Photochemical tuning of dynamic defects for high-performance atomically dispersed catalysts

Developing active and stable atomically dispersed catalysts is challenging because of weak non-specific interactions between catalytically active metal atoms and supports. Here we demonstrate a general method for synthesizing atomically dispersed catalysts via photochemical defect tuning for controlling oxygen-vacancy dynamics, which can induce specific metal-support interactions. The developed synthesis method offers metal-dynamically stabilized atomic catalysts, and it can be applied to reducible metal oxides, including TiO2, ZnO and CeO2, containing various catalytically active transition metals, including Pt, Ir and Cu. The optimized Pt-DSA/TiO2 shows unprecedentedly high photocatalytic hydrogen evolution activity, producing 164 mmol g-1 h-1 with a turnover frequency of 1.27 s-1. Furthermore, it generates 42.2 mmol gsub-1 of hydrogen via a non-recyclable-plastic-photoreforming process, achieving a total conversion of 98%; this offers a promising solution for mitigating plastic waste and simultaneously producing valuable energy sources.

Floatable photocatalytic hydrogel nanocomposites for large-scale solar hydrogen production

Storing solar energy in chemical bonds aided by heterogeneous photocatalysis is desirable for sustainable energy conversion. Despite recent progress in designing highly active photocatalysts, inefficient solar energy and mass transfer, the instability of catalysts and reverse reactions impede their practical large-scale applications. Here we tackle these challenges by designing a floatable photocatalytic platform constructed from porous elastomer-hydrogel nanocomposites. The nanocomposites at the air-water interface feature efficient light delivery, facile supply of water and instantaneous gas separation. Consequently, a high hydrogen evolution rate of 163 mmol h^-1 m^-2 can be achieved using Pt/TiO₂ cryoaerogel, even without forced convection. When fabricated in an area of 1 m² and incorporated with economically feasible single-atom Cu/TiO₂ photocatalysts, the nanocomposites produce 79.2 ml of hydrogen per day under natural sunlight. Furthermore, long-term stable hydrogen production in seawater and highly turbid water and photoreforming of polyethylene terephthalate demonstrate the potential of the nanocomposites as a commercially viable photocatalytic system.

Effect of total cholesterol level variabilities on cerebrovascular disease

OBJECTIVE

Hyperlipidemia is a risk factor of cerebrovascular disease (CVD). However, the relationship between CVD and cholesterol variability is less clear. This study assesses the relationship between cholesterol change and CVD risk.

PATIENTS AND METHODS

We reviewed 480,830 people from 20 to 99 years with 2 health check-ups from 2002 to 2015 from the Korean National Health Insurance (KNHI) database. People's baseline and follow-up cholesterol levels were classified into low (<180 mg/dL), moderate (≥180 mg/dL and <240 mg/dL), and high (≥240 mg/dL). Participants were divided into 9 groups (low-to-low, low-to-moderate, low-to-high, moderate-to-low, moderate-to-moderate, moderate-to-high, high-to-low, high-to-moderate, high-to-high).

RESULTS

Low to high cholesterol level is associated with hemorrhagic stroke (aHR1 = 1.59; 95% CI 1.12-2.28 and aHR2 = 1.56; 95% CI 1.07-2.25). Low to moderate/high cholesterol level is associated with ischemic stroke and occlusion/stenosis (for low to moderate, aHR1 = 1.11; 95% CI 1.04-1.17 and aHR2 = 1.14; 95% CI 1.07-1.21 for ischemic stroke and aHR1 = 1.18; 95% CI 1.07-1.29 and aHR2 = 1.20; 95% CI 1.08-1.32 for occlusion/stenosis, for low to high, aHR1 = 1.42; 95% CI 1.20-1.67 and aHR2 = 1.28; 95% CI 1.08-1.52 for ischemic stroke and aHR1 = 1.86; 95% CI 1.46-2.36 and aHR2= 1.74; 95% CI 1.36-2.23 for occlusion/stenosis). Moderate to high cholesterol level is associated with ischemic stroke and occlusion/stenosis (for ischemic stroke, aHR1 = 1.12; 95% CI 1.05-1.20 and aHR2 = 1.10; 95% CI 1.03-1.17, for occlusion/stenosis, aHR1 = 1.21; 95% CI 1.10-1.33 and aHR2 = 1.19; 95% CI 1.08-1.32). Moderate to low cholesterol level is associated with ischemic and hemorrhagic stroke and occlusion/stenosis (for ischemic, aHR1 = 1.15; 95% CI 1.09-1.21, for hemorrhagic, aHR1 = 1.14; 95% CI 1.01-1.28, for occlusion/stenosis, aHR1 = 1.14; 95% CI 1.05-1.23). High to low cholesterol level is associated with ischemic stroke and occlusion/stenosis (for ischemic stroke, aHR1 = 1.51; 95% CI 1.33-1.71 and aHR2 = 1.20; 95% CI 1.05-1.36, for occlusion/stenosis, aHR1 = 1.50; 95% CI 1.24-1.81).

