Bulk production of medium-chain carboxylates (MCCs) with 6-12 carbon atoms is of great interest to biotechnology. Open cultures (e.g., reactor microbiomes) have been utilized to generate MCCs in ...bioreactors. When in-line MCC extraction and prevention of product inhibition is required, the bioreactors have been operated at mildly acidic pH (5.0-5.5). However, model chain-elongating bacteria grow optimally at neutral pH values. Here, we isolated a chain-elongating bacterium (strain 7D4C2) that grows at mildly acidic pH. We studied its metabolism and compared its whole genome and the reverse β-oxidation (rBOX) genes to other bacteria. Strain 7D4C2 produces lactate, acetate,
-butyrate,
-caproate, biomass, and H
/CO
from hexoses. With only fructose as substrate (pH 5.5), the maximum
-caproate specificity (i.e., products
other carboxylates produced) was 60.9 ± 1.5%. However, this was considerably higher at 83.1 ± 0.44% when both fructose and
-butyrate (electron acceptor) were combined as a substrate. A comparison of 7D4C2 cultures with fructose and
-butyrate with an increasing pH value from 4.5 to 9.0 showed a decreasing
-caproate specificity from ∼92% at mildly acidic pH (pH 4.5-5.0) to ∼24% at alkaline pH (pH 9.0). Moreover, when carboxylates were extracted from the broth (undissociated
-caproic acid was ∼0.3 mM), the
-caproate selectivity (i.e., product
substrate fed) was 42.6 ± 19.0% higher compared to 7D4C2 cultures without extraction. Based on the 16S rRNA gene sequence, strain 7D4C2 is most closely related to the isolates
(99.5%) and
(94.7%), which are chain-elongating bacteria that are also capable of lactate production. Whole-genome analyses indicate that strain 7D4C2,
, and
belong to the same genus of
. Their rBOX genes are conserved and located next to each other, forming a gene cluster, which is different than for other chain-elongating bacteria such as
spp. In conclusion,
spp., comprising strain 7D4C2,
,
, and several unclassified strains, are chain-elongating bacteria that encode a highly conserved rBOX gene cluster.
sp. 7D4C2 (DSM 110548) was studied here to understand
-caproate production better at mildly acidic pH within microbiomes and has the additional potential as a pure-culture production strain to convert sugars into
-caproate.
Initial performance of the COSINE-100 experiment Adhikari, G.; Adhikari, P.; de Souza, E. Barbosa ...
The European physical journal. C, Particles and fields,
02/2018, Letnik:
78, Številka:
2
Journal Article
Recenzirano
Odprti dostop
COSINE is a dark matter search experiment based on an array of low background NaI(Tl) crystals located at the Yangyang underground laboratory. The assembly of COSINE-100 was completed in the summer ...of 2016 and the detector is currently collecting physics quality data aimed at reproducing the DAMA/LIBRA experiment that reported an annual modulation signal. Stable operation has been achieved and will continue for at least 2 years. Here, we describe the design of COSINE-100, including the shielding arrangement, the configuration of the NaI(Tl) crystal detection elements, the veto systems, and the associated operational systems, and we show the current performance of the experiment.
A one‐diode/one‐resistor structure, Pt/NiO/Pt/p‐NiOx/n‐TiOx/Pt, has been fabricated. This novel structure exhibits bistable resistance switching under forward bias, while the diode suppresses ...resistance switching in the Pt/NiO/Pt memory cell under reverse bias (see figure). Its low processing temperature and small cell size, as well as excellent rectifying characteristics, make this Pt/p‐NiOx/n‐TiOx/Pt diode structure a promising switch element for high‐ density, nonvolatile memory devices with 3D stack and cross‐point structures.
Metabolic syndromes are prevalent worldwide and result in various complications including obesity, cardiovascular disease and type II diabetes. Betulinic acid (BA) is a naturally occurring ...triterpenoid that has anti-inflammatory properties. We hypothesized that treatment with BA may result in decreased body weight gain, adiposity and hepatic steatosis in a diet-induced mouse model of obesity.
