Type V Collagen in Scar Tissue Regulates the Size of Scar after Heart Injury.

Scar tissue size following myocardial infarction is an independent predictor of cardiovascular outcomes, yet little is known about factors regulating scar size. We demonstrate that collagen V, a minor constituent of heart scars, regulates the size of heart scars after ischemic injury. Depletion of collagen V led to a paradoxical increase in post-infarction scar size with worsening of heart function. A systems genetics approach across 100 in-bred strains of mice demonstrated that collagen V is a critical driver of postinjury heart function. We show that collagen V deficiency alters the mechanical properties of scar tissue, and altered reciprocal feedback between matrix and cells induces expression of mechanosensitive integrins that drive fibroblast activation and increase scar size. Cilengitide, an inhibitor of specific integrins, rescues the phenotype of increased post-injury scarring in collagen-V-deficient mice. These observations demonstrate that collagen V regulates scar size in an integrin-dependent manner.

miR-22-3p in the rostral ventrolateral medulla promotes hypertension through inhibiting ß-arrestin-1.

It has been documented that increased sympathetic activity contributes to the development of cardiovascular diseases, such as hypertension. We previously reported that ß-arrestin-1, a multifunctional cytoskeletal protein, was downregulated in the rostral ventrolateral medulla (RVLM) of the spontaneously hypertensive rat (SHR), and its overexpression elicited an inhibitory effect on sympathetic activity in hypertension. microRNA (miR)-22-3p has been reported to be associated with the pathological progress of hypertension. The purpose of this study was to determine the role of miR-22-3p in ß-arrestin-1-mediated central cardiovascular regulation in hypertension. It was observed that miR-22-3p was upregulated in the RVLM of SHRs compared with normotensive Wistar-Kyoto (WKY) rats, and it was subsequently confirmed to target the ß-arrestin-1 gene using a dual-luciferase reporter assay. miR-22-3p was downregulated in the RVLM using adeno-associated virus with 'tough decoys', which caused a significant increase of ß-arrestin-1 expression and decrease of noradrenaline and blood pressure (BP) in SHRs. However, upregulation of miR-22-3p using lentivirus in the RVLM of WKY rats significantly increased BP. In in vitro PC12 cells, enhanced oxidative stress activity induced by angiotensin II was counteracted by pretreatment with miR-22-3p inhibitor, and this effect could be abolished by ß-arrestin-1 gene knockdown. Furthermore, microglia exhaustion significantly diminished miR-22-3p expression, and enhanced ß-arrestin-1 expression in the RVLM of SHRs. Activation of BV2 cells in vitro evoked a significant increase of miR-22-3p expression, and this BV2 cell culture medium was also able to facilitate miR-22-3p expression in PC12 cells. Collectively, our findings support a critical role for microglia-derived miR-22-3p in inhibiting ß-arrestin-1 in the RVLM, which is involved in central cardiovascular regulation in hypertension. KEY POINTS: Impairment of ß-arrestin-1 function in the rostral ventrolateral medulla (RVLM) has been reported to be associated with the development of sympathetic overactivity in hypertension. However, little is known about the potential mechanisms of ß-arrestin-1 dysfunction in hypertension. miR-22-3p is implicated in multiple biological processes, but the role of miR-22-3p in central regulation of cardiovascular activity in hypertension remains unknown. We predicted that miR-22-3p could directly bind to the ß-arrestin-1 gene (Arrb1), and this hypothesis was confirmed by using a dual-luciferase reporter assay. Inhibition of ß-arrestin-1 by miR-22-3p was further verified in both in vivo and in vitro experiments. Furthermore, our results suggested miR-22-3p as a risk factor for oxidative stress in the RVLM, thus contributing to sympatho-excitation and hypertension. Our present study provides evidence that microglia-derived miR-22-3p may underlie the pathogenesis and progression of neuronal hypertension by inhibiting ß-arrestin-1 in the RVLM.

In vitro activity of taurolidine against clinical Candida auris isolates: relevance to catheter-related bloodstream infections.

