Enantioconvergent Cu-catalysed N-alkylation of aliphatic amines.

Chiral amines are commonly used in the pharmaceutical and agrochemical industries1. The strong demand for unnatural chiral amines has driven the development of catalytic asymmetric methods1,2. Although the N-alkylation of aliphatic amines with alkyl halides has been widely adopted for over 100 years, catalyst poisoning and unfettered reactivity have been preventing the development of a catalyst-controlled enantioselective version3-5. Here we report the use of chiral tridentate anionic ligands to enable the copper-catalysed chemoselective and enantioconvergent N-alkylation of aliphatic amines with α-carbonyl alkyl chlorides. This method can directly convert feedstock chemicals, including ammonia and pharmaceutically relevant amines, into unnatural chiral α-amino amides under mild and robust conditions. Excellent enantioselectivity and functional-group tolerance were observed. The power of the method is demonstrated in a number of complex settings, including late-stage functionalization and in the expedited synthesis of diverse amine drug molecules. The current method indicates that multidentate anionic ligands are a general solution for overcoming transition-metal-catalyst poisoning.

In Situ Electrochemical Rapid Induction of Highly Active γ-NiOOH Species for Industrial Anion Exchange Membrane Water Electrolyzer.

Limited by the strong oxidation environment and sluggish reconstruction process in oxygen evolution reaction (OER), designing rapid self-reconstruction with high activity and stability electrocatalysts is crucial to promoting anion exchange membrane (AEM) water electrolyzer. Herein, trace Fe/S-modified Ni oxyhydroxide (Fe/S-NiOOH/NF) nanowires are constructed via a simple in situ electrochemical oxidation strategy based on precipitation-dissolution equilibrium. In situ characterization techniques reveal that the successful introduction of Fe and S leads to lattice disorder and boosts favorable hydroxyl capture, accelerating the formation of highly active γ-NiOOH. The Density Functional Theory (DFT) calculations have also verified that the incorporation of Fe and S optimizes the electrons redistribution and the d-band center, decreasing the energy barrier of the rate-determining step (*O→*OOH). Benefited from the unique electronic structure and intermediate adsorption, the Fe/S-NiOOH/NF catalyst only requires the overpotential of 345 mV to reach the industrial current density of 1000 mA cm-2 for 120 h. Meanwhile, assembled AEM water electrolyzer (Fe/S-NiOOH//Pt/C-60 °C) can deliver 1000 mA cm-2 at a cell voltage of 2.24 V, operating at the average energy efficiency of 71% for 100 h. In summary, this work presents a rapid self-reconstruction strategy for high-performance AEM electrocatalysts for future hydrogen economy.

Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO2 for Synergistic Catalytic Elimination of NOx and Chlorobenzene.

The development of efficient technologies for the synergistic catalytic elimination of NOx and chlorinated volatile organic compounds (CVOCs) remains challenging. Chlorine species from CVOCs are prone to catalyst poisoning, which increases the degradation temperature of CVOCs and fails to balance the selective catalytic reduction of NOx with the NH3 (NH3-SCR) performance. Herein, synergistic catalytic elimination of NOx and chlorobenzene has been originally demonstrated by using phosphotungstic acid (HPW) as a dechlorination agent to collaborate with CeO2. The conversion of chlorobenzene was over 80% at 270 °C, and the NOx conversion and N2 selectivity reached over 95% at 270-420 °C. HPW not only allowed chlorine species to leave as inorganic chlorine but also enhanced the BroÌ·nsted acidity of CeO2. The NH4+ produced in the NH3-SCR process can effectively promote the dechlorination of chlorobenzene at low temperatures. HPW remained structurally stable in the synergistic reaction, resulting in good water resistance and long-term stability. This work provides a cheaper and more environmentally friendly strategy to address chlorine poisoning in the synergistic reaction and offers new guidance for multipollutant control.

Differential Proteomic Analysis of Low-Dose Chronic Paralytic Shellfish Poisoning.