CONCLUSIONS

Our study shows that cholesterol changes, especially larger changes, lead to an increase in CVD, which demonstrates that cholesterol variability may increase CVD.

Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508 culture-supernatant ameliorate obesity by inducing thermogenesis in obese-mice

Excessive body fat and the related dysmetabolic diseases affect both developed and developing countries. The aim of this study was to investigate the beneficial role of a bacterial culture supernatant (hereafter: BS) of Lactobacillus and Bifidobacterium and their potential mechanisms of action on white-fat browning and lipolysis. For selection of four candidates among 55 Lactic acid producing bacteria (LAB) from human infant faeces, we evaluated by Oil Red O staining and Ucp1 mRNA quantitation in 3T3-L1 preadipocytes. The expression of browning and lipolysis markers was examined along with in vitro assays. The possible mechanism was revealed by molecular and biological experiments including inhibitor and small interfering RNA (siRNA) assays. In a mouse model, physiological, histological, and biochemical parameters and expression of some thermogenesis-related genes were compared among six experimental groups fed a high-fat diet and one normal-diet control group. The results allow us to speculate that BS treatment promotes browning and lipolysis both in vitro and in vivo. Moreover, the BS may activate thermogenic programs via a mechanism involving PKA-CREB signaling in 3T3-L1 cells. According to our data, we can propose that two LAB strains, Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508, may be good candidates for a dietary supplement against obesity and metabolic diseases; however, further research is required for the development as dietary supplements or drugs.

How Do Caregivers of Children with Congenital Heart Disease Navigate the Health Care System in Ethiopia?

Research Objective

Global surgery is becoming an increasingly important global health agenda. Cardiovascular disease is the major cause of mortality around the world, and congenital heart disease is the leading cause of morbidity in children. This study aimed to investigate and illustrate the caregivers’ experiences of accessing the health care system and undergoing pediatric cardiac surgery for children with congenital heart disease (CHD).

Study Design

A qualitative study was conducted. Interviews were conducted in December 2019 in Amharic, then translated into English using trained local interpreters. Data were transcribed verbatim and analyzed according to the principles of interpretive thematic analysis, informed by the candidacy framework, using NVivo. The candidacy framework explores the access to health care utilization by seven elements: candidacy, navigation, the permeability of services, appearances at health services, adjudications, offers and resistance, and operating conditions and the local production of candidacy.

Population Studied

Interviews were conducted with 13 caregivers of 10 patients with congenital heart disease that received cardiac surgery during the week of the interview.

Principal Findings

The following three themes emerged from the interviews: (a) Recognition of CHD mostly took place at birth, but for those born at home, they found out much later (max 14 years); (b) CHD was misdiagnosed multiple times prior to seeking care at a large hospital; and (c) patients were waiting for the surgery for more than a year, (d) being scheduled for surgery induced both anxiety and hopefulness. In the discussion, caregivers had financial difficulties and struggled in a fragmented delivery system and experienced poor service quality such as the inaccuracy of diagnosis while navigating the Ethiopian health care system.

Conclusions

Major care‐seeking delays were related to the inefficient and complex health care system, largely due to lack of early CHD recognition and financial hardships. Financial protection is low despite the availability of fee waivers for medications. Low education attainment and distance to hospitals are contributing to this challenge.

Implications for Policy or Practice

Overall, Ethiopia needs to prioritize policies that protect the financial status of low‐income households that need health care services. Along with increasing health care workforce capacity for pediatric cardiac surgeries in Ethiopia, there is a need to strengthen the district‐level screening capacity to facilitate earlier diagnosis at easily accessible health care settings.

