Search

• To overcome the limitations of the Xpert MTB/RIF assay in some conditions with low bacillary loads, the re-engineered Xpert MTB/RIF Ultra (Xpert Ultra) assay was developed to improve the sensitivity of Mycobacterium tuberculosis complex detection and avoid false-positive results in the detection of RIF resistance. • Data from 16 studies revealed that Xpert Ultra exhibits a viable alternative in sensitivities in both pulmonary TB (PTB) and extrapulmonary TB (EPTB), which proved to be higher than Xpert in the comparative analysis, and also shows a good performance in the detection of RIF resistance. • Additional studies with comparative consistency tests are needed to precisely describe this finding for more forms of EPTB, TB in children, and TB–HIV co-infected patients with different settings. The re-engineered Xpert MTB/RIF Ultra (Xpert Ultra) assay was developed due to the poor sensitivity of the Xpert MTB/RIF assay for the detection of tuberculosis (TB) in some conditions. This new assay has been recommended by the World Health Organization since 2017. A systematic review and meta-analysis was performed to assess the accuracy of Xpert Ultra for the detection of TB and rifampicin (RIF) resistance. The Medline (via PubMed), Embase (via OvidSP), ISI Web of Science, Cochrane Central Register of Controlled Trials, and Scopus databases were screened for original articles. Summary sensitivity and specificity were calculated with a bivariate mixed-effects model. A Fagan nomogram was used to assess the clinical utility. The sources of heterogeneity were investigated by meta-regression and subgroup analyses. Sixteen studies were identified. The summary diagnostic accuracy of Xpert Ultra for the diagnosis of TB were as follows: sensitivity 87.2% (95% confidence interval (CI) 82.5–90.8%) and specificity 96.5% (95% CI 95.1–97.5%). For the detection of RIF resistance, sensitivity was 95.1% (95% CI 91.6–97.2%) and specificity was 98.9% (95% CI 97.6–99.5%). Meta-regression showed that the category of population, TB prevalence, reference standard, sample state, sample type, and study design attributed to the heterogeneity. Subgroup analyses found good performance of Xpert Ultra in settings with a low TB burden. As a rapid and highly sensitive test for the detection of TB and simultaneous detection of RIF resistance, Xpert Ultra exhibits a viable alternative in sensitivities in both pulmonary TB (PTB) and extrapulmonary TB (EPTB), which was proved to be higher than Xpert in the comparative analysis, and also shows a good performance in the detection of RIF resistance. Additional studies with comparative consistency tests are needed to precisely describe this finding for more forms of EPTB. [ABSTRACT FROM AUTHOR]

Abstract: Uncertainty in the emission factor (EF) usually contributes largely to the overall uncertainty in the emission inventory. In the present study, the locally measured EFs of particulate matter (PM), organic carbon (OC), and elemental carbon (EC) for solid fuels burned in the residential sector are compiled and compared. These fuels are classified into seven sub-groups of anthracite briquette, anthracite chunk, bituminous briquette, bituminous chunk, crop residue, fuel wood log, and brushwood/branches. The EFs of carbonaceous particles for these fuels vary significantly, generally in the order of anthracite (briquette and chunk) < wood log < brushwood/branches < crop residue < bituminous (briquette and chunk), with an exception that the brushwood/branches have a relatively high EF of EC. The ratio of EC/OC varies significantly among different fuels, and is generally higher for biomass fuel than that for coal because of the intense flaming conditions formed during the biomass burning process in improved stoves. Distinct ratios calls for a future study on the potential health and climate impacts of carbonaceous PM from the residential combustions of different fuels. A narrow classification of these fuels significantly reduces the variations in the EFs of PM, OC, and EC, and the temporal and geographical distributions of the emissions could be better characterized. [Copyright &y& Elsevier]

