Synthesis, Molecular Packing and Semiconductor Properties of V-Shaped N-Heteroacene Dimers

This article presents two groups of V-shaped π-scaffolds that consist of two N-heteroacene units fused with either a rigid or flexible eight-membered ring. These rigid and flexible N-heteroacene dimers were synthesized through the condensation of tetraphenylenetetraone with the corresponding diamine and the Pd-catalyzed cross-coupling of tetrabromodibenzo[a,e]cyclooctatetraene with the corresponding diamine, respectively. A comparison of electronic structures and properties of the two groups of V-shaped N-heteroacene dimers shows subtle difference between the rigid and flexible eight-membered ring linkers in forming extended π-systems. X-ray crystallography of these V-shaped molecules has revealed interesting π-π interaction modes, which are dependent on the central connecting units and substituting groups. These π-π interactions between the V-shaped π-scaffolds have enabled the molecules to function as organic semiconductors in solution-processed field effect transistors.

A curvilinear association between therapists' use of discourse particles and therapist empathy in psychotherapy

This study investigates the relationships between therapists' use of discourse particles and therapist empathy. Discourse particles, commonly found in non-English languages, are verbal elements that constitute metacommunication by encoding speakers' emotions and attitudes, which are typically expressed by nonverbal behaviors (e.g., intonation, tone, facial expression, nodding). We hypothesize an inverted U-shaped curvilinear relationship between therapists' use of discourse particles and therapist empathy, given the notion that an optimal level of therapists' emotion in psychotherapy can facilitate clients' inner experiencing and self-expression. Four psychotherapy sessions each from 39 therapist-client dyads were analyzed. After each session, therapist empathy was rated by trained observers using the Therapist Empathy Scale (TES) and by clients using the Barrett-Lennard Relationship Inventory (BLRI). Multilevel modeling shows that both the person-level negative quadratic term and positive linear term for therapists' usage of discourse particles are significant in predicting mean TES with large effect sizes. The same predictors do not yield significant results in predicting mean BLRI but they trend in similar directions of associations with medium effect sizes. Our results suggest the optimal usage of discourse particles by therapists is around 20.3% (out of all utterances). The nonsignificant results in BLRI may be attributed to the relatively small sample size of our data and the noncommunication orientation of the client-rated measure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Too-much-of-a-good-thing? The curvilinear associations among Chinese adolescents' perceived parental career expectation, internalizing problems, and career development: A three-wave longitudinal study

Based on three-annual-wave data from 3,196 Chinese adolescents across the high school years (Mage = 15.55 years old, SD = .44; 52.8% girls at Wave 1, 10th grade), this study examined the curvilinear associations between adolescents' perceived parental career expectation and their career adaptability and ambivalence and also tested the potential mediating role of adolescents' internalizing problems in such associations. Results showed that, after controlling for a set of critical covariates and the baseline levels of outcome variables, there was an inverted U-shaped curvilinear association between adolescents' perceived parental career expectation at Wave 1 and their career adaptability at Wave 3 via adolescent internalizing problems at Wave 2. Similarly, a U-shaped curvilinear association also was identified between adolescents' perceived parental career expectation at Wave 1 and their career ambivalence at Wave 3 via their internalizing problems at Wave 2. These findings suggest that adolescents' perceived parental career expectation may have "too-much-of-a-good-thing" effects on their career development. Implications for future research and practice were discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Comment on "Charge Transfer-Triggered Bi3+ Near-Infrared Emission in Y2Ti2O7 for Dual-Mode Temperature Sensing"

Undoped Y2Ti2O7 exhibits impurity emission bands at low temperatures due to Mn4+ and Cr3+, as established by codoping with these ions. Contrary to a recent report by Wang et al., ACS Appl. Mater. Interfaces 2022, 14, 36834-36844, we do not observe Bi3+ emission in this codoped host, as also is the case for Fe3+. The emission reported in that paper as being due to Bi3+ in fact corresponds to Cr3+ emission. The Cr3+ and Mn4+ emissions are quenched with increasing temperature, so that Mn4+ emission is scarcely observed above 80 K. We present variable temperature optical data for Y2Ti2O7 and this host codoped with Mn, Cr, Fe, and Bi, as well as a theoretical justification of our results.

Physical properties of short chain aqueous organosulfate aerosol

Organosulfates comprise up to 30% of the organic fraction of aerosol. Organosulfate aerosol physical properties, such as water activity, density, refractive index, and surface tension, are key to predicting their impact on global climate. However, current understanding of these properties is limited. Here, we measure the physical properties of aqueous solutions containing sodium methyl or ethyl sulfate and parameterise the data as a function of solute concentration. The experimental data are compared to available literature data for organosulfates, as well as salts (sodium sulfate and sodium bisulfate) and organics (short alkyl chain length alcohols and carboxylic acids) to determine if the physical properties of organosulfates can be approximated by molecules of similar functionality. With the exception of water activity, we find that organosulfates have intermediate physical properties between those of the salts and short alkyl chain organics. This work highlights the importance of measuring and developing models for the physical properties of abundant atmospheric organosulfates in order to better describe aerosol's impact on climate.

Stereoselective Palladium-Catalyzed C-F Bond Alkenylation of Tetrasubstituted gem-Difluoroalkenes via Mizoroki-Heck Reaction

A highly diastereoselective Pd(0)-catalyzed Mizoroki-Heck reaction of gem-difluoroalkenes is described. Unlike previously reported C-F bond functionalization with organometallic reagents, this reaction takes place between two different alkenes to achieve a formal C-F and C-H bond cross-coupling via a distinct pathway. Monofluorinated 1,3-diene products can be synthesized with control of the geometry of each alkene and good functional group tolerability.

Modulation of lncRNA links endothelial glycocalyx to vascular dysfunction of tyrosine kinase inhibitor

AIMS

Novel cancer therapies leading to increased survivorship of cancer patients have been negated by a concomitant rise in cancer therapies-related cardiovascular toxicities. Sunitinib, a first line multi-receptor tyrosine kinase inhibitor, has been reported to cause vascular dysfunction although the initiating mechanisms contributing to this side effect remain unknown. Long non-coding RNAs (lncRNAs) are emerging regulators of biological processes in endothelial cells (ECs); however, their roles in cancer therapies-related vascular toxicities remain underexplored.

METHODS AND RESULTS

We performed lncRNA expression profiling to identify potential lncRNAs that are dysregulated in human-induced pluripotent stem cell-derived ECs (iPSC-ECs) treated with sunitinib. We show that the lncRNA hyaluronan synthase 2 antisense 1 (HAS2-AS1) is significantly diminished in sunitinib-treated iPSC-ECs. Sunitinib was found to down-regulate HAS2-AS1 by an epigenetic mechanism involving hypermethylation. Depletion of HAS2-AS1 recapitulated sunitinib-induced detrimental effects on iPSC-ECs, whereas CRISPR-mediated activation of HAS2-AS1 reversed sunitinib-induced dysfunction. We confirmed that HAS2-AS1 stabilizes the expression of its sense gene HAS2 via an RNA/mRNA heteroduplex formation. Knockdown of HAS2-AS1 led to reduced synthesis of hyaluronic acid (HA) and up-regulation of ADAMTS5, an enzyme involved in extracellular matrix degradation, resulting in disruption of the endothelial glycocalyx which is critical for ECs. In vivo, sunitinib-treated mice showed reduced coronary flow reserve, accompanied by a reduction in Has2os and degradation of the endothelial glycocalyx. Finally, we identified that treatment with high molecular-weight HA can prevent the deleterious effects of sunitinib both in vitro and in vivo by preserving the endothelial glycocalyx.

CONCLUSIONS

Our findings highlight the importance of lncRNA-mediated regulation of the endothelial glycocalyx as an important determinant of sunitinib-induced vascular toxicity and reveal potential novel therapeutic avenues to attenuate sunitinib-induced vascular dysfunction.