Candida auris is an evolving and concerning global threat. Of particular concern are bloodstream infections related to central venous catheters. We evaluated the activity of taurolidine, a broad-spectrum antimicrobial in catheter lock solutions, against 106 C. auris isolates. Taurolidine was highly active with a MIC50/MIC90 of 512/512 mg/L, over 20-fold lower than lock solution concentrations of ≥13,500 mg/L. Our data demonstrate a theoretical basis for taurolidine-based lock solutions for prevention of C. auris catheter-associated infections.

Fecal Microbiota, Live-jslm for the Prevention of Recurrent Clostridioides difficile Infection : Subgroup Analysis of PUNCH CD2 and PUNCH CD3.

GOALS: To assess fecal microbiota, live-jslm (REBYOTA, abbreviated as RBL, formerly RBX2660) efficacy and safety in participants grouped by recurrent Clostridioides difficile infection (rCDI) risk factors and treatment-related variables. BACKGROUND: RBL is the first microbiota-based live biotherapeutic approved by the US Food and Drug Administration for the prevention of rCDI in adults after antibiotic treatment for rCDI. STUDY: Treatment success rates across subgroups for PUNCH CD3 (NCT03244644) were estimated using a Bayesian hierarchical model, borrowing data from PUNCH CD2 (NCT02299570). Treatment-emergent adverse events were summarized for the double-blind treatment period within 8 weeks. RESULTS: Treatment differences between RBL and placebo at 8 weeks were similar to the total population for most subgroups. Treatment effect sizes were similar between CDI tests, higher for oral vancomycin courses >14 days versus ≤14 days and higher for antibiotic washout periods of 3 days versus ≤2 days. The largest reductions in the rate of rCDI with RBL versus placebo were observed for participants with a 3-day CDI antibiotic washout period and participants with ≥4 previous CDI episodes. Most RBL-treated participants experienced TEAEs that were mild or moderate in severity and related to preexisting conditions. CONCLUSION: This analysis provides further evidence of RBL efficacy and safety across subgroups, including those at high risk for rCDI.

The Effects of MicroRNAs in the Development of Heart Failure.

PURPOSE OF REVIEW: Heart failure is a severe clinical syndrome with complex and unclarified mechanisms, and it poses a serious threat to human health. MicroRNA, a non-coding RNA, can directly bind to target genes and regulate their expression. The important role of microRNAs in the development of HF has become a hot topic of research in recent years. This paper summarizes and prospects the mechanisms of microRNAs in regulating cardiac remodeling during heart failure to provide reference ideas for further research and clinical treatment. RECENT FINDINGS: With extensive research, more target genes for microRNAs have been clarified. By modulating various molecules, microRNAs affect the contractile function of the myocardium and alter the process of myocardial hypertrophy, myocyte loss, and fibrosis, thereby interfering with the process of cardiac remodeling and exerting an important effect in the process of heart failure. Based on the above mechanism, microRNAs have promising applications in the diagnosis and treatment of heart failure. MicroRNAs form a complex post-transcriptional control mechanism of gene expression, and the increase or decrease of their content during heart failure largely alters the course of cardiac remodeling. By continuously identifying their target genes, it is expected to achieve more precise diagnosis and treatment of this important topic of heart failure.

Efficacy of bezlotoxumab to prevent recurrent Clostridioides difficile infection (CDI) in patients with multiple prior recurrent CDI.

Among 23 patients with multiply recurrent Clostridioides difficile infection (mrCDI) who received bezlotoxumab at the end of antibiotic treatment a sustained clinical response of 91 % at 30 days and 78 % at 90 days was achieved. Bezlotoxumab administered at the end of antibiotic treatment was effective in patients with mrCDI.

The Design and Development of Instrumented Toys for the Assessment of Infant Cognitive Flexibility.

