Size, distribution, and vulnerability of the global soil inorganic carbon.

Global estimates of the size, distribution, and vulnerability of soil inorganic carbon (SIC) remain largely unquantified. By compiling 223,593 field-based measurements and developing machine-learning models, we report that global soils store 2305 ± 636 (±1 SD) billion tonnes of carbon as SIC over the top 2-meter depth. Under future scenarios, soil acidification associated with nitrogen additions to terrestrial ecosystems will reduce global SIC (0.3 meters) up to 23 billion tonnes of carbon over the next 30 years, with India and China being the most affected. Our synthesis of present-day land-water carbon inventories and inland-water carbonate chemistry reveals that at least 1.13 ± 0.33 billion tonnes of inorganic carbon is lost to inland-waters through soils annually, resulting in large but overlooked impacts on atmospheric and hydrospheric carbon dynamics.

Plant size traits are key contributors in the spatial variation of net primary productivity across terrestrial biomes in China.

Understanding the spatial variability of ecosystem functions is an important step forward in predicting changes in ecosystems under global transformations. Plant functional traits are important drivers of ecosystem functions such as net primary productivity (NPP). Although trait-based approaches have advanced rapidly, the extent to which specific plant functional traits are linked to the spatial diversity of NPP at a regional scale remains uncertain. Here, we used structural equation models (SEMs) to disentangle the relative effects of abiotic variables (i.e., climate, soil, nitrogen deposition, and human footprint) and biotic variables (i.e., plant functional traits and community structure) on the spatial variation of NPP across China and its eight biomes. Additionally, we investigated the indirect influence of climate and soil on the spatial variation of NPP by directly affecting plant functional traits. Abiotic and biotic variables collectively explained 62.6 % of the spatial differences of NPP within China, and 28.0 %-69.4 % across the eight distinct biomes. The most important abiotic factors, temperature and precipitation, had positive effects for NPP spatial variation. Interestingly, plant functional traits associated with the size of plant organs (i.e., plant height, leaf area, seed mass, and wood density) were the primary biotic drivers, and their positive effects were independent of biome type. Incorporating plant functional traits improved predictions of NPP by 6.7 %-50.2 %, except for the alpine tundra on the Qinghai-Tibet Plateau. Our study identifies the principal factors regulating NPP spatial variation and highlights the importance of plant size traits in predictions of NPP variation at a large scale. These results provide new insights for involving plant size traits in carbon process models.

Embryo development, pregnancy and live birth outcomes following IVF treatment were not compromised during the COVID-19 pandemic.

PURPOSE: To evaluate whether outcomes of in vitro fertilization (IVF) are affected during the coronavirus disease-19 (COVID-19) pandemic. METHODS: This was a single-center, retrospective study. Embryo development, pregnancy, and live birth outcomes were compared between COVID-19 and pre-COVID-19 groups. Blood samples from patients during the COVID-19 pandemic were tested for COVID-19. RESULTS: After 1:1 random matching, 403 cycles for each group were included in the study. The rates of fertilization, normal fertilization, and blastocyst formation were higher in the COVID-19 group than in the pre-COVID-19 group. No difference was observed in the rates of day 3 good-quality embryos and good-quality blastocysts between the groups. A multivariate analysis showed that the live birth rate in the COVID-19 group was higher than that in the pre-COVID-19 group (51.4% vs. 41.4%, P = 0.010). In fresh cleavage-stage embryo and blastocyst transfer cycles, there were no differences between the groups in terms of pregnancy, obstetric, and perinatal outcomes. In the freeze-all cycles, the live birth rate was higher during the COVID-19 pandemic (58.0% vs. 34.5%, P = 0.006) than during the pre-COVID-19 period following frozen cleavage stage embryo transfer. The rate of gestational diabetes during the COVID-19 pandemic was higher than that during the pre-COVID-19 period (20.3% vs. 2.4%, P = 0.008) following frozen blastocyst transfer. All the serological results of the patients during the COVID-19 pandemic were negative. CONCLUSION: Our results indicate that embryo development, pregnancy, and live birth outcomes in uninfected patients were not compromised during the COVID-19 pandemic at our center.

MAGEB2-Mediated Degradation of EGR1 Regulates the Proliferation and Apoptosis of Human Spermatogonial Stem Cell Lines.

