Critical role of lattice vacancies in pressure-induced phase transitions of baroplastic diblock copolymers.

Baroplastic diblock copolymers exhibit order-disorder transitions and melt upon compression at low temperatures, in some cases even at ambient temperatures. Their unique low-temperature processability makes them promising candidates for sustainable polymeric materials. Despite their potential, however, the molecular mechanisms governing the pressure-induced phase transitions of these copolymers remain largely unexplored. This study develops a compressible self-consistent field theory for baroplastic copolymers based on a simple lattice vacancy model that explicitly incorporates voids to account for compressibility. The theory shows that the selective presence of voids in compressible domains stabilizes the ordered phase, while a reduction of voids under compression leads to the order-disorder transition. In addition, this work demonstrates for the first time the critical role of gas absorption rates in each segment in the pressure-induced order-disorder transition of baroplastic diblock copolymers. These findings have significant implications for the rational design of baroplastic polymers with tailored low-temperature processability.

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

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.

Why does 2-(2-aminoethylamino)ethanol have superior CO2 separation performance to monoethanolamine? A computational study.

Our computational reaction analysis shows that 2-(2-aminoethylamino)ethanol (AEEA) has superior performance to monoethanolamine for CO2 separation, in terms of its ability to sorb CO2 by its primary amine and desorb CO2 by its secondary amine.

Biodegradation of waste PET: A sustainable solution for dealing with plastic pollution.

The discovery of Ideonella sakaiensis, a plastic-degrading bacterium, creates possibilities for a sustainable "bioeconomy" for recycling plastic waste.

The beneficial effects of long-term enzyme replacement therapy on cardiac involvement in Japanese Fabry patients.

Fabry disease is a hereditary disorder that occurs due to the reduction or absence of alpha-galactosidase A activity, which leads to cardiac involvement including left ventricular hypertrophy (LVH). Enzyme replacement therapy (ERT) provides better patient outcomes by preventing serious complications. However, there have been very few studies on the long-term effects of ERT on the cardiac manifestations in Japanese Fabry patients. We retrospectively analyzed the data from the medical records of 42 Fabry patients (male, n = 17; female, n = 25) who were followed at Jikei University Hospital, and in whom the long-term effects of ERT could be evaluated (median follow-up period: male, 11 years; female, 8 years). The slope of the left ventricular mass (LVM) increase was 3.02 ±â€¯3.41 g/m2/year in males and 1.69 ±â€¯2.73 g/m2/year in females. In a subgroup analysis, the slopes of males with and without LVH did not differ to a statistically significant extent; however, the slope in female patients without LVH was significantly smaller than that of female patients with LVH. We then compared our data to the natural historical data that have previously been reported. In comparison to the previously reported data, we found a significant reduction in the LVM changes (g/height2.7/year) of patients who received long-term ERT (male, 4.07 ±â€¯1.03 to 1.25 ±â€¯1.39; female, 2.31 ±â€¯0.81 to 0.78 ±â€¯1.23). Long-term ERT effectively prevents LVH in Fabry patients. This effect was also observed in the patients with LVH prior to the initiation of ERT.

Effect of amine structure on CO2 capture by polymeric membranes.

Poly(amidoamine)s (PAMAMs) incorporated into a cross-linked poly(ethylene glycol) exhibited excellent CO2 separation properties over H2. However, the CO2 permeability should be increased for practical applications. Monoethanolamine (MEA) used as a CO2 determining agent in the current CO2 capture technology at demonstration scale was readily immobilized in poly(vinyl alcohol) (PVA) matrix by solvent casting of aqueous mixture of PVA and the amine. The resulting polymeric membranes can be self-standing with the thickness above 3 µm and the amine fraction less than 80 wt%. The gas permeation properties were examined at 40 °C and under 80% relative humidity. The CO2 separation performance increased with increase of the amine content in the polymeric membranes. When the amine fraction was 80 wt%, the CO2 permeability coefficient of MEA containing membrane was 604 barrer with CO2 selectivity of 58.5 over H2, which was much higher than the PAMAM membrane (83.7 barrer and 51.8, respectively) under the same operation conditions. On the other hand, ethylamine (EA) was also incorporated into PVA matrix to form a thin membrane. However, the resulting polymeric membranes exhibited slight CO2-selective gas permeation properties. The hydroxyl group of MEA was crucial for high CO2 separation performance.

