Pyrene-Based Organic Photoredox Catalysts for Carbon-Carbon Bond-Forming Reactions: Reductive Coupling of Aromatic Carbonyl and Imine Compounds.

Metal-free photoredox catalysts built upon a pyrene core were developed for carbon-carbon bond-forming reactions. Among these catalysts, a pyrene derivative containing a urea moiety effectively facilitated the reductive coupling of aromatic carbonyl and imine compounds under blue LED irradiation. This process provided the corresponding vicinal diols and diamines in good yields.

Anesthetic management of extracorporeal membrane oxygenation-supported aortic bypass surgery for atypical coarctation with severe left ventricular dysfunction: A case report.

Atypical aortic coarctation is an exceedingly rare condition, and there are very few reported cases of anesthetic management for bypass surgery in patients with severe impaired cardiac function. We present the anesthetic management of a 68-year-old woman with atypical aortic coarctation due to Takayasu arteritis and severely impaired cardiac function, who underwent ascending-to-abdominal aorta bypass surgery under extracorporeal membrane oxygenation (ECMO). The patient's severe cardiac dysfunction was due to sustained afterload from the coarctation, leading to recurrent episodes of heart failure. Surgical intervention was deemed necessary, and a decision was made to perform a bypass operation. The patient experienced a transient state of shock following induction of anesthesia, but subsequent perioperative care was safely managed with the implementation of ECMO. For bypass surgery performed on patients with severe cardiac dysfunction due to atypical coarctation of the aorta, it is crucial to prepare for potential circulatory collapse during anesthesia induction and the surgical procedure. This preparation includes meticulous planning of the anesthesia induction method and ensuring that ECMO can be established promptly if needed.

Anesthetic management of Stanford type B acute aortic dissection that occurred during transcatheter aortic valve implantation under monitored anesthesia care: A case report.

We report a case involving anesthetic management of Stanford type B acute aortic dissection occurred during transcatheter aortic valve implantation (TAVI) under monitored anesthesia care (MAC) in a patient with aortic stenosis (AS). An 87-year-old woman was undergoing TAVI under MAC for severe AS. During the surgery, the patient suddenly moved possibly because of pain. This was followed by hemodynamic collapse. She was then transitioned to general anesthesia, and extracorporeal membrane oxygenation (ECMO) was initiated. Transesophageal echocardiography revealed a Stanford type B acute aortic dissection, which was safely managed perioperatively with appropriate interventions.

Preparation of Various Nanomaterials via Controlled Gelation of a Hydrophilic Polymer Bearing Metal-Coordination Units with Metal Ions.

We investigated the gelation of a hydrophilic polymer with metal-coordination units (HPMC) and metal ions (PdII or AuIII). Gelation proceeded by addition of an HPMC solution in N-methyl-2-pyrrolidone (NMP) to a metal ion aqueous solution. An increase in the composition ratio of the metal-coordination units from 10 mol% to 34 mol% (HPMC-34) increased the cross-linking rate with AuIII. Cross-linking immediately occurred after dropwise addition of an HPMC-34 solution to the AuIII solution, generating the separation between the phases of HPMC-34 and AuIII. The cross-linking of AuIII proceeded from the surface to the inside of the HPMC-34 droplets, affording spherical gels. In contrast, a decrease in the ratio of metal-coordination units from 10 mol% to 4 mol% (HPMC-4) decreased the PdII cross-linking rate. The cross-linking occurred gradually and the gels extended to the bottom of the vessel, forming fibrous gels. On the basis of the mechanism for the formation of gels with different morphologies, the gelation of HPMC-34 and AuIII provided nanosheets via gelation at the interface between the AuIII solution and the HPMC-34 solution. The gelation of HPMC-4 and PdII afforded nanofibers by a facile method, i.e., dropwise addition of the HPMC-4 solution to the PdII solution. These results demonstrated that changing the composition ratio of the metal-coordination units in HPMC can control the gelation behavior, resulting in different types of nanomaterials.

Molecular Design of Isocyanurate Core-Based Acrylates Undergoing Volume Expansion on Radical Photo-Polymerization.