Ambient particulate matter was collected in a megacity, Nanjing in western YRD during the spring and summer periods. Chemical compositions of fine PM including organic carbon, elemental carbon, elements and water soluble ions were analyzed. The light extinction coefficients were reconstructed following the IMPROVE formula. Organic matter was the most abundant composition in PM2.5 (20–25% of total mass), followed by the inorganic ions. During the spring time, geological materials contributed 25% of the total PM2.5. Estimated light extinction coefficient ranged from 133 to 560 Mm−1 with the deciview haze index value of 26–40 dv, indicating strong light extinction by PM and subsequently low visibility in the city. Reconstructed ammonium sulfate, ammonium nitrate, organic matter and light absorption carbon in fine PM contributed significantly (37 ± 10, 16 ± 6, 15 ± 4 and 10 ± 3%, respectively) to the total light extinction of PM, while soil (5–7%) and sea salt fractions (2–4%) in fine PM and coarse PM (6–11%) had relatively minor influences. The results of backward air trajectory showed that the site was strongly influenced by the air from the eastern (39%) and southeastern (29%) areas during the sampling period. Air plumes from the Southeastern had both high PM mass pollution and large light extinction, while the air mass originating from the Northwestern resulted in high PM mass loading but relatively lower light extinction. [ABSTRACT FROM AUTHOR]

Field measurements were conducted to measure emission factors of particulate matter (EFPM), organic carbon (EFOC), elemental carbon (EFEC), 28 parent polycyclic aromatic hydrocarbons (EF28pPAHs), and 4 oxygenated PAHs (EF4oPAHs) for four types of crop straws burned in two stoves with similar structure but different ages. The average EFPM, EFOC, EFEC, EF28pPAHs, and EF4oPAHs were 9.1 ± 5.7 (1.8–22 as range), 2.6 ± 2.9 (0.30–12), 1.1 ± 1.2 (0.086–5.5), 0.26 ± 0.19 (0.076–0.96), 0.011 ± 0.14 (1.3 × 10−4 – 0.063) g/kg, respectively. Much high EF28pPAHs was observed in field compared with the laboratory derived EFs and significant difference in EF28pPAHs was identified among different crop residues, indicating considerable underestimation when laboratory derived EFs were used in the inventory. The field measured EFPM, EFOC, and EFEC were significantly affected by stove age and the EFs of carbonaceous particles for the 15-year old stove were approximately 2.5 times of those for the 1-year old stove. [Copyright &y& Elsevier]

Abstract: Oral ingestion of contaminated soil is an important pathway of human exposure to hydrophobic organic contaminants (HOCs), particularly for children in developing countries. The mobilization potential of various contaminants from ingested soil is often characterized using an in vitro gastrointestinal model, based on the quantities of contaminants remaining in digestive fluid after digestion and separation. Recently, it was experimentally demonstrated that a large fraction of mobilized contaminants sorbed on the digested residue could be released if the dissolved fraction was removed by intestinal absorption. This hypothesis was further tested in this study. Soil spiked with dichlorodiphenyltrichloroethane and its metabolites (DDXs) and polycyclic aromatic hydrocarbons (PAHs) was digested using an in vitro gastrointestinal model. A human colon carcinoma cell line (Caco-2) was cultured in digestive fluid with or without soil residue (pre-equilibrated with the soil) for 2h. A large proportion of the contaminants (37–68%) was sorbed on the digested residue. Without this residue, 66±13% of DDXs and 73±14% of PAHs dissolved in the fluid, as means and standard deviations, were absorbed by the cell monolayer after exposure. With both digestive fluid and residue, the sorbed fraction of PAHs and DDXs decreased by 38–92%, while the ratios of the cellular to the dissolved concentrations were 2.7–2.8 times higher than those without the residue. This supported the hypothesis that the cell absorption of dissolved HOCs induces desorption of the sorbed fraction from digestive residue, and the desorbed HOCs can be absorbed as well. [Copyright &y& Elsevier]

Bulk deposition samples were collected in remote, rural village and urban areas of Beijing–Tianjin region, North China in spring, summer, fall and winter from 2007 to 2008. The annually averaged PAHs concentration and deposition flux were 11.81 ± 4.61 μg/g and 5.2 ± 3.89 μg/m2/day respectively. PHE and FLA had the highest deposition flux, accounting for 35.3% and 20.7% of total deposition flux, respectively. More exposure risk from deposition existed in the fall for the local inhabitants. In addition, the PAHs deposition flux in rural villages (3.91 μg/m2/day) and urban areas (8.28 μg/m2/day) was 3.8 and 9.1 times higher than in background area (0.82 μg/m2/day), respectively. This spatial variation of deposition fluxes of PAHs was related to the PAHs emission sources, local population density and air concentration of PAHs, and the PAHs emission sources alone can explain 36%, 49%, 21% and 30% of the spatial variation in spring, summer, fall and winter, respectively. [Copyright &y& Elsevier]