Spermatogonial stem cells are committed to initiating and maintaining male spermatogenesis, which is the foundation of male fertility. Understanding the mechanisms underlying SSC fate decisions is critical for controlling spermatogenesis and male fertility. However, the key molecules and mechanisms responsible for regulating human SSC development are not clearly understood. Here, we analyzed normal human testis single-cell sequencing data from the GEO dataset (GSE149512 and GSE112013). Melanoma antigen gene B2 (MAGEB2) was found to be predominantly expressed in human SSCs and further validated by immunohistology. Overexpression of MAGEB2 in SSC lines severely weakened cell proliferation and promoted apoptosis. Further, using protein interaction prediction, molecular docking, and immunoprecipitation, we found that MAGEB2 interacted with early growth response protein 1 (EGR1) in SSC lines. Reexpression of EGR1 in MAGEB2 overexpression cells partially rescued decreased cell proliferation. Furthermore, MAGEB2 was shown to be downregulated in specific NOA patients, implying that abnormal expression of MAGEB2 may impair spermatogenesis and male fertility. Our results offer new insights into the functional and regulatory mechanisms in MAGEB2-mediated human SSC line proliferation and apoptosis.

Pathogenic variant in ACTL7A causes severe teratozoospermia characterized by bubble-shaped acrosomes and male infertility.

Teratozoospermia is a common factor associated with male infertility. However, teratozoospermia characterized by bubble-shaped acrosomes (BSAs) has not yet been identified in men and the causative genes are unknown. The present study is of a patient with severe teratozoospermia characterized by BSA and carrying a variant (c.1204G>A, p.Gly402Ser) of actin-like 7A (ACTL7A). For further verification, we generated an Actl7a-mutated mouse model (p.Gly407Ser) carrying an equivalent variant to that in the patient. We found that homozygous Actl7a-mutated (Actl7aMut/Mut) male mice were sterile, and all their sperm showed acrosomal abnormalities. We detected by transmission electron microscopy that during acrosomal biogenesis, the acrosome detaches from the nuclear membrane in Actl7aMut/Mut mice. Furthermore, mutant ACTL7A failed to attach to the acroplaxome and was discharged by cytoplasmic droplets, which led to the absence of ACTL7A in epididymal spermatozoa in mice. The mutant sperm failed to activate the oocyte, and sperm-borne oocyte activation factor phospholipase C zeta (PLCζ) discharge accompanied by ACTL7A was observed, leading to total fertilization failure (TFF). Immunoprecipitation followed by liquid chromatography-mass spectrometry showed that several differentially expressed proteins participate in acrosome assembly and actin filament organization. Furthermore, assisted oocyte activation by calcium ionophore exposure successfully overcame TFF in the couple with an ACTL7A pathogenic variant. Our study defined a novel phenotype of an acrosomal abnormality characterized by BSA, revealed the underlying mechanism of a pathogenic variant in ACTL7A and provided a genetic marker and potential therapeutic option for male infertility.

Distribution Characteristics and Controlling Factors of Soil Total Nitrogen: Phosphorus Ratio Across the Northeast Tibetan Plateau Shrublands.

Nitrogen (N) and phosphorus (P) stoichiometry have significant effects on nutrient cycles in terrestrial ecosystems. However, our understanding of the patterns and the driving factors of soil N:P ratios in the Tibetan Plateau shrublands remains limited. Our study aimed to quantify the distribution of soil N:P ratio and its controlling factors based on soil, plant, and climate factors from 59 sites in shrublands across the northeast Tibetan Plateau. The kriging interpolation method was used to quantify the soil N:P distribution. Spatially, the soil N:P ratio was higher in the south than in the north and lower in the west than in the east. The soil N:P ratio in the northeast Tibetan Plateau shrublands was mainly explained by edaphic factors, which also played an important role in regulating the effects of plant and climate factors on soil N:P ratios. Mean annual precipitation, instead of mean annual temperature, significantly controlled the soil N:P ratios, and its effect on the pattern of soil N:P ratios differed between alpine shrublands and desert shrublands. The N:P ratios of different organs in shrublands also played different roles in shaping the soil N:P ratios in alpine and desert shrublands. These results provide support for the hypothesis that edaphic factors were the dominant drivers of spatial variation in soil N:P ratios across the northeast Tibetan Plateau shrublands, and our study contributes to a deeper understanding of biogeochemical cycling at high altitudes.

Shortened duration and reduced area of frozen soil in the Northern Hemisphere.