Shellfish poisoning is a common food poisoning. To comprehensively characterize proteome changes in the whole brain due to shellfish poisoning, Tandem mass tag (TMT)-based differential proteomic analysis was performed with a low-dose chronic shellfish poisoning model in mice. A total of 6798 proteins were confidently identified, among which 123 proteins showed significant changes (fold changes of >1.2 or <0.83, p < 0.05). In positive regulation of synaptic transmission, proteins assigned to a presynaptic membrane (e.g., Grik2) and synaptic transmission (e.g., Fmr1) changed. In addition, altered proteins in nervous system development were observed, suggesting that mice suffered nerve damage due to the nervous system being activated. Ion transport in model mice was demonstrated by a decrease in key enzymes (e.g., Kcnj11) in voltage-gated ion channel activity and solute carrier family (e.g., Slc38a3). Meanwhile, alterations in transferase activity proteins were observed. In conclusion, these modifications observed in brain proteins between the model and control mice provide valuable insights into understanding the functional mechanisms underlying shellfish poisoning.

SCF/C-kit drives spermatogenesis disorder induced by abscopal effects of cranial irradiation in mice.

Cranial radiotherapy is a major treatment for leukemia and brain tumors. Our previous study found abscopal effects of cranial irradiation could cause spermatogenesis disorder in mice. However, the exact mechanisms are not yet fully understood. In the study, adult male C57BL/6 mice were administrated with 20 Gy X-ray cranial irradiation (5 Gy per day for 4 days consecutively) and sacrificed at 1, 2 and 4 weeks. Tandem Mass Tag (TMT) quantitative proteomics of testis was combined with bioinformatics analysis to identify key molecules and signal pathways related to spermatogenesis at 4 weeks after cranial irradiation. GO analysis showed that spermatogenesis was closely related to oxidative stress and inflammation. Severe oxidative stress occurred in testis, serum and brain, while serious inflammation also occurred in testis and serum. Additionally, the sex hormones related to hypothalamic-pituitary-gonadal (HPG) axis were disrupted. PI3K/Akt pathway was activated in testis, which upstream molecule SCF/C-Kit was significantly elevated. Furthermore, the proliferation and differentiation ability of spermatogonial stem cells (SSCs) were altered. These findings suggest that cranial irradiation can cause spermatogenesis disorder through brain-blood-testicular cascade oxidative stress, inflammation and the secretory dysfunction of HPG axis, and SCF/C-kit drive this process through activating PI3K/Akt pathway.

Copper-Catalyzed Enantioconvergent Radical C(sp3)-N Cross-Coupling of Activated Racemic Alkyl Halides with (Hetero)aromatic Amines under Ambient Conditions.

The enantioconvergent C(sp3)-N cross-coupling of racemic alkyl halides with (hetero)aromatic amines represents an ideal means to afford enantioenriched N-alkyl (hetero)aromatic amines yet has remained unexplored due to the catalyst poisoning specifically for strong-coordinating heteroaromatic amines. Here, we demonstrate a copper-catalyzed enantioconvergent radical C(sp3)-N cross-coupling of activated racemic alkyl halides with (hetero)aromatic amines under ambient conditions. The key to success is the judicious selection of appropriate multidentate anionic ligands through readily fine-tuning both electronic and steric properties for the formation of a stable and rigid chelating Cu complex. Thus, this kind of ligand could not only enhance the reducing capability of a copper catalyst to provide an enantioconvergent radical pathway but also avoid the coordination with other coordinating heteroatoms, thereby overcoming catalyst poisoning and/or chiral ligand displacement. This protocol covers a wide range of coupling partners (89 examples for activated racemic secondary/tertiary alkyl bromides/chlorides and (hetero)aromatic amines) with high functional group compatibility. When allied with follow-up transformations, it provides a highly flexible platform to access synthetically useful enantioenriched amine building blocks.

Identification of a (+)-cubenene synthase from filamentous fungi Acremonium chrysogenum.

Sesquiterpene synthases convert farnesyl diphosphate into various sesquiterpenes, which find wide applications in the food, cosmetics and pharmaceutical industries. Although numerous putative sesquiterpene synthases have been identified in fungal genomes, many lack biochemical characterization. In this study, we identified a putative terpene synthase AcTPS3 from Acremonium chrysogenum. Through sequence analysis and in vitro enzyme assay, AcTPS3 was identified as a sesquiterpene synthase. To obtain sufficient product for NMR testing, a metabolic engineered Saccharomyces cerevisiae was constructed to overproduce the product of AcTPS3. The major product of AcTPS3 was identified as (+)-cubenene (55.46%) by GC-MS and NMR. Thus, AcTPS3 was confirmed as (+)-cubenene synthase, which is the first report of (+)-cubenene synthase. The optimized S. cerevisiae strain achieved a biosynthesis titer of 597.3 mg/L, the highest reported for (+)-cubenene synthesis.