Moment-to-moment affective dynamics in schizophrenia and bipolar disorder

BACKGROUND

Affective disturbances in schizophrenia and bipolar disorder may represent a transdiagnostic etiological process as well as a target of intervention. Hypotheses on similarities and differences in various parameters of affective dynamics (intensity, successive/acute changes, variability, and reactivity to stress) between the two disorders were tested.

METHODS

Experience sampling method was used to assess dynamics of positive and negative affect, 10 times a day over 6 consecutive days. Patients with schizophrenia (n = 46) and patients with bipolar disorder (n = 46) were compared against age-matched healthy controls (n = 46).

RESULTS

Compared to controls, the schizophrenia group had significantly more intense momentary negative affect, a lower likelihood of acute changes in positive affect, and reduced within-person variability of positive affect. The bipolar disorder group was not significantly different from either the schizophrenia group or the healthy control group on any affect indexes. Within the schizophrenia group, level of depression was associated with weaker reactivity to stress for negative affect. Within the bipolar disorder group, level of depression was associated with lower positive affect.

CONCLUSIONS

Patients with schizophrenia endured a more stable and negative affective state than healthy individuals, and were less likely to be uplifted in response to happenings in daily life. There is little evidence that these affective constructs characterize the psychopathology of bipolar disorder; such investigation may have been limited by the heterogeneity within group. Our findings supported the clinical importance of assessing multiple facets of affective dynamics beyond the mean levels of intensity.

Sexting Among Men Who Have Sex with Men in Hong Kong and Taiwan: Roles of Sensation-Seeking, Gay Identity, and Muscularity Ideal

Prior studies found that sexting was associated with risky sexual activities and that men who have sex with men (MSM) engaged in more frequent sexting than their heterosexual counterparts. Therefore, it is pertinent to understand what factors are associated with sexting among MSM. This study explored the relationships between sensation-seeking, gay identity confusion, and muscularity ideal with sexting behaviors. An online survey was administered to 355 and 448 18-34-year-old MSM in Hong Kong and Taiwan, respectively. While the number of sexting partners and the frequency of sexting were similar across the two regions, they had different associations with psychological factors. In Hong Kong, sensation-seeking was positively related to the number of sexting partners, while in Taiwan, it was positively related to the frequency of sending sexts. In Hong Kong, MSM who were more confused about their sexual orientation had fewer sexting partners. In both regions, MSM holding a stronger muscularity ideal also had more sexting partners. Gay identity confusion and muscularity ideal were associated with sexting under pressure in Taiwan; all three psychological factors concerned were associated with sexting under pressure in Hong Kong. Overall, these results showed that some MSM found sexting to be a sensation-fulfilling activity, but some were vulnerable to sexting under pressure. Counseling services to MSM about their sexual identity and concern for muscularity are needed to prevent them from becoming victims of forced sexting. Finally, the inconsistent results for the Hong Kong and Taiwanese samples indicated the importance of considering regional specificity in sexting research.

Over-18%-Efficiency Quasi-2D Ruddlesden-Popper Pb-Sn Mixed Perovskite Solar Cells by Compositional Engineering

Quasi-two-dimensional (2D) Pb-Sn mixed perovskites show great potential in applications of single and tandem photovoltaic devices, but they suffer from low efficiencies due to the existence of horizontal 2D phases. Here, we obtain a record high efficiency of 18.06% based on 2D ⟨n⟩ = 5 Pb-Sn mixed perovskites (iso-BA₂MA₄(Pb_xSn_1-x)₅I₁₆, x = 0.7), by optimizing the crystal orientation through a regulation of the Pb/Sn ratio. We find that Sn-rich precursors give rise to a mixture of horizontal and vertical 2D phases. Interestingly, increasing the Pb content can not only entirely suppress the unwanted horizontal 2D phase in the film but also enhance the growth of vertical 2D phases, thus significantly improving the device performance and stability. It is suggested that an increase of the Pb content in the Pb-Sn mixed systems facilitates the incorporation of iso-butylammonium (iso-BA⁺) ligands in vertically oriented perovskites because of the reduced lattice strain and increased interaction between the organic ligands and inorganic framework. Our work sheds light on the optimal conditions for fabricating stable and efficient 2D Pb-Sn mixed perovskite solar cells.

Plasma vaspin levels and clinical outcome in incident peritoneal dialysis patients

BACKGROUND

Vaspin is an adipokine that regulates glucose and lipid metabolism. Plasma vaspin level is increased in chronic kidney disease but decreased in hemodialysis patients. However, plasma vaspin level in peritoneal dialysis (PD) patients, as well as its prognostic role, has not been studied.

METHODS

We recruited 146 incident PD patients. Their baseline plasma vaspin levels, body anthropometry, the profile of insulin resistance, bioimpedance spectroscopy parameters, dialysis adequacy, and nutritional indices were measured. They were followed for up to 5 years for survival analysis.

RESULTS

The average age was 58.4 ± 11.8 years; 96 patients (65.8%) were men, and 90 (61.6%) had diabetes. The median vaspin level was 0.18 ng/dL (interquartile range [IQR] 0.11 to 0.30 ng/dL). Plasma vaspin level did not have a significant correlation with adipose tissue mass or baseline insulin level. However, plasma vaspin level had a modest correlation with the change in insulin resistance, as represented by the HOMA-IR index, in non-diabetic patients (r = -0.358, p = 0.048). Although the plasma vaspin level quartile did not have a significant association with patient survival in the entire cohort, it had a significant interaction with diabetic status (p < 0.001). In nondiabetic patients, plasma vaspin level quartile was an independent predictor of patient survival after adjusting for confounding clinical factors (adjusted hazard ratio 2.038, 95% confidence interval 1.191-3.487, p = 0.009), while the result for diabetic patients was not significant.

CONCLUSIONS

Plasma vaspin level quartile had a significant association with patient survival in non-diabetic PD patients. Baseline plasma vaspin level also had a modest inverse correlation with the subsequent change in the severity of insulin resistance, but the exact biological role of vaspin deserves further studies.

Bioactivity of human adult stem cells and functional relevance of stem cell-derived extracellular matrix in chondrogenesis

BACKGROUND

Autologous chondrocyte implantation (ACI) has been used to treat articular cartilage defects for over two decades. Adult stem cells have been proposed as a solution to inadequate donor cell numbers often encountered in ACI. Multipotent stem/progenitor cells isolated from adipose, bone marrow, and cartilage are the most promising cell therapy candidates. However, different essential growth factors are required to induce these tissue-specific stem cells to initiate chondrogenic differentiation and subsequent deposition of extracellular matrix (ECM) to form cartilage-like tissue. Upon transplantation into cartilage defects in vivo, the levels of growth factors in the host tissue are likely to be inadequate to support chondrogenesis of these cells in situ. The contribution of stem/progenitor cells to cartilage repair and the quality of ECM produced by the implanted cells required for cartilage repair remain largely unknown. Here, we evaluated the bioactivity and chondrogenic induction ability of the ECM produced by different adult stem cells.

METHODS

Adult stem/progenitor cells were isolated from human adipose (hADSCs), bone marrow (hBMSCs), and articular cartilage (hCDPCs) and cultured for 14 days in monolayer in mesenchymal stromal cell (MSC)-ECM induction medium to allow matrix deposition and cell sheet formation. The cell sheets were then decellularized, and the protein composition of the decellularized ECM (dECM) was analyzed by BCA assay, SDS-PAGE, and immunoblotting for fibronectin (FN), collagen types I (COL1) and III (COL3). The chondrogenic induction ability of the dECM was examined by seeding undifferentiated hBMSCs onto the respective freeze-dried solid dECM followed by culturing in serum-free medium for 7 days. The expression levels of chondrogenic genes SOX9, COL2, AGN, and CD44 were analyzed by q-PCR.

