Organocatalytic stereoselective cyanosilylation of small ketones.

Enzymatic stereoselectivity has typically been unrivalled by most chemical catalysts, especially in the conversion of small substrates. According to the 'lock-and-key theory'1,2, enzymes have confined active sites to accommodate their specific reacting substrates, a feature that is typically absent from chemical catalysts. An interesting case in this context is the formation of cyanohydrins from ketones and HCN, as this reaction can be catalysed by various classes of catalysts, including biological, inorganic and organic ones3-7. We now report the development of broadly applicable confined organocatalysts for the highly enantioselective cyanosilylation of aromatic and aliphatic ketones, including the challenging 2-butanone. The selectivity (98:2 enantiomeric ratio (e.r.)) obtained towards its pharmaceutically relevant product is unmatched by any other catalyst class, including engineered biocatalysts. Our results indicate that confined chemical catalysts can be designed that are as selective as enzymes in converting small, unbiased substrates, while still providing a broad scope.

Nuclear envelope budding enables large ribonucleoprotein particle export during synaptic Wnt signaling.

Localized protein synthesis requires assembly and transport of translationally silenced ribonucleoprotein particles (RNPs), some of which are exceptionally large. Where in the cell such large RNP granules first assemble was heretofore unknown. We previously reported that during synapse development, a fragment of the Wnt-1 receptor, DFrizzled2, enters postsynaptic nuclei where it forms prominent foci. Here we show that these foci constitute large RNP granules harboring synaptic protein transcripts. These granules exit the nucleus by budding through the inner and the outer nuclear membranes in a nuclear egress mechanism akin to that of herpes viruses. This budding involves phosphorylation of A-type lamin, a protein linked to muscular dystrophies. Thus nuclear envelope budding is an endogenous nuclear export pathway for large RNP granules.

Optomechanical dissipative solitons.

Nonlinear wave-matter interactions may give rise to solitons, phenomena that feature inherent stability in wave propagation and unusual spectral characteristics. Solitons have been created in a variety of physical systems and have had important roles in a broad range of applications, including communications, spectroscopy and metrology1-4. In recent years, the realization of dissipative Kerr optical solitons in microcavities has led to the generation of frequency combs in a chip-scale platform5-10. Within a cavity, photons can interact with mechanical modes. Cavity optomechanics has found applications for frequency conversion, such as microwave-to-optical or radio-frequency-to-optical11-13, of interest for communications and interfacing quantum systems operating at different frequencies. Here we report the observation of mechanical micro-solitons excited by optical fields in an optomechanical microresonator, expanding soliton generation in optical resonators to a different spectral window. The optical field circulating along the circumference of a whispering gallery mode resonator triggers a mechanical nonlinearity through optomechanical coupling, which in turn induces a time-varying periodic modulation on the propagating mechanical mode, leading to a tailored modal dispersion. Stable localized mechanical wave packets-mechanical solitons-can be realized when the mechanical loss is compensated by phonon gain and the optomechanical nonlinearity is balanced by the tailored modal dispersion. The realization of mechanical micro-solitons driven by light opens up new avenues for optomechanical technologies14 and may find applications in acoustic sensing, information processing, energy storage, communications and surface acoustic wave technology.

On-chip germanium photodetector with interleaved junctions for the 2-µm wave band.

Recently, the 2-µm wave band has gained increased interest due to its potential application for the next-generation optical communication. As a proven integration platform, silicon photonics also benefit from the lower nonlinear absorption and larger electro-optic coefficient. However, this spectral range is far beyond the photodetection range of germanium, which places an ultimate limit for on-chip applications. In this work, we demonstrate a waveguide-coupled photodetector enabled by a tensile strain-induced absorption in germanium. Responsivity is greatly enhanced by the proposed interleaved junction structure. The device is designed on a 220-nm silicon-on-insulator and is fabricated via a standard silicon photonic foundry process. By utilizing different interleaved PN junction spacing configurations, we were able to measure a responsivity of 0.107 A/W at 1950 nm with a low bias voltage of -6.4 V for the 500-µm-long device. Additionally, the 3-dB bandwidth of the device was measured to be up to 7.1 GHz. Furthermore, we successfully achieved data transmission at a rate of 20 Gb/s using non-return-to-zero on-off keying modulation.