The changes in near-surface soil freeze-thaw cycles (FTCs) are crucial to understanding the related hydrological and biological processes in terrestrial ecosystems under a changing climate. However, long-term dynamics of soil FTCs at the hemisphere scale and the underlying mechanisms are not well understood. In this study, the spatiotemporal patterns and main driving factors of soil FTCs across the Northern Hemisphere (NH) during 1979-2017 were analyzed using multisource data fusion and attribution approaches. Our results showed that the duration and the annual mean area of frozen soil in the NH decreased significantly at rates of 0.13 ± 0.04 days/year and 4.9 × 104 km2/year, respectively, over the past 40 years. These were mainly because the date of frozen soil onset was significantly delayed by 0.1 ± 0.02 days/year, while the end of freezing and onset of thawing were substantially advanced by 0.21 ± 0.02 and 0.15 ± 0.03 days/year, respectively. Moreover, the interannual FTC changes were more drastic in Eurasia than in North America, especially at mid-latitudes (30°-45° N) and in Arctic regions (>75° N). More importantly, our results highlighted that near-surface air temperature (T a ) and snowpack are the main driving factors of the spatiotemporal variations in soil FTCs. Furthermore, our results suggested that the long-term dynamics of soil FTCs at the hemisphere scale should be considered in terrestrial biosphere models to reduce uncertainties in future simulations.

Accelerated increase in vegetation carbon sequestration in China after 2010: A turning point resulting from climate and human interaction.

China has increased its vegetation coverage and enhanced its terrestrial carbon sink through ecological restoration since the end of the 20th century. However, the temporal variation in vegetation carbon sequestration remains unclear, and the relative effects of climate change and ecological restoration efforts are under debate. By integrating remote sensing and machine learning with a modelling approach, we explored the biological and physical pathways by which both climate change and human activities (e.g., ecological restoration, cropland expansion, and urbanization) have altered Chinese terrestrial ecosystem structures and functions, including vegetation cover, surface heat fluxes, water flux, and vegetation carbon sequestration (defined by gross and net primary production, GPP and NPP). Our study indicated that during 2001-2018, GPP in China increased significantly at a rate of 49.1-53.1 TgC/yr2 , and the climatic and anthropogenic contributions to GPP gains were comparable (48%-56% and 44%-52%, respectively). Spatially, afforestation was the dominant mechanism behind forest cover expansions in the farming-pastoral ecotone in northern China, on the Loess Plateau and in the southwest karst region, whereas climate change promoted vegetation cover in most parts of southeastern China. At the same time, the increasing trend in NPP (22.4-24.9 TgC/yr2 ) during 2001-2018 was highly attributed to human activities (71%-81%), particularly in southern, eastern, and northeastern China. Both GPP and NPP showed accelerated increases after 2010 because the anthropogenic NPP gains during 2001-2010 were generally offset by the climate-induced NPP losses in southern China. However, after 2010, the climatic influence reversed, thus highlighting the vegetation carbon sequestration that occurs with ecological restoration.

Case Report: A Novel Heterozygous ZP3 Deletion Associated With Empty Follicle Syndrome and Abnormal Follicular Development.

Background: Empty follicle syndrome (EFS) is defined as the complete failure to retrieve oocytes after ovarian stimulation. Although several mutations in ZP1, ZP2, ZP3, and LHCGR have been identified as genetic causes of EFS, its pathogenesis is still not well-understood. Methods: Whole-exome sequencing (WES) was employed to identify the candidate pathogenic mutations, which were then verified by Sanger sequencing. A study in CHO-K1 cells was performed to analyze the effect of the mutation on protein expression. Additionally, immunohistochemistry (IHC) staining was used to examine follicular development and zona pellucida (ZP) assembly in the ovary of an EFS patient. Results: A novel heterozygous deletion in ZP3 (c.565_579del[p.Thr189_Gly193del]) was identified in the EFS patient. It was inherited dominantly and resulted in significant degradation of the ZP3 protein. Oocytes with degenerated cytoplasm and abnormal ZP assembly were observed in follicles up to the secondary stage, and many empty follicle-like structures were present. Conclusion: We identified a novel ZP3 mutation that expands the mutational spectrum associated with human EFS. We also showed the abnormal follicular development and ZP assembly of the EFS patient with the heterozygous ZP3 mutation, which provides new insights into the pathogenesis of EFS.

Recent leveling off of vegetation greenness and primary production reveals the increasing soil water limitations on the greening Earth.

