Molecular Dynamics Simulation of the Rejuvenation Performance of Waste Cooking Oil with High Acid Value on Aged Asphalt.

Waste cooking oil's (WCO's) potential as a rejuvenator of aged asphalt has received attention in recent years, with the acid value of WCO affecting its rejuvenation effect. This study explored the rejuvenation effect of WCO with a high acid value on aged asphalt by using molecular dynamics simulation. First, the representative molecules of WCO with a high acid value and asphalt were determined. The rejuvenation effect of WCO on aged asphalt was analyzed by adding different contents of WCO to an aged asphalt model. The effect of WCO on the thermodynamic properties of the aged asphalt was analyzed. The results show that WCO can restore the thermodynamic properties of aged asphalt binder to a certain extent. Regarding the microstructure of rejuvenated asphalt, WCO molecules dispersed around asphaltenes weakened the latter's aggregation and improved the colloidal structure of the aged asphalt. In terms of interface adhesion properties, WCO can improve the adhesion properties between asphalt binder and SiO2, but it has limited influence on water sensitivity. The results allowed us to comprehensively evaluate the rejuvenation effect of WCO with a high acid value on aged asphalt and to explore its rejuvenation mechanism.

The prognostic significance of ubiquitination-related genes in multiple myeloma by bioinformatics analysis.

BACKGROUND: Immunoregulatory drugs regulate the ubiquitin-proteasome system, which is the main treatment for multiple myeloma (MM) at present. In this study, bioinformatics analysis was used to construct the risk model and evaluate the prognostic value of ubiquitination-related genes in MM. METHODS AND RESULTS: The data on ubiquitination-related genes and MM samples were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The consistent cluster analysis and ESTIMATE algorithm were used to create distinct clusters. The MM prognostic risk model was constructed through single-factor and multiple-factor analysis. The ROC curve was plotted to compare the survival difference between high- and low-risk groups. The nomogram was used to validate the predictive capability of the risk model. A total of 87 ubiquitination-related genes were obtained, with 47 genes showing high expression in the MM group. According to the consistent cluster analysis, 4 clusters were determined. The immune infiltration, survival, and prognosis differed significantly among the 4 clusters. The tumor purity was higher in clusters 1 and 3 than in clusters 2 and 4, while the immune score and stromal score were lower in clusters 1 and 3. The proportion of B cells memory, plasma cells, and T cells CD4 naïve was the lowest in cluster 4. The model genes KLHL24, HERC6, USP3, TNIP1, and CISH were highly expressed in the high-risk group. AICAr and BMS.754,807 exhibited higher drug sensitivity in the low-risk group, whereas Bleomycin showed higher drug sensitivity in the high-risk group. The nomogram of the risk model demonstrated good efficacy in predicting the survival of MM patients using TCGA and GEO datasets. CONCLUSIONS: The risk model constructed by ubiquitination-related genes can be effectively used to predict the prognosis of MM patients. KLHL24, HERC6, USP3, TNIP1, and CISH genes in MM warrant further investigation as therapeutic targets and to combat drug resistance.

Recombinant hirudin suppresses angiogenesis of diffuse large B-cell lymphoma through regulation of the PAR-1-VEGF.