The first years of an infant's life represent a sensitive period for neurodevelopment where one can see the emergence of nascent forms of executive function (EF), which are required to support complex cognition. Few tests exist for measuring EF during infancy, and the available tests require painstaking manual coding of infant behaviour. In modern clinical and research practice, human coders collect data on EF performance by manually labelling video recordings of infant behaviour during toy or social interaction. Besides being extremely time-consuming, video annotation is known to be rater-dependent and subjective. To address these issues, starting from existing cognitive flexibility research protocols, we developed a set of instrumented toys to serve as a new type of task instrumentation and data collection tool suitable for infant use. A commercially available device comprising a barometer and an inertial measurement unit (IMU) embedded in a 3D-printed lattice structure was used to detect when and how the infant interacts with the toy. The data collected using the instrumented toys provided a rich dataset that described the sequence of toy interaction and individual toy interaction patterns, from which EF-relevant aspects of infant cognition can be inferred. Such a tool could provide an objective, reliable, and scalable method of collecting early developmental data in socially interactive contexts.

KIF21A regulates breast cancer aggressiveness and is prognostic of patient survival and tumor recurrence.

PURPOSE: Invasion of carcinoma cells into surrounding tissue affects breast cancer staging, influences choice of treatment, and impacts on patient outcome. KIF21A is a member of the kinesin superfamily that has been well-studied in congenital extraocular muscle fibrosis. However, its biological relevance in breast cancer is unknown. This study investigated the functional roles of KIF21A in this malignancy and examined its expression pattern in breast cancer tissue. METHODS: The function of KIF21A in breast carcinoma was studied in vitro by silencing its expression in breast cancer cells and examining the changes in cellular activities. Immunohistochemical staining of breast cancer tissue microarrays was performed to determine the expression patterns of KIF21A. RESULTS: Knocking down the expression of KIF21A using siRNA in MDA-MB-231 and MCF7 human breast cancer cells resulted in significant decreases in tumor cell migration and invasiveness. This was associated with reduced Patched 1 expression and F-actin microfilaments. Additionally, the number of focal adhesion kinase- and paxillin-associated focal adhesions was increased. Immunohistochemical staining of breast cancer tissue microarrays showed that KIF21A was expressed in both the cytoplasmic and nuclear compartments of carcinoma cells. Predominance of cytoplasmic KIF21A was significantly associated with larger tumors and high grade cancer, and prognostic of cause-specific overall patient survival and breast cancer recurrence. CONCLUSION: The data demonstrates that KIF21A is an important regulator of breast cancer aggressiveness and may be useful in refining prognostication of this malignant disease.

Endothelial Nitric Oxide Synthase-Deficient Mice: A Model of Spontaneous Cerebral Small-Vessel Disease.

Age-related cerebral small-vessel disease (CSVD) is a major cause of stroke and dementia. Despite a widespread acceptance of small-vessel arteriopathy, lacunar infarction, diffuse white matter injury, and cognitive impairment as four cardinal features of CSVD, a unifying pathologic mechanism of CSVD remains elusive. Herein, we introduce partial endothelial nitric oxide synthase (eNOS)-deficient mice as a model of age-dependent, spontaneous CSVD. These mice developed cerebral hypoperfusion and blood-brain barrier leakage at a young age, which progressively worsened with advanced age. Their brains exhibited elevated oxidative stress, astrogliosis, cerebral amyloid angiopathy, microbleeds, microinfarction, and white matter pathology. Partial eNOS-deficient mice developed gait disturbances at middle age, and hippocampus-dependent memory deficits at older ages. These mice also showed enhanced expression of bone morphogenetic protein 4 (BMP4) in brain pericytes before myelin loss and white matter pathology. Because BMP4 signaling not only promotes astrogliogenesis but also blocks oligodendrocyte differentiation, we posit that paracrine actions of BMP4, localized within the neurovascular unit, promote white matter disorganization and neurodegeneration. These observations point to BMP4 signaling pathway in the aging brain vasculature as a potential therapeutic target. Finally, because studies in partial eNOS-deficient mice corroborated recent clinical evidence that blood-brain barrier disruption is a primary cause of white matter pathology, the mechanism of impaired nitric oxide signaling-mediated CSVD warrants further investigation.

