Normal Abundance Research Articles

Broadband X-ray spectral and timing properties of the accreting millisecond X-ray pulsar IGR J17498−2921 during the 2023 outburst

We report on the broadband spectral and timing properties of the accreting millisecond X-ray pulsar IGR J17498−2921 during its April 2023 outburst. We used data from NICER (1–10 keV), NuSTAR (3–79 keV), Insight-HXMT (2–150 keV), and INTEGRAL (30–150 keV). We detected significant 401 Hz pulsations across the 0.5–150 keV band. The pulse fraction increases from ∼2% at 1 keV to ∼13% at 66 keV. We detected five type-I X-ray bursts, including three photospheric radius expansion bursts, with a rise time of ∼2 s and an exponential decay time of ∼5 s. The recurrence time is ∼9.1 h, which can be explained by unstable thermonuclear burning of hydrogen-deficient material on the neutron star surface. The quasi-simultaneous 1–150 keV broadband spectra from NICER, NuSTAR and INTEGRAL can be aptly fitted by an absorbed reflection model, relxillCp, and a Gaussian line of instrumental origin. The Comptonized emission from the hot corona is characterized by a photon index Γ of ∼1.8 and an electron temperature kTe of ∼40 keV. We obtained a low inclination angle i ∼ 34°. The accretion disk shows properties of strong ionization, log(ξ/erg cm s−1)∼4.5, over-solar abundance, AFe ∼ 7.7, and high density, log(ne/cm−3)∼19.5. However, a lower disk density with normal abundance and ionization could also be possible. Based on the inner disk radius of Rin = 1.67RISCO and the long-term spin-down rate of −3.1(2)×10−15 Hz s−1, we were able to constrain the magnetic field of IGR J17498−2921 to the range of (0.9 − 2.4)×108 G.

The female reproductive tract microbiome and obesity

High-throughput 16S rRNA sequencing has allowed us to identify novel microorganisms and their relationships in the female reproductive tract. However, in obese patients, the female reproductive tract microbiome, unlike the intestinal microbiome, has been understudied. Here, the literature review analyzes and describes microbiome features in the external genitalia, vagina, cervical canal, uterus, and ovaries in overweight and obese nonpregnant and pregnant females. The microbiome of the lower female reproductive tract in obese patients is characterized by increased bacterial diversity, pH, decreased Lactobacillus abundance, and increased abundance of obligate anaerobes and yeasts of the genus Candida. The endometrial microbiome in overweight and obese patients has been studied only in postmenopause and is characterized by higher Proteobacteria abundance. No data on the characteristics of the ovarian microbiome in obese patients are available. The mechanisms accounting for microbiome changes in obese patients are likely to due to the ability of adipose tissue-derived leptin and estrone to inhibit production of pituitary gonadotropic hormones resulting in blocked ovulation and lowered estradiol production in patients of reproductive age. Consequently, a decline in glycogen synthesis in the vaginal epithelium, decreased Lactobacillus abundance followed by elevated vaginal mucus pH value and number of obligate anaerobes, including those associated with bacterial vaginosis are observed. Weight loss can have a beneficial effect on the state of the vaginal microbiome, restoring normal Lactobacillus abundance.

Salt-sensitive hypertension in GR mutant rats is associated with altered plasma polyunsaturated fatty acid levels and aortic vascular reactivity.

In humans, glucocorticoid resistance is attributed to mutations in the glucocorticoid receptor (GR). Most of these mutations result in decreased ligand binding, transactivation, and/or translocation, albeit with normal protein abundances. However, there is no clear genotype‒phenotype relationship between the severity or age at disease presentation and the degree of functional loss of the receptor. Previously, we documented that a GR+/- rat line developed clinical features of glucocorticoid resistance, namely, hypercortisolemia, adrenal hyperplasia, and salt-sensitive hypertension. In this study, we analyzed the GR+/em4 rat model heterozygously mutant for the deletion of exon 3, which encompasses the second zinc finger, including the domains of DNA binding, dimerization, and nuclear localization signals. On a standard diet, mutant rats exhibited a trend toward increased corticosterone levels and a normal systolic blood pressure and heart rate but presented with adrenal hyperplasia. They exhibited increased adrenal soluble epoxide hydroxylase (sEH), favoring an increase in less active polyunsaturated fatty acids. Indeed, a significant increase in nonactive omega-3 and omega-6 polyunsaturated fatty acids, such as 5(6)-DiHETrE or 9(10)-DiHOME, was observed with advanced age (10 versus 5weeks old) and following a switch to a high-salt diet accompanied by salt-sensitive hypertension. In thoracic aortas, a reduced soluble epoxide hydrolase (sEH) protein abundance resulted in altered vascular reactivity upon a standard diet, which was blunted upon a high-salt diet. In conclusion, mutations in the GR affecting the ligand-binding domain as well as the dimerization domain resulted in deregulated GR signaling, favoring salt-sensitive hypertension in the absence of obvious mineralocorticoid excess.