Primary Funding Source

Search Results Web results Korea International Cooperation Agency.

Synthesis and characterization of iodovanadinite using PdI2, an iodine source for the immobilisation of radioiodine

The synthesis of a palladium-containing iodovanadinite derivative, hypothetically “PdPb₉(VO₄)₆I₂”, was attempted using PdI₂ as a source of iodine in searching for a novel waste form for radioiodine. Stoichiometric amounts of Pb₃(VO₄)₂ and PdI₂ were batched and reacted at elevated temperatures in sealed vessels. Batched material was also subjected to high-energy ball-milling (HEBM) in order to reduce reaction time and the potential for iodine volatilization during subsequent reaction at 200–500 °C. The resulting products were characterized using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, IR spectroscopy, thermal analysis and Pd K XANES. Results showed that PdI₂ can function as a sacrificial iodine source for the formation of iodovanadinite, prototypically Pb₁₀(VO₄)₆I₂, however, the incorporation of Pd into this phase was not definitively observed. The sacrificial reaction mechanism involved the decomposition of PdI₂ to Pd metal and nascent I₂, with the latter incorporated into the iodovanadinite Pb₁₀(VO₄)₆I₂ phase. In comparison to processing using standard solid state reaction techniques, the use of HEBM prior to high temperature reaction generates a more homogeneous end-product with better iodine retention for this system. Overall, the key novelty and importance of this work is in demonstrating a method for direct immobilisation of undissolved PdI₂ from nuclear fuel reprocessing, in a composite wasteform in which I-129 is immobilised within a durable iodovandinite ceramic, encapsulating Pd metal.

The synthesis and characterisation of a composite wasteform, comprising iodovanadinite Pb₁₀(VO₄)₆I₂ and Pd metal, is reported, for immobilisation of radioiodine PdI₂; the formation of Pd incorporated iodovanadinite “PdPb₉(VO₄)₆I₂” was not observed.

Vaccinia-based oncolytic immunotherapy Pexastimogene Devacirepvec in patients with advanced hepatocellular carcinoma after sorafenib failure: a randomized multicenter Phase IIb trial (TRAVERSE)

Pexastimogene devacirepvec (Pexa-Vec) is a vaccinia virus-based oncolytic immunotherapy designed to preferentially replicate in and destroy tumor cells while stimulating anti-tumor immunity by expressing GM-CSF. An earlier randomized Phase IIa trial in predominantly sorafenib-naïve hepatocellular carcinoma (HCC) demonstrated an overall survival (OS) benefit. This randomized, open-label Phase IIb trial investigated whether Pexa-Vec plus Best Supportive Care (BSC) improved OS over BSC alone in HCC patients who failed sorafenib therapy (TRAVERSE).

129 patients were randomly assigned 2:1 to Pexa-Vec plus BSC vs. BSC alone. Pexa-Vec was given as a single intravenous (IV) infusion followed by up to 5 IT injections. The primary endpoint was OS. Secondary endpoints included overall response rate (RR), time to progression (TTP) and safety.

A high drop-out rate in the control arm (63%) confounded assessment of response-based endpoints. Median OS (ITT) for Pexa-Vec plus BSC vs. BSC alone was 4.2 and 4.4 months, respectively (HR, 1.19, 95% CI: 0.78–1.80; p = .428). There was no difference between the two treatment arms in RR or TTP. Pexa-Vec was generally well-tolerated. The most frequent Grade 3 included pyrexia (8%) and hypotension (8%). Induction of immune responses to vaccinia antigens and HCC associated antigens were observed.

Despite a tolerable safety profile and induction of T cell responses, Pexa-Vec did not improve OS as second-line therapy after sorafenib failure. The true potential of oncolytic viruses may lie in the treatment of patients with earlier disease stages which should be addressed in future studies.