Hirudin is one of the specific inhibitors of thrombin, which has been confirmed to have strong bioactivities, including inhibiting tumors. However, the function and mechanism of hirudin and protease-activated receptor 1 (PAR-1) in diffuse large B-cell lymphoma (DLBCL) have not been clear. Detecting the expression PAR-1 in DLBCL tissues and cells by RT-qPCR and IHC. Transfected sh-NC, sh-PAR-1, or pcDNA3.1-PAR-1 in DLBCL cells or processed DLBCL cells through added thrombin, Vorapaxar, Recombinant hirudin (RH), or Na2S2O4 and co-culture with EA.hy926. And built DLBCL mice observed tumor growth. Detecting the expression of related genes by RT-qPCR, Western blot, IHC, and immunofluorescence, measured the cellular hypoxia with Hypoxyprobe-1 Kit, and estimated the cell inflammatory factors, proliferation, migration, invasion, and apoptosis by ELISA, CCK-8, flow cytometry, wound-healing and Transwell. Co-immunoprecipitation and pull-down measurement were used to verify the relationship. PAR-1 was highly expressed in DLBCL tissues and cells, especially in SUDHL2. Na2S2O4 induced SUDHL2 hypoxia, and PAR-1 did not influence thrombin-activated hypoxia. PAR-1 could promote SUDHL2 proliferation, migration, and invasion, and it was unrelated to cellular hypoxia. PAR-1 promoted proliferation, migration, and angiogenesis of EA.hy926 or SUDHL2 through up-regulation vascular endothelial growth factor (VEGF). RH inhibited tumor growth, cell proliferation, and migration, promoted apoptosis of DLBCL, and inhibited angiogenesis by down-regulating PAR-1-VEGF. RH inhibits proliferation, migration, and angiogenesis of DLBCL cells by down-regulating PAR-1-VEGF.

Crucial computed tomography and magnetic resonance imaging findings of fallopian tubal tuberculosis for diagnosis: a retrospective study of 26 cases.

Background: Fallopian tubal tuberculosis (FTTB), which typically presents with non-specific clinical symptoms and mimics ovarian malignancies clinically and radiologically, often affects young reproductive females and can lead to infertility if not promptly managed. Early diagnosis by imaging modalities is crucial for initiating timely anti-tuberculosis (anti-TB) treatment. Currently, comprehensive radiological descriptions of this relatively rare disease are limited. We aimed to comprehensively investigate the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of FTTB in patients from the Kashi area, which has the highest incidence of TB in China, to extend radiologists' understanding of this disease. Methods: We conducted a retrospective cross-sectional study of 26 patients diagnosed with FTTB at the First People's Hospital of Kashi Area. All the patients underwent abdominal and pelvic contrast-enhanced CT examinations and/or pelvic contrast-enhanced MRI from January 2017 to June 2022. The imaging findings were evaluated in consensus by two experienced radiologists specialized in abdominal and pelvic imaging. The evaluated sites included the fallopian tubes, ovaries, peritoneum, mesentery, retroperitoneal nodes, and parailiac nodes. The patient characteristics are reported using descriptive statistics. The patient imaging results are presented as percentages. The normally distributed continuous variables are reported as the mean ± standard deviation (SD), and otherwise as the median with the interquartile range (IQR). Results: The median age of the patients was 27 years (IQR: 25-34 years). Bilateral involvement of the fallopian tubes was observed in all patients. The tubal wall appeared coarse with tiny intraductal nodules in 96% (25 of 26) of the patients. The mean CT value of the tubal contents was 34 Hounsfield units (HUs; SD: 3.3 HUs). Ascites was present in 92% (24 of 26) of the patients, with 20 patients showing encapsulated effusion. Among these patients, 20 exhibited the highest CT values of ascites (>20 HUs). Linear enhancement of the parietal peritoneum was observed in 88% (23 of 26) of the patients, of whom 22 had peritoneal nodules measuring a median diameter of 0.4 cm (IQR: 0.3-0.6 cm). Eight patients had retroperitoneal and parailiac nodal enlargement, of whom two showed nodal necrosis, and none displayed nodal calcification. Conclusions: FTTB is consistently accompanied by tuberculous peritonitis. FTTB typically presents with tubal dilation, and coarseness and nodules in the lumen, as well as intraductal caseous material and calcification. Tuberculous peritonitis exhibits high-density ascites, peritoneal adhesion, linear enhancement of the parietal peritoneum, and tiny peritoneal nodules. The co-occurrence of these features strongly suggests a diagnosis of FTTB.