NPAS2 promotes aerobic glycolysis and tumor growth in prostate cancer through HIF-1A signaling.

BACKGROUND: Prostate cancer (PCa), one of the common malignant tumors, is the second leading cause of cancer-related deaths in men. The circadian rhythm plays a critical role in disease. Circadian disturbances are often found in patients with tumors and enable to promote tumor development and accelerate its progression. Accumulating evidence suggests that the core clock gene NPAS2 (neuronal PAS domain-containing protein 2) has been implicated in tumors initiation and progression. However, there are few studies on the association between NPAS2 and prostate cancer. The purpose of this paper is to investigate the impact of NPAS2 on cell growth and glucose metabolism in prostate cancer. METHODS: Quantitative real-time PCR (qRT-PCR), immunohistochemical (IHC) staining, western blot, GEO (Gene Expression Omnibus) and CCLE (Cancer Cell Line Encyclopedia) databases were used to analyze the expression of NPAS2 in human PCa tissues and various PCa cell lines. Cell proliferation was assessed using MTS, clonogenic assays, apoptotic analyses, and subcutaneous tumor formation experiments in nude mice. Glucose uptake, lactate production, cellular oxygen consumption rate and medium pH were measured to examine the effect of NPAS2 on glucose metabolism. The relation of NPAS2 and glycolytic genes was analyzed based on TCGA (The Cancer Genome Atlas) database. RESULTS: Our data showed that NPAS2 expression in prostate cancer patient tissue was elevated compared with that in normal prostate tissue. NPAS2 knockdown inhibited cell proliferation and promoted cell apoptosis in vitro and suppressed tumor growth in a nude mouse model in vivo. NPAS2 knockdown led to glucose uptake and lactate production diminished, oxygen consumption rate and pH elevated. NPAS2 increased HIF-1A (hypoxia-inducible factor-1A) expression, leading to enhanced glycolytic metabolism. There was a positive correlation with the expression of NPAS2 and glycolytic genes, these genes were upregulated with overexpression of NPAS2 while knockdown of NPAS2 led to a lower level. CONCLUSION: NPAS2 is upregulated in prostate cancer and promotes cell survival by promoting glycolysis and inhibiting oxidative phosphorylation in PCa cells.

Exogenous Melatonin Regulates Plant-Disease Interaction by Inducing Maize Resistance and Decreasing the Pathogenicity of Fusarium graminearum.

Plants cannot avoid environmental challenges and are constantly threatened by diverse biotic and abiotic stresses. However, plants have developed a unique immune system to defend themselves against the invasion of various pathogens. Melatonin, N-acetyl-5-methoxytryptamine has positive physiological effects in plants that are involved in disease resistance. The processes underlying melatonin-induced pathogen resistance in plants are still unknown. The current study explores how melatonin regulates the plant-disease interaction in maize. The results showed that 400 µM melatonin strongly reduced the disease lesion on maize stalks by 1.5 cm and corn by 4.0 cm caused by Fusarium graminearum PH-1. Furthermore, after treatment with melatonin, the plant defense enzymes like SOD significantly increased, while POD and APX significantly decreased compared to the control. In addition, melatonin can also improve maize's innate immunity, which is mediated by melatonin treatments through the salicylic acid signaling pathway, and up-regulate the defense-associated expression of PR1, LOX1, OXR, serPIN, and WIPI genes in maize. Melatonin not only inhibits the disease in the maize stalks and corn, but also down-regulates the deoxynivalenol (DON) production-related expression of genes Tri1, Tri4, Tri5, and Tri6 in maize. Overall, this study sheds new light on the mechanisms by which melatonin regulates antioxidant enzymes and defense-related genes involved in plant immunity to effectively suppress plant diseases.

Comparison of prostate volume measured by transabdominal ultrasound and MRI with the radical prostatectomy specimen volume: a retrospective observational study.