ClinicalTrials.gov: NCT01387555

Concurrent hyperthermia and re-irradiation for recurrent high-grade gliomas

Salvage therapy for recurrent high grade gliomas (HGG) includes surgery, radiotherapy and chemotherapy, however, standard treatment does not exist. We evaluated the tolerability and efficacy of re-irradiation (re-RT) with hyperthermia (HT) for patients with recurrent HGG. From September 2010 to July 2015, 20 patients with recurrent HGG were treated with re-RT and HT. The radiotherapy dose of 30 Gray (Gy) was delivered with 2 Gy per fraction daily, and HT was performed twice weekly. Primary endpoints were treatment compliance and toxicity. Second endpoints were overall survival (OS) and progression free survival (PFS). The median interval between initial RT and re-RT was 11 months. During re-RT with HT, there were no significant acute morbidities over grade 3. Median overall survival (OS) from re-irradiation was 8.4 months and the 6 and 12 months survival rate were 67% and 30%, respectively. The median progression free survival (PFS) from re-irradiation was 4.1 month. Our findings suggested that concurrent re-RT with HT was a safe and well-tolerated. In addition, the combination re-RT and HT could be a valuable salvage treatment option for selected recurrent HGG patients with poor performance status.

On the existence of AgM9(VO4)6I (M = Ba, Pb)

Attempts to synthesize “AgM₉(VO₄)₆I” (M = Ba, Pb), potential waste form materials for radioiodine, were unsuccessful, demonstrating that AgI incorporation into an iodine-deficient apatite phase is not feasible under the reported conditions.

A phase 3b study of sofosbuvir plus ribavirin in treatment-naive and treatment-experienced Korean patients chronically infected with genotype 2 hepatitis C virus

In Korea, patients with chronic hepatitis C virus (HCV) infection are typically treated with pegylated interferon-alpha plus ribavirin, but interferons are contraindicated in many patients and are often poorly tolerated, particularly by the elderly and those with advanced liver disease. No interferon-free treatment regimens are approved in Korea. Sofosbuvir is an oral nucleotide analog inhibitor of the HCV nonstructural 5B RNA polymerase. It is approved in the USA, European Union and Japan for treating a number of HCV genotypes, including genotype 2. Genotype 2 has a seroprevalence of 38-46% in Korea. This single-arm, phase 3b study (NCT02021643) examined the efficacy and safety of sofosbuvir plus ribavirin (12-week duration) in chronic genotype 2 HCV-infected treatment-naive and treatment-experienced Korean patients with and without cirrhosis. The proportion of patients with sustained virologic response 12 weeks after treatment discontinuation (SVR12) was 97% (125/129), with 96% (101/105) of treatment-naive and 100% (24/24) of treatment-experienced patients achieving SVR12. Two patients experienced virologic failure (n = 1, on-treatment failure; n = 1, relapse). No patient discontinued study treatment due to an adverse event (AE). The most common treatment-emergent AEs were headache (18%, 23/129) and pruritus (15%, 19/129). Few patients had grade 3 AEs (5%, 6/129) or grade 3 laboratory abnormalities (12%, 15/129). No grade 4 AE was reported. These data suggest that 12 weeks of treatment with the all-oral, interferon-free regimen of sofosbuvir plus ribavirin is effective and well tolerated in Korean patients with chronic genotype 2 HCV infection.

Randomised clinical trial: alisporivir combined with peginterferon and ribavirin in treatment-naïve patients with chronic HCV genotype 1 infection (ESSENTIAL II)

BACKGROUND

Alisporivir (ALV) is an oral, host-targeting agent with pangenotypic anti-hepatitis C virus (HCV) activity and a high barrier to resistance.

AIM

To evaluate efficacy and safety of ALV plus peginterferon-α2a and ribavirin (PR) in treatment-naïve patients with chronic HCV genotype 1 infection.

METHODS

Double-blind, randomised, placebo-controlled, Phase 3 study evaluating ALV 600 mg once daily [response-guided therapy (RGT) for 24 or 48 weeks or 48 weeks fixed duration] or ALV 400 mg twice daily RGT with PR, compared to PR alone. Following a Food and Drug Administration partial clinical hold, ALV/placebo was discontinued and patients completed treatment with PR only. At that time, 87% of patients had received ≥12 weeks and 20% had received ≥24 weeks of ALV/PR triple therapy.