Exploring the diagnostic value of endothelial cell and angiogenesis-related genes in Hashimoto's thyroiditis based on transcriptomics and single cell RNA sequencing.

(1) BACKGROUND: Hashimoto's thyroiditis (HT) can cause angiogenesis in the thyroid gland. However, the molecular mechanism of endothelial cells and angiogenesis related genes (ARGs) has not been extensively studied in HT. (2) METHODS: The HRA001684, GSE29315 and GSE163203 datasets were included in this study. Using single-cell analysis, weighted gene co-expression network analysis (WGCNA), functional enrichment analysis, machine learning algorithms and expression analysis for exploration. And receiver operator characteristic (ROC) curves was draw. Gene set enrichment analysis (GSEA) was utilized to investigate the biological function of the biomarkers. Meanwhile, we investigated into the relationship between biomarkers and different types of immune cells. Additionally, the expression of biomarkers in the TCGA-TC dataset was examined and the mRNA-drug interaction network was constructed. (3) RESULTS: We found 14 cell subtypes were obtained in HT samples after single-cell analysis. A total of 5 biomarkers (CD52, CD74, CD79A, HLA-B and RGS1) were derived, and they had excellent diagnostic performance. Then, 27 drugs targeting biomarkers were predicted. The expression analysis showed that CD74 and HLA-B were significantly up-regulated in HT samples. (4) CONCLUSION: In this study, 5 biomarkers (CD52, CD74, CD79A, HLA-B and RGS1) were screened and their expressions in endothelial cells was compared to offer a new reference for the recognition and management of HT.

In-Ovo Glutamine Administration Enhances Intestinal Development and Functions in Broiler Chickens: Insights from Enteroid Models.

BACKGROUND: Early life events play significant roles in tissue development and animal health in their later life. Early nutrition, through in-ovo delivery, has shown beneficial effects on improving intestinal health in broiler chickens. However, the underlying mechanism is not fully investigated. A recently developed enteroid culture technique allows investigations on intestinal epithelial functions that are close to physiologic conditions. OBJECTIVES: In this study, we evaluated the short- and long-term effects of in-ovo administration of glutamine (Gln) on intestinal epithelial development and functions by using intestinal enteroid culture and tissue electrophysiologic analysis. METHODS: A hundred eggs of commercial Cobb500 broilers were in-ovo injected with 0.2 mL of either phosphate-buffered saline (PBS) or 3% Gln at embryonic day 18 (E18). Chicks were killed on the day of hatch, and at 3- and 14-d posthatch. Enteroids were generated from the small intestine. After 4 d of culture, enteroids were harvested for 5-ethynyl-2'-deoxyuridine proliferation, fluorescein isothiocyanate-4 kDa dextran permeability, and glucose absorption assays. At day 3 (d3) and day 14 (d14), intestinal barrier and nutrient transport functions were measured by the Ussing chamber. The gene expression of epithelial cell markers, nutrient transporters, and tight-junction proteins were analyzed in both intestinal tissues and enteroids. RESULTS: In comparison with the PBS control group, in-ovo Gln increased intestinal villus morphology, epithelial cell proliferation, and differentiation, and altered epithelial cell population toward increased number of enteroendocrine and goblet cells while decreasing Paneth cells. Enteroids gene expression of nutrient transporters (B0AT1, SGLT1, and EAAT3), tight junction (ZO2), glucose absorption, and barrier functions were enhanced on the day of hatch. Long-term increases of intestinal di-peptide and alanine transport were observed at day 14 posthatch. CONCLUSIONS: Together our results suggested that the in-ovo injection of Gln stimulated intestinal epithelium proliferation and programmed the epithelial cell differentiation toward absorptive cells.

Outcomes of Transcatheter Closure of Congenital Left Circumflex Coronary Artery Fistula.