BACKGROUND: Few studies have compared the use of transabdominal ultrasound (TAUS) and magnetic resonance imaging (MRI) to measure prostate volume (PV). In this study, we evaluate the accuracy and reliability of PV measured by TAUS and MRI. METHODS: A total of 106 patients who underwent TAUS and MRI prior to radical prostatectomy were retrospectively analyzed. The TAUS-based and MRI-based PV were calculated using the ellipsoid formula. The specimen volume measured by the water-displacement method was used as a reference standard. Correlation analysis and intraclass correlation coefficients (ICC) were performed to compare different measurement methods and Bland Altman plots were drawn to assess the agreement. RESULTS: There was a high degree of correlation and agreement between the specimen volume and PV measured with TAUS (r = 0.838, p < 0.01; ICC = 0.83) and MRI (r = 0.914, p < 0.01; ICC = 0.90). TAUS overestimated specimen volume by 2.4ml, but the difference was independent of specimen volume (p = 0.19). MRI underestimated specimen volume by 1.7ml, the direction and magnitude of the difference varied with specimen volume (p < 0.01). The percentage error of PV measured by TAUS and MRI was within ± 20% in 65/106(61%) and 87/106(82%), respectively. In patients with PV greater than 50 ml, MRI volume still correlated strongly with specimen volume (r = 0.837, p < 0.01), while TAUS volume showed only moderate correlation with specimen (r = 0.665, p < 0.01) or MRI volume (r = 0.678, p < 0.01). CONCLUSIONS: This study demonstrated that PV measured by MRI and TAUS is highly correlated and reliable with the specimen volume. MRI might be a more appropriate choice for measuring the large prostate.

Efficacy of Deep Brain Stimulation for Camptocormia in Parkinson's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Camptocormia is one of the most common postural disorders of Parkinson's disease (PD) which has limited treatment options. In this review, we summarize the efficacy of deep brain stimulation (DBS) for camptocormia in PD. METHODS: The PubMed (https://pubmed.ncbi.nlm.nih.gov/) and EMBASE databases (https://www.embase.com/) were searched for the terms "Parkinson Disease" and "camptocormia" in combination with "deep brain stimulation". We then explored the efficacy of DBS for camptocormia by statistical analysis of the bending angle, the Unified Parkinson's Disease Rating Scale III (UPDRS-III) and L-dopa equivalent daily dose (LEDD), and by evaluating the prognosis after DBS. RESULTS: Twenty articles that reported results for 152 patients were included in this review. These comprised 136 patients from 16 studies who underwent subthalamic nucleus deep brain stimulation (STN-DBS), and 13 patients from 3 studies who underwent globus pallidus internus deep brain stimulation (GPi-DBS). One study used both STN-DBS (2 patients) and GPi-DBS (one patient). After 3-21 months of follow-up, the mean bending angle during the Off-period was significantly reduced compared to pre-DBS (31.5 ± 21.4 vs. 53.6 ± 22.7, respectively; p < 0.0001). For the STN-DBS trials, the mean post-operative bending angles during both Off- and On-periods were significantly reduced compared to pre-operative (32.1 ± 22.7 vs. 55.4 ± 24.1, p = 0.0003; and 33.1 ± 21.5 vs. 43.7 ± 20.6, p = 0.0003, respectively). For GPi-DBS, the mean bending angle post-DBS during the Off-period was considerably lower than pre-DBS (28.5 ± 10.7 vs. 42.9 ± 9.9, p < 0.001). The decrease in bending angle after DBS was negatively correlated with the duration of camptocormia (R = - 0.433, p = 0.013), whereas positively associated with the pre-bending angle (R = 0.352, p = 0.03). CONCLUSIONS: DBS is an effective treatment for camptocormia in PD. Patients in the early stage of camptocormia with more significant bending angle may benefit more from DBS.

Biologically inspired robotic perception-action for soft fruit harvesting in vertical growing environments.