Low-Temperature Processable Block Copolymers That Preserve the Function of Blended Proteins.

Low-temperature processable polymers have attracted increasing interest as ecological materials because of their reduced energy consumption during processing and suitability for making composites with heat-sensitive biomolecules at ambient temperature. In the current study, low-temperature processable biodegradable block copolymers were synthesized by ring-opening polymerization of l-lactide (LLA) using polyphosphoester as a macroinitiator. The polymer films could be processed under a hydraulic pressure of 35 MPa. The block copolymer films swelled in water because the polyphosphoester block was partially hydrated. Interestingly, the swelling ratio of the films changed with temperature. The pressure-induced order-to-disorder transition of the block copolymers was characterized by small-angle X-ray scattering; a crystallinity reduction in the block copolymers was observed after application of pressure. The crystallinity of the block copolymers was recovered after removing the applied pressure. The Young's modulus of the block copolymer films increased as the LLA unit content increased. Moreover, the modulus did not change after multiple processing cycles and the recyclability of the block copolymers was also confirmed. Finally, polymer films with embedded proteinase K as a model protein were prepared. The activity of catalase loaded into the polymer films was evaluated after processing at different temperatures. The activity of catalase was preserved when the polymer films were processed at room temperature but was significantly reduced after high-temperature processing. The suitability of low-temperature processable biodegradable polymers for making biofunctional composites without reducing protein activity was clarified. These materials will be useful for biomedical and therapeutic applications.

Laser Patterning of Porous Support Membranes to Enhance the Effective Surface Area of Thin-Film Composite-Facilitated Transport Membranes for CO2 Separation.

Although thin-film composite membranes have achieved great success in CO2 separation, further improvements in the CO2 permeance are required to reduce the size and cost of the CO2 separation process. Herein, we report the fabrication of composite membranes with high CO2 permeability using a laser-patterned porous membrane as the support membrane. High-aspect-ratio micropatterns with well-defined micropores on their surface were carved on microporous polymer supports by a direct laser writing process using a short-pulsed laser. By using a Galvano scanner and optimizing the laser conditions and target materials, in-plane micropatterns, such as microhole arrays, microline grating, microlattices, and out-of-plane hierarchical micropatterns, were created on porous membranes. An aqueous suspension of hydrogel microparticles doped with an amine-based mobile carrier was sprayed onto the patterned surface to form a defect-free thin separation layer. The surface area of the separation layer on the patterned support is up to 80% larger than that of flat pristine membranes, resulting in a 52% higher CO2 permeance (1106 GPU) with a CO2/N2 selectivity of 172. The laser-patterned porous membranes allow the development of inexpensive and high-performance functional membranes not only for CO2 separation but also for other applications, such as water treatment, cell culture, micro-TAS, and membrane reactors.

Cardiac tamponade as an independent condition affecting the relationship between the plasma B-type natriuretic peptide levels and cardiac function.

Plasma B-type natriuretic peptide (BNP) is finely regulated by the cardiac function and several extracardiac factors. Therefore, the relationship between the plasma BNP levels and the severity of heart failure sometimes seems inconsistent. The purpose of the present study was to investigate the plasma BNP levels in patients with cardiac tamponade and their changes after pericardial drainage. This study included 14 patients with cardiac tamponade who underwent pericardiocentesis. The cardiac tamponade was due to malignant diseases in 13 patients and uremia in 1 patient. The plasma BNP levels were measured before and 24-48 h after drainage. Although the patients reported severe symptoms of heart failure, their plasma BNP levels were only 71.2 ± 11.1 pg/ml before drainage. After appropriate drainage, the plasma BNP levels increased to 186.0 ± 22.5 pg/ml, which was significantly higher than that before drainage (P = 0.0002). In patients with cardiac tamponade, the plasma BNP levels were low, probably because of impaired ventricular stretching, and the levels significantly increased in response to the primary condition after drainage. This study demonstrates an additional condition that affects the relationship between the plasma BNP levels and cardiac function. If inconsistency is seen in the relationship between the plasma BNP levels and clinical signs of heart failure, the presence of cardiac tamponade should therefore be considered.