BACKGROUND: Congenital left circumflex coronary artery fistula (LCX-CAF) is a relatively rare type of coronary artery fistula (CAF); little is known about the outcomes of transcatheter closure (TCC) of LCX-CAF.Methods and Results: All consecutive patients admitted to Fuwai Hospital and scheduled for TCC of LCX-CAF between January 2012 and December 2022 were reviewed retrospectively. Of the 25 consecutive patients (mean [±SD] age 34±20 years; 48% male) admitted and scheduled for TCC of congenital LCX-CAF, the procedure was feasible in 22 (77.3%). The mean (±SD) diameter of the fistulas was 6.99±2.04 mm; 21 (84%) patients had a large fistula (i.e., diameter >2-fold greater than non-feeding coronary artery). Occluders were deployed via a transarterial approach and arteriovenous loop in 6 (27.3%) and 16 (72.7%) patients, respectively. No procedural complications were recorded. Although the procedural success rates are similar for single LCX-CAF and left anterior descending CAF (81.25% vs. 92.86%; P=0.602), the mean time from initial angiography to first occluder deployment is significantly longer for LCX-CAF (83.06±36.07 vs. 36.00±9.49 min; P<0.001). The mean (±SD) follow-up time was 62.2±45.5 months. The incidence of myocardial infarction and recanalization of the fistula was 4.5% (1/22) and 9.1% (2/22), respectively. CONCLUSIONS: TCC of LCX-CAF is a feasible and effective alternative to surgical repair, with comparable outcomes in selected patients. Optimal medical therapy to prevent post-closure myocardial infarction requires further investigation.

Dragon's Blood-Loaded Mesoporous Silica Nanoparticles for Rapid Hemostasis and Antibacterial Activity.

Dragon's blood (DB) is a traditional Chinese medicine (TCM) with hemostatic effects and antibacterial properties. However, it is still challenging to use for rapid hemostasis because of its insolubility. In this study, different amounts of DB were loaded on mesoporous silica nanoparticles (MSNs) to prepare a series of DB-MSN composites (5DB-MSN, 10DB-MSN, and 20DB-MSN). DB-MSN could quickly release DB and activate the intrinsic blood coagulation cascade simultaneously by DB and MSN. Hemostasis tests demonstrated that DB-MSN showed superior hemostatic effects than either DB or MSNs alone, and 10DB-MSN exhibited the best hemostatic effect. In addition, the antibacterial activities of DB-MSN against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) improved with the increase in DB. Furthermore, the hemolysis assay and cytocompatibility assay demonstrated that all DB-MSNs exhibited excellent biocompatibility. Based on these results, 10DB-MSN is expected to have potential applications for emergency hemostatic and antibacterial treatment in pre-hospital trauma.

Analysis of treatment-related adverse events and wound complications of surgical resection after neoadjuvant chemoimmunotherapy for non-small cell lung cancer.

Neoadjuvant chemoimmunotherapy is becoming an increasingly important part of the management of lung cancer to facilitate surgical resection. This study aimed to summarize the treatment-related adverse events (TRAEs) and wound complications of neoadjuvant chemoimmunotherapy in non-small cell lung cancer (NSCLC). Eligible studies of neoadjuvant chemoimmunotherapy for NSCLC were identified from PubMed, Embase and Web of Science. The endpoints mainly included TRAEs and wound complications. Stata18 software was used for statistical analysis with p < 0.05 considered statistically significant. Twenty studies including a total of 1072 patients were eligible for this study. Among the patients who received neoadjuvant chemoimmunotherapy, the pooled prevalence of any grade TRAEs was 77% (95% confidence interval [CI] [0.64-0.86]), grade 1-2 TRAEs was 77% (95% CI [0.58-0.89]) and grade ≥3 TRAEs was 26% (95% CI [0.16-0.38]). Surgery-related complications rate was 22% (95% CI [0.14-0.33]). Among the wound complications, the pooled rate of air leakage was 10% (95% CI [0.04-0.23]), pulmonary/wound infection was 8% (95% CI [0.05-0.13]), bronchopleural fistula was 8% (95% CI [0.02-0.27]), bronchopulmonary haemorrhage was 3% (95% CI [0.01-0.05]), pneumonia was 5% (95% CI [0.02-0.10]), pulmonary embolism was 1% (95% CI [0.01-0.03]), pleural effusion was 7% (95% CI [0.03-0.14]) and chylothorax was 4% (95% CI [0.02-0.09]). Overall, neoadjuvant chemoimmunotherapy in NSCLC results a high incidence of grade 1-2 TRAEs but a low risk of increasing the incidence of ≥3 grade TRAEs and wound complications. These results need to be confirmed by more large-scale prospective randomized controlled trials and studies.