Abstract: Japanese Rabbits (Oyctolagus cuniculus) were exposed to α-hexachlorocyclohexane (α-HCH) either orally or dermally and concentrations of α-HCH and its two enantiomers were measured at different time intervals in the blood, intestine, liver, kidney, fat, brain, and muscle. The time trends were quantified using toxicokinetic models. It was found that absorption and elimination of α-HCH in blood were first-order processes which can be characterized by a single compartmental kinetic model. The absorption of dermally exposed α-HCH in blood was more than one order of magnitude faster than that of orally exposed α-HCH. The transport of α-HCH from the blood to other tissues was characterized using a two-compartment model. The accumulation rates were different among tissues depending on blood flow rate and fat content. Significant correlation was revealed between α-HCH concentration and fat content for various tissues either before or 1 d after the exposure. However, there was no such correlation at 10min immediately after the exposure. The enantiomeric fraction (EF) of α-HCH in rabbit blood was nearly racemic before the exposure and increased to 0.73 and 0.82 after oral or dermal exposure, respectively. The result of a toxicokinetic modeling suggested that the strong enantioenrichment of (+)-α-HCH was primarily because the elimination rate of (−)-α-HCH was more than two times higher than that of (+)-α-HCH. The EFs for other tissues also increased dramatically after the exposure and the EFs in brain reached as high as 0.99 due to enantioselective transport across the blood brain barrier. [Copyright &y& Elsevier]

The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote–rural village–urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources. [Copyright &y& Elsevier]

The fastest-growing microbe Vibrio natriegens is an excellent platform for bioproduction processes. Until now, this marine bacterium has not been examined for bioremediation applications, where the production of substantial amounts of biomass would be beneficial. V. natriegens can perform extracellular electron transfer (EET) to Fe(III) via a single porin-cytochrome circuit conserved in Vibrionaceae. Electroactive microbes capable of EET to Fe(III) usually also reduce toxic metals such as carcinogenic Cr(VI), which is converted to Cr(III), thus decreasing its toxicity and mobility. Here, the performance of V. natriegens was explored for the bioremediation of Cr(VI). At a density of 100 mg/mL, V. natriegens removed 5–20 mg/L Cr(VI) within 30 s and 100 mg/L Cr(VI) within 10 min. In comparison, the model bacterium Escherichia coli grown to a comparable cell density removed Cr(VI) 36 times slower. To eliminate Cr(VI), V. natriegens had to be metabolically active, and functional outer-membrane c -type cytochromes were required. At the end of the Cr(VI) removal process, V. natriegens had reduced all of it into Cr(III) while adsorbing more than half of the metallic ions. These results demonstrate that V. natriegens , with its fast metabolism, is a viable option for the rapid treatment of aqueous pollution with Cr. [Display omitted] • The fast-growing microbe Vibrio natriegens can reduce and adsorb toxic chromium. • High-density V. natriegens removed 5–20 mg/L Cr(VI) within 30 s. • V. natriegens at the same density also removed 100 mg/L Cr(VI) within minutes. • Cr(VI) was reduced extracellularly and Cr(III) was adsorbed by the microbes. • A porin-cytochrome complex is likely involved in Cr(VI) conversion. [ABSTRACT FROM AUTHOR]