Characteristics of the gut microbiota and serum metabolites in postmenopausal women with reduced bone mineral density.

Emerging evidence suggests that the gut microbiota is closely associated with bone homeostasis. However, little is known about the relationships among the bone mineral density (BMD) index, bone turnover markers, and the gut microbiota and its metabolites in postmenopausal women. In this study, to understand gut microbiota signatures and serum metabolite changes in postmenopausal women with reduced BMD, postmenopausal individuals with normal or reduced BMD were recruited and divided into normal and OS groups. Feces and serum samples were collected for 16S rRNA gene sequencing, liquid chromatography coupled with mass spectrometry (LC-MS)-based metabolomics and integrated analysis. The results demonstrated that bacterial richness and diversity were greater in the OS group than in the normal group. Additionally, distinguishing bacteria were found among the two groups and were closely associated with the BMD index and bone turnover markers. Metabolomic analysis revealed that the expression of serum metabolites, such as etiocholanolone, testosterone sulfate, and indole-3-pyruvic acid, and the corresponding signaling pathways, especially those involved in tryptophan metabolism, fatty acid degradation and steroid hormone biosynthesis, also changed significantly. Correlation analysis revealed positive associations between normal group-enriched Bacteroides abundance and normal group-enriched etiocholanolone and testosterone sulfate abundances; in particular, Bacteroides correlated positively with BMD. Importantly, the tryptophan-indole metabolism pathway was uniquely metabolized by the gut bacteria-derived tnaA gene, the predicted abundance of which was significantly greater in the normal group than in the control group, and the abundance of Bacteroides was strongly correlated with the tnaA gene. Our results indicated a clear difference in the gut microbiota and serum metabolites of postmenopausal women. Specifically altered bacteria and derived metabolites were closely associated with the BMD index and bone turnover markers, indicating the potential of the gut microbiota and serum metabolites as modifiable factors and therapeutic targets for preventing osteoporosis.

#102 Increased expression of carbonic anhydrase 4 in megalin deficiency

Abstract Background and Aims Megalin is an endocytic receptor located in the apical membrane of proximal tubule (PT) cells. It prevents low molecular-weight proteinuria by reuptake of a variety of proteins from the filtrate. Megalin is required for normal uptake of Cubilin-bound proteins, but it is unknown if the receptor is important for other apical PT proteins. Carbonic anhydrase 4 (CA4) is an enzyme crucial for PT bicarbonate reuptake. Our aim was to investigate the relationship between the expression patterns of these two proteins. Method A mouse model of kidney-specific mosaic megalin-knockout (M-KO). Liquid chromatography-mass spectrometry (LC-MS) on mouse kidney cortex. Immunohistochemistry (IHC), electron microscopy (EM) and Western blotting (WB) of mouse kidney. Biochemical analysis of mouse blood and urine. Results LC-MS revealed a 4.23-fold increase in CA4 abundance in M-KO mice together with smaller but also statistically significant alterations in other acid-base-associated proteins. IHC shows that the increase in CA4 abundance specifically was in the cells lacking megalin, while cells with megalin retained normal abundance. The same pattern was observed in a biopsy from a patient lacking megalin. WB revealed increased shedding of CA4 in urine from M-KO mice and EM showed mislocalization of CA4. Conclusion We show a hitherto unknown relationship where the expression and subcellular localization of CA4 is altered in PT-cells lacking megalin and show that M-KO mice have altered acid-base handling. Comparable blood parameters at baseline are maintained despite differences in urinary excretion and when challenged with acetazolamide the urinary excretion of the groups becomes alike, however blood parameters become different. While the mechanisms and full extend are unknown, this links megalin to the acid-base regulating systems of the PT.

A digital twin of the infant microbiome to predict neurodevelopmental deficits.