Progress in study on animal models of trigeminal neuralgia. / ä¸‰å‰ç¥žç»ç—›åŠ¨ç‰©æ¨¡åž‹çš„ç ”ç©¶è¿›å±•.

Trigeminal neuralgia is a manifestation of orofacial neuropathic pain disorder, always deemed to be an insurmountable peak in the field of pain research and treatment. The pain is recurrent, abrupt in onset and termination similar to an electric shock or described as shooting. A poor quality of life has been attributed to trigeminal neuralgia, as the paroxysms of pain may be triggered by innocuous stimuli on the face or inside the oral cavity, such as talking, washing face, chewing and brushing teeth in daily life. The pathogenesis of trigeminal neuralgia has not been fully elucidated, although the microvascular compression in the trigeminal root entry zone is generally considered to be involved in the emergence and progression of the pain disorder. In addition, orofacial neuropathic pain restricted to one or more divisions of the trigeminal nerve might be secondary to peripheral nerve injury. Based on current hypotheses regarding the potential causes, a variety of animal models have been designed to simulate the pathogenesis of trigeminal neuralgia, including models of compression applied to the trigeminal nerve root or trigeminal ganglion, chronic peripheral nerve injury, peripheral inflammatory pain and center-induced pain. However, it has not yet been possible to determine which model can be perfectly employed to explain the mechanisms. The selection of appropriate animal models is of great significance for the study of trigeminal neuralgia. Therefore, it is necessary to discuss the characteristics of the animal models in terms of animal strains, materials, operation methods and behavior observation, in order to gain insight into the research progress in animal models of trigeminal neuralgia. In the future, animal models that closely resemble the features of human trigeminal neuralgia pathogenesis need to be developed, with the aim of making valuable contributions to the relevant basic and translational medical research.

Establishment of monoclonal antibody and scFv immuno-based assay for Cry2Aa toxin in spiked grain samples.

Bacillus thuringiensis (Bt) Cry toxins have been widely used in the development of genetically modified organisms (GMOs) for pest control. This work aimed to establish more cost effective methods for used Cry2Aa toxins. Three immunoassay methods (IC-ELISA, DAS-ELISA, and CLEIA) were successfully developed in this work. The mAb was used as the detecting antibody, for the IC-ELISA, the range of IC20 to IC80 was 1.11 µg/mL - 60.70 µg/mL, and an IC50 of 10.65 µg/mL. For the DAS-ELISA, the limit of detection (LOD) and limit of quantitation (LOQ) were 10.76 ng/mL and 20.70 ng/mL, respectively. For the CLEIA, the LOD and LOQ were 6.17 ng/mL and 7.40 ng/mL, respectively. The scFv-based detections were the most sensitive for detecting Cry2Aa. The LOD and LOQ for the DAS-ELISA were 118.75 ng/mL and 633.48 ng/mL, respectively. The LOD and LOQ for the CLEIA, read as 37.47 ng/mL and 70.23 ng/mL, respectively. The fact that Cry2Aa toxin was recovered in spiked grain samples further demonstrated that the approaches might be used to identify field samples. These methods provided good sensitivity, stability, and applicability for detecting Cry2Aa toxin, promising ultrasensitive monitoring and references for Cry toxins risk assessment.

Generation of Allylmagnesium Reagents by Hydromagnesiation of 2-Aryl-1,3-dienes.

A protocol for the generation of allylmagnesium reagents from 2-aryl-1,3-dienes was developed using magnesium hydride (MgH2 ) that is generated in situ by solvothermal treatment of sodium hydride (NaH) and magnesium iodide (MgI2 ) in tetrahydrofuran (THF). Downstream functionalization of the resulting allylmagnesium reagents with carbonyl compounds or alkyl (pseudo)halides delivers branched products having an allylic quaternary carbon center, whereas that with chlorosilanes resulted in formation of linear allylsilanes in regio and stereoselective manners. Further derivatizations of the homoallylic alcohols and allylsilanes were also demonstrated.