The role of Na+/H+ exchanger in Ca2+ overload and ischemic myocardial damage in hearts from type 2 diabetic db/db mice.

BACKGROUND: A higher increase in intracellular Na(+) via Na(+)/H(+) exchanger (NHE) during ischemia has been reported in type 2 diabetic mouse hearts. We investigated the role of NHE in inducing changes in cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) and alterations in ventricular function during ischemia-reperfusion in type 2 diabetic mouse hearts. METHODS: Hearts from male type 2 diabetic db/db (12-15 weeks old) and age-matched control db/+ mice were subjected to Langendorff perfusion and loaded with 4 µM of the Ca(2+) indicator fura-2. The hearts were exposed to no-flow ischemia for 15 minutes and then reperfused. [Ca(2+)](i) was measured by monitoring fura-2 fluorescence at 500 nm (excitation wavelengths of 340 and 380 nm), while left ventricular (LV) pressure was simultaneously measured. RESULTS: db/db hearts exhibited a lower recovery of LV developed pressure than db/+ hearts during reperfusion following ischemia. Diastolic [Ca(2+)](i) was increased to a greater level in diabetic hearts than in the control hearts during ischemia and reperfusion. Such an increase in cytoplasmic Ca(2+) overload during ischemia-reperfusion in diabetic hearts was markedly reduced in the presence of the NHE inhibitor cariporide. This was accompanied by a significantly improved recovery of ventricular function on reperfusion, as shown by a lower increase in diastolic pressure and increased recovery of developed pressure. CONCLUSION: NHE plays a key role in enhancing cytoplasmic Ca(2+) overload during ischemia-reperfusion and severely impairing post-ischemic cardiac function in hearts from type 2 diabetic db/db mice.

Impact of body mass index on clinical outcome in patients hospitalized with congestive heart failure.

BACKGROUND: Obesity has recently been shown to have a favorable effect on the prognosis of patients with congestive heart failure (CHF), but only a few such studies are available in Japan. The purpose of the present study was to investigate whether the obesity paradox is still present after adjusting for CHF characteristics. METHODS AND RESULTS: A total of 219 patients hospitalized with CHF were reviewed, and the impact of body mass index (BMI) on prognosis was examined. Patients were divided into 4 groups according to BMI quartiles. The endpoint was defined as all-cause death or unplanned CHF hospitalization. According to univariate analysis, a higher BMI was associated with better outcomes. High-BMI patients were younger, likely to be male, and had a higher prevalence of hypertension and diabetes. The plasma B-type natriuretic peptide (BNP) levels and blood urea nitrogen (BUN) levels were lower, while the serum hemoglobin and sodium levels were higher in high-BMI patients. The prevalence of atrial fibrillation was lower in high-BMI patients. Predictors for all-cause death or CHF hospitalization based on univariate analysis were age, prior CHF hospitalization, estimated glomerular filtration rate, plasma BNP levels, BUN levels, and serum hemoglobin and sodium levels. According to multivariate analysis, a high BMI was still associated with better outcomes. CONCLUSIONS: High BMI was associated with better clinical outcomes in Japanese CHF patients.

Effect of rosuvastatin on systemic blood pressure in patients with hypercholesterolemia.