Cyanobacterial biomass and cellulose-based materials have been used separately as green bio-adsorbents for the removal of toxic metals from water. Hybrid materials made of living microbial cells encased in a solid matrix have shown good potential for bioremediation. Here, the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 was embedded in situ into bacterial cellulose (BC), a robust biopolymer rich in hydroxyl groups with excellent water holding capacity. The living material was obtained by injecting S. elongatus into a Komagataeibacter sucrofermentans culture producing BC. Several types of BC/ S. elongatus (BC/SE) materials were developed including small spheroids and flat films with different cyanobacteria loads via simple adjustments of the biosynthesis process parameters. BC/SE spheroids were evaluated for toxic copper removal and exhibited excellent adsorption properties compared to pure BC with a maximum capacity of 156.25 mg g−1. Thus, this simple bio-embedding approach holds promises in the development of living materials for environmental applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• HCC patients were divided into two subtypes (C1 and C2) based on glutamine metabolism-related genes via consensus clustering. • Significant variations exist between the two subtypes in prognosis, biological behavior and immune status. • A hub gene SLC1A5 was generated to determine the HCC classification via machine learning. • The expression of SLC1A5 could predict the responsiveness to immunotherapy. Hepatocellular carcinoma (HCC) stands as one of the most prevalent malignancies. While PD-1 immune checkpoint inhibitors have demonstrated promising therapeutic efficacy in HCC, not all patients exhibit a favorable response to these treatments. Glutamine is a crucial immune cell regulatory factor, and tumor cells exhibit glutamine dependence. In this study, HCC patients were divided into two subtypes (C1 and C2) based on glutamine metabolism-related genes via consensus clustering. The C1 pattern, in contrast to C2, was associated with a lower survival probability among HCC patients. Additionally, the C1 pattern exhibited higher proportions of patients with advanced tumor stages. The activity of C1 in glutamine metabolism and transport is significantly enhanced, while its oxidative phosphorylation activity is reduced. And, C1 was mainly involved in the progression-related pathway of HCC. Furthermore, C1 exhibited high levels of immunosuppressive cells, cytokine-receptor interactions and immune checkpoint genes, suggesting C1 as an immunosuppressive subtype. After stepwise selection based on integrated four machine learning methods, SLC1A5 was finally identified as the pivotal gene that distinguishes the subtypes. The expression of SLC1A5 was significantly positively correlated with immunosuppressive status. SLC1A5 showed the most significant correlation with macrophage infiltration, and this correlation was confirmed through the RNA-seq data of CLCA project and our cohort. Low-SLC1A5-expression samples had better immunogenicity and responsiveness to immunotherapy. As expected, SubMap and survival analysis indicated that individuals with low SLC1A5 expression were more responsive to anti-PD1 therapy. Collectively, this study categorized HCC patients based on glutamine metabolism-related genes and proposed two subclasses with different clinical traits, biological behavior, and immune status. Machine learning was utilized to identify the hub gene SLC1A5 for HCC classification, which also could predict immunotherapy response. [ABSTRACT FROM AUTHOR]

Studies focusing on the effects of combined transcatheter arterial chemoembolization (TACE) + the tyrosine kinase inhibitor apatinib in the treatment of patients with hepatocellular carcinoma (HCC), with the location and extent of portal vein tumor thrombus (PVTT) assessed as the main variable, are rare. This multicenter, retrospective, controlled study was performed to compare the efficacy and tolerability of TACE + apatinib and TACE alone in patients with HCC and PVTT. We retrospectively analyzed data from patients with nonresectable HCC and PVTT who underwent treatment with TACE + apatinib or TACE alone between January 2015 and January 2016. Outcomes in patients who underwent TACE + apatinib were compared with the outcomes of patients who underwent TACE alone, by using the Kaplan–Meier method, according to PVTT type: PVTT in the main portal vein (type A), PVTT in the first-order portal vein branch (type B), and PVTT in second- or lower-order portal vein branches (type C). One hundred eighty-eight patients were included in the analysis; 85 underwent treatment with TACE + apatinib and 103 underwent treatment with TACE. TACE + apatinib was associated with a significantly greater median survival compared with TACE alone in patients with PVTT type B (12.2 vs 7.5 months; P < 0.001) or type C (13.7 vs 7.2 months; P = 0.006). Along with treatment strategies and α-fetoprotein, the absence of main PVTT was an independent factor predictive of survival on uni- and multivariate analysis. Apatinib-related grade 3 adverse events occurred in 27 patients (31.8%). TACE + apatinib can be of potential benefit to patients with advanced HCC with tumor thrombus in the first- and lower-order portal vein branches. Adverse events with apatinib need to be monitored during application, despite the manageable appearance. [ABSTRACT FROM AUTHOR]

