A 60-year record of 129I in Taal Lake sediments (Philippines): Influenceof human nuclear activities at low latitude region

The influence of human nuclear activities on environmental radioactivity is not well known at low latitude regions that are distant from nuclear test sites and nuclear facilities. A sediment core collected from Taal Lake in the central Philippines was analyzed for 129I and 127I to investigate this influence in a low-latitude terrestrial system. A baseline of 129I/127I atomic ratios was established at (2.04e5.14) * 10-12&nbsp;in the pre-nuclear era in this region. Controlled by the northeasterly equatorial trade winds, increased 129I/127I ratios of (20.1e69.3) * 10-12 suggest that atmospheric nuclear weapons tests at the Pacific Proving Grounds in the central Pacific Ocean was the major source of 129I in the sediment during 1956-1962. The 129I/127I ratios, up to 157.5*10-12 after 1964, indicate a strong influence by European nuclear fuel reprocessing plants. The East Asian Winter Monsoon is found to be the dominant driving force in the atmospheric dispersion of radioactive iodine (129I) from the European nuclear fuel reprocessing plants to Southeast Asia, which is also important for dispersion of other airborne pollutants from the middle-high to low latitude regions. A significant 129I/127I peak at 42.8 cm in the Taal Lake core appears to be the signal of the Chernobyl accident in 1986. In addition, volcanic activities are reflected in the iodine isotope profiles in the sediment core, suggesting the potential of using iodine isotopes as an indicator of volcanic eruptions.<br style="line-height: normal; text-align: -webkit-auto; text-size-adjust: auto;" /

Thiophene-Based Conjugated Acetylenic Polymers with Dual Active Sites for Efficient Co-Catalyst-Free Photoelectrochemical Water Reduction in Alkaline Medium

Although being attractive materials for photoelectrochemical hydrogen evolution reaction (PEC HER) under neutral or acidic conditions, conjugated polymers still show poor PEC HER performance in alkaline medium due to the lack of water dissociation sites. Herein, we demonstrate that tailoring the polymer skeleton from poly(diethynylthieno[3,2-b]thiophene) (pDET) to poly(2,6-diethynylbenzo[1,2-b:4,5-b′]dithiophene (pBDT) and poly(diethynyldithieno[3,2-b:2′,3′-d]thiophene) (pDTT) in conjugated acetylenic polymers (CAPs) introduces highly efficient active sites for water dissociation. As a result, pDTT and pBDT, grown on Cu substrate, demonstrate benchmark photocurrent densities of 170 μA cm−2 and 120 μA cm−2 (at 0.3 V vs. RHE; pH 13), which are 4.2 and 3 times higher than that of pDET, respectively. Moreover, by combining DFT calculations and electrochemical operando resonance Raman spectroscopy, we propose that the electron-enriched Cβ of the outer thiophene rings of pDTT are the water dissociation active sites, while the −C≡C− bonds function as the active sites for hydrogen evolution. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH Gmb

Age is a predicting factor for the association between CagA positive Helicobacter pylori (Hp) infection and serum pepsinogen I:II ratio in a high gastric cancer risk region in China

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Pneumatosis intestinalis versus pseudo-pneumatosis: review of CT findings and differentiation

Pneumatosis intestinalis is defined as the presence of gas within the wall of the gastrointestinal tract. Originally described on plain abdominal radiographs, it is an imaging sign rather than a specific diagnosis and it is associated with both benign and life-threatening clinical conditions. The most common life-threatening cause of pneumatosis intestinalis is bowel ischaemia. Computed tomography (CT) is usually requested to detect underlying disease. The presence of pneumatosis intestinalis often leads physicians to make a diagnosis of serious disease. However, an erroneous diagnosis of pneumatosis intestinalis may be made (i.e. pseudo-pneumatosis) when intraluminal beads of gas are trapped within or between faeces and adjacent mucosal folds. The purpose of this pictorial essay is to review and describe the CT imaging findings of pneumatosis and pseudo-pneumatosis intestinalis and to discuss key discriminatory imaging features

Thiophen-basierte konjugierte acetylenische Polymere mit dualen aktiven Zentren für effiziente Cokatalysator-freie photoelektrochemische Wasserreduktion im alkalischen Medium

AbstractKonjugierte Polymere sind attraktive Materialien für die photoelektrochemische Wasserstoffentwicklungsreaktion (PEC‐HER) unter neutralen oder sauren Bedingungen. Jedoch zeigen sie im alkalischen Medium immer noch eine geringe PEC‐HER‐Leistung aufgrund des Fehlens von Wasserdissoziations‐Zentren. Hier zeigen wir, dass durch Anpassung des konjugierten acetylenischen Polymers (CAPs) von Poly(diethinylthieno[3,2‐b]thiophen) (pDET) zu Poly(2,6‐diethinylbenzo[1,2‐b:4,5‐b′]dithiophen (pBDT) und Poly(diethinyldithieno[3,2‐b:2′,3′‐d]thiophen) (pDTT) hocheffiziente aktive Wasserdissoziations‐Zentren in CAPs eingeführt werden können. Infolgedessen zeigen auf Cu‐Substrat gewachsene pDTT und pBDT Benchmark‐Photostromdichten von 170 μA cm−2 und 120 μA cm−2 (bei 0,3 V vs. RHE; pH 13), die 4,2‐ bzw. 3‐mal höher sind als die von pDET. DFT‐Rechnungen und elektrochemische Operando‐Resonanz‐Raman‐Spektroskopie zeigen, dass die elektronenangereicherten Cβ der äußeren Thiophenringe von pDTT die aktiven Zentren für die Wasserdissoziation sind, während die ‐C≡C‐Bindungen als aktive Zentren für die Wasserstoffentwicklung fungieren