RESULTS

hADSCs, hBMSCs, and hCDPCs generated different ECM protein profiles and exhibited significantly different chondrogenic effects. hADSCs produced 20-60% more proteins than hBMSCs and hCDPCs and showed a fibrillar-like ECM pattern (FN^high, COL1^high). hCDPCs produced more COL3 and deposited less FN and COL1 than the other cell types. The dECM derived from hBMSCs and hCDPCs induced spontaneous chondrogenic gene expression in hBMSCs.

CONCLUSIONS

These findings provide new insights on application of adult stem cells and stem cell-derived ECM to enhance cartilage regeneration.

Facial Trustworthiness Influences Age Differences in Visual Attention Toward Credible Versus Non-credible Messages

Background and Objectives

The literature on consumer decision-making and aging suggests that older adults make less optimal buying decisions than younger adults do, partly because older adults tend to perceive salespersons' faces as more trustworthy. This study aims to directly test the difference in the effect of perceived facial trustworthiness on buying intention between younger and older adults. It also aims to reveal the underlying mechanisms of this age-related difference by testing whether a more trustworthy face disrupts older adults' attention toward credible (vs. non-credible) information to a higher degree compared with younger adults.

Research Design and Methods

A sample of 92 younger (aged 18-37 years) and 83 older (aged 60-82 years) adults viewed advertisements for 32 products while their eye movements were captured by an eye tracker to measure their fixation duration (as an indicator of attention). The advertisements varied in terms of the credibility of the content and the trustworthiness of the salesperson's face.

Results

Both age groups showed higher buying intentions for products featured in advertisements with higher credibility and facial trustworthiness. When facial trustworthiness was lower, both age groups showed greater attentional preferences for credible over non-credible content. However, this distinction in attention disappeared in older but not younger adults with an increase in facial trustworthiness.

Discussion and Implications

Our findings suggest that although facial trustworthiness generally increases buying intention of both younger and older adults, it only reduces older (but not younger) adults' attentional discrimination between credible and non-credible content. This paper offers a novel and promising mechanism for the increase in fraud vulnerability in late adulthood.

Amphibious Miniature Soft Jumping Robot with On-Demand In-Flight Maneuver

In nature, some semiaquatic arthropods evolve biomechanics for jumping on the water surface with the controlled burst of kinetic energy. Emulating these creatures, miniature jumping robots deployable on the water surface have been developed, but few of them achieve the controllability comparable to biological systems. The limited controllability and agility of miniature robots constrain their applications, especially in the biomedical field where dexterous and precise manipulation is required. Herein, an insect-scale magnetoelastic robot with improved controllability is designed. The robot can adaptively regulate its energy output to generate controllable jumping motion by tuning magnetic and elastic strain energy. Dynamic and kinematic models are developed to predict the jumping trajectories of the robot. On-demand actuation can thus be applied to precisely control the pose and motion of the robot during the flight phase. The robot is also capable of making adaptive amphibious locomotion and performing various tasks with integrated functional modules.

Early-Life Skin Microbial Biomarkers for Eczema Phenotypes in Chinese Toddlers

Eczema is a common inflammatory skin disorder during infancy. Evidence has shown that skin-microbiome fluctuations may precede eczema development, but their predictive value for eczema phenotypes remains unknown. We aimed to investigate the early-life evolution of the skin microbiome and its temporal associations with different pairs of eczema phenotypes (transient versus persistent, atopic versus non-atopic) in Chinese children. We followed 119 term Chinese infants from birth to 24 months old within a Hong Kong birth cohort. The skin microbes at the left antecubital fossa were serially sampled by flocked swabs at 1, 6, and 12 months for bacterial 16S rRNA gene sequencing. The atopic sensitization at 12 months was strongly associated with eczema persisting to 24 months (odds ratio 4.95, 95% confidence interval 1.29-19.01). Compared with those with non-atopic eczema, the children with atopic eczema had reduced alpha diversity at 12 months (p < 0.001) and transiently higher abundance of the genus Janibacter at 6 months (p < 0.001). Our findings suggest that atopic sensitization at 12 months may predict persistent eczema by 24 months, and atopic eczema at 12 months is associated with unique skin microbiome profiles at 6 and 12 months. Non-invasive skin-microbiome profiling may have predictive value for atopic eczema.

The single-cell chromatin accessibility landscape in mouse perinatal testis development

Spermatogenesis depends on an orchestrated series of developing events in germ cells and full maturation of the somatic microenvironment. To date, the majority of efforts to study cellular heterogeneity in testis has been focused on single-cell gene expression rather than the chromatin landscape shaping gene expression. To advance our understanding of the regulatory programs underlying testicular cell types, we analyzed single-cell chromatin accessibility profiles in more than 25,000 cells from mouse developing testis. We showed that single-cell sequencing assay for transposase-accessible chromatin (scATAC-Seq) allowed us to deconvolve distinct cell populations and identify cis-regulatory elements (CREs) underlying cell-type specification. We identified sets of transcription factors associated with cell type-specific accessibility, revealing novel regulators of cell fate specification and maintenance. Pseudotime reconstruction revealed detailed regulatory dynamics coordinating the sequential developmental progressions of germ cells and somatic cells. This high-resolution dataset also unveiled previously unreported subpopulations within both the Sertoli and Leydig cell groups. Further, we defined candidate target cell types and genes of several genome-wide association study (GWAS) signals, including those associated with testosterone levels and coronary artery disease. Collectively, our data provide a blueprint of the 'regulon' of the mouse male germline and supporting somatic cells.

Stabilization and improved functionality of three-dimensional perfusable microvascular networks in microfluidic devices under macromolecular crowding

BACKGROUND

There is great interest to engineer in vitro models that allow the study of complex biological processes of the microvasculature with high spatiotemporal resolution. Microfluidic systems are currently used to engineer microvasculature in vitro, which consists of perfusable microvascular networks (MVNs). These are formed through spontaneous vasculogenesis and exhibit the closest resemblance to physiological microvasculature. Unfortunately, under standard culture conditions and in the absence of co-culture with auxiliary cells as well as protease inhibitors, pure MVNs suffer from a short-lived stability.

METHODS

Herein, we introduce a strategy for stabilization of MVNs through macromolecular crowding (MMC) based on a previously established mixture of Ficoll macromolecules. The biophysical principle of MMC is based on macromolecules occupying space, thus increasing the effective concentration of other components and thereby accelerating various biological processes, such as extracellular matrix deposition. We thus hypothesized that MMC will promote the accumulation of vascular ECM (basement membrane) components and lead to a stabilization of MVN with improved functionality.

RESULTS

MMC promoted the enrichment of cellular junctions and basement membrane components, while reducing cellular contractility. The resulting advantageous balance of adhesive forces over cellular tension resulted in a significant stabilization of MVNs over time, as well as improved vascular barrier function, closely resembling that of in vivo microvasculature.

CONCLUSION

Application of MMC to MVNs in microfluidic devices provides a reliable, flexible and versatile approach to stabilize engineered microvessels under simulated physiological conditions.

Glycosylated BODIPY- Incorporated Pt(II) Metallacycles for Targeted and Synergistic Chemo-Photodynamic Therapy

Pt(II)-BODIPY complexes combine the chemotherapeutic activity of Pt(II) with the photocytotoxicity of BODIPYs. Additional conjugation with targeting ligands can boost the uptake by cancer cells that overexpress the corresponding receptors. We describe two Pt(II) triangles, 1 and 2, built with pyridyl BODIPYs functionalized with glucose (3) or triethylene glycol methyl ether (4), respectively. Both 1 and 2 showed higher singlet oxygen quantum yields than 3 and 4, due to the enhanced singlet-to-triplet intersystem crossing. To evaluate the targeting effect of the glycosylated derivative, in vitro experiments were performed using glucose transporter 1 (GLUT1)-positive HT29 and A549 cancer cells, and noncancerous HEK293 cells as control. Both 1 and 2 showed higher cellular uptake than 3 and 4. Specifically, 1 was selective and highly cytotoxic toward HT29 and A549 cells. The synergistic chemo- and photodynamic behavior of the metallacycles was also confirmed. Notably, 1 exhibited superior efficacy toward the cisplatin-resistant R-HepG2 cells.