Mice fed a high-fat diet and treated with BA showed less weight gain and tissue adiposity without any change in calorie intake. Gene expression profiling of mouse tissues and cell lines revealed that BA treatment increased expression of lipid oxidative genes and decreased that of lipogenesis-related genes. This modulation was mediated by increased AMP-activated protein kinase (AMPK) phosphorylation, which facilitates energy expenditure, lipid oxidation and thermogenic capacity and exerts protective effects against obesity and nonalcoholic fatty liver disease. Overall, BA markedly inhibited the development of obesity and nonalcoholic fatty liver disease in mice fed a high-fat diet, and AMPK activation in various tissues and enhanced thermogenesis are two possible mechanisms underlying the antiobesity and antisteatogenic effects of BA.
The current findings suggest that treatment with BA is a potential dietary strategy for preventing obesity and nonalcoholic fatty liver disease.
•Betulinic acid (BA) decreased body weight gain, adiposity and hepatic steatosis in a diet-induced obese mouse model.•BA treatment increased expression of lipid oxidative genes and decreased mRNA expression related to lipogenesis.•BA treatment enhanced activation of AMPK, which facilitates energy expenditure, lipid oxidation and thermogenesis.•BA intake may be a potential dietary strategy for preventing obesity and nonalcoholic fatty liver disease.
Experiments were performed herein to investigate the rates and products of heterogeneous reduction of Tc(VII) by Fe(II) adsorbed to hematite and goethite, and by Fe(II) associated with a ...dithionite–citrate–bicarbonate (DCB) reduced natural phyllosilicate mixture structural, ion-exchangeable, and edge-complexed Fe(II) containing vermiculite, illite, and muscovite. The heterogeneous reduction of Tc(VII) by Fe(II) adsorbed to the Fe(III) oxides increased with increasing pH and was coincident with a second event of
Fe
2
+
(aq)
adsorption. The reaction was almost instantaneous above pH 7. In contrast, the reduction rates of Tc(VII) by DCB-reduced phyllosilicates were not sensitive to pH or to added
Fe
2
+
(aq)
that adsorbed to the clay. The reduction kinetics were orders of magnitude slower than observed for the Fe(III) oxides, and appeared to be controlled by structural Fe(II). The following affinity series for heterogeneous Tc(VII) reduction by Fe(II) was suggested by the experimental results: aqueous Fe(II)
∼
adsorbed Fe(II) in phyllosilicates ion-exchangeable and some edge-complexed Fe(II)
≪
structural Fe(II) in phyllosilicates
≪
Fe(II) adsorbed on Fe(III) oxides. Tc-EXAFS spectroscopy revealed that the reduction products were virtually identical on hematite and goethite that were comprised primarily of sorbed octahedral TcO
2 monomers and dimers with significant Fe(III) in the second coordination shell. The nature of heterogeneous Fe(III) resulting from the redox reaction was ambiguous as probed by Tc-EXAFS spectroscopy, although Mössbauer spectroscopy applied to an experiment with
56Fe-goethite with adsorbed
57Fe(II) implied that redox product Fe(III) was goethite-like. The Tc(IV) reduction product formed on the DCB-reduced phyllosilicates was different from the Fe(III) oxides, and was more similar to Tc(IV) oxyhydroxide in its second coordination shell. The heterogeneous reduction of Tc(VII) to less soluble forms by Fe(III) oxide-adsorbed Fe(II) and structural Fe(II) in phyllosilicates may be an important geochemical process that will proceed at very different rates and that will yield different surface species depending on subsurface pH and mineralogy.