E3 ubiquitin ligase NEDD4L inhibits epithelial-mesenchymal transition by suppressing the ß-catenin/HIF-1α positive feedback loop in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyp (CRSwNP) is a refractory inflammatory disease with epithelial-mesenchymal transition (EMT) as one of the key features. Since ubiquitin modification has been shown to regulate the EMT process in other diseases, targeting ubiquitin ligases may be a potential strategy for the treatment of CRSwNP. In this study we investigated whether certain E3 ubiquitin ligases could regulate the EMT process in CRSwNP, and whether these regulations could be the potential drug targets as well as the underlying mechanisms. After screening the potential drug target by bioinformatic analyses, the expression levels of three potential E3 ubiquitin ligases were compared among the control, eosinophilic nasal polyp (ENP) and non-eosinophilic nasal polyp (NENP) group in clinical samples, and the significant decrement of the expression level of NEDD4L was found. Then, IP-MS, bioinformatics and immunohistochemistry studies suggested that low NEDD4L expression may be associated with the EMT process. In human nasal epithelial cells (hNECs) and human nasal epithelial cell line RPMI 2650, knockdown of NEDD4L promoted EMT, while upregulating NEDD4L reversed this effect, suggesting that NEDD4L inhibited EMT in nasal epithelial cells. IP-MS and Co-IP studies revealed that NEDD4L mediated the degradation of DDR1. We demonstrated that NEDD4L inhibited the ß-catenin/HIF-1α positive feedback loop either directly (degrading ß-catenin and HIF-1α) or indirectly (mediating DDR1 degradation). These results were confirmed in a murine NP model in vivo. This study for the first time reveals the regulatory role of ubiquitin in the EMT process of nasal epithelial cells, and identifies a novel drug target NEDD4L, which has promising efficacy against both ENP and NENP by suppressing ß-catenin/HIF-1α positive feedback loop.

Universal DNA-Based Sensing Toolbox for Programming Cell Functions.

By recombining natural cell signaling systems and further reprogramming cell functions, use of genetically engineered cells and bacteria as therapies is an innovative emerging concept. However, the inherent properties and structures of the natural signal sensing and response pathways constrain further development. We present a universal DNA-based sensing toolbox on the cell surface to endow new signal sensing abilities for cells, control cell states, and reprogram multiple cell functions. The sensing toolbox contains a triangular-prismatic-shaped DNA origami framework and a sensing core anchored inside the internal confined space to enhance the specificity and efficacy of the toolbox. As a proof of principle, the sensing toolbox uses the customizable sensing core with signal sensing switches and converters to recognize unconventional signal inputs, deliver functional components to cells, and then control cell responses, including specific tumor cell death, immune cell disinhibition and adhesion, and bacterial expression. This work expands the diversity of cell sensing signals and reprograms biological functions by constructing nanomechanical-natural hybrid cells, providing new strategies for engineering cells and bacteria in diagnosis and treatment applications.

Apple consumption affects cecal health by regulating 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) levels through modifying the microbiota in rats.

Apples are rich in many nutrients and functional components. However, the mechanism of the effect of fresh apple consumption on rats remains unclear. In the present study, fresh apples (10 g kg-1) were added to the diet of Wistar rats, and changes in the microbiota and metabolite content of the cecum were analyzed after 28 days of feeding, and changes in the 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) content and indicators related to inflammation, oxidative stress, and apoptosis were detected. Subsequently, a fecal microbiota transplantation (FMT) protocol was designed and carried out to verify the relationship between the microbiota and 12(S)-HETE, the cecal structure, and inflammatory factors. The results show that apple consumption significantly reduced the serum levels of alanine aminotransferase (ALT) and immunoglobulin G (IgG), altered the cecal histomorphology, and significantly upregulated the gene expression of claudin-1 and zonula occludens-1 (ZO-1), which encode tight junction proteins. Apple consumption also changed the structure of the cecal microbiota, increasing the abundance of some species (such as Shuttleworthia) and decreasing the abundance of others (such as Alphaproteobacteria). Metabolomic screening identified 64 significantly different metabolites. The FMT results showed that apple consumption reduced 12(S)-HETE metabolite levels in the cecal contents, improved the intestinal structure, and reduced the levels of proinflammatory factor expression by altering the cecal microbiota. In conclusion, this study provides further insight into the effects of apples on animals using rats as experimental animals. It provides basic data for future exploration of the mechanisms of the effect of apple consumption on humans.