Structures of NF-κB p52 homodimer-DNA complexes rationalize binding mechanisms and transcription activation

The mammalian NF-κB p52:p52 homodimer together with its cofactor Bcl3 activates transcription of κB sites with a central G/C base pair (bp), while it is inactive toward κB sites with a central A/T bp. To understand the molecular basis for this unique property of p52, we have determined the crystal structures of recombinant human p52 protein in complex with a P-selectin(PSel)-κB DNA (5'-GGGGTGACCCC-3') (central bp is underlined) and variants changing the central bp to A/T or swapping the flanking bp. The structures reveal a nearly two-fold widened minor groove in the central region of the DNA as compared to all other currently available NF-κB-DNA complex structures, which have a central A/T bp. Microsecond molecular dynamics (MD) simulations of free DNAs and p52 bound complexes reveal that free DNAs exhibit distinct preferred conformations, and p52:p52 homodimer induces the least amount of DNA conformational changes when bound to the more transcriptionally active natural G/C-centric PSel-κB, but adopts closed conformation when bound to the mutant A/T and swap DNAs due to their narrowed minor grooves. Our binding assays further demonstrate that the fast kinetics favored by entropy is correlated with higher transcriptional activity. Overall, our studies have revealed a novel conformation for κB DNA in complex with NF-κB and pinpoint the importance of binding kinetics, dictated by DNA conformational and dynamic states, in controlling transcriptional activation for NF-κB.

Nodeless Superconductivity in Kagome Metal CsV3Sb5 with and without Time Reversal Symmetry Breaking

The kagome metal CsV₃Sb₅ features an unusual competition between the charge-density-wave (CDW) order and superconductivity. Evidence for time reversal symmetry breaking (TRSB) inside the CDW phase has been accumulating. Hence, the superconductivity in CsV₃Sb₅ emerges from a TRSB normal state, potentially resulting in an exotic superconducting state. To reveal the pairing symmetry, we first investigate the effect of nonmagnetic impurity. Our results show that the superconducting critical temperature is insensitive to disorder, pointing to conventional s-wave superconductivity. Moreover, our measurements of the self-field critical current (I_c,sf), which is related to the London penetration depth, also confirm conventional s-wave superconductivity with strong coupling. Finally, we measure I_c,sf where the CDW order is removed by pressure and superconductivity emerges from the pristine normal state. Our results show that s-wave gap symmetry is retained, providing strong evidence for the presence of conventional s-wave superconductivity in CsV₃Sb₅ irrespective of the presence of the TRSB.

Real-Time Detection and Visualization of Amyloid-β Aggregates Induced by Hydrogen Peroxide in Cell and Mouse Models of Alzheimer's Disease

Oxidative stress, caused by an imbalance between the production and the accumulation of reactive oxygen species (ROS), is a prominent cause of the neurotoxicity induced by aggregated amyloid-β (Aβ) in Alzheimer's disease (AD). Tools that can directly detect and monitor the presence and amount of Aβ-induced ROS are still lacking. We report herein the first Aβ-targeted ratiometric H₂O₂-responsive fluorescent probe for real-time detection and monitoring of the Aβ-induced H₂O₂ level in cell and AD mouse models. The H₂O₂-responsive probe is constructed based on a methylamino-substituted quinolinium-based cyanine as the fluorescence moiety and a phenylboronate ester as the sensing reaction site. This sensing probe exhibits a large emission wavelength shift of ∼87 nm upon reacting with H₂O₂, a high binding selectivity for Aβ, and a faster response toward H₂O₂ in the presence of Aβ, concomitant with an enhanced fluorescence intensity, hence greatly boosting the sensitivity of in-situ H₂O₂ detection. This biocompatible and nontoxic probe is capable of ratiometrically detecting and imaging endogenous H₂O₂ induced by Aβ in a neuronal cell model. Remarkably, this Aβ-targeted H₂O₂-responsive probe is also able to detect, monitor, and differentiate different Aβ-induced H₂O₂ levels in real time in different age groups of transgenic AD mice in which the cerebral H₂O₂ level increases age dependently concomitant with the plaque contents. Therefore, this smart probe can act as a powerful tool to diagnose high-risk subjects and diseased brains of AD and to further study the role of ROS in AD pathology.

Plasma Phospholipid Monounsaturated Fatty Acids and Gestational Diabetes Mellitus: A Longitudinal Study in the NICHD Fetal Growth Studies-Singletons Cohort

Fatty acids (FAs) have been implicated in the development of gestational diabetes mellitus (GDM), but the role of monounsaturated FAs (MUFAs) remains understudied. We investigated the associations of plasma phospholipid MUFAs in early to mid-pregnancy with cardiometabolic biomarkers and GDM risk. From the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons cohort (2009-2013), we identified 107 women with GDM according to Carpenter and Coustan criteria and 214 control participants without GDM matched (2:1) on age, race/ethnicity, and gestational week (GW) of blood collection. MUFAs were measured at 10-14, 15-26, 23-31, and 33-39 GWs by gas chromatography mass spectrometry. We found that the concentration of total 18:1 MUFAs was significantly lower among women with GDM than those without GDM at 15-26 GWs. Each SD increment in the level of total 18:1 MUFAs was associated with a 40% lower risk of GDM at 15-26 GWs. Moreover, each SD increment in vaccenic acid (18:1n-7) levels at 10-14 and 15-26 GWs were associated with a 36% and 45% lower risk of GDM, respectively. Our extensive assessments of MUFAs advance our understanding of the unique associations of FA composition with GDM risk, suggesting the potentially beneficial role of MUFAs in GDM pathophysiology.

Myopia incidence and lifestyle changes among school children during the COVID-19 pandemic: a population-based prospective study

BACKGROUND

The impacts of social restrictions for COVID-19 on children's vision and lifestyle remain unknown.

AIMS

To investigate myopia incidence, spherical equivalent refraction (SER) and lifestyle changes among schoolchildren during the COVID-19 pandemic.

METHODS

Two separate longitudinal cohorts of children aged 6-8 years in Hong Kong were included. The COVID-19 cohort was recruited at the beginning of the COVID-19 outbreak, whereas the pre-COVID-19 cohort was recruited before the COVID-19 pandemic. All children received ocular examinations, and answered a standardised questionnaire relating to their lifestyle, including time spent on outdoor activities and near work, both at baseline and at follow-up visits.

RESULTS

A total of 1793 subjects were recruited, of whom 709 children comprised the COVID-19 cohort with 7.89±2.30 months of follow-up, and 1084 children comprised the pre-COVID-19 cohort with 37.54±3.12 months of follow-up. The overall incidence was 19.44% in the COVID-19 cohort, and 36.57% in pre-COVID-19 cohort. During the COVID-19 pandemic, the change in SER and axial length was -0.50±0.51 D and 0.29±0.35 mm, respectively; the time spent on outdoor activities decreased from 1.27±1.12 to 0.41±0.90 hours/day (p<0.001), while screen time increased from 2.45±2.32 to 6.89±4.42 hours/day (p<0.001).

CONCLUSIONS

We showed a potential increase in myopia incidence, significant decrease in outdoor time and increase in screen time among schoolchildren in Hong Kong during the COVID-19 pandemic. Our results serve to warn eye care professionals, and also policy makers, educators and parents, that collective efforts are needed to prevent childhood myopia-a potential public health crisis as a result of COVID-19.