We present a comparison of the two types of metallic magnetic calorimeters (MMCs) developed for a large-scale neutrinoless double beta decay (<inline-formula><tex-math notation="LaTeX">0\nu \beta ...\beta</tex-math></inline-formula>) search experiment. As high resolution micro-calorimeters, MMCs employ micro-fabricated superconducting circuits to measure the changes in magnetization of a paramagnetic sensor material. We constructed two alpha spectrometers with two MMC sensors made of Au:Er and Ag:Er (i.e., gold and silver alloys with small concentrations of Er). A piece of gold foil with a heat capacity comparable to that of 350 g CaMoO<inline-formula><tex-math notation="LaTeX">_4</tex-math></inline-formula> crystal near 10 mK was used as the absorber for each alpha spectrometer. These detector setups allowed us to investigate the temperature dependence of magnetization for the different sensor materials over a wide temperature range with various amounts of field current. The magnetization measurements for both the Au:Er and Ag:Er sensors were in good agreement with calculations for field currents of up to 100 mA. Moreover, the measured and estimated pulse heights of alpha events agreed with each other, and were compared between the different sensor materials. We discuss how the excess heat capacity from the nuclear spins in Au:Er influences the pulse size and shape in calorimetric detection. Moreover, we describe the benefit of using Ag:Er sensors in thermal calorimeters with large crystal absorbers in a <inline-formula><tex-math notation="LaTeX">0\nu \beta \beta</tex-math></inline-formula> search experiment.
Purpose
To compare between deep neuromuscular blockade (NMB) and moderate NMB with respect to endoscopic surgical conditions and recovery profiles in patients with general anesthesia for ...transurethral resection of bladder (TURB).
Methods
108 patients undergoing elective TURB were randomized into two groups: the moderate NMB (
n
= 54) or deep NMB (
n
= 54) group. After the operation, NMB was reversed with 2 mg/kg sugammadex at a train-of-four (TOF) count of 1 or 2 (moderate NMB group) or with 4 mg/kg sugammadex at post-tetanic count (PTC) of 2 (deep NMB group). Surgeons, who were blinded to the study design, rated the endoscopic surgical condition on a 5-point scale (1 = extremely poor, 2 = poor, 3 = acceptable, 4 = good, 5 = optimal) immediately following the operation. Recovery profiles, including postoperative residual curarization (PORC), respiratory complication, and recovery time, were recorded.
Results
No difference was observed between the two groups regarding patients and anesthesia characteristics. There were statistically significant differences in endoscopic surgical conditions between the two groups (
P
< 0.001). Thirty-eight patients in the deep NMB group (74%) showed optimal surgical conditions, whereas 16 patients in the moderate NMB group (30%) showed optimal endoscopic surgical conditions. No PORC and respiratory complications occurred in both groups, and no difference was found between the two groups in terms of recovery profiles, including recovery time and other adverse events.
Conclusions
Deep NMB and reversal with sugammadex improved the endoscopic surgical condition without complications compared with moderate NMB and reversal with sugammadex in patients undergoing TURB.
No randomized controlled trials have evaluated the comparative outcomes of cefazolin versus nafcillin for methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia.
A prospective observational ...cohort study including all S. aureus bacteraemia was conducted at 10 hospitals. Patients (≥15 years) with MSSA bacteraemia who received cefazolin or nafcillin as definitive antibiotics were included. The rates of treatment failure (premature discontinuation of antibiotics because of adverse effects, switching of antibiotics because of clinical failure, all-cause mortality within 1 month, or recurrence) were compared between the cefazolin and nafcillin groups. Propensity score matching analyses were performed to balance the factors influencing the selection of antibiotics.
Among the 242 included cases, the bones and joints (36.8%) were the most common sites of infection and 60.7% of the patients had sepsis. The overall treatment failure rate was 43.8% (106/242). All-cause mortality within 1 month was 6.2% (15/242). After propensity score matching, the treatment failure rate of cefazolin was lower than that of nafcillin (30.4% (24/79) vs. 49.4% (39/79), p 0.015) because of a higher rate of discontinuation caused by adverse events. When the data were limited to patients with sepsis, the treatment failure rates of both groups were not significantly different. Approximately 22% (24/110) of MSSA isolates exhibited a cefazolin-inoculum effect (CIE) that had significant impact on the failure rate and mortality of the cefazolin group.