Multiple interlinked factors like demographics, migration patterns, and economics are presently leading to the critical shortage of labour available for low-skilled, physically demanding tasks like soft fruit harvesting. This paper presents a biomimetic robotic solution covering the full 'Perception-Action' loop targeting harvesting of strawberries in a state-of-the-art vertical growing environment. The novelty emerges from both dealing with crop/environment variance as well as configuring the robot action system to deal with a range of runtime task constraints. Unlike the commonly used deep neural networks, the proposed perception system uses conditional Generative Adversarial Networks to identify the ripe fruit using synthetic data. The network can effectively train the synthetic data using the image-to-image translation concept, thereby avoiding the tedious work of collecting and labelling the real dataset. Once the harvest-ready fruit is localised using point cloud data generated by a stereo camera, our platform's action system can coordinate the arm to reach/cut the stem using the Passive Motion Paradigm framework inspired by studies on neural control of movement in the brain. Results from field trials for strawberry detection, reaching/cutting the stem of the fruit, and extension to analysing complex canopy structures/bimanual coordination (searching/picking) are presented. While this article focuses on strawberry harvesting, ongoing research towards adaptation of the architecture to other crops such as tomatoes and sweet peppers is briefly described. Supplementary Information: The online version contains supplementary material available at 10.1007/s11119-023-10000-4.

Synthesis of α-Quaternary ß-Lactams via Copper-Catalyzed Enantioconvergent Radical C(sp3 )-C(sp2 ) Cross-Coupling with Organoboronate Esters.

The copper-catalyzed enantioconvergent radical C(sp3 )-C(sp2 ) cross-coupling of tertiary α-bromo-ß-lactams with organoboronate esters could provide the synthetically valuable α-quaternary ß-lactams. The challenge arises mainly from the construction of sterically congested quaternary stereocenters between the tertiary alkyl radicals and chiral copper(II) species. Herein, we describe our success in achieving such transformations through the utilization of a copper/hemilabile N,N,N-ligand catalyst to forge the sterically congested chiral C(sp3 )-C(sp2 ) bond via a single-electron reduction/transmetalation/bond formation catalytic cycle. The synthetic potential of this approach is shown in the straightforward conversion of the corresponding products into many valuable building blocks. We hope that the developed catalytic cycle would open up new vistas for more enantioconvergent cross-coupling reactions.

Reliability of computed molecular structures.

When the structures of 1342 molecules are optimized by 30 methods and 7 basis sets, there appear 289 (21.54%) problematic molecules and 112 (8.35%) failed ones. When 278 problematic molecules are compared, the best methods are BHandH and LC-wPBE, while B97D, BP86, HFS, VSXC, and HCTH are very unreliable. When 179 problematic molecules are computed with larger basis sets, the smallest mean absolute deviation (MAD) of bond angle (2.3°) is shown by QCISD(T)/cc-pVTZ, while the smallest MAD of bond length (0.021 Å), the best SUM1 (4.9 unit), and the best SUM2 (2.4 unit) are shown by DSDPBEP86(Full), DSDPBEP86, PBE1PBE-D3, MP2, and MP2(Full) in combination with aug-cc-pVQZ, cc-pVQZ, Def2QZVP, Def2TZVPP, and/or 6-311++G(3df,3pd). Very large basis sets, for example, larger than cc-pVTZ usually have to be used to obtain very good structures and the performances of many density-functional theory methods are encouraging. The best results may be the limit of modern computational chemistry.

Nomogram for stratifying patients with lifelong premature ejaculation before using the PHQ-9: An observational study.

OBJECTIVE: A PHQ-9 score ≥ 15, represented as PHQ-9+ , indicates major depressive disorder (MDD). On using PHQ-9, the psychological burden of several patients with lifelong premature ejaculation (LPE) gets aggravated, which may lead to LPE development. We aim to construct a nomogram for predicting the individual risk of PHQ-9+ in patients with LPE and discerning those with low risks, who should avoid the PHQ-9. METHODS: The nomogram was constructed by analysing data of 802 patients from Xijing Hospital and Northwest Women's & Children's Hospital. The LASSO and multivariable logistic regressions were used to identify independent predictors of PHQ-9+ , used for developing the nomogram. The discrimination, calibration and clinical usefulness of the nomogram were assessed in the derivation cohort and an independent validation cohort, which was composed of 505 prospectively enrolled patients from Daxing Hospital and Xijing Hospital. RESULTS: The duration of PE, IELT, a history of PE exacerbation, IIEF-5 score, urinary frequency and physical pain score were identified as independent predictors. The nomogram showed excellent calibration, discrimination and clinical usefulness in the derivation and validation cohorts, with a predictive accuracy of 0.781 and 0.763, respectively. Based on this nomogram, patients were divided into not recommended, recommended and strongly recommended PHQ-9 filling groups, with PHQ-9+ rates of 3.5%, 9.3% and 30.7%, respectively. CONCLUSION: A nomogram to discern LPE patients with low risks of PHQ-9+ was established. This tool can increase the positivity of MDD screening and may improve the therapeutic outcomes of those in the low-risk group.