Growth hormone-releasing hormone receptor signaling in experimental ocular inflammation and neuroprotection

Both inflammation and anti-inflammation are involved in the protection of retinal cells. Antagonists of the hypothalamic growth hormone-releasing hormone receptor (GHRHR) have been shown to possess potent anti-inflammatory properties in experimental disease models of various organs, some with systemic complications. Such effects are also found in ocular inflammatory and neurologic injury studies. In experimental models of mice and rats, both growth hormone-releasing hormone receptor agonists and antagonists may alleviate death of ocular neural cells under certain experimental conditions. This review explores the properties of growth hormone-releasing hormone receptor agonists and antagonists that lead to its protection against inflammatory responses induced by extrinsic agents or neurologic injures in ocular animal models.

Single-cell RNA sequencing uncovers a neuron-like macrophage subset associated with cancer pain

Tumor innervation is a common phenomenon with unknown mechanism. Here, we discovered a direct mechanism of tumor-associated macrophage (TAM) for promoting de novo neurogenesis via a subset showing neuronal phenotypes and pain receptor expression associated with cancer-driven nocifensive behaviors. This subset is rich in lung adenocarcinoma associated with poorer prognosis. By elucidating the transcriptome dynamics of TAM with single-cell resolution, we discovered a phenomenon "macrophage to neuron-like cell transition" (MNT) for directly promoting tumoral neurogenesis, evidenced by macrophage depletion and fate-mapping study in lung carcinoma models. Encouragingly, we detected neuronal phenotypes and activities of the bone marrow-derived MNT cells (MNTs) in vitro. Adoptive transfer of MNTs into NOD/SCID mice markedly enhanced their cancer-associated nocifensive behaviors. We identified macrophage-specific Smad3 as a pivotal regulator for promoting MNT at the genomic level; its disruption effectively blocked the tumor innervation and cancer-dependent nocifensive behaviors in vivo. Thus, MNT may represent a precision therapeutic target for cancer pain.

Electron tomography of prolamellar bodies and their transformation into grana thylakoids in cryofixed Arabidopsis cotyledons

The para-crystalline structures of prolamellar bodies (PLBs) and light-induced etioplast-to-chloroplast transformation have been investigated via electron microscopy. However, such studies suffer from chemical fixation artifacts and limited volumes of 3D reconstruction. Here, we examined Arabidopsis thaliana cotyledon cells by electron tomography (ET) to visualize etioplasts and their conversion into chloroplasts. We employed scanning transmission ET to image large volumes and high-pressure freezing to improve sample preservation. PLB tubules were arranged in a zinc blende-type lattice-like carbon atoms in diamonds. Within 2 h after illumination, the lattice collapsed from the PLB exterior and the disorganized tubules merged to form thylakoid sheets (pre-granal thylakoids), which folded and overlapped with each other to create grana stacks. Since the nascent pre-granal thylakoids contained curved membranes in their tips, we examined the expression and localization of CURT1 (CURVATURE THYLAKOID1) proteins. CURT1A transcripts were most abundant in de-etiolating cotyledon samples, and CURT1A was concentrated at the PLB periphery. In curt1a etioplasts, PLB-associated thylakoids were swollen and failed to form grana stacks. In contrast, PLBs had cracks in their lattices in curt1c etioplasts. Our data provide evidence that CURT1A is required for pre-granal thylakoid assembly from PLB tubules during de-etiolation, while CURT1C contributes to cubic crystal growth in the dark.

The relationship between anxiety, enjoyment, and breakdown fluency during second language speaking tasks: An idiodynamic investigation

Research has found that levels of enjoyment and anxiety fluctuate on a moment-to-moment timescale during second language (L2) spoken task performances as learners attempt to cope with various communication challenges. For L2 speakers, surges in these emotions can limit or expand cognitive resources, affecting speech processing capability. However, at an intra-individual level, there is very little empirical evidence on how emotions and fluency are related during L2 spoken task performances. The present study uses the idiodynamic approach to examine the relationship between enjoyment, anxiety, and breakdown fluency (i.e., average length of pauses) during monolog tasks performed by university students who use English as an L2. After watching a video recording of their task performances, participants rated their anxiety and emotion levels on a per-second basis. Immediately after, they were interviewed about their attributions for fluctuations in their ratings. After segmenting task performances into 26 7-s segments of speech, per-person correlations revealed that (1) the (negative) relationship between anxiety and enjoyment varied from strong to very weak, and (2) the (positive) relationship between anxiety and breakdown fluency was much stronger than the (negative) relationship between enjoyment and breakdown fluency. Triangulation of anxiety and enjoyment ratings, stimulated recall interviews, and performance data led to the identification of four categories of factors that influenced the emotion-fluency relationship: task design factors (task structure, task topic), task implementation factors (pre-task planning, task time limits), cognitive-linguistic factors (momentary breakdowns in conceptualization and formulation speech processes), and achievement outcome factors (self-evaluations of appropriate and inappropriate language used).

Nanographenes and Graphene Nanoribbons as Multitalents of Present and Future Materials Science

As cut-outs from a graphene sheet, nanographenes (NGs) and graphene nanoribbons (GNRs) are ideal cases with which to connect the world of molecules with that of bulk carbon materials. While various top-down approaches have been developed to produce such nanostructures in high yields, in the present perspective, precision structural control is emphasized for the length, width, and edge structures of NGs and GNRs achieved by modern solution and on-surface syntheses. Their structural possibilities have been further extended from "flatland" to the three-dimensional world, where chirality and handedness are the jewels in the crown. In addition to properties exhibited at the molecular level, self-assembly and thin-film structures cannot be neglected, which emphasizes the importance of processing techniques. With the rich toolkit of chemistry in hand, NGs and GNRs can be endowed with versatile properties and functions ranging from stimulated emission to spintronics and from bioimaging to energy storage, thus demonstrating their multitalents in present and future materials science.

Would Chinese Men Who Have Sex With Men Take Up Human Papillomavirus (HPV) Screening as an Alternative Prevention Strategy to HPV Vaccination?

Background

Men who have sex with men (MSM) are at high risk for human papillomavirus (HPV) infection. A community-based organization (CBO)-private clinic service model promoting HPV vaccination among MSM was implemented in Hong Kong. The aim of this study was to evaluate the effectiveness of this service model in increasing HPV screening among MSM.

Methods

This was a secondary analysis of the CBO-private clinic service model in increasing HPV screening among MSM. Participants were Hong Kong Chinese-speaking MSM aged 18–45 years who had never received HPV vaccination. All participants completed a telephone survey at baseline before receiving online intervention promoting HPV vaccination and completed another telephone survey 12 months afterward.

Results

A total of 350 participants completed a baseline telephone survey and received interventions promoting HPV vaccination. Among 274 participants being followed up at Month 12, 33 (12.0%) received any type of HPV screening during the study period. Such uptake rate was similar to the prevalence of HPV screening in the past year measured at baseline (12.0 vs. 9.9%, p = 0.43). More MSM preferred HPV vaccination or HPV vaccination plus HPV screening, and very few preferred HPV screening alone. After adjusting for significant baseline characteristics, higher perceived susceptibility to HPV (adjusted odds ratio (AOR): 1.16, 95% confidence interval (CI): 1.00–1.34) and receiving HPV vaccination during the study period (AOR: 7.03, 95% CI: 3.07–16.13) were significantly associated with higher HPV screening uptake.

Conclusions

The CBO-private clinic service model promoting HPV vaccination had limited impact in increasing HPV screening among MSM in Hong Kong. MSM in Hong Kong may not use HPV screening as an alternative prevention strategy to HPV vaccination. Future programs preventing HPV-related diseases among MSM in Hong Kong should focus on HPV vaccination promotion.