OBJECTIVE: To investigate whether rosuvastatin reduces blood pressure (BP) in patients with hypercholesterolemia. METHODS: The present study investigated the effect of rosuvastatin on lipids and clinical parameters in 25 patients with a mean (± SD) age of 58.4±10.6 years over a three-month period. RESULTS: Rosuvastatin (2.5 mg/day to 5.0 mg/day) reduced systolic BP from 136.3±13.1 mmHg to 130.8±10.7 mmHg (P<0.01), along with a significant reduction in serum low-density lipoprotein cholesterol level (P<0.01). The patients were divided into two groups: 13 responders whose BP decreased by >5 mmHg with rosuvastatin treatment and 12 nonresponders who showed a BP reduction of ≤5 mmHg. Baseline systolic BP was significantly higher in responders than nonresponders (143.6±9.6 mmHg versus 128.4±11.9 mmHg, respectively; P<0.01). Responders also had a lower serum concentration of high-sensitivity C-reactive protein compared with nonresponders (0.11±0.07 mg/dL versus 0.40±0.28 mg/dL; P<0.01). The extent of BP reduction was positively correlated with baseline systolic BP (r=0.585; P=0.0021) but not with the reduction of low-density lipoprotein cholesterol level. Among the patients with baseline systolic BP >130 mmHg, all 11 responders (138.3 mmHg) were nonsmokers, while five of six nonresponders (145.7 mmHg) were smokers. CONCLUSION: Rosuvastatin had an additive antihypertensive effect in patients with poorly controlled hypertension that was independent of its lipid-lowering effect, which may be related to an inflammatory mechanism.

Glycine amino acid transformation under impacts by small solar system bodies, simulated via high-pressure torsion method.

Impacts by small solar system bodies (meteoroids, asteroids, comets and transitional objects) are characterized by a combination of energy dynamics and chemical modification on both terrestrial and small solar system bodies. In this context, the discovery of glycine amino acid in meteorites and comets has led to a hypothesis that impacts by astronomical bodies could contribute to delivery and polymerization of amino acids in the early Earth to generate proteins as essential molecules for life. Besides the possibility of abiotic polymerization of glycine, its decomposition by impacts could generate reactive groups to form other essential organic biomolecules. In this study, the high-pressure torsion (HPT) method, as a new platform for simulation of impacts by small solar system bodies, was applied to glycine. In comparison with high-pressure shock experiments, the HPT method simultaneously introduces high pressure and deformation strain. It was found that glycine was not polymerized in the experimental condition assayed, but partially decomposed to ethanol under pressures of 1 and 6 GPa and shear strains of < 120 m/m. The detection of ethanol implies the inherent availability of remaining nitrogen-containing groups, which can incorporate to the formation of other organic molecules at the impact site. In addition, this finding highlights a possibility of the origin of ethanol previously detected in comets.

Dormant pulmonary vein conduction induced by adenosine in patients with atrial fibrillation who underwent catheter ablation.

BACKGROUND: intravenous administration of adenosine triphosphate (ATP) is used to induce transient pulmonary vein (PV) reconduction (dormant PV conduction) following PV isolation. This study investigated the detailed characteristics of dormant PV conduction in patients with atrial fibrillation (AF) who underwent catheter ablation. METHODS: two hundred sixty consecutive patients (235 men; mean age, 54 ± 10 years) who underwent catheter ablation of their AF were included in this study. ATP was injected following PV isolation to induce dormant PV conduction, which was then eliminated by radiofrequency application. RESULTS: dormant PV conduction was induced by ATP in 60.4% (157/260) of the patients and in 25.3% (258/1,021) of the isolated PVs. This transient PV reconduction was more frequently observed in the left superior PV in comparison with other PVs (P < .0001). There was no significant difference in the prevalence of the dormant PV conduction among patients with paroxysmal AF, persistent AF, and long-lasting AF (62%, 66%, and 48%, respectively; P = .13). During the follow-up period, repeat AF ablation was performed in 70 patients with recurrent AF. The dormant PV conduction was less frequently induced in the repeat procedure than in the initial procedure (60.4% vs 31.4%, P < .0001). CONCLUSIONS: dormant PV conduction was evenly induced among AF types. The repeat PV isolation led to the decrease in incidence of the ATP-induced acute transient pharmacological PV reconduction.