Catalytic enantioselective reductive alkynylation of amides enables one-pot syntheses of pyrrolidine, piperidine and indolizidine alkaloids.

The primary objective in synthetic organic chemistry is to develop highly efficient, selective, and versatile synthetic methodologies, which are essential for discovering new drug candidates and agrochemicals. In this study, we present a unified strategy for a one-pot, catalytic enantioselective synthesis of α-alkyl and α,α'-dialkyl pyrrolidine, piperidine, and indolizidine alkaloids using readily available amides and alkynes. This synthesis is enabled by the identification and development of an Ir/Cu/N-PINAP catalyzed highly enantioselective and chemoselective reductive alkynylation of α-unbranched aliphatic amides, which serves as the key reaction. This reaction is combined with Pd-catalyzed tandem reactions in a one-pot approach, enabling the collective, catalytic enantioselective total syntheses of eight alkaloids and an anticancer antipode with 90-98% ee. The methodology's enantio-divergence is exemplified by the one-step access to either enantiomer of alkaloid bgugaine.

Mechanical Properties and Crack Resistance of Basalt Fiber Self-Compacting High Strength Concrete: An Experimental Study.

Pure self-compacting concrete has many disadvantages, such as early shrinkage and cracking. The addition of fibers can effectively improve the properties of resistance to tension and cracking of self-compacting concrete, thereby the effect of improving its strength and toughness can be achieved. Basalt fiber is a "new green industrial material" that has unique advantages, such as high crack resistance and being lightweight compared with other fiber materials. In order to study the mechanical properties and crack resistance of basalt fiber self-compacting high-strength concrete intensively, the self-compacting high-strength concrete of C50 was designed and obtained using the absolute volume method with multiple proportions. Orthogonal experimental methods were used to study the influence of the water binder ratio, fiber volume fraction, fiber length, and fly ash content on the mechanical properties of the basalt fiber self-compacting high-strength concrete. Meanwhile, the efficiency coefficient method was used to determine the best experiment plan (water binder ratio 0.3, fiber volume ratio 0.2%, fiber length 12 mm, fly ash content 30%), and the effect of fiber volume fraction and fiber length on the crack resistance of the self-compacting high-performance concrete was investigated using improved plate confinement experiments. The results show that (1) the water binder ratio had the greatest impact on the compressive strength of basalt fiber self-compacting high-strength concrete, and as the fiber volume fraction increased, the splitting tensile strength and flexural strength both increased; (2) there was an optimal value for the effect of the fiber length on the mechanical properties; (3) with the increase in fiber volume fraction, the total crack area of the fiber self-compacting high-strength concrete significantly decreased. When the fiber length increased, the maximum crack width first decreased and then slowly increased. The best crack resistance effect was achieved when the fiber volume fraction was 0.3% and the fiber length was 12 mm. Therefore, basalt fiber self-compacting high-strength concrete can be widely used in engineering fields, such as national defense construction, transportation, and building structure reinforcement and repair, due to its excellent mechanical and crack resistance properties.

Predictive Value of Eosinophil Cationic Protein in Nasal Secretions in Eosinophilic Chronic Rhinosinusitis.

OBJECTIVES: To investigate the value of secretions Eosinophilic cationic protein (ECP) detection in the diagnosis of endotypes of Chronic rhinosinusitis (CRS) and its correlation with clinical symptoms, so as to provide guidance for the clinical application of EOS and ECP detection in secretions. METHODS: Patients' nasal secretions and polyps (or middle turbinate for control) were collected and their EOS% and ECP levels were measured. Correlation analysis was performed for EOS% and ECP levels in secretions and tissues, respectively. The correlation between secretions EOS% and ECP and clinical symptom scores (symptomatic visual analog scale (VAS) scores, Lanza-kennedy scores from nasal endoscopy and Lund-Mackay scores from sinus CT) was further analyzed. Receiver operating characteristic curves were used to assess the predictive potential of EOS% and ECP in nasal secretions. RESULTS: Eosinophilic chronic rhinosinusitis (ECRS) patients had higher concentrations of ECP in nasal secretions than healthy subjects and NECRS (non-eosinophilic CRS) (p < 0.0001;0.0001); EOS% in nasal secretions was higher in ECRS than healthy subjects (p = 0.0055), but the differences between ECRS and NECRS were not statistically significant (p = 0.0999). Correlation analysis showed that tissue EOS% was correlated with ECP concentration and EOS% in nasal secretions (R = 0.5943;0.2815). There was a correlation between EOS% in secretions with a total LM score (R = 0.3131); ECP concentration in secretions with a total LK score (R = 0.3792). To diagnose ECRS, the highest area under the curve (0.8230) was determined for ECP in secretions; the highest area under the curve (0.6635) was determined for EOS% in secretions. CONCLUSION: Measurement of ECP in nasal secretions is useful for non-invasive diagnosis of ECRS. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3304-3312, 2023.

