PSI). Inspired by the interesting Z-scheme process, herein a photocatalytic hydrogen evolution reaction (HER) employing chlorophyll (Chl) derivatives, Chl-1 and Chl-2, on the surface of Ti3 C2 Tx MXene with two-dimensional accordion-like morphology, forming Chl-1@Chl-2@Ti3 C2 Tx composite, is demonstrated. Due to the frontier molecular orbital energy alignments of Chl-1 and Chl-2, sublayer Chl-1 is a simulation of PSI, whereas upper layer Chl-2 is equivalent to PSII, and the resultant electron transport can take place from Chl-2 to Chl-1. Under the illumination of visible light (>420 nm), the HER performance of Chl-1@Chl-2@Ti3 C2 Tx photocatalyst was found to be as high as 143 µmol h-1 gcat -1 , which was substantially higher than that of photocatalysts of either Chl-1@Ti3 C2 Tx (20 µmol h-1 g-1 ) or Chl-2@Ti3 C2 Tx (15 µmol h-1 g-1 ).