Global vegetation photosynthesis and productivity have increased substantially since the 1980s, but this trend is heterogeneous in both time and space. Here, we categorize the secular trend in global vegetation greenness into sustained greening, sustained browning and greening-to-browning. We found that by 2016, increased global vegetation greenness had begun to level off, with the area of browning increasing in the last decade, reaching 39.0 million km2 (35.9% of the world's vegetated area). This area is larger than the area with sustained increasing growth (27.8 million km2, 26.4%); thus, 12.0% ± 3.1% (0.019 ± 0.004 NDVI a-1) of the previous earlier increase has been offset since 2010 (2010-2016, P < 0.05). Global gross primary production also leveled off, following the trend in vegetation greenness in time and space. This leveling off was caused by increasing soil water limitations due to the spatial expansion of drought, whose impact dominated over the impacts of temperature and solar radiation. This response of global gross primary production to soil water limitation was not identified by land submodels within Earth system models. Our results provide empirical evidence that global vegetation greenness and primary production are offset by water stress and suggest that as global warming continues, land submodels may overestimate the world's capacity to take up carbon with global vegetation greening.

A coupled human-natural system analysis of water yield in the Yellow River basin, China.

In response to the potential water conflict caused by climate change and increased population, an integrated water yield analysis from the perspective of the coupled human-natural system is clearly required. This paper conducted an integrated water yield analysis in the Yellow River basin (YRB), China, with applications for irrigated cropland water modeling and many field, statistical and satellite images. We found the following during 2000-2017: (1) The irrigation water consumption, rain-fed water consumption of cropland and rain-fed water consumption of natural ecosystems all increased significantly. (2) Ecological restoration caused a consequence of the 81.7 108 m3 water consumption transfer from cropland to natural ecosystems. (3) Water consumption variability was strongly related to irrigation expansion and ecological restoration, and this variability dominated the high water yield variability in the midstream YRB (95.73% ± 0.5%). (4) The increased downstream human water use stress was mainly affected by increased downstream water use and upstream water yield change, with contribution ratios of 1.67 and -0.72, respectively. The study declares the intense relationship between ecological restoration, crop production and socioeconomic activities within the water-limited river basin. This research also highlights that synthetic river basin management is essential to balance the water demand between different sectors and between the upper stream and downstream sections of a basin.

ZP1 mutations are associated with empty follicle syndrome: evidence for the existence of an intact oocyte and a zona pellucida in follicles up to the early antral stage. A case report.

Empty follicle syndrome (EFS) is the complete failure to retrieve oocytes after ovarian stimulation. Although LHCGR and ZP3 were identified as causative genes, it is still unclear what happens to these patients' oocytes, and the pathogenesis of EFS remains obscure. Here, we identified six novel ZP1 mutations associated with EFS and female infertility that was inherited recessively in five unrelated families. Studies in CHO-K1 cells showed that these mutations resulted in either degradation or truncation of ZP1 protein. Immunohistochemistry using ovarian serial sections demonstrated that all preantral follicles had normal architecture, but with a thin ZP, lacking ZP1, surrounding the growing oocytes. The antral follicles were also defective in normal cumulus-oocyte complex organisation, leading us to speculate that the lack of ZP1 might lead to oocyte degeneration or increased fragility of the oocyte during follicular puncture, ultimately resulting in EFS. To our knowledge, this is the first study that presents morphological evidence showing normal preantral folliculogenesis with abnormal ZP assembly in EFS patients. Our data provides a better understanding of the biological functions of ZP1 in human ZP assembly and folliculogenesis and gives new insights into the pathogenesis of EFS and possible therapeutic developments.

Socio-ecological changes on the Loess Plateau of China after Grain to Green Program.

Payment for Ecosystem Services (PES) is now widely accepted as a policy tool for advancing both ecological and social progress. The Chinese government's Grain to Green Program (GTGP) is the world's largest PES program. It was initiated nearly 20 years ago to reverse previous environmental degradation. However, it is difficult to achieve both conservation and economic "win-win" gains, and care is needed in monitoring environmental and socioeconomic outcomes. Here we choose the Loess Plateau (LP), the area where GTGP was implemented most intensively, to study the social-ecological changes after GTGP and determine whether these changes are related to GTGP. The results show that LP has achieved "win-win" gains of restoring environment and promoting socioeconomic development: normalized difference vegetation index (NDVI) time series show a significant greening trend, and soil retention and carbon sequestration services have improved from 2000 to 2015. Simultaneously, grain output from the LP has increased by 56.7%. We also analyzed the effects of afforestation on changes of socio-ecological factors, and find that the changes of NDVI, soil erosion, and carbon sequestration mainly reflect the degree of afforestation rather than climate change, while the correlations between changes of socioeconomic factors and degree of afforestation are insignificant. We conclude that, despite some adverse outcomes such as water yield reduction, GTGP in LP has achieved considerable overall success in environmental factors. However, comprehensive and quantitative evaluation of the social impacts of GTGP is needed, as the impacts are clouded by multiple socioeconomic factors.