The interleukin-enhanced binding factor 3-mediated inhibition of nitric oxide production via phosphoinositide 3-kinase/protein kinase B pathway contributes to central cardiovascular regulation in the rostral ventrolateral medulla in hypertension.

Hypertension is characterized by sympathetic hyperactivity, which is related to the overexcitation of the presympathetic neurons in the rostral ventrolateral medulla (RVLM). Nitric oxide (NO) has been reported to be a vital neuromodulator involved in central cardiovascular regulation. However, the mechanism of interleukin-enhanced binding factor 3 (ILF3) participating in blood pressure (BP) regulation is still unclear. Therefore, this study aims to clarify the role of ILF3 within the rostral ventrolateral medulla (RVLM) in regulating NO in hypertension. It was found that the expression level of ILF3 was significantly increased in the RVLM of spontaneously hypertensive rats (SHR) compared with Wistar-Kyoto (WKY) rats through microarray gene expression analysis, Western blot, and immunofluorescence. Overexpression of ILF3 by injecting constructed adenovirus into the RVLM increased the BP and renal sympathetic nerve activity (RSNA) of the WKY rats, significantly decreasing NO production and neuronal nitric oxide synthase (nNOS) expression. Knockdown of ILF3 in the RVLM of SHR significantly reduced BP but increased NO production and the neuronal nitric oxide synthase (nNOS) expression. Furthermore, it was found that the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway was activated via Western blotting in the RVLM after overexpression of ILF3, whereas it was attenuated after knockdown of ILF3 in SHR. In addition, inhibition of PI3K by intracisternal infusion of the PI-103 attenuated the increase in Akt phosphorylation and decrease in nNOS expression and NO production caused by overexpressing ILF3, which ultimately blunted high BP induced by overexpressing ILF3. Taken together, this current study suggests that ILF3 participates in high BP via reducing NO production in the RVLM through PI3K/Akt pathway.

Avoidant coping as mediator of the relationship between rumination and mental health among family caregivers of Chinese breast cancer patients.

INTRODUCTION: Family caregivers of cancer patients were often referred to the 'forgotten patients', yet little researches have been conducted on their mental health. Rumination might put family caregivers at risk for psychological distress during the caregiving, such as stress and anxiety. The aim of the present study was to explore the relationship between rumination, stress and anxiety among family caregivers of breast cancer patients in China and examine the mediating role of avoidant coping in this relationship. METHODS: Face-to-face questionnaire interviews were conducted with a sample of 99 caregivers from the public oncology hospital. They were assessed with stress, anxiety, rumination and avoidant coping by Chinese Perceived Stress Scale, Zung's Self-Rating Anxiety Scale, Ruminative Responses Scale and Coping Strategy Indicator. Structural equation modelling was applied to assess the mediation analysis. RESULTS: The reporting scores of participants indicated the incidence of anxiety was 17.2%. Rumination could directly predict stress (ß = 0.58, p < 0.01) and anxiety (ß = 0.46, p < 0.01) and also predict stress and anxiety via the mediator of avoidant coping (stress: ß = 0.087, p < 0.01; anxiety: ß = 0.109, p < 0.01). CONCLUSIONS: The important role played by family caregivers in supporting breast cancer patients is well recognised. The findings suggested that rumination and avoidant coping may be two critical risk factors for family caregivers of breast cancer developing stress and anxiety. This study highlights the importance of preventing avoidant coping, which plays a critical role for developing interventions for this vulnerable group.

Effectiveness of Exercise in Improving Sleep Outcomes among Perinatal Women: A Systematic Review and Meta-analysis of randomised Controlled Trials.