A DNA Nanodevice-Based Platform with Diverse Capabilities.

Social biotic colonies often perform intricate tasks by interindividual communication and cooperation. Inspired by these biotic behaviors, a DNA nanodevice community is proposed as a universal and scalable platform. The modular nanodevice as the infrastructure of platform contains a DNA origami triangular prism framework and a hairpin-swing arm machinery core. By coding and decoding a signal domain on the shuttled output strand in different nanodevices, an orthogonal inter-nanodevice communication network is established to connect multi-nanodevices into a functional platform. The nanodevice platform enables implementation of diverse tasks, including signal cascading and feedback, molecular input recording, distributed logic computing, and modeling of simulation for virus transmission. The nanodevice platform with powerful compatibility and programmability presents an elegant example of the combination of the distributed operation of multiple devices and the complicated interdevice communication network, and may become a new generation of intelligent DNA nanosystems.

Concise Total Synthesis of (-)-Quinocarcin Enabled by Catalytic Enantioselective Reductive 1,3-Dipolar Cycloaddition of Secondary Amides.

A concise asymmetric total synthesis of (-)-quinocarcin has been accomplished with high step economy from commercially available starting materials. A catalytic enantioselective reductive 1,3-dipolar cycloaddition reaction of N-heteroaryl secondary amides with reactive dipolarophiles using iridium/copper relay catalysis was developed to prepare the key chiral pyrrolidine intermediate with three stereocenters. This protocol features excellent regio-, exo- and enantioselectivities, broad substrate scope, and good functional group tolerance. The high efficiency was also ensured by a RhIII -catalyzed C-H activation/cyclization and a tandem diastereoselective hydrogenation/cyclization to construct the tetrahydroisoquinoline-pyrrolidine tetracyclic core unit of quinocarcin.

Neoadjuvant PD-1 blockade with sintilimab in mismatch-repair deficient, locally advanced rectal cancer: an open-label, single-centre phase 2 study.