Despite the recognized gut-brain axis link, natural variations in microbial profiles between patients hinder definition of normal abundance ranges, confounding the impact of dysbiosis on infant neurodevelopment. We infer a digital twin of the infant microbiome, forecasting ecosystem trajectories from a few initial observations. Using 16S ribosomal RNA profiles from 88 preterm infants (398 fecal samples and 32,942 abundance estimates for 91 microbial classes), the model (Q-net) predicts abundance dynamics with R2 = 0.69. Contrasting the fit to Q-nets of typical versus suboptimal development, we can reliably estimate individual deficit risk (Mδ) and identify infants achieving poor future head circumference growth with ≈76% area under the receiver operator characteristic curve, 95% ± 1.8% positive predictive value at 98% specificity at 30 weeks postmenstrual age. We find that early transplantation might mitigate risk for ≈45.2% of the cohort, with potentially negative effects from incorrect supplementation. Q-nets are generative artificial intelligence models for ecosystem dynamics, with broad potential applications.

The ALMaQUEST Survey. XII. Dense Molecular Gas as Traced by HCN and HCO+ in Green Valley Galaxies

Abstract We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of two dense gas tracers, HCN (1−0) and HCO+ (1-0) for three galaxies in the green valley and two galaxies on the star-forming main sequence with comparable molecular gas fractions as traced by the CO (1−0) emissions, selected from the ALMaQUEST survey. We investigate whether the deficit of molecular gas star formation efficiency (SFEmol) that leads to the low specific star formation rate (sSFR) in these green valley galaxies is due to a lack of dense gas (characterized by the dense gas fraction f dense) or the low star formation efficiency of dense gas (SFEdense). We find that SFEmol as traced by the CO emissions, when considering both star-forming and retired spaxels together, is tightly correlated with SFEdense and depends only weakly on f dense. The sSFR on kiloparsec scales is primarily driven by SFEmol and SFEdense, followed by the dependence on f mol, and is least correlated with f dense or the dense-gas-to-stellar mass ratio (R dense). When compared with other works in the literature, we find that our green valley sample shows lower global SFEmol and lower SFEdense while exhibiting similar dense gas fractions when compared to star-forming and starburst galaxies. We conclude that the star formation of the three green valley galaxies with a normal abundance of molecular gas is suppressed, mainly due to the reduced SFEdense rather than the lack of dense gas.

High fat intake sustains sorbitol intolerance after antibiotic-mediated Clostridia depletion from the gut microbiota

Carbohydrate intolerance, commonly linked to the consumption of lactose, fructose, or sorbitol, affects up to 30% of the population in high-income countries. Although sorbitol intolerance is attributed to malabsorption, the underlying mechanism remains unresolved. Here, we show that a history of antibiotic exposure combined with high fat intake triggered long-lasting sorbitol intolerance in mice by reducing Clostridia abundance, which impaired microbial sorbitol catabolism. The restoration of sorbitol catabolism by inoculation with probiotic Escherichia coli protected mice against sorbitol intolerance but did not restore Clostridia abundance. Inoculation with the butyrate producer Anaerostipes caccae restored a normal Clostridia abundance, which protected mice against sorbitol-induced diarrhea even when the probiotic was cleared. Butyrate restored Clostridia abundance by stimulating epithelial peroxisome proliferator-activated receptor-gamma (PPAR-γ) signaling to restore epithelial hypoxia in the colon. Collectively, these mechanistic insights identify microbial sorbitol catabolism as a potential target for approaches for the diagnosis, treatment, and prevention of sorbitol intolerance.

The Skin Microbiome and its Significance for Dermatologists.

The skin is a physical and immunological barrier to the external environment. Its large surface area is colonized by diverse communities of microorganisms, including bacteria, viruses, fungi, and Demodex species mites. These microorganisms and their genetic material together create the skin microbiome. Physiologic and anatomic properties of skin sites create biogeographical habitats (dry, moist, and sebaceous) where distinct microbiota communities reside. Although, in general, the composition of these habitats is maintained from person to person, the skin microbiome of an individual also has unique microbial features. Dysbiosis occurs when the normal abundance, composition, or location of the microbiota is changed, most notably there is a decrease in flora diversity. Certain skin diseases, including atopic dermatitis, rosacea, and psoriasis are associated with cutaneous dysbiosis, and even disruption of the gut microbiota. Studies have shown that current treatments for these dermatologic conditions can alter/stabilize the skin microbiome, and there is emerging research detailing the impact of prebiotics, probiotics, and postbiotics on these conditions. Although clinical guidelines do not currently exist, clinical studies support the safety and possible benefits of using topical prebiotics and postbiotics and oral probiotics for a variety of skin conditions. Until such guidelines exist, utilizing carefully designed clinical studies to inform clinical practice is recommended.