BACKGROUND: Sleep problems are prevalent among perinatal women, contributing to the poor overall well-being of mother and child. Exercise is an inexpensive and sustainable intervention to improve sleep outcomes and can be personalized accordingly to individuals. This systematic review and meta-analysis aim to consolidate available evidence to evaluate the effectiveness of exercise on improving sleep outcomes among perinatal women. METHODS: Eight databases (CINAHL, Cochrane, EMBASE, PsycINFO, PubMed, Scopus, Web of Science and ProQuest) were used to perform a systematic search for studies in the English language from the inception of each database to 7 December 2019. The quality of studies was assessed using the risk of bias and GRADE. Review Manager was used for meta-analyses. Heterogeneity was determined by Cochran's Q (chi-square) and I2 values. The overall effect was evaluated using effect size and Z-statistics. RESULTS: A total of 2,139 records were identified. Ten randomized controlled trials were included, with seven in the meta-analysis, involving 998 pregnant and postpartum women across eight countries. With medium to very large effect sizes, the results favored exercise interventions on sleep quality, sleep efficiency, sleep duration, sleep latency, insomnia, diurnal tiredness and daytime dysfunction. CONCLUSION: Exercise interventions produced significant effects on improving sleep among perinatal women. This can increase advocacy for exercise among perinatal women to improve sleep and general health. Future randomized controlled trial designs should adhere to the Consolidated Standards of Reporting Trials and Template to ensure reliability when conducting and reporting such studies.

LncRNA LINC00115 facilitates lung cancer progression through miR-607/ITGB1 pathway.

Dysregulated long noncoding RNAs (lncRNAs) have potential roles in various cancer types. The objective of this study was to investigate the expression and the underlying role of long intergenic nonprotein coding RNA 115 (LINC00115) in lung cancer. The relative expression of LINC00115 and miR-607 in tumor tissues and cells was detected by real-time PCR. After overexpression or knockdown of LINC00115 expression in tumor cells, the changes in the proliferation, migration, and invasion capacities were detected via Counting Kit-8 (CCK-8) assay and transwell assays. The interplay among LINC00115, miR-607, and integrin ß1 (ITGB1) was confirmed by bioinformatics analyses and luciferase reporter assay. In addition, tumor cells with LINC00115 knockdown were injected into nude mice to investigate the effect of LINC00115 on tumorigenesis in vivo. LINC00115 was highly expressed in tumor tissues and cells. LINC00115 promoted the malignant properties of tumor cells. Investigation to its molecular mechanism revealed that LINC00115 functioned as a competitive endogenous RNA (ceRNA), regulating the expression of ITGB1 by sponging miR-607 to affect tumor growth. The LINC00115/miR-607/ITGB1 signaling axis might be a novel therapeutic target in lung cancer.

Activation of Focal Adhesion Kinase Restores Simulated Microgravity-Induced Inhibition of Osteoblast Differentiation via Wnt/Β-Catenin Pathway.

Simulated microgravity (SMG) inhibits osteoblast differentiation (OBD) and induces bone loss via the inhibition of the Wnt/ß-catenin pathway. However, the mechanism by which SMG alters the Wnt/ß-catenin pathway is unknown. We previously demonstrated that SMG altered the focal adhesion kinase (FAK)-regulated mTORC1, AMPK and ERK1/2 pathways, leading to the inhibition of tumor cell proliferation/metastasis and promoting cell apoptosis. To examine whether FAK similarly mediates SMG-dependent changes to Wnt/ß-catenin in osteoblasts, we characterized mouse MC3T3-E1 cells cultured under clinostat-modeled SMG (µg) conditions. Compared to cells cultured under ground (1 g) conditions, SMG reduces focal adhesions, alters cytoskeleton structures, and down-regulates FAK, Wnt/ß-catenin and Wnt/ß-catenin-regulated molecules. Consequently, protein-2 (BMP2), type-1 collagen (COL1), alkaline-phosphatase activity and matrix mineralization are all inhibited. In the mouse hindlimb unloading (HU) model, SMG-affected tibial trabecular bone loss is significantly reduced, according to histological and micro-computed tomography analyses. Interestingly, the FAK activator, cytotoxic necrotizing factor-1 (CNF1), significantly suppresses all of the SMG-induced alterations in MC3T3-E1 cells and the HU model. Therefore, our data demonstrate the critical role of FAK in the SMG-induced inhibition of OBD and bone loss via the Wnt/ß-catenin pathway, offering FAK signaling as a new therapeutic target not only for astronauts at risk of OBD inhibition and bone loss, but also osteoporotic patients.

