CO2 capture over H2 by polymeric membranes for carbon-free H2 Production

Membrane separation is potential alternative technology for liquid amine scrubbing in CO2 capture at mass CO2 emission sources, such as coal-fired plants, due to the low-energy and cost effective process, and various membranes have been developed for effective CO2 capture. Among them, polymeric membranes would be promising because of versatile chemical approaches, synthetic feasibility, large-scale productivity, and good processability in comparison to inorganic membranes. In this research group, polymeric membranes have been investigated for pre-combustion CO2 capture, where CO2 is separated over H2. For preferential CO2 permeation over smaller H2, amines, such as poly(amidoamine)s (PAMAMs), are used to enhance CO2 solubility to the polymeric membrane. When PAMAMs are physically immobilized in cross-linked PEG or PVA to form polymeric membranes, the resulting membranes exhibit high CO2 separation properties over H2 especially under humidified conditions and lower CO2 partial pressure than 100 kPa [1-5]. The PAMAM membrane is waiting for demonstration test by Research Institute of Innovative Technology for the Earth (RITE, Japan). The amine-containing polymeric membranes can be also applicable to on-site H2 refilling station to make the H2 production process carbon-free by capturing CO2 in the off-gas by the membranes as shown in Figure 1. The off-gas consists of H2 and CO2 at ambient pressure and temperature (CO2 partial pressure: 40-50 kPa). In comparison to mass CO2 emission sources, the amount of CO2 is smaller and thus the captured CO2 can be utilized for plant growth or even refrigerant. However, the CO2 permeability should be improved for implementation. Please click Additional Files below to see the full abstract

Deep-Sea-Inspired Chemistry: A Hitchhiker’s Guide to the Bottom of the Ocean for Chemists

「深海インスパイヤード化学」のコンセプトを発表 --カーボンニュートラル実現に向けた新たな深海利用の提案--. 京都大学プレスリリース. 2023-06-09.The ocean constitutes approximately 70% of Earth’s surface. Its average depth is 3688 m, of which depths beyond 200 m are classified as the deep sea. The deep sea is distinct from the surface of the ocean in terms of pressure, temperature, and sunlight. The unique physicochemical processes under the extreme environment of the deep sea and the specialized biochemical mechanisms developed by organisms to survive in the deep sea can serve as a vast source of inspiration for scientific and technological advancements. In this Perspective, we discuss three examples of deep-sea-inspired chemistry: (1) soft materials that respond to high pressures such as those observed in the deep sea; (2) molecular self-assembly inspired by the chemistry of hot and compressed water in deep-sea hydrothermal vents; and (3) nanobiotechnology and biomimetics inspired by survival strategies of deep-sea organisms. Finally, we provide an outlook on deep-sea-inspired chemistry. This Perspective aims to promote the sustainable utilization of the ocean based on knowledge, as opposed to the conventional utilization of the ocean solely based on resources. We hope that this Perspective will encourage chemists to harness their inspiration gleaned from the deep sea

Development of Poly(Amidoamine) Dendrimer/ Poly(Ethylene Glycol) Hybrid Membranes for CO2 Capture at Elevated Pressures

AbstractTo improve CO2 separation performance of Poly (amidoamine) (PAMAM) dendrimer at pressure difference conditions, hybrid membranes have been developed by immobilizing of PAMAM dendrimer into a cross-linked poly(ethylene glycol) dimethacrylate (PEGDMA) polymer matrix. A multifunctional cross-linker (MFX) such as trimethylolpropane trimethacrylate (TMPTMA) was used to enhance membrane separation performance at elevated pressures. The resulting hybrid membrane PAMAM dendrimer / PEGDMA/TMPTMA hybrid membrane exhibited an excellent CO2/H2 selectivity of 30 and above with CO2 permeance of 2.1×10−12m3(STP)/(m2 s Pa) at 660kPa CO2 partial under 820kPa feed pressure with 80% relative humidity at 40°C. The PAMAM dendrimer/cross-linked PEG hybrid membrane shows great potential for CO2 separation from H2 in high pressure applications, such as IGCC process.A compatible crosslinker (CPC) was used to prepare the composite membrane with a thin selectivity layer to enhance CO2 permeance. An isopropyl alkyl hindered amine IAM, tertiary amine TA1 and TA2 were added to the formation solution of membrane for investigating the effect of additive on CO2 separation performance

Cross-Curricular Teaching through Team-Teaching : An Experimental Class of the Ninth Graders : 'Let's Decorate Characters and Letters.'