Developmental alterations of intestinal SGLT1 and GLUT2 induced by early weaning coincides with persistent low-grade metabolic inflammation in female pigs.

Early-life adversity (ELA) is linked with the increased risk for inflammatory and metabolic diseases in later life, but the mechanisms remain poorly understood. Intestinal epithelial glucose transporters sodium-glucose-linked transporter 1 (SGLT1) and glucose transporter 2 (GLUT2) are the major route for intestinal glucose uptake but have also received increased attention as modulators of inflammatory and metabolic diseases. Here, we tested the hypothesis that early weaning (EW) in pigs, an established model of ELA, alters the development of epithelial glucose transporters and coincides with elevated markers of metabolic inflammation. The jejunum and ileum of 90-day-old pigs previously exposed to EW (16 days wean age), exhibited reduced SGLT1 activity (by ∼ 30%, P < 0.05) than late weaned (LW, 28 days wean age) controls. In contrast, GLUT2-mediated glucose transport was increased (P = 0.003) in EW pigs than in LW pigs. Reciprocal changes in SGLT1- and GLUT2-mediated transport coincided with transporter protein expression in the intestinal brush-border membranes (BBMs) that were observed at 90 days and 150 days of age. Ileal SGLT1-mediated glucose transport and BBM expression were inhibited by the ß-adrenergic receptor (ßAR) blocker propranolol in EW and LW pigs. In contrast, propranolol enhanced ileal GLUT2-mediated glucose transport (P = 0.015) and brush-border membrane vesicle (BBMV) abundance (P = 0.035) in LW pigs, but not in EW pigs. Early-weaned pigs exhibited chronically elevated blood glucose and C-reactive protein (CRP) levels, and adipocyte hypertrophy and upregulated adipogenesis-related gene expression in visceral adipose tissue. Altered development of intestinal glucose transporters by EW could underlie the increased risk for later life inflammatory and metabolic diseases.NEW & NOTEWORTHY These studies reveal that early-life adversity in the form of early weaning in pigs causes a developmental shift in intestinal glucose transport from SGLT1 toward GLUT2-mediated transport. Early weaning also induced markers of metabolic inflammation including persistent elevations in blood glucose and the inflammatory marker CRP, along with increased visceral adiposity. Altered intestinal glucose transport might contribute to increased risk for inflammatory and metabolic diseases associated with early-life adversity.

Pathogenesis and Therapeutic Strategies Related to Non-Alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD), one of the most common types of chronic liver disease, is strongly correlated with obesity, insulin resistance, metabolic syndrome, and genetic components. The pathological progression of NAFLD, consisting of non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and liver cirrhosis, is characterized by a broad spectrum of clinical phenotypes. Although patients with mild NAFL are considered to show no obvious clinical symptoms, patients with long-term NAFL may culminate in NASH and further liver fibrosis. Even though various drugs are able to improve NAFLD, there are no FDA-approved medications that directly treat NAFLD. In this paper, the pathogenesis of NAFLD, the potential therapeutic targets, and their underlying mechanisms of action were reviewed.

Five New Polyoxypregnane Glycosides from the Vines of Aspidopterysobcordata and Their Antinephrolithiasis Activity.

From the dried vines of Aspidopterys obcordata Hemsl, five new polyoxypregnane glycosides, named obcordatas J-N (1-5), were obtained. Their structures were fully elucidated and characterized by HRESIMS and extensive spectroscopic data. In addition, all of the new compounds were screened for their antinephrolithiasis activity in vitro. The results showed that compounds 1-3 have prominent protective effects on calcium oxalate crystal-induced human kidney 2 (HK-2) cells, with EC50 values ranging from 6.72 to 14.00 µM, which is consistent with the application value of A. obcordata in folk medicine for kidney stones.

The Biosynthesis Related Enzyme, Structure Diversity and Bioactivity Abundance of Indole-Diterpenes: A Review.

