The stable nitrogen (N) isotope ratio (δ15N) of forest samples (soils, tree foliage, and tree rings) has been used as a powerful indicator to explore the responses of forest N cycling to atmospheric ...N deposition. This review investigated the patterns of δ15N in forest samples between climate zones in relation to N deposition. Forest samples exhibited distinctive δ15N patterns between climate zones due to differences in site conditions (i.e., N availability and retention capacity) and the atmospheric N deposition characteristics (i.e., N deposition rate, N species, and δ15N of deposited N). For example, the δ15N of soil and foliage was higher for tropical forests than for other forests by >1.2 ‰ and 4 ‰, respectively due to the site conditions favoring N losses coupled with relatively low N deposition for tropical forests. This was further supported by the unchanged or increased δ15N of tree rings in tropical forests, which contrasts with other climate zones that exhibited a decreased wood δ15N since the 1920s. Subtropical forests under a high deposition of reduced N (NHy) had a lower δ15N by 2–5 ‰ in the organic layer compared with the other forests, reflecting high retention of 15N-depleted NHy deposition. At severely polluted sites in East Asia, the decreased δ15N in wood also reflected the consistent deposition of 15N-depleted NHy. Though our data analysis represents only a subset of global forest sites where atmospheric N deposition is of interest, the results suggest that the direction and magnitude of the changes in the δ15N of forest samples are related to both atmospheric N and site conditions particularly for tropical vs. subtropical forests. Site-specific information on the atmospheric N deposition characteristics would allow more accurate assessment of the variations in the δ15N of forest samples in relation to N deposition.
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•δ15N of forest samples in different climate zones under N deposition was investigated.•Tropical organic and mineral soil and foilage had highest δ15N due to leaky N cycle.•Subtropical organic soil under heavy N deposition had lowest δ15N via N retention.•Tree ring δ15N reflected long-term changes in N cycling or atmospheric N deposition.•N deposition information is required for accurate interpretation of the δ15N signals.
Background. Although Aeromonas species are known to cause bacteremia in patients with cirrhosis, less is known about spontaneous bacterial peritonitis (SBP) caused by Aeromonas species in these ...patients. Methods. We performed a retrospective, matched case-control study (1:2 ratio) consisting of patients presenting with SBP due to Aeromonas species from January 1997 through December 2006. Control subjects were patients with SBP caused by other organisms and were matched to the patients by age (±1 year) and sex. Results. We identified 43 patients with SBP due to Aeromonas species, 40 (93%) of whom had Aeromonas hydrophila infection and 3 (7%) of whom had Aeromonas sorbia infection. There were 81 control subjects, of whom 38 (47%) were infected with Escherichia coli, 25 (31%) were infected with Klebsiella species, 12 (15%) were infected with Streptococcus species, and 6 (7%) were infected with other bacteria. Baseline Child-Pugh class and model for end-stage liver disease score did not differ between groups. A significant increase in the incidence of infection during the warm season (July–September) was observed in the group with SBP due to Aeromonas species, compared with the group with SBP due to other bacteria (63% vs. 25%; P<.001). Diarrheal episodes were significantly more frequent in the group with SBP due to Aeromonas species (26% vs. 6%; P=.002). There were no statistically significant differences between groups with regard to appropriateness of initial antibiotic therapy, 3-day mortality, and 30-day cumulative survival. In the group with Aeromonas infection, the in-hospital mortality rate was 23%; septic shock was the only independent prognostic factor of in-hospital mortality (odds ratio, 34.5; 95% confidence interval, 1.9–640.6; P=.02). Conclusion. Aeromonas species should be considered to be a causative organism of SBP in cirrhotic patients presenting with diarrheal episodes during the warm season. Compared with SBP caused by other organisms, SBP due to Aeromonas species was not associated with more-advanced cirrhosis.
Theoretical computational studies have claimed that the catalytic activity of a family of heterogeneous catalysts (e.g., metal catalysts) is governed by a linear scaling relationship (LSR) between ...adsorption energy levels of intermediates on active sites of catalysts. The volcano shape of the activity versus the adsorption energy of one of the intermediates was obtained from the LSR and the Brønsted–Evans–Polanyi relationship. An improved activity can be achieved using a catalyst having optimized adsorption energy of the volcano or alternatively by circumventing or breaking the LSR. Herein, we demonstrated that the LSR of a series of transition metal terephthalates (MTPs; M = Fe, Co, Ni, Cu, or Zn) as electrocatalysts for the oxygen reduction reaction (ORR) was broken in the presence of polypyrrole (pPy) as a proton donor. The reason for the LSR breakage was that the intermediate to which the proton of pPy was delivered was different depending on the metal of MTP. Also, pPy affected the adsorption energy of the specific intermediate (the target of the proton transfer) more strongly while the other intermediates were less affected by pPy. Experimentally as well as theoretically, pPy significantly improved the ORR activity of MTPs, altering the activity volcano plot. The most significant improvement was found on CoTP: the onset potential of ORR on CoTP was shifted toward the more easy-to-be-reduced direction from 0.7 to 0.85 VRHE at 1 mA cm–2.