Mesenchymal stem cell transplantation for diffuse alveolar hemorrhage in SLE

Background. A 19-year-old girl was diagnosed with systemic lupus erythematosus, based on findings of arthritis, malar rash, positive antinuclear antibody test and high levels of antibodies to double-stranded DNA. Two months after diagnosis, the patient presented with a sudden drop in blood hemoglobin level. Several days later, she developed bloody sputum, rapidly progressive dyspnea and hypoxemia. High-resolution CT showed diffuse alveolar infiltrates in both lung fields.Investigations. Physical examination, complete blood count, erythrocyte sedimentation rate, urinalysis, 24-h urine protein excretion, fecal occult blood test, d-dimer test, acid hemolysis test, activated partial thromboplastin time and prothrombin time, direct and indirect Coombs tests, bone marrow smear, arterial blood gas, sputum smear and culture, and high-resolution CT scan of the chest.Diagnosis. Diffuse alveolar hemorrhage associated with systemic lupus erythematosus.Management. The patient did not respond to pulsed intravenous methylprednisolone (two courses of 500 mg per day for 3 days) and intravenous immunoglobulin (20 g per day for 5 days). The patient was referred to a specialist treatment center for allogenic transplantation using umbilical-cord-derived mesenchymal stem cells. She underwent transplantation with an infusion of 8 - 10 7 mesenchymal stem cells. After showing dramatic improvements in her clinical condition, oxygenation level, radiographic and hematological status, the patient was discharged from hospital approximately 5 weeks after undergoing transplantation. © 2010 Macmillan Publishers Limited.postprin

An overview of the current status of CMB observations

In this paper we briefly review the current status of the Cosmic Microwave Background (CMB) observations, summarising the latest results obtained from CMB experiments, both in intensity and polarization, and the constraints imposed on the cosmological parameters. We also present a summary of current and future CMB experiments, with a special focus on the quest for the CMB B-mode polarization.Comment: Latest CMB results have been included. References added. To appear in "Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11 July, 200

Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia

<p>Abstract</p> <p>Background</p> <p>The phylum <it>Verrucomicrobia </it>is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the <it>Verrucomicrobia</it>, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia.</p> <p>Results</p> <p>We report the complete genome sequence of strain V4, the first one from a representative of the <it>Verrucomicrobia</it>. Isolate V4, initially named "<it>Methylokorus infernorum</it>" (and recently renamed <it>Methylacidiphilum infernorum</it>) is an autotrophic bacterium with a streamlined genome of ~2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of <it>M. infernorum </it>was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C₁-utilization pathways compared to other known methylotrophs. The <it>M. infernorum </it>genome does not encode tubulin, which was previously discovered in bacteria of the genus <it>Prosthecobacter</it>, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping <it>Planctomycetes</it>, <it>Verrucomicrobia </it>and <it>Chlamydiae </it>into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the <it>M. infernorum </it>lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of <it>M. infernorum </it>shows apparent adaptations for existence under extremely acidic conditions including a major upward shift in the isoelectric points of proteins.</p> <p>Conclusion</p> <p>The results of genome analysis of <it>M. infernorum </it>support the monophyly of the PVC superphylum. <it>M. infernorum </it>possesses a streamlined genome but seems to have acquired numerous genes including those for enzymes of methylotrophic pathways <it>via </it>horizontal gene transfer, in particular, from <it>Proteobacteria</it>.</p> <p>Reviewers</p> <p>This article was reviewed by John A. Fuerst, Ludmila Chistoserdova, and Radhey S. Gupta.</p

Infection with hepatitis B virus carrying novel pre-S/S gene mutations in female siblings vaccinated at birth: two case reports

<p>Abstract</p> <p>Introduction</p> <p>After the initiation of a mass hepatitis B vaccination program in Taiwan, the prevalence of hepatitis B virus infection has declined progressively. However, about 1 percent of the young generation, who received hepatitis B vaccination at birth, remain carriers. Infection with vaccine-escape hepatitis B virus mutants always occurs shortly after birth. Here, we report two female siblings in whom the infection occurred in their adolescence. This report raises the question of whether a booster for hepatitis B vaccination is needed.</p> <p>Case presentation</p> <p>Two 19 and 14-year-old Taiwanese female siblings were born to a mother infected with hepatitis B virus and received a complete course of hepatitis B vaccination at birth. They remained negative for serum hepatitis B surface antigen and positive for serum anti-hepatitis B surface antibody throughout their childhood. However, both were infected with the hepatitis B virus in their adolescence. Hepatitis B virus DNA was extracted from serum samples from the mother and two siblings. Hepatitis B virus pre-S/S sequence was amplified by polymerase chain reaction followed by nucleotide sequencing. When compared with the sequence obtained from the mother, multiple amino acid substitutions located near or in the major hydrophilic region of the surface antigen were identified in the elder sister. Four of these mutations (sL97S, sL98S, sG102R, and sA159P) were novel. A novel in-frame deletion (14 amino acids deleted, pre-S 127-140) was found in the hepatitis B virus pre-S2 region in the younger sister.</p> <p>Conclusions</p> <p>Despite having received hepatitis B vaccination at birth, hepatitis B virus infection can still occur in adolescence with the emergence of novel mutations in the pre-S/S gene. This is a rare event and, to the best of our knowledge, has not been previously reported.</p