Psychological Distress and Protective Behaviors During the COVID-19 Pandemic Among Different Populations: Hong Kong General Population, Taiwan Healthcare Workers, and Taiwan Outpatients

PURPOSE

The novel coronavirus disease 2019 (COVID-19) caused psychological distress and changed human living styles. However, rare studies have examined the psychological distress and protective behaviors across different populations. Therefore, the present study aimed to assess psychological distress, protective behaviors, and potential predictors of psychological distress and protective behaviors across the Hong Kong general population, Taiwan healthcare workers, and Taiwan outpatients.

METHODS

A cross-sectional design was used to recruit participants from Hong Kong and Taiwan. Telephone interviews were carried out for Hong Kong participants (n = 1,067; 30.2% male participants); online surveys were used for Taiwan healthcare workers (n = 500; 8.0% male participants) and Taiwan outpatients (n = 192; 32.8% male participants). All the participants completed questions on psychological distress and protective behaviors. Multiple linear regressions and multivariable logistic regressions were employed to explore the potential predictors of psychological distress and protective behaviors, respectively.

RESULTS

Hong Kong participants had significantly lower levels of psychological distress than Taiwan participants [mean (SD) = 0.16 (0.39) vs. 0.47 (0.59) in healthcare workers and 0.46 (0.65) in outpatients; p < 0.001]. Hong Kong participants (51.7%) and Taiwan outpatients had more people showing fear of COVID-19 (52.0%) than Taiwan healthcare providers (40.8%; p < 0.001). Moreover, Hong Kong participants engaged the most in protective behaviors, followed by Taiwan healthcare providers and Taiwan outpatients (p < 0.001). Moreover, being a female, fear of COVID-19 and worry about personal savings were associated with protective behaviors in general.

CONCLUSIONS

Despite the greater COVID-19 severity and fear of COVID-19 in Hong Kong, the general population in Hong Kong experienced less psychosocial distress with higher compliance to protective behaviors than the other groups in Taiwan.

A glossary of plant cell structures: Current insights and future questions

In this glossary of plant cell structures, we asked experts to summarize a present-day view of plant organelles and structures, including a discussion of outstanding questions. In the following short reviews, the authors discuss the complexities of the plant cell endomembrane system, exciting connections between organelles, novel insights into peroxisome structure and function, dynamics of mitochondria, and the mysteries that need to be unlocked from the plant cell wall. These discussions are focused through a lens of new microscopy techniques. Advanced imaging has uncovered unexpected shapes, dynamics, and intricate membrane formations. With a continued focus in the next decade, these imaging modalities coupled with functional studies are sure to begin to unravel mysteries of the plant cell.

Protein-RNA interaction prediction with deep learning: structure matters

Protein-RNA interactions are of vital importance to a variety of cellular activities. Both experimental and computational techniques have been developed to study the interactions. Because of the limitation of the previous database, especially the lack of protein structure data, most of the existing computational methods rely heavily on the sequence data, with only a small portion of the methods utilizing the structural information. Recently, AlphaFold has revolutionized the entire protein and biology field. Foreseeably, the protein-RNA interaction prediction will also be promoted significantly in the upcoming years. In this work, we give a thorough review of this field, surveying both the binding site and binding preference prediction problems and covering the commonly used datasets, features and models. We also point out the potential challenges and opportunities in this field. This survey summarizes the development of the RNA-binding protein-RNA interaction field in the past and foresees its future development in the post-AlphaFold era.

Application of Optical Coherence Tomography to a Mouse Model of Retinopathy

Optical coherence tomography (OCT) offers a noninvasive method for the diagnosis of retinopathy. The OCT machine can capture retinal crosssectional images from which the retinal thickness can be calculated. Although OCT is widely used in clinical practice, its application in basic research is not as prevalent, especially in small animals such as mice. Because of the small size of their eyeballs, it is challenging to conduct fundus imaging examinations in mice. Therefore, a specialized retinal imaging system is required to accommodate OCT imaging on small animals. This article demonstrates a small-animal-specific system for OCT examination procedures and a detailed method for image analysis. The results of retinal OCT examination of very-low-density lipoprotein receptor (Vldlr) knockout mice and C57BL/6J mice are presented. The OCT images of C57BL/6J mice showed retinal layers, while those of Vldlr knockout mice showed subretinal neovascularization and retinal thinning. In summary, OCT examination could facilitate the noninvasive detection and measurement of retinopathy in mouse models.

Gastric Microbiota beyond H. pylori: An Emerging Critical Character in Gastric Carcinogenesis

Gastric cancer (GC) is one of the global leading causes of cancer death. The association between Helicobacter pylori, which is a predominant risk factor for GC, with GC development has been well-studied. Recently, accumulating evidence has demonstrated the presence of a large population of microorganisms other than H. pylori in the human stomach. Existing sequencing studies have revealed microbial compositional and functional alterations in patients with GC and highlighted a progressive shift in the gastric microbiota in gastric carcinogenesis with marked enrichments of oral or intestinal commensals. Moreover, using a combination of gastric bacterial signatures, GC patients could be significantly distinguished from patients with gastritis. These findings, therefore, emphasize the importance of a collective microbial community in gastric carcinogenesis. Here, we provide an overview of non-H. pylori gastric microbes in gastric carcinogenesis. The molecular mechanisms of gastric microbes-related carcinogenesis and potential clinical applications of gastric microbiota as biomarkers of GC are also explored.

Did Hydro-climatic Extremes, Positive Checks, and Economic Fluctuations Modulate the Epidemics Outbreaks in Late Imperial China?

Empirical research has shown that climate-related variables, the decline in economic well-being, and the mutual reinforcement of positive checks are the primary drivers of epidemic outbreaks in recent human history. However, their relative importance in causing the outbreak of epidemics is rarely examined quantitatively in a single study. I sought to address this issue by analyzing the 1402 epidemic incidents in China between 1841 and 1911, which partially overlaps partly with the Third Pandemic period. Fine-grained historical big data, multiple regression, and wavelet coherence analysis were employed. Statistical results show that economic fluctuations drove the country-wide epidemics outbreaks in China in inter-annual and decadal time scales. Economic fluctuations could cause short-term hardship and long-term impoverishment to the underprivileged social groups since a large portion of the Chinese population lived at the subsistence level in the past. The fluctuations might have sustained the repeated waves of epidemic outbreaks during the Third Pandemic period.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10745-021-00272-7.

Assessing economic, social and environmental impacts on housing prices in Hong Kong: a time-series study of 2006, 2011 and 2016

Given Hong Kong's unique high-density urban environment and limited land resources, more and more general public has been concerned about the living quality. Based on three waves of census data (2006, 2011 and 2016), combined with our spatial-temporal urban environmental database consisting of three local datasets of urban climate and air quality, this paper assesses the impacts of social, economic and environmental factors on the logarithm of housing prices in Hong Kong through linear regression analysis. Specifically, both supply- and demand-side economic factors have significant impacts on housing prices. Demographic factors are not as significant as expected in affecting housing prices. Transportation factors have more significant effects in the short run than in the long run. Environmental factors, including the number of hot night hours, Annual Air Quality Index (AAQI) of nitrogen dioxide (NO₂) and particulates with particle sizes less than 10 microns (PM₁₀), significantly affect housing prices over time. The results have important implications: current policy instruments to prevent housing price escalation are focused on increasing property tax or land supply (economic factors), while little attention is paid to social or environmental factors, which are geographically heterogeneous. Our findings suggest that housing provision in the New Territories may be a feasible solution to alleviate the housing crisis as its demographic pattern, transportation connectivity and air quality are significantly different from Hong Kong Island or Kowloon Peninsula. In regard to urban environmental problems brought by the high-density development in Hong Kong despite land-use saving, intensified urban infrastructure and promotion of public transportation, our study contributes to the understanding of its housing price dynamics from a more holistic perspective by comparing the impacts of economic, social and environmental factors.