BACKGROUND: The current standard treatment for locally advanced rectal cancer is neoadjuvant chemoradiotherapy followed by radical surgery, but this approach can lead to multiple complications. We aimed to investigate the clinical activity and safety of neoadjuvant therapy with sintilimab, a single-agent PD-1 antibody, in patients with mismatch-repair deficient locally advanced rectal cancer. METHODS: This open-label, single-arm, phase 2 study was done at the Sun Yat-sen University Cancer Center, Guangzhou, China. Patients aged 18-75 years with mismatch-repair deficient or microsatellite instability-high locally advanced rectal cancer were enrolled and received neoadjuvant sintilimab monotherapy (200 mg by intravenous infusion) every 21 days. After an initial four cycles of treatment, patients and clinicians could choose one of the following options: total mesorectal excision surgery, followed by four cycles of adjuvant sintilimab with or without CapeOX chemotherapy (capecitabine 1000 mg/m2, orally administered twice daily on days 1-14; oxaliplatin 130 mg/m2, intravenously administered on day 1 every 3 weeks), determined by clinicians; or another four cycles of sintilimab followed by radical surgery or observation (only for patients with a clinical complete response; also known as the watch and wait strategy). The primary endpoint was the complete response rate, which included both a pathological complete response after surgery and a clinical complete response after completion of sintilimab treatment. Clinical response was evaluated by digital rectal examination, MRI, and endoscopy. Response was assessed in all patients who received treatment at least until the first tumour response assessment, after the first two cycles of sintilimab. Safety was analysed in all patients who received at least one dose of treatment. This trial is closed to enrolment and is registered with ClinicalTrials.gov (NCT04304209). FINDINGS: Between Oct 19, 2019, and June 18, 2022, 17 patients were enrolled and received at least one dose of sintilimab. The median age was 50 years (IQR 35-59) and 11 (65%) of 17 patients were male. One patient was excluded from efficacy analyses because they were lost to follow-up after the first sintilimab cycle. Of the remaining 16 patients, six underwent surgery, of whom three had a pathological complete response. Nine other patients had a clinical complete response and chose the watch and wait strategy. One patient had a serious adverse event and discontinued treatment; this patient did not have a complete clinical response and refused to undergo surgery. A complete response was thus noted for 12 (75%; 95% CI 47-92) of 16 patients. One of the three patients who underwent surgery but did not have a pathological complete response showed an increase in tumour volume after the initial four cycles of sintilimab (at which point they underwent surgery); this patient was deemed to have primary resistance to immune checkpoint inhibitors. After a median follow-up of 17·2 (IQR 8·2-28·5) months, all patients were alive and none had disease recurrence. Only one (6%) patient had a grade 3-4 adverse event, which was deemed a serious adverse event (grade 3 encephalitis). INTERPRETATION: The preliminary results of this study suggest that anti-PD-1 monotherapy is effective and tolerable for patients with mismatch-repair deficient locally advanced rectal cancer and could potentially spare some patients from radical surgery. Longer treatment courses might be needed to achieve maximum effects in some patients. Longer follow-up is also needed to observe the duration of response. FUNDING: The National Natural Science Foundation of China, CAMS Innovation Fund for Medical Sciences, Science and Technology Program of Guangzhou, and Innovent Biologics.

Study on mechanical properties of corroded concrete columns strengthened with SMA wires.

Ocean crossing bridges suffer from seawater corrosion all year round and their mechanical properties will be substantially diminished. In order to enhance the mechanical properties of reinforced concrete columns corroded by seawater, SMA wire is used to restrain the reinforced concrete columns corroded by seawater to study their mechanical properties. 14 specimens were produced through the test, and the natural seawater corrosion was simulated by preparing a certain concentration of synthetic seawater. The mechanical properties of SMA strengthened specimens and unreinforced specimens are compared and analyzed, including failure mode, hysteresis curve, bearing capacity, ductility, stiffness and energy dissipation; the effects of different synthetic seawater corrosion concentrations on the mechanical properties of reinforced concrete columns are discussed. The results show that the bearing capacity and stiffness of reinforced concrete columns subjected to synthetic seawater corrosion are substantially diminished than those of uncorroded specimens, and the bearing capacity of specimens decreases more with the increase of synthetic seawater corrosion concentration; synthetic seawater corrosion has obscure effect on the ductility and energy dissipation performance of the specimens. The mechanical properties of the corroded specimens strengthened with SMA wire have been substantially enhanced, particularly the energy dissipation performance and bearing capacity have been notably enhanced, and the ductility and stiffness have also been somewhat enhanced. At the same time, based on the test, the finite element model is created according to the test specimen, while the accuracy of the model is verified, and the effects of the spacing and diameter of SMA wire, the strength of concrete and the thickness of protective layer on the mechanical properties of the specimen are analyzed.

Effect of thermal process on the key aroma components of green tea with chestnut-like aroma.