Multiple reaction monitoring assays for large-scale quantitation of proteins from 20 mouse organs and tissues.

Mouse is the mammalian model of choice to study human health and disease due to its size, ease of breeding and the natural occurrence of conditions mimicking human pathology. Here we design and validate multiple reaction monitoring mass spectrometry (MRM-MS) assays for quantitation of 2118 unique proteins in 20 murine tissues and organs. We provide open access to technical aspects of these assays to enable their implementation in other laboratories, and demonstrate their suitability for proteomic profiling in mice by measuring normal protein abundances in tissues from three mouse strains: C57BL/6NCrl, NOD/SCID, and BALB/cAnNCrl. Sex- and strain-specific differences in protein abundances are identified and described, and the measured values are freely accessible via our MouseQuaPro database: http://mousequapro.proteincentre.com . Together, this large library of quantitative MRM-MS assays established in mice and the measured baseline protein abundances represent an important resource for research involving mouse models.

Pengolahan Limbah Tahu Menjadi Biogas Sebagai Inovasi Guna Mengatasi Krisis Energi

For most Indonesian people, tofu is a processed soybean-based food that is very popular among Indonesian people. Apart from being highly nutritious, tofu is also cheap and easy to make. The price is affordable for the general public and the taste is delicious. At the processing stage, the tofu industry produces both solid and liquid waste. The process of sifting and grouping solid waste produces waste which is mostly sold by experts and processed into animal feed, tempeh gembus which is made from tofu dregs, and leftover tofu flour which is used as a basic ingredient for making bread and baked goods. Meanwhile, a lot of liquid waste is produced during the process of washing tofu, boiling tofu, pressing tofu, and the process of forming tofu. Ecological benefits will be reduced if tofu liquid waste is directly disposed of into waters due to the high content of organic matter, BOD and COD. Therefore, the industry realizes that waste processing is necessary to reduce the current risk of pollution. Handling of tofu waste must continue to be carried out and monitored properly. Indonesia has the ability to create normal abundance in large quantities to channel elective energy. Therefore, the use of fuel sources requires substitute materials that are not harmful to the ecosystem and do not run out. Biogas is an environmentally friendly power plant that has a lot of development potential.

EPCO-31. THE PROGNOSTIC IMPLICATIONS OF THE RELATIVE ABUNDANCE OF DECONVOLVED TUMOR AND NON-TUMORAL SUBPOPULATIONS IN MULTI-REGIONAL BIOPSIES OF HIGH GRADE GLIOMA WITH BULK RNA-SEQ

Abstract High-grade glioma continues to have dismal survival owing in part to its intra- and inter-patient heterogeneity. Standard clinical protocol collects tumor samples with the aim of providing or confirming a diagnosis and determining the status of a few key genes (e.g. IDH1, MGMT). However, this protocol is unable to capture the diversity within tumor regions, immune expression or normal cell abundances that play key roles in the development of the disease. To overcome this, during surgery we collect image-localized multi-regional biopsies to characterize this disease heterogeneity. Data collection is ongoing, and we currently have 202 samples from 58 patients with available bulk RNA-Seq. With a single-cell reference dataset from Columbia University, we used CIBERSORTx, a deconvolution method, to predict relative abundances of 7 normal, 6 glioma, and 5 immune cell subpopulations for each sample. We used Cox proportional hazard models with first-order statistics (mean, minimum, maximum) of abundances within patients to determine whether these are prognostic, then used TCGA RNA-Seq data to validate these findings. We found that one glioma proneural subtype was significantly beneficial for patient survival relative to other glioma subtypes across all statistics (and showed significance in TCGA). Proliferative and mesenchymal glioma subtypes also showed significance for one or two of the calculated statistics. Oligodendrocyte progenitor cell abundances were consistently significantly beneficial for patient survival in our cohort, while an increased abundance of abnormal (reactive) astrocytes is associated with poor prognosis. We also ran these analyses within invasive margin and core tumor regions to determine location-specific population abundances associated with patient survival. In conclusion, understanding the in vivo diversity of cellular subpopulations within high grade glioma is important for treatment stratification and patient benefit.