The Identification of APOBEC3G as a Potential Prognostic Biomarker in Acute Myeloid Leukemia and a Possible Drug Target for Crotonoside.

The apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G) converts cytosine to uracil in DNA/RNA. Its role in resisting viral invasion has been well documented. However, its expression pattern and potential function in AML remain unclear. In this study, we carried out a bioinformatics analysis and revealed that the expression of APOBEC3G was significantly upregulated in AML, and high expression of APOBEC3G was significantly associated with short overall survival (OS). APOBEC3G expression was especially increased in non-M3AML, and correlated with the unfavorable cytogenetic risks. Additionally, Cox regression analyses indicated APOBEC3G is a hazard factor that cannot be ignored for OS of AML patients. In molecular docking simulations, the natural product crotonoside was found to interact well with APOBEC3G. The expression of APOBEC3G is the highest in KG-1 cells, and the treatment with crotonoside can reduce the expression of APOBEC3G. Crotonoside can inhibit the viability of different AML cells in vitro, arrest KG-1 and MV-4-11 cells in the S phase of the cell cycle and affect the expression of cycle-related proteins, and induce cell apoptosis. Therefore, APOBEC3G could be a potential drug target of crotonoside, and crotonoside can be considered as a lead compound for APOBEC3G inhibition in non-M3 AML.

A Tapered-pulsed Fidaxomicin Regimen Following Treatment in Patients With Multiple Clostridioides difficile Infection Recurrences.

We treated 46 patients with multiple recurrent Clostridioides difficile infections (mrCDI) using a tapered-pulsed (T-P) fidaxomicin regimen, the majority of whom failed prior T-P vancomycin treatment. Sustained clinical response rates at 30 and 90 days were 74% (34/46) and 61% (28/46). T-P fidaxomicin shows promise for management of mrCDI.

Pharmacokinetics and dialytic clearance of apixaban during in vitro continuous renal replacement therapy.

BACKGROUND: To evaluate the transmembrane clearance (CLTM) of apixaban during modeled in vitro continuous renal replacement therapy (CRRT), assess protein binding and circuit adsorption, and provide initial dosing recommendations. METHODS: Apixaban was added to the CRRT circuit and serial pre-filter bovine blood samples were collected along with post-filter blood and effluent samples. All experiments were performed in duplicate using continuous veno-venous hemofiltration (CVVH) and hemodialysis (CVVHD) modes, with varying filter types, flow rates, and point of CVVH replacement fluid dilution. Concentrations of apixaban and urea were quantified via liquid chromatography-tandem mass spectrometry. Plasma pharmacokinetic parameters for apixaban were estimated via noncompartmental analysis. CLTM was calculated via the estimated area under the curve (AUC) and by the product of the sieving/saturation coefficient (SC/SA) and flow rate. Two and three-way analysis of variance (ANOVA) models were built to assess the effects of mode, filter type, flow rate, and point of dilution on CLTM by each method. Optimal doses were suggested by matching the AUC observed in vitro to the systemic exposure demonstrated in Phase 2/3 studies of apixaban. Linear regression was utilized to provide dosing estimations for flow rates from 0.5-5 L/h. RESULTS: Mean adsorption to the HF1400 and M150 filters differed significantly at 38 and 13%, respectively, while mean (± standard deviation, SD) percent protein binding was 70.81 ± 0.01%. Effect of CVVH point of dilution did not differ across filter types, although CLTM was consistently significantly higher during CRRT with the HF1400 filter compared to the M150. The three-way ANOVA demonstrated improved fit when CLTM values calculated by AUC were used (adjusted R2 0.87 vs. 0.52), and therefore, these values were used to generate optimal dosing recommendations. Linear regression revealed significant effects of filter type and flow rate on CLTM by AUC, suggesting doses of 2.5-7.5 mg twice daily (BID) may be needed for flow rates ranging from 0.5-5 L/h, respectively. CONCLUSION: For CRRT flow rates most commonly employed in clinical practice, the standard labeled 5 mg BID dose of apixaban is predicted to achieve target systemic exposure thresholds. The safety and efficacy of these proposed dosing regimens warrants further investigation in clinical studies.