RESULTS

A total of 1081 patients were randomised (12% cirrhosis, 55% CT/TT IL28B). Addition of ALV to PR improved virological response in a dose-dependent fashion. Overall, sustained virological response (SVR12; primary endpoint) was 69% in all ALV groups vs. 53% in PR control. Highest SVR12 (90%) was achieved in patients treated with ALV 400 mg twice daily and PR for >24 weeks. Seven cases of pancreatitis were reported, with similar frequency between ALV/PR and PR control groups (0.6% vs. 0.8% respectively). Adverse events seen more frequently with ALV/PR than with PR alone were anaemia, thrombocytopenia, hyperbilirubinaemia and hypertension.

CONCLUSIONS

Alisporivir, especially the 400 mg twice daily regimen, increased efficacy of PR therapy in treatment-naïve patients with HCV genotype 1 infection. The mechanism of action and pangenotypic activity suggest that alisporivir could be useful in interferon-free combination regimens.

Failure of Helicobacter pylori eradication and age are independent risk factors for recurrent neoplasia after endoscopic resection of early gastric cancer in 283 patients

BACKGROUND

Whether the incidence of metachronous gastric dysplasia and cancer could be decreased by eradication of Helicobacter pylori after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC).

AIM

To compare the incidence of metachronous gastric lesion in the eradicated group and the persistent group. Second end point is to evaluate the risk factors for metachronous gastric lesions after ESD for EGC.

METHODS

In a single centre, between May 2007 and May 2010, the patients who had evidence of H. pylori infection at the time of ESD for EGC were included, and the follow-up data were analysed retrospectively.

RESULTS

We enrolled 283 patients who have shown H. pylori infection at the time of ESD for EGC. Successful eradication was achieved for 214 patients (75.6%) (Eradicated group), and 69 patients (24.4%) showed persistent H. pylori infection (Persistent group). Metachronous gastric lesions developed in 13 (18.8%) in the persistent group and 18 (8.4%) in the eradicated group (P = 0.016). In the ≥60-year-old group, the cumulative incidence of metachronous gastric cancer showed a significant increase (P = 0.012). Cumulative hazard ratio of subsequent gastric metachronous lesions differed between the eradication group and the persistent infection group (OR = 2.322, 95% CI = 1.136-4.744, P = 0.021), and ≥60 age at the time of endoscopic resection (OR = 2.803, 95% CI = 1.207-6.509, P = 0.016).

CONCLUSIONS

Both persistent H. pylori infection and old age (≥60) are independent risk factors for the increased incidence of metachronous gastric cancer.

High temperature stable PbS quantum dots

For the fabrication of nanoparticle containing optical fibers by melt and draw technique, nanoparticle stability at high temperatures is a requirement. We report the synthesis of quantum dots at temperatures as high as 1000 °C, compatible with fiber drawing, stabilized for the first time by a prior low temperature heating step. It is observed that quantum dots formed by this two step heating leads to a better emission stability at high powers associated with a reversible phenomenon, making these nanomaterials suitable for further technological applications.

The relation between left ventricular ejection fraction and perfusion defect size by gated SPECT myocardial perfusion imaging in patients with coronary artery disease

AIM

Left ventricular (LV) ejection fraction (EF) and perfusion defect size (PDS) provide independent and incremental prognostic information in patients with coronary artery disease (CAD). The purpose of this study was to examine the correlation between EF and PDS.

METHODS

LVEF and PDS were measured in 96 consecutive patients with CAD and abnormal perfusion scan using well-validated automated programs. The PDS was expressed as % of LV myocardium as total (reversible plus fixed), fixed or reversible.

RESULTS

The EF was 49±15% (range 17-84), the total PDS was 29±15% (2-77) and the fixed PDS was 20±13% (2-58). The end-diastolic volume (EDV) was 131±59 mL (29-342) and end-systolic volume (ESV) was 72±51 mL (4-283). There were moderate but significant correlations between EF and total PDS (r=-0.46, P<0.0001) and fixed PDS (r=-0.45, P<0.0001) but not with reversible PDS. In the subgroup analysis, the correlations were stronger in patients with history of prior coronary artery bypass grafting than without, and higher in men than women. The highest correlations were seen between EF and EDV in both men and women (r=-0.68 and -0.74 respectively, P<0.0001 each), and between EF and ESV (r =-0.80, P<0.0001).

CONCLUSION

Although there is a statistically significant correlation between PDS and EF, the correlation is not strong. This observation provides supportive evidence of why PDS and EF provide incremental prognostic information. It also supports the incremental prognostic merits of LV volume measurements.