Sufficient Cav-1 levels in the endothelium are critical for the maintenance of the neurovascular unit in the retina

BackgroundCaveolin-1 (Cav-1) is a pivotal protein in the plasma membrane. Studies on homozygous Cav-1 deficient mice revealed that Cav-1 is essential for endothelial function and angiogenesis in the retina. However, whether a reduction in Cav-1 content hampers the neurovascular unit (NVU) in the retina is unclear. Thus, this study examines the NVU in the retinas of heterozygous Cav-1 deficient (Cav-1+/−) mice and analyzes possible underlying mechanisms.MethodsThe vascular, glial and neuronal components in the retina were evaluated using retinal morphometry, whole mount retinal immunofluorescence staining, histological analysis and optical coherence tomography. In addition, immunoblotting and immunofluorescence staining, subcellular fractionation, biotin labeling of cell surface proteins, and proximity ligation assay were employed to detect expression and localization of proteins in the retina or endothelial cells (ECs) upon knockdown of Cav-1 with Cav-1 siRNA.ResultsCav-1+/− retinas showed a significant reduction in pericyte coverage along with an increase in acellular capillaries compared to controls at 8 months of age, but not at 1 month. A significant loss and obvious morphological abnormalities of smooth muscle cells were observed in 8-month-old Cav-1+/− retinal arterioles. Macroglial and microglial cells were activated in the Cav-1+/− retinas. A transient significant delay in retinal angiogenesis was detected in Cav-1+/− retinas at p5, which was however no longer detectable at p10. The Cav-1+/− retinas displayed increased vascular permeability and a notable reduction in VEGFR2 content at 8 months. In vitro, siRNA-mediated knockdown experiments in ECs revealed that the loss of Cav-1 in ECs resulted in decreased levels of VEGFR2, VE-Cadherin and their interaction at the plasma membrane as well.ConclusionOur results indicate that a sufficient Cav-1 level over 50% of its normal abundance is vital for the proper localization of VEGFR2 and VE-cadherin, likely in a complex, at the plasma membrane, which is essential for the maintenance of normal NVU in the retina.

Non-LTE abundance analysis of A-B stars with low rotational velocities – II. Do A-B stars with normal abundances exist?

ABSTRACT We present chemical composition and fundamental parameters (the effective temperature, surface gravity, and radius) for four sharp-lined A-type stars γ Gem (HD 41705), o Peg (HD 214994), θ Vir (HD 114330), and ν Cap (HD 193432). Our analysis is based on a self-consistent model fitting of high-resolution spectra and spectrophotometric observations over a wide wavelength range. We refined the fundamental parameters of the stars with the sme (Spectroscopy Made Easy) package and verified their accuracy by comparing with the spectral energy distribution and hydrogen line profiles. We found Teff/log g = 9190 ± 130 K/3.56 ± 0.08, 9600 ± 50 K/3.81 ± 0.04, 9600 ± 140 K/3.61 ± 0.12, and 10200 ± 220 K/3.88 ± 0.08 for γ Gem, o Peg, θ Vir, and ν Cap, respectively. Our detailed abundance analysis employs a hybrid technique for spectrum synthesis based on classical model atmospheres calculated in local thermodynamic equilibrium (LTE) assumption together with the non-LTE (NLTE) line formation for 18 of 26 investigated species. Comparison of the abundance patterns observed in A stars of different types (normal A, Am, and Ap) with similar fundamental parameters reveals significant abundance diversity that cannot be explained by the current mechanisms of abundance peculiarity formation in stellar atmospheres. We found a rise of the heavy element (Zn, Sr, Y, Zr, and Ba) abundance excess up to +1 dex with Teff increasing from 7200 to 10 000 K, with a further decrease down to solar value at Teff = 13 000 K, indicating that stars with solar element abundances can be found among late B-type stars.