There is wide concern about polycyclic aromatic hydrocarbons (PAHs) because of their carcinogenic and mutagenic potential. The coking industry is an important source of PAHs. In this study, 36 arable soil samples, a sensitive medium from the perspective of food safety and health, were collected from one of the largest coke production bases in China. The concentration of total 21 PAHs ranged from 294 to 1665 ng g −1 , with a mean of 822 ± 355 ng g −1 . Approximately 60% of the soil samples were heavily polluted with the level higher than 600 ng g −1 . Particularly high abundances of high molecular weight PAHs were found, and the calculated BaPeq was as high as 54.3 ng g −1 . Soil PAH levels were positively correlated with soil organic matter content. The soil PAHs were from complex mixture sources, and high-temperature pyrogenic sources were most likely responsible for the heavy PAH contamination. Effective control strategies and probable remediation approaches should be proposed to improve soil quality. [ABSTRACT FROM AUTHOR]

Abstract: Coal consumption is one important contributor to energy production, and is regarded as one of the most important sources of air pollutants that have considerable impacts on human health and climate change. Emissions of polycyclic aromatic hydrocarbons (PAHs) from coal combustion were studied in a typical stove. Emission factors (EFs) of 16 EPA priority PAHs from tested coals ranged from 6.25 ± 1.16 mg kg−1 (anthracite) to 253 ± 170 mg kg−1 (bituminous), with NAP and PHE dominated in gaseous and particulate phases, respectively. Size distributions of particulate phase PAHs from tested coals showed that they were mostly associated with particulate matter (PM) with size either between 0.7 and 2.1 μm or less than 0.4 μm (PM0.4). In the latter category, not only were more PAHs present in PM0.4, but also contained higher fractions of high molecular weight PAHs. Generally, there were more than 89% of total particulate phase PAHs associated with PM2.5. Gas-particle partitioning of freshly emitted PAHs from residential coal combustions were thought to be mainly controlled by absorption rather than adsorption, which is similar to those from other sources. Besides, the influence of fuel properties and combustion conditions was further investigated by using stepwise regression analysis, which indicated that almost 57 ± 10% of total variations in PAH EFs can be accounted for by moisture and volatile matter content of coal in residential combustion. [ABSTRACT FROM AUTHOR]

• High aluminum ZSM-5 membrane was prepared by fluoride-containing synthesis gel. • ZSM-5 membrane was prepared from template-free synthesis gel. • ZSM-5 membrane was induced by nano silicalite-1 seeded crystals. • Nano sililcalite-1 provided the TO 4 and isolated five-member ring for zeolite membrane formation. • The membrane had good acid-stability for 1 M H 2 SO 4 solution. The formation progress of the high aluminum ZSM-5 zeolite membrane was investigated and characterized with the organic template-free and fluoride-containing initial synthesis gel. The nano spherical Silicalite-1 seed crystals were dissolved into amorphous by the fluoride-containing precursor synthesis gel. The amorphous contained elementary structural units (TO 4) and isolated five-membered ring structure of MFI zeolites. These were retained to provide the nucleation sites for high aluminum ZSM-5 zeolite. The ZSM-5 zeolite nucleus was grown into fine needle-like ZSM-5 zeolites, which were gradually grown into twin crystals, aggregation and compact ZSM-5 zeolites layer on the support without the organic template initial synthesis gel. In addition, the high aluminum ZSM-5 zeolite membranes kept the identical morphology and structure for separation of high concentration acetic acid (H 2 O/HAc) or inorganic acid (1 M H 2 SO 4) aqueous mixtures by XRD, SEM and NMR characterization. Furthermore, the membrane had a good dehydration performance and acid-stability by pervaporation. The flux and separation factor of the membrane for 10 wt% H 2 O/HAc mixtures were 0.98 kg∙m−2∙h−1 and 3200 at 348 K, respectively. [ABSTRACT FROM AUTHOR]