A Bayesian method for synthesizing multiple diagnostic outcomes of COVID-19 tests

The novel coronavirus disease 2019 (COVID-19) has spread worldwide and threatened human life. Diagnosis is crucial to contain the spread of SARS-CoV-2 infections and save lives. Diagnostic tests for COVID-19 have varying sensitivity and specificity, and the false-negative results would have substantial consequences to patient treatment and pandemic control. To detect all suspected infections, multiple testing is widely used. However, it may be challenging to build an assertion when the testing results are inconsistent. Considering the situation where there is more than one diagnostic outcome for each subject, we proposed a Bayesian probabilistic framework based on the sensitivity and specificity of each diagnostic method to synthesize a posterior probability of being infected by SARS-CoV-2. We demonstrated that the synthesized posterior outcome outperformed each individual testing outcome. A user-friendly web application was developed to implement our analytic framework with free access via http://www2.ccrb.cuhk.edu.hk/statgene/COVID_19/. The web application enables the real-time display of the integrated outcome incorporating two or more tests and calculated based on Bayesian posterior probability. A simulation-based assessment demonstrated higher accuracy and precision of the Bayesian probabilistic model compared with a single-test outcome. The online tool developed in this study can assist physicians in making clinical evaluations by effectively integrating multiple COVID-19 tests.

Low-Density Lipoprotein Receptor-Related Protein 6 Cell Surface Availability Regulates Fuel Metabolism in Astrocytes

Early changes in astrocyte energy metabolism are associated with late-onset Alzheimer's disease (LOAD), but the underlying mechanism remains elusive. A previous study suggested an association between a synonymous SNP (rs1012672, C→T) in LRP6 gene and LOAD; and that is indeed correlated with diminished LRP6 gene expression in the frontal cortex region. The authors show that LRP6 is a unique Wnt coreceptor on astrocytes, serving as a bimodal switch that modulates their metabolic landscapes. The Wnt-LRP6 mediated mTOR-AKT axis is essential for sustaining glucose metabolism. In its absence, Wnt switches to activate the LRP6-independent Ca2+ -PKC-NFAT axis, resulting in a transcription network that favors glutamine and branched chain amino acids (BCAAs) catabolism over glucose metabolism. Exhaustion of these raw materials essential for neurotransmitter biosynthesis and recycling results in compromised synaptic, cognitive, and memory functions; priming for early changes that are frequently found in LOAD. The authors also highlight that intranasal supplementation of glutamine and BCAAs is effective in preserving neuronal integrity and brain functions, proposing a nutrient-based method for delaying cognitive and memory decline when LRP6 cell surface levels and functions are suboptimal.

Ultrafast self-gelling powder mediates robust wet adhesion to promote healing of gastrointestinal perforations

Achieving strong adhesion of bioadhesives on wet tissues remains a challenge and an acute clinical demand because of the interfering interfacial water and limited adhesive-tissue interactions. Here we report a self-gelling and adhesive polyethyleneimine and polyacrylic acid (PEI/PAA) powder, which can absorb interfacial water to form a physically cross-linked hydrogel in situ within 2 seconds due to strong physical interactions between the polymers. Furthermore, the physically cross-linked polymers can diffuse into the substrate polymeric network to enhance wet adhesion. Superficial deposition of PEI/PAA powder can effectively seal damaged porcine stomach and intestine despite excessive mechanical challenges and tissue surface irregularities. We further demonstrate PEI/PAA powder as an effective sealant to enhance the treatment outcomes of gastric perforation in a rat model. The strong wet adhesion, excellent cytocompatibility, adaptability to fit complex sites, and easy synthesis of PEI/PAA powder make it a promising bioadhesive for numerous biomedical applications.

Simeprevir Potently Suppresses SARS-CoV-2 Replication and Synergizes with Remdesivir

The outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global threat to human health. Using a multidisciplinary approach, we identified and validated the hepatitis C virus (HCV) protease inhibitor simeprevir as an especially promising repurposable drug for treating COVID-19. Simeprevir potently reduces SARS-CoV-2 viral load by multiple orders of magnitude and synergizes with remdesivir in vitro. Mechanistically, we showed that simeprevir not only inhibits the main protease (Mpro) and unexpectedly the RNA-dependent RNA polymerase (RdRp) but also modulates host immune responses. Our results thus reveal the possible anti-SARS-CoV-2 mechanism of simeprevir and highlight the translational potential of optimizing simeprevir as a therapeutic agent for managing COVID-19 and future outbreaks of CoV.

Design, Synthesis, Biological Evaluation and In Silico Studies of Pyrazole-Based NH2-Acyl Oseltamivir Analogues as Potent Neuraminidase Inhibitors

Oseltamivir represents one of the most successful neuraminidase (NA) inhibitors in the current anti-influenza therapy. The 150-cavity of NA was identified as an additional binding pocket, and novel NA inhibitors have been designed to occupy the 150-cavity based on the structure information of oseltamivir carboxylate (OC) in complex with NA. In this study, a series of C-5-NH2-acyl derivatives of OC containing the pyrazole moiety were synthesized. Several derivatives exhibited substantial inhibitory activity against NA. Moreover, in silico ADME evaluation indicated that the derivatives were drug-like with higher oral absorption rates and greater cell permeability than OC. Additionally, molecular docking studies revealed that the derivatives interacted with both the NA enzyme active site and 150-cavity as expected. The results provided useful information for further structural optimization of OC.

Identifying anti-coronavirus peptides by incorporating different negative datasets and imbalanced learning strategies

As the current worldwide outbreaks of the SARS-CoV-2, it is urgently needed to develop effective therapeutic agents for inhibiting the pathogens or treating the related diseases. Antimicrobial peptides (AMP) with functional activity against coronavirus could be a considerable solution, yet there is no research for identifying anti-coronavirus (anti-CoV) peptides with the computational approach. In this study, we first investigated the physiochemical and compositional properties of the collected anti-CoV peptides by comparing against three other negative sets: antivirus peptides without anti-CoV function (antivirus), regular AMP without antivirus functions (non-AVP) and peptides without antimicrobial functions (non-AMP). Then, we established classifiers for identifying anti-CoV peptides between different negative sets based on random forest. Imbalanced learning strategies were adopted due to the severe class-imbalance within the datasets. The geometric mean of the sensitivity and specificity (GMean) under the identification from antivirus, non-AVP and non-AMP reaches 83.07%, 85.51% and 98.82%, respectively. Then, to pursue identifying anti-CoV peptides from broad-spectrum peptides, we designed a double-stages classifier based on the collected datasets. In the first stage, the classifier characterizes AMPs from regular peptides. It achieves an area under the receiver operating curve (AUCROC) value of 97.31%. The second stage is to identify the anti-CoV peptides between the combined negatives of other AMPs. Here, the GMean of evaluation on the independent test set is 79.42%. The proposed approach is considered as an applicable scheme for assisting the development of novel anti-CoV peptides. The datasets and source codes used in this study are available at https://github.com/poncey/PreAntiCoV.