Cefazolin might be recommended as an adequate and better-tolerated treatment for MSSA bacteraemia in the absence of CIE.
Fluoride has been widely used for the prevention of dental caries since the mid-20th century. The aim of this study was to investigate the chronologic trends in studies on fluoride mechanisms of ...action against dental caries during the years 1950 to 2015. To this aim, queries such as “fluoride,” “fluoride and demineralization,” “fluoride and remineralization,” “fluoride and (plaque or biofilms),” and “fluoride and (bacteria or microbials)” were submitted to PubMed to collect research article information, including titles, abstracts, publication dates, author affiliations, and publication journals. The article information that PubMed produced was then collected by an automatic web crawler and examined through informetrics and linguistic analyses. We found that the number of articles concerned with fluoride mechanisms of action against dental caries was 6,903 and gradually increased over time during the years 1950 to 2015. They were published by 1,136 journals—most notably, Caries Research and Journal of Dental Research. Of the articles published, those related to bacteria/microbials had a higher percentage (44%) than those dealing with plaque/biofilms, demineralization, and remineralization. With regard to the geographic distribution of authors, Europe and North America accounted for 65% of the articles during the years 1987 to 2015, although the number of authors in Asia sharply increased in recent years. Among the fluoride compounds, NaF was mentioned more frequently than SnF2, Na2PO3F, amine fluoride, and acidulated phosphate fluoride during the years 1986 to 2015. Water fluoridation received the most attention among the various fluoride application methods (toothpastes, mouthwashes, fluoride varnishes, and fluoride gels) during the same period. These results, obtained from employing informetrics and linguistic analyses, suggest that in studies on fluoride mechanisms of action, 1) the unbalanced geographic distribution of articles and 2) the heavy concentration of articles on particular fluoride compounds and application methods should be overcome in future research.
The emergence of pathogenic bacterial strains resistant to agrochemicals and the increasing demand for organic foods have led to the discovery of new antibacterial metabolites that can be used either ...directly or as a lead molecule for development of synthetic bactericides. During the screening of antibacterial fungal cultures, we found that one fungal strain, Aspergillus persii EML‐HPB1‐11, showed strong in vitro antibacterial activity against Xanthomonas arboricola pv. pruni (Xap) with a minimum inhibitory concentration (MIC) of 10% of fermentation broth filtrate. The active compound was identified as penicillic acid (PA: 3‐methoxy‐5‐methyl‐4‐oxo‐2,5‐hexadienoic acid) by mass and NMR spectroscopy. The in vitro antibacterial activity of PA was tested against 12 phytopathogenic bacteria. All of the bacterial pathogens tested were highly inhibited by PA with MIC values of 12·3–111·1 μg ml−1. It also effectively suppressed the development of bacterial spot disease in detached peach leaves, showing control values of 82·4 and 94·1% at concentrations of 111·1 and 333·3 μg ml−1 respectively. This is the first report on the production of PA by A. persii. This study suggests that PA can be used as a lead molecule for development of synthetic bactericides for control of various plant diseases.
Significance and Impact of the Study
Penicillic acid (PA) produced by the seed‐borne fungus Aspergillus persii EML‐HPB1‐11 showed antibacterial activity against various plant pathogenic bacteria. The compound effectively inhibited the growth of 12 plant pathogenic bacteria and successfully controlled bacterial spot disease on peach leaf. These results suggest that PA can be used as a lead molecule for development of synthetic agrochemicals to control plant bacterial diseases.
Significance and Impact of the Study: Penicillic acid (PA) produced by the seed‐borne fungus Aspergillus persii EML‐HPB1‐11 showed antibacterial activity against various plant pathogenic bacteria. The compound effectively inhibited the growth of 12 plant pathogenic bacteria and successfully controlled bacterial spot disease on peach leaf. These results suggest that PA can be used as a lead molecule for development of synthetic agrochemicals to control plant bacterial diseases.
PDF