BACKGROUND: Chestnut-like aroma is one of the unique qualities of Chinese green tea and has become an important factor influencing consumer decisions. However, the chemical formation mechanism of chestnut-like aroma during green tea processing remains unclear. In this study, the dynamic changes of key components contributing to chestnut-like aroma and their precursors were analyzed in fresh leaves, fixation leaves, first baking tea leaves, and green tea. RESULTS: The thermal process had an important effect on volatile components in tea leaves, causing a significant decrease of alcohols and esters and a significant increase of ketones, acids, phenols, and sulfur compounds. Furthermore, 31 volatiles were identified as the key odorants responsible for chestnut-like aroma of green tea, including dimethyl sulfide, methyl isobutenyl ketone, 2-methylbutanal, 2,4-dimethylstyrene, d-limonene, methyl 2-methylvalerate, linalool, decanal, longifolene, phenylethyl alcohol, l-α-terpineol, jasmone, and so on. And the majority of these odorants were only formed in the drying stage. Additionally, isoleucine, theanine, methionine, and glucose were found to be involved in the formation of chestnut-like aroma of green tea. CONCLUSION: The drying process played a vital important role in the formation of chestnut-like aroma of green tea. © 2022 Society of Chemical Industry.

An miRISC-initiated DNA nanomachine for monitoring MicroRNA activity in living cells.

MicroRNAs (miRNAs) play an important role in post-transcriptional regulation of gene expression. However, methods to accurately detect miRNA activity in living cells are still limited. Here we developed a DNA nanomachine initiated by a miRNA-induced silencing complex (miRISC) for imaging miRNA activity in living cells. miRISC-mediated RNA cleavage reaction activated the DNA nanomachine by the specific cleavage of an RNA strand on the machine, resulting in autonomous movement of the walking leg around the AuNP surface with the release of a large number of fluorescently labeled DNA strands. The DNA nanomachine was successfully applied to detect miR-21 activity in three cell lines with different miR-21 expression profiles. We also demonstrated that terminal uridylyltransferase Tut4 knockdown by siRNA significantly increased the activity of let-7b miRNA, which further verifies the versatility of our DNA nanomachine. This new nanomachine has distinct advantages compared with reported methods for detecting miRNA activity, including simple operating procedures, short analysis time and sensitive signal output. Collectively, this work not only expands the application of the DNA nanomachine in the detection of miRNA activity, but also provides a promising tool for basic research in cell biology and development of clinical biomedicine.

Multicatalysis protocol enables direct and versatile enantioselective reductive transformations of secondary amides.

The catalytic asymmetric geminal bis-nucleophilic addition to nonreactive functional groups is a type of highly desirable yet challenging transformation in organic chemistry. Here, we report the first catalytic asymmetric reductive/deoxygenative alkynylation of secondary amides. The method is based on a multicatalysis strategy that merges iridium/copper relay catalysis with organocatalysis. A further combination with the palladium-catalyzed alkyne hydrogenation allows the one-pot enantioselective reductive alkylation of secondary amides. This versatile protocol allows the efficient synthesis of four types of α-branched chiral amines, which are prevalent structural motifs of active pharmaceutical ingredients. The protocol also features excellent enantioselectivity, chemoselectivity, and functional group tolerance to be compatible with more reactive functional groups such as ketone and aldehyde. The synthetic utility of the method was further demonstrated by the late-stage functionalization of two drug derivatives and the concise, first catalytic asymmetric approach to the κ-opioid antagonist aticaprant.

Nano-Biohybrid DNA Engager That Reprograms the T-Cell Receptor.

Although engineered T cells with transgenic chimeric antigen receptors (CARs) have made a breakthrough in cancer therapeutics, this approach still faces many challenges in the specificity, efficacy, and self-safety of genetic engineering. Here, we developed a nano-biohybrid DNA engager-reprogrammed T-cell receptor (EN-TCR) system to improve the specificity and efficacy, mitigate the excessive activation, and shield against risks from transgenesis, thus achieving a diversiform and precise control of the T-cell response. Utilizing modular assembly, the EN-TCR system can graft different specificities on T cells via antibody assembly. Besides, the designability of DNA hybridization enables precise target recognition by the library of multiantigen cell recognition circuits and allows gradual tuning of the T-cell activation level by the signaling switch and independent control over different types of T cells. Furthermore, we demonstrated the effectiveness of the system in tumor models. Together, this study provides a nongenetic T-cell engineering strategy to overcome major hindrances in T-cell therapy and may be extended to a general and convenient cell engineering strategy.