Impact of chronic kidney disease on the severity of initially diagnosed coronary artery disease and the patient prognosis in the Japanese population.

This study evaluated the relationship between the severity of coronary artery disease (CAD) and traditional coronary risk factors, metabolic syndrome, and chronic kidney disease (CKD). Three hundred and forty-three patients (35-90 years of age) with initial diagnosis of CAD were separated into two groups: 165 patients with single-vessel coronary artery disease (SVD group) and 178 patients with multivessel coronary artery disease (MVD group). We compared the risk factors for CAD between the two groups. An adjusted multivariate analysis showed that only CKD was associated with MVD (odds ratio, 2.85; 95% confidence interval [CI], 1.76-4.63; P = 0.00002). Next, the relationship between the severity of CAD, CKD, and the incidence of subsequent major adverse cardiac event (MACE) was investigated in 338 patients during the patient follow-up. The risk of MACE was approximately threefold higher in the group with MVD and CKD stage of 3 or greater than in the group with SVD but without CKD stage of 3 or greater (adjusted hazard ratio, 3.40; 95% CI, 1.26-9.17; P = 0.016). A statistical analysis also suggested that having MVD and advanced CKD was a more powerful risk factor for MACE. The comparison of risk factors between patients with SVD and patients with MVD revealed that CKD was the most important risk factor for MVD. In addition, having MVD and advanced CKD together was a crucial risk factor for subsequent MACE. To reduce the progression of CAD and to improve the prognosis of patients with MVD, the renal status should therefore be carefully assessed during treatment for CAD.

Ideonella sakaiensis, PETase, and MHETase: From identification of microbial PET degradation to enzyme characterization.

Few reports have described the biological degradation or utilization of poly(ethylene terephthalate) (PET) to support microbial growth. We screened environmental samples from a PET bottle recycling site and identified the microbial consortium no. 46, which degraded amorphous PET at ambient temperature; thereafter, we isolated the resident Ideonella sakaiensis 201-F6 strain responsible for the degradation. We further identified two hydrolytic enzymes from I. sakaiensis, PET hydrolase (PETase) and mono(2-hydroxyethyl) terephthalate hydrolase (MHETase), which synergistically converted PET into its monomeric building blocks. Here, we provide original methods of microbial screening and isolation of PET degrading microbe(s). These novel approaches can be adapted for exploring microorganisms that degrade PET and other plastics. Furthermore, our enzyme assay protocols to characterize PETase and MHETase can be applied to evaluate new enzymes that target PET and its hydrolysates.

Assembly of Defect-Free Microgel Nanomembranes for CO2 Separation.

The development of robust and thin CO2 separation membranes that allow fast and selective permeation of CO2 will be crucial for rebalancing the global carbon cycle. Hydrogels are attractive membrane materials because of their tunable chemical properties and exceptionally high diffusion coefficients for solutes. However, their fragility prevents the fabrication of thin defect-free membranes suitable for gas separation. Here, we report the assembly of defect-free hydrogel nanomembranes for CO2 separation. Such membranes can be prepared by coating an aqueous suspension of colloidal hydrogel microparticles (microgels) onto a flat, rough, or micropatterned porous support as long as the pores are hydrophilic and the pore size is smaller than the diameter of the microgels. The deformability of the microgel particles enables the autonomous assembly of defect-free 30-50 nm-thick membrane layers from deformed ∼15 nm-thick discoidal particles. Microscopic analysis established that the penetration of water into the pores driven by capillary force assists the assembly of a defect-free dense hydrogel layer on the pores. Although the dried films did not show significant CO2 permeance even in the presence of amine groups, the permeance dramatically increased when the membranes are adequately hydrated to form a hydrogel. This result indicated the importance of free water in the membranes to achieve fast diffusion of bicarbonate ions. The hydrogel nanomembranes consisting of amine-containing microgel particles show selective CO2 permeation (850 GPU, αCO2/N2 = 25) against post-combustion gases. Acid-containing microgel membranes doped with amines show highly selective CO2 permeation against post-combustion gases (1010 GPU, αCO2/N2 = 216) and direct air capture (1270 GPU, αCO2/N2 = 2380). The membrane formation mechanism reported in this paper will provide insights into the self-assembly of soft matters. Furthermore, the versatile strategy of fabricating hydrogel nanomembranes by the autonomous assembly of deformable microgels will enable the large-scale manufacturing of high-performance separation membranes, allowing low-cost carbon capture from post-combustion gases and atmospheric air.