Potential value of Interleukin-6 as a diagnostic biomarker in human MDD and the antidepressant effect of its receptor antagonist tocilizumab in lipopolysaccharide-challenged rats

Depression is a common mental disease with disastrous effect on the health and wealth globally. Focusing on the role for inflammation and immune activation in the pathogenesis of depression, many tries have been taken into effect targeting at the blockage of inflammatory cytokines, among which interleukin- 6 (IL-6) and its receptor antagonist tocilizumab attracts more attention, with inconsistent findings. Moderate to severe depressive disorder (MSDD) patients were enrolled and the serum concentrations of IL-6 and tumor necrosis factor-α (TNF-α) measured, their correlation with the Hamilton Depression Rating Scale-24 (HAMD-24) scores was analyzed, and their role in discriminating MSDD patients from the health controls were evaluated. Meanwhile, a depression rat model was established by intraperitoneal injection of LPS, and tocilizumab was administrated doing 50 mg/kg via intravenous injection. The behavioral performance was observed, the serum concentration of IL-6, TNF-α, and C-reactive protein (CRP) was measured, and the protein expression of IL-6 and TNF-α in the hippocampus were also detected. The activity of the Hypothalamic-pituitary-adrenal (HPA) axis was observed, and the protein expression levels in the hippocampus were detected via western blot. Moreover, the immunofluorescence staining (IF) technique was used to investigate the co-location of IL-6 and neuron (MAP2), astrocyte (GFAP), or microglial (IBA-1). The results showed that the serum IL-6 level was significantly increased in the MSDD patients and lipopolysaccharide (LPS)-challenged rats, with a significant correlation with the HAMD-24 scores or struggling time in the FST and corticosterone (CORT) abundance. Results of ROC analysis showed a significant diagnosis value of IL-6 in discriminating MSDD patients or depression rats from the controls in the present study. Tocilizumab could relieve the depression-like behaviors induced by LPS, together with a normal abundance of serum CORT and hypothalamic CRH expression. Moreover, tocilizumab could alleviate the “inflammatory storm” and impaired hippocampal synaptic plasticity in LPS-challenged depression rats, inhibiting the hyperactivation of astrocyte and microglia, decreasing the peripheral and central abundance of IL-6, CRP, and TNF-α, and balancing the hippocampal expression levels of synaptic plasticity-associated proteins and key molecular in Wnt/β-catenin signaling pathway. These results indicated a predictive role of IL-6 in discriminating depression from controls, and demonstrated an antidepressant effect of tocilizumab in LPS-challenged rats, targeting at the inflammatory storm and the subsequent impairments of hippocampal synaptic plasticity.

Abundance Analysis of Stars at Large Radius in the Sextans Dwarf Spheroidal Galaxy* *This paper includes data gathered at the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Other observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona. This paper is also based on archival observations

We present the stellar parameters and chemical abundances of 30 elements for five stars located at large radii (3.5–10.7 times the half-light radius) in the Sextans dwarf spheroidal galaxy. We selected these stars using proper motions, radial velocities, and metallicities, and we confirm them as metal-poor members of Sextans with −3.34 ≤ [Fe/H] ≤ −2.64 using high-resolution optical spectra collected with the Magellan Inamori Kyocera Echelle spectrograph. Four of the five stars exhibit normal abundances of C (−0.34 ≤ [C/Fe] ≤ + 0.36), mild enhancement of the α elements Mg, Si, Ca, and Ti ([α/Fe] = +0.12 ± 0.03), and unremarkable abundances of Na, Al, K, Sc, V, Cr, Mn, Co, Ni, and Zn. We identify three chemical signatures previously unknown among stars in Sextans. One star exhibits large overabundances ([X/Fe] > +1.2) of C, N, O, Na, Mg, Si, and K, and large deficiencies of heavy elements ([Sr/Fe] = −2.37 ± 0.25, [Ba/Fe] = −1.45 ± 0.20, [Eu/Fe] < + 0.05), establishing it as a member of the class of carbon-enhanced metal-poor stars with no enhancement of neutron-capture elements. Three stars exhibit moderate enhancements of Eu (+0.17 ≤ [Eu/Fe] ≤ + 0.70), and the abundance ratios among 12 neutron-capture elements are indicative of r-process nucleosynthesis. Another star is highly enhanced in Sr relative to heavier elements ([Sr/Ba] = +1.21 ± 0.25). These chemical signatures can all be attributed to massive, low-metallicity stars or their end states. Our results, the first for stars at large radius in Sextans, demonstrate that these stars were formed in chemically inhomogeneous regions, such as those found in ultra-faint dwarf galaxies.