Identification of the sesquiterpene synthase AcTPS1 and high production of (-)-germacrene D in metabolically engineered Saccharomyces cerevisiae.

BACKGROUND: The sesquiterpene germacrene D is a highly promising product due to its wide variety of insecticidal activities and ability to serve as a precursor for many other sesquiterpenes. Biosynthesis of high value compounds through genome mining for synthases and metabolic engineering of microbial factories, especially Saccharomyces cerevisiae, has been proven to be an effective strategy. However, there have been no studies on the de novo synthesis of germacrene D from carbon sources in microbes. Hence, the construction of the S. cerevisiae cell factory to achieve high production of germacrene D is highly desirable. RESULTS: We identified five putative sesquiterpene synthases (AcTPS1 to AcTPS5) from Acremonium chrysogenum and the major product of AcTPS1 characterized by in vivo, in vitro reaction and NMR detection was revealed to be (-)-germacrene D. After systematically comparing twenty-one germacrene D synthases, AcTPS1 was found to generate the highest amount of (-)-germacrene D and was integrated into the terpene precursor-enhancing yeast strain, achieving 376.2 mg/L of (-)-germacrene D. Iterative engineering was performed to improve the production of (-)-germacrene D, including increasing the copy numbers of AcTPS1, tHMG1 and ERG20, and downregulating or knocking out other inhibitory factors (such as erg9, rox1, dpp1). Finally, the optimal strain LSc81 achieved 1.94 g/L (-)-germacrene D in shake-flask fermentation and 7.9 g/L (-)-germacrene D in a 5-L bioreactor, which is the highest reported (-)-germacrene D titer achieved to date. CONCLUSION: We successfully achieved high production of (-)-germacrene D in S. cerevisiae through terpene synthase mining and metabolic engineering, providing an impressive example of microbial overproduction of high-value compounds.

SO2-Tolerant Catalytic Reduction of NOx via Tailoring Electron Transfer between Surface Iron Sulfate and Subsurface Ceria.

Currently, SO2-induced catalyst deactivation from the sulfation of active sites turns to be an intractable issue for selective catalytic reduction (SCR) of NOx with NH3 at low temperatures. Herein, SO2-tolerant NOx reduction has been originally demonstrated via tailoring the electron transfer between surface iron sulfate and subsurface ceria. Engineered from the atomic layer deposition followed by the pre-sulfation method, the structure of surface iron sulfate and subsurface ceria was successfully constructed on CeO2/TiO2 catalysts, which delivered improved SO2 resistance for NOx reduction at 250 °C. It was demonstrated that the surface iron sulfate inhibited the sulfation of subsurface Ce species, while the electron transfer from the surface Fe species to the subsurface Ce species was well retained. Such an innovative structure of surface iron sulfate and subsurface ceria notably improved the reactivity of NHx species, thus endowing the catalysts with a high NOx reaction efficiency in the presence of SO2. This work unraveled the specific structure effect of surface iron sulfate and subsurface ceria on SO2-toleant NOx reduction and supplied a new point to design SO2-tolerant catalysts by modulating the unique electron transfer between surface sulfate species and subsurface oxides.

Compensation or Aggravation: Pb and SO2 Copoisoning Effects over Ceria-Based Catalysts for NOx Reduction.