Comparison of the clinical outcome after pulmonary vein isolation based on the appearance of adenosine-induced dormant pulmonary vein conduction.

BACKGROUND: The elimination of transient pulmonary vein (PV) reconduction (dormant PV conduction) revealed by adenosine in addition to PV isolation reduced the atrial fibrillation (AF) recurrence after catheter ablation. The dormant PV conduction is induced in approximately half of the AF patients that undergo PV isolation. The present study compared the clinical outcome of AF ablation in patients whose dormant PV conduction was eliminated by additional radiofrequency applications with the outcome in patients without dormant conduction. METHODS: A total of 233 consecutive patients (206 male, 54.2 +/- 10.1 years) that underwent AF ablation were included in the present study. Dormant PV conduction was induced by the administration of adenosine triphosphate after PV isolation and was eliminated by supplemental radiofrequency application. All patients were followed up for >12 months (mean 903 days) after the first ablation. RESULTS: Following PV isolation, dormant PV conduction was induced in 139 (59.7%) of 233 patients and was successfully eliminated in 98% (223/228) of those in the first ablation procedure. After the first procedure, 63.9% (149/233) of patients were free from AF recurrence events. The success rates of a single or final AF ablation in patients with the appearance of the dormant PV conduction were similar to those of patients without dormant conduction (P = .69 and P = .69, respectively). CONCLUSIONS: Dormant PV conduction was induced in over half of the patients with AF. After the elimination of adenosine triphosphate-induced reconnection, the clinical outcome of patients with the dormant PV conduction was equivalent to that of patients without conduction.

Prospective randomized comparison of a steerable versus a non-steerable sheath for typical atrial flutter ablation.

AIMS: Although cavotricuspid isthmus (CTI) ablation can cure typical atrial flutter (AFL), it might be difficult to achieve a bidirectional conduction block in the isthmus in some patients. We investigated the usefulness of a steerable sheath for CTI ablation in patients with typical AFL or atrial fibrillation. METHODS AND RESULTS: A total of 40 consecutive patients (36 males; mean age 55.2 +/- 10.0 years) undergoing CTI ablation were randomized to one of the following two groups: group S (using a steerable long sheath) or group NS (using a non-steerable long sheath). Ablation was performed using an 8 mm tip catheter. The anatomy of the CTI was evaluated by a dual-source computed tomography scan prior to the procedure. The procedural endpoint was the achievement of a bidirectional isthmus conduction block. Bidirectional block in the CTI was achieved in all patients with 485.3 +/- 416.4 s of radiofrequency (RF) application. The CTI anatomy, including the length, depth, and morphology, was similar between the two groups. The duration and total amount of RF energy delivery were significantly shorter and smaller in group S than in group NS (310 +/- 193 vs. 661 +/- 504 s, P = 0.006, and 12,197 +/- 7306 vs. 26,906 +/- 21,238 J, P = 0.006, respectively). CONCLUSION: The use of a steerable sheath reduced the time and amount of energy needed to achieve a bidirectional conduction block in the CTI. For patients in whom the establishment of a conduction block is difficult, a steerable sheath should be considered as a therapeutic option for typical AFL ablation.