Effects of carbon content on cracking phenomenon, which often occurred in cold-rolled light-weight steel plates, were investigated in this study. Three steels were fabricated by varying carbon ...content, and their microstructures and tensile properties were investigated. The steel containing low carbon content of 0.1 wt pct consisted of thin
κ
-carbide bands, coarse band boundary
κ
-carbides, and ferrites. As the carbon content increased, volume fractions of
κ
-carbide bands and total
κ
-carbides increased, and band boundary
κ
-carbides were finely distributed in relatively wide band boundary areas. Microstructural observation of the deformed region of tensile specimens revealed that coarse
κ
-carbides continuously formed along band boundaries worked to initiate the cracking or to facilitate the abrupt crack propagation into ferrites or band boundaries in a cleavage fracture mode, while bands densely populated with fine, lamellar
κ
-carbides did not play a critical role in the cracking. Thus, the increase in carbon content effectively minimized the formation of band boundary carbides and reduced their size, thereby resulting in the prevention of cracking during cold rolling and in the simultaneous improvement of ductility and strength.
Current advancements in biosignal-based user recognition technology are paving the way for a next-generation solution that addresses the limitations of face- and fingerprint-based user recognition ...methods. However, existing biosignal benchmark databases (DBs) for user recognition often suffer from limitations, such as data collection from a small number of subjects in a single session, hindering comprehensive analysis of biosignal variability. This study introduces CSU_MBDB1 and CSU_MBDB2, databases containing electrocardiogram (ECG) and electromyogram (EMG) signals from diverse experimental subjects recorded across multiple sessions. These in-house DBs comprise ECG and EMG data recorded in multiple sessions from 36 and 58 subjects, respectively, with a time interval of more than one day between sessions. During the experiments, subjects performed a total of six gestures while comfortably seated at a desk. CSU_MBDB1 and CSU_MBDB2 consist of three identical gestures, providing expandable data for various applications. When the two DBs are expanded, ECGs and EMGs from 94 subjects can be used, which is the largest number among the multi-biosignal benchmark DBs built by multi-sessions. To assess the usability of the constructed DBs, a user recognition experiment was conducted, resulting in an accuracy of 66.39% for ten subjects. It is important to emphasize that we focused on demonstrating the applicability of the constructed DBs using a basic neural network without signal denoising capabilities. While this approach results in a sacrifice in accuracy, it concurrently provides substantial opportunities for performance enhancement through the implementation of optimized algorithms. Adapting signal denoising processes to the constructed DBs and designing a more sophisticated neural network would undoubtedly contribute to improving the recognition accuracy. Consequently, these constructed DBs hold promise in user recognition, offering valuable research for future investigations. Additionally, DBs can be used in research to analyze the nonlinearity characteristics of ECG and EMG.
Linezolid improves the treatment outcomes of multidrug-resistant tuberculosis substantially. We investigated whether use of linezolid instead of ethambutol increases the proportion of sputum culture ...conversion at 8 weeks of treatment in patients with pulmonary tuberculosis.
We did a phase 2, multicentre, randomised, open-label trial for patients with pulmonary tuberculosis at the three affiliated hospitals to Seoul National University and National Medical Center (Seoul–Seongnam, South Korea). Patients, aged 20–80 years, with a positive sputum for pulmonary tuberculosis, but without resistance to rifampicin, and current treatment administered for 7 days or fewer, were randomly assigned at a 1:1:1 ratio into three groups. The control group received ethambutol (2 months) with isoniazid, rifampicin, and pyrazinamide. The second group used linezolid (600 mg/day) for 2 weeks and the third group for 4 weeks instead of ethambutol for 2 months. We used a minimisation method to randomise, and stratified according to institution, cavitation on chest radiographs, and diabetes. The primary endpoint was the proportion of patients with negative culture conversion of sputum in liquid media after 8 weeks of treatment. The results of this trial were analysed primarily in the modified intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT01994460.
Between Feb 19, 2014, and Jan 13, 2017, a total of 429 patients were enrolled and 428 were randomly assigned into either the control group (142 patients), the linezolid 2 weeks group (143 patients), or the linezolid 4 weeks group (143 patients). Among them, 401 were eligible for primary efficacy analyses. In the modified intention-to-treat analyses, negative cultures in liquid media at 8 weeks of treatment were observed in 103 (76·9%) of 134 control patients, 111 (82·2%) of 135 in the linezolid 2 weeks group, and 100 (75·8%) of 132 in the linezolid 4 weeks groups. The difference from the control group was 5.4% (95% CI −4·3 to 15·0, p=0·28) for the linezolid 2 weeks group and −1·1% (−11·3 to 9·1, p=0·83) for the linezolid 4 weeks group. Numbers of patients who experienced at least one adverse event were similar across the groups (86 62·8% of 137 in control, 79 57·2% of 138 in the linezolid 2 weeks group, and 75 62·0% of 121 in the linezolid 4 weeks group). Resistance to linezolid was not identified in any patient.
Higher rates of culture conversion at 8 weeks of treatment with short-term use of linezolid were not observed. However, safety analyses and the resistance profile suggested the potential role of linezolid in shortening of treatment for drug-susceptible tuberculosis.