A smart TESTER for reliable discrimination of cancer-derived small extracellular vesicles

Cancer-derived small extracellular vesicles (csEVs) are crucial liquid biopsy indicators that reflect the presence and progression of many malignancies. However, reliable discrimination of csEVs remains a great challenge owing to the interference from normal sEVs (nsEVs) and low abundance in the early stages of cancer. In this work, we developed a Two-Elements Selectively Triggered csEVs Recognization (TESTER) strategy for selective identification of csEVs from the complex clinical body fluid samples. This method was based on the MNAzyme-controlled synchronous recognition to EpCAM and CD63 proteins on the membrane of csEVs. Efficient recognition to csEVs via EpCAM aptamer and CD63 aptamer prompted the release of Partzyme A and Partzyme B probes to induce a MNAzyme structure formation, resulting in the cyclic cleavage of substrate chain to produce cascade fluorescence signal amplification. The detection threshold of the developed TESTER approach for csEVs in complicated biological samples was 72 particles μL−1, accomplishing the highly sensitive and selective quantification of csEVs. At the same time, we successfully constructed a new platform for bimolecular simultaneous recognition, which provides a good idea for the construction of bimolecular-activated detection switch in the future.

New Determinations of the Surface Abundances of HD 1280

New abundances for several chemical elements are measured for HD 1280 using updated atomic data and spectrum synthesis. The abundances of calcium and scandium are solar whereas strontium is mildly overabundant. The abundances of helium, magnesium, titanium, chromium, manganese, iron and barium are in good agreement with a former abundance analysis. This reinforces the status of HD 1280 as a normal rapidly rotating A star with essentially normal abundances of elements lighter than iron and mild overabundances of heavier elements which may actually have been present in the environment where the star was born.

Reconversion of Parahydrogen Gas in Surfactant-Coated Glass NMR Tubes.

The application of parahydrogen gas to enhance the magnetic resonance signals of a diversity of chemical species has increased substantially in the last decade. Parahydrogen is prepared by lowering the temperature of hydrogen gas in the presence of a catalyst; this enriches the para spin isomer beyond its normal abundance of 25% at thermal equilibrium. Indeed, parahydrogen fractions that approach unity can be attained at sufficiently low temperatures. Once enriched, the gas will revert to its normal isomeric ratio over the course of hours or days, depending on the surface chemistry of the storage container. Although parahydrogen enjoys long lifetimes when stored in aluminum cylinders, the reconversion rate is significantly faster in glass containers due to the prevalence of paramagnetic impurities that are present within the glass. This accelerated reconversion is especially relevant for nuclear magnetic resonance (NMR) applications due to the use of glass sample tubes. The work presented here investigates how the parahydrogen reconversion rate is affected by surfactant coatings on the inside surface of valved borosilicate glass NMR sample tubes. Raman spectroscopy was used to monitor changes to the ratio of the (J: 0 → 2) vs. (J: 1 → 3) transitions that are indicative of the para and ortho spin isomers, respectively. Nine different silane and siloxane-based surfactants of varying size and branching structures were examined, and most increased the parahydrogen reconversion time by 1.5×-2× compared with equivalent sample tubes that were not treated with surfactant. This includes expanding the pH2 reconversion time from 280 min in a control sample to 625 min when the same tube is coated with (3-Glycidoxypropyl)trimethoxysilane.

Intestinal toxicity and resistance gene threat assessment of multidrug-resistant Shigella: A novel biotype pollutant

Multidrug-resistant bacteria, especially pathogens, pose a serious threat to disease treatment and recovery, but their potential toxicity to animal development is not entirely clear. As the most important site for nutrient absorption, we studied the intestinal microbiome of Xenopus tropicalis by analyzing the effect of multidrug-resistant Shigella on its intestinal health. Unlike in the control, Shigella intake promoted the secretion of neutral mucus and inhibited intestinal development and weight gain. Following 60 days of exposure, intestinal crypt atrophy, intestinal villus shortening, internal cavity enlargement, and external mucosal muscle disintegration were observed. The circular and longitudinal intestinal muscles became thinner with increasing pathogen exposure. In addition, the presence of Shigella altered the expression of multiple cytokines and classic antioxidant enzyme activities in the gut, which may have caused the intestinal lesions that we observed. 16 S rDNA sequencing analysis of intestinal samples showed that exposure to Shigella destroyed the normal gut microbial abundance and diversity and increased the functional bacterial ratio. Notably, the increased abundance of intestinal antibiotic resistance genes (ARGs) may imply that the resistance genes carried by Shigella easily migrate and transmit within the intestine. Our results expand existing knowledge concerning multidrug-resistant Shigella-induced intestinal toxicity in X. tropicalis and provide new insights for the threat assessment of resistance genes carried by drug-resistant pathogens.