Photodynamic treatment with purpurin 18 effectively inhibits triple negative breast cancer by inducing cell apoptosis

This study aims to evaluate the photodynamic efficacy of purpurin 18 (pu-18) on triple negative breast cancer both in vitro and in vivo. Two states of 4T1 cells, 2D culture and 3D spheroids, were used to evaluate the photodynamic action of pu-18 in vitro. The in vitro study results indicated that for the 4T1 2D cell culture, the photodynamic therapy (PDT) treatment showed significant photocytotoxicity at low pu-18 concentrations following light irradiation. Pu-18 was found to distribute on the lysosomes, mitochondria, Golgi apparatus, and endoplasmic reticulum. After irradiation, pu-18 can generate ROS to destroy the mitochondrial membrane potential (MMP) and eventually induce apoptosis in the 2D 4T1 cells. Light-activated pu-18 could also induce the destruction of the 3D 4T1 cell spheroids. The in vivo study was conducted by using a subcutaneous 4T1 breast cancer animal model. The results demonstrated that pu-18 could remain in the tumor for more than 4 days by direct intra-tumoral injection. The PDT treatment was performed every 2 days for a total of 3 times. The results showed that PDT treatment could significantly inhibit tumor growth in vivo, indicating a good photodynamic efficacy of pu-18 in the mouse breast cancer model, without influencing weight and major organ function. The survival pattern results showed that PDT treatment could largely extend the survival time of mice with breast cancer. The preliminary conclusion is that photodynamic treatment using pu-18 is effective at preventing the growth of triple negative breast cancer cells both in vitro and in vivo. A combination of light irradiation and pu-18 could therefore be a worthwhile approach for the treatment of triple negative breast cancer.

The influence of congruency proportion, target eccentricity, and valence strength on the spatial-valence metaphoric congruency effect in a word valence judgment task

In a word valence judgment task, positive words (e.g., excellence) are judged faster when presented at the top (congruent position) than at the bottom of the screen (incongruent position), whereas the opposite pattern occurs for negative words (e.g., disaster). This spatial-valence metaphoric congruency effect reflects top-positive/bottom-negative metaphoric association and may be attributed to at least three possible mechanisms: spreading activation between spatial and valence concepts (activation account), epistemic function that a conceptual metaphor serves to reduce the uncertainty associated with valence concepts (epistemic account), and/or the extent to which spatial-valence metaphoric association is relevant to task demand (relevance account). In three experiments, we manipulated congruency proportion, target eccentricity, and valence strength in a word valence judgment task to test these three possible accounts. Results showed that the metaphoric congruency effect was larger when a high (vs. equal) proportion of targets appears in congruent, relative to incongruent, position, and for targets with strong (vs. weak) valence. However, the effect in reaction time measure was not modulated by whether the target appeared in the position being near vs. far away from the center of the screen. The overall findings are better accommodated by the relevance account. The implications of the current findings on other theoretical accounts, such as Conceptual Metaphor Theory and polarity correspondence account, are also discussed.

Millipede genomes reveal unique adaptations during myriapod evolution

The Myriapoda, composed of millipedes and centipedes, is a fascinating but poorly understood branch of life, including species with a highly unusual body plan and a range of unique adaptations to their environment. Here, we sequenced and assembled 2 chromosomal-level genomes of the millipedes Helicorthomorpha holstii (assembly size = 182 Mb; shortest scaffold/contig length needed to cover 50% of the genome [N50] = 18.11 Mb mainly on 8 pseudomolecules) and Trigoniulus corallinus (assembly size = 449 Mb, N50 = 26.78 Mb mainly on 17 pseudomolecules). Unique genomic features, patterns of gene regulation, and defence systems in millipedes, not observed in other arthropods, are revealed. Both repeat content and intron size are major contributors to the observed differences in millipede genome size. Tight Hox and the first loose ecdysozoan ParaHox homeobox clusters are identified, and a myriapod-specific genomic rearrangement including Hox3 is also observed. The Argonaute (AGO) proteins for loading small RNAs are duplicated in both millipedes, but unlike in insects, an AGO duplicate has become a pseudogene. Evidence of post-transcriptional modification in small RNAs—including species-specific microRNA arm switching—providing differential gene regulation is also obtained. Millipedes possesses a unique ozadene defensive gland unlike the venomous forcipules found in centipedes. We identify sets of genes associated with the ozadene that play roles in chemical defence as well as antimicrobial activity. Macro-synteny analyses revealed highly conserved genomic blocks between the 2 millipedes and deuterostomes. Collectively, our analyses of millipede genomes reveal that a series of unique adaptations have occurred in this major lineage of arthropod diversity. The 2 high-quality millipede genomes provided here shed new light on the conserved and lineage-specific features of millipedes and centipedes. These findings demonstrate the importance of the consideration of both centipede and millipede genomes—and in particular the reconstruction of the myriapod ancestral situation—for future research to improve understanding of arthropod evolution, and animal evolutionary genomics more widely.

Myriapods were among the first arthropods to invade the land over 400 million years ago, and survive today as the herbivorous millipedes and venomous centipedes. This study describes the genome sequences of two millipedes, Helicorthomorpha holstii and Trigoniulus corallinus, revealing unique adaptations not found in other arthropods.

Magnesium-mediated sp3 C-H activation in cascade cyclization of 1-arylethynyl-2-alkyl-o-carboranes: efficient synthesis of carborane-fused cyclopentanes

This work reports an unprecedented cascade cyclization of 1-arylethynyl-2-alkyl-o-carboranes promoted by magnesium-mediated sp3 C-H activation. Treatment of 1-arylethynyl-2-alkyl-o-carboranes with MeMgBr gives a series of carborane-fused cyclopentanes in very good yields. Deuterium labelling and control experiments suggest that HMgBr, resulting in situ from the nucleophilic substitution of cage B-H bonds with Grignard reagent, initiates the reaction, in which magnesium-promoted intramolecular sp3 C-H activation serves as a key step. This work not only offers a new route for the synthesis of carborane-fused cyclopentanes, but also sheds some light on Mg-mediated C-H activation and functionalization.

Dimensionality reduction for single cell RNA sequencing data using constrained robust non-negative matrix factorization

Single cell RNA-sequencing (scRNA-seq) technology, a powerful tool for analyzing the entire transcriptome at single cell level, is receiving increasing research attention. The presence of dropouts is an important characteristic of scRNA-seq data that may affect the performance of downstream analyses, such as dimensionality reduction and clustering. Cells sequenced to lower depths tend to have more dropouts than those sequenced to greater depths. In this study, we aimed to develop a dimensionality reduction method to address both dropouts and the non-negativity constraints in scRNA-seq data. The developed method simultaneously performs dimensionality reduction and dropout imputation under the non-negative matrix factorization (NMF) framework. The dropouts were modeled as a non-negative sparse matrix. Summation of the observed data matrix and dropout matrix was approximated by NMF. To ensure the sparsity pattern was maintained, a weighted ℓ1 penalty that took into account the dependency of dropouts on the sequencing depth in each cell was imposed. An efficient algorithm was developed to solve the proposed optimization problem. Experiments using both synthetic data and real data showed that dimensionality reduction via the proposed method afforded more robust clustering results compared with those obtained from the existing methods, and that dropout imputation improved the differential expression analysis.

Ultra-sensitive hybrid diamond nanothermometer

Nitrogen-vacancy (NV) centers in diamond are promising quantum sensors because of their long spin coherence time under ambient conditions. However, their spin resonances are relatively insensitive to non-magnetic parameters such as temperature. A magnetic-nanoparticle-nanodiamond hybrid thermometer, where the temperature change is converted to the magnetic field variation near the Curie temperature, were demonstrated to have enhanced temperature sensitivity ($11{\rm{\,\,mK\,\,H}}{{\rm{z}}^{ - 1/2}}$) (Wang N, Liu G-Q and Leong W-H et al. Phys Rev X 2018; 8: 011042), but the sensitivity was limited by the large spectral broadening of ensemble spins in nanodiamonds. To overcome this limitation, here we show an improved design of a hybrid nanothermometer using a single NV center in a diamond nanopillar coupled with a single magnetic nanoparticle of copper-nickel alloy, and demonstrate a temperature sensitivity of $76{\rm{\,\,\mu K\,\,H}}{{\rm{z}}^{ - 1/2}}$. This hybrid design enables detection of 2 mK temperature changes with temporal resolution of 5 ms. The ultra-sensitive nanothermometer offers a new tool to investigate thermal processes in nanoscale systems.