Severe catalyst deactivation caused by multiple poisons, including heavy metals and SO2, remains an obstinate issue for the selective catalytic reduction (SCR) of NOx by NH3. The copoisoning effects of heavy metals and SO2 are still unclear and irreconcilable. Herein, the unanticipated differential compensated or aggravated Pb and SO2 copoisoning effects over ceria-based catalysts for NOx reduction was originally unraveled. It was demonstrated that Pb and SO2 exhibited a compensated copoisoning effect over the CeO2/TiO2 (CT) catalyst with sole active CeO2 sites but an aggravated copoisoning effect over the CeO2-WO3/TiO2 (CWT) catalyst with dual active CeO2 sites and acidic WO3 sites. Furthermore, it was uniquely revealed that Pb preferred bonding with CeO2 among CT while further being combined with SO2 to form PbSO4 after copoisoning, which released the poisoned active CeO2 sites and rendered the copoisoned CT catalyst a recovered reactivity. In comparison, Pb and SO2 would poison acidic WO3 sites and active CeO2 sites, respectively, resulting in a seriously degraded reactivity of the copoisoned CWT catalyst. Therefore, this work thoroughly illustrates the internal mechanism of differential compensated or aggravated deactivation effects for Pb and SO2 copoisoning over CT and CWT catalysts and provides effective solutions to design ceria-based SCR catalysts with remarkable copoisoning resistance for the coexistence of heavy metals and SO2.

Associations of long-term exposure to ambient ozone with hypertension, blood pressure, and the mediation effects of body mass index: A national cross-sectional study of middle-aged and older adults in China.

BACKGROUND: The associations between long-term exposure to ozone (O3) and respiratory diseases are well established. However, its association with cardiovascular disease (CVD) remains controversial. In this study, we examined the associations between O3 and the prevalence of hypertension and blood pressure, and the mediation effects of body mass index (BMI) in Chinese middle-aged and older adults. METHODS: In this national cross-sectional study, we estimated the O3 exposure of 12,028 middle-aged and older adults from 126 county-level cities in China, using satellite-based spatiotemporal models. Generalized linear mixed models were used to evaluate the associations of long-term exposure to O3 with hypertension and blood pressure, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP). Mediation effect models were applied to examine the mediation effects of BMI among O3-induced hypertension and elevated blood pressure. RESULTS: Each 10 µg/m3 increase in O3 concentration was significantly associated with an increase of 13.7% (95% confidence interval (CI): 4.8%, 23.3%) in the prevalence of hypertension, an increase of 1.128 mmHg (95% CI: 0.248, 2.005), 0.679 mmHg (95% CI: 0.059, 1.298), 0.820 mmHg (95%CI: 0.245, 1.358) in SBP, DBP, and MAP, respectively. Mediation effect models showed that BMI played 40.08%, 37.25%, 39.95%, and 33.51% mediation roles in the effects of long-term exposure to O3 on hypertension, SBP, DBP, and MAP, respectively. CONCLUSIONS: Long-term exposure to O3 can increase the prevalence of hypertension and blood pressure levels of middle-aged and older adults, and an increase of BMI would be an important modification effect for O3-induced hypertension and blood pressure increase.

Enantioconvergent Cu-Catalyzed Radical C-N Coupling of Racemic Secondary Alkyl Halides to Access α-Chiral Primary Amines.

α-Chiral alkyl primary amines are virtually universal synthetic precursors for all other α-chiral N-containing compounds ubiquitous in biological, pharmaceutical, and material sciences. The enantioselective amination of common alkyl halides with ammonia is appealing for potential rapid access to α-chiral primary amines, but has hitherto remained rare due to the multifaceted difficulties in using ammonia and the underdeveloped C(sp3)-N coupling. Here we demonstrate sulfoximines as excellent ammonia surrogates for enantioconvergent radical C-N coupling with diverse racemic secondary alkyl halides (>60 examples) by copper catalysis under mild thermal conditions. The reaction efficiently provides highly enantioenriched N-alkyl sulfoximines (up to 99% yield and >99% ee) featuring secondary benzyl, propargyl, α-carbonyl alkyl, and α-cyano alkyl stereocenters. In addition, we have converted the masked α-chiral primary amines thus obtained to various synthetic building blocks, ligands, and drugs possessing α-chiral N-functionalities, such as carbamate, carboxylamide, secondary and tertiary amine, and oxazoline, with commonly seen α-substitution patterns. These results shine light on the potential of enantioconvergent radical cross-coupling as a general chiral carbon-heteroatom formation strategy.