Ministry of Health and Welfare, South Korea.
Nitrogen (N) isotope ratios (δ
15
N) of multiple N species including ammonium (NH
4
+
), nitrate (NO
3
−
), dissolved organic N (DON), and total dissolved N (TDN) can serve as indicators of the ...sources of wet N deposition. However, methods for sequential analysis of these multiple N species are not well developed. In this study, methods for the determination of δ
15
N of these multiple N species were proposed through a traditional distillation method for NH
4
+
and NO
3
−
, direct evaporation for TDN, and an isotope mass balance equation for δ
15
N-DON. A series of experiments were conducted 1) to find evaporation conditions including pH (<3.5 vs. 5.4) and evaporation methods (oven drying at 60 and 100°C, infra-red chamber, and freeze-drying), 2) to investigate precision and accuracy of distillation for δ
15
N of NH
4
+
and NO
3
−
, and 3) to determine δ
15
N-TDN by direct evaporation and δ
15
N-DON with mass balance equation. (NH
4
)
2
SO
4
(‒4.0 ± 0.03‰), KNO
3
(‒4.2 ± 0.03‰), and CO(NH
2
)
2
(‒5.4 ± 0.04‰) were used as reference materials for NH
4
+
, NO
3
−
, and DON, respectively. In this study, for the analysis of δ
15
N of NH
4
+
and NO
3
−
, the conventional distillation method was tested in an effort to save cost for laboratories equipped with the distillation system. Evaporation using oven at 60°C (but not 100°C), infra-red chamber, or freeze-drier after acidification to < pH 3.5 prevented
14
NH
3
loss. Analysis of the δ
15
N-NO
3
−
(‒4.4 ± 0.1‰ to ‒3.9 ± 0.5‰) was reliable for a wide range of N content (0.1–0.5 mg), but analytical errors for δ
15
N-NH
4
+
were as high as 2.1‰ when N content was small (e.g., 0.1–0.3 mg N) due to background contamination and potential interference by co-existing DON. Direct evaporation of solution containing NH
4
+
, NO
3
−
, and DON to dryness produced reliable δ
15
N-TDN with accuracy <0.15‰ and precision <0.21‰. However, the analytical errors of δ
15
N-DON were highly dependent on the content of co-existing NH
4
+
as well as DON content. Therefore, the proposed protocol can be applied for rainwater containing a high NH
4
+
concentration (>2.0 mg N L
−1
assuming that 200 ml of sample is used for distillation).
Babesiosis is a tick-transmitted intraerythrocytic zoonosis. In Korea, the first mortalities were reported in 2005 due to Babesia sp. detection in sheep; herein we report epidemiological and genetic ...characteristics of a second case of babesiosis. Microscopic analysis of patient blood revealed polymorphic merozoites. To detect Babesia spp., PCR was performed using Babesia specific primers for β-tubulin, 18S rDNA, COB, and COX3 gene fragments. 18S rDNA analysis for Babesia sp., showed 98% homology with ovine Babesia sp. and with Babesia infections in Korea in 2005. Moreover, phylogenetic analysis of 18S rDNA, COB, and COX3 revealed close associations with B. motasi. For identifying the infectious agent, Haemaphysalis longicornis (296) and Haemaphysalis flava (301) were collected around the previous residence of the babesiosis patient. Babesia genes were identified in three H. longicornis: one sample was identified as B. microti and two samples were 98% homologous to B. motasi. Our study is the first direct confirmation of the infectious agent for human babesiosis. This case most likely resulted from tick bites from ticks near the patient house of the babesiosis patient. H. longicornis has been implicated as a vector of B. microti and other Babesia sp. infections.
The emergence of coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a pandemic, prompting rapid vaccine development. Although vaccines are ...effective, the occurrence of rare adverse events following vaccination highlights the necessity of determining whether the benefits outweigh the risks posed by the infection itself. The recombinant Vesicular Stomatitis Virus (rVSV) platform is a promising vector for vaccines against emerging viruses. However, limited studies have evaluated the genotoxicity and safety pharmacology of this viral vector vaccine, which is crucial to ensure the safety of vaccines developed using this platform. Hence, the present study aimed to assess the genotoxicity and safety pharmacology of the rVSVInd(GML)-mspSGtc COVID-19 vaccine using micronucleus and comet assays, as well as neurobehavioral, body temperature, respiratory, and cardiovascular assessments in Sprague–Dawley rats and beagle dogs. The intramuscular administration of rVSVInd(GML)-mspSGtc at doses up to 1.5 × 10
9
PFU/animal did not increase the number of bone marrow micronucleated polychromatic erythrocytes or cause liver DNA damage. Additionally, it had no significant impact on neurobehavioral functions in rats and showed marginal temporary changes in body temperature, respiratory rate, heart rate, and electrocardiogram parameters in rats and dogs, all of which resolved within 24 h. Overall, following genotoxicity and pharmacological safety assessments, rVSVInd(GML)-mspSGtc displayed no notable systemic adverse effects in rats and dogs, suggesting its potential as a vaccine candidate for human clinical trials.
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