The synthesis of acrylates with an isocyanurate substituent that show significant volume expansion on radical photo-polymerization is reported. The acrylate consisting of benzyl bisurethane moieties exhibits the largest volume expansion among them and contributes to restrict volume change upon its radical photo-copolymerization with a diacrylate exhibiting volume shrinkage. Furthermore, a correlation is revealed between the volume change behavior and the polymer structure through the radical photo-polymerization of the isocyanurate core-based diacrylate with benzyl bisurethane moieties under various concentration conditions.

A Metal-Free Approach to 1,2-Diamines via Visible Light-Driven Reductive Coupling of Imines with Perylene as a Photoredox Catalyst.

A simple, metal-free, and versatile approach to 1,2-diamines has been developed based on reductive coupling reactions of various imines, where perylene, an aromatic hydrocarbon, was used as a photoredox catalyst under visible light irradiation using a white light-emitting diode. The use of 1 mol % perylene enabled almost complete conversion of the imines, leading to the formation of their corresponding 1,2-diamines, which were isolated in good yields. The ratios between dl and meso diamines ranged from 31:69 to 82:18 depending on the substituents of the imines.

Metal-free reductive coupling of C[double bond, length as m-dash]O and C[double bond, length as m-dash]N bonds driven by visible light: use of perylene as a simple photoredox catalyst.

Perylene, a simple polycyclic aromatic hydrocarbon, was used as a photoredox catalyst to enable the reductive coupling reaction of aromatic aldehydes, ketones, and an imine under visible-light irradiation using a white LED.

Production of itaconic acid in Escherichia coli expressing recombinant α-amylase using starch as substrate.

Several studies on fermentative production of a vinyl monomer itaconic acid from hydrolyzed starch using Aspergillus terreus have been reported. Herein, we report itaconic acid production by Escherichia coli expressing recombinant α-amylase, using soluble starch as its sole carbon source. To express α-amylase in E. coli, we first constructed recombinant plasmids expressing α-amylases by using cell surface display technology derived from two amylolytic bacteria, Bacillus amyloliquefaciens NBRC 15535(T) and Streptococcus bovis NRIC 1535. The recombinant α-amylase from S. bovis (SBA) showed activity at 28°C, which is the optimal temperature for production of itaconic acid, while α-amylase from B. amyloliquefaciens displayed no noticeable activity. E. coli cells expressing SBA produced 0.15 g/L itaconic acid after 69 h cultivation under pH-stat conditions, using 1% starch as the sole carbon source. In fact, E. coli cells expressing SBA had similar growth rates when grown in the presence of 1% glucose or starch, thereby highlighting the expression of an active α-amylase that enabled utilization of starch to produce itaconic acid in E. coli.

Production of itaconic acid using metabolically engineered Escherichia coli.

An Escherichia coli system was engineered for the heterologous production of itaconic acid via the expression of cis-aconitate decarboxylase gene (cad), and then maximal itaconic acid levels produced by engineered E. coli were evaluated. Expression of cad in E. coli grown in Luria-Bertani (LB) medium without glucose in a test tube resulted in 0.07 g/L itaconic acid production after 78 h at 20°C. To increase itaconic acid production, E. coli recombinants were constructed by inactivating the isocitrate dehydrogenase gene (icd) and/or the isocitrate lyase gene (aceA). Expression of cad and inactivation of icd resulted in 0.35 g/L itaconic acid production after 78 h, whereas aceA inactivation had no effect on itaconic acid production. The intracellular itaconate concentration in the Δicd strain was higher than that in the cad-expressing strain without icd inactivation, which suggests that the extracellular secretion of itaconate in E. coli is the rate-determining step during itaconic acid production. pH-stat cultivation using the cad-expressing Δicd strain in LB medium with 3% glucose in a jar fermenter resulted in 1.71 g/L itaconic acid production after 97 h at 28°C. To further increase itaconic acid production, the aconitase B gene (acnB) was overexpressed in the cad-expressing Δicd strain. Simultaneous overexpression of acnB with the expression of cad in the Δicd strain led to 4.34 g/L itaconic acid production after 105 h. Our findings indicate that icd inactivation and acnB overexpression considerably enhance itaconic acid production in cad-expressing E. coli.