本稿は, 1999年度第1学期に実施した中学校第3学年における授業実践「文字を飾ろう」に関するものである。数学的な手法や考え方をベースにしながら, コンピュータを用いることによって, 書写と美術とをリンクさせた教科横断的(クロス・カリキュラム形式)な取り組みについて報告し, 検討していく。この授業実践は, 数学科の教官と国語科書写の教官, 美術科の教官の3名でT.T.(ティーム・ティーチング)を組み指導に当たった, いわゆる異教科間T.T.の試みである

Oxidative stress induction of DJ-1 protein in reactive astrocytes scavenges free radicals and reduces cell injury

Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Under cerebral ischemia/reperfusion-induced oxidative conditions, astrocytes accumulate and activate in the ischemic region. DJ-1 has recently been shown to be a sensor of oxidative stress in living cells. However, the function of astrocytic DJ-1 is still unknown. In the present study, to clarify the effect of astrocytic DJ-1 protein under massive oxidative insult, we used a focal ischemic rat model that had been subjected to middle cerebral artery occlusion (MCAO) and reperfusion. We then investigated changes in the distribution of DJ-1 in astrocytes, DJ-1 release from cultured astrocytes, and the effects of recombinant DJ-1 protein on hydrogen peroxide (H2O2)-induced death in normal and DJ-1-knockdown SH-SY5Y cells and on in vitro scavenging of hydroxyl radicals (•OH) by electron spin resonance spectrometry. At 24 h after 2-h MCAO and reperfusion, an infarct lesion was markedly observed using magnetic resonance imaging and 2,3,5-triphenyltetrazolium chloride staining. In addition, reactive astrocytes enhanced DJ-1 expression in the penumbral zone of the ischemic core and that DJ-1 protein was extracellularly released from astrocytes by H2O2 in in vitro primary cultures. Although DJ-1-knockdown SH-SY5Y cells were markedly vulnerable to oxidative stress, treatment with glutathione S-transferase-tagged recombinant human DJ-1 protein (GST-DJ-1) significantly inhibited H2O2-induced cell death. In addition, GST-DJ-1 protein directly scavenged •OH. These results suggest that oxidative stress induces the release of astrocytic DJ-1 protein, which may contribute to astrocyte-mediated neuroprotection

Valsartan in a Japanese population with hypertension and other cardiovascular disease (Jikei Heart Study): a randomised, open-label, blinded endpoint morbidity-mortality study. Lancet 369

Summary Background Drugs that inhibit the renin-angiotensin-aldosterone system benefi t patients at risk for or with existing cardiovascular disease. However, evidence for this eff ect in Asian populations is scarce. We aimed to investigate whether addition of an angiotensin receptor blocker, valsartan, to conventional cardiovascular treatment was eff ective in Japanese patients with cardiovascular disease

Species-Specific Immunity Induced by Infection with Entamoeba histolytica and Entamoeba moshkovskii in Mice

Entamoeba histolytica, the parasitic amoeba responsible for amoebiasis, causes approximately 100,000 deaths every year. There is currently no vaccine against this parasite. We have previously shown that intracecal inoculation of E. histolytica trophozoites leads to chronic and non-healing cecitis in mice. Entamoeba moshkovskii, a closely related amoeba, also causes diarrhea and other intestinal disorders in this model. Here, we investigated the effect of infection followed by drug-cure of these species on the induction of immunity against homologous or heterologous species challenge. Mice were infected with E. histolytica or E. moshkovskii and treated with metronidazole 14 days later. Re-challenge with E. histolytica or E. moshkovskii was conducted seven or 28 days following confirmation of the clearance of amoebae, and the degree of protection compared to non-exposed control mice was evaluated. We show that primary infection with these amoebae induces a species-specific immune response which protects against challenge with the homologous, but not a heterologous species. These findings pave the way, therefore, for the identification of novel amoebae antigens that may become the targets of vaccines and provide a useful platform to investigate host protective immunity to Entamoeba infections