Correlation and the concentrations of Pb, Cd, Hg and As in vegetables and soils of Chongqing, China.

This paper studies the concentration of Pb, Cd, Hg and As in vegetable and soil of 13 main vegetable base, Chongqing, China, as well as the correlation between them. Results show that the concentrations of heavy metals in different vegetables from 13 main vegetable bases of Chongqing are also significantly different. The order of Pb concentration is root vegetable (the average value is 0.203 mg/kg) > leaf vegetable (the average value is 0.065 mg/kg) > solanaceous vegetable (the average value is 0.004 mg/kg); the order of Cd concentration is leaf vegetable (the average value is 0.090 mg/kg) > solanaceous vegetable (the average value is 0.061 mg/kg) > root vegetable (the average value is 0.049 mg/kg); the order of Hg concentration is leaf vegetable (the average value is 0.004 mg/kg) > root vegetable (the average value is 0.003 mg/kg) > solanaceous vegetable (the average value is 0.001 mg/kg); the order of As concentration is root vegetable (the average value is 0.116 mg/kg) > solanaceous vegetable (the average value is 0.057 mg/kg) > leaf vegetable (the average value is 0.026 mg/kg). Significant positive correlation was found between the Cd concentration in vegetables and the Cd concentration in soil, and the linear equation was y = 0.065 + 0.012x. There was no significant correlation between the concentrations of Pb, Hg and As in vegetables and Pb, Hg and As in soil.

New mechanistic pathways for the formation of organosulfates catalyzed by ammonia and carbinolamine formation catalyzed by sulfuric acid in the atmosphere.

In the secondary organic aerosol formation, exploring the formation of nucleation precursors is of paramount importance for understanding the secondary organic aerosol formation. Here, we report new mechanistic pathways for the formation of organosulfates and carbinolamine in the atmospheric gas phase by utilizing a high-level W2X//QCISD/cc-pV(T+d)Z method close to CCSD(T)/CBS accuracy, dual level kinetics strategy by combining multistructural variational the transition state theory, containing small-curvature tunneling at the M08-SO/maug-cc-pVTZ level with the conventional transition state theory at the W2X//QCISD/cc-pV(T+d)Z level, and torsional anharmonicity. However, a previously suggested mechanism indicated that these are only formed in the heterogeneous atmospheric chemical processes. Furthermore, we find that ammonia only exerts a catalytic role in the HCHO + H2SO4 reaction responsible for the formation of organosulfates under some atmospheric conditions, whereas sulfuric acid can significantly promote the HCHO + NH3 reactions, resulting in the formation of carbinolamine in the atmosphere. These calculated results also show that the ammonia-catalyzed reaction of formaldehyde with sulfuric acid can play an important role in the loss of formaldehyde and the sulfuric acid-catalyzed reaction of formaldehyde with ammonia can also contribute towards the loss of ammonia under some atmospheric conditions. In theory, detailed computational strategies have been designed to obtain quantitative rate constants for the reactions investigated here. A remarkable decrease in the rate constant of the reaction between HCHO and H2SO4NH3 is also observed due to recrossing effects. In addition, the calculated results show that M08-SO functional can provide reliable results for describing the reactions studied here with unsigned error bars of less than 1 kcal mol-1.

Asymmetric synthesis of CF2-functionalized aziridines by combined strong Brønsted acid catalysis.

A diastereo- and enantioselective approach to access chiral CF2-functionalized aziridines from difluorodiazoethyl phenyl sulfone (PhSO2CF2CHN2) and in situ-formed aldimines is described. This multicomponent reaction is enabled by a combined strong Brønsted acid catalytic platform consisting of a chiral disulfonimide and 2-carboxyphenylboronic acid. The optical purity of the obtained CF2-substituted aziridines could be further improved by a practical dissolution-filtration procedure.