Novel inactivating mutations in the FSH receptor cause premature ovarian insufficiency with resistant ovary syndrome.

RESEARCH QUESTION: What is the genetic aetiology of three resistant ovary syndrome (ROS) pedigrees from 13 Chinese Han families with non-syndromic premature ovarian insufficiency (POI). DESIGN: The proband in each family was subjected to whole-exome sequencing. Bioinformatic and in-vitro functional analyses were performed for the functional characterization of the FSHR mutations. RESULTS: Four novel mutations, two homozygous mutations (c.419delA, c.1510C>T), and a compound heterozygous mutation (c.44G>A and deletion of exons 1 and 2) of FSHR were identified in the three non-syndromic POI-with-ROS families. Bioinformatic analysis predicted that the three novel point mutations in FSHR are deleterious and associated with POI in the three families, which was confirmed by in-vitro functional analysis, in which FSH-induced adenosine 3',5'-cyclic monophosphate production was abolished for all receptors. CONCLUSIONS: The three novel point mutations in FSHR were all functional inactivating mutations, and were the genetic aetiology of the three non-syndromic POI-with-ROS families. The first FSHR frameshift mutation is reported here, and the first missense mutation in the signal peptide-encoding region of FSHR to be associated with POI. Women affected by ROS should consider undergoing mutation screening for FSHR.

ZP2 pathogenic variants cause in vitro fertilization failure and female infertility.

PURPOSE: The oocyte-borne genetic causes leading to fertilization failure are largely unknown. We aimed to identify novel human pathogenic variants (PV) and genes causing fertilization failure. METHODS: We performed exome sequencing for a consanguineous family with a recessive inheritance pattern of female infertility characterized by oocytes with a thin zona pellucida (ZP) and fertilization failure in routine in vitro fertilization. Subsequent PV screening of ZP2 was performed in additional eight unrelated infertile women whose oocytes exhibited abnormal ZP and similar fertilization failure. Expression of ZP proteins was assessed in mutant oocytes by immunostaining, and functional studies of the wild-type and mutant proteins were carried out in CHO-K1 cells. RESULTS: Two homozygous s PV (c.1695-2A>G, and c.1691_1694dup (p.C566Wfs*5), respectively) of ZP2 were identified in the affected women from two unrelated consanguineous families. All oocytes carrying PV were surrounded by a thin ZP that was defective for sperm-binding. Immunostaining indicated a lack of ZP2 protein in the thin ZP. Studies in CHO cells showed that both PV resulted in a truncated ZP2 protein, which might be intracellularly sequestered and prematurely interacted with other ZP proteins. CONCLUSION: We identified loss-of-function PV of ZP2 causing a structurally abnormal and dysfunctional ZP, resulting in fertilization failure and female infertility.

Drinking-water disinfection by-products and semen quality: a cross-sectional study in China.

BACKGROUND: Exposure to disinfection by-products (DBPs) has been demonstrated to impair male reproductive health in animals, but human evidence is limited and inconsistent. OBJECTIVE: We examined the association between exposure to drinking-water DBPs and semen quality in a Chinese population. METHODS: We recruited 2,009 men seeking semen analysis from the Reproductive Center of Tongji Hospital in Wuhan, China, between April 2011 and May 2012. Each man provided a semen sample and a urine sample. Semen samples were analyzed for sperm concentration, sperm motility, and sperm count. As a biomarker of exposure to drinking-water DBPs, trichloroacetic acid (TCAA) was measured in the urine samples. RESULTS: The mean (median) urinary TCAA concentration was 9.58 (7.97) µg/L (interquartile range, 6.01-10.96 µg/L). Compared with men with urine TCAA in the lowest quartile, increased adjusted odds ratios (ORs) were estimated for below-reference sperm concentration in men with TCAA in the second and fourth quartiles (OR = 1.79; 95% CI: 1.19, 2.69 and OR = 1.51; 95% CI: 0.98, 2.31, respectively), for below-reference sperm motility in men with TCAA in the second and third quartiles (OR = 1.46; 95% CI: 1.12, 1.90 and OR = 1.30; 95% CI: 1.00, 1.70, respectively), and for below-reference sperm count in men with TCAA in the second quartile (OR 1.62; 95% CI: 1.04, 2.55). Nonmonotonic associations with TCAA quartiles were also estimated for semen parameters modeled as continuous outcomes, although significant negative associations were estimated for all quartiles above the reference level for sperm motility. CONCLUSION: Our findings suggest that exposure to drinking-water DBPs may contribute to decreased semen quality in humans.