Indole diterpenes are a large class of secondary metabolites produced by fungi, possessing a cyclic diterpenoid backbone and an indole moiety. Novel structures and important biological activity have made indole diterpenes one of the focuses of synthetic chemists. Although the discovery, identification, structural diversity, biological activity and especially structure-activity relationship of indole diterpenes have been reported in some papers in recent years, they are absent of a systematic and comprehensive analysis, and there is no elucidation of enzymes related to this kind of natural product. Therefore, it is necessary to summarize the relevant reports to provide new perspectives for the following research. In this review, for the first time, the function of related synthases and the structure-activity relationship of indole diterpenes are expounded, and the recent research advances of them are emphasized.

Lobe specificity of iron binding to transferrin modulates murine erythropoiesis and iron homeostasis.

Transferrin, the major plasma iron-binding molecule, interacts with cell-surface receptors to deliver iron, modulates hepcidin expression, and regulates erythropoiesis. Transferrin binds and releases iron via either or both of 2 homologous lobes (N and C). To test the hypothesis that the specificity of iron occupancy in the N vs C lobe influences transferrin function, we generated mice with mutations to abrogate iron binding in either lobe (TfN-bl or TfC-bl). Mice homozygous for either mutation had hepatocellular iron loading and decreased liver hepcidin expression (relative to iron concentration), although to different magnitudes. Both mouse models demonstrated some aspects of iron-restricted erythropoiesis, including increased zinc protoporphyrin levels, decreased hemoglobin levels, and microcytosis. Moreover, the TfN-bl/N-bl mice demonstrated the anticipated effect of iron restriction on red cell production (ie, no increase in red blood cell [RBC] count despite elevated erythropoietin levels), along with a poor response to exogenous erythropoietin. In contrast, the TfC-bl/C-bl mice had elevated RBC counts and an exaggerated response to exogenous erythropoietin sufficient to ameliorate the anemia. Observations in heterozygous mice further support a role for relative N vs C lobe iron occupancy in transferrin-mediated regulation of iron homeostasis and erythropoiesis.

Epitopes prediction for microcystin-LR by molecular docking.

Microcystin-LR (MC-LR) is one of the most worldwide harmful cyanobacterial toxins. A lots of antibodies against MC-LR have been generated and characterized. However, the knowledge about the epitopes of MC-LR was still limited. The objective of this study was to analyze the epitopes of MC-LR and demonstrate the binding mode of MC-LR with its antibody. The variable genes of a mouse hybridoma cell line (Mab5H1-3B3) raised against MC-LR have been cloned and assembled in a single chain variable fragment (scFv), and then soluble expressed in E.coli BL21. Based on the scFv, the IC50 and IC10 for MC-LR were determined to be 7.45 nM and 0.30 nM by competitive ELISA. And the scFv also showed 115% and 112% cross-reactivities to MC-RR and MC-YR, and 59% to MC-LA. By molecular docking, the binding mode between MC-LR and its scFv was demonstrated. A hydrogen bond interaction was observed between the carbonyl group of Adda5 residue of MC-LR and its scFv, and the guanidyl group of Arg4 residue and phenyl group of Adda5 residue of MC-LR were also involved in the interaction. These predicted epitopes were supported by antibody cross-reactivity data. By comparing the antibody informatics of MC-LR scFv with its predicted paratopes, VH-CDR1 was crucial for MC-LR binding, and its specificity could be tuned by engineering in Vκ-CDR1 and Vκ-CDR3. These information would be useful for the hapten design for microcystins or improving the properties of MC-LR scFv in vitro.

Construction of Porous Starch-Based Hydrogel via Regulating the Ratio of Amylopectin/Amylose for Enhanced Water-Retention.

The performance of hydrogels prepared with traditional natural starch as raw materials is considerable; the fixed ratio of amylose/amylopectin significantly limits the improvement of hydrogel structure and performance. In this paper, starch hydrogels were prepared by physical blending and chemical grafting, with the aid of ultrasonic heating. The effects of different amylose/amylopectin ratios on the microstructure and water retention properties of starch hydrogels were studied. The results show that an increase in amylopectin content is beneficial to improve the grafting ratio of acrylamide (AM). The interaction between the AM grafted on amylopectin and amylose molecules through hydrogen bonding increases the pores of the gel network and thins the pore walls. When the amylopectin content was 70%, the water absorption (swelling 45.25 times) and water retention performance (16 days water retention rate 44.17%) were optimal. This study provides new insights into the preparation of starch-based hydrogels with excellent physical and chemical properties.