Evaluation of exposure to trihalomethanes in tap water and semen quality: a prospective study in Wuhan, China.

Trihalomethanes (THMs) have been demonstrated to adversely affect male reproductive health in animals, but the evidence in humans is limited. The study aimed to examine the association between THM exposure and semen quality in a Chinese population. We recruited 324 men from the same water supply district in Wuhan, China between April 2011 and May 2012. Exposure to THMs was evaluated based on their concentrations in tap water measured within 90 days preceding semen collection, the uptake factors of THMs and personal information on ingestion and showering/bathing. We found that TTHM [sum of chloroform (TCM) and brominated THMs (Br-THMs)], TCM and Br-THM uptakes via ingestion were associated with significant or suggestive decreasing trends in sperm concentration (P for trend=0.01, 0.03 and 0.05, respectively) and sperm count (P for trend=0.02, 0.05 and 0.09, respectively). Our results suggest that THM exposure via ingestion may adversely affect semen quality.

Novel strategy combining SYBR Green I with carbon nanotubes for highly sensitive detection of Salmonella typhimurium DNA.

A simple, selective, sensitive and label-free fluorescent method for detecting trpS-harboring Salmonella typhimurium was developed in this study. This assay used the non-covalent interaction of single-stranded DNA (ssDNA) probes with SWNTs, since SWNTs can quench fluorescence. Fluorescence recovery (78% with 1.8 nM target DNA) was detected in the presence of target DNA as ssDNA probes detached from SWNTs hybridized with target DNA, and the resulting double-stranded DNA (dsDNA) intercalated with SYBR Green I (SG) dyes. The increasing fluorescence intensity reached 4.54-fold. In contrast, mismatched oligonucleotides (1- or 3-nt difference to the target DNA) did not contribute to significant fluorescent recovery, which demonstrated the specificity of the assay. The increasing fluorescence intensity increased 3.15-fold when purified PCR products containing complementary sequences of trpS gene were detected. These results confirmed the ability to use this assay for detecting real samples.

Highly specific and cost-efficient detection of Salmonella Paratyphi A combining aptamers with single-walled carbon nanotubes.

In this paper, a panel of single-stranded DNA aptamers with high affinity and specificity against Salmonella Paratyphi A was selected from an enriched oligonucleotide pool by a whole-cell-Systematic Evolution of Ligands by Exponential Enrichment (SELEX) procedure, during which four other Salmonella serovars were used as counter-selection targets. It was determined through a fluorescence assay that the selected aptamers had high binding ability and specificity to this pathogen. The dissociation constant of these aptamers were up to nanomolar range, and aptamer Apt22 with the lowest Kd (47 ± 3 nM) was used in cell imaging experiments. To detect this bacteria with high specificity and cost-efficiently, a novel useful detection method was also constructed based on the noncovalent self-assembly of single-walled carbon nanotubes (SWNTs) and DNAzyme-labeled aptamer detection probes. The amounts of target bacteria could be quantified by exploiting chemoluminescence intensity changes at 420 nm and the detection limit of the method was 103 cfu/mL. This study demonstrated the applicability of Salmonella specific aptamers and their potential for use in the detection of Salmonella in food, clinical and environmental samples.

Enhanced bioremediation of heavy metal from effluent by sulfate-reducing bacteria with copper-iron bimetallic particles support.

The purpose of this study was to investigate the potential of copper-iron bimetallic particles supported sulfate-reducing bacteria (SRB) in enhancing the reduction of Cu(2+) and Zn(2+) in effluent. The results showed that the copper-iron bimetallic particles can enhance Cu(2+) and Zn(2+) removal and the resistance of the sulfate-reducing bacteria towards metals toxicity, the inhibiting concentration of Cu(2+) and Zn(2+) for SRB was significantly increased (from 100 to 200 mg/L for Cu(2+) and 300 to 400 mg/L for Zn(2+)). The removal efficiencies of Cu(2+) and Zn(2+) (initial concentration 100 mg/L) were 98.17% and 99.67% in SRB-Cu/Fe system after 48 h, while only 29.83% Cu(2+), 90.88% Zn(2+) and 63.81% Cu(2+), 72.63% Zn(2+) were removed in the SRB and Cu/Fe system at the same condition.